PURPOSE: To provide a differential pressure casting apparatus, which separates a product and molten metal by supplying inert gas and can prevent damage developed in an inert gas supplying device from happening.
CONSTITUTION: In the differential pressure casting apparatus having a holding furnace 6, a metallic mold 2, an inner cylinder 11 connecting, the upper end with a sprue 5 in the metallic mold and holding the lower end higher than surface 8 of the molten metal 7 in the holding furnace 6, an outer cylinder 12 closing the upper end between this cylinder and outer face on the inner cylinder and submerging the lower end into the molten metal 7, a stoke 10 arranging a hole 14 for communicating annular range 13 formed between the inner and outer cylinders 11, 12 and the outer part and the inert gas supplying device connected with the hole 14 in the stoke 10 through a valve 21, further, a molten metal, surface level meter 15 for measuring height of the surface 8 in the annular range 13 and an auxiliary inert gas supplying unit 23, 24, 25, 26 for supplying the inert gas into the annular range 13 when the height of molten metal surface 8 measured with the molten metal surface level meter 15 exceeds the prescribed value, are arranged.
ONISHI SANETSUGU
IIZUKA YASUO
