| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a forging die having longer life than the conventional one in the forging die which is used for backward extrusion forming of the outer ring member of a constant velocity universal joint. <P>SOLUTION: The forging die 10 includes: a plurality projecting parts 11a, 11b, 11c which are provided at a predetermined interval in the peripheral direction and extended to the top of the forging die 10 along the direction of the center axis X; a plurality of groove parts 12a, 12b, 12c which are provided between the plurality of the projecting parts 11a, 11b, 11c and extended to the top along the direction of the center axis X; and a plurality of collar parts 13a-13c which are provided in the boundary parts between the projecting parts 11a, 11b, 11c and the groove parts 12a, 12b, 12c, respectively and extended to the top along the direction of the center axis X, on the side face 25. On the side face 25 of the top part, a land face 21 which is outward projected is provided over the entire periphery and the land face 21 in the collar parts 13a-13c is constituted of only an inclined face which is inclined with respect to the direction of the center axis X. <P>COPYRIGHT: (C)2012,JPO&INPIT |
