| 摘要 |
PURPOSE:To reduce the mold parting resistance between a core metal and a resin tube formed arround the core metal by a method wherein compressed air is jetted from the air holes of the core metal so as to shift the resin tube in the direction of its axis center line. CONSTITUTION:A large number of air holes 9, through which compressed air 8 can be jetted from the interior to the outer surface, are provided on a core metal 1 in order to jet compressed air through the air holes 9 after the hardening of a resin tube formed around the core metal 1. The resin tube 4 the core metal 1 are separated from each other by the interposition of air film 10 between the resin tube 4 and the core metal 1, resulting in reducing the mold parting resistance due to frictional force and enabling to remove the core metal by smaller force. |
