JP2662166B2 - Cross buckle control method in temper rolling - Google Patents

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 cross buckle size of a temper-rolled strip.

[0002]

2. Description of the Related Art In general, the size of a cross buckle of a temper-rolled strip is an important factor that affects the quality of a sheet as well as the shape of a sheet (elongation of an ear, elongation of a belly) and roughness of a sheet surface. Needs to be managed within the standard. For this reason, the roll crown is controlled by the bender with respect to the plate shape of the strip, and the plate surface roughness is controlled with the roll reduction force of the final stand or each stand, but the size of the cross buckle is controlled. As a method, the roll rolling force or the roll exit side tension of the final stand is adjusted.

[0003] The cross buckle of the strip in the temper rolling is caused by the buckling phenomenon caused by the roll constraining the spread of the strip in the roll width in the strip width (the spread of the strip). Are known. The size of the cross buckle means a crest value or a crest value / wave pitch determined 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 width direction of the plate is generally used. It is said that the size of the cross buckle cannot be measured during the rolling operation.

For this reason, conventionally, the control of the cross buckle size by adjusting the roll rolling force or the roll output side tension is performed by visually observing the size of the cross buckle from the appearance of the strip at the roll entrance side during the line operation. Thus, the roll reduction force or the roll exit side tension is adjusted by manually adjusting the roll reduction force or the roll exit side tension appropriately.

[0005]

As in the prior art, in the method of judging the size of the cross buckle of the strip by the appearance and adjusting the roll exit side tension or the roll reduction force, the cross buckle of the target cross buckle size is not determined. It is unavoidable that an error occurs in the judgment, so that it is easy to perform inaccurate control. Further, it is difficult to adjust the change in the size of the cross buckle during the acceleration and deceleration of the strip line, so that it is difficult to perform the control over the entire length of the strip line. Therefore, there is a problem that it is almost impossible to accurately control the size of the cross buckle.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide a method capable of accurately controlling a target cross buckle size without depending on the appearance. .

[0007]

In order to achieve the above object, according to the present invention, when the strip is temper-rolled, the amount of spread in the sheet width direction and the cross buckle during the temper rolling of the strip prepared beforehand are described. Based on the data representing the correlation with the size of, the response value of the amount of spread in the sheet width direction corresponding to the target value of the size of the cross buckle set for the strip, and the roll entrance side of the temper rolling mill The roll exit side tension or roll rolling force is set so that the difference value of the strip width of the strip obtained by actual measurement on the roll exit side is equal to the spread amount in the sheet width direction as a response value obtained from the correlation data. Is 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 amount of spread in the strip width direction (difference in strip width before and after temper rolling). This is due to the fact that the results of many experiments and investigations led to the discovery of this fact. FIG. 2 is a diagram showing the relationship between the size of the cross buckle of the strip and the spread amount in the plate width direction. The size of the cross buckle is also increased at a specific ratio in proportion to the increase of the spread amount in the plate width direction. It is increasing.

Further, it is experimentally shown that the spread amount of the strip in the sheet width direction increases as the roll-out side tension decreases as shown in FIG. 3 and increases as the roll rolling force increases as shown in FIG. Turned out by. In the present invention, for the strip to be temper rolled,
Using the results of experiments previously performed under various operating conditions, data representing the correlation between the spread amount in the sheet width direction during temper rolling and the corresponding cross buckle size is created.

If a target value of the magnitude of the cross buckle is set according to the operating conditions of the temper rolling, a response value of the spread amount in the sheet width direction corresponding to the target value is obtained from the data representing the correlation. Operating the temper rolling mill, the difference value of the sheet width obtained by actually measuring the roll entrance side and the roll exit side of the rolled strip, the spread amount in the sheet width direction obtained from the data representing the correlation. This is compared with the response value, and the roll exit side tension or the roll rolling force is adjusted according to the amount of the difference to control the difference value of the sheet width 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 exit side tension or the roll reduction force, it is preferable to conduct an experiment in advance to create data indicating a correlation with the amount of spread of the strip in the sheet width direction, and to perform the adjustment using this data. ,
It is not necessary to make adjustments based on this data.

[0012]

FIG. 1 shows an example of equipment used in the present invention.
This shows a line where a plurality of quadruple temper rolling mills are installed. Strip width measuring devices 20 and 20 are arranged along the pass line of the strip 12 on the entrance side and the exit side of the roll 10 of the temper rolling mill of the final stand. These width measuring instruments 2
The strip width of the strip 12 during the line operation is measured using 0 and 20, and the difference between the measured values of the strip width obtained by the two strip width measuring devices 20 and 20 is calculated. The difference value of the sheet width before and after the temper rolling is the actually measured value of the spread amount in the sheet width direction.

On the other hand, data indicating the correlation between the amount of spread of the strip 12 to be rolled in the sheet width direction and the size of the cross buckle is prepared in advance, and a 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 or the roll rolling force of the final stand is adjusted by a known means so that the spread amount in the plate width direction becomes equal to the response value. Thus, 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 sheet width direction corresponding to the target value of the magnitude of the cross buckle generated in the temper-rolled strip represents a correlation created in advance. Determined from the data, so that the value is equal to the amount of spread in the sheet width direction measured during temper rolling,
Since the roll-out side tension or the roll reduction force is adjusted, the size of the cross buckle can be accurately adjusted to the set target value, and the size of the cross buckle changes particularly when the strip line is accelerated or decelerated. Even in such cases, control can follow this change,
It is possible to manufacture a strip having excellent quality without a cross buckle size exceeding a predetermined level over the entire length of the strip line.

[Brief description of the drawings]

FIG. 1 is a schematic view 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 a spread width of a temper-rolled strip in a sheet width direction and a size of a cross buckle.

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

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

[Explanation of symbols]

 10 Roll 12 Strip 20 Sheet width measuring instrument

Claims (1)

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