METHOD FOR PRODUCING GYPSUM MOLD, GYPSUM MOLD, AND METHOD FOR PRODUCING PRECISION PARTS BY THE GYPSUM MOLD

摘要

PROBLEM TO BE SOLVED: To solve the problem that, in a cast product according to a gypsum casting method, by the slight shift in the fitting of the gypsum mold and a difference in the height of feeder heads upon casting, variation occurs in the machining origins to form into post-machining to cause variation in the product dimensions.;SOLUTION: A working margin is further added to a master model to which a shrinkage is imparted to product dimensions, and a gypsum mold 3 is prepared based on a master model 1 in which working standard members 15a to 15d with a cooling promotion action into the working margin. In the case a cast product 4 is produced using the gypsum mold, the working standard members are made into points and points grasping the shrunk conditions of the casting after the casting so as to be a series of working standards, and the product with a dense structure is produced.;COPYRIGHT: (C)2011,JPO&INPIT