JP2663852B2 - Meandering control device in threading line - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a meandering control device used for a continuous sheet passing line such as an electrolytic cleaning line for steel sheets, a hot-dip plating line, and the like.

[0002]

2. Description of the Related Art In a continuous steel sheet passing line, it is indispensable to suppress meandering of the steel sheet for stable operation. For this purpose, a plurality of meandering correction machines are arranged along the threading line. Japanese Patent Application Laid-Open No. Hei 4-300009 discloses that each meandering correction machine is based on meandering amount information obtained from the plurality of meandering correction machines. A meandering control method for centrally controlling the control by a central controller is disclosed.

In this method, each meandering correction device basically detects a meandering amount at each arrangement point and controls each steering mechanism so that the meandering amount becomes a target value. Here, the target value is set to 0, that is, a so-called zero offset state where the plate center coincides with the line center, and is fixed. Then, when the meandering occurs in the meandering correction machine at the i-th stage, the central controller determines (i) based on the meandering amount information.
+1) A steering operation in a direction to suppress the meandering is instructed to the meandering correction machine at the first stage to improve the responsiveness of the meandering control. In addition, the meandering width is prevented.

[0004]

According to such a conventional meandering control method, the intended purpose is achieved when the steel sheet moves while maintaining the state of almost zero offset. However, abnormal conditions that cause large meandering, such as poor flatness of steel plate, base material factors such as camber, line tension / speed, levelness of rolls in the line, frictional force between the roll surface and the steel plate, and operational factors and equipment factors Due to the synergistic fluctuation, as shown in FIG.
If the meandering amount reaches the correction limit at 0 (i), the edge of the steel sheet eventually develops into a state called rollout, in which the steel sheet edge part is separated from the roll, and the sheet often breaks.

[0005] In other words, if the amount of operation for meandering correction becomes extremely large as compared with other arrangement points due to the synergistic effect of the meandering correction disturbance, and once the correction limit is reached, the above-described feed / feed operation is performed. In forward control, it is difficult to avoid rollout. This is because, when the meandering correction machine reaches the correction limit, there is no margin for the operation amount, so that the control responsiveness is extremely deteriorated, and in an extreme case, there is no control.

SUMMARY OF THE INVENTION An object of the present invention is to provide a meandering control device which can quickly correct the meandering even when a large meandering which reaches the correction limit of a specific meandering correcting machine occurs.

[0007]

SUMMARY OF THE INVENTION A meandering control device according to the present invention has a meandering amount detector for detecting a meandering amount of a plate, and a steering for controlling the meandering amount. A plurality of meandering correction machines having a mechanism, the meandering amount distribution in the line is determined from the meandering amount of each correcting machine arrangement point input from the plurality of meandering correcting machines, and the correcting machine arrangement point of the maximum meandering amount is specified. A central controller for shifting a control target value in another meandering correction machine in a direction to reduce the meandering amount.

[0008]

[Function] Even if a specific meandering correction machine reaches the correction limit,
By changing the control target value in another meandering correction machine and changing the meandering amount distribution in the line, meandering is eliminated without depending on the meandering correction machine reaching the correction limit.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a system diagram showing the configuration of an example of the meandering control device embodying the present invention, FIG. 3 is a distribution diagram of the meandering amount and roll displacement for explaining the operation, and FIG. FIG.

As shown in FIG. 2, the meandering control device includes a plurality of meandering correctors 20, 20... Arranged at predetermined intervals in the longitudinal direction of a continuous threading line of the steel plates 10, and these are centrally managed. And a central controller 30 for performing the operations. In the figure, the meandering correction machine is shown at the i-th stage and at the (i-1) -th stage.

Each meandering correction device 20 has a meandering amount detector 21 for detecting the meandering amount of the steel plate 10 and a steering roll 22 for correcting the meandering of the steel plate 10. The steering roll 22 is operated by a drive motor 23, and the operation amount is detected by an operation amount detector 24 using PLG.
Each output of the meandering amount detector 21 and the operation amount detector 24 is input to the control unit 25. The control unit 25 calculates the operation amount by comparing the meandering amount with the target value, and controls the drive motor 23 so that the operation amount matches the actual operation amount.

The central controller 30 receives the meandering amount and the operation amount of each correction machine arrangement point from each controller 25 as variables. Further, the line speed, the plate tension at each correction machine arrangement point, and the like are given as variables, and the distance between each correction machine arrangement point is given as a constant. Further, the allowable meandering amount and the allowable operation amount at each correction machine arrangement point are input in advance as data, and the meandering distribution calculating procedure and the meandering distribution changing procedure are input in advance as software processing programs. Then, an instruction is given to each control unit 25 according to the calculation result based on the processing process. The contents will be specifically described below.

Consider a case where the meandering amount exceeds an allowable range at a point i as shown by a broken line in FIG. In this case, in the meandering correction machine 20 at the point i, the steering roll 22 is operated to the limit in the direction to eliminate the meandering, and therefore, the roll displacement reaches the limit of the allowable range. Since there is no room for roll displacement, there is a danger of leading to rollout if left unattended.

In such a state, the central controller 30
As shown in FIG. 4, (i-1) confirms that there is a sufficient margin Δd for the roll displacement at the preceding point (i-1).
The control target value f (i-1) in the meandering correction device 20 at the point is shifted from zero offset in a direction in which meandering at the point i is eliminated. The shift amount of the control target value f (i-1) is set for a certain period of time until the surplus meandering amount ΔL at the point i becomes zero within a range where the margin Δd of the roll displacement at the point (i-1) does not become zero. Increase gradually in a cycle.

Thus, as shown by the solid line in FIG. 3, at the point i, the meandering amount is reduced to within an allowable range, and the operation becomes possible with a margin for the roll displacement. However, at the point (i-1), the meandering amount increases, and the margin for roll displacement decreases.
If this poses a problem, the same operation is performed at the preceding stage (i-2).

As described above, the central controller 30 controls each control unit 2
5 based on the information of the meandering amount and the operation amount obtained from
By actively shifting each target value, the meandering amount distribution is quickly converged within an allowable range without using the meandering corrector 20 at the i point that has reached the operation limit. As a result, the output saturation of the meandering corrector 20 at the point i is eliminated, and the responsiveness is quickly restored. Therefore, rollout is avoided.

FIG. 1B shows the above control in response to FIG. 1A. It can be seen that the no-control state is immediately canceled by changing the meandering amount distribution by shifting the target value. When the meandering amount distribution converges within the allowable range, the target value is returned to zero offset.

The shift of the target value is not limited to the constant value method.
The control of the meandering amount at the point (i-1) depending on the line speed or the like and propagation to the point i may be considered, or the shift amount may be changed according to the magnitude of the plate tension. Thus, it is possible to change the meandering amount distribution more smoothly and more stably.

In the above description, the center convergence of the meandering amount distribution has been described. However, the changing speed of the meandering amount distribution is set to be equal to or less than a fixed value, or the target of the meandering amount distribution is set and the meandering amount distribution is controlled to the target. Is also possible.

[0020]

SUMMARY OF THE INVENTION A meandering control apparatus for a threading line according to the present invention selects a meandering correction machine having a maximum operation amount.
By shifting the control target value in other meandering correction machines and dynamically changing the meandering amount distribution, the saturation of the control output in each meandering correction machine is eliminated, and by giving a large margin to the operation amount, the control gain is increased. Increase the size to improve responsiveness. Therefore, even when a large disturbance is received, it is possible to prevent rollout and plate breakage due to the rollout.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an outline of a control operation in the present invention.

FIG. 2 is a system diagram showing a configuration of an example of a meandering control device embodying the present invention.

FIG. 3 is a distribution diagram of a meandering amount and a roll displacement for explaining an operation.

FIG. 4 is a time chart showing a change over time in a meandering amount and a roll displacement.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Steel plate 20 Meandering correction machine 21 Meandering amount detector 22 Steering roll 23 Drive motor 24 Operation amount detector 25 Control part 30 Central controller

Claims (1)

(57) [Claims] 1. A wobble amount detector arranged along a passing plate line, each of which has a wobble amount detector for detecting a wobble amount of a plate,
A plurality of meandering correction machines having a steering mechanism for controlling the meandering amount; and a meandering amount distribution in the line is determined from a meandering amount at each correction machine arrangement point input from the plurality of meandering correction machines, thereby correcting the maximum meandering amount. A meandering control device for specifying a machine arrangement point and shifting a control target value of another meandering correction machine in a direction to reduce the meandering amount thereof.