COMPACTING DEVICE FOR CASTING MOLD SAND

摘要

PURPOSE: To prevent the occurrence of a crack in a mold by making the strength at the horizontal cross section of the mold uniform. CONSTITUTION: The apparatus for compacting the foundry sand by rapidly acting a gaseous pressure on the foundry sand inserted into a molding box on a pattern supporting plate having a pattern is a type provided with an air permeable layer to receive the effect of the gaseous pressure right on the surface of the foundry sand to be compacted. The air permeable layer 10 has the air permeability suitable for the height of the foundry sand 11 to be compacted. Then, the air permeability of a range 13 corresponding to the high contour of the pattern or the plateau-like contour is set lower than the air permeability of a range 12 corresponding to the portion of the pattern supporting plate where the pattern does not exist.