CONTROLLING MEHTOD FOR TENSION

摘要

PURPOSE:To correct the motor speed according to the deviation of the actual tension from the target vaule of tension, and to high accurately control the tension, by operating the torque arm of each stand, by obtaining the actual tension from this torque arm, the rolling torque and the rolling load, and by obtaining the deviation of the actual tension from the target value. CONSTITUTION:The arithmetic units 30 of the first and second stands operate the reference values for the torque arms befroe and after feeding the rolled material 1 into the second stand. At the same time, the arithmetic units 30 store as the reference values, the feed-in side sheet thicknesses H1, h1, the roll gaps S1, S2, detected by the roll gap measuring devices 6, and the rolling loads P1, P2, detected by the load cells 5; and the arithmetic units 30 operate the torque arm lengths by substituting the deviations of the detected values from the reference values into the arithmetic formula. Next, the tension arithmetic unit 9 operates the interstand tension from the rolling torques G1, G2, operated by the torque arithmetic units 20 of the first and second stands, the rolling loads P1, P2, detected by the load cells 5, the torque arm lengths opreated by the arithmetic units 30, and the set values of roll radii; then, according to the deviation of thus operated interstand tension from the target value, the correction value for the speed command given to the motor is decided. Or otherwise, if the correction value for the rolling reduction is decided, the same effect can be attained.