Vacuum casting apparatus.

摘要

A vacuum casting apparatus in which a molding cavity (6) is reduced in pressure substantially to a vacuum, and upon opening a gate (10), a molten metal which has been raised to a molten metal retaining dome (8) is charged into the molding cavity (6) via a runner (14) at a high speed. The runner (14) has a first portion (50) making a pool of molten metal, a second portion (56) connecting the molten metal retaining dome (8) to the first portion (50), and a third portion (58) connecting the first portion (50) to the molding cavity (6). A pin (52) is slidably provided in the first portion (50) of the runner (14). An opening of the second portion (56) of the runner to the first portion (50) is located nearer to the pin (52) than an opening of the third portion (58) of the runner to the first portion (50). When the pin (52) is moved into the first portion (50) of the runner, the pin (52) first closes the opening (60) of the second portion (56) and then begins to apply pressure the molten metal in the molding cavity (6).