Method and apparatus for rolling a strip
AssigneeSumitomo Metal Industries, Ltd.
InventorsShinichiro Hiramatsu, Ryuji Hamada
Life of this patent
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Abstract
A method and apparatus for rolling a strip by a rolling mill wherein one back-up roll of the pair of back-up rolls is a variable crown roll having a single oil chamber and the other back-up roll is a variable crown roll having a plurality of oil chambers. The strip shape is detected by a shape meter and approximated by a power function which includes terms of the first, second, fourth, and sixth powers of a distance measured from the center in the width direction and then precisely controlled by a calculation and control unit based on the obtained power function.
Claims12
A method for rolling a strip by means of a rolling mill having a pair of work rolls and a pair of back-up rolls for supporting the work rolls, wherein one back-up roll of the pair of back-up rolls is a variable crown roll having a single oil chamber, and the other back-up roll is a variable crown roll having a plurality of oil chambers;
- which method comprises:
- detecting a strip shape in the width direction;
- approximating the detected strip shape by a power function which includes terms of second and fourth powers of a distance measured from the center of the width;
- adjusting the term of second power by controlling the roll crown of the variable crown roll having a single oil chamber so as to match a target value;
- and
- adjusting the term of fourth power by controlling the roll crown of the variable crown roll having a plurality of oil chambers so as to match a target value.
An apparatus for rolling a strip, which apparatus comprises a rolling mill, a shape meter, and a calculation and control unit, wherein
- the rolling mill comprises a pair of work rolls;
- a pair of back-up rolls for supporting the work rolls;
- left and right pressing-down balancers;
- roll benders;
- and roll coolants;
- one back-up roll of the pair of back-up rolls is a variable crown roll having a single oil chamber and the other back-up roll is a variable crown roll having a plurality of oil chambers;
- the shape meter is disposed at the entrance or exit of the rolling mill to detect a strip shape in the width direction;
- the calculation and control unit approximates the strip shape detected by the shape meter by a power function which includes terms of first, second, fourth, and sixth powers of a distance measured from the center of the width;
- the calculation and control unit calculates the control amount of the pressing-down amount of the left and right pressing-down balancers so as to match a target value of the term of the first power;
- the control amount of the roll crown of the variable crown roll having a single oil chamber so as to match a target value of the term of the second power;
- the control amount of the roll crown of the variable crown roll having a plurality of oil chambers so as to match a target value of the term of the fourth power;
- the control amount of the roll bending force of the roll benders so as to match a target value of the term of sixth power;
- and
- the control amount of the roll coolants so as to obtain an elongation corresponding to the difference between the strip shape detected by the shape meter and a target shape which is approximated by the power function.
Dependencies are inferred from the claim text.