Patent ID: 8550146

Claim:
A valve device for gas drainage, mounted to a metal mold for die-casting, capable of selectively communicating and blocking a gas drainage path used for draining gases from a cavity of the metal mold, the device comprising: a main body in which an exhaust hole configuring a part of the gas drainage path is formed; a valve element capable of opening and closing the exhaust hole; a cylinder housing a piston coupled to the valve element; and an electromagnetic selector valve for selectively switching a supply route of a driving fluid supplied from a fluid supply source of a die-casting machine to the cylinder either to a front chamber of the cylinder or to a rear chamber of the cylinder, the front chamber and the rear chamber being partitioned by the piston, wherein the main body includes a front face and a fitting portion, the front face configuring a part of a parting face of the metal mold, and the fitting portion that adheres to a wall face of a housing hole of the metal mold when the valve device is fitted into the housing hole, wherein the housing hole has a periphery surrounding the housing hole, the periphery being entirely formed on the parting face of the metal mold, and the electromagnetic selector valve is positioned on a rear side of the main body, and at the same time, positioned inwardly of a contour line of the main body formed by the fitting portion when the main body is viewed from the front face, wherein when the main body is viewed from the front face, the contour line of the main body is positioned outermost such that any parts other than the main body are not viewed from the front face, wherein when the valve device is inserted inside the housing hole, only the fitting portion of the main body is adhered to the wall face of the housing hole, and any parts other than the fitting portion are away from the wall face of the housing hole, wherein in the main body, a cooling hole through which coolant passes is formed, the cooling hole being different from the gas drainage path.