JPS6320115A - Meandering control method and device therefor - Google Patents

Abstract

PURPOSE:To perform stable meandering controls by setting the machine center of a rolling mill as the target value of meandering controls for tandem rolling. CONSTITUTION:The target value of meandering controls is set to the machine center by a setter 9 of a rolling mill 10a for tandem rolling. As 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; a comparison computing element 20 compares the difference amount with the target signal and finds a meandering amount deviation signal. This signal 22 is processed by a meandering controlling regulator 21, which outputs draft correction signals 23, 24 to adjust a roll gap. Therefore, stable meandering controls are performed because the machine center is made to be the target position even if a biting position of a stock center is greatly misaligned.

Description

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

[Prior Art] In rolling operations, depending on the conditions during rolling, the rolled material cannot be placed in the center of the rolls, but instead moves toward the ends of the rolls as rolling progresses, as shown in Figure 7. The phenomenon is well known and is called meandering.

Here, to briefly explain the meandering of the rolled material, the sixth
The figure shows a situation in which the rolled material a has shifted to the right side from the center of the work roll b for some reason. When it becomes as shown in Figure 6, the roll gap becomes uneven on the left and right, and the gap on the right side becomes uneven. It will be wider than 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 at the entry side is symmetrical,
On the side of a larger volumetric flow rate, the monthly interest rate will be drawn in more sharply. As a result, as shown in Fig. 7, rolling 4.7
1a moves to the right on the entrance side (AX), and camber (ffly> occurs on the exit side. Therefore, ]] - Lugi V
The difference between the left and right knobs also becomes larger, and the rolled material a approaches the right end more rapidly, causing a phenomenon called meandering. At the same time, 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, as one of the means to prevent meandering, when a rolled material meanders, the force applied to the left and right load cells c and d (see Figure 6) changes, so this is detected and the meandering is known.
A method has been proposed to prevent this by moving a rolling device to narrow the roll gap on the side where the load increases.

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.

Furthermore, if we look at camber, even if the meandering of the rolled material described above can be sufficiently prevented, it may be caused by the fact that the material of the rolled material is asymmetrical, the material itself has camber, there is a temperature difference between the left and right sides, etc. Occur. Conventionally, no correction method has been developed for this problem, and the countermeasure is to obtain a rectangular thick plate of the required dimensions by rolling the plate to a sufficiently large width and cutting off unnecessary parts. This resulted in a significant drop in yield.

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. The meandering control means is provided with meandering amount detectors for detecting the width end position of the rolled material on the work side and the drive side on the entry side of the rolling machine, and calculates the meandering amount by calculating the difference between the output signals of each detector. A computing unit and a device for giving a target position of the rolled material are provided, 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 working side and the driving side. and a meandering control adjustment device that outputs a rolling reduction correction signal, and the working side,
The roll gap on the drive side is changed.

In the case of a tandem rolling mill, the meandering control by the meandering control device is basically to maintain the rolled material in an upstream position. 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. Because it is necessary.

Therefore, when meandering control is performed on all stands of a tandem rolling mill, when the tip of the rolled material is bitten by the rolling mill into which the rolled material is introduced, the position is memorized as the target position for meandering control of the rolling mill. It is possible to do so.

[Problems to be Solved by the Invention] However, in the above meandering control device, when the rolled material is bitten by the rolling mill, the rolled material is caused by the camber of the tip of the rolled material, etc. Since the center line is deviated from the machine center or the center line of the rolled material at steady state, if the position of the rolled material at the time of biting is set as the target position, the position of the rolled material at steady state when it is stable after biting is set to the target position. There is a problem in that the position of the rolled material differs significantly and stable meandering control and thus rolling cannot be performed.

The present invention has been made in view of the above-mentioned circumstances, and has an object of stably meandering control and rolling to achieve 1q.

[Means for Solving the Problems] The present invention provides a means for reducing the rolling distance in each rolling mill from the width end position of the rolled material to at least one of the entry side and exit side of each rolling mill arranged in tandem. The side meandering amount is determined, and the left and right roll correction signals are determined from the difference between the meandering amount and the rolling material meandering control target value of each rolling mill.The left and right roll gills of each rolling mill are adjusted using the rolling correction signal. When performing meandering control, the mechanical center of the rolling mill is given as the 11 target value for meandering control.

[Function] During meandering control, the machine center of each rolling mill is given to each rolling mill as a target value for rolling material meandering control, and the width end of the rolled material in each rolling mill determined by the meandering amount detector is The meandering amount of the rolled material is determined from the position, the left and right rolling correction signals are determined from the meandering amount and the machine center of the rolling mill, the roll gap of each rolling mill is adjusted by the rolling correction signal, and the meandering control of the rolled material is performed. It will be done.

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

1 and 2 show an embodiment of the present invention, and 10 in FIG.
A to 10g are hydraulic rolling mills arranged in tandem, and all of the rolling IJs 10a to 10g can control the meandering of the rolled material 9.

The meandering control devices of the hydraulic rolling mills 10a to 10q are basically the same ('A), so hereinafter referred to as the hydraulic rolling mill 1.
The meandering control device 0a will be explained with reference to FIG.

The upper and lower work rolls 1 and 2, the upper and lower backup rolls 3 and 4, the lower backup roll chocks 5 and 6 that indicate both shaft ends of the upper and lower backup rolls 3 and 4, and the reduction blades on each of the lower back-up roll chocks 5 and 6. The hydraulic cylinder 7.8 is configured to roll the rolled material 9, 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. At the same time, 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 meander control regulator 21 are connected to the hydraulic cylinder 7.8. Addition amplifier 15.1 to compare with
Set up 6. The left and right roll gap is controlled by servo valve LL.
The roll gap is adjusted by controlling the amount of pressure oil flowing into and out of the hydraulic cylinder 7.8 by means of a displacement detector 13.14 which detects the movement of the hydraulic cylinder 7.8. If there is a difference in the signal from the meandering control regulator 21, the servo valves 11 and 12 are adjusted using the difference. do. Further, meandering amount detectors 17 are installed on the left and right sides of the entrance side of the rolling mill 10a to detect the position of the width end of the rolled material 9 based on the light emitted by the rolled material 9,
The difference between the signals from each of the detectors 17, that is, the meandering amount of the rolled material 9, is determined by the calculator 18, and the meandering amount and the target signal from the setting device 19, which sets the target value of the rolled material meandering control, are calculated. A comparator 20 performs a comparison, and the obtained meandering amount deviation signal 22 is processed by a meandering control regulator 21 to produce a left and right reduction correction signal 23.
．． 24 to be added to the addition amplifiers 15 and 16. The machine center of the rolling mill 10a can be set in the setting device 19. Further, the output of the meandering control regulator 21 is, for example, in the direction of tightening the roll gap on the working side and opening the roll gap on the driving side when the rolled material 9 moves toward the working side, or in the direction of moving the rolled material 9 toward the driving side. If the difference occurs, the direction is determined so that the roll gap is controlled in the opposite manner to the above, and the signal is added to the summing amplifiers 15 and 16.

Therefore, in the summing amplifier 15.16, a comparison is made between the actual piston displacement signal of the hydraulic cylinder 7.8 and the reduction correction signal, and the difference signal causes the servo valve 11.12 to adjust the pressure to the hydraulic cylinder 7.8. The amount of oil inflow and outflow is controlled, 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 (mechanical center of the rolling mill) given by the setting device 19. Such control applies to all rolling mills 10.
It is done in a~iog.

3 to 6 show other embodiments of the present invention, in which the rolled material in the previous embodiment was a hot material, whereas in this embodiment the rolled material was a cold material. Therefore, in this embodiment, since the rolled material 9 does not emit light, the light source 25 is provided below the meandering amount detector, and the light projected from the light source 25 is detected by the meandering amount detector 17. Meandering can be detected. In the drawings, the same reference numerals as those shown in FIGS. 1 and 2 indicate the same components.

Although the present invention has been described above and an example of application to a four-high rolling mill has been shown, the present invention can be applied to all types of rolling mills where meandering is a problem, and the control circuit is not hardware but computer software. However, within the scope of the present invention, it is possible to configure the control device of the present invention by attaching meandering detectors to both the inlet and outlet sides of the rolling mill and configuring the control device of the present invention based on the signals from both sides. Of course, various changes can be made.

[Effects of the Invention] According to the meandering control method and device of the present invention, the mechanical center of the rolling mill can be set to the target value for meandering control, thereby making it possible to perform stable meandering control and to perform stable rolling with less meandering. Various excellent effects can be achieved, such as the ability to

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of an embodiment of the meandering control method and device of the present invention, FIG. 2 is an explanatory diagram of a meandering control device applied to the meandering control method and device of FIG. 1, and FIG. FIG. 4 is an explanatory diagram of another embodiment of the meandering control method and device of the invention, FIG. 4 is an explanatory diagram of the meandering control device applied to the meandering control method and device of FIG. 3, and FIG. An explanatory diagram of a meandering amount detector and a light source used in the control device, FIG. 6 is an explanatory diagram showing a state in which the rolled material approaches one end of the roll, and FIG. 7 is a plan view of FIG. 6. In the figure, 1 and 2 are work rolls, 7 and 8 are hydraulic cylinders, 1
0a to 10b are hydraulic rolling machines, 11.12 is a servo valve, 13.14 is a displacement detector, 15.16 is an addition amplifier, 17 is a meandering amount detector, 18 is a calculator, 19 is a setting device,
20 is a comparator, 21 is a meandering control regulator, and 25 is a light source.

Claims (1)

[Claims] 1) Determine the meandering amount of the rolled material in each rolling mill from the position of the width end of the rolled material on at least one of the entry side and exit side of each rolling mill arranged in tandem, and When determining the left and right rolling reduction correction signals from the difference between the meandering amount and the rolling material meandering control target value of each rolling mill, and adjusting the left and right roll gap of each rolling mill using the rolling reduction correction signal to control the rolling material meandering, A meandering control method characterized in that a mechanical center of a rolling mill is given as a target value for meandering control. 2) Difference between a detector installed in tandem on at least one of the inlet side and outlet side of each rolling mill on the work side and drive side to detect the position of the width end of the rolled material, and the output signal of the detector. a meandering amount calculation device that calculates the meandering amount of the rolled material in each rolling mill, a setting device that sets the machine center of each rolling mill as a target value for meandering control, and a meandering control target set by the setting device. A comparison calculation device that compares and calculates the difference between the value signal and the output signal 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 gaps on the work side and the drive side are changed by a reduction correction signal.