JPS55165209A - Controlling method for tension - Google Patents

Abstract

PURPOSE:To finely control the interstand tension, by operating the torque arm from the rolling torque, the rolling load, and the sheet thickness on the feeding side and the run-out side, and by obtaining the tension, in the tandem type hot rolling work, etc. CONSTITUTION:The rolling torque arithmetic unit 20 of the tandem mill, etc., operates the rolling torque. The torque arm arithemtic unit 30 operates the torque arm's reference value, receives the detected values of the sheet thickness, the roll gap and the rolling load, until the rolling stand 1 finished its rolling pass, operates their deviation values, and operates the fluctuation of the torque arm. The tension arithmetic unit 9 receives the outputs G1, G2 of the torque arithmetic unit 20, the detected values P1, P2 of the rolling load, and the outputs l1, l2 of the torque arm arithmetic unit 30, and decides the set point for the work roll's radius and the interstand tension. The deviation of this output of the tension arithmetic unit 9 from the aim tension value is operated and is input to the control/compensation unit 10 which then decides the correction value of the command for the motor speed. According to this method, the high accurate tension control can be performed without using the looper.