JPS6320110A - Meandering controller - Google Patents

Abstract

PURPOSE:To prevent generating of troubles due to a termination speed by calculating a time in which the rear end of a rolled stock reaches end position detectors on the downstream based on a runout signal and terminating meandering controls by a runout signal after the lapse of time. CONSTITUTION:A laser Doppler speed meter 28 and end position detectors 19a, 19b are installed between rolling mills 1a and 1b. When the rear end of a rolled stock 11 runs out from an upstream side rolling mill 1a, a runout signal from a load detector 2 is inputted to a computing element 29 and the speed meter 28 calculates a time (t) in which the rear end reaches position detectors 19a, 19b based on a speed Vs of the stock 11. After a lapse of the time (t), a changeover switch 27 is cut by a switch-off signal to terminate a control by a meandering controller 30. Therefore, the meandering control termination timing is accurately determined, so that various troubles due to a termination speed are prevented.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a device for controlling meandering of rolled material.

[Prior Art] During the rolling operation, the rolled material cannot stay in the center of the rolls due to the conditions during rolling, and moves toward the ends of the rolls as the rolling progresses, as shown in Figure 4. The phenomenon is well known and is called meandering.

Here, to briefly explain the meandering of the rolled material, the third
The figure shows a situation in which the rolled material a has shifted from the center of the work roll b to the right side for some reason. When the rolled material a is deviated from the center of the work roll b to the right side, as shown in Figure 3, the roll gap becomes uneven on the left and right, and the roll gap on the right side becomes uneven. The gap is wider than on the left. 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,
The material will be drawn in faster on the side with a higher volumetric flow rate. As a result, as shown in Fig. 4, the rolled material a moves to the right on the entry side (a
IJ y) occurs.

Therefore, the difference between the left and right roll gaps becomes even larger.
The rolled material a approaches the right end more rapidly, and a phenomenon called meandering occurs. 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 convex crowns as much as possible and to roll the materials so that they have 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 the rolled material meanders, the force applied to the left and right load cells c and d (see Figure 3) changes, so this is detected and the meandering is detected.
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.

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 includes 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 amount of meandering by calculating the difference between the output signals of each detector. a device that compares and calculates the output signal of the arithmetic device with a target signal of the setting device, and a device that processes the signal obtained by the device and communicates with the work side. and a device for outputting a rolling reduction correction signal on the drive side, and the rolling gap on the working side and the driving side is changed by the signal for the rolling reduction correction.

However, with such meandering control means, the meandering control of the rolled material must be terminated when the tail end of the rolled material passes the detector. For this reason, in the meandering control means, when the tail end of the rolled material can handle the upstream rolling mill, the load detector of the upstream rolling mill detects the tail end and the circumferential speed of the upstream work roll is detected. VR is detected by a pulse generator connected to the upstream work roll, and the speed Vs of the rolled material is determined from the circumferential speed VR, and from the distance from the upstream rolling mill to the meandering amount detector installation position of the downstream rolling mill. , the time it takes for the tail end of the rolled material to reach the meandering amount detector of the downstream rolling mill is treated as 1- (when the time t has elapsed, the meandering control in the downstream rolling mill is ended. .

Therefore, the advance rate f of the rolled material is f-(■s/VR)-1
The speed of the rolled material Vs is Vs-(1+f)VR
More demanded.

However, the above-mentioned advance rate f is a function of the friction coefficient μ between the rolled material and the work roll, the work roll radius R1, the rear tension tb of the rolled material, the rolling force P, etc., and f-(μ, R, tb,
P), it is difficult to obtain an accurate value. Therefore, determining the speed Vs of the rolled material from the circumferential speed VR of the work roll will result in a large error and the timing at which meandering control is turned off will be inaccurate. In other words, if the timing of meandering control ends too early, meandering control will not be performed even though there is a board, and the uncontrolled section at the tail end will become long, which is unfavorable for control, and if the timing of meandering control ends too late, there will be no board. However, the meandering control is performed even though it is a problem.

In view of the above-mentioned circumstances, the present invention has been made with the object of accurately determining the timing to turn off the meandering control of the rolled material.

[Means for Solving the Problems] The present invention includes a detector provided on the work side and drive side of the inlet side of the rolling mill to detect the position of the width end of the rolled material, and a detector that calculates the difference between the output signals of the detector. A device that calculates the meandering angle of the rolling material, a device that compares and calculates the output signal of the device and a target position signal of the rolled material, and a device that calculates and outputs rolling reduction correction signals on the work side and the drive side from the signals obtained by the device. The meandering control device is configured to change the roll gap on the work side and the drive side by a rolling reduction correction signal, which includes a laser Doppler speed sensor for detecting the speed of the rolled material on the entry side of the rolling mill, and a laser Doppler speed sensor on the upstream side of the rolling mill. (The tail end of the rolled material in the upstream rolling mill is set to Determined by dividing the distance from the machine to a detector that detects the position of the width end of the rolled material on the entry side of the rolling machine in the first stream by the speed of the rolled material detected by the laser Doppler speedometer, The present invention is provided with a device that issues a command to the meandering control device of the downstream rolling mill to turn off the meandering control when the determined time has elapsed.

[Function] When the rolled material is caught in both the upstream rolling mill and the downstream rolling mill, the amount of meandering is determined from the width end position of the rolled material detected by the detector, and the meandering amount is determined from the width end position of the rolled material detected by the detector. A left and right rolling correction signal is obtained from the difference between the amount and the target position of the rolled material, and the left and right roll gap is adjusted by the rolling correction signal to perform meandering control, so that the tail end of the rolled material moves past the upstream rolling mill. The meandering control is performed as described above in a tension-free condition for the pulled out Shun, and when the tail end of the rolled material reaches the detector that detects the width end position of the rolled material on the downstream side of the rolling mill entry side, the downstream side A command to turn off the meandering control is given to the meandering control device of the rolling mill.

[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, in which 1a is an upstream rolling mill, 1b is a downstream rolling mill, and 2 is a load detection unit for detecting the rolling load of the upstream rolling mill 1a. It is a vessel.

The downstream rolling mill 1b includes upper and lower work rolls 3 and 4, upper and lower backup rolls 5 and 6, lower back-up roll chocks 7 and 8 that support both shaft ends of the upper and lower backup rolls 5 and 6, and each lower backup roll. Jock 7,8
It is equipped with hydraulic cylinders 9 and 10 that act on rolling blades to roll a rolled material 11, and the amount of pressure oil flowing into and out of the left and right hydraulic cylinders 9 and 10 is controlled by Ribo valves 13 and 14. Displacement detectors 15 and 16 are attached to the hydraulic cylinders 9 and 10 to control the movement of the pistons of the hydraulic cylinders 9 and 10, and the signals from the displacement detectors 15 and 16 are compared with the set signal. summing amplifiers 17 and 18 are provided. The left and right roll gaps are set by controlling the amount of pressure oil flowing into and out of the hydraulic cylinders 9 and 10 using servo valves 13 and 14, and fluctuations in the roll gap are controlled by the hydraulic cylinders 9 and 10.
Displacement detector 15.1 that detects the movement of 10 screws
6, and compare it with the setting signal using the summing amplifier 17.18. If there is a difference, the servo valve 13
．． The correction is made by controlling 14. Further, meandering amount detectors 19a and 19b are installed on the left and right sides of the inlet side of the downstream rolling mill 1b to detect the width end position of the rolled material 11 based on the light emitted by the rolled material 11, and the valley detectors 19a and 19b are installed.
The difference between the signals, that is, the meandering amount of the rolled material 11 is determined by the calculator 20, and the meandering amount and the target signal from the setting device 21 are compared and calculated by the comparator 22, and the obtained meandering amount deviation signal 24 is calculated. is processed by the meandering control regulator 23, and the selector switch 2
7 to be applied to the addition amplifiers 17 and 18 as left and right reduction correction signals 25°26. Regulator 23
For example, when the rolled material 11 moves toward the working side, the output is in the direction of tightening the roll gap on the working side and listening to the roll gap on the driving side, and when the rolled material 11 moves toward the driving side. In this case, contrary to the above, the direction is determined so that the roll gap is controlled, and the signals are added to the summing amplifiers 17 and 18.

A laser Doppler speed meter 28 for optically detecting the speed of the rolled material 11 is disposed between the upstream rolling mill 1a and the downstream rolling mill 1b. The signal and the plate resistance signal of the rolled material 11 detected by the upstream rolling mill 111a can be applied to the computing unit 29. The laser Doppler velocimeter 28 detects a frequency change in reflected light due to the Doppler effect via a probe, converts this change into a pulse train, and measures the speed by integrating the pulses. When the tail signal from the load detector 2 of the upstream rolling 11a is applied, the computing unit 29 determines the tail of the rolled material 11 based on the speed Vs of the rolled material 11 detected by the laser Doppler speed meter 28. The time t required for the end to pass through the meandering amount detectors 19a and 19b is calculated, and when the time elapses, a switch-off command signal can be given to the changeover switch 27.

In addition, 30 in the figure is an arithmetic unit 20. Meandering control device 31 equipped with a setting device 21, a comparator 22, and a meandering control regulator 23
is a reduction control device equipped with summing amplifiers 17 and 18 and servo valves 13 and 14.

With such a configuration, the rolled material 11 is rolled on the upstream side 11a.
In the case of normal rolling in which tension is acting on the rolled material 11 caught in both the downstream rolling mill 1b and the downstream rolling mill 1b, the addition amplifier 17.18 calculates the actual displacement of the piston of the hydraulic cylinder 9.10. The signal is compared with the reduction correction signal, and based on the difference signal, the servos 13 and 14 control the inflow and outflow amount of hydraulic pressure to the hydraulic cylinders 9 and 10. As a result, the left and right roll gaps are changed, and the above-mentioned This mechanism prevents the meandering from progressing any further, and the rolled material 11 is returned to the target value given by the setting device 21.

When the tail end of the rolled material 11 is pulled out from the upstream rolling mill 1a, the rolled material 11 on the entry side of the downstream rolling mill a1b is thereafter meandering controlled in a tension-free state. Also, when the tail end of the rolling mill 1,411 can be handled from the upstream rolling mill 1a, the load detector 2 gives a counter plate signal to the computing unit 29, and in the computing unit 29, the laser Doppler speed meter 28 Detected speed V of the rolled material 11
s and the distance from the upstream rolling mill 1a to the set position of the load detector 2, it is determined that the tail end of the rolled material 11 is the meandering amount detector of the upstream rolling mill 1a, the tail end of the upstream rolling mill 1a, and the meandering amount detector of the downstream rolling mill 1b. 19a,
19b, when the time ↑ elapses, a switch-off signal is output from the calculator 29, and the changeover switch 27 is turned off.
Meandering control ends. In this way, when the speed Vs of the rolled material 11 is determined by the laser Doppler speedometer 28 and the timing to turn off the meandering control is determined from this speed Vs, the tail end of the rolled material 11 detects the amount of meandering on the downstream side rolling 1a1b entry side. The timing of arrival at the devices 19a and 19b can be determined accurately.

In the embodiment of the present invention, a case has been described in which the target position of the rolled material is given by the setting device 21, but it is also possible to memorize the initial biting position of the rolled material 11 into the rolling mill and give it as the control target. Alternatively, it can be carried out by freely changing the setting so that the rolled material 11 passes through any position in the width direction of the rolled material, and when the temperature of the rolled material is high, the width end position is detected by the light emitted by the rolled material itself. However, if the temperature of the rolled material is low, it may be possible to provide a light source above or below the rolled material and detect the width end position based on the light from the light source, or otherwise depart from the gist of the present invention. Of course, various changes may be made within the scope.

[Effects of the Invention] According to the meandering control device of the present invention, it is possible to accurately determine the timing to turn off the meandering control of the rolled material, so the uncontrolled section at the tail end of the rolled material can be shortened, and the tail end of the rolled material can be After passing the meandering amount detector on the entrance side of the rolling mill, meandering control is not performed, and this has the excellent effect of avoiding various troubles that would occur if the meandering control is turned off too early or too late.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of one embodiment of the meandering control device of the present invention, Fig. 2 is a detailed explanatory diagram of the meandering control device of Fig. 1, and Fig. 3 is a case where the rolled material meanders toward one end of the roll. Explanatory diagram, 4th
The figure is a plan view of FIG. 3. In the figure, 1a is an upstream rolling mill, 1b is a downstream rolling mill, 2 is a load detector, 3 and 4 are work rolls, 9.10 is a hydraulic cylinder, 11 is a rolled material, 13.14 is a servo valve, 15. 1
6 is a displacement detector, 17.18 is an addition amplifier, and 19a. 19b is a meandering amount detector, 20 is a calculator, 21 is a setting device,
22 is a comparison calculator, 23 is a meandering control regulator, 24 is a meandering amount deviation signal, 27 is a changeover switch, 28 is a laser Doppler speedometer, 29 is a calculator, 30 is a meandering control device,
31 indicates a reduction control device.

Claims (1)

[Claims] 1) A detector installed on the working side and drive side of the rolling mill entry side to detect the position of the width end of the rolled material, a device that calculates the amount of meandering by calculating the difference between the output signals of the detector, and the device. It is equipped with a device that compares and calculates the output signal and the target position signal of the rolled material, and a device that determines and outputs a rolling correction signal for the working side and the driving side from the signal obtained by the device, and a device that calculates and outputs a rolling reduction correction signal for the working side and the driving side based on the rolling correction signal. In the meandering control device for changing the roll gap of the rolling mill, a laser Doppler speedometer detects the speed of the rolled material on the entry side of the rolling mill, and a meandering control device that detects the rolling material speed of the upstream rolling mill provided on the upstream side of the rolling mill. Based on the signal, the time it takes for the tail end of the rolled material to reach the detector that detects the position of the width end of the rolled material on the input side of the rolling mill is calculated from the upstream rolling mill to the rolling mill on the downstream side of the rolling mill. The meandering control device of the downstream rolling mill is determined by dividing the distance to the detector that detects the material width end position by the speed of the rolled material detected by the laser Doppler speedometer, and when the determined time has elapsed. A meandering control device comprising a device for giving a command to turn off meandering control to the meandering control device.