SPEED CONTROL SYSTEM FOR INJECTION PLUNGER IN INJECTION MOLDING MACHINE

摘要

PURPOSE:To obtain an injection molded product of prominent quality by controlling a speed of an injection plunger with a digital signal. CONSTITUTION:A digital type position detector generating a pulse at every unit movement of an injection plunger is equipped and a prssurized oil flow adjusting valve for driving the same plunger is controlled by a digital signal tehrefrom. For example, a position detecting head 15 attached so as to move integrally with a shaft 14 of the injection plunger in a direction of the stroke thereof is opposing to a linear scale 16 arranged in a stopped condition with respect to the shaft 14 relatively and a pulse PT is generated from the detecting head 15 in accordance with a movement of the shaft 14. A plunger moving-speed control system 31 is input with the pulse PT given from the detecting head 15 and is equipped with a setting portion 31-1 for a speed switching position Xi varying a moving speed Vi during a left stroke or a right stroke of the injection plunger shaft 14.