Drive control apparatus for electric injection molding machine

Abstract

A drive control apparatus is provided for an electric injection molding machine, in which a screw is used to inject melted resin into a cavity of a metal mold. Herein, the screw is driven to move in a desired direction by using first and second servo motors, which are connected together using a belt, for example. In the drive control apparatus, a motion controller produces a drive control signal to control operation of the screw. A master servo amplifier inputs the drive control signal to control the first servo motor, wherein a position of a rotor of the first servo motor is detected and is used as a feedback value. The master servo amplifier further produces a torque instruction signal representing a ratio against rated output of the first servo motor by which the first servo motor is to be driven. For example, frequency of the torque instruction represents rotation speed of the motor, while amplitude represents magnitude of torque. A slave servo amplifier controls the second servo motor based on the torque instruction signal. The motion controller is capable of producing a synchronizing signal, which is delivered to the master and slave servo amplifiers so that the first and second servo motors are driven in a synchronized manner.

Dependencies are inferred from the claim text.