| 摘要 |
PURPOSE:To prevent an occurrence of stress concentration on a cylindrical part of a molded piece when the molded piece is ejected by a method wherein an ejector sleeve pin is formed so as to extend outward in the radial direction thereof, and a top end face of the ejector sleeve pin also faces the surface of a ring rib on the bottom side. CONSTITUTION:When a molded piece is ejected, an ejector sleeve pin 14 is formed so as to extend outward in the radial direction thereof. A top end face 14a of the ejector sleeve pin 14 also faces the surface of a ring rib Wb on the bottom side. Therefore, the top end face 14a of the ejector sleeve pin 14 can come into close contact with the outer surface of a molded piece W from the peripheral edge of a bottom part Wc of the molded piece W to the ring rib Wb. Thus, an ejecting load directly acts as a release force to the ring rib Wb. A large compression stress never occurs in a part of a cylindrical part Wa between the ring rib Wb and the molded piece bottom part Wc abutting on the ejector sleeve pin 14. In this manner, since a molding cycle time can be shortened, it can improve productivity. Since a cylindrical part of a molded piece can be thin-walled, it can reduce the quantity of material. |
