KR20030055363A - Apparatus and method for controlling synchronizing line speed of rolls with different diameter by fraying - Google Patents

Abstract

PURPOSE: An apparatus and a method for synchronization controlling realtime speed of rolls with different diameter by abrasion during rolling are provided to reduce deviation of quality such as strength in thickness direction by realtime compensating speed difference generated using current value of driving motor for upper and lower rolls. CONSTITUTION: In an apparatus for synchronization controlling realtime speed of rolls with different diameter by abrasion during rolling comprising first and second motors(1,2) for driving upper and lower rolling rolls, speed indication part(10) for indicating reference rolling speed, first and second speed control parts(4,5) for feedback controlling rotation speed of the first and second motors so that the first and second motors are rotated to the reference speed of the speed indication part, and load cell(3) for detecting rolling force applied to the second motor, the apparatus further comprises a comparison part(21) for detecting current deviation(23) of power voltage impressed to the first and second motors in the first and second speed control parts respectively; and a speed compensation processing part(20) for calculating linear speed compensation from current difference by receiving current deviation of the comparison part, rolling force of the load cell and speed detection values of the first and second motors and for correcting the reference speed of the second motor outputted from the speed indication part by which linear speeds of the upper and lower rolling rolls correspond to each other.

Description

Apparatus and method for real-time speed synchronous control of rolls with different diameters due to wear during rolling {APPARATUS AND METHOD FOR CONTROLLING SYNCHRONIZING LINE SPEED OF ROLLS WITH DIFFERENT DIAMETER BY FRAYING}

The present invention relates to a rolling line for producing hot rolled coils, cold rolled coils, thick plate products, etc., by rolling by two rolling rolls in hot rolling or cold rolling, and more particularly in contact with abrasion by rolling force during rolling. When the diameter difference occurs between two rolling rolls in real time, the upper and lower linear velocity is matched in real time to equalize the upper and lower elongation of the rolled product and to control the tip shape flat. An apparatus and method for real-time speed synchronization control.

In the rolling mill, when a difference occurs in the linear velocity of the up and down rolling rolls, the tip of the rolled material is lifted or bent downward, causing equipment damage or changing the physical properties of the tip, resulting in poor quality. In addition, the difference in the linear velocity of the upper and lower rolls during rolling may cause thickness variation in the thickness direction due to the difference in the upper and lower elongation of the rolled product.

Therefore, it is very important to synchronize the linear velocity of the upper and lower rolling rolls. In the conventional rolling speed control, if only the diameter of the initial roll is given, after measuring the radius R1 of the upper roll and the radius R2 of the lower roll by actual measurement, Only the initial compensation of the roll speed deviation due to the radius difference was performed as in Equation 1 below.

In the above, ΔR = R1-R2, V1 is the upper roll linear speed, V2 is the lower roll linear speed, RPM is the revolutions per minute.

However, during the rolling operation, as shown in FIG. 3, wear occurs in the rolling roll by the continuous rolling operation. In this case, the roll wear occurs because the upper and lower rolls are not equally worn in proportion to the initial rolls, and thus a linear speed difference occurs between the upper and lower rolls.

In order to compensate for the linear velocity change due to the roll wear during rolling, once the rolling roll is stopped and the rolling roll is drawn out to the rolling line, the radius of each part of the roll is measured, averaged, and the speed deviation is calculated accordingly. Should be carried out.

Therefore, in the related art, it was impossible to compensate the difference in the linear velocity of the upper and lower rolls by properly compensating in real time the wear progress of the rolling rolls generated by the accumulation of the rolling work.

The present invention has been made to solve the above problems, the purpose of which is to compensate for the speed difference generated by using the current value of the up and down roll driving motor measured in real time without measuring the roll diameter during rolling, the difference in vertical elongation It is to provide a real-time speed synchronous control device and method for a roll having a different diameter due to wear during rolling, which can reduce the quality deviation of the thickness direction strength and the like.

1 is a block diagram showing a conventional rolling speed control apparatus in a rolling line.

2 is a block diagram showing a speed synchronization control device according to the present invention.

3 is a view showing the wear phenomenon of the rolling rolls.

Figure 4 is a graph showing the change in the current value of the motor for driving the up and down rolling roll at no load.

5 is a graph showing a change state of the motor drive current when the speed deviation occurs due to the rolling roll wear during rolling.

Figure 6 is a flow chart showing a real-time speed synchronization control method for compensating for the speed deviation according to the wear of the rolling roll according to the present invention.

7 is a graph showing a change in motor current when the speed deviation caused by roll wear is compensated for according to the present invention.

* Description of the symbols for the main parts of the drawings *

1,2: 1st, 2nd motor 3: load cell

4,5: 1st, 2nd speed controller 6,7: 1st, 2nd current controller

8,9: first and second voltage control unit 10: speed indicating unit

20: speed compensation processing unit 21: comparison unit

22: switching unit 23: current deviation

24: switching control signal

As a technical means for achieving the above object of the present invention, the apparatus according to the present invention is the first and second motors for driving the upper and lower rolling rolls, the speed indicating portion for indicating the reference rolling speed, and the reference speed of the speed indicating portion The first and second speed control unit for feedback control of the rotational speed of the first and second motors so as to rotate with the motor and the load cell for detecting the rolling load on the second motor, the real-time of the rolls of different diameters due to abrasion during rolling In the speed synchronization control device,

A comparator for detecting a current deviation of a power supply voltage applied from the first and second speed controllers to the first and second motors, respectively;

In the speed indicating section to calculate the linear speed compensation amount from the current difference by receiving the current deviation of the comparison unit, the rolling load of the load cell, the speed detection values of the first and second motors, and the linear velocity of the upper and lower rolling rolls to match. Characterized in that the speed compensation processing unit for correcting the reference speed of the output second motor.

Then, the first and second motors for driving the upper and lower rolling rolls according to the present invention, the speed indicating unit for indicating the reference rolling speed, and the feedback speed control of the rotational speed of the first and second motors to rotate at the reference speed of the speed indicating unit In the real-time speed synchronization control method of a roll having a different diameter due to abrasion during rolling of a rolling equipment including a load cell for detecting a rolling load applied to the first and second speed control unit and the second motor,

A) measuring the current of the first and second motors under no load;

B) setting a maximum value among the current values of the first and second motors measured in the no-load state as a dead zone current value (Idead);

C) measuring currents Ia and Ib and speeds TG1 and TG2 of the first and second motors while applying a reduction force; And

D) calculating the linear speed compensation amount of the upper and lower rolls according to the deviation DV1 of the current measurement values of the first and second motors measured in step c).

Hereinafter, the apparatus and method for real-time speed synchronization of rolls having different diameters due to wear during rolling according to the present invention will be described in detail with reference to the accompanying drawings.

2 shows a rolling speed control device to which a speed synchronous control device according to the present invention is applied, the first and second motors 1 and 2 driving upper and lower rolling rolls respectively, and the second motor for driving the lower rolling rolls ( 2) first and second speed controllers 4 and 5 which control the rotation of the load cell 3 to detect the rolling load attached to 2) and the actual speed of the first and second motors 1 and 2 to rotate at a reference speed. ), First and second current controllers 6 for controlling a power supply voltage so that a set current is applied to the first and second motors 1, and power supply voltages set to the first and second motors 1 and 2, respectively. A voltage control unit (8, 9) for applying a speed, a speed indicating unit (10) for outputting the target speed values (Vbot, Vtop) of the upper and lower rolling rolls according to the rolling schedule, and the first and second motors (1, 2) Calculates the linear speed difference of the upper and lower rolling rolls from the current difference of and calculates the speed indication value Vbot of the second motor 2 output from the speed indicating part 10 to compensate for the linear speed difference. A processing unit 20, a comparing unit 21 for detecting a difference between current values applied from the first and second speed control units 4 and 5 to the first and second motors 1 and 2, and the comparing unit ( And a switching unit 22 for transmitting the output of 21 to the speed compensation processing unit 20.

6 is a flowchart showing the rolling speed control method to which the speed synchronous control device according to the present invention is applied in accordance with the processing procedure, and the operation of the device will be described with reference to the flowchart of FIG. 6.

First, a compensation instruction is given by turning on the switching unit 22.

The current value of the first and second motors 1 and 2 under no load is measured. At this time, a current value of less than 1% to 2% of a rating, which is a load lost by mechanical friction of the first and second motors 1 and 2, is detected. The graph of Figure 4 shows the change in the motor current value during no-load operation in the stationary state.

In the next step, the dead zone current value Idead is measured by applying 1 to 5 times the current value at no load (S602).

The DEAD ZONE current value Idead is selected as the maximum value of the upper roll current value Itop-idle at no load and the lower roll current value Ibot-idle at no load.

Here, Itop-idle is 1 to 5 times the current value of the first motor (1) at no load (IDLE), and Ibot-idle is 1 to 5 times the current value of the second motor (2) at no load (IDLE) Say

As described above, the reason for setting the dead zone current value is that a slight hunting occurs in the current as shown in FIG. 4 due to mechanical error or current deviation during operation. It is to exclude from. When the large zone current difference is smaller than this value, a load difference due to other mechanical factors besides the difference in roll radius is applied, and convergence is slowed when hunting occurs.

In addition, if the large zone current value is larger than this value, the roll wear compensation is reduced, causing the linear velocity difference.

At this time, the speed of the up and down rolling roll may use any of the maximum speed from the minimum speed of the general rolling, but applying the average speed can minimize the mechanical deviation and the like.

After measuring the dead zone current value, while measuring the reduction force of the rolling roll through the load cell (S603), the reduction force was increased to apply 60 to 110% of the average reduction force in general rolling, and then the first and second The current value of the motors 1 and 2 is measured (S604).

This measures the current ia of the first motor 1 and the current ib of the second motor 2 controlled by the first and second speed controllers 4 and 5, and the comparator 21 measures the deviation of the measured current. Calculate and transfer to the speed compensation processing unit 20. In this step, when the reduction of the reduction force is reflected less the speed difference due to roll wear, excessive application of the reduction force may cause a burden on the installation.

DV1 = Ia -ib

In the above equation, Ia is the current measurement value of the first motor 1, Ib is the current measurement value of the second motor 2, DV1 is the first and second motors (1, It is difference of measured value of current of 2).

As described above, when the current of the first and second motors 1 and 2 is measured, the rotational speed of the upper and lower rolling rolls is also measured. This speed measurement uses a pulse generator or a tachometer attached to the first and second motors (1, 2). At this time, the speed (rpm) of the upper roll is called TG1, the speed (rpm) of the lower roll is called TG2, and the roll speed compensation amount is calculated from the measured value, wherein the current deviation DV1 is the dead zone current value. If greater than (Idead) (that is, when DV1> 0), the speed compensation amount Delv of the lower roll is calculated as in Equation 3 below (S606).

Delv = TG2 / (ΔR _max × 100)

TG2 '= TG2 -delv

In Equation 3, ΔR _max is the wear expected maximum value, TG2 'is the lower roll speed after compensation.

In the opposite case, the current deviation DV1 is re-measured and the compensation amount is recalculated by Equation 3 above if DV1> Idead, and the compensation is completed if DV1 <Idead. Finally, re-measure the up and down roll speed and apply the same compensation value to the other speed.

That is, the final wear compensation speed value delvend is expressed by Equation 4 below.

delvend = (TG2'-TG2) / TG1

TG2 '= TG2 + (delvend × TG2)

That is, when Dv1 <0, the speed is compensated for the lower roll by delv as shown in Equation 5 below.

Delv = TG2 / (ΔR _max × 100)

TG2 '= TG2 + delv

In other words, if the absolute value of the current deviation DV1 is> Measured by re-measuring DV1, the compensation value is recompensated by Equation 5, and if the absolute value dv1 <idead, the calculated compensation amount is lowered as shown in Equation 4 above. Apply to the speed of the roll and complete the reward. Finally, re-measure the up and down roll speed and apply the same compensation value to the other speed. That is, the final compensation speed ratio delvend is expressed by Equation 4 above.

As shown in FIG. 7, when the upper speed is faster, the upper current value increases and the lower current value develops current in the opposite direction, and the speed compensation is performed so that the current is consumed in the same direction. .

According to the present invention as described above by minimizing the up and down front end of the rolled material in the roll with abrasion during hot rolling or cold rolling in real time to prevent the equipment accident and to reduce the up and down elongation during rolling By doing the same, it is effective to minimize the material deviation in the thickness direction.

Claims (5)

First and second motors for driving the upper and lower rolling rolls, a speed indicating unit for indicating a reference rolling speed, and a first and second speed control unit for controlling the rotational speeds of the first and second motors so as to rotate at the reference speed of the speed indicating unit. In the real-time speed synchronization control device of a roll having a different diameter due to abrasion during rolling of the rolling equipment including a load cell for detecting a rolling load applied to the second motor, A comparator for detecting a current deviation of a power supply voltage applied from the first and second speed controllers to the first and second motors, respectively; In the speed indicating section to calculate the linear speed compensation amount from the current difference by receiving the current deviation of the comparison unit, the rolling load of the load cell, the speed detection values of the first and second motors, and the linear velocity of the upper and lower rolling rolls to match. Real-time speed synchronization control device for a roll having a different diameter due to abrasion during rolling, characterized in that the speed compensation processing unit for correcting the reference speed of the output second motor. First and second motors for driving the upper and lower rolling rolls, a speed indicating unit for indicating a reference rolling speed, and a first and second speed control unit for controlling the rotational speeds of the first and second motors so as to rotate at the reference speed of the speed indicating unit. In the real-time speed synchronous control method of a roll having a different diameter due to abrasion during rolling of a rolling equipment including a load cell for detecting a rolling load applied to the second motor, A) measuring the current of the first and second motors under no load; B) setting a maximum value among the current values of the first and second motors measured in the no-load state as a dead zone current value (Idead); C) measuring currents Ia and Ib and speeds TG1 and TG2 of the first and second motors while applying a reduction force; And D) calculating the linear speed compensation amount of the upper and lower rolls according to the deviation DV1 of the current measurement values of the first and second motors measured in step c) above; Real-time speed synchronous control method. The method of claim 2, wherein the steps a) and b) The dead zone current value is set to a high current value after applying 1 to 5 times the measured current value in order to exclude the current value lost by mechanical friction of the motor, real-time speed synchronization of rolls having different diameters due to wear during rolling Control method. The method of claim 2, wherein the step c) While measuring the rolling force of the upper and lower rolling rolls with a load cell, the current reduction force of the first and second motors controlled by the first and second speed controllers is increased by applying 60 to 110% of the average reduction force in general rolling by increasing the reduction force. And Ib and measuring the speeds (TG1, TG2) of the upper and lower rolls by the first and second motors. The method of claim 2, wherein d) The wear compensation Delv is calculated by Delv = TG2 / (deltaRmax x 100), When the current deviation DV1 is greater than the large zone current value Idead, After compensation, adjust the lower roll speed (TG2 ') by calculating TG2' = TG2 -Delv, Then, if the current deviation DV1 is less than the large zone current value, After compensation, adjust the lower roll speed (TG2 ') by calculating TG2' = TG2 + Delv, If the current deviation (DV1) is equal to the large zone current value by repeating the above process, Finally, the wear compensation (delvend) is delvend = (TG2 '-TG2) / TG1, and the lower roll indicating speed (TG2') is TG2 '= TG2 + (delvend × TG2) to compensate the line speed according to roll wear. Real-time speed synchronous control method for a roll having a different diameter due to wear during rolling.