| 摘要 |
PURPOSE:To reduce the pressing force of a plunger of internal cooling construction permitting relieving of thermal stress possible and to prolong a life by controlling cooling of molten metal by the use of said plunger. CONSTITUTION:The inside of a plunger 1 is formed of a pipe 3 for blowing out of cooling liquid, and a partition plate 6 for preventing direct contact of cooling liquid with an internal cooling surface 6a. Molten metal 15 is pressurized and filled into a product cavity 14 of a metallic mold formed of a cope 12 and a drag 13. At this time, the supply of the cooling liquid is stopped to interrupt the internal cooling of the plunger 1. After the molten metal 15 in the cavity 14 solidifies, the cooling is resumed. Hence, when the molten metal 15 is filled, the leading end temp. of the plunger 1 is high, by which the fluidity of the molten metal 15 is maintained and the product is thoroughly pressurized and molded. |
