| 摘要 |
<p>PURPOSE:To obtain a uniform back-up ring by providing a ring form cavity at the mold parting face, making possible a part of the cavity to advance and to retreat and installing a thin plate obliquely to the parting face in said part enabled to advance and to retreat, filling resin in the cavity, molding the ring form and pushing out and rotating said molded resin piece. CONSTITUTION:The mold 10 is closed by contacting the movable part 12 of the mold 10 to the stationary part 11. Then, molten resin is forced from the back of the stationary part 11, filled in the cavity 14 and a back-up ring 18 is molded. After that, when the movable part 12 is parted from the stationary part 11, the ejector pin 20 and the support pin 16 are protruded by the equal distance at the same time and the molded back-up ring 18 is ejected from the parting surface 13 together with the part 15. And the back-up ring is obtained by removing the thin plate 17 from the part 15 through pulling the end in front of the thin plate 17 in direction of the arrow mark (a) and rotating the end 182 in direction of the arrow mark (b).</p> |
