Steering column device

1. A steering column device comprising:

a pair of left and right sidewalls which extend downward from a lower part of a steering column and in each of which are formed a tilt-operation-shaft holding hole capable of holding a tilt operation shaft and a spring insertion hole capable of letting a hold end part of a spring inserted thereinto;

a tilt bracket which includes wall surface parts disposed on an outer side of the sidewalls of the steering column in a vehicle width direction, the wall surface parts each including a tilt slot extending in a vertical direction and being capable of letting the tilt operation shaft inserted thereinto, and a plurality of tilt holes spaced from each other in the vertical direction and being capable of holding the hold end part of the spring;

the tilt operation shaft, which extends in the vehicle width direction through the tilt-operation-shaft holding holes in the sidewalls of the steering column and the tilt slots in the wall surface parts of the tilt bracket; and

the spring, which is elastically deformable, is held around an outer peripheral surface of the tilt operation shaft with left and right end parts thereof inserted into the spring insertion holes in the sidewalls of the steering column and ones of the tilt holes in the wall surface parts of the tilt bracket, and is formed in a hat shape in a front view,

wherein, on an outer peripheral surface of a part of the tilt operation shaft between the sidewalls of the steering column, a pair of left and right protrusions are disposed opposite to each other which protrude outward in a radial direction,

the pair of protrusions include mutually facing side surfaces formed as slanted parts defining a truncated V shape in a plan view such that the slanted parts get closer to each other as extending in a circumferential direction of the tilt operation shaft, and

when the tilt operation shaft is rotated, parts of the spring come into contact with the slanted parts of the protrusions and become elastically deformed, thereby pulling the hold end parts of the spring out of the tilt holes in the wall surface parts of the tilt bracket.

2. The steering column device according to claim 1 , wherein

the tilt operation shaft is a cylindrical body extending in the vehicle width direction,

the spring is formed as a single body in a hat shape in a front view with

a base part extending in an axial direction of the tilt operation shaft,

curved parts extending from left and right ends of the base part along the circumferential direction of the tilt operation shaft,

leg parts extending upright from tips of the curved parts outwardly in the radial direction of the tilt operation shaft, and

the hold end parts, extending away from each other from tips of the leg parts along the axial direction of the tilt operation shaft, and

when the tilt operation shaft is rotated, the leg parts of the spring come into contact with the slanted parts of the protrusions and become elastically deformed to get closer to each other, thereby pulling the hold end parts of the spring out of the tilt holes in the wall surface parts of the tilt bracket.