| 摘要 |
PROBLEM TO BE SOLVED: To realize formation of a recessed groove part such as a recessed oil sump to a bearing surface or a groove part for a herringbone difficult to be provided in conventional manufacturing methods, and realize it easily and at low cost. SOLUTION: This method includes a molding process, in which one or more projections 5, etc., for forming recessed grooves are formed on an outer circumferential surface 2f of a core part 2, in which molding material M is charged into a cavity C formed of the core part 2 and die parts 3A, etc., to be pressurized, so that a cylindrical mold Bm is formed in a cavity C formed, in which pressurization is then canceled, so that a springback is generated at least in a radial direction Fs in the cylindrical mold Bm, and in which the core part 2 is then extracted from the cylindrical mold Bm. COPYRIGHT: (C)2006,JPO&NCIPI
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