Steer-by-wire steering apparatus
According to the embodiments of the present invention, the drive feel suitable to given conditions is provided to a driver by generating friction when a steering shaft is rotated to enhance the drive feel of the driver, limiting the maximum steering angle, restoring the steering wheel automatically, and controlling friction on the steering shaft in accordance with the steering angle, vehicle speed and road conditions.
1. A steer-by-wire steering device, comprising:
a first housing having a first hole into which a steering shaft is inserted and a second hole having two opposite radial open ends and communicating with the first hole;
a hollow sliding member screwed to the steering shaft and received in the first hole; and
a pressurizing mechanism received in the second hole and including a first supporting member supported on the sliding member, an elastic member having an end supported on the first supporting member, and a second supporting member supported on another end of the elastic member.
2. The steer-by-wire steering device of claim 1 , wherein a sleeve having a threaded outer circumferential surface is coupled to the steering shaft, and wherein the sliding member is screwed with the sleeve.
3. The steer-by-wire steering device of claim 1 , wherein an outer circumferential surface of each of the first supporting member and the second supporting member has a first flat portion on one side thereof, and an inner circumferential surface of the second hole has a second flat portion supporting the first flat portion.
4. The steer-by-wire steering device of claim 1 , wherein a coupling member supported on a radial outer surface of the second supporting member is coupled to an inner circumferential surface of the second hole.
5. The steer-by-wire steering device of claim 1 , wherein the first supporting member includes a body supported on the elastic member and a protrusion protruding from the body and supported on the sliding member in a circumferential direction of the sliding member.
6. The steer-by-wire steering device of claim 5 , wherein the protrusion is elongated in a direction perpendicular to both an axial direction of the first hole and an axial direction of the second hole.
7. The steer-by-wire steering device of claim 5 , wherein a pair of stepped portions axially facing each other, with the protrusion disposed therebetween, protrude from an outer circumferential surface of the sliding member.
8. The steer-by-wire steering device of claim 7 , wherein the sliding member includes a contact portion provided between the stepped portions, and
wherein the contact portion includes a center portion having a smallest radial thickness and inclined portions having a radial thickness increasing from the center portion to two opposite axial sides.
9. The steer-by-wire steering device of claim 8 , wherein the protrusion is formed to have a circumferential thickness decreasing to an end thereof, and wherein the center portion is depressed.
10. The steer-by-wire steering device of claim 9 , wherein the inclined portions are formed to have a curvature of an outer surface increasing to the center portion.
11. The steer-by-wire steering device of claim 1 , wherein a second housing coupled with a motor for moving back and forth the second supporting member is coupled to the first housing.
12. The steer-by-wire steering device 11 , wherein the second supporting member has a coupling hole passing through the second supporting member in an axial direction of the second hole, and
wherein a rotation shaft rotated by the motor and screwed with the second supporting member is inserted into the coupling hole.
13. The steer-by-wire steering device of claim 12 , wherein the rotation shaft includes a screw portion inserted into the coupling hole and a coupling portion coupled with a worm wheel, and
wherein a motor shaft of the motor is coupled with a worm shaft engaged with the worm wheel.
14. The steer-by-wire steering device of claim 11 , wherein the motor moves back the second supporting member when a vehicle speed is low and moves forth the second supporting member when the vehicle speed is high.