| 摘要 |
PROBLEM TO BE SOLVED: To provide a form rolling die which can securely and inexpensively form a bolt (screw) with a profile combining a male screw part located at least at one end and a profile having a non-circular cross-section from a columnar sock by single form rolling stage, and to provide a method for form-rolling a bolt with a profile. SOLUTION: The form rolling die 1 includes: a pair of upper and lower male screw forming regions 7, 7 located at a pair of confronted forming faces 3a, 3b in a pair of flat dies 2a, 2b and composed of two or more pairs of mountain parts 8 and valley parts 9 parallel each other and also tilted to the feeding direction of a stock W0; and a region 10 of forming a profile with a non-circular cross-section located in parallel between the male screw forming parts 7, 7 in the pair of forming faces 3a, 3b, and in which a plurality of arc form parts 14, 15, 16 are projectingly provided at equal intervals (equal pitch p) along the feeding direction of a stock W0. The plurality of arc form parts 14 to 16 in the profile forming region 10 are projectingly provided in such a manner that the cross-sections of the arc form parts 14 to 16 are successively made larger in order of a chamfering part 4, a parallel part 5 and a relief part 6 in the forming region 10. COPYRIGHT: (C)2011,JPO&INPIT
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