阅读说明：本技术 底盘浮动液压系统及高空作业平台 (Chassis floating hydraulic system and aerial work platform ) 是由 王德红 赵忠立 李绍蕾 李春桥 于 2021-07-26 设计创作，主要内容包括：本发明公开了一种底盘浮动液压系统及高空作业平台,属于高空作业平台技术领域。该底盘浮动液压系统包括第一浮动油缸、第二浮动油缸和浮动控制阀,其中,第一浮动油缸的活塞杆与底盘的前桥连接,用于控制左前轮的浮动；第二浮动油缸的活塞杆与底盘的前桥连接,用于控制右前轮的浮动；第一浮动油缸和第二浮动油缸通过浮动控制阀与进油油路和回油油路连通,浮动控制阀被配置为控制第一浮动油缸的活塞杆和第二浮动油缸的活塞杆的伸缩,浮动控制阀的换向由底盘的后桥的摆动控制。该底盘浮动液压系统及高空作业平台能够实现全时浮动,提高了作业效率；且能够保证作业的安全性。(The invention discloses a chassis floating hydraulic system and an aerial work platform, and belongs to the technical field of aerial work platforms. The chassis floating hydraulic system comprises a first floating oil cylinder, a second floating oil cylinder and a floating control valve, wherein a piston rod of the first floating oil cylinder is connected with a front axle of the chassis and used for controlling the floating of a left front wheel; a piston rod of the second floating oil cylinder is connected with a front axle of the chassis and used for controlling the floating of the right front wheel; the first floating oil cylinder and the second floating oil cylinder are communicated with the oil inlet oil way and the oil return oil way through a floating control valve, the floating control valve is configured to control the extension and contraction of a piston rod of the first floating oil cylinder and a piston rod of the second floating oil cylinder, and the reversing of the floating control valve is controlled by the swinging of a rear axle of the chassis. The chassis floating hydraulic system and the aerial work platform can realize full-time floating, so that the work efficiency is improved; and the safety of the operation can be ensured.)

1. A chassis floating hydraulic system for controlling floating of a chassis (100) of an aerial work platform, comprising:

a piston rod of the first floating oil cylinder (1) is connected with a front axle (1001) of the chassis (100) and is used for controlling the floating of a left front wheel (1002);

a piston rod of the second floating oil cylinder (2) is connected with a front axle (1001) of the chassis (100) and is used for controlling the floating of a right front wheel (1003);

the first floating oil cylinder (1) and the second floating oil cylinder (2) are communicated with an oil inlet oil way (4) and an oil return oil way (5) through the floating control valve (3), the floating control valve (3) is configured to control the extension and contraction of a piston rod of the first floating oil cylinder (1) and a piston rod of the second floating oil cylinder (2), and the reversing of the floating control valve (3) is controlled by the swinging of a rear axle (1004) of the chassis (100).

2. The chassis floating hydraulic system according to claim 1, wherein the floating control valve (3) is a three-position four-way reversing valve.

3. The chassis floating hydraulic system according to claim 1, further comprising an overflow valve (6), wherein an oil inlet of the overflow valve (6) is connected to the oil inlet path (4), and an oil outlet of the overflow valve (6) is connected to the oil return path (5).

4. The chassis floating hydraulic system according to claim 1, further comprising a first check valve (7), wherein the first check valve (7) is disposed on the oil inlet passage (4).

5. The chassis floating hydraulic system according to claim 1, further comprising a flow control valve (8), wherein the flow control valve (8) is arranged on the oil inlet passage (4).

6. The chassis floating hydraulic system according to claim 5, further comprising a pressure reducing valve (9), wherein the pressure reducing valve (9) is disposed on the oil inlet passage (4) and upstream of the flow control valve (8), and the pressure reducing valve (9) is communicated with the oil return passage (5).

7. The chassis floating hydraulic system according to claim 1, characterized in that the first floating cylinder (1) communicates with the floating control valve (3) through a first floating cylinder balancing valve (10), and the second floating cylinder (2) communicates with the floating control valve (3) through a second floating cylinder balancing valve (11).

8. Aerial work platform, characterized in that it comprises a chassis (100) and a chassis floating hydraulic system according to any one of claims 1 to 7, the chassis (100) comprises a front axle (1001) and a rear axle (1004) connected to each other, the two sides of the front axle (1001) are connected with a left front wheel (1002) and a right front wheel (1003), a left rear wheel (1005) and a right rear wheel (1006) are connected with both sides of the rear axle (1004), the first floating oil cylinder (1) is arranged on one side of the front axle (1001) close to the left front wheel (1002), the second floating oil cylinder (2) is arranged on one side of the front axle (1001) close to the right front wheel (1003), the floating control valve (3) is arranged on the rear axle (1004), and is connected with the rear axle (1004) through an adjusting pull rod (1007), and the adjusting pull rod (1007) is used for reversing the floating control valve (3).

9. The aerial work platform of claim 8 wherein said chassis (100) further comprises a transfer case (1008), said transfer case (1008) being disposed between said front axle (1001) and said rear axle (1004), said front axle (1001) being connected to said transfer case (1008) by a first drive shaft, said front axle (1001) being rotationally connected to said first drive shaft to effect oscillation of said front axle (1001); the rear axle (1004) is connected with the transfer case (1008) through a second transmission shaft, and the rear axle (1004) is rotatably connected with the second transmission shaft so as to realize the swinging of the rear axle (1004).

10. The aerial work platform of claim 8 wherein the chassis (100) further comprises a mounting plate (1009), the mounting plate (1009) being secured to the rear axle (1004), the float control valve (3) being secured to the mounting plate (1009).

Technical Field

The invention relates to the technical field of aerial work platforms, in particular to a chassis floating hydraulic system and an aerial work platform.

Background

In the hydraulic system of the existing aerial work platform, the floating mode of the two floating oil cylinders of the front axle is mainly an active floating control mode, namely the two floating oil cylinders are adjusted by detecting the inclination condition of a chassis through a sensor and sending an on-off instruction to an electromagnetic directional valve after logical judgment through an electric system so as to provide pressure oil for the floating oil cylinders and drive the floating oil cylinders to lift, thereby realizing floating control.

When the aerial work platform adopts an active floating control mode, and when the work platform in the aerial work platform is in a working state, in order to avoid the situation that when a worker walks on the work platform, the sensor detects that the chassis is slightly inclined, so that the work platform caused by the lifting of the floating oil cylinder seriously shakes, the floating oil cylinder is generally locked, and the floating oil cylinder cannot float. But the staff can appear and move or the rotation of operation panel itself on the operation panel, cause the condition that whole aerial working platform's focus takes place to squint, if this skew just in time makes unsettled wheel contact ground, suddenly rock and can make the staff have the potential safety hazard. In addition, when the traditional aerial work platform moves, the work platform cannot work to ensure the safety of work, and the work efficiency is reduced.

Therefore, a chassis floating hydraulic system and an aerial work platform which float at all times and are safe are needed to solve the technical problems in the prior art.

Disclosure of Invention

The invention aims to provide a chassis floating hydraulic system and an aerial work platform, wherein the chassis floating hydraulic system and the aerial work platform can realize full-time floating, so that the work efficiency is improved; and the safety of the operation can be ensured.

In order to achieve the purpose, the invention adopts the following technical scheme:

a chassis floating hydraulic system for controlling floating of a chassis of an aerial work platform, comprising:

a piston rod of the first floating oil cylinder is connected with a front axle of the chassis and used for controlling the floating of the left front wheel;

a piston rod of the second floating oil cylinder is connected with a front axle of the chassis and used for controlling the floating of the right front wheel;

the first floating oil cylinder and the second floating oil cylinder are communicated with the oil inlet oil way and the oil return oil way through the floating control valves, the floating control valves are configured to control the extension and contraction of a piston rod of the first floating oil cylinder and a piston rod of the second floating oil cylinder, and the reversing of the floating control valves is controlled by the swinging of a rear axle of the chassis.

As a preferred technical scheme of the chassis floating hydraulic system, the floating control valve is a three-position four-way reversing valve.

As a preferred technical scheme of the chassis floating hydraulic system, the chassis floating hydraulic system further comprises an overflow valve, wherein an oil inlet of the overflow valve is connected to the oil inlet oil way, and an oil outlet of the overflow valve is connected to the oil return oil way.

As a preferred technical scheme of the chassis floating hydraulic system, the chassis floating hydraulic system further comprises a first check valve, and the first check valve is arranged on the oil inlet oil way.

As a preferable technical scheme of the chassis floating hydraulic system, the chassis floating hydraulic system further comprises a flow control valve, and the flow control valve is arranged on the oil inlet oil path.

As a preferred technical scheme of the chassis floating hydraulic system, the chassis floating hydraulic system further comprises a pressure reducing valve, the pressure reducing valve is arranged on the oil inlet oil way and is located at the upstream of the flow control valve, and the pressure reducing valve is communicated with the oil return oil way.

As a preferred technical scheme of the chassis floating hydraulic system, the first floating oil cylinder is communicated with the floating control valve through a first floating oil cylinder balance valve, and the second floating oil cylinder is communicated with the floating control valve through a second floating oil cylinder balance valve.

In order to achieve the above purpose, the invention further provides an aerial work platform, which comprises a chassis and the chassis floating hydraulic system, wherein the chassis comprises a front axle and a rear axle which are connected with each other, a left front wheel and a right front wheel are connected with two sides of the front axle, a left rear wheel and a right rear wheel are connected with two sides of the rear axle, the first floating oil cylinder is arranged on one side of the front axle close to the left front wheel, the second floating oil cylinder is arranged on one side of the front axle close to the right front wheel, the floating control valve is arranged on the rear axle and is connected with the rear axle through an adjusting pull rod, and the adjusting pull rod is used for reversing the floating control valve.

As a preferred technical scheme of the aerial work platform, the chassis further comprises a transfer case, the transfer case is arranged between the front axle and the rear axle, the front axle is connected with the transfer case through a first transmission shaft, and the front axle is rotatably connected with the first transmission shaft so as to realize the swinging of the front axle; the rear axle is connected with the transfer case through a second transmission shaft, and the rear axle is rotatably connected with the second transmission shaft so as to realize the swinging of the rear axle.

As a preferred technical scheme of the aerial work platform, the chassis further comprises an installation plate, the installation plate is fixed on the rear axle, and the floating control valve is fixed on the installation plate.

The invention provides a chassis floating hydraulic system and an aerial work platform, wherein the chassis floating hydraulic system is used for controlling the floating of a chassis of the aerial work platform, the chassis floating hydraulic system comprises a first floating oil cylinder, a second floating oil cylinder and a floating control valve, and a piston rod of the first floating oil cylinder is connected with a front axle of the chassis and is used for controlling the floating of a left front wheel; a piston rod of the second floating oil cylinder is connected with a front axle of the chassis and used for controlling the floating of the right front wheel; the first floating oil cylinder and the second floating oil cylinder are communicated with the oil inlet oil way and the oil return oil way through a floating control valve, the reversing of the floating control valve is controlled by the swinging of a rear axle of the chassis, and then the floating control valve controls the extension and contraction of a piston rod of the first floating oil cylinder and a piston rod of the second floating oil cylinder, namely the swinging of a front axle is controlled by the swinging of the rear axle, and the swinging of the rear axle is automatically controlled according to the terrain, so that the chassis can realize full-time floating; because the four wheels on the chassis can land in real time when the chassis floats at all times, the operation platform can work even when the aerial work platform moves, and the operation efficiency is improved; and when the operation platform works, the chassis can float, so that four wheels on the chassis can be grounded in real time, and the operation safety is ensured.

Drawings

FIG. 1 is a schematic diagram of a chassis floating hydraulic system provided by an embodiment of the present invention;

FIG. 2 is a schematic diagram of a portion of an aerial work platform according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a connection relationship between a second floating cylinder and a front axle according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of the connection of a floating control valve to a rear axle according to an embodiment of the present invention;

FIG. 5 is a schematic view of an aerial work platform according to an embodiment of the present invention in a state of leveling ground;

FIG. 6 is a schematic diagram of the state of the left front wheel of the aerial work platform entering the pit according to the embodiment of the invention;

fig. 7 is a schematic diagram of the state of the right front wheel of the aerial work platform entering the pit according to the embodiment of the invention.

Reference numerals:

1. a first floating cylinder; 2. a second floating cylinder; 3. a float control valve; 4. an oil inlet path; 5. an oil return path; 6. an overflow valve; 7. a first check valve; 8. a flow control valve; 9. a pressure reducing valve; 10. a first floating cylinder balance valve; 11. a second floating cylinder balance valve; 12. a second one-way valve;

100. a chassis; 1001. a front axle; 1002. a left front wheel; 1003. a right front wheel; 1004. a rear axle; 1005. a left rear wheel; 1006. a right rear wheel; 1007. adjusting the pull rod; 1008. a transfer case; 1009. and (7) mounting the plate.

Detailed Description

In order to make the technical problems solved, the technical solutions adopted and the technical effects achieved by the present invention clearer, the technical solutions of the present invention are further described below by way of specific embodiments with reference to the accompanying drawings.

In the description of the present invention, unless expressly stated or limited otherwise, the terms "connected," "connected," and "fixed" are to be construed broadly, e.g., as meaning permanently connected, removably connected, or integral to one another; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

In the description of the present embodiment, the terms "upper", "lower", "left", "right", and the like are used based on the orientations and positional relationships shown in the drawings only for convenience of description and simplification of operation, and do not indicate or imply that the referred device or element 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" and "second" are used only for descriptive purposes and are not intended to have a special meaning.

Example one

As shown in fig. 1 to 4, the present embodiment provides a chassis floating hydraulic system, which is used for controlling the floating of a chassis 100 of an aerial work platform, and includes a first floating cylinder 1, a second floating cylinder 2 and a floating control valve 3, wherein a piston rod of the first floating cylinder 1 is connected with a front axle 1001 of the chassis 100 for controlling the floating of a left front wheel 1002; a piston rod of the second floating cylinder 2 is connected with a front axle 1001 of the chassis 100 and is used for controlling the floating of a right front wheel 1003; the first floating cylinder 1 and the second floating cylinder 2 are communicated with the oil inlet path 4 and the oil return path 5 through a floating control valve 3, the floating control valve 3 is configured to control the extension and contraction of a piston rod of the first floating cylinder 1 and a piston rod of the second floating cylinder 2, and the reversing of the floating control valve 3 is controlled by the swinging of the rear axle 1004 of the chassis 100.

The reversing of the floating control valve 3 is controlled by the swinging of the rear axle 1004 of the chassis 100, and then the floating control valve 3 controls the extension and contraction of the piston rod of the first floating oil cylinder 1 and the piston rod of the second floating oil cylinder 2, namely the swinging of the front axle 1001 is controlled by the swinging of the rear axle 1004, and the swinging of the rear axle 1004 is automatically controlled according to the terrain, so that the chassis 100 can realize full-time floating; because the four wheels on the chassis 100 can land in real time when the chassis 100 of the embodiment floats at all times, the operation platform can work even when the aerial work platform moves, and the operation efficiency is improved; and when the operation platform works, the chassis 100 can float, so that four wheels on the chassis 100 can be grounded in real time, and the operation safety is ensured.

Preferably, the float control valve 3 is a three-position four-way reversing valve. As shown in fig. 1, when the three-position four-way reversing valve is in the neutral position, the floating control valve 3 does not output pressure oil, and the piston rod of the first floating oil cylinder 1 and the piston rod of the second floating oil cylinder 2 do not act; when the three-position four-way reversing valve moves to the upper position under the swinging of the rear axle 1004, pressure oil at the position B of the floating control valve 3 enters a rodless cavity of the first floating oil cylinder 1 and a rod cavity of the second floating oil cylinder 2, a piston rod of the first floating oil cylinder 1 extends out, and a piston rod of the second floating oil cylinder 2 retracts; when the three-position four-way reversing valve moves to the lower position under the swinging of the rear axle 1004, pressure oil at the position A of the floating control valve 3 enters a rod cavity of the first floating oil cylinder 1 and a rodless cavity of the second floating oil cylinder 2, a piston rod of the first floating oil cylinder 1 retracts, and a piston rod of the second floating oil cylinder 2 extends.

Preferably, the chassis floating hydraulic system further comprises an overflow valve 6, an oil inlet of the overflow valve 6 is connected to the oil inlet oil path 4, and an oil outlet of the overflow valve 6 is connected to the oil return oil path 5. When the pressure in the oil inlet oil way 4 is too high, the pressure oil in the oil inlet oil way 4 can overflow to the oil return oil way 5 through the overflow valve 6, so that the stability of the oil pressure in the oil inlet oil way 4 is ensured, and the running safety of the chassis floating hydraulic system is improved. In the present embodiment, the set pressure of the relief valve 6 is 300 bar.

The chassis floating hydraulic system further comprises a first one-way valve 7, and the first one-way valve 7 is arranged on the oil inlet oil way 4, so that the oil inlet oil way 4 is communicated with the floating control valve 3 in a one-way mode from an inlet.

Preferably, the float control valve 3, the overflow valve 6 and the first check valve 7 are made as an integrated valve for practical use.

Preferably, the chassis floating hydraulic system further comprises a flow control valve 8, and the flow control valve 8 is arranged on the oil inlet channel 4. For example, if the flow rate control valve 8 is set to 8L/min, when the pressure oil in the oil inlet passage 4 passes through the flow rate control valve 8, the flow rate downstream of the flow rate control valve 8 becomes a constant 8L/min, and it should be noted that the flow rate of the pressure oil upstream of the flow rate control valve 8 is higher than the set value of the flow rate control valve 8.

Preferably, the chassis floating hydraulic system further comprises a pressure reducing valve 9, the pressure reducing valve 9 is arranged on the oil inlet oil way 4 and located at the upstream of the flow control valve 8, the pressure reducing valve 9 is communicated with the oil return oil way 5, and if oil leakage occurs in the pressure reducing valve 9, oil leakage of the pressure reducing valve can return to the oil tank through the oil return oil way 5. By way of example, setting the pressure reducing valve 9 to 40bar, the pressure of the pressure oil downstream of the pressure reducing valve 9 will stabilize at 40bar when the pressure oil in the oil inlet line 4 passes through the pressure reducing valve 9, it being noted that the pressure of the pressure oil upstream of the pressure reducing valve 9 is higher than the set value of the pressure reducing valve 9. Further preferably, in the present embodiment, the pressure reducing valve 9 is located upstream of the flow control valve 8.

The flow control valve 8 and the pressure reducing valve 9 are arranged on the oil inlet oil way 4 to ensure the floating response speed of the first floating oil cylinder 1 and the second floating oil cylinder 2 and the safety of operators, so that full-time floating can be realized, and potential safety hazards during high-altitude walking are avoided.

Preferably, in this embodiment, the chassis floating hydraulic system further includes a second check valve 12 and a load-sensitive pump control oil path, one end of the load-sensitive pump control oil path is communicated with the oil inlet path 4 and located downstream of the flow control valve 8, and the other end of the load-sensitive pump control oil path is communicated with the load-sensitive pump, and the second check valve 12 is disposed on the load-sensitive pump control oil path and enables the oil inlet path 4 to be communicated with the load-sensitive pump in a one-way manner.

Preferably, the flow control valve 8, the second check valve 12, the load-sensitive pump control circuit and the pressure reducing valve 9 are integrated valves for practical use.

As shown in fig. 1, the first floating cylinder 1 is communicated with the floating control valve 3 through a first floating cylinder balance valve 10, and the second floating cylinder 2 is communicated with the floating control valve 3 through a second floating cylinder balance valve 11. The first floating cylinder balance valve 10 is used to control the rod chamber to return oil when the rod chamber in the first floating cylinder 1 is filled with oil, and the rod chamber of the first floating cylinder 1 is filled with oil. The second floating cylinder balance valve 11 is used to control the rod chamber to return oil when the rod chamber in the second floating cylinder 2 is filled with oil, and the rod chamber of the second floating cylinder 2 is filled with oil. The specific structure and control principle of the first floating cylinder balance valve 10 and the second floating cylinder balance valve 11 are relatively mature technologies in the prior art, and are not described herein again.

Example two

As shown in fig. 2 and 4, the present embodiment provides an aerial work platform, which includes a chassis 100 and a chassis floating hydraulic system in the first embodiment, where the chassis 100 includes a front axle 1001 and a rear axle 1004 connected to each other, a left front wheel 1002 and a right front wheel 1003 are connected to both sides of the front axle 1001, a left rear wheel 1005 and a right rear wheel 1006 are connected to both sides of the rear axle 1004, a first floating cylinder 1 is disposed on one side of the front axle 1001 near the left front wheel 1002, a second floating cylinder 2 is disposed on one side of the front axle 1001 near the right front wheel 1003, a floating control valve 3 is disposed on the rear axle 1004 and is connected to the rear axle 1004 through an adjusting pull rod 1007, and the adjusting pull rod 1007 is used for reversing the floating control valve 3.

Traditional transfer case sets up on the rear axle, and the rear axle passes through the transmission shaft with the front axle to be connected, and the front axle rotates to be connected in the transmission shaft, and rear axle fixed connection is on the transmission shaft, therefore the rear axle can not the swing. Preferably, in this embodiment, the chassis 100 further includes a transfer case 1008, and the transfer case 1008 is disposed between the front axle 1001 and the rear axle 1004, so as to increase the movement space of the rear axle 1004 and facilitate the swinging of the rear axle 1004; the front axle 1001 is connected with the transfer case 1008 through a first transmission shaft, and the front axle 1001 is rotatably connected with the first transmission shaft so as to realize the swinging of the front axle 1001; rear axle 1004 is coupled to transfer case 1008 via a secondary drive shaft, and rear axle 1004 is rotatably coupled to the secondary drive shaft to effect oscillation of rear axle 1004.

Chassis 100 also includes mounting plate 1009, and mounting plate 1009 is fixed on rear axle 1004, and floating control valve 3 is fixed on mounting plate 1009.

The working principle of the aerial work platform of the embodiment under different working conditions is as follows: as shown in fig. 5, when the vehicle body is on the flat ground, the float control valve 3 is in the neutral position, the float control valve 3 does not output pressure oil, and the vehicle body is in a safe working condition; when the left rear wheel 1005 of the rear axle 1004 enters the pit, the rear axle 1004 pulls the floating control valve 3 downwards through the adjusting pull rod 1007, at this time, pressure oil is discharged from the port A of the floating control valve 3, oil is fed into the rodless cavity of the second floating oil cylinder 2 of the front axle 1001, the piston rod extends out, the right front wheel 1003 is forced to land, at this time, the four wheels of the chassis 100 land, and the vehicle body is in a safe working condition; when the right rear wheel 1006 of the rear axle 1004 enters the pit, the rear axle 1004 upwards extrudes the floating control valve 3 through the adjusting pull rod 1007, at this time, pressure oil is discharged from a port B of the floating control valve 3, oil is fed into a rodless cavity of the first floating oil cylinder 1 of the front axle 1001, a piston rod extends out, the left front wheel 1002 is forced to land, at this time, four wheels of the chassis 100 land, and the vehicle body is in a safe working condition; as shown in fig. 6, when the left front wheel 1002 of the front axle 1001 enters the pit, the rear axle 1004 extrudes and pulls the floating control valve 3 upwards through the adjusting pull rod 1007, at this time, pressure oil is discharged from the port B of the floating control valve 3, oil is fed into the rodless cavity of the left first floating oil cylinder 1 of the front axle 1001, the piston rod extends out, the left front wheel 1002 lands on the ground, the distance between the left front wheel 1002 and the chassis 100 is increased, the vehicle body is leveled, at this time, the four wheels of the chassis 100 land, and the vehicle body is in a safe working condition; as shown in fig. 7, when the front right wheel 1003 of the front axle 1001 enters the pit, the rear axle 1004 pulls the floating control valve 3 downwards through the adjusting pull rod 1007, at this time, pressure oil is discharged from the port a of the floating control valve 3, oil is introduced into the rodless cavity of the second floating oil cylinder 2 of the front axle 1001, the piston rod extends out, the front right wheel 1003 lands on the ground, the distance between the front right wheel 1003 and the chassis 100 is increased, the vehicle body is leveled, at this time, the four wheels of the chassis 100 land on the ground, and the vehicle body is in a safe working condition.

The above description is only a preferred embodiment of the present invention, and for those skilled in the art, the present invention should not be limited by the description of the present invention, which should be interpreted as a limitation.