WORKPIECE SPINDLE CONTROL UNIT AND CONTROL METHOD

摘要

A brake means (11) is provided for a workpiece spindle (17) capable of performing spindle control, connecting a workpiece spindle motor. In case of use of the brake means, the generation of position shear of a workpiece spindle owing to the unbalanced contact of brake means is prevented by changing clamp power before and after the contact with the workpiece spindle. After the clamping of the workpiece spindle, the servo controlling state of the workpiece spindle motor is kept and the overheat of the motor is prevented by limiting the torque of the workpiece spindle motor.