| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method for improving the yield by reducing punched parts and for double-forging the inner and outer rings simultaneously by one mold, in the manufacture of the inner/outer ring of a double ball bearing. <P>SOLUTION: With a steel stock 3 machined by upsetting to make an upsetting material 4, the upsetting material is hot forged into a double forged article 7 in which an inner ring base shape 6, with the outer and inner diameter made smaller than those of the outer ring base shape 5 and with bottom face formed with a punched part 8, is stacked on the outer ring base shape 5 and its lower step. The double forged article 7 is then punched and separated into the outer ring base shape 5 and the inner ring base shape 6 having the punched part 8 on the bottom face. Thereafter, the punched part 8 of the inner ring base shape 6 is punched and removed. The outer and inner ring base shapes 5, 6 thus obtained are once heat-treated, and then grounded and finished into the outer ring 9 and the inner ring 10. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
