Kingpin steering device
By designing a master pin steering device including a master pin steering motor, rocker, cross shaft, steering knuckle and rotational drive mechanism, the problems of the influence of the master pin inclination angle and the reduction of the tire grounding area during vehicle steering are solved, and the stability and good maintenance of the tire posture during vehicle steering are achieved.
Patent Information
- Application Number
- CN202411773916.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-05
- Publication Date
- 2025-05-16
- Estimated Expiration
- 2044-12-05
AI Technical Summary
During the vehicle steering process, the main pin inclination will affect each other as the steering angle increases, resulting in a large change in wheel positioning parameters, which in turn requires a larger steering torque or lead to a reduction in the tire grounding area during large-angle steering, increasing tire wear.
A master pin steering device is designed, including a master pin steering motor, rocker, cross shaft, steering knuckle and rotational drive mechanism. Through the coordinated arrangement of these components, the position of the master pin axis can be adaptively changed, the positioning parameters of the vehicle during steering are maintained, and the tire posture is kept the same as when driving normally.
Through the cooperation of the main pin steering motor and other structures, the tire posture can be maintained when the vehicle is steering, avoiding the reduction of the tire grounding area, reducing tire wear, and improving stability and control accuracy during steering.
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Figure CN119239761B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of vehicle steering, and in particular to a kingpin steering device. Background Art
[0002] With the development of electric vehicles, the gradual maturity of electrification technology has promoted the development of distributed drive. Among them, the four wheels of the four-wheel distributed drive vehicle have steering functions, which have different forms and characteristics compared with the traditional vehicle steering system; however, during the wheel steering process, the kingpin inclination will affect each other with the increase of the steering angle, the wheel alignment parameters will change greatly, and it is difficult to achieve the tire posture when each wheel is turned 90° to maintain the grounding effect when it is not turned.
[0003] Therefore, a kingpin steering device is urgently needed to solve the problem that the kingpin inclination will affect each other as the steering angle increases, the wheel alignment parameters will change significantly, and the posture of the large-angle steering wheel will change significantly, requiring a larger steering torque or causing the large-angle steering tire to reduce its contact area and aggravate tire wear. Summary of the invention
[0004] In view of the deficiencies in the prior art, the present invention provides a kingpin steering device to solve the problem that the kingpin inclination angle will affect each other with the increase of the steering angle, the wheel alignment parameters will undergo a large change, so that the posture of the large-angle steering wheel will change significantly, requiring a larger steering torque or causing the large-angle steering tire to reduce its contact area and aggravate tire wear.
[0005] To achieve the above object, the present invention adopts the following technical solutions:
[0006] A kingpin steering device comprises a kingpin steering motor, a rocker, a cross shaft, a steering knuckle and a rotation drive mechanism, wherein the kingpin steering motor is mounted on a vehicle frame, and an output shaft is used to drive the rocker to rotate, the cross shaft is rotationally connected to the rotating end of the rocker and the upper end of the steering knuckle respectively, and a rotation pair formed by the cross shaft and the rocker is perpendicular to a rotation pair formed by the cross shaft and the steering knuckle, one side of the steering knuckle is used to connect to a wheel hub, and the bottom of the other side of the steering knuckle is connected to a rotation drive mechanism for driving the steering knuckle to rotate, and the rotation drive mechanism is connected to the vehicle frame.
[0007] To optimize the above technical solutions, the specific measures taken also include:
[0008] Furthermore, it also includes a kingpin steering reducer, the output end of the kingpin steering motor is connected to the kingpin steering reducer, the output end of the kingpin steering reducer is connected to the rocker, and is used to drive the rocker to rotate.
[0009] Furthermore, it also includes an upper cross arm, and the kingpin steering motor is connected to the upper cross arm and connected to the vehicle frame through the upper cross arm.
[0010] Further, the rocker is provided with a first connection hole and a second connection hole that penetrate through at intervals. The inner side of the second connection hole is a conical surface, and a flat key groove is provided on the side wall. The output shaft of the kingpin steering motor is installed in the second connection hole through a flat key. The first connection hole is located at the rotating end and is used to rotatably connect to the cross shaft through a bolt.
[0011] Further, the cross shaft has a structure with a side cross-section in the shape of "冂". A third connection hole that penetrates through is provided at the top of the cross shaft in the shape of "冂". The third connection hole is used to rotatably connect to the rocker through a bolt. Fourth connection holes that penetrate through are symmetrically provided on both sides of the cross shaft in the shape of "冂". The fourth connection holes are used to rotatably connect to the upper end of the steering knuckle through a bolt.
[0012] Further, the upper end of the steering knuckle is provided with a cross shaft mating end extending away from the wheel hub. A cross shaft hole that penetrates through is provided on the cross shaft mating end. The cross shaft hole is used to rotatably connect to the cross shaft through a bolt. A plurality of wheel hub mounting holes for connecting to the wheel hub are provided around the side wall of the steering knuckle.
[0013] Further, five wheel hub mounting holes are provided in a ring shape at equal intervals.
[0014] Further, the bolt adopts a dowel bolt.
[0015] Further, the rotation driving mechanism includes a steering cross arm, a lower cross arm, and a linear driver. The bottom of the side of the steering knuckle away from the wheel hub is respectively hinged with the steering cross arm and the lower cross arm. The end of the steering cross arm away from the steering knuckle is hinged with the output end of the linear driver. The linear driver is installed on the vehicle frame and is used to telescopically pull the steering cross arm and drive the steering knuckle to rotate. The end of the lower cross arm away from the steering knuckle is installed on the vehicle frame.
[0016] Further, the rotation driving mechanism further includes two swing arm ball joints. An installation plate extends from the bottom of the side of the steering knuckle away from the wheel hub. Two ball head tapered holes are provided on the installation plate at intervals. The two swing arm ball joints respectively pass through the ball head tapered holes and are installed on the steering knuckle. One of the swing arm ball joints is hinged with the lower cross arm, and the other swing arm ball joint is hinged with the steering cross arm.
[0017] The beneficial effects of the present invention are:
[0018] The present invention cooperates with a kingpin steering motor, a rocker arm, a cross shaft, a steering knuckle and a rotation drive mechanism. When in use, the steering knuckle can be driven by the rotation drive mechanism to drive the wheel to rotate as needed, and the kingpin steering motor drives the rocker arm to drive the cross shaft and other structures to rotate, thereby adaptively changing the position of the kingpin axis. Through the change of the kingpin axis, the positioning parameters do not change significantly during the vehicle's steering and driving process. During lateral movement, the posture of the tire is the same as that of a normal driving wheel. That is, the kingpin line angle relationship is adjusted by the kingpin steering motor during the tire steering process, thereby ensuring that the tire maintains a good posture during the steering process and maintains a good grounding effect.
[0019] The kingpin, tire posture and kingpin trail of the present invention are variable, and the posture of the tire is the same as that of the normal driving wheel during lateral movement.
[0020] The upper cross arm of the present invention is more flexible in arrangement and will not be affected by the distance from the motor housing ear piece to the vehicle frame. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 This is a schematic diagram of the overall structure of a kingpin steering device proposed by the present invention;
[0022] Figure 2 A schematic diagram of the connection of a kingpin steering motor of a kingpin steering device proposed by the present invention;
[0023] Figure 3 A schematic structural diagram of a rocker arm of a kingpin steering device proposed by the present invention;
[0024] Figure 4 A schematic structural diagram of a cross shaft of a kingpin steering device proposed by the present invention;
[0025] Figure 5 A schematic structural diagram of a steering knuckle of a kingpin steering device proposed by the present invention;
[0026] Figure 6 A schematic structural diagram of a swing arm ball head of a kingpin steering device proposed by the present invention;
[0027] Figure 7 A schematic diagram of signal transmission for use of a kingpin steering device proposed by the present invention;
[0028] Figure 8 A schematic diagram of a kingpin axis of a kingpin steering device proposed by the present invention;
[0029] Fig. 9 A schematic diagram of the change of the kingpin axis of a kingpin steering device proposed by the present invention;
[0030] Fig.10A schematic diagram of a wheel turning angle of 0 degrees of a kingpin steering device proposed by the present invention;
[0031] Fig.11 A schematic diagram of a kingpin steering device proposed by the present invention with a wheel turning angle of 90 degrees and the kingpin axis unchanged;
[0032] Fig.12 This is a schematic diagram of a 90-degree wheel turning angle and a kingpin axis change of a kingpin steering device proposed by the present invention.
[0033] Figure markings: 1. kingpin steering motor, 2. kingpin steering reducer, 3. upper cross arm, 4. rocker, 41. first connecting hole, 42. second connecting hole, 43. flat keyway, 5. cross shaft, 51. third connecting hole, 52. fourth connecting hole, 6. steering knuckle, 61. cross shaft mating end, 62. cross shaft hole, 63. wheel hub mounting hole, 64. ball head tapered hole, 7. swing arm ball head, 8. steering cross arm, 9. lower cross arm, 10. linear drive, 11. kingpin axis. DETAILED DESCRIPTION
[0034] The present invention will now be described in further detail with reference to the accompanying drawings.
[0035] As attached Figure 1 As shown, a kingpin steering device of an embodiment of the present invention includes a kingpin steering motor 1, a rocker 4, a cross shaft 5, a steering knuckle 6 and a rotation drive mechanism, the kingpin steering motor 1 is installed on the frame, and the output shaft is used to drive the rocker 4 to rotate, the cross shaft 5 is rotatably connected to the rotating end of the rocker 4 and the upper end of the steering knuckle 6 respectively, and the rotation pair formed by the cross shaft 5 and the rocker 4 is perpendicular to the rotation pair formed by the cross shaft 5 and the steering knuckle 6, one side of the steering knuckle 6 is used to connect to the wheel hub, and the bottom of the other side of the steering knuckle 6 is connected to the rotation drive mechanism for driving the steering knuckle 6 to rotate, and the rotation drive mechanism is connected to the frame.
[0036] The present invention is provided with a kingpin steering motor 1, a rocker arm 4, a cross shaft 5, a steering knuckle 6 and a rotation drive mechanism. When in use, the steering knuckle 6 can be driven by the rotation drive mechanism to drive the wheel to rotate as needed, and the kingpin steering motor 1 drives the rocker arm 4 to drive the cross shaft 5 and other structures to rotate, thereby adaptively changing the position of the kingpin axis 11. Through the change of the kingpin axis 11, the positioning parameters do not change significantly during the vehicle steering process. When shifting sideways, the posture of the tire is the same as the state of the normal driving wheel, that is, the kingpin line angle relationship is adjusted by the kingpin steering motor 1 during the tire steering process, so as to ensure that the tire maintains a good posture during the steering process and maintains a good grounding effect.
[0037] As attached Fig.10 and attached Fig.11As shown in the figure, specifically, the traditional kingpin axis has a fixed kingpin inclination angle. When the wheel is turning, the kingpin inclination angle causes the wheel to increase its angle relative to the vertical, and the area of the tire ground contact plane decreases; when the wheel steering angle reaches 90 degrees, the kingpin inclination angle changes to the castor angle or the kingpin inclination angle, and the tire posture changes aggravatedly, causing the sidewall to touch the ground, resulting in increased tire wear. Fig.12 As shown, the device can change the kingpin axis 11 through the cooperation of the kingpin steering motor 1 and other structures, so that when moving sideways, the posture of the tire is the same as the normal driving wheel state.
[0038] Among them, compared with the kingpin steering motor, the conventional steering motor position is a variable kingpin steering motor 1 installation position, and the power of the kingpin steering motor 1 can be smaller.
[0039] As attached Figure 2 As shown, in another specific embodiment, a kingpin steering reducer 2 is further included, the output end of the kingpin steering motor 1 is connected to the kingpin steering reducer 2, and the output end of the kingpin steering reducer 2 is connected to the rocker 4 and is used to drive the rocker 4 to rotate. In this way, the control accuracy and torque output can be improved through the kingpin steering reducer 2.
[0040] In another specific embodiment, an upper cross arm 3 is further included, and the upper cross arm 3 is connected to the kingpin steering motor 1, and the frame is connected through the upper cross arm 3. In the above embodiment including the kingpin steering reducer 2, the upper cross arm 3 can be installed on the kingpin steering reducer 2. Specifically, the kingpin steering motor 1, the kingpin steering reducer 2 and the upper cross arm 3 serve as the kingpin steering reducer, the kingpin steering motor 1 and the kingpin steering reducer 2 are connected by bolts, and the upper cross arm 3 is connected to the housing of the kingpin steering reducer 2 by bolts, that is, one end of the upper cross arm 3 is fixed to the housing of the kingpin steering reducer 2, and the other end is connected to the frame to form a rotational motion pair. In this way, the arrangement of the upper cross arm 3 is more flexible during the suspension arrangement process, and will not be affected by the distance from the kingpin steering motor 1 housing ear to the frame.
[0041] As attached Figure 3 As shown, in another specific embodiment, the rocker 4 is provided with a first connecting hole 41 and a second connecting hole 42 which penetrate through the rocker 4 at intervals, the inner side surface of the second connecting hole 42 is a conical surface, and the side wall is provided with a flat key groove 43, the output shaft of the kingpin steering motor 1 is installed in the second connecting hole 42 through a flat key, and the first connecting hole 41 is located at the rotating end, and is used to be rotatably connected with the cross shaft 5 through a bolt. In this way, the rocker 4 and the kingpin steering motor 1 are transmitted through the conical surface of the second connecting hole 42, wherein the flat key is used as a safety structure to prevent the failure of the steering function due to the failure of the conical transmission, and the flat key is temporarily transmitted to maintain the steering function, and the rotating end of the rocker 4 is connected to the cross shaft 5 through a plug bolt, and forms a rotating motion pair with the cross shaft 5.
[0042] As attached Figure 4As shown, in another specific embodiment, the cross shaft 5 has a structure with a side cross-section in the shape of "冂". A through third connection hole 51 is provided at the top of the cross shaft 5 in the shape of "冂". The third connection hole 51 is used to rotatably connect to the rocker 4 through a bolt. Through fourth connection holes 52 are symmetrically provided on both sides of the cross shaft 5 in the shape of "冂". The fourth connection holes 52 are used to rotatably connect to the upper end of the steering knuckle 6 through a bolt.
[0043] As shown in the attached Figure 5 figure, in another specific embodiment, the upper end of the steering knuckle 6 is provided with a cross shaft mating end 61 extending away from the wheel hub. A through cross shaft hole 62 is formed in the cross shaft mating end 61. The cross shaft hole 62 is used to rotatably connect to the cross shaft 5 through a bolt. A plurality of wheel hub mounting holes 63 for connecting to the wheel hub are provided around the side wall of the steering knuckle 6. In the embodiment based on the above-mentioned cross shaft 5 in the shape of "冂", the inner side surface of the cross shaft 5 in the shape of "冂" cooperates with the cross shaft mating end 61 of the steering knuckle 6 to limit the vertical movement of the steering knuckle 6 along the upper side surface.
[0044] Among them, five of the above-mentioned wheel hub mounting holes 63 are provided in an annular and equally spaced manner. Specifically, the cross shaft hole 62 of the steering knuckle 6 and the fourth connection hole 52 of the above-mentioned cross shaft 5 are connected by a dowel bolt to form a rotating pair. The upper end surface of the cross shaft mating end 61 and the lower end surface inside the cross shaft 5 form a mating surface to limit the movement of the steering knuckle within the mating surface. Five wheel hub mounting holes 63 are provided in the middle. The wheel hub motor mounting pin shaft can pass through the steering knuckle 6 and be installed on the steering knuckle 6.
[0045] Among them, in the above-mentioned embodiment, a dowel bolt is used. The components can be fastened through the thread at the end of the dowel bolt, and the rotation is facilitated through the smooth rod section in the middle of the dowel bolt.
[0046] In another specific embodiment, the rotation driving mechanism includes a steering cross arm 8, a lower cross arm 9, and a linear actuator 10. The bottom of the side of the steering knuckle 6 away from the wheel hub is respectively hinged with the steering cross arm 8 and the lower cross arm 9. One end of the steering cross arm 8 away from the steering knuckle 6 is hinged to the output end of the linear actuator 10. The linear actuator 10 is installed on the vehicle frame and is used to telescopically pull the steering cross arm 8 and drive the steering knuckle 6 to rotate. One end of the lower cross arm 9 away from the steering knuckle 6 is installed on the vehicle frame.
[0047] Among them, in a further embodiment based on the above, the rotation driving mechanism further includes two swing arm ball joints 7. An installation plate extends from the bottom of the side of the steering knuckle 6 away from the wheel hub. Two ball head tapered holes 64 are spaced apart on the installation plate. The two swing arm ball joints 7 are respectively installed on the steering knuckle 6 through the ball head tapered holes 64. And one of the swing arm ball joints 7 is hinged to the lower cross arm 9, and the other swing arm ball joint 7 is hinged to the steering cross arm 8.
[0048] Specifically, two swing arm ball heads 7 are fixedly mounted on the steering knuckle 6, and the swing arm ball heads 7 realize the power transmission of different axes, and stabilize the wheels from swinging. Figure 6 As shown, the above-mentioned swing arm ball head 7 can have a hinged connection structure. One swing arm ball head 7 is connected to the lower cross arm 9 by bolts through the self-contained connection structure, and the other swing arm ball head 7 is connected to the steering cross arm 8 by bolts through the self-contained connection structure; the other end of the steering cross arm 8 is connected to the output shaft of the linear driver 10 by plugging bolts to form a rotary motion pair, and the steering cross arm 8 transmits force from the linear driver 10 to the swing arm ball head 7 to fix the motion state of the steering knuckle 6. Among them, the linear driver 10 is a linear drive device with a built-in worm gear, motor, lead screw, connecting plate and limit rod. The worm on the motor gear drives the worm wheel to rotate, so that the small lead screw in the worm wheel moves axially, and the connecting plate drives the limit rod to move axially accordingly. When the required stroke is reached, the stroke switch is pressed down by adjusting the limit block to cut off the power, and the motor stops running. The housing of the linear driver 10 is fixed on the vehicle body, and the linear driver 10 can control the movement of the steering cross arm 8 by adjusting the length of the lead screw extending.
[0049] As attached Figure 8 and attached Fig. 9 As shown, the specific working principle of the kingpin steering motor 1 and other structures of the present invention is: the output of the kingpin steering motor 1 is reduced in speed and increased in torque by the kingpin steering reducer 2, and then drives the rocker arm 4 to perform circular motion around the axis of the kingpin steering motor 1, that is, the rocker arm 4 drives the cross shaft 5 to rotate around the axis of the kingpin steering motor 1, and the axis of the rotating pair formed by the connection between the cross shaft 5 and the rocker arm 4 is the kingpin axis 11, that is, the active kingpin axis 11 is obtained. When the output shaft of the kingpin steering motor 1 rotates to the set position, the linear drive 10 works at the same time to drive the wheel to perform steering motion, and the ground contact state of the wheel tends to remain unchanged. Among them, the attached Figure 8 and attached Fig. 9 The red line in the figure can reflect the kingpin axis 11.
[0050] As attached Figure 7 As shown, a specific implementation of the present invention is as follows:
[0051] When the driver turns the steering wheel, the steering wheel generates a steering angle signal, which is input to the VCU as a steering wheel input signal. After processing and analyzing the steering wheel input signal, the VCU sends a steering output signal to the kingpin steering device at the four wheel positions, driving the wheels to steer to achieve a change in the vehicle's driving trajectory.
[0052] Steering mode 1:
[0053] When the angle of the steering signal output by the VCU to the kingpin steering device is within ±30°, the kingpin steering motor 1 is not driven, and the motor is controlled at the initial position through the position loop. The rocker 4 and the kingpin steering motor 1 and other kingpin steering devices are relatively stationary, and the steering knuckle 6 and the wheel are driven by the linear drive 10 to rotate around the initial kingpin axis 11.
[0054] Steering mode 2:
[0055] When the angle of the steering signal output by the VCU to the kingpin steering device is outside ±30°, the kingpin steering motor 1 outputs a rotation angle, driving the rocker arm 4 to rotate so that the rocker arm 4 drives the cross shaft 5 to move, thereby changing the position of the initial kingpin axis 11, and the linear drive 10 drives the steering knuckle 6 and the wheel to rotate around the new kingpin axis 11.
[0056] It should be noted that the terms such as "upper", "lower", "left", "right", "front", "back", etc. cited in the invention are only for the convenience of description and are not used to limit the scope of implementation of the present invention. Changes or adjustments in their relative relationships should be regarded as the scope of implementation of the present invention without substantially changing the technical content.
[0057] The above are only preferred embodiments of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should be regarded as the protection scope of the present invention.
Claims
1. A kingpin steering device, characterized in that: It includes a kingpin steering motor (1), a rocker (4), a cross shaft (5), a knuckle (6) and a rotation driving mechanism. The kingpin steering motor (1) is installed on the vehicle frame, and its output shaft is used to drive the rocker (4) to rotate. The cross shaft (5) is respectively rotatably connected to the rotating end of the rocker (4) and the upper end of the knuckle (6). The revolute pair formed by the cross shaft (5) and the rocker (4) is perpendicular to the revolute pair formed by the cross shaft (5) and the knuckle (6). One side of the knuckle (6) is used to connect the wheel hub, and the bottom of the other side of the knuckle (6) is connected to a rotation driving mechanism for driving the knuckle (6) to rotate. The rotation driving mechanism is connected to the vehicle frame. It also includes a kingpin steering reducer (2). The output end of the kingpin steering motor (1) is connected to the kingpin steering reducer (2), and the output end of the kingpin steering reducer (2) is connected to the rocker (4) to drive the rocker (4) to rotate. It further includes an upper cross arm (3). The upper cross arm (3) is connected to the kingpin steering motor (1) and is connected to the vehicle frame through the upper cross arm (3).
2. A kingpin steering device according to claim 1, characterized in that: The rocker (4) is provided with a through first connection hole (41) and a second connection hole (42) at intervals. The inner side surface of the second connection hole (42) is a conical surface, and a flat key groove (43) is provided on the side wall. The output shaft of the kingpin steering motor (1) is installed in the second connection hole (42) through a flat key. The first connection hole (41) is located at the rotating end and is used to rotatably connect to the cross shaft (5) through a bolt.
3. A kingpin steering device according to claim 1, characterized in that: The cross shaft (5) has a structure with a "冂”-shaped side cross section. A through third connection hole (51) is provided at the top of the "冂”-shaped cross shaft (5). The third connection hole (51) is used to rotatably connect to the rocker (4) through a bolt. Through fourth connection holes (52) are symmetrically provided on both sides of the "冂”-shaped cross shaft (5). The fourth connection holes (52) are used to rotatably connect to the upper end of the knuckle (6) through a bolt.
4. A kingpin steering device according to claim 1, characterized in that: The upper end of the knuckle (6) is provided with a cross shaft mating end (61) extending away from the wheel hub. A through cross shaft hole (62) is provided on the cross shaft mating end (61). The cross shaft hole (62) is used to rotatably connect to the cross shaft (5) through a bolt. A plurality of wheel hub mounting holes (63) for connecting the wheel hub are provided around the side wall of the knuckle (6).
5. A kingpin steering device according to claim 4, characterized in that: Five wheel hub mounting holes (63) are provided in a ring at equal intervals.
6. A kingpin steering device according to claim 2, 3 or 4, characterized in that: The bolt uses a shoulder bolt.
7. A kingpin steering device according to claim 1, characterized in that: The rotation driving mechanism includes a steering cross arm (8), a lower cross arm (9) and a linear actuator (10). The bottom of the side of the knuckle (6) away from the wheel hub is respectively hinged with a steering cross arm (8) and a lower cross arm (9). The end of the steering cross arm (8) away from the knuckle (6) is hinged to the output end of the linear actuator (10). The linear actuator (10) is installed on the vehicle frame and is used to telescopically pull the steering cross arm (8) and drive the knuckle (6) to rotate. The end of the lower cross arm (9) away from the knuckle (6) is installed on the vehicle frame.
8. A kingpin steering device according to claim 7, characterized in that: The rotation drive mechanism further comprises two swing arm ball heads (7), a mounting plate extending from a side of the bottom of the steering knuckle (6) away from the wheel hub, two ball head tapered holes (64) are arranged on the mounting plate at intervals, the two swing arm ball heads (7) respectively pass through the ball head tapered holes (64) and are mounted on the steering knuckle (6), one of the swing arm ball heads (7) is hinged to the lower cross arm (9), and the other swing arm ball head (7) is hinged to the steering cross arm (8).
Citation Information
Patent Citations
Steering device
CN110497957A