MODIFIED INJECTION MOLDING MACHINE

摘要

PURPOSE:To make an injection quantity of molten resin into a cavity of a mold constant, by a method wherein the most retreated position of a screw is preset and speed change control at the time of actual injection process is performed by adding a difference between the foregoing preset most reatreated position and a detected value of a screw position directly before an injection process to a preset value of each of speed change positions. CONSTITUTION:The most retreated position of a screw is preset by a presetting device 7 and the screw is made to suspend by making the screw perform backward movement such as a turning or suck back of the same up to a preset screw position by instructions from a sequencer 12. A position of the screw directly before an injection process of the next molding cycle is detected by a screw position detecting device 4 and a deviation between the foregoing value and the value preset by the presetting device 7 of the most retreated position of the screw is computed by an arithmetic unit 8 of the deviation. A deviation value is added respectively to values of screw positions preset by a group 9 of injection process control changeover position presetting devices by an adding device 10 and stored by a corrective injection process control changeover position memory 11. An injection rate is controlled by this stored value.