JPS5921423A - Sheet thickness controlling device - Google Patents

Abstract

PURPOSE:To perform sheet thickness control excellent in responsiveness and accuracy, by inputting the output of a final sheet thickness arithmetic device and the value of sheet thickness measured at the exit of final stand to output a correcting quantity of roll speed. CONSTITUTION:The output of an intermediate thickness 24 disposed between the 1st stand and the final stand is inputted to a roll speed correcting device 28 through a final sheet thickness arithmetic device 26. The output of the device 26 is outputted as the calculated value 27 of the final sheet thickness. The device 28 calculates correcting quantities 31, 32, 33 of roll speed except that of the final stand by using the output 30 of a final thickness gauge 29 and the calculated value 27 of final sheet thickness to output the results to speed controlling devices 10, 11, 12.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a plate thickness control device for a tandem rolling mill for rolling steel plates and the like.

[Technical background of the invention]

In tandem rolling mills, where multiple rolling stands are arranged in series and rolling is performed by fully stretching the rolled material such as steel plate between these rolling stands, there has been an increasing demand in recent years for thickness accuracy in the longitudinal direction of the rolled material. It's getting tougher.

In order to meet this demand, we adopted automatic plate thickness control (
(hereinafter referred to as AGC) has come into use, and plate thickness accuracy has also improved. In particular, based on the output signal of the plate thickness gauge installed on the exit side of the final stand, the first roll I! A feedback control method for correcting the u degree (hereinafter referred to as speed AGC) is employed in most rolling mills as an effective method for controlling finished plate thickness.

[Problems with background technology]

Figures 1 to 4 show cold/E4i with 4 stands.
Simulate the control response of E mill versus l'4AC speed ACC [7 blocks! 1 is a sex diagram. This shows the case where the material plate thickness is gradually changed as a disturbance element〇・
The viscosity diagram 1 shows the (reverse j rapid change ratio, the 2nd diagram shows the tension change, and the 3rd diagram shows the tension change.
The figure shows changes in downstream position, and Figure 4 shows changes in roll speed.

As is clear from Fig. 1, there is a dead time (Y) corresponding to the distance between the final stand and the plate thickness gauge in the speed AGC, so the final plate thickness reaches the target value after the plate thickness disturbance reaches the final stand. It takes a considerable amount of time to reach this value.

[7 Therefore, for a deck thickness disturbance of 1gh, speed 1
The problem is that the No.-AGC cannot respond completely.

[L” of invention]

The purpose of this Kasumei is to provide a plate thickness control device that has excellent responsiveness and is capable of highly accurate plate thickness control. In order to do this, the plate thickness detection value at at least one location between the last stand and the first stand, and the measurement of this plate thickness detection value 81 : a final plate thickness calculating device which inputs 17 and calculates the final stand exit side plate thickness by predictive calculation;
The output of this final plate thickness calculating device and the actual measured value of the exit side plate thickness of the final stand are inputted to correct the roll speed to the roll speed control device? It is characterized by the provision of an output roll speed correction device.

Embodiments of the present invention will be described in detail below with reference to the drawings.

[Embodiments of the invention]

FIG. 5 is a 4-dimensional diagram showing the case where a plate thickness control device u according to an embodiment of the present invention is used in a rolling mill to be controlled.

The rolled material 1 is continuously rolled by passing through each stand in the direction indicated by the arrow in the figure.

Although FIG. 5 shows a rolling mill with four stands for convenience, the present invention is not limited thereto.

Work rolls 2, 3, 4.5 of each stand are
! l<mi'tu, driven by motive 6, 7, 8.9, the rotational speed of each driving city, Choshun is controlled by speed control device 10, 1
1, 12°13.

In addition, the pressure lower part 14 of each stand is a downstream control device 14°15
, 1. (5, 17 II ↓ This is controlled. The tension detection value between each stand detected by the tension meter 18゜19.20 is sent to the tension control device ii 21.22 + field and each tension control device The tension between each stand is maintained at the target value by sending a positive signal (1'f!g) to the downstream side reduction control units 1, 16, and 17 to operate the reduction.

The output 5 of the intermediate plate thickness gage 24 installed between the 1st stand and the final stand is input to the roll speed correction device path via the final plate thickness calculation device/'j26f, which will be described later. 9. Performance 0: The output of the device 26 is output as the final plate thickness performance -(J, lll'1'27. Roll speed correction device 28 (, yo, final plate 1'Et=t29
Using the output 30 and the final plate thickness calculation value 27, modify the roll speed other than the final stand i%', :4+, 32
, 33 calculations and output to the speed control devices 10, 11 and 12.

FIG. 186 is a configuration 1-4 showing details of the roll speed correction device path shown in FIG.

The deviation amount 35 of the final plate thickness calculation value 27 from the final plate thickness L1 target value; 14 is the output of the plate thickness calculation value correction device;
The roll speed correction fluid 31, :32, 33 from the first stand to the third stand is corrected by the proportional-integral 4ih operation circuit composed of the control gain Kl, the integral calculation unit 1, and the delay compensation gain T1. Output.

It should be noted that the scales 11b shown as C+, C2, and C3 in the figure are called leakage shift keins and are correction gains for keeping the ratio of roll speeds from the first stand to the third stand constant.

On the other hand, when the output crab 30 of the 1'& final plate thickness gauge 29 is input to the plate latitude calculation value correction device 36, the deviation from the final plate thickness calculation value 34 is first taken, and this deviation amount: 39 is the control jib- 11 gains, an integral operation H device 1\40, and a delay compensation gain T2. used.

FIG. 7 is a block diagram showing details of the final plate thickness calculating device 6 shown in FIG.

Lower than the output part of the intermediate plate II il 24 and the installation stop of this intermediate plate thickness gauge (rolling speed between stands of Au rolled material "vf+"fx "fs" If f4 is input, delay calculation is performed>1t A final plate thickness calculation value 27 is obtained through a circuit consisting of 42.43 and exit side plate thickness calculation devices 44, 45.46.Next, the operation eζ will be explained.In the continuous rolling mill, C1
, As already mentioned, the stand opening car 5iffi by downstream position operation! l! II. When an oil pressing device i't is used as the pressing device, the constant tension flil]1·111 can be quickly responded to, so it can be considered that the profit and speed balance is always maintained between the stands.

Here, material + balance is a state in which the exit material speed of one stand and the entry material speed of the next stand are equal Ut, C4: (
In a state where the speed is balanced, the actual speed of the material is constant, so the following relationship (1) holds true.

Hj (1+fj-')Vj-+ =J (1+fj)
vj-(1) Here, the left side of equation (1) represents the performance speed IW of the unit 11x1x supplied to the j-th stand,
The right side represents the volume velocity per unit width exiting from the j-th stand. Hj: 1st stand exit thickness hj: 1st stand exit thickness: 1st stand exit thickness Vj: J-th stand Roll speed. Therefore, Mj stand out (111 plate thickness hj
The predicted value hjM of hjM can be calculated according to the following equation (2).

However, Hj': Predicted thickness f at the entrance of the jth stand? : is the predicted value of the j-th stand advance rate. In Equation (2), the predicted value of material speed is calculated from the measured value of the roll speed and the advance rate, but another method is to calculate the material speed using the measured value of the speed of the tension roll installed between the stands. It is also conceivable to perform the ni calculation using M-HJ' vfJ-1-(3) hj-, -, , , -m- fj instead of equation (2).

-Vfj”!Ni J stand ~ Jth ↓; Adjust the tension roll speed between the stands.

Based on the above No. 11, the plate thickness control f unloading η according to the present invention will be explained according to FIGS. 265 to 7.

In Figure 5, the rolled material flows in the direction of the arrow from the left to the right in the figure, but the thickness at the location of the rolled material is the intermediate plate thickness 1.
When the intermediate plate thickness meter is reached, the output part of the intermediate plate thickness meter is inputted to the final plate thickness calculation device 26, and as its output, the final plate thickness calculation value 2
7 is obtained. The internal processing of the final plate thickness calculating device 26 is shown in FIG.

The intermediate plate tri and the word output hl (corresponding to the output δ in FIG. 5) are first input to the delay processing device 41, and the output and (...
' is obtained.

Note that the delay processing device 41 is connected to the first stand outlet thickness gauge and the second stand.
Outputs the amount equivalent to the rolling passing time between stands h1
It is used to make corrections to.

Note that since the delay processing device is already known, details will be omitted here.

The second stand entrance side plate thickness prediction value H': is input to the exit side plate thickness calculation device 44, and is subjected to 4 calculations based on the above-mentioned equation (2) to calculate the second stand exit side plate thickness prediction value h2.

This second stand exit side plate thickness predicted value h! is delay processing device 4
2, and the plate thickness prediction value mountain on the entrance side of the third stand is calculated as the output.〇- The same operation is repeated to obtain the final plate thickness calculation value h4M (corresponding to the final plate thickness calculation value 27 in Fig. 5). ) is obtained, which is input into the roll speed correction device column in FIG. The processing within the roll speed correction device 28 is shown in FIG. When the final plate thickness calculation value h4 is input to the roll speed correction device 28, the deviation (hj-hj) from the final plate thickness target value 34 (symbol h0) is first calculated, and this deviation information 35 is calculated based on the plate thickness. After being corrected by the output 37 of the calculation value correction device 36, the control gain is 1, the integral calculation device and the delay compensation gain TI or C-) are passed through the proportional-integral operation circuit 21, the first stand ~:W: +Stand roll speed correction amount 31.32゜:, <:3 (rie No. △V+,
△V2. Δ■) is obtained.

Now, in the above process, the deviation (h4-h':) is calculated by the plate thickness calculation value correction device 36 (the part surrounded by the broken line in Fig. 6).
There is a process for correcting the outgoing crab 37 (symbol Δh4), but this process will be explained next.

As explained in Fig. 7, final plate thickness calculation device: 2
The final plate thickness calculation value n calculated in step 6 has an offset-like error caused by the advance rate prediction error.

A device (1t is a sheet thickness calculation value correction device 36) is used to correct the error using the output 30 of the final sheet thickness gage 29.

The processing peaks and troughs are first the final plate thickness target value 34 (symbol ha)
Deviation 39 between output 30 on the final plate thickness side (symbol h4)
(ba-heart) is taken away. This deviation cycle 39 is the control gain 2 and the integral (A9, device 10 and delay compensation gain T
2 is added to the 1tiJ difference amount 35 (h4-h4) as an output 37 (symbol Δf). By this processing, for example, the final plate thickness calculation value h4
It is possible to eliminate offset-like errors caused by For example, if h4 is calculated to be large, roll speed IW
The correction %t controls the final plate thickness to be smaller than the target value.
However, by adding the above-mentioned Δh4 to the deviation -35, the input to the control gain 7K and j~ become (h'a -h
4-txli, and the effect of h4 being too large is △h
4 operates in the direction of cancellation, the steady error of +-h4 is almost eliminated. FIGS. 8 to 11 are characteristic diagrams simulated for a cold rolling mill having 4 high-speed UA G Ci stands used in the present invention. As in the case of the conventional speed AGC shown in Figs. 1 to 4, the material plate thickness was changed stepwise as a disturbance factor.

FIG. 8 shows changes in plate thickness, FIG. 9 shows changes in tension, FIG. 10 shows changes in rolling position, and FIG. 11 shows changes in roll speed.

For example, as can be easily seen by comparing FIG. 1 and FIG. 8, it can be seen that the response is extremely excellent because there is no delay in detecting plate thickness as in conventional speed AGC.

〔Effect of the invention〕

As explained above in detail17 based on actual MI+ examples,
Accordingly, using the law of constant volume velocity of rolled material, predict the maximum plate thickness at the exit side of the winter stand, and use the deviation between this predicted value and the equivalent value to calculate the upstream roll speed. and the actual measured value of the outlet side plate thickness of the final stand and the target value. good at sex
tJr>Tsutakacoffin 14) (6 plates jl control can be performed again.

[Brief explanation of the drawing]

Figure 1~) Figure 4 for one person is a board j[
A characteristic diagram showing the simulation results of the 7 system A1111 device, i''jI+5. Fig. 6 is a block diagram showing the details of the roll speed correction device that can be used with the VCC+# of this invention.
Figure j'11.7 is a configuration diagram showing the final plate thickness calculation used in this invention and the :tY' II:III of the device, and Figures 8 to 11 show the final plate thickness used in this invention. 01...Rolled material, 2,3,4.5...Roll, 10,11°12.13...Speed control device, 18
, 19.20...Tension meter, 21.22.2''l...
Tension control device, 24...intermediate plate J! 3Jif, 26・
...Final plate pressure calculation device, ah...roll speed correction device,
29...Final plate thickness gauge. Applicant's agent: Inomata Kiyohaku 1 figure (second) Figure 2 Figure Horse 8 figure Funeral figure 9

Claims (1)

[Claims] A tension control device for controlling inter-stand tension of a rolled material stretched and flowing between fη number of rolling stands;
In a plate thickness control device that is fully equipped with a roll speed control and a roll speed controller 1d that controls the rolling speed of the rolling process, the plate thickness detection value at at least one location between the final stand and the first stand and this plate thickness detection are used. Final plate thickness calculation: Inputs the rolling speed of the rolled material downstream from the value measurement unit and calculates the final stand exit side plate thickness from the prediction calculation WIL: I-i4i and the output of this final plate thickness calculation device A board thickness control bag R characterized in that it is provided with a roll speed correction device that inputs an actual measured value of the exit side board thickness of the final stand and outputs a roll speed correction amount to the roll speed control device.