Steer-by-wire steering device

Abstract

The present invention relates to a steer-by-wire type steering device. The steer-by-wire type steering device includes: a screw shaft that rotates together with a steering shaft; a moving member that is coupled to an outer circumferential side of the screw shaft and moves in an axial direction when the screw shaft rotates; a housing in which the screw shaft and the moving member are embedded; and a guide member that is coupled to the housing to support the moving member and guide the axial movement of the moving member.

Description

Technical Field

[0001] This embodiment relates to a steer-by-wire steering device, and more particularly, to a steer-by-wire steering device that can mechanically stop further rotation of the steering wheel when the rotation of the wheel reaches its maximum point and can provide a steering reaction force even when an error occurs in a motor or an electronic controller. Background Art

[0002] Generally, power steering has been developed and applied to vehicle steering devices to provide convenience in driving operations by assisting the operating force of the driver's steering wheel. The developed and applied power steering is a hydraulic type using hydraulic pressure, an electro-hydraulic type using both hydraulic pressure and the power of a motor, and an electric type using only the power of a motor.

[0003] Recently, instead of removing a mechanical connection device (such as a steering column or a universal joint or a pinion shaft) between the steering wheel and the wheel, a steer-by-wire (SBW) type steering device for manipulating a vehicle using an electric motor has been developed and applied.

[0004] However, in the case of such a steer-by-wire steering device, since there is no mechanical connection between the steering shaft and the wheel, the rotation of the driver's steering wheel can rotate infinitely, thereby reducing the driver's steering feeling and steering stability.

[0005] In addition, in a steer-by-wire steering device, when a motor or an electronic controller fails or malfunctions, a steering reaction force cannot be generated, thereby deteriorating the driver's steering feeling and steering stability.

[0006] Therefore, when the rotation of the wheel reaches the maximum point (when the steering wheel or the wheel is in a full-steering state in a general steering device), it is necessary to prevent the steering wheel from rotating more and to prevent deterioration of the driver's steering feeling and steering stability even when an error occurs in the motor or the electronic controller. Summary of the Invention

[0007] This embodiment can provide a steer-by-wire steering device that can increase the driver's steering feeling and steering stability by preventing the steering wheel from rotating mechanically more when the rotation of the wheel reaches the maximum point.

[0008] In addition, this embodiment can provide a steer-by-wire steering device that can increase the driver's steering feeling and steering stability by generating a physical steering reaction force even when a failure or malfunction of a motor or an electronic controller occurs.

[0009] In addition, the object of this embodiment is not limited thereto, and other objects not mentioned will be clearly understood by those skilled in the art from the following description.

[0010] According to one aspect, the present embodiment provides a steer-by-wire steering device, which includes: a screw shaft having an outer circumferential thread portion provided on an outer circumferential surface thereof and rotating together with a steering shaft; a moving member coupled to an outer circumferential side of the screw shaft and having an inner circumferential thread portion and moving in an axial direction when the screw shaft rotates, the inner circumferential thread portion being threadedly coupled to the outer circumferential thread portion and formed on an inner circumferential surface; a housing in which the screw shaft and the moving member are embedded; and a guide member coupled to the housing to support the moving member and guide an axial movement of the moving member.

[0011] According to the present embodiment, a steer-by-wire steering device can be provided, which can increase a driver's steering feeling and steering stability by preventing the steering wheel from mechanically rotating more when the rotation of the wheel reaches a maximum point.

[0012] In addition, a steer-by-wire steering device can be provided, which can increase a driver's steering feeling and steering stability by generating a physical steering reaction force even when a failure or malfunction of a motor or an electronic controller occurs. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a configuration diagram schematically showing a steer-by-wire steering device according to the present embodiment.

[0014] Figure 2 is a perspective view showing a part of a steer-by-wire steering device according to the present embodiment.

[0015] Figure 3 and Figure 4 are exploded perspective views showing some steer-by-wire steering devices according to the present embodiment.

[0016] Figure 5 is a cross-sectional view showing a part of a steer-by-wire steering device according to the present embodiment.

[0017] Figure 6 and Figure 7 are exploded perspective views showing some steer-by-wire steering devices according to the present embodiment.

[0018] Figure 8 is a front view showing a part of a steer-by-wire steering device according to the present embodiment.

[0019] Figures 9 to 11 is a side view showing some steer-by-wire steering devices according to the present embodiment. DETAILED DESCRIPTION

[0020] In the following description of examples or embodiments of the present disclosure, reference will be made to the accompanying drawings, in which specific examples or embodiments that can be implemented are illustrated by way of illustration, and even when the same or similar components are shown in different drawings from each other, the same reference numerals and symbols may be used to designate the same or similar components. Further, in the following description of examples or embodiments of the present disclosure, when it is determined that the description will make the subject matter in some embodiments of the present disclosure unclear, the detailed description of well-known functions and components incorporated herein will be omitted. Terms such as "comprising", "having", "containing", "consisting of", "constituting", and "forming" as used herein are generally intended to allow the addition of other components, unless the term is used together with the term "only". As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form.

[0021] Terms such as "first", "second", "A", "B", "(A)", or "(B)" may be used herein to describe elements of the present invention. Each of these terms is not used to define the nature, order, sequence, or quantity of elements, etc., but is only used to distinguish the corresponding element from other elements.

[0022] When referring to a first element being "connected or coupled to", "contacting or overlapping", etc., it should be understood that not only is the first element "directly connected or coupled to" or "directly contacting or overlapping" the second element, but also a third element may be "inserted" between the first and second elements, or the first and second elements may be "connected or coupled to", "contacting or overlapping", etc. with each other via a fourth element. Here, the second element may be included in at least one of two or more elements that are "connected or coupled to", "contacting or overlapping", etc. with each other.

[0023] When using relative terms such as "after", "subsequently", "next", "before", etc. to describe a process or operation of an element or configuration, or a flow or step in an operation, process, or manufacturing method, these terms may be used to describe a non - consecutive or non - sequential process or operation unless the term "directly" or "immediately" is used together.

[0024] In addition, when referring to any dimension, relative size, etc., it should be considered that the numerical value or corresponding information (e.g., level, range, etc.) of an element or feature includes a tolerance or error range, which may be caused by various factors (e.g., process factors, internal or external shock, noise, etc.), even when the relevant description is not specified. Further, the term "may" fully encompasses all meanings of the term "able to".

[0025] Figure 1 is a configuration diagram schematically showing a steer - by - wire type steering device according to the present embodiment. Figure 2 is a perspective view showing a part of a steer - by - wire type steering device according to the present embodiment.Figure 3 and Figure 4 is an exploded perspective view showing some steer-by-wire type steering devices according to the present embodiment. Figure 5 is a cross-sectional view showing a part of the steer-by-wire type steering device according to the present embodiment. Figure 6 and Figure 7 is an exploded perspective view showing some steer-by-wire type steering devices according to the present embodiment. Figure 8 is a front view showing a part of the steer-by-wire type steering device according to the present embodiment. Figures 9 to 11 is a side view showing some steer-by-wire type steering devices according to the present embodiment.

[0026] As shown in Figures 1 to 11 According to the present embodiment, the steer-by-wire type steering device may include: a screw shaft having an outer circumferential thread portion provided on an outer circumferential surface thereof and rotating together with a steering shaft; a moving member coupled to an outer circumferential side of the screw shaft and having an inner circumferential thread portion and moving in an axial direction when the screw shaft rotates, the inner circumferential thread portion being threadedly coupled to the outer circumferential thread portion and formed on an inner circumferential surface; a housing in which the screw shaft and the moving member are embedded; and a guide member coupled to the housing to support the moving member and guide the axial movement of the moving member.

[0027] First, referring to Figure 1 , in the steer-by-wire type steering device according to the present embodiment, an angle sensor 105 and a torque sensor 107 are coupled to one side of a steering shaft 103 connected to a steering wheel 101, and when a driver operates the steering wheel 101, the angle sensor 105 and the torque sensor 107 detect this and send an electrical signal to an electronic controller 110 to start a steering shaft motor 120 and a pinion shaft motor 130.

[0028] The electronic controller 110 controls the steering shaft motor 120 and the pinion shaft motor 130 based on the electrical signals transmitted from the angle sensor 105 and the torque sensor 107 and the electrical signals transmitted from other sensors mounted on the vehicle.

[0029] The steering shaft motor 120 is connected to a speed reducer 135 for reducing the number of revolutions of the motor and providing a reaction force to the steering shaft 103 so that a steering reaction force in the opposite direction is felt when the driver operates the steering wheel 101 during normal driving. And during autonomous driving, steering is performed by controlling the electronic controller 110 without the driver's intention.

[0030] The pinion shaft motor 130 slides a rack bar connected to a pinion shaft 113 to steer the wheels 119 on both sides through a tie rod 115 and a steering knuckle arm 117.

[0031] However, in the drawings of the present embodiment, for the sake of explanation, the angle sensor 105 and the torque sensor 107 are shown as examples disposed on the steering shaft 103, but a vehicle speed sensor, a motor position sensor for transmitting steering information to the electronic controller 110, various radars, lidars, image sensors such as cameras, etc. can be provided, and their detailed descriptions will be omitted hereinafter.

[0032] In such a steer-by-wire type steering device, since the steering wheel 101 and the wheels 119 are not mechanically connected, when the driver operates the steering wheel 101, a mechanical restriction is required to stop the rotation of the steering wheel 101 at a certain angle.

[0033] That is to say, when the rotation of the wheels 119 reaches the maximum point (in a general steering device, when the steering wheel 101 or the wheels 119 are in the full steering state), a rotation angle limiting member 150 for mechanically limiting the rotation angle of the steering shaft 103 is provided so that the steering wheel 101 is not rotated further. Therefore, it provides an accurate steering feeling for the driver.

[0034] The rotation angle limiting member 150 is disposed at the lower end of the steering column 100 and includes a screw shaft 140 that rotates together with the steering shaft 103, a moving member 160 that moves in the axial direction when the screw shaft 140 rotates, and a housing 180 and a guide member 170. The screw shaft 140 and the moving member 160 are housed in the housing 180, and the housing 180 is coupled to a speed reducer 135 provided in the lower part of the steering column 100. The guide member 170 is for guiding the axial movement while restricting the rotation of the moving member 160.

[0035] The screw shaft 140 coupled to and rotating together with the steering shaft 103 has an outer circumferential thread portion 141 formed on the outer circumferential surface, and the moving member 160 is coupled to the outer circumferential side of the screw shaft 140 to move in the axial direction.

[0036] The moving member 160 is coupled to the outer circumferential side of the screw shaft 140, and an inner circumferential thread portion 161 that is screwed onto the outer circumferential thread portion 141 of the screw shaft 140 is formed on the inner circumferential surface of the moving member 160. So that when the screw shaft 140 rotates, the moving member 160 moves in the axial direction while being supported by the guide member 170.

[0037] And, the moving member 160 and the screw shaft 140 are housed in the housing 180, and the housing is coupled to the speed reducer 135 provided at the lower part of the steering column 100, and the guide member 170 that supports the moving member 160 and guides the axial movement of the moving member 160 is coupled to the housing 180.

[0038] The moving member 160 includes a main body 162 in which the screw shaft 140 is coupled to the inner circumferential threaded portion 161 , and an extending portion 163 radially extending from an outer circumferential side of the main body 162 and supported by the guide member 170 .

[0039] The extension portions 163 are provided as a pair on one side and the other side of the radial direction of the movable member 160, and each of the extension portions 163 is provided with a guide hole 168, through which the guide member 170 passes, so that the guide hole 168 is supported by the guide member 170, and when the screw shaft 140 rotates, the movable member 160 slides in the axial direction.

[0040] Also, seating grooves 167 recessed in the axial direction are provided on one side and the other side of the extending portion 163 , and guide holes 168 penetrate within the seating grooves 167 in the radial direction.

[0041] The first supporting members 175a and 177a are elastically supported by the seating groove 167 on one side of the extension portion 163, and the partition wall 181a on one side of the shell 180 is connected to one side of the guide member 170, and the second supporting members 175b and 177b are elastically supported by the seating groove 167 on the other side of the extension portion 163 and the partition wall 181b on the other side of the shell 180 are connected to the other side of the guide member 170.

[0042] Therefore, when the moving member 160 moves to one side and the other side in the axial direction, a steering reaction force is provided to the driver by the elastic restoring force of the first and second support members 175a and 177a and 175b and 177b.

[0043] In particular, even if a malfunction or failure of the motor or the electronic controller occurs, the first support members 175a and 177a and the second support members 175b and 177b generate a physical steering reaction force, enabling the driver to steer safely.

[0044] like Figures 3 to 9 As shown, the first and second supporting members 175 a and 175 b have a coil shape, one end of which is supported by the seating groove 167 , and the other end of which is supported by the housing 180 .

[0045] In addition, if Figure 10 As shown, the first support member 177a and the second support member 177b are formed in a hollow shape, one end of which is supported by the seating groove 167 and the other end is supported by the housing 180. The first support member 177a and the second support member 177b may have one or more radially reduced diameter recessed grooves 178 or radially expanded protruding ends 179 on their outer circumferential surfaces.

[0046] In addition, ifFigure 11 As shown, the first support members 175a and the second support members 175b connected to any one of the extension portions 163 have a coil shape in which one end is supported by the placement groove 167 and the other end is supported by the housing 180. And the first support members 177a and the second support members 177b connected to the other end of the extension portion 163 have a hollow shape in which one end is supported by the placement groove 167 and the other end is supported by the housing 180, and one or more radially reduced-diameter recessed grooves 178 or radially enlarged protruding ends 179 are provided on their outer peripheral surfaces.

[0047] In Figure 11 it, for example, the first support members 175a and the second support members 175b having a coil shape are provided at the upper end of the moving member 160, and the first support members 177a and the second support members 177b provided with the recessed grooves 178 or the protruding ends 179 are provided at the lower end of the moving member 160.

[0048] The through holes 182 through which the steering shaft 103 and the screw shaft 140 pass are provided in the one side partition wall 181a and the other side partition wall 181b of the housing 180 in which the screw shaft 140 and the moving member 160 are embedded, and the fixing holes 188 through which both ends of the guide member 170 are fixed are provided on the radially outer side of the through holes 182 so that both ends of the guide member 170 are connected and fixed.

[0049] Here, the fixing holes 188 may be provided in pairs at symmetric positions on one side and the other side with respect to the central axis of the housing 180, that is, at positions corresponding to the guide holes 168 of the moving member 160, and the guide member 170 may be connected to each fixing hole 188.

[0050] The connecting wall 183 connecting the one side partition wall 181a and the other side partition wall 181b is provided to the housing 180, and the space between the one side partition wall 181a and the other side partition wall 181b provided with the fixing holes 188 is formed to be vertically open so that the assembly and operation of the screw shaft 140, the moving member 160, and the guide member 170 are possible.

[0051] In addition, a fastening flange 185 having a fastening hole 186 is provided to the connecting wall 183 that connects the one side partition wall 181a and the other side partition wall 181b of the housing 180. Accordingly, the fastening flange 185 is connected to the housing of the speed reducer 135 provided below the steering column 100.

[0052] On one side and the other side of the moving member 160, stop protrusions 165a and 165b are provided, which protrude in the axial direction between the main body 162 and the extension portion 163.

[0053] And, shaft stop members 150a and 150b of the support protrusion 151 supported by the stop protrusions 165a and 165b of the moving member 160 are coupled to one end and the other end of the screw shaft 140. Accordingly, when the screw shaft 140 rotates, the moving member 160 moves to one side and the other side, while the stop protrusions 165a and 165b are supported by the support protrusion 151 to prevent movement.

[0054] In addition, the first anti-rotation portion 145 is formed as a flat surface or a curved surface formed by a radius of curvature different from the radius of curvature of the outer circumference of the screw shaft 140, and is provided at one end and the other end of the screw shaft 140.

[0055] The second anti-rotation portion 155 is provided on the inner circumferential surface of the shaft stop members 150a and 150b to have a shape corresponding to and coupled to the first anti-rotation portion 145. Accordingly, when the screw shaft 140 rotates, the shaft stop members 150a and 150b are interlocked and rotated without being displaced.

[0056] However, in the drawings of the present embodiment, the first anti-rotation portion 145 and the second anti-rotation portion 155 are shown as flat.

[0057] The steering shaft 103 includes an output shaft 112 connected to the input shaft 111, the screw shaft 140 is coupled to the outer circumferential surface of the output shaft 112, and the input shaft 111 and the output shaft 112 are coupled via a torsion bar 106.

[0058] Corresponding serrations 112a and 143 are provided on the outer circumferential surface of the output shaft 112 and the inner circumferential surface of the screw shaft 140 such that when the steering shaft 103 rotates without being displaced, the output shaft 112 and the screw shaft 140 are interlocked and rotated.

[0059] A bearing 121 for supporting the rotation of the output shaft 112 is coupled between the outer circumferential surface of the output shaft 112 and the inner circumferential surface of the housing of the speed reducer 135, and a stepped portion 112b for axially supporting one end of the screw shaft 140 is provided on the outer circumferential surface of the output shaft 112.

[0060] In addition, a fixing member 195 for axially supporting the other end of the screw shaft 140 is coupled to the end of the output shaft 112 to axially support the screw shaft 140 to prevent separation.

[0061] As described above, according to the present embodiment, the present embodiment can provide a steer-by-wire type steering device that can increase the driver's steering feeling and steering stability by preventing the steering wheel from mechanically rotating more when the rotation of the wheels reaches the maximum point.

[0062] In addition, the present embodiment can provide a steer-by-wire type steering device that can increase the driver's steering feeling and steering stability by generating a physical steering reaction force even when a failure or malfunction of a motor or an electronic controller occurs.

[0063] The above description has been presented to enable any person skilled in the art to make and use the technical idea of the present disclosure, and the above description has been provided in the context of a specific application and its requirements. Various modifications, additions, and substitutions to the described embodiments will be apparent to those skilled in the art, and the general principles defined herein can be applied to other embodiments and applications without departing from the spirit and scope of the present disclosure. The above description and drawings have provided examples of the technical idea of the present disclosure for illustrative purposes only. That is, the disclosed embodiments are intended to illustrate the scope of the technical idea of the present disclosure. Therefore, the scope of the present disclosure is not limited to the illustrated embodiments, but is the broadest scope consistent with the claims. The protection scope of the present disclosure should be interpreted based on the following claims, and all technical ideas within the scope of their equivalents should be interpreted as being included in the scope of the present disclosure.

[0064] Cross-reference to related applications

[0065] This application claims priority to Korean Patent Application No. 10-2021-0027962, filed on Mar. 3, 2021, which is incorporated herein by reference in its entirety for all purposes as if fully set forth herein.

Claims

1. A steer-by-wire steering device, the steer-by-wire steering device comprising: A screw shaft having an outer circumferential thread portion provided on an outer circumferential surface thereof and rotating together with a steering shaft; A moving member coupled to an outer circumferential side of the screw shaft and having an inner circumferential thread portion, and when the screw shaft rotates, the moving member moves in an axial direction, the inner circumferential thread portion being formed on an inner circumferential surface and threadedly coupled to the outer circumferential thread portion; A housing in which the screw shaft and the moving member are embedded; And A guide member coupled to the housing to support the moving member and guide the axial movement of the moving member, Wherein the moving member includes: a main body to which the screw shaft is coupled; and an extension portion radially extending from an outer circumferential side of the main body and supported by the guide member, Wherein the extension portions are provided in pairs on one side and the other side in a radial direction of the moving member, and each of the extension portions is provided with a guide hole through which the guide member is supported, Wherein a first support member elastically supported by a partition wall on one side of the housing and the extension portion is coupled to one side of the guide member, and a second support member elastically supported by a partition wall on the other side of the housing and the extension portion is coupled to the other side of the guide member, and Wherein seating grooves recessed in the axial direction to support the first support member and the second support member are provided on one side and the other side of the extension portion, and the guide holes are provided to pass through an inner side of the seating grooves in the radial direction.

2. The steer-by-wire steering device according to claim 1, wherein, The first support member and the second support member have a coil shape in which one end is supported by the seating groove and the other end is supported by the housing.

3. The steer-by-wire type steering device according to claim 1, wherein, The first support member and the second support member are formed in a hollow shape in which one end is supported by the seating groove and the other end is supported by the housing, and the first support member and the second support member are provided with at least one recessed groove with a radially reduced diameter or a radially enlarged protruding end on an outer circumferential surface.

4. The steer-by-wire type steering apparatus according to claim 1, wherein, The first support member and the second support member coupled to any one of the extension portions have a coil shape in which one end is supported in the seating groove and the other end is supported in the housing, and the first support member and the second support member coupled to the other end of the extension portion have a hollow shape in which one end is supported in the seating groove and the other end is supported in the housing, and the first support member and the second support member are provided with at least one recessed groove with a radially reduced diameter or a radially enlarged protruding end on an outer circumferential surface.

5. The steer-by-wire type steering device according to claim 1, wherein, Through holes are provided in one partition wall and another partition wall of the housing, the steering shaft and the screw shaft pass through the through holes, and fixing holes are provided on the radially outer sides of the through holes, and both ends of the guide member are fixed through the fixing holes.

6. The steer-by-wire type steering apparatus according to claim 5, wherein, The fixing holes are provided in pairs at symmetric positions on one side and the other side with respect to the central axis of the housing, and the guide member is coupled to each of the fixing holes.

7. The steer-by-wire type steering apparatus according to claim 5, wherein, A connecting wall for connecting one partition wall and the other partition wall is provided in the housing, and the space between the one partition wall and the other partition wall where the fixing holes are provided is formed to be vertically open.

8. The steer-by-wire type steering apparatus according to claim 5, wherein, A connecting wall for connecting one partition wall and the other partition wall is provided in the housing, and a fastening flange having a fastening hole coupled to the steering column is provided on the connecting wall.

9. The steer-by-wire type steering apparatus according to claim 1, wherein, Stopping protrusions protruding in the axial direction between the main body and the extension portion are provided on one side and the other side of the moving member, and an axial stopping member having a supporting protrusion supported by the stopping protrusion is coupled to one end and the other end of the screw shaft.

10. The steer-by-wire type steering apparatus according to claim 9, wherein, First anti-rotation portions are provided at one end and the other end of the screw shaft, and the first anti-rotation portions are formed as flat surfaces or curved surfaces having a curvature radius different from the curvature radius of the outer circumferential surface of the screw shaft.

11. The steer-by-wire type steering apparatus according to claim 10, wherein, Second anti-rotation portions are provided on the inner circumferential surface of the axial stopping member, and the second anti-rotation portions have shapes corresponding to the first anti-rotation portions and are coupled to the first anti-rotation portions.

12. The steer-by-wire type steering apparatus according to claim 1, wherein, The steering shaft includes an output shaft connected to the input shaft, and the screw shaft is coupled to the outer circumferential surface of the output shaft.

13. The steer-by-wire type steering apparatus according to claim 12, wherein, Corresponding sawteeth are provided on the outer circumferential surface of the output shaft and the inner circumferential surface of the screw shaft, so that when the steering shaft rotates, the output shaft and the screw shaft are interlocked and rotate.

14. The steer-by-wire type steering apparatus according to claim 12, wherein, A bearing for supporting the rotation of the output shaft is coupled between the outer circumferential surface of the output shaft and the inner circumferential surface of the housing of the speed reducer.

15. The steer-by-wire type steering apparatus according to claim 12, wherein, A stepped portion for axially supporting one end of the screw shaft is provided on the outer circumferential surface of the output shaft.

16. The steer-by-wire type steering device according to claim 15, wherein, A fixing member for axially supporting the other end of the screw shaft is coupled to the end of the output shaft.

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