| 摘要 |
PURPOSE:To contrive to lighten the weight of a suction pipe, miniaturize and simplify the shape of an injection mold and ensure the fixing strengths at functional sites by a method wherein a duct part is formed only by blow molding, and functional sites are integrally provided on portions of the outer periphery of the duct part by injection molding. CONSTITUTION:A bent pipe 20 is produced by below molding, which corresponds to the shape of the duct part 11 in a suction pipe 10. The bent pipe 20, the wall thickness of which is made enough thick in consideration of the deformation, is set as a core in an injection mold 21 having functional-site-forming surfaces 21a, 21b and 21c. Synthetic resin material is injected in the injection mold 21 so as to be applied in a space formed between the mold 21 and the bent pipe 20. Thus, the bent pipe 20 as it is turned into a duct part 11. The injected synthetic resin material is integrally welded to the outside of the duct part 11 so as to form a flange part 12 at one end and a vent pipe 13 and a fitting screw part 14 at a bent part. |
