| 摘要 |
PROBLEM TO BE SOLVED: To provide a working method which reduces the cost of a die by shortening the length of the die for working a shaft with multi-steps and obtains the high efficiency by simultaneously using roller dies having three or more sets. SOLUTION: In a form-rolling method for forming a shaft with multi-steps, the working is continued while following to the extension of a stock in the axial direction, and after stopping the extension of the stock in the axial direction, the stock is finish-worked. In the roller dies used in the form-rolling for forming the shaft with multi-steps, plural wedge-like projections 2a, etc., are provided to a fixed part on the roll 1 surfaces of the roller dies and partsθ1 ,θ2 andθ3 of spiral arrangement separated from the center cross section 4 of the roller dies in any wedge-like projection and a fixed range following these parts are composed of the parallel partθ4 with the same cross section 4. Further, a flat platy die having the shape and the arrangement developed into a plane is obtd.
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