Steer-by-wire device

Abstract

A steer-by-wire device is disclosed. The steer-by-wire device includes a first guide member formed in a shaft shape, a second guide member coupled to or integrally formed with the first guide member and having a spiral guide groove whose diameter gradually decreases from an outer periphery to a center, a housing in which the first guide member and the second guide member are built and in which a radial slot is formed in a portion facing the guide groove, and a moving member whose one end is supported by the slot and whose other end is supported by the guide groove and moves radially along the slot.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit and priority of Korean Patent Application No. 10-2021-0095048, filed with the Korean Intellectual Property Office on July 20, 2021, the entire disclosure of which is incorporated herein by reference for all purposes as fully set forth herein. Technical Field

[0003] Embodiments of this disclosure relate to a steer-by-wire steering apparatus, and more specifically, to a steer-by-wire apparatus capable of mechanically preventing further rotation of the steering wheel when the rotation of the wheel reaches its maximum point. Background Technology

[0004] Power steering has typically been developed and applied to vehicle steering systems to provide ease of driving by assisting the driver in maneuvering the steering wheel. Power steering has been developed and applied to hydraulic systems using hydraulic pressure, electro-hydraulic systems using both hydraulic pressure and electric power from an electric motor, and electric systems using only electric power from an electric motor.

[0005] Recently, instead of removing mechanical connections such as steering columns, universal joints, or pinion shafts between the steering wheel and the wheels, steer-by-wire (SBW) steering systems that use electric motors to steer vehicles have been developed and applied.

[0006] However, in the case of this steer-by-wire system, because there is no mechanical connection between the steering shaft and the wheels, the driver's steering wheel can rotate indefinitely, thereby reducing the driver's steering feel and steering stability.

[0007] In addition, in a steering system, when the motor or electronic control device malfunctions or fails to work, it cannot generate steering reaction force, thereby reducing the driver's steering feel and steering stability.

[0008] Therefore, when the wheel rotation reaches its maximum point (in a conventional steering system, when the steering wheel or wheel is in full rotation), it is necessary to study how to prevent the steering wheel from continuing to rotate. Summary of the Invention

[0009] Embodiments of this disclosure provide a steer-by-wire device that can increase the driver's steering feel and steering stability by preventing the steering wheel from continuing to rotate mechanically when the wheel rotation reaches its maximum point.

[0010] Furthermore, the purposes of the embodiments disclosed herein are not limited thereto, and other unmentioned purposes will be clearly understood by those skilled in the art based on the following description.

[0011] The steer-by-wire device according to embodiments of the present disclosure may include: a first guide member formed in an axle shape; a second guide member coupled to or integrally formed with the first guide member and having a helical guide groove, the diameter of which gradually decreases from the outer periphery to the center; a housing in which the first and second guide members are housed and radial slots are formed in the portion of the housing facing the guide groove; and a moving member, one end of which is supported by the slot and the other end of which is supported by the guide groove and moves radially along the slot.

[0012] According to embodiments of the present disclosure, a steer-by-wire device is provided that increases the driver's steering feel and steering safety by preventing the steering wheel from continuing to rotate mechanically when the wheel rotation reaches its maximum point. Attached Figure Description

[0013] The above and other aspects, features and advantages of this disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, wherein:

[0014] Figure 1 This is a schematic diagram illustrating a steer-by-wire device according to an embodiment of the present disclosure;

[0015] Figures 2 to 4 This is a perspective view showing a steer-by-wire device according to an embodiment of the present disclosure;

[0016] Figures 5 to 7 This is an exploded perspective view showing a steer-by-wire device according to an embodiment of the present disclosure;

[0017] Figure 8 This is a perspective view showing a steer-by-wire device according to an embodiment of the present disclosure;

[0018] Figure 9 This is an exploded perspective view showing a steer-by-wire device according to an embodiment of the present disclosure;

[0019] Figure 10 This is a perspective view showing a steer-by-wire device according to an embodiment of the present disclosure;

[0020] Figure 11 This is an exploded perspective view showing a steer-by-wire device according to an embodiment of the present disclosure;

[0021] Figure 12 This is a front view showing a steer-by-wire device according to an embodiment of the present disclosure. Detailed Implementation

[0022] In the following description of examples or embodiments of this disclosure, reference will be made to the accompanying drawings, which illustrate specific examples or embodiments that may be implemented by way of illustration, and wherein even if the same reference numerals and symbols are shown in different drawings, they may be used to denote the same or similar components. Further, in the following description of examples or embodiments of this disclosure, detailed descriptions of well-known functions and components incorporated herein will be omitted when it is determined that the description might obscure the subject matter of some embodiments of this disclosure. Terms such as “comprising,” “having,” “including,” “constituting,” “forming,” “comprise,” and “form” as used herein are generally intended to allow for the addition of additional components unless these terms are used in conjunction with the term “only.” As used herein, the singular forms are intended to include the plural forms unless the context clearly indicates otherwise.

[0023] Terms such as “first,” “second,” “A,” “B,” “(A),” or “(B)” may be used herein to describe elements of this disclosure. Each of these terms is not used to define elements, order, sequence, or quantity, but only to distinguish the corresponding element from other elements.

[0024] When referring to the first element and the second element as "connected or joined," "in contact or overlapping," etc., it should be explained that the first element can not only be "directly connected or joined" or "directly in contact or overlapping" with the second element, but also that a third element can be "inserted" between the first and second elements, or that the first and second elements can be "connected or joined," "in contact or overlapping," etc., through a fourth element. Here, the second element can be included in at least one of two or more elements that are "connected or joined," "in contact or overlapping," etc., with each other.

[0025] When time-relative terms such as “after,” “following,” “next,” “before” are used to describe a process or operation of an element or configuration, or a flow or step in an operation, processing, or manufacturing method, these terms may also be used to describe a discontinuous or non-sequential process or operation, unless used with the terms “directly” or “immediately after.”

[0026] Furthermore, when referring to any size, relative size, etc., even without a specific description, the numerical value or corresponding information of the element or feature (e.g., grade, range, etc.) should be taken into account, including tolerances or error ranges that may be caused by various factors (e.g., process factors, internal or external influences, noise, etc.). Further, the term "may" fully encompasses all the meanings of the term "able to".

[0027] Figure 1 This is a schematic diagram illustrating a steer-by-wire device according to an embodiment of the present disclosure. Figures 2 to 4 This is a perspective view showing a steer-by-wire device according to an embodiment of the present disclosure. Figures 5 to 7 This is an exploded perspective view showing a steer-by-wire device according to an embodiment of the present disclosure. Figure 8 This is a perspective view showing a steer-by-wire device according to an embodiment of the present disclosure. Figure 9 This is an exploded perspective view showing a steer-by-wire device according to an embodiment of the present disclosure. Figure 10 This is a perspective view showing a steer-by-wire device according to an embodiment of the present disclosure. Figure 11 This is an exploded perspective view showing a steer-by-wire device according to an embodiment of the present disclosure. Figure 12 This is a front view showing a steer-by-wire device according to an embodiment of the present disclosure.

[0028] Reference Figures 1 to 12 According to embodiments of the present disclosure, a steer-by-wire device may include: a first guide member 210, formed in an axle shape; a second guide member 220, connected to or integrally formed with the first guide member 210, and having a spiral guide groove 221, the diameter of which gradually decreases from the outer periphery to the center; a housing 230, in which the first guide member 210 and the second guide member 220 are housed, and a radial slot 231 is formed in a portion of the housing 230 facing the guide groove 221; and a moving member 240, one end of which is supported by the slot 231 and the other end of which is supported by the guide groove 221 and moves radially along the slot 231.

[0029] In the steer-by-wire device according to an embodiment of the present disclosure, an angle sensor 105 and a torque sensor 107 that detect the driver's operation on the steering wheel 101 send electrical signals to an electronic control unit 110 to operate the steering shaft motor 120 and the pinion shaft motor 130.

[0030] The electronic control unit 110 controls the steering shaft motor 120 and the pinion shaft motor 130 based on electrical signals transmitted from the angle sensor 105 and the torque sensor 107, as well as electrical signals transmitted from other sensors installed on the vehicle.

[0031] The steering shaft motor 120 is connected to a reducer 135 to reduce the motor's rotational speed and provides a reaction force to the steering shaft 103 so that the driver feels a steering reaction force in the opposite direction when operating the steering wheel 101 during normal driving. During autonomous driving, steering is performed under the control of the electronic control unit 110 without the driver's intention.

[0032] The pinion shaft motor 130 causes the rack rod 111 connected to the pinion shaft 113 to slide, so as to steer the wheels 119 on both sides through the tie rod 115 and the steering knuckle arm 117.

[0033] However, in the accompanying drawings of the embodiments of this disclosure, for ease of illustration, as an example, angle sensor 105 and torque sensor 107, vehicle speed sensor 104 for transmitting steering information to electronic control unit 110 and wheel rotation angle sensor 106 are shown, but motor position sensor, various radars, lidar, image sensors such as cameras may also be provided, and detailed descriptions thereof are omitted below.

[0034] In this type of steer-by-wire device, since the steering wheel 101 and the wheel 119 are not mechanically connected, mechanical restraint is required when the driver operates the steering wheel 101 to stop the rotation of the steering wheel 101 at a certain angle.

[0035] In other words, when the rotation of wheel 119 reaches its maximum point (in a conventional steering system, when steering wheel 101 or wheel 119 is in full rotation), a rotation angle limiting member 190 is set to mechanically limit the rotation angle of steering shaft 103, so that steering wheel 101 stops rotating. Therefore, it provides the driver with accurate steering feel.

[0036] Depending on the vehicle's assembly specifications, the rotation angle limiting member 190 can be coupled to a separate steering shaft coupled to the steering wheel 101 or directly connected to the steering wheel 101. The rotation angle limiting member 190 includes: a first guide member 210, formed in a shaft shape; a second guide member 220, coupled to or integrally formed with the first guide member 210, and having a helical guide groove 221; a housing 230, having a radial slot 231 in a portion opposite to the guide groove 221; and a moving member 240, supported by the guide groove 221 and the slot 231 and moving radially along the slot 231.

[0037] The rotation angle limiting member 190 limits the rotation angle of the steering wheel 101 by rotating one of the first guide member 210 and the housing 230 and fixing the other of the first guide member 210 and the housing 230.

[0038] When the first guide member 210 rotates and the housing 230 is fixed, the housing 230 is fixed to the vehicle body, and the first guide member 210 is connected to the steering shaft and rotates together. When the housing 230 rotates and the first guide member 210 is fixed, the first guide member 210 is fixed to the vehicle body, and the housing 230 is connected to the steering wheel 101 and rotates together.

[0039] When the housing 230 is fixed, the first guide member 210 is connected to the steering shaft to rotate together with the steering wheel 101 and to rotate the second guide member 220.

[0040] The housing 230 is fixed to a reducer 135, which is connected to the electronic control unit 110 and the motor 120. The reducer 135 is provided with a vehicle body fixing part 138 for connecting the housing 230 to the vehicle body and a wheel connecting part 136 for connecting to the steering wheel 101. Therefore, the housing 230 can be connected to the vehicle body or the steering wheel 101 through the connecting holes 138a of the vehicle body fixing part 138 and the connecting holes 136a of the wheel connecting part 136.

[0041] The second guide member 220 is formed in the shape of a disk that rotates together with the first guide member 210, and can be connected to or integrally formed with the first guide member 210.

[0042] When the second guide member 220 is connected to the first guide member 210, the connecting hole 223 connected to the first guide member 210 is located at the center of the second guide member 220, and the spiral guide groove 221 is formed on one side of the second guide member 220.

[0043] The guide groove 221 is formed on one side of the second guide member 220 and is formed in a spiral shape with the diameter gradually decreasing towards the center.

[0044] At least one anti-slip portion 211 is provided on the outer peripheral surface of the first guide member 210. The anti-slip portion 211 is formed as a plane or curved surface that is recessed inward from the outer peripheral surface of the first guide member 210.

[0045] Furthermore, the connecting portion 225, which is formed to be in close contact with the anti-slip portion 211, is provided on the inner peripheral surface of the connecting hole 223 of the second guide member 220.

[0046] The anti-slip part 211 and the connecting part 225 are not limited to the shapes shown in the figure, as long as the anti-slip part 211 and the connecting part 225 are tightly connected to each other to prevent the first guide member 210 and the second guide member 220 from sliding.

[0047] The first guide member 210 has a threaded portion 213, which is formed on the outer peripheral surface of one end of the first guide member 210 that passes through the connecting hole 223 of the second guide member 220.

[0048] Therefore, the first guide member 210 can be fixed to the second guide member 220 by means of the fastening member 250 connected to the threaded portion 213.

[0049] The housing 230, which includes a first guide member 210 and a second guide member 220, is connected to the reducer 135 by a fastening member passing through a fastening hole 232a formed in the flange 232. The housing 230 includes a cylinder portion 233 formed in the axial direction of the first guide member 210 and a housing partition 235 facing the second guide member 220.

[0050] A through-hole 237 is formed in the housing partition 235, such that the first guide member 210 passes through the through-hole 237 and is connected to the interior of the housing 230.

[0051] Furthermore, a slot 231 is provided on the outer casing partition 235 in the radial direction, opposite to the guide groove 221 of the second guide member 220. One end of the moving member 240 is supported by the slot 231, and the other end is supported by the guide groove 221 and moves radially along the slot 231.

[0052] In addition, the outer casing partition 235 is provided with a protruding partition 239 that protrudes in the axial direction and is connected to the cylinder portion 233, and the slot 231 can be provided in the protruding partition 239.

[0053] Here, slot 231 may include a first slot 231a and a second slot 231b. The first slot 231a is disposed between the inner and outer surfaces of the protruding partition 239 and is formed to open through the radially outer side of the protruding partition 239 and the connecting hole 223. The second slot 231b communicates with the first slot 231a and is connected to the inner surface of the protruding partition 239 and the cylinder portion 233.

[0054] The first slot 231a is disposed between the inner and outer surfaces of the protruding partition 239 and is formed to be longer along the circumferential direction of the protruding partition 239. The upper side of the first slot 231a is formed to be open in the radial direction, and the lower side of the first slot 231a is formed to be open through the connecting hole 223.

[0055] The second slot 231b is formed to pass through the inner surface of the protruding partition 239, and the cylinder portion 233 is also formed to open in the axial direction.

[0056] Then, the movable member 240 may include: a groove support 241 that passes through the second slot 231b and is inserted into the guide groove 221; and a slot support 243 that extends radially from the groove support 241 and is inserted into the first slot 231a.

[0057] Therefore, when the second guide member 220 rotates in association with the first guide member 210, a force is generated to cause the groove support 241 to rotate in a helical direction while being supported by the guide groove 221. At the same time, because the slot support 243 is supported by the slot 231 and its rotation is restricted, the moving member 240 moves radially.

[0058] Additionally, when assembling the movable component 240, the recessed support 241 is inserted into the second slot 231b, which is formed to open in the cylinder portion 233. Simultaneously, assembly is performed in the radial direction by inserting the slot support 243 into the first slot 231a.

[0059] Here, slot 231 may include a third slot 231c, which communicates with the first slot 231a and is formed to open outward along the axial direction of the protruding partition 239.

[0060] The third slot 231c is formed to communicate with the first slot 231a, wherein an outer opening in the axial direction of the protruding partition 239 is provided. The slot support 243 of the movable member 240 can then be seen from the outside.

[0061] Therefore, assembly can be performed during assembly by confirming that the position of the moving member 240 and the position of the guide groove 221 are in the correct positions.

[0062] On the other hand, the support member 260 can be connected between the slot support 243 of the movable member 240 and the inner surface of the protruding partition 239.

[0063] The support member 260 is elastically compressed and connected between the slot support 243 and the protruding partition 239 to support the moving member 240 in the direction of the guide groove 221, thereby preventing noise caused by the gap between the moving member 240 and the housing 230.

[0064] A fixing groove is formed on the outer surface of the slot support, and a fixing protrusion connected to the fixing groove is formed on the inner surface of the support member. Therefore, the support member 260 is connected to the slot support 243, and the support member 260 and the slot support 243 are integrally assembled.

[0065] Additionally, at least one of the guide grooves 221, 221a and 221b, is provided with a damper 270 supported by the groove support 241 of the moving member 240. In the accompanying drawings, as an example, the damper 270 is provided at one end 221a and the other end 221b of the guide groove 221.

[0066] The damper 270 may be formed from at least one of elastic materials that can be elastically compressed to absorb shock and noise, such as NR (natural rubber), BR (butadiene rubber), NBR (nitrile rubber), CR (chloroprene rubber), EPDM (ethylene propylene diene monomer rubber), SBR (styrene-butadiene rubber), CSM (chlorosulfonated polyethylene), fluororubber, silicone, polyurethane, thermoplastic polyurethane (TPU).

[0067] In addition, the damper 270 may be formed of at least one plastic material such as polyacetal (POM), polyamide (PA), polycarbonate (PC), polyimide (PI), polybutylene terephthalate (PBT), polyethylene terephthalate (PET) to absorb loads and vibrations and have rigidity that can fix the position of the damper 270.

[0068] When the rotation of the first guide member 210 and the second guide member 220 in one direction and the other direction is restricted, the groove support 241 is supported by the damper 270 to absorb impact and prevent noise.

[0069] A fastening groove 227 connected to the damper 270 is formed at one end of the guide groove 221, such that one side of the damper 270 is pressed into the fastening groove 227 and fixed.

[0070] In addition, the moving member 240 may be provided with a damping member 280, which is supported by one end of the guide groove 221 on the outer circumferential surface of the groove support portion 241.

[0071] The damping member 280 is formed into a cylindrical shape with an insertion hole 281 and is connected to the outer peripheral surface of the groove support 241, and can be formed of the same material as the damper 270 described above. The damping member 280 can be coated on the outer peripheral surface of the groove support 241 to form an integral part.

[0072] The diameter of the damping member 280 is formed to be equal to or less than the radial width D1 of the guide groove 221, so as to minimize the friction between the guide groove 221 and the damping member 280 and to prevent noise from being generated when the second guide member 220 rotates.

[0073] Furthermore, narrow portions 229 with gradually decreasing widths in the radial direction are formed at one end 221a and the other end 221b of the guide groove 221. When the moving member 240 reaches both ends of the guide groove 221 due to the rotation of the second guide member 220, the elastic compression of the damping member 280 gradually increases, and the impact and noise decrease.

[0074] That is, the width D1 of the guide groove 221 remains constant, and a narrow portion 229 is provided whose width gradually narrows at the two ends 221a and 221b. In the drawings of the embodiments of this disclosure, the width D2 of the narrow portion 229 is reduced to be smaller than the width D1 of the middle portion.

[0075] On the other hand, when the first guide member 210 is fixed, it is fixed to the vehicle body and together with the second guide member 220. The housing 230 is connected to the steering wheel 101 and rotates together with the electronic control unit 110, the motor 120, and the reducer 135. During this rotation, the moving member 240 moves radially along the slot 231, and the groove support 241 is supported by one end of the guide groove 221, thereby restricting the rotation of the steering wheel 101.

[0076] As described above, according to embodiments of the present disclosure, a steer-by-wire device is provided to increase the driver's steering feel and steering safety by preventing further mechanical rotation of the steering wheel when the wheel rotation reaches its maximum point.

[0077] The foregoing description is intended to enable any person skilled in the art to implement and use the technical ideas of this disclosure, and is provided in the context of a particular 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 this disclosure. The foregoing description and accompanying drawings provide examples of the technical ideas of this disclosure for illustrative purposes only. That is, the disclosed embodiments are intended to illustrate the scope of the technical ideas of this disclosure. Therefore, the scope of this disclosure is not limited to the illustrated embodiments, but is consistent with the widest scope consistent with the claims. The scope of protection of this disclosure should be interpreted based on the appended claims, and any technical ideas falling within their equivalent scope should be interpreted as including within the scope of this disclosure.

Claims

1. A steer-by-wire device, comprising: The first guide member is formed in an axle shape; The second guide member is connected to or integrally formed with the first guide member and has a spiral guide groove, the diameter of which gradually decreases from the outer periphery to the center; The housing, the first guide member and the second guide member are built into the housing and radial slots are formed in the portion of the housing facing the guide groove; as well as A movable component, one end of which is supported by the slot and the other end by the guide groove, and moves radially along the slot.

2. The steer-by-wire device according to claim 1, wherein the second guide member is formed in the shape of a disc, and a connection hole connected to the first guide member is disposed at the center of the second guide member.

3. The steer-by-wire device according to claim 2, wherein at least one anti-slip portion is disposed on the outer peripheral surface of the first guide member, and the at least one anti-slip portion is formed as a plane or curved surface recessed inward from the outer peripheral surface of the first guide member.

4. The steer-by-wire device according to claim 3, wherein the connecting portion formed to be in close contact with the anti-slip portion is disposed on the inner peripheral surface of the connecting hole of the second guide member.

5. The steer-by-wire device according to claim 2, wherein a threaded portion is formed on the outer peripheral surface of one end of the first guide member that passes through the connecting hole of the second guide member.

6. The steering-by-wire device according to claim 5, wherein the first guide member is fixed to the second guide member by a fastening member connected to the threaded portion.

7. The steer-by-wire device according to claim 2, wherein the housing comprises: The cylinder portion is formed along the axial direction of the first guide member; as well as The outer casing partition faces the second guide member.

8. The steering-by-wire device according to claim 7, wherein a through-hole through which the first guide member passes is provided in the housing partition.

9. The steer-by-wire device according to claim 8, wherein a protruding partition that extends along the axial direction and is connected to the cylinder portion is disposed in the housing partition.

10. The steer-by-wire device according to claim 9, wherein the slot comprises: The first slot is disposed between the inner and outer surfaces of the protruding partition and is formed to open through the radially outer side of the protruding partition and the connecting hole; as well as The second slot communicates with the first slot and is connected to the inner surface of the protruding partition and the cylinder portion.

11. The steer-by-wire device according to claim 10, wherein the moving member comprises: The groove support passes through the second slot and is inserted into the guide groove; as well as A slot support extends radially from the groove support and is inserted into the first slot.

12. The steering-by-wire device of claim 10, wherein the slot includes a third slot communicating with the first slot and being formed to open outward in the axial direction of the protruding partition.

13. The steer-by-wire device of claim 12, wherein the support member is connected between the slot support of the moving member and the inner surface of the protruding partition.

14. The steering-by-wire device of claim 13, wherein the support member is elastically compressed and connected between the slot support and the protruding partition to support the moving member along the direction of the guide groove.

15. The steer-by-wire device according to claim 13, wherein a fixing groove is formed on the outer surface of the slot support, and a fixing protrusion connected to the fixing groove is formed on the inner surface of the support member.

16. The steer-by-wire device according to claim 11, wherein at least one end of the guide groove and the other end is provided with a damper supported by the groove support.

17. The steer-by-wire device of claim 16, wherein a fastening groove connected to the damper is formed at one end of the guide groove.

18. The steer-by-wire device according to claim 11, wherein a damping member supported by one end of the guide groove is disposed on the outer peripheral surface of the groove support portion of the moving member.

19. The steer-by-wire device according to claim 18, wherein the diameter of the damping member is equal to or less than the radial width of the guide groove.

20. The steer-by-wire device of claim 18, wherein a narrow portion is formed on one end and the other end of the guide groove, and the radial width of the narrow portion gradually decreases.

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