| 摘要 |
PROBLEM TO BE SOLVED: To provide an electric steering column device with high reliability capable of suppressing early abrasion regardless of temperature environment. SOLUTION: Since thermal expansion coefficient of a first screw shaft 12 is approximately equal to thermal expansion coefficient of a body 13a of a first nut 13, even when the environment temperature in a cabin arranged with the electric steering column device is largely varied, an expansion amount or a contraction amount between both members can be approximately equal and generation of rattling and mutual sliding can be suppressed. Further, since a resin member 13c is joined to an inner peripheral surface of the first nut 13 and a female screw groove 13h of the resin member 13c is thread-engaged with a male screw groove 12a of the first screw shaft 12, by making the materials thread-engaged, in such a state that a thread-engaged surface pressure is high, different from each other, fixing of the members can be suppressed and early abrasion can be also suppressed. COPYRIGHT: (C)2010,JPO&INPIT |
