| 摘要 |
PROBLEM TO BE SOLVED: To devise the shape structure of a molding so that a cylindrical plastic molding high in dimensional precision and strength is obtained without being restricted by the shape of the molding. SOLUTION: In the cylindrical plastic molding having a transfer part in a cylindrical peripheral part and a rim, incomplete transfer parts are formed on the back side of a rim and/or in a web, and the ratio between the thickness (t) of the thin wall of a rim side end adjacent to the peripheral part having the transfer part and the width (w) of the transfer part is 0.01<=t/w<=0.2. A step in the widthwise direction exists between the thin wall of a thickness of (t) and the thick wall of the rim, and the thin wall is molded while being held in the radius direction in a mold. |
