| 摘要 |
PROBLEM TO BE SOLVED: To provide an injection-molded tubular component that is geometrically accurate in simple structure.SOLUTION: A cylindrical member 10 as the injection-molded tubular component includes a tubular part having opposite open end faces and a helical groove in an outer or inner circumferential surface, and a plurality of recessed portions arrayed circumferentially in a middle portion of the tubular part so as to keep the helical groove in between. During the molding of the cylindrical member 10, the plurality of recessed portions can keep the middle portion from being at a relatively high temperature and the end face portions from being at a relatively low temperature and implement an uniform mold shrinkage factor throughout to provide a geometrically accurate tubular member. |
