Patent ID: 8049457

Claim:
A press machine controller for controlling a press machine having a servo motor to drive a slide via a reduction mechanism adapted to be changed in reduction ratio in accordance with a position of the slide, comprising: a command generator for generating at least one of a position command, a speed command and a torque command for the servo motor; a vibration command generator for generating a vibration command, which is enough to change a situation in which static friction works to a situation in which a dynamic friction works, based on a parameter preset for the press machine controller; a slide position detector for detecting the position of the slide; and a vibration command adding portion for adding the vibration command to any one of the position command, the speed command and the torque command for the servo motor in a case where the stopped slide position detected by the slide position detector is in a predetermined range including a bottom dead center of the slide, and wherein the torque, required for restarting the press machine after the slide stops at the bottom dead center thereof or in the vicinity of the bottom dead center, becomes small.