MOTOR SPEED CONTROL DEVICE FOR ROLLING MILL

摘要

The purpose of the present invention is to provide a motor speed control device for a rolling mill, said motor speed control device being capable of directly controlling the speed of a rolling roll and thereby improving the precision of speed control. The motor speed control device is for a rolling mill that is provided with a rolling roll that rolls a metal material, a roll rotation shaft that is directly connected to the rolling roll, a motor rotation shaft that transmits power to the roll rotation shaft, and a motor that drives the motor rotation shaft. The motor speed control device is provided with: a non-contact speed sensor that is arranged at a position that is near the rolling roll with a gap between the circumferential surface of the roll rotation shaft and said non-contact speed sensor, and that detects a roll rotation shaft angular velocity that is the angular velocity of the roll rotation shaft; and a speed controller that controls the speed of the motor on the basis of a comparison value for an actual value and a target angular velocity for the roll rotation shaft so that the actual value matches the target angular velocity of the roll rotation shaft. The actual value is the angular velocity of the roll rotation shaft that is fed back to the speed controller.