| 摘要 |
PCT No. PCT/JP79/00032 Sec. 371 Date Oct. 14, 1980 Sec. 102(e) Date May 7, 1979 PCT Filed Feb. 14, 1979 PCT Pub. No. WO80/01655 PCT Pub. Date Aug. 21, 1980.A die-casting apparatus having a runner 31 through which molten metal is injected into a die cavity for die-casting an article, a squeeze passage 17 communicating with the die cavity 30 at a portion other than the portion where the runner 31 is communicated with the die cavity 30, and a squeeze plunger 36 snugly and slidably disposed in the squeeze passage 17 and adapted to commence, before the runner 30 is closed by solidification of metal therein, to forcibly displace the molten metal from the squeeze passage 17 back into the die cavity to effect a squeeze on the molten metal in the die cavity 30. The stroke of the squeeze plunger 36 is greater than one half of the length L of the squeeze passage 17. The cross-sectional area S and the length L of the squeeze passage are given by: S>/=0.35L2 Because the molten metal injected through the runner 31 into the die cavity 30 is squeezed from the side of the squeeze passage 17, the invention is advantageously capable of not only greatly decreasing the formation of voids which adversely affect the gas-tightness and mechanical strength of die-cast products, but also assuring a reliable production of voidless die-cast products. Particularly, the invention can conveniently be used to produce parts which are needed to provide a high gas-tightness, parts which have to withstand a high pressure, as well as parts which have to be worked precisely. For example, the invention may be used for the production of housings of compressors and pumps. |
