| 摘要 |
PROBLEM TO BE SOLVED: To establish compatibility between a shock absorbing function and strength when adding the shock absorbing function by forming an accordion type bellows part on a part of a steering shaft. SOLUTION: When forming the shaft 1 with a bellows by using an electric resistance welded pipe, for example, compatibility between the strength and the shock absorbing function can be established by applying a nitriding treatment to the bellows part 1a and forming the nitride layer on the surface. The thickness rate of the nitride layer to the board thickness of 0.5% or more is preferable in view of the life, that is, the strength. The thickness rate of the nitride layer to the board thickness of 1% or less is preferable in view of the shock absorbing function. In addition, when three or more universal joints are used and torsional load and bending load are applied, they have a large effect on the strength. COPYRIGHT: (C)2007,JPO&INPIT |
