JPH07164030A - Method for controlling shape for multistage rolling mill - Google Patents

Abstract

PURPOSE:To improve a shape at the time of a low speed. CONSTITUTION:In a method for controlling a shape by a multistage rolling mill controlling the shape of a material 1 to be rolled by using an actuator 6 for lateral adjustment and actuators 5 for crown control, plurally provided in the width direction of a sheet, when a rolling speed is low and the acceleration or the deceleration of the rolling speed, is large, the shape is controlled by using the actuator 5 for crown control instead of using the actuator 6 for lateral adjustment.

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 for a multi-high rolling mill used as a thin plate cold rolling mill.

[0002]

2. Description of the Related Art As a shape control method for a multi-high rolling mill of this type, for example, JP-A-62-2114814, JP-A-3-155403, JP-A-4-111910 and JP-A-4-138810. Those described in the publication are known. In the conventional multi-stage rolling mill, a detector for detecting the shape of the rolled material, a shape control actuator for displacing the rolling roll to correct the shape of the rolled material, and a shape value detected by the detector. Originally, it was provided with a shape control device for calculating an operation amount for operating the actuator. And the said shape detector was provided in the downstream of the rolling mill.

As the shape control actuators, there have been crown control actuators, lateral just actuators, and tilt actuators.

[0004]

The lateral adjustment actuator moves the intermediate roll in the axial direction. However, the intermediate roll is moved in the axial direction when the rolling mill operates at a low speed or under a high load. Requires a great deal of power. Therefore, the followability of lateral control at low speed is poor, it takes time to improve the shape, and the yield is poor.

Therefore, an object of the present invention is to solve the above problems.

[0006]

In order to achieve the above object, the present invention has taken the following means. That is, the feature of the present invention is a lateral adjustment actuator, and a shape control method of a multi-stage rolling mill that controls the shape of a rolled material using a plurality of crown control actuators provided in the strip width direction, When the rolling speed is low and the acceleration or deceleration of the rolling speed is large, the shape is controlled by using the crown control actuator instead of using the lateral adjustment actuator.

It is preferable that the crown control actuator has outermost ends on both sides.

[0008]

In general, the crown control has better followability than the lateral control. Therefore, it is more efficient to use the crown control actuator instead of the lateral adjustment actuator for shape control at low speed or under high load. The shape can be modified well.

If the crown control actuators at the outermost ends on both sides are used, the shape can be corrected more efficiently.

[0010]

EXAMPLES Examples of the present invention will be described below. 2 and 3 show an example of a multi-stage rolling mill used in the method of the present invention. The rolling mill has a pair of upper and lower work rolls 2 contacting a rolled material 1 which is a thin plate, and the work roll 2 The intermediate roll 3 supporting the intermediate roll 3 and the backup roll 4 supporting the intermediate roll 3.

The backup roll 4 is a bearing roll divided in the axial direction (plate width direction). Each bearing roll of the predetermined backup roll 4 is provided with a crown actuator 5 for imparting a roll crown. In this embodiment, two backup rolls 4 on each side out of three backup rolls on one side
The crown actuator 5 is provided on the 4. Each of the backup rolls 4 is provided with five crown actuators 5 # 1 to # 5 along the axial direction.

The intermediate roll 3 has a taper portion at one axial end thereof, and is provided with a lateral adjustment actuator 6 for moving the intermediate roll 3 in the axial direction. In this embodiment, the lateral adjustment actuator 6 is provided on the work side, and the intermediate roll 3 has taper portions on the drive side and the work side, respectively.
Move in the axial direction.

Further, this multi-high rolling mill has a tilting and lowering device for tilting the upper housing, and a tilting actuator 7 for driving the device is provided. A plate shape detector 8 is provided on the downstream side slightly away from the work roll 2. The shape detector 8 is composed of a plurality of shape detection sensors arranged in the plate width direction. Further, a plate thickness meter 9 is provided on the upstream side and the downstream side of the work roll 2 with the work roll 2 interposed therebetween.

The plate thickness gauge 9 is connected to a plate thickness control device 10, the shape detector 8 is connected to a shape control device 11, the plate thickness control device 10 is connected to a reduction actuator 9 and a tilt actuator 7. The shape control device 11 is connected to the lateral adjustment actuator 6 and the crown actuator 5. The shape control device 11 is also connected to the tilt actuator 7.

In the shape control, the shape control device 11 performs a predetermined calculation based on the shape detection value of the rolled material 1 detected by the shape detector 8 and each actuator is controlled.
Controls the manipulated variable of 5,6,7. Each of the actuators 5, 6,
The functions of 7 are as follows. That is, the tilt reduction by the tilt actuator 7 contributes to the improvement of the first-order component of the plate shape, and the crown control by the crown actuator 5 contributes to the improvement of the second-order and fourth-order components and the local distortion, and the lateral adjustment. The lateral adjustment by the actuator 6 for use contributes to the improvement of the plate end portion.

The calculation of the operation amount of each of the actuators 5, 6, and 7 is performed by the influence coefficient (actuator unit amount (1 m
m) Using the change amount (I-Unit) of the shape of each shape detection sensor when moved, for example, the above-mentioned Japanese Patent Laid-Open No. 3-1
This is performed by the equation (11) described in Japanese Patent No. 55403.
The relationship between the influence coefficient and the plate shape is expressed by the following equation.

[0017]

[Equation 1] Δfi = Σαji · ΔXj

Where Δfi is the shape change amount detected by the i-th shape detection sensor of the shape detector 8 when the j-th actuator is operated by the operation amount ΔXj αji: The j-th actuator position i-th shape detection sensor position influence coefficient ΔXj: j-th actuator operation amount FIGS. 4 to 11 show the influence coefficients of the shape control actuators 5, 6, and 7 used in the control equation.

The influence coefficients shown in FIGS. 4 to 11 are data for a 12-high rolling mill. # 1 and # shown in FIGS. 4 and 8
5 and the influence coefficient of the crown actuator 5 of FIG.
And the actuator 6 for lateral adjustment shown in FIG.
It can be seen that, since the influence coefficients of (1) and (2) are similar, the same effect can be obtained by using the lateral adjustment actuator 6 and the # 1 and # 5 crown control actuators 5.

However, the influence coefficient of each is lateral: about 4 I-Unit / mm, crown: about 400 I-Unit / mm, and the movable amount within one control cycle (3 sec) is lateral: 1 mm / sec × 3sec = 3mm Crown: 0.0375mm / sec × 3sec = 0.1125mm, so the shape that can be improved in one cycle is lateral: 4 I-Unit / mm × 3mm = 12 I-Unit Crown: 400 I-Unit /Mm×0.1125mm=45 I-Uni
t, and the shape improvement ability of the crown is about 3.5 times larger than that of the lateral.

Therefore, in controlling the shape of the plate end (shape control during acceleration / deceleration), it is more effective to use the actuator 5 for crown control at the outermost end instead of using the actuator 6 for lateral adjustment. It turns out that Instead of the lateral adjustment actuator, only the outermost end # 1 or # 5 crown control actuator may be used.
It is also possible to use a combination of # 1 to # 5.

FIG. 1 shows a flowchart of a shape control method when rolling using the above apparatus. That is,
At the time of accelerating the rolling immediately after the start of rolling, there is an amount of change ΔV (m / min / s) in the rolling speed in the control cycle and the acceleration rate A (m / mi
n / s) or more and rolling speed B with rolling speed V (m / min)
(m / min) or less, remove the lateral adjustment actuator 6 from the control actuator and
Control calculation is performed using the # 1 and # 5 crown control actuators 5 as control actuators. In other cases, the control amounts are calculated with the actuators 5, 6, and 7 as control targets, as in the conventional case.

The reason why the acceleration rate is set to be "certain" is that the coefficient A is a parameter set according to the situation. That is, when the operator gradually increases the speed (when ΔV is small), the amount of change in shape is small, so that lateral movement may be sufficient, and a constant cannot be uniformly set. Also, the reason why the speed is "certain" or less is that the steady speed (for example, 100
This is because the lateral movement becomes easier at mpm), the actuator does not affect the plate thickness, and the actuator works well only at the plate edge as compared with the crowns # 1 and # 5.

The present invention is not limited to the acceleration of rolling in the above embodiment, and for example, even when decelerating the rolling immediately before the end of rolling, the # 1 and # 5 crown control actuators 5 are used as control actuators. Can improve the growth of. That is, at the time of rolling deceleration, each actuator works to improve the shape, there is no symmetrical position with respect to the pass line, and there is a load difference between the work side and the drive side.
Even if the lateral drive side and work side have the same control output, the movement amount may be different and the shape balance may be lost. This will affect the start of the next pass. Therefore, the problem is solved by applying the present invention.

In the above embodiment, the case was described immediately after the start of rolling or immediately before the end of rolling. However, even during rolling,
Needless to say, the present invention can be applied when the rolling speed is low and the acceleration or deceleration of the rolling speed is large and the lateral movement is difficult.

[0026]

According to the present invention, the shape control during the transition period in which the rolling speed is low and the acceleration or deceleration of the rolling speed is large becomes good, and the productivity and the yield can be improved.

[Brief description of drawings]

FIG. 1 is a flowchart showing a procedure of a control method of the present invention.

FIG. 2 is a configuration diagram of a multi-high rolling mill used in the method of the present invention.

FIG. 3 is a control system diagram of a multi-stage rolling mill used in the method of the present invention.

FIG. 4 is a graph showing an influence coefficient of a crown # 1 actuator with respect to a shape detection sensor.

FIG. 5 is a graph showing the coefficient of influence of the crown # 2 actuator on the shape detection sensor.

FIG. 6 is a graph showing an influence coefficient of a crown # 3 actuator with respect to a shape detection sensor.

FIG. 7 is a graph showing the coefficient of influence of the crown # 4 actuator on the shape detection sensor.

FIG. 8 is a graph showing an influence coefficient of a crown # 5 actuator with respect to a shape detection sensor.

FIG. 9 is a graph showing an influence coefficient of a tilt actuator on a shape detection sensor.

FIG. 10 is a graph showing the influence coefficient of the drive side lateral actuator with respect to the shape detection sensor.

FIG. 11 is a graph showing an influence coefficient of the workpiece lateral actuator with respect to the shape detection sensor.

[Explanation of symbols]

 1 Rolled material 5 Actuator for crown control 6 Actuator for lateral adjustment

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location 8315-4E B21B 37/00 116 Q

Claims (2)

[Claims] 1. A shape control method for a multi-high rolling mill which controls the shape of a rolled material by using a lateral adjustment actuator and a plurality of crown control actuators provided in the strip width direction. A shape control method for a multi-high rolling mill, characterized in that, when the acceleration or deceleration of the speed is large, the shape is controlled using a crown control actuator instead of using the lateral adjustment actuator. 2. A shape control method for a multi-high rolling mill which controls the shape of a rolled material by using a lateral adjustment actuator and a plurality of crown control actuators provided in the strip width direction, wherein the rolling speed is low and rolling is performed. A shape control method for a multi-stage rolling mill, characterized in that when the acceleration or deceleration of speed is large, the shape is controlled by using the crown control actuators at the outermost ends of both sides instead of using the lateral adjustment actuator.