| 摘要 |
PROBLEM TO BE SOLVED: To alleviate impact at start of an electric motor and suppress looseness of a steering wheel when the electric motor is not operated, without causing drastic cost increase. SOLUTION: A male screw 61c is formed on an outer peripheral face in the radial direction of a nut 61 screwed to a screw shaft 52, and a female screw 62f screwed to the male screw 61c is formed on the inner peripheral face of a nut case 62. The nut 61 is provided so as to be movable in the axis direction by rotation within the nut case 62. Belleville springs 63 are interposed between both ends in the axial direction of the nut 61 and the nut case 62. At start of the electric motor, the nut 61 is moved in the axial direction within the nut case 62 to press the belleville springs 63. When reaction force of the belleville springs 63 is increased and exceeds static frictional force of a column unit, the nut case 62 is integrated with the nut 61 and moved. Thus, the position of the steering wheel 10 is changed. COPYRIGHT: (C)2009,JPO&INPIT |
