JP5466905B2 - Induction heating apparatus and control method of induction heating apparatus - Google Patents

Description

  The present invention relates to an induction heating device for a metal material, and more particularly to an induction heating device for heating an edge portion of a metal material and a control method for the induction heating device.

 A product having a desired plate thickness is produced by processing a heated material (for example, a metal material such as a steel plate) heated to a predetermined temperature as a processing target with a rolling mill. In recent years, in order to make the temperature in the width direction uniform with respect to the temperature drop at both edges of a metal material, an induction heating device that heats both edges of the metal material, for example, a C-type edge heater, can be installed in a production line. It has become common. The dimension of the overlapping portion between the iron core of the C-type inductor of the C-type edge heater and the metal material to be heat-treated (hereinafter referred to as “lapping amount”) is defined, and the metal is set so as to have this specified lapping amount. The positions of the C-type edge heaters arranged at both edge portions of the material are set.

  However, the temperature of both edges of the metal material is not always the same due to the metal material shifting to one of the sides in the conveyance process or due to temperature unevenness in the heating furnace. In some cases, it could not be warmed.

  In addition, an eddy current generated in the metal material by the induction heating device generates an induced current, and this induced current may generate an arc spot that causes an arc soot on the metal material. The arc spot is promoted by an imbalance of induced currents generated at both edge portions.

  A technique has been proposed for heating both edges of a metal material evenly by calculating the output frequency and output current of a C-type inductor arranged on both sides of the metal material and each inverter arranged on a one-to-one basis. Yes. (For example, refer to Patent Document 1). In the proposed technique, the output power is adjusted or the position of the carriage of the C-type edge heater is adjusted as means for equalizing the temperature rise at both edge portions.

Japanese Patent Laid-Open No. 11-144853

  However, the above method is applicable only when the inverter and the C-type inductor are configured in a one-to-one relationship, and cannot be applied when supplying power to a plurality of C-type inductors from one inverter. In order to reduce the arc spot, it is common to use one inverter so that the power supplied to the C-type inductors installed on both sides of the metal material is equal. In the above method, the output current from the inverter is monitored, and the inductor current flowing in the heating coil of the C-type inductor is not monitored. If the purpose is to control the power of the C-type inductor, it is necessary to directly detect the inductor current flowing in the C-type inductor, not the output current of the inverter.

  In view of the above problems, an object of the present invention is to provide an induction heating apparatus and a control method for the induction heating apparatus that can control the temperature rise at both edges of the metal material to be heat-treated to a predetermined value. .

According to one aspect of the present invention, (a) a first C-type inductor that heats one edge portion of a metal material to be heat-treated, and a second C-type inductor that heats the other edge portion of the metal material. (B) an inverter that supplies power to the first and second C-type inductors, (c) a voltage monitoring device that monitors the output voltage of the inverter, and (d) a heating coil of the first and second C-type inductors First and second current monitoring devices for monitoring the first and second inductor currents respectively flowing in the first and second current sources, and (e) the output voltage immediately after the start of the heat treatment of the metal material and the first and second inductor currents. And calculating the initial value of the second impedance value, respectively, and further calculating the first and second impedance values from the output voltage and the first and second inductor currents at the same time during the heat treatment of the metal material , Heat treatment of metal materials As the first and second impedance values is respectively the initial value to the same in the middle, the induction heating apparatus provided with a control device for controlling the position of the first and second C-shaped inductor to metal material in real time Is done.

According to another aspect of the present invention, there is provided a method for controlling an induction heating apparatus having first and second C-type inductors, wherein (a) one of the metal materials to be heat-treated by the first C-type inductor. Heating the edge portion and heating the other edge portion of the metal material by the second C-type inductor; and (b) monitoring the output voltage of the inverter that supplies power to the first and second C-type inductors. (C) monitoring the first and second inductor currents respectively flowing in the heating coils of the first and second C-type inductors during the heat treatment of the metal material ; and (d) immediately after starting the heat treatment of the metal material. Calculating initial values of the first and second impedance values from the output voltage and the first and second inductor currents, respectively, and (e) the first and second output voltages at the same time during the heat treatment of the metal material. First The inductor current to calculate a first and second impedance values, as in the first and second impedance values during the heat treatment of the metal material is respectively the initial value to the same, the first and second to the metal member And a method for controlling the position of the C-type inductor in real time.

  ADVANTAGE OF THE INVENTION According to this invention, the control method of the induction heating apparatus and induction heating apparatus which can control the temperature rising in the both edge parts of the metal material of heat processing to a predetermined value can be provided.

It is a schematic diagram which shows the structure of the induction heating apparatus which concerns on embodiment of this invention. It is typical sectional drawing which shows the structure of the C type inductor of the induction heating apparatus which concerns on embodiment of this invention. It is a conceptual diagram which shows the flow of the signal in the induction heating apparatus which concerns on embodiment of this invention. It is a schematic diagram for demonstrating the position setting method of the C-type inductor by the induction heating apparatus which concerns on embodiment of this invention. It is a graph which shows the example of a lapping amount correction function. It is a graph which shows the width direction temperature rising distribution at the time of lap amount change. It is a schematic diagram for demonstrating the position setting method of the C-type inductor by the induction heating apparatus which concerns on embodiment of this invention at the time of the board | plate width change of a metal material. It is a schematic diagram which shows the state which the position shift of the metal material produced in the induction heating apparatus which concerns on embodiment of this invention. It is a conceptual diagram which shows the flow of the signal in the induction heating apparatus which concerns on the modification of embodiment of this invention. It is a schematic diagram for demonstrating the example of the position setting method of the C-type inductor by the induction heating apparatus which concerns on the modification of embodiment of this invention.

  Next, an embodiment of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. Further, the embodiments described below exemplify apparatuses and methods for embodying the technical idea of the present invention, and the embodiments of the present invention have the following structure and arrangement of components. It is not something specific. The embodiment of the present invention can be variously modified within the scope of the claims.

  As shown in FIG. 1, the induction heating device 1 according to the embodiment of the present invention includes a first C-type inductor 11 that heats one edge portion of a metal material 100 to be heat-treated, and the other metal material 100. A second C-type inductor 21 that heats the edge portion, an inverter 30 that feeds power to the first and second C-type inductors 11, 21, a voltage monitoring device 140 that monitors the output voltage of the inverter 30, The first and second current monitoring devices 120 and 220 for monitoring the first and second inductor currents flowing in the heating coils of the second C-type inductors 11 and 21, respectively, the output voltage at the same time and the first and second current monitoring devices The first and second impedance values are calculated from the inductor current of 2, and the metal material 1 is set so that the first and second impedance values during the heat treatment of the metal material 100 become a predetermined value. The position of the first and second C-shaped inductors 11 and 21 for 0 and a controller 50 for controlling in real time.

  The induction heating apparatus 1 shown in FIG. 1 is a C-type edge heater having a first C-type inductor 11 and a second C-type inductor 21 on both sides of a metal material 100 to be heat-treated. The first C-type inductor 11 is a “drive-side C-type inductor” disposed on the inverter 30 side of the production line (hereinafter referred to as “drive-side”). The second C-type inductor 21 is a “work-side C-type inductor” disposed on the side facing the drive side (hereinafter referred to as “work side”) across the metal material 100. That is, the induction heating apparatus 1 heats the drive-side edge portion of the metal material 100 and the work-side edge portion facing the drive-side edge portion.

  The first C-type inductor 11 has upper and lower iron cores 11a and 11b across an opening 110, and heating coils 11c and 11d wound around the iron cores 11a and 11b, respectively. Similarly, the 2nd C type inductor 21 has upper and lower iron cores 21a and 21b across opening 210, and heating coils 21c and 21d wound around iron cores 21a and 21b, respectively.

  The metal material 100 is disposed between the first C-type inductor 11 and the second C-type inductor 21, and the metal material 100 is transported in a direction perpendicular to the paper surface (hereinafter referred to as “transport direction”). . At this time, both edge portions of the metal material 100 respectively pass through the opening 110 of the first C-type inductor 11 and the opening 210 of the second C-type inductor 21.

  FIG. 2A shows a sectional structural view of the first C-type inductor 11, and the second C-type inductor 21 has the same structure. As shown in FIG. 2A, the lap amount indicates the length of the overlapping portion between the iron core of the C-type inductor and the metal material. As shown in FIG. 2B, the wrap amount when the edge portion of the metal material 100 and the edge portions on the inner side of the iron cores 11a and 21a are set to 0 mm. That is, when the wrap amount is 0 mm, the area of the overlapping portion between the iron core of the first C-type inductors 11 and 21 and the metal material 100 is the maximum. The wrap amount between the iron core 11a of the first C-type inductor 11 and the metal material 100 is “first wrap amount L1”, and the wrap amount between the iron core 21a of the second C-type inductor 21 and the metal material 100 is It is assumed that “second lap amount L2”.

  The inverter 30 supplies power to the first C-type inductor 11 and the second C-type inductor 21. By passing a current through the heating coils 11c and 11d of the first C-type inductor 11 and the heating coils 21c and 21d of the second C-type inductor 21, magnetic flux is generated in the vertical direction. An eddy current is induced in the metal material 100 by interlinking the magnetic flux with the metal material 100. Joule heat is generated by the resistance of the metal material 100 to the eddy current, and both edge portions of the metal material 100 are heated.

  In the induction heating apparatus 1 shown in FIG. 1, an instrument transformer 40 is connected to the output part of the inverter 30. An instrument current transformer 12 is connected between the power factor adjusting capacitor 13 and the first C-type inductor 11, and an instrument current transformer 22 is connected between the power factor adjusting capacitor 23 and the second C-type inductor 21. Is connected.

  The voltage monitoring device 140 monitors the output voltage Vi (i = 0, 1, 2,..., N) of the inverter 30 detected by the instrument transformer 40. In addition, the first current monitoring device 120 includes a first inductor current Idsi (i = 0, 1, 2) flowing in the heating coils 11 c and 11 d of the first C-type inductor 11 detected by the instrument current transformer 12. ,..., N) are monitored. The second current monitoring device 220 includes a second inductor current Iwsi (i = 0, 1, 2,...) Flowing in the heating coils 21c and 21d of the second C-type inductor 21 detected by the instrument current transformer 22. .., n) is monitored.

  Here, the output voltage V0 is the output voltage of the inverter 30 immediately after the heat treatment of the metal material 100 is started. The first inductor current Ids0 is a first inductor current that flows through the heating coils 11c and 11d of the first C-type inductor 11 immediately after the start of the heat treatment of the metal material 100, and the second inductor current Iws0 is This is the inductor current flowing through the heating coils 21 c and 21 d of the second C-type inductor 21.

  On the other hand, the output voltages V1, V2,..., Vn are output voltages of the inverter 30 during the heat treatment of the metal material 100, and are values measured as the metal material 100 is conveyed through the induction heating device 1. Yes, it is a value measured at regular position intervals or regular time intervals. Similarly, the first inductor currents Ids1, Ids2, ..., Idsn, and the second inductor currents Iws1, Iws2, ..., Iwsn are the first and second values during the heat treatment of the metal material 100. This is a value obtained by measuring the inductor current of the C-type inductors 11 and 21. The output voltage Vi, the first inductor current Idsi, and the second inductor current Iwsi are values measured simultaneously.

  The support body 10 of the first C-type inductor 11 is provided with wheels 15 driven by a motor 14, and the support body 20 of the second C-type inductor 21 is provided with wheels 25 driven by a motor 24. Yes. For this reason, the first C-type inductors 11 and 21 are driven by the motors 14 and 24 to travel on the rail 70 in the width direction of the metal material 100, that is, in the direction perpendicular to the transport direction (hereinafter simply referred to as “width direction”). It can be moved to. As the supports 10 and 20 move on the rail 70, the positions in the width direction of the first C-type inductor 11 and the second C-type inductor 21 are adjusted. The first wrap amount L1 and the second wrap amount L2 change according to changes in the positions of the first C-type inductors 11 and 21. Since the supports 10 and 20 can move independently of each other, the first wrap amount L1 and the second wrap amount L2 can be adjusted independently.

  The positions in the width direction of the first C-type inductors 11 and 21 are adjusted by motor drive devices 61 and 62 that control the operations of the motors 14 and 24, respectively. The control device 50 controls the positions of the first and second C-type inductors 11 and 21 with respect to the metal material 100 in real time by controlling the motor drive devices 61 and 62.

  FIG. 3 is a conceptual diagram illustrating a flow of signals input to the control device 50. A conceptual diagram such as FIG. 3 shows a top view of the metal material 100. The output voltage Vi is transmitted from the voltage monitoring device 140 to the control device 50, the first inductor current Idsi is transmitted from the first current monitoring device 120 to the control device 50, and the second current monitoring device 220 transmits the second inductor. The current Iwsi is transmitted to the control device 50 (i = 0, 1, 2,..., N). Hereinafter, a method of controlling the positions of the first C-type inductor 11 and the second C-type inductor 21 will be described.

  First, the output voltage V 0 immediately after the start of the heat treatment of the metal material 100 is transmitted from the voltage monitoring device 140 to the control device 50. At the same time, the first inductor current Ids0 and the second inductor current Iws0 immediately after the start of the heat treatment of the metal material 100 are transmitted from the first current monitoring device 120 and the second current monitoring device 220 to the control device 50, respectively. .

  The control device 50 calculates an initial value Zds0 of the first impedance value from the output voltage V0 and the first inductor current Ids0. Further, the initial value Zws0 of the second impedance value is calculated from the output voltage V0 and the second inductor current Iws0. The initial value Zds0 of the first impedance value and the initial value Zws0 of the second impedance value are recorded in the control device 50.

  Then, the output voltages V1, V2,..., Vn, the first inductor currents Ids1, Ids2,..., Idsn, and the second inductor currents Iws1, Iws2,. , Iwsn are sequentially transmitted to the control device 50 as the metal material 100 is conveyed through the induction heating device 1. That is, the output voltage Vi, the first inductor current Idsi, and the second inductor current Iwsi are measured values at each position heated in the induction heating device 1. The output voltages V1, V2,..., Vn are transmitted from the voltage monitoring device 140 to the control device 50. The first inductor currents Idsi, Ids2,..., Idsn, and the second inductor currents Iws1, Iws2,..., Iwsn are obtained from the first current monitoring device 120 and the second current monitoring device 220, respectively. Each is transmitted to the control device 50.

  The control device 50 uses the output voltages V1, V2, ..., Vn and the first inductor currents Ids1, Ids2, ..., Idsn to generate first impedance values Zds1, Zds2, ..., Zdsn. Are calculated in real time. As shown in FIG. 4A, the impedance difference dZds1, dZds2,..., Zdsn is the difference between the initial value Zds0 of the first impedance value and the first impedance values Zds1, Zds2,. Calculate dZdsn. Therefore, the impedance differences dZds1, dZds2,..., DZdsn are differences between the impedance value immediately after the start of the heat treatment and the impedance value at each position during heating by the induction heating device 1.

  When the impedance differences dZds1, dZds2,..., DZdsn are respectively calculated, the control device 50 is applied to, for example, the wrap amount correction function shown in FIG. A lap amount difference dL1 corresponding to is determined for the first lap amount L1. The wrap amount correction function is a function indicating the relationship between the impedance value and the wrap amount.

  The control device 50 obtains a new position obtained from the current position of the first C-type inductor 11 and the wrap amount difference dL1 at the time when the wrap amount difference dL1 corresponding to the impedance differences dZds1, dZds2,. A new position set value P1 is determined based on the first lap amount L1. The new position set value P1 is transmitted from the control device 50 to the motor drive device 61. In response to the drive control signal Sd transmitted from the motor drive device 61 to the motor 14 that has received the new position set value P1, the first C-type inductor 11 moves to the new position set value P1. That is, the first wrap amount L1 is adjusted by the wrap amount difference dL1 corresponding to the impedance differences dZds1, dZds2,..., DZdsn, and the position of the first C-type inductor 11 is changed. As a result, the first impedance value Zdsi matches the initial value Zds0.

  Similarly, the second wrap amount L2 is adjusted, and the position of the second C-type inductor 21 is changed. That is, by using the output voltages V1, V2,..., Vn and the second inductor currents Iws1, Iws2,..., Iwsn, the second impedance values Zws1, Zws2,. As shown in FIG. 4B, impedance differences dZws1, dZws2,..., Zwsn between the initial value Zws0 of the second impedance value and the second impedance values Zws1, Zws2,. dZwsn is respectively calculated.

  When the impedance differences dZws1, dZws2,..., DZwsn are calculated, the control device 50 converts the lap amount difference dL2 corresponding to the impedance differences dZws1, dZws2,. Is calculated. Then, a new position setting value P2 determined by the new second lap amount L2 obtained from the current position of the second C-type inductor 21 and the lap amount difference dLd at the time when the lap amount difference dL2 is calculated is controlled. The data is transmitted from the device 50 to the motor drive device 62. The second C-type inductor 21 moves in response to the drive control signal Sw transmitted from the motor drive device 62 that has received the new position set value P2 to the motor 24. As a result, the second impedance value Zwsi matches the initial value Zws0.

  The wrap amount correction function shown in FIG. 5 is determined by the characteristics of the first and second C-type inductors 11 and 21 and the electrical characteristics of the metal material 100. For this reason, it is preferable that the wrap amount and impedance value of each metal material are grasped in advance by actual measurement or the like and the respective wrap amount correction functions are registered in the control device 50 especially for each material of the metal material 100.

  Basically, the first impedance values Zds1, Zds2,..., Zdsn of the first C-type inductor 11 arranged on the drive side and the second impedance values of the second C-type inductor 21 arranged on the work side. The impedance values Zws1, Zws2,..., Zwsn of 2 are preferably controlled so as to be always equal. This is because by supplying power evenly to the drive side and the work side, there is a synergistic effect that the amount of temperature rise on both sides of the metal material 100 becomes uniform and the generation of arc spots is reduced. .

  However, other control methods are possible. For example, when it is known in advance that the temperature rise characteristics are different between both side portions of the metal material 100, the first and second C-type inductors 11 and 21 are arranged at predetermined positions, and both side portions are arranged. It is possible to adopt a method for achieving the soaking of the heat.

  FIG. 6 is a graph showing a temperature increase distribution in the width direction when the lap amount is changed. As shown in FIG. 6, the temperature rise characteristic of the C-type edge heater is a curve in which the temperature rise amount at the edge portion of the metal material 100 is high and becomes lower as the metal material 100 is closer to the center. Further, the temperature control point is defined as a temperature increase amount at a point 25 mm from the edge portion. Therefore, the graph shown in FIG. 6 also represents the temperature distribution in the width direction when the lap amount changes when the temperature rise value at the point of 25 mm from the edge of the metal material 100 is the same.

  The heating by the C-type edge heater uses the characteristic that when the lap amount is increased, the temperature rise amount at the edge portion is increased, and when the lap amount is decreased, the temperature increase amount at the edge portion is decreased. For example, when it is desired to further raise the temperature of either one of the edge portions, the positions of the first and second C-type inductors 11 and 21 may be set so that the wrap amount of one of them is set larger. It should be noted here that the arc spot may increase due to the impedance values of both edges not matching. For this reason, when producing a high-quality metal material 100 that does not allow arc soot, the above-described method of further raising the temperature of one of the edge portions should not be applied.

  FIG. 7 is a diagram illustrating a control method when changing the plate width of the metal material 100 to be heat-treated. In a general C-type edge heater, the first and second C-type inductors 11 are set by tracking control of a plate width value and material position deviation (material tracking) set in the induction heating device 1 or a plate width changing position. 21 position is set. However, position setting may be delayed or too early due to tracking control deviation. As the backup control of the position control, the control method of the induction heating apparatus according to the embodiment of the present invention that controls the position of the first and second C-type inductors 11 and 21 using the impedance value described above is used. It is possible.

  Also in the backup control of the tracking control, as shown in FIG. 7, the calculation results of the first impedance value Zdsi and the second impedance value Zwsi are used as they are. When the plate width change occurs while continuing the heat treatment, the impedance values of both edge portions instantaneously change with the same amount of change at substantially the same timing. When this state occurs, the position is reset by the control method for the induction heating apparatus according to the embodiment of the present invention. With this control, it is possible to reset the positions of the first and second C-type inductors 11 and 21 while minimizing the influence on the tracking control deviation. It is also possible to notify the operator of the occurrence of tracking control deviation. When the difference between the first impedance value Zdsi and the second impedance value Zwsi is 0, there is no tracking control deviation, and it is necessary to perform position setting by the control method of the induction heating apparatus according to the embodiment of the present invention. There is no.

  Further, for example, as shown in FIG. 8, a case is considered in which a positional deviation occurs in which the position of the metal material 100 is shifted to the drive side during conveyance, and the metal material 100 is in a state indicated by a broken line. Even if heating is continued in such a state, the temperature rise at both edge portions becomes unbalanced. At this time, the first inductor current Idsi and the second inductor current Iwsi change, and as a result, the first impedance value Zdsi and the second impedance value Zwsi also change. According to the induction heating device 1 according to the embodiment of the present invention, the amount of change in the first impedance value Zdsi and the second impedance value Zwsi is constantly monitored, and the impedance values at both edges of the metal material 100 are always the same. The positions of the first and second C-type inductors 11 and 21 are controlled so as to maintain the same. Thereby, the synergistic effect of arc spot reduction can be produced at the same time that the temperature rises at both edge portions are balanced.

  As described above, according to the induction heating apparatus 1 according to the embodiment of the present invention, the impedance difference between the first and second impedance values of both edges of the metal material 100 and the initial value during the heat treatment is obtained. The positions of the first and second C-type inductors 11 and 21 are controlled so that the impedance values match the initial values, calculated in real time. As a result, it is possible to provide an induction heating apparatus and a method for controlling the induction heating apparatus that can control the temperature rise at both edges of the metal material 100 to be heat-treated to a predetermined value.

<Modification>
FIG. 9 shows a configuration example when a C-type edge heater is installed in a hot rolling line. In general, in a hot rolling line, a plurality of C-type inductors are arranged on the drive side and the work side, respectively, along the conveying direction of the metal material 100. FIG. 9 shows drive-side entry-side C-type inductor 111 and drive-side exit-side C-type inductor 112 arranged on the drive-side entry side and exit side, and workpieces placed on the work-side entry side and exit side, respectively. In the example, the side entry side C-type inductor 211 and the work side exit side C-type inductor 212 are loaded in one C-type edge heater. All these C-type inductors are powered by a single inverter 30.

  In order to reduce the occurrence of arc spots, a technique for canceling the induced current by connecting opposite C-type inductors in opposite phase has been proposed (see, for example, JP-A-8-69866). For example, in the case of the configuration shown in FIG. 9, the work side input side C-type inductor 211 and the drive side output side C type inductor 112 are connected in antiphase with the drive side input side C type inductor 111, The inductor 212 is connected in phase with the drive-side entry-side C-type inductor 111.

  However, when the position of the conveyed metal material 100 is shifted to one of the sides, this canceling effect is diminished. At this time, it is possible to stably reduce the generation of arc spots by applying the control method of the induction heating apparatus 1 according to the embodiment of the present invention as described above.

In the example illustrated in FIG. 9, the output voltage Vi is from the voltage monitoring device 140, and the inductor current of the drive side input-side C-type inductor 111 is the first inductor current I _E dsi from the first input current monitoring device 120 </ b> A. The inductor current of the drive-side output-side C-type inductor 112 is transmitted as the first inductor current _ID Dsi from the first output-side current monitoring device 120B to the control device 50 (i = 0, 1,...). , N). Furthermore, the inductor current of the work side input side C-type inductor 211 is set as the second inductor current I _E wsi from the second input side current monitoring device 220A, and the inductor current of the work side output side C type inductor 212 is changed to the second inductor current. The current I _D wsi is transmitted from the second outgoing current monitoring device 220B to the control device 50 (i = 0, 1,..., N).

  In the C-type edge heater in which a plurality of C-type inductors are arranged on the drive side and the work side as described above, the distance between the input-side and output-side C-type inductors is short, and the input-side and output-side C-type inductors are short. It is normally not possible for the position of the metal material 100 to be so extreme that a difference appears in the impedance value. For this reason, the impedance may be calculated from the inductor current of either the input side or the output side C-type inductor.

  However, considering the characteristic difference in the C-type inductor itself, the average value calculated by (input-side C-type inductor current + output-side C-type inductor current) / 2 as shown in FIG. It may be used for inductor current. FIG. 10 shows the case where the motor drive device 61 is controlled using the average value of the input-side C-type inductor current and the output-side C-type inductor current for the first inductor current on the drive side. Similarly, the motor drive device 62 may be controlled using an average value of the input-side C-type inductor current and the output-side C-type inductor current.

  As mentioned above, although this invention was described by embodiment, it should not be understood that the description and drawing which form a part of this indication limit this invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art. That is, it goes without saying that the present invention includes various embodiments not described herein. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

  The induction heating device of the present invention is not only an edge heater that heats both edge portions of a metal material to be heat-treated, but also an induction heating that regulates the setting position by defining the setting position of the induction heating device and the metal material. Available to the device.

Idsi ... first inductor current Iwsi ... second inductor current P1, P2 ... position set value Vi ... output voltage 1 ... induction heating device 10, 20 ... support 11 ... first C-type inductor 21 ... second C Type inductors 11a, 11b, 21a, 21b ... Iron cores 11c, 11d, 21c, 21d ... Heating coils 12, 22 ... Current transformers 13, 23 ... Power factor adjusting capacitors 14, 24 ... Motors 15, 25 ... Wheels 30 ... Inverter 40 ... Transformer for instrument 50 ... Control device 61, 62 ... Motor drive device 70 ... Rail 100 ... Metal material 110, 210 ... Openings 111, 112, 211, 212 ... C-type inductor 120 ... First current monitoring Device 120A ... First input current monitoring device 120B ... First output current monitoring device 140 ... Voltage monitoring device 220 ... Second power Monitoring device 220A ... second entrance side current monitoring device 220B ... second output side current monitoring device

Claims (4)

A first C-type inductor that heats one edge portion of the metal material to be heat-treated, and a second C-type inductor that heats the other edge portion of the metal material;
An inverter for feeding power to the first and second C-type inductors;
A voltage monitoring device for monitoring the output voltage of the inverter;
First and second current monitoring devices for monitoring first and second inductor currents flowing in the heating coils of the first and second C-type inductors, respectively;
The initial values of the first and second impedance values are calculated from the output voltage immediately after the start of the heat treatment of the metal material and the first and second inductor currents, respectively, and the metal material is heated during the heat treatment. by the said output voltage and at the time the first and second inductor currents calculate the first and the second impedance value, said first and second impedance values during the heat treatment of the metal material is the initial An induction heating device comprising: a control device that controls the positions of the first and second C-type inductors relative to the metal material in real time so as to be equal to each other . The control device is
Calculating the impedance difference between the first and second impedance values during the heat treatment of the metal material and the initial value of the first and second impedance values in real time;
The first impedance value and the second impedance value are set to the initial value by using a function indicating a relationship between the wrap amount indicating the position of the first and second C-type inductors with respect to the metal material and the impedance difference. The induction heating apparatus according to claim 1, wherein a new wrap amount difference is determined, and new positions of the first and second C-type inductors are determined using the wrap amount difference. A method for controlling an induction heating apparatus having first and second C-type inductors, comprising:
Heating one edge portion of the metal material to be heat-treated by the first C-type inductor, and heating the other edge portion of the metal material by the second C-type inductor;
Monitoring the output voltage of the inverter feeding the first and second C-type inductors;
Monitoring first and second inductor currents respectively flowing in the heating coils of the first and second C-type inductors during the heat treatment of the metal material;
Calculating initial values of the first and second impedance values from the output voltage and the first and second inductor currents immediately after the start of the heat treatment of the metal material, respectively;
Said first and said second impedance value calculated by the output voltage and the first and second inductor current at the same time during the heat treatment of the metal material, the first during the heat treatment of the metal material And in real time, controlling the positions of the first and second C-type inductors with respect to the metal material such that the second impedance value is equal to the initial value, respectively. Control method of the device. Controlling the position of the first and second C-type inductors relative to the metal material;
Calculating in real time the respective impedance differences between the first and second impedance values during the heat treatment of the metal material and the initial values of the first and second impedance values;
The first impedance value and the second impedance value are set to the initial value by using a function indicating a relationship between the wrap amount indicating the position of the first and second C-type inductors with respect to the metal material and the impedance difference. And determining a new position of the first and second C-type inductors using the difference in wrap amount. 4. The induction heating apparatus according to claim 3, further comprising: Control method.

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