| 摘要 |
PURPOSE:To smooth pouring into a casting mold, to prevent inclusion of gas and to reduce excess molten metal by pouring the molten metal into the mold which is kept evacuated from the side opposite to the opening of the runner and upsetting the mold after filling the same with the molten metal. CONSTITUTION:A vacuum pump 7 is driven to maintain the bottom surface of a casting mold in an evacuated state. A molten metal 9 is filled in the mold cavity 1 when the molten metal 9 is poured into the mold through the sprue opening 3 in the upper part thereof. The mold 4 is upset immediately upon waiting for the time when a gate part 2 solidifies after the molten metal is filled up to the opening 3. The molten metal in the opening 3 which is not yet solidified is expelled from the inside of the mold 4 and at the same time, the molten metal filled in the mold cavity is also upset in the cavity 1 and therefore the casting product has a uniformly dense structure. The gas remaining in the upper part of the cavity 1 is thoroughly discharged by upsetting, by which the defects due to gas are thoroughly eliminated. |
