PRESSURE VESSEL CAP MEMBER AND BLOW PIN ENGAGEMENT STRUCTURE, PRESSURE VESSEL CAP STRUCTURE COMPRISING SAME, AND PRESSURE VESSEL MANUFACTURING METHOD

摘要

Disclosed is a pressure vessel such that a cap member is fitted over a blow pin, and that thereby a resin liner is blow-molded. In this pressure vessel, no rotation-wise load is generated in the connection portion between the blow pin and the resin liner during removal of the blow pin. An engagement structure for the cap member (4) and the blow pin (11) of the pressure vessel (1) is such that a parison (12) is disposed around the outer periphery of the cap member (4), which is fitted over the blow pin (11), and that blow-modeling is performed from the outer periphery of the cap member (4) in a state where a metal mold (13) is closed, with the result that there is formed a container-like liner (2) which matches with the metal mold (13). Said engagement structure comprises a ball (22) which is provided on the outer periphery of the blow pin (11) in such a way as to be radially movable, and a relief groove (20) which has a predetermined depth and is provided on the inner periphery of the cap member (4). In a state where the blow pin (11) is inserted into the cap member (4) and where the ball (22) and the relief groove (20) face each other, the ball (22) moves radially outward, and a portion thereof is held in the relief groove (20), resulting in the cap member (4) and the blow pin (11) being engaged with each other.