Steering apparatus

Abstract

The present invention relates to a steering device and is characterized by comprising a driving unit that provides driving force, a knuckle unit connected to the driving unit, a steering unit connected to the knuckle unit and rotating the knuckle unit, and a restraining unit connected to the steering unit and selectively restricting the rotation of the knuckle unit.

Description

Technology Field

[0001] The present invention relates to a steering device, and more specifically, to an independent steering device for a vehicle capable of independently performing driving, braking, suspension, and steering for each wheel of the vehicle. Background Technology

[0003] Generally, an electric vehicle refers to an eco-friendly vehicle that emits no exhaust gases. It is equipped with a high-voltage battery that supplies energy for driving and a driving motor that generates rotational force from the power output from the high-voltage battery, and driving is achieved by transmitting the motor's rotational power to the wheels through a drive shaft.

[0004] Recently, in-wheel motor vehicles, which have the advantage of being able to reduce vehicle weight and minimize energy loss during power transmission by omitting intermediate power transmission devices such as reduction gears or differential gears, are gaining popularity. Furthermore, development of four-wheel independent steering systems, in which the braking, steering, and suspension systems are integrated as a single unit, is also actively underway.

[0005] Conventional independent steering systems perform position control through SW control without a separate locking structure. Consequently, if a problem occurs with one of the four wheels and position control is performed using the remaining three wheels, there is a problem in that control is not smooth if the faulty wheel is not fixed against reverse input.

[0006] The background technology of the present invention is disclosed in Korean Published Patent Application No. 10-2019-0041855 (published April 23, 2019, Title of Invention: Steering System for In-Wheel Motor Vehicle). The problem to be solved

[0008] The purpose of the present invention is to provide an independent steering device for a vehicle that can improve driving stability by actively adjusting the state of steering force transmission to each wheel. means of solving the problem

[0010] To solve the above-mentioned problem, a steering device according to the present invention comprises: a driving unit that provides a driving force; a knuckle unit connected to the driving unit; a steering unit connected to the knuckle unit and rotating the knuckle unit; and a restraining unit connected to the steering unit and selectively restricting the rotation of the knuckle unit.

[0011] The steering unit may include: a steering drive unit that generates rotational force; a steering output unit connected to the knuckle unit and rotating the knuckle unit in conjunction with the rotational force generated from the steering drive unit; and a steering transmission unit provided between the steering drive unit and the steering output unit and transmitting the rotational force generated from the steering drive unit to the steering output unit.

[0012] The steering transmission unit may include: a first steering transmission member connected to the steering drive unit and rotated by receiving rotational force from the steering drive unit; and a second steering transmission member connected to the first steering transmission member and rotating the steering output unit in conjunction with the rotation of the first steering transmission member.

[0013] The first steering transmission member may include: a first sun gear connected to and rotated by the drive shaft of the steering drive unit; a first ring gear spaced apart from the first sun gear; a first planetary gear meshing between the first sun gear and the first ring gear to rotate and revolve; and a first carrier that rotates in conjunction with the revolvement of the first planetary gear.

[0014] The second steering transmission member may include: a second sun gear connected to and rotated with the first carrier; a second ring gear spaced apart from the second sun gear; a second planetary gear meshing between the second sun gear and the second ring gear to perform rotational and orbital motion; and a second carrier that rotates in conjunction with the orbital motion of the second planetary gear and is connected to the steering output unit.

[0015] The above restraint unit may include: a first restraint member disposed between the steering drive unit and the steering transmission unit and rotating together with the drive shaft of the steering drive unit; and a second restraint member disposed facing the first restraint member, extending toward the first restraint member, and restricting or allowing rotation of the first restraint member.

[0016] The first restraint member may include a first restraint body connected to the drive shaft and disposed coaxially with the drive shaft; and a first restraint member formed by being concavely recessed into the inner side of the first restraint body.

[0017] The first restraining member may be provided in multiple numbers and arranged at a predetermined interval along the circumferential direction of the first restraining body.

[0018] The first restraining member may extend in the radial direction of the first restraining body.

[0019] The width of the first restraining member may gradually increase as it moves outward in the radial direction of the first restraining body.

[0020] The second restraint member may include: a second restraint body spaced apart from the first restraint body; a restraint driving unit installed inside the second restraint body and generating electromagnetic force by receiving power from the outside; and a second restraint member movably installed in the second restraint body, reciprocating in conjunction with the electromagnetic force generated from the restraint driving unit, and inserted into the first restraint member or detached from the first restraint member depending on the direction of movement.

[0021] The second restraining member can reciprocate in a direction parallel to the radial direction of the first restraining member.

[0022] The second restraint unit may further include a restoration unit that returns the second restraint member to its initial position as the electromagnetic force generated from the restraint driving unit is released.

[0023] The above restoration member is configured to be elastically deformable and can apply an elastic force to the second restraining member in a direction opposite to the electromagnetic force generated from the restraining driving member.

[0024] The steering device may further include a control unit that controls the operation of the steering unit and the restraint unit.

[0025] If the above control unit is unable to communicate with the above steering unit, it can operate the restraint unit to restrict the rotation of the above knuckle unit. Effects of the invention

[0027] The independent steering device for a vehicle according to the present invention can improve the driving freedom of the vehicle by individually adjusting the steering angle of each wheel by means of a steering unit.

[0028] In addition, the independent steering device for a vehicle according to the present invention can prevent the wheel from being arbitrarily steered by reverse input, etc., by blocking the transmission of steering force to the wheel by a restraining unit when a failure occurs in the steering unit installed on one wheel, and can induce stable position control of the vehicle through the steering unit installed on the remaining wheel.

[0029] In addition, the independent steering device for a vehicle according to the present invention can reduce the magnitude of the load applied to the second restraint by allowing the first restraint to rotate without the rotational force being amplified by the steering transmission unit, as the first restraint is connected to the drive shaft of the steering drive unit and rotates together with the drive shaft. Brief explanation of the drawing

[0031] FIG. 1 is a schematic diagram showing the installation state of an independent steering device for a vehicle according to the first embodiment of the present invention. FIG. 2 is a perspective view schematically showing the configuration of an independent steering device for a vehicle according to a first embodiment of the present invention. FIG. 3 is an exploded perspective view schematically showing the configuration of an independent steering device for a vehicle according to the first embodiment of the present invention. FIG. 4 is a block diagram schematically showing the configuration of an independent steering device for a vehicle according to the first embodiment of the present invention. FIG. 5 is a perspective view schematically showing the configuration of a steering unit and a restraining unit according to a first embodiment of the present invention. FIG. 6 is an exploded perspective view schematically showing the configuration of a steering unit and a restraining unit according to a first embodiment of the present invention. FIG. 7 is an exploded perspective view schematically showing the configuration of a steering transmission unit according to the first embodiment of the present invention. FIG. 8 is a plan view schematically showing the configuration of a restraint unit according to the first embodiment of the present invention. FIG. 9 is a front view schematically showing the configuration of a restraining unit according to the first embodiment of the present invention. FIG. 10 is a flowchart schematically illustrating the operation process of an independent steering device for a vehicle according to the first embodiment of the present invention. FIGS. 11 and 12 are diagrams schematically illustrating the operation process of a restraint unit according to a first embodiment of the present invention. FIG. 13 is a schematic diagram showing the installation state of an independent steering device for a vehicle according to a second embodiment of the present invention. FIG. 14 is a perspective view schematically showing the configuration of an independent steering device for a vehicle according to a second embodiment of the present invention. FIG. 15 is an exploded perspective view schematically showing the configuration of an independent steering device for a vehicle according to a second embodiment of the present invention. FIG. 16 is a block diagram schematically showing the configuration of an independent steering device for a vehicle according to a second embodiment of the present invention. FIG. 17 is a perspective view schematically showing the configuration of a steering unit and a restraining unit according to a second embodiment of the present invention. FIG. 18 is an exploded perspective view schematically showing the configuration of a steering transmission unit according to a second embodiment of the present invention. FIG. 19 is a plan view schematically showing the configuration of a restraint unit according to a second embodiment of the present invention. FIG. 20 is a front view schematically showing the configuration of a restraining unit according to the first embodiment of the present invention. FIG. 21 is a flowchart schematically illustrating the operation process of an independent steering device for a vehicle according to a second embodiment of the present invention. FIGS. 22 and 23 are diagrams schematically illustrating the operation process of a restraint unit according to a second embodiment of the present invention. FIG. 24 is a schematic diagram showing the installation state of an independent steering device for a vehicle according to the third embodiment of the present invention. FIG. 25 is a perspective view schematically showing the configuration of an independent steering device for a vehicle according to a third embodiment of the present invention. FIG. 26 is an exploded perspective view schematically showing the configuration of an independent steering device for a vehicle according to a third embodiment of the present invention. FIG. 27 is a block diagram schematically showing the configuration of an independent steering device for a vehicle according to a third embodiment of the present invention. FIG. 28 is a perspective view schematically showing the configuration of a steering unit and a restraining unit according to a third embodiment of the present invention. FIG. 29 is an exploded perspective view schematically showing the configuration of a steering unit and a restraining unit according to a third embodiment of the present invention. FIG. 30 is an exploded perspective view schematically showing the configuration of a steering transmission unit according to a third embodiment of the present invention. FIG. 31 is a cross-sectional view schematically showing the configuration of a restraining unit according to a third embodiment of the present invention. FIG. 32 is a plan view schematically showing the configuration of a restraining unit according to a third embodiment of the present invention. FIG. 33 is a flowchart schematically illustrating the operation process of an independent steering device for a vehicle according to the third embodiment of the present invention. FIGS. 34 and 35 are schematic diagrams illustrating the operation process of a restraint unit according to a third embodiment of the present invention. Specific details for implementing the invention

[0032] Hereinafter, embodiments of a vehicle equipped with an independent steering device for a vehicle and a method of operating the independent steering device for a vehicle according to the present invention will be described with reference to the attached drawings.

[0033] In this process, the thickness of lines or the size of components depicted in the drawings may be exaggerated for the sake of clarity and convenience of explanation. Furthermore, the terms described below are defined considering their functions in the present invention, and these may vary depending on the intent or convention of the user or operator. Therefore, the definitions of these terms should be based on the content throughout this specification.

[0034] Furthermore, in this specification, when a part is described as being "connected (or joined)" to another part, this includes not only cases where they are "directly connected (or joined)" but also cases where they are "indirectly connected (or joined)" with other members interposed between them. In this specification, when a part is described as "including (or having) a certain component," this means that, unless specifically stated otherwise, it does not exclude other components but may additionally "include (or have)" other components.

[0035] Furthermore, throughout this specification, the same reference numerals may refer to the same components. Even if the same or similar reference numerals are not mentioned or described in a specific drawing, they may be described based on other drawings. Additionally, even if a part is not indicated by a reference numeral in a specific drawing, that part may be described based on other drawings. Furthermore, the number, shape, size, and relative differences in size of the detailed components included in the drawings of this application are set for ease of understanding and do not limit the embodiments, and may be implemented in various forms.

[0036] FIG. 1 is a schematic diagram showing the installation state of an independent steering device for a vehicle according to the first embodiment of the present invention.

[0037] Referring to FIG. 1, the vehicle independent steering device (10) according to the present embodiment is individually installed for each wheel (20) and independently performs driving, braking, steering, and suspension operations for each wheel (20).

[0038] FIG. 2 is a perspective view schematically showing the configuration of an independent steering device for a vehicle according to a first embodiment of the present invention, FIG. 3 is an exploded perspective view schematically showing the configuration of an independent steering device for a vehicle according to a first embodiment of the present invention, and FIG. 4 is a block diagram schematically showing the configuration of an independent steering device for a vehicle according to a first embodiment of the present invention.

[0039] Referring to FIGS. 2 to 4, the independent steering device (10) for a vehicle according to the present embodiment includes a driving unit (100), a knuckle unit (200), a braking unit (300), a suspension unit (400), a steering unit (500), a restraint unit (600), and a control unit (700).

[0040] The drive unit (100) is connected to the wheel (20) of a vehicle and provides driving force to the wheel (20) to rotate the wheel (20). The drive unit (100) according to the present embodiment may be exemplified by various types of in-wheel motors, including a stator that is positioned inside the wheel (20) and forms a magnetic field by receiving power from a vehicle battery (not shown), and a rotor that is rotatably installed inside the stator and rotates by electromagnetic interaction with the stator to rotate the wheel (20). The stator and the rotor may be positioned so that their central axes are aligned with the central axis of the wheel (20) and are stacked concentrically on the inside of the wheel (20). The drive unit (100) may be connected to the knuckle unit (200) described later and supported on the inside of the wheel (20).

[0041] The knuckle unit (200) is positioned facing the wheel (20) and functions as a configuration providing a mechanical connection to the drive unit (100), braking unit (300), suspension unit (400), and steering unit (500).

[0042] The knuckle unit (200) according to the present embodiment includes a first knuckle (210) and a second knuckle (220).

[0043] The first knuckle (210) forms one side of the exterior of the knuckle unit (200) and is positioned apart from the driving unit (100).

[0044] The first knuckle (210) according to the present embodiment is formed to have a roughly "C"-shaped cross-section and is positioned so that the open side faces the drive unit (100). The first knuckle (210) is positioned at a predetermined distance from the drive unit (100) in the width direction of the vehicle. The first knuckle (210) can be connected to and supported by the vehicle body by the suspension arm (410) described later. The specific shape of the first knuckle (210) is not limited to the shape shown in FIGS. 2 and FIGS. 3, and various design changes are possible within the technical concept of a shape that is positioned to face the drive unit (100) and can rotatably support the second knuckle (220) described later.

[0045] The second knuckle (220) forms the outer surface of the other side of the knuckle unit (200) and is rotatably installed on the first knuckle (210). The second knuckle (220) is connected to the drive unit (100) and supports the drive unit (100) from the inside of the wheel (20). The second knuckle (220) rotates relative to the first knuckle (210) and transmits the steering force generated from the steering unit (500), which will be described later, to the wheel (20).

[0046] According to the present embodiment, the second knuckle (220) has both ends rotatably connected to the upper and lower ends of the open side of the first knuckle (210), respectively. In this case, both ends of the second knuckle (220) may be positioned at a predetermined angle of inclination with respect to an axis perpendicular to the ground. The central part of the second knuckle (220) is connected to the drive unit (100). More specifically, the central part of the second knuckle (220) may rotatably support the rotor of the drive unit (100) through a wheel bearing (not shown), etc. The second knuckle (220) is formed to be hollow inside so that the steering output part (530) of the steering unit (500), which will be described later, can be inserted inside, and spline teeth may be formed on the inner surface. The specific shape of the second knuckle (220) is not limited to the shape shown in FIG. 2 and FIG. 3, and various design changes are possible within the technical concept of a shape that can be rotatably installed on the first knuckle (210) to support the driving unit (100), braking unit (300), etc.

[0047] The braking unit (300) interferes with the rotation of the wheel (20) to apply or release braking force to the vehicle.

[0048] The braking unit (300) according to the present embodiment includes a brake disc (310) and a brake caliper (320).

[0049] The brake disc (310) rotates in conjunction with the rotation of the wheel (20). The brake disc (310) according to the present embodiment is formed to have a disc shape and is installed facing the drive unit (100). The brake disc (310) is positioned so that its central axis is aligned with the central axis of the drive unit (100). The brake disc (310) can be integrally connected to the rotor of the drive unit (100) by means of bolting, etc. Accordingly, the brake disc (310) can rotate around its central axis at the same angular velocity as the wheel (20) when the drive unit (100) operates. The diameter of the brake disc (310) can be varied in design depending on the diameter of the wheel (20), the size of the drive unit (100), etc.

[0050] The brake caliper (320) applies braking force by pressing the brake disc (310) when the vehicle is braking. The brake caliper (320) according to the present embodiment may be configured to include a brake pad positioned facing the brake disc (310), a caliper housing coupled to the second knuckle (220) to movably support the brake pad, and a piston installed to move back and forth in the caliper housing to press the brake pad toward the brake disc (310) or release pressure according to the direction of movement. The caliper housing may be detachably coupled to the second knuckle (220) by means of bolting, etc.

[0051] The suspension unit (400) is connected to the knuckle unit (200) and absorbs shocks transmitted from the road surface when the vehicle is driven.

[0052] The suspension unit (400) according to the present embodiment includes a suspension arm (410) and a shock absorber module (420).

[0053] The suspension arm (410) functions as a component that connects the wheel (20) to the vehicle body via the first knuckle (210), absorbs the load applied from the wheel (20) during driving due to its own rigidity, and controls the movement of the wheel (20). The suspension arm (410) according to the present embodiment extends in a longitudinal direction along the width direction of the vehicle. The suspension arm (410) may be formed to have the shape of a wishbone or a link arm. Both ends of the suspension arm (410) are rotatably connected to the lower end of the first knuckle (210) and the vehicle body, such as a subframe, via a ball joint, bushing, etc. The specific shape of the suspension arm (410) is not limited to the shape shown in FIGS. 2 and FIGS. 3, and various design changes are possible within the technical concept of a shape that can be connected to the first knuckle (210) and support the wheel (20).

[0054] The shock absorber module (420) is configured to be extendable along the longitudinal direction to absorb shocks or vibrations transmitted from the road surface.

[0055] The shock absorber module (420) according to the present embodiment includes a cylinder (421), a rod (422), and an elastic body (423).

[0056] The cylinder (421) forms one side of the exterior of the shock absorber module (420) and is connected to the first knuckle (210). The cylinder (421) according to the present embodiment may be formed to have a cylindrical shape with a hollow interior and one side open. The interior of the cylinder (421) is filled with a fluid capable of performing a damping function, such as oil. The lower end of the cylinder (421) may be connected to the upper end of the first knuckle (210).

[0057] The rod (422) forms the outer surface of the other side of the shock absorber module (420) and is connected to the cylinder (421) so as to be slidably movable. The rod (422) according to the present embodiment may be formed to have the shape of a rod, with its lower end inserted into the upper end of the cylinder (421) and installed so as to be slidably movable along the longitudinal direction of the cylinder (421). The upper end of the rod (422) is connected to and supported by a vehicle body such as a wheel housing. Accordingly, when the wheel (20) moves up and down due to the curvature of the road surface, the rod (422) reciprocates along the longitudinal direction of the cylinder (421) and can perform a damping action by the pressure of the fluid filled inside the cylinder (421).

[0058] The elastic body (423) is provided between the cylinder (421) and the rod (422) and elastically supports the rod (422) with respect to the cylinder (421). The elastic body (423) according to the present embodiment is positioned to wrap around the outer surface of the cylinder (421) and the rod (422) and may be formed to have the shape of a coil spring that is elastic and retractable along the longitudinal direction. The elastic body (423) may be supported by being coupled to a lower seat (424) with both ends fixed to the cylinder (421) and an upper seat (425) fixed to the rod (422), respectively. The elastic body (423) is compressed or stretched in the longitudinal direction when the rod (422) slides, accumulates elastic restoring force, and can absorb shocks applied from the road surface by offsetting the movement of the rod (422) with the accumulated elastic restoring force.

[0059] The steering unit (500) adjusts the steering angle of the wheel (20) by rotating the second knuckle (220) relative to the first knuckle (210).

[0060] FIG. 5 is a perspective view schematically showing the configuration of a steering unit and a restraining unit according to a first embodiment of the present invention, and FIG. 6 is an exploded perspective view schematically showing the configuration of a steering unit and a restraining unit according to a first embodiment of the present invention.

[0061] Referring to FIGS. 1 to 6, the steering unit (500) according to the present embodiment includes a steering body (510), a steering drive unit (520), a steering output unit (530), a steering transmission unit (540), and a steering angle sensor (550).

[0062] The steering body (510) forms the general exterior of the steering unit (500) and supports the steering drive unit (520), steering output unit (530), steering transmission unit (540), and steering angle sensor (550) described later. The steering body (510) according to the present embodiment may be formed to have a hollow interior and a cylindrical shape with both sides open. The steering body (510) is positioned to face the second knuckle (220) vertically with respect to the first knuckle (210). The lower end of the steering body (510) is fixed to the upper end of the open side of the first knuckle (210). In this case, the steering body (510) may be integrally joined to the first knuckle (210) by welding, etc., and may also be detachably joined to the first knuckle (210) by bolting, etc.

[0063] The steering drive unit (520) is fixed to the first knuckle (210) and generates rotational force. The steering drive unit (520) according to the present embodiment can be exemplified by various types of electric motors that convert power applied from the outside into rotational force to rotate the drive shaft (521). The steering drive unit (520) can be indirectly fixed to the first knuckle (210) via the steering body (510). More specifically, the lower end of the steering drive unit (520) can be integrally coupled to the upper end of the steering body (510) by means of bolting, etc. The drive shaft (521) of the steering drive unit (520) protrudes from the lower end of the steering drive unit (520) and is positioned inside the steering body (510). The drive shaft (521) is positioned such that its center axis is located coaxial with the rotation center axis of the second knuckle (220). The steering drive unit (520) is electrically connected to the control unit (700) described later, so that the operating state can be controlled by the control unit (700).

[0064] The steering output unit (530) is connected to the second knuckle (220) and rotates the second knuckle (220) relative to the first knuckle (210) in conjunction with the rotational force generated from the steering drive unit (520). The steering output unit (530) can receive the rotational force generated from the steering drive unit (520) through the steering transmission unit (540) described later. The steering output unit (530) according to the present embodiment is positioned inside the steering body (510). The upper end of the steering output unit (530) is positioned so as to be spaced apart from the lower end of the drive shaft (521) by a predetermined distance. Accordingly, the steering output unit (530) can provide a space between itself and the drive shaft (521) where the steering transmission unit (540) described later can be installed. The steering output unit (530) is positioned so that its central axis is located coaxial with the central axis of the drive shaft (521). The lower portion of the steering output unit (530) protrudes downward from the steering body (510) and is inserted into the interior of the second knuckle (220). In this case, the steering output unit (530) may have spline teeth formed on its outer surface and may be spline-coupled to the inner surface of the second knuckle (220). Accordingly, the steering output unit (530) can rotate around a central axis by means of the steering transmission unit (540) described later, thereby rotating the second knuckle (220).

[0065] A stopper (531) may be provided at the lower end of the steering output unit (530) to prevent the steering output unit (530) from detaching from the second knuckle (220). The stopper (531) according to the present embodiment is formed to have a diameter larger than the diameter of the lower end of the steering output unit (530). The stopper (531) may be detachably coupled to the lower end of the steering output unit (530) by means of screw coupling, snap coupling, etc. When the lower end of the steering output unit (530) is inserted into the interior of the second knuckle (220), the upper surface of the stopper (531) is engaged with the inner surface of the second knuckle (220) to prevent the steering output unit (530) from detaching from the second knuckle (220).

[0066] The steering transmission unit (540) is provided between the steering drive unit (520) and the steering output unit (530) and transmits the rotational force generated from the steering drive unit (520) to the steering output unit (530). That is, the steering transmission unit (540) corresponds to a configuration that performs the function of a reduction gear device that amplifies the rotational force transmitted to the steering output unit (530) by reducing the rotational speed of the drive shaft (521) when the steering drive unit (520) operates.

[0067] FIG. 7 is an exploded perspective view schematically showing the configuration of a steering transmission unit according to the first embodiment of the present invention.

[0068] Referring to FIG. 7, the steering transmission unit (540) according to the present embodiment includes a first steering transmission member (540a) and a second steering transmission member (540b).

[0069] The first steering transmission member (540a) is connected to the steering drive unit (520) and rotates by receiving rotational force from the steering drive unit (520).

[0070] The first steering transmission member (540a) according to the present embodiment includes a first sun gear (541), a first ring gear (542), a first planetary gear (543), and a first carrier (544).

[0071] The first sun gear (541) is connected to and rotated by the drive shaft (521) of the steering drive unit (520). The first sun gear (541) according to the present embodiment may be formed to have a rod shape with gear teeth protruding from its outer surface. The first sun gear (541) is positioned so that its center axis is located coaxial with the center axis of the drive shaft (521). The upper end of the first sun gear (541) is positioned so as to be spaced apart from the lower end of the drive shaft (521) by a predetermined distance, and is connected to the drive shaft (521) via the first restraint body (611) of the restraint unit (600) described later. When the drive shaft (521) rotates, the first sun gear (541) rotates at the same angular velocity as the drive shaft (521).

[0072] The first ring gear (542) is positioned spaced apart from the first sun gear (541). The first ring gear (542) according to the present embodiment may be formed to have a hollow cylindrical shape with both sides open and gear teeth protruding from the inner surface. The inner surface of the first ring gear (542) is positioned spaced apart from the outer surface of the first sun gear (541) by a predetermined distance. The first ring gear (542) is positioned so that its center axis is located coaxial with the center axis of the first sun gear (541). The first ring gear (542) may be fixed and supported on the inner surface of the steering body (510).

[0073] The first planetary gear (543) is engaged and coupled between the first sun gear (541) and the first ring gear (542), and rotates and revolves in conjunction with the rotation of the first sun gear (541). The first planetary gear (543) according to the present embodiment may be formed to have a cylindrical shape with gear teeth formed on its outer surface. The first planetary gear (543) has a central axis parallel to the central axis of the first sun gear (541) and is arranged at a predetermined distance apart in the radial direction of the first ring gear (542). One side of the first planetary gear (543) is engaged and coupled with the outer surface of the first sun gear (541), and the other side is engaged and coupled with the inner surface of the first ring gear (542). The first planetary gear (543) receives rotational force from the first sun gear (541) and rotates around its central axis while simultaneously revolving around the central axis of the first sun gear (541). The first planetary gear (543) may be formed in multiple numbers. Multiple first planetary gears (543) are arranged at a predetermined interval along the circumferential direction of the first ring gear (542). Although FIG. 7 illustrates an example where there are three first planetary gears (543), the number of first planetary gears (543) is not limited to this, and the design can be changed to various numbers, such as three or five.

[0074] The first carrier (544) rotates in conjunction with the orbital motion of the first planetary gear (543). The first carrier (544) according to the present embodiment may be formed to have the shape of a disc positioned to face the lower surface of the first planetary gear (543). The first carrier (544) is positioned so that its central axis is located coaxial with the central axis of the first sun gear (541).

[0075] A first connecting shaft (544a) connected to the first planetary gear (543) is formed in the first carrier (544). The first connecting shaft (544a) according to the present embodiment may be formed in the shape of a rod extending vertically from the upper surface of the first carrier (544) facing the first planetary gear (543). The first connecting shaft (544a) has a central axis positioned parallel to the central axis of the first carrier (544) and is positioned at a predetermined distance from the central axis of the first carrier (544) in the radial direction of the first carrier (544). The first connecting shaft (544a) is inserted to penetrate the central axis of the first planetary gear (543) to support the first planetary gear (543) so as to rotate. A plurality of first connecting shafts (544a) are provided to support each first planetary gear (543) individually so as to rotate. The first connecting shaft (544a) transmits rotational force generated by the orbital motion of the first planetary gear (543) to the first carrier (544). Accordingly, the first carrier (544) can rotate around the center axis during the orbital motion of the first planetary gear (543).

[0076] The second steering transmission member (540b) is connected to the first steering transmission member (540a) and the steering output unit (530), and rotates the steering output unit (530) in conjunction with the rotation of the first steering transmission member (540a).

[0077] The second steering transmission member (540b) according to the present embodiment includes a second sun gear (545), a second ring gear (546), a second planetary gear (547), and a second carrier (548).

[0078] The second sun gear (545) is connected to the first carrier (544) and rotates. The second sun gear (545) according to the present embodiment may be formed to have a rod shape with gear teeth protruding from its outer surface. The second sun gear (545) is positioned so that its central axis is coaxial with the central axis of the first carrier (544). The upper end of the second sun gear (545) is integrally coupled to the lower side of the first carrier (544). The second sun gear (545) rotates at the same angular velocity as the first carrier (544) when the first carrier (544) rotates.

[0079] The second ring gear (546) is positioned spaced apart from the second sun gear (545). The second ring gear (546) according to the present embodiment may be formed to have a hollow cylindrical shape with both sides open and gear teeth protruding from the inner surface. The inner surface of the second ring gear (546) is positioned spaced apart from the outer surface of the second sun gear (545) by a predetermined distance. The second ring gear (546) is positioned so that its center axis is coaxial with the center axis of the second sun gear (545) and the first ring gear (542). The second ring gear (546) may be fixed and supported on the inner surface of the steering body (510). The second ring gear (546) may be formed integrally with the first ring gear (542), or it may be formed separately from the first ring gear (542) and arranged spaced apart from the first ring gear (542).

[0080] The second planetary gear (547) is engaged and coupled between the second sun gear (545) and the second ring gear (546), and rotates and revolves in conjunction with the rotation of the second sun gear (545). The second planetary gear (547) according to the present embodiment may be formed to have a cylindrical shape with gear teeth formed on its outer surface. The second planetary gear (547) has a central axis parallel to the central axis of the second sun gear (545) and is arranged at a predetermined distance apart in the radial direction of the second ring gear (546). One side of the second planetary gear (547) is engaged and coupled with the outer surface of the second sun gear (545), and the other side is engaged and coupled with the inner surface of the second ring gear (546). The second planetary gear (547) receives rotational force from the second sun gear (545) and rotates around its central axis while simultaneously revolving around the central axis of the second sun gear (545). The second planetary gear (547) may be formed in multiple numbers. Multiple second planetary gears (547) are arranged at a predetermined interval along the circumferential direction of the second ring gear (546). Although FIG. 7 illustrates an example where there are three second planetary gears (547), the number of second planetary gears (547) is not limited to this, and the design can be changed to various numbers, such as three or five.

[0081] The second carrier (548) is connected to the steering output unit (530) and rotates in conjunction with the orbital motion of the second planetary gear (547), thereby rotating the steering output unit (530). The second carrier (548) according to the present embodiment may be formed to have the shape of a disc that is positioned facing the lower surface of the second planetary gear (547). The second carrier (548) is positioned so that its central axis is located coaxial with the central axis of the second sun gear (545). The second carrier (548) is integrally joined to the upper part of the steering output unit (530) by welding, bolting, etc.

[0082] A second connecting shaft (548a) connected to the second planetary gear (547) is formed in the second carrier (548). The second connecting shaft (548a) according to the present embodiment may be formed in the shape of a rod extending vertically from the upper surface of the second carrier (548) facing the second planetary gear (547). The second connecting shaft (548a) has a central axis positioned parallel to the central axis of the second carrier (548) and is positioned at a predetermined distance from the central axis of the second carrier (548) in the radial direction of the second carrier (548). The second connecting shaft (548a) is inserted to penetrate the central axis of the second planetary gear (547) to support the second planetary gear (547) so as to enable rotation. A plurality of second connecting shafts (548a) are provided to individually support each second planetary gear (547) so as to enable rotation. The second connecting shaft (548a) transmits rotational force generated by the orbital motion of the second planetary gear (547) to the second carrier (548). Accordingly, the second carrier (548) rotates around the center axis during the orbital motion of the second planetary gear (547) and can rotate the steering output unit (530).

[0083] The steering angle sensor (550) is connected to the steering output unit (530) and measures the rotation angle of the steering output unit (530). The steering angle sensor (550) according to the present embodiment may be exemplified by various types of rotation angle sensors that detect the rotation angle of the steering output unit (530) by outputting a change in magnetic field or an electrical change generated during the relative rotation of the sensor ring and the sensor body in the form of an electrical signal, and a sensor ring coupled to the outer surface of the steering output unit (530) and rotating relative to the sensor body.

[0084] The restraint unit (600) is connected to the steering unit (500) and selectively restricts the rotation of the second knuckle (220). More specifically, the restraint unit (600) functions as a configuration that selectively restricts the rotation of the second knuckle (220) by blocking or allowing the transmission of rotational force between the steering unit (500) and the second knuckle (220) under the control of the control unit (700) described later.

[0085] FIG. 8 is a plan view schematically showing the configuration of a restraining unit according to a first embodiment of the present invention, and FIG. 9 is a front view schematically showing the configuration of a restraining unit according to a first embodiment of the present invention.

[0086] Referring to FIGS. 8 and 9, the restraint unit (600) according to the present embodiment includes a first restraint part (610) and a second restraint part (620).

[0087] The first restraint (610) is positioned between the steering drive unit (520) and the steering transmission unit (540) and rotates together with the drive shaft (521) of the steering drive unit (520). Accordingly, the first restraint (610) can be rotated without the rotational force being amplified by the steering transmission unit (540), thereby reducing the magnitude of the load applied to the second restraint (620) described later.

[0088] The first restraint part (610) according to the present embodiment includes a first restraint body (611) and a first restraint member (612).

[0089] The first restraining body (611) is connected to the drive shaft (521) of the steering drive unit (520). The first restraining body (611) according to the present embodiment may be formed to have the shape of a disc that is positioned coaxially with the drive shaft (521). The upper and lower sides of the first restraining body (611) are connected to the lower end of the drive shaft (521) and the upper end of the first sun gear (541), respectively. In this case, the upper and lower sides of the first restraining body (611) may be spline-coupled to the lower end of the drive shaft (521) and the upper end of the first sun gear (541). Accordingly, the first restraining body (611) rotates at the same angular velocity as the drive shaft (521) when the drive shaft (521) rotates, and can transmit the rotational force of the drive shaft (521) to the first sun gear (541).

[0090] The first restraining member (612) functions as a configuration that provides an interference structure with the second restraining part (620) on the first restraining body (611) so that the rotation of the first restraining body (611) can be restricted by the second restraining part (620) described later. The first restraining member (612) according to the present embodiment is formed to have the shape of a groove that is concavely sunken into the inner side of the first restraining body (611). The first restraining member (612) extends from the outer surface of the first restraining body (611) toward the radial inner side of the first restraining body (611). The first restraining member (612) is formed such that its width gradually increases as it moves toward the radial outer side of the first restraining body (611). Accordingly, the first restraining member (612) can induce the second restraining member (632) of the second restraining part (620), which will be described later, to be smoothly inserted into the interior. The first restraining member (612) is provided in multiple numbers and is arranged at a predetermined interval along the circumferential direction of the first restraining body (611). Accordingly, the rotation of the first restraining body (611) can be restricted by the second restraining part (620) regardless of the rotation angle.

[0091] The second restraint part (620) is positioned facing the first restraint part (610), extends toward the first restraint part (610), and restricts or allows rotation of the first restraint part (610).

[0092] The second restraint part (620) according to the present embodiment includes a second restraint body (621), a restraint driving part (622), a second restraint member (623), and a restoration part (624).

[0093] The second restraining body (621) is positioned spaced apart from the first restraining body (611) and supports the restraining drive unit (622), the second restraining member (623), and the restoration unit (624) described later. The second restraining body (621) according to the present embodiment may be formed to have a hollow interior and a cylindrical shape with one side open. The second restraining body (621) is positioned so that the open side faces the first restraining body (611). The second restraining body (621) may be fixed in position by being coupled to the steering body (510) by welding, bolting, etc.

[0094] The restraint drive unit (622) is installed inside the second restraint body (621) and generates electromagnetic force by receiving power from the outside. The restraint drive unit (622) according to the present embodiment may be formed to have a hollow cylindrical shape with a coil of a conductive material wound around its circumference. The central axis of the restraint drive unit (622) is arranged parallel to the radial direction of the first restraint body (611). The restraint drive unit (622) is electrically connected to the control unit (700) described later, and the application of power can be controlled by the control of the control unit (700). As power is applied, the restraint drive unit (622) generates electromagnetic force in a direction parallel to the central axis. For example, as power is applied, the restraint drive unit (622) can generate electromagnetic force directed outward in the radial direction of the first restraint body (611) based on FIG. 8.

[0095] The second restraining member (623) is movably installed on the second restraining body (621) and moves in a linear reciprocating motion in conjunction with the electromagnetic force generated from the restraining drive unit (622). Depending on the direction of movement, the second restraining member (623) is inserted into the interior of the first restraining member (612) or detached from the first restraining member (612), thereby restricting or allowing rotation of the first restraining body (611). The second restraining member (623) according to the present embodiment is formed to have a roughly rod shape and is inserted into the interior of the second restraining body (621). In this case, the second restraining member (623) can be supported to slide within the second restraining body (621) by means of a guide rail (not shown), etc., formed on the second restraining body (621). The second restraining member (623) is positioned so that its outer surface faces the inner surface of the restraining drive unit (622). The second restraining member (623) is positioned so that its central axis is located coaxial with the central axis of the restraining drive unit (622). The second restraining member (623) has its front end protruding outward from the second restraining body (621) and is positioned so that it faces the outer surface of the first restraining body (611). The second restraining member (623) may be formed of a ferromagnetic material capable of being magnetized by a magnetic field generated from the outside. The second restraining member (623) reciprocates in a direction parallel to the radial direction of the first restraining body (611) by means of the second restraining member (623) and the restoration unit (624). For example, when power is applied to the restraint drive unit (622), the second restraint member (623) moves radially outward from the first restraint body (611), that is, in a direction away from the first restraint body (611), by the electromagnetic force generated from the restraint drive unit (622), and the front end is detached from the first restraint member (612).

[0096] The restoration unit (624) returns the second restraining member (623) to its initial position as the electromagnetic force generated from the restraining drive unit (622) is released. Here, the initial position of the second restraining member (623) can be exemplified as a position where the front end of the second restraining member (623) protrudes maximally to the outside of the second restraining body (621). The restoration unit (624) according to the present embodiment can be exemplified as a coil spring that is elastically deformable in the longitudinal direction. The two ends of the restoration unit (624) can be fixed to the rear end of the second restraining member (623) and the bottom surface of the second restraining body (621), respectively. The restoration unit (624) presses the second restraining member (623) toward the first restraining body (611) as the power supply to the restraining drive unit (622) is interrupted and the electromagnetic force generated from the restraining drive unit (622) is released, thereby inducing the front end of the second restraining member (623) to be inserted into the interior of the first restraining member (612). The restoration unit (624) is installed in a state of compression in the longitudinal direction when the second restraining member (623) is in its initial position, that is, when the front end of the second restraining member (623) protrudes maximally to the outside of the second restraining body (621), so that elastic force can be applied to the second restraining member (623) at all times in the opposite direction to the electromagnetic force generated from the restraining drive unit (622). The installation location of the restoration unit (624) is not limited to the details shown in FIGS. 8 and 9, and can be varied in design within a range of locations where the second restraining member (623) can be returned to its initial position by elastic restoring force as the electromagnetic force generated from the restraining drive unit (622) is released.

[0097] The control unit (700) generally controls the operation of the steering unit (500) and the restraint unit (600). More specifically, the control unit (700) receives steering information, such as steering angle and steering torque, generated from the steering input unit (30) as the driver operates the steering wheel, and controls the steering state of the vehicle by controlling the operation of the steering unit (500) based on the received steering information. Here, the steering input unit (30) can be exemplified by an SFA (Steering Feedback Actuator) connected to the steering wheel. The control unit (700) can individually control the operation of a plurality of steering units (500) provided in the vehicle independent steering device (10) installed on each wheel (20) to independently control the steering state of each wheel (20).

[0098] The control unit (700) can communicate with the steering input unit (30), the steering unit (500), and the restraining unit (600) via wired or wireless means. In this case, the control unit (700) can determine whether there is an abnormality in the communication status with the steering unit (500) for each wheel (20). If the control unit (700) determines that the communication status with the steering drive unit (520) is in an incapacitated state, more specifically with one of the steering units (500), the control unit (700) can control the operation of the restraining unit (600) so that the rotation of the second knuckle (220) installed on the wheel (20) is restricted. Accordingly, the control unit (700) can perform stable position control of the vehicle by preventing the wheel (20) on which the steering unit (500) is installed from being steered arbitrarily by reverse input, etc., when a failure occurs in one of the steering units (500), and by controlling the operation of the steering units (500) installed in the remaining wheels (20).

[0099] The control unit (700) may be implemented as an Electronic Control Unit (ECU), a Central Processing Unit (CPU), a Processor, or a System on Chip (SoC), and may control multiple hardware or software components by running an operating system or application, and may perform various data processing and calculations. The control unit (700) may be configured to execute at least one instruction stored in memory and store the execution result data in memory.

[0100] The operation process of an independent steering device for a vehicle according to the first embodiment of the present invention will be described in detail below.

[0101] FIG. 10 is a flowchart schematically showing the operation process of an independent steering device for a vehicle according to the first embodiment of the present invention, and FIG. 11 and FIG. 12 are diagrams schematically showing the operation process of a restraining unit according to the first embodiment of the present invention.

[0102] Referring to FIGS. 1 to 12, while the vehicle is in motion, the steering input unit (30) generates steering information such as steering angle and steering torque as the driver operates the steering wheel, and inputs the steering information to the control unit (700) (S100).

[0103] The control unit (700) controls the steering state of the vehicle by individually controlling the operation of the steering unit (500) for each wheel (20) based on the received steering information (S200).

[0104] More specifically, the control unit (700) transmits a control signal to the steering drive unit (520) based on the received steering information, and the steering drive unit (520) generates a rotational force corresponding to the control signal.

[0105] In this case, the control unit (700) determines whether there is an abnormality in the communication status with the steering unit (500) for each wheel (20) (S300).

[0106] When the control unit (700) determines that the communication state with any one of the steering units (500), namely the steering drive unit (520), is normal, it applies power to the restraint drive unit (622) to generate electromagnetic force.

[0107] The second restraining member (623) is moved away from the first restraining body (611) by the electromagnetic force generated from the restraining drive unit (622) and is detached from the first restraining member (612).

[0108] As the second restraining member (623) is detached from the first restraining member (612), the first restraining body (611) rotates at the same angular velocity as the drive shaft (521) without any interference, and the rotational force generated from the steering drive unit (520) is smoothly transmitted to the steering output unit (530) by sequentially passing through the drive shaft (521), the first restraining body (611), and the steering transmission unit (540).

[0109] The steering output unit (530) rotates around a central axis and rotates the second knuckle (220), and the second knuckle (220) rotates together with the wheel (20) and varies the steering angle of the wheel (20).

[0110] When the control unit (700) determines that communication with one of the steering units (500), i.e., the steering drive unit (520), is impossible, it controls the operation of the restraint unit (600) so that the rotation of the second knuckle (220) installed on the wheel (20) is restricted (S400).

[0111] More specifically, the control unit (700) cuts off the power applied to the restraint drive unit (622) to release the electromagnetic force.

[0112] As the electromagnetic force generated from the restraint drive unit (622) is released, the restoration unit (624) presses the second restraint member (623) toward the first restraint body (611).

[0113] The second restraining member (623) is moved toward the first restraining body (611) by the pressure applied from the restoration member (624), and the front portion is inserted into the interior of the first restraining member (612).

[0114] As the second restraining member (623) is inserted into the interior of the first restraining member (612), the first restraining body (611) is restricted from rotating by the locking force with the second restraining member (623).

[0115] Accordingly, the rotational force generated from the steering drive unit (520) is not transmitted to the steering transmission unit (540), and the steering angle of the wheel (20) is fixed.

[0116] Subsequently, the control unit (700) controls the operation of the remaining steering units (500), excluding the steering unit (500) in a state where communication is impossible, to control the steering state of the vehicle.

[0118] Hereinafter, the configuration of an independent steering device (11) for a vehicle according to the second embodiment of the present invention will be described in detail.

[0119] FIG. 13 is a schematic diagram showing the installation state of an independent steering device for a vehicle according to a second embodiment of the present invention.

[0120] Referring to FIG. 13, the vehicle independent steering device (11) according to the present embodiment is individually installed for each wheel (20) and independently performs driving, braking, steering, and suspension operations for each wheel (20).

[0121] FIG. 14 is a perspective view schematically showing the configuration of an independent steering device for a vehicle according to a second embodiment of the present invention, FIG. 15 is an exploded perspective view schematically showing the configuration of an independent steering device for a vehicle according to a second embodiment of the present invention, and FIG. 16 is a block diagram schematically showing the configuration of an independent steering device for a vehicle according to a second embodiment of the present invention.

[0122] Referring to FIGS. 14 to 16, the independent steering device (11) for a vehicle according to the present embodiment includes a driving unit (100), a knuckle unit (200), a braking unit (300), a suspension unit (400), a steering unit (500), a restraint unit (601), and a control unit (700).

[0123] The drive unit (100) is connected to the wheel (20) of a vehicle and provides driving force to the wheel (20) to rotate the wheel (20). The drive unit (100) according to the present embodiment may be exemplified by various types of in-wheel motors, including a stator that is positioned inside the wheel (20) and forms a magnetic field by receiving power from a vehicle battery (not shown), and a rotor that is rotatably installed inside the stator and rotates by electromagnetic interaction with the stator to rotate the wheel (20). The stator and the rotor may be positioned so that their central axes are aligned with the central axis of the wheel (20) and are stacked concentrically on the inside of the wheel (20). The drive unit (100) may be connected to the knuckle unit (200) described later and supported on the inside of the wheel (20).

[0124] The knuckle unit (200) is positioned facing the wheel (20) and functions as a configuration providing a mechanical connection to the drive unit (100), braking unit (300), suspension unit (400), and steering unit (500).

[0125] The knuckle unit (200) according to the present embodiment includes a first knuckle (210) and a second knuckle (220).

[0126] The first knuckle (210) forms one side of the exterior of the knuckle unit (200) and is positioned apart from the driving unit (100).

[0127] The first knuckle (210) according to the present embodiment is formed to have a roughly "C"-shaped cross-section and is positioned so that the open side faces the drive unit (100). The first knuckle (210) is positioned at a predetermined distance from the drive unit (100) in the width direction of the vehicle. The first knuckle (210) can be connected to and supported by the vehicle body by the suspension arm (410) described later. The specific shape of the first knuckle (210) is not limited to the shape shown in FIGS. 14 and 15, and various design changes are possible within the technical concept of a shape that is positioned to face the drive unit (100) and can rotatably support the second knuckle (220) described later.

[0128] The second knuckle (220) forms the outer surface of the other side of the knuckle unit (200) and is rotatably installed on the first knuckle (210). The second knuckle (220) is connected to the drive unit (100) and supports the drive unit (100) from the inside of the wheel (20). The second knuckle (220) rotates relative to the first knuckle (210) and transmits the steering force generated from the steering unit (500), which will be described later, to the wheel (20).

[0129] According to the present embodiment, the second knuckle (220) has both ends rotatably connected to the upper and lower ends of the open side of the first knuckle (210), respectively. In this case, both ends of the second knuckle (220) may be positioned at a predetermined angle of inclination with respect to an axis perpendicular to the ground. The central part of the second knuckle (220) is connected to the drive unit (100). More specifically, the central part of the second knuckle (220) may rotatably support the rotor of the drive unit (100) through a wheel bearing (not shown), etc. The second knuckle (220) is formed to be hollow inside so that the steering output part (530) of the steering unit (500), which will be described later, can be inserted inside, and spline teeth may be formed on the inner surface. The specific shape of the second knuckle (220) is not limited to the shape shown in FIG. 14 and FIG. 15, and various design changes are possible within the technical concept of a shape that can be rotatably installed on the first knuckle (210) to support the driving unit (100), braking unit (300), etc.

[0130] The braking unit (300) interferes with the rotation of the wheel (20) to apply or release braking force to the vehicle.

[0131] The braking unit (300) according to the present embodiment includes a brake disc (310) and a brake caliper (320).

[0132] The brake disc (310) rotates in conjunction with the rotation of the wheel (20). The brake disc (310) according to the present embodiment is formed to have a disc shape and is installed facing the drive unit (100). The brake disc (310) is positioned so that its central axis is aligned with the central axis of the drive unit (100). The brake disc (310) can be integrally connected to the rotor of the drive unit (100) by means of bolting, etc. Accordingly, the brake disc (310) can rotate around its central axis at the same angular velocity as the wheel (20) when the drive unit (100) operates. The diameter of the brake disc (310) can be varied in design depending on the diameter of the wheel (20), the size of the drive unit (100), etc.

[0133] The brake caliper (320) applies braking force by pressing the brake disc (310) when the vehicle is braking. The brake caliper (320) according to the present embodiment may be configured to include a brake pad positioned facing the brake disc (310), a caliper housing coupled to the second knuckle (220) to movably support the brake pad, and a piston installed to move back and forth in the caliper housing to press the brake pad toward the brake disc (310) or release pressure according to the direction of movement. The caliper housing may be detachably coupled to the second knuckle (220) by means of bolting, etc.

[0134] The suspension unit (400) is connected to the knuckle unit (200) and absorbs shocks transmitted from the road surface when the vehicle is driven.

[0135] The suspension unit (400) according to the present embodiment includes a suspension arm (410) and a shock absorber module (420).

[0136] The suspension arm (410) functions as a component that connects the wheel (20) to the vehicle body via the first knuckle (210), absorbs the load applied from the wheel (20) during driving due to its own rigidity, and controls the movement of the wheel (20). The suspension arm (410) according to the present embodiment extends in a longitudinal direction along the width direction of the vehicle. The suspension arm (410) may be formed to have the shape of a wishbone or a link arm. Both ends of the suspension arm (410) are rotatably connected to the lower end of the first knuckle (210) and the vehicle body, such as a subframe, via a ball joint, bushing, etc. The specific shape of the suspension arm (410) is not limited to the shape shown in FIGS. 2 and FIGS. 3, and various design changes are possible within the technical concept of a shape that can be connected to the first knuckle (210) and support the wheel (20).

[0137] The shock absorber module (420) is configured to be extendable along the longitudinal direction to absorb shocks or vibrations transmitted from the road surface.

[0138] The shock absorber module (420) according to the present embodiment includes a cylinder (421), a rod (422), and an elastic body (423).

[0139] The cylinder (421) forms one side of the exterior of the shock absorber module (420) and is connected to the first knuckle (210). The cylinder (421) according to the present embodiment may be formed to have a cylindrical shape with a hollow interior and one side open. The interior of the cylinder (421) is filled with a fluid capable of performing a damping function, such as oil. The lower end of the cylinder (421) may be connected to the upper end of the first knuckle (210).

[0140] The rod (422) forms the outer surface of the other side of the shock absorber module (420) and is connected to the cylinder (421) so as to be slidably movable. The rod (422) according to the present embodiment may be formed to have the shape of a rod, with its lower end inserted into the upper end of the cylinder (421) and installed so as to be slidably movable along the longitudinal direction of the cylinder (421). The upper end of the rod (422) is connected to and supported by a vehicle body such as a wheel housing. Accordingly, when the wheel (20) moves up and down due to the curvature of the road surface, the rod (422) reciprocates along the longitudinal direction of the cylinder (421) and can perform a damping action by the pressure of the fluid filled inside the cylinder (421).

[0141] The elastic body (423) is provided between the cylinder (421) and the rod (422) and elastically supports the rod (422) with respect to the cylinder (421). The elastic body (423) according to the present embodiment is positioned to wrap around the outer surface of the cylinder (421) and the rod (422) and may be formed to have the shape of a coil spring that is elastic and retractable along the longitudinal direction. The elastic body (423) may be supported by being coupled to a lower seat (424) with both ends fixed to the cylinder (421) and an upper seat (425) fixed to the rod (422), respectively. The elastic body (423) is compressed or stretched in the longitudinal direction when the rod (422) slides, accumulates elastic restoring force, and can absorb shocks applied from the road surface by offsetting the movement of the rod (422) with the accumulated elastic restoring force.

[0142] The steering unit (500) adjusts the steering angle of the wheel (20) by rotating the second knuckle (220) relative to the first knuckle (210).

[0143] FIG. 17 is a perspective view schematically showing the configuration of a steering unit and a restraining unit according to a second embodiment of the present invention.

[0144] Referring to FIGS. 14 to 17, the steering unit (500) according to the present embodiment includes a steering body (510), a steering drive unit (520), a steering output unit (530), a steering transmission unit (540), and a steering angle sensor (550).

[0145] The steering body (510) forms the general exterior of the steering unit (500) and supports the steering drive unit (520), steering output unit (530), steering transmission unit (540), and steering angle sensor (550) described later. The steering body (510) according to the present embodiment may be formed to have a hollow interior and a cylindrical shape with both sides open. The steering body (510) is positioned to face the second knuckle (220) vertically with respect to the first knuckle (210). The lower end of the steering body (510) is fixed to the upper end of the open side of the first knuckle (210). In this case, the steering body (510) may be integrally joined to the first knuckle (210) by welding, etc., and may also be detachably joined to the first knuckle (210) by bolting, etc.

[0146] The steering drive unit (520) is fixed to the first knuckle (210) and generates rotational force. The steering drive unit (520) according to the present embodiment can be exemplified by various types of electric motors that convert power applied from the outside into rotational force to rotate the drive shaft (521). The steering drive unit (520) can be indirectly fixed to the first knuckle (210) via the steering body (510). More specifically, the lower end of the steering drive unit (520) can be integrally coupled to the upper end of the steering body (510) by means of bolting, etc. The drive shaft (521) of the steering drive unit (520) protrudes from the lower end of the steering drive unit (520) and is positioned inside the steering body (510). The drive shaft (521) is positioned such that its center axis is located coaxial with the rotation center axis of the second knuckle (220). The steering drive unit (520) is electrically connected to the control unit (700) described later, so that the operating state can be controlled by the control unit (700).

[0147] The steering output unit (530) is connected to the second knuckle (220) and rotates the second knuckle (220) relative to the first knuckle (210) in conjunction with the rotational force generated from the steering drive unit (520). The steering output unit (530) can receive the rotational force generated from the steering drive unit (520) through the steering transmission unit (540) described later. The steering output unit (530) according to the present embodiment is positioned inside the steering body (510). The upper end of the steering output unit (530) is positioned so as to be spaced apart from the lower end of the drive shaft (521) by a predetermined distance. Accordingly, the steering output unit (530) can provide a space between itself and the drive shaft (521) where the steering transmission unit (540) described later can be installed. The steering output unit (530) is positioned so that its central axis is located coaxial with the central axis of the drive shaft (521). The lower portion of the steering output unit (530) protrudes downward from the steering body (510) and is inserted into the interior of the second knuckle (220). In this case, the steering output unit (530) may have spline teeth formed on its outer surface and may be spline-coupled to the inner surface of the second knuckle (220). Accordingly, the steering output unit (530) can rotate around a central axis by means of the steering transmission unit (540) described later, thereby rotating the second knuckle (220).

[0148] A stopper (531) may be provided at the lower end of the steering output unit (530) to prevent the steering output unit (530) from detaching from the second knuckle (220). The stopper (531) according to the present embodiment is formed to have a diameter larger than the diameter of the lower end of the steering output unit (530). The stopper (531) may be detachably coupled to the lower end of the steering output unit (530) by means of screw coupling, snap coupling, etc. When the lower end of the steering output unit (530) is inserted into the interior of the second knuckle (220), the upper surface of the stopper (531) is engaged with the inner surface of the second knuckle (220) to prevent the steering output unit (530) from detaching from the second knuckle (220).

[0149] The steering transmission unit (540) is provided between the steering drive unit (520) and the steering output unit (530) and transmits the rotational force generated from the steering drive unit (520) to the steering output unit (530). That is, the steering transmission unit (540) corresponds to a configuration that performs the function of a reduction gear device that amplifies the rotational force transmitted to the steering output unit (530) by reducing the rotational speed of the drive shaft (521) when the steering drive unit (520) operates.

[0150] FIG. 18 is an exploded perspective view schematically showing the configuration of a steering transmission unit according to a second embodiment of the present invention.

[0151] Referring to FIG. 18, the steering transmission unit (540) according to the present embodiment includes a first steering transmission member (540a) and a second steering transmission member (540b).

[0152] The first steering transmission member (540a) is connected to the steering drive unit (520) and rotates by receiving rotational force from the steering drive unit (520).

[0153] The first steering transmission member (540a) according to the present embodiment includes a first sun gear (541), a first ring gear (542), a first planetary gear (543), and a first carrier (544).

[0154] The first sun gear (541) is connected to and rotated by the drive shaft (521) of the steering drive unit (520). The first sun gear (541) according to the present embodiment may be formed to have a rod shape with gear teeth protruding from its outer surface. The first sun gear (541) is positioned so that its center axis is located coaxial with the center axis of the drive shaft (521). The upper end of the first sun gear (541) is integrally connected to the lower end of the drive shaft (521). The first sun gear (541) rotates at the same angular velocity as the drive shaft (521) when the drive shaft (521) rotates.

[0155] The first ring gear (542) is positioned spaced apart from the first sun gear (541). The first ring gear (542) according to the present embodiment may be formed to have a hollow cylindrical shape with both sides open and gear teeth protruding from the inner surface. The inner surface of the first ring gear (542) is positioned spaced apart from the outer surface of the first sun gear (541) by a predetermined distance. The first ring gear (542) is positioned so that its center axis is located coaxial with the center axis of the first sun gear (541). The first ring gear (542) may be fixed and supported on the inner surface of the steering body (510).

[0156] The first planetary gear (543) is engaged and coupled between the first sun gear (541) and the first ring gear (542), and rotates and revolves in conjunction with the rotation of the first sun gear (541). The first planetary gear (543) according to the present embodiment may be formed to have a cylindrical shape with gear teeth formed on its outer surface. The first planetary gear (543) has a central axis parallel to the central axis of the first sun gear (541) and is arranged at a predetermined distance apart in the radial direction of the first ring gear (542). One side of the first planetary gear (543) is engaged and coupled with the outer surface of the first sun gear (541), and the other side is engaged and coupled with the inner surface of the first ring gear (542). The first planetary gear (543) receives rotational force from the first sun gear (541) and rotates around its central axis while simultaneously revolving around the central axis of the first sun gear (541). The first planetary gear (543) may be formed in multiple numbers. Multiple first planetary gears (543) are arranged at a predetermined interval along the circumferential direction of the first ring gear (542). Although FIG. 7 illustrates an example where there are three first planetary gears (543), the number of first planetary gears (543) is not limited to this, and the design can be changed to various numbers, such as three or five.

[0157] The first carrier (544) rotates in conjunction with the orbital motion of the first planetary gear (543). The first carrier (544) according to the present embodiment may be formed to have the shape of a disc positioned to face the lower surface of the first planetary gear (543). The first carrier (544) is positioned so that its central axis is located coaxial with the central axis of the first sun gear (541).

[0158] A first connecting shaft (544a) connected to the first planetary gear (543) is formed in the first carrier (544). The first connecting shaft (544a) according to the present embodiment may be formed in the shape of a rod extending vertically from the upper surface of the first carrier (544) facing the first planetary gear (543). The first connecting shaft (544a) has a central axis positioned parallel to the central axis of the first carrier (544) and is positioned at a predetermined distance from the central axis of the first carrier (544) in the radial direction of the first carrier (544). The first connecting shaft (544a) is inserted to penetrate the central axis of the first planetary gear (543) to support the first planetary gear (543) so as to rotate. A plurality of first connecting shafts (544a) are provided to support each first planetary gear (543) individually so as to rotate. The first connecting shaft (544a) transmits rotational force generated by the orbital motion of the first planetary gear (543) to the first carrier (544). Accordingly, the first carrier (544) can rotate around the center axis during the orbital motion of the first planetary gear (543).

[0159] The second steering transmission member (540b) is connected to the first steering transmission member (540a) and the steering output unit (530), and rotates the steering output unit (530) in conjunction with the rotation of the first steering transmission member (540a).

[0160] The second steering transmission member (540b) according to the present embodiment includes a second sun gear (545), a second ring gear (546), a second planetary gear (547), and a second carrier (548).

[0161] The second sun gear (545) is connected to the first carrier (544) and rotates. The second sun gear (545) according to the present embodiment may be formed to have a rod shape with gear teeth protruding from its outer surface. The second sun gear (545) is positioned so that its central axis is coaxial with the central axis of the first carrier (544). The upper end of the second sun gear (545) is integrally coupled to the lower side of the first carrier (544). The second sun gear (545) rotates at the same angular velocity as the first carrier (544) when the first carrier (544) rotates.

[0162] The second ring gear (546) is positioned spaced apart from the second sun gear (545). The second ring gear (546) according to the present embodiment may be formed to have a hollow cylindrical shape with both sides open and gear teeth protruding from the inner surface. The inner surface of the second ring gear (546) is positioned spaced apart from the outer surface of the second sun gear (545) by a predetermined distance. The second ring gear (546) is positioned so that its center axis is coaxial with the center axis of the second sun gear (545) and the first ring gear (542). The second ring gear (546) may be fixed and supported on the inner surface of the steering body (510). The second ring gear (546) may be formed integrally with the first ring gear (542), or it may be formed separately from the first ring gear (542) and arranged spaced apart from the first ring gear (542).

[0163] The second planetary gear (547) is engaged and coupled between the second sun gear (545) and the second ring gear (546), and rotates and revolves in conjunction with the rotation of the second sun gear (545). The second planetary gear (547) according to the present embodiment may be formed to have a cylindrical shape with gear teeth formed on its outer surface. The second planetary gear (547) has a central axis parallel to the central axis of the second sun gear (545) and is arranged at a predetermined distance apart in the radial direction of the second ring gear (546). One side of the second planetary gear (547) is engaged and coupled with the outer surface of the second sun gear (545), and the other side is engaged and coupled with the inner surface of the second ring gear (546). The second planetary gear (547) receives rotational force from the second sun gear (545) and rotates around its central axis while simultaneously revolving around the central axis of the second sun gear (545). The second planetary gear (547) may be formed in multiple numbers. Multiple second planetary gears (547) are arranged at a predetermined interval along the circumferential direction of the second ring gear (546). Although FIG. 7 illustrates an example where there are three second planetary gears (547), the number of second planetary gears (547) is not limited to this, and the design can be changed to various numbers, such as three or five.

[0164] The second carrier (548) is connected to the steering output unit (530) and rotates in conjunction with the orbital motion of the second planetary gear (547), thereby rotating the steering output unit (530). The second carrier (548) according to the present embodiment may be formed to have the shape of a disc that is positioned facing the lower surface of the second planetary gear (547). The second carrier (548) is positioned so that its central axis is located coaxial with the central axis of the second sun gear (545). The second carrier (548) is integrally joined to the upper part of the steering output unit (530) by welding, bolting, etc.

[0165] A second connecting shaft (548a) connected to the second planetary gear (547) is formed in the second carrier (548). The second connecting shaft (548a) according to the present embodiment may be formed in the shape of a rod extending vertically from the upper surface of the second carrier (548) facing the second planetary gear (547). The second connecting shaft (548a) has a central axis positioned parallel to the central axis of the second carrier (548) and is positioned at a predetermined distance from the central axis of the second carrier (548) in the radial direction of the second carrier (548). The second connecting shaft (548a) is inserted to penetrate the central axis of the second planetary gear (547) to support the second planetary gear (547) so as to enable rotation. A plurality of second connecting shafts (548a) are provided to individually support each second planetary gear (547) so as to enable rotation. The second connecting shaft (548a) transmits rotational force generated by the orbital motion of the second planetary gear (547) to the second carrier (548). Accordingly, the second carrier (548) rotates around the center axis during the orbital motion of the second planetary gear (547) and can rotate the steering output unit (530).

[0166] The steering angle sensor (550) is connected to the steering output unit (530) and measures the rotation angle of the steering output unit (530). The steering angle sensor (550) according to the present embodiment may be exemplified by various types of rotation angle sensors that detect the rotation angle of the steering output unit (530) by outputting a change in magnetic field or an electrical change generated during the relative rotation of the sensor ring and the sensor body in the form of an electrical signal, and a sensor ring coupled to the outer surface of the steering output unit (530) and rotating relative to the sensor body.

[0167] The restraining unit (601) is connected to the steering unit (500) and selectively restricts the rotation of the second knuckle (220). More specifically, the restraining unit (601) functions as a configuration that selectively restricts the rotation of the second knuckle (220) by blocking or allowing the transmission of rotational force between the steering unit (500) and the second knuckle (220) under the control of the control unit (700) described later.

[0168] FIG. 19 is a plan view schematically showing the configuration of a restraining unit according to a second embodiment of the present invention, and FIG. 20 is a front view schematically showing the configuration of a restraining unit according to a first embodiment of the present invention.

[0169] Referring to FIG. 19 and FIG. 20, the restraint unit (601) according to the present embodiment includes a first restraint part (630) and a second restraint part (640).

[0170] The first restraining member (630) is provided on the first carrier (544) and rotates together with the first carrier (544). Accordingly, the first restraining member (630) can be rotated with a reduced rotational speed compared to the drive shaft (521), thereby further improving the stability of the connection with the second restraining member (640) described later.

[0171] The first restraining part (630) according to the present embodiment includes a first restraining member (631).

[0172] The first restraining member (631) functions as a configuration that provides an interference structure with the second restraining member (640) on the first carrier (544) so ​​that the rotation of the first carrier (544) can be restricted by the second restraining member (640) described later. The first restraining member (631) according to the present embodiment is formed to have the shape of a groove that is concavely sunken into the inner side of the first carrier (544). The first restraining member (631) extends from the outer surface of the first carrier (544) toward the radial inner side of the first carrier (544). The first restraining member (631) is formed such that its width gradually increases as it moves toward the radial outer side of the first carrier (544). Accordingly, the first restraining member (631) can induce the second restraining member (632) of the second restraining part (640), which will be described later, to be smoothly inserted into the interior. The first restraining member (631) is provided in multiple numbers and arranged at a predetermined interval along the circumferential direction of the first carrier (544). Accordingly, the rotation of the first carrier (544) can be restricted by the second restraining part (640) regardless of the rotation angle.

[0173] The second restraining part (640) is positioned facing the first carrier (544) and extends toward the first restraining part (630), thereby restricting or allowing rotation of the first carrier (544).

[0174] The second restraint part (640) according to the present embodiment includes a second restraint body (641), a restraint driving part (642), a second restraint member (643), and a restoration part (644).

[0175] The second restraining body (641) is positioned spaced apart from the first carrier (544) and supports the restraining drive unit (642), the second restraining member (643), and the restoration unit (644) described later. The second restraining body (641) according to the present embodiment may be formed to have a hollow interior and a cylindrical shape with one side open. The second restraining body (641) is positioned so that the open side faces the first carrier (544). The second restraining body (641) may be fixed in position by being coupled to the steering body (510) by welding, bolting, etc.

[0176] The restraint drive unit (642) is installed inside the second restraint body (641) and generates electromagnetic force by receiving power from the outside. The restraint drive unit (642) according to the present embodiment may be formed to have a hollow cylindrical shape with a coil of a conductive material wound around its circumference. The central axis of the restraint drive unit (642) is arranged parallel to the radial direction of the first carrier (544). The restraint drive unit (642) is electrically connected to the control unit (700) described later, and the application of power can be controlled by the control of the control unit (700). As power is applied, the restraint drive unit (642) generates electromagnetic force in a direction parallel to the central axis. For example, as power is applied, the restraint drive unit (642) can generate electromagnetic force directed outward in the radial direction of the first carrier (544) based on FIG. 19.

[0177] The second restraining member (643) is movably installed in the second restraining body (641) and moves in a linear reciprocating motion in conjunction with the electromagnetic force generated from the restraining drive unit (642). Depending on the direction of movement, the second restraining member (643) is inserted into the interior of the first restraining member (631) or detached from the first restraining member (631), thereby restricting or allowing rotation of the first carrier (544). The second restraining member (643) according to the present embodiment is formed to have a roughly rod shape and is inserted into the interior of the second restraining body (641). In this case, the second restraining member (643) can be supported to slide within the second restraining body (641) by means of a guide rail (not shown), etc., formed in the second restraining body (621). The outer surface of the second restraining member (643) is positioned to face the inner surface of the restraining drive unit (642). The second restraining member (643) is positioned so that its central axis is coaxial with the central axis of the restraining drive unit (642). The second restraining member (643) has its front end protruding outward from the second restraining body (641) and is positioned to face the outer surface of the first carrier (544). The second restraining member (643) may be formed of a ferromagnetic material capable of being magnetized by a magnetic field generated from the outside. The second restraining member (643) reciprocates in a direction parallel to the radial direction of the first carrier (544) by means of the second restraining member (643) and the restoration unit (644). For example, when power is applied to the restraint drive unit (642), the second restraint member (643) moves radially outward from the first carrier (544), that is, in a direction away from the first carrier (544), by the electromagnetic force generated from the restraint drive unit (642), and the front end is detached from the first restraint member (631).

[0178] The restoration unit (644) returns the second restraining member (643) to its initial position as the electromagnetic force generated from the restraining driving unit (642) is released. Here, the initial position of the second restraining member (643) can be exemplified as a position where the front end of the second restraining member (643) protrudes maximally to the outside of the second restraining body (641). The restoration unit (644) according to the present embodiment can be exemplified as a coil spring that is elastically deformable in the longitudinal direction. The two ends of the restoration unit (644) can be fixed to the rear end of the second restraining member (643) and the bottom surface of the second restraining body (641), respectively. The restoration unit (644) presses the second restraining member (643) toward the first carrier (544) as the power supply to the restraining drive unit (642) is interrupted and the electromagnetic force generated from the restraining drive unit (642) is released, thereby inducing the front end of the second restraining member (643) to be inserted into the interior of the first restraining member (631). The restoration unit (644) is installed in a state of compression in the longitudinal direction when the initial position of the second restraining member (643), that is, when the front end of the second restraining member (643) protrudes maximally to the outside of the second restraining body (641), so that elastic force can be applied to the restraining member (623) at all times in the opposite direction to the electromagnetic force generated from the restraining drive unit (642). The installation location of the restoration unit (644) is not limited to the details shown in FIG. 19 and FIG. 20, and can be varied in design within a range of locations where the second restraining member (643) can be returned to its initial position by elastic restoring force as the electromagnetic force generated from the restraining drive unit (642) is released.

[0179] The control unit (700) generally controls the operation of the steering unit (500) and the restraint unit (601). More specifically, the control unit (700) receives steering information, such as steering angle and steering torque, generated from the steering input unit (30) as the driver operates the steering wheel, and controls the steering state of the vehicle by controlling the operation of the steering unit (500) based on the received steering information. Here, the steering input unit (30) can be exemplified by an SFA (Steering Feedback Actuator) connected to the steering wheel. The control unit (700) can independently control the operation of a plurality of steering units (500) provided in the vehicle independent steering device (10) installed on each wheel (20) to independently control the steering state of each wheel (20).

[0180] The control unit (700) can communicate with the steering input unit (30), the steering unit (500), and the restraining unit (601) via wired or wireless means. In this case, the control unit (700) can determine whether there is an abnormality in the communication status with the steering unit (500) for each wheel (20). If the control unit (700) determines that the communication status with any one of the steering units (500), i.e., the steering drive unit (520), is in an incapacitated state, it can control the operation of the restraining unit (601) so that the rotation of the second knuckle (220) installed on the wheel (20) is restricted. Accordingly, the control unit (700) can perform stable position control of the vehicle by preventing the wheel (20) on which the steering unit (500) is installed from being steered arbitrarily by reverse input, etc., when a failure occurs in one of the steering units (500), and by controlling the operation of the steering units (500) installed in the remaining wheels (20).

[0181] The control unit (700) may be implemented as an Electronic Control Unit (ECU), a Central Processing Unit (CPU), a Processor, or a System on Chip (SoC), and may control multiple hardware or software components by running an operating system or application, and may perform various data processing and calculations. The control unit (700) may be configured to execute at least one instruction stored in memory and store the execution result data in memory.

[0182] The operation process of an independent steering device for a vehicle according to the first embodiment of the present invention will be described in detail below.

[0183] FIG. 21 is a flowchart schematically showing the operation process of an independent steering device for a vehicle according to a second embodiment of the present invention, and FIG. 22 and FIG. 23 are diagrams schematically showing the operation process of a restraining unit according to a second embodiment of the present invention.

[0184] Referring to FIGS. 14 to 23, while the vehicle is in motion, the steering input unit (30) generates steering information such as steering angle and steering torque as the driver operates the steering wheel, and inputs the steering information to the control unit (700) (S100).

[0185] The control unit (700) controls the steering state of the vehicle by individually controlling the operation of the steering unit (500) for each wheel (20) based on the received steering information (S200).

[0186] More specifically, the control unit (700) transmits a control signal to the steering drive unit (520) based on the received steering information, and the steering drive unit (520) generates a rotational force corresponding to the control signal.

[0187] In this case, the control unit (700) determines whether there is an abnormality in the communication status with the steering unit (500) for each wheel (20) (S300).

[0188] When the control unit (700) determines that the communication state with any one of the steering units (500), namely the steering drive unit (520), is normal, it applies power to the restraint drive unit (622) to generate electromagnetic force.

[0189] The second restraining member (643) is moved away from the first carrier (544) by the electromagnetic force generated from the restraining drive unit (622) and is detached from the first restraining member (631).

[0190] As the second restraining member (643) is detached from the first restraining member (631), the first carrier (544) rotates at the same angular velocity as the drive shaft (521) without any interference, and the rotational force generated from the steering drive unit (520) is smoothly transmitted to the steering output unit (530) by sequentially passing through the drive shaft (521) and the steering transmission unit (540).

[0191] The steering output unit (530) rotates around a central axis and rotates the second knuckle (220), and the second knuckle (220) rotates together with the wheel (20) and varies the steering angle of the wheel (20).

[0192] When the control unit (700) determines that communication with one of the steering units (500), i.e., the steering drive unit (520), is impossible, it controls the operation of the restraint unit (601) so that the rotation of the second knuckle (220) installed on the wheel (20) is restricted (S400).

[0193] More specifically, the control unit (700) cuts off the power applied to the restraint drive unit (622) to release the electromagnetic force.

[0194] As the electromagnetic force generated from the restraint drive unit (622) is released, the restoration unit (644) presses the second restraint member (643) toward the first carrier (544).

[0195] The second restraining member (643) is moved toward the first carrier (544) by the pressure applied from the restoration member (644), and the front portion is inserted into the interior of the first restraining member (631).

[0196] As the second restraining member (643) is inserted into the interior of the first restraining member (631), the first carrier (544) is restricted from rotating by the locking force with the second restraining member (643).

[0197] Accordingly, the rotational force generated from the steering drive unit (520) is not transmitted to the steering output unit (530), and the steering angle of the wheel (20) is fixed.

[0198] Subsequently, the control unit (700) controls the operation of the remaining steering units (500), excluding the steering unit (500) in a state where communication is impossible, to control the steering state of the vehicle.

[0201] Below, the configuration of an independent steering device (12) for a vehicle according to the third embodiment of the present invention will be described in detail.

[0202] FIG. 24 is a schematic diagram showing the installation state of an independent steering device for a vehicle according to the third embodiment of the present invention.

[0203] Referring to FIG. 24, the vehicle independent steering device (12) according to the present embodiment is individually installed for each wheel (20) and independently performs driving, braking, steering, and suspension operations for each wheel (20).

[0204] FIG. 25 is a perspective view schematically showing the configuration of an independent steering device for a vehicle according to a third embodiment of the present invention, FIG. 26 is an exploded perspective view schematically showing the configuration of an independent steering device for a vehicle according to a third embodiment of the present invention, and FIG. 27 is a block diagram schematically showing the configuration of an independent steering device for a vehicle according to a third embodiment of the present invention.

[0205] Referring to FIGS. 25 to 27, the vehicle independent steering device (12) according to the present embodiment includes a driving unit (100), a knuckle unit (200), a braking unit (300), a suspension unit (400), a steering unit (500), a restraint unit (602), and a control unit (700).

[0206] The drive unit (100) is connected to the wheel (20) of a vehicle and provides driving force to the wheel (20) to rotate the wheel (20). The drive unit (100) according to the present embodiment may be exemplified by various types of in-wheel motors, including a stator that is positioned inside the wheel (20) and forms a magnetic field by receiving power from a vehicle battery (not shown), and a rotor that is rotatably installed inside the stator and rotates by electromagnetic interaction with the stator to rotate the wheel (20). The stator and the rotor may be positioned so that their central axes are aligned with the central axis of the wheel (20) and are stacked concentrically on the inside of the wheel (20). The drive unit (100) may be connected to the knuckle unit (200) described later and supported on the inside of the wheel (20).

[0207] The knuckle unit (200) is positioned facing the wheel (20) and functions as a configuration providing a mechanical connection to the drive unit (100), braking unit (300), suspension unit (400), and steering unit (500).

[0208] The knuckle unit (200) according to the present embodiment includes a first knuckle (210) and a second knuckle (220).

[0209] The first knuckle (210) forms one side of the exterior of the knuckle unit (200) and is positioned apart from the driving unit (100).

[0210] The first knuckle (210) according to the present embodiment is formed to have a roughly "C"-shaped cross-section and is positioned so that the open side faces the drive unit (100). The first knuckle (210) is positioned at a predetermined distance from the drive unit (100) in the width direction of the vehicle. The first knuckle (210) can be connected to and supported by the vehicle body by the suspension arm (410) described later. The specific shape of the first knuckle (210) is not limited to the shape shown in FIGS. 25 and 26, and various design changes are possible within the technical concept of a shape that is positioned to face the drive unit (100) and can rotatably support the second knuckle (220) described later.

[0211] The second knuckle (220) forms the outer surface of the other side of the knuckle unit (200) and is rotatably installed on the first knuckle (210). The second knuckle (220) is connected to the drive unit (100) and supports the drive unit (100) from the inside of the wheel (20). The second knuckle (220) rotates relative to the first knuckle (210) and transmits the steering force generated from the steering unit (500), which will be described later, to the wheel (20).

[0212] According to the present embodiment, the second knuckle (220) has both ends rotatably connected to the upper and lower ends of the open side of the first knuckle (210), respectively. In this case, both ends of the second knuckle (220) may be positioned at a predetermined angle of inclination with respect to an axis perpendicular to the ground. The central part of the second knuckle (220) is connected to the drive unit (100). More specifically, the central part of the second knuckle (220) may rotatably support the rotor of the drive unit (100) through a wheel bearing (not shown), etc. The second knuckle (220) is formed to be hollow inside so that the steering output part (530) of the steering unit (500), which will be described later, can be inserted inside, and spline teeth may be formed on the inner surface. The specific shape of the second knuckle (220) is not limited to the shape shown in FIG. 25 and FIG. 26, and various design changes are possible within the technical concept of a shape that can be rotatably installed on the first knuckle (210) to support the driving unit (100), braking unit (300), etc.

[0213] The braking unit (300) interferes with the rotation of the wheel (20) to apply or release braking force to the vehicle.

[0214] The braking unit (300) according to the present embodiment includes a brake disc (310) and a brake caliper (320).

[0215] The brake disc (310) rotates in conjunction with the rotation of the wheel (20). The brake disc (310) according to the present embodiment is formed to have a disc shape and is installed facing the drive unit (100). The brake disc (310) is positioned so that its central axis is aligned with the central axis of the drive unit (100). The brake disc (310) can be integrally connected to the rotor of the drive unit (100) by means of bolting, etc. Accordingly, the brake disc (310) can rotate around its central axis at the same angular velocity as the wheel (20) when the drive unit (100) operates. The diameter of the brake disc (310) can be varied in design depending on the diameter of the wheel (20), the size of the drive unit (100), etc.

[0216] The brake caliper (320) applies braking force by pressing the brake disc (310) when the vehicle is braking. The brake caliper (320) according to the present embodiment may be configured to include a brake pad positioned facing the brake disc (310), a caliper housing coupled to the second knuckle (220) to movably support the brake pad, and a piston installed to move back and forth in the caliper housing to press the brake pad toward the brake disc (310) or release pressure according to the direction of movement. The caliper housing may be detachably coupled to the second knuckle (220) by means of bolting, etc.

[0217] The suspension unit (400) is connected to the knuckle unit (200) and absorbs shocks transmitted from the road surface when the vehicle is driven.

[0218] The suspension unit (400) according to the present embodiment includes a suspension arm (410) and a shock absorber module (420).

[0219] The suspension arm (410) functions as a component that connects the wheel (20) to the vehicle body via the first knuckle (210), absorbs the load applied from the wheel (20) during driving due to its own rigidity, and controls the movement of the wheel (20). The suspension arm (410) according to the present embodiment extends in the longitudinal direction along the width direction of the vehicle. The suspension arm (410) may be formed to have the shape of a wishbone or a link arm. Both ends of the suspension arm (410) are rotatably connected to the lower end of the first knuckle (210) and the vehicle body, such as a subframe, via a ball joint, bushing, etc. The specific shape of the suspension arm (410) is not limited to the shape shown in FIGS. 25 and 26, and various design changes are possible within the technical concept of a shape that can be connected to the first knuckle (210) and support the wheel (20).

[0220] The shock absorber module (420) is configured to be extendable along the longitudinal direction to absorb shocks or vibrations transmitted from the road surface.

[0221] The shock absorber module (420) according to the present embodiment includes a cylinder (421), a rod (422), and an elastic body (423).

[0222] The cylinder (421) forms one side of the exterior of the shock absorber module (420) and is connected to the first knuckle (210). The cylinder (421) according to the present embodiment may be formed to have a cylindrical shape with a hollow interior and one side open. The interior of the cylinder (421) is filled with a fluid capable of performing a damping function, such as oil. The lower end of the cylinder (421) may be connected to the upper end of the first knuckle (210).

[0223] The rod (422) forms the outer surface of the other side of the shock absorber module (420) and is connected to the cylinder (421) so as to be slidably movable. The rod (422) according to the present embodiment may be formed to have the shape of a rod, with its lower end inserted into the upper end of the cylinder (421) and installed so as to be slidably movable along the longitudinal direction of the cylinder (421). The upper end of the rod (422) is connected to and supported by a vehicle body such as a wheel housing. Accordingly, when the wheel (20) moves up and down due to the curvature of the road surface, the rod (422) reciprocates along the longitudinal direction of the cylinder (421) and can perform a damping action by the pressure of the fluid filled inside the cylinder (421).

[0224] The elastic body (423) is provided between the cylinder (421) and the rod (422) and elastically supports the rod (422) with respect to the cylinder (421). The elastic body (423) according to the present embodiment is positioned to wrap around the outer surface of the cylinder (421) and the rod (422) and may be formed to have the shape of a coil spring that is elastic and retractable along the longitudinal direction. The elastic body (423) may be supported by being coupled to a lower seat (424) with both ends fixed to the cylinder (421) and an upper seat (425) fixed to the rod (422), respectively. The elastic body (423) is compressed or stretched in the longitudinal direction when the rod (422) slides, accumulates elastic restoring force, and can absorb shocks applied from the road surface by offsetting the movement of the rod (422) with the accumulated elastic restoring force.

[0225] The steering unit (500) adjusts the steering angle of the wheel (20) by rotating the second knuckle (220) relative to the first knuckle (210).

[0226] FIG. 28 is a perspective view schematically showing the configuration of a steering unit and a restraining unit according to a third embodiment of the present invention, and FIG. 29 is an exploded perspective view schematically showing the configuration of a steering unit and a restraining unit according to a third embodiment of the present invention.

[0227] Referring to FIGS. 24 to 29, the steering unit (500) according to the present embodiment includes a steering body (510), a steering drive unit (520), a steering output unit (530), a steering transmission unit (540), and a steering angle sensor (550).

[0228] The steering body (510) forms the general exterior of the steering unit (500) and supports the steering drive unit (520), steering output unit (530), steering transmission unit (540), and steering angle sensor (550) described later. The steering body (510) according to the present embodiment may be formed to have a hollow interior and a cylindrical shape with both sides open. The steering body (510) is positioned to face the second knuckle (220) vertically with respect to the first knuckle (210). The lower end of the steering body (510) is fixed to the upper end of the open side of the first knuckle (210). In this case, the steering body (510) may be integrally joined to the first knuckle (210) by welding, etc., and may also be detachably joined to the first knuckle (210) by bolting, etc.

[0229] The steering drive unit (520) is fixed to the first knuckle (210) and generates rotational force. The steering drive unit (520) according to the present embodiment can be exemplified by various types of electric motors that convert power applied from the outside into rotational force to rotate the drive shaft (521). The steering drive unit (520) can be indirectly fixed to the first knuckle (210) via the steering body (510). More specifically, the lower end of the steering drive unit (520) can be integrally coupled to the upper end of the steering body (510) by means of bolting, etc. The drive shaft (521) of the steering drive unit (520) protrudes from the lower end of the steering drive unit (520) and is positioned inside the steering body (510). The drive shaft (521) is positioned such that its center axis is located coaxial with the rotation center axis of the second knuckle (220). The steering drive unit (520) is electrically connected to the control unit (700) described later, so that the operating state can be controlled by the control unit (700).

[0230] The steering output unit (530) is connected to the second knuckle (220) and rotates the second knuckle (220) relative to the first knuckle (210) in conjunction with the rotational force generated from the steering drive unit (520). The steering output unit (530) can receive the rotational force generated from the steering drive unit (520) through the steering transmission unit (540) described later. The steering output unit (530) according to the present embodiment is positioned inside the steering body (510). The upper end of the steering output unit (530) is positioned so as to be spaced apart from the lower end of the drive shaft (521) by a predetermined distance. Accordingly, the steering output unit (530) can provide a space between itself and the drive shaft (521) where the steering transmission unit (540) described later can be installed. The steering output unit (530) is positioned so that its central axis is located coaxial with the central axis of the drive shaft (521). The lower portion of the steering output unit (530) protrudes downward from the steering body (510) and is inserted into the interior of the second knuckle (220). In this case, the steering output unit (530) may have spline teeth formed on its outer surface and may be spline-coupled to the inner surface of the second knuckle (220). Accordingly, the steering output unit (530) can rotate around a central axis by means of the steering transmission unit (540) described later, thereby rotating the second knuckle (220).

[0231] A stopper (531) may be provided at the lower end of the steering output unit (530) to prevent the steering output unit (530) from detaching from the second knuckle (220). The stopper (531) according to the present embodiment is formed to have a diameter larger than the diameter of the lower end of the steering output unit (530). The stopper (531) may be detachably coupled to the lower end of the steering output unit (530) by means of screw coupling, snap coupling, etc. When the lower end of the steering output unit (530) is inserted into the interior of the second knuckle (220), the upper surface of the stopper (531) is engaged with the inner surface of the second knuckle (220) to prevent the steering output unit (530) from detaching from the second knuckle (220).

[0232] The steering transmission unit (540) is provided between the steering drive unit (520) and the steering output unit (530) and transmits the rotational force generated from the steering drive unit (520) to the steering output unit (530). That is, the steering transmission unit (540) corresponds to a configuration that performs the function of a reduction gear device that amplifies the rotational force transmitted to the steering output unit (530) by reducing the rotational speed of the drive shaft (521) when the steering drive unit (520) operates.

[0233] FIG. 30 is an exploded perspective view schematically showing the configuration of a steering transmission unit according to a third embodiment of the present invention.

[0234] Referring to FIG. 30, the steering transmission unit (540) according to the present embodiment includes a first steering transmission member (540a) and a second steering transmission member (540b).

[0235] The first steering transmission member (540a) is connected to the steering drive unit (520) and rotates by receiving rotational force from the steering drive unit (520).

[0236] The first steering transmission member (540a) according to the present embodiment includes a first sun gear (541), a first ring gear (542), a first planetary gear (543), and a first carrier (544).

[0237] The first sun gear (541) is connected to and rotated by the drive shaft (521) of the steering drive unit (520). The first sun gear (541) according to the present embodiment may be formed to have a rod shape with gear teeth protruding from its outer surface. The first sun gear (541) is positioned so that its center axis is located coaxial with the center axis of the drive shaft (521). The upper end of the first sun gear (541) is integrally connected to the lower end of the drive shaft (521). The first sun gear (541) rotates at the same angular velocity as the drive shaft (521) when the drive shaft (521) rotates.

[0238] The first ring gear (542) is positioned spaced apart from the first sun gear (541). The first ring gear (542) according to the present embodiment may be formed to have a hollow cylindrical shape with both sides open and gear teeth protruding from the inner surface. The inner surface of the first ring gear (542) is positioned spaced apart from the outer surface of the first sun gear (541) by a predetermined distance. The first ring gear (542) is positioned so that its center axis is located coaxial with the center axis of the first sun gear (541). The first ring gear (542) may be fixed and supported on the inner surface of the steering body (510).

[0239] The first planetary gear (543) is engaged and coupled between the first sun gear (541) and the first ring gear (542), and rotates and revolves in conjunction with the rotation of the first sun gear (541). The first planetary gear (543) according to the present embodiment may be formed to have a cylindrical shape with gear teeth formed on its outer surface. The first planetary gear (543) has a central axis parallel to the central axis of the first sun gear (541) and is arranged at a predetermined distance apart in the radial direction of the first ring gear (542). One side of the first planetary gear (543) is engaged and coupled with the outer surface of the first sun gear (541), and the other side is engaged and coupled with the inner surface of the first ring gear (542). The first planetary gear (543) receives rotational force from the first sun gear (541) and rotates around its central axis while simultaneously revolving around the central axis of the first sun gear (541). The first planetary gear (543) may be formed in multiple numbers. Multiple first planetary gears (543) are arranged at a predetermined interval along the circumferential direction of the first ring gear (542). Although FIG. 30 illustrates an example where there are three first planetary gears (543), the number of first planetary gears (543) is not limited to this, and the design can be changed to various numbers, such as three or five.

[0240] The first carrier (544) rotates in conjunction with the orbital motion of the first planetary gear (543). The first carrier (544) according to the present embodiment may be formed to have the shape of a disc positioned to face the lower surface of the first planetary gear (543). The first carrier (544) is positioned so that its central axis is located coaxial with the central axis of the first sun gear (541).

[0241] A first connecting shaft (544a) connected to the first planetary gear (543) is formed in the first carrier (544). The first connecting shaft (544a) according to the present embodiment may be formed in the shape of a rod extending vertically from the upper surface of the first carrier (544) facing the first planetary gear (543). The first connecting shaft (544a) has a central axis positioned parallel to the central axis of the first carrier (544) and is positioned at a predetermined distance from the central axis of the first carrier (544) in the radial direction of the first carrier (544). The first connecting shaft (544a) is inserted to penetrate the central axis of the first planetary gear (543) to support the first planetary gear (543) so as to rotate. A plurality of first connecting shafts (544a) are provided to support each first planetary gear (543) individually so as to rotate. The first connecting shaft (544a) transmits rotational force generated by the orbital motion of the first planetary gear (543) to the first carrier (544). Accordingly, the first carrier (544) can rotate around the center axis during the orbital motion of the first planetary gear (543).

[0242] The second steering transmission member (540b) is connected to the first steering transmission member (540a) and the steering output unit (530), and rotates the steering output unit (530) in conjunction with the rotation of the first steering transmission member (540a).

[0243] The second steering transmission member (540b) according to the present embodiment includes a second sun gear (545), a second ring gear (546), a second planetary gear (547), and a second carrier (548).

[0244] The second sun gear (545) is connected to the first carrier (544) and rotates. The second sun gear (545) according to the present embodiment may be formed to have a rod shape with gear teeth protruding from its outer surface. The second sun gear (545) is positioned so that its central axis is coaxial with the central axis of the first carrier (544). The upper end of the second sun gear (545) is integrally coupled to the lower side of the first carrier (544). The second sun gear (545) rotates at the same angular velocity as the first carrier (544) when the first carrier (544) rotates.

[0245] The second ring gear (546) is positioned spaced apart from the second sun gear (545). The second ring gear (546) according to the present embodiment may be formed to have a hollow cylindrical shape with both sides open and gear teeth protruding from the inner surface. The inner surface of the second ring gear (546) is positioned spaced apart from the outer surface of the second sun gear (545) by a predetermined distance. The second ring gear (546) is positioned so that its center axis is coaxial with the center axis of the second sun gear (545) and the first ring gear (542). The second ring gear (546) may be fixed and supported on the inner surface of the steering body (510). The second ring gear (546) may be formed integrally with the first ring gear (542), or it may be formed separately from the first ring gear (542) and arranged spaced apart from the first ring gear (542).

[0246] The second planetary gear (547) is engaged and coupled between the second sun gear (545) and the second ring gear (546), and rotates and revolves in conjunction with the rotation of the second sun gear (545). The second planetary gear (547) according to the present embodiment may be formed to have a cylindrical shape with gear teeth formed on its outer surface. The second planetary gear (547) has a central axis parallel to the central axis of the second sun gear (545) and is arranged at a predetermined distance apart in the radial direction of the second ring gear (546). One side of the second planetary gear (547) is engaged and coupled with the outer surface of the second sun gear (545), and the other side is engaged and coupled with the inner surface of the second ring gear (546). The second planetary gear (547) receives rotational force from the second sun gear (545) and rotates around its central axis while simultaneously revolving around the central axis of the second sun gear (545). The second planetary gear (547) may be formed in multiple numbers. Multiple second planetary gears (547) are arranged at a predetermined interval along the circumferential direction of the second ring gear (546). Although FIG. 30 illustrates an example where there are three second planetary gears (547), the number of second planetary gears (547) is not limited to this, and the design can be changed to various numbers, such as three or five.

[0247] The second carrier (548) is connected to the steering output unit (530) and rotates in conjunction with the orbital motion of the second planetary gear (547), thereby rotating the steering output unit (530). The second carrier (548) according to the present embodiment may be formed to have the shape of a disc that is positioned facing the lower surface of the second planetary gear (547). The second carrier (548) is positioned so that its central axis is located coaxial with the central axis of the second sun gear (545). The second carrier (548) is integrally joined to the upper part of the steering output unit (530) by welding, bolting, etc.

[0248] A second connecting shaft (548a) connected to the second planetary gear (547) is formed in the second carrier (548). The second connecting shaft (548a) according to the present embodiment may be formed in the shape of a rod extending vertically from the upper surface of the second carrier (548) facing the second planetary gear (547). The second connecting shaft (548a) has a central axis positioned parallel to the central axis of the second carrier (548) and is positioned at a predetermined distance from the central axis of the second carrier (548) in the radial direction of the second carrier (548). The second connecting shaft (548a) is inserted to penetrate the central axis of the second planetary gear (547) to support the second planetary gear (547) so as to enable rotation. A plurality of second connecting shafts (548a) are provided to individually support each second planetary gear (547) so as to enable rotation. The second connecting shaft (548a) transmits rotational force generated by the orbital motion of the second planetary gear (547) to the second carrier (548). Accordingly, the second carrier (548) rotates around the center axis during the orbital motion of the second planetary gear (547) and can rotate the steering output unit (530).

[0249] The steering angle sensor (550) is connected to the steering output unit (530) and measures the rotation angle of the steering output unit (530). The steering angle sensor (550) according to the present embodiment may be exemplified by various types of rotation angle sensors that detect the rotation angle of the steering output unit (530) by outputting a change in magnetic field or an electrical change generated during the relative rotation of the sensor ring and the sensor body in the form of an electrical signal, and a sensor ring coupled to the outer surface of the steering output unit (530) and rotating relative to the sensor body.

[0250] The restraint unit (602) is connected to the steering unit (500) and selectively restricts the rotation of the second knuckle (220). More specifically, the restraint unit (602) functions as a configuration that selectively restricts the rotation of the second knuckle (220) by blocking or allowing the transmission of rotational force between the steering unit (500) and the second knuckle (220) under the control of the control unit (700) described later.

[0251] FIG. 31 is a cross-sectional view schematically showing the configuration of a restraining unit according to a third embodiment of the present invention, and FIG. 32 is a plan view schematically showing the configuration of a restraining unit according to a third embodiment of the present invention.

[0252] Referring to FIG. 31 and FIG. 32, the restraint unit (602) according to the present embodiment includes a first restraint part (650) and a second restraint part (660).

[0253] The first restraint (650) is connected to the steering unit (500) and rotates together with the second knuckle (220). More specifically, the first restraint (650) is connected between the steering drive unit (520) and the second knuckle (220) and rotates together with the second knuckle (220) by the rotational force generated from the steering drive unit (520).

[0254] The first restraint part (650) according to the present embodiment includes a restraint disk (651).

[0255] The restraining disc (651) is positioned inside the steering body (510) and connected to the drive shaft (521) of the steering drive unit (520). The restraining disc (651) according to the present embodiment may be formed to have the shape of a hollow disc positioned coaxially with the drive shaft (521). The inner surface of the restraining disc (651) is spline-coupled to the outer surface of the drive shaft (521) so that it rotates at the same angular velocity as the drive shaft (521) when the drive shaft (521) rotates. Accordingly, the restraining disc (651) can be rotated without the rotational force being amplified by the steering transmission unit (540), thereby reducing the magnitude of the load applied to the second restraining unit (660) described later.

[0256] The second restraining part (660) selectively applies pressure to the first restraining part (650) to restrict or allow the rotation of the second knuckle (220). More specifically, the second restraining part (660) functions as a configuration that selectively restricts the rotation of the second knuckle (220) by adding or releasing frictional resistance to the first restraining part (650), which rotates together with the second knuckle (220) by the rotational force generated from the steering drive part (520).

[0257] The second restraint part (660) according to the present embodiment includes a restraint body (661), a restraint driving part (662), a restraint member (663), a guide part (664), and a restoration part (665).

[0258] The restraining body (661) forms the general outline of the second restraining part (660) and supports the restraining drive part (662), restraining member (663), guide part (664), and restoration part (665) described later. The restraining body (661) according to the present embodiment may be formed to have a hollow interior and a cylindrical shape with one side open. The restraining body (661) is positioned so that the open side faces the restraining disk (651) and accommodates the restraining disk (651) inside. The restraining body (661) may be fixed in position by being coupled to the steering body (510) by welding, bolting, etc.

[0259] The restraint drive unit (662) is installed inside the restraint body (661) and generates electromagnetic force by receiving power from the outside. The restraint drive unit (662) according to the present embodiment may be formed to have a hollow cylindrical shape with a coil of a conductive material wound around its circumference. The central axis of the restraint drive unit (662) is positioned parallel to the axial direction of the restraint disk (651). The central axis of the restraint drive unit (662) is positioned at a predetermined distance in the radial direction of the restraint disk (651) from the central axis of the restraint disk (651) so as not to interfere with the rotation of the drive shaft (521). The restraint drive unit (662) is electrically connected to the control unit (700) described later, and the application of power can be controlled by the control of the control unit (700). As power is applied, the restraint drive unit (662) generates electromagnetic force in a direction parallel to the central axis. For example, when power is applied, the restraining drive unit (662) can generate an electromagnetic force directed downward along the axial direction of the restraining disk (651) with respect to FIG. 31. The restraining drive unit (662) may be provided in multiple numbers. The multiple restraining drive units (662) are arranged such that their central axes are spaced apart at a predetermined interval along the circumferential direction of the restraining disk (651). FIG. 31 illustrates an example where there are two restraining drive units (662), but the number of restraining drive units (662) is not limited to this, and the design can be changed to three, four, etc.

[0260] The restraining member (663) is movably installed in the restraining body (661) and moves in a linear reciprocating motion in conjunction with the electromagnetic force generated from the restraining drive unit (662). The restraining member (663) restricts or allows the rotation of the restraining disk (651) by pressing or releasing the restraining disk (651) according to the direction of movement. The restraining member (663) according to the present embodiment is formed to have a roughly disc shape and is placed inside the restraining body (661). The restraining member (663) is positioned so that its central axis is coaxial with the central axis of the restraining disk (651). The restraining member (663) reciprocates in a direction parallel to the axial direction of the restraining disk (651) inside the restraining body (661) by the restraining drive unit (662) and the restoration unit (665), and its upper surface contacts or separates from the lower surface of the restraining disk (651). The restraining member (663) restricts the rotation of the restraining disk (651) by frictional resistance generated between it and the restraining disk (651) when in contact with the restraining disk (651). The restraining member (663) may be formed of a material with a high coefficient of friction, such as ceramic or metal fiber, so as to effectively restrict the rotation of the restraining disk (651) when in contact with the restraining disk (651).

[0261] A restraining rod (663a) is formed in the restraining member (663) and extends from the restraining member (663) and is inserted into the interior of the restraining drive unit (662). The restraining rod (663a) according to the present embodiment may be formed to have a rod shape that extends vertically downward from the lower side of the restraining member (663). The restraining rod (663a) may be formed of a ferromagnetic material capable of being magnetized by a magnetic field generated from the outside. The restraining rod (663a) is positioned so that its central axis is coaxial with the central axis of the restraining drive unit (662). When power is applied to the restraining drive unit (662), the restraining rod (663a) moves downward by the electromagnetic force generated from the restraining drive unit (662) and moves the restraining member (663) downward along the axial direction of the restraining disk (651).

[0262] A guide groove (663b) is formed in the restraining member (663) and connected to the guide portion (664) described later. The guide groove (663b) according to the present embodiment may be formed to have the shape of a groove that is concavely sunken from the outer surface of the restraining member (663) toward the radial inner side of the restraining member (663). A plurality of guide grooves (663b) may be provided and arranged at a predetermined interval along the circumferential direction of the restraining member (663).

[0263] The guide section (664) guides the movement of the restraining member (663) inside the restraining body (661). The guide section (664) according to the present embodiment is formed to have a roughly columnar shape and is installed inside the restraining body (661). The longitudinal direction of the guide section (664) is arranged parallel to the direction of movement of the restraining member (663), that is, the axial direction of the restraining member (663). The guide section (664) is inserted into the interior of a guide groove (663b) formed by a concave depression from the outer surface of the restraining member (663) to support the restraining member (663) so as to be movable. A plurality of guide sections (664) are provided and are individually inserted into the interior of each guide groove (663b). Accordingly, the guide portion (664) can guide the restraining member (663) to move smoothly in the axial direction and prevent the restraining member (663) from rotating around the central axis together with the restraining disk (651) when in contact with the restraining disk (651).

[0264] The restoration unit (665) returns the restraining member (663) to its initial position as the electromagnetic force generated from the restraining drive unit (662) is released. Here, the initial position of the restraining member (663) can be exemplified as the position where the restraining member (663) is moved upward to its maximum extent and contacts the restraining disk (651). The restoration unit (665) according to the present embodiment can be exemplified as a coil spring that is elastically deformable in the longitudinal direction. The two ends of the restoration unit (665) can be fixed to the lower side of the restraining member (663) and the upper side of the restraining drive unit (662), respectively. As the power supply to the restraining drive unit (662) is interrupted and the electromagnetic force generated from the restraining drive unit (662) is released, the restoration unit (665) presses the restraining member (663) toward the restraining disk (651) to induce the restraining member (663) to come into close contact with the restraining disk (651). The restoration unit (665) is installed in a state of being compressed in the longitudinal direction when the restraining member (663) is in the initial position, that is, when the restraining member (663) is in contact with the restraining disk (651), so as to apply elastic force to the restraining member (623) at all times in the opposite direction to the electromagnetic force generated from the restraining drive unit (662). The installation position of the restoration unit (665) is not limited to the details shown in FIGS. 31 and 32, and can be designed in various ways within the range of positions where the restraining member (663) can be returned to its initial position by elastic restoring force as the electromagnetic force generated from the restraining drive unit (662) is released. The restoration unit (665) may be provided in multiple units, and in this case, the multiple restoration units (665) may be arranged at a predetermined interval along the circumferential direction of the restraining member (663).

[0265] The control unit (700) generally controls the operation of the steering unit (500) and the restraint unit (602). More specifically, the control unit (700) receives steering information, such as steering angle and steering torque, generated from the steering input unit (30) as the driver operates the steering wheel, and controls the steering state of the vehicle by controlling the operation of the steering unit (500) based on the received steering information. Here, the steering input unit (30) can be exemplified by an SFA (Steering Feedback Actuator) connected to the steering wheel. The control unit (700) can individually control the operation of a plurality of steering units (500) provided in the vehicle independent steering device (12) installed on each wheel (20) to independently control the steering state of each wheel (20).

[0266] The control unit (700) can communicate with the steering input unit (30), the steering unit (500), and the restraining unit (602) via wired or wireless means. In this case, the control unit (700) can determine whether there is an abnormality in the communication status with the steering unit (500) for each wheel (20). If the control unit (700) determines that the communication status with any one of the steering units (500), i.e., the steering drive unit (520), is in an incapacitated state, it can control the operation of the restraining unit (602) so that the rotation of the second knuckle (220) installed on the wheel (20) is restricted. Accordingly, the control unit (700) can perform stable position control of the vehicle by preventing the wheel (20) on which the steering unit (500) is installed from being steered arbitrarily by reverse input, etc., when a failure occurs in one of the steering units (500), and by controlling the operation of the steering units (500) installed in the remaining wheels (20).

[0267] The control unit (700) may be implemented as an Electronic Control Unit (ECU), a Central Processing Unit (CPU), a Processor, or a System on Chip (SoC), and may control multiple hardware or software components by running an operating system or application, and may perform various data processing and calculations. The control unit (700) may be configured to execute at least one instruction stored in memory and store the execution result data in memory.

[0268] The operation process of an independent steering device for a vehicle according to the third embodiment of the present invention will be described in detail below.

[0269] FIG. 33 is a flowchart schematically showing the operation process of an independent steering device for a vehicle according to a third embodiment of the present invention, and FIG. 34 and FIG. 35 are diagrams schematically showing the operation process of a restraining unit according to a third embodiment of the present invention.

[0270] Referring to FIGS. 24 to 35, while the vehicle is in motion, the steering input unit (30) generates steering information such as steering angle and steering torque as the driver operates the steering wheel, and inputs the steering information to the control unit (700) (S100).

[0271] The control unit (700) controls the steering state of the vehicle by individually controlling the operation of the steering unit (500) for each wheel (20) based on the received steering information (S200).

[0272] More specifically, the control unit (700) transmits a control signal to the steering drive unit (520) based on the received steering information, and the steering drive unit (520) generates a rotational force corresponding to the control signal.

[0273] In this case, the control unit (700) determines whether there is an abnormality in the communication status with the steering unit (500) for each wheel (20) (S300).

[0274] When the control unit (700) determines that the communication state with any one of the steering units (500), namely the steering drive unit (520), is normal, it applies power to the restraint drive unit (662) to generate electromagnetic force.

[0275] The restraining member (663) is moved away from the restraining disk (651) by the electromagnetic force generated from the restraining drive unit (662) and is separated from the restraining disk (651).

[0276] As the restraining member (663) is separated from the restraining disk (651), the restraining disk (651) rotates at the same angular velocity as the drive shaft (521) without any interference, and the rotational force generated from the steering drive unit (520) is smoothly transmitted to the steering output unit (530) by sequentially passing through the drive shaft (521), the restraining disk (651), and the steering transmission unit (540).

[0277] The steering output unit (530) rotates around a central axis and rotates the second knuckle (220), and the second knuckle (220) rotates together with the wheel (20) and varies the steering angle of the wheel (20).

[0278] When the control unit (700) determines that communication with one of the steering units (500), i.e., the steering drive unit (520), is impossible, it controls the operation of the restraint unit (602) so that the rotation of the second knuckle (220) installed on the wheel (20) is restricted (S400).

[0279] More specifically, the control unit (700) cuts off the power applied to the restraint drive unit (662) to release the electromagnetic force.

[0280] As the electromagnetic force generated from the restraint drive unit (662) is released, the restoration unit (665) presses the restraint member (663) toward the restraint disk (651).

[0281] The restraining member (663) is moved toward the restraining disk (651) by the pressure applied from the restoration member (665), and its upper surface is in close contact with the lower surface of the restraining disk (651).

[0282] As the restraining member (663) comes into close contact with the restraining disk (651), the rotation of the restraining disk (651) is restricted by the frictional resistance generated between it and the restraining member (663).

[0283] Accordingly, the rotational force generated from the steering drive unit (520) is not transmitted to the steering transmission unit (540), and the steering angle of the wheel (20) is fixed.

[0284] Subsequently, the control unit (700) controls the operation of the remaining steering units (500), excluding the steering unit (500) in a state where communication is impossible, to control the steering state of the vehicle.

[0285] Although the present invention has been described with reference to the embodiments illustrated in the drawings, this is merely illustrative and those skilled in the art will understand that various modifications and equivalent alternative embodiments are possible therefrom.

[0286] Therefore, the true technical scope of protection of the present invention should be determined by the following claims. Explanation of the symbols

[0288] 10, 11, 12: Vehicle independent steering system 20: Wheel 30 : Steering input unit 100 : Driving unit 200 : Knuckle Unit 210 : 1st Knuckle 220 : 2nd Knuckle 300 : Braking Unit 310: Brake disc 320: Brake caliper 400: Suspension unit 410: Suspension arm 420 : Shock absorber module 500 : Steering unit 510: Steering body 520: Steering drive unit 521: Drive shaft 530: Steering output unit 531 : Stopper 540 : Steering transmission unit 540a: First steering transmission member 541: First sun gear 542: 1st ring gear 543: 1st planetary gear 544 : 1st carrier 540b : 2nd steering transmission member 545 : 2nd sun gear 546 : 2nd ring gear 547 : Second planetary gear 548 : Second carrier 600, 601, 602: Restraint Units 610, 630, 650: First Restraint Section 611 : First restraining body 612, 631 : First restraining member 620, 640, 660: Second restraint section 621, 641: Second restraint body 622, 642, 662: Restraint drive unit 623, 643: Second restraint member 624, 644, 665 : Restoration section 651 : Restraint disk 661 : Restraint body 663 : Restraint absence 664 : Guide section 700 : Control unit

Claims

Claim 1 A steering device comprising: a driving unit providing driving force; a knuckle unit connected to the driving unit; a steering unit connected to the knuckle unit and rotating the knuckle unit; and a restraining unit connected to the steering unit and selectively restricting the rotation of the knuckle unit. Claim 2 In claim 1, the steering unit comprises: a steering drive unit that generates rotational force; a steering output unit connected to the knuckle unit and rotating the knuckle unit in conjunction with the rotational force generated from the steering drive unit; and a steering transmission unit provided between the steering drive unit and the steering output unit and transmitting the rotational force generated from the steering drive unit to the steering output unit. Claim 3 In claim 2, the steering device comprises: a first steering transmission member connected to the steering drive unit and rotated by receiving rotational force from the steering drive unit; and a second steering transmission member connected to the first steering transmission member and rotating the steering output unit in conjunction with the rotation of the first steering transmission member. Claim 4 In claim 3, the first steering transmission member comprises: a first sun gear connected to and rotated by the drive shaft of the steering drive unit; a first ring gear spaced apart from the first sun gear; a first planetary gear meshing between the first sun gear and the first ring gear to rotate and revolve; and a first carrier that rotates in conjunction with the revolvement of the first planetary gear. Claim 5 In claim 4, the second steering transmission member comprises: a second sun gear connected to and rotated with the first carrier; a second ring gear spaced apart from the second sun gear; a second planetary gear meshing between the second sun gear and the second ring gear to rotate and revolve; and a second carrier that rotates in conjunction with the revolvement of the second planetary gear and is connected to the steering output unit. Claim 6 In claim 2, the steering device comprises: a first restraining member disposed between the steering drive unit and the steering transmission unit and rotated together with the drive shaft of the steering drive unit; and a second restraining member disposed facing the first restraining member, extending toward the first restraining member, and restricting or allowing rotation of the first restraining member. Claim 7 In claim 6, the steering device comprises: a first restraining member connected to the drive shaft and disposed coaxially with the drive shaft; and a first restraining member formed by being concavely recessed into the inner side of the first restraining body. Claim 8 In claim 7, the steering device wherein the first restraining member is provided in plurality and arranged at a predetermined interval along the circumferential direction of the first restraining body. Claim 9 In claim 7, the first restraining member is a steering device extending in the radial direction of the first restraining body. Claim 10 In claim 9, the first restraining member is a steering device in which the width gradually increases as it moves radially outward from the first restraining body. Claim 11 In claim 7, the steering device comprises: a second restraining member disposed spaced apart from the first restraining body; a restraining driving member installed inside the second restraining body and generating electromagnetic force by receiving power from the outside; and a second restraining member movably installed in the second restraining body, reciprocating in conjunction with the electromagnetic force generated from the restraining driving member, and inserted into the first restraining member or detached from the first restraining member depending on the direction of movement. Claim 12 In claim 11, the second restraining member is a steering device that reciprocates in a direction parallel to the radial direction of the first restraining member. Claim 13 In claim 11, the steering device further comprises a second restraint member that returns the second restraint member to an initial position as the electromagnetic force generated from the restraint drive member is released. Claim 14 In claim 13, the above-mentioned restoration member is provided to be elastically deformable and is a steering device that applies an elastic force to the second restraining member in a direction opposite to the electromagnetic force generated from the restraining driving member. Claim 15 A steering device according to any one of claims 1 to 14, further comprising a control unit that controls the operation of the steering unit and the restraint unit. Claim 16 In claim 15, the steering device operates the restraint unit to restrict the rotation of the knuckle unit when the control unit is unable to communicate with the steering unit.

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