摘要 |
<p>This invention relates to a method of controlling the molding cycle of an injection molding machine provided with a flow passage opening/closing mechanism capable of interrupting the flow of injected plastic synthetic resin, and intends to reduce the length of time for one cycle of molding and to stabilize the value of weight of the product. The structure is such that said flow passage opening/closing mechanism is closed when plastic synthetic resin is filled into cavities of the metallic dies after injected and put in dwelling. This structure permits simultaneous progress of dwell process by residual dwell on the side of the metallic die and of weight measuring process for the subsequent molding cycle on the side of the screw, whereby the length of time for one cycle of molding can be reduced. With said flow passage opening/closing mechanism and a check valve provided for the screw, the pressure of plastic synthetic resin in the cylinder immediately before injection and during dwelling can be obtained as a definite value and, with the weight value of the product obtained from calculation, the injection molding machine can be controlled so that the weight of molded product may be kept constant.</p> |