초록

An account is given of a method and apparatus for hardening mold parts, such as mold outer parts or mold cores for making metal castings, by using compressed air for forcing catalyst through the sand of the mold parts for reaction with a binding agent mixed with the sand.

대표청구항 ▼

A method for hardening mold parts to be used for making metal castings which parts are made from a mixture of sand and a binding agent capable of being catalyst hardened, the method characterized by an operating cycle having a rest phase and a working phase including the steps of providing a source

A method for hardening mold parts to be used for making metal castings which parts are made from a mixture of sand and a binding agent capable of being catalyst hardened, the method characterized by an operating cycle having a rest phase and a working phase including the steps of providing a source of compressed air, providing a passage connecting said source to the mold part, during said rest phase filling said passage with air at one pressure, isolating a portion of the passage from both the compressed air source and the mold part with air at the one atmospheric pressure trapped therein, introducing under pressure in liquid phase a predetermined quantity of a vaporizable catalyst into said portion, heating the catalyst while isolated in said portion to the vaporization temperature of the catalyst and vaporizing all the catalyst to form an air/catalyst mixture; during said working phase opening said portion to the mold part and said compressed air source to said portion and releasing a quantity of catalyst-free compressed air into and through said portion at a pressure higher than that of the air/catalyst mix in said passage to force the air/catalyst mix as a charge into the mold part and thereafter passing an additional quantity of the catalyst-free compressed air through said portion and the mold part to clear both of residual catalyst, terminating the flow of compressed air through said passage and reinstating said rest phase.