STEER-BY-WIRE STEERING APPARATUS
According to embodiments of the present invention, the maximum rotation angle of a steering wheel can be easily changed, the steering feel provided to a driver can be enhanced by improved noise performance, and the durability of components can be improved.
1 . A steer-by-wire steering device, comprising:
a steering shaft including a wing portion radially extruding from an outer circumferential surface thereof;
a housing having a receiving space for receiving the wing portion, coupled to the steering shaft, and having a rheological fluid in the receiving space; and
an electronic control unit controlling a viscosity of the rheological fluid based on a steering angle of the steering shaft.
2 . The steer-by-wire steering device of claim 1 , wherein the rheological fluid is an electro-rheological fluid, and wherein the housing has an electric field application unit connected with the electronic control unit to apply an electric field to the electro-rheological fluid.
3 . The steer-by-wire steering device of claim 1 , wherein the rheological fluid is a magneto-rheological fluid, and wherein the housing has a magnetic field application unit connected with the electronic control unit to apply a magnetic field to the magneto-rheological fluid.
4 . The steer-by-wire steering device of claim 1 , wherein the electronic control unit increases the viscosity of the rheological fluid to restrain the rotation of the steering shaft if the steering angle of the steering shaft reaches a first rotational angle.
5 . The steer-by-wire steering device of claim 4 , wherein the electronic control unit solidifies the rheological fluid to restrain the rotation of the steering shaft.
6 . The steer-by-wire steering device of claim 4 , wherein the electronic control unit sets the viscosity of the rheological fluid to a base viscosity value if the steering angle is smaller than the first rotational angle.
7 . The steer-by-wire steering device of claim 4 , wherein the electronic control unit increases the viscosity of the rheological fluid as the steering angle increases if the steering angle has a value between the first rotational angle and a second rotational angle smaller than the first rotational angle.
8 . The steer-by-wire steering device of claim 7 , wherein a difference between the first rotational angle and the second rotational angle is 10° or more and 20° or less.
9 . The steer-by-wire steering device of claim 7 , wherein the electronic control unit sets the viscosity of the rheological fluid to a base viscosity value if the steering angle is smaller than the second rotational angle.
10 . The steer-by-wire steering device of claim 4 , wherein the first rotational angle is determined by a driving mode of a vehicle.
11 . The steer-by-wire steering device of claim 10 , wherein the first rotational angle is set to a first value if the driving mode is a comfort mode and is set to a second value smaller than the first value if the driving mode is a sports mode.
12 . The steer-by-wire steering device of claim 11 , wherein the first value is 450°.
13 . The steer-by-wire steering device of claim 11 , wherein the second value is 324°.