JPH11254017A - Method for controlling hydraulic rolling reduction in temper rolling mill and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To execute the hydraulic rolling reduction control in a temper rolling mill, with which a suitable rolling load can be obtd., by aiming a position of rolling reduction obtd. from a rolling load setting value at the time which a welded point passes the rolls, and executing the positional control of rolling reduction even at the time which the welded point passes the rolls. SOLUTION: When the welded point of the steel plate passes the rolls in the temper rolling mill, based on a difference ΔPa between the actual rolling load Pa just before the welded point passes the rolls in the temper rolling mill, and a rolling load setting value Pw at the time of executing the passing treatment of the welded point, a changing quantity ΔSa at the position of rolling reduction is calculated. The position S of rolling reduction is changed by the changing quantity ΔSa just before the welded point passes the rolls in the temper rolling mill to roll the welded point. Just after the welding point passes the rolls in the temper rolling mill, based on a difference ΔPb between the actual rolling load setting value Pw thereat and a rolling load setting value Pb after the welded point passes the rolls in the temper rolling mill, a changing quantity ΔSb at the position of rolling reduction, is calculated. Just after the welded point passes the rolls in the temper rolling mill, the position S of rolling reduction is changed by the changing quantity ΔSb to execute the temper rolling.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for controlling a hydraulic reduction of a temper rolling mill in which the reduction of a roll is controlled by a hydraulic reduction apparatus. The present invention relates to a hydraulic pressure reduction control method and apparatus for a temper rolling mill, in which a reduction position can be changed and an appropriate rolling load can be obtained even when the reduction is performed.

[0002]

2. Description of the Related Art In cold rolling, a temper rolling mill (also referred to as a skin pass mill) for improving the mechanical properties of a coil after annealing, and at the same time, improving the shape and surface finishing such as dull and bright. In order to give a target elongation rate to the steel sheet, as shown in FIG. 3, the rotation speeds of the tension rolls 20 and the deflector rolls 22 installed before and after the temper rolling mill 10 are measured, and based on the measured values, The tension is controlled so that the calculated elongation becomes a predetermined value.
This is generally called elongation rate control. When the elongation rate control is being performed, the tension position is controlled by setting the rolling position S of the hydraulic cylinder 14 of the hydraulic rolling-down device 12 to a constant value. I have. In the drawing, reference numeral 16 denotes a load cell for detecting a rolling load P, and reference numeral 18 denotes a load cell change amount ΔS ′ to be input to the hydraulic pressing device 12 according to the rolling load P detected by the load cell 16. It is an arithmetic unit.

[0003] The steel sheet 8 is joined by welding. Therefore, in order to prevent roll flaws caused by the welded portion, conventionally, the rolling load at the welding point is reduced to a predetermined rolling load from a rolling position set to a predetermined rolling load of the material. Then, after passing through the welding point, it was set to the rolling position as the set rolling load of the next material.

For example, JP-A-6-190422 discloses a temper rolling method in which a singular point or a narrow lap seam welding point reduces the line speed to a mill passing speed just before passing through a temper rolling mill. After reaching the mill passing speed, the line speed is maintained, and the elongation rate control is switched to the constant load control. After the singular point or the narrow lap seam welding point passes through the temper rolling mill, the rolling load or tension is increased. Describes a method of operating at least one of them, switching to elongation control after reaching the target range, and accelerating from the mill passing speed.

FIG. 4 shows an example of the configuration of a computing unit 18 for performing such conventional switching control. In FIG.
18A is a subtractor for calculating the difference ΔP between the set rolling load Pm at the welding point and the actual rolling load P detected by the load cell 16, and 18B is a converter for calculating the rolling position change amount ΔS ′ from the difference ΔP. , 18C is an adder for obtaining the sum of the rolling position change amount and the acceleration / deceleration compensation amount, and 18D outputs the output of the adder 18C as the rolling position change amount ΔS ′ in a steady state to perform the rolling position control. During the welding point passage processing, the switch is a switch for outputting the output of the converter 18B as the rolling-down position change amount ΔS 'to perform load control.

In such a conventional example, since the command value S of the rolling-down position is calculated by the hydraulic rolling-down device 12, the computing unit 18 calculates the position change amount ΔS or the load change amount, respectively. 12 and the hydraulic pressure reduction device 12
Controls the rolling position S of the hydraulic cylinder 14.
Also, the amount of position change due to manual intervention is directly
2 is input. In the hydraulic pressure reduction control, the reduction position change amount ΔS ′ obtained by the arithmetic unit 18 is output to the hydraulic reduction device 12, and the hydraulic reduction device 12 changes the actual reduction position S of the hydraulic cylinder 14 to the hydraulic reduction position. This is done by changing the quantity ΔS ′. When the reduction position change amount ΔS ′ is zero, the hydraulic reduction device 12 holds the actual reduction position S of the hydraulic cylinder 14.

Further, the hydraulic cylinder 14 is controlled by the switch 18D.
And the load control during the welding point passing process is switched.

[0008]

As described above, during the conventional welding point passage processing, the load control for controlling the position of the hydraulic cylinder 14 so that the rolling load P detected by the load cell 16 becomes the set load Pm. Has been done. Therefore, the change of the rolling position performed by acceleration / deceleration during the welding point passage processing to obtain the target surface roughness and elongation of the steel sheet is not performed during the welding point passage processing. Not only cannot be exhibited, but also the problem that the rolling load of the next material greatly differs from the set rolling load. That is, even if it is necessary to change the rolling position by acceleration / deceleration, as shown in FIGS. 5 and 6, for example, as shown in FIGS. Even if the rolling load is returned to the same value after passing through the welding point, the rolling load of the next material is greatly different from the predetermined value.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems. The rolling position can be changed by acceleration / deceleration even during welding point passing processing, and the rolling load of the next material can be reduced. It is an object to prevent deviation from the set rolling load.

[0010]

SUMMARY OF THE INVENTION The present invention relates to a temper rolling mill in which roll reduction is controlled by a hydraulic reduction device.
The present invention has solved the above-described problem by setting a target rolling position obtained from a rolling load set value at the time of passing a welding point, thereby performing a rolling position control also at the time of passing a welding point.

Further, when passing through the welding point, the rolling position controlled by the hydraulic pressure reduction device is changed from the rolling position before passing through the welding point to the rolling position when passing through the welding point, and after passing through the welding point, passing through the welding point. This is to change to the later rolling down position.

Further, the amount of change in the rolling position is determined from the difference between the actual rolling load before the change in the rolling position, the set value of the rolling load after the change in the rolling position, and the mill constant.

[0013] Further, a reduction position compensation amount by acceleration / deceleration is added to the reduction position.

According to the present invention, there is also provided a hydraulic pressure reduction control device for a temper rolling mill provided with a hydraulic pressure reduction device for controlling the reduction of a roll. The above-mentioned problem has been solved by providing a means for inputting the sum of the rolling position compensation amounts according to the above.

[0015]

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

In this embodiment, in the temper rolling mill 10 as shown in FIG.
In passing, as shown in FIG. 1, the actual rolling load Pa immediately before the welding point passes through the temper rolling mill,
When passing through the welding point

[Outside 1] The change amount ΔSa of the rolling position is calculated based on the difference ΔPa, and the rolling position S is changed by the change amount ΔSa just before the welding point passes through the temper rolling mill 10 to roll the welding point. Immediately after the welding point has passed through the temper rolling mill 10, the actual rolling load set value Pw at that time and after the welding point has passed through the temper rolling mill 10.

[Outside 2] The change amount ΔSb of the rolling position is calculated on the basis of the difference ΔPb from the pressure reduction position, and the rolling position S is changed by the change amount ΔSb immediately after the welding point has passed through the temper rolling mill 10 to perform the temper rolling. I do.

That is, in the present invention, before and after the welding point where the elongation rate is controlled, and during the passage processing of the welding point,
The position of the hydraulic cylinder 14 is constantly controlled, and the configuration of the arithmetic unit 18 in the present embodiment is an extremely simple configuration including only an adder 18C without using a switch as shown in FIG.

In the present embodiment, the arithmetic unit 18
The position change amount ΔS is calculated and output to the hydraulic pressure reduction device 12, and the hydraulic pressure reduction device 12 adjusts the pressure reduction position S of the hydraulic cylinder 14.
Is controlled. The rolling position compensation by acceleration / deceleration is performed by adding in the adder 18C. Further, the amount of position change due to maintenance is directly input to the hydraulic pressure reduction device 12.

The difference ΔPa of the rolling load and the change amount ΔSa of the rolling position are as follows, where Sa is the rolling position before passing through the welding point.
It can be calculated by the following equation.

[0020]

(Equation 1)

ΔSa = ΔPa / M (2) where M is a mill constant.

The rolling load difference ΔPb and the rolling position change amount ΔSb can be obtained by the following equations.

[0023]

(Equation 2)

ΔSb = ΔPb / M (4)

As described above, in the pass-through processing of the temper rolling mill 10, the actual rolling load Pa
And during welding point passage processing

[Outside 3] Is calculated by equation (1), and the value ΔP
From the a and the mill constant M, the rolling position change amount ΔSa is calculated by equation (2). Also, when the load returns, the actual rolling load P
w and after passing the welding point

[Outside 4] From the formula (3), the load change amount ΔPb is calculated, and
Since the reduction position change amount ΔSb is calculated by the equation (4), the hydraulic pressure reduction may remain in the position control mode even during the welding point passing process. Therefore, even when the rolling position change ΔSx due to acceleration or deceleration occurs during the welding point passage processing, (5)
Since the roll-down position control may be performed based on the result of adding the roll-down position change amount ΔS by the formula, an appropriate load can be obtained as a result.

ΔS ′ = ΔS + ΔSx (5)

[0027]

[Embodiment] When the actual rolling load Pa before welding point passing is 800 tons and the rolling load set value Pw at welding point passing processing is 100 tons, the load change amount ΔPa is 700 tons according to the equation (1). Assuming that the mill constant M = 380 tons / mm,
From the equation (2), the amount of change ΔSa of the rolling-down position is 1.842 mm.

On the other hand, at the time of load return, if the actual rolling load P during the welding point passing process is 100 tons and the return load set value Ps after the welding point passing process is 600 tons, the load change amount ΔP
b is -500 tons, and the roll-down position change amount ΔSb is -1.316 mm from the equation (4).

Here, assuming that the rolling-down position correction control by acceleration / deceleration has been performed, if the line accelerates before the welding point passing process is completed, if the position change amount ΔSx due to acceleration / deceleration is −0.5 mm, From equation (5), by correcting the final position change amount ΔS ′ to −0.186 mm, a target load can always be obtained by position control, and acceleration / deceleration can be compensated.

[0030]

According to the present invention, the rolling position control is always performed even when the welding point is passed, so that the rolling position can be changed by acceleration / deceleration even during the welding point passing process. It is possible to match the rolling load of the material with the set rolling load.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a processing procedure according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a calculator for calculating a rolling position change amount used in the embodiment.

FIG. 3 is a configuration diagram showing an overall configuration of a temper rolling mill to which the present invention is applied;

FIG. 4 is a block diagram showing a configuration of a conventional arithmetic unit used in the temper rolling mill.

FIG. 5 is a diagram illustrating an example of a change in a rolling position and a rolling load before and after passing through a welding point, for explaining a conventional problem.

FIG. 6 is an enlarged view of a part VI in FIG. 5;

[Explanation of symbols]

 8 ... Steel plate 10 ... Temper rolling mill 12 ... Hydraulic rolling down device 14 ... Hydraulic cylinder S ... Rolling down position 16 ... Load cell P ... Rolling load 18 ... Computing unit 18C ... Adder [Delta] S '... Rolling down position change amount

Claims (5)

[Claims] In a temper rolling mill in which roll reduction is controlled by a hydraulic reduction device, a reduction position determined from a rolling load set value at the time of passing a welding point is set as a target, so that the reduction position is maintained even when the welding point is passed. A method for controlling a hydraulic pressure reduction of a temper rolling mill, comprising performing control. 2. The hydraulic pressure reduction control method for a temper rolling mill according to claim 1, wherein, when the welding point is passed, the rolling position controlled by the hydraulic pressure reduction device is changed from the rolling position before passing the welding point to the welding point. A hydraulic pressure reduction control method for a temper rolling mill, comprising: changing to a reduction position at the time of passing, and changing to a reduction position after passing the welding point after passing the welding point. 3. The method of controlling a hydraulic pressure reduction of a temper rolling mill according to claim 2, wherein the amount of change in the reduction position is determined by a difference between an actual rolling load before the reduction position is changed and a set value of the rolling load after the reduction position is changed. A hydraulic pressure reduction control method for a temper rolling mill, which is obtained from a mill constant. 4. The hydraulic rolling reduction method for a temper rolling mill according to claim 2, wherein a reduction position compensation amount by acceleration / deceleration is added to said rolling position. Control method. 5. A hydraulic pressure reduction control device for a temper rolling mill provided with a hydraulic pressure reduction device for controlling the reduction of a roll. A hydraulic pressure reduction control device for a temper rolling mill, comprising means for inputting the sum of the amounts.