JPS6117318A - Method and device for controllng meandering of rolling material - Google Patents

Abstract

PURPOSE:To enable the meandering control upto the rear end of a rolling material by controlling with the difference in the right and left rolling loads after the rolling material passing through a meandering detector in the controlling method with direct detection of the meandering quantity by a meadering detector of the inside of a rolling mill. CONSTITUTION:A rolling load detector 25, 26, load calculator 27, counter 28, relays 29-31 are provided as shown in the figure. The control prior to the rear end of the rolling material 9 passing through a meandering detector 17 is as before. In the cace of the control thereof the relay 29 is turned on and the relays 30, 31 are off. When the rear end of the rolling material 9 is passed through the detector 17, the signal thereof is transmitted to the relays 29-31 and the relay 29 is turned off and the relays 30, 31 are on. The rolling loads of the right and left detected by detectors 25, 26 are then calculated by a calculator 27 and the signal of the differential load is multiplied by an adeqate constant with a counter 28 and outputted to servo valves 11, 12 as a command signal via adders 15, 16. The oil quantity passing the valves 11, 12 is then adjusted and the pistons of hydraulic cylinders 7, 8 are acted in the direction reducing the meandering quantity of the rolling material 9.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to a hollow strip mill, a skin pass mill,
The present invention relates to a meandering control method and device for rolled material that can be applied to all rolling mills where meandering of rolled material is a problem, such as plate mills.

First, looking at the meandering mechanism of a rolled material, when rolling a rolled material in a rolling mill, factors required of the rolled material itself such as hardness difference in the width direction of the material, taper in the width direction, etc., and the center of the rolled material Due to operational factors such as the roll entering the roll off center, an imbalance occurs in the rolling loads applied to the working side and the driving side of the rolling mill, resulting in a roll gap between the working side and the driving side. There will be a difference.

For this reason, the drawing speed of the material at the entrance side of the rolling mill is faster on the side where the gap is enlarged.

As a result, the rolled material is rolled in the advancing direction (
The rolled material 9 tilts as if swinging its tail toward the wide gap side with respect to the arrow direction), and the inclined rolled material 9 advances perpendicularly to the axes of the work rolls 1 and 2, so the rolled material 9 widens the roll gap. Lateral slip occurs in the direction of
As shown in the figure. As described above, once the rolled material meanderes, it is no longer possible to restore it to a stable state.

As mentioned above, when a difference occurs in the roll gap between the work side and the drive side (hereinafter referred to as left and right) of the rolling mill, the rolled material begins to meander, so in order to prevent meandering, it is necessary to It can be seen that control should be performed to narrow the roll gap of 0. From this idea, one way to prevent meandering of rolled material is
The applicant of the present application proposed a method as shown in Japanese Patent Application No. 58-65109. To explain this using Figure 3,
Upper and lower work rolls 1°2, upper and lower backup rolls 314, lower backup roll chocks 5 and 6 supporting both shaft ends of the upper and lower (7) backup rolls 6.4;
In a hydraulic rolling mill 10 equipped with hydraulic cylinders 7.8 that apply rolling blades to each of the lower back-up roll chocks 5 and 6 to roll a rolled material 9, inflow and outflow to the left and right hydraulic cylinders 7.8 Servo valve 1
1. Displacement detector 1 that detects the movement of the piston of the hydraulic cylinder 7°8 while controlling the Q according to 1.12.
3.14 is attached to the hydraulic cylinder 7.8 and is provided with an adder 15.16 for comparing the signal from the displacement detector 13.14 with the set signal. The left and right roll gaps are set by controlling the amount of pressure oil flowing into and out of the hydraulic cylinder 7.8 by the servo valve 11.12,
The variation in the roll gap ° is measured indirectly by a displacement detector 13.14 which detects the movement of the pistons of the hydraulic cylinders 7, 8 and is compared with the ° setting signal by an adder 15.16. The correction is made by controlling the servo valves 11 and 12 based on the difference between the two. Further, a meandering detector 17 for the rolled material 9 is installed on the entrance side of the rolling mill 10,
The signal from the meandering detector 17 is compared with the output of a target value setting circuit composed of a memory circuit 18 and a relay 19 in an adder 20.The meandering amount deviation signal 22 obtained by the comparison is used for meandering control adjustment. The signal is processed by the device 21 and taken out as left and right reduction correction signals 23 and 24, which are added to the addition m15°1. 1 With the above configuration, the signal from the meandering detector 17 is compared with the output of the target value setting circuit by the adder 2°, and if there is a meandering amount deviation, 1 the deviation signal 22 is sent to the meandering control regulator 21. It will be processed and added to the adders 15, 116 of the reduction control system as reduction correction signals 23, 2.4.
1. When the relay 19 is turned off at an appropriate timing at the beginning of rolling, the value at that moment is given to the memory circuit 18, and its output is sent to the adder 20 as the target value for meandering control.
added to.

When the rolled material 9 meanderes, the amount of deviation is detected by a meandering detector 17 and compared with a target value by an adder 20, and as a result, a meandering amount deviation signal 22 is generated. This signal 2'2 is processed in a meander control regulator 21.

This regulator 21 may, for example, use a simple amplifier circuit, ie a proportional gain circuit, or may use a proportional and differential circuit or a proportional, differential and integral circuit, and the meander detector 17 It should be used appropriately depending on the setting position and the type of rolling disturbance. The output of the regulator 2'1 is added to the adder 15.16 of the reduction control system as left and right reduction correction signals 25.24. A rolling correction signal is applied in the direction of tightening the roll gap and opening the roll gap on the drive side, and when the rolling section 9 moves toward the drive side, the roll gap is controlled in the opposite manner to the above. A direction is determined and a roll correction signal is applied.

Therefore, in the adder 15.16, a comparison is made between the actual displacement signal of the piston of the hydraulic cylinder 7.8 and the reduction correction signal, and the difference signal causes the servo valve 11.12 to adjust the displacement signal to the hydraulic cylinder 7.8. The inflow and outflow amounts of pressure oil are 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 given in the memory circuit 18.

[Problem that the invention seeks to solve]

In the above-mentioned method, the amount of meandering is directly detected by the meandering detector 17 to perform control, so it has an excellent feature of being able to perform stable and highly accurate meandering control. The distance from the meandering detector 17 to the work roll of the rolling mill is approximately 15 to 2.0 m at most, and in practical terms, even if no control is applied during this period, Although no particular problem arises, it is undesirable to have such uncontrolled portions in order to achieve even better meandering control.

In view of the above-mentioned viewpoint, the present invention has been made with the object of making it possible to perform meandering control up to the rear end of a rolled material.

[Means for solving problems]

The present invention provides a meandering detector for detecting the amount of deviation of a rolled material installed on the entry side of a rolling mill, a device for comparing and calculating a signal of the amount of deviation detected by the meandering detector with a target value, and the comparison calculation. A device that processes signals obtained by the device and outputs them as rolling reduction correction signals on the working side and the driving side, a load detector that detects rolling loads on the working side and the driving side of the rolled material, respectively, and the load detector A device is installed in the circuit that calculates the difference in rolling load detected by the sensor, processes the signal of the load difference, and outputs it as a reduction correction signal, and the circuit to which the signal from the meandering detector is sent. A switching circuit is provided with a relay that is kept on while the load detector is in use, and a relay that is installed in the circuit to which the signal from the load detector is sent and is turned on when the rolled material passes through the meandering detector.

[For production]

Therefore, in the present invention, the amount of deviation of the rolled material on the entry side of the rolling machine is directly detected before passing through the meandering detector, and the rolling devices on the work side and the drive side are controlled according to this amount. After the roll gap on the driving side is changed and the rear end of the rolled material passes through the meandering detector, the difference in rolling load between the working side and the driving side of the rolled material is determined, and the difference between the rolling loads on the working side and the driving side is determined according to the load difference. The roll gap on the drive side is changed.

〔Example〕

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

FIG. 4 shows an embodiment of the present invention. In the figure, 25 and 26 are charge detectors such as load cells for detecting the rolling load, 27 is both load detection, and the difference between the rolling loads detected by the output devices 25 and 26. 28 is an adder 15 for calculating the difference in rolling load.
．． 16 is a coefficient multiplier for multiplying the lateral rigidity of the rolling mill by an appropriate constant in order to set the lateral rigidity to an arbitrarily selected value. 29, 50. 31 is a relay, and the reference numerals shown in FIG. The same symbol indicates the same thing.

Note that the lateral rigidity refers to the ease with which the parallelism of the upper and lower rolls can be maintained when there is a difference in the change in rolling force applied to the working side and the driving side of the rolls (see, for example, Japanese Patent Application No. 48-47487).
0 Next, to explain the operation of the present invention, the control before the rear end of the rolled material 9 passes through the meandering detection N17 is the same as the control explained in FIG. 3. Note that during this control, the relay 29 is on and the relays 30 and 31 are off.

When the rear end of the rolled material 9 passes through the meander detector 17, the signal is sent to the relay 29.50.31, which turns off the relay 29 and turns on the relay 30.31. Then, the left and right rolling loads detected by the load detectors 25 and 26 are sent to the load difference calculator 27, and the load difference calculator 27
The signal of the load difference calculated in . Servo valve 11 after '16.
A command signal (-) is output to servo valve 11 and 12.
The piston of the hydraulic cylinder 7.8 operates in a direction that reduces the amount of meandering of the rolled material 9 by adjusting the amount of oil passing through the hydraulic cylinder 7.8. For example, in FIG. 4, if the rolling load detected by the load detector 25 is larger than the rolling load detected by the load detector 26, the rolled material 9 is shifted toward the load detector 25, so the hydraulic The piston of the cylinder 7 moves up, the piston of the hydraulic cylinder 8 moves down, and the work roll 1. ? The left and right gaps are controlled to be equal, and as a result, the rolled material 9 is prevented from meandering after passing through the meandering detector 17.

The present invention has been described above and an example of application to a four-high rolling mill has been shown, but the present invention can be applied to all types of rolling mills where meandering is a problem, and the control circuit uses a computer instead of hardware. It may also be possible to configure the system using software, and within the scope of the invention, such as 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 signals from both sides, without departing from the gist of the present invention. Of course, various changes can be made within the scope.

〔Effect of the invention〕

In the meandering control method and device for a rolled material of the present invention, if the rolled material has not passed through the meandering detector, the amount of deviation of the rolled material on the entrance side of the rolling mill is directly detected, and the deviation between the left and right sides is determined according to the detected amount. The roll gap is controlled to change, and after the rolled material passes through the meandering detector, the left and right roll gaps are controlled according to the rolling load difference detected by the left and right load detectors, so the meandering of the rolled material is controlled. As a result, 1. The camber of the rolled material is reduced, which improves the product yield 9. Accidents caused by meandering of the rolled material can be prevented, improving the operating rate. Since it becomes possible to roll a strip with fewer crowns, various excellent effects can be achieved, such as improving the yield.

[Brief explanation of drawings]

Figure 1 is a plan view showing the inclination of the rolled material when there is a difference between the left and right roll gaps, Figure 2 is a vertical cross-sectional view along the roll axis in Figure 1, and Figure 3 is a control method proposed so far. FIG. 4 is a diagram showing an embodiment of the present invention. In the figure, 1 and 2 are upper and lower work rolls, 7 and 8 are hydraulic cylinders, 9 is a rolled material, 11.12 is a servo valve, 13.14 is a displacement detector, 1.5.16 is an adder 117 is a meandering detector ,
18 is a memory circuit, 20 is an adder, 21 is a meandering control regulator, 29.30.31 is a relay, 25°26 is a load detector, 27 is a load calculator, 28 is a coefficient unit, 29.30.31
indicates a relay.

Claims (1)

[Claims] 1) Before the rear end of the rolled material passes through the meandering detector, the amount of deviation of the rolled material on the entry side of the rolling mill is directly detected, and the rolling devices on the work side and drive side are controlled according to this amount. Then, the roll gap between the working side and the driving side is changed, and after the rear end of the rolled material passes through the meandering detector, the difference in rolling load between the working side and the driving side of the rolled material is determined, and the roll gap is changed according to the load difference. A method for controlling meandering of a rolled material, characterized in that the roll gap on the working side and the driving side is changed by controlling the rolling down device. 2) A meandering detector installed on the entrance side of the rolling mill to detect the amount of deviation of the rolled material, a device that compares and calculates the signal of the amount of deviation detected by the meandering detector with a target value, and the comparison calculation device. A device that processes the obtained signal and outputs it as a reduction correction signal on the working side and the driving side, a load detector that detects the rolling load on the working side and the driving side of the rolled material, respectively, and a load detector that detects the rolling load on the working side and the driving side, respectively, and A device that calculates the difference in rolling load, processes the signal of the load difference, and outputs it as a reduction correction signal, and a device that outputs a reduction correction signal based on the load difference when the rolled material passes through a meandering detector. A meandering control device for rolled material, characterized in that it is provided with a switching device.