JPS54107857A - Controlling method for tension of tandem mill - Google Patents

Abstract

PURPOSE:To improve the quality of product, by obtaining the tension torque from the rolling load and the rolling torque ratio for the nontensile period and the rolling load and rolling torque for the rolling period, and by operating the quantity of correction of the roll speed from the tension torque obtained above, and then, by correcting the roll speed for making the tension to be zero. CONSTITUTION:The arithmetic controller 12 operates the no-load rolling torque soon after the material 13 is bitten into the horizontal mill 1, and at the same time, the load cell 10 measures the no-load rolling load. Next, after the material 13 is bitten into the edging mill 2, the rolling torque of the mill 1 is operated, and the quantity of correction of the speed is obtained and inputted to the controller 7 which then controls the speed of the mill 1 so as to make zero the tension T1. Moreover, the controller 12 measures the speeds of the mill 1 and the edging mill 2, and operates the ratio of these speeds. When the material is bitten into the mill 3, the tension of the mill 1 is controlled so as to be zero, and the speed of the edging mill 2 is corrected by the controllers 7, 8, keeping constant the ratio of speeds of the mill 1 and the edging mill 2; hereby, the tension is controlled at good accuracy and the quality of product is improved.