JP2005040800A - Tension control method for looper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tension control method for a looper by which the tension of the looper can be constantly maintained even when a looper car is moved to the longer end side or moved to the shorter end side. <P>SOLUTION: The looper 14 is adjacently arranged to processing equipment 12 which continuously processes a steel strip S. A drive motor 20 reciprocates the looper car 16, which is provided to the looper 14. When the tension of the processing line is controlled by applying a tension control current to the drive motor 20, the tension control current is changed when the looper car 16 is moved to the longer end side and when moved to the shorter end side. As a result, the tension of the looper can be substantially equally maintained. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
[Technical field to which the invention belongs]
The present invention relates to a looper tension control method, and more particularly to a looper tension control method that is suitable for maintaining a constant tension regardless of the movement direction of the looper car.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in a continuous processing line that performs a predetermined process such as pickling while transporting a belt-like body, for example, a steel strip, a horizontal looper is disposed adjacent to the processing equipment. In such a looper, as shown in the image of the relationship between the fixed roll and the looper car in FIG. 4, the looper car equipped with the moving roll is moved to the long end side (in the direction away from the fixed roll) that lengthens the loop of the steel strip S. By adjusting the length for storing the steel strip S by adjusting the length for storing the steel strip S, or by moving the loop to the short end side to shorten the loop, the speed difference generated on the entrance side and the exit side of the looper is absorbed, The steel strip is secured at a constant speed in the processing equipment.
[0003]
In the continuous processing line, the tension control for holding the steel strip S passing through the processing equipment at a constant tension by the looper is performed by a drive motor for moving the looper car forward and backward to the long end side and the short end side. Yes.
[0004]
Thus, when tension control is performed by the drive motor of the looper car, since various mechanical losses such as frictional resistance exist in the processing equipment, the motor is controlled with the looper tension set value being constant. Then, the tension will fluctuate.
[0005]
Therefore, paying attention to the fact that the mechanical loss is often a function of the line speed, a mechanical loss is added and compensated according to the line speed in the tension controller of the looper car drive motor (for example, , See Patent Document 1).
[0006]
[Patent Document 1]
Japanese Patent Laid-Open No. 2-160116
[Problems to be solved by the invention]
However, since the resistance is large when the looper car moves to the long end side, the motor needs to output larger power than usual, and conversely, when the looper car moves to the short end side, the resistance is small, so a small power is sufficient. Nevertheless, the conventional looper tension control method disclosed in Patent Document 1 and the like has a problem that the tension fluctuates depending on the moving direction of the looper car because the motor power is constant.
[0008]
The present invention has been made to solve the above-mentioned conventional problems. A looper capable of maintaining a constant looper tension regardless of whether the looper car is moved to the long end side or the short end side. It is an object to provide a tension control method.
[0009]
[Means for Solving the Problems]
The present invention controls the tension of a processing line by applying a tension control current to a drive motor for moving a looper car provided in the looper forward and backward by a looper disposed adjacent to a processing facility for continuously processing a strip. In the looper tension control method, the above-described problem is solved by changing the tension control current between when the looper car is moved to the long end side and when it is moved to the short end side.
[0010]
That is, in the present invention, since the tension control current is changed according to the moving direction of the looper car, the short end side which requires less than the case where the looper car is moved to the long end side requiring a large power. It is possible to change the direction of movement to a smaller appropriate value, and thus it is possible to control to substantially the same tension when moving in any direction.
[0011]
In this case, in the present invention, the tension control current is changed to a value at which the tension is substantially the same when the looper car is moved to the long end side and when it is moved to the short end side. You may make it do.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0013]
FIG. 1 shows a continuous processing line to which a tension control method according to an embodiment of the present invention is applied.
[0014]
In this continuous processing line, the steel strip (strip-shaped body) S transported from the upstream is carried into the processing equipment 12 via the bridle roll 10, and after carrying out a predetermined process such as washing, It is continuously conveyed to the next process (not shown) via the horizontal looper 14 disposed adjacent to the processing facility 12.
[0015]
This horizontal looper 14 is provided with a looper car 16, and the looper car 16 winds and unwinds the wire 18 </ b> A by the wire winding drum 18, and pays out the long end side for storing the steel strip S. It is moved forward and backward to the short end side.
[0016]
The wire take-up drum 18 that pulls the looper car 16 is rotationally controlled by a drive motor 20 that is driven by a control current output from a current controller (control device) 22. The current command 24 for setting the tension is input to the current controller 22 so that the tension is maintained at the tension.
[0017]
In the present embodiment, the tension control current command (value) 24 input to the current controller 22 is changed depending on whether the looper car 16 is moved to the long end side or the short end side. Thus, the tension control current applied to the drive motor 20 is changed.
[0018]
FIG. 2 shows an outline of the horizontal looper tension control logic applied to this embodiment.
[0019]
As shown in this figure, a compensation value based on a speed command 32 that is a command value of a line speed (operation speed) is added to a predetermined tension setting value 30 set according to the plate size or the like, and the current In order to generate a tension control signal corresponding to the command 24, there are two cases: a case where the looper car 16 is moved to the long end side (direction) (A) and a case where the looper car 16 is moved to the opposite short end side (direction) (B). A compensation circuit is provided, and the current command value for tension control output to the current controller 22 is changed by switching between the compensation circuits (A) and (B) according to the moving direction.
[0020]
In each of the compensation circuits of (A) the long end side and (B) the short end side, after applying a bias (adjustment term) to the value obtained by multiplying the speed command by the gain, it is based on the value for correcting the mechanical loss due to the speed change. Calculated with mechanical loss correction. Note that (A) the long end side and (B) the short end side have opposite rotation directions of the motor sheaves and differ in mechanical loss value (resistance coefficient).
[0021]
Thus, in the present embodiment, the current command value for tension control for the drive motor 20 is changed depending on whether the looper car is moved to the long end side or the short end side. By setting an appropriate relationship, the power of the drive motor 20 can be set and controlled so that the tension is constant.
[0022]
Setting the current command value in an appropriate relationship in this manner means that the resistance coefficient (mechanical loss) of the drive motor 20, the power of the drive motor 20 that is normally in a constant state, the tension according to the moving direction of the looper car 16. This is equivalent to appropriately changing so as to be constant. By the way, when the current command value is converted into a resistance coefficient and the long end side is 1.0 and the short end side is 0.85, the long end side is 4500 kg and the short end side is A measured tension of 4500 kg was obtained, and the tension in the looper could be made substantially the same in both directions.
[0023]
On the other hand, FIG. 3 shows a conventional tension control logic. In the same manner as in FIG. 2, the current value is generated by adding the compensation value to the tension setting value. Does not consider the direction. Therefore, the measured value of the looper internal tension was about 4300 kg when moved to the long end side, and about 4800 kg when moved to the short end side, and there was a difference of about 500 kg.
[0024]
When the time-dependent change in the looper tension actually measured in the present embodiment and the conventional case is compared, the illustration is omitted, but in the case of the present invention, there was a difference in both directions, whereas in the case of the present invention, there was almost no difference. There was no difference.
[0025]
According to the present embodiment described in detail above, the power of the drive motor 20 is set to be constant for each moving direction of the looper car 16, so that the tension that has been different according to the moving direction in the past is made constant. Since it became possible to manage the tension in the looper appropriately, it became possible to stabilize the quality of the steel strip S.
[0026]
In the above description, the example of changing the setting of the power of the drive motor 20 by switching the current command value for tension control with respect to the current controller 22 according to the moving direction is shown, but the present invention is not limited thereto. You may make it control tension by putting a resistance coefficient in an actual control program.
[0027]
【The invention's effect】
As described above, according to the present invention, the looper internal tension can be controlled to be constant regardless of whether the looper car is moved to the long end side or the short end side.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a main part of a continuous processing line to which a tension control method according to an embodiment of the present invention is applied. FIG. 2 is a block diagram illustrating tension control logic according to the embodiment. Block diagram showing tension control logic [Fig. 4] Explanatory diagram showing looper car moving direction [Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Bridle roll 12 ... Processing equipment 14 ... Looper 16 ... Looper car 18 ... Wire winding drum 20 ... Drive motor 22 ... Current controller 24 ... Current command

Claims (2)

Looper tension control for controlling the tension of a processing line by applying a tension control current to a drive motor for moving the looper car provided in the looper forward and backward by a looper disposed adjacent to a processing facility for continuously processing a belt-like body In the method
A looper tension control method, wherein the tension control current is changed between when the looper car is moved to the long end side and when it is moved to the short end side. The tension control current is set and changed to a value at which the tension is substantially the same between when the looper car is moved to the long end side and when it is moved to the short end side. The looper tension control method described.

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