JP2008267786A - Monitoring system for high frequency heat treatment facility of automobile shaft component or like - Google Patents

Monitoring system for high frequency heat treatment facility of automobile shaft component or like Download PDF

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JP2008267786A
JP2008267786A JP2008023693A JP2008023693A JP2008267786A JP 2008267786 A JP2008267786 A JP 2008267786A JP 2008023693 A JP2008023693 A JP 2008023693A JP 2008023693 A JP2008023693 A JP 2008023693A JP 2008267786 A JP2008267786 A JP 2008267786A
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heat treatment
workpiece
monitoring system
monitoring
range
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Shintaro Suzuki
慎太郎 鈴木
Takeaki Ishidai
健晃 石代
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NTN Corp
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NTN Toyo Bearing Co Ltd
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    • 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

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Abstract

<P>PROBLEM TO BE SOLVED: To provide a monitoring system for a high frequency heat treatment facility capable of reducing material cost and improving work efficiency while suppressing the occurrence of defectives. <P>SOLUTION: A preventive range is set within a monitoring range. When the acquired value of the heat treating state of a treated object exceeds the preventive range, a warning is issued to inform an operator so that a defective can be obviated before it actually occurs. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

本発明は、高周波誘導加熱による熱処理を自動車用シャフト部品等の被処理物に施す高周波熱処理設備において、被処理物の熱処理状態を監視する監視システムに関する。   The present invention relates to a monitoring system for monitoring a heat treatment state of an object to be processed in an induction heat treatment facility that performs heat treatment by high frequency induction heating on the object to be processed such as an automobile shaft part.

高周波誘導加熱による焼入れは、自動車等の各種機械に用いられるシャフトや、その他金属部品を熱処理するために用いられる。一般に、高周波誘導加熱による熱処理では、加熱コイルに高周波電流を流すことで、部品を誘導加熱する。この高周波誘導加熱による熱処理では、加熱炉の場合のように部品全体が均一に加熱されるのではなく、硬化させたい部分のみを局部的に加熱することが可能であり、加熱効率が高められるという利点が得られる。   Quenching by high frequency induction heating is used to heat treat shafts and other metal parts used in various machines such as automobiles. In general, in heat treatment by high frequency induction heating, a component is induction heated by flowing a high frequency current through a heating coil. In this heat treatment by high frequency induction heating, the entire part is not heated uniformly as in the case of a heating furnace, but only the part to be cured can be locally heated, and the heating efficiency is increased. Benefits are gained.

このような高周波誘導加熱による熱処理では、熱処理条件、例えば加熱コイルに供給する電力や、焼入れ用の冷却水の供給時間等を適当な値に設定する必要がある。これらの熱処理条件を設定する方法として、一般には、加工した部品の焼入れ品質を確認しながら最適な条件を導出する。 In such heat treatment by high frequency induction heating, it is necessary to set heat treatment conditions, for example, power supplied to the heating coil, supply time of quenching cooling water, and the like to appropriate values. As a method for setting these heat treatment conditions, generally, optimum conditions are derived while confirming the quenching quality of the processed parts.

しかし、上記に示されている方法により熱処理条件を設定したとしても、その後の熱処理の量産過程における設備の状態や周辺環境の変化に伴って、熱処理条件が変化することがある。例えば、供給する電力を任意の値に設定していても、系統電圧の変動や、加熱コイルの劣化などにより実際に投入される電力が変化する場合がある。また、冷却する時間を任意の値に設定していても、水圧の変動やフィルターの詰まりなどにより必要な冷却水量が得られてない事態が生じる恐れがある。   However, even if the heat treatment conditions are set by the method described above, the heat treatment conditions may change with changes in the state of the equipment and the surrounding environment in the subsequent mass production process of the heat treatment. For example, even if the power to be supplied is set to an arbitrary value, the power actually supplied may change due to fluctuations in the system voltage, deterioration of the heating coil, or the like. Even if the cooling time is set to an arbitrary value, there is a possibility that a necessary amount of cooling water cannot be obtained due to fluctuations in water pressure or clogging of the filter.

このような不具合を回避するために、例えば特許文献１に示されている熱処理設備では、量産過程における各監視項目の取得値に許容される上限値及び下限値を設定し、監視項目の取得値がこの監視域を外れたとき、警報を発して作業を停止することにより、不良品を確実に除去している。具体的には、図７に示すように、監視項目の取得値が予め設定した良否判定の監視域を外れたときに、その被処理物を不良品と判定し、警報を発するものである。   In order to avoid such problems, for example, in the heat treatment facility shown in Patent Document 1, an upper limit value and a lower limit value that are allowed for an acquired value of each monitoring item in a mass production process are set, and an acquired value of the monitoring item is set. When out of this monitoring area, an alarm is issued and the operation is stopped to reliably remove defective products. Specifically, as shown in FIG. 7, when the acquired value of the monitoring item is out of a predetermined quality determination monitoring area, the workpiece is determined to be defective and an alarm is issued.

特開２００６−１４４１２６号公報JP 2006-144126 A

しかし、特許文献１の監視方法によると、実際に不良品が発生して初めて作業者が対処することとなるため、不良品の発生は避けられない。不良品の発生数が多くなると、材料の無駄が生じてコストがかかるだけでなく、作業効率の低下にもつながる。   However, according to the monitoring method of Patent Document 1, since an operator will deal with a defective product only after the defective product is actually generated, the generation of a defective product is unavoidable. When the number of defective products increases, not only is the material wasted and costs increased, but also the work efficiency is reduced.

本発明は、高周波熱処理設備における被処理物の熱処理状態の監視システムにおいて、不良品の発生を抑えることを目的とする。   It is an object of the present invention to suppress the occurrence of defective products in a monitoring system for the heat treatment state of an object to be processed in a high frequency heat treatment facility.

上記の目的を達成するために、本発明は、被処理物を高周波誘導加熱により加熱した後、冷却することにより焼入れ硬化させる高周波熱処理設備において、被処理物の熱処理状態を監視する監視システムであって、被処理物の熱処理状態に関する監視項目の取得値を記録する監視部に、前記取得値に許容される上限値及び下限値からなる監視域を設定すると共に、監視域の範囲内に予防上限値及び予防下限値からなる予防域を設定したことを特徴とする。   In order to achieve the above object, the present invention is a monitoring system for monitoring the heat treatment state of an object to be treated in an induction heat treatment facility in which the object to be treated is heated by high frequency induction heating and then cooled and quenched. And setting a monitoring area consisting of an upper limit value and a lower limit value allowed for the acquired value in the monitoring unit for recording the acquired value of the monitoring item related to the heat treatment state of the workpiece, and a preventive upper limit within the range of the monitoring area. A preventive range consisting of a value and a preventive lower limit value is set.

このように、本発明の監視システムでは、被処理物の熱処理状態の取得値に許容される監視域の範囲内にさらに予防域を設定する。これにより、取得値が予防域から外れた時点で、実際に不良品が発生する前に対処することが可能となるため、不良品の発生数を抑え、材料コストの低減及び作業効率の向上を図ることができる。   As described above, in the monitoring system of the present invention, the prevention zone is further set within the range of the monitoring zone allowed for the acquired value of the heat treatment state of the workpiece. As a result, when the acquired value is out of the preventive range, it is possible to deal with before the actual occurrence of defective products, so the number of defective products can be reduced, material costs can be reduced, and work efficiency can be improved. Can be planned.

ところで、高周波加熱以外の熱処理方法（例えばずぶ焼入れによる熱処理）であれば、被処理物の温度変化が比較的緩やかであるため、被処理物ごとの熱処理条件を一定にすることが比較的容易である。一方、高周波加熱による熱処理の場合、被処理物の温度変化が急激であるため、熱処理設備の状態や周辺環境等の影響を受けやすい。このような場合、本発明のように取得値の予防域を設けることにより注意報を発することが効果的となる。   By the way, in the case of a heat treatment method other than high-frequency heating (for example, heat treatment by soaking), the temperature change of the object to be processed is relatively gradual, so that it is relatively easy to make the heat treatment conditions for each object to be processed constant. is there. On the other hand, in the case of heat treatment by high-frequency heating, the temperature change of the workpiece is abrupt, and therefore, it is easily affected by the state of the heat treatment equipment and the surrounding environment. In such a case, it is effective to issue a warning by providing a preventive range for the acquired value as in the present invention.

この監視域及び予防域の設定は、例えば被処理物のサンプルを熱処理することにより得られた取得値に基づいて行うことができる。また、予防域の幅は、例えば、各監視項目における取得値の標準偏差をσとしたとき、σ以上、３σ以下に設定することが好ましい。予防域の設定幅をσ未満とすると、設定幅が過小であるため、監視システムが取得値の誤差範囲の変化にも反応し、却って作業効率を低下させる。一方、予防域の設定幅が３σを超えると、監視域の設定幅は一般に３σ以上、４σ以下程度に設定されるため、予防域の設定幅が監視域の設定幅よりも大きくなり、予防域がその機能を果たさない恐れがある。   The setting of the monitoring area and the prevention area can be performed, for example, based on an acquired value obtained by heat-treating a sample of the object to be processed. Further, the width of the prevention zone is preferably set to σ or more and 3σ or less, for example, where σ is the standard deviation of the acquired value in each monitoring item. If the set width of the prevention area is less than σ, the set width is too small, so that the monitoring system also reacts to a change in the error range of the acquired value, thereby reducing the work efficiency. On the other hand, when the setting range of the prevention area exceeds 3σ, the setting range of the monitoring area is generally set to about 3σ or more and 4σ or less, so the setting range of the prevention area becomes larger than the setting range of the monitoring area. May not perform its function.

この熱処理方法において、被処理物の取得値の履歴を全数記録すると、予防域を外れた取得値を示した被処理物が、一時的に生じたものか、熱処理状態の時間的変化に伴って生じたものかを判断することができる。これにより、注意報が発せられたときに作業者は的確に対処することができる。   In this heat treatment method, when all the history of the acquired values of the object to be processed are recorded, the object to be processed that showed the acquired value out of the preventive range is temporarily generated or is accompanied by a temporal change in the heat treatment state. It can be judged whether it has occurred. Thereby, when the warning is issued, the worker can deal with it accurately.

また、前記取得値が予防域が外れたときに注意報を発するようにしておくと、取得値の異常を作業者に知らせることができる。このとき、熱処理を続けるか停止するかを任意に選択することができるようにしておくことが好ましい。これによると、例えば、取得値が予防域を外れた原因が一時的なもので、特に熱処理条件の設定を変更しなくても支障がないと判断すれば、熱処理を停止することなくそのまま続ければよいので、作業の停止による作業効率の低下を避けることができる。また、取得値が予防域を外れた原因が熱処理状態の時間的変化に伴うものであっても、熱処理を続けながら対応可能なものであれば、そのまま熱処理を続ければよい。一方、取得値が予防域を外れた原因が特定できない場合や、原因が熱処理状態の時間的変化に伴うものであって熱処理を停止しなければ対応できない場合は、熱処理を一旦停止して対応すればよい。   Further, if an alert is issued when the acquired value is out of the preventive range, the operator can be notified of an abnormality in the acquired value. At this time, it is preferable to be able to arbitrarily select whether to continue or stop the heat treatment. According to this, for example, if the reason why the acquired value is out of the prevention range is temporary, and it is determined that there is no problem even if the heat treatment condition setting is not changed, it is possible to continue without stopping the heat treatment. Therefore, it is possible to avoid a decrease in work efficiency due to work stoppage. Further, even if the cause that the acquired value is out of the preventive range is due to the temporal change of the heat treatment state, the heat treatment may be continued as long as it can be handled while continuing the heat treatment. On the other hand, if the reason why the acquired value is outside the preventive range cannot be identified, or if the cause is due to a temporal change in the heat treatment state and cannot be dealt with without stopping the heat treatment, stop the heat treatment and take action. That's fine.

一方、前記取得値が予防域から外れたときに、該取得値を予防域の範囲内に戻すように熱処理条件を自動的に制御するようにしておくと、作業者が対応することなく取得値を常に予防域の範囲内に収めることができる。   On the other hand, if the heat treatment conditions are automatically controlled so that the acquired value falls within the preventive range when the acquired value is out of the preventive range, the acquired value can be obtained without an operator's response. Can always be within the prevention range.

上記のような監視システムは、例えば、被処理物を高周波誘導加熱する加熱装置と、被処理物を焼入れするための冷却水を供給する冷却装置と、加熱装置及び冷却装置を制御する制御装置とを備え、被処理物に焼入れを施す高周波熱処理設備や、あるいは、被処理物を高周波誘導加熱する加熱装置と、加熱装置を制御する制御装置とを備え、被処理物に焼戻しを施す高周波熱処理設備に適用することができる。これらの高周波熱処理設備によると、不良品の発生を抑え、作業効率良く且つ低コストに焼入れ、焼戻し等の熱処理を行うことができる。   The monitoring system as described above includes, for example, a heating device that performs high-frequency induction heating of the workpiece, a cooling device that supplies cooling water for quenching the workpiece, and a control device that controls the heating device and the cooling device. A high-frequency heat treatment facility for quenching the workpiece, or a high-frequency heat treatment facility for tempering the workpiece with a heating device for induction-heating the workpiece and a control device for controlling the heating device Can be applied to. According to these high-frequency heat treatment facilities, the generation of defective products can be suppressed, and heat treatment such as quenching and tempering can be performed with good work efficiency and at low cost.

以上のように、本発明の高周波熱処理設備の監視システムによると、不良品の発生を抑え、材料コストの低減及び作業効率の向上を図ることができる。   As described above, according to the monitoring system for high-frequency heat treatment equipment of the present invention, it is possible to suppress the occurrence of defective products, reduce the material cost, and improve the work efficiency.

図１に、本発明にかかる監視システムを組み込んだ高周波熱処理設備１００を示す。この高周波熱処理設備１００は、主要な構成要素として、被処理物（ワークピースＷ）を高周波誘導加熱する加熱装置１０と、加熱したワークピースＷを冷却する冷却装置２０と、加熱装置１０及び冷却装置２０を制御する制御装置３０と、ワークピースＷの誘導加熱工程及び冷却工程を監視する監視部４０とを備える。加熱装置１０は、高周波発振機１２と、高周波発振機１２接続された加熱コイル１４を備え、冷却装置２０は、ポンプ２２と、ポンプ２２により送られた冷却水をワークピースＷへ向けて吐出する水冷ジャケット２４と、冷却水の流量を検知する流量センサ２６と、冷却水の圧力を検知する圧力センサ２８と、ワークピースＷを冷却した後の冷却水の温度を検知する温度センサ２９とを備える。また、ワークピースＷの近傍には温度測定器１８が設けられ、この温度測定器１８により熱処理時におけるワークピースＷの温度を検知する。   FIG. 1 shows a high-frequency heat treatment facility 100 incorporating a monitoring system according to the present invention. The high-frequency heat treatment equipment 100 includes, as main components, a heating device 10 that performs high-frequency induction heating of a workpiece (workpiece W), a cooling device 20 that cools the heated workpiece W, a heating device 10, and a cooling device. And a monitoring unit 40 that monitors the induction heating process and the cooling process of the workpiece W. The heating device 10 includes a high-frequency oscillator 12 and a heating coil 14 connected to the high-frequency oscillator 12, and the cooling device 20 discharges the pump 22 and the cooling water sent by the pump 22 toward the workpiece W. A water cooling jacket 24, a flow rate sensor 26 for detecting the flow rate of the cooling water, a pressure sensor 28 for detecting the pressure of the cooling water, and a temperature sensor 29 for detecting the temperature of the cooling water after cooling the workpiece W are provided. . Further, a temperature measuring device 18 is provided in the vicinity of the workpiece W, and the temperature measuring device 18 detects the temperature of the workpiece W during the heat treatment.

制御装置３０は、加熱装置１０の高周波発振機１２に接続され、高周波発振機１２から加熱コイル１４に供給される電力量、電圧、及び電流等を制御する。また、制御装置３０は、冷却装置２０にも接続され、冷却水の吐出の開始・終了、冷却水の温度、冷却水の流量、及び冷却水の圧力等を制御する。   The control device 30 is connected to the high frequency oscillator 12 of the heating device 10 and controls the amount of power, voltage, current, and the like supplied from the high frequency oscillator 12 to the heating coil 14. The control device 30 is also connected to the cooling device 20 and controls the start / end of cooling water discharge, the temperature of the cooling water, the flow rate of the cooling water, the pressure of the cooling water, and the like.

監視部４０は、加熱コイル１４と、冷却装置２０の流量センサ２６、圧力センサ２８、及び温度センサ２９とにそれぞれ接続され、所定の監視項目の取得値を記録する。この取得値をもとに、制御装置３０が上記の項目を制御する。 The monitoring unit 40 is connected to the heating coil 14 and the flow rate sensor 26, the pressure sensor 28, and the temperature sensor 29 of the cooling device 20, respectively, and records the acquired value of a predetermined monitoring item. Based on this acquired value, the control device 30 controls the above items.

図２に、熱処理設備１００のワークピースＷ周辺の詳細を示す。本実施形態では、ワークピースＷとして自動車用シャフト部品を熱処理する場合を示す。加熱コイル１４及び水冷ジャケット２４は、ワークピースＷを加熱・冷却可能な位置に配され、且つ、ワークピースＷに対して軸方向で相対移動可能に設けられる。図２に示す例では、２個の加熱コイル１４と１個の水冷ジャケット２４とをワークピースＷの軸方向に並べてユニットＵを構成し、２組のユニットＵがワークピースＷを挟んだ両側に、互いに対向して配されている。ワークピースＷは、その両端部をセンターピン１７で回転可能に支持されている。尚、本実施形態ではワークピースＷが自動車用シャフト部品である場合を示しているが、これに限らず、他の形状や用途の金属部品であっても良い。   FIG. 2 shows details of the periphery of the workpiece W of the heat treatment facility 100. In this embodiment, the case where the automotive shaft component is heat-treated as the workpiece W is shown. The heating coil 14 and the water cooling jacket 24 are disposed at a position where the workpiece W can be heated and cooled, and are provided so as to be movable relative to the workpiece W in the axial direction. In the example shown in FIG. 2, two heating coils 14 and one water cooling jacket 24 are arranged in the axial direction of the workpiece W to form a unit U, and two sets of units U are arranged on both sides of the workpiece W. Are arranged opposite to each other. Both ends of the workpiece W are rotatably supported by center pins 17. In addition, although the case where the workpiece W is a shaft part for automobiles is shown in the present embodiment, the present invention is not limited thereto, and may be a metal part having another shape or application.

次に、上記の熱処理設備１００による熱処理工程を説明する。この熱処理工程では、ワークピースＷをセンターピン１７、１７を中心に回転させた状態で、ユニットＵ（加熱コイル１４及び水冷ジャケット２４）をワークピースＷの軸方向一方（図２の上方）へ向けて平行移動させながら行う。このとき、高周波発振機１２から加熱コイル１４に高周波電力を供給して磁場を発生させ、この磁場によりワークピースＷを誘導加熱する（誘導加熱工程）。このように、高周波誘導加熱でワークピースＷを加熱することで、ワークピースＷのうち高硬度が必要な部分のみに局部的な加熱が可能となる。また、ワークピースＷを回転させながら上記の誘導加熱を行うことにより、ワークピースＷの表層部分を均一に加熱することができる。 Next, the heat treatment process by the heat treatment equipment 100 will be described. In this heat treatment step, the unit U (the heating coil 14 and the water cooling jacket 24) is directed to one side in the axial direction of the workpiece W (upward in FIG. 2) while the workpiece W is rotated around the center pins 17 and 17. And move it in parallel. At this time, high frequency power is supplied from the high frequency oscillator 12 to the heating coil 14 to generate a magnetic field, and the workpiece W is induction heated by this magnetic field (induction heating step). In this way, by heating the workpiece W by high-frequency induction heating, local heating can be performed only on a portion of the workpiece W that requires high hardness. Further, by performing the induction heating while rotating the workpiece W, the surface layer portion of the workpiece W can be uniformly heated.

この誘導加熱工程に続いて、冷却装置２０より供給された冷却水を水冷ジャケット２４からワークピースＷへ吐出することにより、ワークピースＷの加熱部分が順次冷却される（冷却工程）。この冷却水は、ワークピースＷを冷却した後、冷却水戻り流路２７を介して冷却装置２０に戻される。   Subsequent to the induction heating process, the cooling water supplied from the cooling device 20 is discharged from the water cooling jacket 24 to the workpiece W, whereby the heated portion of the workpiece W is sequentially cooled (cooling process). After cooling the workpiece W, the cooling water is returned to the cooling device 20 via the cooling water return channel 27.

以上のように、本実施形態では、誘導加熱工程及び冷却工程が同一設備内において連続的に行われる。尚、自動車用のシャフト部品として用いられるワークピースＷは、図２に示すように軸方向でその外周形状が異なるため、場所によって加熱条件（例えば加熱コイル１４への投入電力量等）や冷却条件（例えば冷却水の流量等）を異ならせて設定される。 As described above, in this embodiment, the induction heating process and the cooling process are continuously performed in the same facility. In addition, since the outer peripheral shape of the workpiece W used as a shaft part for an automobile is different in the axial direction as shown in FIG. (For example, the flow rate of cooling water, etc.) is set differently.

以上の誘導加熱工程及び冷却工程を経て、ワークピースＷの熱処理が完了する。   The heat treatment of the workpiece W is completed through the induction heating process and the cooling process.

この高周波熱処理設備１００によるワークピースＷの熱処理状態は、本発明にかかる監視システムで監視される。この監視システムは、上記の誘導加熱工程及び冷却工程における所定の監視項目について、監視部４０が取得したワークピースＷの熱処理状態の取得値が、予め設定された予防域の範囲を外れたら注意報を発し（図３参照）、監視域を外れたら警報を発するものである。   The heat treatment state of the workpiece W by the high frequency heat treatment equipment 100 is monitored by the monitoring system according to the present invention. This monitoring system provides a warning when the acquired value of the heat treatment state of the workpiece W acquired by the monitoring unit 40 is out of the preset preventive range for the predetermined monitoring items in the induction heating process and the cooling process. (See FIG. 3), and an alarm is issued when the monitoring area is not met.

以下、この監視システムについて詳しく説明する。   Hereinafter, this monitoring system will be described in detail.

まず、ワークピースＷの熱処理条件の設定方法を、図４のブロック図を用いて以下に説明する。はじめに、ワークピースＷの熱処理に先立って、サンプルの熱処理加工を行う。サンプルの加熱工程（ブロック５１）において、高周波発振機から加熱コイル１４に供給される電力および周波数、電力を投入している時間、サンプルの位置、回転数、加熱コイル１４（ユニットＵ）の相対移動速度、及びワークピースＷの加熱温度等の初期値を適宜設定（ブロック５２）する。尚、ワークピースＷの外周形状は軸方向で異なるため、熱処理温度も加熱場所によって異なる。従って、加熱コイル１４に供給される電力は、加熱場所に応じた値に設定される。一方、サンプルの冷却工程（ブロック５３）において、冷却水の吐出の開始・終了、冷却水の温度、流量、圧力、ワークピースＷの冷却温度等の初期値を適宜設定（ブロック５４）する。加熱工程（ブロック５１）で加熱されたサンプルは、冷却工程（ブロック５３）で冷却され、焼入れされる。焼入れされた部品は破壊検査により硬さ、焼入れ位置、焼入れ金属組織などを調査して、要求される熱処理品質を満足しているか確認する（ブロック５５）。満足していない場合は、加熱工程、冷却工程の各設定値（ブロック５２，５４）を調整して上記手順を繰り返して行い、要求される熱処理品質を満足したときの条件で、熱処理条件を決定する（ブロック５６）。   First, a method for setting the heat treatment conditions for the workpiece W will be described below with reference to the block diagram of FIG. First, prior to the heat treatment of the workpiece W, the sample is heat-treated. In the sample heating step (block 51), the power and frequency supplied from the high frequency oscillator to the heating coil 14, the time during which the power is applied, the position of the sample, the number of rotations, and the relative movement of the heating coil 14 (unit U) Initial values such as the speed and the heating temperature of the workpiece W are appropriately set (block 52). In addition, since the outer peripheral shape of the workpiece W differs in the axial direction, the heat treatment temperature also varies depending on the heating location. Therefore, the electric power supplied to the heating coil 14 is set to a value corresponding to the heating place. On the other hand, in the sample cooling step (block 53), initial values such as start / end of cooling water discharge, cooling water temperature, flow rate, pressure, and cooling temperature of the workpiece W are appropriately set (block 54). The sample heated in the heating step (block 51) is cooled and quenched in the cooling step (block 53). The hardened part is inspected for hardness, quenching position, quenching metallographic structure, and the like by destructive inspection to confirm whether the required heat treatment quality is satisfied (block 55). If not satisfied, adjust each setting value (blocks 52 and 54) of the heating process and cooling process and repeat the above procedure to determine the heat treatment conditions with the conditions when the required heat treatment quality is satisfied (Block 56).

次に、以上の工程で決定した熱処理条件で所定個数のサンプルを加工し（ブロック５７）、熱処理状態に関する監視項目の取得値を記録（ブロック５８）し、取得値の標準偏差σを算出する（ブロック５９）。この標準偏差σに基づいて、各熱処理条件に許容される上限値及び下限値からなる監視域を設定し、さらに、この監視域の範囲内に予防上限値及び予防下限値からなる予防域を設定する（以上、ブロック６０）。監視域は、設定幅が３σ以上、４σ以下となるように設定され、予防域は、設定幅がσ以上、３σ以下となるように設定される。 Next, a predetermined number of samples are processed under the heat treatment conditions determined in the above steps (block 57), the acquired value of the monitoring item regarding the heat treatment state is recorded (block 58), and the standard deviation σ of the acquired value is calculated (block 58). Block 59). Based on this standard deviation σ, a monitoring area consisting of an upper limit value and a lower limit value allowed for each heat treatment condition is set, and further, a prevention area consisting of a prevention upper limit value and a prevention lower limit value is set within the range of this monitoring area. (Block 60). The monitoring area is set so that the setting width is 3σ or more and 4σ or less, and the prevention area is set so that the setting width is σ or more and 3σ or less.

こうして熱処理条件を決定し、監視項目の監視域ならびに予防域を設定した後、図５のブロック図で示すワークピースＷの熱処理、すなわちワークピースＷの誘導加熱工程（ブロック７１）及び冷却工程（ブロック７４）が行われる。これらの工程における所定の監視項目の取得値を、監視部４０により記録する。本実施形態では、高周波発振機から加熱コイル１４に供給される電力及び周波数、加熱コイル１４に電力を投入している加熱時間、熱処理中のワークピースＷの位置及び回転数（これらの項目を加熱パラメータと称する）に関する取得値を、監視部４０により全数記録している。   After determining the heat treatment conditions and setting the monitoring area and the prevention area of the monitoring items, the heat treatment of the workpiece W shown in the block diagram of FIG. 5, that is, the induction heating process (block 71) and the cooling process (block) of the workpiece W 74) is performed. The monitoring unit 40 records acquired values of predetermined monitoring items in these processes. In the present embodiment, the power and frequency supplied to the heating coil 14 from the high frequency oscillator, the heating time during which power is supplied to the heating coil 14, the position and the rotational speed of the workpiece W during the heat treatment (these items are heated) All the acquired values relating to the parameters are recorded by the monitoring unit 40.

この誘導加熱工程（ブロック７１）において、ワークピースＷの熱処理状態の取得値が予防域の範囲から外れたとき、すなわち、取得値が予防上限値を超えるか、あるいは予防下限値を下回ったとき、注意報が発せられる（ブロック７２、図３参照）。この注意報が発せられたときでも、熱処理の作業は中断せずに次の工程に進み、このワークピースＷの熱処理が完了した時点で、作業者は続けて次のワークピースの熱処理を行うか、待機状態とするかを選択する。本実施形態では、上記のように監視項目ごとの取得値を全数記録しているため、その取得値と履歴データとを比較評価することにより、予防域を超えたワークピースが一時的に生じたものであるか、熱処理状態の時間変化により生じたものかを判断することができる。従って、作業者は取得値の履歴を調べて注意報が一時的なものであるか否かを判断し、一時的に生じたものであれば続けて作業を行えばよい。一時的なものでなければ、熱処理状態の時間変化により生じた可能性があるため、必要に応じて作業を待機状態とし、設備やワークピースＷの状態を点検して取得値が予防域を超えた要因を特定し、その要因を除去すべく対応する。このように、取得値の監視域の範囲内に予防域を設定しておくことにより、実際に不良品が発生する前に対応することができるため、不良品の発生が確実に防止され、材料及び作業時間の無駄を省くことができる。 In this induction heating step (block 71), when the acquired value of the heat treatment state of the workpiece W is out of the preventive range, that is, when the acquired value exceeds the preventive upper limit value or falls below the preventive lower limit value, A warning is issued (see block 72, FIG. 3). Even when this warning is issued, the heat treatment operation is not interrupted, and the process proceeds to the next step. When the heat treatment of the workpiece W is completed, the worker continues to heat the next workpiece. Select whether to enter standby mode. In this embodiment, since all the acquired values for each monitoring item are recorded as described above, a workpiece exceeding the preventive range is temporarily generated by comparing and evaluating the acquired values and the history data. It is possible to determine whether the heat treatment is caused by a change in the heat treatment state over time. Therefore, the operator can check the history of the acquired value to determine whether the warning is temporary or not, and if it occurs temporarily, the worker can continue to work. If it is not temporary, it may have occurred due to time changes in the heat treatment state. Therefore, if necessary, put the work in a standby state, check the state of the equipment and workpiece W, and the acquired value exceeds the preventive range. Identify the factors and take action to eliminate them. In this way, by setting the prevention range within the monitoring range of the acquired value, it is possible to respond before the actual occurrence of defective products, so the occurrence of defective products is reliably prevented and the material In addition, waste of work time can be saved.

一方、ワークピースＷの熱処理状態の取得値が監視域の範囲から外れたとき、すなわち、取得値が上限値を超えるか、あるいは下限値を下回ったとき、警報が発せられ（ブロック７３）、その時点で熱処理が終了する（ブロック７７）。このように、各監視項目における取得値が監視域の範囲外となり、不良品が発生したとみなされた場合に作業を中断することで、無駄な作業を省略できると共に、不良品を確実に排除することができる。この警報による作業の中断は、監視部４０と制御装置３０とを接続しておき、警報と同時に制御装置３０が高周波発振機１２による電力の供給を自動的にストップするような制御システムを設けても良い。 On the other hand, when the acquired value of the heat treatment state of the workpiece W is out of the range of the monitoring area, that is, when the acquired value exceeds the upper limit value or falls below the lower limit value, an alarm is issued (block 73). At that point, the heat treatment ends (block 77). In this way, if the acquired value for each monitoring item falls outside the range of the monitoring area, and it is deemed that a defective product has occurred, it is possible to eliminate unnecessary work and to reliably eliminate defective products by interrupting the operation. can do. For the interruption of the work due to the alarm, a monitoring system 40 and the control device 30 are connected, and a control system is provided so that the control device 30 automatically stops the power supply by the high-frequency oscillator 12 simultaneously with the alarm. Also good.

誘導加熱工程に続いて、冷却装置２０から水冷ジャケット２４を介してワークピースＷに冷却水が吐出され、ワークピースＷが急速冷却される（冷却工程）。この冷却工程においても、上記の誘導加熱工程と同様に、加工中の状態を監視する（ブロック７４）。本実施形態では、監視項目として、例えば冷却水の流量・温度・圧力、及び冷却時間、すなわち冷却水の吐出開始時点及び終了時点を監視し、これらの項目を冷却パラメータと称する。この冷却パラメータに関するワークピースＷの熱処理状態の取得値の履歴が、監視部４０により全数記録されている。   Following the induction heating process, cooling water is discharged from the cooling device 20 to the workpiece W via the water cooling jacket 24, and the workpiece W is rapidly cooled (cooling process). Also in this cooling step, the state during processing is monitored (block 74) as in the induction heating step. In this embodiment, as monitoring items, for example, the flow rate / temperature / pressure of cooling water and the cooling time, that is, the cooling water discharge start time and end time are monitored, and these items are referred to as cooling parameters. The history of the acquired values of the heat treatment state of the workpiece W relating to this cooling parameter is recorded in full by the monitoring unit 40.

この冷却工程においても、上記の誘導加熱工程と同様に、ワークピースＷの熱処理状態の取得値が予防域の範囲から外れたとき、注意報が発せられる（ブロック７５）。この注意報が発せられたときでも、熱処理の作業は中断せずに最後まで行われ、熱処理工程が終了する（ブロック７７）。一方、ワークピースＷの熱処理状態の取得値が監視域の範囲から外れたとき、警報が発せられ（ブロック７６）、その時点で熱処理が終了する（ブロック７７）。 Also in this cooling step, a warning is issued when the acquired value of the heat treatment state of the workpiece W is out of the range of the preventive zone, as in the induction heating step (block 75). Even when this warning is issued, the heat treatment operation is completed without interruption, and the heat treatment step is completed (block 77). On the other hand, when the acquired value of the heat treatment state of the workpiece W is out of the range of the monitoring area, an alarm is issued (block 76), and the heat treatment is terminated at that point (block 77).

以上で示したように、本発明の監視システムでは、ワークピースＷが不良品と判定される監視域の範囲内にさらに予防域を設定し、取得値が予防域を外れたときに注意報を発する。これにより、実際に不良品が発生する前に制御装置３０の設定の変更等の対処をすることが可能となるため、不良品の発生を未然に防止し、材料コストの低減および作業効率の向上が図られる。   As described above, in the monitoring system of the present invention, a prevention area is further set within the monitoring area where the workpiece W is determined to be defective, and a warning is issued when the acquired value is outside the prevention area. To emit. As a result, it is possible to take measures such as changing the setting of the control device 30 before a defective product actually occurs, thus preventing the occurrence of a defective product, reducing the material cost and improving the work efficiency. Is planned.

本発明は以上の実施形態に限られない。例えば、監視部４０による監視項目は、上記で示した加熱パラメータ及び冷却パラメータに限らず、熱処理の量産に伴って変動し得るその他の項目であってもよい。 The present invention is not limited to the above embodiment. For example, the monitoring items by the monitoring unit 40 are not limited to the heating parameters and cooling parameters described above, but may be other items that may vary with mass production of heat treatment.

また、上記の実施形態では、取得値が予防域を外れたときに注意報を発しているが、これに限らず、取得値が予防域を外れたとき、熱処理条件（加熱パラメータ、冷却パラメータ）を自動的に制御して取得値を予防域の範囲内に戻すような制御システムを設けても良い。これによると、自動的に不良品の発生を予防することができ、生産効率の向上及び製造コストの低減を図ることができる。 Further, in the above embodiment, a warning is issued when the acquired value is out of the preventive range, but not limited to this, when the acquired value is out of the preventive range, the heat treatment conditions (heating parameter, cooling parameter) A control system may be provided that automatically controls the value to return the acquired value within the range of the prevention range. According to this, generation | occurrence | production of inferior goods can be prevented automatically, and improvement of production efficiency and reduction of manufacturing cost can be aimed at.

また、上記の実施形態では、ワークピースＷに焼入れを施す熱処理設備に本発明の監視システムを適用した場合を示したが、これに限らず、例えば、ワークピースＷに焼戻しを施す熱処理設備に本発明の監視システムを適用してもよい。この場合、図６に示すように、ワークピースＷを挟んだ両側に焼戻し用コイル８０が設けられ、ワークピースＷをセンターピン１７を中心に回転させながら、ワークピースＷの全長に亘って焼戻しが施される。このような焼戻し用の熱処理設備においても、上記と同様に、ワークピースＷが不良品と判定される監視域の範囲内にさらに予防域を設定することにより、不良品の発生を未然に防止することができる。 In the above embodiment, the case where the monitoring system of the present invention is applied to the heat treatment equipment for quenching the workpiece W has been shown. However, the present invention is not limited to this, and for example, the heat treatment equipment for tempering the workpiece W is used. The monitoring system of the invention may be applied. In this case, as shown in FIG. 6, tempering coils 80 are provided on both sides of the workpiece W, and tempering is performed over the entire length of the workpiece W while rotating the workpiece W around the center pin 17. Applied. In such a tempering heat treatment facility, similarly to the above, by setting a preventive zone within the range of the monitoring zone where the workpiece W is determined to be defective, the occurrence of defective products can be prevented. be able to.

高周波熱処理設備を概略的に示す平面図である。It is a top view which shows a high frequency heat processing equipment roughly. 高周波熱処理設備におけるワークピースの周辺を拡大した平面図である。It is the top view to which the periphery of the workpiece in a high frequency heat treatment equipment was expanded. 本発明の監視システムにおける監視域及び予防域を説明するグラフである。It is a graph explaining the monitoring zone and prevention zone in the monitoring system of the present invention. 熱処理条件の設定方法を示すブロック図である。It is a block diagram which shows the setting method of heat processing conditions. 高周波熱処理設備の熱処理工程を示すブロック図である。It is a block diagram which shows the heat processing process of a high frequency heat processing equipment. 他の例の高周波熱処理設備のワークピース周辺を拡大した平面図である。It is the top view to which the workpiece periphery of the high frequency heat treatment equipment of another example was expanded. 従来の監視システムにおける被処理品の良否判定を説明するグラフである。It is a graph explaining the quality determination of the to-be-processed goods in the conventional monitoring system.

符号の説明Explanation of symbols

１０ 加熱装置
１２ 高周波発振機
１４ 加熱コイル
１７ センターピン
１８ 温度測定器
２０ 冷却装置
２２ ポンプ
２４ 水冷ジャケット
２６ 流量センサ
２７ 流路
２８ 圧力センサ
２９ 温度センサ
３０ 制御装置
４０ 監視部
１００ 高周波熱処理設備
Ｗ ワークピース DESCRIPTION OF SYMBOLS 10 Heating device 12 High frequency oscillator 14 Heating coil 17 Center pin 18 Temperature measuring device 20 Cooling device 22 Pump 24 Water cooling jacket 26 Flow rate sensor 27 Flow path 28 Pressure sensor 29 Temperature sensor 30 Control device 40 Monitoring unit 100 High frequency heat treatment equipment W Workpiece

Claims (10)

高周波熱処理設備において被処理物の熱処理状態を監視する監視システムであって、
被処理物の熱処理状態に関する監視項目の取得値を記録する監視部に、前記取得値に許容される上限値及び下限値からなる監視域を設定すると共に、監視域の範囲内に予防上限値及び予防下限値からなる予防域を設定したことを特徴とする高周波熱処理設備の監視システム。 A monitoring system for monitoring a heat treatment state of an object to be processed in a high frequency heat treatment facility,
In the monitoring unit that records the acquired value of the monitoring item related to the heat treatment state of the workpiece, a monitoring area consisting of an upper limit value and a lower limit value allowed for the acquired value is set, and a preventive upper limit value and A monitoring system for high-frequency heat treatment equipment, characterized in that a preventive area consisting of a preventive lower limit is set. 前記監視域及び予防域が、被処理物のサンプルを熱処理することにより得られた取得値に基づいて設定された請求項１記載の高周波熱処理設備の監視システム。   The monitoring system for a high-frequency heat treatment facility according to claim 1, wherein the monitoring area and the prevention area are set based on an acquired value obtained by heat-treating a sample of the object to be processed. 被処理物のサンプルの取得値の標準偏差をσとしたとき、前記予防域の設定幅をσ以上、３σ以下の範囲内に設定した請求項２記載の高周波熱処理設備の監視システム。   The high frequency heat treatment equipment monitoring system according to claim 2, wherein when the standard deviation of the acquired value of the sample of the object to be processed is σ, the setting range of the prevention area is set within a range of σ to 3σ. 被処理物の熱処理状態の取得値の履歴を全数記録した請求項１記載の高周波熱処理設備の監視システム。   The monitoring system for high-frequency heat treatment equipment according to claim 1, wherein the history of the acquired values of the heat treatment state of the workpiece is all recorded. 前記取得値が予防域から外れたときに注意報を発する請求項１記載の高周波熱処理設備の監視システム。   The high frequency heat treatment equipment monitoring system according to claim 1, wherein a warning is issued when the acquired value is out of the preventive range. 注意報が発せられたとき、熱処理を続けるか停止するかを任意に選択することができる請求項５記載の高周波熱処理設備の監視システム。   6. The high frequency heat treatment equipment monitoring system according to claim 5, wherein when the warning is issued, the heat treatment can be arbitrarily selected to be continued or stopped. 前記取得値が予防域から外れたときに、該取得値を予防域の範囲内に戻すように熱処理条件を自動的に制御する請求項１記載の高周波熱処理設備の監視システム。   The monitoring system for high-frequency heat treatment equipment according to claim 1, wherein when the acquired value is out of the preventive range, the heat treatment condition is automatically controlled so that the acquired value is returned to the range of the preventive range. 自動車用シャフト部品に熱処理を施す高周波熱処理設備に組み込まれた請求項１〜７の何れかに記載の高周波熱処理設備の監視システム。   The monitoring system for a high-frequency heat treatment facility according to any one of claims 1 to 7, which is incorporated in a high-frequency heat treatment facility for performing heat treatment on an automobile shaft part. 請求項１〜８の何れかに記載の監視システムと、被処理物を高周波誘導加熱する加熱装置と、被処理物を冷却するための冷却水を供給する冷却装置と、加熱装置及び冷却装置を制御する制御装置とを備え、被処理物に焼入れを施す高周波熱処理設備。   A monitoring system according to any one of claims 1 to 8, a heating device for high-frequency induction heating of a workpiece, a cooling device for supplying cooling water for cooling the workpiece, a heating device and a cooling device. Induction heat treatment equipment that includes a control device for controlling and quenches the workpiece. 請求項１〜８の何れかに記載の監視システムと、被処理物を高周波誘導加熱する加熱装置と、加熱装置を制御する制御装置とを備え、被処理物に焼戻しを施す高周波熱処理設備。   A high-frequency heat treatment facility that includes the monitoring system according to any one of claims 1 to 8, a heating device that performs high-frequency induction heating of a workpiece, and a control device that controls the heating device, and tempering the workpiece.
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JP2012136740A (en) * 2010-12-27 2012-07-19 Neturen Co Ltd Induction hardening device and induction hardening method
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Publication number Priority date Publication date Assignee Title
JP2012031464A (en) * 2010-07-29 2012-02-16 Fuji Electronics Industry Co Ltd Cooling liquid supply confirmation device and cooling liquid supply confirmation method of induction heating device
JP2012136740A (en) * 2010-12-27 2012-07-19 Neturen Co Ltd Induction hardening device and induction hardening method
JP2014185787A (en) * 2013-03-22 2014-10-02 Toyota Motor Corp In-furnace treatment product quality management method and in-furnace treatment device
JP2014224298A (en) * 2013-05-17 2014-12-04 富士電子工業株式会社 Movement hardening apparatus and movement hardening method for long work
CN105586475A (en) * 2014-11-11 2016-05-18 高周波热錬株式会社 Quenching device and quenching method
JP2016089262A (en) * 2014-11-11 2016-05-23 高周波熱錬株式会社 Hardening device and hardening method
WO2017090796A1 (en) * 2015-11-26 2017-06-01 박종규 Apparatus for high-frequency heat treatment of stub shafts, having eddy-current-testing total inspection function
JP7354591B2 (en) 2019-05-29 2023-10-03 マツダ株式会社 Induction hardening method and induction hardening equipment
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