Rear wheel steering apparatus for vehicle

Abstract

A rear wheel steering apparatus for a vehicle includes: a housing; a driver supported by the housing and configured to generate a driving force; a transmission shaft movably accommodated in the housing and configured to reciprocate by receiving a driving force from the driver; an anti-rotation member fixed to the housing and configured to restrict rotation of the propeller shaft; and a guide member coupled to the anti-rotation member to be interposed between the driveshaft and the anti-rotation member and configured to guide movement of the driveshaft. According to the present disclosure, a rear wheel steering apparatus for a vehicle may prevent an axial rotation of a propeller shaft within a housing, the propeller shaft being reciprocated within the housing by an anti-rotation member fixed to the housing and configured to surround the propeller shaft.

Description

Technical Field

[0001] Exemplary embodiments of the present disclosure relate to a rear-wheel steering device for a vehicle, and more particularly, to a rear-wheel steering device for a vehicle that can reduce manufacturing costs by simplifying the configuration. Background Art

[0002] A rear-wheel steering (RWS) device is an all-wheel steering (AWS) device that can enhance the responsiveness and driving safety of a vehicle and reduce the turning radius of the vehicle.

[0003] A rear-wheel steering device for a vehicle generally has a structure in which a lead screw is coupled to a nut. A threaded portion is formed on the lead screw, and the lead screw and the nut are screwed together. When the nut is rotated by a driver, the lead screw moves axially. This operation steers the rear wheels of the vehicle.

[0004] At the same time, the axial rotation of the lead screw is blocked by an anti-roll sleeve that engages with a spline formed on the lead screw, and the radial clearance of the lead screw is blocked by bushings installed on both sides of the lead screw.

[0005] The related art of the present utility model is disclosed in Korean Patent Application No. 10-2018-0120447 (published on November 6, 2018 and titled "Rear-Wheel Steering Device"). Summary of the Utility Model

[0006] An object of the present disclosure is to provide a rear-wheel steering device for a vehicle that can prevent the axial rotation of a drive shaft that receives a rotational force from a driver and reciprocates in a housing, and that can stably guide the linear movement of the drive shaft.

[0007] According to an aspect of the present disclosure, there is provided a rear-wheel steering device for a vehicle, which may include: a housing; a driver supported by the housing and configured to generate a driving force; a drive shaft movably accommodated in the housing and configured to reciprocate by receiving the driving force from the driver; an anti-rotation member fixed to the housing and configured to restrict the rotation of the drive shaft; and a guide member coupled to the anti-rotation member to be interposed between the drive shaft and the anti-rotation member and configured to guide the movement of the drive shaft.

[0008] The drive shaft may include: a first shaft including a screw that converts the rotational force generated by the driver into a linear motion; and a second shaft coupled to the first shaft to extend from the first shaft and configured to contact the guide member.

[0009] The guide member may be formed in a hollow shape to surround the outer peripheral surface of the second shaft. The anti-rotation member may be formed in a hollow shape to surround the outer peripheral surface of the guide member.

[0010] On the first surface of the guide member, a slit hole formed along the longitudinal direction of the guide member may be provided.

[0011] On the second surface of the guide member, a first anti-rotation surface configured to restrict the rotation of the second shaft may be formed. On the inner surface of the anti-rotation member that contacts the second surface of the guide member, a second anti-rotation surface configured to restrict the rotation of the guide member may be formed.

[0012] The anti-rotation member may have an anti-free movement portion, which is formed to be recessed on the inner surface of the anti-rotation member to restrict the free movement of the guide member.

[0013] On one or both sides of the anti-free movement portion, an inclined surface may be formed to be spaced apart from the end portion of the guide member.

[0014] On the end portion of the guide member, a flange placed on the end portion of the anti-rotation member may be provided.

[0015] When the transmission shaft moves axially, the flange may be engaged with the anti-rotation member.

[0016] The anti-rotation member may have a recess, which is formed to be recessed on the inner surface of the anti-rotation member, and the recess is formed along the longitudinal direction of the anti-rotation member.

[0017] On the third surface of the guide member, a third anti-rotation surface configured to restrict the rotation of the second shaft may be formed. On the inner surface of the anti-rotation member that contacts the third surface of the guide member, a fourth anti-rotation surface configured to restrict the rotation of the guide member may be formed.

[0018] The recess may include a plurality of recesses, and the plurality of recesses are arranged on the anti-rotation member at intervals along the inner circumferential surface of the anti-rotation member.

[0019] According to the present disclosure, a rear-wheel steering device for a vehicle can prevent the transmission shaft from axially rotating in the housing, and the transmission shaft reciprocates in the housing by being fixed to the housing and an anti-rotation member configured to surround the transmission shaft.

[0020] In addition, according to the present disclosure, a rear-wheel steering device for a vehicle can stably guide the linear movement of the transmission shaft, and the transmission shaft slides by a guide member coupled to the inside of the anti-rotation member and interposed between the transmission shaft and the anti-rotation member.

[0021] In addition, according to the present disclosure, a rear-wheel steering device for a vehicle can improve productivity by simplifying the structure and reducing the cumulative tolerance between components, and can reduce manufacturing dispersion by increasing the degree of freedom of coaxiality compared with conventional devices. Description of the Drawings

[0022] Figure 1 is a cross-sectional view of one side of a rear-wheel steering device for a vehicle according to an embodiment of the present disclosure.

[0023] Figure 2 is taken along Figure 1 line A-A in

[0024] Figure 3 is a perspective view of one embodiment of a guide member in a rear-wheel steering device for a vehicle according to a first embodiment of the present disclosure.

[0025] Figure 4 is a perspective view of another embodiment of a guide member in a rear-wheel steering device for a vehicle according to a first embodiment of the present disclosure.

[0026] Figure 5 is a cross-sectional view of one side of a guide member coupled to an anti-rotation member in a rear-wheel steering device for a vehicle according to a first embodiment of the present disclosure.

[0027] Figure 6 is a perspective view of one embodiment of a guide member in a rear-wheel steering device for a vehicle according to a second embodiment of the present disclosure.

[0028] Figure 7 is a perspective view of another embodiment of a guide member in a rear-wheel steering device for a vehicle according to a second embodiment of the present disclosure.

[0029] Figure 8 is a perspective view of yet another embodiment of a guide member in a rear-wheel steering device for a vehicle according to a second embodiment of the present disclosure.

[0030] Figure 9 is a cross-sectional view of one side of a guide member coupled to an anti-rotation member in a rear-wheel steering device for a vehicle according to a second embodiment of the present disclosure.

[0031] Figure 10 is a front cross-sectional view of a guide member coupled to an anti-rotation member in a rear-wheel steering device for a vehicle according to a third embodiment of the present disclosure.

[0032] Figure 11 is a front cross-sectional view of a guide member coupled to an anti-rotation member in a rear-wheel steering device for a vehicle according to a fourth embodiment of the present disclosure. Detailed Description

[0033] Exemplary embodiments of a rear-wheel steering device for a vehicle will be described below with reference to the accompanying drawings. It should be considered that, for clarity and convenience of description, the thickness of each line or the size of each component in the drawings may be enlarged. In addition, the terms used herein are defined in consideration of the functions of the present disclosure, and these terms may be changed according to the intention or practice of the user or operator. Therefore, these terms should be defined based on the overall disclosure set forth herein.

[0034] Figure 1 is a cross-sectional view of one side of a rear-wheel steering device for a vehicle according to an embodiment of the present disclosure. Figure 2 is taken along Figure 1 line A-A in Figure 3 is a perspective view showing one embodiment of a guide member in a rear-wheel steering device for a vehicle according to a first embodiment of the present disclosure. Figure 4 is a perspective view showing another embodiment of a guide member in a rear-wheel steering device for a vehicle according to a first embodiment of the present disclosure. Figure 5 is a cross-sectional view of one side of a guide member coupled to an anti-rotation member in a rear-wheel steering device for a vehicle according to a first embodiment of the present disclosure.

[0035] Referring to Figures 1 to 5 , a rear-wheel steering device 1 for a vehicle according to a first embodiment of the present disclosure may include a housing 100, a driver 200, a drive shaft 300, an anti-rotation member 400, and a guide member 500.

[0036] The housing 100 forms a schematic appearance of the rear-wheel steering device 1 for a vehicle according to an embodiment of the present disclosure, and integrally supports the driver 200, the drive shaft 300, the anti-rotation member 400, and the guide member 500 (to be described later).

[0037] The housing 100 may be formed in a hollow cylindrical shape having an empty interior. The housing 100 may be disposed between two rear wheels (not shown) on both sides of the vehicle. The housing 100 may be disposed in the longitudinal direction, which is parallel to the width direction of the vehicle.

[0038] The specific shape of the housing 100 is not limited to the shape shown in Figure 1 , but may vary with design changes within the technical spirit of the shape, which may integrally support the configuration of the rear-wheel steering device 1 for a vehicle according to an embodiment of the present disclosure.

[0039] The housing 100 may include a fixing groove 100a. The fixing groove 100a may be formed to be recessed on the inner surface of the housing 100 and may be formed in the circumferential direction of the housing 100. An anti-rotation member 400 (to be described later) may be disposed inside the fixing groove 100a and fixed to the housing 100.

[0040] The driver 200 is supported by the housing 100 and generates a driving force to move a transmission shaft 300 (to be described later) inside the housing 100. The driver 200 may include a power generation part 210 and a power transmission part 220.

[0041] The power generation part 210 receives power from an external source and generates a rotational force. The power generation part 210 is fixed to the housing 100 and supports the power transmission part 220 (to be described later) as a whole.

[0042] The power generation part 210 may be described by examples of various types of electric motors (such as AC, DC, and BLDC motors, etc.) that convert the power input from an external source into a rotational force. The power generation part 210 may be fixed to the outer surface of the housing 100 by means of bolt connection or welding, etc.

[0043] The power transmission part 220 is connected to the power generation part 210 and the transmission shaft 300 (to be described later), and transmits the rotational force generated by the power generation part 210 to the transmission shaft 300. The power transmission part 220 may include: a first power transmission member 221 that rotates with the output shaft of the power generation part 210; a second power transmission member 222 connected to the first power transmission member 221; and a nut 223 connected to the second power transmission member 222.

[0044] The nut 223 receives the rotational force from the second power transmission member 222 to move the transmission shaft 300. The nut 223 may be formed in a hollow ring shape that is arranged to surround the outer circumferential surface of the transmission shaft 300.

[0045] The nut 223 includes a thread on its inner circumferential surface and is screwed to a threaded portion 311 provided on the transmission shaft 300. When the power generation part 210 is driven, the nut 223 rotates around the central axis of the transmission shaft 300 together with the second power transmission member 222.

[0046] The specific shape of the power transmission part 220 is not limited to the shape shown in Figure 1 but may vary with the design change within the technical spirit of the shape, and this shape may enable the rotational force generated by the power generation part 210 to be transmitted to the transmission shaft 300.

[0047] The drive shaft 300 can be accommodated inside the housing 100 and can move in a direction parallel to the longitudinal direction of the housing 100. Both ends of the drive shaft 300 can be respectively connected to a pair of tie rods (not shown), and this pair of tie rods is connected to the rear wheels of the vehicle.

[0048] The drive shaft 300 receives driving force from the driver 200 to reciprocate inside the housing 100. When the drive shaft 300 reciprocates inside the housing 100, forces are respectively transmitted to the tie rods connected to both ends of the drive shaft 300, thereby changing the angles of the rear wheels. The drive shaft 300 can include a first shaft 310 and a second shaft 320.

[0049] The first shaft 310 can form the appearance of one side of the drive shaft 300. The first shaft 310 is connected to the driver 200 and converts the rotational force generated by the driver 200 into linear motion. Therefore, the first shaft 310 can linearly reciprocate the drive shaft 300 inside the housing 100.

[0050] The first shaft 310 can be formed in a rod shape, and a threaded portion 311 is provided on the outer peripheral surface of the first shaft. The first shaft 310 can be arranged in the longitudinal direction, and this longitudinal direction is parallel to the longitudinal direction of the housing 100.

[0051] The second shaft 320 can extend from the first shaft 310 to form the appearance of the other side of the drive shaft 300. The second shaft 320 can be formed to extend from one end of the first shaft 310 ( Figure 1 the right side in

[0052] in the longitudinal direction parallel to the first shaft 310). The second shaft 320 can be integrally manufactured with the first shaft 310, or alternatively, can be separately manufactured from the first shaft 310 and coupled to the first shaft 310. The outer peripheral surface of the second shaft 320 can contact the inner peripheral surface of the guide member 500 (to be described later).

[0053] The anti-rotation member 400 is coupled to the inside of the housing 100. The anti-rotation member 400 is disposed inside a fixing groove 100a formed on the inner surface of the housing 100 to be fixed to the housing 100. More specifically, the anti-rotation member 400 is coupled to the housing 100 when the inner peripheral surface of the housing 100 and the outer peripheral surface of the anti-rotation member 400 are in contact with each other.

[0054] The anti-rotation member 400 restricts the rotation of the drive shaft 300 to prevent relative rotation between the housing 100 and the drive shaft 300.

[0055] The anti-rotation member 400 allows the drive shaft 300 to reciprocate in the longitudinal direction of the housing 100 while preventing the drive shaft 300 from axially rotating inside the housing 100.

[0056] The anti-rotation member 400 is located on the outer peripheral portion of the second shaft 320. The anti-rotation member 400 can be formed in an empty hollow shape, and its central portion is penetrated in the axial direction of the transmission shaft 300 to surround the entire outer peripheral surface of a guiding member 500 (to be described later) between the anti-rotation member 400 and the second shaft 320.

[0057] The guiding member 500 is coupled to the inside of the anti-rotation member 400. The guiding member 500 is interposed between the second shaft 320 and the anti-rotation member 400. The guiding member 500 can be formed in an empty hollow shape, and its central portion is penetrated in the axial direction of the transmission shaft 300 to surround the entire outer peripheral surface of the second shaft 320.

[0058] The guiding member 500 can be arranged such that the outer peripheral surface of the guiding member 500 contacts the inner peripheral surface of the anti-rotation member 400, and such that the inner peripheral surface of the guiding member 500 contacts the outer peripheral surface of the second shaft 320.

[0059] The guiding member 500 can support the transmission shaft 300 inside the anti-rotation member 400 to guide the sliding movement of the second shaft 320.

[0060] The guiding member 500 can prevent the transmission shaft 300 from deviating from its correct position and can prevent the transmission shaft from freely moving in the radial direction of the housing 100 inside the housing 100. Accordingly, the guiding member 500 can prevent the transmission shaft 300 from getting stuck or colliding with the inner wall of the housing 100 due to deformation or the like.

[0061] The inner peripheral surface of the guiding member 500 can be made of a material having a low coefficient of friction to stably support the transmission shaft 300 while not excessively disturbing the movement of the second shaft 320.

[0062] The guiding member 500 can include a slit hole 501a. The slit hole 501a can be provided on a first surface 501 of the guiding member 500. The slit hole 501a can be formed by penetrating the first surface in the inside-outside direction of the first surface.

[0063] The slit hole 501a can be formed in an elongated hole shape extending in the longitudinal direction of the guiding member 500, and the longitudinal direction of the guiding member is in the same direction as the axial direction of the transmission shaft 300. The slit hole 501a can be formed in a straight line shape or in an oblique line shape toward the longitudinal direction of the guiding member 500.

[0064] When the guiding member 500 is coupled to the anti-rotation member 400, due to the tolerance between the anti-rotation member 400 and the guiding member 500, the slit hole 501a can be loose or stuck, thereby minimizing the dispersion of the frictional force during the sliding movement of the second shaft 320 to achieve uniform performance. In addition, the slit hole 501a can allow air to flow in the longitudinal direction of the guiding member 500.

[0065] The slit hole 501a can be formed by penetrating between two end portions of the guiding member 500, or can be formed at one end portion of the guiding member 500, and the length is about 2 / 3 of the length of the guiding member 500.

[0066] The guiding member 500 can include a first anti-rotation surface 502a. The first anti-rotation surface 502a can be formed on the second surface 502 of the guiding member 500. Here, the second surface 502 can be located on both sides of the first surface 501 respectively. More specifically, a pair of second surfaces 502 can be arranged to be spaced apart from each other and opposite to each other.

[0067] The first anti-rotation surface 502a can be formed in a flat shape. The first anti-rotation surface 502a can limit the axial rotation of the second shaft 320.

[0068] The anti-rotation member 400 in contact with the second surface 502 of the guiding member 500 can include a second anti-rotation surface 401. The second anti-rotation surface 401 can be formed on the inner surface of the anti-rotation member 400 in contact with the second surface 502.

[0069] The second anti-rotation surface 401 can be formed in a flat shape. The second anti-rotation surface 401 can limit the rotation of the guiding member 500 to prevent the guiding member 500 from rotating together with the second shaft 320.

[0070] The anti-rotation member 400 can have an anti-free movement portion 410. The anti-free movement portion 410 can be formed to be recessed on the inner surface of the anti-rotation member 400. The anti-free movement portion 410 can be formed on the inner circumferential surface of the anti-rotation member 400. The guiding member 500 can be placed inside the anti-free movement portion 410, and the outer circumferential surface of the guiding member 500 can be press-fitted to the inner surface of the anti-rotation member 400 so that the guiding member 500 can be fixed.

[0071] Thus, the anti-free movement portion 410 can limit the guiding member 500 to prevent the guiding member 500 from freely moving in the axial direction of the transmission shaft 300 when the transmission shaft 300 moves.

[0072] The inclined surface 411 may be formed inclined at a predetermined angle on one or both sides of the anti-free movement part 410 and spaced apart from the end of the guide member 500. The inclined surface 411 may be chamfered so that the inclined surface 411 does not contact the end of the guide member 500. The inclined surface 411 may minimize the impact sound generated by the collision with the anti-rotation member 400 caused by the free movement of the guide member 500.

[0073] Figure 6 is a perspective view showing one embodiment of a guide member in a rear-wheel steering device for a vehicle according to a second embodiment of the present disclosure. Figure 7 is a perspective view showing another embodiment of a guide member in a rear-wheel steering device for a vehicle according to a second embodiment of the present disclosure. Figure 8 is a perspective view showing still another embodiment of a guide member in a rear-wheel steering device for a vehicle according to a second embodiment of the present disclosure. Figure 9 is a cross-sectional view showing one side of a guide member coupled to an anti-rotation member in a rear-wheel steering device for a vehicle according to a second embodiment of the present disclosure.

[0074] The rear-wheel steering device 1 for a vehicle according to a second embodiment of the present disclosure may include a housing 100, a driver 200, a transmission shaft 300, an anti-rotation member 400, and a guide member 500.

[0075] When describing the rear-wheel steering device 1 for a vehicle according to a second embodiment of the present disclosure, another embodiment of the guide member 500 described in the rear-wheel steering device 1 for a vehicle according to a first embodiment of the present disclosure will be described below.

[0076] For the configuration of elements other than the guide member of the rear-wheel steering device 1 for a vehicle according to a second embodiment of the present disclosure, the same description of the rear-wheel steering device 1 for a vehicle according to a first embodiment of the present disclosure may be used.

[0077] Reference Figures 6 to 9 , the guide member 500 may further include a flange 510. The flange 510 may be integrally provided at one end of the guide member 500 in its longitudinal direction. The flange 510 may be formed to protrude from the outer peripheral surface of the guide member 500 and may be formed along the outer peripheral surface of the guide member 500.

[0078] The flange 510 may be formed to have the same diameter as the anti-rotation member 400 or a larger diameter than the anti-rotation member 400. Thus, when the guide member 500 is coupled to the inside of the anti-rotation member 400, the flange 510 may be placed on one end of the anti-rotation member 400 in its longitudinal direction.

[0079] When the transmission shaft 300 moves axially, the flange 510 can be engaged with the anti-rotation member 400 so that the guide member 500 can be fixed to the anti-rotation member 400.

[0080] The guide member 500 may include a slit hole 501a. The slit hole 501a may be provided on the first surface 501 of the guide member 500. The slit hole 501a may be formed by penetrating the first surface in the inner and outer directions of the first surface.

[0081] The slit hole 501a may be formed in an elongated hole shape extending in the longitudinal direction of the guide member 500, and the longitudinal direction of the guide member is in the same direction as the axial direction of the transmission shaft 300. The slit hole 501a may be formed in a straight line shape or an oblique line shape toward the longitudinal direction of the guide member 500.

[0082] The slit hole 501a may be formed by penetrating between the two end portions of the guide member 500, or may be formed at one end portion or the other end portion of the guide member 500, and the length is about 2 / 3 of the length of the guide member 500.

[0083] Figure 10 is a front cross-sectional view of a guide member coupled to an anti-rotation member in a rear-wheel steering device for a vehicle according to a third embodiment of the present disclosure.

[0084] Reference Figure 10 , the rear-wheel steering device 1 for a vehicle according to a third embodiment of the present disclosure may include a housing 100, a driver 200, a transmission shaft 300, an anti-rotation member 400, and a guide member 500.

[0085] When describing the rear-wheel steering device 1 for a vehicle according to a third embodiment of the present disclosure, another embodiment of the anti-rotation member 400 and the guide member 500 described in the rear-wheel steering device 1 for a vehicle according to a first embodiment or a second embodiment of the present disclosure will be described below.

[0086] For the configuration of elements other than the anti-rotation member and the guide member of the rear-wheel steering device 1 for a vehicle according to a third embodiment of the present disclosure, the same description of the rear-wheel steering device 1 for a vehicle according to a first embodiment or a second embodiment of the present disclosure can be used.

[0087] The anti-rotation member 400 may include a recess 420. The recess 420 may be formed to be recessed on the inner surface of the anti-rotation member 400. The recess 420 may be formed to extend in the longitudinal direction of the anti-rotation member 400, and the longitudinal direction of the anti-rotation member is in the same direction as the axial direction of the transmission shaft 300.

[0088] The recess 420 may be formed by penetrating between two end portions of the anti-rotation member 400, or may be formed at one end portion or the other end portion of the anti-rotation member 400, and has a length of about 2 / 3 of the length of the anti-rotation member 400.

[0089] The recess 420 may be formed in a straight shape or an inclined shape in the longitudinal direction of the anti-rotation member 400. The recess 420 may allow air to flow in the longitudinal direction of the guide member 500.

[0090] The guide member 500 may include a third anti-rotation surface 503a. The third anti-rotation surface 503a may be formed on the third surface 503 of the guide member 500. The third anti-rotation surface 503a may be formed in a flat shape. The third anti-rotation surface 503a may restrict the axial rotation of the second shaft 320.

[0091] The anti-rotation member 400 in contact with the third surface 503 of the guide member 500 may include a fourth anti-rotation surface 402. The fourth anti-rotation surface 402 may be formed on the inner surface of the anti-rotation member 400 that contacts the third surface 503.

[0092] The fourth anti-rotation surface 402 may be formed in a flat shape. The fourth anti-rotation surface 402 may restrict the rotation of the guide member 500 to prevent the guide member 500 from rotating together with the second shaft 320.

[0093] Figure 11 is a front sectional view showing a guide member coupled to an anti-rotation member in a rear-wheel steering device for a vehicle according to a fourth embodiment of the present disclosure.

[0094] Reference Figure 11 , a rear-wheel steering device 1 for a vehicle according to a fourth embodiment of the present disclosure may include a housing 100, a driver 200, a drive shaft 300, an anti-rotation member 400, and a guide member 500.

[0095] When describing the rear-wheel steering device 1 for a vehicle according to the fourth embodiment of the present disclosure, another embodiment of the guide member 500 described in the rear-wheel steering device 1 for a vehicle according to the first embodiment, the second embodiment, or the third embodiment of the present disclosure will be described below.

[0096] For the configuration of elements other than the anti-rotation member of the rear-wheel steering device 1 for a vehicle according to the fourth embodiment of the present disclosure, the same description of the rear-wheel steering device 1 for a vehicle according to the first embodiment, the second embodiment, or the third embodiment of the present disclosure may be used.

[0097] A plurality of recesses 420 may be arranged at intervals from each other along the inner circumferential surface of the anti-rotation member 400.

[0098] A third anti-rotation surface 503a provided on the guide member 500 may be formed on a third surface 503 of the guide member 500. A pair of third surfaces 503 may be arranged at intervals from each other and opposite to each other.

[0099] A fourth anti-rotation surface 402 provided on the anti-rotation member 400 and in contact with the third surface 503 of the guide member 500 may be formed on the inner surface of the anti-rotation member 400.

[0100] A rear-wheel steering device 1 for a vehicle according to an embodiment of the present disclosure may prevent an axial rotation of a drive shaft 300 inside a housing 100, and the drive shaft reciprocates within the housing 100 through an anti-rotation member 400 fixed to the housing 100 and configured to surround the drive shaft 300.

[0101] A rear-wheel steering device 1 for a vehicle according to an embodiment of the present disclosure may stably guide a linear movement of a drive shaft 300, and the drive shaft 300 slidably moves through a guide member 500 coupled to the inside of the anti-rotation member 400 and interposed between the drive shaft 300 and the anti-rotation member 400.

[0102] A rear-wheel steering device 1 for a vehicle according to an embodiment of the present disclosure may improve productivity by simplifying a structure and reducing cumulative tolerances between components, and may reduce manufacturing dispersion by increasing a degree of freedom of coaxiality as compared with a conventional device.

[0103] The present disclosure has been described with reference to the embodiments shown in the drawings, but these embodiments are merely exemplary. Those skilled in the art of the present technology should understand that various modifications and other equivalent embodiments may be made without departing from the spirit and scope of the present disclosure.

Claims

1. A rear-wheel steering device for a vehicle, characterized in that, The rear-wheel steering device includes: A housing; A driver supported by the housing and configured to generate a driving force; A drive shaft movably accommodated in the housing and configured to reciprocate by receiving the driving force from the driver; An anti-rotation member fixed to the housing and configured to restrict the rotation of the drive shaft; and A guide member coupled to the anti-rotation member to be interposed between the drive shaft and the anti-rotation member and configured to guide the movement of the drive shaft.

2. The rear-wheel steering device for a vehicle according to claim 1, characterized in that, The drive shaft includes: A first shaft including a screw that converts the rotational force generated by the driver into linear motion; and A second shaft coupled to the first shaft and configured to contact the guide member.

3. The rear-wheel steering device for a vehicle according to claim 2, characterized in that, The guide member is formed in a hollow shape to surround the outer peripheral surface of the second shaft, and the anti-rotation member is formed in a hollow shape to surround the outer peripheral surface of the guide member.

4. The rear-wheel steering device for a vehicle according to claim 3, characterized in that, A slit hole is provided on a first surface of the guide member and formed along the longitudinal direction of the guide member.

5. The rear wheel steering device for a vehicle according to claim 4, characterized in that, A first anti-rotation surface configured to restrict the rotation of the second shaft is formed on a second surface of the guide member, and a second anti-rotation surface configured to restrict the rotation of the guide member is formed on an inner surface of the anti-rotation member that contacts the second surface of the guide member.

6. The rear-wheel steering device for a vehicle according to claim 5, characterized in that, The anti-rotation member includes an anti-free movement portion formed to be recessed on the inner surface of the anti-rotation member to restrict the free movement of the guide member.

7. The rear-wheel steering device for a vehicle according to claim 6, characterized in that, An inclined surface is formed on one or both sides of the anti-free movement portion, and the inclined surface is formed to be spaced apart from an end portion of the guide member.

8. The rear wheel steering device for a vehicle according to claim 5, characterized in that, A flange is provided on one end portion of the guide member and placed on an end portion of the anti-rotation member.

9. The rear wheel steering device for a vehicle according to claim 8, wherein, When the drive shaft moves axially, the flange engages with the anti-rotation member.

10. The rear-wheel steering device for a vehicle according to claim 3, characterized in that, The anti-rotation member includes a recess formed to be recessed on the inner surface of the anti-rotation member, and the recess is formed along the longitudinal direction of the anti-rotation member.

11. The rear wheel steering device for a vehicle according to claim 10, wherein A third anti-rotation surface configured to restrict the rotation of the second shaft is formed on a third surface of the guide member, and a fourth anti-rotation surface configured to restrict the rotation of the guide member is formed on an inner surface of the anti-rotation member that contacts the third surface of the guide member.

12. The rear-wheel steering device for a vehicle according to claim 10, characterized in that, The recess includes a plurality of recesses arranged at intervals along the inner peripheral surface of the anti-rotation member on the anti-rotation member.

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