JP6997535B2

JP6997535B2 - Heater control mechanism, heat treatment device and heater control method

Info

Publication number: JP6997535B2
Application number: JP2017090554A
Authority: JP
Inventors: 大樹柴田; 昭浩永石
Original assignee: Dowa Thermotech Co Ltd
Current assignee: Dowa Thermotech Co Ltd
Priority date: 2017-04-28
Filing date: 2017-04-28
Publication date: 2022-01-17
Anticipated expiration: 2037-04-28
Also published as: JP2018190555A

Description

本発明はヒータの動作を制御するヒータ制御機構と、そのヒータ制御機構を備えた熱処理装置、およびヒータ制御方法に関する。 The present invention relates to a heater control mechanism for controlling the operation of a heater, a heat treatment device provided with the heater control mechanism, and a heater control method.

自動車部品やその他の機械部品等のワークの熱処理装置には、処理室内を加熱するためのヒータが設けられており、処理室が所定の温度になるように各ヒータの動作が制御されている。従来のヒータの制御機構として、特許文献１には制御部の制御命令により昇温室や浸炭室等の処理室ごとの温度を個別に調節できるようにヒータの出力（発熱量）を制御することが開示されている。また、特許文献２には、電源、温調計と協働するサイリスタ、トランス（変圧器）を用いたヒータ制御機構が開示されている。特許文献２のヒータ制御機構は、ヒータの温度が所定の温度に達するまで回路を導通状態とし、ヒータの温度が所定の温度に達すると、導通状態が解除されるように構成されている。 The heat treatment apparatus for workpieces such as automobile parts and other machine parts is provided with heaters for heating the processing chamber, and the operation of each heater is controlled so that the processing chamber reaches a predetermined temperature. As a conventional heater control mechanism, Patent Document 1 describes that the output (calorific value) of a heater can be controlled so that the temperature of each processing chamber such as a heating chamber or a carburizing chamber can be individually adjusted by a control command of a control unit. It has been disclosed. Further, Patent Document 2 discloses a heater control mechanism using a power source, a thyristor that cooperates with a temperature controller, and a transformer (transformer). The heater control mechanism of Patent Document 2 is configured to keep the circuit in a conductive state until the temperature of the heater reaches a predetermined temperature, and to release the conductive state when the temperature of the heater reaches a predetermined temperature.

特開２００９－９１６３８号公報Japanese Unexamined Patent Publication No. 2009-91638 特開２００８－８１７８１号公報Japanese Unexamined Patent Publication No. 2008-81781

同一仕様の製品の熱処理を行う際には、ワークの熱処理後の品質ばらつきを抑えることが望ましい。このため、熱処理品質のばらつきを抑えるために処理室内の温度ばらつきを抑制してワークの温度をより均一にすることが求められる。しかし、従来の熱処理装置においては、処理室外部の環境温度の変動や、放熱部材とヒータとの距離の違いにより処理室内のホットゾーンで温度ばらつきが生じる場合があった。この温度ばらつきを解消するためにヒータの配置や仕様を変更することも考えられるが、一度、築炉した後にヒータの配置や仕様を変更することはヒータの付け替えといった非常に煩雑な作業を伴うことになり、その作業のために熱処理装置の運転を停止することが必要となる。したがって、処理室内の温度ばらつきを抑制するためには、ヒータの付け替えではなく、既設のヒータの温度制御を行うことで対応することが望まれる。 When heat-treating products with the same specifications, it is desirable to suppress quality variations after heat treatment of the workpiece. Therefore, in order to suppress the variation in heat treatment quality, it is required to suppress the temperature variation in the processing chamber to make the temperature of the work more uniform. However, in the conventional heat treatment apparatus, the temperature may vary in the hot zone of the processing chamber due to the fluctuation of the environmental temperature outside the processing chamber and the difference in the distance between the heat radiating member and the heater. It is conceivable to change the heater arrangement and specifications in order to eliminate this temperature variation, but changing the heater arrangement and specifications once the furnace is built involves extremely complicated work such as replacing the heater. Therefore, it is necessary to stop the operation of the heat treatment apparatus for the work. Therefore, in order to suppress the temperature variation in the processing chamber, it is desirable to control the temperature of the existing heater instead of replacing the heater.

しかしながら、従来のヒータ制御機構においては、処理室内の温度分布に応じて複数のヒータのうちの一部のヒータについてのみ温度を変更する場合、温度を変更するヒータごとに容量の異なるトランスを設けたり、トランスへの投入電圧を変えるためのサイリスタを用いる必要があった。図１は、処理室２１内に設けられた同出力の４つのヒータ２ａ～２ｄのうち、２つのヒータ２ａ、２ｂの出力を変更して発熱温度を調節する場合を示す例であるが、従来のヒータ制御機構５０では、温度を変更する２つのヒータ２ａ、２ｂと残りの２つのヒータ２ｃ、２ｄで、それぞれ異なるトランス３とサイリスタ５１を使用する必要があった。このようなヒータ制御機構は、構造が複雑になると共に、高価なサイリスタの使用により熱処理装置のコスト増加を招いてしまう。したがって、より簡易な構造のヒータ制御機構で温度ばらつきを改善することが求められる。 However, in the conventional heater control mechanism, when the temperature of only a part of the plurality of heaters is changed according to the temperature distribution in the processing chamber, a transformer having a different capacity may be provided for each heater that changes the temperature. , It was necessary to use a thyristor to change the input voltage to the transformer. FIG. 1 is an example showing a case where the heat generation temperature is adjusted by changing the outputs of the two heaters 2a and 2b among the four heaters 2a to 2d having the same output provided in the processing chamber 21. In the heater control mechanism 50 of the above, it was necessary to use different transformers 3 and thyristors 51 for the two heaters 2a and 2b for changing the temperature and the remaining two heaters 2c and 2d, respectively. Such a heater control mechanism has a complicated structure and increases the cost of the heat treatment apparatus due to the use of an expensive thyristor. Therefore, it is required to improve the temperature variation with a heater control mechanism having a simpler structure.

本発明は、上記事情に鑑みてなされたものであり、簡易な構造のヒータ制御機構で処理室内の温度ばらつきを改善することを目的とする。 The present invention has been made in view of the above circumstances, and an object of the present invention is to improve temperature variation in a processing chamber by a heater control mechanism having a simple structure.

上記課題を解決する本発明は、ワークの熱処理を行う熱処理装置に設けられた複数のヒータの動作を制御するヒータ制御機構であって、全てのヒータのＯＮとＯＦＦを切り替える第１スイッチと、前記複数のヒータのうち、一部のヒータのＯＮとＯＦＦを切り替える第２スイッチと、前記ワークが収容される処理室内の温度情報に基づいて前記第１スイッチおよび前記第２スイッチにＯＮとＯＦＦを切り替える動作指示を与えるように構成された制御部とを備え、前記制御部は、さらに前記ワークが収容される処理室内の温度情報に基づいて前記ヒータの作動時間を算出し、算出された作動時間に基づくＯＮとＯＦＦを切り替える動作指示を、前記第１スイッチおよび前記第２スイッチのうち、少なくとも前記第２スイッチに与えるように構成され、前記第１スイッチと前記第２スイッチとがトランスを介して電気的に接続されるように構成されていることを特徴としている。
また、別の観点による本発明は、ワークの熱処理を行う熱処理装置に設けられた複数のヒータの動作を制御する、サイリスタが設けられていないヒータ制御機構であって、全てのヒータのＯＮとＯＦＦを切り替える第１スイッチと、前記複数のヒータのうち、一部のヒータのＯＮとＯＦＦを切り替える第２スイッチと、前記ワークが収容される処理室内の温度情報に基づいて前記第１スイッチおよび前記第２スイッチにＯＮとＯＦＦを切り替える動作指示を与えるように構成された制御部とを備え、前記制御部は、さらに前記ワークが収容される処理室内の温度情報に基づいて前記ヒータの作動時間を算出し、算出された作動時間に基づくＯＮとＯＦＦを切り替える動作指示を、前記第１スイッチおよび前記第２スイッチのうち、少なくとも前記第２スイッチに与えるように構成されていることを特徴としている。 The present invention that solves the above problems is a heater control mechanism that controls the operation of a plurality of heaters provided in a heat treatment apparatus that heats a work, and includes a first switch that switches ON and OFF of all heaters, and the above-mentioned. Of the plurality of heaters, the second switch that switches ON and OFF of some of the heaters, and the first switch and the second switch that switch ON and OFF based on the temperature information in the processing chamber in which the work is housed. A control unit configured to give an operation instruction is provided, and the control unit further calculates the operation time of the heater based on the temperature information in the processing chamber in which the work is housed, and sets the calculated operation time to the calculated operation time. It is configured to give an operation instruction for switching ON and OFF based on at least the second switch among the first switch and the second switch, and the first switch and the second switch are electrically connected via a transformer. It is characterized in that it is configured to be connected to each other.
Further, the present invention from another viewpoint is a heater control mechanism without a cyclist that controls the operation of a plurality of heaters provided in a heat treatment apparatus for heat-treating a work, and all heaters are turned on and off. A first switch for switching between, a second switch for switching ON and OFF of some of the plurality of heaters, and the first switch and the first switch based on temperature information in a processing chamber in which the work is housed. The two switches are provided with a control unit configured to give an operation instruction to switch between ON and OFF, and the control unit further calculates the operating time of the heater based on the temperature information in the processing chamber in which the work is housed. It is characterized in that an operation instruction for switching ON and OFF based on the calculated operation time is given to at least the second switch among the first switch and the second switch.

別の観点による本発明は、ワークの熱処理を行う熱処理装置であって、上記ヒータ制御機構を備えていることを特徴としている。 The present invention from another viewpoint is a heat treatment apparatus for heat-treating a work, and is characterized by including the heater control mechanism.

また、別の観点による本発明は、ワークの熱処理を行う熱処理装置に設けられた複数のヒータの動作を制御するヒータ制御方法であって、全てのヒータのＯＮとＯＦＦを切り替える第１スイッチと、前記複数のヒータのうち、一部のヒータのＯＮとＯＦＦを切り替える第２スイッチと、前記ワークが収容される処理室内の温度情報に基づいて前記第１スイッチおよび前記第２スイッチにＯＮとＯＦＦを切り替える動作指示を与えるように構成された制御部とを備え、前記第１スイッチと前記第２スイッチとがトランスを介して電気的に接続されるように構成されたヒータ制御機構を用い、前記制御部で、前記ワークが収容される処理室内の温度情報に基づいて前記ヒータの作動時間を算出し、算出された作動時間に基づく前記制御部からの動作指示により、前記第１スイッチおよび前記第２スイッチのうち、少なくとも前記第２スイッチのＯＮとＯＦＦを切り替えることを特徴としている。
また、別の観点による本発明は、ワークの熱処理を行う熱処理装置に設けられた複数のヒータの動作を制御するヒータ制御方法であって、全てのヒータのＯＮとＯＦＦを切り替える第１スイッチと、前記複数のヒータのうち、一部のヒータのＯＮとＯＦＦを切り替える第２スイッチと、前記ワークが収容される処理室内の温度情報に基づいて前記第１スイッチおよび前記第２スイッチにＯＮとＯＦＦを切り替える動作指示を与えるように構成された制御部とを備えた、サイリスタが設けられていないヒータ制御機構を用い、前記制御部で、前記ワークが収容される処理室内の温度情報に基づいて前記ヒータの作動時間を算出し、算出された作動時間に基づく前記制御部からの動作指示により、前記第１スイッチおよび前記第２スイッチのうち、少なくとも前記第２スイッチのＯＮとＯＦＦを切り替えることを特徴としている。 Further, the present invention from another viewpoint is a heater control method for controlling the operation of a plurality of heaters provided in a heat treatment apparatus for heat-treating a work, and includes a first switch for switching ON and OFF of all heaters. Of the plurality of heaters, the second switch for switching ON and OFF of some of the heaters, and the first switch and the second switch are turned ON and OFF based on the temperature information in the processing chamber in which the work is housed. The control is provided by using a heater control mechanism configured to include a control unit configured to give a switching operation instruction and to electrically connect the first switch and the second switch via a transformer. The unit calculates the operating time of the heater based on the temperature information in the processing chamber in which the work is housed, and the operation instruction from the control unit based on the calculated operating time causes the first switch and the second switch. Among the switches, at least the second switch is characterized by switching ON and OFF.
Further, the present invention from another viewpoint is a heater control method for controlling the operation of a plurality of heaters provided in a heat treatment apparatus for heat-treating a work, and includes a first switch for switching ON and OFF of all heaters. Of the plurality of heaters, the second switch for switching ON and OFF of some of the heaters, and the first switch and the second switch are turned ON and OFF based on the temperature information in the processing chamber in which the work is housed. Using a heater control mechanism without a cyclist, which includes a control unit configured to give switching operation instructions, the control unit uses the heater based on temperature information in the processing chamber in which the work is housed. The operation time is calculated, and at least the second switch of the first switch and the second switch is switched on and off by an operation instruction from the control unit based on the calculated operation time. There is.

本発明に係るヒータ制御によれば、複数のヒータのうちの一部のヒータの作動時間を調節することができ、複数のトランスやサイリスタを用いずに処理室内の温度ばらつきを改善することができる。 According to the heater control according to the present invention, the operating time of some of the heaters among the plurality of heaters can be adjusted, and the temperature variation in the processing chamber can be improved without using a plurality of transformers and thyristors. ..

本発明によれば、簡易な構造のヒータ制御機構で処理室内の温度ばらつきを改善することができる。 According to the present invention, it is possible to improve the temperature variation in the processing chamber by a heater control mechanism having a simple structure.

従来のヒータ制御機構の概略構成を示す図である。It is a figure which shows the schematic structure of the conventional heater control mechanism. 本発明の実施形態に係るヒータ制御機構の概略構成を示す図である。It is a figure which shows the schematic structure of the heater control mechanism which concerns on embodiment of this invention. 本発明の実施形態に係る各ヒータの作動サイクルを示す図である。It is a figure which shows the operation cycle of each heater which concerns on embodiment of this invention. 実施例における処理室内の温度測定点を示す図である。It is a figure which shows the temperature measurement point in the processing chamber in an Example. ヒータ作動時間と各温度測定点における測定温度のばらつきとの関係を示す図である。It is a figure which shows the relationship between the heater operation time and the variation of the measured temperature at each temperature measurement point.

以下、本発明の実施形態について、図面を参照しながら説明する。なお、本明細書および図面において、実質的に同一の機能構成を有する要素においては、同一の符号を付することにより重複説明を省略する。 Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present specification and the drawings, the elements having substantially the same functional configuration are designated by the same reference numerals, so that duplicate description will be omitted.

図２は本実施形態の熱処理装置２０に設けられたヒータ制御機構１の概略構成を示す図であり、ワークＷが収容される処理室２１を上方から見た図である。図２に示すように本実施形態のヒータ制御機構１は、ワークＷが収容される処理室２１に設けられた４つのヒータ２ａ～２ｄと、供給電力の変圧を行うトランス３（変圧器）と、トランス３への電力の供給と遮断を切り替える第１スイッチ４と、一部のヒータ２ａ、２ｂへのトランス３からの電力の供給と遮断を切り替える第２スイッチ５と、第１スイッチ４および第２スイッチ５に動作指示を与える制御部６とを備えている。 FIG. 2 is a diagram showing a schematic configuration of a heater control mechanism 1 provided in the heat treatment apparatus 20 of the present embodiment, and is a view of a processing chamber 21 in which a work W is housed as viewed from above. As shown in FIG. 2, the heater control mechanism 1 of the present embodiment includes four heaters 2a to 2d provided in the processing chamber 21 in which the work W is housed, and a transformer 3 (transformer) that transforms the supplied power. , A first switch 4 that switches between supply and cut of power to the transformer 3, a second switch 5 that switches between supply and cut of power from the transformer 3 to some heaters 2a and 2b, and a first switch 4 and a first switch. 2 A control unit 6 for giving an operation instruction to the switch 5 is provided.

４つのヒータ２ａ～２ｄは全て同出力のものであり、ワークＷを挟み込むように対向して一対のヒータ２ａ、２ｂおよび２ｃ、２ｄが図２の横方向に並んで配置されている。このうち、図２中の左側に配置された一対のヒータ２ｃ、２ｄはトランス３に接続されている。一方、図２中の右側に配置された残りの一対のヒータ２ａ、２ｂは、第２スイッチ５を介してトランス３に接続されている。また、トランス３は第１スイッチ４を介して電源（不図示）に接続されている。すなわち、第１スイッチ４と第２スイッチ５とはトランス３を介して電気的に接続されるように構成されている。 The four heaters 2a to 2d all have the same output, and a pair of heaters 2a, 2b, 2c, and 2d are arranged side by side in the horizontal direction of FIG. 2 so as to sandwich the work W. Of these, the pair of heaters 2c and 2d arranged on the left side in FIG. 2 are connected to the transformer 3. On the other hand, the remaining pair of heaters 2a and 2b arranged on the right side in FIG. 2 are connected to the transformer 3 via the second switch 5. Further, the transformer 3 is connected to a power source (not shown) via the first switch 4. That is, the first switch 4 and the second switch 5 are configured to be electrically connected via the transformer 3.

このため、第１スイッチ４および第２スイッチ５が共にＯＮ状態となる場合には、トランス３を介して全てのヒータ２ａ～２ｄに電力が供給され、各ヒータ２ａ～２ｄがＯＮ状態となる。一方、第２スイッチ５がＯＮ状態であっても第１スイッチ４がＯＦＦ状態となれば、トランス３への電力供給が遮断される。これにより全てのヒータ２ａ～２ｄに電力が供給されず、各ヒータ２ａ～２ｄがＯＦＦ状態となる。すなわち、第１スイッチ４は、全てのヒータ２ａ～２ｄのＯＮとＯＦＦを切り替える機能を有している。 Therefore, when both the first switch 4 and the second switch 5 are turned on, electric power is supplied to all the heaters 2a to 2d via the transformer 3, and the heaters 2a to 2d are turned on. On the other hand, even if the second switch 5 is in the ON state, if the first switch 4 is in the OFF state, the power supply to the transformer 3 is cut off. As a result, power is not supplied to all the heaters 2a to 2d, and the heaters 2a to 2d are turned off. That is, the first switch 4 has a function of switching ON and OFF of all the heaters 2a to 2d.

また、第１スイッチ４がＯＮの状態で第２スイッチ５がＯＦＦ状態になると、ヒータ２ａ、２ｂへの電力供給が遮断され、ヒータ２ａ、２ｂがＯＦＦ状態となる。すなわち、第２スイッチ５は、複数のヒータ２ａ～２ｄのうちの一部のヒータ２ａ、２ｂのＯＮとＯＦＦを切り替える機能を有している。 When the second switch 5 is turned off while the first switch 4 is turned on, the power supply to the heaters 2a and 2b is cut off, and the heaters 2a and 2b are turned off. That is, the second switch 5 has a function of switching ON and OFF of some of the heaters 2a and 2b among the plurality of heaters 2a to 2d.

処理室２１内には、処理室内温度の温度測定部の一例として熱電対７が設けられており、ここで測定された温度情報は、温調計８を介して制御部６へと送られる。なお、図２では熱電対７が１つだけ設けられているように図示されているが、複数設けられていても良い。熱電対７が複数設けられている場合には、各熱電対７で測定された温度情報は温調計８を介して制御部６へと送られる。制御部６は、温調計８から入力された温度情報に基づいて処理室２１内の温度分布がより均一になるようなヒータ２ａ～２ｄの作動時間を算出する。なお、制御部６は、その情報に基づき、第１スイッチ４および第２スイッチ５に対してＯＮまたはＯＦＦに切り替わるための動作指示を与える。 A thermocouple 7 is provided in the processing chamber 21 as an example of a temperature measuring unit for the temperature in the processing chamber, and the temperature information measured here is sent to the control unit 6 via the temperature controller 8. Although it is shown in FIG. 2 that only one thermocouple 7 is provided, a plurality of thermocouples 7 may be provided. When a plurality of thermocouples 7 are provided, the temperature information measured by each thermocouple 7 is sent to the control unit 6 via the temperature controller 8. The control unit 6 calculates the operating time of the heaters 2a to 2d so that the temperature distribution in the processing chamber 21 becomes more uniform based on the temperature information input from the temperature controller 8. The control unit 6 gives an operation instruction for switching ON or OFF to the first switch 4 and the second switch 5 based on the information.

本実施形態のヒータ制御機構１は以上のように構成されている。なお、第１スイッチ４や第２スイッチ５としては、例えばマグネットスイッチが用いられるが、電力の供給と遮断を切り替えることができれば、他のスイッチであっても良い。また、制御部６は例えばＰＬＣ（プログラマブルロジックコントローラ）が用いられるが、処理室２１内の温度情報に基づきヒータ２ａ～２ｄのＯＮ、ＯＦＦタイミングを設定し、第１スイッチ４および第２スイッチ５に動作指示を与えることができれば他の方法で制御部６を構成しても良い。 The heater control mechanism 1 of the present embodiment is configured as described above. As the first switch 4 and the second switch 5, for example, a magnet switch is used, but other switches may be used as long as the power supply and cutoff can be switched. Further, although a PLC (programmable logic controller) is used for the control unit 6, the ON / OFF timings of the heaters 2a to 2d are set based on the temperature information in the processing chamber 21, and the first switch 4 and the second switch 5 are set. If the operation instruction can be given, the control unit 6 may be configured by another method.

本実施形態のヒータ制御機構１によれば、第１スイッチ４と第２スイッチ５により、複数のヒータ２ａ～２ｄのうちの一部のヒータ２ａ、２ｂの作動時間を変更することができる。これにより、所定のサイクル間におけるヒータ２ａ、２ｂの総発熱量をヒータ２ｃ、２ｄよりも小さくすることができる。ヒータ２ａ、２ｂの総発熱量の調節方法について具体的に説明すると、例えば図３のようなサイクル間においてヒータ２ａ、２ｂの総発熱量をヒータ２ｃ、２ｄの総発熱量の５５％に調節する場合、本実施形態では導通時における各ヒータ２ａ～２ｄの出力が等しいことから、ヒータ２ｃ、２ｄが６０秒サイクルの最初のサイクルで作動し続ける際には、ヒータ２ａ、２ｂは６０秒の５５％の時間、すなわち３３秒間作動すれば良い。これにより、ヒータ２ａ、２ｂの総発熱量はヒータ２ｃ、２ｄの総発熱量の５５％となる。 According to the heater control mechanism 1 of the present embodiment, the operating time of some of the heaters 2a and 2b among the plurality of heaters 2a to 2d can be changed by the first switch 4 and the second switch 5. Thereby, the total calorific value of the heaters 2a and 2b during a predetermined cycle can be made smaller than that of the heaters 2c and 2d. The method of adjusting the total calorific value of the heaters 2a and 2b will be specifically described. For example, the total calorific value of the heaters 2a and 2b is adjusted to 55% of the total calorific value of the heaters 2c and 2d during the cycle as shown in FIG. In this case, since the outputs of the heaters 2a to 2d at the time of conduction are equal in the present embodiment, when the heaters 2c and 2d continue to operate in the first cycle of the 60-second cycle, the heaters 2a and 2b are 55 for 60 seconds. It may operate for% time, that is, 33 seconds. As a result, the total calorific value of the heaters 2a and 2b becomes 55% of the total calorific value of the heaters 2c and 2d.

なお、ヒータ２ａ、２ｂの総発熱量をヒータ２ｃ、２ｄの総発熱量に対し、どの程度小さくするかについては、出荷用製品の熱処理の操業を開始する前に異なる条件の加熱試験を実施することであらかじめ決定される。具体的には加熱試験で、ヒータ２ａ、２ｂの作動時間を上記のように調節し、ヒータ２ｃ、２ｄの総発熱量に対するヒータ２ａ、２ｂの総発熱量と処理室２１内の温度分布の均一性について評価し、温度分布のばらつきが最も小さくなるヒータ２ａ、２ｂの総発熱量の割合を決定する。本実施形態においては、ヒータ２ｃ、２ｄに対するヒータ２ａ、２ｂの最適な総発熱量の割合が５５％である。 Regarding how much the total calorific value of the heaters 2a and 2b should be smaller than the total calorific value of the heaters 2c and 2d, a heating test under different conditions is performed before starting the heat treatment operation of the product for shipment. It is decided in advance. Specifically, in the heating test, the operating times of the heaters 2a and 2b are adjusted as described above, and the total calorific value of the heaters 2a and 2b and the uniform temperature distribution in the processing chamber 21 with respect to the total calorific value of the heaters 2c and 2d. The property is evaluated, and the ratio of the total calorific value of the heaters 2a and 2b having the smallest variation in temperature distribution is determined. In the present embodiment, the ratio of the optimum total calorific value of the heaters 2a and 2b to the heaters 2c and 2d is 55%.

本実施形態のヒータ制御機構１では、制御部６がヒータ２ｃ、２ｄに対するヒータ２ａ、２ｂの総発熱量の割合に応じて上記のようにヒータ２ａ～２ｄの作動時間を算出し、これに基づいて第１スイッチ４および第２スイッチ５に動作指示を与える。具体的に説明すると、制御部６は、まず第１スイッチ４および第２スイッチ５にＯＮ信号を送る。これにより第１スイッチ４および第２スイッチ５がＯＮ状態となり、第１スイッチ４、トランス３、第２スイッチ５が導通した状態となり、全てのヒータ２ａ～２ｄがＯＮ状態となる。それから３３秒後、制御部６は第２スイッチ５にＯＦＦ信号を送る。これにより第２スイッチ５がＯＦＦ状態となり、ヒータ２ａ、２ｂへの電力供給が停止する。それから更に２７秒後、制御部６は第１スイッチ４にＯＦＦ信号を送る。これにより第１スイッチ４がＯＦＦ状態となり、ヒータ２ｃ、２ｄへの電力供給も停止し、全てのヒータ２ａ～２ｄがＯＦＦ状態となる。これにより、所定のサイクル間におけるヒータ２ａ、２ｂの総発熱量がヒータ２ｃ、２ｄの５５％の総発熱量となり、処理室２１内の温度分布に変化を与えることができる。 In the heater control mechanism 1 of the present embodiment, the control unit 6 calculates the operating time of the heaters 2a to 2d as described above according to the ratio of the total calorific value of the heaters 2a and 2b to the heaters 2c and 2d, and based on this. The operation instruction is given to the first switch 4 and the second switch 5. Specifically, the control unit 6 first sends an ON signal to the first switch 4 and the second switch 5. As a result, the first switch 4 and the second switch 5 are turned on, the first switch 4, the transformer 3, and the second switch 5 are turned on, and all the heaters 2a to 2d are turned on. 33 seconds later, the control unit 6 sends an OFF signal to the second switch 5. As a result, the second switch 5 is turned off, and the power supply to the heaters 2a and 2b is stopped. Then, 27 seconds later, the control unit 6 sends an OFF signal to the first switch 4. As a result, the first switch 4 is turned off, the power supply to the heaters 2c and 2d is also stopped, and all the heaters 2a to 2d are turned off. As a result, the total calorific value of the heaters 2a and 2b during a predetermined cycle becomes 55% of the total calorific value of the heaters 2c and 2d, and the temperature distribution in the processing chamber 21 can be changed.

すなわち、本実施形態のヒータ制御機構１によれば、処理室２１内の温度分布がより均一になるように、処理室２１内の温度情報に基づいて複数のヒータ２ａ～２ｄのうちの一部のヒータ２ａ、２ｂの作動時間を調節することができ、これにより複数のトランス３やサイリスタを用いない簡易な構造で処理室２１内の温度ばらつきを改善することができる。 That is, according to the heater control mechanism 1 of the present embodiment, a part of the plurality of heaters 2a to 2d is based on the temperature information in the processing chamber 21 so that the temperature distribution in the processing chamber 21 becomes more uniform. The operating time of the heaters 2a and 2b can be adjusted, whereby the temperature variation in the processing chamber 21 can be improved with a simple structure that does not use a plurality of transformers 3 and thyristors.

ところで、従来のヒータ制御機構１では、処理室２１内の温度分布を均一にできない場合に、ヒータの間引き又は追加や仕様変更、電流容量の変更等の対応が必要となっていた。前述の通り、築炉後のヒータの付け替え作業は非常に手間がかかると共に、付け替えたヒータの構成でも依然として処理室２１内の温度分布を改善できないこともある。この場合、ヒータの配置や仕様の再検討や、再度ヒータの付け替え作業を行うことが必要となる。このため、熱処理対象となるワークＷの形状、個数、配置や、熱処理温度の変更等に応じた最適な加熱条件の条件出しに時間とコストがかかっていた。 By the way, in the conventional heater control mechanism 1, when the temperature distribution in the processing chamber 21 cannot be made uniform, it is necessary to take measures such as thinning out or adding heaters, changing specifications, and changing current capacity. As described above, the work of replacing the heater after the furnace is built is very troublesome, and the temperature distribution in the processing chamber 21 may not be improved even with the configuration of the replaced heater. In this case, it is necessary to reexamine the arrangement and specifications of the heaters and to replace the heaters again. Therefore, it takes time and cost to determine the optimum heating conditions according to the shape, number, and arrangement of the work W to be heat-treated, and the change of the heat treatment temperature.

一方、本実施形態のヒータ制御機構１によれば、処理室２１の温度情報に基づいて複数のヒータ２ａ～２ｄのうちの一部のヒータ２ａ、２ｂの作動時間を調節できる構成であるため、例えばワークＷの形状や個数、配置の変更、処理室２１外部の環境温度の変動等が生じても、ヒータ２ａ～２ｄの付け替えを行うことなく、処理室２１内の温度分布を調節することができる。したがって、本実施形態のヒータ制御機構１によれば、多様な熱処理条件に対し、既設のヒータ２ａ～２ｄをそのまま用いて処理室２１内の温度ばらつきを改善することが可能となる。これにより従前の最適加熱条件の条件出しの際に費やされていた時間とコストを大きく削減することができる。 On the other hand, according to the heater control mechanism 1 of the present embodiment, the operating time of some of the heaters 2a and 2b among the plurality of heaters 2a to 2d can be adjusted based on the temperature information of the processing chamber 21. For example, even if the shape, number, or arrangement of the work W changes, or the environmental temperature outside the processing chamber 21 fluctuates, the temperature distribution inside the processing chamber 21 can be adjusted without replacing the heaters 2a to 2d. can. Therefore, according to the heater control mechanism 1 of the present embodiment, it is possible to improve the temperature variation in the processing chamber 21 by using the existing heaters 2a to 2d as they are for various heat treatment conditions. As a result, it is possible to greatly reduce the time and cost spent in setting the conditions of the conventional optimum heating conditions.

なお、ヒータ２ａ～２ｄのＯＮとＯＦＦの切り替えを行うか否かの判定は例えば３０～１２０秒サイクルで行われる。このサイクルが短すぎると、短時間で何度もスイッチングされることになり、スイッチ寿命が早まることが懸念される。一方、このサイクルが長すぎると、温度ばらつきが大きくなることが懸念される。スイッチ寿命と温度ばらつき軽減の両立を図るためには５０～８０秒サイクルでヒータ２ａ～２ｄのＯＮとＯＦＦの切り替えを行うか否かの判定を実施することが好ましい。 It should be noted that the determination as to whether or not to switch the heaters 2a to 2d on and off is performed, for example, in a cycle of 30 to 120 seconds. If this cycle is too short, it will be switched many times in a short time, and there is a concern that the switch life will be shortened. On the other hand, if this cycle is too long, there is a concern that the temperature variation will increase. In order to achieve both switch life and reduction of temperature variation, it is preferable to determine whether to switch ON and OFF of heaters 2a to 2d in a cycle of 50 to 80 seconds.

また、本実施形態では一対のヒータ２ｃ、２ｄと、残りの一対のヒータ２ａ、２ｂの動作を制御することとしたが、制御するヒータの組み合わせは本実施形態で説明したものに限定されない。例えば、ヒータのＯＮ、ＯＦＦを切り替えるスイッチを更に設け、各ヒータ２ａ～２ｄを個別に制御するようにしても良い。また、ヒータ２ａ～２ｄの個数や配置は本実施形態で説明したものに限定されず、処理室２１の構造等に応じて適宜変更しても良い。また、ヒータ２ａ～２ｄは同一出力でなくても良い。また、ヒータ２ａ～２ｄが設けられる処理室２１は、バッチ式の熱処理装置の処理室であっても良いし、処理室が連続して配置される連続式の熱処理装置の処理室であっても良い。また、ヒータ制御機構１が設けられる熱処理装置２０としては、浸炭処理や窒化処理等の処理室２１の加熱を要する熱処理を行う熱処理装置であれば特に限定されない。また、ヒータ２ａ～２ｄに供給する電力の変圧が必要なければ、トランスを用いなくても良い。 Further, in the present embodiment, the operations of the pair of heaters 2c and 2d and the remaining pair of heaters 2a and 2b are controlled, but the combination of the controlling heaters is not limited to that described in the present embodiment. For example, a switch for switching ON / OFF of the heater may be further provided to control each heater 2a to 2d individually. Further, the number and arrangement of the heaters 2a to 2d are not limited to those described in this embodiment, and may be appropriately changed depending on the structure of the processing chamber 21 and the like. Further, the heaters 2a to 2d do not have to have the same output. Further, the processing chamber 21 provided with the heaters 2a to 2d may be a processing chamber of a batch type heat treatment apparatus or a processing chamber of a continuous type heat treatment apparatus in which the processing chambers are continuously arranged. good. The heat treatment device 20 provided with the heater control mechanism 1 is not particularly limited as long as it is a heat treatment device that performs heat treatment that requires heating of the processing chamber 21 such as carburizing treatment and nitriding treatment. Further, if it is not necessary to transform the electric power supplied to the heaters 2a to 2d, the transformer may not be used.

いずれの場合であってもヒータ制御機構１に、全てのヒータのＯＮとＯＦＦを切り替える第１スイッチ４と、一部のヒータのＯＮとＯＦＦを切り替える第２スイッチ５と、処理室２１内の温度情報に基づいてヒータの作動時間を算出し、算出された作動時間に基づく動作指示を、第１スイッチ４および第２スイッチ５のうちの少なくとも第２スイッチ５に与える制御部６が設けられていれば、処理室２１内の温度分布を変えることができ、温度ばらつきを改善する効果を得ることができる。 In either case, the heater control mechanism 1 has a first switch 4 that switches ON and OFF of all heaters, a second switch 5 that switches ON and OFF of some heaters, and the temperature inside the processing chamber 21. A control unit 6 is provided that calculates the operating time of the heater based on the information and gives an operating instruction based on the calculated operating time to at least the second switch 5 of the first switch 4 and the second switch 5. For example, the temperature distribution in the processing chamber 21 can be changed, and the effect of improving the temperature variation can be obtained.

以上、本発明の実施形態について説明したが、本発明はかかる例に限定されない。当業者であれば、特許請求の範囲に記載された技術的思想の範疇内において、各種の変更例または修正例に想到しうることは明らかであり、それらについても当然に本発明の技術的範囲に属するものと了解される。 Although the embodiments of the present invention have been described above, the present invention is not limited to such examples. It is clear that a person skilled in the art can come up with various modifications or modifications within the scope of the technical ideas described in the claims, and of course, the technical scope of the present invention also includes them. It is understood that it belongs to.

本発明に係るヒータ制御機構が設けられたバッチ式熱処理装置で加熱試験を実施した。 A heating test was carried out with a batch type heat treatment apparatus provided with a heater control mechanism according to the present invention.

本実施例の熱処理装置は図４のように処理室２１内の中央にワークＷを載せる多段式の治具２２が配置され、その治具２２を挟み込むように対向して配置された一対の電熱式のヒータ２ａ、２ｂおよび２ｃ、２ｄが並んで設けられている。また、治具２２の上方には処理室２１内の雰囲気を攪拌するファン２３が設けられ、ファン２３の回転数は１０００ｒｐｍに設定されている。治具２２は立方体形状を有しており、立方体の各頂点および各頂点を結ぶ対角線の交点の計１１点で温度が測定できるように熱電対２４が設置されている。ヒータ制御機構は、図２に示す構造と同一であり、図４の手前側の一対のヒータ２ｃ、２ｄはトランスに接続され、同じトランスに図４の奥側の一対のヒータ２ａ、２ｂがマグネットスイッチからなる第２スイッチを介して接続されている。トランスはマグネットスイッチからなる第１スイッチを介して電源に接続されている。各ヒータ２ａ～２ｄは全て同出力のものである。 In the heat treatment apparatus of this embodiment, as shown in FIG. 4, a multi-stage jig 22 on which the work W is placed is arranged in the center of the processing chamber 21, and a pair of electric heats arranged so as to sandwich the jig 22. The heaters 2a, 2b and 2c, 2d of the formula are provided side by side. Further, a fan 23 for stirring the atmosphere in the processing chamber 21 is provided above the jig 22, and the rotation speed of the fan 23 is set to 1000 rpm. The jig 22 has a cubic shape, and a thermocouple 24 is installed so that the temperature can be measured at a total of 11 points of each vertex of the cube and the intersection of the diagonal lines connecting the vertices. The heater control mechanism is the same as the structure shown in FIG. 2, the pair of heaters 2c and 2d on the front side of FIG. 4 are connected to a transformer, and the pair of heaters 2a and 2b on the back side of FIG. 4 are magnetized in the same transformer. It is connected via a second switch consisting of switches. The transformer is connected to the power supply via a first switch including a magnet switch. The heaters 2a to 2d all have the same output.

また、処理室２１内には、処理室温度測定用の熱電対７も設けられている。熱電対７で測定された処理室２１内の温度情報は、温調計８を介して制御部６であるＰＬＣ（プログラマブルロジックコントローラ）へと送られる。制御部６は、処理室２１内の温度情報に基づきヒータ２ａ～２ｄのＯＮ、ＯＦＦタイミングを設定し、第１スイッチ４および第２スイッチ５に動作指示を与えている。本実施例では図４の手前側に処理室２１に隣り合うように設けられた油槽（不図示）があり、図４の奥側には処理室２１の内壁に設けられた断熱材（不図示）がある。このため、本実施例の処理室２１内においては図４の奥側の温度が図４の手前側の温度よりも下がりにくくなっており、温度が下がりにくい側のヒータ２ａ、２ｂの作動時間を調節できるようにヒータ２ａ、２ｂに第２スイッチが接続されている。第２スイッチはこのように処理室２１内において相対的に温度が下がりにくくなる部分のヒータに接続することが好ましい。なお、本実施例におけるヒータの数や配置等の構成は、発明の効果を得る上で適した構成のうちの一つである。 Further, a thermocouple 7 for measuring the temperature of the processing chamber is also provided in the processing chamber 21. The temperature information in the processing chamber 21 measured by the thermocouple 7 is sent to the PLC (programmable logic controller) which is the control unit 6 via the temperature controller 8. The control unit 6 sets the ON / OFF timings of the heaters 2a to 2d based on the temperature information in the processing chamber 21, and gives an operation instruction to the first switch 4 and the second switch 5. In this embodiment, there is an oil tank (not shown) provided adjacent to the treatment chamber 21 on the front side of FIG. 4, and a heat insulating material (not shown) provided on the inner wall of the treatment chamber 21 on the back side of FIG. ). Therefore, in the processing chamber 21 of this embodiment, the temperature on the inner side of FIG. 4 is less likely to decrease than the temperature on the front side of FIG. 4, and the operating time of the heaters 2a and 2b on the side where the temperature is difficult to decrease is set. A second switch is connected to the heaters 2a and 2b so that they can be adjusted. It is preferable that the second switch is connected to the heater in the portion of the processing chamber 21 where the temperature is relatively difficult to drop. The configuration such as the number and arrangement of heaters in this embodiment is one of the configurations suitable for obtaining the effect of the invention.

加熱試験は、設定温度を９５０℃として、上記熱処理装置を用いて処理室温度測定用の熱電対７で測定される温度が９５０℃となるまで処理室内を加熱することで行う。詳細には、処理室温度測定用の熱電対７からの温度情報により処理室２１内の温度が９５０℃となるまで全てのヒータ２ａ～２ｄをＯＮにして処理室２１内を加熱する。その後、処理室２１内の温度が９５０℃となると、制御部６がヒータ２ａ、２ｂの作動時間を調節するために、処理室２１内の温度情報に基づいてヒータ２ａ、２ｂの作動時間を算出し、算出された作動時間に基づく動作指示を第２スイッチに与える。これによりヒータ２ａ、２ｂの作動時間経過後の、ヒータ２ｃ、２ｄの総発熱量に対するヒータ２ａ、２ｂの総発熱量を抑えるようにしている。なお、第１スイッチおよび第２スイッチのＯＮとＯＦＦの切り替えを行うか否かの判定は６０秒サイクルで行われる。その判定時に処理室温度測定用の熱電対７で測定された温度が９５０℃を超えている場合には第１スイッチがＯＦＦに切り替えられ、その判定時に処理室温度測定用の熱電対７で測定された温度が９５０℃を下回っている場合には第１スイッチがＯＮに切り替えられる。 The heating test is performed by setting the set temperature to 950 ° C. and heating the processing chamber until the temperature measured by the thermocouple 7 for measuring the temperature of the processing chamber reaches 950 ° C. using the above heat treatment apparatus. Specifically, all the heaters 2a to 2d are turned on until the temperature in the processing chamber 21 reaches 950 ° C. based on the temperature information from the thermocouple 7 for measuring the temperature in the processing chamber to heat the inside of the processing chamber 21. After that, when the temperature in the processing chamber 21 reaches 950 ° C., the control unit 6 calculates the operating time of the heaters 2a and 2b based on the temperature information in the processing chamber 21 in order to adjust the operating time of the heaters 2a and 2b. Then, an operation instruction based on the calculated operation time is given to the second switch. As a result, the total calorific value of the heaters 2a and 2b is suppressed with respect to the total calorific value of the heaters 2c and 2d after the operating time of the heaters 2a and 2b has elapsed. It should be noted that the determination as to whether or not to switch ON and OFF of the first switch and the second switch is performed in a cycle of 60 seconds. If the temperature measured by the thermocouple 7 for measuring the temperature of the processing chamber at the time of the determination exceeds 950 ° C., the first switch is switched to OFF, and the thermocouple 7 for measuring the temperature of the processing chamber is used at the time of the determination. When the temperature is lower than 950 ° C., the first switch is switched on.

加熱試験は、ヒータ２ａ、２ｂの作動時間が異なる条件で複数回実施し、治具２２上の熱電対２４の計１１点の温度測定点で測定された温度の平均温度と、それらの温度ばらつきＲを記録した。また、比較例として、ヒータ２ａ、２ｂをヒータ２ｃ、２ｄと同一の作動時間とした場合の加熱試験も実施した。その加熱試験の結果を下記表１および図５に示す。なお、下記表１および図５に記載された「ヒータ２ａ、２ｂの作動時間」とは、処理室内が９５０℃に到達した後のヒータ２ｃ、２ｄの作動時間を基準としたヒータ２ａ、２ｂの作動時間の割合を示している。 The heating test was performed a plurality of times under conditions where the operating times of the heaters 2a and 2b were different, and the average temperature of the temperatures measured at a total of 11 temperature measuring points of the thermocouple 24 on the jig 22 and their temperature variations. R was recorded. Further, as a comparative example, a heating test was also carried out when the heaters 2a and 2b had the same operating time as the heaters 2c and 2d. The results of the heating test are shown in Table 1 and FIG. 5 below. The "operating time of the heaters 2a and 2b" shown in Tables 1 and 5 below is the operating time of the heaters 2a and 2b based on the operating time of the heaters 2c and 2d after the temperature of the processing chamber reaches 950 ° C. Shows the percentage of operating time.

表１および図５に示されるように、ヒータ２ａ、２ｂの作動時間を調節することで、温度ばらつきＲを大きく改善することができた。すなわち、本発明に係るヒータ制御機構によれば、複数のトランスやサイリスタを用いない簡易な構造で処理室の温度ばらつきＲを改善することができる。また、本加熱試験では実施例３で示されるようにヒータ２ａ、２ｂの作動時間が５５％になることで最も温度ばらつきが小さくなる。本発明に係るヒータ制御機構によれば、このような最適な加熱条件の条件出しをヒータ２ａ～２ｄの付け替え作業をせずに行うことができる。 As shown in Table 1 and FIG. 5, the temperature variation R could be greatly improved by adjusting the operating times of the heaters 2a and 2b. That is, according to the heater control mechanism according to the present invention, it is possible to improve the temperature variation R in the processing chamber with a simple structure that does not use a plurality of transformers or thyristors. Further, in this heating test, as shown in Example 3, the operating time of the heaters 2a and 2b is 55%, so that the temperature variation becomes the smallest. According to the heater control mechanism according to the present invention, it is possible to set the optimum heating conditions without replacing the heaters 2a to 2d.

本発明は、ワークの熱処理を行う熱処理装置に設けられるヒータ制御機構に適用することができる。 The present invention can be applied to a heater control mechanism provided in a heat treatment apparatus that heat-treats a work.

１ヒータ制御機構
２ａヒータ
２ｂヒータ
２ｃヒータ
２ｄヒータ
３トランス
４第１スイッチ
５第２スイッチ
６制御部
７熱電対
８温調計
２０熱処理装置
２１処理室
２２治具
２３ファン
２４熱電対
５０従来のヒータ制御機構
５１サイリスタ
Ｗワーク 1 Heater control mechanism 2a Heater 2b Heater 2c Heater 2d Heater 3 Transformer 4 1st switch 5 2nd switch 6 Control unit 7 Thermoelectric pair 8 Temperature controller 20 Heat treatment device 21 Processing room 22 Jig 23 Fan 24 Thermoelectric pair 50 Conventional heater Control mechanism 51 Cylister W work

Claims

It is a heater control mechanism that controls the operation of a plurality of heaters provided in a heat treatment device that heat-treats a work.
The first switch that switches ON and OFF of all heaters,
A second switch that switches ON and OFF of some of the plurality of heaters, and
A control unit configured to give an operation instruction for switching ON and OFF to the first switch and the second switch based on the temperature information in the processing chamber in which the work is housed is provided.
The control unit further calculates the operating time of the heater based on the temperature information in the processing chamber in which the work is housed, and issues an operation instruction for switching ON and OFF based on the calculated operating time to the first switch and the first switch. Of the second switch, it is configured to give at least to the second switch.
A heater control mechanism configured such that the first switch and the second switch are electrically connected via a transformer.

A heater control mechanism without a thyristor that controls the operation of a plurality of heaters provided in a heat treatment device that heat-treats a work.
The first switch that switches ON and OFF of all heaters,
A second switch that switches ON and OFF of some of the plurality of heaters, and
A control unit configured to give an operation instruction for switching ON and OFF to the first switch and the second switch based on the temperature information in the processing chamber in which the work is housed is provided.
The control unit further calculates the operating time of the heater based on the temperature information in the processing chamber in which the work is housed, and issues an operation instruction for switching ON and OFF based on the calculated operating time to the first switch and the first switch. A heater control mechanism configured to give at least the second switch among the second switches.

A heat treatment apparatus for heat-treating a work, provided with the heater control mechanism according to claim 1 or 2.

It is a heater control method for controlling the operation of a plurality of heaters provided in a heat treatment apparatus for heat-treating a work.
The first switch that switches ON and OFF of all heaters,
A second switch that switches ON and OFF of some of the plurality of heaters, and
A control unit configured to give an operation instruction for switching ON and OFF to the first switch and the second switch based on the temperature information in the processing chamber in which the work is housed is provided.
A heater control mechanism configured to electrically connect the first switch and the second switch via a transformer is used.
The control unit calculates the operating time of the heater based on the temperature information in the processing chamber in which the work is housed.
A heater control method for switching ON and OFF of at least the second switch among the first switch and the second switch according to an operation instruction from the control unit based on the calculated operation time.

It is a heater control method for controlling the operation of a plurality of heaters provided in a heat treatment apparatus for heat-treating a work.
The first switch that switches ON and OFF of all heaters,
A second switch that switches ON and OFF of some of the plurality of heaters, and
A thyristor is provided with a control unit configured to give an operation instruction to switch ON and OFF to the first switch and the second switch based on the temperature information in the processing chamber in which the work is housed. Using no heater control mechanism,
The control unit calculates the operating time of the heater based on the temperature information in the processing chamber in which the work is housed.
A heater control method for switching ON and OFF of at least the second switch among the first switch and the second switch according to an operation instruction from the control unit based on the calculated operation time.