JPS57154306A - Speed compensating device of rolling mill - Google Patents

Abstract

PURPOSE:To provide a speed compensating device of a rolling mill capable of avoiding the generation of compressive force, by constituting a titled device which controls the torque of a motor so as to follow up the change of a loading torque of the mill when biting a rolling material. CONSTITUTION:When a rolling material 1 is bitten by a rolling mill 3, a switch 22 closes, and an output DELTAX2 of an operating circuit 21 is inputted to a conversion circuit 23 to add an output DELTAVREF=DELTAX2/G1 of the circuit 23 to a speed standard VREF. Accordingly, an output X2 of a speed controlling circuit 11 changes by DELTAX2, and an output X2 of a current controlling circuit 12 changes rapidly responding to the change DELTAX2 when the input X2 changes by DELTAX2, because the response of the circuit 12 is rapid enough. As the output X2 of the circuit 12 corresponds to an armature current of a motor 5, the armature current of the motor 5 changes rapidly responding to the load change simultaneously with a biting of the material 1 by the mill 3. That is, when the mill bites the material 1, the driving torque of the motor changes rapidly following up the load variation at the same time, thus the ideal impact-drop compensation is performed.