JPH0739007B2 - Flatness control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a flatness control device for increasing the flatness of a rolled material that is roll-formed by a multiple rolling mill, and more specifically, an operation method. The present invention relates to a flatness control device for a multiple rolling mill having a work roll bender and / or an intermediate roll bender as an end and an intermediate roll shift position moving mechanism.

[Conventional technology]

Conventionally, in a rolling mill, an elongation distribution in the plate width direction of a rolled material, that is, a roll bender provided on both or one of a work roll and an intermediate roll as an operation end for controlling plate flatness, and an intermediate roll shift. Generally, a flatness control device having a position moving mechanism is assembled.

The flatness control of the rolled material by the flatness control device provided in this rolling mill is, for example, in the case of JP-A-55-120409, in the case where the roll bender is over the limit, the rolling material on the exit side of the rolling mill The shape is detected, the roll bender force, that is, the roll bender control amount is controlled according to the shape detection signal, and when the roll bender force deviates from the preset range, the intermediate roll is set to this roll bend force within the set range. It is designed to shift inward. Also,
In the case of JP-B-58-48245 and JP-B-58-48246, the optimum roll shift position and the optimum roll bender force are calculated from the required shape correction amount of the rolled material, and one of these calculated values is calculated. By changing the other with the fixed value as, the flatness of the rolled material is feedback-controlled. Further, in the case of JP-A-63-177909,
The shape feedback control correction gain is changed as a function of the intermediate roll shift position to adjust the roll bender force.

[Problems to be Solved by the Invention]

However, in the technique disclosed in JP-A-55-120409, the roll bender force is moved in the correction direction only after the roll bender force exceeds the upper and lower limit values of the allowable range. Since it is not possible to perform sufficient shape control before returning to the controllable range, and the moving speed of the intermediate roll is slow, there is a long period in which the control capability of this roll bender force cannot be utilized, There was a problem that sufficient flatness could not be obtained over the entire length of. In particular, when the rolling speed changes, the rolling load changes significantly, so the flatness of the rolled material is likely to be disturbed, and the amount of change is large, so the roll bender force may fall outside the controllable range. In many cases, it becomes impossible to achieve sufficient flatness control.

Further, in the technology disclosed in JP-B-58-48245 and JP-B-58-48246, there is some effect under the condition that the rolling speed is constant, but the rolling speed changes. In this case, since the roll bender force corresponding to the rolling speed change is large and the intermediate roll shift corresponding to the extremely slow corresponding speed is controlled and changed under exactly the same conditions, there is a problem that the rolling speed change cannot be followed at all. .

Further, in the technique disclosed in Japanese Patent Laid-Open No. 63-177909, the roll bender force is adjusted by a shape feedback control correction gain that changes as a function of an intermediate roll shift amount of a slow corresponding speed to a change in rolling speed. Therefore, there is a problem that the change in rolling speed cannot be sufficiently followed.

As described above, the above-mentioned conventional technique treats the intermediate roll shift, which has a slow follow-up change speed with respect to the rolling speed change, and the roll bender, which has a fast follow-up change speed with respect to the rolling speed change, equally and both As a result, the control delay is inevitably caused by the change in rolling speed. Further, the roll bender force and the intermediate roll shift corresponding to each rolling speed are individually set and controlled to the optimum value for the rolling speed, or to the other set to the optimum value corresponding to the rolling speed. Is controlled to be an one-to-one correspondence by setting to an optimum value, so the follow-up of the roll bender force with a fast follow-up speed to the change in flatness of the rolled material is affected by the intermediate roll shift with a slow follow-up speed. It was supposed to leave the permissible range.

Therefore, the present invention was devised to solve the above-mentioned problems in the prior art, and the flatness of the rolled material is liable to occur, and the roll bender easily deviates from the allowable range. Most of the time when decelerating,
Since the acceleration and deceleration of the rolling speed occur before and after the welding point of the rolled material passes through the rolling mill, by tracking this welding point, the timing of the acceleration and deceleration of the rolling speed can be changed. It is set based on the intermediate roll shift, focusing on the point that it can be recognized before the start of acceleration / deceleration, and that there is a certain allowable range for the change in the roll bender force for any intermediate roll shift position. Control of roll bender force The roll bender force is controlled within the allowable range, and the intermediate roll shift is performed in accordance with the acceleration / deceleration timing of the rolling speed. The object is to keep the flatness of the rolled material satisfactorily and stably without exceeding the allowable range.

[Means for Solving the Problems]

Means of the present invention for achieving the above object is a flatness control device of a multi-rolling mill for controlling a roll bender provided with a roll bender as an operating end and an intermediate roll shift position moving mechanism, and a maximum rolling speed and For at least two types of rolling speeds such as strip rolling speed and welding point passing speed,
It has a setup arithmetic unit that determines the optimum intermediate roll position that maximizes the control range of the roll bender. The optimum intermediate roll position signal from this setup arithmetic unit and the intermediate position from the tracking device that predicts the acceleration / deceleration timing of the rolling speed. And an intermediate roll shift position feedforward controller for setting the intermediate roll shift speed and the movement start time of the intermediate roll based on the roll shift start timing signal.

[Action]

In a flatness control device for a multi-rolling mill that has a roll bender as an operating end and an intermediate roll shift position moving mechanism, the coefficient of influence of the intermediate roll shift position and the roll bender operation on the flatness. Is provided to determine an optimum roll bender control amount.

The setup calculation device, for each of the maximum rolling speed, strip rolling speed, and welding point passing speed that are given in advance,
Rolling conditions, plate thickness of rolled material, plate width, deformation resistance, reduction ratio, etc.
And from the roll information, etc., the rolling load predicted value of the maximum rolling speed range, the rolling load predicted value of the strip rolling speed range, the rolling load predicted value of the welding point passing speed range is calculated, and at these rolling load levels, the roll The shift position of the intermediate roll, that is, the optimum intermediate roll position that can take the widest control range of the vendor force is determined.

The optimum control amount determination device provided in the flatness control device for controlling the roll bender calculates the influence coefficient using the influence coefficient model of the intermediate roll shift position and each operation end of the roll bender with respect to the flatness of the rolled material, Based on this result, the optimum intermediate roll which is arranged in advance on the exit side of the rolling mill and which has been calculated and determined in advance by the setup calculation device with respect to the actual value of the flatness of the rolled material from the shape detector that detects the shape of the rolled material. The positions are combined to determine the optimum roll bender control amount, which is the optimum roll bender force to be manipulated accordingly.

That is, in the state where the rolled material is traveling at the set rolling speed, the intermediate roll is located at the optimum intermediate roll position determined by the setup calculation device, and the roll bender is determined by the optimum control amount determination device. It is operated with an optimum roll bender controlled variable determined according to the optimum intermediate roll position.

In this way, the roll bender is operated with the optimum roll bender force determined according to the optimum intermediate roll position determined by the setup calculation device, but the optimum intermediate roll position itself determined by the setup calculation device is
At the rolling load level in the corresponding rolling speed range, the roll bending force control range is set to a value that can take the widest range, so it is possible to respond to the signal from the shape detector, that is, the variation in the elongation difference ratio. Even if the optimum roll bender force determined by the optimum control amount determination device changes, the optimum roll bender force determined by this optimum control amount determination device does not deviate from the permissible control range, and it is good and stable. Achieving and maintaining the flatness control of the rolled material.

In addition, the intermediate roll shift position feedforward control device (hereinafter simply referred to as the intermediate roll shift position FF control device) is used for the rolling condition, the length of the rolled material, the thickness of the rolled material, the plate width, the deformation resistance, and the reduction ratio. , And roll information, the welding point detection signal from the welding point detector located on the inlet side of the rolling mill, and the rotation record of the work rolls or intermediate rolls A shift start timing signal for setting the movement start time of the intermediate roll from the tracking device that tracks the welding point based on the movement amount signal from the arithmetic unit and predicts and determines the acceleration / deceleration timing of the rolled material based on this tracking When,
Based on the optimum intermediate roll position signal input from the setup calculation device, an intermediate roll shift speed setting and a movement start signal for moving the intermediate roll in a form that suitably corresponds to a change in rolling speed are output to the optimal control amount determination device.

Therefore, when the rolling speed of the rolled material changes, the optimum control amount determination device sends the optimum intermediate roll position signal corresponding to each rolling speed from the setup calculation device and the intermediate roll shift position.
The intermediate roll shift speed setting and the movement start signal from the FF controller are input. In the optimum control amount determination device, based on the optimum intermediate roll position corresponding to the current rolling speed and the optimum intermediate roll position corresponding to the changed rolling speed, the optimum intermediate roll position according to the intermediate roll shift speed setting signal The roll position is calculated, and the shift position of the intermediate roll is sequentially changed from the position corresponding to the current rolling speed to the position corresponding to the changed rolling speed.

In this way, even when the rolling speed changes, the setting of the optimum intermediate roll position is set under the condition that the control range of the roll bender force can be set to the widest range. It will be safely set to a value that will not leave.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram in which an embodiment of a flatness control device according to the present invention is attached to a rolling mill 1. The rolling mill 1 to which the flatness control device is attached is, as shown in FIG. The roll 2, the pair of intermediate rolls 3, and the pair of backup rolls 4 are configured as a six-fold rolling mill,
In this rolling mill 1, as the flatness operation end, a work roll 2 is applied to the operation side OP and the drive side DS of the rolling mill 1, and a work force is applied to the work roll 2 to control the flatness of the rolled material. The roll bender 5 is provided, and the intermediate roll 3 is different from the intermediate roll 3.
An intermediate roll shift position moving mechanism 6 for adjusting the axial position of the is provided. In the embodiment shown in FIG. 2, the upper intermediate roll 3 is shifted to the drive side DS side, and the lower intermediate roll 3 is shifted to the operation side OP side.

The work roll bender 5 is controlled by the roll bender controller 7, and the intermediate roll shift position moving mechanism 6 is controlled by the intermediate roll shift controller 8.

A shape detector 15 is installed on the output side of the rolling mill 1, detects the difference in elongation at each position in the width direction of the rolled material S, and optimally controls the detection result as an elongation difference signal t3. Output to the quantity determination device 13.

The work roll 2 has a rolling material movement amount calculation device 9 for calculating the advance length of the rolled material S from the rotation speed of the work roll 2.
Is attached, and the movement amount of the rolled material S calculated by the rolling material movement amount calculation device 9 is input to the tracking device 10 as a movement amount signal t4.

A welding point detector 14 is installed upstream of the rolling mill 1 on the inlet side, and when the welding point is detected, the detection result is output to the tracking device 10 as a welding point detection signal t2.

The tracking device 10 which inputs the movement amount signal t4 and the welding point detection signal t2, the maximum rolling speed, the strip rolling speed, the rolling speed such as the welding point passing speed, the rolling conditions, the thickness of the rolled material,
Information signals such as width, deformation resistance, rolling reduction, and roll information
t1 is input. In the tracking device 10, the shape of the rolled material S changes greatly from these signals t1, t2, t4,
Roll bender 5 and intermediate roll shift position moving mechanism 6
A shift start timing signal t5 for predicting and determining a change time point of the rolling speed at which the control force of the operating end such as Is output to the intermediate roll shift position FF control device 11.

The maximum rolling speed determined from the rolling operation conditions of the rolling mill 1,
In the set-up computing device 12 in which the information signal t1 such as the strip rolling speed, the rolling speed such as the welding point passing speed, the stretching condition, the thickness of the rolled material, the width, the deformation resistance, the tension, the rolling reduction, and the roll information is input. , The rolling load prediction value at each rolling speed and in the rolling speed region at each rolling speed time is calculated, and the optimum intermediate roll position that can take the widest control range of the roll bender force by the roll bender 5 for each calculated value is set. The optimum intermediate roll position signal t6 as a result of the calculation is output to the intermediate roll shift position FF control device 11 and the optimum control amount determination device 13.

The calculation of the optimum intermediate roll position for each rolling speed in this setup calculation device 12 is performed by setting the rolling speeds to v1, v2, v3.
As (v1>v2> v3), _Pv1 = f (v1, plate thickness, width, deformation resistance, ...) _Pv2 = f (v2, plate thickness, width, deformation resistance, ...) P _{From v3} = f (v3, strip thickness, width, deformation resistance, ...), the predicted load P _v1 , at each rolling speed v1, v2, v3,
P _v2 and P _v3 are calculated, and from these predicted loads P _v1 , P _v2 and P _v3 , the optimum intermediate roll positions Hcδ ₁ , Hcδ ₂ and Hcδ ₃ at the respective rolling speeds v1, v2 and _v3 are calculated and Hcδ ₁ = f ₁ (v1, P _v1 ) Hcδ ₂ = f ₂ (v2, P _v2 ) Hcδ ₃ = f ₃ (v3, P _v3 )

In the above formula, the maximum rolling speed is set as the rolling speed v1, the strip rolling speed is set as the rolling speed v2, and the welding point passing speed is set as the rolling speed v3. Although the position Hcδ is calculated, the optimum intermediate roll position Hcδ for the intermediate speed range of these rolling speeds may be further calculated. Also,
On the contrary, the optimum intermediate roll position Hcδ calculated by the setup calculation device 12 needs to be at least two types, one corresponding to the maximum rolling speed and one corresponding to the strip rolling speed.

The intermediate roll shift position FF control device 11 receives the shift start timing signal from the tracking device 10 based on the optimum intermediate roll position signal t6 input from the setup calculation device 12.
At the timing of decelerating the rolling speed at the time of inputting t5, ΔHcδ ₁₂ = Hcδ ₁ −Hcδ ₂ (movement amount) ΔHcδ ₂₃ = Hcδ ₂ −Hcδ ₃ (movement amount) ΔHcδ ₁₂ × α / (v ₁ −v ₂ ) (shift Change rate) ΔHcδ ₂₃ × α / (v2-v3) (shift change rate) Note that α is the line speed change rate.

The intermediate roll position movement amount is determined according to the following formula, and the shift change rate is determined based on this calculation result. The intermediate roll position movement amount and shift change rate are determined as the intermediate roll shift speed setting and movement start signal t7 to determine the optimum control amount. Output to the device 13. Also, at the timing of increasing the rolling speed, the absolute values were the same, but the directions were reversed.
The intermediate roll position movement amount and shift change rate are output as an intermediate roll shift speed setting and movement start signal t7.

In the optimum control amount determining device 13, the unit variation amounts of the roll bender 5 and the intermediate roll shift position moving mechanism 6 which are the operation ends for flatness control are used to determine the influence coefficient that affects the flatness of the rolled material S by rolling. Based on the conditions etc., (roll bender influence coefficient) ∂β / ∂P _B = f ₃ (plate thickness, plate width, load ...) (intermediate roll shift position influence coefficient) ∂β / ∂Hcδ = f ₃ (Plate thickness, plate width, load ...) Calculated for each coil of the rolled material S according to the equation, and the influence coefficient and the elongation difference rate signal t3 from the shape detector 15 at each control timing are calculated. The optimum roll bender control amount for obtaining the optimum shape of the rolled material S is determined based on the optimum intermediate roll position signal t6 input from the setup calculation device 12, and this value is used as the optimum roll bender control amount signal t8. Output to the vendor control device 7.

Also, when the rolling speed increases or decreases, the intermediate roll shift speed
Degree setting and intermediate roll by the amount according to movement start signal t7
Optimum roll bender control amount signal on the assumption that 3 is moved.
When the number t8 is determined and output to the roll bender control device 7, it is the same.
Sometimes, the intermediate roll shift position from the FF controller 11
While setting the shift speed setting and movement start signal t7
Output to the inter-roll shift control device 8 to increase or decrease the rolling speed
Flatness control at the time of change is performed. Determining the optimum controlled variable
Optimum flatness in device 13 that minimizes the difference from the target
To determine the control amount of roll bender that can be
For this, various methods may be adopted, but for example,
The value of the valence function J isβ_i ^REF= ∂β / ∂Hcδ × ΔHcδ + ∂β / ∂P_B× ΔP_B Note that β Is the actual flatness value that is the difference from the target, and Δ
Hcδ was determined by the intermediate roll shift position FF controller 11
Intermediate roll position movement amount and shift change rate,
ΔP_BIs an unknown number.

The value of this evaluation function J may be minimized.

Thus, when the rolling speed increases or decreases, the optimum roll bender control amount signal t8 is determined on the assumption that the intermediate roll 3 is moved by an amount according to the intermediate roll shift speed setting and the movement start signal t7. At the same time as outputting to the device 7, the intermediate roll shift position FF control device 11 outputs the intermediate roll shift speed setting and movement start signal t7 to the intermediate roll shift control device 8 as it is, but at other times, that is, when the rolling speed is constant. At a certain point of time, control is performed to determine the optimum roll bender control amount for obtaining the optimum shape of the rolled material S based on the optimum intermediate roll position signal t6. At this time, the optimum intermediate roll position and the optimum roll bender control amount may be calculated for each control timing in order to simultaneously control the operation ends of both the roll bender 5 and the intermediate roll shift position moving mechanism 6. One of the optimum intermediate roll position and the optimum roll bender control amount may be prioritized, and the other may be calculated as a control value with which the optimum flatness is obtained.

〔The invention's effect〕

Since the present invention has the above-mentioned configuration, it has the following effects.

Regardless of when the rolling speed of the rolled material is constant or when the rolling speed changes, the optimum intermediate roll position is always set to the position where the control range of the roll bender force can be set to the widest range. Even if the rate of change in degree is large, the operating end does not reach the upper and lower limits of the permissible control range, so that the flatness controllability is deteriorated and the occurrence of flatness defects can be reliably prevented. A product having good flatness can be roll-formed over the entire length of the rolled material coil.

Since the calculation determinations of the optimum intermediate roll position and the optimum roll bender control amount are all automatically achieved, good flatness control can be reliably and smoothly achieved.

Since the optimum intermediate roll position is always set to the position where the control range of the roll bender force can be set to the widest range,
The flatness control can be quickly achieved by the roll bender force having a high responsiveness, and thus the control ability can be effectively utilized to obtain a sufficient flatness.

Since the optimum intermediate roll position is set to the position where the control range of the roll bender force can be set to the widest range, it is possible to effectively utilize the flatness control due to the change of the roll bender force, and thus the sufficient shape can be achieved. Control can be achieved.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the device of the present invention assembled in a six-fold rolling mill. FIG. 2 is a diagram showing an example of an assembling configuration of a roll bender and an intermediate roll shift position moving mechanism for each roll of the six-fold rolling mill shown in FIG. DESCRIPTION OF SYMBOLS 1; 6-fold rolling mill, 2; work roll, 3; intermediate roll, 4; backup roll, 5; work roll bender, 6; intermediate roll shift position moving mechanism, 7; roll bender control device, 8; intermediate Roll shift control device, 9; Rolled material movement amount calculation device, 10;
Tracking device, 11; Intermediate roll shift position FF control device, 12; Setup calculation device, 13; Optimal control amount determination device, 14; Weld point detector, 15; Shape detector, S; Rolled material, t1;
Information signal, t2; welding point detection signal, t3; differential expansion rate signal, t4;
Movement amount signal, t5: shift start timing signal, t6: optimum intermediate roll position signal, t7: intermediate roll shift speed setting and movement start signal, t8: optimal roll bender control amount signal.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location B21B 37/42 8315-4E B21B 37/00 113 Z BBH

Claims (1)

[Claims] 1. A flatness control device for a multiple rolling mill (1), comprising a roll bender (5) as an operating end and an intermediate roll shift position moving mechanism (6) for controlling the roll bender (5), For each of at least two types of rolling speeds such as the maximum rolling speed, the strip rolling speed, and the welding point passing speed,
A setup arithmetic unit (1) for determining an optimum intermediate roll position that maximizes the control range of the roll bender (5).
2), the optimum intermediate roll position signal from the setup calculation device (12), and the intermediate roll shift start timing signal from the tracking device (10) that predicts the acceleration / deceleration timing of the rolling speed. And a flatness control device provided with an intermediate roll shift position feedforward control device (11) for setting the movement start time of the intermediate roll.