| 摘要 |
PURPOSE:To shorten molding time by forming an external drum around the external surface of an internal drum and arranging the internal drum within an injection mold metal for injecting resin for the external drum. CONSTITUTION:A drag 31 for injection molding is provided with a molded recess part 31a of the same shape as the external form of an external drum 3, and a support pin 32 of outer diameter equal to the inner diameter of an external drum 2 is erected at the center of the recess part 31a. And the internal drum 2 is mounted to the support pin 32. In this state, a cope 33 is closed and fibre reinforced resin 3a is injected into a cavity formed by the drag 31 and the cope 33, from the resin passage 33a of the cope 33. Consequently, the external drum 3 is formed around the external surface of the internal drum 2, thereby simplifying a manufacture process very much and shortening molding time. |
