Electric automobile steering knuckle structure integrated with end face sensing
By integrating end-face sensing into the electric vehicle steering knuckle structure, and employing a 1:6 tapered bore design and a lightweight solution without a central shaft, the problems of steering knuckle fatigue failure, increased weight, and susceptibility of the sensing system to environmental interference are solved, achieving efficient load-bearing, stable signal transmission, and simplified maintenance.
Patent Information
- Application Number
- CN202511416720.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-30
- Publication Date
- 2025-12-12
AI Technical Summary
Existing electric vehicle steering knuckle structures suffer from fatigue damage due to point or line contact, increased weight, high maintenance costs, and susceptibility of the sensing system to environmental interference.
It adopts a 1:6 taper hole design, a lightweight structure without a central shaft, and an end face sensing integration solution. Combined with the integrated layout of the ring magnetic encoder and magnetic sensor, it achieves surface contact bearing, eliminates the need for a central shaft connection, and simplifies maintenance.
It improves the load-bearing capacity, weight reduction effect, connection stiffness and maintainability of the steering system, ensures signal stability, and reduces manufacturing costs and maintenance time.
Smart Images
Figure CN121106476A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of electric vehicle knuckle, and particularly relates to an electric vehicle knuckle structure integrated with end face sensing. BACKGROUND
[0002] The front suspension horn part (knuckle) is a core bearing and transmission component of the electric vehicle steering system, directly supports the hub assembly to realize wheel steering, and the rationality of the structure has a decisive influence on the vehicle control stability, driving safety and endurance. Under the background of the increasing requirements of new energy vehicles on light weight and reliability, the existing knuckle structure exposes multiple technical defects: The traditional knuckle generally adopts a straight hole arm structure to connect the suspension rod with a bushing, which concentrates the load on a local contact area, forming a point contact or line contact state. According to the contact stress principle, this contact mode will produce pulsating cyclic shear stress, which is easy to cause fatigue failure such as surface metal spalling and fretting wear under alternating load, eventually leading to bushing loosening, chassis abnormal noise, and seriously affecting the service life of the component.
[0003] The existing knuckle is connected with the hub through a middle shaft structure, which not only increases the weight of the single piece by about 4 kg, but also requires a high-precision bearing seat machining process, which increases the manufacturing cost. For new energy vehicles, the more the weight of the vehicle body increases, the less the endurance mileage will decrease, and the middle shaft design is not consistent with the industry lightweight development trend.
[0004] The traditional wheel speed sensing system adopts a separate layout of an optical encoder and a sensor, and the encoder is exposed to the complex environment in the wheel compartment, which is easy to be affected by dust, oil stains and electromagnetic interference.
[0005] The combination structure of the straight hole bushing cooperation, the middle shaft connection and the separated sensing makes the knuckle maintenance need to disassemble multiple components in sequence. Only the hub replacement requires separate disassembly of the sensor, bearing seat and other components, which increases the working hours and improves the maintenance cost of the integrated structure. SUMMARY
[0006] The present application provides an electric vehicle knuckle structure integrated with end face sensing.
[0007] The application discloses an integrated end face sensing electric vehicle knuckle structure, which comprises a knuckle body and a hub unit, wherein the upper part of the knuckle body is provided with a shock absorber arm taper hole for connecting a tapered joint bearing at the lower end of a shock absorber, the side of the middle part of the knuckle body is provided with a steering arm taper hole for connecting a tapered joint bearing at the end of a steering drag link, and the lower part of the knuckle body is provided with a lower swing arm taper hole for connecting a tapered joint bearing and a tapered bushing at the end of a lower control arm; the taper of the shock absorber arm taper hole, the steering arm taper hole and the lower swing arm taper hole is all set as 1:6, the taper of 1:6 is used for ensuring self-locking and load-carrying capacity, the surface roughness of the hole surface is set as Ra≤1.6 μm, and the central region of the knuckle body is provided with a central mounting hole. The flange plate of the hub unit is embedded with an annular magnetic encoder on the end face of the knuckle body, and the magnetic poles of the annular magnetic encoder are arranged alternately along the circumferential direction. The knuckle body is provided with a mounting hole at a position opposite to the magnetic ring of the end face of the hub unit, the mounting hole is used for fixedly mounting a magnetic sensor, the sensing surface of the magnetic sensor is perpendicular to the rotation axis of the hub unit, the magnetic sensor is used for detecting the periodic change of the magnetic field of the end face of the magnetic ring caused by rotation, and then outputs wheel speed and wheel rotation angle signals. The wire harness of the magnetic sensor is drawn out from the knuckle body and connected to an electronic control unit (ECU) of a vehicle. The hub unit is provided with a mounting journal matched with the central mounting hole, transition fit is adopted between the central mounting hole and the mounting journal of the hub unit, the transition fit is used for ensuring initial positioning accuracy and an interference amount, the certain interference amount is used for transmitting torque, the hub unit is used for fixing the hub unit on the knuckle body through four bolts penetrating through bolt holes on the knuckle body and corresponding holes on the flange plate of the hub unit, and the bolts are uniformly distributed in the circumferential direction.
[0008] Preferably, an elastic positioning sleeve is arranged in the mounting hole of the magnetic sensor, the elastic positioning sleeve is used for keeping the end face gap between the magnetic sensor and the annular magnetic encoder and providing vibration damping.
[0009] Preferably, the web plate of the knuckle body is provided with a lightening hole in a non-stress area, and the flange plate of the hub unit is provided with radial heat dissipation grooves.
[0010] Compared with the prior art, the application has the following beneficial effects: By adopting the integrated design of the shock arm hole, the steering arm hole and the lower swing arm hole with a 1:6 taper, the traditional bushing fitting interface is eliminated. The taper is verified by engineering to ensure that the contact area between the tapered joint bearing and the hole wall is larger, so that the contact stress is distributed from point to surface, solving the problem of fretting wear. At the same time, the finishing precision of the hole surface Ra≤1.6μm further improves the contact strength, and the self-locking characteristics improve the bearing capacity and assembly efficiency compared with the straight hole structure.
[0011] The central shaft is cancelled, and a bolt direct connection scheme of a transition fit of a center hole and a hub unit is adopted, combined with a web lightening hole design, to realize great weight reduction of a single piece, which is better than the average weight reduction level of the industry. In addition, the scheme eliminates the finishing process of the bearing seat, reduces the manufacturing cost, and the combination design of the transition fit and the circumferentially distributed bolts improves the connection stiffness and significantly enhances the torque transmission stability.
[0012] The end face fitting structure of the hub flange plate embedded ring magnetic encoder and the integrated magnetic sensor of the knuckle realizes non-contact signal acquisition by AMR magnetic resistance technology. The integrated layout of the sensor and the hub shortens the hub replacement time and greatly improves the maintainability without separately disassembling the sensing component during maintenance.
[0013] The integrated taper hole structure, lightweight design without a central shaft and end face sensing integrated scheme improve the precision and reliability of the steering system. BRIEF DESCRIPTION OF DRAWINGS
[0014] Figure 1 A perspective structural schematic diagram of an integrated end face sensing electric vehicle knuckle structure according to an embodiment of the present disclosure is shown; Figure 2 A front view plane structural schematic diagram of an integrated end face sensing electric vehicle knuckle structure according to an embodiment of the present disclosure is shown; Figure 3 A top view plane structural schematic diagram of an integrated end face sensing electric vehicle knuckle structure according to an embodiment of the present disclosure is shown; Figure 4 A perspective structural schematic diagram of an integrated end face sensing electric vehicle knuckle structure connected with a brake according to an embodiment of the present disclosure is shown; Figure 5 A top view plane sectional structural schematic diagram of an integrated end face sensing electric vehicle knuckle structure according to an embodiment of the present disclosure is shown; Figure 6 An enlarged plane structural schematic diagram of a sectional plane A-A of an integrated end face sensing electric vehicle knuckle structure according to an embodiment of the present disclosure is shown; Figure 5 Figure 7 A perspective structural schematic diagram of a ring-shaped magnetic encoder in an integrated end-surface sensing electric vehicle knuckle structure according to an embodiment of the present disclosure is shown. Figure 8 A top view structural schematic diagram of a ring-shaped magnetic encoder in an integrated end-surface sensing electric vehicle knuckle structure according to an embodiment of the present disclosure is shown.
[0015] In the figure, 1 is a knuckle body, 2 is a shock absorber arm taper hole, 3 is a steering arm taper hole, 4 is a lower swing arm taper hole, 5 is a center mounting hole, 6 is a hub unit, 7 is a mounting journal, 8 is a bolt, 9 is a bolt hole, 10 is a flange, 12 is a ring-shaped magnetic encoder, 13 is a magnetic sensor, and 601 is a mounting hole. DETAILED DESCRIPTION
[0016] Various exemplary embodiments, features and aspects of the present disclosure will be explained in detail below with reference to the accompanying drawings. The same reference numbers in different drawings denote the same or similar elements. Although various aspects of the embodiments are illustrated in the drawings, the drawings are not necessarily drawn to scale unless specifically indicated.
[0017] The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any implementation described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other implementations.
[0018] In addition, for the purpose of convenience and brevity, detailed descriptions of well-known functions and structures incorporated in the present disclosure are omitted. It will be appreciated that the present disclosure can be practiced with the exact details as
[0019] Reference Figures 1-8 As shown, the integrated end-surface sensing electric vehicle knuckle structure according to the present embodiment includes a knuckle body 1 and a hub unit 6. The knuckle body 1 is a core load-bearing component, and its structural design directly determines the stability of the steering system.
[0020] The upper part of the knuckle body 1 is provided with a shock absorber arm taper hole 2 for connecting the tapered joint bearing at the lower end of the shock absorber, the taper of the hole is 1:6, which is verified by engineering to ensure the self-locking performance and load capacity of the tapered joint bearing and the hole wall, and the hole surface is finished to a roughness of Ra≤1.6μm to reduce the wear of the fitting surface; the middle side of the knuckle body 1 is provided with a steering arm taper hole 3 for connecting the tapered joint bearing at the end of the steering tie rod, which also adopts a 1:6 taper and a Ra≤1.6μm roughness design to ensure the accuracy of the steering force transmission; the lower part of the knuckle body 1 is provided with a lower swing arm taper hole 4 for connecting the tapered joint bearing and the tapered bushing at the end of the lower control arm, and the consistent taper and roughness standard ensures the uniformity of the stress of the three arm holes.
[0021] The center area of the knuckle body 1 is provided with a center mounting hole 5, and the hub unit 6 is correspondingly provided with a mounting journal 7 matched with the center mounting hole 5, and the center mounting hole 5 and the mounting journal 7 adopt a transition fit, which can not only ensure the initial positioning accuracy, but also transmit torque through a certain interference amount; the hub unit 6 is fixed with the knuckle body 1 by four bolts 8 passing through the bolt holes 9 on the knuckle body 1 and the corresponding holes on the flange plate 10 of the hub unit 6, and the four bolts 8 are evenly distributed in the circumferential direction to ensure the balance of the connection stress and avoid local stress concentration.
[0022] The flange plate 10 of the hub unit 6 is embeddedly and fixedly installed with a ring-shaped magnetic encoder 12 on the end face facing the knuckle body 1, and the magnetic poles of the ring-shaped magnetic encoder 12 are alternately arranged in the circumferential direction, which can make the magnetic field change regularly with the rotation of the hub; the position opposite to the ring-shaped magnetic encoder 12 on the knuckle body 1 is provided with a mounting hole 601, and a magnetic sensor 13 is fixedly installed in the mounting hole 601, and the sensing surface of the magnetic sensor 13 is perpendicular to the rotation axis of the hub unit 6, which can ensure that the periodic change of the magnetic field on the end face of the ring-shaped magnetic encoder 12 can be accurately detected, and then the wheel speed and wheel angle signals can be output; the wire harness of the magnetic sensor 13 is directly connected to the electronic control unit ECU of the vehicle after being led out from the knuckle body 1, so that the real-time transmission of the signal is realized.
[0023] In some examples, an elastic positioning sleeve is arranged in the mounting hole 601 of the magnetic sensor 13, which is made of nitrile rubber material, and the inner diameter of the elastic positioning sleeve is tightly fitted with the outer wall of the magnetic sensor 13, and the outer diameter of the elastic positioning sleeve is interference-fitted with the inner wall of the mounting hole 601. The elastic positioning sleeve can not only stably maintain the end face gap between the magnetic sensor 13 and the ring-shaped magnetic encoder 12, avoid the gap deviation leading to signal distortion, but also provide vibration damping through its elasticity to reduce the influence of vehicle driving vibration on the sensor.
[0024] In some examples, the web non-stress area of the knuckle body 1 is provided with three circular lightening holes, and the hole wall is treated with rounding. These lightening holes can reduce the weight of the body without affecting the stress intensity of the knuckle body 1, further improve the lightweight effect in cooperation with the design without the central shaft, and also reduce the material consumption during the processing of the knuckle and reduce the manufacturing cost.
[0025] In some examples, the flange plate 10 of the hub unit 6 is provided with six radial heat dissipation grooves, which are uniformly distributed along the circumference of the flange plate 10. The radial heat dissipation grooves can accelerate the heat dissipation of the heat generated during the operation of the hub unit 6, reduce the surface temperature of the flange plate 10, avoid the influence of high temperature on the magnetic properties of the annular magnetic encoder 12, and also reduce the heat loss of the hub bearing, thereby prolonging the service life of the hub unit 6.
[0026] The working principle of the present application is as follows: In the assembly of the integrated end face sensing tapered hole knuckle structure, first, the installation posture of the knuckle body 1 is determined according to the assembly requirements of the front suspension of the vehicle. The lower end of the shock absorber is embedded into the shock arm tapered hole 2 on the upper part of the knuckle body 1, the lower control arm end is embedded into the lower swing arm tapered hole 4, and the lower control arm end is embedded into the lower swing arm tapered hole 4. Since the three arm holes are designed with a 1:6 taper, and the hole surface is finished to a roughness of Ra≤1.6μm, no additional traditional bushing is needed to realize tight fit, which eliminates the bushing fitting interface and ensures the initial assembly stability through the taper self-locking feature. At the same time, the face contact structure changes the point distribution of contact stress to face distribution, laying a foundation for subsequent load bearing.
[0027] Then, the installation shaft neck 7 of the hub unit 6 is aligned with the center installation hole 5 in the center area of the knuckle body 1, and the transition fit is used to realize precise initial positioning, which not only ensures the coaxiality of the assembly, but also pre-establishes the torque transmission basis through a reasonable interference amount. Then, four bolts 8 are used to pass through the bolt holes 9 of the knuckle body 1 and the corresponding holes of the flange plate 10 of the hub unit 6 in a circumferentially uniform manner, to complete the fixed connection of the two. This process does not need a traditional central shaft structure, and directly realizes the rigid connection of the hub unit and the knuckle through bolts, which not only simplifies the assembly steps, but also avoids the finishing process of the central shaft and the supporting bearing seat, and cooperates with the three circular lightening holes in the web non-stress area of the knuckle body 1 to realize a single-piece weight reduction of about 1.2kg, which is better than the average level in the industry.
[0028] Meanwhile, the annular magnetic encoder 12 is embedded and fixed in advance at the flange plate 10 end face of the wheel hub unit 6 towards the knuckle body 1, and then the magnetic sensor 13 is installed in the mounting hole 601 of the knuckle body 1 opposite to the annular magnetic encoder 12, if the mounting hole 601 is provided with an elastic positioning sleeve, the inner diameter of the positioning sleeve needs to be ensured to tightly fit the outer wall of the magnetic sensor 13, and the outer diameter needs to be in interference fit with the inner wall of the mounting hole 601, finally the wire harness of the magnetic sensor 13 is led out of the knuckle body 1, arranged through a metal fixing buckle and then connected to the vehicle electronic control unit ECU, completing the sensor system assembly.
[0029] During normal driving of the electric vehicle, the knuckle structure realizes functions through the triple core principle: Firstly, the bearing and force transmission principle, the longitudinal and transverse loads received by the wheel are transmitted to the knuckle body 1 through the wheel hub unit 6, the face contact structure of the three 1:6 taper arm holes uniformly disperses the load to the hole wall, avoiding the stress concentration caused by the point contact of the traditional straight hole, and the rigid support of the uniformly distributed bolt connection significantly improves the overall bearing capacity compared with the straight hole structure, and eliminates the risk of liner fretting wear; Secondly, the torque transmission principle, since there is an interference amount in the transition fit between the center mounting hole 5 and the mounting shaft neck 7, and the clamping force of the four circumferentially distributed bolts 8 is added, the torque generated by the rotation of the wheel hub unit 6 can be directly transmitted to the knuckle body 1 without the need for intermediate transmission of the intermediate shaft, reducing torque loss while avoiding transmission deviation caused by deformation of the intermediate shaft, and ensuring the accuracy of the steering response; Thirdly, the sensing and detection principle, when the wheel hub unit 6 rotates with the wheel, the annular magnetic encoder 12 on the flange plate 10 rotates synchronously, the alternating arrangement of the magnetic poles generates a periodically changing end face magnetic field, the magnetic sensor 13 uses AMR magnetic resistance technology to detect the change of the magnetic field, converts the magnetic signal into an electric signal and transmits it to the ECU, and outputs the wheel speed and wheel angle signals in real time. Since the sensing components are arranged in an end face integrated layout and the magnetic sensor 13 has anti-interference characteristics, even in complex environments such as dust and oil stains, the signal stability is still better than that of the traditional separated sensing system.
[0030] The above has described the embodiments of the present disclosure, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes are obvious to those skilled in the art without departing from the scope and spirit of the described embodiments. The selection of the terms used herein is intended to best explain the principles, practical applications or technical improvements in the market of the embodiments, or to enable other ordinary skilled persons in the art to understand the embodiments disclosed herein.
Claims
1. A steering knuckle structure for an electric vehicle with integrated end-face sensing, characterized in that, include: Steering knuckle body (1) and hub unit (6). The upper part of the steering knuckle body (1) is provided with shock absorber tapered hole (2). The shock absorber tapered hole (2) is used to connect the tapered spherical bearing at the lower end of the shock absorber. The side of the middle part of the steering knuckle body (1) is provided with steering arm tapered hole (3). The steering arm tapered hole (3) is used to connect the tapered spherical bearing at the end of the steering tie rod. The lower part of the steering knuckle body (1) is provided with lower control arm tapered hole (4). The lower control arm tapered hole (4) is used to connect the tapered spherical bearing and tapered bushing at the end of the lower control arm. The taper of the shock absorber tapered hole (2), the steering arm tapered hole (3) and the lower control arm tapered hole (4) is all set to 1:
6. The taper is set to 1:6 to ensure self-locking and load-bearing capacity. The surface roughness of the hole surface is set to Ra≤1.6μm. The center mounting hole (5) is provided in the central area of the steering knuckle body (1). On the end face of the flange (10) of the hub unit (6) facing the steering knuckle body (1), a ring magnetic encoder (12) is embedded and fixedly installed, and the magnetic poles of the ring magnetic encoder (12) are alternately arranged along the circumferential direction. A mounting hole (601) is provided on the steering knuckle body (1) at a position directly opposite to the magnetic ring (12) on the end face of the wheel hub unit. The mounting hole (601) is used to fix and install the magnetic sensor (13). The sensing surface of the magnetic sensor (13) is perpendicular to the rotation axis of the wheel hub unit. The magnetic sensor (13) is used to detect the periodic change of the magnetic field on the end face of the magnetic ring (12) as it rotates, and then outputs the wheel speed and wheel angle signals. The wiring harness of the magnetic sensor (13) is led out from the steering knuckle body (1) and connected to the vehicle's electronic control unit (ECU); The hub unit (6) is provided with a mounting journal (7) that mates with the center mounting hole (5). The center mounting hole (5) and the hub unit mounting journal (7) are provided with an transition fit. The transition fit is used to ensure the initial positioning accuracy and interference fit. A certain interference fit is used to transmit torque. The hub unit (6) is fixed to the steering knuckle body (1) by passing four bolts (8) through the bolt holes (9) on the steering knuckle body (1) and the corresponding holes on the flange (10) of the hub unit (6). The bolts (8) are arranged to be evenly distributed in the circumferential direction.
2. The electric vehicle steering knuckle structure with integrated end-face sensing according to claim 1, characterized in that, An elastic positioning sleeve is provided in the mounting hole of the magnetic sensor (13). The elastic positioning sleeve is used to maintain the end face gap between the magnetic sensor (13) and the ring magnetic encoder (12) and to provide vibration damping.
3. The electric vehicle steering knuckle structure with integrated end-face sensing according to claim 1, characterized in that, The non-stressed area of the web of the steering knuckle body (1) is provided with weight reduction holes, and radial heat dissipation grooves are provided on the flange (10) of the hub unit (6).