Injection molding screw for metals

摘要

An injection molding screw is provided to prevent the materials from being left, and reduce the friction of the screw rotation and sliding only by limiting the end position of the screw flight to a certain position according to the position of the feeding opening in the heating cylinder. A screw 16 is rotationally and movably provided in a heating cylinder 10 having a nozzle at a tip end thereof. Granular metals fed from a feeding opening 13 at the rear of the heating cylinder are transferred forward by the screw rotation and melted. Melted metals metered in the end of the heating cylinder 10 are injected from the nozzle 11 by the forward movement of the screw. A rear end 19a of a screw flight 19 formed around the axis of the screw 16 is positioned below the rear edge of the feeding opening 13 at the rearmost position of the screw. At the foremost position of the screw, the rear end 19a is positioned in front of the feeding opening 13 in order to close the feeding opening 13 by the rear portion 18a of the axis 18.