Degassing apparatus for a metal mold.

摘要

A degassing apparatus (12) for a metal mold (11) comprises a valve body and a bypass. The valve body (24) is slidably provided between an end of a vent groove communicating with a metal mold cavity (14) and a valve opening/closing portion before an exhaust hole. When a molten metal flowing from the cavity acts on a surface of the valve body, the valve body moves toward the exhaust hole and blocks a path toward the exhaust hole. The bypass (26) bypasses a valve head (24b) of the valve body from the vent groove and guides gas to the exhaust hole. The valve head of the valve body has a substantially head-cutting conical outer shape projecting in the direction of the vent groove (15). The vent groove has a gas vent path (25) extending from a top portion to the vicinity of the base of the valve head along an outer surface of the valve head. An end portion of the gas vent path corresponding to the base of the valve head communicates with a start portion of the bypass which bypasses the valve head.