A variable damping device for a steering arm, a rear axle, and a damping control method.

Abstract

This invention relates to a variable damping device for a steering arm, a rear axle, and a damping control method, specifically in the field of steering arms. In the variable damping device, a friction disc is perpendicularly and fixedly connected to the upper shaft of the rear wheel steering arm. At least one side of the friction disc is provided with a friction assembly, and a rotation limiting assembly is provided at the outer edge of the friction assembly. A pressurizing assembly is connected to the friction assembly or the rear axle cantilever sleeve and applies an adjustable damping force to the friction assembly, causing it to abut against the friction disc. The damping force applied to the friction assembly by the pressurizing assembly causes the friction assembly to abut against the friction disc, thereby applying a damping force to the friction disc and the upper shaft of the rear wheel steering arm. The damping force is adjustable and can be adjusted according to the vehicle speed, solving the problems of abnormal swaying of the rear wheel steering arm due to excessively low damping force or difficulty in rotating the rear wheel steering arm due to excessively high damping force. This avoids reduced bearing life and decreased high-speed stability of the entire vehicle caused by these problems.

Description

Technical Field

[0001] This invention relates to the field of steering arms, and more specifically to a variable damping device for a steering arm, a rear axle, and a damping control method. Background Technology

[0002] The mower-flattener / dryer can be used for harvesting crops such as alfalfa, oats, reeds, sedges, crested wheat, rapeseed, and milk thistle by changing the flattening or drying platform. It has the advantages of high operating efficiency and good spreading and drying effect.

[0003] The lawnmower / tiller uses front-wheel differential steering technology, with the rear wheels as driven wheels. During steering, the rear wheel steering arm freely deflects in the direction of steering to complete the steering action. Existing technology uses a fixed damping device to provide damping force for the rotation of the rear wheel steering arm. This damping force cannot be adjusted, but in reality, the rotational damping force required by the rear wheel steering arm varies at different vehicle speeds. During low-speed operation, this damping force can maintain the stability of the rear wheel steering arm. However, during high-speed operation, this damping force is insufficient to maintain stability, easily leading to abnormal swaying. This not only reduces the lifespan of the steering arm bearings but also affects the overall high-speed stability of the machine. Summary of the Invention

[0004] The technical problem to be solved by the present invention is how to apply damping force to the rear wheel steering arm.

[0005] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: A variable damping device for a steering arm, the variable damping device includes a rear wheel steering arm upper shaft that rotates through the rear axle cantilever sleeve, and also includes a friction disc, a friction assembly and a pressurizing assembly. The friction disc is perpendicular to and fixedly connected to the rear wheel steering arm upper shaft. The friction assembly is provided on at least one side of the friction disc. A rotation limiting assembly is provided at the outer edge of the friction assembly. The pressurizing assembly is connected to the friction assembly or the rear axle cantilever sleeve, and applies an adjustable damping adjustment force to the friction assembly to make it abut against the friction disc.

[0006] The beneficial effects of this invention are as follows: the friction disc rotates with the upper shaft of the rear wheel steering arm, while the friction assembly does not rotate. A damping adjustment force is applied to the friction assembly via a pressure component, causing the friction assembly to contact the friction disc, thereby applying a damping force to the friction disc and the upper shaft of the rear wheel steering arm. The magnitude of the damping adjustment force is adjustable, allowing for adjustment based on the overall vehicle speed. This solves the problems of abnormal swaying of the rear wheel steering arm due to excessively low damping force or difficulty in rotating the rear wheel steering arm due to excessively high damping force, effectively preventing reduced bearing life and decreased high-speed stability of the entire machine caused by these issues.

[0007] Based on the above technical solution, the present invention can be further improved as follows.

[0008] Furthermore, the variable damping device of the steering arm also includes two pads and a friction disc mounting bolt. The two pads are located on both sides of the center of the friction disc, and the friction disc mounting bolt passes through the two pads and the friction disc and is fixedly connected to the upper shaft of the rear wheel steering arm.

[0009] The advantages of adopting the above-mentioned further solution are: setting two pads facilitates the installation and replacement of the friction disc, and leaving space on both outer edges of the friction disc for installing friction components.

[0010] Furthermore, the friction assembly includes a friction plate located at the outer edge of the friction disk.

[0011] The beneficial effect of adopting the above-mentioned further solution is that the friction plate is used to abut against the friction disk and generate frictional force to form damping on the rotation of the friction disk.

[0012] Furthermore, the friction assembly also includes a friction plate pressure plate, which is fixed or abuts against the side of the friction plate facing away from the friction plate.

[0013] The beneficial effect of adopting the above-mentioned further solution is that the friction plate is pressed against the friction plate by the friction plate pressure plate, and the pressure component acts on the friction plate pressure plate.

[0014] Furthermore, the rotation limiting assembly includes a limiting sleeve, and a limiting notch is formed at the outer edge of the friction assembly along the upper end shaft axis of the rear wheel steering arm. The limiting sleeve is fixedly connected to the rear axle cantilever sleeve and inserted into the limiting notch.

[0015] The beneficial effect of adopting the above-mentioned further solution is that the limiting sleeve is fixedly set, and the rotation of the friction component is restricted by the limiting notch, so that the friction component does not rotate with the friction disc.

[0016] Furthermore, the rotation limiting assembly also includes a limiting plate, a limiting mounting bolt, and a limiting mounting nut. The limiting plate is fixedly connected to the rear axle cantilever sleeve, and one end of the limiting mounting bolt passes through the limiting sleeve and the limiting plate and is threadedly connected to the limiting mounting nut.

[0017] The beneficial effect of adopting the above-mentioned further solution is that the limiting sleeve is fixed to the limiting plate by the limiting mounting bolt.

[0018] Furthermore, the size of the limiting disc is smaller than the size of the friction assembly, and the limiting disc has a lug that protrudes radially outward along the rear axle cantilever sleeve, and the limiting mounting bolt is connected to the lug.

[0019] The beneficial effect of adopting the above-mentioned further solution is that the limiting plate adopts a lug structure, and the rest of the plate does not overlap with the outer edge of the friction component in the axial direction, thereby avoiding the space for installing the pressurizing component.

[0020] Furthermore, the pressurizing assembly includes a hydraulic cylinder, guide columns, a spring pressure plate, and a spring. Multiple guide columns are provided, each passing sequentially through the hydraulic cylinder, the spring pressure plate, and the friction assembly. Guide column nuts are fixed at both ends of each guide column. The hydraulic cylinder is fixedly connected to the guide column. The spring pressure plate is slidably connected to the guide column via a linear bearing. The spring is located between the spring pressure plate and the friction assembly. The piston rod of the hydraulic cylinder abuts against the spring pressure plate and applies a damping adjustment force to the friction assembly via the spring.

[0021] The beneficial effects of adopting the above-mentioned further solution are as follows: When the hydraulic cylinder is not extended, the force provided by the initial compression of the spring presses the friction plate pressure plate, friction plate, and friction disc together. The friction disc is connected to the rear wheel steering arm via the upper shaft of the rear wheel steering arm. When the rear wheel steering arm rotates, it drives the friction disc to rotate and rub against the friction plate, generating a damping force. The damping force in this state is the minimum damping force of the variable damping device. This damping force is not controlled by the hydraulic cylinder and still exists even if the hydraulic cylinder fails, thus preventing the rear wheel from becoming completely free due to hydraulic system failure. Furthermore, the linear bearing can prevent the spring pressure plate from jamming with the guide post during sliding.

[0022] When the hydraulic cylinder piston rod extends, it pushes the spring pressure plate to further compress the spring, increasing the clamping force provided by the spring. This clamping force is the damping adjustment force, thereby increasing the damping force when the rear wheel steering arm rotates. Different extension lengths of the hydraulic cylinder piston rod result in different spring compressions, thus varying the damping adjustment force on the friction components, thereby achieving adjustment of the damping adjustment force.

[0023] Furthermore, the spring is sleeved on the guide post; or, the spring pressure plate has a first spring positioning protrusion protruding towards the side of the friction assembly, the friction assembly has a second spring positioning protrusion on the side facing the spring pressure plate, the two ends of the spring are respectively sleeved on the first spring positioning protrusion and the second spring positioning protrusion, and the piston rod of the hydraulic cylinder extends into the first spring positioning protrusion and abuts against it.

[0024] The present invention also provides a rear axle, including a rear axle crossbeam, two rear wheel steering arms and two variable damping devices for the steering arms. Each end of the rear axle crossbeam is fixed with a rear axle cantilever sleeve. The two rear wheel steering arms are correspondingly arranged with the two variable damping devices. The upper end of the rear wheel steering arm is fixedly connected to or integrally formed with the lower end of the upper shaft of the corresponding rear wheel steering arm.

[0025] The present invention also provides a damping control method, implemented using the aforementioned rear axle, comprising the following steps:

[0026] Step 1: Obtain the real-time vehicle speed signal, and determine the required rear axle rotational damping force at the current vehicle speed based on the real-time vehicle speed signal.

[0027] Step 2: Calculate the target damping adjustment force of the pressurization assembly based on the rear axle rotational damping force;

[0028] Step 3: Obtain the actual pressure of the pressurizing component in real time, and adjust the actual pressure according to the difference between the actual pressure and the target damping adjustment force to adjust the pressure of the pressurizing component to the target damping adjustment force. Attached Figure Description

[0029] Figure 1 This is a structural diagram of the rear axle of the lawn mower flattener of the present invention;

[0030] Figure 2 This is a cross-sectional view of the variable damping device of the steering arm of the present invention;

[0031] Figure 3 This is a three-dimensional view of the variable damping device of the steering arm of the present invention;

[0032] Figure 4 This is a cross-sectional view of the guide post assembly structure of the present invention;

[0033] Figure 5 This is a three-dimensional diagram of another assembly structure of the spring of the present invention;

[0034] Figure 6 This is a schematic diagram of the damping control method of the present invention.

[0035] The attached diagram lists the components represented by each number as follows:

[0036] 1. Rear axle boom tube; 2. Rear axle cantilever; 3. Rear tire; 4. Rear axle connecting bolt; 5. Variable damping device; 6. Hydraulic cylinder; 7. Rear wheel steering arm; 8. Rear axle cantilever sleeve; 9. Upper shaft of rear wheel steering arm; 10. Limiting plate; 11. Limiting sleeve; 12. Upper pressure plate of friction plate; 13. Friction plate; 14. Friction disc; 15. Pad; 16. Guide column; 17. Spring pressure plate; 18. Spring; 19. Linear bearing; 20. Lower pressure plate of friction plate; 21. Cylinder fixing plate; 22. Main controller; 23. Vehicle speed sensor; 24. Pressure sensor; 25. Pressure control valve. Detailed Implementation

[0037] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0038] Example 1

[0039] like Figures 1-5 As shown, this embodiment provides a variable damping device for a steering arm. The variable damping device 5 includes an upper shaft 9 of the rear wheel steering arm that rotates through the rear axle cantilever sleeve 8, and also includes a friction disc 14, a friction assembly, and a pressurizing assembly. The friction disc 14 is perpendicular to and fixedly connected to the upper shaft 9 of the rear wheel steering arm. The friction assembly is provided on at least one side of the friction disc 14. A rotation limiting assembly is provided at the outer edge of the friction assembly. The pressurizing assembly is connected to the friction assembly or the rear axle cantilever sleeve 8 and applies an adjustable damping adjustment force to the friction assembly so that it abuts against the friction disc 14.

[0040] As the upper shaft 9 of the rear wheel steering arm rotates, the friction disc 14 remains stationary. A damping adjustment force is applied to the friction assembly via a pressure component, causing the friction assembly to contact the friction disc 14. This applies a damping force to both the friction disc 14 and the upper shaft 9 of the rear wheel steering arm. The damping adjustment force is adjustable, allowing for adjustments based on the vehicle speed. This solves the problems of abnormal swaying of the rear wheel steering arm due to insufficient damping force or difficulty in rotating the rear wheel steering arm due to excessive damping force, effectively preventing reduced bearing life and decreased high-speed stability caused by these issues.

[0041] Specifically, the friction disc 14 has a plate-like structure, which is perpendicular to the axis of the upper shaft 9 of the rear wheel steering arm. In particular, when the friction disc 14 is circular, the friction disc 14 coincides with the axis of the upper shaft 9 of the rear wheel steering arm.

[0042] Optionally, the upper end of the rear wheel steering arm upper shaft 9 extends out of the rear axle cantilever sleeve 8, and the friction disc 14 is fixedly sleeved on the upper outer wall of the rear wheel steering arm upper shaft 9, or fixed to the upper end face of the rear wheel steering arm upper shaft 9.

[0043] The friction disk 14 has a friction component on at least one side, and preferably, the friction disk 14 has friction components on both sides.

[0044] Optionally, there may be one rotation limit component, or multiple components spaced apart along the circumference of the friction component.

[0045] Based on the above technical solution, the variable damping device of the steering arm also includes two pads 15 and friction disc mounting bolts. The two pads 15 are located on both sides of the center of the friction disc 14, and the friction disc mounting bolts pass through the two pads 15 and the friction disc 14 and are fixedly connected to the upper shaft 9 of the rear wheel steering arm.

[0046] Two pads 15 are provided to facilitate the installation and replacement of the friction disc 14, and space is left on both outer edges of the friction disc 14 for installing friction components.

[0047] Specifically, the friction disc mounting bolts are spaced out in multiples.

[0048] Based on the above technical solution, the friction assembly includes a friction plate 13, which is located on the outer edge of the friction disk 14.

[0049] The friction plate 13 is used to abut against the friction disk 14 and generate frictional force to dampen the rotation of the friction disk 14.

[0050] Specifically, the outer edge of the friction disc 14 refers to the annular area away from the center of the friction disc 14, specifically the area outside the pad 15. In other words, the friction plate 13 is annular and is fitted onto the outside of the pad 15. Alternatively, the friction plate 13 may not be annular; for example, it can be a circular or polygonal plate, as long as it can be arranged in contact with the friction disc 14.

[0051] Based on the above technical solution, the friction assembly further includes a friction plate pressure plate, which is fixed or abuts against the side of the friction plate 13 facing away from the friction disk 14.

[0052] The friction plate 13 is pressed against the friction plate 14 by the friction plate pressure plate, and the pressure component acts on the friction plate pressure plate.

[0053] Based on the above technical solution, the rotation limiting component includes a limiting sleeve 11. A limiting notch is provided at the outer edge of the friction component along the axial direction of the upper shaft 9 of the rear wheel steering arm. The limiting sleeve 11 is fixedly connected to the rear axle cantilever sleeve 8 and inserted into the limiting notch.

[0054] The limiting sleeve 11 is fixedly installed, and the rotation of the friction assembly is restricted by the limiting notch, so that the friction assembly does not rotate with the friction disk 14.

[0055] Specifically, the size of the friction plate pressure plate is larger than the size of the friction plate 13 (when the friction plate pressure plate is annular, the above "size" refers to the outer diameter), and the limiting notch is opened at the outer edge of the friction plate pressure plate.

[0056] Based on the above technical solution, the rotation limiting assembly further includes a limiting plate 10, a limiting mounting bolt, and a limiting mounting nut. The limiting plate 10 is fixedly connected to the rear axle cantilever sleeve 8, and one end of the limiting mounting bolt passes through the limiting sleeve 11 and the limiting plate 10 and is threadedly connected to the limiting mounting nut.

[0057] The limiting sleeve 11 is fixed to the limiting plate 10 by the limiting mounting bolt.

[0058] Based on the above technical solution, the size of the limiting disk 10 is smaller than the size of the friction assembly (when the limiting disk 10 and the friction assembly are annular, the above size refers to the outer diameter), the limiting disk 10 has a lug that protrudes radially outward along the rear axle cantilever sleeve 8, and the limiting mounting bolt is connected to the lug.

[0059] The limiting plate 10 adopts a lug structure, and the rest of the part does not overlap with the outer edge of the friction component in the axial direction, thereby avoiding the space for installing the pressurizing component.

[0060] Based on the above technical solution, one embodiment of the pressurizing component is as follows: the pressurizing component includes a hydraulic cylinder 6, a guide post 16, a spring pressure plate 17, and a spring 18. Multiple guide posts 16 are provided, each of which sequentially passes through the hydraulic cylinder 6, the spring pressure plate 17, and the friction component. Guide post nuts are fixed at both ends of each guide post 16. The hydraulic cylinder 6 is fixedly connected to the guide post 16. The spring pressure plate 17 is slidably connected to the guide post 16 via a linear bearing 19. The spring 18 is located between the spring pressure plate 17 and the friction component. The piston rod of the hydraulic cylinder 6 abuts against the spring pressure plate 17 and applies a damping adjustment force to the friction component through the spring 18.

[0061] When the hydraulic cylinder 6 is not extended, the force provided by the initial compression of the spring 18 presses the friction plate pressure plate, friction plate 13, and friction disc 14 together. The friction disc 14 is connected to the rear wheel steering arm 7 via the upper shaft 9 of the rear wheel steering arm. When the rear wheel steering arm 7 rotates, it drives the friction disc 14 to rotate and rub against the friction plate 13, generating a damping force. The damping force in this state is the minimum damping force of the variable damping device. This damping force is not controlled by the hydraulic cylinder 6 and still exists even if the hydraulic cylinder 6 fails, preventing the rear wheel from becoming completely free due to hydraulic system failure. The linear bearing 19 prevents the spring pressure plate 17 from getting stuck with the guide post 16 during sliding.

[0062] When the piston rod of hydraulic cylinder 6 extends, it pushes the spring pressure plate 17 to further compress spring 18, increasing the clamping force provided by spring 18. This clamping force is the damping adjustment force, thereby increasing the damping force when the rear wheel steering arm 7 rotates. Different extension lengths of the piston rod of hydraulic cylinder 6 result in different compressions of spring 18, thus varying the damping adjustment force on the friction assembly, thereby achieving adjustment of the damping adjustment force.

[0063] Specifically, there are three sets of guide posts 16 and springs 18, each corresponding to a different spring.

[0064] Specifically, both sides of the friction disc 14 have friction plates 13, and each friction plate 13 corresponds to a friction plate pressure plate. The two friction plate pressure plates are the upper friction plate pressure plate 12 and the lower friction plate pressure plate 20, as shown below. Figure 4 As shown, the lower pressure plate 20 of the friction plate is fixedly connected to the lower end of the guide post 16 through a stepped structure and one of the guide post nuts. The upper pressure plate 12 of the friction plate is slidably sleeved on the guide post 16. The spring 18 provides clamping force for the upper pressure plate 12 and the lower pressure plate 20 of the friction plate. The hydraulic cylinder 6 is fixedly connected to the cylinder fixing plate 21, which is fixedly connected to the upper end of the guide post 16 through a stepped structure and another guide post nut. That is, after the multiple guide posts 16, the lower pressure plate 20 of the friction plate, and the cylinder fixing plate 21 are tightened with guide post nuts, a frame is formed. The spring pressure plate 17 and multiple linear bearings 19 slide up and down within the frame to compress the spring 18.

[0065] Optional, such as Figure 5 As shown, the spring 18 is sleeved on the guide post 16; or, as... Figure 2 and Figure 3 As shown, the spring pressure plate 17 has a first spring positioning protrusion protruding towards the friction assembly, and the friction assembly has a second spring positioning protrusion on the side facing the spring pressure plate 17. The two ends of the spring 18 are respectively sleeved on the first spring positioning protrusion and the second spring positioning protrusion. The piston rod of the hydraulic cylinder 6 extends into the first spring positioning protrusion and abuts against it.

[0066] for Figure 2 Specifically, the first and second spring positioning protrusions are both cylindrical structures, with an end plate fixed to the lower end of the first spring positioning protrusion. When the piston rod of the hydraulic cylinder 6 is retracted to its shortest length, the hydraulic cylinder 6 is embedded in the first spring positioning protrusion. This allows for a more compact structure and saves installation space. Simultaneously, the first and second spring positioning protrusions limit the minimum distance between the spring pressure plate 17 and the friction assembly, and the second spring positioning protrusion also protects mounting structures such as the friction plate mounting bolts.

[0067] In the above embodiments, the hydraulic cylinder 6 can be replaced by a linear telescopic mechanism such as a pneumatic cylinder or an electric telescopic rod.

[0068] Another embodiment of the pressurizing assembly is as follows: the pressurizing assembly includes a linear telescopic mechanism, which is a hydraulic cylinder, a pneumatic cylinder, or an electric telescopic rod. The linear telescopic mechanism is fixedly assembled with the rear axle cantilever sleeve 8, and its piston rod extends out and abuts against the friction assembly. This directly applies pressure to the friction assembly and the friction disc 14.

[0069] In this embodiment, by setting a variable damping device for the steering arm, the electronic control system detects the pressure inside the hydraulic cylinder 6 via a pressure sensor and determines whether the current damping force has reached the target value based on this pressure. The hydraulic electronic control system automatically controls the extension and retraction of the piston rod of the hydraulic cylinder 6 by detecting the real-time vehicle speed. This real-time control of the rotational damping force of the rear wheel steering arm maintains rear wheel directional stability, preventing abnormal rear wheel sway that could reduce bearing life and driving stability. Furthermore, as usage time increases, the elasticity of the spring 18 may decay, resulting in a decrease in the damping force provided under the same compression. By calculating the rotational damping force using the working pressure inside the hydraulic cylinder 6, the electronic control system can increase the stroke of the hydraulic cylinder 6 to compensate for the reduced rotational damping force due to spring force decay.

[0070] Example 2

[0071] like Figure 1 As shown, this embodiment also provides a rear axle, including a rear axle crossbeam, two rear wheel steering arms 7, and two variable damping devices for the steering arms described in Embodiment 1. Each end of the rear axle crossbeam is fixed with a rear axle cantilever sleeve 8. The two rear wheel steering arms 7 are arranged in a one-to-one correspondence with the two variable damping devices 5. The upper end of the rear wheel steering arm 7 is fixedly connected to the lower end of the upper shaft 9 of the corresponding rear wheel steering arm or integrally formed.

[0072] The rear axle crossbeam includes a rear axle arm tube 1 and a rear axle cantilever 2. The rear axle cantilever 2 is inserted into the rear axle arm tube 1 and fixed with rear axle connecting bolts 4. The upper end shaft 9 of the rear wheel steering arm 7 is inserted into the rear axle cantilever sleeve 8 at the end of the rear axle cantilever 2 and can rotate around the rear axle cantilever sleeve 8. A variable damping device 5 provides damping force for the rotation of the rear wheel steering arm 7. A hydraulic cylinder 6 adjusts the damping force provided by the variable damping device 5. The rear tire 3 is mounted on the lower end of the rear wheel steering arm 7.

[0073] The rear axle of this embodiment can be used in lawn mowers or other agricultural machinery with a similar rear axle structure.

[0074] Example 3

[0075] like Figure 6 As shown, this embodiment also provides a damping control method, implemented using the rear axle described in Embodiment 2, including the following steps:

[0076] Step 1: Obtain the real-time vehicle speed signal, and determine the required rear axle rotational damping force at the current vehicle speed based on the real-time vehicle speed signal.

[0077] Step 2: Calculate the target damping adjustment force of the pressurization assembly based on the rear axle rotational damping force;

[0078] Step 3: Obtain the actual pressure of the pressurizing component in real time, and adjust the actual pressure according to the difference between the actual pressure and the target damping adjustment force to adjust the pressure of the pressurizing component to the target damping adjustment force.

[0079] Specifically, such as Figure 6 As shown, the vehicle speed sensor 23 is used to acquire the real-time vehicle speed signal and feed the real-time vehicle speed signal back to the main controller 22. The main controller 22 determines the required rear axle rotational damping force at the current vehicle speed based on the real-time vehicle speed signal.

[0080] The main controller 22 calculates the target damping adjustment force of the hydraulic cylinders 6 on both sides of the rear axle based on the rotational damping force of the rear axle, and converts it into an electrical signal input to the pressure control valve 25. The pressure control valve 25 increases or decreases the pressure of the hydraulic cylinders 6 on both sides according to the electrical signal, thereby controlling the pressure of the hydraulic cylinders 6 to compress the corresponding springs 18.

[0081] Pressure sensor 24 acquires the actual pressure of hydraulic cylinder 6 in real time and feeds it back to main controller 22. Main controller 22 compares the difference between the actual pressure and the calculated target damping adjustment force to further adjust the electrical signal of pressure control valve 25, thereby achieving closed-loop control of the damping force of the variable damping devices on both sides. Pressure control valve 25 can be connected in parallel to any pressure oil circuit of the main unit, or a separate hydraulic pump source can be used.

[0082] In the description of this invention, it should be noted that the terms "upper", "lower", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this 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. Therefore, they should not be construed as limitations on this invention.

[0083] In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0084] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0085] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," 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, the 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. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0086] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" 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 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 according to the specific circumstances.

[0087] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A variable damping device for a steering arm, the variable damping device (5) comprising an upper shaft (9) of the rear wheel steering arm that rotates through a rear axle cantilever sleeve (8), characterized in that, It also includes a friction disc (14), a friction assembly, and a pressurizing assembly. The friction disc (14) is perpendicular to and fixedly connected to the upper shaft (9) of the rear wheel steering arm. The friction assembly is provided on at least one side of the friction disc (14). A rotation limiting assembly is provided at the outer edge of the friction assembly. The pressurizing assembly is connected to the friction assembly and applies an adjustable damping force to the friction assembly to make it abut against the friction disc (14). The pressurizing assembly includes a hydraulic cylinder (6), a guide post (16), a spring pressure plate (17), and a spring (18). Multiple guide posts (16) are provided. Each guide post (16) passes through the hydraulic cylinder (6), the spring pressure plate (17), and the friction assembly in sequence. Guide post nuts are fixed at both ends of the guide post (16). The hydraulic cylinder (6) is fixedly connected to the guide post (16), the spring pressure plate (17) is slidably connected to the guide post (16) through the linear bearing (19), the spring (18) is located between the spring pressure plate (17) and the friction assembly, the piston rod of the hydraulic cylinder (6) abuts against the spring pressure plate (17) and applies damping adjustment force to the friction assembly through the spring (18); the spring pressure plate (17) has a first spring positioning protrusion protruding towards the side of the friction assembly, the side of the friction assembly facing the spring pressure plate (17) has a second spring positioning protrusion, the two ends of the spring (18) are respectively sleeved on the first spring positioning protrusion and the second spring positioning protrusion, the piston rod of the hydraulic cylinder (6) extends into the first spring positioning protrusion and abuts against it.

2. The variable damping device for a steering arm according to claim 1, characterized in that, It also includes two pads (15) and friction disc mounting bolts. The two pads (15) are located on both sides of the center of the friction disc (14). The friction disc mounting bolts pass through the two pads (15) and the friction disc (14) and are fixedly connected to the upper shaft (9) of the rear wheel steering arm.

3. The variable damping device for a steering arm according to claim 1, characterized in that, The friction assembly includes a friction plate (13) located on the outer edge of the friction disk (14).

4. The variable damping device for a steering arm according to claim 3, characterized in that, The friction assembly also includes a friction plate pressure plate, which is fixed or abuts against the side of the friction plate (13) facing away from the friction disk (14).

5. The variable damping device for a steering arm according to claim 1, characterized in that, The rotation limiting assembly includes a limiting sleeve (11). A limiting notch is provided at the outer edge of the friction assembly along the upper shaft (9) of the rear wheel steering arm. The limiting sleeve (11) is fixedly connected to the rear axle cantilever sleeve (8) and inserted into the limiting notch.

6. The variable damping device for a steering arm according to claim 5, characterized in that, The rotation limiting assembly also includes a limiting disc (10), a limiting mounting bolt, and a limiting mounting nut. The limiting disc (10) is fixedly connected to the rear axle cantilever sleeve (8). One end of the limiting mounting bolt passes through the limiting sleeve (11) and the limiting disc (10) and is threadedly connected to the limiting mounting nut.

7. The variable damping device for a steering arm according to claim 6, characterized in that, The size of the limiting disc (10) is smaller than the size of the friction assembly. The limiting disc (10) has a lug that protrudes radially outward along the rear axle cantilever sleeve (8). The limiting mounting bolt is connected to the lug.

8. A rear axle, characterized in that, It includes a rear axle crossbeam, two rear wheel steering arms (7) and two variable damping devices for the steering arms as described in any one of claims 1-7. Each end of the rear axle crossbeam is fixed with a rear axle cantilever sleeve (8). The two rear wheel steering arms (7) are arranged in a one-to-one correspondence with the two variable damping devices (5). The upper end of the rear wheel steering arm (7) is fixedly connected to the lower end of the upper shaft (9) of the corresponding rear wheel steering arm or integrally formed.

9. A damping control method, characterized in that, The rear axle as described in claim 8 is used, comprising the following steps: Step 1: Obtain the real-time vehicle speed signal through the vehicle speed sensor (23) and feed the real-time vehicle speed signal back to the main controller (22). The main controller (22) determines the required rear axle rotational damping force at the current vehicle speed based on the real-time vehicle speed signal. Step 2: Based on the rear axle rotation damping force, the main controller (22) calculates the target damping adjustment force of the hydraulic cylinders (6) on both sides of the rear axle and converts it into an electrical signal input to the pressure control valve (25). The pressure control valve (25) increases or decreases the pressure of the hydraulic cylinders (6) on both sides according to the electrical signal, thereby controlling the hydraulic cylinders (6) to compress the corresponding springs (18) with pressure. Step 3: The actual pressure of the hydraulic cylinder (6) is obtained in real time by the pressure sensor (24). The main controller (22) further adjusts the electrical signal of the pressure control valve (25) according to the difference between the actual pressure and the target damping adjustment force, so as to adjust the pressure of the hydraulic cylinder (6) to the target damping adjustment force.

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