METHOD FOR CONTROLLING ROLL COOLANT IN PLATE ROLLING MILL AND MANUFACTURE OF MATERIAL FOR ELECTRONIC AND ELECTRIC EQUIPMENT USING THIS CONTROL METHOD

PROBLEM TO BE SOLVED: To correct the shape deviation of a rolled stock with high accuracy and to manufacture products excellent in flat shape by executing ON-OFF control of a coolant combining the max. specified OFF-time and the max. specified ON-time. SOLUTION: In the case that the variation of the detected value of shape deviation, for example, is over the prescribed value between t1 -t10 and between t20 -t30 and less than a prescribed value between t10 -t20 , in the range where is over the prescribed value that is desired continuance of stopping coolant from the viewpoint of shape control, the ON-OFF control of the coolant is executed by combining the max. OFF-time of 2.5sec and the max. ON-time of 10sec. This ON-OFF period is set in accordance with the shape data detected with a shape detector, the coolant is jetted to work rolls and the period is selected from among stepwise preset ON-OFF patterns. In this way, the rapid change of the roll diameter caused by sudden change of coolant amount is prevented and interference with other control system is prevented.