MOLDING METHOD AND MOLDING MOLD OF OIL SEAL RING

摘要

PROBLEM TO BE SOLVED: To provide a mold for molding an oil seal ring capable of molding the oil seal ring showing excellent sealability and necessitating no post-fabrication. SOLUTION: A core pin 4 movable in an axial direction is mounted on a movable mold plate 2 which forms a cavity 5 with a fixed mold plate 1 to mold an oil seal ring A having a circular protruding portion (b) formed in an inner circumference of a circular portion (a) having a rectangular cross section. The core pin 4 has a small diameter portion 4a forming the inner circumference of the circular protruding portion (b) and a large diameter portion 4b forming one side inner diameter portion of the circular protruding portion (b) on the front edge surface. A molten resin is injected into the cavity 5 to mold the oil seal ring A. After that the movable mold is opened and the oil seal ring is protruded from the movable mold plate 2 by the front edge surface of the large diameter portion (b) driven by the movement of the core pin 4 in the axial direction whereby a trace of projection is prevented from being formed on one side as the seal surface of the circular portion (a). COPYRIGHT: (C)2004,JPO