JPH0456684B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for controlling the width of a steel strip in a cold rolling process.

In the method of rolling steel strip, a means for simultaneously correcting the reduction in both width and thickness directions has been filed as a three-point restraint type edger device by the present applicant, but conventional technology of this type has It concerned the structure of the device, how to use it, etc., and did not specifically explain its control method.

Accordingly, an object of the present invention is to provide a specific sheet width control means in a three-point restraint type edger, so that it is possible to easily improve sheet width accuracy.

Prior to explaining the sheet width control method of the present invention, the configuration of a three-point restraint type edger device, which is the basis of the rolling function, will be explained with reference to FIG. The device is installed symmetrically opposite the positions of both edges of the running steel strip α, and the roll housing 1 is integrally fixed to the sliding bed 11 and is movable in the width direction of the strip. Two horizontal rolls 2 and 3, which form an upper and lower pair, and one vertical roll 4 are incorporated into a roll housing 1.

As shown in Figure 1, three rolls 2, 3, 4
are upper, lower, and on the same line in the width direction of steel strip α.
They are combined and provided in positions where they can be press-fitted and engaged with the steel strip simultaneously from three directions: horizontally and horizontally. The upper presser roll 2 is movable in the vertical direction by a fluid pressure cylinder 21 and is supported so as to be able to adjust the amount of pressure reduction.
Drive motor 22 via a universal joint (not shown)
rotation is transmitted. The lower presser roll 3 is an idle roll and has a bearing fixed to the roll housing 1, and the vertical roll 4 is also an idle roll. The roll housing 1 incorporating these rolls is pressed toward the edge of the steel strip by the reduction cylinder 5, and the vertical roll 4
to achieve the desired reduction. In the present invention, in particular, the upper and lower presser rolls 2 and 3 can be adjusted and moved in the board width direction by a sliding mechanism separate from the vertical roll 4.

As shown in FIG. 2, the vertical rolls 4 that control the sheet width are configured such that one side is a fixed edger vertical roll 41 and the other is a moving edger vertical roll 42, and the width between these two rolls is fixedly set to control the width in the width direction. However, even if the roll forming width is set to the target control width, the rigidity of the device is naturally not infinite, so if the load required for width reduction is relatively large, The moving roll 42 is forced to move backward, and the board width accuracy after control becomes poor.
Therefore, in the present invention, the control circuit shown in FIG. 2 is used and set to predetermined conditions to stabilize the plate width accuracy.

Hereinafter, the process of the control method of the present invention will be specifically explained with reference to FIG. First, during the passage of the steel strip a, the position of the movable roll 42 is determined by operating the reduction cylinder 5, and the distance between the rolls and the fixed roll 41 is maintained at the target setting width _Bp . At this point, the load P _p acting on the moving roll 42 is detected by the load cell 62 and stored in the first comparator 6. From now on, this load is used as the standard value of the edger vertical roll load (hereinafter referred to as the lock-on load). The control circuit system is set to a starting state based on this lock-on load P _p (referred to as a load).

On the other hand, a displacement meter 2 is attached to the holding part of the upper presser roll 2.
3 is provided so that the gap S _p (see FIG. 3A) between the edger vertical roll 42 and the upper presser roll 2 can be measured. Then, the gap S _p at the time when the lock-on load P _p is set is set as a reference position in the first and second comparison calculators 6 and 7.

After setting these reference values, actual rolling is started. First, when the steel strip a runs in the direction of the arrow, the edger vertical roll 42
The applied rolling load (already fixed in position) changes. This rolling load P is continuously detected by the load cell 62 and input to the first comparator 6. The comparison calculator 6 calculates the difference ΔP between the detected load P and the lock-on load P _p (that is, ΔP=P−P _p ) and inputs it to the calculation device 8 .

On the other hand, the displacement meter 23 provided on the upper presser roll 2 is
The roll interval S at the time corresponding to the detected load P is continuously detected and inputted to the second comparator 7 to calculate the difference ΔS between the detected value S and the reference point S _p (i.e., ΔS = S - S _p )
is determined and input to the arithmetic unit 8.

The calculation device 8 calculates the stiffness of this device as K, and calculates C=k×ΔP/K+ΔS (k=1) based on the input values ΔP and ΔS, so that the calculated value C becomes zero. Then, the hydraulic system 9 of the hydraulic sliding mechanism 24 of the upper presser roll 2 is controlled. A controller 81 is actuated by the arithmetic unit 8 to control the servo valve 91 of the hydraulic system 9 to move the position of the upper presser roll 2 in the width direction of the sheet and to control the load applied to the edger vertical roll 42. This sliding movement of the presser roll in the board width direction is adjusted and moved while the upper presser roll 2 and lower presser roll 3 are still combined, and the left and right sides are moved in a symmetrical state. As a result, the load of the extra meat applied to the edger vertical roll 42 becomes a dog bone in the gap between the edger roll 42 and the presser roll. Therefore, only the set load P _p is maintained on the edge roller vertical roll, so the moving edge roller vertical roll does not change its position, and the steel strip coil is rolled down to the target control width B _p over its entire length. Ru.

In the method of the present invention, when the width of the plate before rolling is larger than the target control width B _p , the roll interval S is made wider, and the amount of inward movement of the presser roll 2 becomes larger. In other words, when the board width is B'(B' = B _p + α), which is larger than B _p as shown in Fig. 3B, the roll interval becomes S', and as shown in Fig. 3, the board width becomes B''. When (B″=B _p +β) is large, the roll spacing becomes even wider as S″, and the larger the roll spacing, the larger the plate thickness t between them partially becomes, and the dog-bone shaped part a′ also becomes larger. However, since it is common to apply large tension during cold rolling, the dog bone part does not return in width during cold rolling and smoothly moves in the rolling direction or in the direction of the center of the sheet width. Metal flow is generated to maintain uniform plate thickness.Therefore, width accuracy does not deteriorate.

An embodiment of the control method according to the present invention will be specifically described. The implementation method is to install this device on the outlet side of the pickling line, and hot-roll the plate to a thickness of 3.5mm x width of 1223mm.
× Pickled steel strip with a coil weight of 25 tons and a coil inner width variation of ±4 mm is used as the rolling material, and the target plate width (B _p )
When widthwise rolling was performed using the control method of the present invention by setting 1219 mm, a high precision result of 1219±0.05 mm was obtained. When a similar steel strip material was subjected to conventional fixed position control, the strip width varied by ±2 mm due to the rigidity of the equipment frame and rolls, and the method of the present invention was found to be significantly more effective than the conventional method. It was found that the control accuracy was high.

As described above, according to the plate width control method of the present invention,
Since a product with extremely high precision can be obtained over the entire length of the steel strip, there is no need for trimming, and it also has the effect of preventing sawing. In addition, as a cold-rolled base material, it does not generate dog bones or edge tops at the edges of strips, significantly reducing the yield of TMW products, and can be expected to improve pickling efficiency by eliminating the need for trimming.

[Brief explanation of the drawing]

FIG. 1 is a front view showing a half body of a three-point restraint type edger device used in the strip width control method of the present invention. FIG. 2 is an explanatory diagram schematically showing the configuration of a control circuit of the board width control method according to the present invention. FIG. 3 is an explanatory diagram showing how the roll gap changes depending on the size of the control width. 1: Roll housing, 4: Vertical roll, 6:
First comparison operator, 7: Second comparison operator, 8:
Arithmetic unit, 9: Hydraulic system, 41: Fixed edger vertical roll, 42: Moving edger vertical roll.

Claims (1)

[Claims] 1. A steel strip rolling process in which one or more simultaneous strip thickness and width reduction devices are installed to control strip thickness and strip width simultaneously by combining a pair of vertical edge rolls and steel strip upper and lower surface pressing rolls at the same position. In this step, the load applied to the edge roll at the time immediately after the strip width at the tip of the steel strip is reduced to the target value is stored as a reference value in the comparison calculation circuit, and the width reduction is continued thereafter. The load applied to the vertical Etsuya roll is continuously detected, and the position of the upper and lower presser rolls is adjusted and moved in the board width direction according to the difference between the detected load and the memorized set load. A sheet width control method characterized by changing the roll interval between the rollers and thereby making the load on the vertical rolls constant.