Control method of injection molding machine

Abstract

A control method of an injection molding machine includes the steps of advancing a screw 2, injecting and filling the resin in a barrel cylinder 3 into a mold 4 to fill the mold, and then applying a predetermined holding pressure to the resin in the mold 4. The control method further includes the steps of performing an injecting and filling by using an injection cylinder 5 having a double-rod piston 6 which can advance and retreat the screw 2, and then controlling the injection cylinder 5 by a controlling signal Dc including a predetermined alternating current signal in such a manner that the screw 2 is reciprocated in a longitudinal direction as a center with an advance finish and. stop position Xs and a position at which the screw is moved so as to retreat by a predetermined distance from the advanced finish and stop position Xs. Thereby, the mold failure such an overpack and a burr is eliminated.

Dependencies are inferred from the claim text.