Steering column for vehicle
According to a steering column for a vehicle according to the present embodiments, a wide convenient space can be secured for a driver in a teles-in state by increasing a teles-stroke while securing an installation space for the steering column, the installation of the steering column is spatially convenient despite the increased teles-stroke, and a teles operation can be quickly performed without increasing the output of a motor, and thus a convenient space can be quickly secured for a driver without degraded noise performance.
1. A steering column for a vehicle, comprising:
a mounting bracket having a lower end coupled with a first nut screw;
an upper column having an inner circumferential surface coupled with a steering shaft and having an outer circumferential surface coupled with a second nut screw; and
a lower column including a first bolt screw including a first bolt part coupled to the first nut screw and a second bolt part coupled to the second nut screw and a telescope driving unit including a first motor for rotating the first bolt screw,
wherein the first nut screw includes a nut part having a screw hole through which the first bolt part is inserted and a body part having a coupling hole through which the steering shaft is inserted.
2. The steering column of claim 1 , wherein the first bolt part and the second bolt part are threaded in opposite directions.
3. The steering column of claim 2 , wherein the first bolt part and the second bolt part have the same lead.
4. The steering column of claim 2 , wherein a lead of the first bolt part is smaller than a lead of the second bolt part.
5. The steering column of claim 1 , wherein the telescope driving unit includes a first worm wheel coupled to the first bolt screw and a first worm shaft coupled to a motor shaft of the first motor and engaged with the first worm wheel.
6. The steering column of claim 1 , wherein a pair of first coupling parts provided to face each other with the first nut screw disposed therebetween are formed on the mounting bracket,
wherein a lower end of the lower column has a first guide rail formed to be axially elongated through an inner and outer surface thereof, between the first coupling parts and the first nut screw, and
wherein a first coupling member inserted to the first guide rail and coupled to the first nut screw is coupled to the first coupling parts.
7. The steering column of claim 6 , wherein a first bushing is provided between an inner surface of the first guide rail and an outer surface of the first coupling member.
8. The steering column of claim 6 , wherein an insertion hole is formed in each of two opposite sides of the first nut screw to allow an end of the first coupling member to be inserted therethrough, and
wherein a second bushing is provided between an inner surface of the insertion hole and an outer surface of the first coupling member.
9. The steering column of claim 6 , wherein a pair of second coupling parts provided to face each other with the lower column disposed therebetween are formed on an upper end of the mounting bracket,
wherein a link bracket is hinged to outer circumferential surfaces of the second coupling parts,
wherein an upper end of the lower column is formed with an axially elongated second guide rail as an outer circumferential surface thereof is recessed, and
wherein a second coupling member inserted to the second guide rail is coupled to the link bracket.
10. The steering column of claim 9 , wherein the first guide rail and the second guide rail have the same axial length.
11. The steering column of claim 9 , wherein a third bushing is provided between an outer surface of the second coupling member and an inner surface of the second guide rail.
12. The steering column of claim 9 , wherein a third nut screw is hinged to the link bracket,
wherein a second bolt screw is coupled to the third nut screw, and
wherein a tilt driving unit including a second motor for rotating the second bolt screw is coupled to the mounting bracket.
13. The steering column of claim 12 , wherein the tilt driving unit includes a second worm wheel coupled to the second bolt screw and a second worm shaft coupled to a motor shaft of the second motor and engaged with the second worm wheel.