Patent ID: 6682332
Filing Date: 2004-01-27
Classification: B29C

Abstract:
An injection molding apparatus comprising:means for injecting fluid molding material into a die; and a control system for controlling the means for injecting, the control system including: a programmable logic controller for generating control signals; and a closed loop servo control circuit responsive to the control signals for implementing an integral only control mode for controlling in real time a velocity of the injecting means during injection of fluid molding material into the die under velocity only feedback control or a proportional only control mode for controlling in real time the pressure the injecting means applies to the fluid molding material in the die under pressure only feedback control during an injection cycle wherein, during a first part of the injection cycle the servo control circuit operates in the only control mode and during a second part of the injection cycle, that is contiguous with the first part of the injection cycle, the servo control circuit operates in the only control mode.