JPS6320116A - Meandering control method and device therefor - Google Patents

Abstract

PURPOSE:To prevent generation of shape defects and lapping due to rolling by gradually correcting each meandering control target value at plural downstream rolling mills toward a smaller value from upstream to downstream for tandem rolling. CONSTITUTION:Misalignment amounts from the machine center (l) being the control target value of plural downstream side rolling mills are given to gradually reduce such as DELTAX1>DELTAX2>DELTAX3 for tandem rolling. In the case of a rolling mill 10d, for a meandering amount of a rolled stock 9, a difference between each signal from end position detectors 17 is found by a computing element 18 and a comparison computing element 20 compares the difference amount with the target value of a setter 19 and an obtained deviation signal 22 is processed by a meandering controlling regulator 21 and a roll gap is adjusted by draft correction signals 23, 24. In that time, sudden corrections are eliminated and generation of shape defects and lapping due to rolling is prevented because the setting target values are gradually reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application 1] The present invention relates to a method and apparatus for controlling meandering of a rolling mill.

U Prior Art] In rolling operations, depending on the conditions during rolling, A cannot stay in the center of one call and moves toward the end of the roll as rolling progresses, as shown in Figure 5. This phenomenon is well known and is called meandering.

Here, to briefly explain the meandering of the rolled material, the fourth
The figure shows a state in which the rolling roll 4a has shifted to the right side from the center of the work roll b for some reason.When it becomes like the figure 4, the roll gap becomes uneven on the left and right,
The gap on the right side becomes wider than the gap on the left side. By the way, although the circumferential speed of the work roll b is uniform on the left and right sides, the gap on the right side is wider, so the volumetric flow rate of the rolled material per unit time is larger on the right side.

Also, if the thickness of the rolled material on the entry side is symmetrical to the left, the material will be drawn in faster on the side with a higher volumetric flow rate. As a result, as shown in FIG. 5, the rolling 4Δa approaches the stone side on the entry side (AX), and camber (Ay) occurs on the exit side. Therefore, the difference between the left and right roll gaps becomes even larger, and the rolled material a approaches the right end more rapidly, causing a meandering phenomenon. In addition, camber also increases.

In order to prevent such meandering and the accompanying camber,
It is effective to roll the material under conditions that create a convex crown. However, in recent years, demands for improving the quality and yield of rolled materials have become stricter, and it has become necessary to reduce the convex crown as much as possible and to roll the material so that it has a uniform thickness distribution in both the longitudinal and width directions. Under such conditions, the rolled material tends to meander, making stable operation difficult.

In recent years, rolling (Δ
When the load cells meander, the left and right load cells c and d (see Figure 4)
Since the force applied to the roll changes, a method has been proposed in which this is detected, meandering is detected, and the roll-down device is moved to narrow the roll gap on the side where the load is increased to prevent it.

However, with the above-mentioned means, there are problems such as the output change due to the meandering and the output change due to the operation of the lowering device being mixed, the control system is unstable and tends to cause divergent vibration, and the accuracy is insufficient. The drawback is that it is completely impractical.

Therefore, in order to solve the above problems, the inventors of the present invention,
For example, a meandering control means as disclosed in Japanese Patent Application No. 58-65109 was proposed. In the meandering control means, detectors for detecting the width end position of the rolled material are installed on the work side and the drive side on the entry side of the rolling machine, and the amount of meandering is determined by calculating the difference between the output signals of each detector. A computing unit and a device for giving the target position of the rolled material are installed, a device for comparing and computing the output signal of the computing unit and the target signal, and a device for processing the signal obtained by the device to connect the work side and drive. The roll cap is provided with a meandering control adjustment device that outputs a side rolling reduction correction signal, and the roll caps on the working side and the driving side are changed in accordance with the rolling reduction correction signal.

In the case of a tandem rolling mill, the meandering control by the meandering amount 1 control device is basically to maintain the rolled material at a position following the upstream direction. Therefore, ideally, it is desirable to perform meandering control on all stands to keep the rolled material at the same position.

This is because if meandering control is performed with only one stand and the rolled material is forcibly returned to the center position of the rolling mill, the rolled material may become defective in shape or even squeezed, which may hinder the rolling operation. This is because there is.

However, if it is not possible to control meandering in all stands due to constraints on the responsiveness of the rolling system, a meandering control device may be installed in several rolling mills downstream of the tandem rolling mill, and, for example, the machine center of the rolling mill may be controlled by meandering. It is conceivable to set this as a target position for control and perform meandering control.

[Problems to be Solved by the Invention] However, with the meandering control device described above, when the amount of meandering of the rolled material is large, for example, if the machine center of the rolling mill is set as the target position for meandering control, the stand where meandering control is not performed may Between the stands controlling meandering on the downstream side, 1
Similar to when meandering control is performed using only stands, defects in shape and narrowing occur, which does not interfere with rolling work.
= There is a risk.

The present invention has been made in view of the actual situation described in (e) and (e), with the object of gradually performing meandering control to prevent occurrence of shape defects or narrowing in the rolled material.

[Means for Solving the Problems] The present invention improves the width end position of a rolled material on at least one of the entry side and exit side of a plurality of rolling mills on the downstream side among rolling mills arranged in tandem. The amount of meandering of the rolled material in the rolling mill is determined from the width end position of the rolled material, the left and right rolling correction signals are determined from the difference between the meandering amount and the rolling (A meandering control target value), and the rolling correction signal is When controlling the meandering of the rolled material by adjusting the left and right roll gaps of the plurality of rolling mills, the deviation from the meandering control target value of the rolled material is determined by
The correction is gradually made as the rolled material is sent from the upstream rolling mill to the downstream rolling mill, which performs meandering control.

[Function] When controlling meandering, a target value is given so that the amount of meandering of the rolled material gradually decreases from the upstream side to the downstream side in multiple rolling mills on the downstream side, and the meandering amount determined by the meandering amount detector is given. The meandering amount of the rolled material is determined from the width end position of the rolled material, the left and right rolling correction signals are determined from the meandering amount and the target value, the roll gap is adjusted by the rolling correction signal, and the meandering amount of the rolled material is determined on the upstream side. It gradually becomes smaller downstream.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

Figures 1 to 3 show an embodiment of the present invention, and 10a to 1 in the figures.
0f is a hydraulic rolling mill arranged in tandem,
The rolling mills 10d, 10e, and 10f can control the meandering of the rolled material 9.

Since the meandering control devices used in the hydraulic rolling mills 10d, 10e, and 10f are basically the same, the meandering control device of the hydraulic rolling mill 10d will be explained below with reference to FIG.

A reduction blade is attached to the upper and lower work rolls 1 and 2, the upper and lower backup rolls 3 and 4, the non-backup roll chocks 5 and 6 that indicate both shaft ends of the upper and lower backup rolls 3 and 4, and each lower back-up roll chock 5 and 6. The hydraulic cylinder 7.8 is configured to roll the rolling 419, and the amount of pressure oil flowing into and out of the left and right hydraulic cylinders 7.8 is controlled by a servo valve 11.12. A displacement detector 13.14 for detecting the movement of the piston of the hydraulic cylinder 7.8 is attached to the hydraulic cylinder 7.8, and a signal from the displacement detector 13.14 and a signal from the meandering control regulator 21 are output. Adding amplifier 15 to compare with
．． The left and right roll gap is adjusted by controlling the amount of pressure oil that flows into the hydraulic cylinder 7.8 by a servo valve 1L12. The movement of screws 1 to 7.8 is measured indirectly by the displacement detector 13.14, and compared with the signal from the meandering control regulator 21 by the summing amplifier 15.16. The difference is corrected by rolling the servo valves 11 and 12. Further, rolled materials 9 are installed on the left and right sides of the entrance side of the rolling mill 10d.
A meandering amount detector 17 is installed to detect the width end position of the rolled material 9 based on the light emitted by the trough detector 17. The comparator 20 compares and calculates the target signal from the setting device 19 for setting the target value of the meandering control of the rolled material, and the meandering amount deviation signal 22 obtained is processed by the meandering control regulator 21. The addition amplifier 15°1 serves as the reduction correction signal 23.24.
For example, when the rolled material 9 moves toward the working side, the output of the meandering control regulator 21 configured to be applied to the working side tightens the roll gap on the working side and opens the roll gap on the driving side.
The direction is determined so that the roll gap is controlled in the direction in which the rolled material 9 moves toward the drive side, and in the opposite direction to the above, and added to the adding amplifiers 15 and 16. .

During rolling, the meander control target values set in the setting devices of the rolling mills 10d, 10e, and 10f are, for example, as shown in FIG. , AX3, and AXI>AX2>Ax3.

The meandering amount of the rolled material 9 is determined by the calculator 18 from the width end position of the rolled material detected by the meandering amount detector 17, and the meandering amount is compared with the target value set by the setting device 19 by the comparison calculator 20. The meandering amount deviation signal 22 obtained through the comparison calculation is processed by the meandering control regulator 21, and the reduction correction signal 23.24 is applied to the summing amplifier 15.16, where the actual hydraulic cylinder 7. The displacement signal of screws 1 to 8 and the reduction correction signal are compared, and the servo valve 11 is adjusted based on the difference signal.
．． 12 controls the amount of pressure oil flowing into and out of the hydraulic cylinder 7.8, and as a result, the left and right roll gaps are changed, and the mechanism described above prevents the meandering from progressing further, and the rolled material 9. is returned to the target value given by the setter 19. Such meandering control is performed by the rolling mill 10d,
10e and 10f, but rolling mills 10d and 1
0e, 10f is 71″3 (the target value for meandering control is AXl, AX2, Ax3 away from the rolling mill machine center 1 and AX + > A X 2 > A X 3
Therefore, rolling vJ9 is rolled by rolling mills 10d, 10e,
The meandering is gradually corrected while being fed from the upstream side to the stream side during 10f.

Incidentally, in the embodiments of the present invention, the case where the rolled material is hot-worked material is explained, but if the rolled material is cold-worked material, the present invention can be applied by installing a light source below the meandering amount detector. It is applicable not only to four-high rolling mills but also to all types of rolling mills where meandering is a problem, the control circuit can be configured using computers rather than hardware, and the meandering detector can be used in rolling mills. It goes without saying that it is possible to attach the control device to both the inlet side and the outlet side of the machine and configure a control device based on the signals from both sides, and that various other changes can be made without departing from the gist of the present invention. be.

[Effects of the Invention] According to the meandering control method and device of the present invention, the meandering control of the rolled material is not corrected abruptly but gradually, so that shape defects and narrowing of the rolled material do not occur during rolling. Various excellent effects can be achieved, such as:

[Brief explanation of the drawing]

Fig. 1 is a plan view of an embodiment of the meandering control method and device of the present invention, and Fig. 2 shows how to determine the meandering control target value when meandering control is performed by the meandering control method and device of the present invention. 3 is a detailed diagram of the meandering control method of the present invention and a device applied thereto, FIG. 4 is an explanatory diagram of the case where the rolled material meanders toward one end of the roll, and FIG. FIG. In the figure, 1 and 2 are work rolls, 7 and 8 are hydraulic cylinders, 1
08 to 10f are hydraulic rolling machines, 11.12 are servo valves, 13.1/l are displacement detectors, 15.16 are caulking amplifiers, 17 are meandering amount detectors, 18 are computing units, and 19 are "
20 is a comparison calculator, and 21 is a meandering control adjuster.

Claims (1)

[Claims] 1) Detecting the width end position of a rolled material on at least one of the entry side or exit side of a plurality of rolling mills on the downstream side among rolling mills arranged in tandem; The meandering amount of the rolled material in the rolling mill is determined from the material width end position, the left and right rolling reduction correction signals are determined from the difference between the meandering amount and the rolling material meandering control target value, and the rolling correction signals are used to control the rolling mills. When controlling the meandering of the rolled material by adjusting the left and right roll gaps of A meandering control method characterized by gradually correcting according to the following. 2) Detecting the position of the width end of a rolled material provided on the work side or drive side of at least one of the entry side or exit side of a plurality of rolling mills on the downstream side among rolling mills arranged in tandem. a meandering amount calculation device for calculating the meandering amount of the rolled material in each rolling mill by calculating the difference between the output signals of the detector; and a meandering control target value for the rolling mill in the plurality of rolling mills on the downstream side. a setting device for setting a target value for meandering control so as to gradually correct the deviation from the rolling mill from the upstream side to the downstream side in the plurality of rolling mills on the downstream side; and a meandering control target value signal set by the setting device; A comparison calculation device that compares and calculates the difference between the output signals of the meandering amount calculation device, and a meandering control adjustment device that obtains a reduction correction signal on the work side and the drive side from the difference signal obtained by the comparison calculation device, A meandering control device characterized in that the roll gap on the working side and the driving side is changed by a signal.