| 摘要 |
PURPOSE:To improve the accuracy of a product and exhausting ability of gas by arranging a baffle plate body having pressure reducing part at the upper face position in a lost foam pattern, restraining the pressure of molding sand loading to the lost foam pattern and exhausting the gas generated at the time of pouring molten metal from the pressure reducing part. CONSTITUTION:The lost foam pattern 1 is beforehand manufactured at the other process, and placed on the molding sand 7 on a bottom plate 3. A molding sand packing device 10 is set above a flask 2 and the molding sand 7 is packed without any gap in the outer part of the pattern 1. Successively, the baffle plate body 9 is arranged as attachable, detachable above the pattern 11 and after connecting with a pump 18 through an exhaust pipe 9B, the molding sand 7 is packed to a sprue 13 level. The molten metal 17 is poured and at the time of forming the casting by losing the lost foam pattern 1, the pressure of the molding sand 7 loading to the pattern 11 is reduced by insertion of the baffle plate body 9 to prevent the deformation of the pattern 11. Further, the generated gas is uniformly exhausted from both upper and lower sides. Therefore, the accuracy of the casting and the exhausting ability of the gas are improved. |
