JPS5947006A - Control method of crown and shape - Google Patents

Abstract

PURPOSE:To control a rolling mill having >=3 units of rolling stands so as to satisfy the shape in the transverse direction of a rolled material and the shape in its rolling direction by providing a shape detector and a plate crown detector on the outlet side of the rolling stand on the lowermost stream and controlling the bending forces of the respective stands. CONSTITUTION:A shape detector 3 and a plate crown detector 4 are provided on the outlet side of the 3rd stand, and a difference lambda3 in the rate of elongation and a ratio epsilon3 of a plate crown are detected and are inputted to a control device 2 which compares said value with targer values and determine deviations DELTAlambda3, DELTAepsilon3. The deviation DELTAlambda3 is converted to the correction rates DELTAF3, DELTAF2, DELTAF1 of bending forces by converters 5, 6, 7, and said rates are applied to the respective stands. The deviation DELTAepsilon3 is converted to the correction rates DELTAF2, DELTAF1 of bending forces with converters 5, 9. Waste time circuits 10, 11 apply the correction rates by delaying the rolled material 1 from the 1st stand to the 2nd stand and from the 1st stand to the 3rd stand by the time tau12, tau13. The correction rates DELTAF3, DELTAF2, DELTAF1 are applied with delay by the waste time tau12, tau13 until the material 1 passes through the 2nd and the 3rd stands with the 1st stand as a reference.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for controlling a rolled material so that both the shape in the width direction (hereinafter referred to as temporary crown) and the shape in the rolling direction (hereinafter referred to as shape C) are satisfied. It is.

Shape is considered important as a criterion for determining the quality of a product.
With the advancement of shape detectors, great progress has been made in shape control.

In recent years, there has been a strong demand for improved product yields, and there is a growing need to control the shape and crown of the plate.

Operations when controlling the shape and sheet crown metal (including pending force, coolant amount, and intermediate roll position (6-stage mill only), but in online tlilJ control, the pending force is used as the operating liquid from the viewpoint of coordination. It is most appropriate to do so.

For this reason, if you try to control both the shape and the plate crown while online, it will be difficult to change the plate crown or shape. Since the 1st model is a pending force, there was a problem in that if you tried to bring the plate crown closer to the target, the shape would deteriorate, and if you tried to bring the shape closer to the drift value, the plate crown would deteriorate, causing interference. .

The object of the present invention is to provide a control method that satisfies both the plate crown and shape without causing such interference.

The present invention installs a shape detector and a plate crown detector on the exit side of the final stand, and uses the signals from these detectors to perform predetermined calculations using a control device. By controlling the pending force of the 4-tier stand, there is no interference between the plate crown and shape! This makes it possible to control 1ilJ.

FIG. 1 shows the rolling state of the N-1 and N-th stands.

In the figure, F is the pending force, P is the j-wang load ton, ε is the plate crown ratio, and λ is a parameter called the elongation rate difference, which is as follows.

Assume now that the rolled material on the entry 1011 and exit sides of the N-th stand has a shape as shown in Fig. 2 of the coffin.

The plate crown ratio is a cut cut by ε = ((plate thickness at the center of the plate) - (plate thickness at the edge of the plate)) / (plate j at the center of the plate! 7), so the eyebrow WN stand included 1i ! The plate crown ratio of if is εN-1= (Ha I■-)/llc
Then, the plate crown ratio Ll on the exit side of the N-th stand:, ε
, = (ttc-h,)/ho.

In addition, the elongation rate difference is the amount defined by λ - ((length of the plate end) - (length of the plate center)) / (J (sa) of the plate center, and (The difference in elongation rate of Ill is λN-1
= (L--Lc)/Lc, and it is clear that the elongation rate difference λN on the exit side of the N-th stand is λN = (le-1c)/lc.

Here, the board edge only needs to be a specific position, but generally it is a point 25 points away from the board edge.

A series of [Horatus] I presented at the Spring Lecture on Plasticity in 1978.
As shown in "Research on Crown Shape Control Method of J Tsubu", there are the following two relationships between the plate crowns and plate shapes on the entrance and exit sides of each totand.

λN-ξN (εN-εN-1+ξLλN-1)...
...(1) Ex = ((fN2FN+fgP*+
fN4 C1'N)+ANl'εN-1)/Z
・River・Seal・(2)′Z=hc(I C(1−ξ
N)) Here, ξN is the strain difference ratio of the Nth stand, ξL is called the influence coefficient of the entrance shape, and is a value determined by each stand, fIN* f2N* f3N#A2N'
is the plate width at the exit side of the N stand and the intermediate roll position (
61R mill only) is a value determined from K, and is a value determined from the actual 15' (actual value).

CrN is the crown amount of the work roll of the DZN stand.

(2)′ as h2/ Z=)3N2 + fNs /
Z=BN3 +fN4/ Z=13N+ + A,'
Nl/ Z=B+<+ ff, rewrite using εN=BN1 5N-1+ Bn 2 F N + B
H3PN +J3N4crN
...(2).

Now, the width difference of each variable from the target value will be expressed using Δ.

The amount of operation is only the pending force, and what can be recognized is:
Since there are only the elongation rate difference λ and plate crown ratio ε, the feedback amounts are Δλ and Δε, and considering that the manipulated variable is ΔF, and expressed in the form of (1) and (2)'ffiΔ, ΔλN= ξN (ΔεN−ΔεN−1+ξLΔλN−1)
3) ΔεN=BNlΔεN−, +B
N2ΔFN (11).

Since the shape and plate crown on the entry side of the first stand are known, Δλ0−Δεo=0, and from (3) and (4), a relationship of −1 is generally derived.

al, bl are constants obtained by alternately substituting (3) and (4)e, and "I"'3+ b1~b3
is ΔεI=B12+ΔF1 Δλ1−ξ1・B1□・ΔFI Δε2=B21・B12・ΔF s + 822・ΔF
5Δλ2=ξ5(B22(ξL・ξ4+821 ”ΔF
1+1322・ΔxxslΔε3:B21@B21'B
12'1ΔFI+B511IB22 @ΔF5-to13
32ΔF6Δλ3=ξa ((B3 ,・B21・B1
□-13□1・B12+ξmount・B, 2(ξ1.ξ4+B
a, -1))ΔFr+-(Bll B22-ξ5B22
+ξ5ξ5B221Δl';'z+13gz・ΔF6]
From the relationship, a,=ξ1Bsz s bt=r3tz can be obtained.

Hereinafter, the stands of interest will be described as stands 1, 2, and 3.

3rd stand i (i, shape from version crown, !jc
In order to see the image in perspective, it is assumed that control is performed by focusing on the shape. From this F4 point, firstly, the penting force F of the 1.2nd stand
How to change 1°F2 to get the 3rd stand out (1
1 Find out whether it affects the shape of [.

This condition can be established by setting N=3 in equation (5), Δλ
3: a1ΔI! 'I+22∆F2+83∆F3 is obtained, the pending force of the third stand is over ■jb, and the shape of the exit side remains unchanged, ∆F3=0. Δλ
Substituting 3=0, a1ΔF 1 + a2ΔF2−
0, °, ΔF2=alΔF! ``2.''-(The force is obtained as a relationship in which the shape of the exit side of the third stand is not influenced by the pending force of the 1.2nd stand.

Next, when a plate crown deviation of Δε3 occurs in the third stand out rule, ΔF2. By operating only Δ1"l, an operation lΔFlu ΔF2'c for controlling the third stand without changing its shape is determined.

Since ΔF3 is used only for shape control, here Δ]l
's=0, set N=3 in equation (6), and Δε3=b
1ΔF1+b2ΔF2+b3ΔF3=b, ΔF1+b2
Δp2 ... ΔF that satisfies both (8) and condition (7) that does not affect the shape of the exit side of the third stand! , ΔF2 is the required operation amount, and (7 bar 8
), ΔF□=”2Δε3/(a2bl−a1b2)...
...(9) ΔFz = -811εg/ (a2b1”I
b2) −”・00) is calculated.

Furthermore, if a shape deviation of Δλ3 appears on the exit side of the third stand, eliminate the shape f151 difference by ΔF3, and
Find conditions that do not affect the plate crown deviation on the exit side of the third stand.

Since the deviation Δλ3 is controlled by ΔF3 only, by setting N=3 in equation (5), Δλ3=31ΔFl+22ΔF! +83ΔF3 Assuming N=3 in formula (6), 2g3=b, ΔF 1 + b2ΔF2-1-b3ΔF
3 and ΔF1. ΔF2 is set under the condition that it does not affect the shape of the third stand (the force is Δε3-0 (the plate crown of the third stand remains unchanged), and when it is set and solved, Δ1i
t3-Δλ3/b3 (11
) Δp z == a1Δλ3/ ("2bl"
1b2) ・-”(l'l)Δ1!'1=”2Δλ3
/(a2bl "1b2) --03)" is calculated.

This is an operation amount that controls the shape of the plate crown of the third stand fi111 without changing it when a deviation of Δλ3 occurs.

This true background will be explained below as the Sea family (y:J'r).

FIG. 3 shows the configuration II of this embodiment.

A shape detector 3 and a plate crown detector 4 are installed on the exit side of the third stand, and the elongation rate difference λ3 and plate crown ratio ε
3 is detected and input to the ft1lJ control device 2. λ3.
ε311. i Elongation rate difference, plate crown [Target value of Hi rate λP
, εP, and its deviation Δλ3°Δε3 is determined.

Δλ3 is the pending force correction amount ΔF3. calculated in (u), (12), and (13) above. Δ1・2. It is converted to ΔFl.

The output of the converter 5 is given by ΔF3'(il-, the output of the converter 6 is the pending correction amount of the second stand given by the equation of α, and the output of the converter 7 is given by the first stand given by the zero-order equation Pending amendment 91 has been given.

Next, Δε3 is converted via converters 8 and 9 into the pending force correction amount ΔP2+ΔF1 given by the above equations (9) and (10).

(9) The bending correction amounts given by equations (1,0) and (121θ3) are added to form the bending correction amount for each stand.

However, if this correction amount is given to each stand at the same time, it is not possible to control the shape and plate crown, and the C
The rolled material is the second. I had to think about wasted time and push myself until I reached the third stand.

The dead time circuits 10 and 11 respectively delay the time τ121τ for the rolled material 1 to arrive from the i stand to the second stand and from the first stand to the third stand to give correction amounts.

τ12+ τt s ViH', Fl between stands of rolled material
l'ill is a value that can be easily determined if the rolling speed between each stand is known.

In this way, the plate crown ratio of the third stand Detsuku,
Elongation rate: A: All detected, each eye (11 from 9 values)
Find the difference.

Next, calculate this deviation from the 1j11 shape of the third stand? f? Even if the city is closed, the 3rd stand appears (Il + 4 anti-crown, 1i
(Y'/l''+' pending correction ΔF1.ΔF2゜ΔF3 is 0]) α2) Calculated from equation (13), it is 1, even if ε is corrected for the plate crown on the exit side of the 3rd stand. Modification of the pending function that does not affect the shape of the third stand exit 1111;:.

ΔF! , ΔF2ff1 (9) (10) Equation J: P Pending force (j6
31-', :1i', is determined.

These correction amounts are applied by setting the first stand to 2((6t#I) and delaying the heat in the shade where the rolled material passes through the second and third stands by a delay time of τ1□ and 3.

By carrying out the above-mentioned control, it became possible to control the shape of the plate crown by 10 times by adjusting the pending force of each stand.

This example is based on the first example. Second. As shown in the third stand, this method requires three consecutive rolling mills, a shape detector and a plate crown detector on the outlet side of the most downstream stand among the three. It will be clear that it is possible to control the entire crown.

According to the present invention, it is possible to control the roll bending only by using the operating needle without the plate shape and the plate crown interfering with each other.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the state of rolling, FIG. 2 is a diagram showing the dimensions of each part of the rolled material before and after rolling, and FIG. 3 is a diagram showing an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Rolled material, 2... Control device, 3... Shape detector, 4... Plate crown detector, 5, 6, 7, 8.9.
・Conversion j-Kari-IN

Claims (1)

[Claims] 1. In a method for controlling the crown and shape of rolled material in a rolling mill having three or more rolling stands, a shape detector and a plate crown detector are installed at the exit 1111 of the rolling stand located on the most downstream side, and the Input the signal into the total control device to determine and control the pending power of the three stands. 1! A crown/shape control method using J′ characteristics.