BLOW PIN FOR HOLLOW MOLDING, HOLLOW MOLDING APPARATUS AND MOLDING OF HOLLOW MOLDED PRODUCT

摘要

PROBLEM TO BE SOLVED: To provide a blow pin performing the jetting of at least one of gas and a cooling medium for shaping and cooling a parison and the discharge of the gas or cooling medium by one pin in the hollow molding of a synthetic resin and capable of performing the discharge of the gas or cooling medium simultaneously with cooling. ;SOLUTION: A blow pin for hollow molding is equipped with an inner cylindrical part A having a sharp leading end part and having a plurality of jet orifices jetting at least one of a cooling medium and gas formed in the vicinity of the leading end part thereof and the outer cylinder 23 coaxially provided outside the inner cylindrical part A so as to be relatively movable in the axial direction thereof. A gap 24 is provided between the outer cylinder 23 and the inner cylindrical part A and, when the outer cylinder 23 is relatively moved to an advance position so that the leading end thereof approaches the leading end of the inner cylindrical part A, the gap 24 is closed and, when the outer cylinder 23 is allowed to retreat from the advance position, the gap 24 communicates with a mold to become a cooling medium discharge passage.;COPYRIGHT: (C)1997,JPO