PURPOSE: To enable small-volumed molding to be molded by defining a flow clearance for molten materials in a heating cylinder side in use of shaft member extended in the tip end of an injection screw, and permitting the molten materials in the flow clearance to be injected through a long stroke.
CONSTITUTION: A shaft member 3 is extended to the tip end of an injection screw 2 within a heating cylinder 1 for defining a flow clearance 5 of molten materials in the inside of the heating cylinder. Between the heating cylinder 1 and a nozzle member 9, there Is provide a guide member 6 having a flow passage 8 in communication with the flow clearance 5 around a central guide hole 7. The tip end of the shaft member 3 is movably housed in the guide hole 7 of a guide member 6 so that molten materials in the flow clearance 5 is force-fed into the nozzle member 9 by means of the injection screw 2 that moves together with the shaft member 3.
