Patent ID: 7824164

Claim:
A controller for injection molding machine for controlling each operation process in a molding cycle by variably controlling a rotation speed of a driving motor in a hydraulic pump, comprising: a screw position sensor for detecting a screw position of the injection device; at least one or more injection pressure sensors for detecting an injection pressure on the basis of an operation of an injection cylinder of said injection device; a speed feedback control system for feedback control of a speed on the basis of a speed detected value obtained by converting a position detected value obtained from the screw position sensor at least in an injection process; a pressure feedback control system for feedback control of a pressure on the basis of a pressure detected value obtained from said injection pressure sensor at least at the injection process; and a switching control function portion for carrying out switching from a speed control region to a pressure control region when a pressure deviation between a preset pressure set value and said pressure detected value becomes a preset switching determination value or less and carrying out the switching to said pressure control region after control of a speed command value in said speed control region by a predetermined control pattern.