JP7095651B2 - Edge heater control system - Google Patents

Description

The present invention relates to a system for controlling an edge heater applied to a hot rolling facility.

Generally, in a hot rolling facility, a metal material is rolled by 1 to 3 rough rolling mills and about 7 finishing rolling mills. In hot rolling, a metal material of a predetermined size (for example, thickness 200 to 250 mm, width 800 to 2000 mm, length 5 to 10 m) is preheated to a predetermined temperature (for example, 1200 ° C.) and then put into a rough rolling mill. Will be supplied. In the rough rolling mill, the metal material is rolled in a plurality of passes in the forward direction (direction from the upstream to the downstream of the equipment) and the reverse direction (the direction from the downstream to the upstream of the equipment). The metal material from the rough rolling mill is supplied to the finishing rolling mill. In the finish rolling mill, the metal material is rolled to a desired size. The metal material from the finish rolling mill is cooled on a cooling table and rolled up by a winder.

As described above, in hot rolling, the metal material heated on the upstream side of the rough rolling mill is rolled while being conveyed from the upstream side to the downstream side of the equipment. Therefore, the temperature of the metal material drops in the process of transportation and rolling. In particular, the temperature of the end portion in the width direction of the metal material tends to be lower than that of the central portion. In general, the properties of metallic materials are strongly related to their temperature. Therefore, when a temperature difference occurs between the end portion and the center portion, the strength and ductility tend to change. For example, the lower the temperature, the harder and more brittle the metal material. Therefore, when a temperature difference occurs, cracks occur at the end of the low temperature, and the product tends to be defective. Alternatively, uneven wear is likely to occur in the width direction of the roll of the finishing rolling mill.

For this reason, in recent years, it has become mainstream to install an edge heater for heating the end portion in the width direction on the upstream side of the finishing rolling mill. Examples of such an edge heater include an induction heating type heater. The induction heating type heater includes an inductor to which an alternating current is supplied from a high frequency power source. The inductor is installed so as to sandwich the end of the width in the thickness direction of the metal material. When alternating current is supplied to the inductor, an alternating magnetic field that penetrates in the thickness direction is generated. The magnetic flux of the alternating magnetic field induces eddy currents in the metal material. This eddy current generates Joule heat, which locally heats the ends.

However, if the metal material meanders during transportation, the position of the end will shift to the left or right. This misalignment also occurs when the metal material is bent in the longitudinal direction. When such a misalignment occurs, the length at which the metal material and the inductor overlap in the width direction (hereinafter, also referred to as “wrap dimension”) changes. If the wrap size changes, the edges cannot be heated as intended. That is, it becomes impossible to raise the temperature of the end portion appropriately. Then, the temperature distribution in the width direction becomes non-uniform, which leads to the above-mentioned cracking and uneven wear of the end portion. Furthermore, it may lead to meandering of the metal material during finish rolling, which may induce unstable rolling.

Patent Document 1 (Utility Model Registration No. 2588606) discloses a technique for moving an inductor in the width direction according to the magnitude of the displacement of the end portion. According to this conventional technique, it is possible to keep the lap size constant. Therefore, even when the position shift occurs, it is possible to suppress the temperature distribution in the width direction from becoming non-uniform.

Patent Document 2 (Japanese Unexamined Patent Publication No. 2004-006106) discloses a technique for adjusting a gap between a pair of heating coils located above and below in the thickness direction to form an inductor. In this prior art, the current values flowing through the inductors installed so as to sandwich the left and right ends of the metal material are measured separately. Then, the gap between the heating coils constituting at least one inductor is adjusted so that the deviation of these current values is eliminated. According to this conventional technique, it is possible to make the amount of temperature rise at the left and right ends equal. Therefore, even if the position shift occurs, the temperature distribution in the width direction can be made uniform.

Utility Model Registration No. 2588606 Gazette Japanese Unexamined Patent Publication No. 2004-006106

However, in the technique described in Patent Document 1, it is necessary to move the edge heater having a total weight of about 20 tons in the width direction. Therefore, the response of the edge heater to the change in the lap size may not be in time. In this regard, in the technique described in Patent Document 2, the adjustment of the gap is realized by moving the heating coil in the thickness direction. Therefore, the response speed is higher than that of the technique described in Patent Document 1. However, it is insufficient as a countermeasure when the lap size changes in a short cycle.

The present invention has been made in view of at least one of the above-mentioned problems, and an object of the present invention is to increase the response speed of the edge heater to a change in the lap size.

The first invention is an edge heater control system, which has the following features.
The control system includes an edge heater, first and second high frequency power supplies, first and second mobile devices, first and second measuring instruments, and a control device.
The edge heater is provided between the rough rolling mill and the finish rolling mill. The edge heater has first and second inductors. The first and second inductors heat both ends of the metal material transported on the transport line in the width direction, respectively.
The first high frequency power supply supplies a first alternating current to the first inductor.
The second high frequency power supply supplies a second alternating current to the second inductor.
The first moving device changes the position of the first inductor in a direction orthogonal to the transport direction of the transport line.
The second moving device changes the position of the second inductor in the orthogonal direction.
The first measuring instrument is provided between the rough rolling mill and the edge heater. The first measuring instrument measures the offset amount from the reference position of the transport line to the center position in the width direction.
The second measuring instrument is provided between the rough rolling mill and the edge heater. The second measuring instrument measures the temperature distribution in the width direction as the inlet temperature distribution.
The control device controls the first and second high frequency power supplies and the first and second mobile devices based on the offset amount and the inlet temperature distribution.
The control device is
The offset amount in a predetermined section of the metal material is divided into a long-period component that changes in a relatively long cycle during transportation of the metal material and a short-period component that changes in a relatively short cycle during transportation. Separated
Based on the long-period component, the control amount for controlling the first and second moving devices during heating of the metal material by the edge heater is calculated, respectively.
Based on the inlet temperature distribution, the power preset values of the first and second high frequency power supplies are modified.
Based on the corrected value of the electric power and the short-period component, the frequencies of the first and second alternating currents during the heating of the metal material by the edge heater are set, respectively.

The second invention further has the following features in the first invention.
The first measuring instrument measures the offset amount as the first offset amount.
The second measuring instrument is provided between the first measuring instrument and the edge heater. The second measuring instrument further measures the second offset amount from the reference position to the center position.
The control device modifies the first component with the second offset amount in the predetermined section before calculating the control amount.

The third invention further has the following features in the first or second invention.
The control system further comprises a third measuring instrument.
The third measuring instrument is provided between the edge heater and the finishing rolling mill. The third measuring instrument measures the temperature distribution in the width direction as the exit side temperature distribution.
The control device is
Based on the inlet temperature distribution, the temperature at a predetermined position in the longitudinal direction of the metal material is calculated as the preheating temperature.
Based on the outlet temperature distribution, the temperature of the metal material at the predetermined position is calculated as the temperature after heating.
The preset value or the correction value is modified based on the difference between the pre-heating temperature and the post-heating temperature.

According to the first invention, the offset amount in the predetermined section is separated into long-period and short-period components. Further, the preset values of the power of the first and second high frequency power supplies are corrected based on the inlet temperature distribution. Further, the frequencies of the first and second alternating currents are set, respectively, based on the corrected value of the electric power and the short-period component. Here, the short-period component is a component that changes in a relatively short period during transportation of the metal material. Moreover, the frequency control is excellent in responsiveness. Therefore, by controlling the first and second high frequency power supplies based on the set frequency, it is possible to make the temperature distribution in the width direction uniform even when the lap dimension changes in a short cycle. It will be possible.

Further, according to the first invention, control quantities for controlling the first and second mobile devices are set based on the long-period component, respectively. Here, the long-period component is a component that changes in a relatively long period during transportation of the metal material. Therefore, by controlling the first and second moving devices based on the set control amount, it is possible to make the temperature distribution uniform even when the lap dimension changes in a long cycle. Become.

According to the second invention, the long-period component is modified with the second offset amount in the predetermined interval before the control amount is calculated. Also, before the frequency is set, the short cycle component is modified using the first offset amount in the predetermined section. Here, the second offset amount is measured by a second measuring instrument provided between the first measuring instrument and the edge heater. That is, the second offset amount is measured at a position closer to the edge heater than the first offset amount. Therefore, if the first and second components are corrected by using the second offset amount, the misalignment at the position closer to the edge heater can be reflected in the control of the high frequency power supply and the mobile device. Therefore, it is possible to enhance the effect of these controls.

According to the third invention, the preset value or the modified value thereof is modified based on the difference between the pre-heating temperature and the post-heating temperature. Therefore, it is possible to improve the uniformity of the temperature distribution.

It is a schematic diagram which shows the structural example of the hot rolling equipment to which the control system which concerns on Embodiment 1 is applied. It is a figure explaining the structural example of the edge heater. It is a figure which shows the configuration example of the control system which concerns on Embodiment 1. FIG. It is a block diagram explaining the configuration example of the function of a control device. It is a flowchart explaining the flow of the process performed by the decomposition calculation unit. It is a figure explaining the process of step S11 of FIG. It is a figure which shows an example of the process of steps S12 and S13 of FIG. It is a flowchart explaining the flow of the process performed by a shift control unit. It is a flowchart explaining the flow of processing performed by a frequency control unit. It is a figure which shows an example of the data table which defined the coefficient for frequency calculation. It is a flowchart explaining the flow of processing performed by a power control unit. It is a schematic diagram which shows the structural example of the hot rolling equipment to which the control system which concerns on Embodiment 2 is applied. It is a block diagram explaining the configuration example of the function of a control device.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, when the number, quantity, quantity, range, etc. of each element is referred to in the embodiment shown below, the reference is made unless it is explicitly stated or when the number is clearly specified in principle. The invention is not limited to the number of cases. In addition, the structures, steps, and the like described in the embodiments shown below are not necessarily essential to the present invention, except when explicitly stated or clearly specified in principle.

1. 1. Embodiment 1
First, Embodiment 1 of the present invention will be described with reference to FIGS. 1 to 11.

1.1 Overall Configuration of Hot Rolling Equipment FIG. 1 is a schematic diagram showing a configuration example of a hot rolling equipment to which the control system according to the first embodiment of the present invention is applied. As shown in FIG. 1, the hot rolling mill 1 includes a transfer line 11, a heating furnace 12, a rough rolling mill 13, a finishing rolling mill 14, a cooling table 15, a winder 16, and a plate width meter. It includes 17, a scan thermometer 18, an edge heater 2, a control device 3, and a high-level calculator 4.

The transport line 11 transports the steel plate SS. The transport line 11 is composed of a plurality of transport rollers. The name of the steel plate SS changes depending on the position on the transport line 11. Generally, the steel plate SS between the heating furnace 12 and the rough rolling mill 13 is called a slab. The slab is, for example, a rectangular parallelepiped iron mass formed into a thickness of 200 to 250 mm, a width of 800 to 2000 mm, and a length of 5 to 10 m. The steel plate SS rolled by the rough rolling mill 13 is called a sheet bar. The steel plate SS rolled by the finish rolling mill 14 is called a strip.

The heating furnace 12 is provided upstream of the transfer line 11. The heating furnace 12 heats the steel plate SS. The temperature of the steel plate SS when it comes out of the heating furnace 12 is about 1200 ° C.

The rough rolling mill 13 is provided downstream of the heating furnace 12. The rough rolling mill 13 is composed of, for example, 1 to 3 rolling stands. The rough rolling mill 13 rolls the steel plate SS sent from the upstream side of the transport line 11 while feeding them in the forward and reverse directions. The rough rolling mill 13 rolls down the steel sheet SS until the thickness of the steel sheet SS reaches the target thickness. The rough rolling mill 13 may be provided with a device called an edger for adjusting the width of the steel plate SS.

The finish rolling mill 14 is provided downstream of the rough rolling mill 13. The finish rolling mill 14 is composed of, for example, 5 to 7 rolling stands. The finish rolling mill 14 rolls the steel plate SS sent from the upstream side of the transport line 11 while feeding it only in the forward direction. The finish rolling mill 14 determines the final quality in terms of dimensions such as the thickness and width of the steel sheet SS. The temperature of the steel sheet SS when it comes out of the finish rolling mill 14 is about 900 ° C.

The cooling table 15 is provided downstream of the finishing rolling mill 14. The temperature of the cooling table 15 is lowered by injecting water into the steel plate SS by a water cooling device called a cooling bank. The temperature of the steel plate SS when it comes out of the cooling table 15 is around 200 ° C. for special steel and around 600 ° C. for ordinary steel.

The winder 16 is provided downstream of the cooling table 15. The winder 16 winds the steel plate SS from the finish rolling mill 14 into a coil shape.

The plate width meter 17 is provided between the rough rolling mill 13 and the edge heater 2. The plate width meter 17 measures the width of the steel plate SS (hereinafter, also referred to as “plate width”). The plate width meter 17 also measures the distance from the reference position RL_11 (for example, the center position) of the transport line 11 to the center position CL_SS in the width direction of the steel plate SS (hereinafter, also referred to as “first offset amount OA1”). do. The plate width meter 17 sends the measured plate width and the information of the first offset amount OA1 to the control device 3.

The scan thermometer 18 is provided between the plate width meter 17 and the edge heater 2. The scan thermometer 18 measures the temperature distribution in the width direction of the steel plate SS. The temperature distribution measured by the scan thermometer 18 is also referred to as “inside temperature distribution TD1”. The scan thermometer 18 also measures the distance from the reference position RL_11 to the center position CL_SS (hereinafter, also referred to as "second offset amount OA2"). The scan thermometer 18 sends the measured information on the inlet temperature distribution TD1 and the second offset amount OA2 to the control device 3.

The edge heater 2 is provided between the rough rolling mill 13 and the finishing rolling mill 14. The edge heater 2 heats the left and right ends of the steel plate SS in the width direction. The configuration of the edge heater 2 will be described in item 1.2.

The control device 3 is a microcomputer including a processor, a memory, and an input / output interface. The control device 3 receives various information via the input / output interface. Then, the control device 3 executes various controls of the edge heater 2 based on the received various information. The functions of the control device 3 for executing various controls are described in Item 1.3.

The host computer 4 is composed of a microcomputer having the same configuration as the control device 3. The host computer 4 is also referred to as various information related to hot rolling (hereinafter, also referred to as "hot rolling instruction information") based on various information received via the input / output interface or various information stored in the memory. .) Is generated. The hot rolling instruction information includes information on the transfer speed in the transfer line 11, the control amount of the finishing rolling mill 14, the preset value P of the electric power of the edge heater 2, and the temperature condition on the output side of the edge heater 2. Is done.

1.2 Configuration of Edge Heater FIG. 2 is a diagram illustrating a configuration example of the edge heater 2. As shown in FIG. 2, the edge heater 2 includes an inductor 21L. The inductor 21L includes an iron core 22L and heating coils 23L and 24L. The iron core 22L has a C-shaped cross section and constitutes a magnetic path. The heating coil 23L is wound around the upper leg portion of the iron core 22L. The heating coil 24L is wound around the lower leg portion of the iron core 22L. An opening 25L is formed between the heating coils 23L and 24L. The left end portion of the steel plate SS in the width direction passes through the opening 25L.

When an alternating current is supplied from the high frequency power source to the heating coils 23L and 24L, an alternating magnetic field is generated in the vertical direction (that is, the thickness direction). When this energization is performed while the left end portion of the steel plate SS passes through the opening 25L, the magnetic flux of the alternating magnetic field induces an eddy current at the left end portion. Then, Joule heat is generated by this eddy current, and the left end portion is heated. Hereinafter, for convenience of explanation, the alternating current supplied to the heating coils 23L and 24L is also referred to as "first alternating current".

The edge heater 2 also includes an inductor 21R. The inductor 21R is paired with the inductor 21L. The configuration of the inductor 21R is the same as that of the inductor 21L. An opening 25R is formed between the heating coils 23R and 24R. The right end portion of the steel plate SS in the width direction passes through the opening 25R. The principle of heating the right end of the steel sheet SS is the same as that of the left end. Hereinafter, for convenience of explanation, the alternating current supplied to the heating coils 23R and 24R is also referred to as “second alternating current”.

The operator's private room (that is, the pulpit) side provided in the hot rolling equipment 1 is referred to as an operator side OS. The other side of this private room is called the drive side DS. The inductor 21R is located, for example, on the operator side OS. The inductor 21L is located, for example, on the drive side DS.

1.3 Configuration of Control System 1.3.1 Configuration of Control System FIG. 3 is a diagram showing a configuration example of the control system according to the first embodiment. In FIG. 3, the inductor 21L and the configuration related thereto are omitted for convenience, but these configurations are the same as the inductor 21R and the configuration related thereto. Further, the plate width meter 17, the scan thermometer 18, the control device 3 and the upper calculator 4 are provided in common to the inductors 21L and 21R.

As shown in FIG. 3, the control system according to the first embodiment has an iron core 22R, heating coils 23R and 24R, a moving device 26R, a position measuring instrument 27R, and a motor 28R as configurations related to the inductor 21R. And have. The configurations of the iron core 22R, the heating coils 23R and 24R are as described above. The moving device 26R changes the position of the inductor 21R in the width direction. The position measuring instrument 27R measures the position of the inductor 21R in the width direction. The motor 28R drives the wheels of the moving device 26R.

Further, the configuration related to the inductor 21R further includes a high frequency power supply 5R, a position calculator 6R, and a motor controller 7R. The high frequency power supply 5R supplies alternating current to the heating coils 23R and 24R. The position calculator 6R moves the inductor 21R in the width direction based on the actual position of the inductor 21R sent from the position measuring instrument 27R and the target position S of the inductor 21R sent from the control device 3. (Hereinafter, also referred to as "shift amount") is calculated. The motor controller 7R calculates the control amount of the motor 28R based on the shift amount sent from the position calculator 6R.

1.3.2 Configuration of the control device FIG. 4 is a block diagram illustrating a configuration example of the function of the control device 3. As shown in FIG. 4, the control device 3 includes an information acquisition unit 31, a decomposition calculation unit 32, a shift control unit 33, a frequency control unit 34, and a power control unit 35. A part or all of these parts 31 to 35 function by the processor of the control device 3 executing a program.

The information acquisition unit 31 acquires information sent from various sensors. This information includes information on the inlet temperature distribution TD1, information on the first offset amount OA1, and information on the second offset amount OA2. The information acquisition unit 31 also acquires rolling command information sent from the host computer 4. This information includes a preset value P.

The decomposition calculation unit 32 decomposes the first offset amount OA1 into a low-order component OA1_L and a high-order component OA1_H. The low-order component OA1_L is a component that changes in a relatively long cycle during the transportation of the steel sheet SS. The higher-order component OA1_H is a component that changes in a relatively short cycle during the transportation of the steel sheet SS. The decomposition calculation unit 32 also corrects the low-order component OA1_L by using the second offset amount OA2. The specific processing performed by the decomposition calculation unit 32 will be described in item 1.4. The decomposition calculation unit 32 sends the modified low-order component OA1_L to the shift control unit 33.

The shift control unit 33 sets the target positions S of the inductors 21L and 21R, respectively, based on the low-order component OA1_L sent from the decomposition calculation unit 32. The target position S is a shift amount for making the low-order component OA1_L zero. The specific processing performed by the shift control unit 33 will be described in item 1.4. The shift control unit 33 sends a command value (shift amount command value) indicating the calculated target position S to the position calculators 6L and 6R.

The frequency control unit 34 sets the target frequency based on the higher-order component OA1_H sent from the decomposition calculation unit 32 and the correction value Pmod of the power sent from the power control unit 35. The target frequency is a target value of the frequency of the first and second alternating currents set to remove the higher-order component OA1_H under the power condition of the correction value Pmod, respectively. The specific processing performed by the frequency control unit 34 will be described in item 1.4. The frequency control unit 34 sends a command value (frequency command value) indicating the set target frequency to the high frequency power supplies 5L and 5R, respectively.

The power control unit 35 corrects the preset value P based on the inlet temperature distribution TD1. The specific processing performed by the power control unit 35 will be described in item 1.4. When the preset value P is modified, the power control unit 35 sends the modified power value (that is, the modified value Pmod) to the frequency control unit 34. In addition, the power control unit 35 sends a command value (power command value) indicating the correction value Pmod to the high frequency power supplies 5L and 5R.

1.4 Details of various processes 1.4.1 Decomposition calculation process FIG. 5 is a flowchart illustrating a flow of processes performed by the decomposition calculation unit 32. The routine shown in FIG. 5 is started, for example, at the timing when the tip of the steel plate SS reaches the position of the plate width meter 17.

In the routine shown in FIG. 5, first, the first offset amount OA1i is calculated (step S11). FIG. 6 is a diagram illustrating the process of step S11. In step S11, first, the steel plate SS is divided into n pieces in the longitudinal direction. This division may be performed for the entire length of the steel plate SS, or may be divided into preset lengths and repeated.

Subsequently, the first offset amount OA1i is calculated for the divided region i (1 ≦ i ≦ n). The first offset amount OA1i is the distance from the reference position RL_11 of the transport line 11 shown in FIG. 6 to the central position CL_SS in the region i. The sign of the first offset amount OA1i is negative when the central position CL_SS in the region i is located closer to the driveside DS than the reference position RL_11.

式（１）において、Δｘａｉは、低次の多項式により計算されるΔｘｉの近似値である。この近似値Δｘａｉで表される第１オフセット量ＯＡ１ｉを、低次成分ＯＡ１ｉ＿Ｌとする。なお、低次の多項式の代わりに、スプライン関数を用いてもよい。 Following step S11, the lower order component OA1i_L is calculated (step S12). In step S12, a low-order (for example, third-order and fourth-order) polynomial is set with respect to the measured value Δxi of the first offset amount OA1i. Then, the coefficient of this polynomial is identified by performing a regression analysis that minimizes the error error of the equation (1).

In equation (1), Δxai is an approximate value of Δxi calculated by a low-order polynomial. The first offset amount OA1i represented by this approximate value Δxai is defined as the low-order component OA1i_L. A spline function may be used instead of the low-order polynomial.

Following step S12, the higher order component OA1i_H is calculated (step S13). The higher-order component OA1i_H is represented by a residual Δxi-Δxii obtained by subtracting the approximate value Δxii calculated in step S12 from the measured value Δxii. FIG. 7 is a diagram showing an example of the processing of steps S12 and S13. As shown in FIG. 7, in these steps, it is assumed that the approximate value Δxai corresponds to the low-order component OA1i_L, and the residual Δxi-Δxi is the higher-order component OA1i_H.

Following step S13, the lower order component OA1i_Lmod is calculated (step S14). The low-order component OA1i_Lmod is a modified value of the low-order component OA1i_L calculated in step S13. The modification of the lower order component OA1i_L is performed using the second offset amount OA2. For example, if the difference | Δyi−Δxi | between the measured value Δyi of the second offset amount OA2 and the measured value Δxi is larger than the threshold value ζ, the low-order component OA1i_L is offset and corrected according to this difference.

The second offset amount OA2 is measured by the scan thermometer 18 located downstream of the plate width meter 17. Therefore, if the measured value Δyi is used, the low-order component OA1i_L is slightly corrected by the offset information at the position closer to the edge heater 2.

Following step S14, the low-order component OA1i_L and the high-order component OA1i_H are output (step S15). The low-order component OA1i_L is output to the shift control unit 33. When the correction is made in step S14, the low-order component OA1i_Lmod is output to the shift control unit 33. The higher-order component OA1i_H is output to the frequency control unit 34.

14.2 Shift control processing FIG. 8 is a flowchart illustrating a flow of processing performed by the shift control unit 33. In the routine shown in FIG. 8, first, the low-order component OA1i_L is acquired (step S21).

Following step S21, it is determined whether or not the low-order component OA1i_L is within the specified range (step S22). The specified range is specified by the upper limit Smax and the lower limit Smin of the position S in the width direction of the inductors 21R and 21L. The upper limit Smax and the lower limit Smin are preset based on the specifications of the mobile devices 26L and 26R.

If the determination result in step S22 is affirmative, the target position Si is set to the initial position S0 + the approximate value Δxai (step S23). The target position Si is a target value of the positions of the inductors 21L and 21R when the region i passes through the positions of the inductors 21L and 21R. The initial position S0 is an initial value of the positions of the inductors 21L and 21R, and is set in advance based on the reference position of the transfer line 11.

If the determination result in step S22 is negative, the target position Si is set to the upper limit Smax or the lower limit Smin (step S24). Specifically, when the low-order component OA1i_L exceeds the upper limit Smax, the target position Si is set to the upper limit Smax. When the low-order component OA1i_L is below the lower limit Smin, the target position Si is set to the lower limit Smin.

Following step S23 or S24, the shift amount command value is output (step S25). Specifically, the target position Si set in steps S23 or S24 is output to the position calculators 6L and 6R.

1.4.3 Frequency control processing FIG. 9 is a flowchart illustrating a flow of processing performed by the frequency control unit 34. In the routine shown in FIG. 9, first, the coefficient of the setting formula and the higher-order component OA1i_H are acquired (step S31). The setting formula is a formula for setting the target frequency, and the higher-order component OA1i_H is used as a variable. An exponential function is exemplified as a setting expression.

The coefficients of the setting formula are obtained by referring to the data table. FIG. 10 is a diagram showing an example of a data table. In the example shown in FIG. 10, the coefficients a, the coefficients b, ... Are set for each classification of the steel type and the plate thickness. Coefficients a, coefficients b, ... Are preset based on offline simulations and actual machine tests.

Following step S31, the calculation of the target frequency is performed (step S32). Specifically, the target frequency is calculated by the setting formula specified by using the coefficient acquired in step S31 and the higher-order component OA1i_H acquired in step S31.

Following step S32, the amount of temperature rise WA in the width direction of the steel sheet SS is calculated (step S33). The temperature rise amount WA is calculated based on the preset value P and the target frequency calculated in step S32. When the preset value P is modified by the power control process described later, the modified value Pmod is used in the calculation of the temperature rise amount WA instead of the preset value P. In this case, the temperature rise amount WA of the operator side OS and that of the drive side DS are calculated separately.

Following step S33, it is determined whether or not the target frequency needs to be corrected (step S34). In step S34, specifically, a determination regarding the amount of temperature rise and a determination regarding the number of treatments are performed. In the determination regarding the temperature rise amount, it is determined whether or not the difference | WA-TWA | between the temperature rise amount WA and the target temperature rise amount TWA is equal to or less than the threshold value ε. The target temperature rise amount TWA is a target value of the temperature rise amount of the steel sheet SS set based on the preset value P. In the determination regarding the number of processes, it is determined whether or not the number of repetitions N in step S34 is greater than the threshold value Norop.

If it is determined in the process of step S34 that the difference | WA-TWA |> threshold value ε, it is determined that the target frequency needs to be corrected. Further, when it is determined that the number of repetitions N ≦ the threshold value Noop, it is determined that correction is necessary. In either case, the target frequency is modified (step S35). Then, after correcting the target frequency, the process of step S34 is performed again. The processes of steps S34 and S35 are repeated in the process of step S34 until a positive determination result regarding the amount of temperature rise or the number of processes is obtained.

If a positive determination result is obtained in the process of step S34, it is determined that the correction of the target frequency is unnecessary. In this case, the frequency command value is output (step S35). Specifically, the latest values of the target frequencies used in the calculation of the temperature rise amount WA in the process of step S33 are output to the high frequency power supplies 5L and 5R, respectively.

1.4.4 Power control processing FIG. 11 is a flowchart illustrating a flow of processing performed by the power control unit 35. In the routine shown in FIG. 11, first, the inlet temperature distribution TD1i and the preset value P are acquired (step S41). The entry-side temperature distribution TD1i is the entry-side temperature distribution TD1 in the region i.

Following step S41, the temperature difference between the left end portion and the right end portion in the width direction of the steel plate SS is calculated (step S42). The temperature difference is calculated based on the inlet temperature distribution TD1i. The position for calculating the temperature difference is a position separated by a predetermined distance from the left end and the right end of the region i, respectively.

式（２ａ）および（２ｂ）において、Ｐｉは、領域ｉにおける事前設定値Ｐである。また、Ｔｉは、領域ｉの左端部および右端部の鋼板ＳＳの温度である。右辺第２項は、温度差の絶対値を変数とする事前設定値Ｐの関数である。 Following step S42, the modified values Pmod and i are calculated (step S43). The modified values Pmod and i are modified values Pmod in the region i. The correction values Pmod and i are calculated so that the temperature difference calculated in step S42 becomes zero. For example, when the temperature of the drive side DS is higher than the temperature of the operator side OS, the correction values Pmod and i are calculated based on the equations (2a) and (2b), respectively.

In the formulas (2a) and (2b), Pi is a preset value P in the region i. Further, Ti is the temperature of the steel plate SS at the left end portion and the right end portion of the region i. The second term on the right side is a function of the preset value P with the absolute value of the temperature difference as a variable.

Following step S43, the correction values Pmod and i are output (step S44). The modified values Pmod and i are used in the calculation of the temperature rise amount WA in the frequency control process. The modified values Pmod and i are also output to the high frequency power supplies 5L and 5R, respectively.

1.5 Effect According to the control system according to the first embodiment, the first offset amount OA1 is separated into a low-order component OA1_L and a high-order component OA1_H. Further, the preset value P is corrected based on the inlet temperature distribution TD1. Further, the target frequencies of the high frequency power supplies 5L and 5R are set based on the modified value Pmod and the higher-order component OA1_H, respectively.

As already described, the higher-order component OA1_H is a component that changes in a relatively short cycle during the transportation of the steel sheet SS. And the frequency control is excellent in responsiveness. Therefore, by controlling the high frequency power supplies 5L and 5R respectively based on the set target frequency, even if the lap dimension (see FIG. 2) changes in a short cycle, the width direction of the steel plate SS It is possible to make the temperature distribution uniform.

Further, according to the control system according to the first embodiment, the target positions S of the inductors 21L and 21R are set based on the low-order component OA1_L, and the control amount of the motor is calculated based on the target positions S. To. As already described, the low-order component OA1_L is a component that changes in a relatively long cycle during the transportation of the steel sheet SS. Therefore, by controlling the motor based on the calculated control amount, it is possible to make the temperature distribution in the width direction of the steel sheet SS uniform even when the lap dimension changes in a long cycle. Become.

1.6 Modification of Embodiment 1 In Embodiment 1 described above, the low-order component OA1_L was modified by using the second offset amount OA2 (see step S14 in FIG. 5). However, this correction process may be omitted. In this case, the process of step S14 may be omitted, and the low-order component OA1_L and the high-order component OA1_H calculated in steps S12 and S13 may be output in step S15. Further, in this case, since it is not necessary to measure the second offset amount OA2, the scan thermometer 18 only needs to measure the upstream temperature distribution. Therefore, the positions of the plate width meter 17 and the scan thermometer 18 may be opposite to those shown in FIG. That is, the scan thermometer 18 may be provided upstream of the plate width meter 17.

1.7 Correspondence between the first embodiment and the first invention In the first embodiment described above, the inductor 21L corresponds to the "first inductor" of the first invention, and the inductor 21R is the "second inductor" of the same invention. Corresponds to "inductor". The high frequency power supply 5L corresponds to the "first high frequency power supply" of the same invention, and the high frequency power supply 5R corresponds to the "second high frequency power supply" of the same invention. The mobile device 26R corresponds to the "first mobile device" of the present invention, and the mobile device paired with the mobile device 26R corresponds to the "second mobile device" of the same invention. The plate width meter 17 corresponds to the "first measuring instrument" of the same invention, and the scan thermometer 18 corresponds to the "second measuring instrument" of the same invention. The low-order component OA1_L corresponds to the "long-period component" of the present invention, and the high-order component OA1_H corresponds to the "short-period component" of the same invention.

2. 2. Embodiment 2
Next, Embodiment 2 of the present invention will be described with reference to FIGS. 12 to 13. Hereinafter, the description overlapping with the description of the first embodiment will be omitted as appropriate.

2.1 Overall Configuration of Hot Rolling Equipment FIG. 12 is a schematic diagram showing a configuration example of a hot rolling equipment to which the control system according to the second embodiment of the present invention is applied. As shown in FIG. 12, the hot rolling equipment 1 includes a scan thermometer 19. Other configurations are the same as those shown in FIG.

The scan thermometer 19 is provided between the edge heater 2 and the finish rolling mill 14. The scan thermometer 19 measures the temperature distribution in the width direction of the steel plate SS. The temperature distribution measured by the scan thermometer 19 is also referred to as “outside temperature distribution TD2”. The scan thermometer 19 sends the measured information of the output side temperature distribution TD2 to the control device 3.

2.2 Configuration of the control device FIG. 13 is a block diagram illustrating a configuration example of the function of the control device 3. As shown in FIG. 13, the control device 3 includes a power correction unit 36. The configuration of other functions is basically the same as the configuration shown in FIG.

The power correction unit 36 calculates the actual temperature rise amount AWA based on the inlet side temperature distribution TD1 and the outlet side temperature distribution TD2. The temperature rise amount AWA is calculated based on the temperature difference DT calculated separately for the left end portion and the right end portion of the region i. The temperature difference DT is the temperature at a predetermined position of the steel sheet SS calculated based on the inlet temperature distribution TD1 (that is, the temperature before heating) and that calculated based on the outlet temperature distribution TD2 (that is, the temperature after heating). ). The predetermined position is a position separated from the left end and the right end of the area i by a predetermined distance, respectively.

The power correction unit 36 sets a correction coefficient for making the error between the calculated temperature rise amount AWA and the temperature rise amount WA calculated in the frequency control process zero. This correction coefficient is preset according to the temperature difference DT. The power correction unit 36 sends the set correction coefficient to the power control unit 35. When the temperature difference DT at the left end portion of the region i is different from that at the right end portion of the region i, the power correction unit 36 sends the correction coefficients set for each of the left end portion and the right end portion to the power control unit 35.

The power control unit 35 corrects the preset value P by using the correction coefficient sent from the power correction unit 36. When the preset value P has already been corrected by the power control process, the power control unit 35 further corrects the correction value Pmod using the correction coefficient. When the correction using the correction coefficient is performed, the power control unit 35 sends the corrected power value to the frequency control unit 34. In addition, the power control unit 35 sends a command value (power command value) indicating the corrected power value to the high frequency power supplies 5L and 5R.

2.3 Effect According to the control system according to the second embodiment, the preset value P or the modified value Pmod is modified based on the temperature difference DT. Therefore, it is possible to improve the uniformity of the temperature distribution in the width direction of the steel sheet SS.

2.4 Correspondence between the second embodiment and the third invention In the second embodiment described above, the scan thermometer 19 corresponds to the "third measuring instrument" of the third invention.

1 Hot rolling equipment 2 Edge heater 3 Control device 4 High-level calculator 5L, 5R High-frequency power supply 11 Conveyance line 13 Rough rolling mill 14 Finish rolling mill 17 Plate width meter 18, 19 Scan thermometer 21L, 21R Incubator 26R Moving device 31 Information Acquisition unit 32 Decomposition calculation unit 33 Shift control unit 34 Frequency control unit 35 Power control unit 36 Power correction unit OA1 First offset amount OA2 Second offset amount OA1_H Higher-order component OA1_L Low-order component P Preset value Pmod Correction value SS Steel plate

Claims (3)

An edge heater provided between the rough rolling mill and the finishing rolling mill, which has first and second inductors for heating both ends of the metal material transported on the transport line in the width direction, respectively.
A first high frequency power supply that supplies a first alternating current to the first inductor,
A second high frequency power supply that supplies a second alternating current to the second inductor,
A first moving device that changes the position of the first inductor in a direction orthogonal to the transport direction of the transport line.
A second moving device that changes the position of the second inductor in the orthogonal direction, and
A first measuring instrument provided between the rough rolling mill and the edge heater and measuring the offset amount from the reference position of the transport line to the center position in the width direction.
A second measuring instrument provided between the rough rolling mill and the edge heater and measuring the temperature distribution in the width direction as the inlet temperature distribution,
A control device for controlling the first and second high frequency power supplies and the first and second mobile devices based on the offset amount and the inlet temperature distribution is provided.
The control device is
The offset amount in a predetermined section of the metal material is divided into a long-period component that changes in a relatively long cycle during transportation of the metal material and a short-period component that changes in a relatively short cycle during transportation. Separated
Based on the long-period component, the control amount for controlling the first and second moving devices during heating of the metal material by the edge heater is calculated, respectively.
Based on the inlet temperature distribution, the power preset values of the first and second high frequency power supplies are modified.
Control of the edge heater, characterized in that the frequencies of the first and second alternating currents during heating of the metal material by the edge heater are set, respectively, based on the corrected value of the electric power and the short cycle component. system. The first measuring instrument measures the offset amount as the first offset amount.
The second measuring instrument is provided between the first measuring instrument and the edge heater, and further measures the second offset amount from the reference position to the center position.
The control device is
Before calculating the control amount, the long-period component is modified using the second offset amount in the predetermined section.
The edge heater control system according to claim 1, wherein the short-period component is corrected by using the second offset amount in the predetermined section before setting the frequency. A third measuring instrument provided between the edge heater and the finishing rolling mill and measuring the temperature distribution in the width direction as the output side temperature distribution is further provided.
The control device is
Based on the inlet temperature distribution, the temperature at a predetermined position in the longitudinal direction of the metal material is calculated as the preheating temperature.
Based on the outlet temperature distribution, the temperature of the metal material at the predetermined position is calculated as the temperature after heating.
The edge heater control system according to claim 1 or 2, wherein the preset value or the modified value is modified based on the difference between the preheating temperature and the postheating temperature.

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