WO2018155043A1 - Heat treatment equipment and heat treatment method - Google Patents

Heat treatment equipment and heat treatment method Download PDF

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Publication number
WO2018155043A1
WO2018155043A1 PCT/JP2018/001890 JP2018001890W WO2018155043A1 WO 2018155043 A1 WO2018155043 A1 WO 2018155043A1 JP 2018001890 W JP2018001890 W JP 2018001890W WO 2018155043 A1 WO2018155043 A1 WO 2018155043A1
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Prior art keywords
heating
workpiece
heating coil
heat treatment
coil
Prior art date
Application number
PCT/JP2018/001890
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French (fr)
Japanese (ja)
Inventor
勇輝 田渕
慎太郎 鈴木
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Ntn株式会社
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Publication of WO2018155043A1 publication Critical patent/WO2018155043A1/en

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    • 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
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/36—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for balls; for rollers
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C33/00—Parts of bearings; Special methods for making bearings or parts thereof
    • F16C33/30—Parts of ball or roller bearings
    • F16C33/32—Balls
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C33/00—Parts of bearings; Special methods for making bearings or parts thereof
    • F16C33/30—Parts of ball or roller bearings
    • F16C33/34—Rollers; Needles
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B6/00—Heating by electric, magnetic or electromagnetic fields
    • H05B6/02—Induction heating
    • H05B6/06—Control, e.g. of temperature, of power
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B6/00—Heating by electric, magnetic or electromagnetic fields
    • H05B6/02—Induction heating
    • H05B6/10—Induction heating apparatus, other than furnaces, for specific applications
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B6/00—Heating by electric, magnetic or electromagnetic fields
    • H05B6/02—Induction heating
    • H05B6/36—Coil arrangements
    • H05B6/44—Coil arrangements having more than one coil or coil segment
    • 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 a heat treatment facility and a heat treatment method, and more particularly, to a heat treatment facility and a heat treatment method applied when heat treating a rotatable workpiece.
  • a quench hardening treatment as a heat treatment is performed.
  • This heat treatment includes a heating step for heating the workpiece to a predetermined temperature (quenching temperature), a cooling step for cooling the heated workpiece, etc., and the heating step is, for example, atmospheric heating typified by a mesh belt type continuous furnace. It can be carried out using a furnace.
  • the atmosphere heating furnace needs to heat the atmosphere together, there are problems such as low energy efficiency and a large installation space.
  • the above heating process may be performed using a high frequency induction heating apparatus.
  • Inductive heating has the advantage that a compact heat treatment facility can be realized in addition to achieving high energy efficiency because only the workpiece can be directly heated.
  • the induction heating device of Patent Document 1 is a guide tube as a guide member that guides and moves a work, a heating coil that is arranged on the outer periphery of the guide tube and induction-heats the work that moves in the guide tube, and an inlet side of the guide tube.
  • pushing means for sequentially pushing the workpiece into the guide tube. In this case, a feeding force is applied to the workpiece in the guide tube as the subsequent workpiece is pushed into the guide tube.
  • JP 2005-331005 A Japanese Patent Laying-Open No. 2015-67881
  • Patent Document 1 has the following problems. (1) Immediately after the start of heat treatment (initial stage) or just before the end (final stage), at a stage where the inner circumference of the heating coil is not satisfied with a predetermined number of workpieces, the inner circumference of the heating coil Since the magnetic flux concentrates on each workpiece as compared with the case where the workpiece is satisfied, the workpiece is easily overheated. The overheated workpiece cannot be obtained because it cannot obtain the desired metal structure, and hence the mechanical strength and hardness, and therefore the product yield is lowered. (2) Since each workpiece is conveyed and induction heated in a state of being in contact with the adjacent workpiece, each workpiece is easily affected by the magnetic flux change of the adjacent workpiece. Therefore, the heating temperature of each workpiece is not stable.
  • the problem of (1) is that the output of the high-frequency power supply depends on the number of workpieces existing in the opposed region of the heating coil, as disclosed in, for example, Japanese Patent Application Laid-Open No. 2015-67881 (Patent Document 2). It can be solved by changing. However, in order to implement such a method, it is necessary to set an output pattern of power in advance for each workpiece model number (product type) by repeatedly performing a field test and a simulation in advance. For this reason, a great amount of man-hours are required for preparation for implementation, which is difficult in terms of cost.
  • the first invention of the present application which was created to solve the above problems, is a transport device that transports a rotatable workpiece at a predetermined speed along a linear guide transport path, and is transported along the guide transport path.
  • a heat treatment equipment including a heating coil that includes a heating coil that induction-heats a workpiece that is heated to a predetermined temperature, and the heating coil has a total length that allows induction heating of a plurality of workpieces simultaneously.
  • the heating device has a plurality of work support portions provided apart from each other in the conveying direction, and the heating device includes a high-frequency power source electrically connected to the heating coil, and a current value flowing through the heating coil during heating of the work
  • examples of the “rotatable workpiece” mentioned here include a rolling element of a rolling bearing.
  • the rolling bearing here is a concept including a ball bearing, a cylindrical roller bearing, a tapered roller bearing, a needle roller bearing and the like. Therefore, the rolling element is a concept including a ball, a cylindrical roller, a tapered roller, a needle roller, and the like.
  • a plurality of workpieces can be induction-heated simultaneously is synonymous with the ability to arrange a plurality of workpieces on the inner periphery.
  • various modes of “controlling the operation of the high frequency power supply” are conceivable. For example, it is conceivable to control the ON / OFF switching time (switching time) of a transistor provided in the high frequency power supply. The same applies to other inventions of the present application described later.
  • the heating coil has a total length dimension that allows induction heating of a plurality of workpieces at the same time
  • the workpiece transfer device includes a plurality of workpiece support portions provided apart from each other in the workpiece transfer direction. If so, the plurality of workpieces can be simultaneously induction-heated while being supported and transported while being separated from each other. In this case, since each of the workpieces can be induction-heated without being affected by the magnetic flux change of the adjacent workpieces, each workpiece can be accurately heated to a predetermined temperature.
  • the heating device has a measuring unit that measures the current value flowing through the heating coil during heating of the workpiece, and the current value flowing through the heating coil during heating of the workpiece is always based on the current value measured by the measuring unit.
  • a control unit that controls the operation of the high-frequency power supply so as to have a predetermined constant value.
  • each workpiece can be accurately heated to a predetermined temperature regardless of the number of workpieces conveyed through the opposed region of the heating coil. As a result, it is possible to prevent the workpiece from being overheated as much as possible, and the product yield reduction problem can be solved.
  • the impedance (R) of the heating coil increases or decreases accordingly.
  • the second invention of the present application transports a rotatable workpiece along a linear guide transport path at a predetermined speed, and transports along a guide transport path.
  • a heating coil that includes a heating coil that induction-heats the workpiece being heated to a predetermined temperature, and the heating coil has a full length dimension capable of induction heating the plurality of workpieces simultaneously.
  • the heating device has a plurality of workpiece support portions provided apart from each other in the workpiece conveyance direction, and the heating device has a high-frequency power source electrically connected to the heating coil and a voltage across the heating coil during heating of the workpiece.
  • the conveying device for example, the first shaft member and the second shaft member which are arranged in parallel and spaced apart from each other, and at least one of the shaft members is driven to rotate around the axis.
  • a spiral groove that has at least one of the shaft members and has a spiral shaft having a spiral convex portion extending along the outer periphery thereof, and is defined by the convex portion on the one shaft member.
  • a guide conveyance path and a work support portion can be formed between the groove bottom surface and the surface of the other shaft member facing the groove bottom surface.
  • induction heating can be performed while rotating the work transported along the guide transport path. Thereby, it is possible to prevent as much as possible a temperature difference in each part of the work (temperature unevenness occurs in the work) and to heat the work with high accuracy.
  • a conveying device With such a conveying device, a plurality of workpieces can be reliably conveyed in a state of being separated from each other by appropriately setting the pitch of the convex portions, and the workpiece can be conveyed without being pushed by a subsequent workpiece. can do. For this reason, it can be preferably applied even when the work to be heat-treated is one or several small lots.
  • both shaft members are made of a nonmagnetic material such as ceramics.
  • the other shaft member can be constituted by a cylindrical shaft whose outer diameter surface is formed as a cylindrical surface having a constant diameter.
  • a transfer device that can transfer the workpiece in the above-described manner can be realized at a relatively low cost.
  • Rotation mechanism can also be configured to rotate both shaft members in the same direction at the same speed. If it does in this way, the work conveyed along a guidance conveyance way can be rotated smoothly.
  • the heating coil is disposed relatively on the rear side in the workpiece conveyance direction, and is disposed relatively on the front side in the workpiece conveyance direction with respect to the first heating unit in which the coil pitch is set relatively densely.
  • a second heating unit having a relatively sparse pitch can be provided.
  • the heating coil has a characteristic that the output increases as the coil pitch becomes dense and the output becomes low as the coil pitch becomes sparse. For this reason, if the heating coil is provided with the first and second heating units as described above, the workpiece can be actively heated while the workpiece is transported in the area opposite to the first heating unit. Thus, it is possible to keep the workpiece at a predetermined temperature (quenching temperature) while the workpiece is transported through the area facing the second heating unit. In this way, for example, when a heat treatment is performed on a workpiece made of a steel material having a carbon content of 0.8% by mass or more, a preferable amount of carbon can be dissolved in the workpiece. This is advantageous in increasing the mechanical strength.
  • the heat treatment facility may further include a cooling device for cooling (quenching) the workpiece heated to a predetermined temperature by the heating device.
  • a cooling device for cooling (quenching) the workpiece heated to a predetermined temperature by the heating device.
  • the heat treatment facility according to the present invention can be preferably used when a heat treatment is performed on a workpiece made of a steel material (for example, high carbon steel or alloy steel) having a carbon content of 0.8% by mass or more.
  • a steel material for example, high carbon steel or alloy steel
  • the heat treatment method includes a heating step of induction heating the workpiece to a predetermined temperature, and in the heating step, the conveyance device capable of conveying a plurality of workpieces while being separated from each other, and the plurality of workpieces are simultaneously induction heated. Control the operation of the high-frequency power supply so that the value of the high-frequency current supplied from the high-frequency power supply to the heating coil is always a predetermined constant value based on the value of the current flowing through the heating coil. It is characterized by doing.
  • the heat treatment method includes a heating step of induction heating the workpiece to a predetermined temperature, and in the heating step, the conveyance device capable of conveying a plurality of workpieces while being separated from each other, and the plurality of workpieces are simultaneously induction heated.
  • the operation of a high-frequency power supply that is electrically connected to the heating coil so that the voltage across the heating coil is always a predetermined constant value based on the voltage value across the heating coil, while using a heating coil that has a possible overall length It is characterized by controlling.
  • a workpiece to be heat-treated can be induction-heated to a predetermined temperature efficiently and accurately without generating a defective heating product and without requiring complicated advance preparation. It becomes. Thereby, it is possible to reduce the manufacturing cost of high-quality mechanical parts having desired mechanical strength and hardness.
  • FIG. 4B is a schematic sectional view taken along line BB in FIG. 4A. It is a figure which shows the relationship between "the number of the workpiece
  • FIG. 10 is a partially enlarged plan view of the transfer device, showing a case where the posture of the workpiece to be transferred is changed.
  • FIG. 13B is a schematic cross-sectional view taken along line BB in FIG. 13A.
  • FIG. 1 is a diagram conceptually showing the overall structure of a heat treatment facility 1 according to the first embodiment of the present invention.
  • the heat treatment facility 1 shown in FIG. 1 is a workpiece W (this embodiment) made of, for example, a steel material having a carbon content of 0.8% by mass or more (SUJ2 or SUJ3 classified as high carbon chromium bearing steel defined in JIS G4805).
  • a heat treatment equipment for performing a quench hardening treatment as a heat treatment on a tapered roller base material see FIG. 2, FIG. 4A, etc.
  • the heating process and the cooling process of cooling and quenching the workpiece W heated to the quenching temperature are continuously performed.
  • a heat treatment facility 1 shown in FIG. 1 includes a transport device 10 that transports a workpiece W along a linear guide transport path M from the left side of the sheet to the right side of the sheet at a predetermined speed (constant speed), and the workpiece W being transported.
  • a heating device 2 for induction heating to a quenching temperature and a cooling unit 20 as a cooling device for cooling and quenching the workpiece W discharged from the heating device 2 are provided.
  • the cooling unit 20 is composed of a cooling liquid tank in which a cooling liquid such as quenching oil is stored, for example.
  • the heating device 2 includes a heating coil 3 supported by a frame body 19 (see FIGS. 2 and 3), and a high-frequency power source 4 electrically connected to the heating coil 3.
  • the heating coil 3 of the present embodiment is a so-called multi-turn coil in which a tubular body made of a conductive metal such as a copper tube is spirally wound at a constant pitch, and the overall length dimension (axial dimension) Y of the workpiece W (Fig. (See 4A). Therefore, the heating device 2 can induction heat the plurality of workpieces W at the same time.
  • the heating device 2 further includes a measuring unit 5 that measures a current value flowing through the heating coil 3 during the heating process (hereinafter referred to as a “coil current value”), the measuring unit 5, and the high-frequency power source 4. And a control unit 6 that controls the operation of the high-frequency power source 4 during the heating process.
  • a non-contact current sensor typified by a Hall current sensor (HCT) or a Rogowski coil can be used.
  • the control unit 6 includes a storage device 6a and a feedback circuit 6b.
  • the storage device 6a stores a current command value set to a predetermined value (a constant value) for each model number (product type) of the workpiece W.
  • a current command value Ia corresponding to the model number of the workpiece W to be heat-treated is output from the storage device 6a to the feedback circuit 6b.
  • the feedback circuit 6b the current command value Ia and the measurement are performed.
  • the difference (Ia ⁇ Ib) from the coil current value Ib measured by the unit 5 and output from the measuring unit 5 to the feedback circuit 6b is always calculated.
  • a signal for controlling the switch time of the provided transistor (not shown) is output to the high frequency power supply 4. More specifically, when Ia> Ib, a signal for increasing the switch time, that is, a signal for increasing the amount of current supplied from the high frequency power supply 4 to the heating coil 3 is output from the feedback circuit 6b to the high frequency power supply 4. Is done.
  • the current command value Ia is set so as to be heated to the quenching temperature while the work W is conveyed along the guide conveyance path M along the opposite area of the heating coil 3, but is set to a constant value as described above. It does not change even when the number of workpieces W conveyed through the opposed region of the heating coil 3 increases or decreases as in the initial stage and final stage of the heat treatment (heating process). Therefore, as shown in FIGS. 5A and 5B, the high-frequency power source 4 has a current supply amount (amount of current flowing through the heating coil 3) to the heating coil 3 that is always a constant value (current command value Ia) during the heating process. The operation is controlled so that The current command value Ia is set, for example, by investigating the correlation between the current command value Ia and the temperature of the workpiece W by an oscillation heating test.
  • the transport device 10 includes a first shaft member 11 and a second shaft member 12 that are spaced apart from each other in parallel, and at least one of the shaft members 11, 12. (In the present embodiment, both are described in detail later) and a rotating mechanism 7 that rotates around the axis thereof.
  • Both shaft members 11 and 12 are rotatably supported with respect to the frame body 19 with their axis lines (rotation centers) positioned at the same height (on the same plane). Both shaft members 11, 12 are longer than the heating coil 3, and one end and the other end protrude outside the heating coil 3.
  • the first shaft member 11 is composed of a solid cylindrical shaft having an outer diameter surface 11a formed on a cylindrical surface having a constant diameter
  • the second shaft member 12 is It consists of a solid screw shaft in which a spiral convex portion 13 is integrally provided along the outer periphery.
  • Both shaft members 11 and 12 are formed of a nonmagnetic material.
  • the nonmagnetic material for example, ceramics (for example, alumina, zirconia, silicon carbide, etc.) having high hardness and excellent heat resistance are preferably used.
  • the groove bottom surface 15 of the spiral groove 14 defined on the outer periphery of the second shaft member 12 by the spiral convex portion 13 is the first shaft member facing this.
  • a guide conveyance path M for guiding and conveying the workpiece W and the workpiece support 16 are formed.
  • the outer peripheral surface of the workpiece W is contact-supported by the workpiece support unit 16.
  • the pitch and width dimension of the convex portions 13 are set so that the relational expression of Y ⁇ X is established between the groove width X of the spiral groove 14 and the overall length Y of the workpiece W.
  • a linear guide conveyance path M is formed in the conveyance device 10 by the cooperation of the first shaft member 11 and the second shaft member 12, and each can contact and support the workpiece W (the outer peripheral surface thereof).
  • a plurality of workpiece support portions 16 are formed at a plurality of locations separated in the extending direction of the guide conveyance path M (the conveyance direction of the workpiece W).
  • the rotation mechanism 7 includes an electric motor 8 such as a servo motor, and a power transmission mechanism 9 that transmits the rotational power of the electric motor 8 to both shaft members 11 and 12.
  • an electric motor 8 such as a servo motor
  • a power transmission mechanism 9 that transmits the rotational power of the electric motor 8 to both shaft members 11 and 12.
  • the power transmission mechanism 9 includes a gear shaft 18 ⁇ / b> A having a small gear 9 a and connected to an end portion on one axial direction side of the first shaft member 11 via a connection pin 17.
  • the small shaft 9B has a small gear 9b and is rotatably supported by a frame 19 and a gear shaft 18B connected to one end in the axial direction of the second shaft member 12 via a connecting pin 17.
  • 9b meshed with the large gear 9c, the drive pulley 9d connected to the output shaft of the electric motor 8, the driven pulley 9e connected to the large gear 9c, and the pulleys 9d and 9e are stretched over the outer peripheral surface.
  • an endless belt member (which may be a chain) 9f.
  • the pitches of the tooth surfaces of the small gears 9a and 9b are the same, and, among the large gear 9c, the pitch of the tooth surfaces meshing with the small gear 9a and the pitch of the tooth surfaces meshing with the small gear 9b are the same.
  • the heat treatment (heating step and cooling step) for the workpiece W is performed, for example, in the following manner.
  • the heating coil 3 is energized and the conveying device 10 is driven (the first shaft member and the second shaft member are driven to rotate), and then Then, the workpiece W is loaded into the transfer device 10.
  • the workpiece W is loaded from the workpiece loading position shown in FIG. 2 with respect to the transport apparatus 10 (the workpiece support portion 16 thereof), whereby the outer peripheral surface of the workpiece W is contacted and supported by the workpiece support portion 16.
  • the workpiece support 16 (and the guide conveyance path M) is formed by the groove bottom surface 15 of the spiral groove 14 defined in the second shaft member 12 formed of a screw shaft.
  • the workpiece W supported by the workpiece support 16 is continuously applied with a feed force for conveying the workpiece W along the guide conveyance path M. . Accordingly, the workpiece W is heated to the quenching temperature by the heating coil 3 while being conveyed along the guide conveyance path M at a predetermined speed. As shown in FIG. 1, the workpiece W discharged from the heating coil 3 is charged into the coolant stored in the cooling unit 20 by free fall, and cooled to a predetermined temperature range and hardened by hardening.
  • the workpiece W that is contact-supported by the workpiece support unit 16 is continuously given a rotational force that rotates the workpiece W about its axis. . Accordingly, the workpiece W conveyed along the guide conveyance path M is induction-heated while continuously rotating around its axis. Thereby, each part of the workpiece
  • work W can be induction-heated uniformly, without producing temperature nonuniformity in the workpiece
  • the power transmission mechanism 9 is configured so that the rotational speeds of the shaft members 11 and 12 are the same, the workpiece W supported by the workpiece support 16 is smoothly and continuously rotated. Can be made.
  • both the shaft members 11 and 12 are formed of a nonmagnetic material, it is possible to prevent heat transfer cooling from occurring at the contact portion between the workpiece W and the both shaft members 11 and 12 as much as possible. Therefore, it is possible to more effectively prevent temperature unevenness from occurring in the workpiece W after the heating is completed.
  • a plurality of workpieces W are transported in a state of being separated from each other by feeding the workpieces W one by one with a predetermined interval from the workpiece loading position shown in FIG.
  • a plurality of workpieces W are simultaneously induction-heated.
  • the workpiece W can be heated with higher accuracy.
  • the work support portion 16 can provide the outer peripheral surface of the work W.
  • contact support only a single workpiece W is contact-supported at each workpiece support portion 16.
  • the possibility that each workpiece W is affected by the heat of the adjacent workpieces W can be further effectively reduced. .
  • the transfer device 10 described above, the workpiece W can be transferred without being pushed by a subsequent workpiece. Therefore, the heating device 2 provided with the transfer device 10 is excellent in versatility that can be preferably applied even when the work W to be heated is one or several small lots. The workpiece W can be heated with high accuracy.
  • the heating device 2 includes the measuring unit 5 that measures the current value (coil current value Ib) flowing through the heating coil 3 during the heating process, and the coil current value measured by the measuring unit 5. And a control unit 6 that controls the operation of the high-frequency power source 4 so that the coil current value Ib always becomes a predetermined constant value (current command value Ia) based on Ib. That is, the heating device 2 of the present embodiment has a configuration for realizing so-called constant current control. For this reason, even if the impedance of the heating coil 3 changes as the number of workpieces W conveyed along the guide conveyance path M along the guide conveyance path M changes during the heating process, the coil The current value Ib is always controlled to a predetermined constant value (current command value Ia).
  • each workpiece W can be accurately heated to a predetermined temperature regardless of the number of workpieces W transported through the opposed region of the heating coil 3. As a result, it is possible to prevent the workpiece W from being overheated as much as possible, and the product yield reduction problem can be solved.
  • each workpiece W can be uniformly heated without temperature unevenness, which is advantageous in obtaining high-quality mechanical parts having no variation in mechanical strength.
  • FIG. 6 is a plan view conceptually showing the overall structure of the heat treatment equipment 21 according to the second embodiment of the present invention.
  • the main difference between the heat treatment facility 21 of this embodiment and the heat treatment facility 1 according to the first embodiment described above is that the current sensor as the measurement unit 5 provided in the heating device 2 of the heat treatment facility 1 uses the work W It is in the point that it is replaced with the measurement unit 25 that measures the voltage across the heating coil 3 during the execution of the heating process for induction heating.
  • the structure of the heating coil 3 and the conveying apparatus 10 in the heat processing equipment 21 is based on what was employ
  • the heating device 2 of the heat treatment facility 21 includes a measuring unit 25 that measures the voltage across the heating coil 3 during the heating process (hereinafter also referred to as “coil voltage value”), the measuring unit 25, and the high-frequency power source 24. And a control unit 26 that is electrically connected and controls the operation of the high-frequency power source 24 during the heating process.
  • a measurement unit 25 voltage sensor
  • a differential probe or a voltage detection transformer is used as the measurement unit 25 (voltage sensor).
  • the control unit 26 includes a storage device 26a and a feedback circuit 26b, and the storage device 26a stores a voltage command value set to a predetermined constant value for each model number of the workpiece W.
  • the voltage command value Va corresponding to the workpiece W model number is output from the storage device 26a to the feedback circuit 26b, and the feedback circuit 26b measures the voltage command value Va and the measurement unit 25.
  • the difference (Va ⁇ Vb) from the coil voltage value Vb is always calculated.
  • a signal for controlling the switch time of the transistor (not shown) is output to the high frequency power supply 24.
  • the voltage command value Va is set to a predetermined constant value as described above, and the number of workpieces W transported through the opposed region of the heating coil 3 is the same as in the initial stage and final stage of the heating process. It does not change even when it increases or decreases.
  • the heating device 2 in the heat treatment facility 21 of the present embodiment has a configuration for realizing so-called constant voltage control, and the high-frequency power source 24 is configured as shown in FIGS. 7A and 7B during the heating process.
  • the operation is controlled so that the voltage across the heating coil 3 always becomes a predetermined constant value (voltage command value Va), and the number of workpieces W transported in the opposed region of the heating coil 3 increases or decreases.
  • the power is automatically increased as the number of workpieces W (impedance of the heating coil 3) conveyed through the opposed region of the heating coil 3 increases or decreases. Increase or decrease. Therefore, even if the number of workpieces W increases or decreases, the electric power supplied to each workpiece W is constant. Therefore, if the voltage command value Va is set appropriately, each workpiece W can be overheated. Therefore, each workpiece W can be accurately heated to a predetermined temperature. Further, it is not necessary to set an output pattern of power in advance according to the number of workpieces W transported through the facing region of the heating coil 3.
  • the heat treatment equipment 21 (and heat treatment method) according to the second embodiment of the present invention can also enjoy the same effects as the heat treatment equipment 1 according to the first embodiment of the present invention.
  • the heat treatment facilities 1 and 21 according to the first and second embodiments of the present invention have been described above. However, the heat treatment facilities 1 and 21 may be appropriately modified without departing from the gist of the present invention. Is possible.
  • the heating coil 3 is provided relatively on the rear side in the conveyance direction of the workpiece W (left side in FIG. 1 and FIG. 6), and the coil pitch D1 is relatively
  • the first heating unit 3A that is set densely
  • the second heating unit 3B that is provided relatively on the rear side in the conveyance direction of the workpiece W and the coil pitch D2 is set relatively sparsely connected in series. Things can also be used. Although detailed illustration is omitted, the second heating unit 3B is longer than the first heating unit 3A.
  • the heating process is performed using the metal structure of the workpiece. It is preferable that about 0.6% by mass of carbon is dissolved in (austenite) and the rest is left as carbide.
  • the main reason is that if the amount of carbon penetration is about 0.6% by mass, the amount of retained austenite, which causes problems such as a decrease in hardness and aging, can be suppressed. This is because it is possible to suppress the growth of austenite crystal grains during heating.
  • the amount of carbon dissolved in the workpiece as shown in FIG.
  • the workpiece is actively heated for a predetermined time (t1) until the workpiece is heated to a predetermined temperature (quenching temperature) T, and then It is effective to heat the work for a predetermined time (t2) so as to maintain the work at the quenching temperature T (to keep the work soaked for a predetermined time).
  • the heating coil for inductively heating the workpiece generally has a characteristic that the output increases as the coil pitch becomes dense and the output becomes low as the coil pitch becomes sparse. For this reason, if the heating coil 3 as shown in FIG. 8 is used, the workpiece W can be actively heated while the workpiece W is transported in the area opposite to the first heating unit 3A. While W is transported through the opposite area of the second heating unit 3B, the workpiece W can be held at a predetermined temperature. Therefore, the workpiece W can be induction-heated so as to draw a desired temperature locus as shown in FIG. 9A.
  • both the heating units 3A and 3B may be connected by means such as welding, but both the heating units 3A and 3B are connected. Can also be detachably connected.
  • FIG. 10 shows an example thereof, with respect to a tubular connecting member 3C made of a conductive metal disposed between both heating units 3A and 3B, the end of the first heating unit 3A and the end of the second heating unit 3B.
  • the heating coil 3 is configured by fitting. In this case, for example, when it is necessary to change the coil pitch of either one or both of the heating units 3A and 3B in accordance with the change of the model number of the workpiece W to be heat-treated, the coil pitch is different. What is necessary is just to replace
  • the workpiece W is induction-heated to a predetermined temperature (quenching temperature) by the substantially one heating coil 3 provided in the heating device 2.
  • the present invention is preferably applied to a heat treatment facility in which a plurality of heating coils are spaced apart from each other along the extending direction of M (the conveyance direction of the workpiece W), and a high-frequency power source is individually connected to each heating coil. it can.
  • FIG. 11 is a specific example, and is a plan view conceptually showing the overall structure of the heat treatment equipment 31 according to the third embodiment of the present invention.
  • the heating device 2 of the heat treatment equipment 31 is relatively positioned on the first heating coil 32 disposed on the rear side (left side in the drawing) of the workpiece W and relatively on the front side (right side in the drawing) of the workpiece W.
  • a second heating coil 33 arranged, a first high-frequency power source 34 ⁇ / b> A electrically connected to the first heating coil 32, and a second high-frequency power source 34 ⁇ / b> B electrically connected to the second heating coil 33 are provided.
  • the first and second heating coils 31 and 32 are so-called multi-turn coils having the same coil pitch, but the second heating coil 33 is longer than the first heating coil 32.
  • the heating device 2 of the heat treatment equipment 31 controls the current values (coil current values) flowing through the first and second heating coils 32 and 33 during the heating process to predetermined constant values (current command values), respectively. It has the composition for doing. That is, the heating device 2 of the heat treatment facility 31 is electrically connected to the measurement unit 35A that measures (measures and outputs) the coil current value Ib1 of the first heating coil 32, the measurement unit 35A, and the first high-frequency power source 34A.
  • the control unit 36A that controls the operation of the first high-frequency power source 34A during the heating process, the measurement unit 35B that measures the coil current value Ib2 of the second heating coil 33, the measurement unit 35B, and the second high-frequency power source 34B A control unit 36B that is electrically connected and controls the operation of the second high-frequency power source 34B during the heating process.
  • the control unit 36A includes a storage device 36Aa and a feedback circuit 36Ab
  • the control unit 36B includes a storage device 36Ba and a feedback circuit 36Bb.
  • current command values Ia1 and Ia2 set to a predetermined constant value for each model number of the rod-shaped workpiece W are stored. However, the current command value Ia1 stored in the storage device 36Aa is larger than the current command value Ia2 stored in the storage device 36Ba.
  • the heat treatment equipment 31 in addition to the effects that can be enjoyed when the heat treatment equipment 1 shown in FIG. 1 is adopted, it is enjoyed when the heating coil 3 shown in FIG. 8 (and FIG. 10) is adopted.
  • the effect which can be enjoyed can be enjoyed. That is, with the heat treatment facility 31 having the above-described configuration, the workpiece W can be actively heated while the workpiece W is transported through the opposed region of the first heating coil 32, while the workpiece W is The workpiece W can be held at a predetermined temperature (quenching temperature) while being conveyed in the area opposite to the two heating coils 33. Therefore, the workpiece W can be induction-heated so as to draw a desired temperature locus as shown in FIG. 9A.
  • the coil pitches of the first heating coil 32 and the second heating coil 33 are set to be the same, but the coil pitches of both the heating coils 32 and 33 are not necessarily set to be the same, and are different from each other. Also good.
  • the measurement unit connected to each of the first heating coil 32 and the second heating coil 33 may be replaced with one that measures the voltage across the heating coils 32 and 33 during the execution of the heating process. That is, also in the heat treatment equipment 31 shown in FIG. 11, as in the heat treatment equipment 21 shown in FIG. 6, a voltage constant control method for controlling the voltage across the heating coil to a predetermined constant value during the execution of the heating process is adopted. Can do.
  • a support member (support roller) 29 that contacts and supports a circumferential region other than the circumferential region that forms the portion 16 may be provided. If such a support roller 29 is provided, it is possible to prevent the shaft members 11 and 12 from being bent as much as possible, so that the workpiece W can be supported and transported with high accuracy. Good induction heating.
  • work W was contact-supported by the workpiece
  • the support mode of the workpiece W by the workpiece support unit 16 (the posture of the workpiece W during conveyance) is not limited to this.
  • the workpiece W is in contact with and supported on one end surface by the groove bottom surface 15 of the spiral groove 14 of the second shaft member 12, and the outer peripheral surface thereof is supported by the first shaft member 11.
  • the outer diameter surface 11a may be contact-supported.
  • the workpiece W is transported along the guide transport path M in a state in which the axis thereof intersects (orthogonal) with the extending direction of the guide transport path M.
  • the workpiece W is a tapered roller (base material) or a cylindrical roller (base material) as in this embodiment, the workpiece W is formed in the manner shown in FIGS. 13A and 13B. It is preferable to support and convey. This is because the outer peripheral surface of the tapered roller or cylindrical roller is a surface that rolls along the raceway surfaces of the inner ring and outer ring that constitute the rolling bearing, and is a surface that requires high shape accuracy and mechanical strength.
  • the rotational speeds of the shaft members 11 and 12 are not necessarily the same, and may be different from each other.
  • the pitch of the tooth surfaces of the small gear 9a provided on the first shaft member 11 and the large gear 9c meshing with the small gear 9a and the second shaft member 12 What is necessary is just to make the pitch of the tooth surface of the small gear 9b and the large gear 9c meshing with this differ from each other.
  • a rotating mechanism 7 having a configuration different from that of the rotating mechanism 7 described above may be employed.
  • the rotation mechanism 7 may be configured to rotate only the shaft member formed of the screw shaft. In this case, since it is not necessary to provide the rotation mechanism 7 with a complicated mechanism (power transmission mechanism 9) for synchronously rotating the shaft members 11 and 12, the conveyance device 10 can be simplified and reduced in cost. Can do.
  • the second shaft member 12 of the both shaft members 11 and 12 is configured by a screw shaft, but the first shaft member 11 is configured by a screw shaft similar to the second shaft member 12. It is also possible to configure (not shown).
  • the guide conveyance path M and the work support portion 16 are formed on the groove bottom surface 15 of the spiral groove 14 formed on each of the shaft members 11 and 12.
  • the transport device 10 described above is merely an example, and has other configurations in the case where it is not necessary to rotate the workpiece W along the guide transport path M at a predetermined speed and simultaneously with the transport. You may employ
  • the heat treatment equipment 1, 21, 31 according to the present invention is a ball (ball) constituting a ball bearing, a cylinder constituting a cylindrical roller bearing. It can also be preferably used in the case where heat treatment is applied to the rolling elements of other rolling bearings such as rollers or needle rollers constituting a needle roller bearing. Further, the heat treatment facilities 1, 21, 31 according to the present invention can be preferably used not only for the solid workpiece W such as the various rolling elements described above, but also when the hollow workpiece W is subjected to heat treatment.
  • the heat treatment equipment 1, 21, 31 is used when heat-treating the workpiece W made of a steel material having a carbon content of 0.8 mass% or more.
  • Such heat treatment equipment 1, 21, 31 (and heat treatment method) can be preferably used also when heat-treating a workpiece W made of other metal materials that can be hardened.

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Abstract

This heat treatment equipment 1 is provided with: a conveying device 10 which conveys a workpiece W at a predetermined speed along a straight guide conveying path M; and a heating device 2 having a heating coil 3 which can inductively heat a plurality of workpieces W simultaneously. The conveying device 10 has a plurality of workpiece support parts 16 provided spaced apart each other in the conveying direction of the workpieces W. The heating device 2 has: a high-frequency power source 4 electrically connected to the heating coil 3; a measuring part 6 which measures a value of current flowing through the heating coil 3 during heating of the workpieces W; and a control part 6 which controls, on the basis of the value of current measured by the measuring part 6, the operation of the high-frequency power source 4 so that the value of current flowing through the heating coil 3 during the heating of the workpieces W is always a predetermined constant value.

Description

熱処理設備および熱処理方法Heat treatment equipment and heat treatment method
　本発明は、熱処理設備および熱処理方法に関し、より詳細には、回転可能なワークに熱処理を施す際に適用される熱処理設備および熱処理方法に関する。 The present invention relates to a heat treatment facility and a heat treatment method, and more particularly, to a heat treatment facility and a heat treatment method applied when heat treating a rotatable workpiece.
　例えば、転がり軸受を構成するころ等の転動体のように、高い機械的強度や硬度を要求されるワークの製造過程においては、熱処理としての焼入硬化処理が実施される。この熱処理は、ワークを所定温度（焼入温度）に加熱する加熱工程や、加熱されたワークを冷却する冷却工程などを含み、加熱工程は、例えば、メッシュベルト型連続炉に代表される雰囲気加熱炉を用いて実施することができる。しかしながら、雰囲気加熱炉は、雰囲気も併せて加熱する必要があるためにエネルギー効率が低い、広大な設置スペースが必要、などという問題がある。 For example, in the process of manufacturing a workpiece that requires high mechanical strength and hardness, such as a rolling element such as a roller constituting a rolling bearing, a quench hardening treatment as a heat treatment is performed. This heat treatment includes a heating step for heating the workpiece to a predetermined temperature (quenching temperature), a cooling step for cooling the heated workpiece, etc., and the heating step is, for example, atmospheric heating typified by a mesh belt type continuous furnace. It can be carried out using a furnace. However, since the atmosphere heating furnace needs to heat the atmosphere together, there are problems such as low energy efficiency and a large installation space.
　そこで、例えば下記の特許文献１に記載されているように、上記の加熱工程を、高周波誘導加熱装置を用いて実施する場合がある。誘導加熱であれば、ワークのみを直接加熱することができるために高いエネルギー効率を達成できることに加え、コンパクトな熱処理設備を実現できる、という利点がある。 Therefore, for example, as described in Patent Document 1 below, the above heating process may be performed using a high frequency induction heating apparatus. Inductive heating has the advantage that a compact heat treatment facility can be realized in addition to achieving high energy efficiency because only the workpiece can be directly heated.
　特許文献１の誘導加熱装置は、ワークを案内移動させる案内部材としての案内管と、案内管の外周に配置され、案内管内を移動するワークを誘導加熱する加熱コイルと、案内管の入口側に配置され、案内管内にワークを順次押し込む押し込み手段と、を備える。この場合、案内管内に後続のワークが押し込まれるのに伴って案内管内のワークに送り力が付与される。 The induction heating device of Patent Document 1 is a guide tube as a guide member that guides and moves a work, a heating coil that is arranged on the outer periphery of the guide tube and induction-heats the work that moves in the guide tube, and an inlet side of the guide tube. And pushing means for sequentially pushing the workpiece into the guide tube. In this case, a feeding force is applied to the workpiece in the guide tube as the subsequent workpiece is pushed into the guide tube.
特開２００５－３３１００５号公報JP 2005-331005 A 特開２０１５－６７８８１号公報Japanese Patent Laying-Open No. 2015-67881
　しかしながら、特許文献１に開示された技術手段では、以下のような問題がある。
（１）加熱処理の開始直後（初期段階）や終了間際（最終段階）のように、加熱コイルの内周が所定個数のワークで充足されていない段階では、加熱コイルの内周が所定個数のワークで充足されている場合に比べて個々のワークに磁束が集中するため、ワークが過加熱され易くなる。過加熱されたワークは、所望の金属組織、ひいては機械的強度や硬度を得ることができないために廃棄処分せざるを得ず、従って、製品歩留の低下を招来する。
（２）各ワークが、隣り合うワークと接触した状態で搬送・誘導加熱されるため、各ワークが隣接するワークの磁束変化の影響を受け易い。従って、各ワークの加熱温度が安定しない。 However, the technical means disclosed in Patent Document 1 has the following problems.
(1) Immediately after the start of heat treatment (initial stage) or just before the end (final stage), at a stage where the inner circumference of the heating coil is not satisfied with a predetermined number of workpieces, the inner circumference of the heating coil Since the magnetic flux concentrates on each workpiece as compared with the case where the workpiece is satisfied, the workpiece is easily overheated. The overheated workpiece cannot be obtained because it cannot obtain the desired metal structure, and hence the mechanical strength and hardness, and therefore the product yield is lowered.
(2) Since each workpiece is conveyed and induction heated in a state of being in contact with the adjacent workpiece, each workpiece is easily affected by the magnetic flux change of the adjacent workpiece. Therefore, the heating temperature of each workpiece is not stable.
　なお、上記（１）の問題は、例えば、特開２０１５－６７８８１号公報（特許文献２）に開示されているように、高周波電源の出力を、加熱コイルの対向領域に存在するワーク個数に応じて変化させることで解消することができる。しかしながら、このような方法を実施するためには、事前に実地試験やシミュレーションを繰り返し実施することにより、ワークの型番（品種）毎に電力の出力パターンを予め設定しておく必要がある。そのため、実施の準備に多大な工数が必要であり、コスト面で難がある。 Note that the problem of (1) is that the output of the high-frequency power supply depends on the number of workpieces existing in the opposed region of the heating coil, as disclosed in, for example, Japanese Patent Application Laid-Open No. 2015-67881 (Patent Document 2). It can be solved by changing. However, in order to implement such a method, it is necessary to set an output pattern of power in advance for each workpiece model number (product type) by repeatedly performing a field test and a simulation in advance. For this reason, a great amount of man-hours are required for preparation for implementation, which is difficult in terms of cost.
　以上の実情に鑑み、本発明の課題は、加熱不良品を発生させることなく、また、煩雑な事前準備を必要とすることなく、熱処理対象のワークを効率良く所定温度に誘導加熱することを可能とし、もって、所望の機械的強度や硬度を具備した高品質の機械部品を低コストに製造（量産）可能とすることにある。 In view of the above circumstances, it is an object of the present invention to efficiently inductively heat a workpiece to be heat-treated to a predetermined temperature without generating defective heating products and without requiring complicated prior preparation. Thus, it is possible to manufacture (mass-produce) high-quality mechanical parts having desired mechanical strength and hardness at low cost.
　上記の課題を解決するために創案された本願の第１発明は、回転可能なワークを直線状の案内搬送路に沿って所定速度で搬送する搬送装置と、案内搬送路に沿って搬送されているワークを所定温度に誘導加熱する加熱コイルを含み、この加熱コイルが複数のワークを同時に誘導加熱可能な全長寸法を有する加熱装置と、を備えた熱処理設備であって、搬送装置は、ワークの搬送方向で相互に離間して設けられた複数のワーク支持部を有し、加熱装置は、加熱コイルと電気的に接続された高周波電源と、ワークの加熱中に加熱コイルに流れている電流値を測定する測定部と、測定部により測定された電流値に基づき、ワークの加熱中に加熱コイルに流れる電流値が常に所定の一定値になるように高周波電源の動作を制御する制御部と、を有することを特徴とする。 The first invention of the present application, which was created to solve the above problems, is a transport device that transports a rotatable workpiece at a predetermined speed along a linear guide transport path, and is transported along the guide transport path. A heat treatment equipment including a heating coil that includes a heating coil that induction-heats a workpiece that is heated to a predetermined temperature, and the heating coil has a total length that allows induction heating of a plurality of workpieces simultaneously. The heating device has a plurality of work support portions provided apart from each other in the conveying direction, and the heating device includes a high-frequency power source electrically connected to the heating coil, and a current value flowing through the heating coil during heating of the work A control unit for controlling the operation of the high-frequency power source so that the current value flowing through the heating coil during heating of the workpiece is always a predetermined constant value based on the current value measured by the measurement unit, Have It is characterized in.
　なお、ここでいう「回転可能なワーク」としては、例えば、転がり軸受の転動体を挙げることができる。ここでいう転がり軸受とは、玉軸受、円筒ころ軸受、円すいころ軸受、針状ころ軸受などを含む概念である。従って、転動体とは、玉（ボール）、円筒ころ、円すいころおよび針状ころ等を含む概念である。また、「複数のワークを同時に誘導加熱可能」とは、複数のワークを内周に配置可能、と同義である。さらに、「高周波電源の動作を制御する」態様には種々のものが考えられるが、例えば、高周波電源内に設けられるトランジスタのＯＮ／ＯＦＦ切替時間（スイッチ時間）を制御することが考えられる。後述する本願の他の発明においても同様である。 In addition, examples of the “rotatable workpiece” mentioned here include a rolling element of a rolling bearing. The rolling bearing here is a concept including a ball bearing, a cylindrical roller bearing, a tapered roller bearing, a needle roller bearing and the like. Therefore, the rolling element is a concept including a ball, a cylindrical roller, a tapered roller, a needle roller, and the like. Further, “a plurality of workpieces can be induction-heated simultaneously” is synonymous with the ability to arrange a plurality of workpieces on the inner periphery. Further, various modes of “controlling the operation of the high frequency power supply” are conceivable. For example, it is conceivable to control the ON / OFF switching time (switching time) of a transistor provided in the high frequency power supply. The same applies to other inventions of the present application described later.
　上記のように、加熱コイルが複数のワークを同時に誘導加熱可能な全長寸法を有し、また、ワークの搬送装置が、ワークの搬送方向で相互に離間して設けられた複数のワーク支持部を有していれば、複数のワークを相互に離間した状態で支持・搬送しながら、該複数のワークを同時に誘導加熱することができる。この場合、ワークのそれぞれを、隣り合うワークの磁束変化の影響を受けることなく誘導加熱することができるので、各ワークを精度良く所定温度に加熱することができる。 As described above, the heating coil has a total length dimension that allows induction heating of a plurality of workpieces at the same time, and the workpiece transfer device includes a plurality of workpiece support portions provided apart from each other in the workpiece transfer direction. If so, the plurality of workpieces can be simultaneously induction-heated while being supported and transported while being separated from each other. In this case, since each of the workpieces can be induction-heated without being affected by the magnetic flux change of the adjacent workpieces, each workpiece can be accurately heated to a predetermined temperature.
　また、加熱装置は、ワークの加熱中に加熱コイルに流れている電流値を測定する測定部と、測定部により測定された電流値に基づき、ワークの加熱中に加熱コイルに流れる電流値が常に所定の一定値になるように高周波電源の動作を制御する制御部と、を有する。このような構成によれば、加熱処理の実施中に、加熱コイルの対向領域を搬送されるワークの個数が変化（増減）するのに伴って加熱コイルのインピーダンスが変化しても、加熱コイルに流れる電流値（以下、これを「コイル電流値」ともいう）を常に所定の一定値に制御することができる。 In addition, the heating device has a measuring unit that measures the current value flowing through the heating coil during heating of the workpiece, and the current value flowing through the heating coil during heating of the workpiece is always based on the current value measured by the measuring unit. And a control unit that controls the operation of the high-frequency power supply so as to have a predetermined constant value. According to such a configuration, during the heat treatment, even if the impedance of the heating coil changes as the number of workpieces conveyed through the opposed area of the heating coil changes (increases or decreases), the heating coil The flowing current value (hereinafter also referred to as “coil current value”) can always be controlled to a predetermined constant value.
　ここで、コイルに電流が流れたときにコイルに生じる磁束（Φ）は自己インダクタンス（Ｌ：定数）と電流（Ｉ）の積で算出され（Φ＝Ｌ×Ｉ）、磁束の強さは電流値に比例することから、コイル電流値が常に所定の一定値に制御されれば、コイル内に生じる磁束の強さも一定にすることができる。そして、ワークは相互に離間した状態で支持・搬送されることから、加熱コイルの対向領域を搬送されるワーク個数に関わらず、コイル内の各ワークに生じる誘導電流量も均一化することができる。そのため、加熱コイルに対する電流供給量を適切に設定しておけば、加熱コイルの対向領域を搬送されるワークの個数に関わらず、各ワークを所定温度に精度良く加熱することができる。これにより、ワークが過加熱されるのを可及的に防止することが可能となり、製品歩留の低下問題を解消することができる。 Here, the magnetic flux (Φ) generated in the coil when a current flows through the coil is calculated by the product of the self-inductance (L: constant) and the current (I) (Φ = L × I), and the strength of the magnetic flux is the current. Since it is proportional to the value, if the coil current value is always controlled to a predetermined constant value, the strength of the magnetic flux generated in the coil can be made constant. Since the workpieces are supported and conveyed in a state of being separated from each other, the amount of induced current generated in each workpiece in the coil can be made uniform regardless of the number of workpieces conveyed in the opposing area of the heating coil. . Therefore, if the amount of current supplied to the heating coil is appropriately set, each workpiece can be accurately heated to a predetermined temperature regardless of the number of workpieces conveyed through the opposed region of the heating coil. As a result, it is possible to prevent the workpiece from being overheated as much as possible, and the product yield reduction problem can be solved.
　なお、加熱コイルの対向領域を搬送されるワークの個数が増加又は減少すると、これに伴って加熱コイルのインピーダンス（Ｒ）も増加又は減少するが、上記のとおりコイル電流値は常に一定に制御されるため、インピーダンスの増減に応じて電力（Ｐ）の値は自動的に増減する（∵Ｐ＝Ｉ2Ｒ）。従って、特許文献２のように、加熱コイルの対向領域を搬送されるワーク個数等に応じて電力の出力パターンを予め設定する必要もない。 As the number of workpieces conveyed through the opposed area of the heating coil increases or decreases, the impedance (R) of the heating coil increases or decreases accordingly. However, as described above, the coil current value is always controlled to be constant. Therefore, the value of power (P) automatically increases and decreases according to the increase and decrease of impedance (増 減 P = I 2 R). Therefore, unlike Patent Document 2, there is no need to set an output pattern of power in advance according to the number of workpieces conveyed through the opposed region of the heating coil.
　また、上記の課題を解決するために創案された本願の第２発明は、回転可能なワークを直線状の案内搬送路に沿って所定速度で搬送する搬送装置と、案内搬送路に沿って搬送されているワークを所定温度に誘導加熱する加熱コイルを含み、この加熱コイルが複数のワークを同時に誘導加熱可能な全長寸法を有する加熱装置と、を備えた熱処理設備であって、搬送装置は、ワークの搬送方向で相互に離間して設けられた複数のワーク支持部を有し、加熱装置は、加熱コイルと電気的に接続された高周波電源と、ワークの加熱中における加熱コイルの両端電圧を測定する測定部と、測定部により測定された電圧値に基づき、ワークの加熱中における加熱コイルの両端電圧が常に所定の一定値になるように高周波電源の動作を制御する制御部と、を有することを特徴とする。 Further, the second invention of the present application, which was created to solve the above-mentioned problems, transports a rotatable workpiece along a linear guide transport path at a predetermined speed, and transports along a guide transport path. A heating coil that includes a heating coil that induction-heats the workpiece being heated to a predetermined temperature, and the heating coil has a full length dimension capable of induction heating the plurality of workpieces simultaneously. The heating device has a plurality of workpiece support portions provided apart from each other in the workpiece conveyance direction, and the heating device has a high-frequency power source electrically connected to the heating coil and a voltage across the heating coil during heating of the workpiece. A measuring unit for measuring, and a control unit for controlling the operation of the high-frequency power source so that the voltage across the heating coil during heating of the workpiece is always a predetermined constant value based on the voltage value measured by the measuring unit; Characterized in that it has.
　上記の構成を有する熱処理設備によれば、基本的に、上記の第１発明と同様の作用効果を享受することができる。 According to the heat treatment equipment having the above-described configuration, basically, the same operational effects as those of the first invention can be enjoyed.
　以上の構成において、搬送装置としては、例えば、相互に離間して平行に配置された第１軸部材及び第２軸部材と、両軸部材のうち少なくとも一方の軸部材をその軸線回りに回転駆動させる回転機構とを備え、少なくとも上記一方の軸部材が、その外周に沿って延びた螺旋状の凸部を有するねじ軸からなり、凸部によって上記一方の軸部材に画成される螺旋状溝の溝底面と、他方の軸部材の上記溝底面との対向面とで案内搬送路およびワーク支持部が形成されるものを使用できる。 In the above configuration, as the conveying device, for example, the first shaft member and the second shaft member which are arranged in parallel and spaced apart from each other, and at least one of the shaft members is driven to rotate around the axis. A spiral groove that has at least one of the shaft members and has a spiral shaft having a spiral convex portion extending along the outer periphery thereof, and is defined by the convex portion on the one shaft member. In this case, a guide conveyance path and a work support portion can be formed between the groove bottom surface and the surface of the other shaft member facing the groove bottom surface.
　このような搬送装置を採用すれば、案内搬送路に沿って搬送されるワークを回転させながら誘導加熱することができる。これにより、ワークの各部で温度差が生じる（ワークに温度ムラが生じる）のを可及的に防止し、ワークを精度良く加熱することができる。また、このような搬送装置であれば、凸部のピッチを適宜設定することによって複数のワークを確実に相互に離間した状態で搬送できることに加え、後続のワークによる押し込みがなくてもワークを搬送することができる。このため、熱処理対象のワークが一個又は数個程度の小ロットである場合にも好ましく適用することができる。 If such a transport device is employed, induction heating can be performed while rotating the work transported along the guide transport path. Thereby, it is possible to prevent as much as possible a temperature difference in each part of the work (temperature unevenness occurs in the work) and to heat the work with high accuracy. Also, with such a conveying device, a plurality of workpieces can be reliably conveyed in a state of being separated from each other by appropriately setting the pitch of the convex portions, and the workpiece can be conveyed without being pushed by a subsequent workpiece. can do. For this reason, it can be preferably applied even when the work to be heat-treated is one or several small lots.
　第１軸部材及び第２軸部材を金属等の磁性材料（導電性材料）で形成した場合、軸部材とワークの接触部で伝熱冷却が生じ、ワークを効率良くかつ精度良く所定温度に加熱できなくなる可能性がある。そのため、両軸部材は、セラミックス等の非磁性材料で形成するのが好ましい。 When the first shaft member and the second shaft member are formed of a magnetic material (conductive material) such as metal, heat transfer cooling occurs at the contact portion between the shaft member and the workpiece, and the workpiece is efficiently and accurately heated to a predetermined temperature. It may not be possible. Therefore, it is preferable that both shaft members are made of a nonmagnetic material such as ceramics.
　上記他方の軸部材は、その外径面が径一定の円筒面に形成された円柱軸で構成することができる。この場合、上記態様でワークを搬送し得る搬送装置を比較的低コストに実現することができる。 The other shaft member can be constituted by a cylindrical shaft whose outer diameter surface is formed as a cylindrical surface having a constant diameter. In this case, a transfer device that can transfer the workpiece in the above-described manner can be realized at a relatively low cost.
　回転機構は、両軸部材を同一速度で同一方向に回転駆動させるように構成することもできる。このようにすれば、案内搬送路に沿って搬送されるワークを滑らかに回転させることができる。 Rotation mechanism can also be configured to rotate both shaft members in the same direction at the same speed. If it does in this way, the work conveyed along a guidance conveyance way can be rotated smoothly.
　上記加熱コイルには、相対的にワークの搬送方向後方側に配置され、コイルピッチが相対的に密に設定された第１加熱部と、相対的にワークの搬送方向前方側に配置され、コイルピッチが相対的に疎に設定された第２加熱部とを設けることができる。 The heating coil is disposed relatively on the rear side in the workpiece conveyance direction, and is disposed relatively on the front side in the workpiece conveyance direction with respect to the first heating unit in which the coil pitch is set relatively densely. A second heating unit having a relatively sparse pitch can be provided.
　一般に、加熱コイルは、コイルピッチが密になるほど出力が高まり、コイルピッチが疎になるほど出力が低くなるという特性を有する。このため、加熱コイルに上記のような第１及び第２加熱部を設けておけば、ワークが第１加熱部の対向領域を搬送される間にワークを積極的に昇温させることができる一方で、ワークが第２加熱部の対向領域を搬送される間、ワークを所定温度（焼入温度）に保持することが可能となる。このようにすれば、例えば、炭素含有量０．８質量％以上の鋼材からなるワークに対して熱処理を施す場合、ワークに対して好ましい量の炭素を溶け込ませることが可能となるので、ワークの機械的強度等を高める上で有利となる。 Generally, the heating coil has a characteristic that the output increases as the coil pitch becomes dense and the output becomes low as the coil pitch becomes sparse. For this reason, if the heating coil is provided with the first and second heating units as described above, the workpiece can be actively heated while the workpiece is transported in the area opposite to the first heating unit. Thus, it is possible to keep the workpiece at a predetermined temperature (quenching temperature) while the workpiece is transported through the area facing the second heating unit. In this way, for example, when a heat treatment is performed on a workpiece made of a steel material having a carbon content of 0.8% by mass or more, a preferable amount of carbon can be dissolved in the workpiece. This is advantageous in increasing the mechanical strength.
　熱処理設備には、加熱装置で所定温度に加熱されたワークを冷却（焼入れ）する冷却装置をさらに設けることができる。これにより、ワークを適切に焼入硬化することができる。 The heat treatment facility may further include a cooling device for cooling (quenching) the workpiece heated to a predetermined temperature by the heating device. Thereby, a workpiece | work can be hardened and hardened appropriately.
　本発明に係る熱処理設備は、炭素含有量０．８質量％以上の鋼材（例えば、高炭素鋼や合金鋼）からなるワークに熱処理を施す際に好ましく用いることができる。 The heat treatment facility according to the present invention can be preferably used when a heat treatment is performed on a workpiece made of a steel material (for example, high carbon steel or alloy steel) having a carbon content of 0.8% by mass or more.
　また、上記の課題を解決するために創案された本願の第３発明は、回転可能なワークを直線状の案内搬送路に沿って所定速度で搬送しながら通電状態の加熱コイルの対向領域を通過させることにより、ワークを所定温度に誘導加熱する加熱工程を有する熱処理方法であって、加熱工程では、複数のワークを相互に離間した状態で搬送可能な搬送装置、および複数のワークを同時に誘導加熱可能な全長寸法を有する加熱コイルを使用すると共に、加熱コイルに流れる電流値に基づき、高周波電源から加熱コイルに供給する高周波電流の値が常に所定の一定値になるように高周波電源の動作を制御することを特徴とする。 Further, the third invention of the present application, which was created to solve the above-mentioned problems, passes through the opposed region of the energized heating coil while transporting a rotatable workpiece along the linear guide transport path at a predetermined speed. The heat treatment method includes a heating step of induction heating the workpiece to a predetermined temperature, and in the heating step, the conveyance device capable of conveying a plurality of workpieces while being separated from each other, and the plurality of workpieces are simultaneously induction heated. Control the operation of the high-frequency power supply so that the value of the high-frequency current supplied from the high-frequency power supply to the heating coil is always a predetermined constant value based on the value of the current flowing through the heating coil. It is characterized by doing.
　また、上記の課題を解決するために創案された本願の第４発明は、回転可能なワークを直線状の案内搬送路に沿って所定速度で搬送しながら通電状態の加熱コイルの対向領域を通過させることにより、ワークを所定温度に誘導加熱する加熱工程を有する熱処理方法であって、加熱工程では、複数のワークを相互に離間した状態で搬送可能な搬送装置、および複数のワークを同時に誘導加熱可能な全長寸法を有する加熱コイルを使用すると共に、加熱コイルの両端電圧値に基づき、加熱コイルの両端電圧が常に所定の一定値になるように加熱コイルと電気的に接続された高周波電源の動作を制御することを特徴とする。 Further, the fourth invention of the present application, which was created to solve the above-mentioned problems, passes through the opposing region of the energized heating coil while transporting a rotatable workpiece along the linear guide transport path at a predetermined speed. The heat treatment method includes a heating step of induction heating the workpiece to a predetermined temperature, and in the heating step, the conveyance device capable of conveying a plurality of workpieces while being separated from each other, and the plurality of workpieces are simultaneously induction heated. The operation of a high-frequency power supply that is electrically connected to the heating coil so that the voltage across the heating coil is always a predetermined constant value based on the voltage value across the heating coil, while using a heating coil that has a possible overall length It is characterized by controlling.
　以上より、本発明によれば、加熱不良品を発生させることなく、また、煩雑な事前準備を必要とすることなく、熱処理対象のワークを効率良くかつ精度良く所定温度に誘導加熱することが可能となる。これにより、所望の機械的強度や硬度を具備した高品質の機械部品の製造コストを低減することができる。 As described above, according to the present invention, a workpiece to be heat-treated can be induction-heated to a predetermined temperature efficiently and accurately without generating a defective heating product and without requiring complicated advance preparation. It becomes. Thereby, it is possible to reduce the manufacturing cost of high-quality mechanical parts having desired mechanical strength and hardness.
本発明の第１実施形態に係る熱処理設備の全体構造を概念的に示す図である。It is a figure which shows notionally the whole structure of the heat processing equipment which concerns on 1st Embodiment of this invention. 搬送装置の部分拡大平面図である。It is a partial enlarged plan view of a conveying apparatus. 搬送装置の概略正面図である。It is a schematic front view of a conveying apparatus. 搬送装置の要部拡大平面図である。It is a principal part enlarged plan view of a conveying apparatus. 図４ＡのＢ－Ｂ線矢視概略断面図である。FIG. 4B is a schematic sectional view taken along line BB in FIG. 4A. 図１に示す熱処理設備で実施される加熱工程の初期段階における“加熱コイルの対向領域に存在するワーク個数”と“加熱コイルに流れる電流値”との関係を示す図である。It is a figure which shows the relationship between "the number of the workpiece | work which exists in the opposing area | region of a heating coil" and "the electric current value which flows into a heating coil" in the initial stage of the heating process implemented with the heat processing equipment shown in FIG. 図１に示す熱処理設備で実施される加熱工程の最終段階における“加熱コイルの対向領域に存在するワーク個数”と“加熱コイルに流れる電流値”との関係を示す図である。It is a figure which shows the relationship between "the number of the workpiece | work which exists in the opposing area | region of a heating coil" and "the electric current value which flows into a heating coil" in the last step of the heating process implemented with the heat processing equipment shown in FIG. 図１に示す熱処理設備で実施される加熱工程の初期段階における“加熱コイルの対向領域に存在するワーク個数”と“加熱コイルでの消費電力”との関係を示す図である。It is a figure which shows the relationship between "the number of the workpiece | work which exists in the opposing area | region of a heating coil" and "power consumption in a heating coil" in the initial stage of the heating process implemented with the heat processing equipment shown in FIG. 図１に示す熱処理設備で実施される加熱工程の最終段階における“加熱コイルの対向領域に存在するワーク個数”と“加熱コイルでの消費電力”との関係を示す図である。It is a figure which shows the relationship between "the number of the workpiece | work which exists in the opposing area | region of a heating coil" and the "power consumption in a heating coil" in the last step of the heating process implemented with the heat processing equipment shown in FIG. 本発明の第２実施形態に係る熱処理設備の全体構造を概念的に示す図である。It is a figure which shows notionally the whole structure of the heat processing equipment which concerns on 2nd Embodiment of this invention. 図６に示す熱処理設備で実施される加熱工程の初期段階における“加熱コイルの対向領域に存在するワーク個数”と“加熱コイルに流れる電流値”との関係を示す図である。It is a figure which shows the relationship between "the number of the workpiece | work which exists in the opposing area | region of a heating coil" and "the electric current value which flows into a heating coil" in the initial stage of the heating process implemented with the heat processing equipment shown in FIG. 図６に示す熱処理設備で実施される加熱工程の最終段階における“加熱コイルの対向領域に存在するワーク個数”と“加熱コイルに流れる電流値”との関係を示す図である。It is a figure which shows the relationship between "the number of the workpiece | work which exists in the opposing area | region of a heating coil" and "the electric current value which flows into a heating coil" in the last step of the heating process implemented with the heat processing equipment shown in FIG. 図６に示す熱処理設備で実施される加熱工程の初期段階における“加熱コイルの対向領域に存在するワーク個数”と“加熱コイルでの消費電力”との関係を示す図である。It is a figure which shows the relationship between "the number of the workpiece | work which exists in the opposing area | region of a heating coil" and the "power consumption in a heating coil" in the initial stage of the heating process implemented with the heat processing equipment shown in FIG. 図６に示す熱処理設備で実施される加熱工程の最終段階における“加熱コイルの対向領域に存在するワーク個数”と“加熱コイルでの消費電力”との関係を示す図である。It is a figure which shows the relationship between "the number of the workpiece | work which exists in the opposing area | region of a heating coil" and the "power consumption in a heating coil" in the last step of the heating process implemented with the heat processing equipment shown in FIG. 他の実施形態に係る加熱コイルの要部を拡大して示す概要図である。It is a schematic diagram which expands and shows the principal part of the heating coil which concerns on other embodiment. ワークを誘導加熱する際における好ましい温度軌跡を示す図である。It is a figure which shows the preferable temperature locus at the time of carrying out induction heating of a workpiece | work. 図８に示す加熱コイルを用いて棒状ワークを誘導加熱した場合における棒状ワークの温度軌跡を示す図である。It is a figure which shows the temperature locus | trajectory of a rod-shaped workpiece | work at the time of carrying out induction heating of the rod-shaped workpiece | work using the heating coil shown in FIG. 図８に示す加熱コイルの変形例を示す概要図である。It is a schematic diagram which shows the modification of the heating coil shown in FIG. 本発明の第３実施形態に係る熱処理設備の全体構造を概念的に示す図である。It is a figure which shows notionally the whole structure of the heat processing equipment which concerns on 3rd Embodiment of this invention. 搬送装置を構成する第１及び第２軸部材の支持態様の一例を示す概略図である。It is the schematic which shows an example of the support aspect of the 1st and 2nd shaft member which comprises a conveying apparatus. 搬送装置の部分拡大平面図であって、搬送されるワークの姿勢を異ならせた場合を示す図である。FIG. 10 is a partially enlarged plan view of the transfer device, showing a case where the posture of the workpiece to be transferred is changed. 図１３ＡのＢ－Ｂ線矢視概略断面図である。FIG. 13B is a schematic cross-sectional view taken along line BB in FIG. 13A.
　以下、本発明の実施の形態を図面に基づいて説明する。 Hereinafter, embodiments of the present invention will be described with reference to the drawings.
　図１は、本発明の第１実施形態に係る熱処理設備１の全体構造を概念的に示す図である。同図に示す熱処理設備１は、例えば、炭素含有量０．８質量％以上の鋼材（ＪＩＳ　Ｇ４８０５に規定の高炭素クロム軸受鋼に分類されるＳＵＪ２やＳＵＪ３等）からなるワークＷ（本実施形態では円すいころの基材：図２、図４Ａ等を参照）に対して熱処理としての焼入硬化処理を施すための熱処理設備であって、ワークＷを所定温度（焼入温度）に誘導加熱する加熱工程と、焼入温度に加熱されたワークＷを冷却して焼入れする冷却工程とが続けて実施されるように構成されている。 FIG. 1 is a diagram conceptually showing the overall structure of a heat treatment facility 1 according to the first embodiment of the present invention. The heat treatment facility 1 shown in FIG. 1 is a workpiece W (this embodiment) made of, for example, a steel material having a carbon content of 0.8% by mass or more (SUJ2 or SUJ3 classified as high carbon chromium bearing steel defined in JIS G4805). Then, it is a heat treatment equipment for performing a quench hardening treatment as a heat treatment on a tapered roller base material (see FIG. 2, FIG. 4A, etc.), and inductively heats the workpiece W to a predetermined temperature (quenching temperature). The heating process and the cooling process of cooling and quenching the workpiece W heated to the quenching temperature are continuously performed.
　図１に示す熱処理設備１は、ワークＷを直線状の案内搬送路Ｍに沿って紙面左側から紙面右側に向けて所定速度（一定速度）で搬送する搬送装置１０と、搬送中のワークＷを焼入温度に誘導加熱する加熱装置２と、加熱装置２から排出されたワークＷを冷却して焼入れする冷却装置としての冷却部２０とを備える。冷却部２０は、例えば、焼入油等の冷却液が貯留された冷却液漕で構成される。 A heat treatment facility 1 shown in FIG. 1 includes a transport device 10 that transports a workpiece W along a linear guide transport path M from the left side of the sheet to the right side of the sheet at a predetermined speed (constant speed), and the workpiece W being transported. A heating device 2 for induction heating to a quenching temperature and a cooling unit 20 as a cooling device for cooling and quenching the workpiece W discharged from the heating device 2 are provided. The cooling unit 20 is composed of a cooling liquid tank in which a cooling liquid such as quenching oil is stored, for example.
　加熱装置２は、枠体１９（図２，３参照）に支持された加熱コイル３と、加熱コイル３と電気的に接続された高周波電源４とを備える。本実施形態の加熱コイル３は、銅管等の導電性金属製の管状体を一定ピッチで螺旋状に巻き回したいわゆる多巻きコイルからなり、ワークＷの全長寸法（軸方向寸法）Ｙ（図４Ａ参照）の数倍～数十倍程度の全長寸法を有する。従って、この加熱装置２は、複数のワークＷを同時に誘導加熱することができる。 The heating device 2 includes a heating coil 3 supported by a frame body 19 (see FIGS. 2 and 3), and a high-frequency power source 4 electrically connected to the heating coil 3. The heating coil 3 of the present embodiment is a so-called multi-turn coil in which a tubular body made of a conductive metal such as a copper tube is spirally wound at a constant pitch, and the overall length dimension (axial dimension) Y of the workpiece W (Fig. (See 4A). Therefore, the heating device 2 can induction heat the plurality of workpieces W at the same time.
　加熱装置２は、さらに、加熱工程の実行中に加熱コイル３に流れる電流値（以下、これを「コイル電流値」という）を測定する測定部５と、測定部５及び高周波電源４と電気的に接続され、加熱工程の実行中に高周波電源４の動作を制御する制御部６とを備える。測定部５としては、例えば、ホール式電流センサ（ＨＣＴ）やロゴスキーコイルなどに代表される非接触式の電流センサを使用することができる。 The heating device 2 further includes a measuring unit 5 that measures a current value flowing through the heating coil 3 during the heating process (hereinafter referred to as a “coil current value”), the measuring unit 5, and the high-frequency power source 4. And a control unit 6 that controls the operation of the high-frequency power source 4 during the heating process. As the measurement unit 5, for example, a non-contact current sensor typified by a Hall current sensor (HCT) or a Rogowski coil can be used.
　制御部６は、記憶装置６ａ及びフィードバック回路６ｂを有し、記憶装置６ａには、ワークＷの型番（品種）毎に所定値（一定値）に設定された電流指令値が保存されている。加熱工程の実行中には、熱処理対象のワークＷの型番に応じた電流指令値Ｉａが記憶装置６ａからフィードバック回路６ｂに対して出力され、フィードバック回路６ｂでは、上記の電流指令値Ｉａと、測定部５で測定され、測定部５からフィードバック回路６ｂに対して出力されるコイル電流値Ｉｂとの差（Ｉａ－Ｉｂ）が常時演算される。そして、この演算結果に基づき、フィードバック回路６ｂは、コイル電流値Ｉｂが常に上記の電流指令値Ｉａになるように（Ｉａ－Ｉｂ＝０の関係式が常に成立するように）、高周波電源４に設けられたトランジスタ（図示せず）のスイッチ時間を制御する信号を高周波電源４に対して出力する。より詳細に述べると、Ｉａ＞Ｉｂの場合、スイッチ時間を早めるための信号、すなわち高周波電源４から加熱コイル３に対する電流供給量を増加させるための信号がフィードバック回路６ｂから高周波電源４に対して出力される。これとは逆に、Ｉａ＜Ｉｂの場合、スイッチ時間を遅くするための信号、すなわち高周波電源４から加熱コイル３に対する電流供給量を減少させるための信号がフィードバック回路６ｂから高周波電源４に対して出力される。 The control unit 6 includes a storage device 6a and a feedback circuit 6b. The storage device 6a stores a current command value set to a predetermined value (a constant value) for each model number (product type) of the workpiece W. During the execution of the heating process, a current command value Ia corresponding to the model number of the workpiece W to be heat-treated is output from the storage device 6a to the feedback circuit 6b. In the feedback circuit 6b, the current command value Ia and the measurement are performed. The difference (Ia−Ib) from the coil current value Ib measured by the unit 5 and output from the measuring unit 5 to the feedback circuit 6b is always calculated. Based on this calculation result, the feedback circuit 6b causes the high-frequency power source 4 to keep the coil current value Ib always equal to the current command value Ia (so that the relational expression of Ia−Ib = 0 is always satisfied). A signal for controlling the switch time of the provided transistor (not shown) is output to the high frequency power supply 4. More specifically, when Ia> Ib, a signal for increasing the switch time, that is, a signal for increasing the amount of current supplied from the high frequency power supply 4 to the heating coil 3 is output from the feedback circuit 6b to the high frequency power supply 4. Is done. On the contrary, when Ia <Ib, a signal for delaying the switch time, that is, a signal for reducing the amount of current supplied from the high frequency power supply 4 to the heating coil 3 is output from the feedback circuit 6b to the high frequency power supply 4. Is output.
　電流指令値Ｉａは、ワークＷが案内搬送路Ｍに沿って加熱コイル３の対向領域を搬送される間に焼入温度に加熱されるように設定されるが、上記のとおり一定値に設定され、熱処理（加熱工程）の初期段階や最終段階のように加熱コイル３の対向領域を搬送されるワークＷの個数が増加又は減少する段階においても変化しない。従って、高周波電源４は、図５Ａおよび図５Ｂに示すように、加熱工程の実行中に加熱コイル３に対する電流供給量（加熱コイル３を流れる電流量）が常に一定値（電流指令値Ｉａ）になるように動作が制御される。なお、電流指令値Ｉａは、例えば、電流指令値ＩａとワークＷの温度との相関を発振加熱テストで調査することにより設定される。 The current command value Ia is set so as to be heated to the quenching temperature while the work W is conveyed along the guide conveyance path M along the opposite area of the heating coil 3, but is set to a constant value as described above. It does not change even when the number of workpieces W conveyed through the opposed region of the heating coil 3 increases or decreases as in the initial stage and final stage of the heat treatment (heating process). Therefore, as shown in FIGS. 5A and 5B, the high-frequency power source 4 has a current supply amount (amount of current flowing through the heating coil 3) to the heating coil 3 that is always a constant value (current command value Ia) during the heating process. The operation is controlled so that The current command value Ia is set, for example, by investigating the correlation between the current command value Ia and the temperature of the workpiece W by an oscillation heating test.
　図２、図４Ａおよび図４Ｂに示すように、搬送装置１０は、相互に離間して平行に配置された第１軸部材１１及び第２軸部材１２と、両軸部材１１，１２の少なくとも一方（本実施形態では双方。詳細は後述する。）をその軸線回りに回転させる回転機構７とを備える。両軸部材１１，１２は、その軸線（回転中心）を同一高さ（同一平面上）に位置させた状態で枠体１９に対して回転自在に支持されている。両軸部材１１，１２は、加熱コイル３よりも長寸であり、その一端及び他端は加熱コイル３の外側に突出している。 As shown in FIGS. 2, 4A, and 4B, the transport device 10 includes a first shaft member 11 and a second shaft member 12 that are spaced apart from each other in parallel, and at least one of the shaft members 11, 12. (In the present embodiment, both are described in detail later) and a rotating mechanism 7 that rotates around the axis thereof. Both shaft members 11 and 12 are rotatably supported with respect to the frame body 19 with their axis lines (rotation centers) positioned at the same height (on the same plane). Both shaft members 11, 12 are longer than the heating coil 3, and one end and the other end protrude outside the heating coil 3.
　図２、図４Ａおよび図４Ｂに示すように、第１軸部材１１は、外径面１１ａが径一定の円筒面に形成された中実の円柱軸からなり、第２軸部材１２は、その外周に沿って螺旋状の凸部１３が一体的に設けられた中実のねじ軸からなる。両軸部材１１，１２は、非磁性材料で形成される。非磁性材料としては、例えば、高硬度で耐熱性に優れたセラミックス（例えば、アルミナ、ジルコニア、炭化ケイ素等）が好ましく使用される。 As shown in FIG. 2, FIG. 4A and FIG. 4B, the first shaft member 11 is composed of a solid cylindrical shaft having an outer diameter surface 11a formed on a cylindrical surface having a constant diameter, and the second shaft member 12 is It consists of a solid screw shaft in which a spiral convex portion 13 is integrally provided along the outer periphery. Both shaft members 11 and 12 are formed of a nonmagnetic material. As the nonmagnetic material, for example, ceramics (for example, alumina, zirconia, silicon carbide, etc.) having high hardness and excellent heat resistance are preferably used.
　図２、図４Ａおよび図４Ｂに示すように、螺旋状の凸部１３によって第２軸部材１２の外周に画成される螺旋状溝１４の溝底面１５は、これに対向する第１軸部材１１の外径面１１ａと協働して、ワークＷを案内搬送するための案内搬送路Ｍ及びワーク支持部１６を形成する。本実施形態では、ワーク支持部１６でワークＷの外周面が接触支持される。凸部１３のピッチ及び幅寸法は、螺旋状溝１４の溝幅ＸとワークＷの全長寸法Ｙとの間に、Ｙ＜Ｘの関係式が成立するように設定されている。従って、搬送装置１０には、第１軸部材１１と第２軸部材１２の協働により、直線状の案内搬送路Ｍが形成されると共に、それぞれがワークＷ（の外周面）を接触支持可能なワーク支持部１６が案内搬送路Ｍの延在方向（ワークＷの搬送方向）で離間した複数箇所に形成される。 As shown in FIG. 2, FIG. 4A and FIG. 4B, the groove bottom surface 15 of the spiral groove 14 defined on the outer periphery of the second shaft member 12 by the spiral convex portion 13 is the first shaft member facing this. In cooperation with the outer diameter surface 11 a of 11, a guide conveyance path M for guiding and conveying the workpiece W and the workpiece support 16 are formed. In the present embodiment, the outer peripheral surface of the workpiece W is contact-supported by the workpiece support unit 16. The pitch and width dimension of the convex portions 13 are set so that the relational expression of Y <X is established between the groove width X of the spiral groove 14 and the overall length Y of the workpiece W. Accordingly, a linear guide conveyance path M is formed in the conveyance device 10 by the cooperation of the first shaft member 11 and the second shaft member 12, and each can contact and support the workpiece W (the outer peripheral surface thereof). A plurality of workpiece support portions 16 are formed at a plurality of locations separated in the extending direction of the guide conveyance path M (the conveyance direction of the workpiece W).
　図３に示すように、回転機構７は、サーボモータ等の電動モータ８と、電動モータ８の回転動力を両軸部材１１，１２に伝達する動力伝達機構９とを備える。 As shown in FIG. 3, the rotation mechanism 7 includes an electric motor 8 such as a servo motor, and a power transmission mechanism 9 that transmits the rotational power of the electric motor 8 to both shaft members 11 and 12.
　動力伝達機構９は、図２及び図３に示すように、小ギヤ９ａを有し、連結ピン１７を介して第１軸部材１１の軸線方向一方側の端部に連結されたギヤ軸１８Ａと、小ギヤ９ｂを有し、連結ピン１７を介して第２軸部材１２の軸線方向一方側の端部に連結されたギヤ軸１８Ｂと、枠体１９に回転自在に支持され、両小ギヤ９ａ，９ｂに噛合した大ギヤ９ｃと、電動モータ８の出力軸に連結された駆動プーリ９ｄと、大ギヤ９ｃに連結された従動プーリ９ｅと、両プーリ９ｄ，９ｅの外周面に架け渡された無端状のベルト部材（チェーンでも良い）９ｆとを備える。小ギヤ９ａ，９ｂの歯面のピッチは同一であり、また、大ギヤ９ｃのうち、小ギヤ９ａに噛合する歯面のピッチと小ギヤ９ｂに噛合する歯面のピッチは同一である。以上の構成を有する動力伝達機構９により、電動モータ８が駆動されると、第１軸部材１１及び第２軸部材１２は同一速度で同一方向に回転駆動される。 As shown in FIGS. 2 and 3, the power transmission mechanism 9 includes a gear shaft 18 </ b> A having a small gear 9 a and connected to an end portion on one axial direction side of the first shaft member 11 via a connection pin 17. The small shaft 9B has a small gear 9b and is rotatably supported by a frame 19 and a gear shaft 18B connected to one end in the axial direction of the second shaft member 12 via a connecting pin 17. , 9b meshed with the large gear 9c, the drive pulley 9d connected to the output shaft of the electric motor 8, the driven pulley 9e connected to the large gear 9c, and the pulleys 9d and 9e are stretched over the outer peripheral surface. And an endless belt member (which may be a chain) 9f. The pitches of the tooth surfaces of the small gears 9a and 9b are the same, and, among the large gear 9c, the pitch of the tooth surfaces meshing with the small gear 9a and the pitch of the tooth surfaces meshing with the small gear 9b are the same. When the electric motor 8 is driven by the power transmission mechanism 9 having the above configuration, the first shaft member 11 and the second shaft member 12 are rotationally driven in the same direction at the same speed.
　以上の構成を有する熱処理設備１を用いた場合、ワークＷに対する熱処理（加熱工程及び冷却工程）は、例えば以下の態様で実施される。 When the heat treatment facility 1 having the above configuration is used, the heat treatment (heating step and cooling step) for the workpiece W is performed, for example, in the following manner.
　熱処理対象のワークＷの型番に応じた電流指令値Ｉａを設定してから、加熱コイル３に通電すると共に、搬送装置１０を駆動（第１軸部材及び第２軸部材を回転駆動）させ、その後、搬送装置１０に対してワークＷを投入する。ワークＷは、図２中に示すワーク投入位置から搬送装置１０（のワーク支持部１６）に対して投入され、これにより、ワークＷの外周面がワーク支持部１６で接触支持される。前述のとおり、ワーク支持部１６（及び案内搬送路Ｍ）は、ねじ軸からなる第２軸部材１２に画成された螺旋状溝１４の溝底面１５で形成されることから、両軸部材１１，１２がその軸線回りに連続回転している間、ワーク支持部１６で接触支持されたワークＷには、これを案内搬送路Ｍに沿って搬送するための送り力が連続的に付加される。これにより、ワークＷは、案内搬送路Ｍに沿って所定速度で搬送されながら、加熱コイル３によって焼入温度に加熱される。そして、図１に示すように、加熱コイル３から排出されたワークＷは、自由落下により冷却部２０に貯留された冷却液中に投入され、所定の温度域に冷却されて焼入硬化する。 After setting the current command value Ia corresponding to the model number of the workpiece W to be heat-treated, the heating coil 3 is energized and the conveying device 10 is driven (the first shaft member and the second shaft member are driven to rotate), and then Then, the workpiece W is loaded into the transfer device 10. The workpiece W is loaded from the workpiece loading position shown in FIG. 2 with respect to the transport apparatus 10 (the workpiece support portion 16 thereof), whereby the outer peripheral surface of the workpiece W is contacted and supported by the workpiece support portion 16. As described above, the workpiece support 16 (and the guide conveyance path M) is formed by the groove bottom surface 15 of the spiral groove 14 defined in the second shaft member 12 formed of a screw shaft. , 12 is continuously rotated around its axis, the workpiece W supported by the workpiece support 16 is continuously applied with a feed force for conveying the workpiece W along the guide conveyance path M. . Accordingly, the workpiece W is heated to the quenching temperature by the heating coil 3 while being conveyed along the guide conveyance path M at a predetermined speed. As shown in FIG. 1, the workpiece W discharged from the heating coil 3 is charged into the coolant stored in the cooling unit 20 by free fall, and cooled to a predetermined temperature range and hardened by hardening.
　上記態様でワークＷを搬送する際、ワークＷの外周面を接触支持した第１及び第２軸部材１１，１２が同一方向に回転駆動されることから、ワーク支持部１６で支持されたワークＷには、図４Ａおよび図４Ｂ中に黒塗り矢印で示すように、ワークＷをその軸線回りに回転させる回転力が連続的に付与される（なお、回転方向は、両軸部材１１，１２の回転方向とは反対方向である）。 When the workpiece W is transported in the above-described manner, the first and second shaft members 11 and 12 that support and support the outer peripheral surface of the workpiece W are rotationally driven in the same direction. Therefore, the workpiece W supported by the workpiece support unit 16 is supported. 4A and 4B, a rotational force that continuously rotates the workpiece W around its axis is continuously applied as shown by black arrows in FIG. Opposite to the direction of rotation).
　そのため、ワーク支持部１６で接触支持されたワークＷには、案内搬送路Ｍの延在方向に沿った送り力に加え、ワークＷをその軸線回りに回転させる回転力が連続的に付与される。従って、案内搬送路Ｍに沿って搬送されるワークＷはその軸線回りに連続回転しながら誘導加熱されることになる。これにより、加熱完了後のワークＷに温度ムラを発生させることなく、ワークＷの各部を均一に誘導加熱することができる。特に、本実施形態では、両軸部材１１，１２の回転速度が同一となるように動力伝達機構９が構成されていることから、ワーク支持部１６で接触支持されたワークＷを滑らかに連続回転させることができる。また、両軸部材１１，１２が非磁性材料で形成されることから、ワークＷと両軸部材１１，１２の接触部分で伝熱冷却が生じるのを可及的に防止することができる。従って、加熱完了後のワークＷに温度ムラが生じるのを一層効果的に防止することができる。 Therefore, in addition to the feed force along the extending direction of the guide conveyance path M, the workpiece W that is contact-supported by the workpiece support unit 16 is continuously given a rotational force that rotates the workpiece W about its axis. . Accordingly, the workpiece W conveyed along the guide conveyance path M is induction-heated while continuously rotating around its axis. Thereby, each part of the workpiece | work W can be induction-heated uniformly, without producing temperature nonuniformity in the workpiece | work W after completion of a heating. In particular, in this embodiment, since the power transmission mechanism 9 is configured so that the rotational speeds of the shaft members 11 and 12 are the same, the workpiece W supported by the workpiece support 16 is smoothly and continuously rotated. Can be made. Moreover, since both the shaft members 11 and 12 are formed of a nonmagnetic material, it is possible to prevent heat transfer cooling from occurring at the contact portion between the workpiece W and the both shaft members 11 and 12 as much as possible. Therefore, it is possible to more effectively prevent temperature unevenness from occurring in the workpiece W after the heating is completed.
　本実施形態では、図２中に示すワーク投入位置から、搬送装置１０に対して所定の間隔を空けてワークＷを一個ずつ投入することにより、複数のワークＷを相互に離間した状態で搬送しながら、複数のワークＷを同時に誘導加熱するようにしている。この場合、搬送中のワークＷが相互に接触してワークＷ同士が溶着する、各ワークＷが隣接するワークＷの熱影響を受ける、などといった問題発生を可及的に防止することができるので、ワークＷを一層精度良く加熱することができる。なお、例えば、螺旋状溝１４の溝幅ＸとワークＷの全長寸法Ｙとの間に、Ｘ＜２Ｙの関係式が成立するようにしておけば、ワーク支持部１６でワークＷの外周面を接触支持する場合、各ワーク支持部１６では単一のワークＷのみが接触支持されることになる。この場合、複数のワークＷを確実に相互に離間した状態で搬送・加熱することができるので、各ワークＷが隣接するワークＷの熱影響を受ける可能性を一層効果的に低減することができる。 In this embodiment, a plurality of workpieces W are transported in a state of being separated from each other by feeding the workpieces W one by one with a predetermined interval from the workpiece loading position shown in FIG. However, a plurality of workpieces W are simultaneously induction-heated. In this case, it is possible to prevent the occurrence of problems such as the workpieces W being transported coming into contact with each other and welding the workpieces W, and each workpiece W being affected by the heat of the neighboring workpieces W as much as possible. The workpiece W can be heated with higher accuracy. For example, if the relational expression of X <2Y is established between the groove width X of the spiral groove 14 and the overall length Y of the work W, the work support portion 16 can provide the outer peripheral surface of the work W. In the case of contact support, only a single workpiece W is contact-supported at each workpiece support portion 16. In this case, since the plurality of workpieces W can be reliably transported and heated in a state of being separated from each other, the possibility that each workpiece W is affected by the heat of the adjacent workpieces W can be further effectively reduced. .
　また、以上で説明した搬送装置１０であれば、後続のワークによる押し込みがなくても、ワークＷを搬送することができる。そのため、この搬送装置１０を備えた加熱装置２は、加熱対象のワークＷが一個又は数個程度の小ロットである場合にも好ましく適用することができる汎用性に優れたものであり、しかも各ワークＷを精度良く加熱することができる。 Further, with the transfer device 10 described above, the workpiece W can be transferred without being pushed by a subsequent workpiece. Therefore, the heating device 2 provided with the transfer device 10 is excellent in versatility that can be preferably applied even when the work W to be heated is one or several small lots. The workpiece W can be heated with high accuracy.
　また、前述のとおり、加熱装置２は、加熱工程の実行中に加熱コイル３に流れている電流値（コイル電流値Ｉｂ）を測定する測定部５と、測定部５により測定されたコイル電流値Ｉｂに基づき、コイル電流値Ｉｂが常に所定の一定値（電流指令値Ｉａ）になるように高周波電源４の動作を制御する制御部６と、を有する。すなわち、本実施形態の加熱装置２は、いわゆる電流一定制御を実現するための構成を有している。このため、加熱工程の実行中に、案内搬送路Ｍに沿って加熱コイル３の対向領域を搬送されるワークＷの個数が変化するのに伴って加熱コイル３のインピーダンスが変化しても、コイル電流値Ｉｂは常に所定の一定値（電流指令値Ｉａ）に制御される。 As described above, the heating device 2 includes the measuring unit 5 that measures the current value (coil current value Ib) flowing through the heating coil 3 during the heating process, and the coil current value measured by the measuring unit 5. And a control unit 6 that controls the operation of the high-frequency power source 4 so that the coil current value Ib always becomes a predetermined constant value (current command value Ia) based on Ib. That is, the heating device 2 of the present embodiment has a configuration for realizing so-called constant current control. For this reason, even if the impedance of the heating coil 3 changes as the number of workpieces W conveyed along the guide conveyance path M along the guide conveyance path M changes during the heating process, the coil The current value Ib is always controlled to a predetermined constant value (current command value Ia).
　コイルに電流が流れたときにコイルに生じる磁束（Φ）は自己インダクタンス（Ｌ：定数）と電流（Ｉ）の積で算出され（Φ＝Ｌ×Ｉ）、磁束の強さは電流値に比例することから、上記のようにコイル電流値Ｉｂが常に電流指令値Ｉａに制御されれば、加熱コイル３内に生じる磁束の強さも一定になる。また、本実施形態のように、複数のワークＷを同時に誘導加熱する場合であっても、複数のワークＷは相互に離間した状態で支持・搬送されることから、各ワークＷに生じる誘導電流量も一定にすることができる。そのため、電流指令値Ｉａを適切に設定しておけば、加熱コイル３の対向領域を搬送されるワークＷの個数に関わらず、各ワークＷを所定温度に精度良く加熱することができる。これにより、ワークＷが過加熱されるのを可及的に防止することが可能となり、製品歩留の低下問題を解消することができる。 The magnetic flux (Φ) generated in the coil when a current flows through the coil is calculated by the product of self-inductance (L: constant) and current (I) (Φ = L × I), and the strength of the magnetic flux is proportional to the current value. Therefore, if the coil current value Ib is always controlled to the current command value Ia as described above, the strength of the magnetic flux generated in the heating coil 3 becomes constant. In addition, even when a plurality of workpieces W are simultaneously induction-heated as in the present embodiment, since the plurality of workpieces W are supported and transported in a state of being separated from each other, an induced current generated in each workpiece W The amount can also be constant. Therefore, if the current command value Ia is set appropriately, each workpiece W can be accurately heated to a predetermined temperature regardless of the number of workpieces W transported through the opposed region of the heating coil 3. As a result, it is possible to prevent the workpiece W from being overheated as much as possible, and the product yield reduction problem can be solved.
　上記のとおり、本実施形態の熱処理設備１では、加熱工程の初期段階や最終段階のように案内搬送路Ｍに沿って加熱コイル３の対向領域を搬送されるワークＷの個数（加熱コイル３のインピーダンス）が増加又は減少する段階においても、コイル電流値Ｉｂは常に一定に制御される。そのため、加熱コイル３における消費電力は、図５Ｃおよび図５Ｄに示すように、加熱コイル３の対向領域を搬送される棒状ワークＷの個数が増減するのに伴って自動的に増減する（∵Ｐ＝Ｉ2Ｒ）。従って、電力の出力パターンを予め設定する必要がなく、ワークＷの熱処理に要するコストを減じることができる。 As described above, in the heat treatment facility 1 of the present embodiment, the number of workpieces W (of the heating coil 3) conveyed along the guide conveyance path M along the guide conveyance path M as in the initial stage and the final stage of the heating process. Even when the impedance is increased or decreased, the coil current value Ib is always controlled to be constant. Therefore, as shown in FIGS. 5C and 5D, the power consumption in the heating coil 3 automatically increases / decreases as the number of rod-shaped workpieces W conveyed through the opposing area of the heating coil 3 increases / decreases (∵P = I 2 R). Therefore, it is not necessary to set the power output pattern in advance, and the cost required for the heat treatment of the workpiece W can be reduced.
　以上より、本発明の第１実施形態に係る熱処理設備１（及び熱処理方法）によれば、加熱不良品を発生させることなく、また、煩雑な事前準備を必要とすることなく、熱処理対象のワークＷを効率良くかつ精度良く所定温度に誘導加熱し、その後冷却することができる。これにより、所望の機械的強度や硬度を具備した高品質の機械部品を低コストに製造・量産することができる。特に、本実施形態の熱処理設備１によれば、各ワークＷを温度ムラ無く均一に加熱することができるので、機械的強度にバラツキがない高品質の機械部品を得る上で有利となる。 As described above, according to the heat treatment facility 1 (and heat treatment method) according to the first embodiment of the present invention, a workpiece to be heat treated without generating a defective heating product and without requiring complicated prior preparation. W can be induction-heated to a predetermined temperature efficiently and accurately, and then cooled. As a result, high-quality mechanical parts having desired mechanical strength and hardness can be manufactured and mass-produced at low cost. In particular, according to the heat treatment facility 1 of the present embodiment, each workpiece W can be uniformly heated without temperature unevenness, which is advantageous in obtaining high-quality mechanical parts having no variation in mechanical strength.
　図６は、本発明の第２実施形態に係る熱処理設備２１の全体構造を概念的に示す平面図である。この実施形態の熱処理設備２１が、上述した第１実施形態に係る熱処理設備１と異なる主な点は、熱処理設備１の加熱装置２に設けていた測定部５としての電流センサが、ワークＷを誘導加熱する加熱工程の実行中に加熱コイル３の両端電圧を測定する測定部２５に置き換えられている点にある。なお、熱処理設備２１における加熱コイル３や搬送装置１０の構成は図１に示す熱処理設備１で採用したものに準ずるので詳細説明を省略することとし、以下では、異なる構成についてのみ詳細に説明する。 FIG. 6 is a plan view conceptually showing the overall structure of the heat treatment equipment 21 according to the second embodiment of the present invention. The main difference between the heat treatment facility 21 of this embodiment and the heat treatment facility 1 according to the first embodiment described above is that the current sensor as the measurement unit 5 provided in the heating device 2 of the heat treatment facility 1 uses the work W It is in the point that it is replaced with the measurement unit 25 that measures the voltage across the heating coil 3 during the execution of the heating process for induction heating. In addition, since the structure of the heating coil 3 and the conveying apparatus 10 in the heat processing equipment 21 is based on what was employ | adopted with the heat processing equipment 1 shown in FIG. 1, detailed description shall be abbreviate | omitted and only a different structure is demonstrated in detail below.
　熱処理設備２１の加熱装置２は、加熱工程の実行中における加熱コイル３の両端電圧（以下、これを「コイル電圧値」ともいう）を測定する測定部２５と、測定部２５及び高周波電源２４と電気的に接続され、加熱工程の実行中に高周波電源２４の動作を制御する制御部２６とを備える。測定部２５（電圧センサ）としては、例えば、差動プローブや電圧検出用トランスなどが使用される。 The heating device 2 of the heat treatment facility 21 includes a measuring unit 25 that measures the voltage across the heating coil 3 during the heating process (hereinafter also referred to as “coil voltage value”), the measuring unit 25, and the high-frequency power source 24. And a control unit 26 that is electrically connected and controls the operation of the high-frequency power source 24 during the heating process. As the measurement unit 25 (voltage sensor), for example, a differential probe or a voltage detection transformer is used.
　制御部２６は、記憶装置２６ａ及びフィードバック回路２６ｂを有し、記憶装置２６ａには、ワークＷの型番毎に所定の一定値に設定された電圧指令値が保存されている。加熱工程の実行中には、ワークＷの型番に応じた電圧指令値Ｖａが記憶装置２６ａからフィードバック回路２６ｂに対して出力され、フィードバック回路２６ｂでは、電圧指令値Ｖａと、測定部２５で測定されたコイル電圧値Ｖｂとの差（Ｖａ－Ｖｂ）が常時演算される。そして、この演算結果に基づき、フィードバック回路２６ｂは、コイル電圧値Ｖｂが常に電圧指令値Ｖａになるように（Ｖａ－Ｖｂ＝０の関係式が常に成立するように）、高周波電源２４に設けられた図示外のトランジスタのスイッチ時間を制御する信号を高周波電源２４に対して出力する。 The control unit 26 includes a storage device 26a and a feedback circuit 26b, and the storage device 26a stores a voltage command value set to a predetermined constant value for each model number of the workpiece W. During execution of the heating process, the voltage command value Va corresponding to the workpiece W model number is output from the storage device 26a to the feedback circuit 26b, and the feedback circuit 26b measures the voltage command value Va and the measurement unit 25. The difference (Va−Vb) from the coil voltage value Vb is always calculated. Based on the calculation result, the feedback circuit 26b is provided in the high-frequency power supply 24 so that the coil voltage value Vb always becomes the voltage command value Va (so that the relational expression Va−Vb = 0 is always established). A signal for controlling the switch time of the transistor (not shown) is output to the high frequency power supply 24.
　加熱工程の実行中、電圧指令値Ｖａは、上記のとおり所定の一定値に設定され、加熱工程の初期段階や最終段階のように、加熱コイル３の対向領域を搬送されるワークＷの個数が増加又は減少する段階においても変化しない。要するに、本実施形態の熱処理設備２１における加熱装置２は、いわゆる電圧一定制御を実現するための構成を有しており、加熱工程の実行中、高周波電源２４は、図７Ａおよび図７Ｂに示すように、加熱コイル３の両端電圧が常に所定の一定値（電圧指令値Ｖａ）になるように動作が制御され、加熱コイル３の対向領域を搬送されるワークＷの個数が増減するのに応じて加熱コイル３に対する電流供給量を増減させる。そのため、電力（消費電力）は、図７Ｃおよび図７Ｄに示すように、加熱コイル３の対向領域を搬送されるワークＷの個数（加熱コイル３のインピーダンス）が増減するのに伴って自動的に増減する。従って、ワークＷの個数が増減しても各ワークＷに投入される電力は一定となるため、電圧指令値Ｖａを適切に設定しておけば、各ワークＷが過加熱されるのを可及的に防止して、各ワークＷを所定温度に精度良く加熱することができる。また、加熱コイル３の対向領域を搬送されるワークＷの個数等に応じて電力の出力パターンを予め設定する必要がない。 During execution of the heating process, the voltage command value Va is set to a predetermined constant value as described above, and the number of workpieces W transported through the opposed region of the heating coil 3 is the same as in the initial stage and final stage of the heating process. It does not change even when it increases or decreases. In short, the heating device 2 in the heat treatment facility 21 of the present embodiment has a configuration for realizing so-called constant voltage control, and the high-frequency power source 24 is configured as shown in FIGS. 7A and 7B during the heating process. In addition, the operation is controlled so that the voltage across the heating coil 3 always becomes a predetermined constant value (voltage command value Va), and the number of workpieces W transported in the opposed region of the heating coil 3 increases or decreases. Increase or decrease the amount of current supplied to the heating coil 3. Therefore, as shown in FIG. 7C and FIG. 7D, the power (power consumption) is automatically increased as the number of workpieces W (impedance of the heating coil 3) conveyed through the opposed region of the heating coil 3 increases or decreases. Increase or decrease. Therefore, even if the number of workpieces W increases or decreases, the electric power supplied to each workpiece W is constant. Therefore, if the voltage command value Va is set appropriately, each workpiece W can be overheated. Therefore, each workpiece W can be accurately heated to a predetermined temperature. Further, it is not necessary to set an output pattern of power in advance according to the number of workpieces W transported through the facing region of the heating coil 3.
　以上より、本発明の第２実施形態に係る熱処理設備２１（及び熱処理方法）によっても、本発明の第１実施形態に係る熱処理設備１と同様の作用効果を享受することができる。 As described above, the heat treatment equipment 21 (and heat treatment method) according to the second embodiment of the present invention can also enjoy the same effects as the heat treatment equipment 1 according to the first embodiment of the present invention.
　以上、本発明の第１及び第２実施形態に係る熱処理設備１，２１について説明を行ったが、熱処理設備１，２１には、本発明の要旨を逸脱しない範囲で適宜の変更を施すことが可能である。 The heat treatment facilities 1 and 21 according to the first and second embodiments of the present invention have been described above. However, the heat treatment facilities 1 and 21 may be appropriately modified without departing from the gist of the present invention. Is possible.
　例えば、加熱コイル３としては、図８に模式的に示すように、相対的にワークＷの搬送方向後方側（図１，図６においては紙面左側）に設けられ、コイルピッチＤ１が相対的に密に設定された第１加熱部３Ａと、相対的にワークＷの搬送方向後方側に設けられ、コイルピッチＤ２が相対的に疎に設定された第２加熱部３Ｂとが直列に連結されたものを使用することもできる。詳細な図示は省略しているが、第２加熱部３Ｂは第１加熱部３Ａよりも長寸である。 For example, as schematically shown in FIG. 8, the heating coil 3 is provided relatively on the rear side in the conveyance direction of the workpiece W (left side in FIG. 1 and FIG. 6), and the coil pitch D1 is relatively The first heating unit 3A that is set densely and the second heating unit 3B that is provided relatively on the rear side in the conveyance direction of the workpiece W and the coil pitch D2 is set relatively sparsely connected in series. Things can also be used. Although detailed illustration is omitted, the second heating unit 3B is longer than the first heating unit 3A.
　ここで、以上で説明した実施形態のように、炭素含有量が０．８質量％以上の鋼材で作製されたワークＷに対して焼入硬化処理を施す場合、加熱工程は、ワークの金属組織（オーステナイト）中に０．６質量％程度の炭素を溶かし込み、残りは炭化物として残留させるようにして行うのが好ましい。その主な理由は、炭素の溶け込み量を０．６質量％程度にしておけば、硬度低下や経年劣化などの問題を引き起こす原因となる残留オーステナイトの発生量を抑制することができ、また、炭化物を残留させれば、加熱中にオーステナイトの結晶粒が成長することを抑制できるからである。なお、ワークに対する炭素の溶け込み量を制御するには、図９Ａに示すように、ワークが所定温度（焼入温度）Ｔに昇温するまでワークを所定時間（ｔ１）積極的に加熱し、その後、ワークを焼入温度Ｔに維持するようにしてワークを所定時間（ｔ２）加熱する（ワークを所定時間均熱保持する）のが有効である。 Here, as in the embodiment described above, in the case where the hardening process is performed on the workpiece W made of a steel material having a carbon content of 0.8% by mass or more, the heating process is performed using the metal structure of the workpiece. It is preferable that about 0.6% by mass of carbon is dissolved in (austenite) and the rest is left as carbide. The main reason is that if the amount of carbon penetration is about 0.6% by mass, the amount of retained austenite, which causes problems such as a decrease in hardness and aging, can be suppressed. This is because it is possible to suppress the growth of austenite crystal grains during heating. In order to control the amount of carbon dissolved in the workpiece, as shown in FIG. 9A, the workpiece is actively heated for a predetermined time (t1) until the workpiece is heated to a predetermined temperature (quenching temperature) T, and then It is effective to heat the work for a predetermined time (t2) so as to maintain the work at the quenching temperature T (to keep the work soaked for a predetermined time).
　そして、ワークを誘導加熱するための加熱コイルは、一般に、コイルピッチが密になるほど出力が高まり、コイルピッチが疎になるほど出力が低くなるという特性を有する。このため、図８に示すような加熱コイル３を使用すれば、ワークＷが第１加熱部３Ａの対向領域を搬送される間にワークＷを積極的に昇温させることができる一方で、ワークＷが第２加熱部３Ｂの対向領域を搬送される間、ワークＷを所定温度に保持することが可能となる。従って、図９Ａに示すような所望の温度軌跡を描くようにして、ワークＷを誘導加熱することができる。 And, the heating coil for inductively heating the workpiece generally has a characteristic that the output increases as the coil pitch becomes dense and the output becomes low as the coil pitch becomes sparse. For this reason, if the heating coil 3 as shown in FIG. 8 is used, the workpiece W can be actively heated while the workpiece W is transported in the area opposite to the first heating unit 3A. While W is transported through the opposite area of the second heating unit 3B, the workpiece W can be held at a predetermined temperature. Therefore, the workpiece W can be induction-heated so as to draw a desired temperature locus as shown in FIG. 9A.
　実際のところ、ワークＷを焼入温度としての約９００℃に誘導加熱するに際して、図８に示す加熱コイル３を加熱装置２に適用した図１に示す熱処理設備１を用いたところ、図９Ｂに示すように、図９Ａに示す温度軌跡に近似した軌跡を描くようにしてワークＷを加熱できることが確認できた。 Actually, when the workpiece W is induction-heated to about 900 ° C. as the quenching temperature, the heat treatment equipment 1 shown in FIG. 1 in which the heating coil 3 shown in FIG. As shown, it was confirmed that the workpiece W could be heated so as to draw a locus approximate to the temperature locus shown in FIG. 9A.
　コイルピッチが相互に異なる第１加熱部３Ａ及び第２加熱部３Ｂを有する加熱コイル３においては、両加熱部３Ａ，３Ｂを溶接等の手段で連結しても良いが、両加熱部３Ａ，３Ｂは分離可能に連結することもできる。図１０はその一例であり、両加熱部３Ａ，３Ｂの間に配置した導電性金属からなる管状の連結部材３Ｃに対し、第１加熱部３Ａの端部と第２加熱部３Ｂの端部とを嵌合することで加熱コイル３を構成している。この場合、例えば、熱処理対象のワークＷの型番変更に伴って、両加熱部３Ａ，３Ｂの何れか一方又は双方のコイルピッチ等を変更する必要が生じた際にも、コイルピッチが異なるものに交換すれば良く、煩雑なコイルピッチの調整作業を省略することができる。従って、型番変更時の段取り作業を迅速化することができる。 In the heating coil 3 having the first heating unit 3A and the second heating unit 3B having different coil pitches, both the heating units 3A and 3B may be connected by means such as welding, but both the heating units 3A and 3B are connected. Can also be detachably connected. FIG. 10 shows an example thereof, with respect to a tubular connecting member 3C made of a conductive metal disposed between both heating units 3A and 3B, the end of the first heating unit 3A and the end of the second heating unit 3B. The heating coil 3 is configured by fitting. In this case, for example, when it is necessary to change the coil pitch of either one or both of the heating units 3A and 3B in accordance with the change of the model number of the workpiece W to be heat-treated, the coil pitch is different. What is necessary is just to replace | exchange, and the adjustment operation of a complicated coil pitch can be skipped. Therefore, the setup work when changing the model number can be speeded up.
　以上で説明した実施形態においては、加熱装置２に設けた実質的に一の加熱コイル３でワークＷを所定温度（焼入温度）に誘導加熱するようにしたが、本発明は、案内搬送路Ｍの延在方向（ワークＷの搬送方向）に沿って複数の加熱コイルが相互に離間して配置され、かつ各加熱コイルに高周波電源が個別に接続された熱処理設備にも好ましく適用することができる。 In the embodiment described above, the workpiece W is induction-heated to a predetermined temperature (quenching temperature) by the substantially one heating coil 3 provided in the heating device 2. The present invention is preferably applied to a heat treatment facility in which a plurality of heating coils are spaced apart from each other along the extending direction of M (the conveyance direction of the workpiece W), and a high-frequency power source is individually connected to each heating coil. it can.
　図１１は、その具体的な一例であって、本発明の第３実施形態に係る熱処理設備３１の全体構造を概念的に示す平面図である。この熱処理設備３１の加熱装置２は、相対的にワークＷの搬送方向後方側（紙面左側）に配置された第１加熱コイル３２と、相対的にワークＷの搬送方向前方側（紙面右側）に配置された第２加熱コイル３３と、第１加熱コイル３２に電気的に接続された第１高周波電源３４Ａと、第２加熱コイル３３に電気的に接続された第２高周波電源３４Ｂとを備える。第１及び第２加熱コイル３１，３２は、コイルピッチを同一としたいわゆる多巻きコイルであるが、第２加熱コイル３３は第１加熱コイル３２よりも長寸である。 FIG. 11 is a specific example, and is a plan view conceptually showing the overall structure of the heat treatment equipment 31 according to the third embodiment of the present invention. The heating device 2 of the heat treatment equipment 31 is relatively positioned on the first heating coil 32 disposed on the rear side (left side in the drawing) of the workpiece W and relatively on the front side (right side in the drawing) of the workpiece W. A second heating coil 33 arranged, a first high-frequency power source 34 </ b> A electrically connected to the first heating coil 32, and a second high-frequency power source 34 </ b> B electrically connected to the second heating coil 33 are provided. The first and second heating coils 31 and 32 are so-called multi-turn coils having the same coil pitch, but the second heating coil 33 is longer than the first heating coil 32.
　さらに、この熱処理設備３１の加熱装置２は、加熱工程の実行中に第１及び第２加熱コイル３２，３３に流れる電流値（コイル電流値）をそれぞれ所定の一定値（電流指令値）に制御するための構成を有する。すなわち、熱処理設備３１の加熱装置２は、第１加熱コイル３２のコイル電流値Ｉｂ１を測定（測定して出力）する測定部３５Ａと、測定部３５Ａ及び第１高周波電源３４Ａと電気的に接続され、加熱工程の実行中に第１高周波電源３４Ａの動作を制御する制御部３６Ａと、第２加熱コイル３３のコイル電流値Ｉｂ２を測定する測定部３５Ｂと、測定部３５Ｂ及び第２高周波電源３４Ｂと電気的に接続され、加熱工程の実行中に第２高周波電源３４Ｂの動作を制御する制御部３６Ｂとを有する。制御部３６Ａは、記憶装置３６Ａａ及びフィードバック回路３６Ａｂを有し、また、制御部３６Ｂは、記憶装置３６Ｂａ及びフィードバック回路３６Ｂｂを有する。記憶装置３６Ａａ，３６Ｂａには、それぞれ、棒状ワークＷの型番毎に所定の一定値に設定された電流指令値Ｉａ１，Ｉａ２が保存されている。但し、同一型番の棒状ワークＷにおける電流指令値は、記憶装置３６Ｂａに保存された電流指令値Ｉａ２よりも記憶装置３６Ａａに保存された電流指令値Ｉａ１の方が大きくなっている。 Further, the heating device 2 of the heat treatment equipment 31 controls the current values (coil current values) flowing through the first and second heating coils 32 and 33 during the heating process to predetermined constant values (current command values), respectively. It has the composition for doing. That is, the heating device 2 of the heat treatment facility 31 is electrically connected to the measurement unit 35A that measures (measures and outputs) the coil current value Ib1 of the first heating coil 32, the measurement unit 35A, and the first high-frequency power source 34A. The control unit 36A that controls the operation of the first high-frequency power source 34A during the heating process, the measurement unit 35B that measures the coil current value Ib2 of the second heating coil 33, the measurement unit 35B, and the second high-frequency power source 34B A control unit 36B that is electrically connected and controls the operation of the second high-frequency power source 34B during the heating process. The control unit 36A includes a storage device 36Aa and a feedback circuit 36Ab, and the control unit 36B includes a storage device 36Ba and a feedback circuit 36Bb. In the storage devices 36Aa and 36Ba, current command values Ia1 and Ia2 set to a predetermined constant value for each model number of the rod-shaped workpiece W are stored. However, the current command value Ia1 stored in the storage device 36Aa is larger than the current command value Ia2 stored in the storage device 36Ba.
　以上の構成を有する熱処理設備３１であれば、図１に示す熱処理設備１を採用する場合に享受し得る作用効果に加え、図８（及び図１０）に示す加熱コイル３を採用する場合に享受し得る作用効果を享受することができる。すなわち、以上の構成を有する熱処理設備３１であれば、ワークＷが第１加熱コイル３２の対向領域を搬送される間にワークＷを積極的に昇温させることができる一方で、ワークＷが第２加熱コイル３３の対向領域を搬送される間、ワークＷを所定温度（焼入温度）に保持することが可能となる。従って、図９Ａに示すような所望の温度軌跡を描くようにして、ワークＷを誘導加熱することができる。 In the case of the heat treatment equipment 31 having the above configuration, in addition to the effects that can be enjoyed when the heat treatment equipment 1 shown in FIG. 1 is adopted, it is enjoyed when the heating coil 3 shown in FIG. 8 (and FIG. 10) is adopted. The effect which can be enjoyed can be enjoyed. That is, with the heat treatment facility 31 having the above-described configuration, the workpiece W can be actively heated while the workpiece W is transported through the opposed region of the first heating coil 32, while the workpiece W is The workpiece W can be held at a predetermined temperature (quenching temperature) while being conveyed in the area opposite to the two heating coils 33. Therefore, the workpiece W can be induction-heated so as to draw a desired temperature locus as shown in FIG. 9A.
　本実施形態では、第１加熱コイル３２と第２加熱コイル３３のコイルピッチを同一に設定したが、両加熱コイル３２，３３のコイルピッチは必ずしも同一に設定する必要はなく、相互に異ならせても良い。 In the present embodiment, the coil pitches of the first heating coil 32 and the second heating coil 33 are set to be the same, but the coil pitches of both the heating coils 32 and 33 are not necessarily set to be the same, and are different from each other. Also good.
　また、第１加熱コイル３２及び第２加熱コイル３３にそれぞれ接続する測定部は、加熱工程の実行中に加熱コイル３２，３３の両端電圧を測定するものに置き換えても良い。すなわち、図１１に示す熱処理設備３１においても、図６に示す熱処理設備２１と同様に、加熱工程の実行中における加熱コイルの両端電圧を所定の一定値に制御する電圧一定制御方式を採用することができる。 Further, the measurement unit connected to each of the first heating coil 32 and the second heating coil 33 may be replaced with one that measures the voltage across the heating coils 32 and 33 during the execution of the heating process. That is, also in the heat treatment equipment 31 shown in FIG. 11, as in the heat treatment equipment 21 shown in FIG. 6, a voltage constant control method for controlling the voltage across the heating coil to a predetermined constant value during the execution of the heating process is adopted. Can do.
　以上、本発明の実施形態について具体的に説明したが、本発明の実施の形態はこれに限定されるものではない。 Although the embodiment of the present invention has been specifically described above, the embodiment of the present invention is not limited to this.
　例えば、搬送装置１０を構成する第１及び第２軸部材１１，１２に撓みが生じるおそれがある場合には、図１２に示すように、両軸部材１１，１２の外周面のうち、ワーク支持部１６を形成する周方向領域以外の周方向領域を接触支持する支持部材（サポートローラ）２９を設けても良い。このようなサポートローラ２９を設けておけば、両軸部材１１，１２に撓みが生じるのを可及的に防止することができるので、ワークＷを精度良く支持・搬送可能とし、ワークＷを精度良く誘導加熱することができる。 For example, when there is a possibility that the first and second shaft members 11 and 12 constituting the conveying device 10 are bent, as shown in FIG. A support member (support roller) 29 that contacts and supports a circumferential region other than the circumferential region that forms the portion 16 may be provided. If such a support roller 29 is provided, it is possible to prevent the shaft members 11 and 12 from being bent as much as possible, so that the workpiece W can be supported and transported with high accuracy. Good induction heating.
　また、以上で説明した実施形態では、図４Ａおよび図４Ｂに示すように、ワーク支持部１６でワークＷの外周面を接触支持し、ワークＷをその軸方向に沿って搬送するようにしたが、ワーク支持部１６によるワークＷの支持態様（搬送時のワークＷの姿勢）はこれに限られない。 Moreover, in embodiment described above, as shown to FIG. 4A and FIG. 4B, the outer peripheral surface of the workpiece | work W was contact-supported by the workpiece | work support part 16, and the workpiece | work W was conveyed along the axial direction. The support mode of the workpiece W by the workpiece support unit 16 (the posture of the workpiece W during conveyance) is not limited to this.
　すなわち、ワークＷは、例えば図１３Ａおよび図１３Ｂに示すように、その一端面を第２軸部材１２の螺旋状溝１４の溝底面１５で接触支持すると共に、その外周面を第１軸部材１１の外径面１１ａで接触支持するようにしても構わない。この場合、ワークＷは、その軸線を案内搬送路Ｍの延在方向に対して交差（直交）させた状態で案内搬送路Ｍに沿って搬送されることになる。 That is, for example, as shown in FIGS. 13A and 13B, the workpiece W is in contact with and supported on one end surface by the groove bottom surface 15 of the spiral groove 14 of the second shaft member 12, and the outer peripheral surface thereof is supported by the first shaft member 11. The outer diameter surface 11a may be contact-supported. In this case, the workpiece W is transported along the guide transport path M in a state in which the axis thereof intersects (orthogonal) with the extending direction of the guide transport path M.
　図４Ａおよび図４Ｂに示すように、ワーク支持部１６でワークＷの外周面を接触支持した場合、案内搬送路Ｍに沿って搬送されるワークＷは、その外周面が第１軸部材１１の外径面１１ａおよび第２軸部材１２の溝底面１５に対して滑りを伴いながら転がり接触する。これに対し、図１３Ａおよび図１３Ｂに示す態様でワークＷを支持・搬送する場合には、ワークＷは、その外周面が第１軸部材１１の外径面１１ａ及び第２軸部材１２の螺旋状の凸部１３に対して滑りを伴うことなく転がり接触する。従って、加熱完了後のワークＷの外周面に温度ムラが発生するのを防止する上で、また、ワークＷの外周面にキズ等の微小欠陥が生じるのを防止する上で有利となる。特に、ワークＷが、本実施形態のように円すいころ（の基材）である場合、あるいは円筒ころ（の基材）である場合などには、図１３Ａおよび図１３Ｂに示す態様でワークＷを支持・搬送するのが好ましい。円すいころや円筒ころの外周面は、転がり軸受を構成する内輪および外輪の軌道面に沿って転動する面であり、高い形状精度や機械的強度を要求される面であるからである。 As shown in FIGS. 4A and 4B, when the outer peripheral surface of the workpiece W is contact-supported by the workpiece support unit 16, the outer peripheral surface of the workpiece W transported along the guide transport path M is the first shaft member 11. The outer surface 11a and the groove bottom surface 15 of the second shaft member 12 are in rolling contact with sliding. On the other hand, when the workpiece W is supported and transported in the mode shown in FIGS. 13A and 13B, the outer circumference of the workpiece W is the outer diameter surface 11a of the first shaft member 11 and the spiral of the second shaft member 12. The rolling contact comes into contact with the convex portion 13 without sliding. Therefore, it is advantageous for preventing the occurrence of temperature unevenness on the outer peripheral surface of the work W after completion of heating, and for preventing the occurrence of minute defects such as scratches on the outer peripheral surface of the work W. In particular, when the workpiece W is a tapered roller (base material) or a cylindrical roller (base material) as in this embodiment, the workpiece W is formed in the manner shown in FIGS. 13A and 13B. It is preferable to support and convey. This is because the outer peripheral surface of the tapered roller or cylindrical roller is a surface that rolls along the raceway surfaces of the inner ring and outer ring that constitute the rolling bearing, and is a surface that requires high shape accuracy and mechanical strength.
　また、以上で説明した実施形態のように、両軸部材１１，１２を回転駆動させる場合、両軸部材１１，１２の回転速度は必ずしも同一とする必要はなく、互いに異ならせても構わない。両軸部材１１，１２の回転速度を互いに異ならせるには、例えば、第１軸部材１１に設けられる小ギヤ９ａおよびこれに噛合う大ギヤ９ｃの歯面のピッチと、第２軸部材１２に設けられる小ギヤ９ｂおよびこれに噛合う大ギヤ９ｃの歯面のピッチとを互いに異ならせれば良い。また、両軸部材１１，１２を回転駆動させる場合でも、上述した回転機構７とは異なる構成の回転機構７を採用しても構わない。例えば、電動モータを２つ設け、一方の電動モータの出力軸に第１軸部材１１を連結すると共に、他方の電動モータの出力軸に第２軸部材１２を連結することも可能である。 In addition, as in the embodiment described above, when the shaft members 11 and 12 are rotationally driven, the rotational speeds of the shaft members 11 and 12 are not necessarily the same, and may be different from each other. In order to make the rotational speeds of both the shaft members 11 and 12 different from each other, for example, the pitch of the tooth surfaces of the small gear 9a provided on the first shaft member 11 and the large gear 9c meshing with the small gear 9a and the second shaft member 12 What is necessary is just to make the pitch of the tooth surface of the small gear 9b and the large gear 9c meshing with this differ from each other. Even when both the shaft members 11 and 12 are driven to rotate, a rotating mechanism 7 having a configuration different from that of the rotating mechanism 7 described above may be employed. For example, it is possible to provide two electric motors, connect the first shaft member 11 to the output shaft of one electric motor, and connect the second shaft member 12 to the output shaft of the other electric motor.
　また、以上で説明した実施形態では、第１軸部材１１及び第２軸部材１２を同一方向に同一速度で回転駆動（同期回転）させることにより、案内搬送路Ｍに沿って搬送されるワークＷに回転力を付与するようにしたが、このような回転力は、ねじ軸からなる軸部材（以上で説明した実施形態では第２軸部材１２）のみを回転駆動させることによってもワークＷに付与することができる。従って、回転機構７は、ねじ軸からなる軸部材のみを回転駆動させるものであっても構わない。この場合、回転機構７には、両軸部材１１，１２を同期回転させるための複雑な機構（動力伝達機構９）を設けずとも足りるので、搬送装置１０の簡素化・低コスト化を図ることができる。 In the embodiment described above, the workpiece W conveyed along the guide conveyance path M by rotating (synchronously rotating) the first shaft member 11 and the second shaft member 12 in the same direction at the same speed. However, such a rotational force is also applied to the workpiece W by rotating only the shaft member (the second shaft member 12 in the embodiment described above). can do. Therefore, the rotation mechanism 7 may be configured to rotate only the shaft member formed of the screw shaft. In this case, since it is not necessary to provide the rotation mechanism 7 with a complicated mechanism (power transmission mechanism 9) for synchronously rotating the shaft members 11 and 12, the conveyance device 10 can be simplified and reduced in cost. Can do.
　また、以上で説明した実施形態では、両軸部材１１，１２のうち、第２軸部材１２のみをねじ軸で構成したが、第１軸部材１１を第２軸部材１２と同様のねじ軸で構成することも可能である（図示省略）。この場合、両軸部材１１，１２のそれぞれに形成される螺旋状溝１４の溝底面１５で案内搬送路Ｍ及びワーク支持部１６が形成される。 Further, in the embodiment described above, only the second shaft member 12 of the both shaft members 11 and 12 is configured by a screw shaft, but the first shaft member 11 is configured by a screw shaft similar to the second shaft member 12. It is also possible to configure (not shown). In this case, the guide conveyance path M and the work support portion 16 are formed on the groove bottom surface 15 of the spiral groove 14 formed on each of the shaft members 11 and 12.
　また、以上で説明した搬送装置１０はあくまでも一例であり、ワークＷを案内搬送路Ｍに沿って所定速度で連続搬送するのと同時に回転させる必要がないような場合には、その他の構成を有する搬送装置１０（例えば、搬送コンベヤ）を採用しても構わない。 Further, the transport device 10 described above is merely an example, and has other configurations in the case where it is not necessary to rotate the workpiece W along the guide transport path M at a predetermined speed and simultaneously with the transport. You may employ | adopt the conveying apparatus 10 (for example, conveyance conveyor).
　以上の説明では、ワークＷとして円すいころ（の基材）を例示したが、本発明に係る熱処理設備１，２１，３１は、玉軸受を構成する玉（ボール）、円筒ころ軸受を構成する円筒ころ、あるいは針状ころ軸受を構成する針状ころ等、その他の転がり軸受の転動体に熱処理を施す場合にも好ましく用いることができる。また、本発明に係る熱処理設備１，２１，３１は、上述した各種転動体等の中実のワークＷのみならず、中空のワークＷに熱処理を施す場合にも好ましく用いることができる。 In the above description, a tapered roller (base material) is exemplified as the workpiece W. However, the heat treatment equipment 1, 21, 31 according to the present invention is a ball (ball) constituting a ball bearing, a cylinder constituting a cylindrical roller bearing. It can also be preferably used in the case where heat treatment is applied to the rolling elements of other rolling bearings such as rollers or needle rollers constituting a needle roller bearing. Further, the heat treatment facilities 1, 21, 31 according to the present invention can be preferably used not only for the solid workpiece W such as the various rolling elements described above, but also when the hollow workpiece W is subjected to heat treatment.
　また、以上の説明では、炭素含有量が０．８質量％以上の鋼材で作製されたワークＷに熱処理を施す際に本発明に係る熱処理設備１，２１，３１を用いたが、本発明に係る熱処理設備１，２１，３１（及び熱処理方法）は、焼入可能なその他の金属材料で作製されたワークＷに熱処理を施す場合にも好ましく用いることができる。 In the above description, the heat treatment equipment 1, 21, 31 according to the present invention is used when heat-treating the workpiece W made of a steel material having a carbon content of 0.8 mass% or more. Such heat treatment equipment 1, 21, 31 (and heat treatment method) can be preferably used also when heat-treating a workpiece W made of other metal materials that can be hardened.
　本発明は前述した実施形態に何ら限定されるものではなく、本発明の要旨を逸脱しない範囲内において、さらに種々なる形態で実施し得る。すなわち、本発明の範囲は、請求の範囲によって示され、さらに請求の範囲に記載の均等の意味、および範囲内のすべての変更を含む。 The present invention is not limited to the embodiment described above, and can be implemented in various forms without departing from the gist of the present invention. That is, the scope of the present invention is defined by the terms of the claims, and includes the equivalent meanings recited in the claims and all modifications within the scope.
１　　　熱処理設備
２　　　加熱装置
３　　　加熱コイル
４　　　高周波電源
５　　　測定部（電流センサ）
６　　　制御部
６Ａ　　記憶装置
６Ｂ　　フィードバック回路
７　　　回転機構
９　　　動力伝達機構
１０　　搬送装置
１１　　第１軸部材
１２　　第２軸部材
１３　　螺旋状の凸部
１４　　螺旋状溝
１５　　溝底面
１６　　ワーク支持部
２０　　冷却部（冷却装置）
２１　　熱処理設備
２４　　高周波電源
２５　　測定部（電圧センサ）
２６　　制御部
３１　　熱処理設備
３４Ａ、３４Ｂ　高周波電源
３５Ａ、３５Ｂ　測定部（電流センサ）
３６Ａ、３６Ｂ　制御部
Ｍ　　　案内搬送路
Ｗ　　　ワーク 1 Heat Treatment Equipment 2 Heating Device 3 Heating Coil 4 High Frequency Power Supply 5 Measuring Unit (Current Sensor)
6 Control unit 6A Storage device 6B Feedback circuit 7 Rotating mechanism 9 Power transmission mechanism 10 Conveying device 11 First shaft member 12 Second shaft member 13 Helical convex portion 14 Helical groove 15 Groove bottom surface 16 Work support portion 20 Cooling portion ( Cooling system)
21 Heat treatment equipment 24 High frequency power supply 25 Measuring section (voltage sensor)
26 Control Unit 31 Heat Treatment Equipment 34A, 34B High Frequency Power Supply 35A, 35B Measuring Unit (Current Sensor)
36A, 36B Control unit M Guide conveyance path W Workpiece

Claims (11)

  1. 　回転可能なワークを直線状の案内搬送路に沿って所定速度で搬送する搬送装置と、
    　前記案内搬送路に沿って搬送されている前記ワークを所定温度に誘導加熱する加熱コイルを含み、該加熱コイルが複数の前記ワークを同時に誘導加熱可能な全長寸法を有する加熱装置と、を備えた熱処理設備であって、
    　前記搬送装置は、前記ワークの搬送方向で相互に離間して設けられた複数のワーク支持部を有し、
    　前記加熱装置は、前記加熱コイルと電気的に接続された高周波電源と、前記ワークの加熱中に前記加熱コイルに流れる電流値を測定する測定部と、該測定部により測定された電流値に基づき、前記ワークの加熱中に前記加熱コイルに流れる電流値が常に所定の一定値になるように前記高周波電源の動作を制御する制御部と、を有することを特徴とする熱処理設備。     A transport device for transporting a rotatable workpiece along a linear guide transport path at a predetermined speed;
    A heating coil that includes a heating coil that induction-heats the workpiece conveyed along the guide conveyance path to a predetermined temperature, and the heating coil has a full length dimension capable of induction heating the plurality of workpieces simultaneously. Heat treatment equipment,
    The transport device has a plurality of work support portions provided apart from each other in the transport direction of the work,
    The heating device includes a high-frequency power source electrically connected to the heating coil, a measurement unit that measures a current value flowing through the heating coil during heating of the workpiece, and a current value measured by the measurement unit And a control unit for controlling the operation of the high-frequency power source so that the value of the current flowing through the heating coil always becomes a predetermined constant value during the heating of the workpiece.
  2. 　回転可能なワークを直線状の案内搬送路に沿って所定速度で搬送する搬送装置と、
    　前記案内搬送路に沿って搬送されている前記ワークを所定温度に誘導加熱する加熱コイルを含み、該加熱コイルが複数の前記ワークを同時に誘導加熱可能な全長寸法を有する加熱装置と、を備えた熱処理設備であって、
    　前記搬送装置は、前記ワークの搬送方向で相互に離間して設けられた複数のワーク支持部を有し、
    　前記加熱装置は、前記加熱コイルと電気的に接続された高周波電源と、前記ワークの加熱中における前記加熱コイルの両端電圧を測定する測定部と、該測定部により測定された電圧値に基づき、前記ワークの加熱中における前記加熱コイルの両端電圧が常に所定の一定値になるように前記高周波電源の動作を制御する制御部と、を有することを特徴とする熱処理設備。     A transport device for transporting a rotatable workpiece along a linear guide transport path at a predetermined speed;
    A heating coil that includes a heating coil that induction-heats the workpiece conveyed along the guide conveyance path to a predetermined temperature, and the heating coil has a full length dimension capable of induction heating the plurality of workpieces simultaneously. Heat treatment equipment,
    The transport device has a plurality of work support portions provided apart from each other in the transport direction of the work,
    The heating device is based on a high-frequency power source electrically connected to the heating coil, a measurement unit that measures a voltage across the heating coil during heating of the workpiece, and a voltage value measured by the measurement unit, And a control unit that controls the operation of the high-frequency power supply so that the voltage across the heating coil is always a predetermined constant value during heating of the workpiece.
  3. 　前記搬送装置は、相互に離間して平行に配置された第１軸部材及び第２軸部材と、両軸部材のうち少なくとも一方の軸部材をその軸線回りに回転駆動させる回転機構とを備え、
    　少なくとも前記一方の軸部材が、その外周に沿って延びた螺旋状の凸部を有するねじ軸からなり、前記凸部によって前記一方の軸部材に画成される螺旋状溝の溝底面と、他方の軸部材の前記溝底面との対向面とで前記案内搬送路および前記ワーク支持部が形成される請求項１又は２に記載の熱処理設備。     The transport device includes a first shaft member and a second shaft member disposed in parallel and spaced apart from each other, and a rotation mechanism that rotationally drives at least one of the shaft members around the axis thereof,
    At least one of the shaft members includes a screw shaft having a spiral convex portion extending along an outer periphery thereof, the groove bottom surface of the spiral groove defined on the one shaft member by the convex portion, and the other The heat treatment equipment according to claim 1, wherein the guide conveyance path and the work support portion are formed by a surface of the shaft member facing the groove bottom surface.
  4. 　前記他方の軸部材は、その外径面が径一定の円筒面に形成された円柱軸からなる請求項３に記載の熱処理設備。 The heat treatment facility according to claim 3, wherein the other shaft member is a cylindrical shaft having an outer diameter surface formed in a cylindrical surface having a constant diameter.
  5. 　前記回転機構が、両軸部材を同一速度で同一方向に回転駆動させるように構成されている請求項３又は４に記載の熱処理設備。 The heat treatment equipment according to claim 3 or 4, wherein the rotation mechanism is configured to rotationally drive both shaft members in the same direction at the same speed.
  6. 　前記加熱コイルは、相対的に前記ワークの搬送方向後方側に配置され、コイルピッチが相対的に密に設定された第１加熱部と、相対的に前記ワークの搬送方向前方側に配置され、コイルピッチが相対的に疎に設定された第２加熱部とを有する請求項１～５の何れか一項に記載の熱処理設備。 The heating coil is relatively arranged on the rear side in the conveyance direction of the workpiece, and is arranged relatively on the front side in the conveyance direction of the workpiece, with the first heating unit having a coil pitch set relatively densely, The heat treatment facility according to any one of claims 1 to 5, further comprising a second heating unit in which the coil pitch is set relatively sparse.
  7. 　前記加熱装置で所定温度に加熱された前記ワークを冷却する冷却装置をさらに有する請求項１～６の何れか一項に記載の熱処理設備。 The heat treatment equipment according to any one of claims 1 to 6, further comprising a cooling device that cools the workpiece heated to a predetermined temperature by the heating device.
  8. 　前記ワークが、炭素含有量０．８質量％以上の鋼材からなる請求項１～７の何れか一項に記載の熱処理設備。 The heat treatment equipment according to any one of claims 1 to 7, wherein the workpiece is made of a steel material having a carbon content of 0.8 mass% or more.
  9. 　前記ワークが、転がり軸受の転動体である請求項１～８の何れか一項に記載の熱処理設備。 The heat treatment equipment according to any one of claims 1 to 8, wherein the workpiece is a rolling element of a rolling bearing.
  10. 　回転可能なワークを直線状の案内搬送路に沿って所定速度で搬送しながら通電状態の加熱コイルの対向領域を通過させることにより、前記ワークを所定温度に誘導加熱する加熱工程を有する熱処理方法であって、
    　前記加熱工程では、複数の前記ワークを相互に離間した状態で搬送可能な搬送装置、および複数の前記ワークを同時に誘導加熱可能な全長寸法を有する前記加熱コイルを使用すると共に、前記加熱コイルに流れる電流値に基づき、前記加熱コイルに流れる電流値が常に所定の一定値になるように前記加熱コイルと電気的に接続された高周波電源の動作を制御することを特徴とする熱処理方法。     A heat treatment method including a heating step of induction heating the workpiece to a predetermined temperature by passing the rotatable workpiece along a linear guide conveyance path at a predetermined speed while passing through a facing region of the energized heating coil. There,
    In the heating step, a transport device capable of transporting the plurality of workpieces in a state of being separated from each other, and the heating coil having a total length capable of induction heating the plurality of workpieces at the same time are used, and the heating coil flows to the heating coil. A heat treatment method, comprising: controlling an operation of a high-frequency power source electrically connected to the heating coil such that a current value flowing through the heating coil is always a predetermined constant value based on a current value.
  11. 　回転可能なワークを直線状の案内搬送路に沿って所定速度で搬送しながら通電状態の加熱コイルの対向領域を通過させることにより、前記ワークを所定温度に誘導加熱する加熱工程を有する熱処理方法であって、
    　前記加熱工程では、複数の前記ワークを相互に離間した状態で搬送可能な搬送装置、および複数の前記ワークを同時に誘導加熱可能な全長寸法を有する前記加熱コイルを使用すると共に、前記加熱コイルの両端電圧値に基づき、前記加熱コイルの両端電圧が常に所定の一定値になるように前記加熱コイルと電気的に接続された高周波電源の動作を制御することを特徴とする熱処理方法。     A heat treatment method including a heating step of induction heating the workpiece to a predetermined temperature by passing the rotatable workpiece along a linear guide conveyance path at a predetermined speed while passing through a facing region of the energized heating coil. There,
    In the heating step, a transport device capable of transporting the plurality of workpieces in a state of being separated from each other, and the heating coil having a total length dimension capable of induction heating the plurality of workpieces simultaneously, and both ends of the heating coil are used. A heat treatment method characterized by controlling the operation of a high-frequency power source electrically connected to the heating coil so that the voltage across the heating coil is always a predetermined constant value based on the voltage value.
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