TW202146131A - Control method for continuous heat treatment equipment - Google Patents

Abstract

[Problem to be solved] The application discloses a control method for continuous heat treatment equipment that can achieve good temperature uniformity in the width direction in total. [Solution] The continuous heat treatment equipment 1 is provided with a first heating section, a second heating section and a third heating section, which are arranged along a conveyance direction F of a metal member, a control section that controls a first output power, a second output power and a third output power output to each of the first heating section, the second heating section and the third heating section, respectively, and a first measurement section that measures a first voltage and a first current in the first heating section. The first heating section, the second heating section and the third heating section are solenoidal induction heating, transverse induction heating and resistance heating, respectively. The control section rationally proportions the output share of each heating section, and also calculates a equivalent impedance in a parallel resonance circuit based on the first voltage and first current, and controls the first output power so that the first output power decreases when the equivalent impedance becomes larger than a threshold value.

Description

Control method of continuous heat treatment equipment

The present invention relates to a control method of continuous heat treatment equipment for continuously heat treatment of metal components.

Electromagnetic induction heating can achieve rapid temperature rise and real-time temperature adjustment because the metal member itself heats up by the induced current. Electromagnetic induction heating is roughly classified into a solenoid type and a horizontal type. In the solenoid type, a heating coil wound in a solenoid shape is arranged around a metal member, and an alternating current flows in the heating coil to generate an induced current on the surface of the metal member, thereby heating the metal member. In the transverse type, a pair of heating coils are separated in the thickness direction of the metal member and arranged to face each other so as to sandwich the metal member, and the alternating magnetic field generated from the heating coils penetrates in the thickness direction of the metal member.

Patent Document 1 discloses a heating device including a transverse induction heating section and a solenoid induction heating section, and the transverse induction heating section responds to a temperature in the width direction caused by roll cooling water, etc. due to rolling delay. The non-uniformity is temperature compensated, and the above-mentioned solenoid-type induction heating section performs temperature compensation for the temperature non-uniformity in the longitudinal direction.

Patent Document 2 discloses a method of preheating a thin steel sheet to a specific preheating temperature (lower than Curie temperature (Curie temperature) Tc) is lower than the temperature of 200°C or more, and the preheating temperature. Furthermore, Patent Document 2 discloses a method of providing a heating zone and a soaking zone on the downstream side of the preheating zone. prior art literature Patent Literature

Patent Document 1: Japanese Patent Laid-Open No. 2003-290812 Patent Document 2: Japanese Patent Application Laid-Open No. 2016-98420

The problem to be solved by the invention

Although the solenoid type has excellent temperature uniformity in the width direction of the metal member, when the temperature of the metal member increases and approaches the Curie temperature of the metal member, the relative magnetic permeability of the metal member is greatly reduced, so the induced current is The penetration depth will be deeper. As a result, in the thin metal member, the induced current flowing on the front surface of the metal member and the induced current flowing on the back surface of the metal member cancel each other out, and the heating efficiency is greatly reduced. On the other hand, in the horizontal type, the thickness of the metal member is not easily affected, but the temperature in the width direction of the metal member is uniform because the induced current concentrates on the end portion in the width direction of the metal member and the end portion is overheated. Sex will be worse than the solenoid type.

In Patent Document 1, although it is attempted to compensate for the temperature non-uniformity by the transverse induction heating section and the solenoid induction heating section, it is difficult to say that sufficient temperature uniformity can be obtained for thin metal members. sex.

Patent Document 2 only discloses a method of rapidly heating a thin steel sheet to around the Curie temperature by a solenoid-type induction heating section, and does not disclose a method for making the temperature uniformity in the width direction good as a whole in a continuous annealing facility. control.

Then, the subject of this invention is to provide the control method of the continuous heat processing facility which can make the temperature uniformity in the width direction perpendicular|vertical to the conveyance direction of a metal member integrally formed favorable. means of solving problems

In order to solve the above-mentioned problem, a control method of a continuous heat treatment facility according to an aspect of the present invention is characterized in that the continuous heat treatment facility includes a first heating unit, a second heating unit, and a third heating unit, which are arranged along the conveyance direction of the metal member. are arranged in sequence and continuously; the control part controls the first output power, the second output power and the third output power respectively output to the first heating part, the second heating part and the third heating part; and The first measuring unit measures the first voltage and the first current in the first heating unit, The first heating part, the second heating part and the third heating part are respectively a solenoid type induction heating part, a transverse type induction heating part and a resistance heating part, In the continuous heat treatment equipment, the control unit calculates the equivalent impedance in the parallel resonant circuit based on the first voltage and the first current measured by the first measurement unit, and controls the first output power Success: When the calculated equivalent impedance becomes larger than the threshold value, the first output power is reduced. Invention effect

According to this invention, when the equivalent impedance in the parallel resonance circuit of the first heating unit (ie, the solenoid-type induction heating unit) becomes larger than the threshold value, the first output power is reduced. In other words, before the temperature of the metal member heated by the first heating portion becomes the Curie temperature of the metal member, the first output is reduced in advance. Thereby, since the temperature of the metal member is lower than the Curie temperature of the metal member, the heating by the solenoid-type induction heating portion can be maintained, and the aforementioned solenoid-type induction heating portion is in the conveying direction. Since the temperature uniformity in the orthogonal width direction is excellent, the overall temperature uniformity in the width direction can be made good.

Form for carrying out the invention

Hereinafter, an embodiment of the control method of the continuous heat treatment facility 1 of the present invention will be described with reference to the drawings.

[embodiment] A control method of the continuous heat treatment facility 1 according to one embodiment will be described with reference to FIGS. 1 to 4 . FIG. 1 is a perspective view schematically illustrating a continuous heat treatment facility 1 according to an embodiment. FIG. 2 is a block diagram of the continuous heat treatment apparatus 1 shown in FIG. 1 . FIG. 3 is a flowchart at the time of determining the optimum setting value in the continuous heat treatment facility 1 . FIG. 4 is a flowchart when the continuous heat treatment facility 1 is operated.

[Overall composition of continuous heat treatment equipment] As shown in FIG. 1 , the continuous heat treatment facility 1 includes a first heating unit 10 , a second heating unit 20 , and a third heating unit 30 , and the heating units 10 , 20 , and 30 are directed from the upstream side along the conveyance direction F of the metal member 3 . The downstream side is arranged sequentially and continuously. The continuous heat treatment facility 1 performs continuous heat treatment (for example, continuous annealing treatment) while conveying the metal member 3 in the conveyance direction F through conveyance rollers (not shown). The metal member 3 as the workpiece may be, for example, a thin metal sheet (eg, a steel sheet), or a long metal strip obtained by rolling a metal sheet. The thickness of the metal member 3 is, for example, 0.1 mm to 5 mm.

The 1st temperature sensor 16 is arrange|positioned at the downstream side of the conveyance direction F of the 1st heating part 10 (the carrying out side of the 1st heating part 10). The 1st temperature sensor 16 is a radiation thermometer which measures the temperature of the unloading side (namely, the 1st unloading side temperature) of the center part in the width direction W of the metal member 3 in a dot shape. The second temperature sensor 26 is disposed on the downstream side (the carry-out side of the second heating unit 20 ) in the conveyance direction F of the second heating unit 20 . The second temperature sensor 26 measures the temperature on the delivery side of the metal member 3 (ie, the second temperature on the delivery side) in the width direction W perpendicular to the conveyance direction F while scanning. The second temperature sensor 26 may be, for example, a scanning pyrometer. The third temperature sensor 36 is disposed on the downstream side (the unloading side of the third heating unit 30 ) in the conveyance direction F of the third heating unit 30 . The third temperature sensor 36 measures the temperature on the delivery side of the metal member 3 in the width direction W perpendicular to the conveyance direction F (that is, the third temperature on the delivery side). The third temperature sensor 36 may be, for example, a scanning pyrometer.

As shown in FIG. 2 , the continuous heat treatment facility 1 includes a first heating unit 10 , a second heating unit 20 , a third heating unit 30 , a first temperature sensor 16 , a second temperature sensor 26 , and a third temperature sensor the detector 36 and the control unit 5 .

The first heating unit 10 is a solenoid-type induction heating unit, and includes a first heating coil 12 , a first power source 13 , a first output control unit 14 , and a first measurement unit 18 . The first heating coil 12 is a coil wound around the metal member 3 . The first power supply 13 outputs the first output power of the high-frequency alternating current to the first heating coil 12 . The first output power control unit 14 controls the first output power output to the first heating coil 12 by the first power supply 13 . An alternating magnetic field is generated by the first heating coil 12 so as to penetrate the longitudinal section of the metal member 3 , and induced currents are generated on the front, back and side surfaces of the metal member 3 by the alternating magnetic field. Then, the metal member 3 is heated by Joule heating based on the induced current and the resistance of the metal member 3 . The first measurement unit 18 measures the first voltage and the first current of the first output power output to the first heating coil 12 . The control part 5 controls so that each measured value of the 1st voltage and the 1st electric current which were measured may be acquired, and each measured value may be memorize|stored in the memory|storage part 7. FIG.

The second heating unit 20 is a horizontal induction heating unit, and includes a second heating coil 22 , a second power source 23 , and a second output power control unit 24 . The second heating coil 22 is a pair of heating coils that are spaced apart in the thickness direction of the metal member 3 and arranged to face each other so as to sandwich the metal member 3 therebetween. The second power supply 23 outputs the second output power of the high-frequency alternating current to the second heating coil 22 . The second output power control unit 24 controls the second output power output to the second heating coil 22 by the second power supply 23 . The alternating magnetic field generated from the second heating coil 22 penetrates in the thickness direction of the metal member 3 . An induced current is generated on the surface of the metal member 3 by this alternating magnetic field, and the metal member 3 is heated by Joule heating based on the induced current and the resistance of the metal member 3 .

The third heating unit 30 is a resistance heating unit, and includes a heating heater 32 , a third power source 33 , and a third output power control unit 34 . The heating heater 32 is a resistance heating element. The third power source 33 outputs the third output power of the alternating current to the heating heater 32 . The third output power control unit 34 controls the third output power output to the heating heater 32 by the third power supply 33 . In the third heating unit 30 , the metal member 3 is heated by indirect resistance heating that transmits heat energy generated by energizing the heating heater 32 to the metal member 3 for heating.

The control part 5 controls each heating part of the continuous heat processing apparatus 1, and controls each heating part of the 1st heating part 10, the 2nd heating part 20, and the 3rd heating part 30 in detail. The control unit 5 is, for example, a computer, and includes an arithmetic unit (CPU: Central Processing Unit) 6 and a memory unit (memory such as ROM or RAM) 7 .

The memory unit 7 performs, for example, the following memory operations. That is, the memory|storage part 7 memorize|stores various programs for performing the heat processing in each of the 1st heating part 10, the 2nd heating part 20, and the 3rd heating part 30. The memory unit 7 memorizes data (for example, Curie temperature, heat content, specific resistance, width, thickness, or heat treatment conditions) about the heat treatment object, that is, various metal members 3 , or the first rated output power of the first heating unit 10 . , the second rated output power of the second heating part 20 and the third rated output power of the third heating part 30 . The memory unit 7 memorizes the temperature data (the temperature on the first delivery side, the temperature on the second delivery side, and the 3rd outgoing side temperature). The memory unit 7 memorizes a first calculation formula, and the first calculation formula is used to calculate the width of the first heating unit 10 from the temperature rise range (the temperature on the first delivery side - the temperature on the first delivery side) in the first heating unit 10 . The first temperature in the direction W is uneven. The memory unit 7 memorizes a second calculation formula, and the second calculation formula is used to calculate the width of the second heating unit 20 from the temperature increase range (the temperature on the second outlet side - the temperature at the second inlet side) in the second heating unit 20 . The second temperature in the direction W is uneven. The memory unit 7 memorizes the third calculation formula, and the third calculation formula is used to calculate the temperature difference from the first calculation based on the heat treatment conditions of the metal member 3, the third rated output power, and the calculated cumulative temperature unevenness caused by induction heating. 3. The size T of the final temperature unevenness (hereinafter, referred to as the third temperature unevenness) in the width direction of the metal member 3 carried out by the heating unit 30 .

The arithmetic unit 6 performs, for example, the following arithmetic operations. That is, the calculating part 6 calculates the 1st output power output to the 1st heating part 10, the 2nd output power outputted to the 2nd heating part 20, and the 3rd output power outputted to the 3rd heating part 30, respectively. The calculation unit 6 calculates an optimum set value for making the magnitude T of the third temperature unevenness smaller than the allowable value based on the Curie temperature of the metal member 3 and the heat treatment conditions. Specifically, the optimum set values are set values for the first delivery side temperature, the second delivery side temperature, the first output power, the second output power, and the third output power. The computing unit 6 calculates the equivalent impedance based on the first voltage and the first current measured by the first measuring unit 18 . The computing unit 6 calculates the threshold value based on the material of the metal member 3 and the width dimension of the metal member 3 in the width direction W orthogonal to the conveyance direction F. Thereby, the threshold value can be optimized according to the material and width of the metal member 3 .

The solenoid-type induction heating unit as the first heating unit 10 has the following problem: although the temperature uniformity in the width direction W of the metal member 3 is excellent, when the thickness of the metal member 3 is thin, when the metal member 3 is thin When the temperature of the member 3 approaches its Curie temperature, the heating efficiency is greatly reduced. That is, the penetration depth of the induced current will be in a relationship proportional to the square root of the resistivity of the metal member 3 and inversely proportional to the square root of the relative magnetic permeability of the metal member 3 . When the temperature of the metal member 3 rises and approaches the Curie temperature of the metal member 3, since the relative magnetic permeability of the metal member 3 is greatly reduced, the penetration depth of the induced current becomes deeper. As a result, when the thickness of the metal member 3 is thin, the induced current flowing on the front surface of the metal member 3 and the induced current flowing on the back surface of the metal member 3 cancel each other out, thereby greatly reducing the heating efficiency.

Although the horizontal induction heating portion as the second heating portion 20 does not reduce the heating efficiency even if the thickness of the metal member 3 is reduced, there is a problem that the induced current is concentrated at the end of the width direction W of the metal member 3 . Therefore, the temperature uniformity in the width direction W will be worse than that of the solenoid type.

Although the resistance heating part as the third heating part 30 has excellent temperature uniformity in the width direction W of the metal member 3 and the heating efficiency does not decrease even if the thickness of the metal member 3 is reduced, it needs to perform a rapid temperature rise and fall operation will be difficult.

In this way, while the solenoid type induction heating unit 10 , the lateral type induction heating unit 20 and the resistance heating unit 30 have strengths and weaknesses, the width direction of the metal member 3 will be described with reference to FIGS. 3 and 4 . The temperature uniformity above W is generally well controlled.

[Control method of continuous heat treatment equipment] FIG. 3 is a flowchart at the time of determining the optimum setting value in the continuous heat treatment facility 1 . FIG. 4 is a flowchart when the continuous heat treatment facility 1 is operated.

In FIG. 3 , before the continuous heat treatment equipment 1 is operated, a step for determining the optimum setting value is started. Optimum setting value (step S1). In step S2, the control part 5 calculates how many degreeC the temperature of the 1st unloading side of the 1st heating part 10 should be based on the Curie temperature of the metal member 3 memorize|stored in the memory part 7. In step S3 , the control unit 5 calculates the first output power to be output to the first heating unit 10 according to the width or thickness of the metal member 3 stored in the memory unit 7 and the heat treatment conditions (including the difference in heat content). In step S4 , the control unit 5 calculates the temperature on the second outgoing side of the second heating unit 20 (in other words, the temperature of the second outgoing side of the second heating unit 20 (in other words, the The temperature of the metal member 3 of the third heating part 30 is approximately the temperature).

In step S5 , the control unit 5 calculates the second output power to be output to the second heating unit 20 according to the width or thickness of the metal member 3 and the heat treatment conditions (including the difference in heat content) stored in the memory unit 7 . In step S6 , the control unit 5 calculates the first temperature variation of the first heating unit 10 and the second temperature variation of the second heating unit 20 from the first calculation formula and the second calculation formula stored in the memory unit 7 , respectively. all. Then, the control unit 5 controls to calculate the square root of the sum of the squares of the calculated first temperature unevenness and the second temperature unevenness, and uses the value of the square root of the calculated square sum as the cumulative temperature by induction heating It is uneven to let the memory part 7 memorize.

In step S7, the control part 5 calculates the third output power to be output to the third heating part 30 according to the width or thickness of the metal member 3 and the heat treatment conditions (including the difference in heat content) stored in the memory part 7, and then , the magnitude T of the third temperature unevenness is calculated from the third calculation formula similarly stored in the memory unit 7 .

In step S8, the control part 5 determines whether the magnitude|size T of the 3rd temperature unevenness is smaller than an allowable value.

When the magnitude T of the third temperature unevenness is greater than or equal to the allowable value in step S8, the process proceeds to step S9, and the control unit 5 determines whether the third output power of the third heating unit 30 has reached the upper limit, that is, 3rd rated output power. When the third output of the third heating unit 30 does not reach the upper limit in step S9, the control unit 5 sets the third output of the third heating unit 30 to increase (step S10). And it returns to step S4, and the control part 5 calculates the temperature of the metal member 3 carried in the 3rd heating part 30.

In step S9, when the third output power of the third heating unit 30 has reached the upper limit, the process proceeds to step S13, and the control unit 5 determines whether or not the temperature on the first unloading side of the first heating unit 10 has reached the limit. temperature. When the temperature on the first discharge side of the first heating unit 10 has reached the limit temperature in step S13, the control unit 5 notifies a setting error and ends the setting flow (step S16). In addition, the limit temperature is a temperature lower than the Curie temperature at which the relative magnetic permeability of the metal member 3 becomes 1, and is a temperature at which the heating efficiency is greatly reduced.

In step S13, when the temperature on the first delivery side of the first heating unit 10 does not reach the limit temperature, the control unit 5 sets the temperature on the first delivery side of the first heating unit 10 to be higher, and uses the first delivery side temperature of the first heating unit 10 to increase. 1. The first output side temperature of the heating unit 10 is calculated by referring to the method of the above paragraph number [0029] (step S14). In step S15, the control part 5 judges whether the 1st output power of the 1st heating part 10 has reached the upper limit, ie, the 1st rated output power.

In step S15, when the 1st output power of the 1st heating part 10 does not reach the upper limit, it returns to step S3, and the control part 5 calculates the output power of the 1st heating part 10. In step S15, when the 1st output power of the 1st heating part 10 has reached the upper limit, it progresses to step S16, and the control part 5 notifies the setting error and complete|finishes a setting process.

When the magnitude T of the third temperature unevenness is smaller than the allowable value in step S8, the control unit 5 compares the calculated first and second discharge-side temperatures with the first output power, the first The optimum setting values of the second output power and the third output power are stored in the memory unit 7 (step S11). That is, the control unit 5 preliminarily calculates the relationship between the first delivery side temperature, the second delivery side temperature, the first output power, the second output power, and the third output power based on the Curie temperature of the metal member 3 and the heat treatment conditions. The respective optimum setting values are stored in the memory unit 7 so that the magnitude T of the third temperature unevenness becomes smaller than the allowable value. Thereby, the magnitude T of the third temperature unevenness can be made smaller than the allowable value by using the optimal setting value calculated in advance as the initial value when operating the continuous heat treatment facility 1 .

In addition, in step S12, the flow of determining the optimum setting value in the continuous heat treatment facility 1 ends.

FIG. 4 is a flowchart showing a case where the first heating coil 12 and a capacitor (not shown) constitute a parallel resonance circuit.

In FIG. 4, the step for operating the continuous heat treatment apparatus 1 is started (step S21). In step S22, the control unit 5 sets each optimum setting value memorized in the memory unit 7 (that is, the temperature and the first output power for the first outgoing side of the first heating unit 10 and the first output power for the second heating unit 20 the temperature on the second delivery side and the second output, the third output to the third heating unit 30 ), and the target temperature on the delivery side of the third heating unit 30 . In step S23, the control part 5 acquires each measured value of the 1st voltage and the 1st current output to the 1st heating coil 12 through the 1st measurement part 18. In step S24, the control unit 5 calculates the equivalent impedance based on the respective measured values of the first voltage and the first current measured in step S23.

In step S25, the control part 5 determines whether the calculated equivalent impedance is larger than a threshold value. When the equivalent impedance calculated in step S24 is larger than the threshold value, the control unit 5 sets the temperature on the first unloading side of the first heating unit 10 to be lower (step S26 ). In step S27, the control unit 5 calculates the first output power of the first heating unit 10 and the first output power of the second heating unit 20, respectively, based on the temperature on the first unloading side of the first heating unit 10 set in step S26. 2 output power. Therefore, in steps S26 and 27 , when the calculated equivalent impedance is larger than the threshold value, the control unit 5 controls the first output power so as to decrease the first output power of the first heating unit 10 . Then, it returns to step S23, and the control part 5 acquires each measurement value of the 1st voltage and the 1st current output to the 1st heating coil 12 through the 1st measurement part 18.

When the equivalent impedance calculated in step S25 is equal to or smaller than the threshold value, the control unit 5 measures the final width direction of the metal member 3 carried out from the third heating unit 30 through the third temperature sensor 36 . The size T of the temperature unevenness (that is, the third temperature unevenness) (step S28). In step S29, the control part 5 determines whether the magnitude|size T of the 3rd temperature unevenness is smaller than an allowable value.

When the magnitude T of the third temperature unevenness is smaller than the allowable value in step S29 , the process returns to step S23 , and the control unit 5 obtains the output to the first heating coil 12 through the first measuring unit 18 . The respective measured values of the first voltage and the first current.

When the magnitude T of the third temperature unevenness is greater than or equal to the allowable value in step S29, the process proceeds to step S30, and the control unit 5 determines whether the third output power of the third heating unit 30 has reached the upper limit, that is, 3rd rated output power. When the third output of the third heating unit 30 does not reach the upper limit in step S30, the control unit 5 sets the third output of the third heating unit 30 to increase (step S31). Thereby, since the share ratio of the 3rd heating part 30 excellent in temperature uniformity (that is, a resistance heating part) becomes large, the temperature uniformity in the width direction W improves.

In step S32, the control part 5 calculates the temperature of the metal member 3 carried into the 3rd heating part 30. In step S34, the control part 5 calculates the temperature of the second carrying-out side of the second heating part 20 calculated in step S32 (that is, it is similar to the temperature of the metal member 3 carried into the third heating part 30), respectively. The first output of the first heating unit 10 and the second output of the second heating unit 20 are calculated. Then, it returns to step S23, and the control part 5 acquires each measurement value of the 1st voltage and the 1st current output to the 1st heating coil 12 through the 1st measurement part 18.

When the third output power of the third heating unit 30 has reached the upper limit in step S30, the process proceeds to step S35, and the control unit 5 determines whether or not the temperature on the first unloading side of the first heating unit 10 has reached the limit. temperature. In step S35, when the temperature on the first unloading side of the first heating unit 10 has reached the limit temperature, the control unit 5 notifies the reduction of the conveyance speed (step S37). Then, returning to step S34, the control part 5 calculates the 1st output power of the 1st heating part 10 and the 2nd output power of the 2nd heating part 20, respectively.

In step S35, when the temperature on the first delivery side of the first heating unit 10 does not reach the limit temperature, the control unit 5 sets the temperature on the first delivery side of the first heating unit 10 to increase (step S36). . Thereby, since the share ratio of the 1st heating part 10 excellent in the temperature uniformity in the width direction W (namely, a solenoid induction heating part) becomes large, the temperature uniformity in the width direction W can be improved. Then, returning to step S34, the control part 5 calculates the 1st output power of the 1st heating part 10 and the 2nd output power of the 2nd heating part 20, respectively.

Unless a certain abnormality such as a calculation error occurs, the operation of the continuous heat treatment apparatus 1 is continuously performed in accordance with the flowchart of FIG. 4 .

[Variation] A control method of the continuous heat treatment facility 1 according to the modification will be described with reference to FIG. 5 . FIG. 5 is a flowchart showing a modification when the continuous heat treatment facility 1 is operated.

FIG. 5 is a flowchart showing a case where the first heating coil 12 and a capacitor (not shown) constitute a series resonance circuit.

In FIG. 5, the step for operating the continuous heat treatment apparatus 1 is started (step S41). In step S42, the control unit 5 sets each optimum setting value memorized in the memory unit 7 (that is, the temperature and the first output power for the first discharge side of the first heating unit 10 and the first output power for the second heating unit 20 the second temperature on the delivery side and the second output, the third output to the third heating unit 30 ), and the target temperature on the delivery side of the third heating unit 30 . In step S43, the control part 5 acquires each measured value of the 1st voltage and the 1st current output to the 1st heating coil 12 through the 1st measurement part 18. In step S44, the control unit 5 calculates the equivalent impedance based on the respective measured values of the first voltage and the first current measured in step S43.

In step S45, the control part 5 determines whether the calculated equivalent impedance is smaller than a threshold value. When the equivalent impedance calculated in step S44 is smaller than the threshold value, the control unit 5 sets the temperature of the first unloading side of the first heating unit 10 to be lowered (step S46 ). In step S47, the control unit 5 calculates the first output power of the first heating unit 10 and the first output power of the second heating unit 20, respectively, based on the temperature on the first unloading side of the first heating unit 10 set in step S46. 2 output power. Therefore, in steps S46 and 47 , when the calculated equivalent impedance is larger than the threshold value, the control unit 5 controls the first output power to decrease the first output power of the first heating unit 10 . Then, returning to step S43 , the control unit 5 acquires the respective measured values of the first voltage and the first current output to the first heating coil 12 through the first measuring unit 18 .

When the equivalent impedance calculated in step S45 is equal to or greater than the threshold value, the control unit 5 measures the final width direction of the metal member 3 carried out from the third heating unit 30 through the third temperature sensor 36 . The size T of the temperature unevenness (that is, the third temperature unevenness) (step S48). In step S49, the control part 5 determines whether the magnitude|size T of the 3rd temperature unevenness is smaller than an allowable value.

When the magnitude T of the third temperature unevenness is smaller than the allowable value in step S49 , the process returns to step S43 , and the control unit 5 obtains the output to the first heating coil 12 through the first measuring unit 18 . The respective measured values of the first voltage and the first current.

When the magnitude T of the third temperature unevenness is greater than or equal to the allowable value in step S49, the process proceeds to step S50, and the control unit 5 determines whether the third output power of the third heating unit 30 has reached the upper limit, that is, 3rd rated output power. When the third output power of the third heating unit 30 does not reach the upper limit in step S50, the control unit 5 sets the third output power of the third heating unit 30 to increase (step S51). Thereby, since the share ratio of the 3rd heating part 30 excellent in temperature uniformity (that is, a resistance heating part) becomes large, the temperature uniformity in the width direction W improves.

In step S52, the control part 5 calculates the temperature of the metal member 3 carried into the 3rd heating part 30. In step S54, the control part 5 calculates the temperature of the second carrying-out side of the second heating part 20 calculated in step S52 (that is, it is similar to the temperature of the metal member 3 carried into the third heating part 30), respectively. The first output of the first heating unit 10 and the second output of the second heating unit 20 are calculated. Then, it returns to step S43, and the control part 5 acquires each measurement value of the 1st voltage and the 1st current output to the 1st heating coil 12 through the 1st measurement part 18.

When the third output power of the third heating unit 30 has reached the upper limit in step S50, the process proceeds to step S55, and the control unit 5 determines whether or not the temperature on the first unloading side of the first heating unit 10 has reached the limit. temperature. In step S55, when the temperature of the 1st unloading side of the 1st heating part 10 has reached the limit temperature, the control part 5 will notify to reduce a conveyance speed (step S57). Then, returning to step S54, the control part 5 calculates the 1st output power of the 1st heating part 10 and the 2nd output power of the 2nd heating part 20, respectively.

In step S55, when the temperature on the first delivery side of the first heating unit 10 does not reach the limit temperature, the control unit 5 sets the temperature on the first delivery side of the first heating unit 10 to increase (step S56). . Thereby, since the share ratio of the 1st heating part 10 excellent in the temperature uniformity in the width direction W (namely, a solenoid induction heating part) becomes large, the temperature uniformity in the width direction W can be improved. Then, returning to step S54, the control part 5 calculates the 1st output power of the 1st heating part 10 and the 2nd output power of the 2nd heating part 20, respectively.

Unless a certain abnormality such as a calculation error occurs, the operation of the continuous heat treatment apparatus 1 is continuously performed according to the flowchart of FIG. 5 .

Although the specific embodiment of the present invention and numerical values have been described, the present invention is not limited to the invention of the above-described embodiment, and can be implemented with various modifications within the scope of the present invention.

The first heating unit 10 does not necessarily have to be constituted by a single heating zone, and may be configured to be divided into a plurality of heating zones and arrange the plurality of heating zones in the conveyance direction F in series. Similarly to the first heating unit 10 , the second heating unit 20 and the third heating unit 30 may be configured by arranging a plurality of heating zones in series in the conveyance direction F, respectively.

When the present invention and the embodiments are put together, it becomes as follows.

The control method of the continuous heat treatment equipment 1 according to an aspect of the invention is characterized in that: the continuous heat treatment equipment 1 includes: The first heating unit 10, the second heating unit 20 and the third heating unit 30 are sequentially and continuously arranged along the conveying direction F of the metal member 3; the control unit 5, respectively controlling the first output power, the second output power and the third output power output to the first heating unit 10, the second heating unit 20 and the third heating unit 30; and The first measuring unit 18 measures the first voltage and the first current in the first heating unit 10, The first heating part 10 , the second heating part 20 and the third heating part 30 are respectively a solenoid type induction heating part, a transverse induction heating part and a resistance heating part, In the continuous heat treatment apparatus 1, the control unit 5 calculates the equivalent impedance in the parallel resonant circuit based on the first voltage and the first current measured by the first measuring unit 18, and calculates the first The output power is controlled so as to decrease the first output power when the calculated equivalent impedance becomes larger than the threshold value.

According to the above-described control method, when the equivalent impedance in the parallel resonance circuit of the first heating unit 10 (ie, the solenoid-type induction heating unit) becomes larger than the threshold value, the first output power is reduced. In other words, before the temperature of the metal member 3 heated by the first heating unit 10 becomes the Curie temperature of the metal member 3, the first output is reduced in advance. Thereby, since the temperature of the metal member 3 is lower than the Curie temperature of the metal member 3, the heating by the solenoid-type induction heating portion can be maintained, and the aforementioned solenoid-type induction heating portion is in and Since the temperature uniformity in the width direction W perpendicular to the conveyance direction F is excellent, the temperature uniformity in the width direction W can be made good as a whole. Furthermore, since the heating efficiency is greatly reduced when the temperature of the metal member 3 reaches the Curie temperature, the threshold value of the equivalent impedance can be selected to be a value before the Curie temperature.

Another aspect of the control method of the continuous heat treatment equipment 1 of the present invention is characterized in that: the aforementioned continuous heat treatment equipment 1 has: The first heating unit 10, the second heating unit 20 and the third heating unit 30 are sequentially and continuously arranged along the conveying direction F of the metal member 3; the control unit 5, respectively controlling the first output power, the second output power and the third output power output to the first heating unit 10, the second heating unit 20 and the third heating unit 30; and The first measuring unit 18 measures the first voltage and the first current in the first heating unit 10, The first heating part 10 , the second heating part 20 and the third heating part 30 are respectively a solenoid type induction heating part, a transverse induction heating part and a resistance heating part, In the continuous heat treatment apparatus 1, the control unit 5 calculates the equivalent impedance in the series resonant circuit based on the first voltage and the first current measured by the first measurement unit 18, and calculates the first The output power is controlled to decrease the first output power when the calculated equivalent impedance becomes smaller than the threshold value.

According to the above-described control method, when the equivalent impedance in the series resonance circuit of the first heating unit 10 (ie, the solenoid-type induction heating unit) becomes smaller than the threshold value, the first output power is reduced. In other words, before the temperature of the metal member 3 heated by the first heating unit 10 becomes the Curie temperature of the metal member 3, the first output is reduced in advance. Thereby, since the temperature of the metal member 3 is lower than the Curie temperature of the metal member 3, the heating by the solenoid-type induction heating portion can be maintained, and the aforementioned solenoid-type induction heating portion is in and Since the temperature uniformity in the width direction W perpendicular to the conveyance direction F is excellent, the temperature uniformity in the width direction W can be made good as a whole.

Furthermore, in the control method of the continuous heat treatment facility 1 according to one embodiment, the threshold value is calculated based on the material of the metal member 3 and the width dimension in the width direction W perpendicular to the conveyance direction F of the metal member 3 .

According to the above-described embodiment, the threshold value can be optimized according to the material and width of the metal member 3 .

In addition, in the control method of the continuous heat treatment facility 1 according to an embodiment, the continuous heat treatment facility 1 includes a third temperature sensor 36 that measures the amount of the temperature carried out from the third heating unit 30 . The third temperature unevenness in the width direction W of the metal member 3 perpendicular to the conveying direction F is The control unit 5 determines whether the magnitude T of the third temperature unevenness is greater than or equal to the allowable value, and controls the third output power so that when the magnitude T of the third temperature unevenness is greater than or equal to the allowable value, The aforementioned third output power is increased.

According to the above-described embodiment, since the share ratio of the third heating portion 30 (that is, the resistance heating portion) excellent in temperature uniformity is increased, the temperature uniformity in the width direction W is improved.

In addition, in the control method of the continuous heat treatment facility 1 according to an embodiment, the control unit 5 determines whether the third output power becomes the third rated output power of the third heating unit 30, and controls the first output power Success: When the third output power becomes the third rated output power, the temperature on the unloading side of the first heating unit 10 is increased.

According to the above-described embodiment, since the share ratio of the first heating unit 10 having excellent temperature uniformity in the width direction W (ie, the solenoid induction heating unit) is increased, the temperature uniformity in the width direction W can be improved.

Another aspect of the control method of the continuous heat treatment equipment 1 of the present invention is characterized in that: the aforementioned continuous heat treatment equipment 1 has: The first heating unit 10, the second heating unit 20 and the third heating unit 30 are sequentially and continuously arranged along the conveying direction F of the metal member 3; the control unit 5, respectively controlling the first output power, the second output power and the third output power output to the first heating unit 10, the second heating unit 20 and the third heating unit 30; and The third temperature sensor 36 measures the third temperature unevenness in the width direction W of the metal member 3 carried out from the third heating unit 30 and orthogonal to the carrying direction F, The first heating part 10 , the second heating part 20 and the third heating part 30 are respectively a solenoid type induction heating part, a transverse induction heating part and a resistance heating part, In the continuous heat treatment facility 1, the control unit 5 calculates in advance the temperature of the first unloading side of the first heating unit 10 and the temperature of the second heating unit 20 based on the Curie temperature of the metal member 3 and the heat treatment conditions. The optimal setting values related to the temperature on the delivery side, the first output power, the second output power, and the third output power are such that the magnitude T of the third temperature unevenness becomes smaller than the allowable value.

According to the above-mentioned control method, the third temperature of the metal member 3 carried out from the third heating unit 30 can be made different by using the optimal setting value calculated in advance as the initial value when operating the continuous heat treatment facility 1 . The average size T becomes smaller than the allowable value.

1: Continuous heat treatment equipment 3: Metal components 5: Control Department 6: Operation Department 7: Memory Department 10: The first heating part (solenoid induction heating part) 12: 1st heating coil 13: 1st power supply 14: The first output power control unit 16: 1st temperature sensor 18: The first measurement section 20: Second heating section (horizontal induction heating section) 22: 2nd heating coil 23: 2nd power supply 24: Second output power control unit 26: 2nd temperature sensor 30: The third heating part (resistance heating part) 32: Heating heater 33: 3rd power supply 34: The third output power control unit 36: 3rd temperature sensor F: conveying direction T: The magnitude of the third temperature unevenness (the final temperature unevenness in the width direction of the metal member carried out from the third heating section) W: width direction S1~S16, S21~S32, S34~S37, S41~S52, S54~S57: Steps

FIG. 1 is a perspective view schematically illustrating a continuous heat treatment facility according to an embodiment. FIG. 2 is a block diagram of the continuous heat treatment apparatus shown in FIG. 1. FIG. Fig. 3 is a flow chart for determining the optimum setting value in the continuous heat treatment facility. Fig. 4 is a flow chart when the continuous heat treatment facility is operated. FIG. 5 is a flowchart of a modification when operating the continuous heat treatment facility.

S21~S32, S34~S37: Steps

Claims (6)

A control method of continuous heat treatment equipment, the aforementioned continuous heat treatment equipment has: The first heating unit, the second heating unit and the third heating unit are sequentially and continuously arranged along the conveying direction of the metal member; a control unit for respectively controlling the first output power, the second output power and the third output power output to the first heating unit, the second heating unit and the third heating unit; and The first measuring unit measures the first voltage and the first current in the first heating unit, The first heating part, the second heating part and the third heating part are respectively a solenoid type induction heating part, a transverse type induction heating part and a resistance heating part, In the continuous heat treatment equipment, the control unit calculates the equivalent impedance in the parallel resonant circuit based on the first voltage and the first current measured by the first measurement unit, and controls the first output power Success: When the calculated equivalent impedance becomes larger than the threshold value, the first output power is reduced. A control method of continuous heat treatment equipment, the aforementioned continuous heat treatment equipment has: The first heating unit, the second heating unit and the third heating unit are sequentially and continuously arranged along the conveying direction of the metal member; a control unit for respectively controlling the first output power, the second output power and the third output power output to the first heating unit, the second heating unit and the third heating unit; and The first measuring unit measures the first voltage and the first current in the first heating unit, The first heating part, the second heating part and the third heating part are respectively a solenoid type induction heating part, a transverse type induction heating part and a resistance heating part, In the continuous heat treatment equipment, the control unit calculates an equivalent impedance in the series resonance circuit based on the first voltage and the first current measured by the first measurement unit, and controls the first output power Success: When the calculated equivalent impedance becomes smaller than the threshold value, the first output power is reduced. The control method of a continuous heat treatment apparatus according to claim 1 or 2, wherein the threshold value is calculated based on the material of the metal member and the width dimension in the width direction orthogonal to the conveyance direction of the metal member. The control method of a continuous heat treatment facility according to claim 1, wherein the continuous heat treatment facility includes a third temperature sensor, and the third temperature sensor measures the direction of the metal member unloaded from the third heating unit and the conveyance direction The third temperature unevenness in the orthogonal width direction, The control unit judges whether the magnitude of the third temperature unevenness is greater than or equal to the allowable value, and controls the third output power so that when the magnitude of the third temperature unevenness is greater than or equal to the allowable value, the third output Output power increases. The control method of the continuous heat treatment equipment according to claim 4, wherein the control unit determines whether the third output power becomes the third rated output power of the third heating unit, and controls the first output power to be: When the output power becomes the third rated output power, the temperature on the unloading side of the first heating unit is increased. A control method of continuous heat treatment equipment, the aforementioned continuous heat treatment equipment has: The first heating unit, the second heating unit and the third heating unit are sequentially and continuously arranged along the conveying direction of the metal member; a control unit for respectively controlling the first output power, the second output power and the third output power output to the first heating unit, the second heating unit and the third heating unit; and a third temperature sensor for measuring the third temperature unevenness in the width direction of the metal member carried out from the third heating section and perpendicular to the carrying direction, The first heating part, the second heating part and the third heating part are respectively a solenoid type induction heating part, a transverse type induction heating part and a resistance heating part, In the continuous heat treatment facility, the control unit calculates in advance the temperature on the first delivery side of the first heating unit, the temperature on the second delivery side of the second heating unit, the temperature on the delivery side of the second heating unit, and the The optimum setting values for the first output power, the second output power, and the third output power are such that the magnitude of the third temperature unevenness becomes smaller than an allowable value.

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