| 摘要 |
PURPOSE: To prevent the leakage of a molten resin to the outside by intermittently repeating the operation forcibly moving an injection screw in a retreat direction in predetermined timing by predetermined quantity during a period plasticizing and weighing a resin by a preset temporary weighing stroke. CONSTITUTION: The pressure in a resin storage chamber R is forcibly lowered by suck back operation and the leakage of a molten resin to the outside is prevented. When the clocking by a suck back timer is completed, a two-position solenoid changeover valve is returned. By this method, the suck back operation is performed only for a predetermined time in predetermined timing. By intermittently performing this operation, the leakage of the molten resin from the nozzle orifice 34a of a nozzle 34 is prevented. A three-position solenoid changeover valve is changed over when an injection screw 36 retreats by a temporarily set weighing stroke to stop the rotation of a hydraulic motor 12 and a plasticizing and weighing process before molding rising is completed. |
