WO2007102306A1 - Method of high-frequency quenching, high-frequency quenching apparatus, and product of high-frequency quenching - Google Patents

Method of high-frequency quenching, high-frequency quenching apparatus, and product of high-frequency quenching Download PDF

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Publication number
WO2007102306A1
WO2007102306A1 PCT/JP2007/053033 JP2007053033W WO2007102306A1 WO 2007102306 A1 WO2007102306 A1 WO 2007102306A1 JP 2007053033 W JP2007053033 W JP 2007053033W WO 2007102306 A1 WO2007102306 A1 WO 2007102306A1
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WO
WIPO (PCT)
Prior art keywords
temperature
quenching
tempering
workpiece
heating
Prior art date
Application number
PCT/JP2007/053033
Other languages
French (fr)
Japanese (ja)
Inventor
Takumi Fujita
Nobuyuki Suzuki
Original Assignee
Ntn Corporation
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP2006064463A external-priority patent/JP2007239044A/en
Priority claimed from JP2006064249A external-priority patent/JP2007239039A/en
Priority claimed from JP2006064453A external-priority patent/JP2007239043A/en
Application filed by Ntn Corporation filed Critical Ntn Corporation
Publication of WO2007102306A1 publication Critical patent/WO2007102306A1/en

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Classifications

    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/06—Surface hardening
    • C21D1/09—Surface hardening by direct application of electrical or wave energy; by particle radiation
    • C21D1/10—Surface hardening by direct application of electrical or wave energy; by particle radiation by electric induction
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/18—Hardening; Quenching with or without subsequent tempering
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/34—Methods of heating
    • C21D1/42—Induction heating
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/68—Temporary coatings or embedding materials applied before or during heat treatment
    • C21D1/70—Temporary coatings or embedding materials applied before or during heat treatment while heating or quenching
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D11/00—Process control or regulation for heat treatments
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/40—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for rings; for bearing races
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P10/00—Technologies related to metal processing
    • Y02P10/25—Process efficiency

Definitions

  • the present invention relates to an induction hardening method, an induction hardening apparatus, and an induction hardening product, and more specifically, an induction hardening method and induction hardening in which an object to be processed is quenched by induction heating. Equipment and induction-hardened products that have been quenched by induction heating.
  • Induction hardening is a heat treatment method in which an object to be processed set adjacent to the induction coil is induction-heated by flowing a high-frequency current through the induction coil to quench the object to be processed.
  • This induction hardening is a work environment and is able to efficiently process small lots of products in a short time compared to carburizing quenching and bright heat treatment, which are generally adopted as heat treatment methods for steel. This is advantageous. Therefore, many studies have been made on the induction hardening method and induction hardening apparatus for the purpose of controlling the hardness of the workpiece and improving the efficiency of heat treatment, and various proposals have been made (Japanese Patent Laid-Open No. 2004-315851). (Patent Document 1) and JP 2004-225081 (Patent Document 2)).
  • Patent Document 1 JP 2004-315851 A
  • Patent Document 2 JP 2004-225081 A
  • the induction hardening unlike the quenching method in which the workpiece is heated via the atmosphere in the furnace like heating in a general atmospheric furnace, the workpiece is directly heated by induction heating. The Therefore, in order to measure the temperature of the workpiece, it is necessary to directly measure the temperature of the workpiece. However, it is difficult to install a contact-type thermometer in the induction hardening apparatus, which often has a drive mechanism for rotating the object to be processed in order to heat the object to be processed uniformly. There are many cases.
  • the object of the present invention is to enable temperature control and to easily determine the conditions for heat treatment, so that past production results are less accumulated, or an inexperienced manufacturer is required.
  • induction hardening can be performed easily and efficiently, and heat treatment quality such as desired hardness and retained austenite amount can be imparted to a wide range of workpieces.
  • an induction hardening apparatus for performing the induction hardening method is another object of the present invention.
  • Another object of the present invention is to provide an induction-hardened product with reduced production costs and stable quality.
  • the induction hardening method according to the present invention is an induction hardening method in which the whole object to be processed is heated and hardened by induction heating, and is a temperature control method in which the temperature of the object to be processed is adjusted. And a quenching control step in which the timing at which the heated workpiece is to be cooled is determined and the workpiece is cooled. In the temperature control process, the temperature of the workpiece is measured. Temperature control process and temperature control process that outputs temperature control signals for controlling the heating state of the workpiece based on the temperature information measured in the temperature control process. And a heating step in which the workpiece is heated by high frequency heating based on the temperature control signal.
  • the quenching control process includes a high-temperature portion in the workpiece to be treated with a high-temperature portion where the temperature rise due to high-frequency heating is larger than the inside of the workpiece, and a temperature rise due to high-frequency heating within the workpiece.
  • the heating time is adjusted based on the measured temperature information in the quenching temperature measurement process in which the temperature of the lower temperature part, which is a smaller surface area, is measured, and the quenching temperature measurement process.
  • the cooling timing adjustment process in which the timing at which the workpiece is to be cooled is determined and a cooling start signal is output, and the workpiece is quenched and hardened by cooling the workpiece based on the cooling start signal. Cooling process.
  • the temperature history conditions including the temperature history including the temperature and the heating time in the high temperature portion are less than the predetermined upper limit value of the desired retained austenite amount.
  • the heating time is adjusted so that the temperature history including the temperature in the low temperature part and the heating time satisfies the condition of the temperature history at which the hardness exceeding the lower limit of the desired hardness obtained in advance is satisfied.
  • a start signal is output.
  • the transition of power output (power output pattern), which also includes power and time parameters as heat treatment conditions, is determined based on past heat treatment results and operator experience. (Power control).
  • the heat treatment conditions are determined by actually heat-treating the sample of the object to be processed while changing the power and time in consideration of the shape, size, material, etc. of the object to be processed. Therefore, experience and labor are required to determine the heat treatment conditions.
  • the temperature control step and the quench control step In contrast, in the induction hardening method of the present invention, the temperature control step and the quench control step Thus, heating of the workpiece is controlled using temperature and time as parameters (temperature control). For this reason, it is possible to accurately grasp the heating history of the object to be processed, and after quenching it after giving the necessary heating history to the object to be processed, quenching can be performed.
  • the composition of the steel constituting the workpiece is determined, the hardness of the workpiece, the amount of retained austenite of the steel constituting the workpiece, and the heat treatment quality such as the microstructure, the heating temperature and time Determined by. Therefore, it is relatively easy for an operator who performs heat treatment to determine the approximate heating time and temperature conditions necessary for imparting desired heat treatment quality to the workpiece as temporary heat treatment conditions.
  • the temperature history condition in the high temperature portion is a temperature history condition that provides a residual austenite amount that is less than or equal to a predetermined upper limit value of the retained austenite amount.
  • the heating history is adjusted so as to satisfy the temperature history condition in which the temperature history in the low temperature part is higher than the predetermined lower limit of the desired hardness, and a cooling start signal is output.
  • the object to be processed is not heated completely and uniformly. At the part where the amount of magnetic flux entering the induction coil is large, the temperature is high, and conversely, the magnetic flux far from the induction coil. The temperature is lowered at the site where the intrusion amount is small.
  • the lower limit value of the hardness required to ensure the strength and rigidity required for the object to be processed is determined.
  • the upper limit of the amount of retained austenite necessary to ensure the dimensional stability required for the workpiece small change in shape over time
  • the hardness of the workpiece is affected by the amount of carbon that is dissolved in the steel substrate during quenching, so basically the heating temperature before cooling in quenching is high and the heating time is high. The longer the is, the larger the solid solution of carbon and the higher the hardness. On the other hand, the amount of retained austenite is also affected by the amount of carbon dissolved in the steel substrate during quenching. The higher the heating temperature before cooling in quenching and the longer the heating time, the greater the amount of carbon dissolved. , M
  • the amount of retained austenite increases. Therefore, the part where the amount of magnetic flux penetrates is low and the temperature is low (low temperature part).
  • the part is heated at the temperature and time required to obtain the hardness exceeding the 1S lower limit, and the part where the magnetic flux penetrates much and the temperature is high. (High temperature part) is less than upper limit
  • the lower limit value of the hardness at the part heated to a temperature between the high temperature part and the low temperature part by being heated below the temperature and time necessary to obtain the retained austenite amount and being quenched. And the upper limit of the amount of retained austenite is satisfied.
  • the detailed heat treatment conditions are determined based on the conditions of the desired hardness and the amount of retained austenite. Since quenching is performed, the desired hardness and the amount of retained austenite can be easily imparted to the workpiece.
  • the high temperature part and the low temperature part are preferably the part where the penetration of the magnetic flux is the most and the part where the penetration is the smallest.
  • the part has the highest temperature and the part having the lowest temperature.
  • the temperature rises at the protrusions and corners.
  • the induction hardening method of the present invention it is possible to control the temperature, and it is possible to easily determine the conditions of the heat treatment, so that the accumulation of past production results is small. Even when inexperienced workers perform heat treatment work, they can be easily and efficiently carried out, and heat treatment quality such as desired hardness and residual austenite content can be given to a wide range of workpieces. It is possible to provide an induction hardening method that can be performed.
  • An induction hardening apparatus is an induction hardening apparatus used in the above induction hardening method for heating and hardening an entire object to be processed by induction heating.
  • the temperature control device is connected to a temperature control temperature measuring device that acquires temperature data of the object to be processed and outputs temperature information based on the temperature data of the object to be processed, and a temperature control temperature measuring device.
  • the temperature control device outputs a temperature control signal for controlling the heating state of the workpiece based on the temperature information of the temperature control device for temperature control, and is connected to the temperature control device.
  • a heating device for heating the object to be processed by high-frequency heating based on the temperature control signal.
  • a quenching control device acquires temperature data of a high temperature portion and a low temperature portion of a workpiece, and outputs a temperature information based on the temperature data of the workpiece, and a quenching temperature measuring device.
  • Cooling timing adjustment that is connected to the temperature measuring device, adjusts the heating time based on the temperature information of the quenching temperature measuring device, determines the timing at which the workpiece should be cooled, and outputs a cooling start signal And a cooling device connected to the cooling timing adjusting device and quenching and hardening the workpiece by cooling the workpiece based on the cooling start signal.
  • the induction hardening apparatus of the present invention capable of heat-treating an object to be processed by the above-described induction hardening method of the present invention, temperature control can be performed and conditions for heat treatment can be easily set. By making this possible, quenching can be carried out easily and efficiently even when there is little accumulation of past production results, or even when an inexperienced V ⁇ operator performs heat treatment work. Furthermore, according to the induction hardening apparatus of the present invention, heat treatment quality such as desired hardness and retained austenite amount can be imparted to a wide range of workpieces.
  • the induction-hardened product according to the present invention is characterized by being heat-treated by the above-described induction-quenching method of the present invention.
  • the temperature can be controlled and the conditions for the heat treatment can be easily determined, so that the quenching is easily and efficiently performed and the workpiece is processed. Since the quenching is performed by the induction hardening method of the present invention capable of imparting desired heat treatment quality to a wide range of products, the manufacturing cost is suppressed and the induction hardened product with stable quality is obtained. Can be provided.
  • the induction-hardened product of the present invention can be applied to, for example, steel parts such as rolling bearing raceways and rolling elements.
  • the induction heat treatment equipment is an induction heat treatment equipment for heat-treating an object to be processed by induction heating, and includes an apparatus for transferring the object to be processed and an apparatus for transferring the object. It is equipped with an induction hardening apparatus that heats and hardens the conveyed workpiece by induction heating.
  • the induction hardening apparatus includes a quenching temperature control device for adjusting the temperature of the workpiece and a quenching timing control device for adjusting the timing at which the heated workpiece is cooled.
  • the induction hardening device is a quenching temperature control device that supplies power to the quenching induction coil to heat the workpiece.
  • the quenching process includes the quenching output transition data, which is the transitional data of the power output that is applied, and the quenching timing data for identifying the timing at which the workpiece is cooled in the quenching timing control device.
  • a quenching storage device for storing data is included.
  • the quenching temperature control device acquires the temperature data of the object to be processed, and outputs a temperature information based on the temperature data of the object to be processed, and a quenching temperature control device for quenching temperature control.
  • a quenching temperature control device that outputs a quenching temperature control signal for controlling the heating state of the workpiece based on the temperature information of the quenching temperature control temperature measuring device force.
  • Quenching heating including a quenching power supply and a quenching induction coil, connected to the quenching temperature control device, and heats the workpiece by induction heating based on the quenching temperature control signal from the quenching temperature control device Device.
  • the quenching timing control device acquires the temperature data of the workpiece and outputs the temperature information based on the workpiece temperature data, and the quenching timing control temperature measurement device. Quenching that is connected to the equipment, adjusts the heating time based on temperature information from the quenching timing control temperature measuring device, determines the timing at which the workpiece should be cooled, and outputs a quenching cooling start signal. There is a timing adjustment device and a quenching cooling device that is connected to the quenching timing adjustment device and quenches and hardens the workpiece by cooling the workpiece based on the quenching cooling start signal. is doing.
  • the transition of power output (power output pattern), which also includes power and time parameters as heat treatment conditions, is determined based on past heat treatment results and operator experience. (Power control).
  • the heat treatment conditions are determined by actually heat-treating the sample of the object to be processed while changing the power and time in consideration of the shape and material of the object to be processed. Therefore, experience and labor are required to determine the heat treatment conditions.
  • the heating of the workpiece is controlled by the induction temperature control device and the induction timing control device using the temperature and time as parameters ( Temperature control). Therefore, accurately grasp the heating history of the workpiece Quenching can be performed by giving a necessary heating history to the object to be processed and then rapidly cooling it.
  • the heat treatment quality such as the hardness of the workpiece, the micro yarns and weaves of the steel constituting the workpiece and the amount of retained austenite is determined by the heating temperature. And can be easily controlled by time. For this reason, the worker who performs the heat treatment should determine the heating time and temperature conditions necessary for imparting the desired heat treatment quality to the workpiece as the heat treatment conditions! And labor is greatly reduced. As a result, it is possible to easily perform high-frequency heat treatment even when there is little accumulation of past production results, or even when an inexperienced worker performs heat treatment work.
  • the induction hardening apparatus stores the hardening output transition data and the quenching cooling timing data as the quenching process data. Is included.
  • the heat treatment conditions for performing the same quenching and curing process performed by the temperature control by the power control are stored in the quenching storage device. For this reason, after confirming the appropriateness of the heat treatment conditions of induction hardening performed under temperature and time conditions, in the actual mass production process, high-frequency power control is performed by power control that is easy to control according to the stored heat treatment conditions. Heat treatment can be performed.
  • the high-frequency heat treatment equipment of the present invention includes a transfer device for transferring an object to be processed.
  • a transfer device for transferring an object to be processed.
  • the high-frequency heat treatment equipment of the present invention it is possible to control the temperature, and it is possible to easily determine the conditions for the heat treatment, so that the past production results are less accumulated.
  • the above-described temperature measuring device for quenching temperature control avoids an excessive amount of retained austenite due to excessive heating of the object to be processed, so that the temperature of the object to be processed is high. It is preferable to be able to measure the temperature of a part near the induction coil, for example, the part where the magnetic flux intrudes most. Further, the above-described temperature measuring device for quenching timing control avoids insufficient heating of the workpiece before quenching, so that a portion of the workpiece to be cooled, for example, induction coil force far away magnetic flux It is preferable that the temperature of the part where the intrusion is the smallest is measurable.
  • the temperature measuring device for quenching temperature control and the temperature measuring device for quenching timing control can use, for example, a radiation thermometer. If possible, a contact-type thermometer such as a thermocouple on the layout of the device. Even so.
  • the induction heat treatment equipment further includes an induction tempering apparatus connected to an induction hardening apparatus and tempering the object to be hardened and hardened in the induction hardening apparatus by heating with induction heating.
  • the induction tempering device includes a tempering temperature control device for adjusting the temperature of the workpiece, and a tempering end timing control device for adjusting the timing at which the heated workpiece is cooled.
  • the induction tempering device is a tempering temperature control device, which is the tempering power data that is output to the induction coil for tempering for high-frequency heating to heat the workpiece.
  • Tempering storage device that stores output transition data for tempering and cooling timing data for tempering to identify when the workpiece is cooled in the tempering end timing control device as tempering process data Including /!
  • the tempering temperature control device acquires temperature data of the object to be processed, and outputs a temperature information based on the temperature data of the object to be processed.
  • a tempering temperature adjusting device that is connected to a temperature measuring device for outputting a tempering temperature control signal for controlling the heating state of the object to be processed based on temperature information from the temperature measuring device for tempering temperature control.
  • Tempering heating including power supply for tempering and induction coil for tempering, which is connected to the tempering temperature control device and heats the workpiece by high frequency heating based on the tempering temperature control signal from the tempering temperature control device With equipment.
  • the tempering end timing control device acquires temperature data of the object to be processed, and outputs a temperature information based on the temperature data of the object to be processed, and a temperature measuring device for tempering end timing control, and tempering end Timing control temperature measuring device connected to the timing control temperature control device for controlling the tempering end timing.
  • the tempering end timing adjusting device that outputs the tempering cooling start signal and the tempering end timing adjusting device to cool the workpiece based on the tempering cooling start signal.
  • a tempering end device for ending the tempering of the workpiece.
  • the induction hardening apparatus and the induction tempering apparatus can constitute a single production line. Therefore, it is possible to carry out the quenching and tempering process efficiently by continuously tempering the workpiece that has been quenched and hardened in the induction hardening apparatus without holding it as an in-process product.
  • the induction tempering apparatus has a configuration capable of performing heat treatment by temperature control, like the induction hardening apparatus. Therefore, it is possible to accurately grasp the heating history of the object to be processed, and after providing the necessary and sufficient heating history to the object to be processed, tempering can be performed by cooling.
  • the hardness of the most important workpiece can be easily controlled by heating temperature and time. Therefore, the operator who performs the heat treatment should determine the temperature and heating time conditions necessary to impart the desired heat treatment quality to the workpiece as the heat treatment conditions! And labor are greatly reduced.
  • the induction tempering apparatus includes a tempering storage device that stores tempering output transition data and tempering cooling timing data as tempering process data, the high frequency As with the quenching equipment, after confirming the validity of the heat treatment conditions of induction tempering performed by temperature control, in the actual mass production process, high frequency is controlled by power control that is easy to control according to the stored heat treatment conditions. Tempering can be performed.
  • the tempering end timing control temperature measuring device has a hardness that is too high due to excessive heating of the workpiece, and insufficient heating of the workpiece.
  • the temperature of the object to be processed increases in temperature, for example, the vicinity of the induction coil and the part where the magnetic flux intrudes most and the object to be processed in It is preferable to be able to measure the temperature at both of the parts where the temperature is low, for example, the part where the inductive coil force has the least penetration of the magnetic flux far away.
  • the tempering end timing control temperature measuring device includes a plurality of temperature measuring devices such as a radiation thermometer, and may be configured to measure a plurality of portions.
  • a radiation thermometer can be used as a temperature measuring device for tempering temperature control and a temperature measuring device for tempering completion timing control. A meter may be used.
  • the validity of the heat treatment conditions of induction hardening and induction tempering performed by temperature control is, for example, the hardness of the workpiece, the microstructure of the steel constituting the workpiece, the amount of retained austenite, etc. It is possible to check and confirm the material data.
  • the material data includes the temperature data measured by the temperature measuring device and the heating time in the quenching storage device and the tempering storage device when induction hardening and induction tempering are performed by temperature control. A force that can be stored and estimated based on this can be obtained by actually investigating a sample of the workpiece after heat treatment.
  • the hardness of the workpiece is obtained by cutting the workpiece after heat treatment, polishing the cut surface, and then measuring the hardness of the cut surface with a hardness meter such as a Vickers hardness meter or Rockwell hardness meter. Can.
  • a hardness meter such as a Vickers hardness meter or Rockwell hardness meter.
  • the microstructure of the steel that forms the workpiece is cut after the workpiece after heat treatment, the cut surface is polished, and then the cut surface is corroded by a corrosive liquid such as nitral (nitric alcohol solution). It can be investigated by observing with a microscope such as a microscope.
  • the amount of retained austenite can be determined by, for example, electropolishing a desired portion of the object to be treated after heat treatment, and using an X-ray diffractometer (XRD) to obtain the martensite ⁇ (211) plane and austenite ⁇ (220 It can be calculated by measuring the diffraction intensity with respect to the surface.
  • XRD X-ray diffractometer
  • the high-frequency heat treatment equipment of the present invention can be applied to heat treatment of machine parts made of steel, such as bearing rings and rolling elements, and manufactured by quench hardening.
  • the high-frequency heat treatment method is a high-frequency heat treatment method in which an object to be processed is heated and hardened by induction heating.
  • the high-frequency heat treatment method includes a surface stabilization step in which a stabilization layer having higher acid resistance than the treatment object is formed on the surface of the treatment object in a temperature range where the treatment object is heated, Stable in the stabilization process And a quench hardening step in which the object to be processed on which the conversion layer is formed is hardened by hardening.
  • a temperature control process in which the temperature of the workpiece on which the stabilization layer is formed is adjusted, and a timing at which the heated workpiece is to be cooled are determined. And a quenching control process in which the workpiece is cooled.
  • the temperature control process the temperature of the surface of the stable layer formed on the surface of the object to be processed is measured by a temperature control measurement process in which the temperature of the surface is measured by a radiation thermometer, and a temperature control temperature measurement process.
  • a temperature control process that outputs a temperature control signal for controlling the heating state of the workpiece based on the temperature information, and heating that heats the workpiece by high-frequency heating based on the temperature control signal Process.
  • the quenching control process is performed in a quenching temperature measurement process in which the temperature of the surface of the stabilization layer formed on the surface of the workpiece is measured by a radiation thermometer, and in the quenching temperature measurement process.
  • the heating time is adjusted based on the measured temperature information, the timing at which the workpiece should be cooled is determined and the cooling start signal is output, and the workpiece is processed based on the cooling start signal.
  • a cooling step in which the object to be processed is hardened by being cooled.
  • the transition of power output (power output pattern), which also includes power and time parameters as heat treatment conditions, is determined based on past heat treatment results and operator experience. (Power control).
  • the heat treatment conditions are determined by actually heat-treating the sample of the object to be processed while changing the power and time in consideration of the shape and material of the object to be processed. Therefore, experience and labor are required to determine the heat treatment conditions.
  • heating of the workpiece is controlled using the temperature and time as parameters during the quench hardening process (temperature control). Therefore, it is possible to accurately grasp the heating history of the object to be processed, and quenching can be performed by rapidly cooling after giving the necessary heating history to the object to be processed. As a result, actual In addition, it is not always necessary to investigate the quality of the workpiece, such as hardness and microstructure, obtained by heat treatment, and experience and effort are not necessarily required to determine the heat treatment conditions. Thus, according to the high-frequency heat treatment method in one aspect of the present invention, the above-described problems of high-frequency heat treatment are solved.
  • the temperature measurement accuracy of the workpiece is extremely important.
  • a contact thermometer such as a thermocouple for measuring the temperature of the object to be processed due to the layout problem of the heat treatment apparatus. Therefore, also in the high-frequency heat treatment method according to one aspect of the present invention, a radiation thermometer is employed for temperature measurement of the workpiece.
  • the atmosphere is not normally controlled, and the workpiece is heated in the atmosphere (in the air).
  • the oxidation resistance of the object to be processed is low, the surface of the object to be processed is oxidized at the initial stage of the heat treatment, and the surface state is hardly changed thereafter. Therefore, the influence of the change of the surface state on the temperature measurement accuracy is Relatively small.
  • the workpiece is made of steel containing 3% or more of chromium, for example, «Martensitic stainless steel such as JIS standard SUS440C or high-speed steel such as AISI standard M50, etc. Since it takes a relatively long time, the influence of changes in the surface condition on the temperature measurement accuracy becomes large.
  • the surface of the workpiece in the surface stabilization step, is more resistant to acid than the workpiece in the temperature range where the workpiece is heated. A highly stable stable layer is formed. For this reason, in the quench hardening process, changes in the surface state due to oxidation of the surface of the workpiece are suppressed, and a decrease in temperature measurement accuracy by the radiation thermometer is avoided. As a result, according to the high frequency heat treatment method in one aspect of the present invention, the quality of the object to be processed can be stabilized.
  • thermocontrol is possible, heat treatment conditions can be easily set, and an object to be treated is obtained. It is possible to provide a high-frequency heat treatment method capable of stabilizing the quality of the material.
  • the temperature of the workpiece in order to avoid an excessive amount of retained austenite due to excessive heating of the workpiece, the temperature of the workpiece is not reduced. It is preferable to measure the temperature at a site where the magnetic flux increases most, for example, a region where the magnetic flux intrudes most frequently.
  • the portion of the workpiece to be cooled for example, the induction coil force is far away from the magnetic flux. It is preferred that the temperature of the site with the least amount of intrusion be measured.
  • a high-frequency heat treatment method is a high-frequency heat treatment method in which an object to be treated is heated and hardened by high-frequency heating.
  • the high-frequency heat treatment method includes a data acquisition process, a storage process, a confirmation process, and a mass production process.
  • process data is acquired by heating and hardening the sample of the workpiece.
  • the memory process in order to identify the transition data of the power output output to the induction coil and the cooling power of the sample of the object to be processed in order to heat the sample of the object to be processed in the data acquisition process Are stored as process data.
  • the confirmation process the validity of the transition data of the power output and the cooling timing data is confirmed based on the material data of the workpiece that has been quenched and hardened in the data acquisition process.
  • the workpiece is quenched and hardened according to the transition data of the power output and the cooling timing data that are stored in the storage process and validated in the confirmation process.
  • the quench hardening in the data acquisition process is performed by the high frequency heat treatment method in one aspect of the present invention.
  • a radiation thermometer is employed for temperature measurement of an object to be processed. Then, by performing the surface stabilization process, the influence of disturbance on the temperature measurement accuracy is suppressed. However, for example, if dirt or water droplets adhere to the lens of the radiation thermometer, the measured temperature may contain an error, and it is preferable to take further measures against disturbance.
  • the data acquisition step is performed.
  • a storage process is provided for storing process data such as temperature measurement data, and the stored process After a confirmation process to confirm the validity of the data, the mass production process is heat-treated based on the process data whose validity is guaranteed.
  • temperature control can be performed, heat treatment conditions can be easily set, and the quality of the workpiece can be further stabilized.
  • a high-frequency heat treatment method can be provided.
  • the material data to be investigated in order to confirm the validity of the power output transition data and the cooling timing data are, for example, the hardness of the workpiece, and the microscopic value of the steel constituting the workpiece. Force, amount of retained austenite, etc. Can be one or more material data selected.
  • the material data is stored in the storage process as temperature data measured in the temperature acquisition process and temperature measurement process for quenching in the data acquisition process. Although it can be estimated based on the stored cooling timing data, actually investigate and obtain a sample of the workpiece after heat treatment.
  • the hardness of the workpiece is obtained by cutting the workpiece after the heat treatment, polishing the cut surface, and then measuring the hardness of the cut surface with a hardness meter such as a Vickers hardness meter or a Rockwell hardness meter. Can.
  • a hardness meter such as a Vickers hardness meter or a Rockwell hardness meter.
  • the microstructure of the steel that forms the workpiece is cut after the workpiece after heat treatment, the cut surface is polished, and then the cut surface is corroded by a corrosive liquid such as nitral (nitric alcohol solution). It can be investigated by observing with a microscope such as a microscope.
  • the amount of retained austenite can be determined by, for example, electropolishing a desired portion of the workpiece after heat treatment and using an X-ray diffractometer (XRD) to obtain martensite ⁇ (211) surface and austenite ⁇ (220) surface. It can be calculated by measuring the diffraction intensity.
  • XRD X-ray diffractometer
  • a high frequency heat treatment method is a high frequency heat treatment method in which an object to be treated is heated and tempered by high frequency heating.
  • the high-frequency heat treatment method includes a surface stabilization process in which a stable layer having higher acid resistance than the object to be processed is formed on the surface of the object to be processed, and a stable layer is formed in the surface stabilization process.
  • a tempering step in which the processed object is heated and tempered.
  • the tempering process is a temperature at which the temperature of the workpiece is adjusted.
  • a tempering control step in which the timing at which the heating of the workpiece is to be finished is determined and the workpiece is cooled.
  • the temperature of the surface of the stabilization layer formed on the surface of the object to be processed is measured in a temperature control temperature measurement process in which the temperature is measured with a radiation thermometer, and the temperature control temperature measurement process.
  • a temperature adjusting process for outputting a temperature control signal for controlling the heating state of the object to be processed based on the temperature information, and a heating process for heating the object to be processed by high frequency heating based on the temperature control signal And have.
  • the tempering control process consists of a tempering temperature measurement process in which the temperature of the surface of the stabilization layer formed on the surface of the workpiece is measured by a radiation thermometer, and a temperature measured in the tempering temperature measurement process. The heating time is adjusted based on the above information, the timing for cooling the workpiece is determined and the cooling start signal is output, and the workpiece is cooled based on the cooling start signal. And a cooling step in which the tempering of the object to be processed is completed.
  • heat treatment by temperature control is employed in the tempering step. Therefore, similarly to the high-frequency heat treatment method in the above aspect, it is possible to accurately grasp the heating history of the object to be processed, and after giving the necessary heating history to the object to be processed, cooling is performed. You can go back. As a result, it is not always necessary to investigate the material of the workpiece, such as hardness, obtained by actually carrying out the heat treatment, and experience and labor are not necessarily required to determine the heat treatment conditions.
  • the surface of the workpiece in the surface stabilization step, is more resistant to oxidation than the workpiece in the temperature range where the workpiece is heated. A high stabilization layer is formed. Therefore, in the tempering process, changes in the surface state due to oxidation of the surface of the workpiece are suppressed, and a decrease in temperature measurement accuracy by the radiation thermometer is avoided. As a result, according to the high-frequency heat treatment method in another aspect of the present invention, the quality of the workpiece can be stabilized.
  • temperature control can be performed, heat treatment conditions can be easily set, and the quality of an object to be processed can be stabilized. It is possible to provide a high-frequency heat treatment method that can be performed.
  • a high-frequency heat treatment method that can be performed.
  • the temperature is measured.
  • a high-frequency heat treatment method is a high-frequency heat treatment method in which an object to be treated is heated and tempered by high-frequency heating.
  • the high-frequency heat treatment method includes a data acquisition process, a storage process, a confirmation process, and a mass production process.
  • process data is acquired by heating and tempering the sample of the workpiece.
  • the memory process in order to identify the transition data of the power output output to the induction coil and the cooling power of the sample of the object to be processed in order to heat the sample of the object to be processed in the data acquisition process Are stored as process data.
  • the confirmation step the validity of the power output transition data and the cooling timing data is confirmed based on the material data of the workpiece tempered in the data acquisition step.
  • the workpiece is tempered according to the power output transition data and the cooling timing data that are stored in the storage process and validated in the confirmation process.
  • the tempering in the data acquisition step is performed by the induction heat treatment method according to another aspect of the present invention.
  • induction heat treatment method after performing induction tempering on the sample of the workpiece by the induction heat treatment method according to another aspect of the present invention as a data acquisition step, temperature measurement is performed.
  • a storage process for storing process data such as data is provided, followed by a confirmation process for confirming the validity of the stored process data, and then heat treatment for the mass production process is performed based on the process data for which validity is ensured. Done.
  • temperature control can be performed, heat treatment conditions can be easily set, and the quality of the object to be processed can be further stabilized. Therefore, it is possible to provide a high-frequency heat treatment method capable of performing
  • the material data investigated to confirm the validity of the power output transition data and the cooling timing data is the most important characteristic in tempering the workpiece, for example.
  • the hardness of the workpiece can be set.
  • the material data is stored in the storage process as temperature data measured during the temperature control temperature measurement process and the tempering temperature measurement process in the data acquisition process, and is used as the data and process data.
  • a sample of the workpiece after heat treatment may be actually investigated and acquired.
  • the surface stabilization step includes a black body paint application step in which a black body paint is applied to the surface of the object to be processed.
  • the emissivity change is extremely small over the temperature range where the workpiece is heated!
  • the black body paint for example, a silicon-based mat paint can be used. More specifically, for example, Pyromark High Temperature Paint made by TEMPIL, made by Japan Sensor Co., Ltd. High temperature black body paint JSC No.3 can be used.
  • the surface stabilization step includes a thermal oxidation step in which an iron oxide layer is formed on the surface of the object to be processed by thermal oxidation of the object to be processed.
  • a thermal oxidation step in which an iron oxide layer is formed on the surface of the object to be processed by thermal oxidation of the object to be processed.
  • an oxidation iron oxide layer having higher oxidation resistance than that of the workpiece and a small change in emissivity is formed on the surface of the workpiece, and then high-frequency heat treatment is performed.
  • a change in emissivity on the surface of the object to be processed during the heat treatment is suppressed.
  • the accuracy of temperature measurement with the radiation thermometer is further improved, and the quality of the workpiece is more stable.
  • the iron oxide layer is preferably a thick and acidic iron layer, but the effect is obtained by the acidic iron layer.
  • the degree of formation of the iron oxide layer is preferable to determine the degree of formation of the iron oxide layer in consideration of improving the efficiency of heat treatment.
  • a sample of the object to be processed is heated at a high frequency, and at that time, a contact thermometer such as a thermocouple is brought into contact with the surface of the object to be processed, and the temperature is measured.
  • a radiation thermometer is measured with a radiation thermometer, and the temperature measurement data of both is acquired.
  • the rate of change of the difference between the two temperature measurement data is 3% or less per 10 seconds, it can be considered that a sufficient iron oxide layer has been formed.
  • adjust the emissivity setting of the radiation thermometer By applying, the temperature of the surface of the workpiece on which the iron oxide layer is formed can be accurately measured with a radiation thermometer.
  • the surface stabilization step is an acidic process in which an iron oxide layer is formed on the surface of the object to be processed by immersing the object in an acidic solution. Includes a solution dipping process.
  • an iron oxide layer having higher oxidation resistance than that of the workpiece and having a small change in emissivity is formed on the surface of the workpiece.
  • sulfuric acid, hydrochloric acid, nitric acid, or the like can be used as the acidic solution for immersing the workpiece.
  • the surface temperature of the object to be processed was measured with a contact thermometer and a radiation thermometer in the same manner as described above, and the iron oxide layer was sufficiently formed in the same procedure. It is possible to determine whether or not it is a problem.
  • a high-frequency heat-treated product according to the present invention is characterized by being manufactured by heat treatment using the above-described high-frequency heat treatment method.
  • heat treatment is performed by temperature control, and heat treatment is performed by a high-frequency heat treatment method that makes it easy to determine heat treatment conditions, so that low cost is possible and quality is stable.
  • High-frequency heat-treated products can be provided.
  • the induction heat treatment product of the present invention can be applied to mechanical parts made of steel, such as bearing races and rolling elements, and manufactured by quench hardening.
  • the induction hardening apparatus, induction heat treatment equipment, induction hardening method and high frequency heat treatment method of the present invention can be carried out independently.
  • the induction hardening apparatus of the present invention can be employed.
  • the induction hardening method of the present invention can be employed.
  • the induction hardening method and induction hardening apparatus of the present invention it is possible to control the temperature and easily determine the conditions for the heat treatment. As a result, it is possible to carry out heat treatment easily and efficiently even when there is little accumulation of past production results or when an inexperienced worker performs heat treatment work, and the desired hardness can be applied to a wide range of workpieces. It is possible to provide an induction hardening method capable of imparting heat treatment quality such as the amount of retained austenite and an induction hardening apparatus for performing the induction hardening method. Moreover, according to the induction-hardened product of the present invention, it is possible to provide an induction-hardened product with reduced production costs and stable quality.
  • FIG. 1 is a schematic cross-sectional view showing a configuration of a rolling bearing outer ring that is manufactured by heat treatment using an induction hardening apparatus according to Embodiment 1.
  • FIG. 2 is a schematic diagram showing the configuration of the induction hardening apparatus in the first embodiment.
  • FIG. 3 is a diagram showing an outline of the induction hardening method in the first embodiment.
  • FIG. 4 is a diagram for explaining a method for producing a TTA diagram in the first embodiment.
  • FIG. 5 is a diagram for explaining a method for performing a cooling timing adjustment process using a TTA diagram.
  • FIG. 6 is a schematic cross-sectional view showing the configuration of a rolling bearing outer ring manufactured by heat treatment using the high-frequency heat treatment facility in Embodiment 2.
  • FIG. 7 is a schematic diagram showing a configuration of a high-frequency heat treatment facility in a second embodiment.
  • FIG. 8 is a schematic diagram showing the configuration of an induction hardening apparatus included in the induction heat treatment facility of Embodiment 2.
  • FIG. 9 is a schematic diagram showing the configuration of an induction tempering device included in the induction heat treatment facility of Embodiment 2.
  • FIG. 10 is a diagram showing an outline of an example of a high-frequency heat treatment method using the high-frequency heat treatment equipment of Embodiment 2.
  • FIG. 11 is a diagram for explaining the operation of the induction hardening apparatus in the second embodiment based on the flow of data and commands.
  • FIG. 12 is a diagram for explaining the operation of the induction tempering apparatus according to Embodiment 2 based on the flow of data and instructions.
  • FIG. 15 is a graph showing changes in hardness and processing time with respect to the value of D *.
  • FIG. 16 is a graph showing the temperature transition of the object to be treated during heating.
  • FIG. 20 is a diagram showing a distribution of solute carbon concentrations on the quenching temperature control side and the quenching timing control side when quenching is performed by the quenching cooling timing determination method of the modification. It is a figure which shows the change of the heat transformation point by the temperature increase rate in steel with a carbon content of 1 mass%.
  • FIG. 22 is a diagram for explaining a method of determining the calculation start temperature of the solute carbon concentration in consideration of the rate of temperature rise.
  • FIG. 23 is a condition diagram showing a relationship between a tempering temperature T and a tempering time t for obtaining a predetermined hardness after tempering.
  • FIG. 24 is an explanatory view showing the relationship between the tempering temperature and the holding time for explaining a method of integrating the hardness value after tempering with the temperature transition force.
  • FIG. 25 is a schematic cross-sectional view showing a configuration of a rolling bearing outer ring in the third embodiment.
  • FIG. 26 is a schematic diagram showing the configuration of the induction hardening apparatus in the third embodiment.
  • FIG. 27 is a diagram showing an outline of the induction hardening method in the third embodiment.
  • ⁇ 28 This is a diagram showing an outline of the configuration of the induction hardening apparatus in the fourth embodiment.
  • FIG. 29 is a diagram showing an outline of the induction hardening method in the fourth embodiment.
  • FIG. 30 shows the flow of data and commands in each process of induction hardening according to Embodiment 4.
  • FIG. 30 shows the flow of data and commands in each process of induction hardening according to Embodiment 4.
  • FIG. 31 is a schematic diagram showing the configuration of an induction tempering apparatus used in the induction heat treatment method of Embodiment 5.
  • FIG. 32 shows an outline of the induction tempering method in the fifth embodiment.
  • FIG. 33 is a diagram showing a schematic configuration of an induction tempering apparatus according to Embodiment 6.
  • FIG. 34 shows an outline of the induction tempering method in the sixth embodiment.
  • FIG. 35 is a diagram showing the flow of data and instructions in each step of induction tempering according to the sixth embodiment.
  • FIG. 36 is a diagram showing test results when the outer ring of a rolling bearing made of IS SUJ2 is heated.
  • FIG. 37 is a diagram showing test results when a rolling bearing outer ring made of IS SUS440C is heated.
  • FIG. 38 is a diagram showing test results when a black body paint is applied to the surface of an IS SUS440C rolling bearing outer ring and then heated.
  • rolling bearing outer ring 1 as an induction hardened product in the present embodiment has an annular shape.
  • the rolling bearing outer ring 1 is formed with a rolling surface 1C for rolling while the balls, rollers, etc. as rolling elements are in contact with the inner peripheral surface 1B, and in contact with other members to roll. It has an outer peripheral surface 1A for holding the bearing outer ring against the other members.
  • the rolling bearing outer ring 1 preferably has a hardness of 58H RC or more from the viewpoint of rolling fatigue life and rigidity. From the viewpoint of dimensional stability, the amount of retained austenite is preferably suppressed to 12% by volume or less.
  • the rolling bearing outer ring 1 is manufactured by heat treatment by the induction hardening method in the first embodiment of the present invention using the high-frequency quenching apparatus in the first embodiment of the present invention described below. Therefore, it is an induction-hardened product with reduced manufacturing costs and stable quality.
  • the induction hardening apparatus 90 in this embodiment is an induction hardening method used in an induction hardening method for heating and hardening the entire rolling bearing outer ring 1 as a workpiece by induction heating.
  • a quenching device for adjusting the temperature of the rolling bearing outer ring 1 A temperature control device 50 and a quenching control device 60 for adjusting the timing at which the heated rolling bearing outer ring 1 is to be cooled are provided.
  • the temperature control device 50 acquires temperature data of the rolling bearing outer ring 1, and outputs a temperature information based on the temperature data of the rolling bearing outer ring 1, and the first radiation thermometer 3 as a temperature control temperature measuring device 3
  • a temperature control device 4 connected to the first radiation thermometer 3 and outputting a temperature control signal for controlling the heating state of the rolling bearing outer ring 1 based on the temperature information from the first radiation thermometer 3.
  • a heating device 2 that is connected to the temperature control device 4 and heats the rolling bearing outer ring 1 by high-frequency heating based on a temperature control signal from the temperature control device 4.
  • the quenching control device 60 includes an outer peripheral surface 1A (surface facing the induction coil) which is the high temperature portion of the rolling bearing outer ring 1 and an inner peripheral surface 1B (back side of the surface facing the induction coil) which is the low temperature portion.
  • the first radiation thermometer 3 and the second radiation thermometer 5 are used as temperature measuring devices for quenching, which acquire temperature data of each of them and output temperature information based on the temperature data of the rolling bearing outer ring 1.
  • a cooling timing adjusting device 6 for determining a timing to be output and outputting a cooling start signal; and connected to the cooling timing adjusting device 6; Including a cooling device 7 to cure and harden That.
  • the cooling device 7 is a quenching liquid ejecting device that cools, for example, by injecting a cooling liquid onto the rolling bearing outer ring 1.
  • the first radiation thermometer 3 is installed as both a temperature control temperature measuring device and a quenching control temperature measuring device.
  • the temperature adjustment device 4 and the cooling timing adjustment device 6 are each a personal computer, for example, and one personal computer may serve as both the temperature adjustment device 4 and the cooling timing adjustment device 6.
  • the type of the temperature measuring device used for the temperature controlling temperature measuring device and the quenching temperature measuring device may be a radiation thermometer as described above, but if it is possible in the layout of the device, it is a thermocouple. Any contact thermometer.
  • induction hardening method 10 in the present embodiment is an induction hardening in which the whole object to be treated (rolling bearing outer ring 1) is heated and hardened by induction heating.
  • the temperature control step 20 in which the temperature of the rolling bearing outer ring 1 is adjusted by the temperature control device 50 and the timing at which the heated rolling bearing outer ring 1 should be cooled are determined by the quenching control device 60.
  • the temperature control step 20 includes a temperature control temperature measurement step 23 in which the temperature of the outer ring 1 of the rolling bearing is measured by the first radiation thermometer 3, and a temperature control temperature measurement step 23 by the temperature control device 4. Then, based on the measured temperature information, the temperature adjustment process 24 in which a temperature control signal for controlling the heating state of the rolling bearing outer ring 1 is output, and the heating device 2 is used, based on the temperature control signal, And a heating step 22 in which the rolling bearing outer ring 1 is heated by high frequency heating.
  • the quench control process 30 includes a quenching temperature measurement process 35, a cooling timing adjustment process 36, and a cooling process 37.
  • the temperature measurement process 35 for quenching in the outer ring 1 of the rolling bearing, the temperature rise due to high-frequency heating is the largest in the outer ring 1 of the rolling bearing, and the outer peripheral surface 1A as a high-temperature part, which is the surface portion, and the high-frequency heating.
  • the temperature rise due to the temperature is measured by the first radiation thermometer 3 and the second radiation thermometer 5, respectively, with the inner peripheral surface 1B as the low temperature part, which is the smallest surface portion of the rolling bearing outer ring 1. .
  • the cooling timing adjustment device 6 adjusts the heating time based on the temperature information measured in the quenching temperature measurement step 35, and determines when the rolling bearing outer ring 1 should be cooled. Then, a cooling start signal is output. In the cooling process 37, the cooling device 7 cools the rolling bearing outer ring 1 to a temperature range that is not less than the point A and not higher than the point M based on the cooling start signal. Hardened
  • the temperature history force including the temperature on the outer peripheral surface 1A and the calorie heat time.
  • the temperature history at which the amount of retained austenite less than the upper limit of the desired amount of retained austenite obtained in advance is obtained.
  • Temperature history including the temperature and heating time on the inner peripheral surface 1B, satisfying the condition of (temperature results at each time after heating starts) Force The heating time is adjusted so as to satisfy the condition of temperature history for obtaining a hardness equal to or higher than the lower limit of the desired hardness obtained in advance, and a cooling start signal is output.
  • the adjustment of the heating time includes the conditional expression showing the relationship between the heating time and the heating temperature for obtaining the desired hardness obtained in advance, and the heating time and calorie for obtaining the desired amount of retained austenite. This is implemented based on a conditional expression showing a relationship with the heat temperature.
  • the temperature can be controlled and the conditions for the heat treatment can be easily determined. Quenching and hardening can be performed easily and efficiently, even when there is little accumulation of past production results, or when inexperienced workers perform heat treatment work, and rolling bearing outer rings as workpieces Heat treatment quality such as desired hardness and retained austenite amount can be imparted to a wide range of 1.
  • point A is a point corresponding to a temperature at which the steel structure starts transformation from ferrite to austenite when the steel is heated.
  • the S point refers to the point corresponding to the temperature at which martensite cracking starts when austenitic steel is cooled.
  • cooling timing adjustment step 36 for example, a TTA (Time Temperature Austinitization) diagram is created as shown below and based on the conditional expression in the TTA diagram! This can be done by adjusting the heating time.
  • TTA Time Temperature Austinitization
  • a small test piece made of SUJ2 capable of uniform heating and cooling (6206 model ball bearing outer ring, outer ring ⁇ 62mm, inner diameter ⁇ 52mm, thickness tl6mm ring shape) Quenching is performed by heating at various heating rates and quenching after various times, and further tempering the specimen by holding at 180 ° C for 120 minutes. Then, the amount of retained austenite and the hardness of each test piece are measured.
  • the hardness of the test piece can be obtained, for example, by polishing a part of the workpiece after the heat treatment and measuring the hardness of the polished surface with a hardness meter such as a Rockwell hardness meter or a Vickers hardness meter.
  • the amount of retained austenite can be determined by, for example, electropolishing a test piece after heat treatment, and using an X-ray diffractometer (XRD) to diffract the polished surface from the manoletensite ⁇ (211) surface and the austenite ⁇ (220) surface. It can be calculated by measuring the intensity.
  • XRD X-ray diffractometer
  • Fig. 4 shows the heating history of the specimen when the heating rate is about 311 ° CZ seconds (dashed line), about 65 ° CZ seconds (dashed line), and about 20 ° CZ seconds (solid line). Yes.
  • the heating rate is 311 ° C for Z seconds
  • the point at which the hardness is 58HRC is indicated by a
  • the point at which the amount of retained austenite is 12% by volume is indicated by ⁇ .
  • the hardness at about 65 ° CZ seconds is 58HRC.
  • FIG. 5 shows the horizontal axis representing the elapsed time from the start of heating, and the vertical axis represents the temperature.
  • FIG. 5 also shows the temperature measurement results of the high temperature part (outer peripheral surface 1A) and the low temperature part (inner peripheral surface 1B) of the rolling bearing outer ring 1 during high frequency heating.
  • the hardness: 58HRC curve shows that the hardness is 58HRC or higher on the higher temperature side than the curve, and the calculated curve formula is
  • the curve of residual austenite 12% by volume shows that the amount of residual austenite is 12% by volume or less on the lower temperature side than the curve, and the calculated curve formula is
  • a cooling start signal is output during a time period greater than ⁇ , and the workpiece (rolling
  • the outer ring 1) is cooled and hardened by cooling.
  • peripheral surface 1B is higher than the curve of hardness: 58HRC, and the temperature of the hot part (outer peripheral surface 1A) is lower than the curve of residual austenite content: 12% by volume.
  • the entire workpiece can be hardened with a hardness of 58H RC and a residual austenite amount of 12% by volume or less.
  • rolling bearing outer ring 201 as the high frequency heat treatment product in the present embodiment has an annular shape.
  • the rolling bearing outer ring 201 is formed with a rolling surface 201C for rolling while the balls, rollers, and the like as rolling elements are in contact with the inner peripheral surface 201B, and in contact with other members, the rolling bearing It has an outer peripheral surface 201 A that holds the outer ring against the other members.
  • the rolling bearing outer ring 201 preferably has a hardness of 58 HRC or more from the viewpoint of rolling fatigue strength and rigidity. From the viewpoint of dimensional stability, the amount of retained austenite is preferably suppressed to 12% by volume or less.
  • the rolling bearing outer ring 201 is manufactured by heat treatment using the high-frequency heat treatment equipment in Embodiment 2 of the present invention described below, the production cost is suppressed, and high-frequency heat treatment with stable quality is achieved. It is a product.
  • the induction heat treatment equipment of the present embodiment is an induction heat treatment equipment for heating an object to be treated (for example, rolling bearing outer ring 201) by high frequency heating,
  • a workpiece holding device 291, a workpiece confirmation device 292, an induction hardening device 293, a cleaning device 294, an induction tempering device 295, and a heat treatment product holding device 296 are provided.
  • the apparatus is connected in this order from the conveyors 299A, 299B, 299C, 299D, and 299E.
  • the workpiece holding device 291 includes, for example, a basket that holds a rolling bearing outer ring 201 that is a workpiece, and has a function of holding the rolling bearing outer ring 201 before heat treatment.
  • the workpiece confirmation device 292 includes, for example, a shape discriminating device for measuring the shape of the rolling bearing outer ring 201, and the outer diameter size of the rolling bearing outer ring 201 conveyed from the workpiece holding device 291 by the conveying device 299A. It has a function to confirm that there is no contamination by measuring the width, etc.
  • the induction hardening device 293 includes, for example, an induction coil, a high frequency power source, a quenching oil tank, etc., and has a function of heating and hardening the rolling bearing outer ring 201 conveyed by the conveying device 299B by high frequency heating. is doing.
  • Cleaning device 294 includes a cleaning tank for storing cleaning liquid, a drying device for drying rolling bearing outer ring 201 after cleaning, and the like. By cleaning, it has a function of removing deposits such as quenching oil adhering to the surface of the rolling bearing outer ring 201 in the quench hardening process.
  • the induction tempering apparatus 295 is connected to the induction hardening apparatus 293 via the cleaning apparatus 294 and the conveying apparatuses 299C and 299D, and is hardened and hardened in the induction hardening apparatus 293, and is a rolling bearing conveyed by the conveying apparatuses 299C and 299D.
  • the outer ring 201 has a function of heating and tempering by high frequency heating.
  • the heat-treated product holding device 296 includes, for example, a basket that holds the rolling bearing outer ring 201, and has a function of holding the heat-treated product after quenching and tempering.
  • a high-frequency quenching device 293 cools the quenching temperature control device 250 for adjusting the temperature of the rolling bearing outer ring 201 that is the object to be processed, and the heated rolling bearing outer ring 201.
  • the quenching timing control device 260 for adjusting the power timing and the quenching temperature control device 250 the quenching power source is supplied from the quenching power source to the quenching induction coil to heat the rolling bearing outer ring 201.
  • the quenching output transition data which is the transition data of the power output that is applied, and the quenching cooling timing data for specifying the timing when the rolling bearing outer ring 201 is cooled in the quenching timing control device 260 are quenched.
  • a quenching storage device 270 which stores it as process data.
  • the quenching temperature control device 250 acquires the temperature data of the rolling bearing outer ring 201, outputs the temperature information based on the temperature data of the rolling bearing outer ring 201, and the quenching temperature control temperature measuring device 203.
  • Quenching temperature control device 203 is connected to the quenching temperature control temperature measuring device 203 and outputs a quenching temperature control signal for controlling the heating state of the rolling bearing outer ring 201 based on the power temperature information.
  • a quenching power source connected to the temperature control device 204 and the quenching temperature control device 204, which heats the rolling bearing outer ring 201 by high-frequency heating based on the quenching temperature control signal from the quenching temperature control device 204, and And a quenching heating device 202 including a quenching induction coil.
  • the quenching timing control device 260 acquires temperature data of the rolling bearing outer ring 201 and outputs temperature information based on the temperature data of the rolling bearing outer ring 201. It is connected to the quenching timing control temperature measuring device 205, adjusts the heating time based on the temperature information from the quenching timing control temperature measuring device 205, and determines the timing at which the rolling bearing outer ring 201 should be cooled.
  • the quenching timing adjusting device 206 that outputs a quenching cooling start signal and the quenching timing adjusting device 206 are connected to the rolling bearing outer ring 201 by cooling the rolling bearing outer ring 201 based on the cooling start signal. And a quenching cooling device 207 for quench hardening.
  • the quenching cooling device 207 holds an oil tank 207B in which quenching oil is stored and a rolling bearing outer ring 201 which is an object to be processed, and moves or tilts based on a cooling start signal to roll.
  • a workpiece holding base 207A for feeding the bearing outer ring 201 into the oil tank 207B is provided.
  • the quenching storage device 270 is connected to the quenching and heating device 202, the quenching temperature adjusting device 204, and the quenching timing adjusting device 206.
  • the induction tempering device 295 includes a tempering temperature control device 251 for adjusting the temperature of the rolling bearing outer ring 201 that is the object to be processed, and a heated rolling bearing outer ring.
  • Tempering end timing control device 261 for adjusting the timing at which 01 should be cooled
  • the tempering output transition that is the transition data of the power output output to the induction coil for tempering Tempering end timing control device 261 includes a tempering storage device 271 for storing tempering cooling timing data for specifying the timing at which the rolling bearing outer ring 201 is cooled as tempering process data. It is out.
  • the tempering temperature control device 251 acquires temperature data of the rolling bearing outer ring 201, outputs temperature information based on the temperature data of the rolling bearing outer ring 201, and a tempering temperature control temperature measuring device 213.
  • Tempering temperature control device 213 is connected to the tempering temperature control temperature sensor 213 and outputs a tempering temperature control signal for controlling the heating state of the rolling bearing outer ring 201 based on the temperature information of the tempering temperature control 213.
  • a temperature control device 214 and a tempering power supply and a tempering device connected to the tempering temperature control device 214 and heating the bearing outer ring 201 by high frequency heating based on a tempering temperature control signal from the tempering temperature control device 214.
  • a tempering heating device 212 including a return induction coil.
  • a tempering end timing control device 261 obtains temperature data of the rolling bearing outer ring 201 and outputs temperature information based on the temperature data of the rolling bearing outer ring 201.
  • the tempering end timing control temperature measuring device 215 is connected, the heating time is adjusted based on the temperature information from the tempering end timing control temperature measuring device 215, and the timing at which the rolling bearing outer ring 201 should be cooled is determined.
  • the tempering end timing adjusting device 216 that outputs a tempering cooling start signal and the tempering end timing adjusting device 216 are connected to cool the rolling bearing outer ring 201 based on the tempering cooling start signal 216.
  • a tempering end device 217 for ending the tempering of the rolling bearing outer ring 201.
  • the tempering end device 217 has a function of, for example, holding the rolling bearing outer ring 201 and moving the rolling bearing outer ring 201 from the heating range by the induction coil for tempering by moving based on the tempering cooling start signal. It has a to-be-processed object holding stand.
  • the tempering storage device 271 is connected to a tempering heating device 212, a tempering temperature adjusting device 214, and a tempering end timing adjusting device 216.
  • the induction heat treatment method of the present embodiment includes a quenching condition determining step, a tempering condition determining step, a final confirmation step, and a mass production step.
  • the quenching condition determination step for determining the quenching condition and the tempering condition determination process for determining the tempering condition are performed independently to determine the quenching condition and the tempering condition, respectively.
  • a final confirmation process is performed to confirm the appropriateness of the quenching conditions and tempering conditions when quenching and tempering are continuously performed.
  • the mass production process is then carried out based on the quenching and tempering conditions that have been validated.
  • the quenching condition determination step will be described.
  • a quenching data acquisition step in which process data is acquired by heating and quenching the sample of the rolling bearing outer ring 201 as the object to be processed.
  • Temporary heat treatment conditions for carrying out this quenching data acquisition process can be determined as conditions in which the operator also has conditions of temperature and time. Therefore, even when the past production record is sufficient or when the worker has sufficient experience in heat treatment, it can be easily determined.
  • a quenching data storage step is performed in which the transition data and quenching cooling timing data for specifying the cooling timing of the sample of the rolling bearing outer ring 201 are stored as quenching process data.
  • the quenching condition confirmation that the validity of the quenching output transition data and quenching cooling timing data is confirmed. The process is carried out.
  • the validity of the quenching output transition data and the quenching cooling timing data is, for example, the material data of the sample of the rolling bearing outer ring 201 actually hardened and hardened.
  • the microstructure of the steel constituting the outer ring 201, the amount of retained austenite, etc. are actually measured by experiments, and it is judged whether these materials are within the range of the desired standard.
  • the material data stores the temperature transition data of the workpiece in the quenching data acquisition process, and based on the data and quenching cooling timing data, It is also possible to estimate.
  • the quenching condition confirmation process if the material data of the rolling bearing outer ring 201 that is the object to be processed is not within the desired standard range, for example, a condition that is lower than the initial provisional heat treatment condition and for a long time.
  • the tempering data acquisition process is performed again by changing the provisional heat treatment condition so that the heating is performed at the same time.
  • the material data of the rolling bearing outer ring 201, which is the workpiece is within the desired standard range in the quenching condition confirmation process, the transition of the quenching output stored in the quenching data storage process is stored.
  • the data and quenching cooling timing data are determined as heat treatment conditions (quenching conditions) for performing quench hardening by power control.
  • the tempering condition determination step first, the process data is acquired by heating and tempering the sample of the rolling bearing outer ring 201 as the hardened and hardened workpiece. Tempering data acquisition process is implemented. Temporary heat treatment conditions for carrying out this tempering data acquisition process can also be given in terms of temperature and time, so that past production results are sufficient as in the case of the quenching data acquisition process! Even if the worker has sufficient experience in heat treatment, it can be easily determined.
  • the power supply power for high-frequency heating to heat the sample of the rolling bearing outer ring 201, the output transition data for tempering output to the induction coil, and the cooling of the sample of the rolling bearing outer ring 201 A tempering data storage step is performed in which tempering cooling timing data for specifying timing is stored as tempering process data. Then, based on the material data of the rolling bearing outer ring 201 tempered in the tempering data acquisition step, there is a tempering condition confirmation step in which the validity of the tempering output transition data and the tempering cooling timing data is confirmed. To be implemented.
  • the validity of the tempering output transition data and the tempering cooling timing data is, for example, the hardness that is most important in the material data of the sample of the outer ring 201 of the rolling bearing outer ring that has been actually tempered. Is actually measured by experiment, and is judged by whether the hardness is within the range of the desired standard.
  • the material data stores the temperature transition data of the workpiece in the tempering data acquisition process, and the tempering cooling timing data. It is also possible to estimate based on
  • the tempering condition confirmation process if the material data of the rolling bearing outer ring 201, which is the object to be processed, is not within the desired standard range, for example, a condition at a lower temperature and longer time than the initial provisional heat treatment condition.
  • the tempering data acquisition step is performed again by changing the provisional heat treatment conditions so that the heating is performed at the same time.
  • the tempering output stored in the tempering data storage step! Transition data and cooling timing data for tempering are determined as heat treatment conditions (tempering conditions) for performing tempering by electric power control.
  • the final confirmation process power control is first performed based on the quenching condition determined in the quenching condition determination process and the tempering condition determined in the tempering condition determination process.
  • a mass production test process in which quenching and tempering are continuously performed on the rolling bearing outer ring 201 as the object to be processed is performed.
  • the validity of the quenching condition determined in the quenching condition determination process and the tempering condition determined in the tempering condition determination process is performed.
  • a heat treatment condition confirmation process for confirming is performed.
  • the appropriateness of the quenching condition determined in the quenching condition determination step and the tempering condition determined in the tempering condition determination step is, for example, the rolling that is actually quenched and tempered.
  • the hardness which is the material data of the sample of the bearing outer ring 201, the microstructure of the steel constituting the rolling bearing outer ring 201, the amount of retained austenite, etc. are actually measured by experiments, and these materials are within the range of the desired standard. It is judged by whether or not.
  • the heat treatment condition confirmation step if the material data of the rolling bearing outer ring 201 that is the object to be processed is not within the desired specification range, it is determined whether the cause is the quenching condition or the tempering condition.
  • the cause identifying step is performed. This cause identification process can be performed based on, for example, the material data acquired through the heat treatment condition confirmation process. That is, only the hardness of the material data, the microstructure of the steel constituting the rolling bearing outer ring 201, and the amount of retained austenite is outside the standard range of the material.
  • the tempering conditions are considered to be the cause of the quenching conditions that affect the microstructure and retained austenite content.
  • the tempering condition determination step is performed again in consideration of the material data.
  • the quenching condition determination process is performed again in consideration of the material data. Then, the final confirmation process is performed again based on the determined quenching conditions and tempering conditions.
  • the heat treatment condition confirmation step when the material data of the rolling bearing outer ring 201 which is the object to be processed is within a desired standard range, the heat treatment condition for performing quenching and tempering by electric power control is The quenching conditions and tempering conditions are determined. Based on these quenching conditions and tempering conditions, a mass production process for quenching and tempering by electric power control is performed.
  • FIG. 11 the flow of data and commands in the quenching data acquisition process is solid arrows, the flow of data and commands in the quenching data storage process is broken arrows, and the flow of data and commands in the final confirmation process and mass production process is Displayed with double solid arrows.
  • the operation of the induction hardening apparatus in the present embodiment will be described with reference to FIG. 8, FIG. 10, and FIG.
  • the quenching data acquisition process first, temporary quenching conditions by temperature control are determined, and the heat treatment conditions are determined by quenching temperature control apparatus 204 and It is input to the quenching timing adjusting device 206 and heat treatment is started.
  • the temperature data of the sample of the rolling bearing outer ring 201 as the workpiece measured by the temperature measuring device 203 for quenching temperature control is sent to the quenching temperature adjusting device 204.
  • the target heating temperature of the rolling bearing outer ring 201 and the obtained temperature data power of the sample of the rolling bearing outer ring 201 are also determined, and the necessary power output is also determined. Command output.
  • the quenching power source Upon receiving the command, the quenching power source outputs power to the quenching induction coil of the quenching heating device 202, and the sample of the rolling bearing outer ring 201 is heated to a target temperature.
  • the sample temperature data of the rolling bearing outer ring 201 measured by the quenching timing control temperature measuring device 205 is sent to the quenching timing adjusting device 206.
  • the cooling timing is judged from the obtained temperature and heating time of the sample of the rolling bearing outer ring 201, and the cooling start device 207 is instructed to start cooling. Thereby, the sample of the rolling bearing outer ring 201 is rapidly cooled and quenched and hardened.
  • the temperature data acquired by the quenching temperature control unit 204 and the quenching timing control unit 206 is quenched as temperature transition data. It is stored in the incoming storage device 270.
  • the power output output from the quenching power source of the quenching heating device 202 to the quenching induction coil is stored in the quenching storage device 270 as quenching output transition data.
  • the timing of the cooling start command output from the quenching timing adjusting device 206 to the quenching cooling device 207 is stored in the quenching storage device 270 as quenching cooling timing data.
  • the quenching cooling timing is stored as the time from the start of heating, for example.
  • the quenching condition confirmation process after the validity of the quenching output transition data and quenching cooling timing data is confirmed based on the material data of the sample of the rolling bearing outer ring 201, the final confirmation In the process and the mass production process, the rolling bearing outer ring 201 is heated and quenched based on the quenching output transition data and quenching cooling timing data stored in the quenching storage device 270.
  • the induction hardening apparatus 293 directly responds to material changes due to quenching, and therefore quenching by temperature control that allows easy setting of quenching conditions, and the flow of data and commands. It is simple and can be implemented by switching between quenching with highly reliable power control. As a result, even if the past production results are not sufficient or when a worker with little experience in heat treatment is working, the desired hardness to be imparted to the workpiece and the residual steel constituting the workpiece. From the austenite amount and microstructure, the quenching data acquisition process can be performed under quenching conditions with temperature control that can be easily set. In the mass production process, quenching can be performed by highly reliable power control based on quenching conditions that have been validated.
  • FIG. 12 the flow of data and commands in the tempering data acquisition process is solid arrows, the flow of data and commands in the tempering data storage process is broken arrows, and the flow of data and commands in the final confirmation process and mass production process is Displayed with double solid arrows.
  • the operation of the induction tempering apparatus according to the present embodiment will be described with reference to FIG. 9, FIG. 10, and FIG.
  • a temporary tempering condition is determined by temperature control, and the heat treatment condition is determined by tempering temperature adjusting device 214 and It is input to the tempering end timing adjustment device 216 and heat treatment is started.
  • the temperature data of the sample of the rolling bearing outer ring 201 as the object to be processed measured by the tempering temperature control temperature measuring device 213 is sent to the tempering temperature adjusting device 214.
  • the target heating temperature of the rolling bearing outer ring 201 and the obtained temperature data of the sample of the rolling bearing outer ring 201 are also determined to determine the necessary power output, and the tempering power supply for the tempering heating device 212 is used. Command the power output to.
  • the power supply for tempering that receives the command outputs electric power to the induction coil for quenching of the tempering heating device 212, and the sample of the rolling bearing outer ring 201 is heated to a target temperature.
  • the temperature data of the sample of the rolling bearing outer ring 201 measured by the tempering end timing control temperature measuring device 215 is sent to the tempering end timing adjusting device 216.
  • the tempering end timing adjusting device 216 the cooling timing is judged from the obtained temperature and heating time of the sample of the rolling bearing outer ring 201, and the tempering end device 217 is instructed to start the cooling. Thereby, the sample of the rolling bearing outer ring 201 is cooled, and the tempering is finished.
  • the temperature data acquired by the tempering temperature adjustment device 214 and the tempering end timing adjustment device 216 is used as temperature transition data in the tempering data acquisition step. It is stored in the tempering storage device 271.
  • the power output output from the tempering power supply of the tempering heating device 212 to the tempering induction coil is stored in the tempering storage device 271 as tempering output transition data.
  • the timing of the cooling start command output from the tempering end timing adjusting device 216 to the tempering end device 217 is stored in the tempering storage device 271 as tempering cooling timing data.
  • the tempering cooling timing timing data is For example, it is stored as the time from the start of heating.
  • the tempering condition confirmation step the validity of the tempering output transition data and the tempering cooling timing data is confirmed based on the sample material data of the rolling bearing outer ring 201, and then the final confirmation.
  • the rolling bearing outer ring 201 is heated and tempered based on the tempering output transition data and the tempering cooling timing data stored in the tempering storage device 271.
  • the flow of data and commands is simple with tempering by temperature control in which tempering conditions can be easily set. Yes, it is possible to switch between tempering with highly reliable power control. As a result, even if the past production record is not sufficient or when an operator with little experience in heat treatment is working, the quenching data acquisition process is performed under quenching conditions with temperature control that can be set easily. In the mass production process, tempering can be performed with reliable power control based on the tempering conditions that have been validated.
  • conveying apparatuses 299C, 299D, and 299E are configured to be able to take out an object to be processed.
  • the transport apparatuses 299C, 299D, and 299E are provided with a cover
  • the cover is provided with a workpiece extraction port that can be opened and closed.
  • a branch that can change the transport direction of the object to be processed may be provided to take out the object to be processed.
  • the quenching storage device 270 may be installed as an independent device.
  • the quenching temperature control device 204 and the quenching timing adjustment may be performed by a personal computer having a storage unit such as a node or a disk.
  • a device such as the device 206 may also be installed.
  • the tempering storage device 271 may be installed as an independent device, but for example, a tempering temperature adjustment device 214, tempering end timing adjustment can be performed by a personal computer having a storage unit such as a node disk.
  • a device such as the device 216 may also be installed.
  • each step of the above-described high-frequency heat treatment method is performed, for example, as a personal device as a control device. This can be implemented by operating the personal computer using one or more programs corresponding to each process.
  • the hardness after tempering when tempering at 180 ° C is strength strength HRC58 or higher (HV653 or higher), and the amount of retained austenite is 1 from the viewpoint of dimensional stability.
  • the standard value is set to 2% by volume or less.
  • FIG. 13 is a TTA (Time Temperature Austinitization) diagram of the SUJ2 material showing the relationship between the quenching temperature and the holding time for satisfying the standard value of heat treatment.
  • the horizontal axis represents the quenching temperature (° C)
  • the vertical axis represents the holding time (seconds).
  • Region A is a range that does not satisfy the hardness standard
  • region B is a range where the retained austenite amount does not satisfy the standard
  • region C is a range that satisfies any heat treatment quality standard.
  • provisional heat treatment conditions conditions for heating temperature and heating time in quenching
  • the hardness of the rolling bearing outer ring 201 made of SUJ2 easily satisfies the standard as the quenching temperature and the holding time increase.
  • the amount of austenite satisfies the standard as the quenching temperature and holding time increase.
  • setting the conditions for a long time at a relatively low temperature makes it easier to control the heat treatment quality.
  • the holding time for ensuring the heat treatment quality standard is 15 seconds or longer, but if the holding time is 17 seconds or longer, the standard cannot be satisfied.
  • the holding time for ensuring the heat treatment quality is 20 seconds or more, and the standard can be satisfied up to 60 seconds.
  • FIG. 13 shows a TTA diagram related to SUJ2.
  • a temporary heat treatment condition can be determined in the same manner as described above by creating a TTA diagram corresponding to the force material.
  • the heat treatment conditions are input to a quenching temperature adjusting device 204 such as a personal computer with reference to FIG.
  • the quenching temperature control device 204 is connected to the quenching temperature control temperature measuring device 203 and the quenching heating device 202.
  • the PID Proportional With the integral differential control, a quenching temperature control signal is output to the quenching and heating device 202, and the temperature transition of the outer peripheral surface 201A that is the temperature measuring unit of the quenching temperature control temperature measuring device 203 can be controlled.
  • the outer peripheral surface 201A has the largest penetration of magnetic flux in the rolling bearing outer ring 201, and is the largest temperature rise due to high frequency heating.
  • the temperature measurement data of the quenching timing control temperature measuring device 205 is taken into the quenching timing adjusting device 206 such as a personal computer, and it is determined from the temperature transition whether the heating is sufficient, Adjust the cooling timing.
  • the determination of the cooling timing is made based on whether or not the temperature transition of the inner peripheral surface 201B, which is the temperature measuring portion of the quenching timing control temperature measuring device 205, falls within the standard on the TTA diagram.
  • the inner peripheral surface 201B is a portion where the penetration of the magnetic flux is the smallest in the rolling bearing outer ring 201 and the temperature rise due to the high frequency heating is the smallest.
  • the quenching temperature adjusting device 204 and the quenching timing adjusting device 206 can be used as the same personal computer.
  • Equation (3) and formula (5) A force that can use the following formula (3) and formula (5) for determining whether or not the TTA diagram is within the specification, that is, determining the quenching cooling timing, is preferably treated. Equations (4) and (5), which are obtained by correcting Equation (3) in consideration of the fact that the temperature of a physical object changes every moment, are used.
  • D diffusion constant of carbon in steel
  • t retention time (seconds)
  • A correction factor
  • D D exp (—QZRT) ⁇ ⁇ ⁇ ⁇ (5)
  • D Entropy term of diffusion constant
  • Q Activity energy
  • R Gas constant
  • T Absolute temperature
  • the value of the correction coefficient A is a value obtained by the following equation (6).
  • Equation (4) is an equation that calculates the diffusion length D of carbon when the value of C in Equation (6) becomes C.
  • thermodynamic equilibrium calculation it can be determined by thermodynamic equilibrium calculation. Cooling is performed when the value of carbon diffusion length D in equation (4) reaches a certain value (D *).
  • the temperature measuring unit 205 of the quenching timing control temperature measuring device 205 does not necessarily have to be one place. By using a plurality of temperature measuring sections, it is possible to ensure heat treatment quality at a plurality of sites.
  • the horizontal axis is time t and the vertical axis is temperature T.
  • the quenching temperature control side (outer peripheral surface 201A of the rolling bearing outer ring 201) and the quenching timing control side (rolling bearing outer ring).
  • the temperature transition on the inner peripheral surface 201B) of 201 is shown.
  • the upper right figure is an enlarged view of the area ⁇ in the upper left graph.
  • the lower part shows the formula for integrating the ep value of correction D from the temperature transition!
  • the temperature measurement part for determining the cooling timing that is, the inner peripheral surface which is the temperature measurement part of quenching timing control temperature measurement device 205) Since the temperature of 201B) changes from moment to moment, the value of correction D (corrected D in equation (4), hereinafter referred to as D in ep ep) is calculated as D ⁇ D ⁇ D as shown in Fig. 14. Need to ep el ep2 epn
  • the quenching timing control side (inner peripheral surface 201B side) has less magnetic flux entering than the quenching temperature control side (outer peripheral surface 201A side).
  • the temperature rises with a delay compared to the side. Normally, when the temperature exceeds 727 ° C, iron austenite starts, but when the heating rate is fast, the iron transformation temperature changes. Therefore, the temperature for calculating the diffusion length must be changed according to the heating rate.
  • the rate of temperature rise varies depending on the power source capacity, the shape of the coil and workpiece, etc. It is preferable that the temperature for calculating the diffusion length is appropriately changed depending on the type of the apparatus and the object to be processed. From the point where the quenching timing control temperature exceeds the heating transformation temperature, the diffusion length D is calculated using the formula in the figure. If D force 3 ⁇ 4 * at any time is exceeded, ep epn ep
  • the value of D * is within the range that can maintain the prescribed heat treatment quality.
  • the value is as small as possible from the viewpoint of reducing the heat treatment time. However, it is desirable to set the viewpoint that stabilizes the quality to a set value that is somewhat safe.
  • Figure 15 shows the results when the maximum temperature reached 900 ° C, the temperature drop rate was 0 ° CZ seconds, and tempering was performed at 180 ° C for 120 minutes after quenching.
  • the horizontal axis indicates the value of D * (m ep m), and the vertical axis indicates the hardness (HV) and the processing time (seconds).
  • black circles indicate hardness and white circles indicate processing time.
  • the value of * is considered to be desirable to be 0.015mm or less.
  • D * is set to 0.015 mm, and D accumulated as described above becomes 0.015 mm ep epn
  • a cooling start signal is output from the quenching timing adjusting device 206 to the quenching cooling device 207, whereby the cooling timing is determined. Based on this, the quenching cooling device 207 moves the rolling bearing outer ring 201 from the temperature of the A point or higher to the temperature of the M point or lower.
  • the rolling bearing outer ring 201 is hardened and hardened.
  • the quenching cooling timing in the present modification is determined using Equation (7) and Equation (5).
  • Cooling timing is determined by solving Equation (8) under certain boundary conditions and determining whether the solid solution state of carbon in the material satisfies a predetermined condition.
  • the boundary condition is, for example, iron carbide (cementite; Fe C) and the base material in the steel constituting the rolling bearing outer ring 201 during heating.
  • the carbon solid solution concentration at a certain temperature can be given under the assumption that the solid solubility of carbon at that temperature is equal.
  • the horizontal axis represents time (seconds), and the vertical axis represents temperature (° C).
  • the horizontal axis represents the distance (position) (mm) from the reference boundary point, and the vertical axis represents the carbon concentration (mass%).
  • the distance between 3 is 0.012 mm, and the amount of solute carbon (carbon concentration at the boundary point (the interface between Fe C and substrate))
  • the value (mass%) was set to a value (calculated with thermodynamic equilibrium calculation software) that can also obtain the solid solubility curve force of SUJ2.
  • This solid solubility curve equation (solid solubility equation) can be obtained in advance for each material by experimental or thermodynamic equilibrium calculation.
  • the solute carbon concentration is lowest at the position of 0.006 mm), and as the time passes, the solute carbon concentration increases as a whole and the central position And the difference between both ends (the interface between Fe C and the substrate) tends to be small.
  • the quenching cooling timing can be determined, for example, as the point in time when the inner peripheral surface 201B of the rolling bearing outer ring 201 satisfies the above-described quenching condition of the solute carbon concentration at the center position.
  • the distance between two boundary points can be appropriately changed depending on the difference in structure and material before quenching of the workpiece.
  • the quenching cooling timing in this modification is determined as follows, for example.
  • the quenching timing control side temperature is measured by the quenching timing control temperature measuring device 205 (step A), and the carbon content at the boundary is calculated from the measured temperature (step B).
  • Equation (8) is calculated by applying the boundary carbon content to the boundary condition of Equation (8) (Step C).
  • Step D it is possible to calculate the solid solution carbon concentration distribution as shown in Fig. 17 to Fig. 19 (Step D). From the obtained solute carbon concentration distribution, it is confirmed whether the carbon concentration at the center of the solute carbon concentration distribution is a predetermined carbon concentration (eg, 0.6 to 0.8 mass%). (Step E). If the carbon concentration at the central position has reached the predetermined carbon concentration, cooling is started (Step F). If not, cooling is not started and heating is continued and the process returns to Step A again.
  • a predetermined carbon concentration eg, 0.6 to 0.8 mass%
  • the carbon concentration at both ends of the carbon distribution in Figs. 17 to 19 is the carbon concentration at the carbide substrate interface. Therefore, carbon is supplied from this position to the substrate at a certain concentration (solid solubility of carbon).
  • C binding is located at the interface between carbide and substrate.
  • the formula power of solid solubility can also give the value of carbon concentration. As a result, there are five simultaneous equations and five unknowns, so the values of C, C, C, C, and C can be obtained.
  • Fig. 20 shows the quenching temperature control side (temperature control side) and the quenching timing control side (quenching control side) when quenching is performed by the quenching cooling timing determination method of this variation. It is a figure which shows distribution of the solid solution carbon concentration in.
  • the horizontal axis represents the distance (position) (mm) of the reference boundary point force, and the vertical axis represents the carbon concentration (mass%).
  • This data shows that the quenching temperature (heating temperature) is constant at 950 ° C, the heating rate up to the quenching temperature is 300 ° CZ seconds, the distance between carbides is 0.012 mm, and the cooling start condition is the carbon concentration. When the value at the center position is 0.6 mass%. From FIG.
  • solute carbon concentration value is generally higher on the quenching temperature control side than on the quenching timing control side. This is because the induction coil for quenching included in the quenching heating device 202 in the outer ring 201 of the rolling bearing. This is because the temperature on the quenching temperature control side is higher than that on the quenching timing control side.
  • the starting temperature of the calculation of the above-mentioned solid solution carbon concentration that is, the starting temperature of the solid solution of carbon in the substrate, in consideration of the rate of temperature rise.
  • the determination method will be described below.
  • the horizontal axis indicates the heating rate (° CZ seconds), and the vertical axis indicates the heating transformation point A (° C).
  • the heating transformation point A changes from 727 ° C to 950 ° C.
  • the heating transformation point A is obtained from the velocity, and the above solute carbon is calculated based on the heating transformation point A.
  • the concentration calculation start temperature (carbon solid solution start temperature) can be determined.
  • the horizontal axis represents time, and the vertical axis represents temperature. 22 shows the temperature transition on the quenching temperature control side (outer peripheral surface 201A of the rolling bearing outer ring 201 in FIG. 8) and the temperature on the quenching timing control side (inner peripheral surface 201B of the rolling bearing outer ring 201 in FIG. 8). Transition and heating transformation point A
  • the heating on the quenching temperature control side is rapidly performed, so the heating rate on the quenching timing control side is also increased, and the heating transformation point is increased.
  • the temperature on the quenching temperature control side approaches a predetermined set temperature
  • heating is controlled by the quenching temperature adjusting device 204 so that the rate of temperature rise becomes slow.
  • the rate of temperature increase on the quenching timing control side also becomes moderate, and the heating transformation point A decreases.
  • the heating transformation point A intersects with the temperature transition on the quenching timing control side. This intersection is
  • the calculation of the solute carbon concentration can be started from the temperature of this intersection (that is, the start temperature of the austenite cake).
  • X rate of change of mechanical properties
  • k reaction rate coefficient
  • t tempering time (seconds)
  • N time index
  • A vibration factor term
  • Q activation energy
  • R gas constant
  • T tempering Tempering temperature (K)
  • M Hardness after tempering
  • ⁇ Hardness after quenching
  • ⁇ Raw material hardness
  • the hardness M and the raw material hardness M after quenching in the formula (10) can be measured.
  • N, A, and Q are experiments
  • the tempering time t can be calculated by Equation (10) by substituting the value of the tempering temperature T.
  • the timing at which the workpiece should be cooled can be determined by adjusting the tempering time t based on the equation (10).
  • Expression (10) is a relational expression between the heat treatment temperature and the retention time with respect to the standard quality (hardness) of the workpiece, and can be used effectively regardless of the shape of the rolling bearing outer ring 201.
  • the horizontal axis represents the tempering temperature (° C) and the vertical axis represents the holding time (seconds).
  • Region A is a range of HRC62 or higher
  • region B is a range of HRC58 or lower
  • region C is a range of HRC58-62.
  • the condition diagram shown in Fig. 23 can be created based on Equation (10) for obtaining the tempering time t. wear.
  • Equation (10) for obtaining the tempering time t. wear.
  • the higher the tempering temperature the shorter the tempering becomes possible. For this reason, a higher tempering temperature is desirable from the viewpoint of reducing the heat treatment time.
  • the tempering temperature can be determined in terms of the balance between heat treatment time and tempering unevenness.
  • the tempering conditions are input to a tempering temperature adjusting device 214 such as a personal computer with reference to FIG.
  • the tempering temperature adjusting device 214 is connected to the tempering temperature control temperature measuring device 213 and the tempering heating device 212. Based on the temperature information from the tempering temperature control temperature measuring device 213, the temperature is controlled by PID control. A control signal is output to the tempering heating device 212 to control the temperature transition of the rolling bearing outer ring 201.
  • the temperature information of the tempering end timing control temperature measuring device 215 is taken into the tempering end timing adjusting device 216 such as a personal computer, and it is judged from the temperature transition whether the heating is sufficient, Adjust the timing to be cooled.
  • the temperature transition is shown with time t on the horizontal axis and temperature T on the vertical axis.
  • the upper right figure shows an enlarged view of the area j8 in the upper left graph.
  • the lower part shows the formula for integrating the temperature transition force of the hardness M after tempering.
  • the temperature information from the tempering end timing control temperature measuring device 215 changes every moment, so the value of M (hardness after tempering) is calculated as t *. It is desirable to calculate by integrating as shown in FIG. When the condition that the hardness after tempering becomes the target hardness is satisfied, the rolling bearing outer ring 201 is cooled by the tempering end device 217. Note that the tempering temperature adjusting device 214 and the tempering end timing adjusting device 216 are also used as the same personal computer.
  • FIG. 25 is a schematic cross-sectional view showing a configuration of a rolling bearing outer ring as a high-frequency heat-treated product in the third embodiment which is an embodiment of the present invention.
  • the configuration of the rolling bearing outer ring in the third embodiment will be described.
  • rolling bearing outer ring 3 as the high frequency heat treatment product in the third embodiment 01 has an annular shape.
  • the rolling bearing outer ring 301 has a rolling surface 301C for rolling while the balls, rollers, etc., as rolling elements are in contact with the inner peripheral surface 301B, and is also in contact with other members. It has an outer peripheral surface 301A for holding the outer ring against the other members.
  • the rolling bearing outer ring 301 preferably has a hardness of 58 HRC or more from the viewpoint of rolling fatigue strength and rigidity. From the viewpoint of dimensional stability, the retained austenite content is preferably suppressed to 12% by volume or less.
  • the rolling bearing outer ring 301 is manufactured by heat treatment using the high-frequency heat treatment method in one embodiment of the present invention described below, a high-frequency heat-treated product with reduced manufacturing cost and stable quality is provided. It has become.
  • induction hardening apparatus 391 in Embodiment 3 is an induction heat treatment according to the present invention in which an object to be treated (for example, rolling bearing outer ring 301) is quenched and hardened by induction heating.
  • Induction hardening apparatus used in the method the temperature control device 350 for adjusting the temperature of the rolling bearing outer ring 301 as the object to be treated, and the timing at which the heated rolling bearing outer ring 301 should be cooled And a quenching control device 360 for adjusting the temperature.
  • the outer peripheral surface 301A and the inner peripheral surface 301B of the rolling bearing outer ring 301 are more resistant to oxidation than the rolling bearing outer ring 301 in the temperature range in which the rolling bearing outer ring 301 is heated, that is, in the quenching temperature.
  • a highly stable layer 309 is formed.
  • the temperature control device 350 acquires temperature data of the outer peripheral surface 301A that is considered to have the highest temperature due to high-frequency heating in the rolling bearing outer ring 301, and outputs temperature information based on the temperature data of the rolling bearing outer ring 301.
  • a first radiation thermometer 303 as a temperature control temperature measuring device, and connected to the first radiation thermometer 303, and controls the heating state of the object to be processed based on the temperature information from the first radiation thermometer 303.
  • a temperature control device 304 that outputs a temperature control signal for heating, and a heating device 302 that is connected to the temperature control device 304 and heats the rolling bearing outer ring 301 by high-frequency heating based on the temperature control signal from the temperature control device 304.
  • the heating device 302 includes, for example, an induction coil for flowing a high-frequency current, an induction coil And a power source that is connected to the coil and generates a high-frequency current.
  • the quenching control device 360 obtains temperature data of the inner peripheral surface 301B, which is considered to have the smallest temperature rise farthest from the outer peripheral surface 301A that is considered to have the highest temperature due to high-frequency heating, and 2nd radiation thermometer 305 as temperature measuring device for quenching that outputs temperature information based on temperature data of surface 301B, and connected to 2nd radiation thermometer 305, the temperature from 2nd radiation thermometer 305
  • a cooling timing adjusting device 306 that adjusts the heating time based on the information, determines the timing at which the rolling bearing outer ring 301 should be cooled, and outputs a cooling start signal, and is connected to the cooling timing adjusting device 306 and based on the cooling start signal
  • a cooling liquid injection device 307 as a cooling device for quenching and hardening the rolling bearing outer ring 301 by cooling the rolling bearing outer ring 301.
  • the temperature adjustment device 304 and the cooling timing adjustment device 306 are each a personal computer, for example, and have a configuration in which the temperature adjustment device 304 and the cooling timing adjustment device 306 are combined with one personal computer. May be.
  • the induction hardening method of the third embodiment is an induction heat treatment method in which the workpiece (rolling bearing outer ring 301) is heated and hardened by induction heating.
  • a surface stabilization step 311 is formed on the surface of the rolling bearing outer ring 301 in a temperature layer where the rolling bearing outer ring 301 is heated.
  • the surface stabilization step 311 includes a quench hardening step 310 in which the rolling bearing outer ring 301 on which the stabilization layer 309 is formed is quenched and hardened.
  • the quench hardening process 310 includes a temperature control process 320 in which the temperature of the rolling bearing outer ring 301 on which the stable layer 309 is formed is adjusted, and a timing at which the heated rolling bearing outer ring 301 is to be cooled. And a quench control step 330 in which the rolling bearing outer ring 301 is cooled.
  • the temperature control step 320 includes a temperature control temperature measurement step 323 in which the surface temperature of the stable layer 309 formed on the outer peripheral surface 301A of the rolling bearing outer ring 301 is measured by the first radiation thermometer 303, Rolling bearing based on temperature information measured in temperature measurement process 323 A temperature adjustment step 324 in which a temperature control signal for controlling the heating state of the outer ring 301 is output; and a heating step 322 in which the rolling bearing outer ring 301 is heated by high-frequency heating based on the temperature control signal.
  • the quenching control step 330 is a quenching temperature measurement step 335 in which the surface temperature of the stable layer 309 formed on the inner peripheral surface 301B of the rolling bearing outer ring 301 is measured by the second radiation thermometer 305. And a cooling timing adjusting step 336 in which the heating time is adjusted based on the temperature information measured in the quenching temperature measuring step 335, the timing at which the rolling bearing outer ring 301 should be cooled is determined, and a cooling start signal is output. And a cooling step 337 in which the rolling bearing outer ring 301 is quenched and hardened by cooling the rolling bearing outer ring 301 based on the cooling start signal.
  • the induction hardening method according to the third embodiment is performed by temperature control and is easy to determine the conditions for heat treatment. Therefore, the manufacturing cost of the rolling bearing outer ring 301 can be suppressed and the quality can be stabilized. It is pretty.
  • the black body paint is applied to the surface of the rolling bearing outer ring 301, so that the black body paint layer as the above-described stability layer 309 is formed. Good.
  • an iron oxide layer may be formed instead of the black body paint layer. This iron oxide layer may be formed, for example, by thermally oxidizing the surface of the rolling bearing outer ring 301, or may be formed by immersing the rolling bearing outer ring 301 in an acidic solution.
  • the hardness after tempering when tempering at 180 ° C is strength strength of HRC58 or higher (HV653 or higher), and the amount of retained austenite is 1 from the viewpoint of dimensional stability.
  • the standard value is set to 2% by volume or less.
  • the target heat treatment conditions condition of heating temperature and heating time in quenching.
  • the hardness of the SUJ2 rolling bearing outer ring increases as the quenching temperature and holding time increase. It becomes easy to satisfy the case.
  • the amount of austenite becomes difficult to meet the specifications as the quenching temperature and holding time increase.
  • it is easier to control the heat treatment quality by setting conditions at a relatively low temperature for a long time.
  • the holding time for ensuring the heat treatment quality standard is 15 seconds or more, but if it is kept for 17 seconds or more, the standard cannot be satisfied.
  • the holding time for ensuring the heat treatment quality is 20 seconds or more, and the standard can be satisfied up to 60 seconds.
  • FIG. 13 is a TTA diagram related to SUJ2. If a TTA diagram corresponding to the force material can be created, the heat treatment conditions may be determined according to the diagram.
  • the high-frequency heat treatment method 3 can be used regardless of the type of material.
  • the heat treatment conditions are input to temperature control device 304 such as a personal computer.
  • the temperature adjustment device 304 is connected to the first radiation thermometer 303 and the heating device 302. Based on the temperature information from the first radiation thermometer 303, the temperature control signal is transmitted by P ID (Proportional Integral Differential) control.
  • P ID Proportional Integral Differential
  • the temperature can be output to the heating device 302, and the temperature transition of the outer peripheral surface 301A, which is the temperature measuring unit of the first radiation thermometer 303, can be controlled.
  • the outer peripheral surface 301A is the part where the magnetic flux penetrates most in the rolling bearing outer ring 301 and the temperature rises most due to high frequency heating.
  • the temperature measurement data of the second radiation thermometer 305 is taken into the cooling timing adjustment device 306 such as a personal computer, and the temperature transition force is judged whether the heating is sufficient and the cooling timing is adjusted. . Judgment of the cooling timing is made based on whether or not the temperature transition of the inner peripheral surface 301B, which is the temperature measuring section of the second radiation thermometer 303, is within the specifications on the TTA diagram.
  • the inner peripheral surface 301B is a part where the magnetic flux intrudes most in the rolling bearing outer ring 301 and the temperature rise due to high frequency heating is the smallest.
  • the temperature adjustment device 304 and the cooling timing adjustment device 306 can be combined with the same personal computer. I'll do it with you.
  • equations (4) and (5) can be used, but preferably, equations (4) and (5) are used, which are obtained by correcting equation (3) in consideration of the fact that the temperature of the workpiece changes every moment.
  • D diffusion constant of carbon in steel
  • t retention time (seconds)
  • A correction factor
  • the value of the correction coefficient A is a value obtained by the following equation (6).
  • Equation (4) is an equation that calculates the diffusion length D of carbon when the value of C in Equation (6) becomes C.
  • thermodynamic equilibrium calculation it can be determined by thermodynamic equilibrium calculation. Cooling is performed when the value of carbon diffusion length D in equation (4) reaches a certain value (D *).
  • the temperature measuring section of the second radiation thermometer 305 does not necessarily have to be one place. By using a plurality of temperature measuring sections, it is possible to ensure heat treatment quality at a plurality of sites.
  • the temperature measurement part for determining the cooling timing (that is, inner peripheral surface 301B which is the temperature measurement part of second radiation thermometer 305) is determined. Since the temperature changes from moment to moment, the value of correction D (corrected D in equation (4), hereinafter simply referred to as D) ep ep ep must be integrated as D ⁇ D ⁇ D, as shown in Figure 14. is there. Rolling axis e l ep2 epn
  • the quenching control side (inner peripheral surface 301B side) is delayed compared to the temperature control side because the magnetic flux entry is less than the temperature control side (outer peripheral surface 301A side). Temperature rises. Normally, when the temperature exceeds 727 ° C, iron austenite begins, but when the rate of temperature rise is fast, the heating transformation temperature of iron changes. Therefore, the temperature for calculating the diffusion length The degree must be changed by the heating rate.
  • the temperature for calculating the diffusion length is preferably changed as appropriate depending on the type of the apparatus and object to be processed.
  • the diffusion length D is calculated using the formula in the figure.
  • the viewpoint power of reducing the heat treatment time is also desirable. However, from the standpoint of stabilizing quality, it is desirable to set a value that is somewhat safe.
  • the value of * is considered to be desirable to be 0.015mm or less.
  • D * is set to 0.015 mm, and D accumulated as described above becomes 0.015 mm ep epn
  • a cooling start signal is output from the cooling timing adjustment device 306 to the coolant injection device 307, and based on this, the coolant injection device 307 moves the rolling bearing outer ring 301 from a temperature higher than the A point to a temperature lower than the M point.
  • the rolling bearing outer ring 301 is quenched by cooling to the temperature.
  • the high-frequency heat treatment method, high-frequency heat treatment apparatus, and high-frequency heat treatment product in the modification of the third embodiment basically have the same configuration as that of the third embodiment described above.
  • the following equation (7) and equation (5) are used to determine whether the temperature transition of the inner peripheral surface 301B of the rolling S bearing outer ring 301 is within the standard on the TTA diagram in determining the cooling timing. It is different in point.
  • a method is used to determine whether the temperature transition of the inner peripheral surface 301B of the rolling bearing outer ring 301 falls within the standard on the TTA diagram, using Equation (7) and Equation (5). explain.
  • D Carbon diffusion constant in steel
  • C Carbon concentration (% by mass)
  • t Time (seconds)
  • X Distance
  • D D exp (—QZRT)
  • Q Activity energy
  • R Gas constant
  • T Absolute temperature
  • Cooling timing is determined by solving Equation (8) under certain boundary conditions and determining whether the solid solution state of carbon in the material satisfies a predetermined condition.
  • the boundary conditions are, for example, iron carbide (cementite; Fe C) and the base material in the steel constituting the rolling bearing outer ring 301 during heating.
  • the carbon solid solution concentration at a certain temperature can be given under the assumption that the solid solubility of carbon at that temperature is equal.
  • the solute carbon concentration is lowest at the position of 0.006 mm), and as the time passes, the solute carbon concentration increases as a whole and the central position And the difference between both ends (the interface between Fe C and the substrate) tends to be small.
  • the cooling start signal in the cooling timing adjustment step 336 is output when, for example, the inner peripheral surface 301B of the rolling bearing outer ring 301 satisfies the solute carbon concentration condition as the quenching condition described above at the center position. be able to.
  • the distance between two boundary points can be changed as appropriate depending on the structure and material before quenching of the workpiece.
  • the determination of the cooling timing in the present modification is performed as follows, for example.
  • the temperature on the quenching control side is measured by the second radiation thermometer 305 (Step A), and the carbon content at the boundary is calculated from the measured temperature (Step B).
  • Eq. (8) is calculated by applying the boundary carbon value to the boundary condition of Eq. (8) (Step C).
  • Step D it is possible to calculate the solid solution carbon concentration distribution as shown in Fig. 17 to Fig. 19 (Step D). From the obtained solute carbon concentration distribution, it is confirmed whether the carbon concentration at the center position of the solute carbon concentration distribution has reached a predetermined carbon concentration (eg, 0.6 to 0.8 mass%) (step E). If the carbon concentration at the center has reached the specified carbon concentration, start cooling ( Step F), if not, cooling is not started and heating is continued and the process returns to Step A again.
  • a predetermined carbon concentration eg, 0.6 to 0.8 mass%
  • equation (8) in step C above can be solved by the difference method as follows.
  • the carbon concentration at both ends of the carbon distribution in Figs. 17 to 19 is the carbon concentration at the carbide substrate interface. Therefore, carbon is supplied from this position to the substrate at a certain concentration (solid solubility of carbon).
  • C binding is located at the interface between carbide and substrate.
  • the formula power of solid solubility can also give the value of carbon concentration. As a result, there are five simultaneous equations and five unknowns, so the values of C, C, C, C, and C can be obtained.
  • the amount of retained austenite on the temperature control side is estimated from the solid solution state of the carbon on the temperature control side by performing the above calculation of the solid solution carbon concentration not only on the quenching control side but also on the temperature control side. be able to.
  • the value of the solute carbon concentration is generally higher on the temperature control side than on the quenching control side. This is because in the rolling bearing outer ring 301, the temperature on the temperature control side is higher than that on the quenching control side near the induction coil included in the heating device 302.
  • the starting temperature of the calculation of the solid solution carbon concentration that is, the starting temperature of the solid solution of carbon in the substrate. The determination method will be described below.
  • the heating transformation point A increases from 727 ° C to 950 ° C.
  • the heating transformation point A is determined from the above, and based on the heating transformation point A, the solute carbon concentration is
  • Calculation start temperature (carbon solid solution start temperature) can be determined.
  • heating on the temperature control side is performed rapidly, so that the rate of temperature increase on the quenching control side is also increased, and the heating transformation point is increased.
  • the temperature control device 304 controls the heating so that the rate of temperature increase becomes slow.
  • the rate of temperature increase on the quenching control side also becomes slow, and the heating transformation point A decreases.
  • the heating transformation point A becomes the quench control.
  • the carbon concentration at the center position of the distribution of the solute carbon concentration exceeds a predetermined carbon concentration (for example, 0.6 to 0.8 mass%).
  • a predetermined carbon concentration for example, 0.6 to 0.8 mass%.
  • induction hardening apparatus 392 in the fourth embodiment has basically the same configuration as induction hardening apparatus 391 in the third embodiment.
  • the induction hardening apparatus 392 in the embodiment 4 is connected to the heating apparatus 302, the temperature adjustment apparatus 304, and the cooling timing adjustment apparatus 306, and stores the transition data of the power output and the cooling timing data as process data. It is different from the induction hardening apparatus 391 of Embodiment 3 in that the storage apparatus 370 is provided.
  • the induction hardening method in the fourth embodiment is an induction heat treatment method in which a workpiece (for example, the rolling bearing outer ring 301) is heated and hardened by induction heating.
  • a workpiece for example, the rolling bearing outer ring 301
  • the data acquisition process, the storage process, the confirmation process, and the mass production process are provided.
  • the validity of the transition data of the power output and the cooling timing data is confirmed based on the material data of the rolling bearing outer ring 301 that has been hardened and hardened in the data acquisition process. That is, for example, the temperature transition data of the object to be processed in the data acquisition process is stored, and the stored temperature transition data is analyzed to determine whether or not there is an influence of disturbance, and is stored in the storage process. The validity of the power output transition data and cooling timing data, which are the process data, is confirmed. In addition, the material data of the sample of the rolling bearing outer ring 301 that has been actually heat-treated may be actually obtained by experiments, and the validity of the transition data of the power output and the cooling timing data may be confirmed.
  • the stored temperature transition data force can be determined whether there is a disturbance or not. is there. For example, if there is a discontinuous area in the temperature transition data, it can be determined that there was a disturbance.
  • a contact or non-contact thermometer that measures the temperature of the same part can be provided, and the presence or absence of disturbance can be determined based on the consistency of both data. As a specific judgment method, for example, when the difference between the two data power temperatures is 5% or more, it can be judged that there is a disturbance.
  • the disturbance can be determined by the operator confirming the temperature transition data, but can also be performed by another automated device. Specifically, for example, when the differential value of the temperature transition of the stored temperature transition data is 1000 ° CZ seconds or more or -1000 ° CZ seconds or less, there is a method of determining that there is a disturbance, or the same as described above. A thermometer that measures the temperature of the part is provided, and there is a means to judge that there is a disturbance when a difference of 5% or more occurs between the two data.
  • the rolling bearing outer ring 301 is subjected to high-frequency quenching according to the power output transition data and the cooling timing data that are stored in the storage process and validated in the confirmation process.
  • the quench hardening in the data acquisition process is the high frequency of the present invention. This is performed by a wave heat treatment method, for example, the induction hardening method of the third embodiment.
  • the process data can be obtained simply by quenching and hardening the rolling bearing outer ring 30 1 as the object to be processed by the induction hardening method in Embodiment 4, thereby making it possible to control the temperature and to easily determine the conditions for the heat treatment.
  • the influence of disturbance on the workpiece is further suppressed, and the quality of the workpiece (rolling bearing outer ring 301) is stabilized.
  • the rolling bearing outer ring 301 as the induction-hardened product in the fourth embodiment which has been hardened by the induction hardening method in the fourth embodiment, is a low-frequency and more stable high-frequency product. It is hardened.
  • FIG. 30 the data flow in the data acquisition process is a solid arrow, the data flow in the storage process is a broken arrow, the data flow in the confirmation process is a double dashed arrow, and the data flow in the mass production process is a double solid line. It is displayed with an arrow.
  • the data flow in each step of induction hardening according to the fourth embodiment will be described.
  • the temperature data of the sample of the rolling bearing outer ring 301 as the workpiece measured by the temperature control temperature measuring device is Sent to temperature controller 304.
  • the target heating temperature of the rolling bearing outer ring 301 and the obtained temperature data of the sample of the rolling bearing outer ring 301 are determined, and the necessary power output is determined, and the power output is commanded to the power supply of the heating device 302.
  • the power source that has received the command outputs power to the induction coil of the heating device 302, and the sample of the rolling bearing outer ring 301 is heated to a target temperature.
  • the temperature data of the sample of the rolling bearing outer ring 301 measured by the quenching temperature measuring device is sent to the cooling timing adjusting device 306.
  • the cooling timing adjusting device 306 determines the cooling timing from the acquired temperature and calorie heat time of the sample of the rolling bearing outer ring 301 and commands the cooling device such as the coolant injection device 307 to start cooling.
  • the sample of the rolling bearing outer ring 301 is quenched and hardened by hardening.
  • the heating history of the sample of the rolling bearing outer ring 301 is clear. Therefore, as long as the temperature data is accurate, appropriate heat treatment is performed, and the rolling bearing outer ring 301 having the desired quality is obtained.
  • the temperature data acquired by the temperature adjustment device 304 and the cooling timing adjustment device 306 in the data acquisition step is stored in the storage device 370 as temperature transition data.
  • the power supply output from the power supply of the heating device 302 to the induction coil is stored in the storage device 370 as the power output transition data.
  • the timing of the cooling start command output from the cooling timing adjusting device 310 to the cooling device such as the coolant injection device 307 is stored in the storage device 370 as cooling timing data.
  • the cooling timing is stored as, for example, the time from the start of heating.
  • thermometers capable of measuring the same part as the first radiation thermometer 303 and the second radiation thermometer 305 are provided, and the temperature of the part is measured. By comparing the temperature measurement data with the temperature transition data measured by the first radiation thermometer 303 and the second radiation thermometer 305 and stored in the storage device 370, the presence or absence of disturbance is determined.
  • the rolling bearing outer ring 301 is heated and hardened based on the power output transition data and the cooling timing data that are stored in the storage process and validated in the confirmation process. At this time, this mass production process is not performed based on real-time temperature data from the first radiation thermometer 303 and the second radiation thermometer 305, which may cause disturbance, and the validity of the power supply output has been confirmed. It is implemented by power control based on transition data and cooling timing data. Therefore, the rolling bearing outer ring 301 having a stable quality can be obtained.
  • the storage device 370 may be installed as an independent device, but for example, a personal computer having a storage unit such as a node disk may also be used as a device such as the temperature adjustment device 304 and the cooling timing adjustment device 306. May be installed.
  • each step of the induction hardening method of the present embodiment can be performed by using a personal computer as a control device, for example, and operating the personal computer with one or more programs corresponding to each step. it can.
  • a personal computer as a control device, for example, and operating the personal computer with one or more programs corresponding to each step. it can.
  • induction tempering apparatus 393 is a high-frequency tempering apparatus according to the present invention that performs tempering by heating an object to be treated (for example, rolling bearing outer ring 301) by induction heating.
  • the outer peripheral surface 301A and the inner peripheral surface 301B of the rolling bearing outer ring 301 are more resistant to oxidation than the rolling bearing outer ring 301 in the temperature range in which the rolling bearing outer ring 301 is heated, that is, the tempering temperature.
  • a high stability layer 309 is formed.
  • the temperature control device 351 obtains temperature data of the outer peripheral surface 301A that is considered to have the highest temperature due to high-frequency heating in the rolling bearing outer ring 301, and outputs temperature information based on the temperature data of the rolling bearing outer ring 301.
  • the first radiation thermometer 313 as a temperature control temperature measuring device and the first radiation thermometer 313 are connected to control the heating state of the object to be processed based on the temperature information from the first radiation thermometer 313.
  • a temperature control device 314 that outputs a temperature control signal for heating, and a heating device 312 that is connected to the temperature control device 314 and heats the rolling bearing outer ring 301 by high-frequency heating based on the temperature control signal from the temperature control device 314. Contains.
  • the heating device 312 has, for example, an induction coil for flowing a high-frequency current, and a power source that is connected to the induction coil and generates a high-frequency current.
  • the tempering control device 361 obtains the temperature data of the inner peripheral surface 301B, which is considered to have the smallest temperature rise farthest from the outer peripheral surface 301A, which is considered to have the highest temperature due to high-frequency heating.
  • a second radiant thermometer 315 that outputs temperature information based on the temperature data of surface 301B and a second radiant thermometer 315 connected to the second radiant thermometer 315. Based on the information, the heating time is adjusted, the timing at which the rolling bearing outer ring 301 should be cooled is determined and a cooling start signal is output, and the cooling timing adjusting device 316 is connected to the cooling timing adjusting device 316 and is based on the cooling start signal.
  • a cooling fluid injection device 317 as a cooling device that terminates tempering of the rolling bearing outer ring 301 by cooling the rolling bearing outer ring 301 is included.
  • the temperature adjustment device 314 and the cooling timing adjustment device 316 are each a personal computer, for example, and each personal computer is configured to serve as both the temperature adjustment device 314 and the cooling timing adjustment device 316. May be.
  • the induction tempering method of the fifth embodiment is an induction heat treatment in which an object to be treated (for example, the rolling bearing outer ring 301) is heated and tempered by induction heating.
  • a surface stabilizing step 311 in which a stabilizing layer 309 having higher oxidation resistance than the rolling bearing outer ring 301 is formed on the surface of the rolling bearing outer ring 301, and a stable layer in the surface stabilizing step.
  • a tempering step 410 in which the rolling bearing outer ring 301 formed with 309 is heated and tempered.
  • the temperature control step 420 in which the temperature of the rolling bearing outer ring 301 is adjusted, the timing at which the heating of the rolling bearing outer ring 301 should be finished, are determined, and the rolling bearing outer ring 301 is cooled. And tempering control step 430.
  • the temperature control step 420 includes a temperature control step 423 in which the surface temperature of the stable layer 309 formed on the surface of the rolling bearing outer ring 301 is measured by a radiation thermometer, and a temperature control temperature measurement step 423.
  • a temperature adjustment step 424 in which a temperature control signal for controlling the heating state of the rolling bearing outer ring 301 is output based on the temperature information measured in step 423, and a rolling bearing outer ring by high-frequency heating based on the temperature control signal.
  • the tempering control process 430 includes a tempering temperature measurement process 435 in which the surface temperature of the stable layer 309 formed on the surface of the rolling bearing outer ring 301 is measured by a radiation thermometer, and a tempering measurement process 430.
  • a cooling timing adjustment step 436 in which the heating time is adjusted based on the temperature information measured in the temperature range 435, the timing at which the rolling bearing outer ring 301 should be cooled is determined, and a cooling start signal is output.
  • a cooling step 437 in which tempering of the rolling bearing outer ring 301 is completed by cooling the rolling bearing outer ring 301 based on the start signal.
  • the induction tempering method in the fifth embodiment is performed by temperature control, and it is easy to determine the conditions for heat treatment. Therefore, the manufacturing cost of the rolling bearing outer ring 301 is suppressed, and the quality is reduced. Can be determined.
  • the induction tempering method of the fifth embodiment for example, the workpiece having the same configuration as the rolling bearing outer ring 301 of the third embodiment described with reference to FIG. Tempering can be carried out.
  • the rolling bearing outer ring 301 as the high frequency heat-treated product in the fifth embodiment which is one embodiment of the present invention, is a high-frequency heat treated product with reduced manufacturing cost and stable quality.
  • a black body paint is applied to the surface of the rolling bearing outer ring 301 so that the black body as the stabilization layer 309 described above is applied.
  • a coating layer may be formed, or an iron oxide layer may be formed instead of the black body paint layer.
  • This acid iron layer may be formed by, for example, the surface of the rolling bearing outer ring 301 being thermally oxidized, or may be formed by immersing the rolling bearing outer ring 301 in an acidic solution. Good.
  • the high-frequency heat treatment method of the fifth embodiment will be specifically described taking a rolling bearing outer ring 301 made of SUJ2 as an example.
  • the outer ring 301 of the rolling bearing is quenched by being rapidly cooled from 850 ° C. in an RX gas atmosphere furnace.
  • the heat treatment standard of the workpiece after tempering is set to hardness HRC58 or more and HRC62 or less.
  • X rate of change of mechanical properties
  • k reaction rate coefficient
  • t tempering time (seconds)
  • N time index
  • A vibration factor term
  • Q activation energy
  • R gas constant
  • T tempering Tempering temperature (K)
  • M Hardness after tempering
  • ⁇ Hardness after quenching
  • ⁇ Raw material hardness
  • the hardness M and the raw material hardness M after quenching in the formula (10) can be measured.
  • N, A, and Q are experiments
  • the tempering time t can be calculated by Equation (10) by substituting the value of the tempering temperature T.
  • tempering is performed based on the equation (10).
  • the time t can be adjusted.
  • Expression (10) is a relational expression between the heat treatment temperature and the retention time with respect to the standard quality (hardness) of the workpiece, and can be used effectively regardless of the shape of the rolling bearing outer ring 301.
  • the condition diagram shown in FIG. 23 can be prepared based on the equation (10) for obtaining the tempering time t.
  • the higher the tempering temperature the shorter the tempering becomes possible. For this reason, a higher tempering temperature is desirable from the viewpoint of reducing the heat treatment time.
  • the tempering temperature can be determined in terms of the balance between heat treatment time and tempering unevenness.
  • the tempering conditions are input to temperature control device 314 such as a personal computer.
  • the temperature adjustment device 314 is connected to the first radiation thermometer 313 and the heating device 312, and based on the temperature information from the first radiation thermometer 313, outputs a temperature control signal to the heating device 312 by PID control. Controls temperature transition of rolling bearing outer ring 301.
  • the temperature information of the second radiation thermometer 315 is taken into a cooling timing adjustment device 316 such as a personal computer, and it is judged whether the heating is sufficient from the temperature transition, and the tempering end time is adjusted.
  • the temperature information from the second radiation thermometer 315 changes every moment.
  • the value of M (hardness after tempering) should be calculated by integrating t * as shown in Fig. 24.
  • the rolling bearing outer ring 301 is cooled by the coolant injection device 317.
  • the temperature adjusting device 314 and the cooling timing adjusting device 316 can also be used as the same personal computer.
  • the heat treatment apparatus of the fifth embodiment has basically the same configuration as the heat treatment apparatus of the third embodiment described above. Therefore, for example, by using a personal computer as a control device and using a program corresponding to the desired heat treatment, the induction hardening device and the induction tempering device can be combined.
  • induction tempering apparatus 394 in the sixth embodiment has basically the same configuration as induction tempering apparatus 393 in the fifth embodiment.
  • the induction tempering apparatus 394 in Embodiment 6 is connected to the heating apparatus 312, the temperature adjustment apparatus 314, and the cooling timing adjustment apparatus 316 and stores the power output transition data and the cooling timing data as process data. This is different from the induction tempering apparatus 393 of Embodiment 5 in that the storage apparatus 371 is provided.
  • the induction tempering method in the sixth embodiment is an induction heat treatment method in which an object to be treated (for example, the rolling bearing outer ring 301) is heated and tempered by induction heating. Therefore, it has a data acquisition process, a storage process, a confirmation process, and a mass production process.
  • the process data is acquired by heating and tempering the sample of the rolling bearing outer ring 301.
  • the memory process in order to heat the sample of the rolling bearing outer ring 301 in the data acquisition process, the transitional data of the power output output to the induction coil and the power supply power for high-frequency heating and the cooling timing of the sample of the rolling bearing outer ring 301 are specified. And cooling timing data for the storage are stored as process data.
  • the validity of the transition data of the power output and the cooling timing data is confirmed based on the material data of the rolling bearing outer ring 301 tempered in the data acquisition process. That is, for example, the temperature transition data of the object to be processed in the data acquisition process is stored, and the stored temperature transition data is analyzed to determine the presence or absence of the influence of the disturbance. The validity of the transition data of the power output and the cooling timing data, which are the processed process data, is confirmed. It should be noted that the material data of the sample of the rolling bearing outer ring 301 that has been actually heat-treated may be actually obtained through experiments to confirm the validity of the power output transition data and the cooling timing data.
  • the disturbance can be determined by the operator confirming the temperature transition data, but can also be performed by another automated device. Specifically, for example, when the differential value of the temperature transition of the stored temperature transition data is 1000 ° CZ seconds or more or -1000 ° CZ seconds or less, there is a method of determining that there is a disturbance, or the same as described above. A thermometer that measures the temperature of the part is provided, and there is a means to judge that there is a disturbance when a difference of 5% or more occurs between the two data.
  • high-frequency tempering of the rolling bearing outer ring 301 is performed in accordance with the transition data and cooling timing data of the power output stored in the storage process and validated in the confirmation process.
  • the tempering in the data acquisition step is performed by the high frequency heat treatment method of the present invention, for example, the high frequency heat treatment method of the fifth embodiment.
  • the rolling bearing outer ring 301 as the induction tempered product in the sixth embodiment tempered by the induction tempering method in the sixth embodiment is reduced in price and further improved in quality. It is a tempered product.
  • FIG. 35 the data flow in the data acquisition process is a solid arrow, the data flow in the storage process is a broken arrow, the data flow in the confirmation process is a double dashed arrow, and the data flow in the mass production process is a double solid line. It is displayed with an arrow.
  • FIG. 35 a data flow in each step of induction tempering according to the sixth embodiment will be described.
  • the data is sent to temperature controller 314.
  • the target heating temperature of the rolling bearing outer ring 301 and the obtained temperature data of the sample of the rolling bearing outer ring 301 are judged, and the necessary power output is determined, and the power output of the heating device 312 is commanded.
  • the power source that receives the command outputs power to the induction coil of the heating device 312 and the sample of the rolling bearing outer ring 301 is heated to a target temperature.
  • the temperature data of the sample of the rolling bearing outer ring 301 measured by the tempering temperature measuring device is sent to the cooling timing adjusting device 316.
  • the cooling timing adjusting device 316 determines the cooling timing from the obtained temperature and calorie heat time of the sample of the rolling bearing outer ring 301 and commands a cooling device such as a coolant injection device to start cooling. Thereby, the sample of the rolling bearing outer ring 301 is cooled, and tempering is completed.
  • this data acquisition process is performed by temperature control, the heating history of the sample of the rolling bearing outer ring 301 is clear. Therefore, as long as the temperature data is accurate, an appropriate heat treatment is performed, and the rolling bearing outer ring 301 having the desired quality is obtained. As a result, it is easy to determine conditions that do not need to be determined while checking the quality of the workpiece.
  • a stabilization layer is formed on the surface of the workpiece, the accuracy of temperature measurement with a radiation thermometer is increasing.
  • the temperature data acquired by the temperature adjustment device 314 and the cooling timing adjustment device 316 in the data acquisition step is stored in the storage device 370 as temperature transition data.
  • the power output output from the power supply of the heating device 312 to the induction coil is stored in the storage device 371 as the power output transition data.
  • the timing of the cooling start command output from the cooling timing adjusting device 316 to the cooling device such as the coolant injection device is stored in the storage device 371 as the cooling timing data.
  • the cooling timing is stored as the time from the start of heating, for example.
  • thermometers capable of measuring the same part as the first radiation thermometer 313 and the second radiation thermometer 315 are provided, and the temperature of the part is measured. By comparing this temperature measurement data with the temperature transition data measured by the first radiation thermometer 313 and the second radiation thermometer 315 and stored in the storage device 371, the presence or absence of disturbance is determined.
  • the rolling bearing outer ring 301 is heated and tempered based on the transition data and cooling timing data of the power output stored in the storage process and validated in the confirmation process.
  • the mass production process is not performed based on the real-time temperature data from the first radiation thermometer 313 and the second radiation thermometer 315, which may cause disturbance, and the validity of the power output is confirmed. It is implemented by power control based on transition data and cooling timing data. Therefore, the rolling bearing outer ring 301 having a stable quality can be obtained.
  • the storage device 371 may be installed as an independent device.
  • a personal computer having a storage unit such as a node disk may be used as a device such as the temperature adjustment device 314 and the cooling timing adjustment device 316. May be installed.
  • each step of the induction tempering method of the present embodiment can be performed by using a personal computer as a control device, for example, and operating the personal computer with one or more programs corresponding to each step. it can.
  • induction hardening was performed by the induction hardening method of the present invention, and a test was performed to confirm the effectiveness.
  • the test procedure is as follows.
  • the target values for hardness and retained austenite were 58HRC (653HV) or more and 12% by volume or less, respectively. Table 1 shows the test results.
  • Example 2 of the present invention will be described below.
  • a test was conducted to confirm the effect of the surface stabilization process in the high-frequency heat treatment method of the present invention.
  • the test procedure is as follows.
  • JIS SUJ2 rolling bearing outer rings and JIS SUS440C rolling bearing outer rings were selected as objects to be tested. Then, the respective parts to be processed were measured with a radiation thermometer and a thermocouple while holding the objects to be processed at a temperature of 900 ° C. or higher. JIS SUS440C rolling bearing outer rings must be at the heating temperature before heating! It has excellent oxidation resistance and almost no change in emissivity! A similar test was performed after applying black body paint (Pyromark High Temperature Paint, manufactured by TE MPIL) on the surface.
  • black body paint Pant High Temperature Paint, manufactured by TE MPIL
  • the horizontal axis indicates the heating time
  • the vertical axis indicates the heating temperature
  • the solid line indicates the temperature measurement data of the radiation thermometer
  • the broken line indicates the temperature measurement data of the thermocouple.
  • the temperature measurement data of the radiation thermometer and the temperature measurement data of the thermocouple are measured in a short time from the start of heating, specifically about 15 seconds.
  • the ratio is almost constant. This is because in the case of a SUJ2 rolling bearing outer ring, an iron oxide layer is formed on the surface of the outer ring by thermal oxidation within a short time after the start of the heating described above. This is thought to be because the surface condition changed and became strong.
  • thermocouple temperature measurement data is almost horizontal when 170 seconds have elapsed from the start of heating. After that, the ratio between the temperature measurement data of the radiation thermometer and the temperature measurement data of the thermocouple is almost constant. This is because SUS440C has superior acid resistance compared to SUJ2, so it takes longer time to form the acid iron layer to the extent that the surface state does not change due to thermal oxidation. This is probably because of this. In other words, SUS440C needs to be held at 920 ° C for about 170 seconds in order for the iron oxide layer to be formed to such an extent that the surface state does not change.
  • the measurement accuracy of the radiation thermometer is improved by carrying out the surface stabilization process of the present invention.
  • a material with high acid resistance such as stainless steel (for example, SUS440 C, M50 It has been confirmed that it is possible to stabilize the quality of high-frequency heat-treated products composed of
  • the induction hardening method and the induction hardening apparatus of the present invention can be applied particularly advantageously to an induction hardening method and an induction hardening apparatus in which an object to be processed is quenched by induction heating.
  • the induction-hardened product of the present invention can be applied particularly advantageously to an induction-hardened product that is heated and hardened by induction heating.

Abstract

A method of high-frequency quenching (10) in which temperature control is possible, quenching can be easily and efficiently conducted, and a desired heat-treatment quality can be imparted to a wide range in a work. It comprises a temperature control step (20) and a quenching control step (30). The temperature control step (20) comprises a temperature measurement step (23) for temperature control, a temperature regulation step (24), and a heating step (22). The quenching control step (30) comprises a temperature measurement step (35) for quenching in which the temperatures of a high-temperature part and low-temperature part of the work are measured, a cooling timing regulation step (36), and a cooling step (37). In the cooling timing regulation step (36), the heating time is regulated so that the temperature history in the high-temperature part satisfies a temperature history requirement resulting in a residual austenite amount not larger than a desired upper limit and that the temperature history in the low-temperature part satisfies a requirement resulting in a hardness not lower than a desired lower limit, and a cooling start signal is output accordingly.

Description

明 細 書  Specification
高周波焼入方法、高周波焼入装置および高周波焼入品  Induction hardening method, induction hardening equipment and induction hardening products
技術分野  Technical field
[0001] 本発明は高周波焼入方法、高周波焼入装置および高周波焼入品に関し、より特定 的には、高周波加熱により被処理物を加熱して焼入を行なう高周波焼入方法および 高周波焼入装置、高周波加熱により加熱されて焼入れられた高周波焼入品に関す るものである。  TECHNICAL FIELD [0001] The present invention relates to an induction hardening method, an induction hardening apparatus, and an induction hardening product, and more specifically, an induction hardening method and induction hardening in which an object to be processed is quenched by induction heating. Equipment and induction-hardened products that have been quenched by induction heating.
背景技術  Background art
[0002] 高周波焼入は、誘導コイルに高周波電流を流すことにより、誘導コイルに隣接して セットされた被処理物を誘導加熱し、被処理物の焼入を行なう熱処理方法である。こ の高周波焼入は、一般的に鋼の熱処理方法として採用されている浸炭焼入や光輝 熱処理などに比べて、作業環境カ^リーンであり、少量ロットの製品を短時間で効率 よく処理できるといった点で有利である。そのため、高周波焼入方法や高周波焼入 装置に関しては、被処理物の硬度の制御や、熱処理の効率向上を目的として多くの 検討がなされ、種々の提案がなされて 、る（特開 2004 - 315851号公報 (特許文献 1)および特開 2004— 225081号公報 (特許文献 2) )。  [0002] Induction hardening is a heat treatment method in which an object to be processed set adjacent to the induction coil is induction-heated by flowing a high-frequency current through the induction coil to quench the object to be processed. This induction hardening is a work environment and is able to efficiently process small lots of products in a short time compared to carburizing quenching and bright heat treatment, which are generally adopted as heat treatment methods for steel. This is advantageous. Therefore, many studies have been made on the induction hardening method and induction hardening apparatus for the purpose of controlling the hardness of the workpiece and improving the efficiency of heat treatment, and various proposals have been made (Japanese Patent Laid-Open No. 2004-315851). (Patent Document 1) and JP 2004-225081 (Patent Document 2)).
特許文献 1：特開 2004 - 315851号公報  Patent Document 1: JP 2004-315851 A
特許文献 2 :特開 2004— 225081号公報  Patent Document 2: JP 2004-225081 A
発明の開示  Disclosure of the invention
発明が解決しょうとする課題  Problems to be solved by the invention
[0003] 高周波焼入においては、一般的な雰囲気炉における加熱のように炉内の雰囲気を 介して被処理物が加熱される焼入方法とは異なり、被処理物が誘導加熱により直接 加熱される。そのため、被処理物の温度を測定するためには、被処理物を直接測温 する必要がある。しかし、高周波焼入装置には、被処理物を均一に加熱するため、被 処理物を回転等させるための駆動機構が設けられている場合が多ぐ接触式の温度 計の設置が困難である場合が多い。  [0003] In the induction hardening, unlike the quenching method in which the workpiece is heated via the atmosphere in the furnace like heating in a general atmospheric furnace, the workpiece is directly heated by induction heating. The Therefore, in order to measure the temperature of the workpiece, it is necessary to directly measure the temperature of the workpiece. However, it is difficult to install a contact-type thermometer in the induction hardening apparatus, which often has a drive mechanism for rotating the object to be processed in order to heat the object to be processed uniformly. There are many cases.
[0004] このように、高周波焼入においては被処理物の測温が容易ではなぐ温度と時間と の熱処理条件による熱処理の制御（温度制御）が難しい。そのため、一般に、高周波 焼入においては、電力と時間との熱処理条件による熱処理の制御（電力制御）が採 用される場合が多い。この電力制御による高周波焼入においては、被処理物に付与 される加熱履歴が明確ではない。そのため、過去の生産実績や作業者の経験に基 づいて仮の熱処理条件が設定され、被処理物のサンプルが実際に焼入されて当該 サンプルの硬度、残留オーステナイト量などの熱処理品質が確認されることを繰返し つつ、試行錯誤により熱処理条件が設定されている。その結果、所望の熱処理品質 を被処理物に付与するためには、被処理物の形状や大きさが変更されるたびに、熱 処理品質を確認しながらの熱処理の試行錯誤を繰返して熱処理条件を設定する必 要がある。このように、熱処理の条件出しに手間が力かるだけでなぐ過去の生産実 績の十分な蓄積や作業者の高周波焼入に関する十分な経験が必要となる点が高周 波焼入の問題点となって 、る。 [0004] Thus, in induction hardening, the temperature and time that make it difficult to measure the temperature of the workpiece It is difficult to control the heat treatment (temperature control) according to the heat treatment conditions. For this reason, in general, in the induction hardening, heat treatment control (power control) based on heat treatment conditions of electric power and time is often employed. In induction hardening by this power control, the heating history applied to the workpiece is not clear. Therefore, provisional heat treatment conditions are set based on past production results and operator experience, and the sample of the workpiece is actually quenched to confirm the heat treatment quality such as hardness and residual austenite amount of the sample. Repeatedly, heat treatment conditions were set by trial and error. As a result, in order to impart the desired heat treatment quality to the workpiece, each time the shape or size of the workpiece is changed, trial and error of the heat treatment is repeated while checking the heat treatment quality. Must be set. As described above, the problem with high-frequency quenching is that sufficient accumulation of past production results and sufficient experience of induction-hardening by the operator are required in addition to the effort required to determine the conditions for heat treatment. It becomes.
[0005] また、高周波加熱においては、被処理物は、その全体が完全には均一に加熱され ないため、被処理物の内部において温度分布が生じ、被処理物の広い範囲に所望 の硬度や残留オーステナイト量などの熱処理品質を付与することが難し 、と 、う問題 点もあった。  [0005] In addition, in high-frequency heating, the entire object to be processed is not completely heated uniformly, so that a temperature distribution is generated inside the object to be processed, and a desired hardness and a wide range of the object to be processed can be obtained. It was difficult to impart heat treatment quality such as the amount of retained austenite, and there was a problem.
[0006] そこで、本発明の目的は、温度制御を可能にし、熱処理の条件出しを容易に行なう ことを可能にすることにより、過去の生産実績の蓄積が少ない場合や、経験の浅い作 業者が熱処理の作業を行なう場合でも、容易にかつ効率よく実施することができると ともに、被処理物の広い範囲に所望の硬度や残留オーステナイト量などの熱処理品 質を付与することが可能な高周波焼入方法、および当該高周波焼入方法を実施す るための高周波焼入装置を提供することである。また、本発明の他の目的は、製造コ ストが抑制され、品質の安定した高周波焼入品を提供することである。  [0006] Therefore, the object of the present invention is to enable temperature control and to easily determine the conditions for heat treatment, so that past production results are less accumulated, or an inexperienced manufacturer is required. In the case of heat treatment work, induction hardening can be performed easily and efficiently, and heat treatment quality such as desired hardness and retained austenite amount can be imparted to a wide range of workpieces. And an induction hardening apparatus for performing the induction hardening method. Another object of the present invention is to provide an induction-hardened product with reduced production costs and stable quality.
課題を解決するための手段  Means for solving the problem
[0007] 本発明に従った高周波焼入方法は、高周波加熱により被処理物の全体を加熱して 焼入硬化する高周波焼入方法であって、被処理物の温度が調節される温度制御ェ 程と、加熱された被処理物が冷却されるべきタイミングが決定されて、被処理物が冷 却される焼入制御工程とを備えている。温度制御工程は、被処理物の温度が測定さ れる温度制御用測温工程と、温度制御用測温工程にお!、て測定された温度の情報 に基づき、被処理物の加熱状態を制御するための温度制御信号が出力される温度 調節工程と、温度制御信号に基づいて、高周波加熱により被処理物が加熱される加 熱工程とを含んでいる。 [0007] The induction hardening method according to the present invention is an induction hardening method in which the whole object to be processed is heated and hardened by induction heating, and is a temperature control method in which the temperature of the object to be processed is adjusted. And a quenching control step in which the timing at which the heated workpiece is to be cooled is determined and the workpiece is cooled. In the temperature control process, the temperature of the workpiece is measured. Temperature control process and temperature control process that outputs temperature control signals for controlling the heating state of the workpiece based on the temperature information measured in the temperature control process. And a heating step in which the workpiece is heated by high frequency heating based on the temperature control signal.
[0008] 焼入制御工程は、被処理物において、高周波加熱による温度の上昇が被処理物 の内部よりも大きい表面の部位である高温部と、高周波加熱による温度の上昇が被 処理物の内部よりも小さい表面の部位である低温部との温度が測定される焼入用測 温工程と、焼入用測温工程にぉ 、て測定された温度の情報に基づき加熱時間が調 節され、被処理物が冷却されるべきタイミングが決定されて冷却開始信号が出力され る冷却タイミング調節工程と、冷却開始信号に基づいて、被処理物が冷却されること により被処理物が焼入硬化される冷却工程とを含んでいる。  [0008] The quenching control process includes a high-temperature portion in the workpiece to be treated with a high-temperature portion where the temperature rise due to high-frequency heating is larger than the inside of the workpiece, and a temperature rise due to high-frequency heating within the workpiece. The heating time is adjusted based on the measured temperature information in the quenching temperature measurement process in which the temperature of the lower temperature part, which is a smaller surface area, is measured, and the quenching temperature measurement process. The cooling timing adjustment process in which the timing at which the workpiece is to be cooled is determined and a cooling start signal is output, and the workpiece is quenched and hardened by cooling the workpiece based on the cooling start signal. Cooling process.
[0009] そして、冷却タイミング調節工程においては、高温部における温度および加熱時間 を含む温度履歴が、予め求められた所望の残留オーステナイト量の上限値以下の残 留オーステナイト量が得られる温度履歴の条件を満たし、低温部における温度およ び加熱時間を含む温度履歴が、予め求められた所望の硬度の下限値以上の硬度が 得られる温度履歴の条件を満たすように加熱時間が調節されて、冷却開始信号が出 力される。  [0009] Then, in the cooling timing adjustment step, the temperature history conditions including the temperature history including the temperature and the heating time in the high temperature portion are less than the predetermined upper limit value of the desired retained austenite amount. The heating time is adjusted so that the temperature history including the temperature in the low temperature part and the heating time satisfies the condition of the temperature history at which the hardness exceeding the lower limit of the desired hardness obtained in advance is satisfied. A start signal is output.
[0010] 一般に、高周波焼入においては、まず熱処理条件として電力と時間とのパラメータ 力もなる電源出力の推移 (電源出力パターン)が、過去の熱処理の実績や作業者の 経験に基づいて決定される (電力制御)。そして、熱処理条件は、被処理物の形状、 大きさ、材質等を考慮しつつ電力と時間とを変化させて被処理物のサンプルを実際 に熱処理して決定される。そのため、熱処理条件の決定に経験と手間が必要となる。 また、鋼製品の焼入においては、被処理物を所定温度に所定時間以上保持した後、 急冷する必要がある。しかし、上記方法 (電力制御）では被処理物の加熱履歴を正確 に把握することは困難である。そのため、熱処理条件を決定するためには、実際に熱 処理を実施して得られた被処理物の硬度、残留オーステナイト量等の品質を調査す る必要がある。  [0010] Generally, in induction hardening, first, the transition of power output (power output pattern), which also includes power and time parameters as heat treatment conditions, is determined based on past heat treatment results and operator experience. (Power control). The heat treatment conditions are determined by actually heat-treating the sample of the object to be processed while changing the power and time in consideration of the shape, size, material, etc. of the object to be processed. Therefore, experience and labor are required to determine the heat treatment conditions. Also, in quenching steel products, it is necessary to rapidly cool the workpiece after holding it at a predetermined temperature for a predetermined time. However, it is difficult to accurately grasp the heating history of the workpiece by the above method (power control). Therefore, in order to determine the heat treatment conditions, it is necessary to investigate the quality, such as the hardness and the amount of retained austenite, of the workpiece obtained by actually carrying out the heat treatment.
[0011] これに対し、本発明の高周波焼入方法では、温度制御工程および焼入制御工程 により、温度と時間とをパラメータとして被処理物の加熱が制御される（温度制御)。そ のため、被処理物の加熱履歴を正確に把握することが可能であり、被処理物に必要 な加熱履歴を与えた後、急冷することで焼入を行なうことができる。 In contrast, in the induction hardening method of the present invention, the temperature control step and the quench control step Thus, heating of the workpiece is controlled using temperature and time as parameters (temperature control). For this reason, it is possible to accurately grasp the heating history of the object to be processed, and after quenching it after giving the necessary heating history to the object to be processed, quenching can be performed.
[0012] ここで、被処理物を構成する鋼の組成が決まれば、被処理物の硬度、被処理物を 構成する鋼の残留オーステナイト量およびミクロ組織などの熱処理品質は、加熱温 度および時間により決定される。そのため、熱処理を行なう作業者が、所望の熱処理 品質を被処理物に付与するために必要な、およその加熱時間および温度の条件を 仮の熱処理条件として決定することは、比較的容易である。  [0012] Here, if the composition of the steel constituting the workpiece is determined, the hardness of the workpiece, the amount of retained austenite of the steel constituting the workpiece, and the heat treatment quality such as the microstructure, the heating temperature and time Determined by. Therefore, it is relatively easy for an operator who performs heat treatment to determine the approximate heating time and temperature conditions necessary for imparting desired heat treatment quality to the workpiece as temporary heat treatment conditions.
[0013] さらに、本発明の高周波焼入方法では、冷却タイミング調節工程において、高温部 における温度履歴力 予め求められた所望の残留オーステナイト量の上限値以下の 残留オーステナイト量が得られる温度履歴の条件を満たし、低温部における温度履 歴カ 予め求められた所望の硬度の下限値以上の硬度が得られる温度履歴の条件 を満たすように加熱時間が調節されて、冷却開始信号が出力される。  [0013] Further, in the induction hardening method of the present invention, in the cooling timing adjustment step, the temperature history condition in the high temperature portion is a temperature history condition that provides a residual austenite amount that is less than or equal to a predetermined upper limit value of the retained austenite amount. And the heating history is adjusted so as to satisfy the temperature history condition in which the temperature history in the low temperature part is higher than the predetermined lower limit of the desired hardness, and a cooling start signal is output.
[0014] 高周波加熱においては、被処理物は全体が完全に均一に加熱されるのではなぐ 誘導コイルに近ぐ磁束の侵入量が多い部位では温度が高ぐ逆に誘導コイルから 遠ぐ磁束の侵入量が少ない部位では温度が低くなる。ここで、被処理物の用途を考 慮すると、被処理物に求められる強度や剛性を確保するために必要な硬度の下限値 が決定される。一方、同様に被処理物の用途を考慮すると、被処理物に求められる 寸法安定性 (形状の経時的変化の小ささ）を確保するために必要な残留オーステナ イト量の上限値が決定される。  [0014] In high-frequency heating, the object to be processed is not heated completely and uniformly. At the part where the amount of magnetic flux entering the induction coil is large, the temperature is high, and conversely, the magnetic flux far from the induction coil. The temperature is lowered at the site where the intrusion amount is small. Here, considering the use of the object to be processed, the lower limit value of the hardness required to ensure the strength and rigidity required for the object to be processed is determined. On the other hand, considering the usage of the workpiece, the upper limit of the amount of retained austenite necessary to ensure the dimensional stability required for the workpiece (small change in shape over time) is determined. .
[0015] 被処理物の硬度は、焼入の際に鋼の素地中に固溶している炭素量に影響を受け るため、基本的には焼入における冷却前の加熱温度が高く加熱時間が長いほど炭 素の固溶量が大きくなり、硬度は高くなる。一方、残留オーステナイト量も焼入の際に 鋼の素地中に固溶している炭素量に影響を受け、焼入における冷却前の加熱温度 が高く加熱時間が長いほど炭素の固溶量が大きくなり、 M  [0015] The hardness of the workpiece is affected by the amount of carbon that is dissolved in the steel substrate during quenching, so basically the heating temperature before cooling in quenching is high and the heating time is high. The longer the is, the larger the solid solution of carbon and the higher the hardness. On the other hand, the amount of retained austenite is also affected by the amount of carbon dissolved in the steel substrate during quenching. The higher the heating temperature before cooling in quenching and the longer the heating time, the greater the amount of carbon dissolved. , M
S点の温度が低下するため Because temperature of S point falls
、残留オーステナイト量が多くなる。そのため、磁束の侵入量が少なく温度の低い部 位 (低温部） 1S 下限値以上の硬度を得るために必要な温度および時間以上に加熱 されており、かつ磁束の侵入量が多く温度の高い部位 (高温部）が、上限値以下の残 留オーステナイト量を得るために必要な温度および時間以下に加熱されて焼入が実 施されることにより、高温部と低温部との間の温度に加熱された部位においては、硬 度の下限値および残留オーステナイト量の上限値の双方の条件が満たされる。 The amount of retained austenite increases. Therefore, the part where the amount of magnetic flux penetrates is low and the temperature is low (low temperature part). The part is heated at the temperature and time required to obtain the hardness exceeding the 1S lower limit, and the part where the magnetic flux penetrates much and the temperature is high. (High temperature part) is less than upper limit The lower limit value of the hardness at the part heated to a temperature between the high temperature part and the low temperature part by being heated below the temperature and time necessary to obtain the retained austenite amount and being quenched. And the upper limit of the amount of retained austenite is satisfied.
[0016] したがって、本発明の高周波焼入方法によれば、上記仮の条件で熱処理が開始さ れた後、詳細な熱処理条件は、所望の硬度および残留オーステナイト量の条件に基 づ 、て決定されて焼入が実施されるため、所望の硬度および残留オーステナイト量 を容易に被処理物に付与することができる。なお、被処理物における広い範囲に所 望の硬度および残留オーステナイト量を付与するためには、上記の高温部および低 温部は、磁束の侵入が最も多い部位および最も少ない部位であることが好ましぐさ らに被処理物と誘導コイルとの距離だけでなぐ被処理物の形状をも考慮して最も温 度の高い部位および最も温度の低い部位であることがより好ましい。なお、被処理物 の形状において、たとえば突起部や角部は温度の上昇が大きくなる。  [0016] Therefore, according to the induction hardening method of the present invention, after the heat treatment is started under the provisional conditions, the detailed heat treatment conditions are determined based on the conditions of the desired hardness and the amount of retained austenite. Since quenching is performed, the desired hardness and the amount of retained austenite can be easily imparted to the workpiece. In order to give the desired hardness and the retained austenite amount to a wide range in the workpiece, the high temperature part and the low temperature part are preferably the part where the penetration of the magnetic flux is the most and the part where the penetration is the smallest. In consideration of the shape of the object to be processed, which is determined only by the distance between the object to be processed and the induction coil, it is more preferable that the part has the highest temperature and the part having the lowest temperature. In the shape of the object to be processed, for example, the temperature rises at the protrusions and corners.
[0017] 以上のように、本発明の高周波焼入方法によれば、温度制御を可能にし、熱処理 の条件出しを容易に行なうことを可能にすることにより、過去の生産実績の蓄積が少 ない場合や、経験の浅い作業者が熱処理の作業を行なう場合でも、容易にかつ効率 よく実施することができるとともに、被処理物の広い範囲に所望の硬度や残留オース テナイト量などの熱処理品質を付与することが可能な高周波焼入方法を提供するこ とがでさる。  [0017] As described above, according to the induction hardening method of the present invention, it is possible to control the temperature, and it is possible to easily determine the conditions of the heat treatment, so that the accumulation of past production results is small. Even when inexperienced workers perform heat treatment work, they can be easily and efficiently carried out, and heat treatment quality such as desired hardness and residual austenite content can be given to a wide range of workpieces. It is possible to provide an induction hardening method that can be performed.
[0018] 本発明に従った高周波焼入装置は、高周波加熱により被処理物の全体を加熱して 焼入硬化する上記の高周波焼入方法に使用される高周波焼入装置であって、被処 理物の温度を調節するための温度制御装置と、加熱された前記被処理物が冷却さ れるべきタイミングを調節するための焼入制御装置とを備えている。  [0018] An induction hardening apparatus according to the present invention is an induction hardening apparatus used in the above induction hardening method for heating and hardening an entire object to be processed by induction heating. A temperature control device for adjusting the temperature of the physical object and a quenching control device for adjusting the timing at which the heated object to be processed is cooled are provided.
[0019] 温度制御装置は、被処理物の温度データを取得し、被処理物の温度データに基 づく温度の情報を出力する温度制御用測温装置と、温度制御用測温装置に接続さ れ、温度制御用測温装置力 の温度の情報に基づき被処理物の加熱状態を制御す るための温度制御信号を出力する温度調節装置と、温度調節装置に接続され、温 度調節装置からの温度制御信号に基づき、高周波加熱により被処理物を加熱する 加熱装置とを含んでいる。 [0020] 焼入制御装置は、被処理物の高温部および低温部の温度データを取得し、被処 理物の温度データに基づく温度の情報を出力する焼入用測温装置と、焼入用測温 装置に接続され、焼入用測温装置力 の温度の情報に基づき加熱時間を調節し、 被処理物が冷却されるべきタイミングを決定して冷却開始信号を出力する冷却タイミ ング調節装置と、冷却タイミング調節装置に接続され、冷却開始信号に基づいて、被 処理物を冷却することにより被処理物を焼入硬化する冷却装置とを含んでいる。 [0019] The temperature control device is connected to a temperature control temperature measuring device that acquires temperature data of the object to be processed and outputs temperature information based on the temperature data of the object to be processed, and a temperature control temperature measuring device. The temperature control device outputs a temperature control signal for controlling the heating state of the workpiece based on the temperature information of the temperature control device for temperature control, and is connected to the temperature control device. And a heating device for heating the object to be processed by high-frequency heating based on the temperature control signal. [0020] A quenching control device acquires temperature data of a high temperature portion and a low temperature portion of a workpiece, and outputs a temperature information based on the temperature data of the workpiece, and a quenching temperature measuring device. Cooling timing adjustment that is connected to the temperature measuring device, adjusts the heating time based on the temperature information of the quenching temperature measuring device, determines the timing at which the workpiece should be cooled, and outputs a cooling start signal And a cooling device connected to the cooling timing adjusting device and quenching and hardening the workpiece by cooling the workpiece based on the cooling start signal.
[0021] 上述の本発明の高周波焼入方法により被処理物を熱処理することが可能な本発明 の高周波焼入装置によれば、温度制御を可能にし、熱処理の条件出しを容易に行 なうことを可能にすることにより、過去の生産実績の蓄積が少ない場合や、経験の浅 Vヽ作業者が熱処理の作業を行なう場合でも、容易にかつ効率よく焼入を実施するこ とができる。さらに、本発明の高周波焼入装置によれば、被処理物の広い範囲に、所 望の硬度や残留オーステナイト量などの熱処理品質を付与することができる。  [0021] According to the induction hardening apparatus of the present invention capable of heat-treating an object to be processed by the above-described induction hardening method of the present invention, temperature control can be performed and conditions for heat treatment can be easily set. By making this possible, quenching can be carried out easily and efficiently even when there is little accumulation of past production results, or even when an inexperienced V ヽ operator performs heat treatment work. Furthermore, according to the induction hardening apparatus of the present invention, heat treatment quality such as desired hardness and retained austenite amount can be imparted to a wide range of workpieces.
[0022] 本発明に従った高周波焼入品は、上述の本発明の高周波焼入方法で熱処理され て作製されたことを特徴とする。本発明の高周波焼入品によれば、温度制御が可能 で、熱処理の条件出しを容易に行なうことが可能であることにより、容易にかつ効率よ く焼入が実施されているとともに、被処理物の広い範囲に所望の熱処理品質を付与 することが可能な本発明の高周波焼入方法により焼入が実施されているため、製造 コストが抑制されているとともに、品質の安定した高周波焼入品を提供することができ る。 [0022] The induction-hardened product according to the present invention is characterized by being heat-treated by the above-described induction-quenching method of the present invention. According to the induction-hardened product of the present invention, the temperature can be controlled and the conditions for the heat treatment can be easily determined, so that the quenching is easily and efficiently performed and the workpiece is processed. Since the quenching is performed by the induction hardening method of the present invention capable of imparting desired heat treatment quality to a wide range of products, the manufacturing cost is suppressed and the induction hardened product with stable quality is obtained. Can be provided.
[0023] なお、本発明の高周波焼入品は、たとえば、転がり軸受の軌道輪、転動体などの鋼 力 なる機械部品に適用することができる。  [0023] It should be noted that the induction-hardened product of the present invention can be applied to, for example, steel parts such as rolling bearing raceways and rolling elements.
[0024] 本発明に従った高周波熱処理設備は、高周波加熱により被処理物を加熱して熱処 理するための高周波熱処理設備であって、被処理物を搬送する搬送装置と、搬送装 置により搬送された被処理物を、高周波加熱により加熱して焼入硬化する高周波焼 入装置とを備えている。高周波焼入装置は、被処理物の温度を調節するための焼入 温度制御装置と、加熱された被処理物が冷却されるべきタイミングを調節するための 焼入タイミング制御装置とを含んでいる。さらに、高周波焼入装置は、焼入温度制御 装置において、被処理物を加熱するために焼入用電源力 焼入用誘導コイルに出 力される電源出力の推移データである焼入用出力推移データと、焼入タイミング制御 装置において、被処理物が冷却されるタイミングを特定するための焼入用冷却タイミ ングデータとを焼入プロセスデータとして記憶する焼入用記憶装置を含んでいる。 [0024] The induction heat treatment equipment according to the present invention is an induction heat treatment equipment for heat-treating an object to be processed by induction heating, and includes an apparatus for transferring the object to be processed and an apparatus for transferring the object. It is equipped with an induction hardening apparatus that heats and hardens the conveyed workpiece by induction heating. The induction hardening apparatus includes a quenching temperature control device for adjusting the temperature of the workpiece and a quenching timing control device for adjusting the timing at which the heated workpiece is cooled. . In addition, the induction hardening device is a quenching temperature control device that supplies power to the quenching induction coil to heat the workpiece. The quenching process includes the quenching output transition data, which is the transitional data of the power output that is applied, and the quenching timing data for identifying the timing at which the workpiece is cooled in the quenching timing control device. A quenching storage device for storing data is included.
[0025] そして、焼入温度制御装置は、被処理物の温度データを取得し、被処理物の温度 データに基づく温度の情報を出力する焼入温度制御用測温装置と、焼入温度制御 用測温装置に接続され、焼入温度制御用測温装置力 の温度の情報に基づき被処 理物の加熱状態を制御するための焼入温度制御信号を出力する焼入温度調節装 置と、焼入温度調節装置に接続され、焼入温度調節装置からの焼入温度制御信号 基づき、高周波加熱により被処理物を加熱する、焼入用電源および焼入用誘導コィ ルを含む焼入加熱装置とを有している。焼入タイミング制御装置は、被処理物の温 度データを取得し、被処理物の温度データに基づく温度の情報を出力する焼入タイ ミング制御用測温装置と、焼入タイミング制御用測温装置に接続され、焼入タイミング 制御用測温装置からの温度の情報に基づき加熱時間を調節し、被処理物が冷却さ れるべきタイミングを決定して焼入用冷却開始信号を出力する焼入タイミング調節装 置と、焼入タイミング調節装置に接続され、焼入用冷却開始信号に基づいて、被処 理物を冷却することにより被処理物を焼入硬化する焼入用冷却装置とを有している。  Then, the quenching temperature control device acquires the temperature data of the object to be processed, and outputs a temperature information based on the temperature data of the object to be processed, and a quenching temperature control device for quenching temperature control. A quenching temperature control device that outputs a quenching temperature control signal for controlling the heating state of the workpiece based on the temperature information of the quenching temperature control temperature measuring device force. Quenching heating, including a quenching power supply and a quenching induction coil, connected to the quenching temperature control device, and heats the workpiece by induction heating based on the quenching temperature control signal from the quenching temperature control device Device. The quenching timing control device acquires the temperature data of the workpiece and outputs the temperature information based on the workpiece temperature data, and the quenching timing control temperature measurement device. Quenching that is connected to the equipment, adjusts the heating time based on temperature information from the quenching timing control temperature measuring device, determines the timing at which the workpiece should be cooled, and outputs a quenching cooling start signal There is a timing adjustment device and a quenching cooling device that is connected to the quenching timing adjustment device and quenches and hardens the workpiece by cooling the workpiece based on the quenching cooling start signal. is doing.
[0026] 一般に、高周波焼入においては、まず熱処理条件として電力と時間とのパラメータ 力もなる電源出力の推移 (電源出力パターン)が、過去の熱処理の実績や作業者の 経験に基づいて決定される (電力制御)。そして、熱処理条件は、被処理物の形状、 材質等を考慮しつつ電力と時間とを変化させて被処理物のサンプルを実際に熱処 理して決定される。そのため、熱処理条件の決定に経験と手間が必要となる。また、 鋼製品の焼入においては、被処理物を所定温度に所定時間以上保持した後、急冷 する必要がある。しかし、上記方法 (電力制御）では被処理物の加熱履歴を正確に把 握することは困難である。そのため、熱処理条件を決定するためには、実際に熱処理 を実施して得られた被処理物の硬度、ミクロ組織等の品質を調査する必要がある。  [0026] Generally, in induction hardening, first, the transition of power output (power output pattern), which also includes power and time parameters as heat treatment conditions, is determined based on past heat treatment results and operator experience. (Power control). The heat treatment conditions are determined by actually heat-treating the sample of the object to be processed while changing the power and time in consideration of the shape and material of the object to be processed. Therefore, experience and labor are required to determine the heat treatment conditions. In the quenching of steel products, it is necessary to rapidly cool the workpiece after holding it at a predetermined temperature for a predetermined time. However, with the above method (power control), it is difficult to accurately grasp the heating history of the workpiece. Therefore, in order to determine the heat treatment conditions, it is necessary to investigate the quality, such as the hardness and microstructure of the workpiece obtained by actually performing the heat treatment.
[0027] これに対し、本発明の高周波熱処理設備では、高周波焼入装置の焼入温度制御 装置および焼入タイミング制御装置により、温度と時間とをパラメータとして被処理物 の加熱が制御される（温度制御)。そのため、被処理物の加熱履歴を正確に把握す ることが可能であり、被処理物に必要な加熱履歴を与えた後、急冷することで焼入を 行なうことができる。 In contrast, in the induction heat treatment equipment of the present invention, the heating of the workpiece is controlled by the induction temperature control device and the induction timing control device using the temperature and time as parameters ( Temperature control). Therefore, accurately grasp the heating history of the workpiece Quenching can be performed by giving a necessary heating history to the object to be processed and then rapidly cooling it.
[0028] ここで、被処理物を構成する鋼の組成が決まれば、被処理物の硬度、被処理物を 構成する鋼のミクロ糸且織および残留オーステナイト量などの熱処理品質は、加熱温 度および時間により容易に制御することができる。そのため、熱処理を行なう作業者 は、所望の熱処理品質を被処理物に付与するために必要な加熱時間および温度の 条件を熱処理条件として決定すればよ!、ので、熱処理条件の決定に必要な経験や 手間が大幅に軽減される。その結果、過去の生産実績の蓄積が少ない場合や、経 験の浅 ヽ作業者が熱処理の作業を行なう場合でも、容易に高周波熱処理を実施す ることが可能となる。  [0028] Here, if the composition of the steel constituting the workpiece is determined, the heat treatment quality such as the hardness of the workpiece, the micro yarns and weaves of the steel constituting the workpiece and the amount of retained austenite is determined by the heating temperature. And can be easily controlled by time. For this reason, the worker who performs the heat treatment should determine the heating time and temperature conditions necessary for imparting the desired heat treatment quality to the workpiece as the heat treatment conditions! And labor is greatly reduced. As a result, it is possible to easily perform high-frequency heat treatment even when there is little accumulation of past production results, or even when an inexperienced worker performs heat treatment work.
[0029] さらに、本発明の高周波熱処理設備では、高周波焼入装置が、焼入用出力推移デ ータと、焼入用冷却タイミングデータとを焼入プロセスデータとして記憶する焼入用記 憶装置を含んでいる。これにより、温度制御により実施された焼入硬化処理と同一の 焼入硬化処理を、電力制御により実施するための熱処理条件が当該焼入用記憶装 置に記憶される。そのため、温度および時間の条件で実施された高周波焼入の熱処 理条件の妥当性を確認した上で、実際の量産工程では、記憶された熱処理条件に 従って、制御の容易な電力制御により高周波熱処理を実施することが可能となる。  [0029] Further, in the induction heat treatment facility of the present invention, the induction hardening apparatus stores the hardening output transition data and the quenching cooling timing data as the quenching process data. Is included. As a result, the heat treatment conditions for performing the same quenching and curing process performed by the temperature control by the power control are stored in the quenching storage device. For this reason, after confirming the appropriateness of the heat treatment conditions of induction hardening performed under temperature and time conditions, in the actual mass production process, high-frequency power control is performed by power control that is easy to control according to the stored heat treatment conditions. Heat treatment can be performed.
[0030] さらに、本発明の高周波熱処理設備では、被処理物を搬送する搬送装置を備えて いる。これにより、高周波焼入を実施するための被処理物の加熱が終了すると、直ち に次の被処理物を搬送装置により高周波焼入装置に搬送することが可能となる。そ の結果、高周波熱処理の処理効率を向上させることができる。  [0030] Further, the high-frequency heat treatment equipment of the present invention includes a transfer device for transferring an object to be processed. As a result, as soon as the heating of the object to be induction-hardened is completed, the next object to be processed can be transferred to the induction hardening apparatus by the transfer device. As a result, the processing efficiency of the high frequency heat treatment can be improved.
[0031] 以上のように、本発明の高周波熱処理設備によれば、温度制御を可能にし、熱処 理の条件出しを容易に行なうことを可能にすることにより、過去の生産実績の蓄積が 少ない場合や、経験の浅い作業者が熱処理の作業を行なう場合でも、容易にかつ効 率よく高周波熱処理を実施することができる高周波熱処理設備を提供することができ る。  [0031] As described above, according to the high-frequency heat treatment equipment of the present invention, it is possible to control the temperature, and it is possible to easily determine the conditions for the heat treatment, so that the past production results are less accumulated. In addition, even when an inexperienced worker performs heat treatment work, it is possible to provide a high-frequency heat treatment facility capable of performing high-frequency heat treatment easily and efficiently.
[0032] なお、上述の焼入温度制御用測温装置は、被処理物が加熱され過ぎることにより 残留オーステナイト量が過多となることを回避するため、被処理物のうち温度の高くな る部位、たとえば誘導コイルに近接し、磁束の侵入の最も多い部位の温度を測定可 能に構成されることが好ましい。また、上述の焼入タイミング制御用測温装置は、被 処理物の焼入前の加熱が不足することを回避するため、被処理物のうち温度の低く なる部位、たとえば誘導コイル力 遠ぐ磁束の侵入の最も少ない部位の温度が測定 可能に構成されていることが好ましい。また、焼入温度制御用測温装置および焼入タ イミング制御用測温装置は、たとえば放射温度計を用いることができ、装置のレイァゥ ト上、可能であれば熱電対などの接触式温度計であってもよ ヽ。 [0032] Note that the above-described temperature measuring device for quenching temperature control avoids an excessive amount of retained austenite due to excessive heating of the object to be processed, so that the temperature of the object to be processed is high. It is preferable to be able to measure the temperature of a part near the induction coil, for example, the part where the magnetic flux intrudes most. Further, the above-described temperature measuring device for quenching timing control avoids insufficient heating of the workpiece before quenching, so that a portion of the workpiece to be cooled, for example, induction coil force far away magnetic flux It is preferable that the temperature of the part where the intrusion is the smallest is measurable. The temperature measuring device for quenching temperature control and the temperature measuring device for quenching timing control can use, for example, a radiation thermometer. If possible, a contact-type thermometer such as a thermocouple on the layout of the device. Even so.
[0033] 上記高周波熱処理設備において好ましくは、高周波焼入装置に接続され、高周波 焼入装置において焼入硬化された被処理物を、高周波加熱により加熱して焼戻す 高周波焼戻装置をさらに備えている。高周波焼戻装置は、被処理物の温度を調節 するための焼戻温度制御装置と、加熱された被処理物が冷却されるべきタイミングを 調節するための焼戻終了タイミング制御装置とを含んでいる。さらに、高周波焼戻装 置は焼戻温度制御装置において、被処理物を加熱するために高周波加熱用の焼戻 用電源力 焼戻用誘導コイルに出力される電源出力の推移データである焼戻用出 力推移データと、焼戻終了タイミング制御装置において、被処理物が冷却されるタイ ミングを特定するための焼戻用冷却タイミングデータとを焼戻プロセスデータとして記 憶する焼戻用記憶装置を含んで!/、る。  [0033] Preferably, the induction heat treatment equipment further includes an induction tempering apparatus connected to an induction hardening apparatus and tempering the object to be hardened and hardened in the induction hardening apparatus by heating with induction heating. Yes. The induction tempering device includes a tempering temperature control device for adjusting the temperature of the workpiece, and a tempering end timing control device for adjusting the timing at which the heated workpiece is cooled. Yes. In addition, the induction tempering device is a tempering temperature control device, which is the tempering power data that is output to the induction coil for tempering for high-frequency heating to heat the workpiece. Tempering storage device that stores output transition data for tempering and cooling timing data for tempering to identify when the workpiece is cooled in the tempering end timing control device as tempering process data Including /!
[0034] そして、焼戻温度制御装置は、被処理物の温度データを取得し、被処理物の温度 データに基づく温度の情報を出力する焼戻温度制御用測温装置と、焼戻温度制御 用測温装置に接続され、焼戻温度制御用測温装置からの温度の情報に基づき被処 理物の加熱状態を制御するための焼戻温度制御信号を出力する焼戻温度調節装 置と、焼戻温度調節装置に接続され、焼戻温度調節装置からの焼戻温度制御信号 基づき、高周波加熱により被処理物を加熱する、焼戻用電源および焼戻用誘導コィ ルを含む焼戻加熱装置とを有して 、る。  [0034] Then, the tempering temperature control device acquires temperature data of the object to be processed, and outputs a temperature information based on the temperature data of the object to be processed. A tempering temperature adjusting device that is connected to a temperature measuring device for outputting a tempering temperature control signal for controlling the heating state of the object to be processed based on temperature information from the temperature measuring device for tempering temperature control. Tempering heating including power supply for tempering and induction coil for tempering, which is connected to the tempering temperature control device and heats the workpiece by high frequency heating based on the tempering temperature control signal from the tempering temperature control device With equipment.
[0035] 焼戻終了タイミング制御装置は、被処理物の温度データを取得し、被処理物の温 度データに基づく温度の情報を出力する焼戻終了タイミング制御用測温装置と、焼 戻終了タイミング制御用測温装置に接続され、焼戻終了タイミング制御用測温装置 力 の温度の情報に基づき加熱時間を調節し、被処理物が冷却されるべきタイミング を決定して焼戻用冷却開始信号を出力する焼戻終了タイミング調節装置と、焼戻終 了タイミング調節装置に接続され、焼戻用冷却開始信号に基づいて、被処理物を冷 却することにより被処理物の焼戻を終了させる焼戻終了装置とを有している。 The tempering end timing control device acquires temperature data of the object to be processed, and outputs a temperature information based on the temperature data of the object to be processed, and a temperature measuring device for tempering end timing control, and tempering end Timing control temperature measuring device connected to the timing control temperature control device for controlling the tempering end timing. The tempering end timing adjusting device that outputs the tempering cooling start signal and the tempering end timing adjusting device to cool the workpiece based on the tempering cooling start signal. And a tempering end device for ending the tempering of the workpiece.
[0036] 高周波焼戻装置が接続されることにより、高周波焼入装置および高周波焼戻装置 が単一の製造ラインを構成することができる。そのため、高周波焼入装置において焼 入硬化された被処理物を、仕掛品として保持することなぐ連続的に焼戻を実施し、 焼入焼戻処理を効率的に実施することが可能となる。  [0036] By connecting the induction tempering apparatus, the induction hardening apparatus and the induction tempering apparatus can constitute a single production line. Therefore, it is possible to carry out the quenching and tempering process efficiently by continuously tempering the workpiece that has been quenched and hardened in the induction hardening apparatus without holding it as an in-process product.
[0037] さらに、当該高周波焼戻装置は、上記高周波焼入装置と同様に温度制御による熱 処理が可能な構成となっている。そのため、被処理物の加熱履歴を正確に把握する ことが可能であり、被処理物に必要かつ十分な加熱履歴を与えた後、冷却することで 焼戻を行なうことができる。  [0037] Further, the induction tempering apparatus has a configuration capable of performing heat treatment by temperature control, like the induction hardening apparatus. Therefore, it is possible to accurately grasp the heating history of the object to be processed, and after providing the necessary and sufficient heating history to the object to be processed, tempering can be performed by cooling.
[0038] ここで、焼戻により制御される熱処理品質のうち、最も重要な被処理物の硬度は、 加熱温度および時間により容易に制御することができる。そのため、熱処理を行なう 作業者は、所望の熱処理品質を被処理物に付与するために必要な温度および加熱 時間の条件を熱処理条件として決定すればよ!、ので、熱処理条件の決定に必要な 経験や手間が大幅に軽減される。  [0038] Here, among the heat treatment quality controlled by tempering, the hardness of the most important workpiece can be easily controlled by heating temperature and time. Therefore, the operator who performs the heat treatment should determine the temperature and heating time conditions necessary to impart the desired heat treatment quality to the workpiece as the heat treatment conditions! And labor are greatly reduced.
[0039] さらに、高周波焼戻装置が、焼戻用出力推移データと、焼戻用冷却タイミングデー タとを焼戻プロセスデータとして記憶する焼戻用記憶装置を含んで 、るため、上記高 周波焼入装置と同様に、温度制御により実施された高周波焼戻の熱処理条件の妥 当性を確認した上で、実際の量産工程では、記憶された熱処理条件に従って、制御 の容易な電力制御により高周波焼戻を実施することが可能となる。  [0039] Further, since the induction tempering apparatus includes a tempering storage device that stores tempering output transition data and tempering cooling timing data as tempering process data, the high frequency As with the quenching equipment, after confirming the validity of the heat treatment conditions of induction tempering performed by temperature control, in the actual mass production process, high frequency is controlled by power control that is easy to control according to the stored heat treatment conditions. Tempering can be performed.
[0040] その結果、過去の生産実績の蓄積が少な!/、場合や、経験の浅!、作業者が熱処理 の作業を行なう場合でも、一層容易にかつ効率よく高周波熱処理を実施することが 可能となる。  [0040] As a result, the accumulation of past production results is small! / In cases where the experience is inexperienced, and even when an operator performs heat treatment work, it is possible to perform high-frequency heat treatment more easily and efficiently. It becomes.
[0041] なお、焼戻終了タイミング制御用測温装置は、被処理物が加熱され過ぎることによ り硬度の低下が大きくなり過ぎること、および被処理物の加熱が不足することにより硬 度が十分低下しないことを回避するため、被処理物のうち温度の高くなる部位、たと えば誘導コイルに近接し、磁束の侵入の最も多い部位の温度と、被処理物のうち温 度の低くなる部位、たとえば誘導コイル力 遠ぐ磁束の侵入の最も少ない部位の双 方の温度が測定可能に構成されていることが好ましい。この場合、焼戻終了タイミン グ制御用測温装置は、複数の放射温度計などの測温装置を含んでおり、複数の部 位を測温可能に構成されていてもよい。また、焼戻温度制御用測温装置および焼戻 終了タイミング制御用測温装置としては、たとえば放射温度計を用いることができ、装 置のレイアウト上、可能であれば熱電対などの接触式温度計を用いてもよい。 [0041] It should be noted that the tempering end timing control temperature measuring device has a hardness that is too high due to excessive heating of the workpiece, and insufficient heating of the workpiece. In order to avoid a sufficient decrease, the temperature of the object to be processed increases in temperature, for example, the vicinity of the induction coil and the part where the magnetic flux intrudes most and the object to be processed in It is preferable to be able to measure the temperature at both of the parts where the temperature is low, for example, the part where the inductive coil force has the least penetration of the magnetic flux far away. In this case, the tempering end timing control temperature measuring device includes a plurality of temperature measuring devices such as a radiation thermometer, and may be configured to measure a plurality of portions. As a temperature measuring device for tempering temperature control and a temperature measuring device for tempering completion timing control, for example, a radiation thermometer can be used. A meter may be used.
[0042] また、温度制御により実施された高周波焼入および高周波焼戻の熱処理条件の妥 当性は、たとえば被処理物の硬度、被処理物を構成する鋼のミクロ組織、残留オース テナイト量などの材質データを調査して確認することができる。当該材質データは、 温度制御により高周波焼入および高周波焼戻を実施する際に、焼入用記憶装置お よび焼戻用記憶装置に、測温装置により測温された温度データと加熱時間とを記憶 しておき、これに基づいて推定することができる力 熱処理後の被処理物のサンプル を実際に調査して取得してもよ 、。  [0042] Further, the validity of the heat treatment conditions of induction hardening and induction tempering performed by temperature control is, for example, the hardness of the workpiece, the microstructure of the steel constituting the workpiece, the amount of retained austenite, etc. It is possible to check and confirm the material data. The material data includes the temperature data measured by the temperature measuring device and the heating time in the quenching storage device and the tempering storage device when induction hardening and induction tempering are performed by temperature control. A force that can be stored and estimated based on this can be obtained by actually investigating a sample of the workpiece after heat treatment.
[0043] 被処理物の硬度は、熱処理後の被処理物を切断し、切断面を研磨した後、当該切 断面の硬度をビッカース硬度計、ロックウェル硬度計などの硬度計により測定して得 ることができる。また、被処理物を構成する鋼のミクロ組織は、熱処理後の被処理物を 切断し、切断面を研磨した後、当該切断面をナイタル (硝酸アルコール溶液)などの 腐食液により腐食し、光学顕微鏡などの顕微鏡により観察することにより調査すること ができる。また、残留オーステナイト量は、たとえば熱処理後の被処理物の所望の部 位を電解研磨し、 X線回折計 (XRD)を用いて、当該部位のマルテンサイト α (211) 面とオーステナイト γ (220)面との回折強度とを測定することにより、算出することが できる。  [0043] The hardness of the workpiece is obtained by cutting the workpiece after heat treatment, polishing the cut surface, and then measuring the hardness of the cut surface with a hardness meter such as a Vickers hardness meter or Rockwell hardness meter. Can. In addition, the microstructure of the steel that forms the workpiece is cut after the workpiece after heat treatment, the cut surface is polished, and then the cut surface is corroded by a corrosive liquid such as nitral (nitric alcohol solution). It can be investigated by observing with a microscope such as a microscope. The amount of retained austenite can be determined by, for example, electropolishing a desired portion of the object to be treated after heat treatment, and using an X-ray diffractometer (XRD) to obtain the martensite α (211) plane and austenite γ (220 It can be calculated by measuring the diffraction intensity with respect to the surface.
[0044] なお、本発明の高周波熱処理設備は、たとえば、軸受の軌道輪、転動体など、鋼か らなり、焼入硬化されて製造される機械部品の熱処理に適用することができる。  [0044] The high-frequency heat treatment equipment of the present invention can be applied to heat treatment of machine parts made of steel, such as bearing rings and rolling elements, and manufactured by quench hardening.
[0045] 本発明の一の局面における高周波熱処理方法は、高周波加熱により被処理物を 加熱して焼入硬化する高周波熱処理方法である。当該高周波熱処理方法は、被処 理物の表面に、被処理物が加熱される温度域において当該被処理物よりも耐酸ィ匕 性の高い安定化層が形成される表面安定化工程と、表面安定化工程において安定 化層が形成された被処理物が焼入硬化される焼入硬化工程とを備えている。 [0045] The high-frequency heat treatment method according to one aspect of the present invention is a high-frequency heat treatment method in which an object to be processed is heated and hardened by induction heating. The high-frequency heat treatment method includes a surface stabilization step in which a stabilization layer having higher acid resistance than the treatment object is formed on the surface of the treatment object in a temperature range where the treatment object is heated, Stable in the stabilization process And a quench hardening step in which the object to be processed on which the conversion layer is formed is hardened by hardening.
[0046] そして、焼入硬化工程は、安定化層が形成された被処理物の温度が調節される温 度制御工程と、加熱された被処理物が冷却されるべきタイミングが決定されて、被処 理物が冷却される焼入制御工程とを含んでいる。温度制御工程は、被処理物の表面 に形成された安定ィヒ層の表面の温度が放射温度計により測定される温度制御用測 温工程と、温度制御用測温工程にぉ 、て測定された温度の情報に基づき被処理物 の加熱状態を制御するための温度制御信号が出力される温度調節工程と、温度制 御信号に基づ ヽて、高周波加熱により被処理物が加熱される加熱工程とを有して 、 る。  [0046] In the quench hardening process, a temperature control process in which the temperature of the workpiece on which the stabilization layer is formed is adjusted, and a timing at which the heated workpiece is to be cooled are determined. And a quenching control process in which the workpiece is cooled. In the temperature control process, the temperature of the surface of the stable layer formed on the surface of the object to be processed is measured by a temperature control measurement process in which the temperature of the surface is measured by a radiation thermometer, and a temperature control temperature measurement process. A temperature control process that outputs a temperature control signal for controlling the heating state of the workpiece based on the temperature information, and heating that heats the workpiece by high-frequency heating based on the temperature control signal Process.
[0047] 焼入制御工程は、被処理物の表面に形成された安定化層の表面の温度が放射温 度計により測定される焼入用測温工程と、焼入用測温工程において測定された温度 の情報に基づき加熱時間が調節され、被処理物が冷却されるべきタイミングが決定さ れて冷却開始信号が出力される冷却タイミング調節工程と、冷却開始信号に基づい て、被処理物が冷却されることにより被処理物が焼入硬化される冷却工程とを有して いる。  [0047] The quenching control process is performed in a quenching temperature measurement process in which the temperature of the surface of the stabilization layer formed on the surface of the workpiece is measured by a radiation thermometer, and in the quenching temperature measurement process. The heating time is adjusted based on the measured temperature information, the timing at which the workpiece should be cooled is determined and the cooling start signal is output, and the workpiece is processed based on the cooling start signal. And a cooling step in which the object to be processed is hardened by being cooled.
[0048] 一般に、高周波焼入においては、まず熱処理条件として電力と時間とのパラメータ 力もなる電源出力の推移 (電源出力パターン)が、過去の熱処理の実績や作業者の 経験に基づいて決定される (電力制御)。そして、熱処理条件は、被処理物の形状、 材質等を考慮しつつ電力と時間とを変化させて被処理物のサンプルを実際に熱処 理して決定される。そのため、熱処理条件の決定に経験と手間が必要となる。また、 鋼製品の焼入においては、被処理物を所定温度に所定時間以上保持した後、急冷 する必要がある。しかし、上記方法 (電力制御）では被処理物の加熱履歴を正確に把 握することは困難である。そのため、熱処理条件を決定するためには、実際に熱処理 を実施して得られた被処理物の硬度、ミクロ組織等の品質を調査する必要がある。  [0048] Generally, in induction hardening, first, the transition of power output (power output pattern), which also includes power and time parameters as heat treatment conditions, is determined based on past heat treatment results and operator experience. (Power control). The heat treatment conditions are determined by actually heat-treating the sample of the object to be processed while changing the power and time in consideration of the shape and material of the object to be processed. Therefore, experience and labor are required to determine the heat treatment conditions. In the quenching of steel products, it is necessary to rapidly cool the workpiece after holding it at a predetermined temperature for a predetermined time. However, with the above method (power control), it is difficult to accurately grasp the heating history of the workpiece. Therefore, in order to determine the heat treatment conditions, it is necessary to investigate the quality, such as the hardness and microstructure of the workpiece obtained by actually performing the heat treatment.
[0049] これに対し、本発明の一の局面における高周波熱処理方法では、焼入硬化工程に ぉ 、て、温度と時間とをパラメータとして被処理物の加熱が制御される（温度制御)。 そのため、被処理物の加熱履歴を正確に把握することが可能であり、被処理物に必 要な加熱履歴を与えた後、急冷することで焼入を行なうことができる。その結果、実際 に熱処理を実施して得られた被処理物の硬度、ミクロ組織等の品質の調査を必ずし も行なう必要がなぐまた、熱処理条件の決定に経験や手間が必ずしも必要ない。こ のように、本発明の一の局面における高周波熱処理方法によれば、前述の高周波熱 処理の問題点が解消される。 [0049] On the other hand, in the induction heat treatment method according to one aspect of the present invention, heating of the workpiece is controlled using the temperature and time as parameters during the quench hardening process (temperature control). Therefore, it is possible to accurately grasp the heating history of the object to be processed, and quenching can be performed by rapidly cooling after giving the necessary heating history to the object to be processed. As a result, actual In addition, it is not always necessary to investigate the quality of the workpiece, such as hardness and microstructure, obtained by heat treatment, and experience and effort are not necessarily required to determine the heat treatment conditions. Thus, according to the high-frequency heat treatment method in one aspect of the present invention, the above-described problems of high-frequency heat treatment are solved.
[0050] また、温度制御を採用する本発明の一の局面における高周波熱処理方法におい ては、被処理物の測温精度が極めて重要である。前述のように、高周波熱処理にお いては、熱処理装置のレイアウト上の問題により、被処理物の測温に熱電対などの接 触式温度計の採用は困難である。そのため、本発明の一の局面における高周波熱 処理方法においても、被処理物の測温には、放射温度計が採用される。一方、高周 波熱処理では、通常、雰囲気の制御は行なわれず、大気中（空気中）で被処理物が 加熱される。そのため、鋼からなる被処理物が熱処理される場合、被処理物は熱処 理の進行とともに大気中の酸素により酸ィ匕される。その結果、熱処理の進行中に被 処理物の表面状態が変化し、これに伴い放射率が変化するため、放射温度計による 被処理物の測温の精度が低下する。  [0050] In addition, in the high-frequency heat treatment method according to one aspect of the present invention that employs temperature control, the temperature measurement accuracy of the workpiece is extremely important. As described above, in the high-frequency heat treatment, it is difficult to employ a contact thermometer such as a thermocouple for measuring the temperature of the object to be processed due to the layout problem of the heat treatment apparatus. Therefore, also in the high-frequency heat treatment method according to one aspect of the present invention, a radiation thermometer is employed for temperature measurement of the workpiece. On the other hand, in high-frequency heat treatment, the atmosphere is not normally controlled, and the workpiece is heated in the atmosphere (in the air). For this reason, when a workpiece made of steel is heat-treated, the workpiece is oxidized by oxygen in the atmosphere as the heat treatment proceeds. As a result, the surface condition of the object to be processed changes during the heat treatment, and the emissivity changes accordingly, so that the accuracy of temperature measurement of the object to be processed by the radiation thermometer decreases.
[0051] 被処理物の耐酸化性が低い場合、被処理物の表面は、熱処理の初期に酸化され 、その後、表面状態はほとんど変化しないため、測温精度に及ぼす表面状態の変化 の影響は比較的小さい。しかし、被処理物が 3%以上のクロムを含む鋼、たとえ «JIS 規格 SUS440Cなどのマルテンサイト系ステンレス鋼や、 AISI規格 M50などの高 速度鋼などから構成されている場合、表面の酸ィ匕に比較的長い時間を要するため、 測温精度に及ぼす表面状態の変化の影響が大きくなる。  [0051] When the oxidation resistance of the object to be processed is low, the surface of the object to be processed is oxidized at the initial stage of the heat treatment, and the surface state is hardly changed thereafter. Therefore, the influence of the change of the surface state on the temperature measurement accuracy is Relatively small. However, if the workpiece is made of steel containing 3% or more of chromium, for example, «Martensitic stainless steel such as JIS standard SUS440C or high-speed steel such as AISI standard M50, etc. Since it takes a relatively long time, the influence of changes in the surface condition on the temperature measurement accuracy becomes large.
[0052] これに対し、本発明の一の局面における高周波熱処理方法では、表面安定化工程 において、被処理物の表面に、被処理物が加熱される温度域において被処理物より も耐酸ィ匕性の高い安定ィ匕層が形成される。そのため、焼入硬化工程において、被処 理物の表面の酸化による表面状態の変化が抑制され、放射温度計による測温精度 の低下が回避される。その結果、本発明の一の局面における高周波熱処理方法によ れば、被処理物の品質を安定させることができる。  [0052] In contrast, in the high-frequency heat treatment method according to one aspect of the present invention, in the surface stabilization step, the surface of the workpiece is more resistant to acid than the workpiece in the temperature range where the workpiece is heated. A highly stable stable layer is formed. For this reason, in the quench hardening process, changes in the surface state due to oxidation of the surface of the workpiece are suppressed, and a decrease in temperature measurement accuracy by the radiation thermometer is avoided. As a result, according to the high frequency heat treatment method in one aspect of the present invention, the quality of the object to be processed can be stabilized.
[0053] 以上のように、本発明の一の局面における高周波熱処理方法によれば、温度制御 を可能にし、熱処理の条件出しを容易に行なうことが可能であるとともに、被処理物 の品質を安定させることが可能な高周波熱処理方法を提供することができる。 [0053] As described above, according to the high-frequency heat treatment method of one aspect of the present invention, temperature control is possible, heat treatment conditions can be easily set, and an object to be treated is obtained. It is possible to provide a high-frequency heat treatment method capable of stabilizing the quality of the material.
[0054] なお、上述の温度制御用測温工程にお!、ては、被処理物が加熱され過ぎることに より残留オーステナイト量が過多となることを回避するため、被処理物のうち温度の高 くなる部位、たとえば誘導コイルに近接し、磁束の侵入の最も多い部位の温度が測定 されることが好ましい。また、上述の焼入用測温工程においては、被処理物の焼入前 の加熱が不足することを回避するため、被処理物のうち温度の低くなる部位、たとえ ば誘導コイル力 遠ぐ磁束の侵入の最も少な 、部位の温度が測定されることが好ま しい。  [0054] Note that in the above temperature control temperature measurement step, in order to avoid an excessive amount of retained austenite due to excessive heating of the workpiece, the temperature of the workpiece is not reduced. It is preferable to measure the temperature at a site where the magnetic flux increases most, for example, a region where the magnetic flux intrudes most frequently. In addition, in the temperature measurement process for quenching described above, in order to avoid insufficient heating of the workpiece before quenching, the portion of the workpiece to be cooled, for example, the induction coil force is far away from the magnetic flux. It is preferred that the temperature of the site with the least amount of intrusion be measured.
[0055] 本発明の他の局面における高周波熱処理方法は、高周波加熱により被処理物を 加熱して焼入硬化する高周波熱処理方法である。当該高周波熱処理方法は、デー タ取得工程と、記憶工程と、確認工程と、量産工程とを備えている。データ取得工程 では、被処理物のサンプルが加熱されて焼入硬化されることにより、プロセスデータ が取得される。記憶工程では、データ取得工程において被処理物のサンプルを加熱 するために高周波加熱用の電源力も誘導コイルに出力された電源出力の推移デー タと、被処理物のサンプルの冷却タイミングを特定するための冷却タイミングデータと がプロセスデータとして記憶される。  [0055] A high-frequency heat treatment method according to another aspect of the present invention is a high-frequency heat treatment method in which an object to be treated is heated and hardened by high-frequency heating. The high-frequency heat treatment method includes a data acquisition process, a storage process, a confirmation process, and a mass production process. In the data acquisition process, process data is acquired by heating and hardening the sample of the workpiece. In the memory process, in order to identify the transition data of the power output output to the induction coil and the cooling power of the sample of the object to be processed in order to heat the sample of the object to be processed in the data acquisition process Are stored as process data.
[0056] 確認工程では、データ取得工程において焼入硬化された被処理物の材質データ に基づき、電源出力の推移データおよび冷却タイミングデータの妥当性が確認され る。量産工程では、記憶工程で記憶され、かつ確認工程で妥当性が確認された電源 出力の推移データおよび冷却タイミングデータに従って被処理物が焼入硬化される 。そして、データ取得工程における焼入硬化は、上記本発明の一の局面における高 周波熱処理方法により実施される。  [0056] In the confirmation process, the validity of the transition data of the power output and the cooling timing data is confirmed based on the material data of the workpiece that has been quenched and hardened in the data acquisition process. In the mass production process, the workpiece is quenched and hardened according to the transition data of the power output and the cooling timing data that are stored in the storage process and validated in the confirmation process. The quench hardening in the data acquisition process is performed by the high frequency heat treatment method in one aspect of the present invention.
[0057] 上記本発明の一の局面における高周波熱処理方法においては、被処理物の測温 に放射温度計が採用されている。そして、表面安定ィ匕工程が実施されることにより、 測温精度に及ぼす外乱の影響が抑制されている。しかし、たとえば放射温度計のレ ンズに汚れや水滴が付着した場合、測定された温度には誤差が含まれるおそれがあ り、外乱への更なる対策を講じることが好ましい。  [0057] In the high-frequency heat treatment method according to one aspect of the present invention, a radiation thermometer is employed for temperature measurement of an object to be processed. Then, by performing the surface stabilization process, the influence of disturbance on the temperature measurement accuracy is suppressed. However, for example, if dirt or water droplets adhere to the lens of the radiation thermometer, the measured temperature may contain an error, and it is preferable to take further measures against disturbance.
[0058] これに対し、上記他の局面における高周波熱処理方法では、データ取得工程とし て上記本発明の一の局面における高周波熱処理方法による高周波焼入を被処理物 のサンプルに対して行なった後、測温データ等のプロセスデータを記憶する記憶ェ 程を設け、さらに記憶されたプロセスデータの妥当性を確認する確認工程を経た上 で、妥当性が担保されたプロセスデータに基づ 、て量産工程の熱処理が行なわれる 。これにより、本発明の他の局面における高周波熱処理方法によれば、温度制御を 可能にし、熱処理の条件出しを容易に行なうことが可能であるとともに、被処理物の 品質をさらに安定させることが可能な高周波熱処理方法を提供することができる。 [0058] On the other hand, in the high-frequency heat treatment method according to the other aspect described above, the data acquisition step is performed. In addition, after the induction hardening by the induction heat treatment method according to one aspect of the present invention is performed on the sample of the workpiece, a storage process is provided for storing process data such as temperature measurement data, and the stored process After a confirmation process to confirm the validity of the data, the mass production process is heat-treated based on the process data whose validity is guaranteed. Thereby, according to the high frequency heat treatment method in another aspect of the present invention, temperature control can be performed, heat treatment conditions can be easily set, and the quality of the workpiece can be further stabilized. A high-frequency heat treatment method can be provided.
[0059] なお、上記確認工程において、電源出力の推移データおよび冷却タイミングデータ の妥当性を確認するために調査される材質データは、たとえば被処理物の硬度、被 処理物を構成する鋼のミクロ組織、残留オーステナイト量など力 選択される 1以上の 材質データとすることができる。また、当該材質データは、データ取得工程の温度制 御用測温工程および焼入用測温工程にぉ 、て測定された温度データを、記憶工程 にお 、て記憶し、当該データとプロセスデータとして記憶された冷却タイミングデータ に基づいて推定することができるが、熱処理後の被処理物のサンプルを実際に調査 して取得してちょい。  [0059] In the above confirmation process, the material data to be investigated in order to confirm the validity of the power output transition data and the cooling timing data are, for example, the hardness of the workpiece, and the microscopic value of the steel constituting the workpiece. Force, amount of retained austenite, etc. Can be one or more material data selected. In addition, the material data is stored in the storage process as temperature data measured in the temperature acquisition process and temperature measurement process for quenching in the data acquisition process. Although it can be estimated based on the stored cooling timing data, actually investigate and obtain a sample of the workpiece after heat treatment.
[0060] 被処理物の硬度は、熱処理後の被処理物を切断し、切断面を研磨した後、当該切 断面の硬度をビッカース硬度計、ロックウェル硬度計などの硬度計により測定して得 ることができる。また、被処理物を構成する鋼のミクロ組織は、熱処理後の被処理物を 切断し、切断面を研磨した後、当該切断面をナイタル (硝酸アルコール溶液)などの 腐食液により腐食し、光学顕微鏡などの顕微鏡により観察することにより調査すること ができる。また、残留オーステナイト量は、たとえば熱処理後の被処理物の所望の部 位を電解研磨し、 X線回折計 (XRD)を用いて、マルテンサイト《(211)面とオーステ ナイト γ (220)面との回折強度とを測定することにより、算出することができる。  [0060] The hardness of the workpiece is obtained by cutting the workpiece after the heat treatment, polishing the cut surface, and then measuring the hardness of the cut surface with a hardness meter such as a Vickers hardness meter or a Rockwell hardness meter. Can. In addition, the microstructure of the steel that forms the workpiece is cut after the workpiece after heat treatment, the cut surface is polished, and then the cut surface is corroded by a corrosive liquid such as nitral (nitric alcohol solution). It can be investigated by observing with a microscope such as a microscope. The amount of retained austenite can be determined by, for example, electropolishing a desired portion of the workpiece after heat treatment and using an X-ray diffractometer (XRD) to obtain martensite << (211) surface and austenite γ (220) surface. It can be calculated by measuring the diffraction intensity.
[0061] 本発明の別の局面における高周波熱処理方法は、高周波加熱により被処理物を 加熱して焼戻を実施する高周波熱処理方法である。当該高周波熱処理方法は、被 処理物の表面に、被処理物よりも耐酸ィ匕性の高い安定ィ匕層が形成される表面安定 化工程と、表面安定ィ匕工程において安定ィ匕層が形成された被処理物が加熱されて 焼戻される焼戻工程とを備えている。焼戻工程は、被処理物の温度が調節される温 度制御工程と、被処理物の加熱が終了されるべきタイミングが決定されて、被処理物 が冷却される焼戻制御工程とを含んで 、る。 [0061] A high frequency heat treatment method according to another aspect of the present invention is a high frequency heat treatment method in which an object to be treated is heated and tempered by high frequency heating. The high-frequency heat treatment method includes a surface stabilization process in which a stable layer having higher acid resistance than the object to be processed is formed on the surface of the object to be processed, and a stable layer is formed in the surface stabilization process. A tempering step in which the processed object is heated and tempered. The tempering process is a temperature at which the temperature of the workpiece is adjusted. And a tempering control step in which the timing at which the heating of the workpiece is to be finished is determined and the workpiece is cooled.
[0062] 温度制御工程は、被処理物の表面に形成された安定化層の表面の温度が放射温 度計により測定される温度制御用測温工程と、温度制御用測温工程において測定さ れた温度の情報に基づき、被処理物の加熱状態を制御するための温度制御信号が 出力される温度調節工程と、温度制御信号に基づいて、高周波加熱により被処理物 が加熱される加熱工程とを有している。焼戻制御工程は、被処理物の表面に形成さ れた安定化層の表面の温度が放射温度計により測定される焼戻用測温工程と、焼 戻用測温工程において測定された温度の情報に基づき加熱時間が調節され、被処 理物が冷却されるべきタイミングが決定されて冷却開始信号が出力される冷却タイミ ング調節工程と、冷却開始信号に基づいて、被処理物が冷却されることにより被処理 物の焼戻が終了する冷却工程とを有して 、る。  [0062] In the temperature control process, the temperature of the surface of the stabilization layer formed on the surface of the object to be processed is measured in a temperature control temperature measurement process in which the temperature is measured with a radiation thermometer, and the temperature control temperature measurement process. A temperature adjusting process for outputting a temperature control signal for controlling the heating state of the object to be processed based on the temperature information, and a heating process for heating the object to be processed by high frequency heating based on the temperature control signal And have. The tempering control process consists of a tempering temperature measurement process in which the temperature of the surface of the stabilization layer formed on the surface of the workpiece is measured by a radiation thermometer, and a temperature measured in the tempering temperature measurement process. The heating time is adjusted based on the above information, the timing for cooling the workpiece is determined and the cooling start signal is output, and the workpiece is cooled based on the cooling start signal. And a cooling step in which the tempering of the object to be processed is completed.
[0063] 本発明の別の局面における高周波熱処理方法では、焼戻工程において、温度制 御による熱処理が採用される。そのため、上記一の局面における高周波熱処理方法 と同様に、被処理物の加熱履歴を正確に把握することが可能であり、被処理物に必 要な加熱履歴を与えた後、冷却することで焼戻を行なうことができる。その結果、実際 に熱処理を実施して得られた被処理物の材質、たとえば硬度の調査を必ずしも行な う必要がなぐまた、熱処理条件の決定に経験や手間が必ずしも必要ない。  [0063] In the induction heat treatment method according to another aspect of the present invention, heat treatment by temperature control is employed in the tempering step. Therefore, similarly to the high-frequency heat treatment method in the above aspect, it is possible to accurately grasp the heating history of the object to be processed, and after giving the necessary heating history to the object to be processed, cooling is performed. You can go back. As a result, it is not always necessary to investigate the material of the workpiece, such as hardness, obtained by actually carrying out the heat treatment, and experience and labor are not necessarily required to determine the heat treatment conditions.
[0064] また、本発明の別の局面における高周波熱処理方法では、表面安定化工程にお いて、被処理物の表面に、被処理物が加熱される温度域において被処理物よりも耐 酸化性の高い安定化層が形成される。そのため、焼戻工程において、被処理物の表 面の酸化による表面状態の変化が抑制され、放射温度計による測温精度の低下が 回避される。その結果、本発明の別の局面における高周波熱処理方法によれば、被 処理物の品質を安定させることができる。  [0064] Further, in the high-frequency heat treatment method according to another aspect of the present invention, in the surface stabilization step, the surface of the workpiece is more resistant to oxidation than the workpiece in the temperature range where the workpiece is heated. A high stabilization layer is formed. Therefore, in the tempering process, changes in the surface state due to oxidation of the surface of the workpiece are suppressed, and a decrease in temperature measurement accuracy by the radiation thermometer is avoided. As a result, according to the high-frequency heat treatment method in another aspect of the present invention, the quality of the workpiece can be stabilized.
[0065] 以上のように、本発明の別の局面における高周波熱処理方法によれば、温度制御 を可能にし、熱処理の条件出しを容易に行なうことが可能であるとともに、被処理物 の品質を安定させることが可能な高周波熱処理方法を提供することができる。なお、 上述の焼戻用測温工程においては、被処理物の品質を安定させるため、複数部位 の温度が測定されることが好ま 、。 [0065] As described above, according to the high-frequency heat treatment method according to another aspect of the present invention, temperature control can be performed, heat treatment conditions can be easily set, and the quality of an object to be processed can be stabilized. It is possible to provide a high-frequency heat treatment method that can be performed. In the above tempering temperature measurement process, in order to stabilize the quality of the object to be processed, a plurality of parts Preferably, the temperature is measured.
[0066] 本発明のさらに別の局面における高周波熱処理方法は、高周波加熱により被処理 物を加熱して焼戻を実施する高周波熱処理方法である。当該高周波熱処理方法は 、データ取得工程と、記憶工程と、確認工程と、量産工程とを備えている。データ取 得工程では、被処理物のサンプルが加熱されて焼戻されることによりプロセスデータ が取得される。記憶工程では、データ取得工程において被処理物のサンプルを加熱 するために高周波加熱用の電源力も誘導コイルに出力された電源出力の推移デー タと、被処理物のサンプルの冷却タイミングを特定するための冷却タイミングデータと がプロセスデータとして記憶される。  [0066] A high-frequency heat treatment method according to still another aspect of the present invention is a high-frequency heat treatment method in which an object to be treated is heated and tempered by high-frequency heating. The high-frequency heat treatment method includes a data acquisition process, a storage process, a confirmation process, and a mass production process. In the data acquisition process, process data is acquired by heating and tempering the sample of the workpiece. In the memory process, in order to identify the transition data of the power output output to the induction coil and the cooling power of the sample of the object to be processed in order to heat the sample of the object to be processed in the data acquisition process Are stored as process data.
[0067] 確認工程では、データ取得工程において焼戻された被処理物の材質データに基 づき、電源出力の推移データおよび冷却タイミングデータの妥当性が確認される。量 産工程では、記憶工程で記憶され、かつ確認工程で妥当性が確認された電源出力 の推移データおよび冷却タイミングデータに従って被処理物が焼戻される。そして、 データ取得工程における焼戻は、上記本発明の別の局面における高周波熱処理方 法により実施される。  [0067] In the confirmation step, the validity of the power output transition data and the cooling timing data is confirmed based on the material data of the workpiece tempered in the data acquisition step. In the mass production process, the workpiece is tempered according to the power output transition data and the cooling timing data that are stored in the storage process and validated in the confirmation process. The tempering in the data acquisition step is performed by the induction heat treatment method according to another aspect of the present invention.
[0068] 本発明のさらに別の局面における高周波熱処理方法では、データ取得工程として 上記本発明の別の局面における高周波熱処理方法による高周波焼戻を被処理物の サンプルに対して行なった後、測温データ等のプロセスデータを記憶する記憶工程 を設け、さらに記憶されたプロセスデータの妥当性を確認する確認工程を経た上で、 妥当性が担保されたプロセスデータに基づ 、て量産工程の熱処理が行なわれる。こ れにより、本発明のさらに別の局面における高周波熱処理方法によれば、温度制御 を可能にし、熱処理の条件出しを容易に行なうことが可能であるとともに、被処理物 の品質をさらに安定させることが可能な高周波熱処理方法を提供することができる。  [0068] In the induction heat treatment method according to yet another aspect of the present invention, after performing induction tempering on the sample of the workpiece by the induction heat treatment method according to another aspect of the present invention as a data acquisition step, temperature measurement is performed. A storage process for storing process data such as data is provided, followed by a confirmation process for confirming the validity of the stored process data, and then heat treatment for the mass production process is performed based on the process data for which validity is ensured. Done. Thus, according to the high-frequency heat treatment method according to still another aspect of the present invention, temperature control can be performed, heat treatment conditions can be easily set, and the quality of the object to be processed can be further stabilized. Therefore, it is possible to provide a high-frequency heat treatment method capable of performing
[0069] なお、上記確認工程において、電源出力の推移データおよび冷却タイミングデータ の妥当性を確認するために調査される材質データは、たとえば被処理物の焼戻にお いて最も重要な特性である被処理物の硬度とすることができる。また、当該材質デー タは、データ取得工程の温度制御用測温工程および焼戻用測温工程にぉ 、て測定 された温度データを、記憶工程において記憶し、当該データとプロセスデータとして 記憶された冷却タイミングデータに基づ 、て推定することができる力 熱処理後の被 処理物のサンプルを実際に調査して取得してもよ 、。 [0069] In the confirmation process, the material data investigated to confirm the validity of the power output transition data and the cooling timing data is the most important characteristic in tempering the workpiece, for example. The hardness of the workpiece can be set. In addition, the material data is stored in the storage process as temperature data measured during the temperature control temperature measurement process and the tempering temperature measurement process in the data acquisition process, and is used as the data and process data. A force that can be estimated based on the stored cooling timing data. A sample of the workpiece after heat treatment may be actually investigated and acquired.
[0070] 上記高周波熱処理方法にお!、て好ましくは、表面安定化工程は、被処理物の表面 に黒体塗料が塗布される黒体塗料塗布工程を含んで 、る。被処理物が加熱される 温度域にぉ ヽて、放射率の変化の極めて小さ！ヽ黒体塗料を被処理物の表面に塗布 した上で、高周波熱処理が実施されることにより、熱処理中の被処理物の表面にお ける放射率の変化が抑制される。その結果、放射温度計による測温の精度が一層向 上し、被処理物の品質がより安定する。  [0070] In the above-described high-frequency heat treatment method, preferably, the surface stabilization step includes a black body paint application step in which a black body paint is applied to the surface of the object to be processed. The emissivity change is extremely small over the temperature range where the workpiece is heated! By applying the black body paint to the surface of the object to be treated and then performing the high frequency heat treatment, the change of the emissivity on the surface of the object to be treated during the heat treatment is suppressed. As a result, the accuracy of temperature measurement with the radiation thermometer is further improved, and the quality of the workpiece is further stabilized.
[0071] ここで、黒体塗料としては、たとえばシリコン系の艷消し塗料などを使用することがで き、より具体的には、たとえば TEMPIL社製の Pyromark High Temperature P aint、ジャパンセンサー株式会社製の高温黒体塗料 JSC3号などを採用することがで きる。 [0071] Here, as the black body paint, for example, a silicon-based mat paint can be used. More specifically, for example, Pyromark High Temperature Paint made by TEMPIL, made by Japan Sensor Co., Ltd. High temperature black body paint JSC No.3 can be used.
[0072] 上記高周波熱処理方法において好ましくは、表面安定化工程は、被処理物が熱酸 化されることにより、被処理物の表面に酸化鉄層が形成される熱酸化工程を含んで いる。被処理物が加熱される温度域において、被処理物よりも耐酸化性が高ぐ放射 率の変化の小さい酸ィ匕鉄層を被処理物の表面に形成した上で、高周波熱処理が実 施されることにより、熱処理中の被処理物の表面における放射率の変化が抑制され る。その結果、放射温度計による測温の精度が一層向上し、被処理物の品質がより 安定する。  [0072] Preferably, in the high-frequency heat treatment method, the surface stabilization step includes a thermal oxidation step in which an iron oxide layer is formed on the surface of the object to be processed by thermal oxidation of the object to be processed. In the temperature range where the workpiece is heated, an oxidation iron oxide layer having higher oxidation resistance than that of the workpiece and a small change in emissivity is formed on the surface of the workpiece, and then high-frequency heat treatment is performed. As a result, a change in emissivity on the surface of the object to be processed during the heat treatment is suppressed. As a result, the accuracy of temperature measurement with the radiation thermometer is further improved, and the quality of the workpiece is more stable.
[0073] ここで、上記酸化鉄層は、放射率の変化を抑制する観点からは、厚みの厚!、酸ィ匕 鉄層であることが好ましいが、その効果は当該酸ィ匕鉄層により被処理物の表面全体 が完全に覆われることによりほぼ飽和する。したがって、酸化鉄層の形成の程度は熱 処理の効率向上の観点も考慮して決定することが好ましい。  [0073] Here, from the viewpoint of suppressing the change in emissivity, the iron oxide layer is preferably a thick and acidic iron layer, but the effect is obtained by the acidic iron layer. When the entire surface of the workpiece is completely covered, it is almost saturated. Therefore, it is preferable to determine the degree of formation of the iron oxide layer in consideration of improving the efficiency of heat treatment.
[0074] 具体的には、たとえば、被処理物のサンプルを高周波加熱し、その際に当該被処 理物の表面に熱電対などの接触式温度計を接触させて温度を測定するとともに、同 一部位を放射温度計により測温して両者の測温データを取得する。そして、たとえば 両者の測温データの差の変化率が 10秒間あたり 3%以下となれば、十分な酸化鉄 層が形成されたと考えることができる。その後、放射温度計の放射率設定の調整を実 施することで、当該酸化鉄層が形成された被処理物の表面の温度を、放射温度計に より正確に測定することができる。 Specifically, for example, a sample of the object to be processed is heated at a high frequency, and at that time, a contact thermometer such as a thermocouple is brought into contact with the surface of the object to be processed, and the temperature is measured. One part is measured with a radiation thermometer, and the temperature measurement data of both is acquired. And, for example, if the rate of change of the difference between the two temperature measurement data is 3% or less per 10 seconds, it can be considered that a sufficient iron oxide layer has been formed. Then adjust the emissivity setting of the radiation thermometer. By applying, the temperature of the surface of the workpiece on which the iron oxide layer is formed can be accurately measured with a radiation thermometer.
[0075] 上記高周波熱処理方法にお!、て好ましくは、表面安定化工程は、被処理物が酸性 の溶液中に浸漬されることにより、被処理物の表面に酸化鉄層が形成される酸性溶 液浸漬工程を含んでいる。上述の場合と同様に、被処理物が加熱される温度域にお いて、被処理物よりも耐酸化性が高ぐ放射率の変化の小さい酸化鉄層を被処理物 の表面に形成した上で、高周波熱処理が実施されることにより、熱処理中の被処理 物の表面における放射率の変化が抑制される。その結果、放射温度計による測温の 精度が一層向上し、被処理物の品質がより安定する。  [0075] In the above high-frequency heat treatment method, preferably, the surface stabilization step is an acidic process in which an iron oxide layer is formed on the surface of the object to be processed by immersing the object in an acidic solution. Includes a solution dipping process. As in the case described above, in the temperature range where the workpiece is heated, an iron oxide layer having higher oxidation resistance than that of the workpiece and having a small change in emissivity is formed on the surface of the workpiece. Thus, by performing the high-frequency heat treatment, a change in emissivity on the surface of the object to be treated during the heat treatment is suppressed. As a result, the accuracy of temperature measurement by the radiation thermometer is further improved, and the quality of the workpiece is more stable.
[0076] ここで、被処理物を浸漬するための酸性の溶液としては、硫酸、塩酸、硝酸などを 採用することができる。また、酸化鉄層の形成後に、上述と同様に接触式温度計と放 射温度計とによる被処理物の表面の測温を行ない、同様の手順で酸ィ匕鉄層が十分 に形成されたカゝ否かを判断することができる。  [0076] Here, sulfuric acid, hydrochloric acid, nitric acid, or the like can be used as the acidic solution for immersing the workpiece. After forming the iron oxide layer, the surface temperature of the object to be processed was measured with a contact thermometer and a radiation thermometer in the same manner as described above, and the iron oxide layer was sufficiently formed in the same procedure. It is possible to determine whether or not it is a problem.
[0077] 本発明に従った高周波熱処理品は、上述の高周波熱処理方法で熱処理されて作 製されたことを特徴とする。本発明の高周波熱処理品によれば、温度制御により熱処 理されるとともに、熱処理の条件出しが容易な高周波熱処理方法により熱処理されて いるため、低価格ィヒが可能であり、かつ品質の安定した高周波熱処理品を提供する ことができる。  [0077] A high-frequency heat-treated product according to the present invention is characterized by being manufactured by heat treatment using the above-described high-frequency heat treatment method. According to the high-frequency heat treatment product of the present invention, heat treatment is performed by temperature control, and heat treatment is performed by a high-frequency heat treatment method that makes it easy to determine heat treatment conditions, so that low cost is possible and quality is stable. High-frequency heat-treated products can be provided.
[0078] なお、本発明の高周波熱処理品は、たとえば、軸受の軌道輪、転動体など、鋼から なり、焼入硬化されて製造される機械部品に適用することができる。  [0078] The induction heat treatment product of the present invention can be applied to mechanical parts made of steel, such as bearing races and rolling elements, and manufactured by quench hardening.
[0079] 上記本発明の高周波焼入装置、高周波熱処理設備、高周波焼入方法および高周 波熱処理方法は、それぞれ単独で実施することもできるが、たとえば、上記本発明の 高周波熱処理設備においては、上記本発明の高周波焼入装置を採用することがで きる。さらに、上記本発明の高周波熱処理方法においては、上記本発明の高周波焼 入方法を採用することができる。  [0079] The induction hardening apparatus, induction heat treatment equipment, induction hardening method and high frequency heat treatment method of the present invention can be carried out independently. For example, in the induction heat treatment equipment of the present invention, The induction hardening apparatus of the present invention can be employed. Furthermore, in the induction heat treatment method of the present invention, the induction hardening method of the present invention can be employed.
発明の効果  The invention's effect
[0080] 以上の説明から明らかなように、本発明の高周波焼入方法および高周波焼入装置 によれば、温度制御を可能にし、熱処理の条件出しを容易に行なうことを可能にする ことにより、過去の生産実績の蓄積が少ない場合や、経験の浅い作業者が熱処理の 作業を行なう場合でも、容易にかつ効率よく実施することができるとともに、被処理物 の広い範囲に所望の硬度や残留オーステナイト量などの熱処理品質を付与すること が可能な高周波焼入方法、および当該高周波焼入方法を実施するための高周波焼 入装置を提供することができる。また、本発明の高周波焼入品によれば、製造コスト が抑制され、品質の安定した高周波焼入品を提供することができる。 As apparent from the above description, according to the induction hardening method and induction hardening apparatus of the present invention, it is possible to control the temperature and easily determine the conditions for the heat treatment. As a result, it is possible to carry out heat treatment easily and efficiently even when there is little accumulation of past production results or when an inexperienced worker performs heat treatment work, and the desired hardness can be applied to a wide range of workpieces. It is possible to provide an induction hardening method capable of imparting heat treatment quality such as the amount of retained austenite and an induction hardening apparatus for performing the induction hardening method. Moreover, according to the induction-hardened product of the present invention, it is possible to provide an induction-hardened product with reduced production costs and stable quality.
図面の簡単な説明 Brief Description of Drawings
[図 1]実施の形態 1における高周波焼入装置により熱処理されて作製される、転がり 軸受外輪の構成を示す概略断面図である。 FIG. 1 is a schematic cross-sectional view showing a configuration of a rolling bearing outer ring that is manufactured by heat treatment using an induction hardening apparatus according to Embodiment 1.
[図 2]実施の形態 1における高周波焼入装置の構成を示す概略図である。  FIG. 2 is a schematic diagram showing the configuration of the induction hardening apparatus in the first embodiment.
[図 3]実施の形態 1における高周波焼入方法の概略を示す図である。  FIG. 3 is a diagram showing an outline of the induction hardening method in the first embodiment.
[図 4]実施の形態 1における TTA線図の作製方法を説明するための図である。  FIG. 4 is a diagram for explaining a method for producing a TTA diagram in the first embodiment.
[図 5]TTA線図を用いた冷却タイミング調節工程の実施方法を説明するための図で ある。  FIG. 5 is a diagram for explaining a method for performing a cooling timing adjustment process using a TTA diagram.
[図 6]実施の形態 2における高周波熱処理設備により熱処理されて製造される、転が り軸受外輪の構成を示す概略断面図である。  FIG. 6 is a schematic cross-sectional view showing the configuration of a rolling bearing outer ring manufactured by heat treatment using the high-frequency heat treatment facility in Embodiment 2.
[図 7]実施の形態 2における高周波熱処理設備の構成を示す概略図である。  FIG. 7 is a schematic diagram showing a configuration of a high-frequency heat treatment facility in a second embodiment.
[図 8]実施の形態 2の高周波熱処理設備に含まれる高周波焼入装置の構成を示す 概略図である。  FIG. 8 is a schematic diagram showing the configuration of an induction hardening apparatus included in the induction heat treatment facility of Embodiment 2.
[図 9]実施の形態 2の高周波熱処理設備に含まれる高周波焼戻装置の構成を示す 概略図である。  FIG. 9 is a schematic diagram showing the configuration of an induction tempering device included in the induction heat treatment facility of Embodiment 2.
[図 10]実施の形態 2の高周波熱処理設備を用いた高周波熱処理方法の一例の概略 を示す図である。  FIG. 10 is a diagram showing an outline of an example of a high-frequency heat treatment method using the high-frequency heat treatment equipment of Embodiment 2.
[図 11]実施の形態 2における高周波焼入装置の動作を、データおよび指令の流れに 基づいて説明するための図である。  FIG. 11 is a diagram for explaining the operation of the induction hardening apparatus in the second embodiment based on the flow of data and commands.
[図 12]実施の形態 2における高周波焼戻装置の動作を、データおよび指令の流れに 基づいて説明するための図である。  FIG. 12 is a diagram for explaining the operation of the induction tempering apparatus according to Embodiment 2 based on the flow of data and instructions.
[図 13]熱処理の規格値を満足するための焼入温度と保持時間との関係を示した SUJ 2材の TTA線図である。 [Figure 13] SUJ showing the relationship between quenching temperature and holding time to satisfy the standard value of heat treatment It is a TTA diagram of two materials.
[図 14]補正 D の値を温度推移力 積算する方法を説明するための、焼入温度と保 ep  [Fig. 14] Quenching temperature and maintenance ep are used to explain the method of integrating the value of correction D with the temperature transition force.
持時間との関係を示す説明図である。 It is explanatory drawing which shows the relationship with holding time.
[図 15]D *の値に対する硬度と処理時間との変化を示す図である。  FIG. 15 is a graph showing changes in hardness and processing time with respect to the value of D *.
ep  ep
[図 16]加熱中の被処理物の温度推移を示す図である。  FIG. 16 is a graph showing the temperature transition of the object to be treated during heating.
[図 17]炭素の固溶開始カゝら 0. 4秒後における、 2つの Fe C間の各位置における炭  [Fig.17] Carbon solution at the start of solid solution 0.4 seconds later at each position between two Fe C
3  Three
素分布を示す図である。 It is a figure which shows elementary distribution.
[図 18]炭素の固溶開始力も 0. 8秒後における、 2つの Fe C間の各位置における炭  [Fig.18] The carbon solid solution starting force was also 0.8 seconds later, and the charcoal at each position between the two Fe C
3  Three
素分布を示す図である。 It is a figure which shows elementary distribution.
[図 19]炭素の固溶開始から 1. 2秒後における、 2つの Fe C間の各位置における炭  [Figure 19] Charcoal at each position between two Fe C, 1.2 seconds after the start of solid solution of carbon
3  Three
素分布を示す図である。 It is a figure which shows elementary distribution.
[図 20]変形例の焼入用冷却タイミングの決定方法で焼入を実施した場合の、焼入温 度制御側および焼入タイミング制御側における固溶炭素濃度の分布を示す図である 圆 21]炭素含有量 1質量％の鋼における昇温速度による加熱変態点の変化を示す 図である。  FIG. 20 is a diagram showing a distribution of solute carbon concentrations on the quenching temperature control side and the quenching timing control side when quenching is performed by the quenching cooling timing determination method of the modification. It is a figure which shows the change of the heat transformation point by the temperature increase rate in steel with a carbon content of 1 mass%.
[図 22]昇温速度を考慮して固溶炭素濃度の計算開始温度を決定する方法を説明す るための図である。  FIG. 22 is a diagram for explaining a method of determining the calculation start temperature of the solute carbon concentration in consideration of the rate of temperature rise.
[図 23]焼戻後に所定の硬度を得るための焼戻温度 Tと焼戻時間 tとの関係を示す条 件線図である。  FIG. 23 is a condition diagram showing a relationship between a tempering temperature T and a tempering time t for obtaining a predetermined hardness after tempering.
圆 24]焼戻後の硬度の値を温度推移力も積算する方法を説明するための焼戻温度 と保持時間との関係を示す説明図である。 [24] FIG. 24 is an explanatory view showing the relationship between the tempering temperature and the holding time for explaining a method of integrating the hardness value after tempering with the temperature transition force.
圆 25]実施の形態 3における転がり軸受外輪の構成を示す概略断面図である。 圆 26]実施の形態 3における高周波焼入装置の構成を示す概略図である。 25] FIG. 25 is a schematic cross-sectional view showing a configuration of a rolling bearing outer ring in the third embodiment. [26] FIG. 26 is a schematic diagram showing the configuration of the induction hardening apparatus in the third embodiment.
[図 27]実施の形態 3における高周波焼入方法の概略を示す図である。  FIG. 27 is a diagram showing an outline of the induction hardening method in the third embodiment.
圆 28]実施の形態 4における高周波焼入装置の構成の概略を示す図である。 圆 28] This is a diagram showing an outline of the configuration of the induction hardening apparatus in the fourth embodiment.
[図 29]実施の形態 4における高周波焼入方法の概略を示す図である。  FIG. 29 is a diagram showing an outline of the induction hardening method in the fourth embodiment.
[図 30]実施の形態 4に係る高周波焼入の各工程におけるデータおよび指令の流れを 示す図である。 FIG. 30 shows the flow of data and commands in each process of induction hardening according to Embodiment 4. FIG.
[図 31]実施の形態 5の高周波熱処理方法に使用される高周波焼戻装置の構成を示 す概略図である。  FIG. 31 is a schematic diagram showing the configuration of an induction tempering apparatus used in the induction heat treatment method of Embodiment 5.
[図 32]実施の形態 5における高周波焼戻方法の概略を示す図である。  FIG. 32 shows an outline of the induction tempering method in the fifth embodiment.
[図 33]実施の形態 6における高周波焼戻装置の構成の概略を示す図である。  FIG. 33 is a diagram showing a schematic configuration of an induction tempering apparatus according to Embodiment 6.
[図 34]実施の形態 6における高周波焼戻方法の概略を示す図である。  FIG. 34 shows an outline of the induction tempering method in the sixth embodiment.
[図 35]実施の形態 6に係る高周波焼戻の各工程におけるデータおよび指令の流れを 示す図である。  FIG. 35 is a diagram showing the flow of data and instructions in each step of induction tempering according to the sixth embodiment.
[図 36 IS SUJ2製の転がり軸受外輪を加熱した場合の試験結果を示す図である。  [FIG. 36 is a diagram showing test results when the outer ring of a rolling bearing made of IS SUJ2 is heated.
[図 37 IS SUS440C製の転がり軸受外輪を加熱した場合の試験結果を示す図で ある。 [FIG. 37 is a diagram showing test results when a rolling bearing outer ring made of IS SUS440C is heated.
[図 38 IS SUS440C製の転がり軸受外輪に黒体塗料を表面に塗布した後、加熱 した場合の試験結果を示す図である。  [FIG. 38 is a diagram showing test results when a black body paint is applied to the surface of an IS SUS440C rolling bearing outer ring and then heated.
符号の説明 Explanation of symbols
1, 201, 301 転がり軸受外輪 (被処理物）、 1A, 201A, 301A 外周面、 1B, 20 IB, 301B 内周面、 1C, 201C, 301C 転走面、 2, 302, 312 カロ熱装置、 3, 30 3, 313 第 1放射温度計、 4, 304, 314 温度調節装置、 5, 305, 315 第 2放射 温度計、 6, 306, 316 冷却タイミング調節装置、 7 冷却装置、 10 高周波焼入方 法、 20, 320 温度制御工程、 22, 322 カロ熱工程、 23, 323 温度制御用測温工 程、 24, 324 温度調節工程、 30, 330 焼入制御工程、 35, 335 焼入用測温ェ 程、 36, 336 冷却タイミング調節工程、 37, 337 冷却工程、 50, 350, 351 温度 制御装置、 60, 360 焼入制御装置、 90, 293, 391, 392 高周波焼入装置、 202 焼入加熱装置、 203 焼入温度制御用測温装置、 204 焼入温度調節装置、 205 焼入タイミング制御用測温装置、 206 焼入タイミング調節装置、 207 焼入用冷却 装置、 207A 被処理物保持台、 207B 油槽、 212 焼戻加熱装置、 213 焼戻温 度制御用測温装置、 214 焼戻温度調節装置、 215 焼戻終了タイミング制御用測 温装置、 216 焼戻終了タイミング調節装置、 217 焼戻終了装置、 250 焼入温度 制御装置、 251 焼戻温度制御装置、 260 焼入タイミング制御装置、 261 焼戻終 了タイミング制御装置、 270 焼入用記憶装置、 271 焼戻用記憶装置、 291 被処 理物保持装置、 292 被処理物確認装置、 294 洗浄装置、 295, 393, 394 高周 波焼戻装置、 296 熱処理品保持装置、 299A, 299B, 299C, 299D, 299E 搬 送装置、 307, 317 冷却液噴射装置、 309 安定化層、 310 焼入硬化工程、 311 表面安定化工程、 361 焼戻制御装置、 370, 371 記憶装置、 410 焼戻工程、 420 温度制御工程、 422 加熱工程、 423 温度制御用測温工程、 424 温度調 節工程、 430 焼戻制御工程、 435 焼戻用測温工程、 436 冷却タイミング調節ェ 程、 437 冷却工程。 1, 201, 301 Rolling bearing outer ring (processed object), 1A, 201A, 301A outer peripheral surface, 1B, 20 IB, 301B inner peripheral surface, 1C, 201C, 301C rolling surface, 2, 302, 312 3, 30 3, 313 First radiation thermometer, 4, 304, 314 Temperature control device, 5, 305, 315 Second radiation thermometer, 6, 306, 316 Cooling timing control device, 7 Cooling device, 10 Induction hardening Method, 20, 320 Temperature control process, 22, 322 Caro heat process, 23, 323 Temperature control process for temperature control, 24, 324 Temperature control process, 30, 330 Quenching control process, 35, 335 Quenching measurement Temperature, 36, 336 Cooling timing adjustment process, 37, 337 Cooling process, 50, 350, 351 Temperature control device, 60, 360 Quenching control device, 90, 293, 391, 392 Induction quenching device, 202 Quenching Heating device, 203 Temperature measuring device for quenching temperature control, 204 Quenching temperature adjusting device, 205 Temperature measuring device for quenching timing control, 206 Quenching timing adjusting device, 207 Quenching cooling device, 207A Workpiece holder , 207B Tank, 212 Tempering heating device, 213 Temperature measuring device for tempering temperature control, 214 Tempering temperature adjusting device, 215 Temperature measuring device for tempering end timing control, 216 Tempering end timing adjusting device, 217 Tempering end device , 250 Quenching temperature control device, 251 Tempering temperature control device, 260 Quenching timing control device, 261 Tempering end 270 Timing storage device, 270 Quenching storage device, 271 Tempering storage device, 291 Workpiece holding device, 292 Workpiece confirmation device, 294 Cleaning device, 295, 393, 394 High frequency tempering device, 296 Heat treatment product holding device, 299A, 299B, 299C, 299D, 299E Transport device, 307, 317 Coolant injection device, 309 Stabilization layer, 310 Quenching and curing process, 311 Surface stabilization process, 361 Tempering control device, 370, 371 Storage device, 410 Tempering process, 420 Temperature control process, 422 Heating process, 423 Temperature control process for temperature control, 424 Temperature adjustment process, 430 Tempering control process, 435 Tempering process for tempering, 436 Cooling Timing adjustment process, 437 cooling process.
発明を実施するための最良の形態  BEST MODE FOR CARRYING OUT THE INVENTION
[0083] 以下、図面に基づいて本発明の実施の形態を説明する。なお、以下の図面におい て同一または相当する部分には同一の参照番号を付しその説明は繰返さない。  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference numerals, and the description thereof will not be repeated.
[0084] (実施の形態 1)  [0084] (Embodiment 1)
図 1を参照して、本実施の形態における転がり軸受外輪の構成を説明する。  With reference to FIG. 1, the configuration of the rolling bearing outer ring in the present embodiment will be described.
[0085] 図 1を参照して、本実施の形態における高周波焼入品としての転がり軸受外輪 1は 、円環状の形状を有している。そして、転がり軸受外輪 1は、内周面 1Bに転動体とし ての玉、ころなどが接触しつつ転走するための転走面 1Cが形成されているとともに、 他の部材と接触して転がり軸受外輪を当該他の部材に対して保持する外周面 1Aを 有している。ここで、転がり軸受外輪 1は転動疲労寿命および剛性の観点から、 58H RC以上の硬度を有していることが好ましい。また、寸法安定性の観点から、残留ォ ーステナイト量は 12体積％以下に抑制されていることが好ましい。  Referring to FIG. 1, rolling bearing outer ring 1 as an induction hardened product in the present embodiment has an annular shape. The rolling bearing outer ring 1 is formed with a rolling surface 1C for rolling while the balls, rollers, etc. as rolling elements are in contact with the inner peripheral surface 1B, and in contact with other members to roll. It has an outer peripheral surface 1A for holding the bearing outer ring against the other members. Here, the rolling bearing outer ring 1 preferably has a hardness of 58H RC or more from the viewpoint of rolling fatigue life and rigidity. From the viewpoint of dimensional stability, the amount of retained austenite is preferably suppressed to 12% by volume or less.
[0086] そして、転がり軸受外輪 1は、以下に説明する本発明の実施の形態 1における高周 波焼入装置を用い、本発明の実施の形態 1における高周波焼入方法で熱処理され て作製されているため、製造コストが抑制され、かつ品質の安定した高周波焼入品と なっている。  [0086] Then, the rolling bearing outer ring 1 is manufactured by heat treatment by the induction hardening method in the first embodiment of the present invention using the high-frequency quenching apparatus in the first embodiment of the present invention described below. Therefore, it is an induction-hardened product with reduced manufacturing costs and stable quality.
[0087] 次に、本発明の実施の形態 1における高周波焼入装置について説明する。  Next, the induction hardening apparatus according to Embodiment 1 of the present invention will be described.
図 2を参照して、本実施の形態における高周波焼入装置 90は、高周波加熱により 被処理物としての転がり軸受外輪 1の全体を加熱して焼入硬化する高周波焼入方法 に使用される高周波焼入装置であって、転がり軸受外輪 1の温度を調節するための 温度制御装置 50と、加熱された転がり軸受外輪 1が冷却されるべきタイミングを調節 するための焼入制御装置 60とを備えている。 Referring to FIG. 2, the induction hardening apparatus 90 in this embodiment is an induction hardening method used in an induction hardening method for heating and hardening the entire rolling bearing outer ring 1 as a workpiece by induction heating. A quenching device for adjusting the temperature of the rolling bearing outer ring 1 A temperature control device 50 and a quenching control device 60 for adjusting the timing at which the heated rolling bearing outer ring 1 is to be cooled are provided.
[0088] 温度制御装置 50は、転がり軸受外輪 1の温度データを取得し、転がり軸受外輪 1の 温度データに基づく温度の情報を出力する温度制御用測温装置としての第 1放射温 度計 3と、第 1放射温度計 3に接続され、第 1放射温度計 3からの温度の情報に基づ き転がり軸受外輪 1の加熱状態を制御するための温度制御信号を出力する温度調 節装置 4と、温度調節装置 4に接続され、温度調節装置 4からの温度制御信号に基 づき、高周波加熱により転がり軸受外輪 1を加熱する加熱装置 2とを含んでいる。  [0088] The temperature control device 50 acquires temperature data of the rolling bearing outer ring 1, and outputs a temperature information based on the temperature data of the rolling bearing outer ring 1, and the first radiation thermometer 3 as a temperature control temperature measuring device 3 A temperature control device 4 connected to the first radiation thermometer 3 and outputting a temperature control signal for controlling the heating state of the rolling bearing outer ring 1 based on the temperature information from the first radiation thermometer 3. And a heating device 2 that is connected to the temperature control device 4 and heats the rolling bearing outer ring 1 by high-frequency heating based on a temperature control signal from the temperature control device 4.
[0089] 焼入制御装置 60は、転がり軸受外輪 1の高温部である外周面 1A (誘導コイルに対 向する面）および低温部である内周面 1B (誘導コイルに対向する面の裏側）のそれ ぞれの温度データを取得し、転がり軸受外輪 1の温度データに基づく温度の情報を 出力する焼入用測温装置としての第 1放射温度計 3および第 2放射温度計 5と、第 1 放射温度計 3および第 2放射温度計 5に接続され、第 1放射温度計 3および第 2放射 温度計 5からの温度の情報に基づき加熱時間を調節し、転がり軸受外輪 1が冷却さ れるべきタイミングを決定して冷却開始信号を出力する冷却タイミング調節装置 6と、 冷却タイミング調節装置 6に接続され、冷却開始信号に基づいて、転がり軸受外輪 1 を冷却することにより転がり軸受外輪 1を焼入硬化する冷却装置 7とを含んでいる。冷 却装置 7は、たとえば冷却液を転がり軸受外輪 1に噴射することにより冷却する、焼入 液噴出装置である。  [0089] The quenching control device 60 includes an outer peripheral surface 1A (surface facing the induction coil) which is the high temperature portion of the rolling bearing outer ring 1 and an inner peripheral surface 1B (back side of the surface facing the induction coil) which is the low temperature portion. The first radiation thermometer 3 and the second radiation thermometer 5 are used as temperature measuring devices for quenching, which acquire temperature data of each of them and output temperature information based on the temperature data of the rolling bearing outer ring 1. 1 Connected to radiation thermometer 3 and 2nd radiation thermometer 5, adjusts heating time based on temperature information from 1st radiation thermometer 3 and 2nd radiation thermometer 5, and cools rolling bearing outer ring 1 A cooling timing adjusting device 6 for determining a timing to be output and outputting a cooling start signal; and connected to the cooling timing adjusting device 6; Including a cooling device 7 to cure and harden That. The cooling device 7 is a quenching liquid ejecting device that cools, for example, by injecting a cooling liquid onto the rolling bearing outer ring 1.
[0090] ここで、第 1放射温度計 3は、温度制御用測温装置と焼入制御用測温装置とを兼ね て設置されている。また、温度調節装置 4および冷却タイミング調節装置 6は、たとえ ばそれぞれパーソナルコンピュータであり、 1台のパーソナルコンピュータで温度調 節装置 4と冷却タイミング調節装置 6とを兼ねる構成であってもよい。  Here, the first radiation thermometer 3 is installed as both a temperature control temperature measuring device and a quenching control temperature measuring device. Further, the temperature adjustment device 4 and the cooling timing adjustment device 6 are each a personal computer, for example, and one personal computer may serve as both the temperature adjustment device 4 and the cooling timing adjustment device 6.
[0091] なお、温度制御用測温装置および焼入用測温装置に用いる測温装置の種類は、 上述のように放射温度計でもよいが、装置のレイアウト上可能であるならば熱電対な どの接触式温度計でもよ 、。  [0091] The type of the temperature measuring device used for the temperature controlling temperature measuring device and the quenching temperature measuring device may be a radiation thermometer as described above, but if it is possible in the layout of the device, it is a thermocouple. Any contact thermometer.
[0092] 次に、上述の高周波焼入装置を用いた本発明の実施の形態 1における高周波焼 入方法について説明する。 [0093] 図 2および図 3を参照して、本実施の形態における高周波焼入方法 10は、高周波 加熱により被処理物 (転がり軸受外輪 1)の全体を加熱して焼入硬化する高周波焼入 方法であって、転がり軸受外輪 1の温度が温度制御装置 50により調節される温度制 御工程 20と、焼入制御装置 60により、加熱された転がり軸受外輪 1が冷却されるべ きタイミングが決定されて、転がり軸受外輪 1が冷却される焼入制御工程 30とを備え ている。 Next, the induction hardening method in Embodiment 1 of the present invention using the above-described induction hardening apparatus will be described. Referring to FIGS. 2 and 3, induction hardening method 10 in the present embodiment is an induction hardening in which the whole object to be treated (rolling bearing outer ring 1) is heated and hardened by induction heating. The temperature control step 20 in which the temperature of the rolling bearing outer ring 1 is adjusted by the temperature control device 50 and the timing at which the heated rolling bearing outer ring 1 should be cooled are determined by the quenching control device 60. And a quenching control step 30 in which the rolling bearing outer ring 1 is cooled.
[0094] 温度制御工程 20は、転がり軸受外輪 1の温度が、第 1放射温度計 3により測定され る温度制御用測温工程 23と、温度調節装置 4により、温度制御用測温工程 23にお いて測定された温度の情報に基づき、転がり軸受外輪 1の加熱状態を制御するため の温度制御信号が出力される温度調節工程 24と、加熱装置 2を用いて、温度制御 信号に基づいて、高周波加熱により転がり軸受外輪 1が加熱される加熱工程 22とを 含んでいる。  [0094] The temperature control step 20 includes a temperature control temperature measurement step 23 in which the temperature of the outer ring 1 of the rolling bearing is measured by the first radiation thermometer 3, and a temperature control temperature measurement step 23 by the temperature control device 4. Then, based on the measured temperature information, the temperature adjustment process 24 in which a temperature control signal for controlling the heating state of the rolling bearing outer ring 1 is output, and the heating device 2 is used, based on the temperature control signal, And a heating step 22 in which the rolling bearing outer ring 1 is heated by high frequency heating.
[0095] 焼入制御工程 30は、焼入用測温工程 35と、冷却タイミング調節工程 36と、冷却ェ 程 37とを含んでいる。焼入用測温工程 35においては、転がり軸受外輪 1において、 高周波加熱による温度の上昇が転がり軸受外輪 1にお 、て最も大き 、表面の部位で ある高温部としての外周面 1Aと、高周波加熱による温度の上昇が転がり軸受外輪 1 において最も小さい表面の部位である低温部としての内周面 1Bとの温度力 それぞ れ第 1放射温度計 3と第 2放射温度計 5とにより測定される。冷却タイミング調節工程 36においては、冷却タイミング調節装置 6により、焼入用測温工程 35において測定 された温度の情報に基づき加熱時間が調節され、転がり軸受外輪 1が冷却されるべ きタイミングが決定されて冷却開始信号が出力される。冷却工程 37においては、冷 却装置 7により、冷却開始信号に基づいて、転がり軸受外輪 1が A点以上の温度域 力 M点以下の温度域に冷却されることにより、転がり軸受外輪 1が焼入硬化される The quench control process 30 includes a quenching temperature measurement process 35, a cooling timing adjustment process 36, and a cooling process 37. In the temperature measurement process 35 for quenching, in the outer ring 1 of the rolling bearing, the temperature rise due to high-frequency heating is the largest in the outer ring 1 of the rolling bearing, and the outer peripheral surface 1A as a high-temperature part, which is the surface portion, and the high-frequency heating. The temperature rise due to the temperature is measured by the first radiation thermometer 3 and the second radiation thermometer 5, respectively, with the inner peripheral surface 1B as the low temperature part, which is the smallest surface portion of the rolling bearing outer ring 1. . In the cooling timing adjustment step 36, the cooling timing adjustment device 6 adjusts the heating time based on the temperature information measured in the quenching temperature measurement step 35, and determines when the rolling bearing outer ring 1 should be cooled. Then, a cooling start signal is output. In the cooling process 37, the cooling device 7 cools the rolling bearing outer ring 1 to a temperature range that is not less than the point A and not higher than the point M based on the cooling start signal. Hardened
S S
[0096] そして、冷却タイミング調節工程 36においては、外周面 1Aにおける温度およびカロ 熱時間を含む温度履歴力 予め求められた所望の残留オーステナイト量の上限値以 下の残留オーステナイト量が得られる温度履歴 (加熱開始後の各時間における温度 の実績)の条件を満たし、内周面 1Bにおける温度および加熱時間を含む温度履歴 力 予め求められた所望の硬度の下限値以上の硬度が得られる温度履歴の条件を 満たすように加熱時間が調節されて、冷却開始信号が出力される。具体的には、加 熱時間の調節は、予め求められた所望の硬度を得るための加熱時間と加熱温度との 関係を示す条件式、および所望の残留オーステナイト量を得るための加熱時間とカロ 熱温度との関係を示す条件式に基づいて、実施される。 [0096] Then, in the cooling timing adjustment step 36, the temperature history force including the temperature on the outer peripheral surface 1A and the calorie heat time. The temperature history at which the amount of retained austenite less than the upper limit of the desired amount of retained austenite obtained in advance is obtained. Temperature history including the temperature and heating time on the inner peripheral surface 1B, satisfying the condition of (temperature results at each time after heating starts) Force The heating time is adjusted so as to satisfy the condition of temperature history for obtaining a hardness equal to or higher than the lower limit of the desired hardness obtained in advance, and a cooling start signal is output. Specifically, the adjustment of the heating time includes the conditional expression showing the relationship between the heating time and the heating temperature for obtaining the desired hardness obtained in advance, and the heating time and calorie for obtaining the desired amount of retained austenite. This is implemented based on a conditional expression showing a relationship with the heat temperature.
[0097] 本実施の形態における高周波焼入装置を用いて、本実施の形態における高周波 焼入方法を実施することにより、温度制御が可能となり、熱処理の条件出しを容易に 行なうことができるため、過去の生産実績の蓄積が少ない場合や、経験の浅い作業 者が熱処理の作業を行なう場合でも、容易にかつ効率よく焼入硬化処理を実施する ことができるとともに、被処理物としての転がり軸受外輪 1の広い範囲に所望の硬度 や残留オーステナイト量などの熱処理品質を付与することができる。  [0097] By performing the induction hardening method in the present embodiment using the induction hardening apparatus in the present embodiment, the temperature can be controlled and the conditions for the heat treatment can be easily determined. Quenching and hardening can be performed easily and efficiently, even when there is little accumulation of past production results, or when inexperienced workers perform heat treatment work, and rolling bearing outer rings as workpieces Heat treatment quality such as desired hardness and retained austenite amount can be imparted to a wide range of 1.
[0098] なお、 A点とは鋼を加熱した場合に、鋼の組織がフェライトからオーステナイトに変 態を開始する温度に相当する点をいう。また、 M  [0098] Note that the point A is a point corresponding to a temperature at which the steel structure starts transformation from ferrite to austenite when the steel is heated. M
S点とはオーステナイトィ匕した鋼が冷 却される際に、マルテンサイトイ匕を開始する温度に相当する点をいう。  The S point refers to the point corresponding to the temperature at which martensite cracking starts when austenitic steel is cooled.
[0099] 次に、本実施の形態における高周波焼入装置 90を用いた本実施の形態における 高周波焼入方法 10、特に冷却タイミング調節工程 36の具体的手順について、素材 として JIS SUJ2を採用した場合を例に詳細に説明する。  [0099] Next, in the case of adopting JIS SUJ2 as a material for the specific procedure of the induction hardening method 10 in this embodiment using the induction hardening apparatus 90 in this embodiment, particularly the cooling timing adjustment step 36 Is described in detail as an example.
[0100] 冷却タイミング調節工程 36は、たとえば以下のように TTA (Time Temperature Austinitization)線図を作成し、当該 TTA線図における条件式に基づ！/ヽて加熱時 間を調節することにより実施することができる。  [0100] In the cooling timing adjustment step 36, for example, a TTA (Time Temperature Austinitization) diagram is created as shown below and based on the conditional expression in the TTA diagram! This can be done by adjusting the heating time.
[0101] 図 4を参照して、 TTA線図の作製方法を説明する。  [0101] A method for producing a TTA diagram will be described with reference to FIG.
図 4を参照して、たとえば、均一な加熱および冷却が可能な SUJ2製の小型の試験 片（6206型番玉軸受外輪、外径 φ 62mm,内径 φ 52mm,厚み tl6mmのリング状 )に対して、種々の昇温速度で加熱し、種々の時間経過後に急冷することにより、焼 入を実施し、さらに、 180°Cで 120分間保持することにより、当該試験片に焼戻を実 施する。そして、各試験片の残留オーステナイト量および硬度を測定する。試験片の 硬度は、たとえば熱処理後の被処理物の一部を研磨し、当該研磨面の硬度をロック ゥエル硬度計、ビッカース硬度計などの硬度計により測定して得ることができる。また 、残留オーステナイト量は、たとえば熱処理後の試験片を電解研磨し、 X線回折計（ XRD)を用いて、当該研磨面のマノレテンサイト α (211)面とオーステナイト γ (220) 面との回折強度とを測定することにより、算出することができる。 Referring to Fig. 4, for example, for a small test piece made of SUJ2 capable of uniform heating and cooling (6206 model ball bearing outer ring, outer ring φ 62mm, inner diameter φ 52mm, thickness tl6mm ring shape) Quenching is performed by heating at various heating rates and quenching after various times, and further tempering the specimen by holding at 180 ° C for 120 minutes. Then, the amount of retained austenite and the hardness of each test piece are measured. The hardness of the test piece can be obtained, for example, by polishing a part of the workpiece after the heat treatment and measuring the hardness of the polished surface with a hardness meter such as a Rockwell hardness meter or a Vickers hardness meter. Also The amount of retained austenite can be determined by, for example, electropolishing a test piece after heat treatment, and using an X-ray diffractometer (XRD) to diffract the polished surface from the manoletensite α (211) surface and the austenite γ (220) surface. It can be calculated by measuring the intensity.
[0102] 図 4には、昇温速度約 311°CZ秒 (一点鎖線）、約 65°CZ秒 (破線)および約 20°C Z秒 (実線)の場合の試験片の加熱履歴が示されている。そして、昇温速度 311°C Z秒の場合、硬度が 58HRCとなった点が a 、残留オーステナイト量が 12体積％と なった点が α で示されている。同様に、約 65°CZ秒の場合の硬度が 58HRCとなつ [0102] Fig. 4 shows the heating history of the specimen when the heating rate is about 311 ° CZ seconds (dashed line), about 65 ° CZ seconds (dashed line), and about 20 ° CZ seconds (solid line). Yes. When the heating rate is 311 ° C for Z seconds, the point at which the hardness is 58HRC is indicated by a, and the point at which the amount of retained austenite is 12% by volume is indicated by α. Similarly, the hardness at about 65 ° CZ seconds is 58HRC.
2  2
た点、および残留オーステナイト量が 12体積％となった点がそれぞれ |8 および |8 、  And 8% of retained austenite is 12% by volume,
1 2 約 20°CZ秒の場合の硬度が 58HRCとなった点、および残留オーステナイト量が 12 体積％となった点がそれぞれ γ および γ として、記載されている。このような実験を  1 2 The points where the hardness at about 20 ° CZ seconds was 58HRC and the residual austenite amount was 12% by volume are described as γ and γ, respectively. Such an experiment
1 2  1 2
種々の昇温速度で実施し、 58HRCとなった点、および残留オーステナイト量が 12体 積％となった点を、それぞれたとえば指数関数でフィッティングして硬度： 58HRCを 示す曲線、および残留オーステナイト量 12体積％を示す曲線を算出する。そして、 当該曲線を作図することにより、 ΤΤΑ線図が完成する。この ΤΤΑ線図は、形状に関 係なく素材により決定されるため、被処理物の形状が変更されても、素材が同種であ る限り、使用することができる。  The points where the temperature reached 58HRC and the amount of retained austenite reached 12 volume% were fitted with an exponential function, for example, and a curve showing hardness: 58HRC and the amount of retained austenite 12 A curve showing volume% is calculated. Then, draw the curve to complete the shoreline diagram. Since this X-ray diagram is determined by the material regardless of the shape, it can be used as long as the material is the same, even if the shape of the workpiece is changed.
[0103] 次に、当該 ΤΤΑ線図を用いた冷却タイミング調節工程 36の実施方法について説 明する。図 5において、横軸は加熱開始からの経過時間、縦軸は温度を示している。 また、図 5には、高周波加熱中の転がり軸受外輪 1の高温部（外周面 1A)および低温 部（内周面 1B)の測温結果が合わせて示されて 、る。  [0103] Next, a method of performing the cooling timing adjustment step 36 using the X-ray diagram will be described. In FIG. 5, the horizontal axis represents the elapsed time from the start of heating, and the vertical axis represents the temperature. FIG. 5 also shows the temperature measurement results of the high temperature part (outer peripheral surface 1A) and the low temperature part (inner peripheral surface 1B) of the rolling bearing outer ring 1 during high frequency heating.
[0104] 図 5を参照して、硬度： 58HRCの曲線は、当該曲線よりも高温側では 58HRC以上 の硬度となっていることを示しており、算出された曲線の式は  [0104] Referring to FIG. 5, the hardness: 58HRC curve shows that the hardness is 58HRC or higher on the higher temperature side than the curve, and the calculated curve formula is
温度 Τ =0. 02exp (9. 2823t"a 05) + 790 · · · (1) Temperature = 0 = 0. 02exp (9. 2823t " a 05 ) + 790 (1)
H  H
である。また、残留オーステナイト量： 12体積％の曲線は、当該曲線よりも低温側で は 12体積％以下の残留オーステナイト量となっていることを示しており、算出された 曲線の式は  It is. In addition, the curve of residual austenite: 12% by volume shows that the amount of residual austenite is 12% by volume or less on the lower temperature side than the curve, and the calculated curve formula is
温度 T = 8. 06 X 10"18exp (45t"a 01) + 860 · · · (2) Temperature T = 8. 06 X 10 " 18 exp (45t" a 01 ) + 860 (2)
である。 [0105] 冷却タイミング調節工程 36においては、加熱が開始されると各時間においてリアル タイムに高温部（外周面 1A)の温度が式（2)の T と比較され、高温部の温度が T よ りも低いことが確認される。一方、同時に低温部（内周面 1B)の温度が式（1)の Tと It is. [0105] In the cooling timing adjustment step 36, when heating is started, the temperature of the high temperature part (outer peripheral surface 1A) is compared with T in the equation (2) in real time at each time, and the temperature of the high temperature part is equal to T. It is confirmed that it is low. On the other hand, at the same time, the temperature of the low temperature part (inner peripheral surface 1B)
H  H
比較され、 τよりも大きくなつた時間帯に冷却開始信号が出力され、被処理物 (転が  Compared, a cooling start signal is output during a time period greater than τ, and the workpiece (rolling
H  H
り軸受外輪 1)が冷却されることにより、焼入硬化される。  The outer ring 1) is cooled and hardened by cooling.
[0106] すなわち、図 5を参照して、時間 tにおいては、低温部（内周面 1B)の温度が硬度： 58HRCの曲線よりも低温側にあるため、加熱が不足している。また、時間 tにおいて That is, referring to FIG. 5, at time t, since the temperature of the low temperature portion (inner peripheral surface 1B) is on the low temperature side of the curve of hardness: 58HRC, heating is insufficient. Also at time t
3 は、高温部（外周面 1A)の温度が残留オーステナイト量： 12体積％の曲線よりも高温 側となっているため、加熱が過剰となっている。一方、時間 tにおいては、低温部（内  3 is overheated because the temperature of the high temperature part (outer peripheral surface 1A) is higher than the curve of residual austenite: 12% by volume. On the other hand, at time t,
2  2
周面 1B)の温度が硬度： 58HRCの曲線よりも高温側にあり、かつ高温部（外周面 1A )の温度が残留オーステナイト量： 12体積％の曲線よりも低温側となっているため、こ の時点で冷却開始信号を出力し、冷却を開始することで、被処理物全体が硬度 58H RCかつ残留オーステナイト量 12体積％以下の条件を満たす焼入を実施することが できる。  This is because the temperature of peripheral surface 1B) is higher than the curve of hardness: 58HRC, and the temperature of the hot part (outer peripheral surface 1A) is lower than the curve of residual austenite content: 12% by volume. When the cooling start signal is output at this point in time and the cooling is started, the entire workpiece can be hardened with a hardness of 58H RC and a residual austenite amount of 12% by volume or less.
[0107] (実施の形態 2)  [Embodiment 2]
図 6を参照して、本実施の形態における転がり軸受外輪の構成を説明する。  The configuration of the rolling bearing outer ring in the present embodiment will be described with reference to FIG.
[0108] 図 6を参照して、本実施の形態における高周波熱処理品としての転がり軸受外輪 2 01は、円環状の形状を有している。そして、転がり軸受外輪 201は、内周面 201Bに 転動体としての玉、ころなどが接触しつつ転走するための転走面 201Cが形成されて いるとともに、他の部材と接触して転がり軸受外輪を当該他の部材に対して保持する 外周面 201 Aを有している。ここで、転がり軸受外輪 201は転動疲労強度および剛性 の観点から、 58HRC以上の硬度を有していることが好ましい。また、寸法安定性の 観点から、残留オーステナイト量は 12体積％以下に抑制されていることが好ましい。  Referring to FIG. 6, rolling bearing outer ring 201 as the high frequency heat treatment product in the present embodiment has an annular shape. The rolling bearing outer ring 201 is formed with a rolling surface 201C for rolling while the balls, rollers, and the like as rolling elements are in contact with the inner peripheral surface 201B, and in contact with other members, the rolling bearing It has an outer peripheral surface 201 A that holds the outer ring against the other members. Here, the rolling bearing outer ring 201 preferably has a hardness of 58 HRC or more from the viewpoint of rolling fatigue strength and rigidity. From the viewpoint of dimensional stability, the amount of retained austenite is preferably suppressed to 12% by volume or less.
[0109] そして、転がり軸受外輪 201は、以下に説明する本発明の実施の形態 2における高 周波熱処理設備で熱処理されて作製されているため、製造コストが抑制され、かつ 品質の安定した高周波熱処理品となっている。  [0109] Since the rolling bearing outer ring 201 is manufactured by heat treatment using the high-frequency heat treatment equipment in Embodiment 2 of the present invention described below, the production cost is suppressed, and high-frequency heat treatment with stable quality is achieved. It is a product.
[0110] 次に、図 7〜図 9を参照して、本実施の形態における高周波熱処理設備について 説明する。 [0111] 図 7を参照して、本実施の形態の高周波熱処理設備は、高周波加熱により被処理 物（たとえば、転がり軸受外輪 201)を加熱して熱処理するための高周波熱処理設備 であって、被処理物保持装置 291と、被処理物確認装置 292と、高周波焼入装置 29 3と、洗浄装置 294と、高周波焼戻装置 295と、熱処理品保持装置 296とを備えてい る。また、当該装置は、上記の順に、コンベアやロボットアームなどの搬送装置 299A 、 299B、 299C、 299D、 299E【こより連結されて!ヽる。 [0110] Next, with reference to Figs. 7 to 9, the high frequency heat treatment equipment in the present embodiment will be described. Referring to FIG. 7, the induction heat treatment equipment of the present embodiment is an induction heat treatment equipment for heating an object to be treated (for example, rolling bearing outer ring 201) by high frequency heating, A workpiece holding device 291, a workpiece confirmation device 292, an induction hardening device 293, a cleaning device 294, an induction tempering device 295, and a heat treatment product holding device 296 are provided. In addition, the apparatus is connected in this order from the conveyors 299A, 299B, 299C, 299D, and 299E.
[0112] 被処理物保持装置 291は、たとえば被処理物である転がり軸受外輪 201を保持す るバスケットを含んでおり、熱処理前の転がり軸受外輪 201を保持する機能を有して いる。被処理物確認装置 292は、たとえば転がり軸受外輪 201の形状を測定する形 状判別装置を含んでおり、被処理物保持装置 291から搬送装置 299Aにより搬送さ れた転がり軸受外輪 201の外径寸法、幅などを測定することにより、異品の混入が無 いことを確認する機能を有している。高周波焼入装置 293は、たとえば誘導コイル、 高周波電源、焼入用油槽などを含んでおり、搬送装置 299Bにより搬送された転がり 軸受外輪 201を、高周波加熱により加熱して焼入硬化する機能を有している。  [0112] The workpiece holding device 291 includes, for example, a basket that holds a rolling bearing outer ring 201 that is a workpiece, and has a function of holding the rolling bearing outer ring 201 before heat treatment. The workpiece confirmation device 292 includes, for example, a shape discriminating device for measuring the shape of the rolling bearing outer ring 201, and the outer diameter size of the rolling bearing outer ring 201 conveyed from the workpiece holding device 291 by the conveying device 299A. It has a function to confirm that there is no contamination by measuring the width, etc. The induction hardening device 293 includes, for example, an induction coil, a high frequency power source, a quenching oil tank, etc., and has a function of heating and hardening the rolling bearing outer ring 201 conveyed by the conveying device 299B by high frequency heating. is doing.
[0113] 洗浄装置 294は、洗浄液を溜めるための洗浄槽、洗浄後の転がり軸受外輪 201を 乾燥させるための乾燥装置などを含んでおり、搬送装置 299Cにより搬送された転が り軸受外輪 201を洗浄することにより、焼入硬化処理において転がり軸受外輪 201の 表面に付着した焼入油などの付着物を除去する機能を有している。高周波焼戻装置 295は、洗浄装置 294および搬送装置 299C、 299Dを介して高周波焼入装置 293 に接続され、高周波焼入装置 293において焼入硬化され、搬送装置 299C、 299D により搬送された転がり軸受外輪 201を、高周波加熱により加熱して焼戻す機能を有 している。熱処理品保持装置 296は、たとえば転がり軸受外輪 201を保持するバスケ ットを含んでおり、焼入焼戻が終了した熱処理品を保持する機能を有している。  [0113] Cleaning device 294 includes a cleaning tank for storing cleaning liquid, a drying device for drying rolling bearing outer ring 201 after cleaning, and the like. By cleaning, it has a function of removing deposits such as quenching oil adhering to the surface of the rolling bearing outer ring 201 in the quench hardening process. The induction tempering apparatus 295 is connected to the induction hardening apparatus 293 via the cleaning apparatus 294 and the conveying apparatuses 299C and 299D, and is hardened and hardened in the induction hardening apparatus 293, and is a rolling bearing conveyed by the conveying apparatuses 299C and 299D. The outer ring 201 has a function of heating and tempering by high frequency heating. The heat-treated product holding device 296 includes, for example, a basket that holds the rolling bearing outer ring 201, and has a function of holding the heat-treated product after quenching and tempering.
[0114] 次に、高周波焼入装置 293の構成について詳細に説明する。図 8を参照して、高 周波焼入装置 293は、被処理物である転がり軸受外輪 201の温度を調節するため の焼入温度制御装置 250と、加熱された転がり軸受外輪 201が冷却されるべきタイミ ングを調節するための焼入タイミング制御装置 260と、焼入温度制御装置 250にお いて、転がり軸受外輪 201を加熱するために焼入用電源から焼入用誘導コイルに出 力される電源出力の推移データである焼入用出力推移データと、焼入タイミング制御 装置 260において、転がり軸受外輪 201が冷却されるタイミングを特定するための焼 入用冷却タイミングデータとを焼入プロセスデータとして記憶する焼入用記憶装置 27 0とを含んでいる。 [0114] Next, the configuration of the induction hardening apparatus 293 will be described in detail. Referring to FIG. 8, a high-frequency quenching device 293 cools the quenching temperature control device 250 for adjusting the temperature of the rolling bearing outer ring 201 that is the object to be processed, and the heated rolling bearing outer ring 201. In the quenching timing control device 260 for adjusting the power timing and the quenching temperature control device 250, the quenching power source is supplied from the quenching power source to the quenching induction coil to heat the rolling bearing outer ring 201. The quenching output transition data, which is the transition data of the power output that is applied, and the quenching cooling timing data for specifying the timing when the rolling bearing outer ring 201 is cooled in the quenching timing control device 260 are quenched. And a quenching storage device 270 which stores it as process data.
[0115] 焼入温度制御装置 250は、転がり軸受外輪 201の温度データを取得し、転がり軸 受外輪 201の温度データに基づく温度の情報を出力する焼入温度制御用測温装置 203と、焼入温度制御用測温装置 203に接続され、焼入温度制御用測温装置 203 力 の温度の情報に基づき転がり軸受外輪 201の加熱状態を制御するための焼入 温度制御信号を出力する焼入温度調節装置 204と、焼入温度調節装置 204に接続 され、焼入温度調節装置 204からの焼入温度制御信号基づき、高周波加熱により転 力 Sり軸受外輪 201を加熱する、焼入用電源および焼入用誘導コイルを含む焼入加熱 装置 202とを有している。  [0115] The quenching temperature control device 250 acquires the temperature data of the rolling bearing outer ring 201, outputs the temperature information based on the temperature data of the rolling bearing outer ring 201, and the quenching temperature control temperature measuring device 203. Quenching temperature control device 203 is connected to the quenching temperature control temperature measuring device 203 and outputs a quenching temperature control signal for controlling the heating state of the rolling bearing outer ring 201 based on the power temperature information. A quenching power source connected to the temperature control device 204 and the quenching temperature control device 204, which heats the rolling bearing outer ring 201 by high-frequency heating based on the quenching temperature control signal from the quenching temperature control device 204, and And a quenching heating device 202 including a quenching induction coil.
[0116] 焼入タイミング制御装置 260は、転がり軸受外輪 201の温度データを取得し、転が り軸受外輪 201の温度データに基づく温度の情報を出力する焼入タイミング制御用 測温装置 205と、焼入タイミング制御用測温装置 205に接続され、焼入タイミング制 御用測温装置 205からの温度の情報に基づき加熱時間を調節し、転がり軸受外輪 2 01が冷却されるべきタイミングを決定して焼入用冷却開始信号を出力する焼入タイミ ング調節装置 206と、焼入タイミング調節装置 206に接続され、冷却開始信号に基 づいて、転がり軸受外輪 201を冷却することにより転がり軸受外輪 201を焼入硬化す る焼入用冷却装置 207とを有している。焼入用冷却装置 207は、焼入用の油が溜め られている油槽 207Bと、被処理物である転がり軸受外輪 201を保持し、冷却開始信 号に基づいて移動または傾斜することにより、転がり軸受外輪 201を油槽 207Bに投 入する被処理物保持台 207Aとを有している。また、焼入用記憶装置 270は、焼入 加熱装置 202と、焼入温度調節装置 204と、焼入タイミング調節装置 206とに接続さ れている。  [0116] The quenching timing control device 260 acquires temperature data of the rolling bearing outer ring 201 and outputs temperature information based on the temperature data of the rolling bearing outer ring 201. It is connected to the quenching timing control temperature measuring device 205, adjusts the heating time based on the temperature information from the quenching timing control temperature measuring device 205, and determines the timing at which the rolling bearing outer ring 201 should be cooled. The quenching timing adjusting device 206 that outputs a quenching cooling start signal and the quenching timing adjusting device 206 are connected to the rolling bearing outer ring 201 by cooling the rolling bearing outer ring 201 based on the cooling start signal. And a quenching cooling device 207 for quench hardening. The quenching cooling device 207 holds an oil tank 207B in which quenching oil is stored and a rolling bearing outer ring 201 which is an object to be processed, and moves or tilts based on a cooling start signal to roll. A workpiece holding base 207A for feeding the bearing outer ring 201 into the oil tank 207B is provided. The quenching storage device 270 is connected to the quenching and heating device 202, the quenching temperature adjusting device 204, and the quenching timing adjusting device 206.
[0117] 一方、図 9を参照して、高周波焼戻装置 295は、被処理物である転がり軸受外輪 2 01の温度を調節するための焼戻温度制御装置 251と、加熱された転がり軸受外輪 2 01が冷却されるべきタイミングを調節するための焼戻終了タイミング制御装置 261と 、焼戻温度制御装置 251において、転がり軸受外輪 201を加熱するために高周波加 熱用の焼戻用電源力 焼戻用誘導コイルに出力される電源出力の推移データであ る焼戻用出力推移データと、焼戻終了タイミング制御装置 261において、転がり軸受 外輪 201が冷却されるタイミングを特定するための焼戻用冷却タイミングデータとを 焼戻プロセスデータとして記憶する焼戻用記憶装置 271とを含んでいる。 On the other hand, referring to FIG. 9, the induction tempering device 295 includes a tempering temperature control device 251 for adjusting the temperature of the rolling bearing outer ring 201 that is the object to be processed, and a heated rolling bearing outer ring. 2 Tempering end timing control device 261 for adjusting the timing at which 01 should be cooled In the tempering temperature control device 251, the tempering power for high-frequency heating to heat the rolling bearing outer ring 201 The tempering output transition that is the transition data of the power output output to the induction coil for tempering Tempering end timing control device 261 includes a tempering storage device 271 for storing tempering cooling timing data for specifying the timing at which the rolling bearing outer ring 201 is cooled as tempering process data. It is out.
[0118] 焼戻温度制御装置 251は、転がり軸受外輪 201の温度データを取得し、転がり軸 受外輪 201の温度データに基づく温度の情報を出力する焼戻温度制御用測温装置 213と、焼戻温度制御用測温装置 213に接続され、焼戻温度制御用測温装置 213 力 の温度の情報に基づき転がり軸受外輪 201の加熱状態を制御するための焼戻 温度制御信号を出力する焼戻温度調節装置 214と、焼戻温度調節装置 214に接続 され、焼戻温度調節装置 214からの焼戻温度制御信号基づき、高周波加熱により転 力 ^軸受外輪 201を加熱する、焼戻用電源および焼戻用誘導コイルを含む焼戻加熱 装置 212とを有している。  The tempering temperature control device 251 acquires temperature data of the rolling bearing outer ring 201, outputs temperature information based on the temperature data of the rolling bearing outer ring 201, and a tempering temperature control temperature measuring device 213. Tempering temperature control device 213 is connected to the tempering temperature control temperature sensor 213 and outputs a tempering temperature control signal for controlling the heating state of the rolling bearing outer ring 201 based on the temperature information of the tempering temperature control 213. A temperature control device 214 and a tempering power supply and a tempering device connected to the tempering temperature control device 214 and heating the bearing outer ring 201 by high frequency heating based on a tempering temperature control signal from the tempering temperature control device 214. And a tempering heating device 212 including a return induction coil.
[0119] 焼戻終了タイミング制御装置 261は、転がり軸受外輪 201の温度データを取得し、 転がり軸受外輪 201の温度データに基づく温度の情報を出力する焼戻終了タイミン グ制御用測温装置 215と、焼戻終了タイミング制御用測温装置 215に接続され、焼 戻終了タイミング制御用測温装置 215からの温度の情報に基づき加熱時間を調節し 、転がり軸受外輪 201が冷却されるべきタイミングを決定して焼戻用冷却開始信号を 出力する焼戻終了タイミング調節装置 216と、焼戻終了タイミング調節装置 216に接 続され、焼戻用冷却開始信号に基づいて、転がり軸受外輪 201を冷却することにより 転がり軸受外輪 201の焼戻を終了させる焼戻終了装置 217とを有している。焼戻終 了装置 217は、たとえば転がり軸受外輪 201を保持し、焼戻用冷却開始信号に基づ いて移動することにより、転がり軸受外輪 201を焼戻用誘導コイルによる加熱範囲か ら離脱させる機能を有する被処理物保持台を有している。また、焼戻用記憶装置 27 1は、焼戻加熱装置 212と、焼戻温度調節装置 214と、焼戻終了タイミング調節装置 216とに接続されている。  A tempering end timing control device 261 obtains temperature data of the rolling bearing outer ring 201 and outputs temperature information based on the temperature data of the rolling bearing outer ring 201. The tempering end timing control temperature measuring device 215 is connected, the heating time is adjusted based on the temperature information from the tempering end timing control temperature measuring device 215, and the timing at which the rolling bearing outer ring 201 should be cooled is determined. The tempering end timing adjusting device 216 that outputs a tempering cooling start signal and the tempering end timing adjusting device 216 are connected to cool the rolling bearing outer ring 201 based on the tempering cooling start signal 216. And a tempering end device 217 for ending the tempering of the rolling bearing outer ring 201. The tempering end device 217 has a function of, for example, holding the rolling bearing outer ring 201 and moving the rolling bearing outer ring 201 from the heating range by the induction coil for tempering by moving based on the tempering cooling start signal. It has a to-be-processed object holding stand. The tempering storage device 271 is connected to a tempering heating device 212, a tempering temperature adjusting device 214, and a tempering end timing adjusting device 216.
[0120] 次に、本実施の形態の高周波熱処理設備を用いた高周波熱処理方法の一例につ いて説明する。 [0121] 図 10を参照して、本実施の形態の高周波熱処理方法は、焼入条件決定工程と、 焼戻条件決定工程と、最終確認工程と、量産工程とを備えている。まず、焼入条件を 決定するための焼入条件決定工程と、焼戻条件を決定するための焼戻条件決定ェ 程がそれぞれ独立に実施されて焼入条件および焼戻条件がそれぞれ決定され、そ の後、焼入焼戻を連続して実施した場合の焼入条件および焼戻条件の妥当性を確 認する最終確認工程が実施される。そして、妥当性の確認された焼入条件および焼 戻条件に基づいて量産工程が実施される。 Next, an example of a high-frequency heat treatment method using the high-frequency heat treatment equipment of this embodiment will be described. Referring to FIG. 10, the induction heat treatment method of the present embodiment includes a quenching condition determining step, a tempering condition determining step, a final confirmation step, and a mass production step. First, the quenching condition determination step for determining the quenching condition and the tempering condition determination process for determining the tempering condition are performed independently to determine the quenching condition and the tempering condition, respectively. Then, a final confirmation process is performed to confirm the appropriateness of the quenching conditions and tempering conditions when quenching and tempering are continuously performed. The mass production process is then carried out based on the quenching and tempering conditions that have been validated.
[0122] まず、焼入条件決定工程について説明する。図 10を参照して、焼入条件決定工程 においては、まず、被処理物としての転がり軸受外輪 201のサンプルが加熱されて 焼入硬化されることによりプロセスデータが取得される焼入データ取得工程が実施さ れる。この焼入データ取得工程を実施するための仮の熱処理条件は、作業者が温度 および時間の条件力もなる条件として、決定することができる。そのため、過去の生産 実績が十分でな 、場合や、作業者の熱処理の経験が十分でな 、場合であっても、 容易に決定することができる。  [0122] First, the quenching condition determination step will be described. Referring to FIG. 10, in the quenching condition determination step, first, a quenching data acquisition step in which process data is acquired by heating and quenching the sample of the rolling bearing outer ring 201 as the object to be processed. Is implemented. Temporary heat treatment conditions for carrying out this quenching data acquisition process can be determined as conditions in which the operator also has conditions of temperature and time. Therefore, even when the past production record is sufficient or when the worker has sufficient experience in heat treatment, it can be easily determined.
[0123] その後、焼入データ取得工程において転がり軸受外輪 201のサンプルを加熱する ために高周波加熱用の焼入用電源力 焼入用誘導コイルに出力された出力の推移 データである焼入用出力推移データと、転がり軸受外輪 201のサンプルの冷却タイミ ングを特定するための焼入用冷却タイミングデータとが焼入用プロセスデータとして 記憶される焼入データ記憶工程が実施される。そして、焼入データ取得工程におい て焼入硬化された転がり軸受外輪 201の材質データに基づき、焼入用出力推移デ ータおよび焼入用冷却タイミングデータの妥当性が確認される焼入条件確認工程が 実施される。  [0123] Then, in the quenching data acquisition process, the power supply for quenching for high frequency heating to heat the sample of the rolling bearing outer ring 201. Transition of the output output to the induction coil for quenching. A quenching data storage step is performed in which the transition data and quenching cooling timing data for specifying the cooling timing of the sample of the rolling bearing outer ring 201 are stored as quenching process data. Then, based on the material data of the hardened and hardened rolling bearing outer ring 201 in the quenching data acquisition process, the quenching condition confirmation that the validity of the quenching output transition data and quenching cooling timing data is confirmed. The process is carried out.
[0124] ここで、焼入用出力推移データおよび焼入用冷却タイミングデータの妥当性は、た とえば、実際に焼入硬化された転がり軸受外輪 201のサンプルの材質データである 硬度、転がり軸受外輪 201を構成する鋼のミクロ組織、残留オーステナイト量などを 実験により実際に測定し、これらの材質が所望の規格の範囲内であるかどうかにより 判断される。なお、上記材質データは、焼入データ取得工程における被処理物の温 度推移のデータを記憶し、当該データと焼入用冷却タイミングデータとに基づ 、て、 推定することも可能である。 Here, the validity of the quenching output transition data and the quenching cooling timing data is, for example, the material data of the sample of the rolling bearing outer ring 201 actually hardened and hardened. The microstructure of the steel constituting the outer ring 201, the amount of retained austenite, etc. are actually measured by experiments, and it is judged whether these materials are within the range of the desired standard. The material data stores the temperature transition data of the workpiece in the quenching data acquisition process, and based on the data and quenching cooling timing data, It is also possible to estimate.
[0125] 焼入条件確認工程において、被処理物である転がり軸受外輪 201の材質データが 所望の規格範囲内ではな力つた場合、たとえば当初の仮の熱処理条件よりも低温、 かつ長時間の条件での加熱になるように、当該仮の熱処理条件を変更して、再度焼 入データ取得工程が実施される。一方、焼入条件確認工程において、被処理物であ る転がり軸受外輪 201の材質データが所望の規格範囲内であった場合、焼入データ 記憶工程にぉ 、て記憶された焼入用出力推移データおよび焼入用冷却タイミングデ ータが電力制御により焼入硬化処理を実施するための熱処理条件 (焼入条件）として 、決定される。  [0125] In the quenching condition confirmation process, if the material data of the rolling bearing outer ring 201 that is the object to be processed is not within the desired standard range, for example, a condition that is lower than the initial provisional heat treatment condition and for a long time. The tempering data acquisition process is performed again by changing the provisional heat treatment condition so that the heating is performed at the same time. On the other hand, if the material data of the rolling bearing outer ring 201, which is the workpiece, is within the desired standard range in the quenching condition confirmation process, the transition of the quenching output stored in the quenching data storage process is stored. The data and quenching cooling timing data are determined as heat treatment conditions (quenching conditions) for performing quench hardening by power control.
[0126] 次に、焼戻条件決定工程について説明する。図 10を参照して、焼戻条件決定ェ 程においては、まず、焼入硬化された被処理物としての転がり軸受外輪 201のサン プルが加熱されて焼戻されることによりプロセスデータが取得される焼戻データ取得 工程が実施される。この焼戻データ取得工程を実施するための仮の熱処理条件も、 温度および時間の条件で与えることができるため、焼入データ取得工程と同様に、過 去の生産実績が十分でな!、場合や、作業者の熱処理の経験が十分でな!、場合であ つても、容易に決定することができる。  Next, the tempering condition determination step will be described. Referring to FIG. 10, in the tempering condition determination step, first, the process data is acquired by heating and tempering the sample of the rolling bearing outer ring 201 as the hardened and hardened workpiece. Tempering data acquisition process is implemented. Temporary heat treatment conditions for carrying out this tempering data acquisition process can also be given in terms of temperature and time, so that past production results are sufficient as in the case of the quenching data acquisition process! Even if the worker has sufficient experience in heat treatment, it can be easily determined.
[0127] その後、焼戻データ取得工程において転がり軸受外輪 201のサンプルを加熱する ために高周波加熱用の電源力 誘導コイルに出力された焼戻用出力推移データと、 転がり軸受外輪 201のサンプルの冷却タイミングを特定するための焼戻用冷却タイミ ングデータとが焼戻プロセスデータとして記憶される焼戻データ記憶工程が実施され る。そして、焼戻データ取得工程において焼戻された転がり軸受外輪 201の材質デ ータに基づき、焼戻用出力推移データおよび焼戻用冷却タイミングデータの妥当性 が確認される焼戻条件確認工程が実施される。  [0127] After that, in the tempering data acquisition process, the power supply power for high-frequency heating to heat the sample of the rolling bearing outer ring 201, the output transition data for tempering output to the induction coil, and the cooling of the sample of the rolling bearing outer ring 201 A tempering data storage step is performed in which tempering cooling timing data for specifying timing is stored as tempering process data. Then, based on the material data of the rolling bearing outer ring 201 tempered in the tempering data acquisition step, there is a tempering condition confirmation step in which the validity of the tempering output transition data and the tempering cooling timing data is confirmed. To be implemented.
[0128] ここで、焼戻用出力推移データおよび焼戻用冷却タイミングデータの妥当性は、た とえば、実際に焼戻された転がり軸受外輪 201のサンプルの材質データにおいて最 も重要な、硬度を実験により実際に測定し、当該硬度が所望の規格の範囲内である 力どうかにより判断される。なお、上記材質データは、焼戻データ取得工程における 被処理物の温度推移のデータを記憶し、当該データと焼戻用冷却タイミングデータと に基づいて、推定することも可能である。 Here, the validity of the tempering output transition data and the tempering cooling timing data is, for example, the hardness that is most important in the material data of the sample of the outer ring 201 of the rolling bearing outer ring that has been actually tempered. Is actually measured by experiment, and is judged by whether the hardness is within the range of the desired standard. The material data stores the temperature transition data of the workpiece in the tempering data acquisition process, and the tempering cooling timing data. It is also possible to estimate based on
[0129] 焼戻条件確認工程において、被処理物である転がり軸受外輪 201の材質データが 所望の規格範囲内ではな力つた場合、たとえば当初の仮の熱処理条件よりも低温、 かつ長時間の条件での加熱になるように、当該仮の熱処理条件を変更して、再度焼 戻データ取得工程が実施される。一方、焼戻条件確認工程において、被処理物であ る転がり軸受外輪 201の材質データが所望の規格範囲内であった場合、焼戻データ 記憶工程にお!、て記憶された焼戻用出力推移データおよび焼戻用冷却タイミングデ ータが電力制御により焼戻処理を実施するための熱処理条件 (焼戻条件）として、決 定される。  [0129] In the tempering condition confirmation process, if the material data of the rolling bearing outer ring 201, which is the object to be processed, is not within the desired standard range, for example, a condition at a lower temperature and longer time than the initial provisional heat treatment condition. The tempering data acquisition step is performed again by changing the provisional heat treatment conditions so that the heating is performed at the same time. On the other hand, if the material data of the rolling bearing outer ring 201, which is the object to be processed, is within the desired standard range in the tempering condition confirmation step, the tempering output stored in the tempering data storage step! Transition data and cooling timing data for tempering are determined as heat treatment conditions (tempering conditions) for performing tempering by electric power control.
[0130] 次に、最終確認工程について説明する。図 10を参照して、最終確認工程では、ま ず、上述の焼入条件決定工程において決定された焼入条件と、焼戻条件決定工程 において決定された焼戻条件とに基づいて、電力制御により、被処理物としての転が り軸受外輪 201に対して、焼入および焼戻が連続して実施される量産テスト工程が 実施される。そして、量産テスト工程において焼入焼戻された転がり軸受外輪 201の 材質データに基づき、焼入条件決定工程において決定された焼入条件および焼戻 条件決定工程において決定された焼戻条件の妥当性が確認される熱処理条件確認 工程が実施される。  Next, the final confirmation process will be described. Referring to FIG. 10, in the final confirmation process, power control is first performed based on the quenching condition determined in the quenching condition determination process and the tempering condition determined in the tempering condition determination process. Thus, a mass production test process in which quenching and tempering are continuously performed on the rolling bearing outer ring 201 as the object to be processed is performed. Based on the material data of the rolling bearing outer ring 201 that has been quenched and tempered in the mass production test process, the validity of the quenching condition determined in the quenching condition determination process and the tempering condition determined in the tempering condition determination process. A heat treatment condition confirmation process for confirming is performed.
[0131] ここで、焼入条件決定工程において決定された焼入条件および焼戻条件決定ェ 程において決定された焼戻条件の妥当性は、たとえば、実際に焼入焼戻された転が り軸受外輪 201のサンプルの材質データである硬度、転がり軸受外輪 201を構成す る鋼のミクロ組織、残留オーステナイト量などを実験により実際に測定し、これらの材 質が所望の規格の範囲内であるかどうかにより判断される。  [0131] Here, the appropriateness of the quenching condition determined in the quenching condition determination step and the tempering condition determined in the tempering condition determination step is, for example, the rolling that is actually quenched and tempered. The hardness, which is the material data of the sample of the bearing outer ring 201, the microstructure of the steel constituting the rolling bearing outer ring 201, the amount of retained austenite, etc. are actually measured by experiments, and these materials are within the range of the desired standard. It is judged by whether or not.
[0132] 熱処理条件確認工程において、被処理物である転がり軸受外輪 201の材質データ が所望の規格範囲内ではな力つた場合、その原因が焼入条件および焼戻条件のど ちらにあるのかが判断される、原因特定工程が実施される。この原因特定工程は、た とえば、熱処理条件確認工程にぉ ヽて取得された材質データに基づ ヽて実施するこ とができる。すなわち、当該材質データである硬度、転がり軸受外輪 201を構成する 鋼のミクロ組織、残留オーステナイト量のうち、硬度のみが材質の規格範囲外であつ た場合、ミクロ組織や残留オーステナイト量に影響を与える焼入条件ではなぐ焼戻 条件に原因があったものと考えられる。この場合、当該材質データを考慮して、焼戻 条件決定工程が再度実施される。一方、硬度以外の材質データが所望の規格範囲 外であった場合、焼戻条件ではなぐ焼入条件に原因があったものと考えられる。こ の場合、当該材質データを考慮して、焼入条件決定工程が再度実施される。そして 、決定された焼入条件および焼戻条件に基づいて、再度最終確認工程が実施され る。 [0132] In the heat treatment condition confirmation step, if the material data of the rolling bearing outer ring 201 that is the object to be processed is not within the desired specification range, it is determined whether the cause is the quenching condition or the tempering condition. The cause identifying step is performed. This cause identification process can be performed based on, for example, the material data acquired through the heat treatment condition confirmation process. That is, only the hardness of the material data, the microstructure of the steel constituting the rolling bearing outer ring 201, and the amount of retained austenite is outside the standard range of the material. In this case, the tempering conditions are considered to be the cause of the quenching conditions that affect the microstructure and retained austenite content. In this case, the tempering condition determination step is performed again in consideration of the material data. On the other hand, if the material data other than hardness is out of the desired standard range, it is probable that the quenching condition is the cause of the tempering condition. In this case, the quenching condition determination process is performed again in consideration of the material data. Then, the final confirmation process is performed again based on the determined quenching conditions and tempering conditions.
[0133] 一方、熱処理条件確認工程において、被処理物である転がり軸受外輪 201の材質 データが所望の規格範囲内であった場合、焼入焼戻を電力制御により実施するため の熱処理条件が、当該焼入条件および焼戻条件に確定される。そして、この焼入条 件および焼戻条件に基づいて、電力制御により焼入焼戻を行なう量産工程が実施さ れる。  [0133] On the other hand, in the heat treatment condition confirmation step, when the material data of the rolling bearing outer ring 201 which is the object to be processed is within a desired standard range, the heat treatment condition for performing quenching and tempering by electric power control is The quenching conditions and tempering conditions are determined. Based on these quenching conditions and tempering conditions, a mass production process for quenching and tempering by electric power control is performed.
[0134] 次に、本実施の形態における高周波熱処理設備に含まれる高周波焼入装置 293 の動作について詳細に説明する。図 11において、焼入データ取得工程におけるデ ータおよび指令の流れは実線矢印、焼入データ記憶工程におけるデータおよび指 令の流れは破線矢印、最終確認工程および量産工程におけるデータおよび指令の 流れは二重実線矢印で表示されている。図 8、図 10および図 11を参照して、本実施 の形態における高周波焼入装置の動作について説明する。  Next, the operation of the induction hardening apparatus 293 included in the induction heat treatment facility in the present embodiment will be described in detail. In Fig. 11, the flow of data and commands in the quenching data acquisition process is solid arrows, the flow of data and commands in the quenching data storage process is broken arrows, and the flow of data and commands in the final confirmation process and mass production process is Displayed with double solid arrows. The operation of the induction hardening apparatus in the present embodiment will be described with reference to FIG. 8, FIG. 10, and FIG.
[0135] 図 8、図 10および図 11を参照して、焼入データ取得工程においては、まず、温度 制御による仮の焼入条件が決定され、当該熱処理条件が焼入温度調節装置 204お よび焼入タイミング調節装置 206に入力されて熱処理が開始される。そして、焼入温 度制御用測温装置 203により測定された被処理物としての転がり軸受外輪 201のサ ンプルの温度データは焼入温度調節装置 204に送られる。焼入温度調節装置 204 においては転がり軸受外輪 201の目標加熱温度および取得した転がり軸受外輪 20 1のサンプルの温度データ力も必要な電源出力を判断し、焼入加熱装置 202の焼入 用電源に電源出力を指令する。指令を受けた焼入用電源は焼入加熱装置 202の焼 入用誘導コイルに電力を出力し、転がり軸受外輪 201のサンプルは目的の温度に加 熱される。 [0136] 一方、焼入タイミング制御用測温装置 205により測定された転がり軸受外輪 201の サンプルの温度データは、焼入タイミング調節装置 206に送られる。焼入タイミング調 節装置 206においては、取得した転がり軸受外輪 201のサンプルの温度および加熱 時間から冷却タイミングを判断し、冷却開始を焼入用冷却装置 207に指令する。これ により、転がり軸受外輪 201のサンプルは急冷され、焼入硬化される。 Referring to FIG. 8, FIG. 10, and FIG. 11, in the quenching data acquisition process, first, temporary quenching conditions by temperature control are determined, and the heat treatment conditions are determined by quenching temperature control apparatus 204 and It is input to the quenching timing adjusting device 206 and heat treatment is started. The temperature data of the sample of the rolling bearing outer ring 201 as the workpiece measured by the temperature measuring device 203 for quenching temperature control is sent to the quenching temperature adjusting device 204. In the quenching temperature control device 204, the target heating temperature of the rolling bearing outer ring 201 and the obtained temperature data power of the sample of the rolling bearing outer ring 201 are also determined, and the necessary power output is also determined. Command output. Upon receiving the command, the quenching power source outputs power to the quenching induction coil of the quenching heating device 202, and the sample of the rolling bearing outer ring 201 is heated to a target temperature. On the other hand, the sample temperature data of the rolling bearing outer ring 201 measured by the quenching timing control temperature measuring device 205 is sent to the quenching timing adjusting device 206. In the quenching timing adjusting device 206, the cooling timing is judged from the obtained temperature and heating time of the sample of the rolling bearing outer ring 201, and the cooling start device 207 is instructed to start cooling. Thereby, the sample of the rolling bearing outer ring 201 is rapidly cooled and quenched and hardened.
[0137] 焼入データ記憶工程にお!、ては、焼入データ取得工程にお!、て焼入温度調節装 置 204および焼入タイミング調節装置 206が取得した温度データが温度推移データ として焼入用記憶装置 270に記憶される。また、焼入加熱装置 202の焼入用電源が 焼入用誘導コイルに出力した電源出力が焼入用出力推移データとして焼入用記憶 装置 270に記憶される。さらに、焼入タイミング調節装置 206が焼入用冷却装置 207 に出力した冷却開始指令のタイミングが焼入用冷却タイミングデータとして焼入用記 憶装置 270に記憶される。ここで、焼入用冷却タイミングは、たとえば加熱開始からの 時間として記憶される。  [0137] In the quenching data storage process! In the quenching data acquisition process !, the temperature data acquired by the quenching temperature control unit 204 and the quenching timing control unit 206 is quenched as temperature transition data. It is stored in the incoming storage device 270. The power output output from the quenching power source of the quenching heating device 202 to the quenching induction coil is stored in the quenching storage device 270 as quenching output transition data. Further, the timing of the cooling start command output from the quenching timing adjusting device 206 to the quenching cooling device 207 is stored in the quenching storage device 270 as quenching cooling timing data. Here, the quenching cooling timing is stored as the time from the start of heating, for example.
[0138] そして、焼入条件確認工程において、転がり軸受外輪 201のサンプルの材質デー タに基づいて、焼入用出力推移データおよび焼入用冷却タイミングデータの妥当性 が確認された後、最終確認工程および量産工程においては、焼入用記憶装置 270 に記憶された当該焼入用出力推移データおよび焼入用冷却タイミングデータに基づ き、転がり軸受外輪 201が加熱されて焼入が行なわれる。  [0138] Then, in the quenching condition confirmation process, after the validity of the quenching output transition data and quenching cooling timing data is confirmed based on the material data of the sample of the rolling bearing outer ring 201, the final confirmation In the process and the mass production process, the rolling bearing outer ring 201 is heated and quenched based on the quenching output transition data and quenching cooling timing data stored in the quenching storage device 270.
[0139] すなわち、本実施の形態の高周波焼入装置 293は、焼入による材質変化に直接対 応するため焼入条件の設定が容易な温度制御による焼入と、データおよび指令の流 れがシンプルであり、信頼性の高い電力制御による焼入とを切り替えて実施すること が可能となっている。その結果、過去の生産実績が十分でない場合や、熱処理の経 験の浅い作業者が作業する場合であっても、被処理物に付与すべき所望の硬度、 被処理物を構成する鋼の残留オーステナイト量やミクロ組織から、容易に設定可能 な温度制御による焼入条件で、焼入データ取得工程を実施することができる。そして 、量産工程においては、妥当性が確認された焼入条件に基づき、信頼性の高い電 力制御により焼入を実施することができる。  That is, the induction hardening apparatus 293 according to the present embodiment directly responds to material changes due to quenching, and therefore quenching by temperature control that allows easy setting of quenching conditions, and the flow of data and commands. It is simple and can be implemented by switching between quenching with highly reliable power control. As a result, even if the past production results are not sufficient or when a worker with little experience in heat treatment is working, the desired hardness to be imparted to the workpiece and the residual steel constituting the workpiece. From the austenite amount and microstructure, the quenching data acquisition process can be performed under quenching conditions with temperature control that can be easily set. In the mass production process, quenching can be performed by highly reliable power control based on quenching conditions that have been validated.
[0140] 次に、本実施の形態における高周波熱処理設備に含まれる高周波焼戻装置 295 の動作について詳細に説明する。図 12において、焼戻データ取得工程におけるデ ータおよび指令の流れは実線矢印、焼戻データ記憶工程におけるデータおよび指 令の流れは破線矢印、最終確認工程および量産工程におけるデータおよび指令の 流れは二重実線矢印で表示されている。図 9、図 10および図 12を参照して、本実施 の形態における高周波焼戻装置の動作について説明する。 Next, an induction tempering apparatus included in the induction heat treatment equipment in the present embodiment 295 Will be described in detail. In Fig. 12, the flow of data and commands in the tempering data acquisition process is solid arrows, the flow of data and commands in the tempering data storage process is broken arrows, and the flow of data and commands in the final confirmation process and mass production process is Displayed with double solid arrows. The operation of the induction tempering apparatus according to the present embodiment will be described with reference to FIG. 9, FIG. 10, and FIG.
[0141] 図 9、図 10および図 12を参照して、焼戻データ取得工程においては、まず、温度 制御による仮の焼戻条件が決定され、当該熱処理条件が焼戻温度調節装置 214お よび焼戻終了タイミング調節装置 216に入力されて熱処理が開始される。そして、焼 戻温度制御用測温装置 213により測定された被処理物としての転がり軸受外輪 201 のサンプルの温度データは、焼戻温度調節装置 214に送られる。焼戻温度調節装 置 214においては、転がり軸受外輪 201の目標加熱温度および取得した転がり軸受 外輪 201のサンプルの温度データ力も必要な電源出力を判断し、焼戻加熱装置 21 2の焼戻用電源に電源出力を指令する。指令を受けた焼戻用電源は焼戻加熱装置 212の焼入用誘導コイルに電力を出力し、転がり軸受外輪 201のサンプルは目的の 温度に加熱される。 Referring to FIG. 9, FIG. 10, and FIG. 12, in the tempering data acquisition step, first, a temporary tempering condition is determined by temperature control, and the heat treatment condition is determined by tempering temperature adjusting device 214 and It is input to the tempering end timing adjustment device 216 and heat treatment is started. Then, the temperature data of the sample of the rolling bearing outer ring 201 as the object to be processed measured by the tempering temperature control temperature measuring device 213 is sent to the tempering temperature adjusting device 214. In the tempering temperature adjusting device 214, the target heating temperature of the rolling bearing outer ring 201 and the obtained temperature data of the sample of the rolling bearing outer ring 201 are also determined to determine the necessary power output, and the tempering power supply for the tempering heating device 212 is used. Command the power output to. The power supply for tempering that receives the command outputs electric power to the induction coil for quenching of the tempering heating device 212, and the sample of the rolling bearing outer ring 201 is heated to a target temperature.
[0142] 一方、焼戻終了タイミング制御用測温装置 215により測定された転がり軸受外輪 20 1のサンプルの温度データは、焼戻終了タイミング調節装置 216に送られる。焼戻終 了タイミング調節装置 216においては、取得した転がり軸受外輪 201のサンプルの 温度および加熱時間から冷却タイミングを判断し、冷却開始を焼戻終了装置 217〖こ 指令する。これにより、転がり軸受外輪 201のサンプルは冷却され、焼戻が終了する  On the other hand, the temperature data of the sample of the rolling bearing outer ring 201 measured by the tempering end timing control temperature measuring device 215 is sent to the tempering end timing adjusting device 216. In the tempering end timing adjusting device 216, the cooling timing is judged from the obtained temperature and heating time of the sample of the rolling bearing outer ring 201, and the tempering end device 217 is instructed to start the cooling. Thereby, the sample of the rolling bearing outer ring 201 is cooled, and the tempering is finished.
[0143] 焼戻データ記憶工程にお!、ては、焼戻データ取得工程にぉ 、て焼戻温度調節装 置 214および焼戻終了タイミング調節装置 216が取得した温度データが、温度推移 データとして焼戻用記憶装置 271に記憶される。また、焼戻加熱装置 212の焼戻用 電源が焼戻用誘導コイルに出力した電源出力が、焼戻用出力推移データとして焼戻 用記憶装置 271に記憶される。さらに、焼戻終了タイミング調節装置 216が焼戻終了 装置 217に出力した冷却開始指令のタイミングが焼戻用冷却タイミングデータとして 焼戻用記憶装置 271に記憶される。ここで、焼戻用冷却タイミングタイミングデータは 、たとえば加熱開始からの時間として記憶される。 [0143] In the tempering data storage process, the temperature data acquired by the tempering temperature adjustment device 214 and the tempering end timing adjustment device 216 is used as temperature transition data in the tempering data acquisition step. It is stored in the tempering storage device 271. The power output output from the tempering power supply of the tempering heating device 212 to the tempering induction coil is stored in the tempering storage device 271 as tempering output transition data. Further, the timing of the cooling start command output from the tempering end timing adjusting device 216 to the tempering end device 217 is stored in the tempering storage device 271 as tempering cooling timing data. Here, the tempering cooling timing timing data is For example, it is stored as the time from the start of heating.
[0144] そして、焼戻条件確認工程において、転がり軸受外輪 201のサンプルの材質デー タに基づいて、焼戻用出力推移データおよび焼戻用冷却タイミングデータの妥当性 が確認された後、最終確認工程および量産工程においては、焼戻用記憶装置 271 に記憶された当該焼戻用出力推移データおよび焼戻用冷却タイミングデータに基づ き、転がり軸受外輪 201が加熱されて焼戻が行なわれる。  [0144] In the tempering condition confirmation step, the validity of the tempering output transition data and the tempering cooling timing data is confirmed based on the sample material data of the rolling bearing outer ring 201, and then the final confirmation. In the process and the mass production process, the rolling bearing outer ring 201 is heated and tempered based on the tempering output transition data and the tempering cooling timing data stored in the tempering storage device 271.
[0145] すなわち、本実施の形態の高周波焼戻装置 295は、高周波焼入装置 293と同様 に、焼戻条件の設定が容易な温度制御による焼戻と、データおよび指令の流れがシ ンプルであり、信頼性の高い電力制御による焼戻とを切り替えて実施することが可能 となっている。その結果、過去の生産実績が十分でない場合や、熱処理の経験の浅 い作業者が作業する場合であっても、容易に設定可能な温度制御による焼入条件 で焼入データ取得工程を実施し、量産工程においては、妥当性が確認された焼戻 条件に基づき、信頼性の高い電力制御により焼戻を実施することができる。  That is, in the induction tempering apparatus 295 of the present embodiment, similar to the induction hardening apparatus 293, the flow of data and commands is simple with tempering by temperature control in which tempering conditions can be easily set. Yes, it is possible to switch between tempering with highly reliable power control. As a result, even if the past production record is not sufficient or when an operator with little experience in heat treatment is working, the quenching data acquisition process is performed under quenching conditions with temperature control that can be set easily. In the mass production process, tempering can be performed with reliable power control based on the tempering conditions that have been validated.
[0146] なお、上述のように、材質の確認を目的として、焼入後、および焼戻後に被処理物 を高周波熱処理設備から取り出し可能とするために、本実施の形態の高周波熱処理 設備においては、図 7を参照して、搬送装置 299C、 299D、 299Eが、被処理物を取 り出し可能に構成されていることが好ましい。具体的には、搬送装置 299C、 299D、 299Eにカバーが設けられている場合、当該カバーには開閉可能な被処理物取り出 し口が設けられていることが好ましい。また、搬送装置 299C、 299D、 299E力 たと えばコンベアである場合、被処理物を取り出すための、被処理物の搬送方向を切り 替え可能な分岐が設けられて 、てもよ 、。  [0146] As described above, for the purpose of confirming the material, in order to make it possible to remove the workpiece from the induction heat treatment equipment after quenching and after tempering, in the induction heat treatment equipment of the present embodiment, Referring to FIG. 7, it is preferable that conveying apparatuses 299C, 299D, and 299E are configured to be able to take out an object to be processed. Specifically, in the case where the transport apparatuses 299C, 299D, and 299E are provided with a cover, it is preferable that the cover is provided with a workpiece extraction port that can be opened and closed. Further, in the case of the conveyors 299C, 299D, and 299E, for example, a conveyor, a branch that can change the transport direction of the object to be processed may be provided to take out the object to be processed.
[0147] また、焼入用記憶装置 270は、独立の装置として設置されてもよいが、たとえばノ、 ードディスクなどの記憶部を有するパーソナルコンピュータにより、焼入温度調節装 置 204、焼入タイミング調節装置 206などの装置を兼用して設置されてもよい。同様 に、焼戻用記憶装置 271は、独立の装置として設置されてもよいが、たとえばノヽード ディスクなどの記憶部を有するパーソナルコンピュータにより、焼戻温度調節装置 21 4、焼戻終了タイミング調節装置 216などの装置を兼用して設置されてもよい。また、 上記の高周波熱処理方法の各工程は、たとえば制御装置としてパーソナルコンビュ ータを用い、各工程に対応した単数または複数のプログラムにより当該パーソナルコ ンピュータを動作させることにより実施することができる。 [0147] The quenching storage device 270 may be installed as an independent device. For example, the quenching temperature control device 204 and the quenching timing adjustment may be performed by a personal computer having a storage unit such as a node or a disk. A device such as the device 206 may also be installed. Similarly, the tempering storage device 271 may be installed as an independent device, but for example, a tempering temperature adjustment device 214, tempering end timing adjustment can be performed by a personal computer having a storage unit such as a node disk. A device such as the device 216 may also be installed. In addition, each step of the above-described high-frequency heat treatment method is performed, for example, as a personal device as a control device. This can be implemented by operating the personal computer using one or more programs corresponding to each process.
[0148] 次に、上述の実施の形態における温度制御による高周波焼入 (焼入データ取得ェ 程)の具体的手順について、転がり軸受外輪 201の材質が JIS SUJ2である場合を 例に、詳細に説明する。  [0148] Next, the specific procedure of induction hardening (quenching data acquisition process) by temperature control in the above-described embodiment will be described in detail, taking as an example the case where the material of the rolling bearing outer ring 201 is JIS SUJ2. explain.
[0149] ここでは、 180°Cで焼戻した場合の焼戻後の硬度 (焼戻硬度）が強度の観点力 H RC58以上 (HV653以上)であり、寸法安定性の観点から残留オーステナイト量が 1 2体積％以下であることを規格値として設定する。  [0149] Here, the hardness after tempering when tempering at 180 ° C (tempering hardness) is strength strength HRC58 or higher (HV653 or higher), and the amount of retained austenite is 1 from the viewpoint of dimensional stability. The standard value is set to 2% by volume or less.
[0150] 図 13は、熱処理の規格値を満足するための焼入温度と保持時間との関係を示した SUJ2材の TTA(Time Temperature Austinitization)線図である。図 13にお いて横軸は焼入温度 (°C)、縦軸は保持時間 (秒)を示している。また、領域 Aは硬度 規格を満足しない範囲であり、領域 Bは残留オーステナイト量が規格を満足しない範 囲であり、領域 Cはいずれの熱処理品質規格をも満足する範囲である。図 13を参照 して、本実施の形態における焼入データ取得工程におけるの熱処理条件の決定方 法について説明する。  [0150] FIG. 13 is a TTA (Time Temperature Austinitization) diagram of the SUJ2 material showing the relationship between the quenching temperature and the holding time for satisfying the standard value of heat treatment. In Fig. 13, the horizontal axis represents the quenching temperature (° C), and the vertical axis represents the holding time (seconds). Region A is a range that does not satisfy the hardness standard, region B is a range where the retained austenite amount does not satisfy the standard, and region C is a range that satisfies any heat treatment quality standard. With reference to FIG. 13, a method for determining the heat treatment conditions in the quenching data acquisition process of the present embodiment will be described.
[0151] 本実施の形態における焼入データ取得工程においては、まず、仮の熱処理条件（ 焼入における加熱温度および加熱時間の条件）を決定する必要がある。図 13を参照 して、 SUJ2製の転がり軸受外輪 201の硬度は焼入温度と保持時間とが大きくなるに つれて規格を満たしやすくなる。これに対して、オーステナイト量は焼入温度と保持 時間とが大きくなるにつれて規格を満たしに《なる。熱処理の規格値 (硬度規格お よび残留オーステナイト量の規格値)を満たすためには、比較的低温で長時間の条 件設定の方が熱処理品質を制御しやすい。たとえば、 1050°Cの比較的高温での処 理では、熱処理品質規格を確保するための保持時間は 15秒以上であるが、 17秒以 上保持してしまうと規格を満たすことができない。これに対し、 950°Cの処理では、熱 処理品質を確保するための保持時間は 20秒以上であり、 60秒までは規格を満たす ことができる。一方、短時間での昇温が可能であるという高周波熱処理の利点を生か すためには、できるだけ高温、短時間での処理が望ましい。すなわち、図 13を参照し て、熱処理品質の制御の容易性と、熱処理の効率とのバランスを考慮しつつ、仮の 熱処理条件を決定することができる。 [0151] In the quenching data acquisition step in the present embodiment, first, provisional heat treatment conditions (conditions for heating temperature and heating time in quenching) must be determined. Referring to FIG. 13, the hardness of the rolling bearing outer ring 201 made of SUJ2 easily satisfies the standard as the quenching temperature and the holding time increase. In contrast, the amount of austenite satisfies the standard as the quenching temperature and holding time increase. In order to meet the standard values for heat treatment (standard values for hardness and retained austenite), setting the conditions for a long time at a relatively low temperature makes it easier to control the heat treatment quality. For example, in processing at a relatively high temperature of 1050 ° C, the holding time for ensuring the heat treatment quality standard is 15 seconds or longer, but if the holding time is 17 seconds or longer, the standard cannot be satisfied. On the other hand, in the treatment at 950 ° C, the holding time for ensuring the heat treatment quality is 20 seconds or more, and the standard can be satisfied up to 60 seconds. On the other hand, in order to take advantage of the high-frequency heat treatment that temperature can be increased in a short time, it is desirable to perform the treatment at as high a temperature as possible for a short time. In other words, referring to FIG. 13, the temporary heat treatment quality is easily controlled while considering the balance between the heat treatment efficiency and the heat treatment efficiency. Heat treatment conditions can be determined.
[0152] なお、図 13は SUJ2に関する TTA線図である力 材料が変更された場合、それに 応じた TTA線図を作成することで、上述と同様に仮の熱処理条件を決定することが できる。  [0152] FIG. 13 shows a TTA diagram related to SUJ2. When the force material is changed, a temporary heat treatment condition can be determined in the same manner as described above by creating a TTA diagram corresponding to the force material.
[0153] 熱処理条件が決まると、図 8を参照して、熱処理条件をパーソナルコンピュータなど の焼入温度調節装置 204に入力する。焼入温度調節装置 204は、焼入温度制御用 測温装置 203と、焼入加熱装置 202とに接続されており、焼入温度制御用測温装置 203からの温度情報に基づき、 PID (Proportional Integral Differential)制御 により焼入温度制御信号を焼入加熱装置 202に出力し、焼入温度制御用測温装置 203の測温部である外周面 201Aの温度推移を制御することができる。なお、外周面 201Aは、転がり軸受外輪 201において磁束の侵入が最も多くなり、高周波加熱によ る温度上昇の最も大き ヽ部位である。  [0153] When the heat treatment conditions are determined, the heat treatment conditions are input to a quenching temperature adjusting device 204 such as a personal computer with reference to FIG. The quenching temperature control device 204 is connected to the quenching temperature control temperature measuring device 203 and the quenching heating device 202. Based on the temperature information from the quenching temperature control temperature measuring device 203, the PID (Proportional With the integral differential control, a quenching temperature control signal is output to the quenching and heating device 202, and the temperature transition of the outer peripheral surface 201A that is the temperature measuring unit of the quenching temperature control temperature measuring device 203 can be controlled. The outer peripheral surface 201A has the largest penetration of magnetic flux in the rolling bearing outer ring 201, and is the largest temperature rise due to high frequency heating.
[0154] このとき同時に、焼入タイミング制御用測温装置 205の測温データをパーソナルコ ンピュータなどの焼入タイミング調節装置 206に取り込み、その温度推移から加熱が 十分であるかどうかを判断し、冷却タイミングを調節する。冷却タイミングの判断は、 焼入タイミング制御用測温装置 205の測温部である内周面 201Bの温度推移が TT A線図上で規格内におさまったかどうかで行なう。なお、内周面 201Bは、転がり軸受 外輪 201において磁束の侵入が最も少なくなり、高周波加熱による温度上昇の最も 小さい部位である。また、焼入温度調節装置 204と焼入タイミング調節装置 206とを 同一のパーソナルコンピュータで兼ねることもできる。  [0154] At the same time, the temperature measurement data of the quenching timing control temperature measuring device 205 is taken into the quenching timing adjusting device 206 such as a personal computer, and it is determined from the temperature transition whether the heating is sufficient, Adjust the cooling timing. The determination of the cooling timing is made based on whether or not the temperature transition of the inner peripheral surface 201B, which is the temperature measuring portion of the quenching timing control temperature measuring device 205, falls within the standard on the TTA diagram. The inner peripheral surface 201B is a portion where the penetration of the magnetic flux is the smallest in the rolling bearing outer ring 201 and the temperature rise due to the high frequency heating is the smallest. Further, the quenching temperature adjusting device 204 and the quenching timing adjusting device 206 can be used as the same personal computer.
[0155] TTA線図上で規格内におさまったかどうかという判断、すなわち焼入用冷却タイミ ングの決定には、下記の式（3)および式（5)を用いることができる力 好ましくは被処 理物の温度が刻一刻と変化することを考慮して式（3)を補正した式 (4)および式（5) が用いられる。  [0155] A force that can use the following formula (3) and formula (5) for determining whether or not the TTA diagram is within the specification, that is, determining the quenching cooling timing, is preferably treated. Equations (4) and (5), which are obtained by correcting Equation (3) in consideration of the fact that the temperature of a physical object changes every moment, are used.
[0156] D = 2 (Dt) 1/2' . '式（3) [0156] D = 2 (Dt) 1/2 '.' Formula (3)
ep  ep
D =AX 2 (Dt) 1/2…式（4) D = AX 2 (Dt) 1/2 ... Formula (4)
ep  ep
D:鋼中の炭素の拡散定数、 t:保持時間 (秒)、 A:補正係数  D: diffusion constant of carbon in steel, t: retention time (seconds), A: correction factor
D=D exp (— QZRT) · · ·式（5) D：拡散定数のエントロピ一項、 Q :活性ィ匕エネルギー、 R:気体定数、 T:絶対温度D = D exp (—QZRT) · · · · (5) D: Entropy term of diffusion constant, Q: Activity energy, R: Gas constant, T: Absolute temperature
0 0
(K)  (K)
ここで補正係数 Aの値は、以下の式 (6)力 得られる値である。  Here, the value of the correction coefficient A is a value obtained by the following equation (6).
[0157] erf (A) = 1 -0. 1573C /C · · ·式（6) [0157] erf (A) = 1 -0. 1573C / C · · · · Equation (6)
1 2  1 2
C : 727°Cの Cの固溶度（SUJ2の場合： 0. 52)  C: Solid solubility of C at 727 ° C (SUJ2: 0.52)
1  1
C：任意の温度における Cの固溶度  C: Solid solubility of C at any temperature
2  2
式 (4)は、式 (6)の Cの値が、 Cになった場合の炭素の拡散長 D を計算する式で  Equation (4) is an equation that calculates the diffusion length D of carbon when the value of C in Equation (6) becomes C.
1 2 ep  1 2 ep
ある。 Cの値は任意の温度における炭素の固溶度であり、これらの値は、実験的もし is there. The value of C is the solid solubility of carbon at any temperature, and these values are experimental if
2 2
くは、熱力学の平衡計算により、あら力じめ求めることができる。冷却は、式 (4)中の 炭素の拡散長 D の値がある値 (D *)に達した時に行なう。  Alternatively, it can be determined by thermodynamic equilibrium calculation. Cooling is performed when the value of carbon diffusion length D in equation (4) reaches a certain value (D *).
ep ep  ep ep
[0158] なお、焼入タイミング制御用測温装置 205の測温部は、必ずしも 1箇所である必要 はない。測温部を複数とすることにより、複数の部位での熱処理品質を確保すること ができる。  [0158] Note that the temperature measuring unit 205 of the quenching timing control temperature measuring device 205 does not necessarily have to be one place. By using a plurality of temperature measuring sections, it is possible to ensure heat treatment quality at a plurality of sites.
[0159] 図 14の上段左のグラフにおいては横軸を時間 t、縦軸を温度 Tとして焼入温度制 御側（転がり軸受外輪 201の外周面 201A)および焼入タイミング制御側（転がり軸受 外輪 201の内周面 201B)における温度推移が示されている。また、上段右の図は上 段左のグラフの領域 αの部分を拡大して示した図である。また、下段には補正 D の ep 値を温度推移から積算するための計算式が示されて!/ヽる。  In the upper left graph of FIG. 14, the horizontal axis is time t and the vertical axis is temperature T. The quenching temperature control side (outer peripheral surface 201A of the rolling bearing outer ring 201) and the quenching timing control side (rolling bearing outer ring). The temperature transition on the inner peripheral surface 201B) of 201 is shown. The upper right figure is an enlarged view of the area α in the upper left graph. The lower part shows the formula for integrating the ep value of correction D from the temperature transition!
[0160] 図 14を参照して、被処理物が加熱されている間、冷却タイミングを決定するための 測温部位 (つまり焼入タイミング制御用測温装置 205の測温部位である内周面 201B )の温度は刻一刻と変化するので、補正 D (式 (4)における補正された D 、以下単 ep ep に D という）の値は図 14に示すように、 D →D → D と積算する必要があ ep e l ep2 epn [0160] Referring to FIG. 14, while the workpiece is heated, the temperature measurement part for determining the cooling timing (that is, the inner peripheral surface which is the temperature measurement part of quenching timing control temperature measurement device 205) Since the temperature of 201B) changes from moment to moment, the value of correction D (corrected D in equation (4), hereinafter referred to as D in ep ep) is calculated as D → D → D as shown in Fig. 14. Need to ep el ep2 epn
る。転がり軸受外輪 201の昇温が開始されると、焼入タイミング制御側（内周面 201B 側）は、磁束の進入が焼入温度制御側 (外周面 201A側)より少ないので、焼入温度 制御側に比べて遅れて温度が上昇する。通常、温度が 727°Cを越えると、鉄のォー ステナイトイ匕が始まるが、昇温速度が速いと鉄の加熱変態温度は変化する。そのため 、拡散長を計算するための温度は、昇温速度によって変化させなくてはならない。  The When the temperature rise of the rolling bearing outer ring 201 is started, the quenching timing control side (inner peripheral surface 201B side) has less magnetic flux entering than the quenching temperature control side (outer peripheral surface 201A side). The temperature rises with a delay compared to the side. Normally, when the temperature exceeds 727 ° C, iron austenite starts, but when the heating rate is fast, the iron transformation temperature changes. Therefore, the temperature for calculating the diffusion length must be changed according to the heating rate.
[0161] 昇温速度は、電源の能力、コイルおよび被処理物の形状などによって異なるので、 装置や被処理物の種類によって、拡散長を計算するための温度は適宜変更されるこ とが好ましい。焼入タイミング制御側の温度が加熱変態温度を越えたところから、図 中の式によって拡散長 D を計算する。任意の時間における D 力 ¾ *を越えると、 ep epn ep [0161] The rate of temperature rise varies depending on the power source capacity, the shape of the coil and workpiece, etc. It is preferable that the temperature for calculating the diffusion length is appropriately changed depending on the type of the apparatus and the object to be processed. From the point where the quenching timing control temperature exceeds the heating transformation temperature, the diffusion length D is calculated using the formula in the figure. If D force ¾ * at any time is exceeded, ep epn ep
ただちに焼入を開始する。 D *の値は、所定の熱処理品質を維持できる範囲で、で ep  Immediately start quenching. The value of D * is within the range that can maintain the prescribed heat treatment quality.
きるだけ小さな値である方が、熱処理時間低減という観点力もは望ましい。しかし、品 質を安定させる観点力もは、ある程度安全をみた設定値とするのが望ましい。  It is desirable that the value is as small as possible from the viewpoint of reducing the heat treatment time. However, it is desirable to set the viewpoint that stabilizes the quality to a set value that is somewhat safe.
[0162] 図 15は、最高到達温度を 900°C、降温速度を 0°CZ秒とし、焼入後に焼戻を 180 °Cで 120分行なった場合の結果を示している。図 15において、横軸は D *の値 (m ep m)、縦軸は硬度 (HV)および処理時間（秒)を示している。また、図中の黒丸は硬度 、白丸は処理時間を示している。 [0162] Figure 15 shows the results when the maximum temperature reached 900 ° C, the temperature drop rate was 0 ° CZ seconds, and tempering was performed at 180 ° C for 120 minutes after quenching. In FIG. 15, the horizontal axis indicates the value of D * (m ep m), and the vertical axis indicates the hardness (HV) and the processing time (seconds). In the figure, black circles indicate hardness and white circles indicate processing time.
[0163] 図 15を参照して、処理時間は、 D *を大きく設定するほど、必要な拡散長が長くな ep [0163] Referring to Fig. 15, the processing time increases as D * is set larger.
るため増加することが分かる。また硬度は、 D *の値を大きく設定するほど、処理時間 ep  Therefore, it turns out that it increases. In addition, the hardness increases as the value of D * is increased.
が増加するので、高くなつていくことが分かる。ただし、硬度は、加熱が長すぎると飽 和する領域が存在し、 D *が約 0. 015mmで最高硬さに達していた。したがって、 D ep e As it increases, it can be seen that it will rise. However, there was a region where the hardness saturated when the heating was too long, and the maximum hardness was reached at D * of about 0.015 mm. Therefore, D ep e
*の値は 0. 015mm以下が望ましい考えられる。つまり、本実施の形態の場合、たとThe value of * is considered to be desirable to be 0.015mm or less. In other words, in the case of this embodiment,
P P
えば D *の値を 0. 015mmとし、上述のように積算された D が 0. 015mmとなった ep epn  For example, the value of D * is set to 0.015 mm, and D accumulated as described above becomes 0.015 mm ep epn
時点で、焼入タイミング調節装置 206から冷却開始信号が焼入用冷却装置 207に向 けて出力されることにより、冷却タイミングが決定される。そして、これに基づいて焼入 用冷却装置 207が、転がり軸受外輪 201を A点以上の温度から M点以下の温度に  At that time, a cooling start signal is output from the quenching timing adjusting device 206 to the quenching cooling device 207, whereby the cooling timing is determined. Based on this, the quenching cooling device 207 moves the rolling bearing outer ring 201 from the temperature of the A point or higher to the temperature of the M point or lower.
1 S  1 S
冷却することにより、転がり軸受外輪 201が焼入硬化される。  By cooling, the rolling bearing outer ring 201 is hardened and hardened.
[0164] 次に、熱処理条件が TTA線図上で規格内におさまったかどうかという判断、すなわ ち焼入用冷却タイミングの決定方法の変形例について説明する。 [0164] Next, a description will be given of a modification of the method for determining whether the heat treatment conditions are within the specifications on the TTA diagram, that is, for determining the quenching cooling timing.
[0165] 本変形例における焼入用冷却タイミングの決定は、式（7)および式（5)を用いて行 なわれる。 [0165] The quenching cooling timing in the present modification is determined using Equation (7) and Equation (5).
[0166] 3 CZ ( 3 t) =D 3 2CZ ( 3 x2) ' . '式（7) [0166] 3 CZ (3 t) = D 3 2 CZ (3 x 2 ) '.
D:鋼中の炭素の拡散定数、 C :炭素濃度 (質量％)、 t:時間 (秒)、 X：距離 D=D exp (— QZRT) · · ·式（5)  D: Carbon diffusion constant in steel, C: Carbon concentration (% by mass), t: Time (seconds), X: Distance D = D exp (—QZRT)
0  0
D：拡散定数のエントロピ一項、 Q :活性ィ匕エネルギー、 R:気体定数、 T:絶対温度 (κ) D: Entropy term of diffusion constant, Q: Activity energy, R: Gas constant, T: Absolute temperature (κ)
ここで、式 (7)を差分方程式で表すと、以下の式になる。  Here, when Expression (7) is expressed by a difference equation, the following expression is obtained.
[0167] C =rC + (l - 2r) C +rC · · ·式（8) [0167] C = rC + (l-2r) C + rC · · · · (8)
m,n+l m+ι,η m,n m - l，n  m, n + l m + ι, η m, n m-l, n
r=D X AtZ( Ax)2…式（9) r = DX AtZ (Ax) 2 ... Formula (9)
冷却タイミングは、式 (8)をある境界条件で解き、材料中の炭素の固溶状態が所定 の条件を満たしているかどうかで決定する。ここで、境界条件は、たとえば加熱中の 転がり軸受外輪 201を構成する鋼中における鉄炭化物 (セメンタイト; Fe C)と素地と  Cooling timing is determined by solving Equation (8) under certain boundary conditions and determining whether the solid solution state of carbon in the material satisfies a predetermined condition. Here, the boundary condition is, for example, iron carbide (cementite; Fe C) and the base material in the steel constituting the rolling bearing outer ring 201 during heating.
3  Three
の界面において、ある温度での炭素固溶濃度が当該温度での炭素の固溶度に等し くなつているとの仮定の下に与えることができる。  At the interface, the carbon solid solution concentration at a certain temperature can be given under the assumption that the solid solubility of carbon at that temperature is equal.
[0168] 図 16において、横軸は時間（秒）、縦軸は温度 (°C)を示している。また、図 17〜図 19において、横軸は基準となる境界点からの距離 (位置）（mm)、縦軸は炭素濃度（ 質量％)を示している。この炭素の固溶状態の計算においては、 2つの Fe C In FIG. 16, the horizontal axis represents time (seconds), and the vertical axis represents temperature (° C). In FIGS. 17 to 19, the horizontal axis represents the distance (position) (mm) from the reference boundary point, and the vertical axis represents the carbon concentration (mass%). In the calculation of the solid solution state of carbon, two Fe C
3 間の距 離を 0. 012mmとし、境界点 (Fe Cと素地との界面）における固溶炭素量 (炭素濃度  The distance between 3 is 0.012 mm, and the amount of solute carbon (carbon concentration at the boundary point (the interface between Fe C and substrate))
3  Three
(質量％)の値)を SUJ2の固溶度曲線力も得られる値 (熱力学平衡計算ソフトで計算 )とした。この固溶度曲線の式（固溶度の式）は、実験的もしくは熱力学平衡計算によ つて、材料別にあらかじめ求めておくことができる。  The value (mass%) was set to a value (calculated with thermodynamic equilibrium calculation software) that can also obtain the solid solubility curve force of SUJ2. This solid solubility curve equation (solid solubility equation) can be obtained in advance for each material by experimental or thermodynamic equilibrium calculation.
[0169] 図 16〜図 19を参照して、たとえば図 16に示すように転がり軸受外輪 201が加熱さ れた場合、固溶炭素濃度の分布は、図 17〜図 19に示すように中央位置（2つの Fe [0169] Referring to Figs. 16 to 19, for example, when the rolling bearing outer ring 201 is heated as shown in Fig. 16, the distribution of the solute carbon concentration is the central position as shown in Figs. (Two Fe
3 Three
C間の距離を 0. 012mmとした場合には 0. 006mmの位置）において固溶炭素濃度 が最も低くなつており、時間が経過するにつれて固溶炭素濃度が全体として増加す るとともに、中央位置と両端 (Fe Cと素地との界面）との差が小さくなる傾向にある。 When the distance between C is 0.012 mm, the solute carbon concentration is lowest at the position of 0.006 mm), and as the time passes, the solute carbon concentration increases as a whole and the central position And the difference between both ends (the interface between Fe C and the substrate) tends to be small.
3  Three
[0170] 焼入用冷却タイミングは、たとえば転がり軸受外輪 201の内周面 201Bが上述の焼 入条件である固溶炭素濃度の条件を上記中央位置において満たした時点として決 定することができる。また 2つの境界点間の距離 (炭化物間距離)は、被処理物の焼 入前の組織や材料の違いによって適宜変更することができる。  [0170] The quenching cooling timing can be determined, for example, as the point in time when the inner peripheral surface 201B of the rolling bearing outer ring 201 satisfies the above-described quenching condition of the solute carbon concentration at the center position. In addition, the distance between two boundary points (the distance between carbides) can be appropriately changed depending on the difference in structure and material before quenching of the workpiece.
[0171] つまり本変形例の焼入用冷却タイミングの決定はたとえば以下のように行なわれる 。まず焼入タイミング制御側の温度を焼入タイミング制御用測温装置 205により測定 し (ステップ A)、その測定された温度から境界部の炭素量を計算する (ステップ B)。 境界部の炭素量の値を式 (8)の境界条件に与えて式 (8)を計算する (ステップ C)。 以上の工程により、図 17〜図 19に示すような固溶炭素濃度の分布を計算することが できる (ステップ D)。得られた固溶炭素濃度の分布から、固溶炭素濃度の分布の中 央位置における炭素濃度が所定の炭素濃度 (たとえば 0. 6〜0. 8質量％)になった 力どうかの確認を行なう（ステップ E)。もし中央位置における炭素濃度が所定の炭素 濃度に達していたら冷却を開始し (ステップ F)、達していなければ冷却は開始されず に加熱が継続されて再度ステップ Aに戻る。 That is, the quenching cooling timing in this modification is determined as follows, for example. First, the quenching timing control side temperature is measured by the quenching timing control temperature measuring device 205 (step A), and the carbon content at the boundary is calculated from the measured temperature (step B). Equation (8) is calculated by applying the boundary carbon content to the boundary condition of Equation (8) (Step C). Through the above process, it is possible to calculate the solid solution carbon concentration distribution as shown in Fig. 17 to Fig. 19 (Step D). From the obtained solute carbon concentration distribution, it is confirmed whether the carbon concentration at the center of the solute carbon concentration distribution is a predetermined carbon concentration (eg, 0.6 to 0.8 mass%). (Step E). If the carbon concentration at the central position has reached the predetermined carbon concentration, cooling is started (Step F). If not, cooling is not started and heating is continued and the process returns to Step A again.
[0172] また、上記ステップ Cにおける式 (8)は以下のように差分法により解くことができる。 [0172] Further, the equation (8) in the above step C can be solved by the difference method as follows.
まず図 17〜図 19の炭素分布の両端における炭素濃度は、炭化物素地界面の炭素 濃度である。したがって、この位置からある濃度 (炭素の固溶度)で炭素が素地へ供 給される。  First, the carbon concentration at both ends of the carbon distribution in Figs. 17 to 19 is the carbon concentration at the carbide substrate interface. Therefore, carbon is supplied from this position to the substrate at a certain concentration (solid solubility of carbon).
[0173] たとえば図 17〜図 19のように、隣り合う Fe Cの間に区切りを 5点とると（境界点を入  [0173] For example, as shown in Fig. 17 to Fig. 19, if there are 5 delimiters between adjacent Fe C (
3  Three
れると 7点）、 5個の連立方程式が得られる力 未知数は、 C 、C 、C 、C 、C 、  7 points), the force to obtain 5 simultaneous equations The unknowns are C, C, C, C, C,
Ο,η Ι,η 2,η 3,η 4,η Ο, η Ι, η 2, η 3, η 4, η
C 、C の 7つになる。このうち C とじ とは炭化物と素地との界面の位置となるためThere are 7 C and C. Of these, C binding is located at the interface between carbide and substrate.
5,η ο,η Ο,η 6,η 5, η ο, η Ο, η 6, η
、固溶度の式力も炭素濃度の値を与えることができる。これにより、連立方程式は 5個 で、未知数が 5個となるため、 C 、C 、C 、C 、C の値を求めることができる。  The formula power of solid solubility can also give the value of carbon concentration. As a result, there are five simultaneous equations and five unknowns, so the values of C, C, C, C, and C can be obtained.
Ι,η 2,η 3,η 4,η 5,η  Ι, η 2, η 3, η 4, η 5, η
[0174] なお、上記固溶炭素濃度の計算を、焼入タイミング制御側だけでなぐ焼入温度制 御側でも行なうことにより、焼入温度制御側の炭素の固溶状態から、焼入温度制御 側の残留オーステナイト量を推測することができる。  [0174] The above calculation of the solid solution carbon concentration is performed not only on the quenching timing control side but also on the quenching temperature control side, so that the quenching temperature control is performed from the solid solution state of the carbon on the quenching temperature control side. The amount of retained austenite on the side can be estimated.
[0175] 図 20は、本変形例の焼入用冷却タイミングの決定方法で焼入を実施した場合の、 焼入温度制御側 (温度制御側)および焼入タイミング制御側 (焼入制御側）における 固溶炭素濃度の分布を示す図である。図 20において、横軸は基準となる境界点力も の距離 (位置）（mm)、縦軸は炭素濃度 (質量％)を示している。このデータは、焼入 温度 (加熱温度）を 950°Cで一定とし、焼入温度までの昇温速度を 300°CZ秒とし、 炭化物間距離を 0. 012mmとし、冷却開始の条件を炭素濃度の中央位置での値を 0. 6質量％とした場合のものである。図 20から、固溶炭素濃度の値は、焼入タイミン グ制御側よりも焼入温度制御側のほうが全体的に高くなつて 、ることが分かる。これ は、転がり軸受外輪 201において、焼入加熱装置 202に含まれる焼入用誘導コイル に近 、焼入温度制御側の温度が、焼入タイミング制御側よりも高くなるためである。 [0175] Fig. 20 shows the quenching temperature control side (temperature control side) and the quenching timing control side (quenching control side) when quenching is performed by the quenching cooling timing determination method of this variation. It is a figure which shows distribution of the solid solution carbon concentration in. In FIG. 20, the horizontal axis represents the distance (position) (mm) of the reference boundary point force, and the vertical axis represents the carbon concentration (mass%). This data shows that the quenching temperature (heating temperature) is constant at 950 ° C, the heating rate up to the quenching temperature is 300 ° CZ seconds, the distance between carbides is 0.012 mm, and the cooling start condition is the carbon concentration. When the value at the center position is 0.6 mass%. From FIG. 20, it can be seen that the solute carbon concentration value is generally higher on the quenching temperature control side than on the quenching timing control side. This is because the induction coil for quenching included in the quenching heating device 202 in the outer ring 201 of the rolling bearing. This is because the temperature on the quenching temperature control side is higher than that on the quenching timing control side.
[0176] さらに、上述固溶炭素濃度の計算の開始温度、すなわち炭素の素地への固溶の 開始温度は、昇温速度を考慮して決定することが好ましい。以下、その決定方法に ついて説明する。  [0176] Furthermore, it is preferable to determine the starting temperature of the calculation of the above-mentioned solid solution carbon concentration, that is, the starting temperature of the solid solution of carbon in the substrate, in consideration of the rate of temperature rise. The determination method will be described below.
[0177] 鋼が平衡状態を保ちつつ 727°C (A点温度）以上に加熱されると、オーステナイト 化が始まり、これに伴って炭素の固溶が始まる。しかし、昇温速度が速い場合、 A点 温度は昇温速度に影響されて変化し、 A 点 (加熱変態点)温度にお!、てオーステ  [0177] When the steel is heated to 727 ° C (point A temperature) or higher while maintaining an equilibrium state, austenitization begins, and carbon solid solution starts accordingly. However, if the rate of temperature rise is fast, the temperature at point A changes depending on the rate of temperature rise and changes to the point A (heating transformation point) temperature!
C1  C1
ナイトイ匕を開始する。したがって、上記計算の開始温度は、昇温速度を考慮して変化 させることが好ましい。  Start night 匕. Therefore, it is preferable to change the starting temperature of the above calculation in consideration of the rate of temperature increase.
[0178] 図 21にお 、て、横軸は昇温速度 (°CZ秒）、縦軸は加熱変態点 A (°C)を示して  [0178] In Fig. 21, the horizontal axis indicates the heating rate (° CZ seconds), and the vertical axis indicates the heating transformation point A (° C).
C1  C1
いる。図 21を参照して、昇温速度が変化すると、加熱変態点 A は、 727°Cから 950  Yes. Referring to FIG. 21, when the heating rate changes, the heating transformation point A changes from 727 ° C to 950 ° C.
C1  C1
°cまで変化することが分かる。よって、被処理物の組成における昇温速度の変化に 対する加熱変態点 A の変化を予め調べておき、被処理物の加熱時における昇温  It turns out that it changes to ° c. Therefore, the change in the heating transformation point A with respect to the change in the heating rate in the composition of the workpiece is examined in advance, and the temperature rise during heating of the workpiece
C1  C1
速度から加熱変態点 A を求めて、その加熱変態点 A に基づいて上記固溶炭素  The heating transformation point A is obtained from the velocity, and the above solute carbon is calculated based on the heating transformation point A.
CI C1  CI C1
濃度の計算開始温度 (炭素の固溶開始温度)を決定することができる。  The concentration calculation start temperature (carbon solid solution start temperature) can be determined.
[0179] 図 22において、横軸は時間、縦軸は温度を示している。図 22中には、焼入温度制 御側（図 8の転がり軸受外輪 201の外周面 201A)の温度推移と焼入タイミング制御 側（図 8の転がり軸受外輪 201の内周面 201B)の温度推移と加熱変態点 A とが示  In FIG. 22, the horizontal axis represents time, and the vertical axis represents temperature. 22 shows the temperature transition on the quenching temperature control side (outer peripheral surface 201A of the rolling bearing outer ring 201 in FIG. 8) and the temperature on the quenching timing control side (inner peripheral surface 201B of the rolling bearing outer ring 201 in FIG. 8). Transition and heating transformation point A
C1 されている。  C1 has been.
[0180] 図 22を参照して、加熱初期においては、焼入温度制御側での加熱が急速に行な われるため、焼入タイミング制御側の昇温速度も速くなり、加熱変態点は高くなる。焼 入温度制御側の温度が所定の設定温度に近づくと、焼入温度調節装置 204により 昇温速度が緩やかになるように加熱が制御される。そのため、焼入タイミング制御側 の昇温速度も緩やかになり、加熱変態点 A が低下していく。そして、時間が経過す  [0180] Referring to FIG. 22, in the initial stage of heating, the heating on the quenching temperature control side is rapidly performed, so the heating rate on the quenching timing control side is also increased, and the heating transformation point is increased. . When the temperature on the quenching temperature control side approaches a predetermined set temperature, heating is controlled by the quenching temperature adjusting device 204 so that the rate of temperature rise becomes slow. As a result, the rate of temperature increase on the quenching timing control side also becomes moderate, and the heating transformation point A decreases. And time passes
C1  C1
ると、加熱変態点 A は、焼入タイミング制御側の温度推移と交わる。この交点がォ  Then, the heating transformation point A intersects with the temperature transition on the quenching timing control side. This intersection is
C1  C1
ーステナイトイ匕の開始温度を示していることになるため、この交点の温度（つまりォー ステナイトイ匕の開始温度)から上記固溶炭素濃度の計算を開始することができる。  Since the start temperature of the austenite cake is indicated, the calculation of the solute carbon concentration can be started from the temperature of this intersection (that is, the start temperature of the austenite cake).
[0181] そして、図 17〜図 19を用いて説明したように、固溶炭素濃度の分布の中央位置に おける炭素濃度が所定の炭素濃度 (たとえば 0. 6〜0. 8質量％)を越えた時点で、 ただちに冷却を開始して、被処理物 (転がり軸受外輪 201)を焼入硬化することがで きる。 [0181] Then, as described with reference to FIGS. 17 to 19, at the central position of the distribution of the solute carbon concentration. When the carbon concentration exceeds a predetermined carbon concentration (for example, 0.6 to 0.8 mass%), cooling can be started immediately and the workpiece (rolling bearing outer ring 201) can be hardened and hardened. wear.
[0182] 次に、上述の実施の形態における温度制御による高周波焼戻 (焼戻データ取得ェ 程)の具体的手順について、転がり軸受外輪 201の材質が JIS SUJ2である場合を 例に、詳細に説明する。ここでは、強度の観点から、焼戻後の被処理物の熱処理規 格を、硬度 HRC58以上 HRC62以下と設定する。  [0182] Next, the specific procedure of induction tempering (tempering data acquisition process) by temperature control in the above-described embodiment will be described in detail, taking the case where the material of the rolling bearing outer ring 201 is JIS SUJ2 as an example. explain. Here, from the viewpoint of strength, the heat treatment standard of the workpiece after tempering is set to hardness HRC58 or more and HRC62 or less.
[0183] 材料強度と、焼戻温度および焼戻時間との間には、次の関係式が成立する。 [0183] The following relational expression is established between the material strength, the tempering temperature, and the tempering time.
X= l -exp{ - (kt) N} X = l -exp {-(kt) N }
k=Aexp (-Q/RT)  k = Aexp (-Q / RT)
M = M—（M -M )X  M = M— (M -M) X
o o f  o o f
X:機械的性質の変化率、 k:反応速度係数、 t:焼戻時間 (秒)、 N:時間指数、 A:振 動因子項、 Q :活性化エネルギー、 R:気体定数、 T:焼戻温度 (K)、 M :焼戻後の硬 度、 Μ：焼入後の硬度、 Μ：生材硬度  X: rate of change of mechanical properties, k: reaction rate coefficient, t: tempering time (seconds), N: time index, A: vibration factor term, Q: activation energy, R: gas constant, T: tempering Tempering temperature (K), M: Hardness after tempering, Μ: Hardness after quenching, Μ: Raw material hardness
0 f  0 f
したがって、これらの式力も焼戻時間 tにつ 、ての次式を導くことができる。  Therefore, these formula forces can also be derived from the following formula for the tempering time t.
[0184] t=〔ln{ (M— M ) Z (M— M ) } X {Aexp (— QZRT) }_N〕1/N…式（10) [0184] t = [ln {(M- M) Z ( M- M)} X {Aexp (- QZRT)} _N ] 1 / N ... (10)
0 f f  0 f f
式（10)中の焼入後の硬度 Mと生材硬度 Mは実測できる。また、 Nと Aと Qは実験  The hardness M and the raw material hardness M after quenching in the formula (10) can be measured. N, A, and Q are experiments
0 f  0 f
的に求めることができるから、焼戻温度 Tの値を代入して式（10)により焼戻時間 tを 計算できる。本実施の形態の焼戻データ取得工程においては、被処理物が冷却さ れるべきタイミングは、式（10)に基づき焼戻時間 tを調節することで決定することがで きる。式（10)は、被処理物の規格品質 (硬度）に対する熱処理温度とその保持時間 との関係式であり、転がり軸受外輪 201の形状を問わず有効に利用することができる  Therefore, the tempering time t can be calculated by Equation (10) by substituting the value of the tempering temperature T. In the tempering data acquisition process of the present embodiment, the timing at which the workpiece should be cooled can be determined by adjusting the tempering time t based on the equation (10). Expression (10) is a relational expression between the heat treatment temperature and the retention time with respect to the standard quality (hardness) of the workpiece, and can be used effectively regardless of the shape of the rolling bearing outer ring 201.
[0185] 図 23を参照して、焼戻の加熱温度および時間の条件 (焼戻条件)の決定方法を説 明する。図 23において、横軸は焼戻温度 (°C)、縦軸は保持時間（秒)を示している。 また、領域 Aは HRC62以上の範囲であり、領域 Bは HRC58以下の範囲であり、領 域 Cが HRC58〜62の範囲である。 [0185] With reference to FIG. 23, a method of determining the tempering heating temperature and time conditions (tempering conditions) will be described. In FIG. 23, the horizontal axis represents the tempering temperature (° C) and the vertical axis represents the holding time (seconds). Region A is a range of HRC62 or higher, region B is a range of HRC58 or lower, and region C is a range of HRC58-62.
[0186] 図 23に示す条件線図は、焼戻時間 tを求める式（10)に基づいて作成することがで きる。図 23を参照して、焼戻温度が高温になるほど短時間での焼戻が可能になる。 このため、焼戻温度は高い方が、熱処理時間の低減という観点からは望ましい。しか し、焼戻温度が高くなると、温度ムラによる焼戻ムラが発生しやすくなると考えられる ので、焼戻温度は、熱処理時間と焼戻ムラとの兼ね合いなど力 決定することができ る。 [0186] The condition diagram shown in Fig. 23 can be created based on Equation (10) for obtaining the tempering time t. wear. Referring to FIG. 23, the higher the tempering temperature, the shorter the tempering becomes possible. For this reason, a higher tempering temperature is desirable from the viewpoint of reducing the heat treatment time. However, if the tempering temperature increases, tempering unevenness due to temperature unevenness is likely to occur. Therefore, the tempering temperature can be determined in terms of the balance between heat treatment time and tempering unevenness.
[0187] 焼戻条件が決定すると、図 9を参照して、当該焼戻条件がパーソナルコンピュータ などの焼戻温度調節装置 214に入力される。焼戻温度調節装置 214は、焼戻温度 制御用測温装置 213と、焼戻加熱装置 212に接続されており、焼戻温度制御用測 温装置 213からの温度情報に基づき、 PID制御により温度制御信号を焼戻加熱装 置 212に出力し、転がり軸受外輪 201の温度推移を制御する。このとき同時に、焼戻 終了タイミング制御用測温装置 215の温度情報をパソコンなどの焼戻終了タイミング 調節装置 216に取り込み、その温度推移から加熱が十分であるかどうかを判断し、被 処理物が冷却されるべきタイミングを調節する。  [0187] When the tempering conditions are determined, the tempering conditions are input to a tempering temperature adjusting device 214 such as a personal computer with reference to FIG. The tempering temperature adjusting device 214 is connected to the tempering temperature control temperature measuring device 213 and the tempering heating device 212. Based on the temperature information from the tempering temperature control temperature measuring device 213, the temperature is controlled by PID control. A control signal is output to the tempering heating device 212 to control the temperature transition of the rolling bearing outer ring 201. At the same time, the temperature information of the tempering end timing control temperature measuring device 215 is taken into the tempering end timing adjusting device 216 such as a personal computer, and it is judged from the temperature transition whether the heating is sufficient, Adjust the timing to be cooled.
[0188] 図 24の上段左のグラフにおいては横軸を時間 t、縦軸を温度 Tとして温度推移が示 されている。また、上段右の図は上段左のグラフの領域 j8の部分を拡大して示した図 である。また、下段には焼戻後の硬度 Mの値を温度推移力 積算するための計算式 が示されている。  [0188] In the upper left graph of FIG. 24, the temperature transition is shown with time t on the horizontal axis and temperature T on the vertical axis. The upper right figure shows an enlarged view of the area j8 in the upper left graph. The lower part shows the formula for integrating the temperature transition force of the hardness M after tempering.
[0189] 図 24を参照して、焼戻終了タイミング制御用測温装置 215からの温度情報は刻一 刻と変化するので、 M (焼戻後の硬度）の値は t *を算出しつつ、図 24のように積算し て算出することが望ましい。そして、焼戻後の硬度が目標の硬度になる条件が満たさ れた時点で、焼戻終了装置 217により転がり軸受外輪 201が冷却される。なお、焼戻 温度調節装置 214と焼戻終了タイミング調節装置 216とを同一のパソコンで兼ねるこ とちでさる。  [0189] Referring to FIG. 24, the temperature information from the tempering end timing control temperature measuring device 215 changes every moment, so the value of M (hardness after tempering) is calculated as t *. It is desirable to calculate by integrating as shown in FIG. When the condition that the hardness after tempering becomes the target hardness is satisfied, the rolling bearing outer ring 201 is cooled by the tempering end device 217. Note that the tempering temperature adjusting device 214 and the tempering end timing adjusting device 216 are also used as the same personal computer.
[0190] (実施の形態 3)  [0190] (Embodiment 3)
図 25は、本発明の一実施の形態である実施の形態 3における高周波熱処理品とし ての転がり軸受外輪の構成を示す概略断面図である。図 25を参照して、実施の形態 3における転がり軸受外輪の構成を説明する。  FIG. 25 is a schematic cross-sectional view showing a configuration of a rolling bearing outer ring as a high-frequency heat-treated product in the third embodiment which is an embodiment of the present invention. With reference to FIG. 25, the configuration of the rolling bearing outer ring in the third embodiment will be described.
[0191] 図 25を参照して、実施の形態 3における高周波熱処理品としての転がり軸受外輪 3 01は、円環状の形状を有している。そして、転がり軸受外輪 301は、内周面 301Bに 転動体としての玉、ころなどが接触しつつ転走するための転走面 301Cが形成されて いるとともに、他の部材と接触して転がり軸受外輪を当該他の部材に対して保持する ための外周面 301Aを有している。ここで、転がり軸受外輪 301は転動疲労強度およ び剛性の観点から、 58HRC以上の硬度を有していることが好ましい。また、寸法安 定性の観点から、残留オーステナイト量は 12体積％以下に抑制されていることが好 ましい。 Referring to FIG. 25, rolling bearing outer ring 3 as the high frequency heat treatment product in the third embodiment 01 has an annular shape. The rolling bearing outer ring 301 has a rolling surface 301C for rolling while the balls, rollers, etc., as rolling elements are in contact with the inner peripheral surface 301B, and is also in contact with other members. It has an outer peripheral surface 301A for holding the outer ring against the other members. Here, the rolling bearing outer ring 301 preferably has a hardness of 58 HRC or more from the viewpoint of rolling fatigue strength and rigidity. From the viewpoint of dimensional stability, the retained austenite content is preferably suppressed to 12% by volume or less.
[0192] そして、転がり軸受外輪 301は、以下に説明する本発明の一実施の形態における 高周波熱処理方法で熱処理されて作製されているため、製造コストが抑制され、 つ品質の安定した高周波熱処理品となっている。  [0192] Since the rolling bearing outer ring 301 is manufactured by heat treatment using the high-frequency heat treatment method in one embodiment of the present invention described below, a high-frequency heat-treated product with reduced manufacturing cost and stable quality is provided. It has become.
[0193] 次に、図 26を参照して、本発明の一実施の形態である実施の形態 3における高周 波熱処理装置としての高周波焼入装置について説明する。  Next, with reference to FIG. 26, an induction hardening apparatus as a high-frequency heat treatment apparatus in Embodiment 3, which is an embodiment of the present invention, will be described.
[0194] 図 26を参照して、実施の形態 3における高周波焼入装置 391は、高周波加熱によ り被処理物 (たとえば転がり軸受外輪 301)を加熱して焼入硬化する本発明の高周波 熱処理方法に使用される高周波焼入装置であって、被処理物としての転がり軸受外 輪 301の温度を調節するための温度制御装置 350と、加熱された転がり軸受外輪 3 01が冷却されるべきタイミングを調節するための焼入制御装置 360とを備えている。 また、後述するように、転がり軸受外輪 301の外周面 301Aおよび内周面 301Bには 、転がり軸受外輪 301が加熱される温度域、すなわち焼入温度において、転がり軸 受外輪 301よりも耐酸ィ匕性の高い安定ィ匕層 309が形成されている。  Referring to FIG. 26, induction hardening apparatus 391 in Embodiment 3 is an induction heat treatment according to the present invention in which an object to be treated (for example, rolling bearing outer ring 301) is quenched and hardened by induction heating. Induction hardening apparatus used in the method, the temperature control device 350 for adjusting the temperature of the rolling bearing outer ring 301 as the object to be treated, and the timing at which the heated rolling bearing outer ring 301 should be cooled And a quenching control device 360 for adjusting the temperature. As will be described later, the outer peripheral surface 301A and the inner peripheral surface 301B of the rolling bearing outer ring 301 are more resistant to oxidation than the rolling bearing outer ring 301 in the temperature range in which the rolling bearing outer ring 301 is heated, that is, in the quenching temperature. A highly stable layer 309 is formed.
[0195] 温度制御装置 350は、転がり軸受外輪 301において、高周波加熱により最も温度 が高くなると考えられる外周面 301Aの温度データを取得し、転がり軸受外輪 301の 温度データに基づく温度の情報を出力する温度制御用測温装置としての第 1放射温 度計 303と、第 1放射温度計 303に接続され、第 1放射温度計 303からの温度の情 報に基づき被処理物の加熱状態を制御するための温度制御信号を出力する温度調 節装置 304と、温度調節装置 304に接続され、温度調節装置 304からの温度制御 信号に基づき、高周波加熱により転がり軸受外輪 301を加熱する加熱装置 302とを 含んでいる。加熱装置 302は、たとえば高周波電流を流すための誘導コイルと、誘導 コイルに接続され高周波電流を発生させる電源とを有している。 [0195] The temperature control device 350 acquires temperature data of the outer peripheral surface 301A that is considered to have the highest temperature due to high-frequency heating in the rolling bearing outer ring 301, and outputs temperature information based on the temperature data of the rolling bearing outer ring 301. A first radiation thermometer 303 as a temperature control temperature measuring device, and connected to the first radiation thermometer 303, and controls the heating state of the object to be processed based on the temperature information from the first radiation thermometer 303. A temperature control device 304 that outputs a temperature control signal for heating, and a heating device 302 that is connected to the temperature control device 304 and heats the rolling bearing outer ring 301 by high-frequency heating based on the temperature control signal from the temperature control device 304. Contains. The heating device 302 includes, for example, an induction coil for flowing a high-frequency current, an induction coil And a power source that is connected to the coil and generates a high-frequency current.
[0196] 焼入制御装置 360は、高周波加熱により最も温度が高くなると考えられる外周面 3 01Aから最も遠ぐ温度の上昇が最も小さいと考えられる内周面 301Bの温度データ を取得し、内周面 301Bの温度データに基づく温度の情報を出力する焼入用測温装 置としての第 2放射温度計 305と、第 2放射温度計 305に接続され、第 2放射温度計 305からの温度の情報に基づき加熱時間を調節し、転がり軸受外輪 301が冷却され るべきタイミングを決定して冷却開始信号を出力する冷却タイミング調節装置 306と、 冷却タイミング調節装置 306に接続され、冷却開始信号に基づいて、転がり軸受外 輪 301を冷却することにより転がり軸受外輪 301を焼入硬化する冷却装置としての冷 却液噴射装置 307とを含んで 、る。  [0196] The quenching control device 360 obtains temperature data of the inner peripheral surface 301B, which is considered to have the smallest temperature rise farthest from the outer peripheral surface 301A that is considered to have the highest temperature due to high-frequency heating, and 2nd radiation thermometer 305 as temperature measuring device for quenching that outputs temperature information based on temperature data of surface 301B, and connected to 2nd radiation thermometer 305, the temperature from 2nd radiation thermometer 305 A cooling timing adjusting device 306 that adjusts the heating time based on the information, determines the timing at which the rolling bearing outer ring 301 should be cooled, and outputs a cooling start signal, and is connected to the cooling timing adjusting device 306 and based on the cooling start signal And a cooling liquid injection device 307 as a cooling device for quenching and hardening the rolling bearing outer ring 301 by cooling the rolling bearing outer ring 301.
[0197] ここで、温度調節装置 304および冷却タイミング調節装置 306は、たとえばそれぞ れパーソナルコンピュータであり、 1台のパーソナルコンピュータで温度調節装置 30 4と冷却タイミング調節装置 306とを兼ねる構成であってもよい。  Here, the temperature adjustment device 304 and the cooling timing adjustment device 306 are each a personal computer, for example, and have a configuration in which the temperature adjustment device 304 and the cooling timing adjustment device 306 are combined with one personal computer. May be.
[0198] 次に、上述の高周波焼入装置を用いた本発明の一実施の形態である実施の形態 3における高周波熱処理方法としての高周波焼入方法について説明する。  [0198] Next, an induction hardening method as an induction heat treatment method in Embodiment 3, which is an embodiment of the present invention, using the above-described induction hardening apparatus will be described.
[0199] 図 26および図 27を参照して、実施の形態 3の高周波焼入方法は、高周波加熱に より被処理物 (転がり軸受外輪 301)を加熱して焼入硬化する高周波熱処理方法で あって、転がり軸受外輪 301の表面に、転がり軸受外輪 301が加熱される温度域に おいて転がり軸受外輪 301よりも耐酸ィ匕性の高い安定ィ匕層 309が形成される表面安 定化工程 311と、表面安定化工程 311にお 、て安定化層 309が形成された転がり軸 受外輪 301が焼入硬化される焼入硬化工程 310とを備えて 、る。  Referring to FIG. 26 and FIG. 27, the induction hardening method of the third embodiment is an induction heat treatment method in which the workpiece (rolling bearing outer ring 301) is heated and hardened by induction heating. Thus, a surface stabilization step 311 is formed on the surface of the rolling bearing outer ring 301 in a temperature layer where the rolling bearing outer ring 301 is heated. In addition, the surface stabilization step 311 includes a quench hardening step 310 in which the rolling bearing outer ring 301 on which the stabilization layer 309 is formed is quenched and hardened.
[0200] 焼入硬化工程 310は、安定ィ匕層 309が形成された転がり軸受外輪 301の温度が 調節される温度制御工程 320と、加熱された転がり軸受外輪 301が冷却されるべきタ イミングが決定されて、転がり軸受外輪 301が冷却される焼入制御工程 330とを含ん でいる。  [0200] The quench hardening process 310 includes a temperature control process 320 in which the temperature of the rolling bearing outer ring 301 on which the stable layer 309 is formed is adjusted, and a timing at which the heated rolling bearing outer ring 301 is to be cooled. And a quench control step 330 in which the rolling bearing outer ring 301 is cooled.
[0201] 温度制御工程 320は、転がり軸受外輪 301の外周面 301Aに形成された安定ィ匕層 309の表面の温度が第 1放射温度計 303により測定される温度制御用測温工程 323 と、温度制御用測温工程 323において測定された温度の情報に基づき、転がり軸受 外輪 301の加熱状態を制御するための温度制御信号が出力される温度調節工程 3 24と、温度制御信号に基づいて、高周波加熱により転がり軸受外輪 301が加熱され る加熱工程 322とを有して 、る。 [0201] The temperature control step 320 includes a temperature control temperature measurement step 323 in which the surface temperature of the stable layer 309 formed on the outer peripheral surface 301A of the rolling bearing outer ring 301 is measured by the first radiation thermometer 303, Rolling bearing based on temperature information measured in temperature measurement process 323 A temperature adjustment step 324 in which a temperature control signal for controlling the heating state of the outer ring 301 is output; and a heating step 322 in which the rolling bearing outer ring 301 is heated by high-frequency heating based on the temperature control signal. RU
[0202] 焼入制御工程 330は、転がり軸受外輪 301の内周面 301Bに形成された安定ィ匕層 309の表面の温度が第 2放射温度計 305により測定される焼入用測温工程 335と、 焼入用測温工程 335において測定された温度の情報に基づき加熱時間が調節され 、転がり軸受外輪 301が冷却されるべきタイミングが決定されて冷却開始信号が出力 される冷却タイミング調節工程 336と、冷却開始信号に基づいて、転がり軸受外輪 3 01が冷却されることにより転がり軸受外輪 301が焼入硬化される冷却工程 337とを有 している。 [0202] The quenching control step 330 is a quenching temperature measurement step 335 in which the surface temperature of the stable layer 309 formed on the inner peripheral surface 301B of the rolling bearing outer ring 301 is measured by the second radiation thermometer 305. And a cooling timing adjusting step 336 in which the heating time is adjusted based on the temperature information measured in the quenching temperature measuring step 335, the timing at which the rolling bearing outer ring 301 should be cooled is determined, and a cooling start signal is output. And a cooling step 337 in which the rolling bearing outer ring 301 is quenched and hardened by cooling the rolling bearing outer ring 301 based on the cooling start signal.
[0203] 実施の形態 3における高周波焼入方法は、温度制御により実施され、熱処理の条 件出しが容易であるため、転がり軸受外輪 301の製造コストを抑制し、かつ品質を安 定させることが可會である。  [0203] The induction hardening method according to the third embodiment is performed by temperature control and is easy to determine the conditions for heat treatment. Therefore, the manufacturing cost of the rolling bearing outer ring 301 can be suppressed and the quality can be stabilized. It is pretty.
[0204] なお、表面安定ィ匕工程 311においては、転がり軸受外輪 301の表面に黒体塗料が 塗布されること〖こより、上述の安定ィ匕層 309としての黒体塗料層を形成してもよい。ま た、黒体塗料層に代えて、酸化鉄層が形成されてもよい。この酸化鉄層は、たとえば 転がり軸受外輪 301の表面が熱酸化されることにより形成されてもよ ヽし、転がり軸受 外輪 301が酸性の溶液中に浸漬されることにより形成されてもよい。  [0204] In the surface stabilization step 311, the black body paint is applied to the surface of the rolling bearing outer ring 301, so that the black body paint layer as the above-described stability layer 309 is formed. Good. Further, an iron oxide layer may be formed instead of the black body paint layer. This iron oxide layer may be formed, for example, by thermally oxidizing the surface of the rolling bearing outer ring 301, or may be formed by immersing the rolling bearing outer ring 301 in an acidic solution.
[0205] 次に、上述の実施の形態 3における高周波焼入方法の具体的手順について、転が り軸受外輪 301の材質が JIS SUJ2である場合を例に、詳細に説明する。  [0205] Next, a specific procedure of the induction hardening method in the above-described third embodiment will be described in detail by taking as an example the case where the material of the rolling bearing outer ring 301 is JIS SUJ2.
[0206] ここでは、 180°Cで焼戻した場合の焼戻後の硬度 (焼戻硬度）が強度の観点力 H RC58以上 (HV653以上)であり、寸法安定性の観点から残留オーステナイト量が 1 2体積％以下であることを規格値として設定する。  [0206] Here, the hardness after tempering (tempering hardness) when tempering at 180 ° C is strength strength of HRC58 or higher (HV653 or higher), and the amount of retained austenite is 1 from the viewpoint of dimensional stability. The standard value is set to 2% by volume or less.
[0207] 図 13を参照して、実施の形態 3における高周波焼入方法のうち、冷却タイミング調 節工程の熱処理条件の決定につ!、て説明する。  Referring to FIG. 13, the determination of the heat treatment conditions in the cooling timing adjustment step in the induction hardening method in the third embodiment will be described.
[0208] 実施の形態 3における高周波焼入においては、まず、目標の熱処理条件 (焼入に おける加熱温度および加熱時間の条件）を決定する必要がある。図 13を参照して、 SUJ2製の転がり軸受外輪の硬度は焼入温度と保持時間とが大きくなるにつれて規 格を満たしやすくなる。これに対して、オーステナイト量は焼入温度と保持時間とが大 きくなるにつれて規格を満たしにくくなる。熱処理の規格値 (硬度規格および残留ォ ーステナイト量の規格値)を満たすためには、比較的低温で長時間の条件設定の方 が熱処理品質を制御しやすい。たとえば、 1050°Cの比較的高温での処理では、熱 処理品質規格を確保するための保持時間は 15秒以上であるが、 17秒以上保持して しまうと規格を満たすことができない。これに対し、 950°Cの処理では、熱処理品質を 確保するための保持時間は 20秒以上であり、 60秒までは規格を満たすことができる 。一方、短時間での昇温が可能であるという高周波熱処理の利点を生かすためには 、できるだけ高温、短時間での処理が望ましい。すなわち、図 13を参照して、熱処理 品質の制御の容易性と、熱処理の効率とのバランスを考慮しつつ、目標の熱処理条 件を決定することができる。 [0208] In the induction hardening in the third embodiment, first, it is necessary to determine the target heat treatment conditions (conditions of heating temperature and heating time in quenching). Referring to Fig. 13, the hardness of the SUJ2 rolling bearing outer ring increases as the quenching temperature and holding time increase. It becomes easy to satisfy the case. In contrast, the amount of austenite becomes difficult to meet the specifications as the quenching temperature and holding time increase. In order to satisfy the standard values for heat treatment (hardness standard and residual austenite standard value), it is easier to control the heat treatment quality by setting conditions at a relatively low temperature for a long time. For example, in the treatment at a relatively high temperature of 1050 ° C, the holding time for ensuring the heat treatment quality standard is 15 seconds or more, but if it is kept for 17 seconds or more, the standard cannot be satisfied. On the other hand, in the treatment at 950 ° C, the holding time for ensuring the heat treatment quality is 20 seconds or more, and the standard can be satisfied up to 60 seconds. On the other hand, in order to take advantage of the high-frequency heat treatment that the temperature can be raised in a short time, it is desirable to perform the treatment at as high a temperature as possible for a short time. That is, referring to FIG. 13, a target heat treatment condition can be determined in consideration of the balance between the ease of control of heat treatment quality and the efficiency of heat treatment.
[0209] なお、図 13は SUJ2に関する TTA線図である力 材料に応じた TTA線図を作成す ることができれば、その線図に応じて熱処理条件を決定すればよいので、本実施の 形態 3の高周波熱処理方法は材料の種類を問わず利用することができる。  [0209] FIG. 13 is a TTA diagram related to SUJ2. If a TTA diagram corresponding to the force material can be created, the heat treatment conditions may be determined according to the diagram. The high-frequency heat treatment method 3 can be used regardless of the type of material.
[0210] 熱処理条件が決まると、図 26を参照して、熱処理条件をパーソナルコンピュータな どの温度調節装置 304に入力する。温度調節装置 304は、第 1放射温度計 303と、 加熱装置 302とに接続されており、第 1放射温度計 303からの温度情報に基づき、 P ID (Proportional Integral Differential)制御により温度制御信号を加熱装置 3 02に出力し、第 1放射温度計 303の測温部である外周面 301 Aの温度推移を制御 することができる。なお、外周面 301Aは、転がり軸受外輪 301において磁束の侵入 が最も多くなり、高周波加熱による温度上昇の最も大きい部位である。  [0210] When the heat treatment conditions are determined, referring to FIG. 26, the heat treatment conditions are input to temperature control device 304 such as a personal computer. The temperature adjustment device 304 is connected to the first radiation thermometer 303 and the heating device 302. Based on the temperature information from the first radiation thermometer 303, the temperature control signal is transmitted by P ID (Proportional Integral Differential) control. The temperature can be output to the heating device 302, and the temperature transition of the outer peripheral surface 301A, which is the temperature measuring unit of the first radiation thermometer 303, can be controlled. The outer peripheral surface 301A is the part where the magnetic flux penetrates most in the rolling bearing outer ring 301 and the temperature rises most due to high frequency heating.
[0211] このとき同時に、第 2放射温度計 305の測温データをパーソナルコンピュータなど の冷却タイミング調節装置 306に取り込み、その温度推移力 加熱が十分であるかど うかを判断し、冷却タイミングを調節する。冷却タイミングの判断は、第 2放射温度計 3 05の測温部である内周面 301Bの温度推移が TTA線図上で規格内におさまつたか どうかで行なう。なお、内周面 301Bは、転がり軸受外輪 301において磁束の侵入が 最も少なくなり、高周波加熱による温度上昇の最も小さい部位である。また、温度調 節装置 304と冷却タイミング調節装置 306とを同一のパーソナルコンピュータで兼ね ることちでさる。 [0211] At the same time, the temperature measurement data of the second radiation thermometer 305 is taken into the cooling timing adjustment device 306 such as a personal computer, and the temperature transition force is judged whether the heating is sufficient and the cooling timing is adjusted. . Judgment of the cooling timing is made based on whether or not the temperature transition of the inner peripheral surface 301B, which is the temperature measuring section of the second radiation thermometer 303, is within the specifications on the TTA diagram. The inner peripheral surface 301B is a part where the magnetic flux intrudes most in the rolling bearing outer ring 301 and the temperature rise due to high frequency heating is the smallest. Also, the temperature adjustment device 304 and the cooling timing adjustment device 306 can be combined with the same personal computer. I'll do it with you.
[0212] TTA線図上で規格内におさまったかどうかという判断には、下記の式（3)および式  [0212] The following equation (3) and equation are used to determine whether or not the values are within the standard on the TTA diagram.
(5)を用いることができるが、好ましくは被処理物の温度が刻一刻と変化することを考 慮して式（3)を補正した式 (4)および式（5)が用いられる。  (5) can be used, but preferably, equations (4) and (5) are used, which are obtained by correcting equation (3) in consideration of the fact that the temperature of the workpiece changes every moment.
[0213] D = 2 (Dt) 1/2' . '式（3) [0213] D = 2 (Dt) 1/2 '.
ep  ep
D =A X 2 (Dt) 1/2…式（4) D = AX 2 (Dt) 1/2 ... Formula (4)
ep  ep
D :鋼中の炭素の拡散定数、 t :保持時間 (秒)、 A:補正係数  D: diffusion constant of carbon in steel, t: retention time (seconds), A: correction factor
D=D exp (— QZRT) · · ·式（5)  D = D exp (—QZRT) · · · · (5)
0  0
D：拡散定数のエントロピ一項、 Q :活性ィ匕エネルギー、 R:気体定数、 T:絶対温度 D: Entropy term of diffusion constant, Q: Activity energy, R: Gas constant, T: Absolute temperature
0 0
(K)  (K)
ここで補正係数 Aの値は、以下の式 (6)力 得られる値である。  Here, the value of the correction coefficient A is a value obtained by the following equation (6).
[0214] erf (A) = 1 -0. 1573C /C · · ·式（6) [0214] erf (A) = 1 -0. 1573C / C · · · · Equation (6)
1 2  1 2
C : 727°Cの Cの固溶度（SUJ2の場合： 0. 52)  C: Solid solubility of C at 727 ° C (SUJ2: 0.52)
1  1
C：任意の温度における Cの固溶度  C: Solid solubility of C at any temperature
2  2
式 (4)は、式 (6)の Cの値が、 Cになった場合の炭素の拡散長 D を計算する式で  Equation (4) is an equation that calculates the diffusion length D of carbon when the value of C in Equation (6) becomes C.
1 2 ep  1 2 ep
ある。 Cの値は任意の温度における炭素の固溶度であり、これらの値は、実験的もし is there. The value of C is the solid solubility of carbon at any temperature, and these values are experimental if
2 2
くは、熱力学の平衡計算により、あら力じめ求めることができる。冷却は、式 (4)中の 炭素の拡散長 D の値がある値 (D *)に達した時に行なう。  Alternatively, it can be determined by thermodynamic equilibrium calculation. Cooling is performed when the value of carbon diffusion length D in equation (4) reaches a certain value (D *).
ep ep  ep ep
[0215] なお、第 2放射温度計 305の測温部は、必ずしも 1箇所である必要はな 、。測温部 を複数とすることにより、複数の部位での熱処理品質を確保することができる。  [0215] The temperature measuring section of the second radiation thermometer 305 does not necessarily have to be one place. By using a plurality of temperature measuring sections, it is possible to ensure heat treatment quality at a plurality of sites.
[0216] 図 14を参照して、被処理物が加熱されている間、冷却タイミングを決定するための 測温部位 (つまり第 2放射温度計 305の測温部位である内周面 301B)の温度は刻 一刻と変化するので、補正 D (式 (4)における補正された D 、以下単に D という） ep ep ep の値は図 14に示すように、 D →D → D と積算する必要がある。転がり軸 e l ep2 epn  [0216] Referring to FIG. 14, while the workpiece is heated, the temperature measurement part for determining the cooling timing (that is, inner peripheral surface 301B which is the temperature measurement part of second radiation thermometer 305) is determined. Since the temperature changes from moment to moment, the value of correction D (corrected D in equation (4), hereinafter simply referred to as D) ep ep ep must be integrated as D → D → D, as shown in Figure 14. is there. Rolling axis e l ep2 epn
受外輪 301の昇温が開始されると、焼入制御側（内周面 301B側）は、磁束の進入が 温度制御側（外周面 301A側）より少な ヽので、温度制御側に比べて遅れて温度が 上昇する。通常、温度が 727°Cを越えると、鉄のオーステナイトィ匕が始まるが、昇温 速度が速いと鉄の加熱変態温度は変化する。そのため、拡散長を計算するための温 度は、昇温速度によって変化させなくてはならない。 When the temperature increase of the outer ring 301 is started, the quenching control side (inner peripheral surface 301B side) is delayed compared to the temperature control side because the magnetic flux entry is less than the temperature control side (outer peripheral surface 301A side). Temperature rises. Normally, when the temperature exceeds 727 ° C, iron austenite begins, but when the rate of temperature rise is fast, the heating transformation temperature of iron changes. Therefore, the temperature for calculating the diffusion length The degree must be changed by the heating rate.
[0217] 昇温速度は、電源の能力、コイルと被処理物の形状などによって異なるので、装置 と被処理物の種類によって、拡散長を計算するための温度は適宜変更されることが 好ましい。焼入制御側の温度が加熱変態温度を越えたところから、図中の式によって 拡散長 D を計算する。任意の時間における D が D *を越えると、ただちに焼入を ep epn ep  [0217] Since the rate of temperature rise varies depending on the power supply capacity, the shape of the coil and the object to be processed, etc., the temperature for calculating the diffusion length is preferably changed as appropriate depending on the type of the apparatus and object to be processed. When the temperature on the quenching control side exceeds the heating transformation temperature, the diffusion length D is calculated using the formula in the figure. When D at any time exceeds D *, quenching is immediately performed ep epn ep
開始する。 D *の値は、所定の熱処理品質を維持できる範囲で、できるだけ小さな値 ep  Start. The value of D * is as small as possible within the range that can maintain the prescribed heat treatment quality ep
である方が、熱処理時間低減という観点力もは望ましい。しかし、品質を安定させる観 点からは、ある程度安全をみた設定値とするのが望ましい。  The viewpoint power of reducing the heat treatment time is also desirable. However, from the standpoint of stabilizing quality, it is desirable to set a value that is somewhat safe.
[0218] 図 15を参照して、処理時間は、 D *を大きく設定するほど、必要な拡散長が長くな ep [0218] Referring to Fig. 15, the processing time increases as D * is set larger.
るため増加することが分かる。また硬度は、 D *の値を大きく設定するほど、処理時間 ep  Therefore, it turns out that it increases. In addition, the hardness increases as the value of D * is increased.
が増加するので、高くなつていくことが分かる。ただし、硬度は、加熱が長すぎると飽 和する領域が存在し、 D *が約 0. 015mmで最高硬さに達していた。したがって、 D ep e As it increases, it can be seen that it will rise. However, there was a region where the hardness saturated when the heating was too long, and the maximum hardness was reached at D * of about 0.015 mm. Therefore, D ep e
*の値は 0. 015mm以下が望ましい考えられる。つまり、本実施の形態の場合、たとThe value of * is considered to be desirable to be 0.015mm or less. In other words, in the case of this embodiment,
P P
えば D *の値を 0. 015mmとし、上述のように積算された D が 0. 015mmとなった ep epn  For example, the value of D * is set to 0.015 mm, and D accumulated as described above becomes 0.015 mm ep epn
時点で、冷却タイミング調節装置 306から冷却開始信号が冷却液噴射装置 307に向 けて出力され、これに基づいて冷却液噴射装置 307が転がり軸受外輪 301を A点 以上の温度から M点以下の温度に冷却することにより、転がり軸受外輪 301を焼入  At this time, a cooling start signal is output from the cooling timing adjustment device 306 to the coolant injection device 307, and based on this, the coolant injection device 307 moves the rolling bearing outer ring 301 from a temperature higher than the A point to a temperature lower than the M point. The rolling bearing outer ring 301 is quenched by cooling to the temperature.
S  S
硬ィ匕することができる。  Can be hard.
[0219] 次に、実施の形態 3の変形例について説明する。実施の形態 3の変形例における 高周波熱処理方法、高周波熱処理装置および高周波熱処理品は基本的に上述し た実施の形態 3と同様の構成を有している。しかし、冷却タイミングの判断において転 力 Sり軸受外輪 301の内周面 301Bの温度推移が TTA線図上で規格内におさまった どうかの判断に下記の式（7)および式（5)を用いる点で異なっている。以下、転がり 軸受外輪 301の内周面 301Bの温度推移が TTA線図上で規格内におさまつたどう かの判断を、式（7)および式（5)を用いて行なう方法にっ 、て説明する。  [0219] Next, a modification of the third embodiment will be described. The high-frequency heat treatment method, high-frequency heat treatment apparatus, and high-frequency heat treatment product in the modification of the third embodiment basically have the same configuration as that of the third embodiment described above. However, the following equation (7) and equation (5) are used to determine whether the temperature transition of the inner peripheral surface 301B of the rolling S bearing outer ring 301 is within the standard on the TTA diagram in determining the cooling timing. It is different in point. In the following, a method is used to determine whether the temperature transition of the inner peripheral surface 301B of the rolling bearing outer ring 301 falls within the standard on the TTA diagram, using Equation (7) and Equation (5). explain.
[0220] 3 CZ ( 3 t) =D 3 2CZ ( 3 x2) ' . '式（7) [0220] 3 CZ (3 t) = D 3 2 CZ (3 x 2 ) '.' (7)
D:鋼中の炭素の拡散定数、 C :炭素濃度 (質量％)、 t:時間 (秒)、 X：距離 D=D exp (— QZRT) · · ·式（5) D：拡散定数のエントロピ一項、 Q :活性ィ匕エネルギー、 R:気体定数、 T:絶対温度D: Carbon diffusion constant in steel, C: Carbon concentration (% by mass), t: Time (seconds), X: Distance D = D exp (—QZRT) D: Entropy term of diffusion constant, Q: Activity energy, R: Gas constant, T: Absolute temperature
0 0
(K)  (K)
ここで、式 (7)を差分方程式で表すと、以下の式になる。  Here, when Expression (7) is expressed by a difference equation, the following expression is obtained.
[0221] C =rC + (l - 2r) C +rC · · ·式（8) [0221] C = rC + (l-2r) C + rC · · · · (8)
m,n+l m+ι,η m,n m - l，n  m, n + l m + ι, η m, n m-l, n
r=D X AtZ( Ax)2…式（9) r = DX AtZ (Ax) 2 ... Formula (9)
冷却タイミングは、式 (8)をある境界条件で解き、材料中の炭素の固溶状態が所定 の条件を満たしているかどうかで決定する。ここで、境界条件は、たとえば加熱中の 転がり軸受外輪 301を構成する鋼中における鉄炭化物 (セメンタイト; Fe C)と素地と  Cooling timing is determined by solving Equation (8) under certain boundary conditions and determining whether the solid solution state of carbon in the material satisfies a predetermined condition. Here, the boundary conditions are, for example, iron carbide (cementite; Fe C) and the base material in the steel constituting the rolling bearing outer ring 301 during heating.
3  Three
の界面において、ある温度での炭素固溶濃度が当該温度での炭素の固溶度に等し くなつているとの仮定の下に与えることができる。  At the interface, the carbon solid solution concentration at a certain temperature can be given under the assumption that the solid solubility of carbon at that temperature is equal.
[0222] 図 16〜図 19を参照して、たとえば図 16に示すように転がり軸受外輪 301が加熱さ れた場合、固溶炭素濃度の分布は、図 17〜図 19に示すように中央位置（2つの Fe [0222] Referring to FIGS. 16 to 19, for example, when the rolling bearing outer ring 301 is heated as shown in FIG. 16, the distribution of the solute carbon concentration is the central position as shown in FIGS. (Two Fe
3 Three
C間の距離を 0. 012mmとした場合には 0. 006mmの位置）において固溶炭素濃度 が最も低くなつており、時間が経過するにつれて固溶炭素濃度が全体として増加す るとともに、中央位置と両端 (Fe Cと素地との界面）との差が小さくなる傾向にある。 When the distance between C is 0.012 mm, the solute carbon concentration is lowest at the position of 0.006 mm), and as the time passes, the solute carbon concentration increases as a whole and the central position And the difference between both ends (the interface between Fe C and the substrate) tends to be small.
3  Three
[0223] 冷却タイミング調節工程 336における冷却開始信号は、たとえば転がり軸受外輪 3 01の内周面 301Bが上述の焼入条件である固溶炭素濃度の条件を上記中央位置 において満たした時点で出力することができる。また 2つの境界点間の距離 (炭化物 間距離）は、被処理物の焼入前の組織や材料の違いによって適宜変更することがで きる。  [0223] The cooling start signal in the cooling timing adjustment step 336 is output when, for example, the inner peripheral surface 301B of the rolling bearing outer ring 301 satisfies the solute carbon concentration condition as the quenching condition described above at the center position. be able to. The distance between two boundary points (distance between carbides) can be changed as appropriate depending on the structure and material before quenching of the workpiece.
[0224] つまり本変形例の冷却タイミングの決定はたとえば以下のように行なわれる。まず焼 入制御側の温度を第 2放射温度計 305により測定し (ステップ A)、その測定された温 度から境界部の炭素量を計算する (ステップ B)。境界部の炭素量の値を式 (8)の境 界条件に与えて式 (8)を計算する (ステップ C)。以上の工程により、図 17〜図 19に 示すような固溶炭素濃度の分布を計算することができる (ステップ D)。得られた固溶 炭素濃度の分布から、固溶炭素濃度の分布の中央位置における炭素濃度が所定の 炭素濃度 (たとえば 0. 6〜0. 8質量％)になったかどうかの確認を行なう（ステップ E) 。もし中央位置における炭素濃度が所定の炭素濃度に達していたら冷却を開始し (ス テツプ F)、達していなければ冷却は開始されずに加熱が継続されて再度ステップ A に戻る。 That is, the determination of the cooling timing in the present modification is performed as follows, for example. First, the temperature on the quenching control side is measured by the second radiation thermometer 305 (Step A), and the carbon content at the boundary is calculated from the measured temperature (Step B). Eq. (8) is calculated by applying the boundary carbon value to the boundary condition of Eq. (8) (Step C). Through the above process, it is possible to calculate the solid solution carbon concentration distribution as shown in Fig. 17 to Fig. 19 (Step D). From the obtained solute carbon concentration distribution, it is confirmed whether the carbon concentration at the center position of the solute carbon concentration distribution has reached a predetermined carbon concentration (eg, 0.6 to 0.8 mass%) (step E). If the carbon concentration at the center has reached the specified carbon concentration, start cooling ( Step F), if not, cooling is not started and heating is continued and the process returns to Step A again.
[0225] また、上記ステップ Cにおける式 (8)は以下のように差分法により解くことができる。  [0225] Furthermore, equation (8) in step C above can be solved by the difference method as follows.
まず図 17〜図 19の炭素分布の両端における炭素濃度は、炭化物素地界面の炭素 濃度である。したがって、この位置からある濃度 (炭素の固溶度)で炭素が素地へ供 給される。  First, the carbon concentration at both ends of the carbon distribution in Figs. 17 to 19 is the carbon concentration at the carbide substrate interface. Therefore, carbon is supplied from this position to the substrate at a certain concentration (solid solubility of carbon).
[0226] たとえば図 17〜図 19のように、隣り合う Fe Cの間に区切りを 5点とると（境界点を入  [0226] For example, as shown in Figs.
3  Three
れると 7点）、 5個の連立方程式が得られる力 未知数は、 C 、C 、C 、C 、C 、  7 points), the force to obtain 5 simultaneous equations The unknowns are C, C, C, C, C,
Ο,η Ι,η 2,η 3,η 4,η Ο, η Ι, η 2, η 3, η 4, η
C 、C の 7つになる。このうち C とじ とは炭化物と素地との界面の位置となるためThere are 7 C and C. Of these, C binding is located at the interface between carbide and substrate.
5,η ο,η Ο,η 6,η 5, η ο, η Ο, η 6, η
、固溶度の式力も炭素濃度の値を与えることができる。これにより、連立方程式は 5個 で、未知数が 5個となるため、 C 、C 、C 、C 、C の値を求めることができる。  The formula power of solid solubility can also give the value of carbon concentration. As a result, there are five simultaneous equations and five unknowns, so the values of C, C, C, C, and C can be obtained.
Ι,η 2,η 3,η 4,η 5,η  Ι, η 2, η 3, η 4, η 5, η
[0227] なお、上記固溶炭素濃度の計算を、焼入制御側だけでなぐ温度制御側でも行なう ことにより、温度制御側の炭素の固溶状態から、温度制御側の残留オーステナイト量 を推測することができる。  Note that the amount of retained austenite on the temperature control side is estimated from the solid solution state of the carbon on the temperature control side by performing the above calculation of the solid solution carbon concentration not only on the quenching control side but also on the temperature control side. be able to.
[0228] 図 20から、固溶炭素濃度の値は、焼入制御側よりも温度制御側のほうが全体的に 高くなつていることが分かる。これは、転がり軸受外輪 301において、加熱装置 302に 含まれる誘導コイルに近 、温度制御側の温度が、焼入制御側よりも高くなるためであ る。  [0228] From FIG. 20, it can be seen that the value of the solute carbon concentration is generally higher on the temperature control side than on the quenching control side. This is because in the rolling bearing outer ring 301, the temperature on the temperature control side is higher than that on the quenching control side near the induction coil included in the heating device 302.
[0229] さらに、上述固溶炭素濃度の計算の開始温度、すなわち炭素の素地への固溶の 開始温度は、昇温速度を考慮して決定することが好ましい。以下、その決定方法に ついて説明する。  [0229] Furthermore, it is preferable to determine the starting temperature of the calculation of the solid solution carbon concentration, that is, the starting temperature of the solid solution of carbon in the substrate, in consideration of the rate of temperature rise. The determination method will be described below.
[0230] 鋼が平衡状態を保ちつつ 727°C (A点温度）以上に加熱されると、オーステナイト 化が始まり、これに伴って炭素の固溶が始まる。しかし、昇温速度が速い場合、 A点 温度は昇温速度に影響されて変化し、 A 点 (加熱変態点)温度にお!、てオーステ  [0230] When the steel is heated to 727 ° C (point A temperature) or higher while maintaining an equilibrium state, austenitization starts, and carbon solid solution starts accordingly. However, if the rate of temperature rise is fast, the temperature at point A changes depending on the rate of temperature rise and changes to the point A (heating transformation point) temperature!
C1  C1
ナイトイ匕を開始する。したがって、上記計算の開始温度は、昇温速度を考慮して変化 させることが好ましい。  Start night 匕. Therefore, it is preferable to change the starting temperature of the above calculation in consideration of the rate of temperature increase.
[0231] 図 21を参照して、昇温速度が変化すると、加熱変態点 A は、 727°Cから 950°Cま  [0231] Referring to FIG. 21, when the heating rate changes, the heating transformation point A increases from 727 ° C to 950 ° C.
C1  C1
で変化することが分かる。よって、被処理物の組成における昇温速度の変化に対す る加熱変態点 A の変化を予め調べておき、被処理物の加熱時における昇温速度 It can be seen that changes. Therefore, against the change in the heating rate in the composition of the workpiece The temperature change rate during the heating of the workpiece
C1  C1
から加熱変態点 A を求めて、その加熱変態点 A に基づいて上記固溶炭素濃度の  The heating transformation point A is determined from the above, and based on the heating transformation point A, the solute carbon concentration is
CI C1  CI C1
計算開始温度 (炭素の固溶開始温度)を決定することができる。  Calculation start temperature (carbon solid solution start temperature) can be determined.
[0232] 図 22を参照して、加熱初期においては、温度制御側での加熱が急速に行なわれる ため、焼入制御側の昇温速度も速くなり、加熱変態点は高くなる。温度制御側の温 度が所定の設定温度に近づくと、温度調節装置 304により昇温速度が緩やかになる ように加熱が制御される。そのため、焼入制御側の昇温速度も緩やかになり、加熱変 態点 A が低下していく。そして、時間が経過すると、加熱変態点 A は、焼入制御 Referring to FIG. 22, in the initial stage of heating, heating on the temperature control side is performed rapidly, so that the rate of temperature increase on the quenching control side is also increased, and the heating transformation point is increased. When the temperature on the temperature control side approaches a predetermined set temperature, the temperature control device 304 controls the heating so that the rate of temperature increase becomes slow. As a result, the rate of temperature increase on the quenching control side also becomes slow, and the heating transformation point A decreases. When time passes, the heating transformation point A becomes the quench control.
CI C1 側の温度推移と交わる。この交点がオーステナイトイ匕の開始温度を示していることに なるため、この交点の温度 (つまりオーステナイト化の開始温度)から上記固溶炭素 濃度の計算を開始することができる。 Intersects with temperature change on CI C1 side. Since this intersection point indicates the start temperature of austenite cake, the calculation of the solute carbon concentration can be started from the temperature of this intersection point (that is, the start temperature of austenitization).
[0233] そして、図 17〜図 19を用いて説明したように、固溶炭素濃度の分布の中央位置に おける炭素濃度が所定の炭素濃度 (たとえば 0. 6〜0. 8質量％)を越えた時点で、 ただちに冷却を開始して、被処理物 (転がり軸受外輪 301)を焼入硬化することがで きる。  [0233] As described with reference to Figs. 17 to 19, the carbon concentration at the center position of the distribution of the solute carbon concentration exceeds a predetermined carbon concentration (for example, 0.6 to 0.8 mass%). Immediately after that, cooling can be started and the workpiece (rolling bearing outer ring 301) can be hardened by hardening.
[0234] (実施の形態 4)  [0234] (Embodiment 4)
図 28および図 29を参照して、実施の形態 4における高周波焼入装置および高周 波焼入方法について説明する。  With reference to FIG. 28 and FIG. 29, the induction hardening apparatus and the high frequency hardening method in the fourth embodiment will be described.
[0235] 図 28を参照して、実施の形態 4における高周波焼入装置 392は、基本的には実施 の形態 3における高周波焼入装置 391と同様の構成を有している。しかし、実施の形 態 4における高周波焼入装置 392は、加熱装置 302、温度調節装置 304および冷却 タイミング調節装置 306に接続され、電源出力の推移データと、冷却タイミングデータ とをプロセスデータとして記憶する記憶装置 370を備えている点において、実施の形 態 3の高周波焼入装置 391とは異なっている。  Referring to FIG. 28, induction hardening apparatus 392 in the fourth embodiment has basically the same configuration as induction hardening apparatus 391 in the third embodiment. However, the induction hardening apparatus 392 in the embodiment 4 is connected to the heating apparatus 302, the temperature adjustment apparatus 304, and the cooling timing adjustment apparatus 306, and stores the transition data of the power output and the cooling timing data as process data. It is different from the induction hardening apparatus 391 of Embodiment 3 in that the storage apparatus 370 is provided.
[0236] また、図 29を参照して、実施の形態 4における高周波焼入方法は高周波加熱によ り被処理物 (たとえば転がり軸受外輪 301)を加熱して焼入硬化する高周波熱処理方 法であって、データ取得工程と、記憶工程と、確認工程と、量産工程とを備えている。  [0236] Referring to Fig. 29, the induction hardening method in the fourth embodiment is an induction heat treatment method in which a workpiece (for example, the rolling bearing outer ring 301) is heated and hardened by induction heating. The data acquisition process, the storage process, the confirmation process, and the mass production process are provided.
[0237] データ取得工程では、転がり軸受外輪 301のサンプルが加熱されて焼入硬化され ることによりプロセスデータが取得される。記憶工程では、データ取得工程において 転がり軸受外輪 301のサンプルを加熱するために高周波加熱用の電源力 誘導コィ ルに出力された電源出力の推移データと、転がり軸受外輪 301のサンプルの冷却タ イミングを特定するための冷却タイミングデータとがプロセスデータとして記憶される。 [0237] In the data acquisition process, a sample of the rolling bearing outer ring 301 is heated and quenched and hardened. As a result, process data is acquired. In the memory process, the transition data of the power output output to the power supply induction coil for high-frequency heating to heat the sample of the rolling bearing outer ring 301 in the data acquisition process and the cooling timing of the sample of the rolling bearing outer ring 301 are used. Cooling timing data for specifying is stored as process data.
[0238] 確認工程では、データ取得工程において焼入硬化された転がり軸受外輪 301の材 質データに基づき、電源出力の推移データおよび冷却タイミングデータの妥当性が 確認される。すなわち、たとえば、データ取得工程における被処理物の温度推移の データを記憶し、記憶された温度推移データが分析されることで、外乱の影響の有無 が判定され、記憶工程にぉ ヽて記憶されたプロセスデータである電源出力の推移デ ータおよび冷却タイミングデータの妥当性が確認される。なお、実際に熱処理された 転がり軸受外輪 301のサンプルの材質データを実験により実際に取得し、電源出力 の推移データおよび冷却タイミングデータの妥当性が確認されてもよい。  [0238] In the confirmation process, the validity of the transition data of the power output and the cooling timing data is confirmed based on the material data of the rolling bearing outer ring 301 that has been hardened and hardened in the data acquisition process. That is, for example, the temperature transition data of the object to be processed in the data acquisition process is stored, and the stored temperature transition data is analyzed to determine whether or not there is an influence of disturbance, and is stored in the storage process. The validity of the power output transition data and cooling timing data, which are the process data, is confirmed. In addition, the material data of the sample of the rolling bearing outer ring 301 that has been actually heat-treated may be actually obtained by experiments, and the validity of the transition data of the power output and the cooling timing data may be confirmed.
[0239] ここで、転がり軸受外輪 301の測温において、外乱の影響があった場合、温度推移 データに異常な値が記録されるため、記憶された温度推移データ力 外乱の有無は 判断可能である。たとえば、温度推移データに不連続な領域が存在する場合、外乱 があったものと判断することができる。また、より正確な判断を行なうためには、同一の 部位の温度を測定する接触式または非接触式の温度計を設け、双方のデータの整 合性により外乱の有無を判断することもできる。具体的判断の手法としては、たとえば 双方のデータ力 温度差が 5%以上となった場合に外乱有りと判断することができる 。また、外乱の判断は作業者が温度推移データを確認して行なうことができるが、自 動化された他の装置により行なうこともできる。具体的にはたとえば記憶された温度推 移データの温度推移の微分値が 1000°CZ秒以上または— 1000°CZ秒以下となつ た場合に外乱有りと判断する方法や、前述のように同一の部位の温度を測定する温 度計を設け、両者のデータに 5%以上の差が生じた場合に外乱有りと判断するような 手段が挙げられる。  [0239] Here, if there is a disturbance in the temperature measurement of the rolling bearing outer ring 301, an abnormal value is recorded in the temperature transition data, so the stored temperature transition data force can be determined whether there is a disturbance or not. is there. For example, if there is a discontinuous area in the temperature transition data, it can be determined that there was a disturbance. In order to make a more accurate determination, a contact or non-contact thermometer that measures the temperature of the same part can be provided, and the presence or absence of disturbance can be determined based on the consistency of both data. As a specific judgment method, for example, when the difference between the two data power temperatures is 5% or more, it can be judged that there is a disturbance. In addition, the disturbance can be determined by the operator confirming the temperature transition data, but can also be performed by another automated device. Specifically, for example, when the differential value of the temperature transition of the stored temperature transition data is 1000 ° CZ seconds or more or -1000 ° CZ seconds or less, there is a method of determining that there is a disturbance, or the same as described above. A thermometer that measures the temperature of the part is provided, and there is a means to judge that there is a disturbance when a difference of 5% or more occurs between the two data.
[0240] 量産工程では、記憶工程で記憶され、かつ確認工程で妥当性が確認された電源 出力の推移データおよび冷却タイミングデータに従って転がり軸受外輪 301の高周 波焼入が行なわれる。そして、データ取得工程における焼入硬化は、本発明の高周 波熱処理方法、たとえば実施の形態 3の高周波焼入方法により実施される。 [0240] In the mass production process, the rolling bearing outer ring 301 is subjected to high-frequency quenching according to the power output transition data and the cooling timing data that are stored in the storage process and validated in the confirmation process. The quench hardening in the data acquisition process is the high frequency of the present invention. This is performed by a wave heat treatment method, for example, the induction hardening method of the third embodiment.
[0241] 実施の形態 4における高周波焼入方法により被処理物としての転がり軸受外輪 30 1を焼入硬化することにより、温度制御が可能となり、熱処理の条件出しが容易となる だけでなぐプロセスデータへの外乱の影響が一層抑制され、被処理物（転がり軸受 外輪 301)の品質が安定する。  [0241] The process data can be obtained simply by quenching and hardening the rolling bearing outer ring 30 1 as the object to be processed by the induction hardening method in Embodiment 4, thereby making it possible to control the temperature and to easily determine the conditions for the heat treatment. The influence of disturbance on the workpiece is further suppressed, and the quality of the workpiece (rolling bearing outer ring 301) is stabilized.
[0242] そして、実施の形態 4における高周波焼入方法により焼入硬化された実施の形態 4 における高周波焼入品としての転がり軸受外輪 301は、低価格化され、かつ一層品 質の安定した高周波焼入品となっている。  [0242] The rolling bearing outer ring 301 as the induction-hardened product in the fourth embodiment, which has been hardened by the induction hardening method in the fourth embodiment, is a low-frequency and more stable high-frequency product. It is hardened.
[0243] 次に、実施の形態 4における高周波焼入の詳細について説明する。図 30において 、データ取得工程におけるデータの流れは実線矢印、記憶工程におけるデータの流 れは破線矢印、確認工程におけるデータの流れは二重破線矢印、量産工程におけ るデータの流れは二重実線矢印で表示されている。図 30を参照して、実施の形態 4 に係る高周波焼入の各工程におけるデータの流れを説明する。  [0243] Next, details of induction hardening in the fourth embodiment will be described. In FIG. 30, the data flow in the data acquisition process is a solid arrow, the data flow in the storage process is a broken arrow, the data flow in the confirmation process is a double dashed arrow, and the data flow in the mass production process is a double solid line. It is displayed with an arrow. With reference to FIG. 30, the data flow in each step of induction hardening according to the fourth embodiment will be described.
[0244] 図 30を参照して、データ取得工程においては、温度制御用測温装置 (第 1放射温 度計 303)により測定された被処理物としての転がり軸受外輪 301のサンプルの温度 データは温度調節装置 304に送られる。温度調節装置 304においては転がり軸受 外輪 301の目標加熱温度および取得した転がり軸受外輪 301のサンプルの温度デ 一タカゝら必要な電源出力を判断し、加熱装置 302の電源に電源出力を指令する。指 令を受けた電源は加熱装置 302の誘導コイルに電力を出力し、転がり軸受外輪 301 のサンプルは目的の温度に加熱される。  [0244] Referring to FIG. 30, in the data acquisition process, the temperature data of the sample of the rolling bearing outer ring 301 as the workpiece measured by the temperature control temperature measuring device (first radiation thermometer 303) is Sent to temperature controller 304. In the temperature control device 304, the target heating temperature of the rolling bearing outer ring 301 and the obtained temperature data of the sample of the rolling bearing outer ring 301 are determined, and the necessary power output is determined, and the power output is commanded to the power supply of the heating device 302. The power source that has received the command outputs power to the induction coil of the heating device 302, and the sample of the rolling bearing outer ring 301 is heated to a target temperature.
[0245] 一方、焼入用測温装置 (第 2放射温度計 305)により測定された転がり軸受外輪 30 1のサンプルの温度データは冷却タイミング調節装置 306に送られる。冷却タイミング 調節装置 306においては取得した転がり軸受外輪 301のサンプルの温度およびカロ 熱時間から冷却タイミングを判断し、冷却開始を冷却液噴射装置 307などの冷却装 置に指令する。これにより、転がり軸受外輪 301のサンプルは急冷され、焼入硬化さ れる。このとき、このデータ取得工程は温度制御により実施されるため、転がり軸受外 輪 301のサンプルの加熱履歴は明確である。そのため、温度データが正確である限 り適切な熱処理が行なわれており、目的の品質を有する転がり軸受外輪 301が得ら れている。その結果、被処理物の品質を確認しながら熱処理の条件出しが行なわれ る必要がなぐ条件出しが容易に行なわれる。また、被処理物の表面には、安定化層 が形成されているため、放射温度計による測温の精度は高くなつている。 On the other hand, the temperature data of the sample of the rolling bearing outer ring 301 measured by the quenching temperature measuring device (second radiation thermometer 305) is sent to the cooling timing adjusting device 306. The cooling timing adjusting device 306 determines the cooling timing from the acquired temperature and calorie heat time of the sample of the rolling bearing outer ring 301 and commands the cooling device such as the coolant injection device 307 to start cooling. Thereby, the sample of the rolling bearing outer ring 301 is quenched and hardened by hardening. At this time, since the data acquisition process is performed by temperature control, the heating history of the sample of the rolling bearing outer ring 301 is clear. Therefore, as long as the temperature data is accurate, appropriate heat treatment is performed, and the rolling bearing outer ring 301 having the desired quality is obtained. It is. As a result, it is easy to determine conditions that do not need to be determined while confirming the quality of the workpiece. In addition, since a stabilization layer is formed on the surface of the workpiece, the accuracy of temperature measurement with a radiation thermometer is increasing.
[0246] 記憶工程においては、データ取得工程において温度調節装置 304および冷却タイ ミング調節装置 306が取得した温度データが温度推移データとして記憶装置 370に 記憶される。また、加熱装置 302の電源が誘導コイルに出力した電源出力が電源出 力の推移データとして記憶装置 370に記憶される。さらに、冷却タイミング調節装置 3 06が冷却液噴射装置 307などの冷却装置に出力した冷却開始指令のタイミングが 冷却タイミングデータとして記憶装置 370に記憶される。ここで、冷却タイミングはたと えば加熱開始からの時間として記憶される。  In the storage step, the temperature data acquired by the temperature adjustment device 304 and the cooling timing adjustment device 306 in the data acquisition step is stored in the storage device 370 as temperature transition data. In addition, the power supply output from the power supply of the heating device 302 to the induction coil is stored in the storage device 370 as the power output transition data. Further, the timing of the cooling start command output from the cooling timing adjusting device 310 to the cooling device such as the coolant injection device 307 is stored in the storage device 370 as cooling timing data. Here, the cooling timing is stored as, for example, the time from the start of heating.
[0247] 確認工程においては、たとえば第 1放射温度計 303および第 2放射温度計 305と 同一部位を測定可能な温度計がそれぞれ設けられ、当該部位が測温される。この測 温データと、第 1放射温度計 303および第 2放射温度計 305により測定されて記憶装 置 370に記憶された温度推移データとが比較されることにより、外乱の有無が判断さ れる。  [0247] In the confirmation step, for example, thermometers capable of measuring the same part as the first radiation thermometer 303 and the second radiation thermometer 305 are provided, and the temperature of the part is measured. By comparing the temperature measurement data with the temperature transition data measured by the first radiation thermometer 303 and the second radiation thermometer 305 and stored in the storage device 370, the presence or absence of disturbance is determined.
[0248] 量産工程においては、記憶工程で記憶され、かつ確認工程で妥当性が確認された 電源出力の推移データおよび冷却タイミングデータに基づき、転がり軸受外輪 301 が加熱されて焼入が行なわれる。このとき、この量産工程は外乱のおそれのある第 1 放射温度計 303および第 2放射温度計 305からのリアルタイムの温度データに基づ いて実施されるのではなぐ妥当性が確認された電源出力の推移データおよび冷却 タイミングデータに基づいて電力制御により実施される。そのため、安定した品質の 転がり軸受外輪 301が得られる。  In the mass production process, the rolling bearing outer ring 301 is heated and hardened based on the power output transition data and the cooling timing data that are stored in the storage process and validated in the confirmation process. At this time, this mass production process is not performed based on real-time temperature data from the first radiation thermometer 303 and the second radiation thermometer 305, which may cause disturbance, and the validity of the power supply output has been confirmed. It is implemented by power control based on transition data and cooling timing data. Therefore, the rolling bearing outer ring 301 having a stable quality can be obtained.
[0249] なお、記憶装置 370は、独立の装置として設置されてもよいが、たとえばノヽードディ スクなどの記憶部を有するパーソナルコンピュータにより、温度調節装置 304、冷却 タイミング調節装置 306などの装置を兼用して設置されてもよい。また、本実施の形 態の高周波焼入方法の各工程は、たとえば制御装置としてパーソナルコンピュータ を用い、各工程に対応した単数または複数のプログラムにより当該パーソナルコンビ ユータを動作させることにより実施することができる。 [0250] (実施の形態 5) [0249] Note that the storage device 370 may be installed as an independent device, but for example, a personal computer having a storage unit such as a node disk may also be used as a device such as the temperature adjustment device 304 and the cooling timing adjustment device 306. May be installed. In addition, each step of the induction hardening method of the present embodiment can be performed by using a personal computer as a control device, for example, and operating the personal computer with one or more programs corresponding to each step. it can. [0250] (Embodiment 5)
図 31を参照して、実施の形態 5における高周波焼戻装置の構成を説明する。  Referring to FIG. 31, the configuration of the induction tempering apparatus according to Embodiment 5 will be described.
[0251] 図 31を参照して、実施の形態 5における高周波焼戻装置 393は、高周波加熱によ り被処理物 (たとえば転がり軸受外輪 301)を加熱して焼戻を実施する本発明の高周 波熱処理方法に使用される高周波焼戻装置であって、被処理物としての転がり軸受 外輪 301の温度を調節するための温度制御装置 351と、加熱された転がり軸受外輪 301が冷却されるべきタイミングを調節するための焼戻制御装置 361とを備えて!/、る 。また、後述するように、転がり軸受外輪 301の外周面 301Aおよび内周面 301Bに は、転がり軸受外輪 301が加熱される温度域、すなわち焼戻温度において、転がり 軸受外輪 301よりも耐酸ィ匕性の高い安定ィ匕層 309が形成されている。  Referring to FIG. 31, induction tempering apparatus 393 according to Embodiment 5 is a high-frequency tempering apparatus according to the present invention that performs tempering by heating an object to be treated (for example, rolling bearing outer ring 301) by induction heating. A high-frequency tempering device used in the frequency heat treatment method, a temperature control device 351 for adjusting the temperature of the rolling bearing outer ring 301 as the object to be processed, and the heated rolling bearing outer ring 301 should be cooled. With a tempering control device 361 for adjusting the timing! Further, as will be described later, the outer peripheral surface 301A and the inner peripheral surface 301B of the rolling bearing outer ring 301 are more resistant to oxidation than the rolling bearing outer ring 301 in the temperature range in which the rolling bearing outer ring 301 is heated, that is, the tempering temperature. A high stability layer 309 is formed.
[0252] 温度制御装置 351は、転がり軸受外輪 301において、高周波加熱により最も温度 が高くなると考えられる外周面 301Aの温度データを取得し、転がり軸受外輪 301の 温度データに基づく温度の情報を出力する温度制御用測温装置としての第 1放射温 度計 313と、第 1放射温度計 313に接続され、第 1放射温度計 313からの温度の情 報に基づき被処理物の加熱状態を制御するための温度制御信号を出力する温度調 節装置 314と、温度調節装置 314に接続され、温度調節装置 314からの温度制御 信号に基づき、高周波加熱により転がり軸受外輪 301を加熱する加熱装置 312とを 含んでいる。加熱装置 312は、たとえば高周波電流を流すための誘導コイルと、誘導 コイルに接続され高周波電流を発生させる電源とを有している。  [0252] The temperature control device 351 obtains temperature data of the outer peripheral surface 301A that is considered to have the highest temperature due to high-frequency heating in the rolling bearing outer ring 301, and outputs temperature information based on the temperature data of the rolling bearing outer ring 301. The first radiation thermometer 313 as a temperature control temperature measuring device and the first radiation thermometer 313 are connected to control the heating state of the object to be processed based on the temperature information from the first radiation thermometer 313. A temperature control device 314 that outputs a temperature control signal for heating, and a heating device 312 that is connected to the temperature control device 314 and heats the rolling bearing outer ring 301 by high-frequency heating based on the temperature control signal from the temperature control device 314. Contains. The heating device 312 has, for example, an induction coil for flowing a high-frequency current, and a power source that is connected to the induction coil and generates a high-frequency current.
[0253] 焼戻制御装置 361は、高周波加熱により最も温度が高くなると考えられる外周面 3 01Aから最も遠ぐ温度の上昇が最も小さいと考えられる内周面 301Bの温度データ を取得し、内周面 301Bの温度データに基づく温度の情報を出力する焼戻用測温装 置としての第 2放射温度計 315と、第 2放射温度計 315に接続され、第 2放射温度計 315からの温度の情報に基づき加熱時間を調節し、転がり軸受外輪 301が冷却され るべきタイミングを決定して冷却開始信号を出力する冷却タイミング調節装置 316と、 冷却タイミング調節装置 316に接続され、冷却開始信号に基づいて、転がり軸受外 輪 301を冷却することにより転がり軸受外輪 301の焼戻を終了させる冷却装置として の冷却液噴射装置 317とを含んで ヽる。 [0254] ここで、温度調節装置 314および冷却タイミング調節装置 316は、たとえばそれぞ れパーソナルコンピュータであり、 1台のパーソナルコンピュータで温度調節装置 31 4と冷却タイミング調節装置 316とを兼ねる構成であってもよい。 [0253] The tempering control device 361 obtains the temperature data of the inner peripheral surface 301B, which is considered to have the smallest temperature rise farthest from the outer peripheral surface 301A, which is considered to have the highest temperature due to high-frequency heating. A second radiant thermometer 315 that outputs temperature information based on the temperature data of surface 301B and a second radiant thermometer 315 connected to the second radiant thermometer 315. Based on the information, the heating time is adjusted, the timing at which the rolling bearing outer ring 301 should be cooled is determined and a cooling start signal is output, and the cooling timing adjusting device 316 is connected to the cooling timing adjusting device 316 and is based on the cooling start signal. Thus, a cooling fluid injection device 317 as a cooling device that terminates tempering of the rolling bearing outer ring 301 by cooling the rolling bearing outer ring 301 is included. [0254] Here, the temperature adjustment device 314 and the cooling timing adjustment device 316 are each a personal computer, for example, and each personal computer is configured to serve as both the temperature adjustment device 314 and the cooling timing adjustment device 316. May be.
[0255] 次に、上述の高周波焼戻装置を用いた本発明の一実施の形態である実施の形態 5における高周波熱処理方法としての高周波焼戻方法について説明する。  [0255] Next, an induction tempering method as an induction heat treatment method in Embodiment 5, which is an embodiment of the present invention, using the above-described induction tempering apparatus will be described.
[0256] 図 31および図 32を参照して、実施の形態 5の高周波焼戻方法は、高周波加熱に より被処理物 (たとえば転がり軸受外輪 301)を加熱して焼戻を実施する高周波熱処 理方法であって、転がり軸受外輪 301の表面に、転がり軸受外輪 301よりも耐酸化性 の高い安定化層 309が形成される表面安定化工程 311と、表面安定化工程におい て安定ィ匕層 309が形成された転がり軸受外輪 301が加熱されて焼戻される焼戻工程 410とを備えている。  Referring to FIG. 31 and FIG. 32, the induction tempering method of the fifth embodiment is an induction heat treatment in which an object to be treated (for example, the rolling bearing outer ring 301) is heated and tempered by induction heating. A surface stabilizing step 311 in which a stabilizing layer 309 having higher oxidation resistance than the rolling bearing outer ring 301 is formed on the surface of the rolling bearing outer ring 301, and a stable layer in the surface stabilizing step. And a tempering step 410 in which the rolling bearing outer ring 301 formed with 309 is heated and tempered.
[0257] 焼戻工程 410は、転がり軸受外輪 301の温度が調節される温度制御工程 420と、 転がり軸受外輪 301の加熱が終了されるべきタイミングが決定されて、転がり軸受外 輪 301が冷却される焼戻制御工程 430とを含んで 、る。  [0257] In the tempering step 410, the temperature control step 420 in which the temperature of the rolling bearing outer ring 301 is adjusted, the timing at which the heating of the rolling bearing outer ring 301 should be finished, are determined, and the rolling bearing outer ring 301 is cooled. And tempering control step 430.
[0258] 温度制御工程 420は、転がり軸受外輪 301の表面に形成された安定ィ匕層 309の 表面の温度が放射温度計により測定される温度制御用測温工程 423と、温度制御 用測温工程 423において測定された温度の情報に基づき、転がり軸受外輪 301の 加熱状態を制御するための温度制御信号が出力される温度調節工程 424と、温度 制御信号に基づいて、高周波加熱により転がり軸受外輪 301が加熱される加熱工程 422とを有して!/ヽる。  [0258] The temperature control step 420 includes a temperature control step 423 in which the surface temperature of the stable layer 309 formed on the surface of the rolling bearing outer ring 301 is measured by a radiation thermometer, and a temperature control temperature measurement step 423. A temperature adjustment step 424 in which a temperature control signal for controlling the heating state of the rolling bearing outer ring 301 is output based on the temperature information measured in step 423, and a rolling bearing outer ring by high-frequency heating based on the temperature control signal. With a heating step 422 in which 301 is heated!
[0259] 焼戻制御工程 430は、転がり軸受外輪 301の表面に形成された安定ィ匕層 309の 表面の温度が放射温度計により測定される焼戻用測温工程 435と、焼戻用測温ェ 程 435において測定された温度の情報に基づき加熱時間が調節され、転がり軸受外 輪 301が冷却されるべきタイミングが決定されて冷却開始信号が出力される冷却タイ ミング調節工程 436と、冷却開始信号に基づいて、転がり軸受外輪 301が冷却され ることにより転がり軸受外輪 301の焼戻が終了する冷却工程 437とを有している。  [0259] The tempering control process 430 includes a tempering temperature measurement process 435 in which the surface temperature of the stable layer 309 formed on the surface of the rolling bearing outer ring 301 is measured by a radiation thermometer, and a tempering measurement process 430. A cooling timing adjustment step 436 in which the heating time is adjusted based on the temperature information measured in the temperature range 435, the timing at which the rolling bearing outer ring 301 should be cooled is determined, and a cooling start signal is output. And a cooling step 437 in which tempering of the rolling bearing outer ring 301 is completed by cooling the rolling bearing outer ring 301 based on the start signal.
[0260] 実施の形態 5における高周波焼戻方法は、温度制御により実施され、熱処理の条 件出しが容易であるため、転がり軸受外輪 301の製造コストを抑制し、かつ品質を安 定させることが可能である。また、実施の形態 5の高周波焼戻方法においては、たと えば図 25に基づいて説明した実施の形態 3の転がり軸受外輪 301と同様の構成を 有し、焼入硬化された被処理物に対して焼戻を実施することができる。その結果、本 発明の一実施の形態である実施の形態 5における高周波熱処理品としての転がり軸 受外輪 301は、製造コストが抑制され、かつ品質の安定した高周波熱処理品となつ ている。 [0260] The induction tempering method in the fifth embodiment is performed by temperature control, and it is easy to determine the conditions for heat treatment. Therefore, the manufacturing cost of the rolling bearing outer ring 301 is suppressed, and the quality is reduced. Can be determined. In addition, in the induction tempering method of the fifth embodiment, for example, the workpiece having the same configuration as the rolling bearing outer ring 301 of the third embodiment described with reference to FIG. Tempering can be carried out. As a result, the rolling bearing outer ring 301 as the high frequency heat-treated product in the fifth embodiment, which is one embodiment of the present invention, is a high-frequency heat treated product with reduced manufacturing cost and stable quality.
[0261] なお、表面安定ィ匕工程 311においては、実施の形態 3と同様に、転がり軸受外輪 3 01の表面に黒体塗料が塗布されることにより、上述の安定化層 309としての黒体塗 料層を形成してもよいし、黒体塗料層に代えて、酸化鉄層が形成されてもよい。この 酸ィ匕鉄層は、たとえば転がり軸受外輪 301の表面が熱酸ィ匕されることにより形成され てもよいし、転がり軸受外輪 301が酸性の溶液中に浸漬されることにより形成されても よい。  [0261] In the surface stabilization step 311, as in the third embodiment, a black body paint is applied to the surface of the rolling bearing outer ring 301 so that the black body as the stabilization layer 309 described above is applied. A coating layer may be formed, or an iron oxide layer may be formed instead of the black body paint layer. This acid iron layer may be formed by, for example, the surface of the rolling bearing outer ring 301 being thermally oxidized, or may be formed by immersing the rolling bearing outer ring 301 in an acidic solution. Good.
[0262] 次に、実施の形態 5の高周波熱処理方法について、 SUJ2製の転がり軸受外輪 30 1を例に、具体的に説明する。この転がり軸受外輪 301は、 RXガス雰囲気炉にて 85 0°Cから急冷されることにより焼入されたものである。ここでは、強度の観点から、焼戻 後の被処理物の熱処理規格を、硬度 HRC58以上 HRC62以下と設定する。  [0262] Next, the high-frequency heat treatment method of the fifth embodiment will be specifically described taking a rolling bearing outer ring 301 made of SUJ2 as an example. The outer ring 301 of the rolling bearing is quenched by being rapidly cooled from 850 ° C. in an RX gas atmosphere furnace. Here, from the viewpoint of strength, the heat treatment standard of the workpiece after tempering is set to hardness HRC58 or more and HRC62 or less.
[0263] 材料強度と、焼戻温度および焼戻時間との間には、次の関係式が成立する。 [0263] The following relational expression is established between the material strength and the tempering temperature and tempering time.
X= l -exp{ - (kt) N} X = l -exp {-(kt) N }
k=Aexp (-Q/RT)  k = Aexp (-Q / RT)
M = M—（M -M )X  M = M— (M -M) X
o o f  o o f
X:機械的性質の変化率、 k:反応速度係数、 t:焼戻時間 (秒)、 N:時間指数、 A:振 動因子項、 Q :活性化エネルギー、 R:気体定数、 T:焼戻温度 (K)、 M :焼戻後の硬 度、 Μ：焼入後の硬度、 Μ：生材硬度  X: rate of change of mechanical properties, k: reaction rate coefficient, t: tempering time (seconds), N: time index, A: vibration factor term, Q: activation energy, R: gas constant, T: tempering Tempering temperature (K), M: Hardness after tempering, Μ: Hardness after quenching, Μ: Raw material hardness
0 f  0 f
したがって、これらの式力も焼戻時間 tにつ 、ての次式を導くことができる。  Therefore, these formula forces can also be derived from the following formula for the tempering time t.
[0264] t=〔ln{ (M— M ) Z (M— M ) } X {Aexp (— QZRT) }_N〕1/N…式（10) [0264] t = [ln {(M- M) Z ( M- M)} X {Aexp (- QZRT)} _N ] 1 / N ... (10)
0 f f  0 f f
式（10)中の焼入後の硬度 Mと生材硬度 Mは実測できる。また、 Nと Aと Qは実験  The hardness M and the raw material hardness M after quenching in the formula (10) can be measured. N, A, and Q are experiments
0 f  0 f
的に求めることができるから、焼戻温度 Tの値を代入して式（10)により焼戻時間 tを 計算できる。本実施の形態 5の冷却タイミング調節工程では、式（10)に基づき焼戻 時間 tを調節することができる。式（10)は、被処理物の規格品質 (硬度）に対する熱 処理温度とその保持時間との関係式であり、転がり軸受外輪 301の形状を問わず有 効に利用することができる。 Therefore, the tempering time t can be calculated by Equation (10) by substituting the value of the tempering temperature T. In the cooling timing adjustment process of the fifth embodiment, tempering is performed based on the equation (10). The time t can be adjusted. Expression (10) is a relational expression between the heat treatment temperature and the retention time with respect to the standard quality (hardness) of the workpiece, and can be used effectively regardless of the shape of the rolling bearing outer ring 301.
[0265] 図 23を参照して、焼戻の加熱温度および時間の条件 (焼戻条件)の決定方法を説 明する。 [0265] With reference to FIG. 23, a method of determining the tempering heating temperature and time conditions (tempering conditions) will be described.
[0266] 図 23に示す条件線図は、焼戻時間 tを求める式（10)に基づいて作製することがで きる。図 23を参照して、焼戻温度が高温になるほど短時間での焼戻が可能になる。 このため、焼戻温度は高い方が、熱処理時間の低減という観点からは望ましい。しか し、焼戻温度が高くなると、温度ムラによる焼戻ムラが発生しやすくなると考えられる ので、焼戻温度は、熱処理時間と焼戻ムラとの兼ね合いなど力 決定することができ る。  [0266] The condition diagram shown in FIG. 23 can be prepared based on the equation (10) for obtaining the tempering time t. Referring to FIG. 23, the higher the tempering temperature, the shorter the tempering becomes possible. For this reason, a higher tempering temperature is desirable from the viewpoint of reducing the heat treatment time. However, if the tempering temperature increases, tempering unevenness due to temperature unevenness is likely to occur. Therefore, the tempering temperature can be determined in terms of the balance between heat treatment time and tempering unevenness.
[0267] 焼戻条件が決定すると、図 31を参照して、当該焼戻条件がパーソナルコンピュータ などの温度調節装置 314に入力される。温度調節装置 314は、第 1放射温度計 313 と、加熱装置 312に接続されており、第 1放射温度計 313からの温度情報に基づき、 PID制御により温度制御信号を加熱装置 312に出力し、転がり軸受外輪 301の温度 推移を制御する。このとき同時に、第 2放射温度計 315の温度情報をパソコンなどの 冷却タイミング調節装置 316に取り込み、その温度推移から加熱が十分であるかどう かを判断し、焼戻終了時期を調節する。  [0267] When the tempering conditions are determined, referring to Fig. 31, the tempering conditions are input to temperature control device 314 such as a personal computer. The temperature adjustment device 314 is connected to the first radiation thermometer 313 and the heating device 312, and based on the temperature information from the first radiation thermometer 313, outputs a temperature control signal to the heating device 312 by PID control. Controls temperature transition of rolling bearing outer ring 301. At the same time, the temperature information of the second radiation thermometer 315 is taken into a cooling timing adjustment device 316 such as a personal computer, and it is judged whether the heating is sufficient from the temperature transition, and the tempering end time is adjusted.
[0268] 図 24を参照して、第 2放射温度計 315からの温度情報は刻一刻と変化するので、 [0268] Referring to FIG. 24, the temperature information from the second radiation thermometer 315 changes every moment.
M (焼戻後の硬度)の値は t *を算出しつつ、図 24のように積算して算出することが望 ましい。そして、焼戻後の硬度が目標の硬度になる条件が満たされた時点で、冷却 液噴射装置 317により転がり軸受外輪 301が冷却される。なお、温度調節装置 314 と冷却タイミング調節装置 316とを同一のパソコンで兼ねることもできる。 The value of M (hardness after tempering) should be calculated by integrating t * as shown in Fig. 24. When the condition that the hardness after tempering becomes the target hardness is satisfied, the rolling bearing outer ring 301 is cooled by the coolant injection device 317. The temperature adjusting device 314 and the cooling timing adjusting device 316 can also be used as the same personal computer.
[0269] なお、本実施の形態 5の熱処理装置は上述の実施の形態 3の熱処理装置と基本的 に同様の構成を有している。したがって、たとえば制御装置としてパソコンを用い、目 的の熱処理に対応したプログラムを使い分けることにより、高周波焼入装置と高周波 焼戻装置を兼ねることができる。  Note that the heat treatment apparatus of the fifth embodiment has basically the same configuration as the heat treatment apparatus of the third embodiment described above. Therefore, for example, by using a personal computer as a control device and using a program corresponding to the desired heat treatment, the induction hardening device and the induction tempering device can be combined.
[0270] (実施の形態 6) 図 33および図 34を参照して、実施の形態 6における高周波焼戻装置および高周 波焼戻方法にっ 、て説明する。 [0270] (Embodiment 6) With reference to FIG. 33 and FIG. 34, the induction tempering apparatus and the high-frequency tempering method in the sixth embodiment will be described.
[0271] 図 33を参照して、実施の形態 6における高周波焼戻装置 394は、基本的には実施 の形態 5における高周波焼戻装置 393と同様の構成を有している。しかし、実施の形 態 6における高周波焼戻装置 394は、加熱装置 312、温度調節装置 314および冷却 タイミング調節装置 316に接続され、電源出力の推移データと、冷却タイミングデータ とをプロセスデータとして記憶する記憶装置 371を備えている点において、実施の形 態 5の高周波焼戻装置 393とは異なって 、る。  Referring to FIG. 33, induction tempering apparatus 394 in the sixth embodiment has basically the same configuration as induction tempering apparatus 393 in the fifth embodiment. However, the induction tempering apparatus 394 in Embodiment 6 is connected to the heating apparatus 312, the temperature adjustment apparatus 314, and the cooling timing adjustment apparatus 316 and stores the power output transition data and the cooling timing data as process data. This is different from the induction tempering apparatus 393 of Embodiment 5 in that the storage apparatus 371 is provided.
[0272] また、図 34を参照して、実施の形態 6における高周波焼戻方法は高周波加熱によ り被処理物 (たとえば転がり軸受外輪 301)を加熱して焼戻を実施する高周波熱処理 方法であって、データ取得工程と、記憶工程と、確認工程と、量産工程とを備えてい る。  [0272] Referring to Fig. 34, the induction tempering method in the sixth embodiment is an induction heat treatment method in which an object to be treated (for example, the rolling bearing outer ring 301) is heated and tempered by induction heating. Therefore, it has a data acquisition process, a storage process, a confirmation process, and a mass production process.
[0273] データ取得工程では、転がり軸受外輪 301のサンプルが加熱されて焼戻されること によりプロセスデータが取得される。記憶工程では、データ取得工程において転がり 軸受外輪 301のサンプルを加熱するために高周波加熱用の電源力も誘導コイルに 出力された電源出力の推移データと、転がり軸受外輪 301のサンプルの冷却タイミン グを特定するための冷却タイミングデータとがプロセスデータとして記憶される。  [0273] In the data acquisition step, the process data is acquired by heating and tempering the sample of the rolling bearing outer ring 301. In the memory process, in order to heat the sample of the rolling bearing outer ring 301 in the data acquisition process, the transitional data of the power output output to the induction coil and the power supply power for high-frequency heating and the cooling timing of the sample of the rolling bearing outer ring 301 are specified. And cooling timing data for the storage are stored as process data.
[0274] 確認工程では、データ取得工程において焼戻された転がり軸受外輪 301の材質デ ータに基づき、電源出力の推移データおよび冷却タイミングデータの妥当性が確認 される。すなわち、たとえば、データ取得工程における被処理物の温度推移のデータ を記憶し、記憶された温度推移データが分析されることで、外乱の影響の有無が判 定され、記憶工程にぉ 、て記憶されたプロセスデータである電源出力の推移データ および冷却タイミングデータの妥当性が確認される。なお、実際に熱処理された転が り軸受外輪 301のサンプルの材質データを実験により実際に取得し、電源出力の推 移データおよび冷却タイミングデータの妥当性が確認されてもよい。  [0274] In the confirmation process, the validity of the transition data of the power output and the cooling timing data is confirmed based on the material data of the rolling bearing outer ring 301 tempered in the data acquisition process. That is, for example, the temperature transition data of the object to be processed in the data acquisition process is stored, and the stored temperature transition data is analyzed to determine the presence or absence of the influence of the disturbance. The validity of the transition data of the power output and the cooling timing data, which are the processed process data, is confirmed. It should be noted that the material data of the sample of the rolling bearing outer ring 301 that has been actually heat-treated may be actually obtained through experiments to confirm the validity of the power output transition data and the cooling timing data.
[0275] ここで、転がり軸受外輪 301の測温において、外乱の影響があった場合、温度推移 データに異常な値が記録されるため、記憶された温度推移データ力 外乱の有無は 判断可能である。たとえば、温度推移データに不連続な領域が存在する場合、外乱 があったものと判断することができる。また、より正確な判断を行なうためには、同一の 部位の温度を測定する接触式または非接触式の温度計を設け、双方のデータの整 合性により外乱の有無を判断することもできる。具体的判断の手法としては、たとえば 双方のデータ力 温度差が 5%以上となった場合に外乱有りと判断することができる 。また、外乱の判断は作業者が温度推移データを確認して行なうことができるが、自 動化された他の装置により行なうこともできる。具体的にはたとえば記憶された温度推 移データの温度推移の微分値が 1000°CZ秒以上または— 1000°CZ秒以下となつ た場合に外乱有りと判断する方法や、前述のように同一の部位の温度を測定する温 度計を設け、両者のデータに 5%以上の差が生じた場合に外乱有りと判断するような 手段が挙げられる。 [0275] Here, if there is a disturbance in the temperature measurement of the rolling bearing outer ring 301, an abnormal value is recorded in the temperature transition data, so the stored temperature transition data force can be judged whether there is a disturbance or not. is there. For example, if there is a discontinuous area in the temperature transition data, It can be judged that there was. In order to make a more accurate determination, a contact or non-contact thermometer that measures the temperature of the same part can be provided, and the presence or absence of disturbance can be determined based on the consistency of both data. As a specific judgment method, for example, when the difference between the two data power temperatures is 5% or more, it can be judged that there is a disturbance. In addition, the disturbance can be determined by the operator confirming the temperature transition data, but can also be performed by another automated device. Specifically, for example, when the differential value of the temperature transition of the stored temperature transition data is 1000 ° CZ seconds or more or -1000 ° CZ seconds or less, there is a method of determining that there is a disturbance, or the same as described above. A thermometer that measures the temperature of the part is provided, and there is a means to judge that there is a disturbance when a difference of 5% or more occurs between the two data.
[0276] 量産工程では、記憶工程で記憶され、かつ確認工程で妥当性が確認された電源 出力の推移データおよび冷却タイミングデータに従って転がり軸受外輪 301の高周 波焼戻が行なわれる。そして、データ取得工程における焼戻は、本発明の高周波熱 処理方法、たとえば実施の形態 5の高周波熱処理方法により実施される。  [0276] In the mass production process, high-frequency tempering of the rolling bearing outer ring 301 is performed in accordance with the transition data and cooling timing data of the power output stored in the storage process and validated in the confirmation process. The tempering in the data acquisition step is performed by the high frequency heat treatment method of the present invention, for example, the high frequency heat treatment method of the fifth embodiment.
[0277] 実施の形態 6における高周波焼戻方法により被処理物としての転がり軸受外輪 30 1を焼戻すことにより、温度制御が可能となり、熱処理の条件出しが容易となるだけで なぐプロセスデータへの外乱の影響が一層抑制され、被処理物（転がり軸受外輪 3 01)の品質が安定する。  [0277] By tempering the rolling bearing outer ring 301 as the object to be processed by the induction tempering method in the sixth embodiment, temperature control becomes possible, and the process data can be converted to the process data that only makes it easy to determine the conditions for the heat treatment. The influence of disturbance is further suppressed, and the quality of the workpiece (rolling bearing outer ring 301) is stabilized.
[0278] そして、実施の形態 6における高周波焼戻方法により焼戻された実施の形態 6にお ける高周波焼戻品としての転がり軸受外輪 301は、低価格化され、かつ一層品質の 安定した高周波焼戻品となっている。  [0278] Then, the rolling bearing outer ring 301 as the induction tempered product in the sixth embodiment tempered by the induction tempering method in the sixth embodiment is reduced in price and further improved in quality. It is a tempered product.
[0279] 次に、実施の形態 6における高周波焼戻の詳細について説明する。図 35において 、データ取得工程におけるデータの流れは実線矢印、記憶工程におけるデータの流 れは破線矢印、確認工程におけるデータの流れは二重破線矢印、量産工程におけ るデータの流れは二重実線矢印で表示されている。図 35を参照して、実施の形態 6 に係る高周波焼戻の各工程におけるデータの流れを説明する。  [0279] Next, details of induction tempering in the sixth embodiment will be described. In FIG. 35, the data flow in the data acquisition process is a solid arrow, the data flow in the storage process is a broken arrow, the data flow in the confirmation process is a double dashed arrow, and the data flow in the mass production process is a double solid line. It is displayed with an arrow. With reference to FIG. 35, a data flow in each step of induction tempering according to the sixth embodiment will be described.
[0280] 図 35を参照して、データ取得工程においては、温度制御用測温装置 (第 1放射温 度計 313)により測定された被処理物としての転がり軸受外輪 301のサンプルの温度 データは温度調節装置 314に送られる。温度調節装置 314においては転がり軸受 外輪 301の目標加熱温度および取得した転がり軸受外輪 301のサンプルの温度デ 一タカゝら必要な電源出力を判断し、加熱装置 312の電源に電源出力を指令する。指 令を受けた電源は加熱装置 312の誘導コイルに電力を出力し、転がり軸受外輪 301 のサンプルは目的の温度に加熱される。 [0280] Referring to FIG. 35, in the data acquisition process, the temperature of the sample of the rolling bearing outer ring 301 as the workpiece measured by the temperature control temperature measuring device (first radiation thermometer 313). The data is sent to temperature controller 314. In the temperature control device 314, the target heating temperature of the rolling bearing outer ring 301 and the obtained temperature data of the sample of the rolling bearing outer ring 301 are judged, and the necessary power output is determined, and the power output of the heating device 312 is commanded. The power source that receives the command outputs power to the induction coil of the heating device 312 and the sample of the rolling bearing outer ring 301 is heated to a target temperature.
[0281] 一方、焼戻用測温装置 (第 2放射温度計 315)により測定された転がり軸受外輪 30 1のサンプルの温度データは冷却タイミング調節装置 316に送られる。冷却タイミング 調節装置 316においては取得した転がり軸受外輪 301のサンプルの温度およびカロ 熱時間から冷却タイミングを判断し、冷却開始を冷却液噴射装置などの冷却装置に 指令する。これにより、転がり軸受外輪 301のサンプルは冷却され、焼戻が終了する 。このとき、このデータ取得工程は温度制御により実施されるため、転がり軸受外輪 3 01のサンプルの加熱履歴は明確である。そのため、温度データが正確である限り適 切な熱処理が行なわれており、目的の品質を有する転がり軸受外輪 301が得られて いる。その結果、被処理物の品質を確認しながら熱処理の条件出しが行なわれる必 要がなぐ条件出しが容易に行なわれる。また、被処理物の表面には、安定化層が 形成されているため、放射温度計による測温の精度は高くなつている。  On the other hand, the temperature data of the sample of the rolling bearing outer ring 301 measured by the tempering temperature measuring device (second radiation thermometer 315) is sent to the cooling timing adjusting device 316. The cooling timing adjusting device 316 determines the cooling timing from the obtained temperature and calorie heat time of the sample of the rolling bearing outer ring 301 and commands a cooling device such as a coolant injection device to start cooling. Thereby, the sample of the rolling bearing outer ring 301 is cooled, and tempering is completed. At this time, since this data acquisition process is performed by temperature control, the heating history of the sample of the rolling bearing outer ring 301 is clear. Therefore, as long as the temperature data is accurate, an appropriate heat treatment is performed, and the rolling bearing outer ring 301 having the desired quality is obtained. As a result, it is easy to determine conditions that do not need to be determined while checking the quality of the workpiece. In addition, since a stabilization layer is formed on the surface of the workpiece, the accuracy of temperature measurement with a radiation thermometer is increasing.
[0282] 記憶工程においては、データ取得工程において温度調節装置 314および冷却タイ ミング調節装置 316が取得した温度データが温度推移データとして記憶装置 370に 記憶される。また、加熱装置 312の電源が誘導コイルに出力した電源出力が電源出 力の推移データとして記憶装置 371に記憶される。さらに、冷却タイミング調節装置 3 16が冷却液噴射装置などの冷却装置に出力した冷却開始指令のタイミングが冷却 タイミングデータとして記憶装置 371に記憶される。ここで、冷却タイミングはたとえば 加熱開始からの時間として記憶される。  In the storage step, the temperature data acquired by the temperature adjustment device 314 and the cooling timing adjustment device 316 in the data acquisition step is stored in the storage device 370 as temperature transition data. In addition, the power output output from the power supply of the heating device 312 to the induction coil is stored in the storage device 371 as the power output transition data. Further, the timing of the cooling start command output from the cooling timing adjusting device 316 to the cooling device such as the coolant injection device is stored in the storage device 371 as the cooling timing data. Here, the cooling timing is stored as the time from the start of heating, for example.
[0283] 確認工程においては、たとえば第 1放射温度計 313および第 2放射温度計 315と 同一部位を測定可能な温度計がそれぞれ設けられ、当該部位が測温される。この測 温データと、第 1放射温度計 313および第 2放射温度計 315により測定されて記憶装 置 371に記憶された温度推移データとが比較されることにより、外乱の有無が判断さ れる。 [0284] 量産工程においては、記憶工程で記憶され、かつ確認工程で妥当性が確認された 電源出力の推移データおよび冷却タイミングデータに基づき、転がり軸受外輪 301 が加熱されて焼戻が行なわれる。このとき、この量産工程は外乱のおそれのある第 1 放射温度計 313および第 2放射温度計 315からのリアルタイムの温度データに基づ いて実施されるのではなぐ妥当性が確認された電源出力の推移データおよび冷却 タイミングデータに基づいて電力制御により実施される。そのため、安定した品質の 転がり軸受外輪 301が得られる。 [0283] In the confirmation step, for example, thermometers capable of measuring the same part as the first radiation thermometer 313 and the second radiation thermometer 315 are provided, and the temperature of the part is measured. By comparing this temperature measurement data with the temperature transition data measured by the first radiation thermometer 313 and the second radiation thermometer 315 and stored in the storage device 371, the presence or absence of disturbance is determined. [0284] In the mass production process, the rolling bearing outer ring 301 is heated and tempered based on the transition data and cooling timing data of the power output stored in the storage process and validated in the confirmation process. At this time, the mass production process is not performed based on the real-time temperature data from the first radiation thermometer 313 and the second radiation thermometer 315, which may cause disturbance, and the validity of the power output is confirmed. It is implemented by power control based on transition data and cooling timing data. Therefore, the rolling bearing outer ring 301 having a stable quality can be obtained.
[0285] なお、記憶装置 371は、独立の装置として設置されてもよいが、たとえばノヽードディ スクなどの記憶部を有するパーソナルコンピュータにより、温度調節装置 314、冷却 タイミング調節装置 316などの装置を兼用して設置されてもよい。また、本実施の形 態の高周波焼戻方法の各工程は、たとえば制御装置としてパーソナルコンピュータ を用い、各工程に対応した単数または複数のプログラムにより当該パーソナルコンビ ユータを動作させることにより実施することができる。  [0285] The storage device 371 may be installed as an independent device. For example, a personal computer having a storage unit such as a node disk may be used as a device such as the temperature adjustment device 314 and the cooling timing adjustment device 316. May be installed. In addition, each step of the induction tempering method of the present embodiment can be performed by using a personal computer as a control device, for example, and operating the personal computer with one or more programs corresponding to each step. it can.
[0286] (実施例 1)  [0286] (Example 1)
以下、本発明の実施例について説明する。本発明の高周波焼入装置を用い、本発 明の高周波焼入方法による高周波焼入を実施し、その有効性を確認する試験を行 なった。試験の手順は以下のとおりである。  Examples of the present invention will be described below. Using the induction hardening apparatus of the present invention, induction hardening was performed by the induction hardening method of the present invention, and a test was performed to confirm the effectiveness. The test procedure is as follows.
[0287] 転がり軸受の軌道輪を想定した SUJ2製のリング状試験片（外径 φ 62mm X内径 φ 52mm X幅 tl6mmのリング状試験片）を準備し、図 2に基づいて説明した上記実 施の形態 1の高周波焼入装置を用い、図 3に基づいて説明した上記実施の形態 1の 高周波焼入方法により焼入を実施した。焼入の条件としては、温度制御工程におけ る保持温度を 900°C、 950°C、 1000°Cの 3水準とし、昇温速度は 210°CZ秒で一定 とする条件を採用した。そして、焼入後、 180°Cで 120分間保持することにより焼戻を 行なった。その後、試験片の外周面 (高温部）および内周面 (低温部）の硬度および 残留オーステナイト量を測定した。なお、硬度および残留オーステナイト量の目標値 はそれぞれ 58HRC (653HV)以上、 12体積％以下とした。表 1に試験の結果を示 す。  [0287] SUJ2 ring-shaped specimens (outer diameter 62 mm x inner diameter 52 mm x width tl6 mm ring-shaped specimens) assuming rolling bearing raceways were prepared, and the implementation described above based on Fig. 2 was performed. Using the induction hardening apparatus of Embodiment 1, quenching was performed by the induction hardening method of Embodiment 1 described above with reference to FIG. As the quenching conditions, the holding temperature in the temperature control process was set to three levels of 900 ° C, 950 ° C, and 1000 ° C, and the temperature rising rate was constant at 210 ° CZ seconds. After quenching, tempering was performed by holding at 180 ° C for 120 minutes. Thereafter, the hardness and residual austenite amount of the outer peripheral surface (high temperature portion) and inner peripheral surface (low temperature portion) of the test piece were measured. The target values for hardness and retained austenite were 58HRC (653HV) or more and 12% by volume or less, respectively. Table 1 shows the test results.
[0288] [表 1] 温度制御工程加熱条件 硬度測定結果 残留オーステナイ ト S測定結果 昇温 度 外周面 内周面 外周面 内周面 [0288] [Table 1] Temperature control process heating conditions Hardness measurement result Residual austenite S measurement result Temperature rise Outer surface Inner surface Outer surface Inner surface
(°c) (。C/秒） (HV) (HV) (体積 %) (体積 %)  (° c) (.C / sec) (HV) (HV) (Volume%) (Volume%)
900 718 673 4. 1 1. 3 900 718 673 4. 1 1. 3
950 210 725 682 5. 1 2. 5950 210 725 682 5. 1 2. 5
1000 740 690 7. 0 3. 3 1000 740 690 7. 0 3. 3
[0289] 表 1を参照して、温度制御工程の保持温度の条件にかかわらず、測定された硬度 および残留オーステナイト量はいずれも目標値をクリアしていた。このことから、本発 明の高周波焼入方法および高周波焼入装置によれば、 1000°Cという高温での焼入 処理が可能であるため、焼入の際の加熱時間の短縮を可能とし、焼入硬化処理の効 率ィ匕に寄与しうることが確認された。 [0289] Referring to Table 1, regardless of the holding temperature condition in the temperature control step, the measured hardness and the retained austenite amount both cleared the target values. Therefore, according to the induction quenching method and induction quenching apparatus of the present invention, it is possible to quench at a high temperature of 1000 ° C, so that the heating time during quenching can be shortened. It was confirmed that it can contribute to the efficiency of quench hardening.
[0290] (実施例 2)  [0290] (Example 2)
以下、本発明の実施例 2について説明する。本発明の高周波熱処理方法における 表面安定ィ匕工程の効果を確認する試験を行なった。試験の手順は以下のとおりであ る。  Example 2 of the present invention will be described below. A test was conducted to confirm the effect of the surface stabilization process in the high-frequency heat treatment method of the present invention. The test procedure is as follows.
[0291] 試験の対象となる被処理物としては、 JIS SUJ2製の転がり軸受外輪、および JIS SUS440C製の転がり軸受外輪を選択した。そして、それぞれの被処理物を 900°C 以上の温度に加熱して保持しつつ、被処理物の同一部位を放射温度計および熱電 対で測定した。また、 JIS SUS440C製の転がり軸受外輪については、加熱前に当 該加熱温度にお！ヽて耐酸化性に優れ、放射率のほとんど変化しな！ヽ黒体塗料 (TE MPIL社製の Pyromark High Temperature Paint)を表面に塗布した後、同 様の試験を実施した。  [0291] JIS SUJ2 rolling bearing outer rings and JIS SUS440C rolling bearing outer rings were selected as objects to be tested. Then, the respective parts to be processed were measured with a radiation thermometer and a thermocouple while holding the objects to be processed at a temperature of 900 ° C. or higher. JIS SUS440C rolling bearing outer rings must be at the heating temperature before heating! It has excellent oxidation resistance and almost no change in emissivity! A similar test was performed after applying black body paint (Pyromark High Temperature Paint, manufactured by TE MPIL) on the surface.
[0292] 図 36〜図 38において、横軸は加熱時間、縦軸は加熱温度を示しており、実線は 放射温度計の測温データ、破線は熱電対の測温データを示している。図 36〜図 38 を参照して、本実施例 2の試験結果にっ 、て説明する。  36 to 38, the horizontal axis indicates the heating time, the vertical axis indicates the heating temperature, the solid line indicates the temperature measurement data of the radiation thermometer, and the broken line indicates the temperature measurement data of the thermocouple. The test results of Example 2 will be described with reference to FIGS.
[0293] 図 36を参照して、 SUJ2製の転がり軸受外輪の場合、加熱開始からわずかな時間、 具体的には 15秒程度で放射温度計の測温データと熱電対の測温データとの比がほ ぼ一定となっている。これは、 SUJ2製の転がり軸受外輪の場合、上述の加熱開始か らわずかな時間で、熱酸化により当該外輪の表面に酸化鉄層が形成され、その後表 面状態が変化しな力つたためであると考えられる。 [0293] Referring to Fig. 36, in the case of a rolling bearing outer ring made of SUJ2, the temperature measurement data of the radiation thermometer and the temperature measurement data of the thermocouple are measured in a short time from the start of heating, specifically about 15 seconds. The ratio is almost constant. This is because in the case of a SUJ2 rolling bearing outer ring, an iron oxide layer is formed on the surface of the outer ring by thermal oxidation within a short time after the start of the heating described above. This is thought to be because the surface condition changed and became strong.
[0294] 一方、図 37を参照して、 SUS440C製の転がり軸受外輪の場合、加熱開始から 17 0秒経過した時点で、熱電対の測温データを示す破線がほぼ水平となっており、その 後は放射温度計の測温データと熱電対の測温データとの比がほぼ一定となっている 。これは、 SUS440Cは SUJ2に比べて耐酸ィ匕性に優れているため、熱酸化により表 面状態が変化しない程度にまで酸ィ匕鉄層が形成されるために、より長い時間を要す るためであると考えられる。つまり、 SUS440Cは、表面状態が変化しない程度にま で酸化鉄層が形成されるためには、 920°Cで 170秒程度保持する必要がある。  [0294] On the other hand, referring to FIG. 37, in the case of a rolling bearing outer ring made of SUS440C, the broken line indicating the thermocouple temperature measurement data is almost horizontal when 170 seconds have elapsed from the start of heating. After that, the ratio between the temperature measurement data of the radiation thermometer and the temperature measurement data of the thermocouple is almost constant. This is because SUS440C has superior acid resistance compared to SUJ2, so it takes longer time to form the acid iron layer to the extent that the surface state does not change due to thermal oxidation. This is probably because of this. In other words, SUS440C needs to be held at 920 ° C for about 170 seconds in order for the iron oxide layer to be formed to such an extent that the surface state does not change.
[0295] 以上の結果より、 SUJ2製の被処理物に関しては、表面安定化工程を実施すること が好ましいものの、 960°C以上の高温で熱処理が実施される場合には、表面安定ィ匕 工程を実施しない場合の測温精度への影響は比較的小さいといえる。なお、図 36に 示すように、放射温度計の測温データと熱電対の測温データとの間に差が認められ るが、当該差は放射温度計の放射率の設定により解消し、本来の正確な温度である 熱電対の測温データに放射温度計の測温データを一致させることができる。  [0295] From the above results, it is preferable to carry out the surface stabilization process for the SUJ2 workpiece, but when the heat treatment is performed at a high temperature of 960 ° C or higher, the surface stabilization process It can be said that the influence on the temperature measurement accuracy when not carrying out is relatively small. As shown in Fig. 36, there is a difference between the temperature measurement data of the radiation thermometer and the temperature measurement data of the thermocouple, but this difference is eliminated by setting the emissivity of the radiation thermometer. It is possible to match the temperature measurement data of the radiation thermometer with the temperature measurement data of the thermocouple which is the exact temperature.
[0296] 一方、 SUS440製の被処理物に関しては、表面安定化工程を実施しない場合の 測温精度への影響は大きぐ表面安定ィ匕工程を実施する必要性が高いといえる。そ して、当該表面安定化工程を熱酸化により実施する場合、 920°Cで 170秒程度保持 する必要があることが分力つた。  [0296] On the other hand, for SUS440 workpieces, it can be said that it is highly necessary to perform the surface stabilization process, which has a great influence on the temperature measurement accuracy when the surface stabilization process is not performed. In addition, when the surface stabilization process was performed by thermal oxidation, it was necessary to hold at 920 ° C for about 170 seconds.
[0297] また、図 38を参照して、黒体塗料を塗布した後、加熱を実施した SUS440製の被 処理物に関しては、加熱の初期から放射温度計の測温データと熱電対の測温デー タとの比がほぼ一定となっている。このことから、表面安定ィ匕工程として黒体塗料の塗 布を実施することにより、 SUS440製の被処理物の放射温度計による測温精度を大 幅に向上させることが可能であることが確認された。  [0297] Also, referring to Fig. 38, with regard to the SUS440 processed material that was heated after the black body paint was applied, the temperature measurement data of the radiation thermometer and the temperature measurement of the thermocouple were measured from the beginning of heating. The ratio with the data is almost constant. From this, it was confirmed that the temperature measurement accuracy of the SUS440 processing object by the radiation thermometer can be greatly improved by applying black body paint as the surface stabilization process. It was done.
[0298] 以上の結果より、本発明の表面安定ィ匕工程を実施することで放射温度計による測 温精度が向上し、特にステンレス鋼などの耐酸ィ匕性の高い素材 (たとえば SUS440 C、 M50など)で構成される高周波熱処理品の品質を安定させることが可能となるこ とが確認された。  [0298] From the above results, the measurement accuracy of the radiation thermometer is improved by carrying out the surface stabilization process of the present invention. In particular, a material with high acid resistance such as stainless steel (for example, SUS440 C, M50 It has been confirmed that it is possible to stabilize the quality of high-frequency heat-treated products composed of
[0299] 今回開示された実施の形態および実施例はすべての点で例示であって、制限的な ものではないと考えられるべきである。本発明の範囲は上記した説明ではなくて請求 の範囲によって示され、請求の範囲と均等の意味、および範囲内でのすべての変更 が含まれることが意図される。 [0299] The embodiments and examples disclosed this time are illustrative in all respects and are restrictive. It should be considered not. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.
産業上の利用可能性 Industrial applicability
本発明の高周波焼入方法および高周波焼入装置は、高周波加熱により被処理物 を加熱して焼入を行なう高周波焼入方法および高周波焼入装置に特に有利に適用 され得る。また、本発明の高周波焼入品は、高周波加熱により加熱されて焼入硬化さ れる高周波焼入品に特に有利に適用され得る。  The induction hardening method and the induction hardening apparatus of the present invention can be applied particularly advantageously to an induction hardening method and an induction hardening apparatus in which an object to be processed is quenched by induction heating. Moreover, the induction-hardened product of the present invention can be applied particularly advantageously to an induction-hardened product that is heated and hardened by induction heating.

Claims

請求の範囲 The scope of the claims
高周波加熱により被処理物（1)の全体を加熱して焼入硬化する高周波焼入方法（ 10)であって、  An induction hardening method (10) in which the whole object to be treated (1) is heated and hardened by induction heating,
前記被処理物（1)の温度が調節される温度制御工程 (20)と、  A temperature control step (20) in which the temperature of the workpiece (1) is adjusted;
加熱された前記被処理物（1)が冷却されるべきタイミングが決定されて、前記被処 理物（1)が冷却される焼入制御工程（30)とを備え、  A quenching control step (30) in which a timing at which the heated workpiece (1) is to be cooled is determined, and the workpiece (1) is cooled, and
前記温度制御工程（20)は、  The temperature control step (20)
前記被処理物（1)の温度が測定される温度制御用測温工程 (23)と、  A temperature control temperature measurement step (23) in which the temperature of the object to be treated (1) is measured;
前記温度制御用測温工程 (23)において測定された温度の情報に基づき、前記被 処理物（1)の加熱状態を制御するための温度制御信号が出力される温度調節工程 Temperature adjusting step for outputting a temperature control signal for controlling the heating state of the object to be processed (1) based on the temperature information measured in the temperature controlling temperature measuring step (23)
(24)と、 (24) and
前記温度制御信号に基づいて、前記高周波加熱により前記被処理物（1)が加熱さ れる加熱工程（22)とを含み、  A heating step (22) in which the workpiece (1) is heated by the high-frequency heating based on the temperature control signal,
前記焼入制御工程 (30)は、  The quenching control step (30)
前記被処理物（1)において、前記高周波加熱による温度の上昇が前記被処理物（ 1)の内部よりも大きい表面の部位である高温部（1A)と、前記高周波加熱による温度 の上昇が前記被処理物（1)の内部よりも小さい表面の部位である低温部（1B)との温 度が測定される焼入用測温工程 (35)と、  In the object to be treated (1), the high temperature part (1A) which is a surface portion where the temperature increase due to the high frequency heating is larger than the inside of the object (1), and the temperature increase due to the high frequency heating A quenching temperature measurement step (35) in which the temperature of the low temperature portion (1B), which is a surface portion smaller than the inside of the workpiece (1), is measured;
前記焼入用測温工程 (35)において測定された温度の情報に基づき加熱時間が 調節され、前記被処理物（1)が冷却されるべきタイミングが決定されて冷却開始信号 が出力される冷却タイミング調節工程（36)と、  Cooling in which the heating time is adjusted based on the temperature information measured in the quenching temperature measuring step (35), the timing at which the workpiece (1) should be cooled is determined, and a cooling start signal is output. Timing adjustment step (36);
前記冷却開始信号に基づいて、前記被処理物（1)が冷却されることにより前記被 処理物（1)が焼入硬化される冷却工程 (37)とを含み、  A cooling step (37) in which the workpiece (1) is quenched and hardened by cooling the workpiece (1) based on the cooling start signal,
前記冷却タイミング調節工程（36)においては、  In the cooling timing adjustment step (36),
前記高温部（1A)における温度および加熱時間を含む温度履歴が、予め求められ た所望の残留オーステナイト量の上限値以下の残留オーステナイト量が得られる温 度履歴の条件を満たし、  The temperature history including the temperature and heating time in the high temperature part (1A) satisfies the temperature history conditions for obtaining a retained austenite amount equal to or less than a predetermined upper limit value of the retained austenite amount,
前記低温部（1B)における温度および加熱時間を含む温度履歴が、予め求められ た所望の硬度の下限値以上の硬度が得られる温度履歴の条件を満たすように前記 加熱時間が調節されて、前記冷却開始信号が出力される、高周波焼入方法 (10)。 A temperature history including the temperature and heating time in the low temperature part (1B) is obtained in advance. The induction hardening method (10), wherein the heating time is adjusted so as to satisfy a condition of a temperature history at which a hardness equal to or higher than a lower limit value of a desired hardness is obtained, and the cooling start signal is output.
[2] 高周波加熱により被処理物（1)の全体を加熱して焼入硬化する請求の範囲第 1項 に記載の高周波焼入方法（10)に使用される高周波焼入装置（90)であって、 前記被処理物（1)の温度を調節するための温度制御装置（50)と、 [2] In an induction hardening apparatus (90) used in the induction hardening method (10) according to claim 1, wherein the whole object to be treated (1) is heated and hardened by induction heating. A temperature control device (50) for adjusting the temperature of the workpiece (1);
加熱された前記被処理物（1)が冷却されるべきタイミングを調節するための焼入制 御装置 (60)とを備え、  A quench control device (60) for adjusting the timing at which the heated workpiece (1) should be cooled,
前記温度制御装置（50)は、  The temperature control device (50)
前記被処理物（1)の温度データを取得し、前記被処理物（1)の温度データに基づ く温度の情報を出力する温度制御用測温装置 (3)と、  A temperature control temperature measuring device (3) for acquiring temperature data of the object to be processed (1) and outputting temperature information based on the temperature data of the object to be processed (1);
前記温度制御用測温装置（3)に接続され、前記温度制御用測温装置（3)からの温 度の情報に基づき前記被処理物（1)の加熱状態を制御するための温度制御信号を 出力する温度調節装置 (4)と、  A temperature control signal connected to the temperature control temperature measuring device (3) for controlling the heating state of the workpiece (1) based on the temperature information from the temperature control temperature measuring device (3). A temperature control device (4) that outputs
前記温度調節装置 (4)に接続され、前記温度調節装置 (4)からの前記温度制御信 号に基づき、高周波加熱により前記被処理物（1)を加熱する加熱装置 (2)とを含み、 前記焼入制御装置 (60)は、  A heating device (2) connected to the temperature control device (4) and heating the workpiece (1) by high-frequency heating based on the temperature control signal from the temperature control device (4), The quenching control device (60)
前記被処理物（1)の前記高温部（1A)および前記低温部（1B)の温度データを取 得し、前記被処理物（1)の温度データに基づく温度の情報を出力する焼入用測温 装置 (3, 5)と、  The temperature data of the high temperature part (1A) and the low temperature part (1B) of the workpiece (1) is acquired, and the temperature information based on the temperature data of the workpiece (1) is output. A temperature measuring device (3, 5),
前記焼入用測温装置（3, 5)に接続され、前記焼入用測温装置（3, 5)からの温度 の情報に基づき加熱時間を調節し、前記被処理物（1)が冷却されるべきタイミングを 決定して冷却開始信号を出力する冷却タイミング調節装置 (6)と、  Connected to the quenching temperature measuring device (3, 5), the heating time is adjusted based on the temperature information from the quenching temperature measuring device (3, 5), and the workpiece (1) is cooled. A cooling timing adjusting device (6) for determining a timing to be performed and outputting a cooling start signal,
前記冷却タイミング調節装置 (6)に接続され、前記冷却開始信号に基づいて、前 記被処理物（1)を冷却することにより前記被処理物（1)を焼入硬化する冷却装置（7 )とを含む、高周波焼入装置 (90)。  A cooling device (7) connected to the cooling timing adjusting device (6) and quenching and hardening the workpiece (1) by cooling the workpiece (1) based on the cooling start signal. Induction hardening equipment including (90).
[3] 請求の範囲第 1項に記載の高周波焼入方法（10)で熱処理されて作製されたことを 特徴とする、高周波焼入品（1)。 [3] An induction-hardened product (1), which is manufactured by heat treatment using the induction hardening method (10) according to claim 1.
PCT/JP2007/053033 2006-03-09 2007-02-20 Method of high-frequency quenching, high-frequency quenching apparatus, and product of high-frequency quenching WO2007102306A1 (en)

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2728965A1 (en) * 2008-09-30 2014-05-07 Aktiebolaget SKF Bearing heater
WO2014069149A1 (en) * 2012-10-31 2014-05-08 Ntn株式会社 Heat treatment method and method for manufacturing machine part
CN106319168A (en) * 2016-08-25 2017-01-11 江苏大学 Metal plate induction heating device capable of realizing closed-loop temperature control
CN114561513A (en) * 2022-02-21 2022-05-31 郑州科创电子有限公司 Quenching induction heating system and method

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH11293336A (en) * 1998-04-14 1999-10-26 High Frequency Heattreat Co Ltd Production of high strength steel
JP2003213380A (en) * 2002-01-22 2003-07-30 Nsk Ltd Rolling apparatus
JP2005048292A (en) * 1994-03-29 2005-02-24 Mazda Motor Corp Carburizing and quenching method
JP2005310645A (en) * 2004-04-23 2005-11-04 Ntn Corp High-frequency induction hardening device

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005048292A (en) * 1994-03-29 2005-02-24 Mazda Motor Corp Carburizing and quenching method
JPH11293336A (en) * 1998-04-14 1999-10-26 High Frequency Heattreat Co Ltd Production of high strength steel
JP2003213380A (en) * 2002-01-22 2003-07-30 Nsk Ltd Rolling apparatus
JP2005310645A (en) * 2004-04-23 2005-11-04 Ntn Corp High-frequency induction hardening device

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2728965A1 (en) * 2008-09-30 2014-05-07 Aktiebolaget SKF Bearing heater
WO2014069149A1 (en) * 2012-10-31 2014-05-08 Ntn株式会社 Heat treatment method and method for manufacturing machine part
JP2014088607A (en) * 2012-10-31 2014-05-15 Ntn Corp Heat treatment method and method of producing machine part
EP2915886A4 (en) * 2012-10-31 2016-06-29 Ntn Toyo Bearing Co Ltd Heat treatment method and method for manufacturing machine part
US10161015B2 (en) 2012-10-31 2018-12-25 Ntn Corporation Heat treatment method and method of manufacturing machine part
CN106319168A (en) * 2016-08-25 2017-01-11 江苏大学 Metal plate induction heating device capable of realizing closed-loop temperature control
CN106319168B (en) * 2016-08-25 2018-06-01 江苏大学 A kind of metal blank induction heating apparatus of achievable temperature scaling factor
CN114561513A (en) * 2022-02-21 2022-05-31 郑州科创电子有限公司 Quenching induction heating system and method

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