| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a blank for a bearing ring of a rolling bering capable of increasing the yield of a material. <P>SOLUTION: An inner ring blank 21 and an outer ring blank 22 are manufactured by forging a single raw material. A disk member 10 prepared by upsetting molding a cylindrical raw material is pressurized, and a center part 5 and an outer side part 4 are formed. A center side of the center part 5 is punched by a punch, and a prepared hole 24 having a diameter d1 smaller than an inside diameter d2 of the inner ring blank 21 is formed. An inner cylinder part 25 having a hole expanded in diameter as an inner periphery is molded while expanding the prepared hole 24 in diameter by forward extruding the center part 5 by a male mold, and an outer cylinder part 26 is molded by backward extruding the outer side part 4. The inner cylinder part 25 and the outer cylinder part 26 are separated, and the inner ring blank 21 and the outer ring blank 22 are obtained. <P>COPYRIGHT: (C)2012,JPO&INPIT |
