| 摘要 |
PURPOSE:To prevent drastical lowering of temp. of cast molten metal caused by contact with lost foam pattern and to stably produce a high quality casting by making hollow shape of a feeding head pattern arranged at runner in molding sand or including exothermic material in the feeder head pattern in a lost foam pattern casting device. CONSTITUTION:The lost foam pattern 5 formed with foam polystyrene resin is embedded into the molding sand ina flask 1 and on the way of a runner 11 for the molten metal 9 to be cast, the hollow shape feeder head pattern 13 is set at front or rear of the pattern 5 and the exothermic material 21 is included therein. The molten metal 9 in a cap 7 is caused to flow into the foaming polystyrene-made lost foam pattern 5 through the runner 11, and the pattern 5 is lost with heat of the molten metal to cast the molten metal into the pattern 5. In this case, at intermediate between the runner 11 and the pattern 5 or at rear of the pattern 5, the hollow shape feeder head pattern 13 is laid and as the molten metal 9 temp. is not lowered in the feeder head pattern 13, but contrarily, raised with the exothermic material, the molten metal 9 temp. is not remarkably lowered in spite of the reaction with the lost foam pattern 5 and further, as the feeder head pattern is hollow shape, the casting having only a little contamination of carbon, etc., caused by decomposition of foaming styrene at this part is cast at good dimensional accuracy. |
