Electric power steering gear and vehicle having the same

Abstract

The application discloses an electric power steering gear and a vehicle with the same, and relates to the field of vehicle engineering. The electric power steering gear comprises an input shaft, a torsion bar shaft, a shaft coupling assembly, the shaft coupling assembly comprising a first shaft coupling part and a second shaft coupling part, the first shaft coupling part being connected with the input shaft and rotating synchronously, the second shaft coupling part being connected with the torsion bar shaft and rotating synchronously, at least one of the first shaft coupling part and the second shaft coupling part being movable between a combined position and a separated position, the first shaft coupling part being connected with the second shaft coupling part to rotate synchronously at the combined position, the first shaft coupling part being separated from the second shaft coupling part at the separated position, and a clutch driving part, the clutch driving part being matched with the movable first shaft coupling part or the second shaft coupling part to drive the movable first shaft coupling part or the second shaft coupling part to move between the combined position and the separated position. Thus, when the actual steering center of the vehicle deviates from the calibration center, the angle deviation between the input shaft and the torsion bar shaft can be adjusted, so that the actual steering center of the steering wheel is adjusted to coincide with the calibration center again.

Description

Technical Field

[0001] This invention relates to the field of vehicle engineering, and more specifically to an electric steering system and a vehicle having the same. Background Technology

[0002] With the development of commercial vehicle technology, the market's demands for interior refinement and driving comfort are increasing, and OEMs are shifting towards passenger-oriented interiors and driving experience. For example, in models equipped with electric power steering, the vehicle's center position will deviate from the calibrated center position due to the interference of the suspension system when the load changes, causing the steering wheel to turn and resulting in a continuous self-centering torque.

[0003] To address the aforementioned issues, existing technical solutions primarily focus on eliminating the persistent self-centering force in the steering feel. A typical strategy is as follows: when the steering wheel is detected to be deviating from its calibrated center position for an extended period, and the vehicle speed is higher than a preset value while the deviation angle is less than a preset value, it is determined that the actual steering center position of the vehicle deviates from the calibrated center position. The controller then resets the current steering wheel angle to the calibrated center position, at which point the persistent self-centering force disappears, and the steering feel returns to normal.

[0004] The above solution only addresses the feel issue after center deflection, but because the steering wheel, steering gear, and wheels are rigidly connected in terms of rotation direction, it cannot solve the problem of actual steering wheel deflection. Summary of the Invention

[0005] The present invention aims to at least solve one of the technical problems existing in the prior art. To this end, the present invention proposes an electric steering system and a vehicle having the same, which can adjust the steering angle deviation when the actual steering center position of the vehicle deviates from the calibrated center position, so that the actual steering center position of the steering wheel is adjusted to coincide with the calibrated center position again.

[0006] An electric steering system according to an embodiment of the present invention includes: an input shaft for transmission connection with a steering wheel; a torsion bar shaft for transmitting torque; a coupling assembly including: a first coupling and a second coupling, the first coupling being connected to the input shaft and rotating synchronously, the second coupling being connected to the torsion bar shaft and rotating synchronously, at least one of the first coupling and the second coupling being movable between an engaged position and a disengaged position, wherein in the engaged position the first coupling and the second coupling are connected to rotate synchronously, and in the disengaged position the first coupling and the second coupling are disengaged; and a clutch drive cooperating with the movable first coupling or the second coupling to drive it to move between the engaged position and the disengaged position.

[0007] According to an embodiment of the electric steering system of the present invention, when the actual steering center position of the steering wheel deviates from the calibrated center position, the clutch drive unit drives the first coupling and the second coupling to separate, causing the torsion bar shaft to rotate relative to the input shaft under the drive of the return force. After returning to center, the clutch drive unit drives the first coupling and the second coupling to reconnect and engage, at which point the input shaft and the torsion bar shaft are reconnected to transmit power. In this way, when the actual steering center position of the vehicle deviates from the calibrated center position, the angular deviation between the input shaft and the torsion bar shaft can be adjusted, so that the actual steering center position of the steering wheel is adjusted to coincide with the calibrated center position again.

[0008] In some embodiments, the clutch drive includes a first magnetic element, and the movable first coupling or the second coupling includes a second magnetic element. The first magnetic element is an electromagnet, and the first magnetic element cooperates with the second magnetic element.

[0009] Specifically, the electric steering system further includes a housing, the coupling assembly is located within the housing, and the input shaft and the torsion bar shaft are at least partially located within the housing; The first magnetic chuck is fixedly connected to the housing. The first magnetic chuck and the second magnetic chuck are annular and arranged around the axis of the coupling assembly.

[0010] In some embodiments, the clutch drive further includes: an elastic element, the elastic element being used to drive the first coupling and the second coupling to engage; When the first coupling is movable, one end of the elastic element is connected to the input shaft and the other end is connected to the first coupling. The elastic element is used to drive the first coupling to move to the engagement position. When the second coupling is movable, one end of the elastic element is connected to the torsion bar shaft, and the other end is connected to the second coupling. The elastic element is used to drive the second coupling to move to the engagement position.

[0011] Specifically, the elastic element is a disc spring, and it is sleeved on the input shaft or the torsion bar shaft.

[0012] In some embodiments, the first coupling includes a first bracket and a first friction plate, the first bracket being connected to the input shaft, and the first friction plate being disposed on the side of the first bracket facing the second coupling; The second coupling includes a second bracket and a second friction plate. The second bracket is connected to the torsion bar shaft, and the second friction plate is located on the side of the second bracket facing the first coupling.

[0013] Specifically, the first bracket sleeve is connected to the input shaft and is axially movable; And / or, the second bracket sleeve is connected to the torsion bar shaft and is axially movable.

[0014] In some embodiments, the electric steering system further includes an angle limiting structure disposed between the first coupling and the second coupling to limit the relative turning angle range between them.

[0015] Specifically, the angle limiting structure includes: A limiting hole is provided on one of the first coupling and the second coupling. The limiting hole is an elongated arc-shaped hole, and the center of the limiting hole is located on the axis of the coupling assembly. A limiting post is provided on the other of the first coupling and the second coupling, and the limiting post passes through the limiting hole.

[0016] In some embodiments, the electric steering system further includes: a first angle sensor for detecting the relative rotation angle between the first coupling and the second coupling, the first angle sensor being electrically connected to the clutch drive.

[0017] The vehicle according to an embodiment of the present invention is equipped with the electric power steering system described in the above embodiment.

[0018] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0019] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 A top view of an electric steering system according to some embodiments; Figure 2 for Figure 1 A cross-sectional view along the BB direction; Figure 3 A partial cross-sectional view of the electric steering system at the coupling assembly in some embodiments; Figure 4 for Figure 2 A cross-sectional view along the AA direction.

[0020] Figure label: Electric steering gear 100 10. Casing Input shaft 21, first spline shaft 211, torsion bar shaft 22, output shaft 23, input gear 24, reduction transmission structure 25. Assist motor 31 Coupling assembly 40, first coupling 41, first bracket 411, first spline hole 4111, first friction plate 412, second coupling 43, second bracket 434, second friction plate 435, shaft L1. Clutch drive component 50, first magnetic attraction component 51, elastic component 52 Angle limiting structure 70, limiting hole 71, limiting post 72, First angle sensor 81, second steering sensor 82. Detailed Implementation

[0021] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0022] In the description of this invention, it should be understood that the terms "center," "length," "width," "thickness," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, features defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0023] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0024] The following is for reference. Figures 1-4 An electric power steering system 100 according to an embodiment of the present invention is described. The electric power steering system 100 operates by precisely controlling the power assist motor 31 to output power assist torque according to the driver's steering intention and the vehicle status via an electronic control unit, thereby assisting the driver in completing steering operations.

[0025] According to an embodiment of the electric steering system 100, referring to Figure 2 and Figure 3It includes: an input shaft 21, a torsion bar shaft 22, a coupling assembly 40, and a clutch drive unit 50. The input shaft 21 is used for transmission connection with the steering wheel, and the torsion bar shaft 22 is used for transmitting torque.

[0026] Specifically, such as Figure 1 As shown, the electric steering system 100 also includes an output shaft 23, and a torsion bar shaft 22 is the torque transmission shaft between the input shaft 21 and the output shaft 23 within the electric steering system 100.

[0027] The coupling assembly 40 includes a first coupling 41 and a second coupling 43. The first coupling 41 is connected to the input shaft 21 and rotates synchronously, and the second coupling 43 is connected to the torsion bar shaft 22 and rotates synchronously. At least one of the first coupling 41 and the second coupling 43 is movable between an engaged position and a disengaged position. In the engaged position, the first coupling 41 and the second coupling 43 are connected to rotate synchronously, and in the disengaged position, the first coupling 41 and the second coupling 43 are separated.

[0028] The clutch drive 50 engages with a movable first coupling 41 or a second coupling 43 to drive it to move between an engaged position and a disengaged position.

[0029] According to an embodiment of the electric steering system 100 of the present invention, when the actual steering center position of the steering wheel deviates from the calibrated center position, the clutch drive member 50 drives the first coupling member 41 and the second coupling member 43 to separate, causing the torsion bar shaft 22 to rotate relative to the input shaft 21 under the drive of the return force. After returning to center, the clutch drive member 50 drives the first coupling member 41 and the second coupling member 43 to reconnect and engage, at which point the input shaft 21 and the torsion bar shaft 22 are reconnected to transmit power. In this way, when the actual steering center position of the vehicle deviates from the calibrated center position, the angular deviation between the input shaft 21 and the torsion bar shaft 22 can be adjusted, so that the actual steering center position of the steering wheel is adjusted to coincide with the calibrated center position again.

[0030] As is known to those skilled in the art, the self-centering force is the force that enables the steering wheel to automatically return to the straight-line position after turning. This force does not originate from the electronic control system but is determined by the physical structural design of the vehicle chassis and tires. When the vehicle load remains constant, the center position of the vehicle is usually aligned with the center position of the steering wheel. However, when the vehicle load changes, due to interference from the suspension system, the center position of the vehicle deviates from the center position of the steering wheel, causing the steering wheel to deflect and resulting in a continuous self-centering torque. Existing solutions only address how to eliminate this continuous self-centering force on the steering wheel but do not align the center position of the vehicle with the center position of the steering wheel.

[0031] The proposed solution improves the electric steering system 100 so that when there is a deviation between the vehicle's center position and the calibrated center position of the steering wheel, the clutch drive 50 disengages from the coupling assembly 40, and the return force drives the torsion bar shaft 22 to rotate, but the steering wheel does not turn. In other words, the steering wheel remains in the calibrated center position under the driver's control. Once the return force disappears, or once the rotation angle has been compensated (i.e., the deviation angle between the vehicle's center position and the calibrated center position of the steering wheel), the clutch drive 50 engages with the coupling assembly 40, allowing the input shaft 21 to normally output torque to the torsion bar shaft 22, and the electric steering system 100 to perform its steering control function normally.

[0032] In some specific embodiments, such as Figure 2 As shown, the electric steering system 100 includes a power steering motor 31, which is connected to the housing 10. The motor shaft of the power steering motor 31 is connected to an output gear (not shown). An input gear 24 is provided on the torsion bar shaft 22. The output gear meshes with the input gear 24, so that after the power steering motor 31 outputs torque, it is transmitted to the torsion bar shaft 22 after being decelerated and increased in torque through the cooperation of the output gear and the input gear 24, and then transmitted to the output shaft 23 by the torsion bar shaft 22.

[0033] Specifically, such as Figure 2 As shown, a speed reduction transmission structure 25 is also provided between the torsion bar shaft 22 and the output shaft 23. The speed reduction transmission structure 25 can be a worm gear structure, etc., to further realize speed reduction and torque increase output torque.

[0034] Optionally, such as Figure 2 As shown, the electric steering system 100 also includes a second steering sensor 82. The second steering sensor 82 detects the angle of the input shaft 21, thereby detecting the steering wheel angle and obtaining the driver's steering intention. The second steering sensor 82 is electrically connected to the controller of the power assist motor 31. The controller calculates the optimal assist value based on the driver's steering intention and vehicle speed, and the power assist motor 31 outputs the corresponding torque. The method by which the controller calculates the output torque of the power assist motor 31 based on the steering intention and vehicle speed is existing technology and will not be elaborated here.

[0035] See Figure 2 and Figure 3 The clutch drive component 50 includes a first magnetic absorbing component 51, and the movable first coupling component 41 or second coupling component 43 includes a second magnetic absorbing component. The first magnetic absorbing component 51 is an electromagnet, and the first magnetic absorbing component 51 cooperates with the second magnetic absorbing component.

[0036] The use of electromagnets is relatively safe because the action of the first coupling 41 or the second coupling 43 is controlled by electromagnetic force. The control response of the electromagnets is fast, even as short as a few milliseconds, thereby improving the control accuracy and response speed of the clutch drive 50 to the coupling assembly 40.

[0037] In addition, the electromagnet is small in size and light in weight, which makes it easy to lay out in the electric steering gear 100, saves internal installation space, and has less interference with other structures.

[0038] Specifically, the electromagnet includes an iron core and windings wound around the iron core. By controlling the conduction and de-energization of the windings, the magnetic switch on the iron core can be controlled. When the iron core is magnetic, it attracts a second magnetic attractor, thereby controlling the movement of the movable first coupling 41 or the second coupling 43.

[0039] Specifically, the second magnetic component is a magnetic metal component. For example, the first coupling 41 includes a first bracket 411, which is made of iron. The first bracket 411 itself serves as the second magnetic component and can be attracted when an electromagnet is energized. The second magnetic component can also be a separate component, installed and fixed on the first bracket 411.

[0040] For example, the second coupling 43 includes a second bracket 434, which is made of iron. The second bracket 434 itself acts as a second magnetic attractor and can be attracted when an electromagnet is energized. The second magnetic attractor can also be a separate component, installed and fixed on the second bracket 434.

[0041] The type of magnetic metal component is not limited, such as permanent magnet ferrite, neodymium iron boron, iron chromium cobalt, etc.

[0042] Optionally, the first magnetic attractor 51 and the second magnetic attractor are annular and arranged around the axis L1 of the coupling assembly 40. Thus, the force generated when they attract each other is around the axis L1 of the coupling assembly 40. The combined force thus formed is easily exerted axially, which is beneficial for driving the movable parts on the first coupling 41 or the second coupling 43 to move axially. This ensures that the switching between engagement and disengagement is efficient with a short moving distance for the movable parts, resulting in high state switching efficiency.

[0043] Of course, the solution of this application is not limited to this. For example, there are multiple first magnetic accumulators 51, and the multiple first magnetic accumulators 51 are distributed around the axis L1 of the coupling assembly 40. In this case, the second magnetic accumulators can be set in a one-to-one correspondence with the first magnetic accumulators 51, and the number of the second magnetic accumulators and the number of the first magnetic accumulators 51 can also be different. For example, the second magnetic accumulator is a single complete ring, and the first magnetic accumulators 51 are multiple discrete ones distributed circumferentially.

[0044] In some specific embodiments, such as Figure 2 and Figure 3 As shown, the electric steering gear 100 also includes a housing 10, a coupling assembly 40 located inside the housing 10, and an input shaft 21 and a torsion bar shaft 22 located at least partially inside the housing 10. The housing 10 serves as the external protection and support base for the electric steering gear 100.

[0045] Specifically, the first magnetic chuck 51 is fixedly connected to the housing 10. The first magnetic chuck 51 is not on the transmission shaft 21 or the torsion bar shaft 22, which reduces the rotational load and reduces consumption.

[0046] Of course, this application does not exclude the possibility that in some schemes, the first magnetic suction element 51 is set on the transmission shaft 21 or the torsion bar shaft 22.

[0047] In some embodiments, such as Figure 2 and Figure 3 As shown, the clutch drive unit 50 also includes an elastic element 52, which is used to drive the first coupling 41 and the second coupling 43 to engage. The elastic element 52 ensures that the first coupling 41 and the second coupling 43 remain engaged when other control parts of the clutch drive unit 50 fail, providing a preload force for their engagement, so that the input shaft 21 and the torsion bar shaft 22 remain connected, preventing them from disconnecting and preventing steering operation in case of failure.

[0048] Thus, in this application, the clutch drive component 50 can be combined into various structural forms.

[0049] In one alternative embodiment, the clutch drive unit 50 includes only a first magnetic attractor 51. When the first magnetic attractor 51 attracts the second magnetic attractor, it engages the first coupling 41 and the second coupling 43. When the first magnetic attractor 51 and the second magnetic attractor repel each other, it disengages the first coupling 41 and the second coupling 43. In other words, the first magnetic attractor 51 can drive the first coupling 41 and the second coupling 43 to engage, and it can also drive the first coupling 41 and the second coupling 43 to disengage.

[0050] In another alternative embodiment, the clutch drive 50 includes a first magnetic chuck 51 and an elastic element 52. The elastic element 52 drives the first coupling 41 and the second coupling 43 to engage, while the first magnetic chuck 51 drives the first coupling 41 and the second coupling 43 to disengage. In the disengaged position, the magnetic force between the first magnetic chuck 51 and the second magnetic chuck overcomes the elastic force of the elastic element 52. When the circuit of the first magnetic chuck 51 fails, i.e., the magnetism disappears, the elastic element 52 automatically drives the first coupling 41 and the second coupling 43 to engage again.

[0051] In another alternative embodiment, the clutch drive 50 employs a linkage assembly, which includes a control lever rotatably connected to the housing 10. One end of the control lever is located outside the housing 10, and the other end corresponds to at least one of the first coupling 41 and the second coupling 43. The first coupling 41 and the second coupling 43 remain engaged when there is no interference from the control lever, for example, by means of an elastic element 52, or the engaged portion of the first coupling 41 and the second coupling 43 is an elastic part. When the vehicle is stopped, the control lever can be manually moved, causing the first coupling 41 and the second coupling 43 to move away from each other, thus disengaging the first coupling 41 and the second coupling 43.

[0052] In some specific embodiments, such as Figure 2 and Figure 3 As shown, the first coupling 41 is movable, and the elastic element 52 is connected at one end to the input shaft 21 and at the other end to the first coupling 41. The elastic element 52 is used to drive the first coupling 41 to move towards the engagement position. In this way, the elastic element 52 does not need to rotate relative to the first coupling 41, making it easy to set the connection relationship and preventing the connection position from breaking.

[0053] Similar to the above scheme, when the second coupling 43 is movable, one end of the elastic element 52 is connected to the torsion bar shaft 22, and the other end is connected to the second coupling 43. The elastic element 52 is used to drive the second coupling 43 to move towards the engagement position. This also achieves the protection function of the elastic element 52.

[0054] Here, when only the first coupling 41 is movable, the elastic element 52 can be provided only on the first coupling 41. When only the second coupling 43 is movable, the elastic element 52 can be provided only on the second coupling 43. When both the first coupling 41 and the second coupling 43 are movable, the elastic element 52 can be provided on both the first coupling 41 and the second coupling 43.

[0055] There are many types of elastic elements 52 to choose from, such as cylindrical springs, torsion springs, and conical springs.

[0056] Preferably, the elastic element 52 is a disc spring, and its outer sleeve is connected to the input shaft 21 or the torsion bar shaft 22. In this way, the disc spring can withstand a large load in a very limited axial space, and its design is flexible, safe and reliable.

[0057] In some embodiments, such as Figure 3As shown, the first coupling 41 includes a first bracket 411 and a first friction plate 412. The first bracket 411 is connected to the input shaft 21, and the first friction plate 412 is located on the side of the first bracket 411 facing the second coupling 43. The second coupling 43 includes a second bracket 434 and a second friction plate 435. The second bracket 434 is connected to the torsion bar shaft 22, and the second friction plate 435 is located on the side of the second bracket 434 facing the first coupling 41.

[0058] By employing a first friction plate 412 and a second friction plate 435, high torque can be transmitted efficiently and controllably within limited space and cost, while also providing overload protection and buffering functions. As a friction element, the wear of the friction plate is a gradual and observable process, facilitating the development of maintenance plans. Furthermore, through optimization of materials and structure (such as adding elastic elements), it can be ensured that the friction plates maintain complete separation even after wear, avoiding additional wear and heat generation, thereby improving overall lifespan.

[0059] The use of a first bracket 411 and a second bracket 434 facilitates the installation and fixation of the friction plate, and provides convenient connection and assembly positions with the input shaft 21 and the torsion bar shaft 22. It also improves the stability and reliability of the clamping, and simplifies the installation and maintenance process.

[0060] Optionally, the first friction plate 412 is detachably mounted on the first bracket 411. Optionally, the second friction plate 435 is detachably mounted on the second bracket 434. In this way, the friction plates can be easily removed and replaced after wear, effectively reducing maintenance costs.

[0061] Specifically, when the first coupling 41 is movable to switch between the engaged and disengaged positions, the first bracket 411 is sleeved and connected to the input shaft 21 and is axially movable. In this way, the input shaft 21 can guide the movement of the first coupling 41, making the first coupling 41 less prone to skewing or jamming.

[0062] Specifically, the first bracket 411 is provided with a first spline hole 4111, and the input shaft 21 includes a first spline shaft 211. The first bracket 411 is sleevedly connected to the first spline shaft 211 through the first spline hole 4111. The spline assembly connection has high load-bearing capacity, good centering, and strong guiding properties, while also being very compact in structure. It enables the first coupling 41 to move axially on the input shaft 21, and can transmit torque when it moves to the engagement position.

[0063] The first spline hole 4111 has a certain length limitation in the axial direction, which limits the movement distance of the first coupling 41 on the input shaft 21.

[0064] Similar to the above scheme, when the second coupling 43 is movable to switch between the engaged and disengaged positions, the second bracket 434 is sleeved on the torsion bar shaft 22 and is axially movable. In this way, the torsion bar shaft 22 can guide the movement of the second coupling 43, making the second coupling 43 less prone to skewing or jamming.

[0065] Specifically, the second bracket 434 is provided with a second spline hole (not shown in the figure), and the torsion bar shaft 22 includes a second spline shaft (not shown in the figure). The second bracket 434 is sleeved and connected to the second spline shaft through the second spline hole.

[0066] In some embodiments, such as Figure 3 and Figure 4 As shown, the electric steering system 100 also includes an angle limiting structure 70 disposed between the first coupling 41 and the second coupling 43 to limit the relative turning angle range between them. In this way, when the clutch drive unit 50 fails, a reasonable turning angle range between the first coupling 41 and the second coupling 43 can be limited, avoiding dangerous consequences such as friction plate wear or abnormal separation that could cause the steering system to lose its steering function. Optionally, such as Figure 3 and Figure 4 As shown, the angle limiting structure 70 includes a limiting hole 71 and a limiting post 72. The limiting hole 71 is located on one of the first coupling 41 and the second coupling 43, and is an elongated arc-shaped hole with its center located on the axis L1 of the coupling assembly 40. The limiting post 72 is located on the other of the first coupling 41 and the second coupling 43, and passes through the limiting hole 71. This limiting structure ensures that the limiting post 72 is not easily detached from the limiting hole 71, resulting in high reliability of angle limiting.

[0067] Specifically, the size of the central angle at both ends of the arc of the limiting hole 71 limits the rotation range of the limiting post 72. For example, the central angle at both ends of the limiting hole 71 is 40°. The limiting hole 71 can be set to allow a deflection angle of ±20°.

[0068] Specifically, when the steering wheel deflection is less than ±15°, the allowable deflection angle between the first coupling 41 and the second coupling 43 can be set to ±20°. When a specific value is reached, the limiting post 72 abuts against the end of the limiting hole 71. If it is at the end, the first friction plate 412 on the input shaft 21 is in direct contact with the limiting hole 71, which can directly transmit steering force and avoid danger.

[0069] In some embodiments, such as Figure 2 As shown, the electric steering gear 100 also includes a first angle sensor 81, which is used to detect the relative rotation angle between the first coupling 41 and the second coupling 43. The first angle sensor 81 is electrically connected to the clutch drive 50.

[0070] In this way, the relative steering angle and direction can be identified by the first steering angle sensor 81. When the relative steering angle matches the center offset angle, the clutch drive 50 drives the coupling assembly 40 to engage, and the steering gear returns to normal operation. This improves the controllability of steering adjustment.

[0071] The vehicle according to an embodiment of the present invention is provided with the electric power steering 100 of the above embodiment.

[0072] When the actual steering center position of the steering wheel deviates from the calibrated center position, the clutch drive unit 50 drives the first coupling 41 and the second coupling 43 to separate, causing the torsion bar shaft 22 to rotate relative to the input shaft 21 under the drive of the return force. After returning to center, the clutch drive unit 50 drives the first coupling 41 and the second coupling 43 to reconnect and engage, at which point the input shaft 21 and the torsion bar shaft 22 are reconnected to transmit power. In this way, when the actual steering center position of the vehicle deviates from the calibrated center position, the angular deviation between the input shaft 21 and the torsion bar shaft 22 can be adjusted to make the actual steering center position of the steering wheel coincide with the calibrated center position again.

[0073] Other components of the vehicle according to embodiments of the present invention, such as the drive unit and its operation, are known to those skilled in the art and will not be described in detail here. In this specification, references to the terms "embodiment," "example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0074] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. An electric steering system, characterized in that, include: An input shaft, which is used for connection to the steering wheel drive; A torsion bar shaft, which is used to transmit torque; A coupling assembly, comprising: a first coupling and a second coupling, wherein the first coupling is connected to the input shaft and rotates synchronously, and the second coupling is connected to the torsion bar shaft and rotates synchronously, and at least one of the first coupling and the second coupling is movable between an engaged position and a disengaged position, wherein in the engaged position the first coupling and the second coupling are connected to rotate synchronously, and in the disengaged position the first coupling and the second coupling are separated; A clutch drive unit, which cooperates with a movable first coupling or a second coupling to drive it to move between the engaged position and the disengaged position.

2. The electric steering system according to claim 1, characterized in that, The clutch drive includes a first magnetic chuck, and the movable first coupling or the second coupling includes a second magnetic chuck. The first magnetic chuck is an electromagnet, and the first magnetic chuck cooperates with the second magnetic chuck.

3. The electric steering system according to claim 2, characterized in that, The electric steering system also includes a housing, the coupling assembly is located within the housing, and the input shaft and the torsion bar shaft are at least partially located within the housing; The first magnetic chuck is fixedly connected to the housing. The first magnetic chuck and the second magnetic chuck are annular and arranged around the axis of the coupling assembly.

4. The electric steering system according to claim 1, characterized in that, The clutch drive further includes an elastic element, which is used to drive the first coupling and the second coupling to engage; When the first coupling is movable, one end of the elastic element is connected to the input shaft and the other end is connected to the first coupling. The elastic element is used to drive the first coupling to move to the engagement position. When the second coupling is movable, one end of the elastic element is connected to the torsion bar shaft, and the other end is connected to the second coupling. The elastic element is used to drive the second coupling to move to the engagement position.

5. The electric steering system according to claim 1, characterized in that, The first coupling includes a first bracket and a first friction plate. The first bracket is connected to the input shaft, and the first friction plate is disposed on the side of the first bracket facing the second coupling. The second coupling includes a second bracket and a second friction plate. The second bracket is connected to the torsion bar shaft, and the second friction plate is located on the side of the second bracket facing the first coupling.

6. The electric steering system according to claim 5, characterized in that, The first bracket is connected to the input shaft and is movable along the axial direction; And / or, the second bracket sleeve is connected to the torsion bar shaft and is axially movable.

7. The electric steering system according to any one of claims 1-6, characterized in that, It also includes an angle limiting structure disposed between the first coupling and the second coupling to limit the relative rotation angle range between them.

8. The electric steering system according to claim 7, characterized in that, The angle limiting structure includes: A limiting hole is provided on one of the first coupling and the second coupling. The limiting hole is an elongated arc-shaped hole, and the center of the limiting hole is located on the axis of the coupling assembly. A limiting post is provided on the other of the first coupling and the second coupling, and the limiting post passes through the limiting hole.

9. The electric steering system according to any one of claims 1-6, characterized in that, Also includes: A first angle sensor is used to detect the relative rotation angle between the first coupling and the second coupling, and the first angle sensor is electrically connected to the clutch drive.

10. A vehicle, characterized in that, The device is equipped with an electric steering system as described in any one of claims 1-9.

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