| 摘要 |
PURPOSE:To prevent inflow of gas into a cavity and to obtain a defectless casting in vacuum casting in a die casting method, etc. by evacuating the mating surface of a die, the sliding surface of a core, etc. together with the inside of the cavity. CONSTITUTION:A molten metal is charged into a sleeve and solenoid operated selector valves 14, 18 are opened to connect the inside of a cavity 2 and the groove 16 provided in the outside circumferential part thereof to a vacuum generator 15 to evacuate the inside thereof, when a plunger tip advances to the position where the charging port of an injection sleeve is closed in the stage of connecting a venting device 3 to the separating surface part of a die 1 and performing vacuum casting. Then the flow of gas between the groove 16 part and the cavity 2 is eliminated. The moisture, etc. remaining on the mating surface of the die 1 and the sliding surface 20a of the core are thus not sucked into the cavity 2. The flow of the gas between the plunger tip and the injection sleeve is prevented by the similar means. The casting having no intrusion of the gas is thus obtd. |
