JPS63238917A - Tension correcting automatic plate thickness controller - Google Patents

Abstract

PURPOSE:To improve an accuracy of a plate thickness control by obtaining the deflection of a tension between a front and rear stands and a reference tension between the front and rear stands, and by correcting a rolling load of an arbitrary stand based on the deflection. CONSTITUTION:A present roll gap S, rolling load P, front tension ti and rear tension ti-1 are inputted to a tension correcting automatic plate thickness control section 6. In order to obtain the deflection of the roll gap 0, an initial set value S0 of the roll gap and the present roll gap S are compared by a comparator 11. To obtained the deflection P of the rolling load, the front tension ti and the rear tension ti-1 are inputted into a target load tension corrector 16, a tension correcting absolute load value PAB' is calculated to output. The tension correcting absolute load value P'AB and rolling load P are compared by the comparator 12, the rolling load deflection P is inputted into a computing element 13 for a mill elongation 13. The computing element 13 outputs the mill elongation deflection P/M to an adder 14 to add to the roll gap deflection S0, then a plate thickness deflection h is calculated to input into a plate thickness controlling and regulating device 15, the control output S is obtained.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a tension correction automatic plate thickness control device, and more particularly, to a tension correction device for controlling tension on the front side and the rear side of a rolled material during rolling. The present invention relates to a tension correction automatic plate thickness control device that corrects rolling load based on changes.

(Prior art) Conventionally, in rolling equipment, absolute values A G C (A
Autoaatlc Gauge Control) has been used. The absolute value AGC is a control that predicts and calculates the steady-state rolling load in the rolling mill, sets the target plate thickness based on this, and controls the plate thickness so as to eliminate the difference between the target plate thickness and the actual plate thickness of the rolled material. It is.

FIG. 4 shows such a conventional automatic plate thickness control device. As shown in the figure, a rolling material 1 is rolled by a rolling mill 2. As shown in FIG. The rolling device 3 includes upper and lower rolls 2a of the rolling mill 2,
Adjust the gap between 2a. The roll gap S of the rolling mill 2 is sent from the reduction device 3 to the automatic plate thickness control device 4. On the other hand, the rolling load ff1P is sent from the rolling load detector 5 to the six-movement plate thickness control device 4. The gap S between the upper and lower rolls 2a, 2a of the rolling mill 2 is the control output ΔS from the automatic plate thickness control device 4, that is, the plate thickness deviation Δh, which is the difference between the target plate thickness and the actual plate thickness (see Fig. 5). It is controlled by the compression device 3 according to the following. Gap adjustment during rolling by the rolling down device 3 is performed hydraulically from the viewpoint of high speed response and power.

Now, as mentioned earlier, the automatic plate thickness control device 4 receives the roll gap S1 from the rolling device 3 and the rolling load P from the rolling load detector 5, and its output is the control output ΔS.
(Plate thickness deviation Δh) is sent to the rolling down device 3, and the absolute value AG
Although plate thickness control is performed using C, the principle of absolute value AGC will be explained here.

First, the thickness of the plate on the exit side of the rolling mill 2 can be determined using the following formula.

h −S + (P/M) (m+s)...
...(1) S two-roll gap (IIll) P: Rolling load (ton) M: Mill constant, which is a constant specific to rolling mill 2 P/M, the second term on the right side of equation (1), is the rolling mill 2. This is the amount of deflection due to the load, which is called mill elongation.

In absolute value AGC, using equation (1), absolute value AGC
The target plate thickness hAB in is set using equation (2).

hAB-S5 + (PAB/M) (in order)...
...(2) S: Roll gap initial setting value PAB:Il! , vs. price load city (ton) For PCAL with large rolling load, for example, formula (3) % formula %: R': Flat roll radius (Dragon) H: Inlet side plate thickness (mwi) h: Compression side plate thickness (Dragon) Q : Thickness lower blade function Here, the absolute value load ff1pA8 is determined from equation (3).

From the rolling schedule, the rolled material width setting value B1 Material deformation resistance K 1 Rear tension reference tREF (1-1), front tension reference t Deviation 11 J-roll radius R/, entry side plate thickness reference RE
FlゝH outlet side plate thickness reference h Reduction force function Qp is REF'
Since REP is set, predictive calculation can be performed using these as shown in equation (4).

h −h (am) --<5)RL:
In the F AB absolute value AGC, plate thickness control is performed so that the target plate thickness hAB is achieved. Therefore, the plate thickness deviation Δh from the actual exit plate thickness during rolling is Δh−hAB−h −(So+ (PAB/M) ) − (S+(P/M)) from equations (1) and (2). -(S -8) + ((PAB-P) /M)〇-ΔS + (ΔP/M) (m proverb) ... (6) ΔS = S -8 (ms)
・・・・・・(7) ΔP −= P AB−
P (ton) -- (8), and by controlling the rolling down device 3 so as to set this plate thickness deviation Δh to "0", the target plate thickness hAll can be obtained.

FIG. 5 shows the absolute value AC3 of the automatic plate thickness control device 4 in FIG.
1 shows a block diagram of the section. In the figure, the comparator 11 receives the roll Φ gap S and the roll gap initial setting value S, and outputs the roll gap deviation ΔS. On the other hand, comparator 1
2, rolling load ff1P and absolute value load PAB are input,
Sends the rolling load deviation ΔP. The mill elongation calculator 13 multiplies the rolling load deviation ΔP by 1/M and outputs ΔP/M. The adder 14 receives the output ΔP of the Mill extension calculator 13.
/M and the output ΔS of the comparator 11 to obtain the plate thickness deviation Δh, which is sent to the plate thickness control regulator 15. The plate thickness control regulator 15 multiplies the plate thickness deviation Δh by a gain (proportional integral gain) G for conversion to a gap and thickness control, and outputs the control output Δ via a switch A that closes during rolling.
Sent as S.

In this configuration, when the current roll gap S and rolling load P are input, the roll gear initial setting value S and the current roll gap S are compared in the comparator 11 to determine the roll gap deviation ΔS. . On the other hand, in order to obtain the rolling load deviation ΔP, the absolute value load PAB and the rolling load P are manually input to the comparator 12. The mill elongation calculator 13 receives the rolling load deviation ΔP from the comparator 12 and outputs the mill elongation deviation ΔP/M. The mill elongation deviation ΔP/M is input to the adder 14 together with the roll O gap deviation ΔS, and the sum is input to the plate thickness control adjuster 15 as the plate thickness deviation Δh. Here, the plate thickness deviation Δh is multiplied by the proportional integral gain G, and the control output ΔS(m+e
) is output as The effective period of this control output ΔS is the period during which contact A is closed during material rolling.

(Problems to be solved by the invention) FIG. 3 is an explanatory diagram of the rolling process, and (1) in the same figure shows the rolled material 1
(11) in the same figure shows that the tip 1a of the rolled material 1 is (i+1) before it is bitten into the (i+1) stand ST1+1.
1) After being bitten by the stand ST tri, the same figure (
iii) shows a state in which the rear end 1b of the rolled material 1 is still caught in the stand 5T1-, (lv) in the same figure.
The rear end 1b of the rolled material 1 is (i-1) stand S T
The state after removal from IT is shown respectively.

In the state shown in Fig. 3(i), the i-stand ST of the rolled material
and the forward tension t between the (i+1) stand S T tit
1 is zero. Next, when the state advances to the state shown in the figure (it), the front tension tl is generated, but since tension control is being performed, the front tension t1 is near the front tension reference tREPI. In other words, since there is a state transition between (1) and (11) in Fig. 3, in absolute value AGC, the absolute value load P of equation (4)
Since AB is a constant value in the rolling steady state, rolled material 1
At the tip of the plate, an error occurs in the direction in which the plate thickness increases.

Similarly, the rear end of the rolled material 1 is (i-1) stand 5T1-
In the state transition from FIG. 3 (111) passing through 1 to FIG.
This results in an error in the direction in which the plate thickness of the rear end portion 1b increases.

As described above, variations in the front and rear tensions at the leading and trailing ends of the rolled material 1 have a large effect on the plate thickness accuracy. On the other hand, even in the steady rolling section, even if the tension is controlled to be close to the tension standard, the tension may deviate significantly from the standard due to changes in the characteristics of the rolled material 1. Thickness accuracy will be reduced.

In recent years, the control plate thickness accuracy of rolling equipment is strict, ranging from a dozen microns to several microns, and the accuracy must be covered over the entire length of the rolled material 1. Therefore, deterioration of plate thickness accuracy due to such tension fluctuations is critical to equipment operation.

SUMMARY OF THE INVENTION An object of the present invention is to provide a tension correction automatic plate thickness control device that can prevent deterioration in plate thickness accuracy caused by tension fluctuations at the front and rear ends of a rolled material during rolling.

[Structure of the invention]

(Means for Solving the Problems) The present invention provides a plurality of stands for rolling a rolled material by applying a rolling load, an arbitrary stand among the stands, and an upstream side adjacent to the upstream position and downstream position of the stand, respectively. tension detection means for respectively detecting the front inter-stand tension and the rear inter-stand tension of the rolled material between the stand and the downstream stand; Rolling load correction means for correcting the rolling load of the arbitrary stand based on the deviation from the rear inter-stand tension standard;
It is configured as having the following.

(Function) The rolled material is rolled on an arbitrary stand. At that time, the tension between the front stands and the tension between the rear stands of the rolled material are detected by the tension detection means.

On the other hand, the tension reference between the front and rear stands is predictively calculated. The deviation between the tension between the front and rear stands and the reference tension between the front and rear stands is determined. The rolling load of the arbitrary stand is corrected based on the deviation.

Thereby, the rolled plate thickness of the rolled material is adjusted.

(Example) Before explaining the present invention in detail, the theoretical background will be explained.

The problem with conventional absolute value AGC is that the absolute value load PAB
Since is the r-side wave calculation value in the rolling steady state,
The problem is that errors occur in relation to actual tension fluctuations. Therefore, instead of the absolute value load PAB, it is sufficient to use the tension-corrected absolute value load PAn' corrected by the tension variation.

The tension correction absolute value load PAB' is determined as follows.

First, by differentiating equation (3) with respect to the front and rear tensions, an influence coefficient representing the degree to which each tension affects the rolling load is formulated.

Using these equations (')) and (10), i-stand S
The absolute value load PAH of T is corrected by the tension, and the tension correction absolute value cylinder "PA11' is determined by the following formula.

(ton) ......(11)"1 -i-1
-” REF (i-1) (kg / vuA) ・
...(12) Δt −t −t (k
g/sj) ...(13) i i
REPi Equation (12) is the deviation Δt of the rear tension of i-stand ST and rear tension from the rear tension reference (tension reference between rear stands) tREF (1-1), and Equation (13) is i-stand ST (i-1) , is the deviation Δt1 of the front tension from the front tension reference (front inter-stand tension reference) t.

REl'1 By using the tension correction absolute value cylinder "PAB' obtained by equation (11) in place of the absolute value load TrrPAB, for example, the tip of the rolled material 1 until it bites into the (i+1) stand S T 1+1 Since the forward tension is t1-0 in 1a, equation (13) is as follows: Δti"-tRE)'i ・・・・・・・・・(■
4). In addition, (i-1) In the stand 5T1-1, when the rear end 1b comes out, the rear tension is ts-i-0, so the equation (12) is ``=-tREF(1-1) ``°''' (1
5), and correction is made due to tension fluctuations.

Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is an overall configuration diagram of an automatic plate thickness control device for tension ha according to an embodiment of the present invention. The configuration in this figure is different from that in Figure 4. (i-1) A rear plate tension (tension between rear stands) detector 8 is installed between stands ST and i-stand ST, i+1) Stand ST, front plate tension (tension between front stands)
The structure is such that the detectors 7 are respectively provided and the detected values (backward tension) tl- and the detectors (frontal tension) tl are sent to the tension correction automatic plate pressure control section 6.

FIG. 2 is a block diagram showing details of the tension correction automatic plate pressure control section 6 of FIG. 1, and particularly shows the absolute value AC3 section. In the figure, the target load tension corrector 16 is configured to calculate each detected value t of the front force plate tension detector 7 and the rear plate tension detector 8.
i, ti-1 are input, and the tension correction absolute value load PAB'
is sent to the comparator 12. The comparator 12 receives the tension correction absolute value load PAB' and the rolling load P, and outputs the rolling load deviation ΔP. The rest of the configuration is the same as in FIG. 5, and the same components as in FIG. 5 are given the same reference numerals.

In each figure of FIG. 1 and FIG. 2, the tension correction automatic sheet pressure control section 6 includes the current roll gap S1 rolling load
The front tension t and the rear tension tI-1 are manually applied.

In order to obtain the roll gap deviation ΔS, a comparator 11 compares the roll gap initial setting value S with the current roll gap S, as shown in FIG. On the other hand, in order to obtain the rolling load deviation ΔP, the front tension t1 and the rear tension t1-1 are input to the target load tension corrector 16, and (11)
The tension correction absolute value load TiIPA11' obtained by the formula is calculated and output. Next, this tension correction absolute value load PAB'
The comparator 12 compares the rolling load P with the rolling load P, and inputs the rolling load deviation ΔP into the elongation calculator 13 of the mill. The mill elongation calculator 13, which manually inputs the rolling load deviation ΔP, outputs the mill elongation deviation ΔP/M to the adder 14, where it is added to the cloud gap deviation ΔS.As a result, the plate thickness deviation Δh is calculated and input to the plate thickness control regulator 15. Here, the plate thickness deviation Δh is multiplied by a gain (proportional integral gain) for conversion to a gap and plate thickness control to obtain a control output ΔS. , the valid period of this output ΔS is while the contact A is closed.

Therefore, since the tension variation can be found using equations (12) and (13), the error can be reduced by correcting the absolute value load PAB and using it as the tension correction absolute value load PAB' as shown in equation (11). You can get the standard. As a result, the control accuracy of the plate thickness hI on the exit side of the i-stand ST is improved in the absolute value AGC, and it becomes possible to roll the plate material with high precision and high quality over the entire length of the rolled material 1.

〔Effect of the invention〕

According to the present invention, since the tension-corrected absolute value load corrected by the tension fluctuation is used instead of the absolute value load, the tension-corrected automatic plate thickness makes it possible to improve the precision of plate thickness control using absolute value AGC. A control device can be obtained.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram of a tension correction automatic plate thickness control device according to an embodiment of the present invention, FIG. 2 is a block diagram of a tension correction automatic plate thickness control section in the device shown in FIG. 1, and FIG. )～(n
) is an explanatory diagram of the rolling process, FIG. 4 is an overall configuration diagram of a conventional automatic plate thickness control device, and FIG. 5 is a block diagram of the absolute value AC 3 section of the automatic plate thickness control device of FIG. 4. 1... Rolled material, 2... Rolling machine, 3... Rolling device,
5... Rolling load detector, 6... Tension correction automatic plate pressure control section, 7... Front plate tension detector, 8... Rear plate tension detector, 11.12... Comparator, 13... Mil extension calculator, 14... Adder, 15... Plate thickness control adjuster, 16... Target load tension corrector. Applicant's agent Yukyu Sato Figure 3

Claims (1)

[Claims] a plurality of stands that apply a rolling load to roll the rolled material;
Tension detection means for detecting a front inter-stand tension and a rear inter-stand tension of the rolled material between an arbitrary stand among the stands and an upstream stand and a downstream stand adjacent to the upstream and downstream positions thereof, respectively. and rolling load correction means for correcting the rolling load of the arbitrary stand based on the deviation between the front and rear stand tension detected by the tension detection means and the predicted and calculated front and rear stand tension reference. A tension correction automatic plate thickness control device characterized by: