| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a high-quality pipe member and its manufacturing method. <P>SOLUTION: This pipe member is an injection-molded object which is integrally constituted of a holder part 20, a pipe part 30 and a plurality of ribs 40 which are equally distributed on the outer circumference of the pipe part 30, protrude in a radial direction and reach the holder part 20 halfway through the pipe part 30. In addition, the pipe member has a resin injection position 20f on the surface of a part excepting the pipe part 30 and the rib 40. Therefore, a molten resin injected through a resin injection aperture flows toward a formation space where the ribs 40 are arranged uniformly and makes its uniform/rapid flow unbiasedly in the peripheral direction through a rib formation space with a large flow and a formation space which communicates with the former and extends from the rear end of the pipe part through the halfway point. Thus the flow reaches the tip of the formation space of the pipe part on the tip side before the bias could be generated in the periphery on account of the short flow path of the formation space. Further, a bending of the pipe part 30 is avoided and a thickness difference between the pipe part 30a on the tip side and the pipe part 30b including the ribs 40 is limited to the ribs 40 only, inhibiting the generation of a thickness sinkmark. In addition, the protection of a molding tool against damage is ensured. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
