| 摘要 |
PURPOSE:To reduce the size of a vacuum device and to improve the quality of a product by filling a molten metal into the space formed of an injection plunger and injection sleeve then injecting the molten metal while evacuating the inside of the cavity and the injection sleeve. CONSTITUTION:A limit switch 32 stops a plunger 16 when the plunger advances to the position where the space formed of the injection sleeve 15 and the plunger 16 is filled to 80-100% by the molten metal. The thermally cracking gas, etc. generated in the sleeve 15 is released through a passage 17 and a solenoid valve 105 to the atm. during this process. The thermal cracking gas, etc. in the sleeve are sucked by the signal of the switch 32 into a vacuum device 100 upon stopping of the plunger 16. Since the vacuum-sucked space is small, the size of the device 100 is reduced and the time for the evacuation is reduced. The molten metal is injected in the evacuated state and therefore the product having good quality with less blowholes, etc. is obtd.
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