JPH0724511A - Method for controlling cross buckle in skin pass rolling - Google Patents

Abstract

PURPOSE:To exactly control the dimension of cross buckle of a strip to which skin pass rolling is applied so as to be equal to the target value. CONSTITUTION:With width measuring devices 20, 20 which are arranged on the inlet and outlet sides of the rolls 10 of the skin pass mill of the final stand, the width of a strip 12 is measured and the difference between both measured values (difference between widths before and after skin pass rolling) is determined. Data by which the relationship between the spreading amounts in the width direction (difference in width) at the time of skin pass rolling of the strip and the dimension of cross buckle in accordance with that is shown are preliminarily prepared, the response value of the spreading amount in the width direction in accordance with the target value of the dimension of cross buckle that is set about the strip 12 based on those data is determined and tension on the outlet side of the rolls or the rolling force of roll is adjusted so that the measured value of the difference in width is equal to this response value. In this way, the dimension of cross buckle generated on the strip 12 is equal to the set target value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for accurately controlling the size of a cross buckle of a temper-rolled strip.

[0002]

2. Description of the Related Art Generally, the size of the cross buckle of a temper-rolled strip is an important factor that influences the quality of the quality characteristics together with the plate shape (edge extension, belly extension) and plate surface roughness. It is necessary to manage it so that it falls within the standard. Therefore, the roll crown is controlled by the bender for the strip plate shape, and the roll reduction force of the final stand or each stand is used for the plate surface roughness, but the size of the cross buckle is controlled. As a method, the roll rolling force of the final stand or the roll exit side tension is adjusted.

The occurrence of strip buckling in temper rolling is caused by the buckling phenomenon caused by the roll restraining the spread of the strip in the strip width direction (spread width) of the roll bite. Are known. The size of the cross buckle means a crest value or a crest value / wave pitch obtained from a cross-sectional profile in the width direction when the strip is allowed to stand. To create this cross-sectional profile in the width direction, a method of reading the vertical displacement of the stylus when the stylus in contact with the plate surface is translated in the plate width direction is generally used. It is said that the size of the cross buckle cannot be measured during the rolling operation.

Therefore, in the conventional control of the size of the cross buckle by adjusting the roll reduction force or the tension on the roll exit side, the size of the cross buckle can be visually recognized from the appearance of the strip on the roll entrance / exit side during line operation. Therefore, the roll rolling force or the roll exit side tension is manually adjusted appropriately according to this.

[0005]

As in the conventional method, the size of the cross buckle of the strip is judged from the external appearance to adjust the roll exit side tension or the roll reduction force, so that the target size of the cross buckle is reduced. Since it is inevitable that the judgment will be incorrect, inaccurate control is likely to occur, and it is difficult to make adjustments that follow changes in the size of the crossbuckle during acceleration / deceleration of the stripline. Therefore, there is a problem that it is almost impossible to accurately control the size of the cross buckle.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a method capable of accurately controlling the size of a target cross buckle without depending on the appearance. .

[0007]

In order to achieve the above object, in the present invention, when the strip is temper-rolled, the amount of expansion of the strip in the plate-width direction and the cross buckle at the time of temper-rolling the strip. Based on the data indicating the correlation with the size of the strip, the response value of the spread amount in the strip width direction corresponding to the target value of the size of the cross buckle set for the strip is obtained, and the roll entry side of the temper rolling mill The roll exit side tension or roll reduction force is adjusted so that the difference between the strip strip widths actually measured on the roll exit side is equal to the spread amount in the strip width direction as the response value obtained from the correlation data. To adjust.

In the present invention, the above configuration is adopted because there is a certain correlation between the size of the cross buckle of the strip and the spread amount in the strip width direction (difference in strip width before and after temper rolling). This is due to the fact that we have come to discover something through the results of many experiments and investigations. FIG. 2 is a diagram illustrating the relationship between the size of the cross buckle of the strip and the spread amount in the plate width direction. The cross buckle size is also proportional to the spread amount in the plate width direction at a specific ratio. It shows that it will increase.

Experiments have shown that the spread amount of the strip in the plate width direction becomes larger as the roll-out tension becomes smaller as shown in FIG. 3 and becomes larger as the roll reduction force becomes larger as shown in FIG. Turned out by. In the present invention, for the strip to be temper rolled,
Data representing the correlation between the amount of spread in the strip width direction during temper rolling and the size of the corresponding cross buckle is created using the results of experiments conducted in advance under various operating conditions.

If a target value of the size of the cross buckle is set according to the operating condition of temper rolling, the response value of the spread amount in the strip width direction corresponding to this target value can be obtained from the data representing the correlation. Operating the temper rolling mill, the difference value of the strip width obtained by actually measuring the roll entrance side and the roll exit side of the rolled strip, the spread amount in the strip width direction obtained from the data representing the correlation. By comparing with the response value and adjusting the roll exit side tension or the roll reduction force according to the amount of the difference, the difference value of the plate width is controlled to be equal to the response value.

As a result, the size of the cross buckle of the temper-rolled strip matches the target value set at the beginning of rolling. Regarding the adjustment of the roll-out side tension or the roll reduction force, it is preferable to conduct an experiment in advance to create data showing the correlation with the spread amount of the strip in the plate width direction, and to use this data. ,
It is not always necessary to make adjustments based on this data.

[0012]

EXAMPLE FIG. 1 shows an example of equipment used in the present invention.
The figure shows a line in which multiple quadruple temper rolling mills are installed. Sheet width measuring devices 20, 20 are arranged along the pass line of the strip 12 on the inlet side and the outlet side of the roll 10 of the temper rolling mill of the final stand. These plate width measuring devices 2
0 and 20 are used to measure the strip width of the strip 12 during the line operation, and the difference between the strip width measurement values obtained by the strip width measuring devices 20 and 20 is calculated. The difference value of the strip width before and after the temper rolling is the measured value of the spread amount in the strip width direction.

On the other hand, data representing the correlation between the spread amount of the strip 12 to be rolled in the plate width direction and the size of the cross buckle is prepared in advance, and the target set for the size of the cross buckle is prepared from this data. The response value of the spread amount in the plate width direction corresponding to the value is obtained. Therefore, the roll exit side tension of the final stand or the roll rolling down force is adjusted by a known means so that the spread amount in the plate width direction becomes equal to the response value. In this way, when the measured value of the spread amount in the plate width direction becomes equal to the response value, the size of the cross buckle becomes the same as the set target value.

[0014]

As described above, according to the present invention, the spread amount in the strip width direction corresponding to the target value of the size of the cross buckle generated in the temper-rolled strip represents the correlation created in advance. Obtained from the data, so that the value becomes equal to the spread amount in the strip width direction measured during temper rolling,
Since the roll exit side tension or roll rolling force is adjusted, the size of the crossbuckle can be accurately adjusted to the set target value, and especially the size of the crossbuckle changes during strip line acceleration / deceleration. Even in this case, the control can follow this change.
It is possible to manufacture a strip with excellent quality in which the size of the cross buckle does not exceed a predetermined level over the entire length of the strip line.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an example of a temper rolling facility used in the method of the present invention.

FIG. 2 is a diagram showing a correlation between the spread amount of the temper-rolled strip in the plate width direction and the size of the cross buckle.

FIG. 3 is a diagram showing a correlation between a roll exit side tension of a temper rolling mill and a strip spread amount in a strip width direction.

FIG. 4 is a diagram showing the correlation between the roll rolling force of the temper rolling mill and the spread amount of the strip in the strip width direction.

[Explanation of symbols]

 10 rolls 12 strips 20 plate width measuring instrument

Claims (1)

[Claims] 1. When temper-rolling a strip, the strip is prepared in advance on the basis of data representing the correlation between the spread amount of the strip in the sheet width direction and the size of the cross buckle during temper rolling. About the strip width obtained by measuring the response value of the spread amount in the strip width direction corresponding to the target value of the size of the cross buckle set for, and measuring the strip width on the roll entrance side and the roll exit side of the temper rolling mill. Cross buckle control in temper rolling characterized in that the difference value adjusts the roll exit side tension or roll reduction force so that it becomes equal to the spread amount in the strip width direction as the response value obtained from the correlation data. Method.