POWER TRANSMISSION SHAFT OF STEERING DEVICE AND METHOD FOR ASSEMBLING IT

摘要

PROBLEM TO BE SOLVED: To reduce the cost of the power transmission shaft of a steering device and to ensure impact absorption by preventing wasting manufacturing and assembling processes. SOLUTION: A power transmission shaft, for use in a steering shaft which absorbs impacts by being shortened in the direction of its axis when exerted with an impact load of not less than a predetermined value, comprises a hollow shaft 8 with a locking recess in its inner periphery and an insertion shaft 9 with a locking projection on its outer periphery which locks into the locking recess in the hollow shaft when it is inserted into the hollow shaft 8. The hollow shaft 8 and the insertion shaft 9 are connected to each other by engagement of the locking recess with the locking projection in such a way that power can be transmitted in the circumferential direction and that they can be displaced along the direction of the axis. A recess for forming a dent is provided in a portion of the locking projection on the outer periphery of the insertion shaft, and an inwardly dented part 8b machined by use of the dent forming recess in the insertion shaft 9 is provided in the portion of the hollow shaft where the locking recess is present, so that the locking projection of the insertions shaft 9 bites into the dented part 8b of the hollow shaft.