| 摘要 |
PURPOSE:To control the flow of a molten metal in a way as to avoid generation of turbulence by providing a control valve which can vary the effective sectional area of a suction port to a part of a stalk which introduces the molten metal in a holding furnace into the product cavity of an evacuated casting mold. CONSTITUTION:A casting device places a casting mold 1 delineating a product cavity 2 on an installation base 4, evacuates the inside of a cover 9 forming a hermetic space by a vacuum pump 11 and sucks the molten metal 5 in a holding furnace 6 through the suction port 8 of a stalk 7 into the cavity 2. A suction port control valve 13 which can vary the effective sectional area of the port 8 is provided to a part of the stalk 7 of such casting device. The opening degree of the valve 13 is then decreased in the initial period of suction casting and after the molten metal is introduced to some extent into the cavity 2, the valve 13 is fully opened. The flow condition of the molten metal is thus controlled so as to avoid generation of turbulence. |
