| 摘要 |
PURPOSE:To discharge the molten metal in the riser and runner in an air permeable casting mold in a molten state without solidifying said metal from the casting mold in the stage of dipping the lower part of the casting mold into the molten metal and performing suction casting by specifying the diameter of the sprue of the casting mold and the area of the gate thereof to specific values. CONSTITUTION:A sprue 10 provided to a drag 5 is dipped into the melt of a stainless steel or the like to be cast below the melt surface 3 thereof and the inside of a vacuum chamber 1 contg. a cope 4 is evacuated to suck the molten metal through the sprue 10 and to cast the same into the casting space 8 attached with a core 9 via a riser 6 in the stage of performing suction casting with the casting mold consisting of the cope 4 and drag 5 formed of an air permeable material. The sprue 10 is spaced by a distance 11 of 1-2 times the diameter of the sprue 10 from the end of the space 8 and the diameter or width thereof is made 20-40mm.. The area of the gate 7 between the sprue 10 and the space 8 is made <=100mm.<2>. The molten metal in the riser 6 and the runner flows out in the molten state from the casting mold when the entire part of the casting mold is pulled upward from the surface 3 and therefore the need for the operation of breaking the gate or grinding flash after the casting is eliminated and the excellent effect of lessening manpower is obtd. |
