JPH05169125A - Rolling controller - Google Patents

Abstract

PURPOSE:To obtain reference plate thickness, while executing rolling control so that a load ratio between each rolling mill approaches a target ratio, at the time of controlling a roll gap of the rolling mill, based on a deviation signal of plate thickness and a plate thickness reference value of a steel plate taken out of the rolling mill. CONSTITUTION:From a plate thickness distribution ratio calculated by a plate thickness distribution ratio arithmetic unit 11 from a plate thickness deviation measured by a plate thickness deviation measuring instrument 4, and a load detected by a load detector 10, a plate thickness correction quantity to each rolling mill 2a, 2b is calculated by multipliers 6A and 6B and inputted to control signal generating devices 7a, 7b of each stand, and a rolling reduction control signal to each rolling mill 2a, 2b is generated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rolling control device which improves the sheet thickness dimensional accuracy of a steel sheet rolled and fed by a rolling mill.

[0002]

2. Description of the Related Art FIG. 2 is a block diagram showing a conventional rolling control device. In the figure, 1 is a steel plate conveyed in the direction of the arrow, 2
a to 2c are rolling mills for rolling the steel plate 1, 3 are rolling mills 2a to
A plate thickness detector installed on the downstream side of 2c, 4 is a plate thickness deviation measurement which measures a deviation between the plate thickness detection value detected by the plate thickness detector 3 and a reference plate thickness and outputs a plate thickness deviation signal 5. Device, 6
a to 6c are multipliers that multiply the plate thickness deviation signal 5 by a gain,
7a and 7b are control signals 8 for roll gap control of the rolling mills 2a to 2c based on the strip thickness deviation signal multiplied by the gain.
Control signal generators 9a to 9c generate a to 8c, and 9a to 9c are reduction drive devices for controlling the rolling mills 2a to 2c according to the control signals 8a to 8c.

Next, the operation of the conventional rolling control device shown in FIG. 2 will be described. The steel sheet 1 is rolled by the rolling mills 2a to 2c while moving in the arrow direction. The rolled steel plate 1 is detected by the plate thickness detector 3 downstream of the rolling mill and output to the plate thickness measuring device 4.

In the strip thickness measuring device 4, the strip thickness detection value is compared with a preset standard strip thickness value, and the strip thickness deviation signal 5 is controlled through the multipliers 6a to 6c installed for each rolling mill. It is output to the devices 7a to 7c.

At this time, the strip thickness control devices 7a to 7c operate the rolling mill 2a when the strip thickness deviation signal 5 is positive, that is, when the strip thickness of the steel sheet 1 immediately below the strip thickness detector 3 is larger than the reference strip thickness. Control signals 8a to 8c are supplied to the reduction driving device 3 so as to narrow the roll gap of .about.2c.

On the contrary, when the plate thickness deviation signal 5 is negative, that is, when the plate thickness of the steel plate 1 is too thin, the rolling mills 2a-2
Control signals 8a to 8c that spread the roll gap of c
Is output to the reduction driving devices 9a to 9c.

The strip thickness deviation signal 5 sent to the strip thickness control devices 7a to 7c is multiplied by the multipliers 6a to 6c corresponding to the rolling mills 2a to 2c.
The predetermined gain is multiplied by 6c, and the sensitivity to the plate thickness deviation 5 is adjusted for each stand.

[0008]

As described above, in the conventional rolling control device, the control signals 8a to 8c supplied to the respective reduction driving devices 9a to 9c follow the control signals 8a to 8c. Rolling mill 2 caused by gear change
Since it is determined irrespective of the load fluctuations of a to 2c,
As a result of the reduction control, the steel plate 1 is loaded under a certain rolling mill.
There was a problem that the quality of the product deteriorates.

Further, multipliers 6a to 6c are provided corresponding to the rolling mills 2a to 2c, the gain of the multipliers 6a to 6c is set for each stand, and the load ratio between the rolling mills 2a to 2c is adjusted. However, it was difficult to determine the gain of each of the multipliers 6a to 6c so that the load ratio becomes the target ratio.

The present invention has been made to solve the above problems, and when controlling the roll gap based on the deviation signal between the plate thickness of the steel plate leaving the rolling mill and the plate thickness reference value, An object of the present invention is to provide a rolling control device that controls rolling so that the load ratio of each rolling mill approaches a target load ratio.

[0011]

A rolling mill control apparatus according to the present invention is a sheet thickness deviation measuring apparatus for measuring a sheet thickness of a steel sheet exiting a rolling mill to obtain a deviation from a reference sheet thickness value and generating a deviation signal. , A control signal generator that generates a control signal for controlling the roll gap of the rolling mill based on the deviation signal, a load detector that detects the load of each rolling mill, and each rolling mill from each load detection value And a control signal calculating device for calculating the control signal so that the load ratio between the rolling mills approaches a predetermined value.

[0012]

In the present invention, the control signal arithmetic unit calculates the strip thickness distribution ratio from the load input from the load detector provided for each rolling mill, and based on the strip thickness correction amount determined according to this ratio. By generating and outputting a control signal to each rolling reduction device, the load ratio between each rolling mill is brought close to the target ratio.

[0013]

【Example】

Example 1. The first embodiment of the present invention will be described below with reference to FIG. In the figure, the same reference numerals as those in FIG. 2 indicate the same or corresponding parts. In the figure, 6A to 6C correspond to the multipliers 6a to 6c. Reference numerals 10a to 10c are load detectors, and 11 is a plate thickness distribution ratio calculation device for calculating the plate thickness distribution ratios ma and mb based on the detection values of the load detectors 10a to 10c.

Next, the operation of the first embodiment of the present invention shown in FIG. 1 will be described. The control operation is basically the same as that described in the prior art and will not be described here.

A fluctuation amount ΔF of the rolling force (load on the rolling mill) resulting from the sheet thickness correction by the sheet thickness control devices 7a to 7c.
a, ΔFb, ΔFc are obtained from the following relationships.

That is, Qa, Qb, and Qc are the influence coefficients that influence the change in strip thickness on the inlet side of the rolling mills 2a to 2c, and the influence that the change in strip thickness on the outlet side of the rolling mills 2a to 2c influences the rolling force. Coefficients are qa, qb, qc, change in plate thickness on the inlet side of each stand is ΔHa, ΔHb, ΔHc, and change in plate thickness on the outlet side is Δ.
If ha, Δhb, Δhc,

ΔFa = qaΔha + qaΔha (1) ΔFb = qbΔhb + qbΔhb (2) ΔFc = qc Δhc + qcΔhc (3)

[0018]

Assuming that there is no plate thickness variation upstream of the first stand

ΔHa = 0 (4)

Since the plate thickness on the outlet side of each stand and the plate thickness on the inlet side of the next stand are equal,

ΔHb = Δha (5) ΔHc = Δhb (6)

[0023] Expressions (4) to (6) are expressed as (1) to
By substituting in equation (3)

ΔFa = + qaΔha (7) ΔFb = QbΔha + qbΔhb (8) ΔFc = QcΔhb + qcΔhc (9)

Is obtained.

Here, the target rolling force ratio is 1: C.
b: If Cc, ΔFa, ΔFb, ΔFc are

ΔFa = K-Fa (10) ΔFb = CbK-Fb (11) ΔFc = CcK-Fc (12)

[0028] Furthermore, if the target rolling force distribution ratio is expressed as a ratio based on the desired plate thickness correction amount of each stand based on the plate thickness correction amount Δhc of the final stand,

Δha = maΔhc (13) Δhb = mbΔhc (14) Δhc = mbΔhc (15)

It becomes Expressions (10) to (15) are converted into expressions (7) to
Substituting into equation (9)

K-Fa = + qamaΔhc (16) CbK-Fb = QbmaΔhc + qcmbΔhc (17) CcK-Fc = QcmbΔhc + qcΔhc (18)

It becomes Here, Fa, Fb, and Fc are values detected by the load detection devices 10a to 10c. Further, Δhc is a value obtained by multiplying the plate thickness deviation signal 5 by an appropriate gain by the multiplier 6d. Cb and Cc are target rolling force distribution ratios given in advance. Therefore, the unknown quantities in the equations (16) to (18) are only k ₁ , ma, mb, and by solving the simultaneous equations, k, ma, mb
mb can be determined.

Specifically, (16), (17), (18)
By modifying the formula, Fa = k- (qaΔhc) ma (19) Fb = Cbk- (QbΔhc) ma- (qbΔhc) mb (20) Fc = FcΔhc = Cck-QcΔhcmb (21) and the equations (19), (20), and (21) are expressed by a matrix, they are summarized as follows.

[0034]

[Equation 1]

[0035]

[Equation 2]

[0036]

[Equation 3]

Describing equations (22) to (24) in detail, the plate thickness distribution ratio calculating device 11 is configured so that each of the rolling mills 2a to 2c.
The strip thickness distribution ratios ma and mb are calculated based on the rolling forces detected by the corresponding load detectors 10a to 10c, that is, the loads Fa, Fb, and Fc of the rolling mill.

Next, the plate thickness distribution ratios ma and mb are input to the multipliers 6A and 6B, respectively, and are multiplied by the gain-multiplied plate thickness deviation signal Δhc output from the multiplier 6C, and the plate thickness of each stand is multiplied. The correction amounts ha and hb are calculated.

By outputting the calculated plate thickness correction amounts ha and hb to the control signal generators 7a and 7b, respectively, the reduction drive devices 9a and 9b approach the load ratio of the rolling mill to a target ratio. As described above, the reference plate thickness is obtained while controlling the rolling mill.

In the above embodiment, the case where the load of the rolling mills 2a to 2c is the rolling force has been described as an example, but the present invention can be similarly applied even when the current of the rolling mill drive motor is used as the load. ..

In the above embodiment, three rolling mills 2a are used.
The same applies to the case of using ~ 2c.

[0042]

As described above, according to the present invention, a plate thickness deviation measuring device for measuring a plate thickness of a steel plate exiting a rolling mill to obtain a deviation from a reference plate thickness value and generating a deviation signal, and the deviation signal A control signal generator that generates a control signal for controlling the roll gap of the rolling mill based on the above, a load detector that detects the load of each rolling mill, and a strip thickness distribution of each rolling mill from each load detection value. The load ratio between the rolling mills is provided with a control signal calculation device that calculates the control signal so that the load ratio between the rolling mills approaches a predetermined value, so that the load ratio between the rolling mills approaches the target ratio. Thus, it is possible to obtain a steel sheet having a target sheet thickness while controlling rolling, and it is possible to obtain a steel sheet having a desired sheet thickness while preventing deterioration of the quality of the steel sheet due to a change in load ratio.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a configuration diagram showing a conventional rolling control device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Steel plate 2A-2c Rolling mill 3 Plate thickness detector 4 Plate thickness deviation measuring device 5 Plate thickness deviation signal 6A-6C Multiplier 7a-7c Control signal generating device 9a-9c Reduction drive device 10a-10c Load detector 11 Plate thickness Allocation ratio calculator

Claims (1)

[Claims] 1. A plate thickness deviation measuring device for measuring a plate thickness of a steel plate exiting a rolling mill to obtain a deviation from a reference plate thickness value and generating a deviation signal, and a roll gap of the rolling machine based on the deviation signal. A control signal generator that generates a control signal for controlling, a load detector that detects the load of each rolling mill, and a plate thickness distribution ratio of each rolling mill from each load detection value are calculated, and between each rolling mill. Control device for calculating the control signal so that the load ratio of the control signal approaches a predetermined value.