| 摘要 |
PROBLEM TO BE SOLVED: To provide an impact absorbing steering shaft that can smoothly perform relative displacement in an axial direction between an outer shaft 12a and an inner shaft 13a, caused by an impact load accompanied by a secondary collision, and to achieve a manufacturing method thereof.SOLUTION: A tip portion of a large-diameter portion 16a of an inner shaft 13a is internally fitted and fixed, with a fitting strength that enables an outer shaft 12a and an inner shaft 13a to yield relative displacement in an axial direction, along with an impact exerted at the time of secondary collision, on a base end portion of a small-diameter portion 14 of the outer shaft 12a. A chamfer portion 21 is provided at an outer peripheral edge of a tip portion of the large-diameter portion 16a, and the closer to the tip edge of the large-diameter portion 16a, the smaller an outer diameter of the large-diameter portion 16a is made. Consequently, the tip edge of the large-diameter portion 16a is prevented from biting an inner peripheral surface of the small-diameter portion 14 at the time of assembly of the both shafts 12a, 13a. |
