| 摘要 |
PURPOSE:To prevent agglomeration of sands caused by solidification of liquid monomer and to reutilize the molding and by embedding a lost foam pattern into the molding sand to form the mold, making dilute condition of oxygen in the mold and again taking the oxygen in the mold after pouring molten metal. CONSTITUTION:The lost foam pattern 3 is laid on bed sand in the flask 1 and the molding sand 7 is packed to form the mold. The upper part of the flask 1 is sealed with a cover body 8 and the air in the flask 1 is sucked through the pressure-reducing chamber 2 to make the dilute condition for the oxygen. The molten metal 9 is poured into the pattern body 4 through a runner 6 and a runner gate 5. As the oxygen in the mold is dilute-state, combustion is restrained and the lost foam pattern is thermal- decomposed and made to liquid monomer 10 and extruded into the sand grains for the molding sand 7. The molten metal 9 is filled up in place of the lost foam pattern 3. After pouring, the cover body 8 is taken out to make oxygen-rich state in the mold. As the liquid monomer 10 extruded into the molding sand 7 is high temp., at the tie of bringing into contact with the oxygen, it becomes gas into the sand grains, and is burnt with the residual heat in the mold and removed from the molding sand 7. |
