JP6356094B2 - Rolling control device and rolling control method - Google Patents

Description

  The present invention relates to a rolling control device and a rolling control method for suppressing meandering and camber of a rolled material in a tandem rolling mill.

  Patent Document 1 discloses a control method for suppressing camber in rolling a thick plate. In the method described in Patent Document 1, a rolling load difference at both ends of a rolling mill and a rolling length of a rolled material in a pass immediately before the final pass among a plurality of passes are measured. These pieces of information are information indicating the distribution state of the rolling load difference in the rolling direction of the rolled material. The control device reads the information, and in the final pass, feedback control is performed so as to reduce the rolling load difference, the roll opening is set, and the rolling mill is controlled.

  Patent Document 2 discloses a meandering control method for suppressing meandering of a tail end of a rolled material in a tandem rolling mill. In the method described in Patent Document 2, in the steady state where the rolling material is caught in all the rolling stands, the driving side and the working side are provided by the load cell provided in the looper between the i + 1th stand and the ith stand. And the tension difference is obtained from the detected value. Next, the leveling amount of the i-th stand is adjusted so that the obtained tension difference is zero. The above control is performed until the tail end of the rolled material is positioned between the i-2th stand before the i-th stand and the i-1th stand before the i-th stand.

JP 2001-105013 A JP-A-3-165913

  The rolling load difference is not only the rolling reduction difference in the width direction of the rolled material, but also the temperature difference in the width direction in the rolled material, the deformation resistance difference in the width direction in the rolled material (that is, the rigidity difference), and the rolling material from the center of the rolling mill. It is affected by deviation. Therefore, in the method described in Patent Document 1, meandering and camber cannot be sufficiently suppressed due to the above-described factors other than the rolling reduction difference even if the rolling mill is controlled so that the rolling load difference becomes small.

  The rolled material generates meandering and camber not only at the tail end but also at the tip. However, in the method described in Patent Document 2, in order to obtain the tension difference of the rolled material in a steady state, the meandering and camber are performed only at the tail end of the rolled material. Camber cannot be suppressed.

  This invention is made | formed in view of such a situation, The main objective is to provide the rolling control apparatus and rolling control method which can solve the said subject.

In order to solve the above-described problems, a rolling control device according to one aspect of the present invention is a rolling control device for controlling a tandem rolling mill in which a plurality of rolling stands for rolling a rolled material are arranged. After the i-th rolling stand (where i is an integer not less than 2 and not more than the number of rolling stands ) bites the tip of the rolled material, the i-th rolling stand and the i-th rolling stand are upstream. Rolling between the driving side and the working side of the i-th rolling stand before and after the tension applying portion provided between the i-1th rolling stand adjacent to the side applies tension to the rolled material Determining means for determining a reduction leveling amount on each of the drive side and the work side of the i-th rolling stand based on a change amount of the load difference;

  In this aspect, the rolling control device further includes an estimation unit that estimates a difference in sheet thickness at both ends in the width direction of the rolled material after applying the tension by the tension applying unit, based on the amount of change in the rolling load difference. The determining means is configured to determine a reduction leveling amount on each of the driving side and the working side of the i-th rolling stand so that the difference in thickness estimated by the estimating means is reduced. Also good.

  Further, in the above aspect, the estimation means includes the amount of change in the rolling load difference and the plate thickness that are determined with respect to the change in the bending stiffness coefficient of the rolled material before and after the tension applying unit applies tension to the rolled material. The plate thickness difference may be estimated according to the relationship with the difference.

  Moreover, the said aspect WHEREIN: The said rolling control apparatus is the variation | change_quantity of the rolling load difference between the drive side and work side of the said i-th rolling stand before and after the said tension | tensile_strength provision part provides tension | tensile_strength to the said rolling material. The bending load is determined based on the change in the bending stiffness coefficient determined by the bending stiffness coefficient determining means. The plate thickness difference may be estimated according to the relationship between the difference change amount and the plate thickness difference.

  Moreover, the said aspect WHEREIN: The said rolling control apparatus may further be equipped with the adjustment means which adjusts the said i-th rolling stand by the amount of reduction leveling determined by the said determination means.

  Moreover, the said aspect WHEREIN: A looper may be sufficient as the said tension | tensile_strength provision part.

  Moreover, the said aspect WHEREIN: A pinch roller may be sufficient as the said tension | tensile_strength provision part.

The rolling control method according to one aspect of the present invention is a rolling control method for controlling a tandem rolling mill in which a plurality of rolling stands for rolling a rolled material are arranged side by side, wherein the i th (however, i is an integer equal to or greater than 2 and equal to or less than the number of rolling stands ) , and the i-th rolling stand is adjacent to the i-th rolling stand on the upstream side after the rolling stand bites the tip of the rolled material. The tension applying part provided between the rolling stand and the first rolling stand measures the first rolling load difference between the drive side and the working side of the i-th rolling stand before applying tension to the rolled material. Measuring the second rolling load difference between the driving side and the working side of the i-th rolling stand after the tension applying unit applied tension to the rolled material, and the measured First rolling load difference and previous Based on the difference between the second rolling load difference, and a step of determining the reduction leveling amount in each of the drive side and the work side of the i-th rolling stand.

  According to the present invention, without being affected by the temperature difference in the width direction of the rolled material, the deformation resistance difference in the width direction of the rolled material, the deviation of the rolled material from the center of the rolling mill, etc. Camber can be suppressed.

The schematic diagram which shows the structure of the rolling system which concerns on embodiment. Sectional drawing when a tandem rolling mill is cut in the width direction of the rolled material. The block diagram which shows the structure of the rolling control apparatus which concerns on embodiment. The schematic diagram which shows the model of the rolling-material front-end | tip part in tandem rolling. The flowchart which shows the flow of operation | movement of the rolling control apparatus which concerns on embodiment. The graph which shows the relationship between a rolling load difference and a bending rigidity coefficient. The graph which shows the relationship between the variation | change_quantity of the rolling load difference when the bending rigidity coefficient (alpha) changes from 0.02 to 0.8, and the board | plate thickness difference of the width direction of a rolling material.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

  The rolling control device according to the present embodiment suppresses meandering and camber at the leading end of a rolled material in a tandem rolling mill in which a plurality of rolling stands are arranged.

  FIG. 1 is a schematic diagram showing a configuration of a rolling system. The rolling system 100 includes a tandem rolling mill 200 and a rolling control device 300.

[Configuration of tandem rolling mill]
The configuration of the tandem rolling mill 200 will be described. As shown in FIG. 1, the tandem rolling mill 200 includes a plurality of rolling stands 210 arranged in a line. When rolling, the rolling material 400 is sent to each rolling stand 210 from the left to the right in the drawing. That is, the left side in the figure is the upstream side, and the right side in the figure is the downstream side. Hereinafter, the rolling stands 210 are referred to as the first rolling stand 210, the second rolling stand 210, the third rolling stand 210,.

  On each rolling stand 210, a pair of work rolls 211 are vertically opposed to each other. The rolled material 400 is sandwiched and rolled by the work roll 211. The work roll 211 is driven by a roll drive motor 212. A control unit 213 is connected to the roll drive motor 212, and the control unit 213 controls the roll drive motor 212.

  Each rolling stand 210 is provided with a reduction motor 214. The reduction leveling amount of the work roll 211 is adjusted by the reduction motor 214. A control unit 215 is connected to the reduction motor 214, and the control unit 215 controls the reduction motor 214.

  Each rolling stand 210 is provided with a rolling load meter 216. The rolling load meter 216 is a load cell and measures a load (hereinafter referred to as “rolling load”) applied to the rolled material 400 by the work roll 211.

  FIG. 2 is a cross-sectional view when the tandem rolling mill 200 is cut in the width direction of the rolled material. As shown in FIG. 2, one end side of the work roll 211 is a drive side, and the other end side is a work side. One roll drive motor 212 is connected to each drive side end of the two work rolls 211, and each work roll 211 is driven individually.

  One reduction motor 214 is connected to each of the drive side end and the work side end of the work roll 211. The two leveling motors 214 individually adjust the leveling levels at the drive side end and work side end of the work roll 211.

  One rolling load meter 216 is attached to each of the drive side end and the work side end of the work roll 211. The two rolling load meters 216 individually detect the driving side rolling load and the working side rolling load.

  Refer to FIG. 1 again. A looper 220 is provided between adjacent rolling stands. The looper 220 is a tension applying unit that applies tension to the rolled material 400. The looper 220 is driven by a looper drive motor 221. A control unit 222 is connected to the looper drive motor 221, and the control unit 222 controls the looper drive motor 221.

  The looper 220 is driven by the looper drive motor 221 and rises up to push up the rolled material 400. As the looper 220 pushes up the rolled material 400, tension is applied to the rolled material 400.

  Each control unit 215 and each rolling load meter 216 that controls the reduction motor 214 are connected to the rolling control device 300 so as to communicate with each other. The rolling control device 300 receives the rolling load detection value from the rolling load meter 216 and transmits a control signal to each control unit 215 to control the reduction motor 214.

[Configuration of rolling control device]
FIG. 3 is a block diagram showing a configuration of the rolling control apparatus according to the present embodiment. The rolling control device 300 is realized by a computer 301. As shown in FIG. 3, the computer 301 includes a main body 310, an input unit 320, and a display unit 330. The main body 310 includes a CPU 311, ROM 312, RAM 313, hard disk 315, reading device 314, input / output interface 316, and image output interface 317, and CPU 311, ROM 312, RAM 313, hard disk 315, reading device 314, input / output interface 316, The image output interface 317 is connected by a bus.

  The CPU 311 can execute a computer program loaded in the RAM 313. The computer 301 functions as the rolling control device 300 when the CPU 311 executes a rolling control program 340 that is a computer program for rolling control. The rolling control program 340 controls the rolling leveling amount of each rolling stand 210 and enables the rolling material 400 to meander and camber is suppressed.

  The ROM 312 is configured by a mask ROM, PROM, EPROM, EEPROM, or the like, and stores a computer program executed by the CPU 311 and data used for the same.

  The RAM 313 is configured by SRAM, DRAM, or the like. The RAM 313 is used for reading the rolling control program 340 recorded on the hard disk 315. Further, when the CPU 311 executes a computer program, it is used as a work area of the CPU 311.

  The hard disk 315 is installed with various computer programs to be executed by the CPU 311 such as an operating system and application programs, and data used for executing the computer programs. A rolling control program 340 is also installed in the hard disk 315.

  In the hard disk 315, for example, an operating system such as Windows (registered trademark) manufactured and sold by US Microsoft Corporation is installed. In the following description, it is assumed that the rolling control program 340 according to the present embodiment operates on the operating system.

  The reading device 314 includes a flexible disk drive, a CD-ROM drive, a DVD-ROM drive, or the like, and can read a computer program or data recorded on a portable recording medium. The portable recording medium stores a rolling control program 340 for causing the computer to function as a residual stress estimation device. The computer 301 reads the rolling control program 340 from the portable recording medium, and the rolling control program 340 is stored in the hard disk. 315 can be installed.

  The input / output interface 316 includes, for example, a serial interface such as USB, IEEE1394, or RS-232C, a parallel interface such as SCSI, IDE, or IEEE1284, and an analog interface including a D / A converter, an A / D converter, and the like. It is configured. An input unit 320 including a keyboard and a mouse is connected to the input / output interface 316, and the user can input data to the computer 301 by using the input unit 320. The input / output interface 316 is connected to each control unit 215 and each rolling load meter 216, receives a detected value of the rolling load from each rolling load meter 216, and transmits a control signal to each control unit 215. .

  The image output interface 317 is connected to a display unit 330 configured by an LCD, a CRT, or the like, and outputs a video signal corresponding to image data given from the CPU 311 to the display unit 330. The display unit 330 displays an image (screen) according to the input video signal.

[Disturbance component included in rolling load difference]
Here, the rolling load will be described using a model of the rolling material tip in tandem rolling. FIG. 4 is a schematic diagram showing a model of the rolling material tip in tandem rolling. FIG. 4 shows a state where the tip of the rolled material 400 is caught in the i-th rolling stand 210.

Due to the reduction leveling amount on the driving side and the working side set in the i-th rolling stand 210, a difference in the reverse travel rate occurs in the width direction of the rolled material 400, and the rolled material 400 tends to meander. However, since the rolling material 400 is fixed by the i-th rolling stand 210 and the (i-1) -th rolling stand 210 on the upstream side thereof, the i-th stand 210 and i-1 of the rolling material 400 are fixed. The portion sandwiched between the second stand 210 (hereinafter referred to as “target portion”) bends in the plane of the main surface (upper surface and lower surface) and is pressed down by the downstream end of the target portion (i-th rolling stand 210). Moment) and upstream ends (locations squeezed by the (i-1) -th rolling stand 210). Assuming that the deflection at the downstream end of the portion of interest is 0 and the moment M _i is applied to the upstream end, the angular velocity ω _i is expressed by the following equation.

  Here, the bending stiffness coefficient is an index indicating the ease of buckling (out-of-plane deformation) of the rolled material 400. In the present embodiment, the bending rigidity coefficient takes a value of 0 or more and 1 or less, and the larger the value, the higher the bending rigidity and the less the buckling.

Due to the moment, a tension distributed in the width direction is generated at the downstream end of the target portion. This tension reduces the reverse speed in the width direction and suppresses meandering. When it is assumed that the tension is linearly distributed, the inclination a of the tension distribution in the width direction is expressed by the following equation.

If the entry side tension is s and the rolling reduction rate is r, the advance rate fs is expressed by the following equation.

Since the volume of the part of interest does not change before and after the deformation, the backward movement rate fb is obtained by the following equation.

The reverse ratio drive side _{fb DS, fb WS} a reverse rate of the working side, when the peripheral speed of the work rolls 211 _{v r,} angular velocity omega _i is given by the following equation.

At this time, the angular velocity omega _i calculated by Equation (1), since it must coincide with the angular velocity omega _i calculated by Equation (6), the tension distribution, moments M _i, omega _i is determined. If the tension distribution is determined, it is possible to determine the rolling load on the driving side and the working side by using a known method such as Hill's formula, thereby obtaining the rolling load difference between the driving side and the working side. Can do. However, the rolling load difference thus obtained includes disturbance components such as a temperature difference in the width direction of the rolled material, a deformation resistance difference in the width direction of the rolled material, and a deviation of the rolled material from the center of the rolling mill. . For this reason, if the reduction leveling amount of the i-th rolling stand 210 is adjusted so as to reduce the rolling load difference obtained by the above calculation, meandering and camber cannot be sufficiently suppressed.

[Operation of rolling control device]
The rolling control apparatus 300 according to the present embodiment estimates the thickness difference in the width direction of the rolled material 400 based on the amount of change in the rolling load difference before and after applying tension to the rolled material, and rolls according to the thickness difference. A reduction leveling amount of the stand 210 is determined. Hereinafter, the operation of the rolling control apparatus 300 will be described.

  FIG. 5 is a flowchart showing a flow of operations of the rolling control device 300.

  When the operation of the tandem rolling mill 200 is started, the tip of the rolled material 400 is sent in order from the first rolling stand 210 to the downstream side. After the tip of the rolled material 400 is caught in the i-th rolling stand 210, the rolling load meter 216 of the i-th stand 210 measures the rolling load on each of the driving side and the working side. However, when the number of rolling stands of the tandem rolling mill 200 is N, i is an integer of 2 or more and N or less.

  The rolling load measurement data output from the rolling load meter 216 is transmitted to the rolling control device 300. The rolling control apparatus 300 receives the rolling load measurement data (step S101).

  The CPU 311 calculates a difference between the rolling load on the driving side and the rolling load on the operating side (hereinafter referred to as “rolling load difference”) (step S102). Thereby, the 1st rolling load difference which is a rolling load difference before tension | tensile_strength is provided to the rolling material 400 is obtained.

  The looper 220 provided between the i-th rolling stand 210 and the (i-1) -th rolling stand 210 adjacent to the i-th rolling stand 210 rises, and tension is applied to the rolled material 400. After the looper 220 is raised, the rolling load meter 216 of the i-th stand 210 measures again the rolling load on each of the driving side and the working side.

  The rolling load measurement data output from the rolling load meter 216 is transmitted to the rolling control device 300. The rolling control device 300 receives the rolling load measurement data (step S103).

  The CPU 311 calculates a rolling load difference using the received measurement data (step S104). Thereby, the 2nd rolling load difference which is a rolling load difference after tension | tensile_strength is provided to the rolling material 400 is obtained.

  The CPU 311 calculates the difference between the first rolling load difference and the second rolling load difference (step S105). The calculated difference is the amount of change in the rolling load difference before and after the tension is applied to the rolled material 400.

  Next, the CPU 311 estimates the plate thickness difference in the width direction of the rolled material 400 using the amount of change in the rolling load difference (step S106).

  Here, the estimation of the plate | board thickness difference of the width direction of the rolling material 400 is demonstrated. At the time before applying the tension to the rolled material 400 immediately after the leading end of the rolled material 400 is bitten into the rolling stand 210, it is in a state of being nearly buckled and easily buckled, and the bending stiffness coefficient α is considered to be small. On the other hand, after the tension is applied to the rolled material 400 by the looper 220, it is considered that the apparent sectional secondary moment is a value close to the actual sectional secondary moment, and α is a value close to 1.

  FIG. 6 is a graph showing the relationship between the rolling load difference and the bending stiffness coefficient. In the figure, the vertical axis represents the rolling load difference, and the horizontal axis represents the bending stiffness coefficient. As shown in FIG. 6, the rolling load difference and the bending stiffness coefficient are in a monotonically increasing relationship. Before tension is applied to the rolled material 400, the rolling load difference is small. When tension is applied to the rolled material 400, the bending rigidity increases and the moment acting on the rolled material 400 increases. By increasing the moment, a compressive force in the rolling direction is generated at one end in the width direction of the rolled material 400, and a tensile force is generated at the other end. That is, a tension difference occurs at both ends in the width direction of the rolled material 400. Since the compressive force increases the rolling load and the tensile force decreases the rolling load, the rolling load difference in the width direction increases by applying tension to the rolled material 400. Therefore, the bending stiffness coefficient α is small before the tension is applied to the rolled material 400, and the bending stiffness coefficient α is increased after the tension is applied to the rolled material 400.

The change in the rolling load difference before and after applying tension to the rolled material 400 is caused only by the change in the relationship between the moment M _i and the angular velocity ω _i (see FIG. 4) due to the change in the bending stiffness coefficient. The moment M _i and the angular velocity ω _i are caused by the thickness difference in the width direction of the rolled material 400. Therefore, the sheet thickness difference in the width direction of the rolled material 400 causing the meandering and cambering of the rolled material 400 (that is, causing the moment M _i and the angular velocity ω _i ) is obtained using the change amount of the rolling load difference. It can be estimated. If the reduction leveling amount of the i-th rolling stand 210 is adjusted so as to reduce the estimated thickness difference of the rolled material 400, the moment M _i and the angular velocity ω _i are reduced, and the meandering and camber of the rolled material 400 are suppressed. can do.

  In the present embodiment, the bending stiffness coefficient before and after applying the tension is measured in advance by an actual experiment, and each bending stiffness coefficient is stored in the hard disk 315.

  For example, consider a case where the bending stiffness coefficient α changes from 0.02 to 0.8 before and after applying tension to the rolled material 400. FIG. 7 is a graph showing the relationship between the amount of change in the rolling load difference and the thickness difference in the width direction of the rolled material 400 in this case. In FIG. 7, the vertical axis indicates the amount of change in the rolling load difference, and the horizontal axis indicates the plate thickness difference in the width direction of the rolled material 400 generated by rolling by the rolling stand 210. As shown in FIG. 7, it can be seen that the amount of change in the rolling load difference changes according to the plate thickness difference. Therefore, if the relationship between the change amount of the rolling load difference and the plate thickness difference is known, the plate thickness difference can be estimated based on the change amount of the rolling load difference. The relationship between the amount of change in the rolling load difference and the plate thickness difference is determined for each bending stiffness coefficient before and after the application of tension. The relationship between the change amount of the rolling load difference determined for each bending stiffness coefficient before and after the tension is applied and the plate thickness difference is stored in the hard disk 315 as, for example, a lookup table or a function. Based on the bending rigidity coefficient stored before and after the application of the tension stored in the hard disk 315, data indicating the relationship between the corresponding change amount of the rolling load difference and the plate thickness difference is specified and used for estimating the plate thickness difference. In the process of step S106, the CPU 311 obtains a plate thickness difference corresponding to the change amount of the rolling load difference as an estimated value by using this lookup table or function.

  Note that the bending stiffness coefficient before and after applying the tension need not be stored in advance. In this case, the relationship data between the rolling load difference and the bending stiffness coefficient as shown in FIG. 6 is stored in the hard disk 315, and the bending stiffness coefficient before applying the tension is determined by the first rolling load difference obtained in step S102. The bending stiffness coefficient after applying the tension may be determined based on the second rolling load difference obtained in step S104.

  Refer to FIG. 5 again. The CPU 311 determines the reduction leveling amount of the i-th rolling stand 210 based on the estimated plate thickness difference (step S107). In the process of step S107, the CPU 311 calculates the amount of reduction that causes the meandering and cambering of the rolled material 400 using the plate thickness difference. A known relationship between the plate thickness difference and the reduction amount is used for calculating the reduction amount. The CPU 311 sets a reduction amount that cancels the calculated reduction amount (that is, a value opposite to the calculated reduction amount) as the reduction leveling amount.

  The CPU 311 transmits a control signal for setting the rolling stand 210 with the determined reduction leveling amount to the control unit 215 of the i-th rolling stand (step S108). The control unit 215 receives the control signal and controls the reduction motor 214 so that the determined reduction leveling amount is obtained.

  After step S108, the CPU 311 ends the process.

  The CPU 311 executes the control process as described above for each of the second rolling stand 210 to the Nth rolling stand 210.

  By the control process as described above, meandering and camber of the tip portion of the rolled material 400 are suppressed in the second rolling stand 210 to the N-th rolling stands 210.

(Other embodiments)
In the above embodiment, the sheet thickness difference in the width direction of the rolled material 400 is estimated based on the amount of change in the rolling load difference before and after the application of tension to the rolled material 400. However, the present invention is limited to this. It is not a thing. The relationship between the amount of change in the rolling load difference before and after the application of tension to the rolled material 400 and the amount of reduction in the rolling stand is stored, and the amount of reduction to be adjusted is estimated based on the amount of change in the rolling load difference. It is good also as a structure.

  In the above embodiment, the configuration in which the tandem rolling mill 200 is controlled so as to suppress the meandering and camber of the rolled material 400 by the rolling control device 300 configured by a computer has been described. However, the present invention is not limited to this. It is not a thing. A dedicated control board may be provided in the tandem rolling mill 200, and the control process as in the above embodiment may be executed by this control board.

  Moreover, in said embodiment, although rolling control of the tandem rolling mill 200 provided with the looper 220 as a tension | tensile_strength provision part was described, it is not limited to this. The structure which performs rolling control of a tandem rolling mill provided with a pinch roller as a tension | tensile_strength provision part may be sufficient. In this case, the amount of change in the rolling load difference between the drive side and the working side before and after the pinch roller applies tension to the rolled material is obtained, and the thickness difference corresponding to the amount of change in the rolling load difference is estimated.

  The rolling control device and the rolling control method of the present invention are useful as a rolling control device and a rolling control method for suppressing meandering and camber of a rolled material in a tandem rolling mill.

DESCRIPTION OF SYMBOLS 100 Rolling system 200 Tandem rolling mill 210 Rolling stand 211 Work roll 214 Reduction motor 215 Control part 216 Rolling load meter 220 Looper 300 Rolling control apparatus 301 Computer 311 CPU
315 Hard disk 340 Roll control program 400 Rolled material

Claims (8)

A rolling control device for controlling a tandem rolling mill in which a plurality of rolling stands for rolling a rolled material are arranged,
After the i-th (where i is an integer greater than or equal to 2 and less than the number of rolling stands ) bites the tip of the rolled material, the i-th rolling stand and the i-th rolling stand are upstream. Rolling load difference between the driving side and the working side of the i-th rolling stand before and after the tension applying portion provided between the adjacent i-1th rolling stands applies tension to the rolled material. Determining means for determining a reduction leveling amount on each of the drive side and the work side of the i-th rolling stand based on the amount of change in
A rolling control device. Based on the amount of change in the rolling load difference, further comprising an estimation means for estimating the thickness difference at both ends in the width direction of the rolled material after applying the tension by the tension applying unit,
The determining means is configured to determine a reduction leveling amount on each of the driving side and the working side of the i-th rolling stand so that the difference in thickness estimated by the estimating means is reduced. ,
The rolling control apparatus according to claim 1. The estimation means is configured according to a relationship between a change amount of the rolling load difference determined with respect to a change in a bending rigidity coefficient of the rolled material before and after the tension applying unit applies tension to the rolled material, and the thickness difference. Configured to estimate the plate thickness difference,
The rolling control device according to claim 2. The change in the bending stiffness coefficient is determined based on the amount of change in the rolling load difference between the driving side and the working side of the i-th rolling stand before and after the tension applying unit applies tension to the rolled material. A bending stiffness coefficient determining means for
The estimation means estimates the sheet thickness difference according to a relationship between a change amount of the rolling load difference determined with respect to a change in the bending rigidity coefficient determined by the bending rigidity coefficient determination means and the sheet thickness difference. Configured as
The rolling control apparatus according to claim 3. An adjusting means for adjusting the i-th rolling stand according to the reduction leveling amount determined by the determining means;
The rolling control apparatus in any one of Claims 1 thru | or 4. The tension applying unit is a looper.
The rolling control device according to any one of claims 1 to 5. The tension applying unit is a pinch roller.
The rolling control device according to any one of claims 1 to 5. A rolling control method for controlling a tandem rolling mill in which a plurality of rolling stands for rolling a rolled material are arranged,
After the i-th (where i is an integer greater than or equal to 2 and less than the number of rolling stands ) bites the tip of the rolled material, the i-th rolling stand and the i-th rolling stand are upstream. First rolling between the driving side and the working side of the i-th rolling stand before the tension applying unit provided between the adjacent i-1th rolling stands applies tension to the rolled material. Measuring a load difference;
Measuring a second rolling load difference between the driving side and the working side of the i-th rolling stand after the tension applying unit has applied tension to the rolled material;
Determining a reduction leveling amount on each of the driving side and the working side of the i-th rolling stand based on the difference between the measured first rolling load difference and the second rolling load difference;
A rolling control method.

Images