JPH03114607A - Controller for plat thickness of rolling mill - Google Patents

Abstract

PURPOSE:To improve the accuracy of the plate thickness control by removing the effect of disturbance and finding a correct roll gap in the case of detecting the roll gap with the use of a noncontact type roll gap detector. CONSTITUTION:Roll gap detecting devices 6L and 6R for detecting roll gaps XL, YL, XR, YR, computing elements 14L and 14R finding the upper and lower work roll gaps ZL and ZR from the detection value thereof, band pass filter circuits 15L and 15R, a cross correlation analysis device 18 and comparators 26L and 26R are provided on a rolling mill plate thickness control unit and the effect of the disturbance due to the drift held by the rolling mill plate thickness control unit itself and the vibration of a roll gap detecting device, etc., is removed. Consequently, the plate thickness control accuracy can be improved by finding a true roll gap.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a rolling mill plate thickness control device.

[Prior art] Generally, in rolling mills, automatic sheet thickness control is performed by controlling the roll gap between the upper and lower work rolls, but detection of the roll gap between the upper and lower work rolls is performed using a hydraulic reduction device. This is done by detecting the amount of movement of the hydraulic lowering device piston rod using a position detector such as a Magnescale.

However, the conventional means described above has a problem in that control accuracy is poor due to the effects of deflection and eccentricity of the rolling mill back rolls and collapse of elasticity between the rolls.

Therefore, as a result of intensive research, the applicant of this application has, for example,
1-[120g As shown in the specification and drawings, there is a roll gap detection device equipped with a non-contact type roll gap detector for detecting the roll gap in the roll barrel portion, and a roll gap detection device that detects the roll gap detected by the roll gap detection device. A device for determining the deviation between the roll gap and a standard roll gap, and a device installed in a pipe that sends pressure oil to a hydraulic reduction device that adjusts the roll gap of the rolling mill, and control based on the deviation determined by the device for determining the deviation. We proposed a hydraulic pressure-down device equipped with a control valve.

[Problems to be Solved by the Invention] However, with the above-mentioned hydraulic pressure reduction control device, there is a problem with the drift (phenomenon in which the zero point of the detector shifts) of the roll gap detector itself and the plate thickness control device itself, and the lack of support for the detector. However, there was a problem in that it was difficult to accurately detect the roll gap because it was impossible to eliminate the influence of disturbance caused by slight rattling of the lever.

In view of the above-mentioned circumstances, an object of the present invention is to remove the influence of external disturbances and obtain an accurate roll gap when detecting the roll gap using a non-contact type roll gap detector. This is what was done.

[Means for Solving the Problems] The present invention provides non-contact type roll gap detectors 12L, 13+.
-, 12R, 13R and the detection '512+-, 13L
, 12R, 13R to the work rolls 2a, 2b, a roll gap detection device B+-, 6R that detects the roll gaps XL, YL, XR, YR, and the roll gap detection device 6L.
, the roll gap Xt- detected by 6R.

Upper and lower work rolls 2a from YL, XR, and YR.

A computing unit 14L that calculates the roll gaps ZL and ZR of 2b.

14R, and the roll gap ZL calculated by the calculators 14L and 14R, among the signals 33L and 33R of the signals 33R and 33R, a high response frequency component exceeding the response frequency f of the hydraulic reduction devices 5L and 5R or the rolling machine output. A low frequency response frequency component fL that is equal to or less than a time constant T obtained by multiplying the time t1 until the disturbance X reaches the plate thickness detector 21 provided on the side 31 by a predetermined coefficient γ.
bandpass filter circuits 15m and 15R that remove at least one of the frequency components; The cross-correlation analysis device 18 calculates the cross-correlation correction amounts ΔZLA and ΔZRA, and the cross-correlation correction amounts ΔZLA and ΔZRA given from the cross-correlation analysis device 18 and the set roll gap ZLOtZRO on the exit side 31 of the rolling mill are detected. Deviation of plate thickness at rolling mill exit side 31 from AZ+-o I,,
Find ΔZRo r and calculate the deviation lJZ+-o ■, ', ΔZ
Hydraulic piping 24L, 24R connected Ro r to rolling mill 1 rolling unit 5L, 5R
A comparator 26 and 28R are provided to provide signals 82L and 32R to the control valves 25c and 25R.

The present invention also provides a non-contact type roll gap detector 12L, 1
8L.

12R and 13R, and the detectors 12L and 13L
, 12R.

Roll gap X from 13R to work rolls 2a, 2b
Roll gap detection devices OL, 6R that detect L+ YL, XR+ YR, and the roll gap detection devices 6L, 6R
Roll gaps xL, yL detected by.

Calculating units 14L and 14R that calculate roll gaps ZL and ZR between the upper and lower work rolls 2a and 2b from XR and YR, and roll gaps ZL and ZR calculated by the calculating units 14L and 14R.
Differentiators 17L and 17R calculate the roll gap change AZ and ΔZR, and the cross correlation correction amount A Z L A + from the roll gap change JZL and ff1ZR found by the differentiators 17L and 17R. , ΔZRA, the cross-correlation correction amounts AZL A, 1JZRA given from the cross-correlation analyzer I8, the set roll gaps ZLO, ZRO on the rolling mill exit side 31, and the set rolling mill exit side 31. Deviation of the thickness of side 31 from ΔZLDT
.

, ΔZRDI and the deviation AZLU)1. , ΔZRo
Comparators 26L and 2 supply I as signals 32L and 32R to control valves 25L and 25R of hydraulic pipes 24L and 24R connected to the rolling mill 1 hydraulic lowering devices 5L and 5R.
6R may be provided, or non-contact type roll gap detectors 12L, 13L, 12R, laR may be provided and the detectors 12L, lk, 12R, 13R may be connected to the work roll 2a.

Roll gap detection devices 6L, BR that detect roll gaps XL, YL, XR, YR up to 2b, and roll gaps XL detected by the roll gap detection devices 8L, 6R,
Computing units 14L and 14 calculate the roll gaps zL and zR between the upper and lower work rolls 2a and 2b from YL, XR, and YR;
R and the roll gap ZL determined by the calculators 14L and 14R.
, ZR signals 33L and 33R, hydraulic lowering device 5
m, response frequency f of 5R.

High response frequency component element exceeding + or rolling mill exit side 31
The time t until the disturbance X reaches the plate thickness detector 21 installed at
Bandpass filter circuits 15L and 15R that remove at least one frequency component of 0 out of the low frequency response frequency components fL below a time constant T obtained by multiplying 1 by a predetermined coefficient γ; and the bandpass filter circuit 15L. , 15R, and differentiate the roll gap components ZL' and ZR' to calculate the change in roll gap A ZL
, A The differentiators 17m and 17R for calculating Zp, and the change in roll gap AZL and JZR determined by the differentiators 17L and 17R, the cross-correlation correction amount AZLA,
, ΔZRA, and the cross-correlation correction amount AZLA- given from the cross-correlation analyzer 18.
, 711ZRA, the set roll gap ZLO, ZRO, and the set plate thickness of the rolling mill exit side 31, find the deviation AZLo, , ΔZRo r, and calculate the deviation AZLDT.

, ΔZRDI to the rolling mill 1 hydraulic lowering device 5L, , 5R hydraulic piping 24L, control valve 25L of 24R
, 25R as command signals 32L, 32R.

2BR may be provided.

[Function] In the present invention, a non-contact roll gap detector +21. ,
+3L, 12R, 13R, detector 12L,
1 fat, 12R, 13R to work rolls 2a, 2
The roll gaps XL, YL, XR, and YR are detected from the roll gaps XL, YL, XR, and YR to the roll gap ZL between the upper and lower work rolls 2a and 2b.

ZR is calculated and the roll gap ZL, signal 33L of ZR is calculated.
, 83R, a predetermined time t1 until the disturbance X reaches the high response frequency component H exceeding the response frequency fO of the hydraulic rolling down devices 5L and 5R or the plate thickness detector 21 provided on the rolling mill exit side 31. At least one of the low-frequency response frequency components fL below the time constant T multiplied by the coefficient γ is removed, and the lesser of the high-frequency response frequency component H or the low-frequency response frequency component is removed. The roll gap component zL' with one of the frequency components removed.

The cross-correlation correction amounts ΔZLA and ΔZRA for the left and right work rolls 2a and 2b are calculated from zR', and the cross-correlation correction amount ΔZ
LA, ΔZRA, the set roll gap ZL O, ZRO, and the detected plate thickness of the rolling mill exit side 31, AZLo I, ΔZRo
■ is the command signal 32L.

2 32R is applied to control valves 25L and 25R.

Further, in the present invention, the roll gaps ZL and ZR obtained by the computing units 14L and 14R are differentiated to obtain the changes ΔZL and ΔZR in the roll gaps, and the changes IUZL, , Δ
The cross-correlation correction amounts 1UZLA and ΔZRA are calculated from ZR, and the cross-correlation correction amounts AZ and A are obtained.

1JZRA, the set roll gap ZLO, ZRO of the rolling mill exit side 31, and the detected plate thickness of the rolling mill exit side 31, the deviation IJZLo■.

, ΔZRDI are given to the control valves 25L, 25R as command signals 32+-, 32R.

Furthermore, in the present invention, the calculated work rolls 2a, 2b
Roll gap ZL, signal 33L of ZR.

33R, a predetermined time t1 until the disturbance X reaches the high response frequency component H exceeding the response frequency fo of the hydraulic rolling down devices 5L and 5R or the plate thickness detector 21 provided on the rolling mill outlet side 31. At least one of the low-frequency response frequency components fL below the time constant T multiplied by the coefficient γ is removed, and the high-frequency response frequency component H or the low-frequency response layer 3 wavenumber component is removed. The roll gap components ZL' and ZR' from which at least one frequency component has been removed are differentiated to determine roll gap changes ΔZL and ΔZR, and the changes AZ
Cross correlation correction amount ΔZLA, ΔZRA from L, ff1ZR
are determined, and the deviation AZLo, ΔZRo determined from the cross-correlation correction amounts ΔZLA, ΔZRA, the set roll gaps ZLO, ZRO on the rolling mill exit side 31, and the detected plate thickness on the rolling mill exit side 31. Command signal 32L, 32R
It is given to the control valves 25L and 25R as follows.

[Example] Hereinafter, an example of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows an embodiment of the present invention. 1 in the figure is a rolling mill;
The rolling mill 1 is equipped with a pair of upper and lower work rolls 2a, 2b and a pair of lower back rolls 3a, 3b that back up the work rolls 2a, 2b, and a pair of left and right back rolls that rotatably support the lower back roll 3b. The axle boxes 4L, 4R are supported so as to be movable up and down by roller pressure devices 5L, 5R which are capable of adjusting the roll gap between the upper and lower work rolls 2a, 2b.

The roll gap detection devices 6L and +3R are arranged on both sides of the work rolls 2a and 2b in the axial direction so as to be able to detect the left and right gaps between the upper and lower work rolls 2a and 2b. The roll gap detection devices 6L and 6R are attached to a frame 8 that can be moved back and forth in a direction parallel to the traveling direction of the rolled material P by a fluid pressure cylinder 7, and are attached to each of the rolling mill 1. 2 which can be opened and closed via a pin 9 parallel to the roll and can be fixed by a fixing device (not shown).
A pair of scissor-shaped levers 10, 11, the levers 10.1
Overcurrent type non-contact type roll gap detectors 12+-, 13L attached to the tips of the work rolls 2a and 2b of 1;
It is composed of 12R and 13R.

Detector 12 detected by roll gap detection devices SL and 6R
Work roll 2 from +-, 13L, 12R, +3R
Left and right roll gaps XL, YL, and XR up to a and 2b.

YR can be given to two sets of computing units 14L and 14R installed corresponding to the roll gap detection devices 6L and 6R, and the left and right roll gaps zL and zR found by each computing unit 14L and 14R are calculated as the rolling material. A speed detector 16 arranged on the rolling mill exit side 31 so as to be able to feed the feed speed VP of P to the band pass filter circuits 15L and 15R linked with the feed speed VP of the rolling mill.
The feeding speed V p of the rolled material P detected by the above can be applied to the band pass filter circuits 15L and 15R.

A roll gap component z LI obtained by removing the high frequency response frequency component t-+ and the low response frequency component output from each of the band pass filter circuits 15L and 15R.

ZR' can be given to the differentiating circuits 17L and 17R, respectively, and the changes ΔZL and ΔZR in the left and right roll gaps of the work rolls 2a and 2b output from the differentiating circuits 17L and 17R are sent to the cross-correlation analyzer 18. It is now possible to input into Moreover, in the cross-correlation analysis device 18,
The cross-correlation of the changes ΔZL, , ΔZR is taken, and the left and right cross-correlation correction QIUZ+-A, which is proportional to the strength of the correlation, is carried out.
It is designed to be able to output ΔZRA.

The roll gaps ZLO and zpo determined by the left and right roll gap setters 191 and 19R are determined by the comparators 20L and 6.
26R, and detected by an X-ray non-contact plate thickness detector 21.
Position detectors 22L, 22 such as Magnescale installed in the hydraulic rolling down devices 5L, 5R
The piston lifting amounts SL and SR of the hydraulic pressure lowering devices 5L and 5R detected at R can also be input to the comparators 26L and 20R.

Comparators 26L and 20R calculate Lareta deviation, i! IZL
D.

, ΔZRD and the cross-correlation corrections mΔZLA and ΔZRA obtained by the cross-correlation analyzer 18 are calculated by the comparators 23L and 2.
3R, comparator 23L,
23R deviation ΔzLor.

7!1ZRDI has command signals 32c and 32R,
Hydraulic lowering device 5L, 5R hydraulic piping 24L, 24
It is designed so that it can be supplied to control valves 25+ and 25R attached to R. If the comparators after the cross-correlation analyzer 18 are displayed separately for each signal red road, as shown in Figure 1,
The comparators 26L, 26R, 23L, and 23R output a command signal 32 from the set roll gaps zLo, zρo1 plate thickness t, and cross-correlation correction amounts AZLA and 1JZRA.
In order to obtain L and 32R, it is ultimately sufficient to have arithmetic units 28L and 26R shown by virtual lines in FIG.

Next, the operation of the present invention will be explained.

Prior to operation, first set the roll gaps ZLO and ZRO using the setters 17L and 17R. Roll gap ZLO
, ZRO are comparators 26L and 26R.

Command signals 32L, 32R via 23L, 23R
is given to the control valves 25L and 25R, and the control valve 25
L and 25R open in proportion to the roll gaps ZLO and ZRO, and the oil passes through the control valves 25L and 25R to the hydraulic piping 24.
It is supplied from L and 24R to hydraulic rolling down devices 5L and 5R, and the roll gap between the upper and lower work rolls 2a and 2b is set.

At this time, the piston lifting amount S of the hydraulic pressure lowering devices 5L and 5R
L and SR are detected by position detectors 22+- and 22R and given to comparators 201 and 20R, and the deviation ΔZ]4)
, 1Zpo becomes zero (when the gap between the rolls and the rolls reaches a predetermined gap), the control valves 25L and 25R are closed, and oil is no longer supplied to the hydraulic pressure reduction devices 5L and 5R.

In addition, a roll gap detection device 6L is provided by the fluid pressure cylinder 7,
6R moves back and forth with respect to the rolled material P, and the roll gap detectors 12L, 13L, 12R, 13R are stopped at predetermined positions near the necks of the upper and lower work rolls 2a, 2b.

The rolled material P is introduced between the upper and lower work rolls 2a and 2b of the rolling mill 1 from the upstream side in the traveling direction, and is rolled and transferred to the rolling mill 1.
sent downstream. During this rolling, the roll gap detector 1
2L, 13L, 12R, and 13R are the roll gaps Xl-, YL, and XR from each detector to the outer periphery of the left and right neck portions of the work rolls 2a and 2b.

YR is detected and sent to arithmetic units 14+- and 14ρ, and the arithmetic units 14L and 14R output the upper and lower work rolls 2a.

The left and right roll gaps ZL and ZR of 2b are zL -x.

10YL+QL, ZR-XR+YR1QR, and is sent to the bandpass filter circuits 15+- and 15R. Here, QL, Qρ are roll gaps Zl-, +Z
This is a correction value for obtaining R.

Among the signals 33L and 33R of the o-hole gaps ZL and ZR applied to the bandpass filter circuits 15L and 15R, the response frequency f of the hydraulic lowering devices 5L and 5R. High frequency response component element H and work rolls 2a and 2b exceeding
A time constant T is obtained by multiplying the time t1 until the disturbance X reaches the plate thickness detector 21 by a predetermined coefficient γ. ) The lower response frequency components below are the bandpass filter circuit 15L.

The roll gap components ZL' and zR' from which the high-frequency response frequency component H and the low-frequency response frequency component H and the low response frequency components have been cut are passed through a differentiating circuit 17L.

Sent to 17R.

The range of the high-frequency response frequency component + and the low-frequency response frequency component that are cut by the bandpass filter circuits 15L and 15R is determined by the range of the high-frequency response frequency component + and the low-frequency response frequency component (+) of the rolling mill output side 31 sent from the speed detector 16 as described above. It is determined by the feeding speed Vp of the material P.

That is, as shown in FIGS. 2 and 3, the feeding speed V
If La is the plate thickness variation pitch (the pitch at which the plate thickness t changes from peak to peak, from 0 to 0, or from valley to valley) in the traveling direction of the rolled material P being fed at P, then the plate thickness detector 21 The period To at which the peaks or valleys of the rolled material P appear is:
It is expressed as TO-La/Vp, and the plate thickness fluctuation frequency fd at that time is fd-1/T.

becomes. In addition, in FIGS. 2 and 3, for example, the plate thickness t
The mountain becomes disturbance X.

As shown in FIG. 2, when the plate thickness variation pitch La is small and the plate thickness variation frequency fd is high, that is, fd>αf
In the case of H (α is a coefficient determined from the time constant), there is a time delay before the disturbance X of the rolled material P generated in the rolling mill 1 reaches the plate thickness detector 21, and the hydraulic rolling down devices 5L and 5R are activated. Therefore, the plate thickness t cannot be controlled. Therefore, as described above, the roll gap ZL, ZR signals 33L, 3 applied to the bandpass filter circuits 15L, 15R
Among 3R, the response frequency f of hydraulic lowering device 5L, 5R
The high frequency response component H exceeding o is cut.

As shown in Fig. 3, when the plate thickness variation pitch La is large and the plate thickness variation frequency fd is low, 1, that is, fd<βfL (β is a coefficient determined from the time constant).
In this case, the thickness variation of the rolled material P is gradual, and the hydraulic rolling devices 5L and 5R are operated based on the thickness t detected by the plate thickness detector 21.
It is possible to sufficiently control the plate thickness by controlling the . For this reason,
As mentioned above, the bandpass filter circuit 15L,
The low response frequency components of the signals 3'lL and 33R added to 15R are cut.

The roll gap components ZL' and zR', which are cut from the high frequency response frequency component H1 and the low response frequency component component H1 and sent to the differentiating circuits 17L and 17R, are the differentiating circuits 17L and 17R.
Differentiated at, the change, dZL.

ΔZR is calculated. In other words, the following operations are performed. Here, S is the Laplace operator, T'
is a time constant, and G is a gain. The reason why the differentiation is performed in this way is to feed back only the change in the roll gap, 1UZLJZR.

2. The changes ΔZL and ΔZR in the roll gap determined by the differentiating circuits 17L and 17R are given to the cross-correlation analyzer 18, which calculates the change JZL in the left and right roll gaps.

, ΔZR are subjected to special processing similar to cross-correlation analysis, and changes with strong correlation among the changes AZ+-, ΔZR are weighted based on the left and right cross-correlation correction amounts ΔZLA, ΔZ.
Find RA by If the fraction on the right side of equation (f) is negative, the entire fraction is set to zero, and the integration time is set to be extremely short.

Cross-correlation correction amount ΔZ obtained by the cross-correlation analyzer 18
LA and ΔZRA are provided to comparators 23L and 23R. Also, the plate thickness of the rolled material P detected by the plate thickness detector 21 and the set roll gap ZLO.

ZRo is sent to comparators 20L and 20R, and comparator 2
0+-, 20R deviation AZLo, 1JZRo, IJZ
Lo-Z+-o-t,, ΔZRo-ZRO-t3, and the deviations AZ, D, , ΔZRD are determined by the comparator 2.
Sent to 3L, 23R, deviation JZLDI.

, ΔZRo ■ is AZLo I-AZLo-AZLA-
.

, ΔZRo 1-, ΔZRo-, ΔZRA, the deviation is 1 UzLD! , AzRDI uses the command signals 32L, 32R as the control valves 25L, 25R.
The amount of oil supplied to the hydraulic pressure reduction devices 5L, 5R through the control valves 25L, 25R is controlled, and the left and right roll gaps ZL, ZR of the work rolls 2a, 2b are adjusted by the hydraulic pressure reduction devices 5L, 5R. Ru. Deviation AZL0
1. , If ΔZRor becomes zero, the hydraulic lowering device 5L,
5R stops.

In the case of comparators 26c and 26R, the deviation is JZLDT.

AZRDI is AZLo 1-ZLO-t-AZLAIJ
It is determined by ZRo r =ZRo-t-, ΔZRA, but the key is ZLO, ZRO, t, and AZLA.

, the deviation AZLD by ΔZRA 1. Any combination of comparators may be used as long as AZpor is determined.

1, by weighting the changes with a strong correlation among the changes in the left and right roll gaps 4 AZL and AZR, it is possible to remove the influence of disturbances and obtain accurate roll gaps.

FIG. 4 shows another embodiment of the present invention. In this embodiment, the rolling loads WL and WR detected by load detectors 27L and 27R such as load cells are applied to computing units 28L and 28R to calculate the rolling loads WL and WR. Rolling mill 1 housing 29L,
The displacement amounts ΔZKL and AZKR of 29R are determined by AZKR, and the displacement AZKL is used to control the roll gap.

ff1ZKR is also taken into consideration.

Here, C is a gain and K is a Mill constant.

In addition, 30L, 30R are comparators 26L, 20
Deviations AZL, o, AZRo from R and displacements AZKL of the housings 29+-, 29R from the computing units 28+-, 28R.

This is a comparator that compares AZKR with the deviation AZLD, ΔZRo obtained by the comparator 3030R and the deviation 1JZLD of the positions A ZK L and A ZK R.
'.

, ΔZRo' can be given to comparators 23L and 23R.

In this embodiment, the comparator 20L is used during automatic plate thickness control.

20R, there is a deviation Δ between the roll gaps ZLO and ZRO set by the setters 17L and 17R and the plate thickness t of the rolled material P on the rolling mill outlet side 31 detected by the plate thickness detector 21.
ZLD,,l! If there is IZRD, its deviation A ZLo
, AZRo signals are sent to comparators 80L and 30ρ.

Further, the rolling loads WL and WR detected by the load detectors 27L and 27R are sent to the computing units 28L and 28R, and the computing units 281 and 28R calculate the rolling load WL according to the (revised) equation (1).

Displacement amount AZ of housings 29L and 29R due to WR
KL, 711ZKR are obtained, and the displacement IJZKL,
AZKp is given to comparators RoL and 30R, and the comparator 30L and 30R provide a Teja deviation AZLD.

, ΔZRo and the deviation lU of displacement IJZKL, AZKR
Z+-o', ΔZRo' is AZLD = AZLDAZ
KL, 1UZRD-, ΔZRo-AZKR6, and the deviations JZLo', dZRO' are provided to comparators 23L and 23R.

On the other hand, the roll gaps XL, XR, YL, and YR detected by the roll gap detection device 6L and BR are processed in the same manner as in the previous embodiment, and the cross-correlation analysis device 18 calculates the left and right gaps by the following equations. Roll gap cross-correlation correction mAZLA,
AZpA is determined and sent to comparators 23L and 23R, and the comparators 23L and 23R calculate the cross-correlation correction amount AZ.
A, ΔZRA and ff1ZLD'.

The deviation of A ZRD' is AZLo r,, ΔZRo I is AZLo r-AZLo'-AZLA,, ΔZRo ■
−A ZRo '−A ZRA, and the obtained deviation AZLo r, 1JZRo I is the command signal 3
2+-, 32R are given to the control valves 25L, 25R, and from the control valves 25L, 25R to the hydraulic pressure lowering device 5L.
, 5R is controlled. Thus, the deviation AZLor is output from the comparators 23L and 23R.

When JZRDT becomes zero, control valves 25L and 25R are closed.

As described above, when the displacement amounts A ZK L and A ZK R of the housings 29L and 29R due to the rolling loads 7 wL and wR are taken into consideration during automatic plate thickness control, even more accurate plate thickness control can be performed.

In each of the embodiments shown in FIGS. 1 and 4 above, bandpass filter circuits 15L and 15R and a differentiation circuit 17L are used.
, 17R are connected in series, but if there is either one of the bandpass filter circuits 15L, 15R or the differential circuits 17L, 17R,
The invention is workable.

For example, if the band-pass filter circuits 15L and 15R are present but the differentiating circuits 17L and 17R are not present, the roll gap components ZL' and ZR' output from the band-pass filter circuits 15L and 15R are input to the cross-correlation analyzer 18. and the cross-correlation correction amount AZLA.

, ΔZRA are determined. Cross-correlation correction amount A in this case
ZL A , IJ ZRA is determined by:

8 Also, for example, a bandpass filter circuit 15L.

If there is no 15R and only the differentiating circuits 17L and 17R, the roll gaps ZL and ZR output from the arithmetic units 14L and 14R can be differentiated without removing the high-frequency response frequency component or the low-frequency response frequency component. Vessel 17L, 1
Given to 7R. For this reason, the differentiators 17L and 17R
The changes in the roll gap ΔZL and IJZR given to the cross-correlation analyzer 18 from the above include all frequency components.

In addition, in the embodiment of the present invention, the case where both the high-frequency response frequency component and the low-frequency response frequency component are removed in the band-pass filter circuit has been described, but if at least one of the response frequency components is removed, It goes without saying that various modifications may be made within the scope of the present invention without departing from the spirit of the present invention.

[Effects of the Invention] According to the rolling mill plate thickness control device of the present invention, it is possible to eliminate the effects of disturbances such as drift of the plate thickness control device itself and vibration of the roll gap detection device, so that The excellent effect of being able to detect the roll gap and therefore accurately controlling the plate thickness can be achieved.

[Brief explanation of drawings]

Fig. 1 is a block diagram of an embodiment of the present invention, and Fig. 2 is a principle explaining how the high frequency response frequency component is cut when the plate thickness variation pitch is small, that is, when the plate thickness variation frequency is high. Figure 3 is a principle diagram explaining how to cut the low frequency response frequency component when the plate thickness variation pitch is large, that is, the plate thickness variation frequency is low in Fig. FIG. 2 is a block diagram of an embodiment of the invention. In the figure, 1 is a rolling mill, 2a and 2b are work rolls, 5L,
5R is a hydraulic pressure reduction device, 6L and 8R are roll gap detection devices, 12L and 12R are roll gap detectors, 131,
13R is a roll gap detector, 14c and 14R are calculation HL 15L, 15R is a band pass filter circuit,
16 is a speed detector, 171, 17R is a differential circuit, 18
is a cross-correlation analyzer, 19+, , 19R is a roll gap setting device, 201 and 20R are comparators, 21 is a plate thickness detector,
22L, 22R are position detectors, 23L, 23R
is a comparator, 24+-, 24R is hydraulic piping, 25L,
25R is a control valve, 2G+-, 26R is a comparator, 28L
, 28R is a computing unit, 31 is the rolling mill exit side, 32L,
32R is a command signal, 33L. 33R is the signal, XL, XR, YL, YR are the gaps from the detector to the rolls, zL, zR are the roll gaps between the work rolls, P is the rolled material, Vρ is the feeding speed, ZL', ZR' are the roll gaps , AZL. , ΔZR is the amount of change, AZL A , AZRA is the cross-correlation correction amount, ZLO, ZRO are the set roll gaps, t is the thickness of the rolled material, AZLo, , ΔZRD is the deviation,
AZ+-o ■, 1JZRor is the deviation, fH is the high frequency response frequency component, f is the low response frequency component, fo is the response frequency, X is the disturbance, 1. is time, γ is coefficient, T is time constant, fd is plate thickness fluctuation frequency, JZLo', ff1ZRo
' indicates deviation.

Claims (1)

[Claims] 1) Non-contact roll gap detectors 12_L, 13_L,
The detectors 12_L and 13_L include 12_R and 13_R.
, 12_R, 13_R to the work rolls 2a, 2b. Roll gap detection devices 6_L, 6_R detect roll gaps X_L, Y_L, X_R, Y_R, and roll gap X_ detected by the roll gap detection devices 6_L, 6_R.
Upper and lower work rolls 2 from L, Y_L, X_R, Y_R
Calculator 1 for determining roll gaps Z_L and Z_R of a and 2b
4_L, 14_R, and a signal 33_L of the roll gaps Z_L and Z_R obtained by the calculation units 14_L and 14_R,
33_R, a predetermined coefficient γ is applied to the high response frequency component f_H exceeding the response frequency f_0 of the hydraulic rolling down devices 5_L and 5_R, or the time t_1 until the disturbance X reaches the plate thickness detector 21 provided on the rolling mill outlet side 31. bandpass filter circuits 15_L, 15_R that remove at least one frequency component of the low frequency response frequency component f_L below the time constant T multiplied by From the components Z_L' and Z_R', the cross-correlation correction amounts ΔZ_L_A and ΔZ for the left and right work rolls 2a and 2b are calculated.
A cross-correlation analyzer 18 that calculates _R_A and a cross-correlation correction amount ΔZ_L_A given from the cross-correlation analyzer 18
, ΔZ_R_A and the set roll gaps Z_L_O, Z_R_O of the rolling mill exit side 31 and the detected plate thickness of the rolling mill exit side 31 from the deviations ΔZ_L_D_I, ΔZ_R_D
Find the deviation ΔZ_L_D_I, ΔZ_R_D_I
a comparator 26_L that provides signals 32_L, 32_R to control valves 25_L, 25_R of hydraulic pipes 24_L, 24_R connected to the rolling mill 1 hydraulic reduction devices 5_L, 5_R;
A rolling mill plate thickness control device characterized by providing a 26_R. 2) Non-contact roll gap detectors 12_L, 13_L,
12_R, 13_R, and the detectors 12_L, 13_
Roll gap detection devices 6_L, 6_R that detect roll gaps X_L, Y_L, X_R, Y_R from L, 12_R, 13_R to work rolls 2a, 2b, and roll gap X detected by the roll gap detection devices 6_L, 6_R.
Arithmetic units 14_L, 14_R calculate the roll gaps Z_L, Z_R between the upper and lower work rolls 2a, 2b from _L, Y_L, A differentiator 17_L that calculates the changes ΔZ_L and ΔZ_R,
17_R, and the cross-correlation analysis device 18 that calculates the cross-correlation correction amounts ΔZ_L_A and ΔZ_R_A from the roll gap changes ΔZ_L and ΔZ_R obtained by the differentiators 17_L and 17_R, and the cross-correlation correction amount given from the cross-correlation analysis device 18. Deviation ΔZ_L_ from ΔZ_L_A, ΔZ_R_A, the set roll gaps Z_L_O, Z_R_O, and the set plate thickness t of the rolling mill exit side 31
D_I, ΔZ_R_D_I and the deviation ΔZ_L_D_
I, ΔZ_R_D_I to rolling mill 1 hydraulic reduction device 5_L,
A rolling mill plate thickness control device characterized in that comparators 26_L and 28_R are provided to provide signals 32_L and 32_R to control valves 25_L and 25_R of hydraulic pipes 24_L and 24_R connected to a rolling mill. 3) Non-contact roll gap detectors 12_L, 13_L,
The detectors 12_L and 13_L include 12_R and 13_R.
, 12_R, 13_R to the work rolls 2a, 2b. Roll gap detection devices 6_L, 6_R detect roll gaps X_L, Y_L, X_R, Y_R, and roll gap X_ detected by the roll gap detection devices 6_L, 6_R.
Upper and lower work rolls 2 from L, Y_L, X_R, Y_R
Calculator 1 for determining roll gaps Z_L and Z_R of a and 2b
4_L, 14_R, and signals 33_L, 33_ of the roll gaps Z_L, Z_R obtained by the calculation units 14_L, 14_R.
Of R, the response frequency f_ of the hydraulic pressure lowering devices 5_L, 5_R
A high frequency response frequency component f_H exceeding 0 or a low response frequency below a time constant T obtained by multiplying the time t_1 until the disturbance X reaches the plate thickness detector 21 provided at the outlet side 31 of the rolling mill by a predetermined coefficient γ. A bandpass filter circuit 15_L, 1 that removes at least one frequency component of the component f_L.
5_R, and the bandpass filter circuits 15_L, 15_
Differentiators 17_L, 17_R that differentiate the roll gap components Z_L', Z_R' output from R to obtain roll gap changes ΔZ_L, ΔZ_R, and the differentiators 17_L, 1
Changes in roll gap determined by 7_R ΔZ_L, ΔZ
a cross-correlation analyzer 18 that calculates cross-correlation correction amounts ΔZ_L_A and ΔZ_R_A from _R; and a cross-correlation analyzer 18
The cross-correlation correction amounts ΔZ_L_A, ΔZ_R_A given from
Find ΔZ_R_D_I and calculate the deviations ΔZ_L_D_I, ΔZ
Control valve 25_L of hydraulic piping 24_L, 24_R connecting _R_D_I to rolling mill 1 hydraulic reduction device 5_L, 5_R
, 25_R as command signals 32_L, 32_R.