A mechanism for blowing molding sand in blowing machines

摘要

A molding sand blowing mechanism is provided wherein compressed air blown into the mechanism can pass through the inner cylindrical chamber with little resistance applied thereto, the inner cylinder can be easily manufactured, and whether the model box is adequately filled with molding sand does not depend on the quantity of molding sand in the inner cylindrical tube. The sand blowing mechanism comprises outer and inner cylindrical tubes 5,7, to form exhaust and air supply guiding chambers 11,12, and a plurality of nozzles 19,39 provided in the inner tube 7 for jetting compressed air into the air supply guiding chamber 12 toward the periphery of the inside of the inner tube 7.