Flow guide shell structure of 3D sand mold printing equipment

The utility model discloses a flow guide shell structure of 3D sand mold printing equipment, which comprises a conical cover shell, a through air suction pipe is welded at the lower end of the cover shell, a filter bag is fixedly mounted at the lower end of the air suction pipe through a hoop, a circular ring is welded at the lower end of the cover shell, external threads are arranged on the outerwall of the circular ring, and the circular ring is in threaded connection with a circular pipe. A filtering mechanism is installed at the lower end of the round pipe, an axial flow fan is installedat the lower end of the filtering mechanism, the filtering mechanism comprises a cylinder, a cylindrical sponge is placed in an inner cavity of the cylinder, a top cover is installed at the upper endof the cylinder, and a plurality of round air suction holes are formed in the top cover. During printing, the axial flow fan is started, the axial flow fan sucks air downwards from the filtering mechanism, so that negative pres