SHAFT THICKENING METHOD, AND SHAFT MEMBER FOR SHAFT THICKENING

摘要

PROBLEM TO BE SOLVED: To form a thickened part without causing a crack.;SOLUTION: A shaft thickening method by which a work-piece W, which is a metal shaft member, is gripped by a first metal mold 11 and a second metal mold 12 which are spaced from each other, an area K of the work-piece W between the first metal mold 11 and the second metal mold 12 is bent, and a compression stress is applied to the work-piece W while rotating the work-piece W around a central axis X1, whereby a thickened part Wa having a diameter larger than the work-piece W is formed in the area K of the work-piece W between the first metal mold 11 and the second metal mold 12. According to this method, a stress amplitude, which is a stress amplitude generated by a bending angle θ of the area K of the work-piece W between the first metal mold 11 and the second metal mold 12 and a compression stress Pa acting on the work-piece W, and which acts on the work-piece W and the thickened part Wa, is detected, and an allowable cumulative rotation number according to a numeric value of the detected stress amplitude is calculated, and thus, processing is performed so that a cumulative rotation number of the work-piece W falls within the allowable cumulative rotation number.;SELECTED DRAWING: Figure 8;COPYRIGHT: (C)2019,JPO&INPIT