| 摘要 |
PROBLEM TO BE SOLVED: To make impact absorption function and durability compatible when the impact absorption function is added by forming a bellows-like bellows part on a part of a steering shaft. SOLUTION: When a shaft 1 with a bellows having a bellows-like bellows part 1a is formed, for example, using an electric welding steel pipe, surface roughness of an outer side of the bellows part 1a is made to 2.0μmRa or less, preferably 1.0μmRa or less to relax stress concentration, and fatigue life is enhanced by suppressing generation of a crack to ensure durability. Further, a radius of curvature of a bottom part of the outer side of the bellows part 1a is made to 1.1 to 2.1 mm, preferably 1.5 to 1.9 mm to obtain high fatigue strength and low buckling strength, thereby, compatibility of durability and impact absorption function is realized. COPYRIGHT: (C)2007,JPO&INPIT |
