| 摘要 |
PURPOSE:To keep stress from remaining in thermoplastic resin and in reinforcing fibers in accompany with the application of bending force and at the same time prevent crack from developing in a portion to be bent by a method wherein the portion to be bent is heated and bending force is applied under the condition that said portion is restricted from its surroundings. CONSTITUTION:A fiber reinforced thermoplastic resin bar 10 is made of glass fibers, carbon fibers, ceramic fibers or their mixture. In order to do bending work, the bar is heated up to a temperature near the melting point of resin so as to allow the relative displacement of the reinforcing fiber at the portion to be bent 12 of the bar 10. The application of bending force is done by applying external force so as to abut a part of the portion to be worked 12 against the peripheral surface of a metal heating cylinder 14 after the portion to be worked 12 is moved outside a hot air space. During the application of the bending force, the change in cross section and the lowering of the bending strength of the working can be checked by restricting the portion to be worked 12 from the surroundings by means of string 16 or the like. Further, by applying twisting to the portion to be worked 12 before the application of the bending force, the difference of strains among fibers and the lowering of the bending strength can be prevented from occurring. |
