Steer-By-Wire Type Steering Apparatus

Abstract

The embodiments relate to a steer-by-wire steering system, and a steer-by-wire steering system can be provided that can improve the driver's steering feel and steering stability by accurately measuring the rotation angle of the wheel to enable precise steering control and reducing the measurement error of the wheel rotation angle even in a worn state.

Description

Technology Field

[0001] The embodiments relate to a steer-by-wire steering system, and more specifically, to a steer-by-wire steering system that can improve the steering feel and steering stability of the driver by accurately measuring the rotation angle of the wheel to enable precise steering control and reducing the measurement error of the wheel rotation angle even when wear is progressing. Background Technology

[0002] Generally, power steering systems have been developed and applied to vehicle steering devices to assist the driver's steering wheel operation force and provide convenience in driving. Power steering systems have been developed and applied in various forms, including hydraulic types utilizing hydraulic pressure, electro-hydraulic types utilizing both hydraulic pressure and motor power, and electric types utilizing only motor power.

[0003] Recently, a Steer By Wire (SBW) steering system has been developed and applied, which uses an electric motor to steer the vehicle instead of removing mechanical connecting devices such as a steering column, universal joint, or pinion shaft between the steering wheel and the wheel.

[0004] However, in the case of such steer-by-wire steering systems, there is no mechanical connection between the steering shaft and the wheels, so there is a problem where an error occurs between the actual rotation angle of the wheels and the driver's steering wheel rotation angle, which reduces the driver's steering feel and steering stability.

[0005] In addition, as the vehicle's durability deteriorated due to operation, the measurement error of the wheel rotation angle increased, which caused a problem that reduced the driver's steering feel and stability.

[0006] Therefore, there is a growing need for research to minimize the error between the driver's steering wheel rotation angle and the actual wheel rotation angle, and to maintain the driver's steering feel and stability even as durability deteriorates due to vehicle operation.

[0007] Accordingly, the embodiments described above have been devised from the background and can provide a steer-by-wire steering system that can improve the steering feel and steering safety of the driver by accurately measuring the rotation angle of the wheel in the steer-by-wire steering system and enabling steering control.

[0008] In addition, these embodiments can provide a steer-by-wire steering system that can improve the driver's steering feel and steering stability by reducing the measurement error of the wheel's rotation angle even when durability has progressed in the steer-by-wire steering system.

[0009] Furthermore, the problems that the embodiments of the present invention aim to solve are not limited thereto, and other unmentioned problems will be clearly understood by a person skilled in the art from the description below.

[0010] According to the embodiments, a steer-by-wire steering device may be provided, comprising: an input shaft coupled to a reduction gear to transmit the driving force of a motor and having an input gear formed on its outer surface; an output shaft having an output gear formed on one side of its outer surface to be coupled to the input gear, having a first gear coupled to one end and a pitman arm coupled to the other end to operate a link; a sensor shaft having a second gear coupled to one end to be coupled to the first gear; and an angle sensor coupled to the outer surface of the sensor shaft to sense the rotation angle of the sensor shaft and transmit it to an electronic control unit.

[0011] In addition, according to the embodiments, a steer-by-wire steering device may be provided, comprising: an input shaft coupled to a reduction gear to transmit the driving force of a motor and having an input gear formed on its outer surface; an output shaft having an output gear formed on one side of its outer surface that is coupled to the input gear, with a first pulley coupled to one end and a pitman arm coupled to the other end to operate a link; a sensor shaft having a second pulley coupled to one end that is coupled to the first pulley by a belt; and an angle sensor coupled to the outer surface of the sensor shaft to sense the rotation angle of the sensor shaft and transmit it to an electronic control unit.

[0012] According to these embodiments, steering control is achieved by accurately measuring the rotation angle of the wheel in a steer-by-wire steering system, thereby increasing the driver's steering feel and steering safety.

[0013] In addition, in a steer-by-wire steering system, the measurement error of the wheel rotation angle can be reduced even when durability has progressed, thereby increasing the driver's steering feel and steering stability. Brief explanation of the drawing

[0014] FIG. 1 is a schematic diagram showing a steer-by-wire steering system according to the embodiments thereof. FIG. 2 is a cross-sectional view showing a part of a steer-by-wire steering device according to the embodiments thereof, FIGS. 3 and FIGS. 4 are perspective views showing a part of a steer-by-wire steering device according to the embodiments thereof. FIG. 5 is a front view showing a part of a steer-by-wire steering device according to the embodiments thereof, FIG. 6 is a perspective view showing a part of a steer-by-wire steering device according to the embodiments thereof. FIGS. 7 and FIGS. 8 are cross-sectional views showing a part of a steer-by-wire steering device according to the embodiments thereof. FIGS. 9 to 11 are perspective views showing some of the steer-by-wire steering devices according to the embodiments of the present invention. Specific details for implementing the invention

[0015] Hereinafter, some embodiments of the present disclosure will be described in detail with reference to the exemplary drawings. In assigning reference numerals to the components of each drawing, the same components may have the same reference numeral as much as possible, even if they are shown in different drawings. Furthermore, in describing the embodiments, if it is determined that a detailed description of related known components or functions may obscure the essence of the technical concept, such detailed description may be omitted. Where terms such as "comprising," "having," or "consisting of" are used in this specification, other parts may be added unless "only" is used. Where a component is expressed in the singular, it may include a plural unless otherwise specified.

[0016] Additionally, terms such as first, second, A, B, (a), (b), etc., may be used to describe the components of the present disclosure. These terms are used merely to distinguish the components from other components, and the nature, order, sequence, or number of the components are not limited by such terms.

[0017] In describing the positional relationship of components, where it is stated that two or more components are "connected," "combined," or "joined," it should be understood that while the two or more components may be directly "connected," "combined," or "joined," they may also be "connected," "combined," or "joined" with other components "intervened." Here, the other components may be included in one or more of the two or more components that are "connected," "combined," or "joined" with one another.

[0018] In describing the temporal flow relationship regarding components, methods of operation, or methods of production, for example, when the temporal or sequential relationship is described using "after," "following," "next," or "before," it may include cases where the relationship is not continuous unless "immediately" or "directly" is used.

[0019] Meanwhile, where numerical values ​​or corresponding information regarding a component (e.g., levels, etc.) are mentioned, even without separate explicit notation, the numerical values ​​or corresponding information may be interpreted as including a range of error that may occur due to various factors (e.g., process factors, internal or external shocks, noise, etc.).

[0020] FIG. 1 is a schematic diagram showing a steer-by-wire steering system according to the embodiments of the present invention; FIG. 2 is a cross-sectional view showing a part of the steer-by-wire steering system according to the embodiments of the present invention; FIG. 3 and FIG. 4 are perspective views showing a part of the steer-by-wire steering system according to the embodiments of the present invention; FIG. 5 is a front view showing a part of the steer-by-wire steering system according to the embodiments of the present invention; FIG. 6 is a perspective view showing a part of the steer-by-wire steering system according to the embodiments of the present invention; FIG. 7 and FIG. 8 are cross-sectional views showing a part of the steer-by-wire steering system according to the embodiments of the present invention; and FIG. 9 to 11 are perspective views showing a part of the steer-by-wire steering system according to the embodiments of the present invention.

[0021] As illustrated in these drawings, the steer-by-wire steering device according to the embodiments comprises: an input shaft (210) coupled with a reduction gear (130) to transmit the driving force of a motor (120) and having an input gear (211) formed on its outer surface; an output shaft (135) having an output gear (135a) formed on one side of its outer surface to be coupled with the input gear (211), a first gear (230) coupled to one end, and a pitman arm (137) coupled to the other end to operate links (111, 115, 117); a sensor shaft (220) having a second gear (250) coupled with the first gear (230) coupled to one end; and an angle sensor (240) coupled to the outer surface of the sensor shaft (220) to sense the rotation angle of the sensor shaft (220) and transmit it to an electronic control device (110).

[0022] Additionally, the steer-by-wire steering device according to the embodiments includes an input shaft (210) coupled to a reduction gear (130) to transmit the driving force of a motor (120) and having an input gear (211) formed on its outer surface; an output shaft (135) having an output gear (135a) formed on one side of its outer surface to be coupled to the input gear (211), a first pulley (280) coupled to one end, and a pitman arm (137) coupled to the other end to operate links (111, 115, 117); a sensor shaft (220) having a second pulley (290) coupled to one end to the first pulley (280) by a belt; and an angle sensor (240) coupled to the outer surface of the sensor shaft (220) to sense the rotation angle of the sensor shaft (220) and transmit it to an electronic control device.

[0023] First, referring to FIG. 1, the steer-by-wire steering system according to the embodiments is configured such that a torque sensor (107) is provided on a steering shaft (103) connected to a steering wheel (101), and when the driver operates the steering wheel (101), the torque sensor (107) detects this and transmits an electrical signal to an electronic control unit (110), and the electronic control unit (110) transmits an operation signal value to a motor (120).

[0024] The electronic control unit (110) controls the operating current value of the motor (120) based on the electrical signal transmitted from the torque sensor (107) and the electrical signals transmitted from various sensors such as the vehicle speed sensor (102), yaw rate sensor (104), acceleration sensor (106), and camera image sensor (108) mounted on the vehicle.

[0025] The motor (120) is connected to a reduction gear (130) that reduces the rotational speed of the motor, and during normal driving, the electronic control unit (110) provides steering force according to the driver's operation of the steering wheel (101), and during autonomous driving, steering is performed by the control of the electronic control unit (110) based on electrical signals transmitted from the various sensors mentioned above, regardless of the driver's will.

[0026] In these embodiments, the driving force and rotational direction of the motor (120) are controlled according to a signal value received from the electronic control unit (110), and the pitman arm (137) connected to the output shaft (135) is actuated to perform steering of both wheels (119L, 119R) through the links (111, 115, 117) connected to the pitman arm (137).

[0027] In addition, an angle sensor (240) is provided to measure the actual steering angle of the vehicle, that is, the rotational position of the wheel, and the actual steering angle of the vehicle is transmitted to the electronic control unit (110).

[0028] However, for convenience of explanation, the drawings in the embodiments briefly illustrate the provision of a torque sensor (107), an angle sensor (240), a vehicle speed sensor (102), a yaw rate sensor (104), an acceleration sensor (106), and a camera image sensor (108). However, a motor position sensor and various radars, lidars, etc., for sending steering information to an electronic control unit (110) may be provided, and a detailed description of these various sensors will be omitted.

[0029] The driving force of the motor (120), which is driven according to the signal value received from the electronic control unit (110), rotates the input shaft (210) through the reduction gear (130), and the input shaft (210) transmits the driving force of the motor (120) to the output shaft (135).

[0030] An input gear (211) is formed on the outer surface of the input shaft (210) and is coupled with the output gear (135a) of the output shaft (135), so that when the input shaft (210) rotates, the output shaft (135) rotates in conjunction.

[0031] An output gear (135a) that is coupled to an input gear (211) is formed on one side of the outer surface of the output shaft (135), and a first gear (230) is coupled to one end of the output shaft (135) so that it is coupled to the second gear (250) of the sensor shaft (220), and when the output shaft (135) rotates, the sensor shaft (220) rotates in conjunction.

[0032] A pitman arm (137) is connected to the other end of the output shaft (135), and the two wheels (119L, 119R) are steered through links (111, 115, 117) connected to the pitman arm (137).

[0033] The sensor shaft (220) has a second gear (250) coupled to the first gear (230) of the output shaft (135) at one end, so that it rotates in conjunction with the rotation of the output shaft (135) and provides the rotation angle of the output shaft (135) to the angle sensor (240).

[0034] The angle sensor (240) is coupled to the outer surface of the sensor shaft (220) to sense the rotation angle of the sensor shaft (220) and transmit it to the electronic control device.

[0035] Here, the first gear (230) coupled to one end of the output shaft (135) includes a ring-shaped end coupling part (233) having a first insertion hole (231) into which the one end of the output shaft (135) is inserted, and a gear forming part (237) connected to the outer surface of the end coupling part (233), formed in a fan shape, and having a first gear tooth (239) on its outer surface.

[0036] The second gear (250) coupled to one end of the sensor shaft (220) is formed in a ring shape with a second insertion hole (256) into which the one end of the sensor shaft (220) is inserted, and a second gear tooth (253) that meshes with the first gear tooth (239) of the output shaft (135) is provided on the outer surface of the second gear (250).

[0037] And, the outer surface diameter of the second gear (250) is formed to become smaller as it approaches the end portion of the sensor shaft (220), and the second gear tooth (253) formed in the axial direction is formed such that the tooth thickness becomes smaller as it approaches from the lower portion (253a) of the second gear tooth (253) to the upper portion (235b) of the second gear tooth (253).

[0038] Additionally, the first gear tooth (239) formed on the outer surface of the gear forming part (237) is formed such that the tooth thickness increases from the lower part (239a) of the first gear tooth (239) toward the upper part (239b).

[0039] Additionally, the first gear tooth (239) can be formed such that the tooth thickness increases from the lower part (239a) of the first gear tooth (239) toward the upper part (239b), and the second gear tooth (253) can be formed such that the tooth thickness decreases from the lower part (253a) of the second gear tooth (253) toward the upper part (235b) of the second gear tooth (253).

[0040] That is, the first gear tooth (239) and the second gear tooth (253) are formed to be joined at the central portion in the axial direction, so that when the first gear tooth (239) and the second gear tooth (253) wear out after the durability has progressed, the second gear (250) moves in the axial direction by means of the elastic member (260) to be described later, thereby compensating for the play between the first gear tooth (239) and the second gear tooth (253).

[0041] In addition, at least one first recessed surface (138) is formed on the outer surface of one end of the output shaft (135), and a first protruding surface (235) that is in close contact with the first recessed surface (138) is formed on the inner surface of the first insertion hole (231) of the first gear (230), so that slip or detachment is prevented while the first gear (230) is coupled to the output shaft (135).

[0042] Additionally, at least one second recessed surface (225) is formed on the outer surface of one end of the sensor shaft (220), and an elastic protrusion (255) is formed on the inner surface of the second insertion hole (256) of the second gear (250) to be in close contact with the second recessed surface (225) and elastically deformed.

[0043] Here, the elastic protrusion (255) includes a connecting part (255a) that protrudes radially from the inner surface of the second insertion hole (256), and a supporting part (255b) that extends axially from the connecting part (255a) to the sensor shaft (220) and is spaced apart from the inner surface of the second insertion hole (256).

[0044] These embodiments further include an elastic member (260) that is supported on the shoulder portion of the sensor shaft (220) and elastically supports the second gear (250) toward the axial end.

[0045] In addition, a support end (251) is formed at the bottom of the second gear (250) and protrudes radially from the outer surface, so that the elastic member (260) supports the support end (251) in the axial direction and does not detach.

[0046] These embodiments further include a housing (140) in which an input shaft (210), an output shaft (135), a sensor shaft (220), and an angle sensor (240) are housed.

[0047] Additionally, referring to FIGS. 8 to 11, the steer-by-wire steering device according to the embodiments comprises: an input shaft (210) coupled to a reduction gear (130) to transmit the driving force of a motor (120) and having an input gear (211) formed on its outer surface; an output shaft (135) having an output gear (135a) formed on one side of its outer surface that is coupled to the input gear (211), a first pulley (280) coupled to one end, and a pitman arm (137) coupled to the other end to operate links (111, 115, 117); a sensor shaft (220) having a second pulley (290) coupled to one end that is coupled to the first pulley (280) by a belt (285); and a sensor shaft (220) coupled to the outer surface of the sensor shaft (220) to sense the rotation angle of the sensor shaft (220) and transmit it to an electronic control device (110). It includes an angle sensor (240).

[0048] An axial pulley serration (289, 299) is formed on the outer surface of the first pulley (280) and the second pulley (290), and a belt serration (285a) that engages with the pulley serration (289, 299) of the first pulley (280) and the second pulley (290) is formed on the inner surface of the belt (285), so that slip or detachment of the belt (285) does not occur.

[0049] In addition, at least one first recessed surface (138) is formed on the outer surface of one end of the output shaft (135), and a first protruding surface (283) that is in close contact with the first recessed surface (138) is formed on the inner surface of the coupling hole (281) into which the output shaft (135) is inserted in the first pulley (280), so that slip or detachment is prevented while the first pulley (280) is coupled to one end of the output shaft (135).

[0050] These embodiments further include a housing (140) in which an input shaft (210), an output shaft (135), a sensor shaft (220), and an angle sensor (240) are housed, and the housing (140) is provided with a belt support member (300) that supports the outer surface of the belt (285) inwardly, so that the belt (285) can be prevented from coming off or loosening from the first pulley (280) and the second pulley (290) after the durability has progressed.

[0051] Here, the belt support member (300) includes a connecting member (310) having one end rotatably coupled to a housing (140), a support member (330) having the other end of the connecting member (310) rotatably coupled to support the outer surface of the belt (285), and an elastic support member (325) that is bent and extended from a main body (321) coupled to one end of the connecting member (310) and elastically supported by the housing (140).

[0052] A rotational support hole (313) is formed at one end of the connecting member (310) so as to be rotatably coupled to a fastening member (340) that is fastened to a housing (140), and a protruding shaft (315) is formed at the other end of the connecting member (310) so as to be rotatably coupled to a supporting member (330).

[0053] The support member (330) has a ball (335) coupled between the inner ring (331) and the outer ring (333), and a protruding shaft (315) is coupled to the center hole (338) of the inner ring (331), and when the belt (285) is operated, the outer ring (333) rotates and supports the outer surface of the belt (285).

[0054] The elastic support member (325), which applies a force to rotate the support member (330) toward the belt (285) by elastically supporting the connecting member (310), has a communication hole (323) formed in the main body (321) which is coupled to one end of the connecting member (310), and is supported by the fastening member (340) and is rotatably coupled together with the connecting member (310).

[0055] The main body (321) is formed in a shape that wraps around the upper side and both sides of one end of the connecting member (310), and the elastic support member (325) is bent outward from the side end of the main body (321) and extended to be elastically supported by the inner partition wall (145) of the housing (140) so as to elastically support the connecting member (310) and the support member (330) toward the belt (285).

[0056] Accordingly, the belt support member (300), which is elastically supported in the housing (140), supports the belt (285) inwardly, thereby preventing the belt (285) from coming off or becoming loose from the first pulley (280) and the second pulley (290).

[0057] As explained above, according to the embodiments, steering control is achieved by accurately measuring the rotation angle of the wheel in a steer-by-wire steering system, thereby increasing the driver's steering feel and steering safety.

[0058] In addition, in a steer-by-wire steering system, the measurement error of the wheel rotation angle can be reduced even when durability has progressed, thereby increasing the driver's steering feel and steering stability.

[0059] The foregoing description is merely an illustrative explanation of the technical concept of the present disclosure, and those skilled in the art to which the present disclosure pertains may make various modifications and variations within the scope of the essential characteristics of the technical concept. Furthermore, since these embodiments are intended to explain, not limit, the scope of the technical concept of the present disclosure is not limited by these embodiments. The scope of protection of the present disclosure shall be interpreted by the claims below, and all technical concepts within an equivalent scope shall be interpreted as being included within the scope of rights of the present disclosure. Explanation of the symbols

[0060] 101: Steering wheel 103: Steering shaft 140: Screw shaft 150: Moving member 160: Support member 170: Fixing member 180: Housing 190: Rotation angle limiting member

Claims

Claim 1 A steer-by-wire steering device comprising: an input shaft coupled to a reduction gear to transmit the driving force of a motor and having an input gear formed on its outer surface; an output shaft having an output gear formed on one side of its outer surface to be coupled to the input gear, a first gear coupled to one end, and a pitman arm coupled to the other end to operate a link; a sensor shaft having a second gear coupled to one end to be coupled to the first gear; and an angle sensor coupled to the outer surface of the sensor shaft to sense the rotation angle of the sensor shaft and transmit it to an electronic control device; wherein the first gear includes a ring-shaped end coupling portion having a first insertion hole into which one end of the output shaft is inserted. Claim 2 A steer-by-wire steering device according to claim 1, further comprising: a gear forming part in which the first gear is connected to the outer surface of the end coupling part, is formed in a fan shape, and has a first gear tooth provided on the outer surface. Claim 3 A steer-by-wire steering device according to claim 2, wherein the second gear is formed in a ring shape having a second insertion hole into which one end of the sensor shaft is inserted, and a second gear tooth that meshes with the first gear tooth is provided on the outer surface. Claim 4 A steer-by-wire steering device according to claim 3, characterized in that the outer circumferential diameter of the second gear becomes smaller as it approaches the end portion of the sensor shaft. Claim 5 A steer-by-wire steering device according to claim 4, characterized in that the thickness of the second gear tooth decreases from the lower part to the upper part of the second gear tooth. Claim 6 A steer-by-wire steering device according to claim 5, characterized in that the thickness of the first gear tooth increases from the lower end to the upper end of the first gear tooth. Claim 7 A steer-by-wire steering device according to claim 4, characterized in that the first gear tooth has a tooth thickness that increases from the lower end to the upper end of the first gear tooth, and the second gear tooth has a tooth thickness that decreases from the lower end to the upper end of the second gear tooth. Claim 8 A steer-by-wire steering device according to claim 2, characterized in that at least one first recessed surface is formed on the outer surface of one end of the output shaft. Claim 9 A steer-by-wire steering device according to claim 8, characterized in that a first protruding surface is formed on the inner circumferential surface of the first insertion hole to be in close contact with the first recessed surface. Claim 10 A steer-by-wire steering device according to claim 3, characterized in that at least one second recessed surface is formed on the outer surface of one end of the sensor shaft. Claim 11 A steer-by-wire steering device according to claim 10, characterized in that an elastic protrusion is formed on the inner circumferential surface of the second insertion hole, which is in close contact with and elastically deformed by the second recessed surface. Claim 12 In claim 11, the elastic protrusion comprises: a connecting portion protruding radially from the inner circumferential surface of the second insertion hole; and a supporting portion extending in the axial direction of the sensor shaft from the connecting portion and spaced apart from the inner circumferential surface of the second insertion hole; comprising a steer-by-wire type steering device. Claim 13 A steer-by-wire steering device according to claim 1, further comprising an elastic member supported on the stepped portion of the sensor shaft and elastically supporting the second gear toward the axial end. Claim 14 A steer-by-wire steering device according to claim 13, characterized in that a support end protruding radially from the outer surface is formed at the lower end of the second gear. Claim 15 A steer-by-wire steering device comprising: an input shaft coupled to a reduction gear to transmit the driving force of a motor and having an input gear formed on its outer surface; an output shaft having an output gear formed on one side of its outer surface that is coupled to the input gear, a first pulley coupled to one end, and a pitman arm coupled to the other end to operate a link; a sensor shaft having a second pulley coupled to one end that is coupled to the first pulley by a belt; and an angle sensor coupled to the outer surface of the sensor shaft to sense the rotation angle of the sensor shaft and transmit it to an electronic control unit; wherein axial pulley serrations are formed on the outer surfaces of the first pulley and the second pulley, and belt serrations that mesh with the pulley serrations are formed on the inner surface of the belt. Claim 16 delete Claim 17 A steer-by-wire steering device according to claim 15, characterized in that at least one first recessed surface is formed on the outer surface of one end of the output shaft. Claim 18 A steer-by-wire steering device according to claim 17, characterized in that the first pulley has a first protruding surface formed on the inner circumference of a coupling hole into which the output shaft is inserted, which is in close contact with the first recessed surface. Claim 19 A steer-by-wire steering device according to claim 15, further comprising a housing in which the input shaft, output shaft, sensor shaft, and angle sensor are housed, wherein the housing is provided with a belt support member that supports the outer surface of the belt inwardly. Claim 20 In claim 19, the belt support member comprises: a connecting member having one end rotatably coupled to the housing; a supporting member having the other end rotatably coupled to the connecting member and supporting the outer surface of the belt; and a main body coupled to one end of the connecting member and an elastic supporting member that is bent from the main body and extends to be elastically supported by the housing; a steer-by-wire steering device.

Images