| 摘要 |
PURPOSE:To prevent the pressure loss and generation of heat at injection and consequently the clogging of a nozzle from occurring by a structure wherein a screw extruder is fixed in the vicinity of the base of an injection plunger and the hole at the tip of the plunger is communicatingly connected to the screw extruder so as to allow to freely reciprocate the plunger together with the extruder. CONSTITUTION:An injection plunger 5 is inserted into the lower part of the chamber 17 of an injection cylinder 15 and a material is extruded through a non-return valve 10, a direction converting hole 14 and a hole 6 in the order named into the chamber 17 while being plasticized by the rotation of a screw 11. At the same time, the injection plunger 5 together with a ram 8 is slowly lifted in the direction indicated with the arrows B by the predetermined amount and then stopped in order to finish the metering. After that, the tip of a nozzle 16 is pushed against a mold 3 and the injection plunger 5 is pressed so as to inject the metered material in the cavity of the mold 3. |
