CN117703983A - Hydro-pneumatic spring and cross-country chassis independent suspension system - Google Patents

Abstract

The invention relates to vehicle equipment, in particular to a hydro-pneumatic spring and an independent suspension system for an off-road chassis, wherein the off-road chassis independent suspension system uses the hydro-pneumatic spring as an elastic element and a shock absorber as a damping element. The hydro-pneumatic spring comprises a first cylinder body, a first piston rod, a first piston, a second cylinder body and a second piston, wherein the first piston is arranged in a hollow cavity of the first piston rod, a first cavity is formed between the first piston rod and the inner wall of the first cylinder body, the hollow cavity of the first piston rod is divided into a second cavity and a third cavity by the first piston, and the second cavity of the second cylinder body is divided into a fifth cavity and a sixth cavity by the second piston. The hydro-pneumatic spring has two-stage rigidity, can reduce the instantaneous impact of a suspension on a vehicle body, reduce the instantaneous frequency, improve the running smoothness and improve the maneuvering speed of the vehicle. The damper is a high-capacity single-cylinder nitrogen damper, can effectively increase damping force, forms multi-gear damping, and is suitable for complex off-road environments.

Description

Hydro-pneumatic spring and cross-country chassis independent suspension system

Technical Field

The invention relates to vehicle equipment, in particular to a hydro-pneumatic spring and an independent suspension system for an off-road chassis.

Background

The off-road vehicle has complex and severe driving conditions, and a large amount of vibration energy can be generated by the vibration of the suspension system caused by the excitation of the road surface unevenness. Part of the vibration energy is transferred to the vehicle body and eventually absorbed by the vehicle body, occupants, etc., and the other part is converted into heat by damping and dissipated to the atmosphere. The energy caused by the vibration of the suspension is transmitted to the passenger, and if the passenger absorbs excessive energy, the passenger feels fatigue and discomfort and is forced to lower the vehicle speed, which indicates that the off-road vehicle speed is limited by the vibration energy of the suspension. Therefore, the suspension system is a key to improve the ride quality of the vehicle, to control stability, and to reduce damage to components caused by dynamic loads. Particularly, for an off-road vehicle with complex driving road conditions, the excellent suspension system structure and characteristics are critical, and the method is a key for determining the motor off-road vehicle speed. The running condition of the existing off-road vehicle determines that the rigidity of the suspension system of the off-road vehicle is variable, and when the off-road vehicle is in a balanced position,

the suspension has lower rigidity, so that the chassis has lower natural frequency, and smoothness is improved; as the wheel jumps up Cheng Zengda,

the rigidity of the suspension is increased to improve the rigidity of the roll angle of the suspension system, so that the chassis has good steering stability; as the wheel jumps down Cheng Zengda, the suspension stiffness is reduced to maintain the tire grounding and improve the safety; when the large wheel jumps, the rigidity of the suspension cannot be too high, and the rising speed of the suspension needs to be slowed down; otherwise, the elastic force is rapidly increased, so that the running smoothness is poor, the further increase of the off-road speed is affected, and the maneuverability advantage cannot be exerted; meanwhile, the larger elastic force is directly transmitted to the vehicle body, and the strength and fatigue life of the related structural members are adversely affected by the instant impact, so that the overall lightweight design is not facilitated. The existing suspension system has the problem that the rigidity of the suspension cannot be changed due to the limited structure of the hydro-pneumatic spring, so that the performance of the off-road vehicle is affected. Meanwhile, the traditional shock absorber has smaller damping force, is easy to generate heat to cause unstable damping force and even damage, and cannot better adapt to the requirements of the cross-country chassis.

Disclosure of Invention

The invention aims to solve the technical problem of providing the hydro-pneumatic spring and the cross-country chassis independent suspension system which have two-stage rigidity, can effectively reduce the elastic force and rigidity when the compression amount is large, further reduce the instantaneous impact of the suspension on a vehicle body, reduce the instantaneous frequency, improve the running smoothness and improve the maneuvering speed of the vehicle.

In order to solve the technical problems, the application provides the following technical scheme:

the invention discloses an oil-gas spring, which comprises a first cylinder body, a first piston rod, a first piston, a second cylinder body and a second piston, wherein the first cylinder body and the second cylinder body are arranged side by side, the first cylinder body and the second cylinder body are connected with each other, the first piston rod is a hollow rod, the first piston is arranged in a hollow cavity of the first piston rod, one end of the first piston rod is arranged in the first cylinder body, a first cavity is formed between the first piston rod and the inner wall of the first cylinder body, the hollow cavity of the first piston rod is divided into a second cavity and a third cavity by the first piston, a first through hole is formed at the end part of the first piston rod, the first cavity is communicated with the second cavity, the second piston is arranged in the second cylinder body, the second piston divides the inner cavity of the second cylinder body into a fifth cavity and a sixth cavity, the first cavity is communicated with the fifth cavity, a pressure gas is pre-filled in the sixth cavity, the pre-filled cavity is a pressure chamber P < 01 >, and the pressure is in the first cylinder body is in a pressure-filled chamber P < 01 >, and the pressure-gas-filled vehicle frame is in a pressure-filled pressure-loaded pressure-spring is in the first end-equipped with P < 02 >.

The end part of one end of the first piston rod, which is positioned in the first cylinder body, is a matching end, the first through hole is formed in the matching end, the outer diameter of the matching end is larger than the outer diameter of the rest part of the first piston rod, the outer wall of the matching end is matched with the inner wall of the first cylinder body, a fourth cavity is formed between the outer wall of the rest part of the first piston rod and the inner wall of the first cylinder body, the matching end is provided with a second through hole so that the first cavity is communicated with the fourth cavity, and a displacement sensor is integrated in the inner wall of the first cylinder body and is used for measuring the real-time length of the hydro-pneumatic spring.

The invention discloses an off-road chassis independent suspension system, which comprises the hydro-pneumatic spring.

The invention discloses an independent suspension system of an off-road chassis, wherein a first support lug is arranged at one end of a first cylinder body, which is used for being connected with a frame, a second support lug is arranged at one end of a first piston rod, which is used for being connected with the frame, a first joint bearing and a second joint bearing are respectively arranged in the first support lug and the second support lug, a first connecting pin penetrates through the first joint bearing, the first connecting pin is connected with the frame, a second connecting pin penetrates through the second joint bearing, and the second connecting pin is connected with the frame.

The invention discloses an off-road chassis independent suspension system, which further comprises second check rings, wherein the second check rings are respectively arranged at two ends of a first joint bearing on a first connecting pin, and the second check rings are respectively arranged at two ends of a second joint bearing on a second connecting pin.

The invention discloses an independent suspension system of an off-road chassis, which further comprises a first cross arm, a second cross arm and a steering knuckle, wherein one ends of the first cross arm and the second cross arm are respectively connected with the steering knuckle through a ball pin assembly, and the other ends of the first cross arm and the second cross arm are respectively connected with a frame.

The invention discloses an independent suspension system of an off-road chassis, wherein the first cross arm and the second cross arm are connected in the same mode, one end of the first cross arm connected with a vehicle frame is divided into a first connecting support leg and a second connecting support leg, the first connecting support leg and the second connecting support leg are respectively connected with the vehicle frame through a rubber bushing, and a first check ring is respectively arranged on the outer sides of the rubber bushing on the first connecting support leg and the second connecting support leg.

The invention discloses an off-road chassis independent suspension system, wherein a connecting point of a second cross arm connected with a frame is a first connecting point, a connecting point of the second cross arm connected with a steering knuckle is a second connecting point, and the height of the first connecting point is higher than that of the second connecting point.

The invention discloses an off-road chassis independent suspension system, which further comprises a damper, wherein the damper and an oil-gas spring are respectively positioned at two sides of a second cross arm, the damper comprises a damper cylinder barrel, a damper piston rod, a high-pressure air cylinder, a floating piston and a damping valve assembly, the floating piston is arranged in the high-pressure air cylinder, a sixth chamber is formed between the floating piston and the top of the high-pressure air cylinder, a seventh chamber is formed between the floating piston and the bottom of the high-pressure air cylinder, high-pressure air is filled in the seventh chamber, one end of the damper piston rod is arranged in the damper cylinder barrel, the other end of the damper piston rod is arranged outside the damper cylinder barrel, a fifth chamber is formed between the damper piston rod and the inner wall of the damper cylinder barrel, the fifth chamber is communicated with the sixth chamber, the fifth chamber and the sixth chamber are filled with oil, the damper cylinder barrel and the high-pressure air cylinder are mutually connected, one end of the damper cylinder barrel and one end of the high-pressure air cylinder are connected to the frame, and the high-pressure air cylinder is arranged outside the damper cylinder barrel and the damper cylinder barrel.

The invention discloses an independent suspension system of an off-road chassis, wherein a first limiting block is connected to a position, above a first cross arm, close to the first cross arm on a frame, a second limiting block is arranged on the bottom surface of the first cross arm, a third limiting block is arranged on the second cross arm, close to a steering knuckle, and the third limiting block is used for limiting steering of the steering knuckle.

Compared with the prior art, the hydro-pneumatic spring has at least the following beneficial effects:

the hydro-pneumatic spring comprises the second cylinder body and the first cylinder body, wherein the inner cavities of the second cylinder body and the inner cavities of the first cylinder body respectively form the main air chamber and the auxiliary air chamber, one air chamber is respectively arranged in the main air chamber and the auxiliary air chamber, different inflation pressures are filled in the two air chambers through the design of the two air chambers, two-stage rigidity can be formed, the elastic force and the rigidity of the hydro-pneumatic spring can be effectively reduced when the compression amount is large, the instantaneous impact of the suspension on a vehicle body can be further reduced, the instantaneous frequency can be reduced, the driving smoothness can be improved, the maneuvering speed of the vehicle can be improved, the hydro-pneumatic spring can be conveniently designed in series, and different air chamber volumes and pre-inflation pressures can be matched, so that a series of products can be conveniently formed, and different rigidity characteristic requirements can be met; meanwhile, the first cylinder body and the second cylinder body are integrated into the hydro-pneumatic spring body, an external design energy accumulator is not needed, and the structural complexity of the suspension system is reduced.

The hydro-pneumatic spring and the off-road chassis independent suspension system of the invention are further described below with reference to the accompanying drawings.

Drawings

FIG. 1 is a schematic diagram of the front view of a hydro-pneumatic spring of the present invention;

FIG. 2 is a schematic side view of a hydro-pneumatic spring of the present invention;

FIG. 3 is a schematic cross-sectional view of a hydro-pneumatic spring of the present invention;

FIG. 4 is an enlarged view of a portion of FIG. 3 at A;

FIG. 5 is a schematic view of the mounting structure of the displacement sensor of the hydro-pneumatic spring of the present invention;

FIG. 6 is a schematic diagram of the front view of the off-road chassis independent suspension system of the present invention;

FIG. 7 is a schematic side elevational view of the off-road chassis independent suspension system of the present invention;

FIG. 8 is a cross-sectional view taken along A-A of FIG. 7;

FIG. 9 is a B-B cross-sectional view of FIG. 7;

FIG. 10 is a schematic rear view of the cross-country chassis independent suspension system of the present invention;

FIG. 11 is a C-C cross-sectional view of FIG. 10;

FIG. 12 is a schematic perspective view of an off-road chassis independent suspension system of the present invention;

FIG. 13 is a graph of spring force versus compression of a hydro-pneumatic spring in an off-road chassis independent suspension system of the present invention;

FIG. 14 is a schematic view of the structure of a shock absorber in the off-road chassis independent suspension system of the present invention;

fig. 15 is a cross-sectional view taken along A-A of fig. 14.

Detailed Description

As shown in fig. 1, 2, 3 and 4, the hydro-pneumatic spring of the invention comprises a first cylinder 21, a first piston rod 22, a first piston 23, a second cylinder 24 and a second piston 25, wherein the first cylinder 21 and the second cylinder 24 are arranged side by side, the inner cavity of the second cylinder 24 and the inner cavity of the first cylinder 21 respectively form a main air chamber and an auxiliary air chamber, the first cylinder 21 and the second cylinder 24 are connected with each other, the first piston rod 22 is a hollow rod, the first piston 23 is arranged in the hollow cavity of the first piston rod 22, one end of the first piston rod 22 is arranged in the first cylinder 21, a first chamber 26 is formed between the first piston rod 22 and the inner wall of the first cylinder 21, the hollow cavity of the first piston rod 22 is divided into a second chamber 27 and a third chamber 28 by the first piston rod 23, a first through hole 221 is arranged at the end of the first piston rod 22 to enable the first chamber 26 to be communicated with the second chamber 27, one end of the first cylinder 21 is used for connecting a frame, one end of the first piston rod 22, which is positioned outside the first cylinder body 21, is used for being connected with a frame, the second piston 25 is arranged in the second cylinder body 24, the second piston 25 divides the inner cavity of the second cylinder body 24 into a fifth cavity 29 and a sixth cavity 30, the first cavity 26 is communicated with the second cavity 27 and the fifth cavity 29, the first cavity 26, the second cavity 27 and the fifth cavity 29 are oil cavities, the sixth cavity 30 is an air cavity of a main air chamber, the sixth cavity 30 is pre-filled with pressure gas, the pre-filled pressure in the sixth cavity 30 is P01, the third cavity 28 is an air cavity of an auxiliary air chamber, the third cavity 28 is pre-filled with pressure gas, the pre-filled pressure in the third cavity 28 is P02, the pressure gas can adopt high-pressure nitrogen, when the hydro-pneumatic spring is in a full load static balance state after being mounted on the vehicle, the oil pressure in the hydro-pneumatic spring is determined by load, p01< Ps < P02, namely, in a static balance state, the system pressure is lower than the pre-charging pressure in the auxiliary air chamber, namely, the third chamber 28, the auxiliary air chamber does not work, and the auxiliary air chamber starts to work after the system pressure reaches and is higher than the pre-charging pressure in the auxiliary air chamber, namely, the third chamber 28, so that the hydro-pneumatic spring has two-stage rigidity, generally, P02 is about 1.5Ps, after the auxiliary air chamber starts to work, the two air chambers are connected in parallel for working due to the increased air volume, at the moment, the elastic force and rigidity of the hydro-pneumatic spring can be effectively reduced, and the elastic force curve comparison graph of the two-stage rigidity hydro-pneumatic spring and the single-stage rigidity hydro-pneumatic spring is shown as 13. Specifically, the first cylinder 21 and the second cylinder 24 are integrally formed, and a through hole 227 is provided in a connecting wall of the first cylinder 21 and the second cylinder 24 to communicate the first chamber 26 with the fifth chamber 29. The hydro-pneumatic spring comprises the second cylinder body 24 and the first cylinder body 21, wherein the inner cavities of the second cylinder body 24 and the inner cavity of the first cylinder body 21 respectively form the main air chamber and the auxiliary air chamber, one air chamber is respectively arranged in the main air chamber and the auxiliary air chamber, different inflation pressures are filled in the two air chambers through the design of the two air chambers, two-stage rigidity can be formed, the elastic force and the rigidity of the hydro-pneumatic spring in large compression amount can be effectively reduced, the instantaneous impact of a suspension on a vehicle body can be further reduced, the instantaneous frequency can be reduced, the driving smoothness can be improved, the maneuvering speed of the vehicle can be improved, the hydro-pneumatic spring can be conveniently designed in series, and the serialized products can be conveniently formed through matching different air chamber volumes and pre-inflation pressures, so that the requirements of different rigidity characteristics can be met; meanwhile, the first cylinder body 21 and the second cylinder body 24 are integrated into the hydro-pneumatic spring body, an external design accumulator is not needed, and the structural complexity of the suspension system is reduced. The damping force is not designed deliberately in the hydro-pneumatic spring, i.e. the hydro-pneumatic spring only provides the elastic force.

Optionally, an end portion of the first piston rod 22 located inside the first cylinder 21 is a mating end 222, the first through hole 221 is disposed on the mating end 222, an outer diameter of the mating end 222 is larger than an outer diameter of the rest of the first piston rod 22, an outer wall of the mating end 222 is matched with an inner wall of the first cylinder 21, a fourth chamber 31 is formed between the outer wall of the rest of the first piston rod 22 and the inner wall of the first cylinder 21, and the mating end 222 is provided with a second through hole 223 to enable the first chamber 26 to be communicated with the fourth chamber 31. The length of the matching end 222 is far smaller than that of the first piston rod 22, friction force between the first piston rod 22 and the inner wall of the first cylinder body 21 is reduced, the second through hole 223 is formed in the matching end 222 to enable the first chamber 26 to be communicated with the fourth chamber 31, and accordingly volume change of the fourth chamber 31 when the first piston rod 22 moves up and down can be compensated.

Alternatively, as shown in fig. 5, the displacement sensor 31 is integrated with the inner wall of the first cylinder 21. The real-time length of the hydro-pneumatic spring is measured through the displacement sensor 31, so that the height information of the chassis is obtained, and a closed-loop control signal is provided for vehicle posture adjustment. Specifically, the displacement sensor 31 is connected to the inner wall of the first cylinder 21, the displacement sensor 31 and the first cylinder 21 synchronously move, the inner cavity of the first piston rod 22 is provided with a magnetic ring 32 and a sleeve 33, the bottom of the sleeve 33 is connected with the bottom of the inner cavity of the first piston rod 22, the first piston 23 is provided with a through hole for the sleeve 33 to pass through, the first piston 23 is matched with the outer wall of the sleeve 33, the magnetic ring 32 is connected to the top of the sleeve 33, the magnetic ring 32 and the first piston rod 22 synchronously move, the bottom of the displacement sensor 31 penetrates through the magnetic ring 32 and stretches into the sleeve 33, when the first piston rod 22 moves, the sleeve 33, the magnetic ring 32 and the first piston rod 22 synchronously move, and when the hydro-pneumatic spring moves, namely, the first piston rod 22 moves relative to the first cylinder 21, and the magnetic ring 32 and the displacement sensor 31 move relatively at the moment. The displacement of the hydro-pneumatic spring at this time is measured according to the displacement of the magnetic ring 32 relative to the displacement sensor 31.

The invention discloses an off-road chassis independent suspension system, which comprises the hydro-pneumatic spring. The cross-country chassis independent suspension system comprises the hydro-pneumatic spring, wherein the hydro-pneumatic spring comprises the second cylinder body 24 and the first cylinder body 21, the inner cavity of the second cylinder body 24 and the inner cavity of the first cylinder body 21 respectively form a main air chamber and an auxiliary air chamber, the main air chamber and the auxiliary air chamber are respectively provided with one air chamber, different inflation pressures are filled in the two air chambers through the design of the two air chambers, two-stage rigidity can be formed, the elastic force and the rigidity of the hydro-pneumatic spring in large compression amount can be effectively reduced, the instantaneous impact of the suspension system on a vehicle body can be further reduced, the instantaneous frequency can be further reduced, the driving smoothness can be improved, the maneuvering speed of the vehicle can be improved, meanwhile, the first cylinder body 21 and the second cylinder body 24 are integrated into the hydro-pneumatic spring body, an external design accumulator is not needed, and the structural complexity of the independent suspension system can be reduced.

Alternatively, as shown in fig. 1, 6, 7 and 8, in the cross-country chassis independent suspension system of the present invention, a first support lug 211 is disposed at one end of a first cylinder 21 of the hydro-pneumatic spring for connecting with a vehicle frame, a second support lug 225 is disposed at one end of a first piston rod 22 for connecting with the vehicle frame, a first joint bearing 212 and a second joint bearing 226 are disposed in the first support lug 211 and the second support lug 225, respectively, a first connecting pin 213 passes through the first joint bearing 212, the first connecting pin 213 is connected with the vehicle frame 05, a second connecting pin passes through the second joint bearing 226, and the second connecting pin is connected with the vehicle frame 05. Specifically, the first joint bearing 212 and the second joint bearing 226 are maintenance-free joint bearings, so that maintenance-free in the use process is realized, subsequent maintenance workload is reduced, and the workload of maintenance personnel is reduced.

Optionally, the first connecting pin 213 is further provided with a second retainer 214 on two sides of the first joint bearing 212, and the second connecting pin is provided with a second retainer 214 on two ends of the second joint bearing 226, and by arranging the second retainer 214, the adjustment and positioning of the axial gaps between the first connecting pin 213 and the first joint bearing 212 and between the second connecting pin and the second joint bearing 226 are realized.

Optionally, the vehicle further comprises a first cross arm 11, a second cross arm 12 and a steering knuckle 13, wherein one ends of the first cross arm 11 and the second cross arm 12 are respectively connected with the steering knuckle 13 through a ball pin assembly, and the other ends of the first cross arm 11 and the second cross arm 12 are respectively connected with the vehicle frame 05. Specifically, the ball pin assembly is connected with the first cross arm 11 and the second cross arm 12 through threads.

Alternatively, as shown in fig. 9 and 12, the first cross arm 11 and the second cross arm 12 are connected in the same manner, wherein one end of the first cross arm 11 connected with the frame 05 is divided into a first connecting leg 111 and a second connecting leg 112, and the first connecting leg 111 and the second connecting leg 112 are respectively connected with the frame 05 through a rubber bushing 113. Specifically, taking the first connecting leg 111 as an example, the metal skeleton outside the rubber bushing 113 is in interference fit with the inner hole of the first connecting leg 111, the connecting pin inside the rubber bushing 113 is vulcanized with the metal skeleton through rubber, the connecting pin can relatively rotate within a certain range relative to the metal skeleton, the rotation of the first cross arm 11 and the second cross arm 12 is realized, and the rubber bushing 113 is connected with the frame 05 through the bolt 115 and the nut 116, so that the first cross arm 11 and the second cross arm 12 are connected with the frame 05. The first connecting support leg 111 and the second connecting support leg 112 are connected with the frame through the rubber bushing 113, the rubber deformation of the rubber bushing absorbs the high-frequency vibration of the first cross arm 11 and the second cross arm 12, and riding comfort of the chassis is improved. Because the first cross arm 11 is divided into the first connecting supporting leg 111 and the second connecting supporting leg 112, acting forces of the hydro-pneumatic spring and the shock absorber act on the inside of the triangle formed by the first connecting supporting leg 111, the second connecting supporting leg 112 and the ball pin point of the first cross arm 11 connected with the steering knuckle, the stability of the first cross arm can be ensured to the greatest extent, and the excessive torsion of the cross arm is avoided.

Optionally, the device further comprises a first check ring 114, the first connection support leg 111 and the second connection support leg 112 are respectively provided with a first check ring 114 on the outer side of the rubber bushing 113, the first connection support leg 111 is provided with a mounting hole, one side in the mounting hole is provided with a boss, one end of the rubber bushing is in contact with the boss for axial positioning, and the other end of the rubber bushing is axially positioned in the other direction through the first check ring 114.

Optionally, the connection point of the second cross arm 12 connected with the frame 05 is a first connection point, the point of the second cross arm 12 connected with the knuckle 13 is a second connection point, the height of the first connection point is higher than that of the second connection point, and a certain height difference is provided, so that the roll center height of the independent suspension system is higher, the lateral moment is smaller under the action of lateral force, the roll angle rigidity does not need to be designed to be too large, the roll angle rigidity provided by the hydro-pneumatic spring can meet the design and use requirements, the larger roll angle rigidity does not need to be provided by designing a transverse stabilizer bar, the system structure is simplified, and the cost is reduced.

Optionally, as shown in fig. 6, 8, 10, 14 and 15, the cross-country chassis independent suspension system of the present invention further includes a damper 06, the damper 06 is a high-capacity mono-tube type nitrogen damper, specifically, the damper 06 includes a damper cylinder 61, a damper piston rod 62, a high-pressure cylinder 63, a floating piston 64, a damping valve assembly 65, an adjusting knob 66, a sheath 67, a third lug 68, a fourth lug 69, the floating piston 64 is disposed in the high-pressure cylinder 63, a sixth chamber 72 is formed between the floating piston 64 and the top of the high-pressure cylinder 63, a seventh chamber 73 is formed between the floating piston 64 and the bottom of the high-pressure cylinder 63, high-pressure nitrogen is injected into the seventh chamber 73 to form a nitrogen chamber, one end of the damper piston rod 62 is disposed in the damper cylinder 61, the other end of the damper piston rod 62 is disposed outside the damper cylinder 61, A fifth chamber 71 is formed between the damper piston rod 62 and the inner wall of the damper cylinder 61, the fifth chamber 71 is communicated with the sixth chamber 72, the fifth chamber 71 and the sixth chamber 72 are filled with oil to form an oil cavity, one end of the damper piston rod 62, which is positioned outside the damper cylinder 61, is connected with a fourth support lug 69, one ends of the damper cylinder 61 and the high-pressure air cylinder 63, which correspond to the fourth support lug 69, are connected with a third support lug 68, the damper cylinder 61 and the high-pressure air cylinder 63 are arranged side by side, a sheath 67 is connected to the fourth support lug 69, the sheath 67 is positioned outside the damper piston rod 62, the sheath 67 can play a role of protecting the piston rod, a damping valve assembly 65 is arranged in the third support lug 68, an adjusting knob 66 is arranged outside the third support lug 68, and the damping force of the damping valve assembly 65 can be adjusted by rotating the adjusting knob 66. When the ground heave damper 06 compresses, the damper piston rod 62 compresses relative to the damper cylinder 61, resulting in a reduction in the volume of the fifth chamber 71, and due to the incompressibility of the oil, the oil enters the sixth chamber 72, acting on the floating piston 64, the floating piston 64 compresses the high pressure nitrogen within the seventh chamber 73, causing a reduction in the volume of the seventh chamber 73, an increase in the volume of the sixth chamber 72, ensuring a constant total volume of the oil chamber, absorbing the vibration energy. The third support lug 68 and the fourth support lug 69 are respectively provided with a third joint bearing and a fourth joint bearing, a third pin shaft 161 penetrates into the third joint bearings to connect the shock absorber 06 with the frame 05, and a fourth check ring 162 is respectively arranged at two ends of the third joint bearing on the third pin shaft 161 to realize the adjustment and the positioning of the axial gap; the lower end of the shock absorber is connected to the fourth pin shaft 163, and is provided with a gasket 164 and a nut 165 to realize axial positioning; the gasket 164 is pressed on the shoulder position of the fourth pin shaft 163, so that a certain gap is formed in the axial direction of the damper 06, and the damper is prevented from being pressed down in the axial direction to influence the movement of the damper; the fourth pin 163 is connected to the second cross arm 12 by a bolt, and limits the rotational and axial freedom of movement of the fourth pin 163 of the damper. The shock absorber 06 utilizes the gas compressibility of high-pressure nitrogen to ensure that the volume compensation is performed by utilizing gas when the oil flows, so that the oil is not affected by emulsification, vacuum and the like, the performance is extremely stable, the vibration and noise can be greatly reduced, and the vibration reduction effect during small-amplitude high-frequency vibration is ensured; the damping valve is adjusted through the adjusting knob so as to adjust the damping force to be required, the operation is simple and convenient, and compared with the traditional double-cylinder hydraulic shock absorber with the outer cylinder barrel, the double-cylinder hydraulic shock absorber has the following advantages:

the working cylinder barrel is directly exposed in the air, so that a better heat dissipation effect can be obtained, vibration energy is effectively dissipated, the shock absorber is prevented from being burnt out at a high temperature, and the off-road vehicle speed is improved; on the premise that the outer diameters of the cylinder barrels are the same, the shock absorber has a single-cylinder structure, and a piston with a larger diameter can be adopted, so that the working pressure is reduced, the damping force is improved, a large-capacity shock absorber is formed, the vibration energy can be better absorbed, and the shock absorber is suitable for off-road working conditions; the shock absorber has a damping adjusting function, realizes damping adjustment on different road surfaces and under different working conditions, and has reasonable damping force under various working conditions; for example, when the vehicle is traveling on an expressway, the vehicle is adjusted to have a small damping characteristic; when the vehicle runs on off-road, the vehicle is regulated to have large damping characteristics; the cross-country chassis independent suspension system comprises the hydro-pneumatic spring and the damper, so that decoupling of the elastic element and the damping element can be realized, impact load born by the hydro-pneumatic spring is reduced, the design light weight of the hydro-pneumatic spring is realized, meanwhile, the stability of oil in the hydro-pneumatic spring can be reduced, the stability of elastic force is improved, the service life of the hydro-pneumatic spring is greatly prolonged, and the maintenance and replacement cost is reduced.

Optionally, the damper 06 and the hydro-pneumatic spring are respectively located at two sides of the second cross arm 12, so as to reduce the torque applied to the second cross arm 12.

Optionally, as shown in fig. 10 and 12, a first limiting block 51 is connected to a position, above the first cross arm 11, near the first cross arm 11 on the frame 05, when the wheel jumps, the first cross arm 11 swings upwards, when the first cross arm 11 contacts with the first limiting block 51, limiting on the wheel jump is achieved, a second limiting block 115 is arranged on the bottom surface of the first cross arm 11, when the wheel jumps downwards, when the second limiting block 115 contacts with the frame support, limiting on the wheel jump is achieved, and vibration generated by the suspension system when the road surface is uneven is reduced by arranging the first limiting block 51 and the second limiting block 115; the position on the second cross arm 12, which is close to the steering knuckle, is provided with a third limiting block 122, and when the wheels steer, limiting screws on the steering knuckle are contacted with limiting surfaces of the third limiting block 122, so that the limiting of the steering angle of the wheels is realized. Specifically, the first limiting block 51 and the second limiting block 115 are made of elastic materials, the first limiting block 51 and the second limiting block 115 are installed in a bolt connection mode, disassembly, assembly and replacement are convenient, and the third limiting block 122 and the second cross arm 12 are integrally formed.

The above examples are only illustrative of the preferred embodiments of the present invention and are not intended to limit the scope of the present invention, and various modifications and improvements made by those skilled in the art to the technical solution of the present invention should fall within the scope of protection defined by the claims of the present invention without departing from the spirit of the present invention.

Claims (10)

1. The hydro-pneumatic spring is characterized by comprising a first cylinder body (21), a first piston rod (22), a first piston (23), a second cylinder body (24) and a second piston (25), wherein the first cylinder body (21) and the second cylinder body (24) are arranged side by side, the first cylinder body (21) and the second cylinder body (24) are mutually connected, the first piston rod (22) is a hollow rod, the first piston (23) is arranged in a hollow cavity of the first piston rod (22), one end of the first piston rod (22) is arranged in the first cylinder body (21), a first cavity (26) is formed between the first piston rod (22) and the inner wall of the first cylinder body (21), the hollow cavity of the first piston rod (22) is divided into a second cavity (27) and a third cavity (28), the end of the first piston rod (22) is provided with a first through hole (221) so that the first cavity (26) is communicated with the second cavity (27), the second cavity (24) is divided into a fifth cavity (29), the second cavity (25) is communicated with the fifth cavity (29), the device is characterized in that pressure gas is pre-filled in the sixth chamber (30), the pre-filling pressure in the sixth chamber (30) is P01, the pressure gas is pre-filled in the third chamber (28), the pre-filling pressure in the third chamber (28) is P02, the oil pressure in the oil-gas spring is Ps and is P01< Ps < P02 when the oil-gas spring is in a full-load static balance state, one end of the first cylinder body (21) is used for being connected with a frame, and one end of the first piston rod (22) positioned outside the first cylinder body (21) is used for being connected with the frame.

2. The hydro-pneumatic spring as claimed in claim 1, wherein an end portion of the first piston rod (22) located inside the first cylinder (21) is a mating end (222), the first through hole (221) is disposed on the mating end (222), an outer diameter of the mating end (222) is larger than an outer diameter of the rest of the first piston rod (22), an outer wall of the mating end (222) is mated with an inner wall of the first cylinder (21), a fourth chamber (31) is formed between an outer wall of the rest of the first piston rod (22) and the inner wall of the first cylinder (21), a second through hole (223) is disposed on the mating end (222) to enable the first chamber (26) to be communicated with the fourth chamber (31), a displacement sensor (31) is integrated on an inner wall of the first cylinder (21), and the displacement sensor (31) is used for measuring a real-time length of the hydro-pneumatic spring.

3. An off-road chassis independent suspension system comprising a hydro-pneumatic spring as claimed in any one of claims 1 to 2.

4. An off-road chassis independent suspension system according to claim 3, characterized in that one end of the first cylinder (21) for connecting with a frame is provided with a first support lug (211), one end of the first piston rod (22) for connecting with a frame is provided with a second support lug (225), the first support lug (211) and the second support lug (225) are respectively provided with a first joint bearing (212) and a second joint bearing (226), a first connecting pin (213) penetrates through the first joint bearing (212), the first connecting pin (213) is connected with the frame (05), a second connecting pin penetrates through the second joint bearing (226), and the second connecting pin is connected with the frame (05).

5. The off-road chassis independent suspension system of claim 4, further comprising a second retainer ring (214), wherein said first connecting pin (213) is provided with one said second retainer ring (214) at each end of said first knuckle bearing (212), and wherein said second connecting pin is provided with one said second retainer ring (214) at each end of said second knuckle bearing (226).

6. The off-road chassis independent suspension system according to claim 5, further comprising a first cross arm (11), a second cross arm (12) and a knuckle (13), wherein one end of the first cross arm (11) and one end of the second cross arm (12) are respectively connected with the knuckle (13) through a ball pin assembly, and the other ends of the first cross arm (11) and the second cross arm (12) are respectively connected with the frame (05).

7. The off-road chassis independent suspension system according to claim 6, wherein the first cross arm (11) and the second cross arm (12) are connected in the same manner, wherein one end of the first cross arm (11) connected with the frame (05) is divided into a first connecting leg (111) and a second connecting leg (112), the first connecting leg (111) and the second connecting leg (112) are respectively connected with the frame (05) through a rubber bushing (113), and a first check ring (114) is respectively arranged on the first connecting leg (111) and the second connecting leg (112) outside the rubber bushing (113).

8. The off-road chassis independent suspension system according to claim 7, wherein the connection point of the second cross arm (12) with the frame (05) is a first connection point, the connection point of the second cross arm (12) with the knuckle (13) is a second connection point, and the first connection point is higher than the second connection point.

9. The off-road chassis independent suspension system according to claim 8, further comprising a damper (06), wherein the damper (06) and the hydro-pneumatic spring are respectively located at two sides of the second cross arm (12), the damper (06) comprises a damper cylinder (61), a damper piston rod (62), a high-pressure air cylinder (63), a floating piston (64) and a damping valve assembly (65), the floating piston (64) is arranged in the high-pressure air cylinder (63), a sixth chamber (72) is formed between the floating piston (64) and the top of the high-pressure air cylinder (63), a seventh chamber (73) is formed between the floating piston (64) and the bottom of the high-pressure air cylinder (63), high-pressure air is injected into the seventh chamber (73), one end of the damper piston rod (62) is arranged in the damper cylinder (61), the other end of the damper piston rod (62) is arranged outside the damper cylinder (61), a fifth chamber (71) is formed between the damper piston rod (62) and the inner wall of the damper cylinder (61), the fifth chamber (71) is filled with high-pressure air cylinder (72), the fifth chamber (71) is filled with oil liquid, one end of the shock absorber cylinder barrel (61) and one end of the high-pressure air cylinder (63) are connected to the frame (05), one end of the shock absorber piston rod (62) located outside the shock absorber cylinder barrel (61) is connected to the second cross arm (12), the shock absorber cylinder barrel (61) and the high-pressure air cylinder (63) are arranged side by side, and a damping valve assembly (65) is arranged between the shock absorber cylinder barrel (61) and the high-pressure air cylinder (63).

10. The off-road chassis independent suspension system according to claim 9, wherein a first limiting block (51) is connected to the frame (05) at a position above the first cross arm (11) and close to the first cross arm (11), a second limiting block (115) is arranged on the bottom surface of the first cross arm (11), a third limiting block (122) is arranged on the second cross arm (12) at a position close to the steering knuckle, and the third limiting block (122) is used for limiting steering of the steering knuckle.