Nsk Corporation

Yukihiro Matsumoto

Naoki Sawada

Kouji Andou

A steering device includes: an outer shaft around a center axis and includes an inner space with a spline hole portion; and an inner shaft at least a part of which is disposed in the inner space. The inner shaft includes a first spline shaft portion including a synthetic resin surface and includes a shaft portion that is adjacent to one side of the first spline shaft portion, includes one end of the inner shaft in the inner space, and includes a synthetic resin surface. A distance between the center axis and the surface of the shaft portion is smaller than a distance between the center axis and the surface of the first spline shaft portion. The spline hole portion and the first spline shaft portion are spline-fitted to each other, and the outer and inner shafts are relatively movable in the axial direction.

Steering device and method for manufacturing steering device

According to an aspect, a steering device includes: an outer shaft disposed around a center axis and includes an inner space with a spline hole portion; and an inner shaft that includes a spline shaft portion including a surface disposed around the center axis, at least a part of the inner shaft being disposed in the inner space. The spline shaft portion includes a first spline shaft portion including a first surface formed of synthetic resin and includes a second spline shaft portion including a second surface formed of metal. A distance between the center axis and the second surface is smaller than a distance between the center axis and the first surface. The spline hole portion and the first spline shaft portion are spline-fitted to each other, and the outer shaft and the inner shaft are relatively movable in the axial direction.

Method for manufacturing steering device

A steering device easily sets an absorption amount of impact energy to a predetermined magnitude at a time when a female male shaft and a male shaft undergo relative contraction upon occurrence of a vehicle collision. If the male shaft undergoes contraction by a length against the female shaft, a serrated edge on a right-end surface of the female shaft is butted against a left-end surface of an impact-energy absorption part. Then, the serrated edge of a female serration is firmly butted against a left-end surface of the impact-energy absorption part to undergo plastic deformation, whereupon resistance to collapsing increases, thereby absorbing impact energy.

Growing community of inventors

Gunma, Japan

Yukihiro Matsumoto