| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve a problem in which a gate mark has a risk of projectingly remaining as if torn-off, where two gate ports formed in a fixed mold are expanded in a flare toward the direction of an elastic cylinder being pulled out, making the runner side of the gate port in a rim of an acute angle and the opposite side in a rim of an obtuse angle, so that when the gate is detached from the elastic cylinder, it is cut off with the gate port on the obtuse-angled rim side, causing the torn-off gate mark. Ž<P>SOLUTION: The shaft is an injection molded cylindrical shaft composed of resin material. A gate part to be cut off after the molding is extended and situated on the inner periphery of the shaft. After the cut-off of the gate part, a gate mark is positioned on the inner periphery of the shaft barrel. Further, the shaft is configured such that a tapered face is formed inclining from the front end face of the shaft barrel to the inner hole and that a part of the gate mark is positioned at the end part in the inner hole side of the tapered face. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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