| 摘要 |
PURPOSE:To eliminate blowing out of a shell sand and to permit easy clamping of metallic molds by sucking and evacuating the inside of the metallic molds and supplying and packing the shell sand in a sand hopper into the metallic molds by a differential pressure. CONSTITUTION:A cylinder 5 is actuated to lift a table 6 and to lift top and bottom metallic molds 1, 2 from a roller conveyor 7. The mold 1 is pressed to a sand hopper 4. Press contact valves 10, 11 are brought into press contact with the molds 1, 2 and ventilation passages 11, 11 and a vacuum pump are communicated with each other. The inside of the molds 1, 2 is sucked and evacuated through vent holes 12, 12 communicating with the passages 11, 11. As a result, a differential pressure is generated between the inside of the molds 1, 2 and the upper part of the hopper 4, by which shell sand 3 is sucked to be supplied and packed into the molds 1, 2. The top and bottom metallic molds are then moved to the position for calcining the shell sand where the sand is calcined for a prescribed time. The calcined shell mold for casting is thus obtd. |
