CN108116492B

CN108116492B - Vehicle and traveling unit thereof

Info

Publication number: CN108116492B
Application number: CN201711451805.8A
Authority: CN
Inventors: 柯德钧; 朱恒
Original assignee: Wuhan Mengma Yiteng Intelligent Automobile Technology Co ltd
Current assignee: Wuhan Mengma Yiteng Intelligent Automobile Technology Co ltd
Priority date: 2017-12-28
Filing date: 2017-12-28
Publication date: 2024-04-09
Anticipated expiration: 2037-12-28
Also published as: CN108116492A

Abstract

The invention provides a vehicle and a traveling unit thereof, wherein the traveling unit comprises wheels, hydro-pneumatic springs and a steering driving device; the steering driving device comprises a spline shaft and a steering driving mechanism; the spline shaft is coaxially arranged on the oil cylinder of the hydro-pneumatic spring in a penetrating way, a shaft section positioned outside the oil cylinder is connected with the steering driving mechanism so as to rotate around the axis of the spline shaft, and a shaft section positioned inside the oil cylinder is in spline connection with a piston rod of the oil cylinder; the bottom end of the piston rod is connected with a wheel axle seat, and a wheel axle with the axial direction being the horizontal direction is arranged on the wheel axle seat; the wheel is provided with an in-wheel motor and is assembled on the wheel shaft, and the center of the wheel is positioned on the extension line of the central axis of the piston rod. According to the traveling unit of the vehicle, the functions of the hydro-pneumatic spring and the steering function are combined into a whole, the spline shaft penetrating through the top of the oil cylinder drives the spline sleeve of the piston rod to rotate, and the steering of the wheels can be realized under the condition that the basic functions of the hydro-pneumatic spring are ensured, so that the operability of the vehicle is effectively improved.

Description

Vehicle and traveling unit thereof

Technical Field

The invention belongs to the technical field of automobiles, and particularly relates to a traveling unit of a vehicle and the vehicle adopting the traveling unit.

Background

In the existing chassis design of the high-trafficability unmanned vehicle, the two main types of crawler type and wheel type are generally divided.

The former crawler-type vehicle has good off-road performance, can climb certain steps after passing through a wider trench, but has low speed on a highway; the steering is realized by the speed difference between left and right tracks, and the damage to the road surface is large in running; the device can not translate sideways and obliquely, and the maneuverability is limited.

The latter wheeled vehicle has high speed when running on a road, and has no damage to the road surface during running. However, the existing wheeled vehicles have poor off-road performance due to the influence of suspension system and steering system design schemes, and the height of the step on which the existing wheeled vehicle can climb is generally not more than the radius of the wheel because the wheel of the existing wheeled vehicle cannot lift off the ground by itself and cannot extend downwards to contact the ground below by itself. The spanning width of the moat is limited to a depth exceeding the radius of the wheel. Meanwhile, the left steering wheel and the right steering wheel of the existing wheeled vehicle are mechanically connected by adopting a steering tie rod so as to form a steering trapezoid, and the steering tie rod is limited by a guiding mechanism of a suspension system of the existing wheeled vehicle, so that the in-situ steering of all the wheels which roll around the center of the vehicle can not be realized, the lateral translation and the oblique translation can not be realized, and the maneuverability is limited. In addition, the existing wheeled vehicles all design the steering main pin to have a certain inward inclination and backward inclination and a certain steering offset distance, so that the aim is to obtain low-speed and high-speed automatic aligning capability, but the defects of increased steering resistance, increased tire abrasion, increased occupied space of the steering wheel and the like are caused.

In order to obtain good smoothness and operation stability when the vehicle runs on a good road, the vehicle is expected to have smaller ground clearance, lower center of gravity, smaller rigidity and smaller damping of the suspension system, and the dynamic travel of the suspension system can be smaller. In off-road running, the vehicle is expected to have larger ground clearance, the rigidity and damping of the suspension system are larger, and the dynamic range of the suspension system is larger to improve the average vehicle speed in off-road running. These requirements are difficult to achieve in existing unmanned vehicles.

Disclosure of Invention

The invention provides a traveling unit of a vehicle and the vehicle adopting the traveling unit, which at least can solve part of defects in the prior art.

In order to achieve the above purpose, the invention adopts the following technical scheme: the vehicle walking unit comprises wheels, a hydro-pneumatic spring and a steering driving device;

the steering driving device comprises a spline shaft and a steering driving mechanism; the spline shaft is coaxially arranged on the oil cylinder of the hydro-pneumatic spring in a penetrating way, a shaft section positioned outside the oil cylinder is connected with the steering driving mechanism so as to rotate around the axis of the spline shaft, and a shaft section positioned inside the oil cylinder is in spline connection with a piston rod of the oil cylinder;

The bottom end of the piston rod is connected with a wheel axle seat, and a wheel axle with the axial direction being the horizontal direction is arranged on the wheel axle seat;

the wheel is provided with an in-wheel motor and is assembled on the wheel shaft, and the center of the wheel is positioned on the extension line of the central axis of the piston rod.

As one of the embodiments, the hydro-pneumatic spring comprises the oil cylinder, an elastic damping mechanism and an oil circuit mechanism, wherein the oil cylinder comprises the piston rod and a multi-stage cylinder barrel which is nested step by step from outside to inside;

in each two adjacent cylinders, the outer wall of the inner cylinder is of a stepped shaft structure with a wide upper part and a narrow lower part, the large-diameter section of the inner cylinder is embedded in the outer cylinder in a sliding manner, the top end of the inner cylinder is provided with an oil through hole communicated with the inner cavity of the outer cylinder, and the small-diameter section of the inner cylinder is penetrated at the bottom end of the outer cylinder and surrounds the inner wall of the outer cylinder to form an annular oil chamber; the piston rod comprises a piston part and a rod part connected to the bottom end of the piston part, the piston part is embedded in the innermost cylinder barrel in a sliding manner, and the rod part penetrates through the bottom end of the innermost cylinder barrel and forms an annular oil chamber with the inner wall of the innermost cylinder barrel in a surrounding manner;

the upper part of the outermost cylinder barrel is provided with an elastic damping interface and is connected with the elastic damping mechanism, the upper part of the outermost cylinder barrel and each annular oil chamber are provided with an oil way interface, and each oil way interface is connected with the oil way mechanism;

The spline shaft and each cylinder barrel are coaxially arranged, the top end of the spline shaft is located above the cylinder barrel on the outermost layer, the bottom end of the spline shaft extends into the inner cavity of the rod part, and the piston part is in spline connection with the spline shaft.

As one of the embodiments, at least one spline housing is sleeved on the spline shaft from inside to outside in sequence, the top and the bottom of each spline housing are respectively provided with a limiting part, and the piston part is in spline connection with the outermost spline housing.

As one of the embodiments, the elastic damping mechanism comprises a high damping pipeline, a low damping pipeline and an elastic air bag structure, wherein the high damping pipeline is connected with the low damping pipeline in parallel and is connected with the elastic damping interface and the elastic air bag structure, the high damping pipeline and the low damping pipeline are respectively provided with a damper and a first control valve, and the damping value of the damper on the high damping pipeline is higher than that of the damper on the low damping pipeline.

As one of the embodiments, the elastic air bag structure comprises a large air bag chamber and a small air bag chamber which are arranged in parallel, and the branch where the two air bag chambers are located is provided with a second control valve.

As one of the embodiments, the hydro-pneumatic spring comprises the oil cylinder, a damping plate and a floating piston;

The oil cylinder comprises a cylinder barrel and a hollow piston rod, the top end of the piston rod is slidably arranged in the cylinder barrel, the bottom end of the piston rod is positioned outside the cylinder barrel, and the inner cavity of the piston rod is communicated with the oil cavity of the cylinder barrel through an oil passing hole formed in the top end of the piston rod;

the spline shaft penetrates through the cylinder barrel and is in spline connection with the top end of the piston rod, and the bottom end of the spline shaft extends into the inner cavity of the piston rod;

the damping plate is embedded in the inner cavity of the piston rod in a sliding manner and fixedly connected with the bottom end of the spline shaft, and a damping oil passage is formed in the damping plate;

the floating piston is slidably arranged in the inner cavity of the piston rod and positioned below the damping plate, and divides the inner cavity of the piston rod into an upper oil chamber and a lower air chamber.

As one embodiment, the damping oil passing channel comprises a compression damping hole and an extension damping hole which are arranged on the damping plate, the compression damping hole is provided with a first unidirectional control unit for controlling the oil passing direction of the compression damping hole to be a top-down direction, and the extension damping hole is provided with a second unidirectional control unit for controlling the oil passing direction of the extension damping hole to be a bottom-up direction.

As one of the embodiments, the first unidirectional control unit includes a first elastic cover plate disposed on the lower surface of the damping plate, the second unidirectional control unit includes a second elastic cover plate disposed on the upper surface of the damping plate, and the first elastic cover plate and the second elastic cover plate are respectively attached to the plate surface of the damping plate in parallel and cover the corresponding damping holes.

As one of the embodiments, the spline shaft is further connected with a steering angle sensor.

The invention also provides a vehicle, which comprises a vehicle body, and further comprises a plurality of groups of traveling units of the vehicle, wherein the oil cylinders of the hydro-pneumatic springs are fixedly arranged on the vehicle body.

The invention has the beneficial effects that:

according to the traveling unit of the vehicle, the functions of the hydro-pneumatic spring and the steering function are combined into a whole, the spline shaft penetrating through the top of the oil cylinder drives the spline sleeve of the piston rod to rotate, and the steering of the wheels can be realized under the condition that the basic functions of the hydro-pneumatic spring are ensured, so that the operability of the vehicle is effectively improved; the running unit can control the rotation and steering of the wheels at any angle, so that the vehicle can realize the functions of in-situ rotation and steering at any angle, lateral translation, oblique translation, road steering and running at various speeds and the like around the center of the vehicle according to the requirements of various running conditions. Based on the running unit of the vehicle, the wheels of the vehicle are not mechanically connected with the steering tie rod or the transmission system, so that the vehicle has good trafficability and maneuverability.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the embodiments or the description of the prior art will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of a hydro-pneumatic spring according to an embodiment of the present invention;

fig. 2 is a block diagram of a traveling unit of a vehicle according to a second embodiment of the present invention;

fig. 3 is a block diagram of a traveling unit of a vehicle according to a third embodiment of the present invention

Fig. 4 and fig. 5 are schematic views of an up-and-down step of a vehicle according to an embodiment of the present invention;

FIG. 6 is a schematic diagram of a vehicle steering operation according to an embodiment of the present invention;

FIG. 7 is a schematic diagram of a vehicle according to an embodiment of the present invention traveling on a side slope;

FIG. 8 is a schematic view of a vehicle diagonal translation provided by an embodiment of the present invention;

FIG. 9 is a schematic illustration of lateral translation of a vehicle provided by an embodiment of the present invention;

FIG. 10 is a schematic diagram of a vehicle turning according to an embodiment of the present invention;

Fig. 11 is a schematic diagram of a vehicle turning around in situ according to an embodiment of the present invention.

Detailed Description

In order to make the technical problems, technical schemes and beneficial effects to be solved more clear, the invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.

It will be understood that when an element is referred to as being "mounted" or "disposed" on another element, it can be directly on the other element or be indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or be indirectly connected to the other element.

In the description of the present invention, it should be understood that the terms "center," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate orientations or positional relationships based on the orientation or positional relationships shown in the drawings, are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present invention, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

In the description of the present invention, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

Example 1

As shown in fig. 1 and 2, the embodiment of the invention provides a hydro-pneumatic spring, which comprises an oil cylinder, an elastic damping mechanism and an oil circuit mechanism, wherein the oil cylinder comprises a piston rod 3 and a multi-stage cylinder barrel which is nested step by step from outside to inside; in each two adjacent cylinders, the outer wall of the inner cylinder 2 is of a stepped shaft structure with a wide upper part and a narrow lower part, a large diameter section 201 of the inner cylinder 2 is embedded in the outer cylinder 1 in a sliding manner, an oil through hole communicated with the inner cavity of the outer cylinder 1 is formed in the top end of the inner cylinder, and a small diameter section 202 of the inner cylinder 2 is arranged at the bottom end of the outer cylinder 1 in a penetrating manner and forms an annular oil chamber 7 with the inner wall of the outer cylinder 1 in a surrounding manner; the piston rod 3 comprises a piston part 301 and a rod part 302 connected to the bottom end of the piston part 301, the piston part 301 is embedded in the innermost cylinder 2 in a sliding manner, and the rod part 302 penetrates through the bottom end of the innermost cylinder 2 and forms an annular oil chamber 8 with the inner wall of the innermost cylinder 2 in a surrounding manner; the upper part of the outermost cylinder 1 is provided with an elastic damping interface and is connected with the elastic damping mechanism, the upper part of the outermost cylinder 1 and each annular oil chamber are provided with an oil path interface, and each oil path interface is connected with the oil path mechanism.

Generally, each cylinder is a cylindrical cylinder, and the inner cavities of the cylinders are cylindrical inner cavities; in each two adjacent cylinders, the bottom end of the outer cylinder 1 is provided with a penetrating hole, the aperture of the penetrating hole is basically the same as the outer diameter of the small diameter section 202 of the inner cylinder 2, so that the small diameter section 202 of the inner cylinder 2 can be tightly and slidably arranged on the penetrating hole, and the large diameter section 201 of the inner cylinder 2 is embedded and slidably arranged in the inner cavity of the outer cylinder 1, thereby forming the piston of the outer cylinder 1. Similarly, the bottom end of the innermost cylinder is also provided with a through hole in which the rod portion 302 is tightly slid, and the piston portion 301 is fitted into the innermost cylinder 2 to form a piston of the innermost cylinder 2.

The hydro-pneumatic spring provided by the embodiment adopts a structure that the multistage cylinder barrel and the piston rod are nested step by step, and the position height of the center of each wheel, the size of the dynamic travel, the elastic coefficient and the like can be adjusted according to the requirements of various running conditions, so that the hydro-pneumatic spring meets the requirements of different running conditions and has the advantages of high trafficability, high maneuverability and the like.

Further, as shown in fig. 1 and 2, a low friction coefficient high wear-resistant lower pressure-bearing sleeve 10 is embedded on the wall of the hole penetrating through the bottom end of each cylinder barrel, and the lower pressure-bearing sleeve 10 is sleeved on the outer wall of the cylinder barrel of the corresponding penetrating small-diameter section 202 or the outer wall of the rod part 302; an upper pressure-bearing sleeve 9 with low friction coefficient and high wear resistance is embedded on the outer peripheral surface of the large-diameter section 201 of each cylinder barrel except the outermost cylinder barrel 1, and the upper pressure-bearing sleeve 9 is abutted against the inner wall of the corresponding sliding outer cylinder barrel 1; an upper pressure-bearing sleeve 9 with a low friction coefficient and high wear resistance is embedded on the outer peripheral surface of the piston part 301, and the upper pressure-bearing sleeve 9 is abutted against the inner wall of the corresponding sliding innermost cylinder barrel 2. When the wheels 34 are subjected to longitudinal force and lateral force transmitted from the ground, the upper pressure-bearing sleeves 9 and the lower pressure-bearing sleeves 10 are subjected to radial force, so that the service life and the working reliability of the equipment are ensured.

Further, as shown in fig. 1 and 2, oil seals are provided on the wall of the hole penetrating the bottom end of each cylinder, on the outer circumferential surface of the large diameter section 201 of each cylinder except the outermost cylinder 1, and on the outer circumferential surface of the piston portion 301, so as to prevent leakage of pressure oil, and each oil seal is preferably provided below a corresponding/adjacent pressure-receiving jacket, and more preferably is provided immediately adjacent to the pressure-receiving jacket. In addition, the bottom of each cylinder barrel is provided with a dustproof sleeve on the wall of the penetrating hole, so as to prevent muddy water dust outside the oil cylinder from entering the cylinder, and the dustproof sleeve is preferably arranged below the corresponding oil seal.

The oil circuit mechanism comprises an oil storage chamber 15, a high-pressure oil pump 17 and a high-pressure oil chamber 16, and specifically, each oil circuit interface is connected with an oil inlet pipeline and an oil discharge pipeline, the oil inlet pipeline and the oil discharge pipeline are arranged in parallel and are communicated with the oil storage chamber 15, the high-pressure oil pump 17 and the high-pressure oil chamber 16 are uniformly distributed on the oil inlet pipeline, the oil inlet pipeline is provided with an oil inlet control valve, the oil discharge pipeline is provided with an oil discharge control valve, and each oil inlet control valve and each oil discharge control valve are preferably electromagnetic valves. The high-pressure oil pump 17 is preferably disposed between the high-pressure oil chamber 16 and the oil reservoir chamber 15, and the oil feed control valve is preferably disposed between the high-pressure oil chamber 16 and the corresponding oil passage port. Further preferably, each oil path interface shares one high-pressure oil chamber 16, that is, the high-pressure oil chamber 16 is communicated with the oil storage chamber 15 through the high-pressure oil pump 17, and the outlet end of the high-pressure oil chamber 16 is communicated with each oil path interface through a plurality of branch oil pipes, and each branch oil pipe is correspondingly provided with one oil inlet control valve.

Continuing the structure of above-mentioned hydro-pneumatic spring, as in fig. 2, elastic damping mechanism includes high damping pipeline, low damping pipeline and elasticity gasbag structure, high damping pipeline with low damping pipeline is parallelly connected and all with elasticity damping interface reaches elasticity gasbag structure is connected, high damping pipeline with all be equipped with attenuator and first control valve on the low damping pipeline, just the damping value of attenuator on the high damping pipeline is higher than the damping value of attenuator on the low damping pipeline. The above-mentioned damper is a conventional technology in the art, and the specific structure thereof will not be described herein again, the damper on the high damping pipeline is the high damper 26, and the damper on the low damping pipeline is the low damper 24. Each of the first control valves is preferably a solenoid valve. Further, as shown in fig. 2, the elastic air bag structure includes a large air bag chamber 30 and a small air bag chamber 31 which are arranged in parallel, and two air bag chambers are respectively provided with a second control valve on a branch, and the two second control valves are preferably electromagnetic valves. The specific implementation effect of the elastic damping mechanism adopted in this embodiment will be further described in the following embodiments, which are omitted here.

In this embodiment, as shown in fig. 1 and 2, the cylinder barrel described in two stages is adopted, so that requirements of adjustment of a vehicle ground clearance, matching of a suspension moving stroke and the like can be satisfied.

Example two

As shown in fig. 2, the present embodiment provides a traveling unit of a vehicle, including wheels 34, a hydro-pneumatic spring, and a steering drive device;

the steering driving device comprises a spline shaft 4 and a steering driving mechanism; the spline shaft 4 is coaxially arranged on the oil cylinder of the hydro-pneumatic spring in a penetrating way, a shaft section positioned outside the oil cylinder is connected with the steering driving mechanism so as to rotate around the axis of the spline shaft, and a shaft section positioned inside the oil cylinder is in spline connection with the piston rod 3 of the oil cylinder;

the bottom end of the piston rod 3 is connected with a wheel axle seat 33, and a wheel axle 35 with the axial direction being the horizontal direction is arranged on the wheel axle seat 33;

the wheel 34 is provided with an in-wheel motor 36 and is mounted on the wheel axle 35, and the center of the wheel 34 is located on the extension of the central axis of the piston rod 3.

The hydro-pneumatic spring is preferably a hydro-pneumatic spring provided in the first embodiment, and the specific structure of the hydro-pneumatic spring is not described herein. Specifically, as shown in fig. 2, the spline shaft 4 is coaxially disposed with each cylinder, the top end of the spline shaft 4 is located above the outermost cylinder 1, the bottom end of the spline shaft extends into the inner cavity of the rod 302, the piston 301 is in spline connection with the spline shaft 4, that is, a spline shaft through hole is disposed on the piston 301 to allow the spline shaft 4 to pass through, the spline shaft 4 sequentially passes through the oil passing holes of each cylinder and the spline shaft through hole and extends into the inner cavity of the rod 302, a spline sleeve 5 is mounted on the piston 301 and is in spline connection with the spline shaft 4 through the spline sleeve 5, so that the spline shaft 4 can drive the piston 301 and the rod 302 to rotate, and meanwhile, the vertical sliding motion of the piston rod 3 and each cylinder is not affected, and the wheel 34 can be driven to rotate by connecting the wheel 34 at the bottom end of the rod 302, thereby realizing the steering of the wheel 34; the spline shaft 4 passes out of the top end of the outermost cylinder 1, and thus can be connected to a steering drive device to drive it to rotate about its own axis. In the embodiment, by arranging the spline shaft 4, the steering of the wheels 34 can be realized under the condition of ensuring the basic function of the hydro-pneumatic spring, so that the operability of the vehicle is effectively improved; in addition, the spline shaft 4 can guide the vertical sliding movement of the piston rod 3 and each cylinder barrel, so that the working stability of the wheels 34 is ensured. Further preferably, as shown in fig. 1 and fig. 2, the spline shaft 4 is sequentially sleeved with at least one spline housing 5 from inside to outside, the top and the bottom of each spline housing 5 are respectively provided with a limiting part 501, and the piston part 301 is in spline connection with the outermost spline housing 5, so that the requirement of large travel of the vehicle suspension can be met. The stopper 501 may be a circlip for a shaft engaged with the spline housing 5.

In this embodiment, as shown in fig. 1 and 2, the steering driving device preferably includes a driving motor 12, a steering worm wheel 14 and a steering worm 13, the steering worm wheel 14 is coaxially sleeved with the spline shaft 4, and the steering worm 13 is meshed with the steering worm wheel 14 and is connected with the driving motor 12. Since the driving motor 12 controls the steering of the wheels 34 through the steering worm 13 and the steering worm wheel 14, the steering interference of the wheels 34 can be counteracted because the worm has a certain self-locking effect on the worm wheel.

Further preferably, the spline shaft 4 is further connected with a steering angle sensor 11, and the steering angle sensor 11 can feed back the steering angle information of the wheel 34 to the vehicle control system, and under the coordination of the control system, the steering system can enable the wheel 34 to determine the steering angle of the wheel 34 according to the timely movement direction angle and the cornering characteristics of the tire, so that excellent operation stability is obtained, and the abrasion of the tire can be reduced to the greatest extent.

As shown in fig. 1 and 2, the driving motor 12 and the steering angle sensor 11 are preferably disposed at the top end of the outermost cylinder 1, and the structure is relatively simple.

Further, as shown in fig. 2, the axle seat 33 includes a vertical section 332 for connecting with the axle 35, and a horizontal section 331 connected to the top end of the vertical section 332 and extending toward the outer direction of the vehicle body, and the bottom end of the lever 302 is fixedly connected to the top end of the horizontal section 331. The vertical section 332 and the horizontal section 331 are preferably each of a disc-like configuration. In the above-described structure of the axle seat 33, it is easy to understand that the vertical section 332 is provided on the side of the wheel 34 closer to the chassis/farther from the outside of the vehicle body, or on both sides of the tire opposite to the rim, respectively.

The wheel center is on the extension line of the central axis of each cylinder of the hydro-pneumatic spring/the central axis of the piston rod 3, forces in all directions of the ground borne by the wheel 34 are transmitted to each cylinder of each level by the piston rod 3 and then transmitted to the vehicle body, so that the stability is good.

Further preferably, as shown in fig. 2, the rotor 362 of the in-wheel motor 36 is sleeved on the axle 35 and connected with the wheel 34, and the stator housing 361 abuts against the vertical segment 332. The wheel 34 is independently driven by the hub motor 36, so that the excellent control performance of the hydro-pneumatic spring and the steering structure provided with the hydro-pneumatic spring can be better matched, the wheel rotating speed requirement under various road conditions can be met in real time, the wheel 34 can roll on the ground without skid and abrasion, and the good stability of the operation is realized, so that the excellent coordination, stability and control performance of the vehicle are ensured. As will be readily appreciated, the in-wheel motor 36 is electrically connected to the vehicle control system.

Further preferably, as shown in fig. 2, a lateral force sensor 37 is provided on the vertical section 332, and the lateral force sensor 37 is located on an abutting surface of the vertical section 332 abutting against the stator housing 361; the lateral force sensor 37 is electrically connected to a vehicle control system, and the lateral force applied to the wheel 34 can be detected in real time by the lateral force sensor 37, so as to improve the operation stability of the wheel 34/the vehicle. For example: when the steering angle of the wheel 34 is not proper, the connecting line of the wheel center and the instantaneous movement center of the vehicle is not perpendicular to the actual movement direction line of the wheel 34, so that the wheel 34 and the ground generate lateral sliding and grinding, and the operation stability is affected; the additional lateral force generated by the wheel 34 is detected by the lateral force sensor 37 in the vertical section 332 of the axle seat 33 and fed back to the vehicle control system, which adjusts the steering angle of the wheel 34 so that the additional lateral force applied to the wheel 34 is eliminated; this closed loop control measure will further reduce tire wear and improve handling stability.

Further preferably, as shown in fig. 2, a vertical load sensor 32 is disposed at the bottom end of the lever 302, and the vertical load sensor 32 is electrically connected to a vehicle control system, and the vertical load applied to the wheels 34 can be detected in real time by the vertical load sensor 32, and one of the functions is to provide the vertical load information to the vehicle control system for resolving the tire slip angle, thereby more precisely improving the operation stability of the vehicle.

Example III

As shown in fig. 3, the present embodiment provides a traveling unit of a vehicle, including wheels 34, a hydro-pneumatic spring, and a steering drive device;

the steering driving device comprises a spline shaft 400 and a steering driving mechanism; the spline shaft 400 is coaxially arranged on the oil cylinder of the hydro-pneumatic spring in a penetrating way, a shaft section positioned outside the oil cylinder is connected with the steering driving mechanism so as to rotate around the axis of the spline shaft, and a shaft section positioned inside the oil cylinder is in spline connection with the piston rod 300 of the oil cylinder;

the bottom end of the piston rod 300 is connected with a wheel axle seat 33, and a wheel axle 35 with the axial direction being the horizontal direction is arranged on the wheel axle seat 33;

the wheel 34 is provided with an in-wheel motor 36 and is mounted on the wheel shaft 35, and the center of the wheel 34 is located on the extension line of the central axis of the piston rod 300.

Wherein, the hydro-pneumatic spring comprises an oil cylinder, a damping plate 400 and a floating piston 500; the oil cylinder comprises a cylinder barrel 100 and a hollow piston rod 300, wherein the top end of the piston rod 300 is slidably arranged in the cylinder barrel 100, the bottom end of the piston rod is positioned outside the cylinder barrel 100, and an inner cavity of the piston rod 300 is communicated with an oil cavity of the cylinder barrel 100 through an oil passing hole formed in the top end of the piston rod 300; the spline shaft 400 is arranged on the cylinder barrel 100 in a penetrating way and is in spline connection with the top end of the piston rod 300, the top end of the spline shaft 400 is connected with the steering driving device so as to rotate around the axis of the spline shaft 400, and the bottom end of the spline shaft 400 extends into the inner cavity of the piston rod 300; the damping plate 400 is embedded in the inner cavity of the piston rod 300 and fixedly connected with the bottom end of the spline shaft 400, and a damping oil passage is arranged on the damping plate 400; the floating piston 500 is slidably disposed in the inner cavity of the piston rod 300 below the damping plate 400, and divides the inner cavity of the piston rod 300 into an upper oil chamber and a lower air chamber.

In the above-mentioned hydro-pneumatic spring, the damping plate 400 can generate a damping effect on the pressure oil passing through, and at the same time, it can limit the descending travel of the piston rod 300, and can block the spline housing 310 of the piston rod when the piston rod 300 descends, so as to prevent the piston rod 300 from sliding out of the cylinder 100. Further preferably, as shown in fig. 3, the damping oil passing channel includes a compression damping hole 401 and an extension damping hole 402 which are formed on the damping plate 400, the compression damping hole 401 is configured with a first unidirectional control unit for controlling the oil passing direction thereof to be a top-down direction, and the extension damping hole 402 is configured with a second unidirectional control unit for controlling the oil passing direction thereof to be a bottom-up direction. The compression damping hole 401 dampens the pressure oil flowing from above the damping plate 400 to below the damping plate 400, and the extension damping hole 402 dampens the pressure oil flowing from below the damping plate 400 to above the damping plate, thereby ensuring that the piston rod 300 can play a good damping role in both the upward and downward directions relative to the cylinder 100. Compressed air is filled in the air chamber below the floating piston 500, and the air chamber is used as a medium for generating elastic performance of the hydro-pneumatic spring. Specifically:

when the wheel 34 encounters a road surface protrusion, the piston rod 300 moves upward relative to the cylinder 100, that is, upward relative to the spline shaft 400 and the damping plate 400, the distance between the damping plate 400 and the floating piston 500 decreases, the pressure oil between the two pushes the floating piston 500 to move downward, and the compressed air under the floating piston 500 is further compressed, thereby generating an elastic effect; because the floating piston 500 moves downwards, the pressure oil above the floating piston 500 flows downwards, the pressure oil above the piston rod spline housing 310 can flow downwards through the holes on the piston rod spline housing 310, and the pressure oil above the damping plate 400 can flow downwards through the compression damping holes 401 on the damping plate 400, so that compression damping force is generated in the process;

When the wheel 34 encounters a road pit, the piston rod 300 moves downward relative to the cylinder 100, that is, downward relative to the spline shaft 400 and the damping plate 400, the distance between the damping plate 400 and the floating piston 500 increases, and compressed air below the floating piston 500 expands to push the floating piston 500 to move upward, thereby generating an elastic effect; the pressure oil above the floating piston 500 flows upward, the pressure oil below the piston rod spline housing 310 flows upward through the holes on the piston rod spline housing 310, and the pressure oil below the damping plate 400 flows upward through the expansion damping holes 402 on the damping plate 400, thereby generating expansion damping force in the process.

The first unidirectional control unit and the second unidirectional control unit described above function as unidirectional valves, and it is easy to understand that they may use unidirectional valves having a certain opening pressure threshold, and in the preferred embodiment provided in this example, as shown in fig. 3, the first unidirectional control unit includes a first elastic cover plate 403 disposed on the lower surface of the damping plate 400, and the second unidirectional control unit includes a second elastic cover plate 404 disposed on the upper surface of the damping plate 400, where the first elastic cover plate 403 and the second elastic cover plate 404 are both attached parallel to the plate surface of the damping plate 400 and cover the corresponding damping holes respectively. A certain opening pressure threshold value can be provided through the elastic action of the elastic cover plate, and meanwhile, the function of controlling the unidirectional passage of pressure oil can be achieved; when the pressure of the pressure oil on the corresponding side is greater than the opening pressure threshold, the pressure oil can push the elastic cover plate open. Further preferably, the aperture of the compression damping hole 401 is larger than the aperture of the extension damping hole 402, that is, the extension damping force is controlled to be larger than the compression damping force, so as to ensure the stability of the vehicle under various road conditions. As shown in fig. 3, two elastic cover plates may be fastened to the damping plate 400 by bolts.

In connection with the steering structure of the wheels 34, as shown in fig. 3, the steering driving device includes a driving motor 12, a steering worm wheel 14 and a steering worm 13, the steering worm wheel 14 is coaxially sleeved with the spline shaft 400, and the steering worm 13 is meshed with the steering worm wheel 14 and is connected with the driving motor 12. Since the driving motor 12 controls the steering of the wheels 34 through the steering worm 13 and the steering worm wheel 14, the steering interference of the wheels 34 can be counteracted because the worm has a certain self-locking effect on the worm wheel.

Further, as shown in fig. 3, the spline shaft 400 is further connected with a steering angle sensor 11. The steering angle sensor 11 can feed back the steering angle information of the wheel 34 to the vehicle control system, and under the coordination of the control system, the steering system can enable the wheel 34 to determine the steering angle of the wheel 34 according to the timely movement direction angle and the cornering characteristic of the tire, so that excellent operation stability is obtained, and the abrasion of the tire can be reduced to the greatest extent. As shown in fig. 3, the driving motor 12 and the steering angle sensor 11 are preferably provided at the top end of the cylinder tube 100, and the structure is relatively simple.

Further, as shown in fig. 3, a piston rod bearing sleeve 901 with a low friction coefficient and high wear resistance is embedded on the outer side wall of the top of the piston rod 300, the piston rod bearing sleeve 901 correspondingly abuts against the inner annular wall of the cylinder 100, a cylinder barrel bearing sleeve 902 with a low friction coefficient and high wear resistance is embedded on the inner annular wall surface of the bottom of the cylinder barrel 100, the cylinder barrel bearing sleeve 902 correspondingly abuts against the outer side wall of the piston rod 300, and when the wheels 34 receive longitudinal force and lateral force transmitted from the ground, the piston rod bearing sleeve 901 and the cylinder barrel bearing sleeve 902 bear radial force, so that the service life and the working reliability of equipment are ensured. An oil seal is further provided on the inner circumferential wall of the bottom of the cylinder 100 to prevent leakage of the pressure oil, and the oil seal is preferably located below the cylinder pressure-bearing sleeve 902, and more preferably is adjacent to the cylinder pressure-bearing sleeve 902; in addition, a dust cover is further disposed on the inner wall surface of the bottom of the cylinder barrel 100, so as to prevent muddy water dust outside the cylinder from entering the cylinder, and the dust cover is preferably disposed below the corresponding oil seal.

Further, an oil seal is embedded on the outer sidewall of the floating piston 500 to separate the pressure oil from the compressed air, so as to prevent the pressure oil from leaking into the air chamber. As will be readily understood, the bottom end of the piston rod 300 is closed to prevent leakage of compressed air, and may be an integrally formed structure, or may be a structure in which the lower piston rod seat 311 is detachably and fixedly connected to the piston rod 300, and the lower piston rod seat 311 is used to seal the cavity of the piston rod 300, that is, seal the air chamber, and the lower piston rod seat 311 is fixedly connected to the piston rod 300 by bolts, and an air seal ring may be disposed on the contact surface of the lower piston rod seat 311 and the piston rod 300 to enhance the air tightness of the connection therebetween.

Preferably, an air charging valve is provided at the bottom of the piston rod 300 to charge the air chamber with compressed air to a rated pressure; for the above structure using the lower piston rod seat 311, the inflation valve is disposed on the lower piston rod seat 311. An oil injection valve is provided in the floating piston 500 to fill the upper oil chamber with pressurized oil.

The specific structure and the mutual assembly connection structure of the wheel 34, the axle seat 33, the in-wheel motor 36, etc. are referred to in the second embodiment, and will not be described in detail herein.

Example IV

The present embodiment provides a vehicle including a vehicle body, and a plurality of sets of the traveling units of the vehicle as provided in the second or third embodiment. It will be appreciated by those skilled in the art that the number of such travel units is sufficient to accommodate the need for the vehicle to travel, and typically is not less than 4, preferably 8 or more, such travel units, i.e., includes 8 or more wheels 34.

In one embodiment, the vehicle comprises 8 wheels 34, the running system of the vehicle is four axles 8×8, and the center of gravity of the whole vehicle is between 2 axles and 3 axles; the rotational speeds, torques, etc. of the 8 wheels 34 are determined by the vehicle control system according to the running mode, running speed, steering mode, etc.

The power source of the vehicle can be a diesel engine, the diesel engine drives a generator to generate electricity for charging a storage battery, and the storage battery supplies power for all motors, electric appliances and the like of the whole vehicle. Of course, energy sources such as gasoline are suitable for use in the present embodiment.

In the 8-group traveling units, the 8-group steering drive mechanisms control the steering angles of the 8 wheels 34, respectively. The driver manipulates the steering command device through the steering wheel; the steering wheel is provided with a return spring, and when the driver releases the steering wheel after steering the steering wheel, the steering wheel automatically returns to the straight-going position. The steering command device sends out a command to directly control the action of the steering driving mechanism of the left front wheel of the vehicle, so that the steering angle of the left front wheel of the vehicle is directly controlled, and the steering angle of the left front wheel always keeps consistent with the steering angle of the steering command device. The steering angles of the other 7 wheels are determined by the vehicle control system in coordination according to the value of the steering angle of the left front wheel. Three steering mode selection buttons are arranged on the steering wheel, namely 'normal', 'in-situ rotation', 'translation' are respectively selected by a driver. The vehicle control system coordinates and determines the steering angles of the other 7 wheels according to the buttons selected by the driver and the values of the steering angles of the left front wheel, so that the conventional road steering running, the in-situ rotation steering around the center of the vehicle at any angle, the lateral translation or the oblique translation are respectively realized. The vehicle control system calculates and determines the rotational speed of each wheel and the steering angle of each wheel according to the steering mode selection button information selected by the driver, the steering wheel 9 rotational angle information, the accelerator pedal position information, the vehicle speed information, the feedback information of the rotational speed of each wheel, the feedback information of the steering angle of each wheel, the vertical load information of each wheel and the lateral force information of each wheel. The information transmission is completed by a vehicle CAN bus.

Based on the traveling unit of the vehicle provided in the second embodiment, the suspension system may be controlled, and the operation command for the suspension system is displayed on the screen of the touch instrument, and the driver clicks the menu selection.

Example five

The following describes a driving method of the vehicle according to the above embodiment, using an eight-wheel vehicle as an example, and the traveling unit of the vehicle according to the second embodiment is disposed.

Taking a vehicle comprising 8 wheels 34, each wheel 34 configured with a two-stage cylinder as shown in fig. 1 as an example:

defining an annular oil chamber between the outer cylinder 1 and the inner cylinder 2 as a first annular oil chamber 7, and defining an annular oil chamber between the inner cylinder 2 and the piston rod 3 as a second annular oil chamber 8; the oil way interface arranged at the upper part of the outer cylinder barrel 1 is defined as a first oil way interface, the oil way interface arranged on the first annular oil chamber 7 is defined as a second oil way interface, and the oil way interface arranged on the second annular oil chamber 8 is defined as a third oil way interface.

Defining an electromagnetic valve on an oil inlet pipeline connected with the upper part of the outer cylinder barrel 1 as a first electromagnetic valve 18, and an electromagnetic valve on an oil discharge pipeline connected with the outer cylinder barrel as a second electromagnetic valve 19; the electromagnetic valves on the oil inlet pipeline and the oil outlet pipeline connected with the first annular oil chamber 7 are a third electromagnetic valve 20 and a fourth electromagnetic valve 21 respectively; the electromagnetic valves on the oil inlet pipeline and the oil outlet pipeline connected with the second annular oil chamber 8 are a fifth electromagnetic valve 22 and a sixth electromagnetic valve 23 respectively; defining the electromagnetic valve on the low damping pipeline as a seventh electromagnetic valve 25, and defining the electromagnetic valve on the high damping pipeline as an eighth electromagnetic valve 27; the solenoid valve defining the elastic bladder branch where the small bladder chamber 31 is located is the ninth solenoid valve 28, and the solenoid valve defining the elastic bladder branch where the large bladder chamber 30 is located is the tenth solenoid valve 29.

When the vehicle is going on a good road, it is desirable that the ground clearance of the vehicle is reduced, the center of gravity is lowered, the suspension system is in a less stiff and less damped elastic state to obtain good smoothness, and the dynamic range required by the suspension system is also smaller. The driver need only select the "good road" mode on the screen of the touch meter.

Under the coordination of the vehicle control system, the seventh solenoid valve 25, the ninth solenoid valve 28, the tenth solenoid valve 29, the second solenoid valve 19, and the third solenoid valve 20 are opened, and the eighth solenoid valve 27, the first solenoid valve 18, and the fourth solenoid valve 21 are closed. Each hydro-pneumatic spring closes the high damper 26 through the eighth electromagnetic valve 27, and opens the low damper 24 through the seventh electromagnetic valve 25, so that each hydro-pneumatic spring is in a low damping working condition. The oil in the space above the large diameter section 201 of the inner cylinder 2 in the outer cylinder 1 and the space above the piston rod 3 in the inner cylinder 2 can be communicated with the large air bag chamber 30 through the seventh electromagnetic valve 25, the low damper 24 and the tenth electromagnetic valve 29, and can be communicated with the small air bag chamber 31 through the seventh electromagnetic valve 25, the low damper 24 and the ninth electromagnetic valve 28, so that all the hydro-pneumatic springs are in an elastic state with smaller rigidity and smaller damping.

The first oil way interface of the oil-gas spring is closed through the first electromagnetic valve 18 and connected with the high-pressure oil chamber 16, and the first oil way interface of the oil-gas spring is opened through the second electromagnetic valve 19 and connected with the oil storage chamber 15, so that the oil pressure of pressure oil in the space above the large-diameter section 201 of the inner-layer cylinder 2 in the outer-layer cylinder 1 and the space above the piston rod 3 in the inner-layer cylinder 2 is reduced, and the oil can be extruded to the oil storage chamber 15.

Meanwhile, the connection between the second oil way interface of the hydro-pneumatic spring and the oil storage chamber 15 is closed through the fourth electromagnetic valve 21, the connection between the second oil way interface of the hydro-pneumatic spring and the high-pressure oil chamber 16 is opened through the third electromagnetic valve 20, and at the moment, high-pressure oil of the high-pressure oil chamber 16 flows into the first annular oil chamber 7 through the second oil way interface. When the piston rod 3 moves upwards, the piston rod spline housing 6 fixed at the head of the piston rod 3 slides on an external spline of the spline housing 5, and when the top of the spline housing 5 slides to touch a retainer ring on the spline housing 5, the spline housing 5 is driven to slide upwards on the spline shaft 4, so that the spline housing 5 is prevented from being collided with the bottom of the piston rod 3. In the full stroke movement of the wheels 34 relative to the vehicle body up and down, the bottoms of the piston rods 3 cannot collide with the spline shaft 4 and the spline sleeve 5. And the 8 steering motors can reliably drive the steering worm 13, the steering worm wheel 14, the spline shaft 4, the spline sleeve 5, the piston rod spline sleeve 6, the piston rod 3 and the wheel shaft seat 33 to rotate under the coordination of a control system, so as to drive the 8 wheels 34 to steer. When the wheels 34 move upward relative to the vehicle body, the ground clearance decreases and the center of gravity decreases. The upward distance of the wheels 34 relative to the vehicle body depends on the upward distance of the inner cylinder tube 2, and can be determined according to the requirement, but the adjusted distance is the reduction of the dynamic travel of the suspension system. The inner cylinder 2 can be adjusted to move up to the top of the outer cylinder 1 all the time, if the adjusted distance is not enough, the upward stroke of the piston rod 3 can be used for adjustment by a similar method; namely, the third oil way interface of the hydro-pneumatic spring is closed through the sixth electromagnetic valve 23 and connected with the oil storage chamber 15, the third oil way interface of the hydro-pneumatic spring is opened through the fifth electromagnetic valve 22 and connected with the high-pressure oil chamber 16, high-pressure oil in the high-pressure oil chamber 16 flows into the second annular oil chamber 8 chamber through the third oil way interface, the high-pressure oil generates thrust to the upper surface of the second annular oil chamber 8 to push the piston rod 3 to move upwards, and the piston rod 3 drives the axle seat 33 and the whole wheel 34 to move upwards; of course, the travel distance required for driving must be kept. Generally, when traveling on a good road, the required dynamic travel is small, and it is desired that the ground clearance is reduced and the center of gravity is lowered. As to whether to drive on a good road, it is generally determined by a debugger how high the vehicle body is and how large the ground clearance is. The control system has a memory function, and a driver only needs to select a good road mode on a screen of the touch instrument; if the driver is not satisfied with the adjustment, the vehicle body can be lifted by clicking the lifting button in the good road mode; and then the 'down' button is pressed down to lower the car body. The control system has a memory function, and the next time the driver selects the 'good road' mode, the vehicle body height is adjusted according to the last determination.

After the adjustment of the wheel center position is completed, the first electromagnetic valve 18 still closes the connection between the first oil way interface of each wheel hydro-pneumatic spring and the high-pressure oil chamber 16, and then the second electromagnetic valve 19 also closes the connection between the first oil way interface of each wheel hydro-pneumatic spring and the oil storage chamber 15, that is, the first oil way interface is completely closed, so that the total oil quantity in the upper space of each wheel outer cylinder 1 is kept unchanged, and can only flow through the elastic damping interface, the seventh electromagnetic valve 25, the low damper 24, the ninth electromagnetic valve 28 and the small air bag chamber 31, and can also flow through the elastic damping interface, the seventh electromagnetic valve 25, the low damper 24, the tenth electromagnetic valve 29 and the large air bag chamber 30, and then the balance position of the center of each wheel is fixed. The oil pressure in the space above the piston rod 3 compresses the volume of nitrogen in the large air bag chamber 30 and the small air bag chamber 31, and the volume of the large air bag and the small air bag is inversely proportional to the oil pressure when the temperature is unchanged. After the adjustment of the wheel center position is completed, the second oil way interface of the hydro-pneumatic spring is closed through the third electromagnetic valve 20 and connected with the high-pressure oil chamber 16, and the second oil way interface of the hydro-pneumatic spring is closed through the fourth electromagnetic valve 21 and connected with the oil storage chamber 15, so that the second oil way interface of the hydro-pneumatic spring is completely closed, at the moment, the positions of the inner cylinder barrel 2 in the outer cylinder barrel 1 are completely and relatively fixed, and the outer cylinder barrel 1 only plays a role in adjusting and adjusting the positions of the centers of all wheels without a moving stroke role. The connection between the third oil passage interface and the high-pressure oil chamber 16 is closed by the fifth electromagnetic valve 22, and the connection between the third oil passage interface of the hydro-pneumatic spring and the oil storage chamber 15 is opened by the sixth electromagnetic valve 23; when the wheels 34 are raised due to the protrusion of the road surface, the piston rod 3 is driven to push the pressure oil to flow into the small air bag chamber 31 through the elastic damping interface, the seventh electromagnetic valve 25, the low damper 24 and the ninth electromagnetic valve 28, and flow into the large air bag chamber 30 through the elastic damping interface, the seventh electromagnetic valve 25, the low damper 24 and the tenth electromagnetic valve 29, and at the moment, the oil pressure is raised, and the nitrogen volume in the large air bag and the small air bag is compressed. When the wheels 34 meet the pits on the road surface and extend downwards, the piston rod 3 is driven to draw pressure oil downwards to flow out of the small air bag chamber 31 through the elastic damping interface, the seventh electromagnetic valve 25, the low damper 24 and the ninth electromagnetic valve 28, and flow out of the large air bag chamber 30 through the elastic damping interface, the seventh electromagnetic valve 25, the low damper 24 and the tenth electromagnetic valve 29; at this time, the oil pressure was reduced, and the volume of nitrogen in the large and small air bags was expanded. In this process the ground reaction forces experienced by the wheels are balanced by the product of the space oil pressure above the piston rod 3 and the area of the head of the piston rod 3.

When the vehicle is to travel on an off-road, it is desirable that the vehicle ground clearance increases and the center of gravity increases, and the suspension system is in an elastic state with high rigidity and high damping, and the required dynamic range of the suspension system is also large. The driver only has to select the "off-road" mode on the screen of the touch meter at this time.

At this time, under the coordination of the control system, the eighth solenoid valve 27, the tenth solenoid valve 29, the first solenoid valve 18, and the fourth solenoid valve 21 are opened, and the seventh solenoid valve 25, the ninth solenoid valve 28, the second solenoid valve 19, and the third solenoid valve 20 are closed. Each hydro-pneumatic spring is in a high damping working condition by opening the high damper 26 through the eighth electromagnetic valve 27 and closing the low damper 24 through the seventh electromagnetic valve 25. Oil in the outer cylinder 1, which is located in the space above the large diameter section 201 of the inner cylinder 2, and in the space above the piston rod 3 in the inner cylinder 2, can flow into the large air bag chamber 30 through the elastic damping interface, the eighth electromagnetic valve 27, the high damper 26 and the tenth electromagnetic valve 29, so that each hydro-pneumatic spring is in an elastic state. The ninth electromagnetic valve 28 is not opened, and the nitrogen in the small bag chamber 31 does not participate in the elastic action, so that the rigidity of the suspension system is increased somewhat, as compared with the above-described case when traveling on a good road; if the rigidity is not enough, the rigidity can be selected on the screen of the touch instrument, the ninth electromagnetic valve 28 is opened, the tenth electromagnetic valve 29 is closed, the large air bag chamber 30 taking part in the elastic action is changed into the small air bag chamber 31, the rigidity of the suspension system is increased, the ground grabbing force of the wheels 34 is increased, and the operability is improved.

The first oil way interface of the oil-gas spring is opened through the first electromagnetic valve 18 and connected with the high-pressure oil chamber 16, and then the first oil way interface of the oil-gas spring is closed through the second electromagnetic valve 19 and connected with the oil storage chamber 15, so that oil in the high-pressure oil chamber 16 flows into the upper space of the outer cylinder barrel 1 to push the inner cylinder barrel 2 and the piston rod 3 to move downwards. The high-pressure oil pump 17 is linked with the first electromagnetic valve 18, and the high-pressure oil pump 17 pumps oil from the oil storage chamber 15 into the high-pressure oil chamber 16 for replenishment at any time. The oil pressure of the pressure oil in the space above the large diameter section 201 of each wheel inner cylinder 2 and the space above the piston 301 is P, and the sum of the areas of the upper end surface of the large diameter section 201 of each wheel inner cylinder 2 and the upper end surface of the piston 301 is S, and the product of P and S is balanced with the ground reaction force applied to the corresponding wheel 34. The second oil way interface of the hydro-pneumatic spring is opened through the fourth electromagnetic valve 21 and connected with the oil storage chamber 15, the second oil way interface of the hydro-pneumatic spring is closed through the third electromagnetic valve 20 and connected with the high-pressure oil chamber 16, at the moment, oil in the first annular oil chamber 7 is extruded and flows into the oil storage chamber 15 through the fourth electromagnetic valve 21 and the second oil way interface of the hydro-pneumatic spring, the piston rod 3, the wheel axle seat 33 and the whole wheel 34 are driven to move downwards along with the downward movement of the inner-layer cylinder barrel 2 and the piston rod 3, the wheel 34 moves downwards relative to the vehicle body, the ground clearance is increased, and the gravity center is raised; the distance of the wheels 34 going down relative to the vehicle body depends on the distance of the inner cylinder 2 going down, and the distance it adjusts is the increase of the upward stroke of the inner cylinder 2. The inner cylinder 2 can directly descend to the middle part of the outer cylinder 1, and the upward movement stroke and the downward movement stroke of the inner cylinder 2 are equal. The fourth electromagnetic valve 21 is temporarily closed, then the third oil way interface of the hydro-pneumatic spring is opened through the sixth electromagnetic valve 23 to be connected with the oil storage chamber 15, the third oil way interface of the hydro-pneumatic spring is closed through the fifth electromagnetic valve 22 to be connected with the high-pressure oil chamber 16, oil in the second annular oil chamber 8 chamber is extruded to flow into the oil storage chamber 15 when the piston rod 3 moves downwards, and the wheel center position is adjusted after the piston rod 3 moves downwards and the ground clearance is raised to a desired state. After that, the fourth electromagnetic valve 21 is opened, the sixth electromagnetic valve 23 is closed, the first electromagnetic valve 18, the second electromagnetic valve 19, the third electromagnetic valve 20 and the fifth electromagnetic valve 22 are still closed, at this time, the first oil passage port and the third oil passage port of each wheel oil and gas spring are completely closed, and the second oil passage port of the oil and gas spring is connected with the oil storage chamber 15, so that the second annular oil chamber 8 is closed, the positions between the inner cylinder 2 and the piston rod 3 are relatively fixed into a whole, and the inner cylinder 2 and the outer cylinder 1 can relatively move. When the wheel 34 encounters uneven road surface and jolts, the inner cylinder 2 and the outer cylinder 1 move relatively, and the pressure oil in the upper spaces of the inner cylinder 2 and the piston rod 3 can flow mutually through the elastic damping interface, the eighth electromagnetic valve 27, the high damper 26, the tenth electromagnetic valve 29 and the oil in the large air bag chamber 30. Since the sum of the area of the upper end surface of the large diameter section 201 of the inner cylinder tube 2 and the area of the upper end surface of the piston portion 301 is larger than the area of the upper end surface of the piston portion 301, only one of them also makes the rigidity of the suspension system larger when the vehicle is traveling on an off-road than when the vehicle is traveling on a good road. If the rigidity is not enough, the rigidity can be selected on the screen of the touch instrument, the ninth electromagnetic valve 28 is opened, the tenth electromagnetic valve 29 is closed, the large air bag chamber 30 participating in the elastic action is changed into the small air bag chamber 31, and the rigidity of the suspension system is increased. As described above, the invention can realize that when the vehicle runs on the off-road, the ground clearance of the vehicle is increased, the gravity center is raised, the suspension system is in an elastic state with larger rigidity and larger damping, and the dynamic travel required by the suspension system is also in a state with larger dynamic travel.

Also, it is generally determined by a debugger to determine how high the vehicle body is and how large the ground clearance is when the vehicle is traveling on an off-road. The control system has a memory function, and a driver only needs to select an off-road mode on a screen of the touch instrument; if the driver is not satisfied with the adjustment, the vehicle body can be lifted by pressing the lifting button again in the cross-country mode; the vehicle body can be lowered by pressing the down button. The control system has a memory function, and the next time the driver selects the cross-country mode on the screen of the touch instrument, the vehicle body height is adjusted according to the last determination.

As shown in fig. 4, when the vehicle encounters a step that is higher than the radius of the wheel 34, the driver first presses the "up" button if the step is high. The first electromagnetic valve 18 is used for opening the connection between the first oil way interface and the high-pressure oil chamber 16, the second electromagnetic valve 19 is used for closing the connection between the first oil way interface and the oil storage chamber 15, so that the oil in the high-pressure oil chamber 16 flows into the upper space of the outer cylinder 1, and the inner cylinder 2 and the piston rod 3 are pushed to move downwards. The high-pressure oil pump 17 is linked with the first electromagnetic valve 18, and the high-pressure oil pump 17 pumps oil from the oil storage chamber 15 into the high-pressure oil chamber 16 for supplementing at any time; the oil pressure of the upper space of the inner cylinder 2 and the piston rod 3 is P, the sum of the head areas of the inner cylinder 2 and the piston rod 3 is S, and the product of P and S is balanced with the ground reaction force born by the corresponding wheel 34. Simultaneously, the connection between the second oil way interface and the oil storage chamber 15 is opened through the fourth electromagnetic valve 21, the connection between the second oil way interface and the high-pressure oil chamber 16 is closed through the third electromagnetic valve 20, and at the moment, the oil in the first annular oil chamber 7 is extruded and flows into the oil storage chamber 15 through the fourth electromagnetic valve 21 and the second oil way interface; the connection of the third oil passage connection to the high-pressure oil chamber 16 is closed by the fifth solenoid valve 22, and the oil of the second annular oil chamber 8 is pushed out into the oil reservoir chamber when the piston rod 3 moves downward. As the inner cylinder 2 and the piston rod 3 move downward to drive the piston rod 3, the wheel axle seat 33 and the whole wheel 34 to move downward, the ground clearance is increased, and the vehicle body is lifted. The wheel 34 is set to a distance which depends on the sum of the distances of the inner cylinder 2 and the piston rod 3; the inner cylinder 2 can be directly downwards moved to the bottom of the outer cylinder 1, and the piston rod 3 can be directly moved to the bottom of the inner cylinder 2. After the body is raised to the desired height, the driver releases the "lift" button and the body lift adjustment is completed, creating more room for the wheels 34 of each axle to lift off the ground. The driver then selects a step-on-bridge mode in turn to step each bridge wheel 34 in turn. At this time, the vehicle control system firstly closes the elastic damping interface of the bridge hydro-pneumatic spring through the seventh electromagnetic valve 25 and the eighth electromagnetic valve 27 of the bridge hydro-pneumatic spring, so that the bridge hydro-pneumatic spring loses elasticity; then the connection between the bridge first oil way interface and the high-pressure oil chamber 16 is closed through the first electromagnetic valve 18; then the connection between the first oil way interface of the bridge and the oil storage chamber 15 is opened through the second electromagnetic valve 19, so that the oil pressure reducing oil in the upper spaces of the inner cylinder barrel 2 and the piston rod 3 in the oil cylinder is extruded to flow to the oil storage chamber 15; simultaneously, the connection between the bridge second oil path interface and the oil storage chamber 15 is closed through the fourth electromagnetic valve 21; opening the connection of the bridge second oil passage interface with the high-pressure oil chamber 16 by the third solenoid valve 20; at the same time, the connection of the bridge third oil passage connection to the oil reservoir chamber 15 is closed by the sixth solenoid valve 23, and the connection of the bridge third oil passage connection to the high-pressure oil chamber 16 is opened by the fifth solenoid valve 22. In this way, the high-pressure oil in the bridge high-pressure oil chamber 16 flows into the first annular oil chamber 7 through the second oil passage port, flows into the second annular oil chamber 8 through the third oil passage port, and the high-pressure oil pump 17 is linked with the fifth solenoid valve 22 and the third solenoid valve 20, so that the high-pressure oil pump 17 pumps the oil from the oil reservoir chamber 15 into the high-pressure oil chamber 16 to be replenished at any time. The high pressure oil generates pushing force to the upper surfaces of the two annular oil chambers to push the inner cylinder 2 and the piston rod 3 to move upwards, and the piston rod 3 drives the wheel shaft seat 33 and the wheels 34 to move upwards to leave the ground. The product of the oil pressure in the second annular oil chamber 8 and the area on the annular oil chamber is now balanced with the sum of the weights of the axle seat 33 and the wheel 34. Because the gravity center of the whole vehicle is between the 2 and 3 bridges, the wheels 34 of any one bridge ascend to leave the ground, and the load borne by the bridge can be transferred to other bridges to bear without losing balance of the whole vehicle. When a certain bridge climbs a step, the vehicle control system firstly opens an elastic damping interface of the hydro-pneumatic spring through a seventh electromagnetic valve 25 of the hydro-pneumatic spring of the bridge so as to enable the hydro-pneumatic spring to recover elasticity; the connection between the bridge first oil passage interface and the high-pressure oil chamber 16 is opened through a first electromagnetic valve 18, and the connection between the wheel first oil passage interface and the oil storage chamber 15 is closed through a second electromagnetic valve 19; the connection of the wheel second oil passage port to the oil reservoir chamber 15 is opened by the fourth solenoid valve 21. Closing the connection of the wheel second oil passage interface with the high-pressure oil chamber 16 by a third electromagnetic valve 20; the third oil way interface of the wheel is opened through the sixth electromagnetic valve 23 and connected with the oil storage chamber 15, the third oil way interface of the wheel is closed through the fifth electromagnetic valve 22 and connected with the high-pressure oil chamber 16, so that high-pressure oil of the high-pressure oil chamber 16 flows into the upper space of the outer cylinder 1 through the first oil way interface to press the inner cylinder 2 and the piston rod 3 to move downwards, oil in the first annular oil chamber 7 and the second annular oil chamber 8 respectively flows into the oil storage chamber 15 from the second oil way interface and the third oil way interface, and the piston rod 3 moves downwards to drive the wheel shaft seat 33 and the wheel 34 to move downwards to the step ground and bear the counter force of the bridge. The reaction force will be balanced with the product of the oil pressure in the upper space of the piston rod 3 and the surface area on the piston rod 3. The process of the vehicle having the bridge wheels 34 stepped over the radius of the wheels 34 is completed so far, and the process of the vehicle having the other bridge wheels 34 stepped over the radius of the wheels 34 is the same. After all wheels 34 climb over the steps, the driver cancels the step mode on a certain bridge, selects the cross-country mode or the good road mode, and adjusts the position of the center of each wheel, the size of the dynamic travel, the elastic coefficient and the damping coefficient according to the requirements of the driving working conditions under the coordination of a control system.

Because the running system of the vehicle provided by the invention is four-axle 8 multiplied by 8, the center of gravity of the whole vehicle is between 2 and 3 axles, and therefore, the width of the deep trench spanned by the vehicle depends on the wheel base of 1 and 2 axles and the wheel base of 3 and 4 axles plus one tire diameter. The width of the moat that the vehicle can span is not limited if the moat depth is less than the total travel of the suspension system. The problem becomes to descend the step first and then climb the step. When a certain axle is driven to the edge of a trench, the driver presses the down button first, and the vehicle control system first enables the whole vehicle body to descend to the lowest level, as shown in fig. 5. That is, the first electromagnetic valve 18 closes the connection between the first oil passage port and the high-pressure oil chamber 16, and the second electromagnetic valve 19 opens the connection between the first oil passage port and the oil reservoir chamber 15, so that the oil pressure in the upper space of the outer cylinder 1 is reduced, and the oil can be pushed toward the oil reservoir chamber 15. Simultaneously, the connection between the second oil way interface and the oil storage chamber 15 is closed through the fourth electromagnetic valve 21, and the connection between the second oil way interface and the high-pressure oil chamber 16 is opened through the third electromagnetic valve 20; and then the connection between the third oil passage interface and the oil storage chamber 15 is closed through the sixth electromagnetic valve 23, the connection between the third oil passage interface and the high-pressure oil chamber 16 is opened through the fifth electromagnetic valve 22, and at this time, the high-pressure oil in the high-pressure oil chamber 16 flows into the first annular oil chamber 7 through the second oil passage interface and flows into the second annular oil chamber 8 through the third oil passage interface. The high pressure oil generates pushing force on the upper surfaces of the two annular oil chambers to push the inner cylinder barrel 2 and the piston rod 3 to move upwards. The inner cylinder 2 moves up to the top of the outer cylinder 1, the piston rod 3 moves up to the upper spigot surface of the inner hole of the inner cylinder 2, and the piston rod 3 drives the wheel axle seat 33 and the whole wheel 34 to move up to the highest position relative to the vehicle body. At this time, the vehicle body is lowest, the ground clearance is smallest, and the center of gravity is lowest. The driver selects the "front axle downstairs" mode and the vehicle is propelled forward until the front axle wheels 34 are driven into the trench, suspended and the vehicle weight is carried by the other wheels 34. At this time, the vehicle control system opens the connection between the front axle first oil path interface and the high-pressure oil chamber 16 through the first electromagnetic valve 18, and closes the connection between the wheel first oil path interface and the oil storage chamber 15 through the second electromagnetic valve 19; the connection between the wheel second oil passage interface and the oil storage chamber 15 is opened through a fourth electromagnetic valve 21, and the connection between the wheel second oil passage interface and the high-pressure oil chamber 16 is closed through a third electromagnetic valve 20; the connection between the third oil way interface of the wheel and the oil storage chamber 15 is opened through a sixth electromagnetic valve 23, and the connection between the third oil way interface of the wheel and the high-pressure oil chamber 16 is closed through a fifth electromagnetic valve 22; the high pressure oil in the high pressure oil chamber 16 flows into the upper space of the outer cylinder 1 through the first oil passage interface to press the inner cylinder 2 and the piston rod 3 to move downward, so that the oil in the first annular oil chamber 7 and the second annular oil chamber 8 is squeezed to flow into the oil storage chamber 15 from the second oil passage interface and the third oil passage interface, respectively. The piston rod 3 descends to drive the wheel shaft seat 33 and the front axle wheel 34 to descend to the ground at the bottom of the trench and bear the counterforce of the ground facing the wheel; the reaction force will be balanced with the product of the oil pressure in the upper space of the piston rod 3 and the surface area on the piston rod 3. The process of lowering the front axle wheels 34 of the vehicle down the trench and continuing to advance at the bottom of the trench is completed, the 2-axle is driven to the edge of the trench again, the driver selects the 2-axle lower step mode again, and the process is repeated under the coordination of the vehicle control system to enable the 2-axle wheels 34 to lower to the bottom of the trench and continue to advance at the bottom of the trench. The same applies to the other 3, 4-axle wheels 34 under the moat. After all wheels 34 have been lowered into the trench, the operator removes a certain underbridge step pattern and the vehicle continues to travel, and the problem becomes to climb the steps when the wheels 34 at the bottom of the trench reach the trench edge and hit the trench wall, as described in detail above.

Example six

The following describes a driving method of the vehicle provided in the above embodiment, taking an eight-wheel vehicle as an example, and the traveling unit of the vehicle provided in the above second embodiment may be disposed, or the traveling unit of the vehicle provided in the above third embodiment may be disposed; the case is similar for electric vehicles driven by the in-wheel motor 36 for four or more wheels.

As shown in fig. 6, when the vehicle is traveling in a steering direction, the outer wheel load increases and the inner wheel load decreases due to the centrifugal force, so that the conventional vehicle body is tilted outward by one roll angle, and the stability is also affected by the uncomfortable feeling added to the occupant. Under the coordination of the control system, the vehicle calculates centripetal acceleration according to the vehicle speed information and the corner information so as to send instructions to the hydro-pneumatic spring, so that the inner wheel and the outer wheel of the vehicle are lifted and lowered, the vehicle body is inclined inwards by an angle instead, the resultant force of the gravitational attraction and the centrifugal force borne by passengers or cargoes in the vehicle is exactly coincident with the vertical line of the floor of the vehicle body, the passengers or cargoes in the vehicle cannot feel the existence of the centrifugal force at the moment, and even if the vehicle is full of water, the water cannot spill. This will greatly increase the speed of the vehicle hunting and will greatly increase ride comfort and stability.

As shown in fig. 7, when the vehicle is traveling on a high-side slope on a low-side and high-side road, the vehicle body is also low on the left and high-side, and in order to level the vehicle body, the control system lowers the left wheels 34 of the vehicle and raises the right wheels 34 according to the road surface gradient detected by the vehicle-mounted radar or ultrasonic scanning, and the vehicle body is raised and lowered to the horizontal, so that the vehicle stability is improved and the riding is more comfortable.

The vehicle control system selects a steering mode button at the steering wheel and manipulates the steering wheel to select a travel route. When the vehicle is traveling at a certain speed along a road turn on a normal road, the driver selects the "normal" steering mode button on the steering wheel and manipulates the steering wheel to control the left front wheel by a certain steering angle, and the vehicle control system can determine the instantaneous center of motion of the vehicle. As shown in fig. 10, there is a connection from the center to each of the 8 wheel centers. If the influence of the cornering stiffness of the tire on the actual movement direction angle of each wheel is not considered, under the coordination of the vehicle control system, the 8 wheels 34 respectively rotate at different steering angles, so that the connecting line of the center of each wheel 34 and the instantaneous movement center of the vehicle is perpendicular to the plane of the wheel, and the distance between the center of each wheel and the instantaneous movement center of the vehicle is also in direct proportion to the rotational speed of the wheel, therefore, each wheel can roll on the ground without skid when the vehicle runs along various curves and turns. However, in actual traveling, the vehicle generates centrifugal force when traveling around various curves. Centripetal force is generated on each wheel, a slip angle is generated under the action of the centripetal force in the rolling process of the tire, and the slip angle is related to the rigidity of the tire, the air pressure of the tire and the vertical load of the tire. Taking these factors into consideration, under the coordination of the vehicle control system, the 8 wheels 34 respectively turn at different steering angles, so that the connecting line of each wheel center and the instantaneous movement center of the vehicle is perpendicular to the actual movement direction line of the wheel 34, and the distance between each wheel center and the instantaneous movement center of the vehicle is also in direct proportion to the rotational speed of the wheel, thus the wheels can roll on the ground without skidding and have good operation stability when the vehicle runs along various curves at various speeds. When the steering angle of a certain wheel 34 is not proper, the connecting line of the wheel center and the instantaneous movement center of the vehicle is not perpendicular to the actual movement direction line of the wheel 34, so that the wheel 34 and the ground generate lateral sliding abrasion, and the operation stability is affected; the wheel 34 now generates additional lateral force which is detected by the lateral force sensor 37 in the axle seat 33 and fed back to the vehicle control system, which adjusts the steering angle of the wheel so that the additional lateral force of the wheel is eliminated. This closed loop control measure will further reduce tire wear and improve handling stability.

When the vehicle is parked on the roadside or in the parking lot, if other vehicles or obstacles are arranged on the front side and the rear side, the vehicle is hard to drive out, the vehicle provided by the invention is easy to operate, a driver only needs to select a 'translation' steering mode button on the steering wheel and control the steering wheel to control the left front wheel to rotate by 90 degrees, the vehicle rotates 8 wheels 34 by the same 90-degree steering angle under the coordination of a vehicle control system, and the vehicle can translate out sideways as shown in fig. 9, and the rotation speeds of all wheels are consistent.

As shown in fig. 8, when the vehicle is running on a narrow street, the driver only needs to select a "shift" steering mode button on the steering wheel and operate the steering wheel to control the left front wheel to rotate by a certain angle, and 8 wheels 34 simultaneously rotate by a certain angle to perform oblique shift so as to avoid running on the narrow street, and at the same time, the rotation speeds of the wheels are consistent.

As shown in fig. 11, when the vehicle is required to turn around the vehicle center 180 ° in situ or to turn through a certain angle and then travel, the vehicle is braked first to stop. The driver only needs to select a 'in-situ rotation' steering mode button on the steering wheel to loosen the steering wheel; under the coordination of the control system, 8 wheels 34 respectively rotate at different steering angles, so that the plane of each wheel 34 is perpendicular to the connecting line between the wheel center and the vehicle center, an indicator light is turned on after the steering angles of the wheels are adjusted in place, a driver releases a brake pedal to step on an accelerator pedal, the vehicle starts to rotate around the vehicle center in situ, the rotating speed of each wheel is directly proportional to the distance between the wheel center and the vehicle center, and all wheels roll on the ground without skidding in the process. As to whether to turn around or how much to turn around, depending on the duration of the rotation. When the driver turns the required angle, the driver releases the accelerator pedal to press the brake pedal to finish the in-situ rotation, then selects other steering mode buttons, and controls the steering wheel to continue running. The 8 wheels 34 adjust their steering angles in a new steering manner under the coordination of the control system.

The foregoing description of the preferred embodiments of the invention is not intended to be limiting, but rather is intended to cover all modifications, equivalents, and alternatives falling within the spirit and principles of the invention.

Claims

1. A travel unit for a vehicle comprising wheels, characterized in that: the steering device also comprises a hydro-pneumatic spring and a steering driving device;

the bottom end of the piston rod is connected with a wheel axle seat, and a wheel axle with the axial direction being the horizontal direction is arranged on the wheel axle seat; the wheel is provided with a hub motor and is assembled on the wheel shaft, and the center of the wheel is positioned on the extension line of the central axis of the piston rod;

the hydro-pneumatic spring comprises the oil cylinder, an elastic damping mechanism and an oil way mechanism, wherein the oil cylinder comprises the piston rod and a multi-stage cylinder barrel which is nested step by step from outside to inside;

in each two adjacent cylinders, the outer wall of the inner cylinder is of a stepped shaft structure with a wide upper part and a narrow lower part, the large-diameter section of the inner cylinder is embedded in the outer cylinder in a sliding manner, the top end of the inner cylinder is provided with an oil through hole communicated with the inner cavity of the outer cylinder, and the small-diameter section of the inner cylinder is penetrated at the bottom end of the outer cylinder and surrounds the inner wall of the outer cylinder to form an annular oil chamber;

The piston rod comprises a piston part and a rod part connected to the bottom end of the piston part, the piston part is embedded in the innermost cylinder barrel in a sliding manner, and the rod part penetrates through the bottom end of the innermost cylinder barrel and forms an annular oil chamber with the inner wall of the innermost cylinder barrel in a surrounding manner;

the spline shaft and each cylinder barrel are coaxially arranged, the top end of the spline shaft is positioned above the outermost cylinder barrel, the bottom end of the spline shaft extends into the inner cavity of the rod part, and the piston part is in spline connection with the spline shaft;

the oil way mechanism comprises an oil storage chamber, a high-pressure oil pump and a high-pressure oil chamber, the outlet end of the high-pressure oil chamber is communicated with each oil way interface through a plurality of branch oil pipes, and each branch oil pipe is correspondingly provided with an oil inlet control valve;

the elastic damping mechanism comprises a high damping pipeline, a low damping pipeline and an elastic air bag structure, wherein the high damping pipeline is connected with the low damping pipeline in parallel and is connected with the elastic damping interface and the elastic air bag structure, the high damping pipeline and the low damping pipeline are respectively provided with a damper and a first control valve, and the damping value of the damper on the high damping pipeline is higher than that of the damper on the low damping pipeline;

The elastic air bag structure comprises a large air bag chamber and a small air bag chamber which are arranged in parallel, and second control valves are arranged on branches where the two air bag chambers are located;

the spline shaft is also connected with a steering angle sensor.

2. The vehicle travel unit of claim 1, wherein: at least one spline housing is sleeved on the spline shaft from inside to outside in sequence, limiting pieces are arranged at the top and the bottom of each spline housing, and the piston part is in spline connection with the outermost spline housing.

3. A vehicle comprising a body, characterized in that: further comprising a plurality of sets of the traveling units of the vehicle according to any one of claims 1 to 2, the cylinder of each of the hydro-pneumatic springs being fixedly mounted on the vehicle body.