CYLINDRICAL RESIN MOLDED OBJECT, INJECTION MOLD AND INJECTION MOLDING METHOD

摘要

PURPOSE:To obtain a molded object of high accuracy and high quality by performing gate cutting with high accuracy while a molded object is received in a mold regardless of the presence of the odd-shaped of a key groove and certainly preventing the generation of a sink regardless of the kind of a resin. CONSTITUTION:A core pin 9 is fitted in a fixed mold 1 and the tip part of the core pin 9 is arranged in a cavity 7 to close fixed and movable molds 1, 2. A molten resin is ejected from the sprue 5 provided in the core pin 9 and charged in the cavity 7 through the disc gate 6 provided between the tip surface of the core pin 9 and the movable mold 2 opposed thereto. After the filling of the cavity 7 with the resin, the gate cutting punch 12 received in the movable mold 2 so as to be able to advance and retreat is allowed to advance and the tip part thereof is fitted to the outer periphery of the tip of the core pin 9 while the molten resin in a communication part 8 is pushed in the cavity.