JP2608250B2 - Shape control method and shape control device for multi-high rolling mill - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shape control method and a shape control method for a multi-high rolling mill, wherein the shape of a rolled material is controlled using a multi-high rolling mill having a pair of upper and lower work rolls, an intermediate roll and a reinforcing roll. Related to the device.

[0002]

2. Description of the Related Art Conventionally, a shape control method of a multi-high rolling mill, in which the shape of a rolled material is controlled by using a multi-high (6 high) rolling mill having a pair of upper and lower work rolls, an intermediate roll, and a reinforcing roll, has been known. A shape control device is known from JP-A-56-66307. This multi-high rolling mill includes a bending device for bending a work roll and an intermediate roll,
It has a moving device for moving the intermediate roll in the horizontal direction, and a shape detector for detecting a longitudinal elongation at each position in the width direction of the rolled material, and according to the elongation of the rolled material detected by the shape detector. By bending the upper and lower work rolls and intermediate rolls convexly or concavely to the rolled material side, or by moving the upper and lower intermediate rolls horizontally in opposite directions, the rolled material is rolled into a desired cross-sectional shape. I have to. Thereby, not only a simple distribution in which the widthwise distribution of the longitudinal elongation of the rolled material at the time of rolling is convex or concave, but also a W-shaped or M-shaped composite elongation is restored.

In order to control a rolled material to a desired shape, the axial elongation of the rolled material is detected at each point in the width direction of the rolled material, and the width distribution of the detected elongation is accurately determined. Must be expressed in Conventionally, the distribution represented by a higher-order equation including fourth-order or higher-order terms is known from, for example, Japanese Patent Application Laid-Open No. 55-42165. If the elongation distribution in the width direction of a rolled material is represented by a polynomial including higher-order terms of three or more degrees, it is generally difficult to directly determine the substance of the plate shape from the polynomial, and the rolled material represented by the higher-order equation The relationship between the shape and the bending direction and the bending amount of the work roll and the intermediate roll is not clear, and there is a problem that the shape control of the rolling mill cannot be appropriately performed.

Therefore, as an approximate expression for evaluating the distribution of elongation in the width direction of the rolled material, a predetermined position existing between the center of the width of the rolled material and the end of the width of the rolled material is set as a boundary, and the center of the width of the plate is set to The shape of the rolled material in the central region on the side is approximated by a quadratic expression, and the shape of the rolled material in the end region on the plate width end side from the boundary is also approximated by a different quadratic expression. Japanese Patent Application Laid-Open No. 4-178208 proposes a shape control method for bending a work roll or an intermediate roll or moving the intermediate roll in a horizontal direction.

[0005]

However, even in the control of the shape of a rolled material according to Japanese Patent Application Laid-Open No. 4-178208, the distribution of elongation in the width direction of the rolled material must be approximated by a quadratic equation. In order to accurately express the distribution by a quadratic expression, it is necessary to provide a large number of measurement points in the width direction of the rolled material and measure the elongation at each point. Further, depending on the capacity of the control device, there is also a problem that as the number of measurement points increases, the calculation takes more time, the feedback period becomes longer, and accurate shape control becomes difficult.

The present invention has been made in order to solve such a problem, and the shape data is not represented by a higher-order equation including a quadratic term or more, and the distribution of the elongation of the rolled material in the width direction is determined according to the following formula. It is an object of the present invention to provide a shape control method and a shape control device for a multi-high rolling mill in which a bending amount of a work roll and an intermediate roll is accurately adjusted, and the shape correcting ability such as a composite elongation is excellent.

[0007]

According to the present invention, a multi-high rolling mill having a pair of upper and lower work rolls, an intermediate roll, and a reinforcing roll is used according to the present invention. In a shape control method of a multi-high rolling mill for controlling a shape of a rolled material by adjusting a bending amount of a work roll, a central portion in a width direction and a longitudinal extension of an end portion of the rolled material are measured, and the central portion is measured. Wherein the intermediate roll is bent in accordance with a difference value between elongation of the end portion and the work roll in accordance with a rate of change of the end portion in a width direction. A method is provided.

According to another aspect of the invention, there is provided a work roll bending device having a pair of upper and lower work rolls, an intermediate roll and a reinforcing roll, and bending the work roll, and an intermediate roll bending device for bending the intermediate roll. Using a multi-high rolling mill comprising a, in a shape control device of a multi-high rolling mill to control the shape of the rolled material by adjusting the bending amount of the intermediate roll and the work roll, at least a central portion in the width direction of the rolled material A shape detecting means for measuring the longitudinal elongation of the end, and a first drive means for driving the intermediate roll bending device by an actuation amount corresponding to the difference between the elongation of the central part and the elongation measured by the shape detecting means. Driving means, and the working row by an operation amount corresponding to a rate of change in the width direction of the extension of the end portion measured by the shape detecting means. Characterized in that it comprises a second driving means for driving the bending device, the multi-high rolling mill of the shape control device is provided.

Preferably, the shape detecting means divides each of the rolled material into a plurality of regions at the central portion, the outermost portion at the end portion, and the adjacent inner portion adjacent to the outermost portion. The first drive means measures the difference between the average value of elongation measured in each region of the central portion and the average value of elongation measured in each region of the outermost portion. The second drive means calculates the change rate from the average value of elongation measured in each region of the outermost portion and the average value of elongation measured in each region of the adjacent inner portion. good.

[0010]

The work roll, which is in direct contact with the rolled material, is bent by driving the work roll bending device by an operation amount corresponding to the rate of change of the elongation at the end of the rolled material in the width direction by the second driving means. The shape of the end portion of the material is restored, and the intermediate roll is moved by the first drive means by the intermediate roll bending device by an operation amount corresponding to the difference between the longitudinal elongation of the center portion and the end portion in the width direction of the rolled material. Bending is performed by driving, thereby restoring the shape of the entire width of the rolled material.

[0011]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIGS. 1 and 2 show a schematic overall configuration of a rolling mill 10. The rolling mill 10 is a six-stage (multi-stage) rolling mill, and has a pair of upper and lower work rolls 11 and 12 and a larger diameter than the work rolls. And the reinforcing rolls 15 and 16 having a larger diameter than the intermediate rolls. The work rolls 11 and 12 perform rolling while sandwiching the rolled material W of the work between the two rolls. The rolling load of the work roll is applied by upper and lower auxiliary rolls 15 and 16 via intermediate rolls 13 and 14. Can be A hydraulic pressure reduction device 23 is disposed below the roll axis of the lower auxiliary roll 16, and a rolling load is applied to the lower auxiliary roll 16 by the reduction device 23. A hydraulic control circuit 24 is connected to the pressure reducing device 23, and the hydraulic pressure is supplied from the hydraulic control circuit 24. On the other hand, a load cell (not shown) is attached to the upper auxiliary roll 15 that receives the rolling load of the lower auxiliary roll 16, and measures the rolling load.

The roll diameters of the work rolls 11 and 12, the roll body length, and the distance between the chocks are appropriately selected according to the material to be rolled. In this embodiment, the roll diameters are 135mm, 850mm and 10mm, respectively.
75 mm. A pair of upper and lower work roll benders 21 (see FIG. 1 and indicated by arrows in FIG. 2) are disposed at both ends of the work roll shafts 11a and 12a, respectively. 11a and 12a are bent (bent) in a direction that becomes convex with respect to the rolled material W as a work (the plus direction shown in FIG. 3) or a direction that becomes concave with respect to the rolled material W (in the minus direction shown in FIG. 4). ), The shape of the end portion of the rolled material W is mainly corrected.

The roll diameter, the roll body length, and the distance between the chocks of the intermediate rolls 13 and 14 are also appropriately selected according to the material to be rolled, but in this embodiment, they are 300 mm and 85 mm, respectively.
0 mm and 1660 mm. A pair of upper and lower intermediate roll benders 22 is provided at each end of the intermediate roll shafts 13a and 14a.
(See FIG. 1 and indicated by an arrow in FIG. 2), and the roll shaft 13a,
14a is bent (bent) in a direction that becomes convex with respect to the rolled material W as a workpiece (a plus direction shown in FIG. 3) or a direction that becomes concave with respect to the rolled material W (a minus direction shown in FIG. 4), Correct the overall shape of the rolled material W. Although not shown, the intermediate rolls 13 and 14 include an intermediate roll 1
An intermediate roll shift for moving the rolls 3 and 14 in the axial direction (see FIG. 2) is provided, and by moving the intermediate rolls 13 and 14 in opposite directions, it is possible to correct the elongation distribution of the rolled material in the width direction. I can do it.

Hydraulic control circuits 25 and 26 are connected to the work roll bender 21 and the intermediate roll bender 22, respectively. The work rolls 11 and 12 and the intermediate rolls 13 and 14 are controlled by hydraulic pressure supplied from corresponding hydraulic control circuits.
Is bent to the above-mentioned plus side or minus side. The hydraulic control circuits 24 to 26
Control elements such as solenoid valves for adjusting the oil pressure from an unillustrated oil pressure source and supplying the oil to the corresponding hydraulic pressure reduction device 23 and the roll benders 21 and 22 are supplied from the controller 30. The operation is controlled by a control signal. The work roll bender 21 forms a part of a work roll bending device, and the hydraulic control circuit 25 and the controller 30 form a part of a second driving unit. The intermediate roll bender 22 forms a part of an intermediate roll bending device, and the hydraulic control circuit 26 and the controller 30 form a part of a first driving unit.

Each roll of the six-high rolling mill 10 can be rotated forward and reverse, and the rolled material W can be rolled by reciprocating by rotating the rolls forward and reverse. Therefore, the deflector rolls 32 and 33 and the winders 34 and 35 are disposed before and after the rolling mill 10, respectively. When rolling is performed in the direction indicated by the arrow A in FIG. It is wound by a winder 35 via a roll 33.

Spray devices 38 and 39 for spraying a coolant (or lubricant) toward the upper and lower work rolls 11 and 12 are provided before and after the rolling mill 10, respectively. Work roll 11,
A number of nozzles are provided at predetermined intervals in 12 axial directions, and the coolant injection amount of each nozzle is configured to be controllable. Then, when the rolled material W is rolled in the direction indicated by the arrow A in FIG. 1, the coolant whose spray amount is adjusted is sprayed from each nozzle of the rear spray device 38. From each nozzle of the spray device, work rolls 11,
The thickness distribution in the width direction of the rolled material W to be rolled, that is, the width distribution (shape) of the elongation in the longitudinal direction can also be controlled by adjusting the distribution of the amount of coolant injected into the roll 12.

As shown in FIG. 5 (b), the deflector roll 32 is formed by coaxially arranging a large number (30 in the embodiment) of small rolls 32a that rotate together. A known sensor for measuring the tension applied to the outer periphery of the roll is incorporated. Each sensor is connected to the input side of the controller 30 and supplies a sensor output to the controller 30. These sensors constitute the shape detector 32b (FIG. 1). The tension detected by each sensor corresponds to the elongation of the rolled material W in the longitudinal direction, and the output distribution of the shape detector 32b corresponds to the elongation distribution (plate shape) as shown in FIG. Become. Deflector roll 32 and small roll 32
Each roll width a varies depending on the width of the rolled material to be rolled, but is 780 mm and 26 mm (30 zones) in the embodiment, respectively. Therefore, in the embodiment, the elongation measured by one small roll 32a means that the average value of the elongation in the area of 26 mm in the width direction of the rolled material W is detected. Then, in the embodiment, the width direction of the rolled material W is divided into a number of regions corresponding to the roll width of the small rolls, and the elongation of the central portion C of the rolled material W is divided into four small rolls 32a corresponding to the central portion. , And the sensors of the four small rolls 32a corresponding to the positions detect the elongation of both ends (E + Q) of the rolled material W.

The deflector roll 33 has the same configuration as the deflector roll 32, and the sensors of the respective small rolls constituting the shape detector 33b of the deflector roll 33 are also connected to the input side of the controller 30, and the sensor output is controlled by the controller. 30. The controller 30 includes an input / output device (not shown), a central processing unit, an RO
It comprises a storage device such as M or RAM, an operation panel for inputting a command signal by an operator, and the like. The controller 30 executes a shape control program stored in the ROM according to a rolling start command from the operation panel, and based on the program, the shape detector 32b,
Elongation data of the rolled material W is taken in from 33b, and the bending amounts (bender operation amounts) of the work rolls 11, 12 and the intermediate rolls 13, 14 by the work roll bender 21 and the intermediate roll bender 22 are calculated, respectively, and the calculated bending amount is calculated. It is configured to output a corresponding control signal to the hydraulic control circuits 25 and 26 via the input / output device. A monitor device 31 is connected to the output side of the controller 30, and can display the elongation distribution and the like of the rolled material W detected by the shape detectors 32b and 33b described above.

Next, a rolling procedure (shape correcting procedure) of the rolled material W by the controller 30 will be described with reference to FIGS. FIG. 6 shows a shape correction procedure by an intermediate roll bender. When a rolling start command is input from an operation panel, this program is executed. The shape correction by the intermediate roll bender controls the amount of operation of the intermediate roll bender 22 based on data on the elongation of the central portion C and the outermost end E of the rolled material W from the shape detectors 32b and 33b. 30 first reads the target value MEC (Step S)
10). FIG. 8A shows a target elongation distribution of the rolled material W, and this elongation distribution is set in consideration of a post-rolling process and the like. The above-mentioned target value MEC is obtained by calculating the average of the elongation values obtained at the center (C region shown in FIG. 5A) and at the end (E region shown in FIG. 5A) of the target elongation distribution. The difference value (a value obtained by subtracting the center average value from the end average value) is set in advance, and the target value MEC is stored in the storage device of the controller 30.

Next, the controller 30 proceeds to step S1.
Then, the process proceeds to step 1 where the elongation data of the above-described C and E regions of the rolled material W detected by the shape detector 33b is read.
In the case of rolling and rolling the rolled material W in the direction opposite to the direction indicated by the arrow A in FIG. 1, the elongation data detected by the shape detector 32b is used. Then, based on the detected elongation value, the average values MC and ME of the elongation of the central portion C and the end portion E (or E + Q) of the rolled material W are calculated (step S12). Although it is not particularly limited how many detection values of the sensors are averaged to obtain the average elongation values MC and ME, the average elongation value MC in the case of the embodiment is shown in FIG.
The average elongation value ME is obtained from the average value of the detection values of the four central sensors corresponding to the region C shown in FIG.
It is obtained from the average value of the four sensor detection values corresponding to the two left and right E regions shown in FIG. Note that this average value may be a simple average value of the detection values of each sensor,
The average value may be obtained after multiplying the detection value of each sensor by a different weight coefficient.

Next, the difference between the average elongation value ME at the end and the average elongation value MC at the center is calculated (step S13).
In order to compare this with the above-mentioned target value MEC, a difference DEC between the above-mentioned difference value (ME-MC) and the target value MEC is obtained (step S14). DEC = (ME−MC) −MEC If the difference DEC is within a predetermined error range (zero difference), the bending amounts of the intermediate rolls 13 and 14 are not corrected (step S16), and will be described later. If the difference DEC exceeds the predetermined error range and becomes negative, the flow proceeds to step S17, in which the operation amount of the intermediate roll bender 22 is corrected (ie, the daily roll is performed). Bend in the direction.
On the other hand, if the difference DEC exceeds the predetermined error range and is positive, the process proceeds to step S18, in which the operation amount of the intermediate roll bender 22 is corrected (increased), and bending is performed in the positive direction shown in FIG. .

Various methods can be used for correcting the bending amount. For example, the difference DEC is displayed on the above-mentioned monitor device 31 and the operator operates the operation panel while watching the display to display the difference DEC. May be adjusted, or according to the difference DEC, the operation amount of the intermediate roll bender 22 may be feedback-controlled by a known PID control method or the like. In either case,
The controller 30 outputs a control signal corresponding to the difference DEC to the hydraulic control circuit 26 to correct the operation amount of the intermediate roll bender 22.

When the correction of the bending amount is completed, the process proceeds to step S19, and it is determined whether or not the rolling is completed. If the answer is negative (No), the process returns to step S11 described above and repeats the procedure from step S11.
If affirmative (Yes), the program is terminated. Next, a description will be given of a shape correction procedure by the work roll bender in FIG. This program is also executed by inputting a rolling start command from the operation panel. The shape correction by the work roll bender is performed by changing the widthwise change rate of the elongation of the end of the rolled material W from the shape detectors 32b and 33b, more specifically, the elongation of the outermost end E and the adjacent inner end Q. The operation amount of the work roll bender 21 is controlled from the data, and the controller 30 first reads the target value MEQ (step S20). The target value MEQ is also the elongation change rate at the end of the target elongation distribution shown in FIG. 8A, in this embodiment, the outermost end (E region shown in FIG. 5A) and the adjacent inner end ( The difference between the average values of elongation obtained in the Q region shown in FIG. 5A (the value obtained by subtracting the average value of the Q region from the average value of the E region) is set in advance.
Are also stored in the storage device of the controller 30.

Next, the controller 30 proceeds to step S2.
Then, the process proceeds to step 1 where the elongation data of the E and Q regions of the rolled material W detected by the shape detector 33b is read. In the case of rolling and rolling the rolled material W in the direction opposite to the direction indicated by the arrow A in FIG. 1, the elongation data detected by the shape detector 32b is used. Then, the average values ME and MQ of the elongation of the outermost end E and the adjacent inner end Q of the rolled material W are calculated based on the detected elongation (step S22). The average elongation value ME in the case of the embodiment is obtained from the average value of the detection values of the four sensors corresponding to the two left and right E regions shown in FIG.
Is obtained from the average value of the detection values of the four sensors corresponding to the two left and right Q regions shown in FIG. In this case as well, the average value is calculated from, for example, the following equation by weighting the detection value of each sensor.

ME = (E1 × 90 + E2 × 110 + E3 × 110 + E4 × 90) ÷ 400 Here, E1 to E4 are detection values of four sensors in the E region. Next, a difference value between the average elongation value ME at the outermost end and the average elongation value MQ at the adjacent inner end is calculated (step S23), and the difference value is compared with the target value MEQ described above. (ME-MQ) and the difference DE between the target value MEQ
Q is obtained (step S24).

DEQ = (ME-MQ) -MEQ When the difference DEC is within a predetermined error range (zero difference), the bending amounts of the work rolls 11 and 12 are not corrected (step S26). If the difference DEQ exceeds the predetermined error range and is negative, the process proceeds to step S27, in which the operation amount of the work roll bender 21 is corrected (ie, the vehicle is decremented), and the process proceeds to step S29. Bend in the minus direction shown in.
On the other hand, if the difference DEQ exceeds the predetermined error range and is positive, the process proceeds to step S28, in which the operation amount of the work roll bender 21 is corrected (increased), and the bending is performed in the positive direction shown in FIG. .

For the method of correcting the bending amount, for example, the difference DEQ is displayed on the above-mentioned monitor device 31 and the operator operates the operation panel while watching the display to adjust the operation amount of the work roll bender 21. Alternatively, the operation amount of the work roll bender 21 may be feedback controlled by a known PID control method or the like according to the difference DEQ. In any case, the controller 3
A value of 0 outputs an E control signal to the hydraulic control circuit 25 in accordance with the difference DEQ to correct the operation amount of the work roll bender 21.

When the correction of the bending amount is completed, the process proceeds to step S29, and it is determined whether or not the rolling is completed. If the answer is negative (No), the procedure returns to step S21 and repeats the procedure from step S21.
If affirmative (Yes), the program is terminated. It should be noted that, by repeating several passes, the rolled material W
When rolling is performed, the above-described steps S10 and subsequent steps may be automatically executed at the start of each pass, or the operation panel may be operated at each pass to supply a rolling start command to the controller 30. You may make it.

FIG. 8 shows a typical example in which the shape of the rolled material W is corrected by the above-described two shape correction controls, and when the rolled material W is convex downward beyond the target shape (FIG. 8B). ), The work roll bender (WRB) 21 is corrected to the increase (plus) side, and mainly corrects the shape of the end of the rolled material W, and the intermediate roll bender (IMRB) 2
2 is also corrected to the increase (plus) side, and corrects the entire width of the rolled material W. The work rolls 11 and 12 are small in diameter and easily bent as compared with the intermediate rolls 13 and 14, and are in direct contact with the work to be rolled, so that the shape of the end of the work is greatly affected. 14
Affects the work via the work rolls 11 and 12, and corrects the entire width of the work in a flat direction or in the opposite direction.

Similarly, when the shape is upwardly convex beyond the target shape (case (c) of FIG. 8), the work roll bender (WRB) 21 is corrected to the decrease (minus) side, and The shape of the end portion of W is corrected, and the intermediate roll bender (IMRB) 22 is also corrected to the decrease (minus) side, thereby correcting the entire shape of the rolled material W in the sheet width.

When the rolled material W has an M character shape (case (d) in FIG. 8), the work roll bender (WRB) 21 is corrected to the decrease (minus) side, and the intermediate roll bender (IMRB) 22 is an increase (plus)
When corrected to the side, the rolled material W is corrected in the target shape direction. When the rolled material W has a W character shape (case (e) of FIG. 8), the work roll bender (WR)
When B) 21 is corrected to the increase (plus) side and the intermediate roll bender (IMRB) 22 is corrected to the decrease (minus) side, the rolled material W is corrected in the target shape direction.

In the present invention, the shape control of the rolled material W is performed by adjusting the bending amounts of the work roll bender and the intermediate roll bender. Shape control may be performed by combining shift control, coolant control, tilting control of a work roll and / or an intermediate roll, and the like.

[0033]

As is apparent from the above description, according to the shape control method and the shape control device for a multi-high rolling mill of the present invention, the elongation of the rolled material in the longitudinal direction at the center and in the end in the width direction is respectively determined. Measured, the intermediate roll was bent according to the difference between the elongation at the center and the end, and the work roll was bent according to the rate of change of the elongation at the end in the width direction. It is not necessary to express the elongation distribution of the rolled material by a higher-order polynomial, and therefore, the number of shape measurement points can be reduced, so that the control calculation speed can be increased. Since the shape of the plate end is corrected by the work roll and the shape of the entire width of the plate is corrected by the intermediate roll, the shape correcting ability such as composite elongation is excellent. Further, since only the bending amount of the intermediate roll and the work roll is adjusted only by the shape data of the end portion and the center portion of the rolled material, an excellent effect that the control is simple and the control speed is fast is exhibited.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of a shape control device of a multi-high rolling mill according to the present invention.

FIG. 2 is a front view of the rolling mill 10 shown in FIG.

FIG. 3 is a diagram showing a bending direction on a plus side of a rolling roll.

FIG. 4 is a diagram showing a bending direction on a minus side of a rolling roll.

FIG. 5 is a diagram showing the relationship between the configuration of deflector rolls 32 and 33 shown in FIG. 1 and output values of shape detectors 32b and 33b incorporated therein.

FIG. 6 is a flowchart showing a procedure for controlling the shape of an intermediate roll according to the present invention.

FIG. 7 is a flowchart showing a procedure for controlling the shape of a work roll according to the present invention.

FIG. 8: Rolled material shape and work roll bender (WRB)
6 is a graph showing the relationship between the correction direction of an intermediate roll bender (IMRB).

[Explanation of symbols]

 Reference Signs List 10 Multi-high rolling mill 11, 12 Work roll 13, 14 Intermediate roll 15, 16 Auxiliary roll 21 Work roll bender 22 Intermediate roll bender 30 Controller 32, 33 Deflector roll 32b, 33b Shape detector

Claims (3)

(57) [Claims] 1. A multi-stage rolling mill which uses a multi-stage rolling mill having a pair of upper and lower work rolls, an intermediate roll and a reinforcing roll, and adjusts the bending amount of the intermediate roll and the work roll to control the shape of a rolled material. In the shape control method,
Measure the elongation in the longitudinal direction of the center portion and the end portion in the width direction of the rolled material, and bend the intermediate roll according to the difference value of the elongation of the center portion and the end portion, the width of the elongation of the end portion A shape control method for a multi-high rolling mill, wherein the work roll is bent in accordance with a rate of change in direction. 2. A multi-stage rolling mill having a pair of upper and lower work rolls, an intermediate roll and a reinforcing roll, and comprising a work roll bending device for bending the work roll and an intermediate roll bending device for bending the intermediate roll. Then, in the shape control device of a multi-high rolling mill for controlling the shape of the rolled material by adjusting the amount of bending of the intermediate roll and the work roll, the longitudinal elongation of at least the central portion and the end portion in the width direction of the rolled material. A shape detecting means for measuring each, a first driving means for driving the intermediate roll bending device by an actuation amount corresponding to a difference between the elongation of the central part and the elongation measured by the shape detecting means, and the shape detecting means Drives the work roll bending device by an operation amount according to the rate of change in the width direction of the extension of the end portion measured by And a second driving means for causing the multi-high rolling mill to have a shape. 3. The shape detecting means divides each of the rolled material into a plurality of regions at the central portion, the outermost portion at the end portion, and the adjacent inner portion adjacent to the outermost portion. The first driving means measures the elongation in each region of the central portion and the average value of the elongation measured in each region of the outermost portion and the average value of the elongation measured in each region of the outermost portion. A difference value is obtained, and the second driving unit obtains the change rate from an average value of elongation measured in each region of the outermost portion and an average value of elongation measured in each region of the adjacent inner portion. The shape control device of a multi-high rolling mill according to claim 2, characterized in that: