CN115257233A

CN115257233A - Traveling chassis capable of expanding bridge in situ and aerial work platform

Info

Publication number: CN115257233A
Application number: CN202211023850.4A
Authority: CN
Inventors: 许树根; 许仲
Original assignee: Zhejiang Dingli Machinery Co Ltd
Current assignee: Zhejiang Dingli Machinery Co Ltd
Priority date: 2022-08-25
Filing date: 2022-08-25
Publication date: 2022-11-01

Abstract

The invention relates to the technical field of aerial work equipment, in particular to a traveling chassis and an aerial work platform capable of expanding a bridge in situ, wherein the traveling chassis comprises a main frame, wheel assemblies and a front axle unit and a rear axle unit, the axle units comprise a left half-bridge structure and a right half-bridge structure which are symmetrically arranged and respectively rotatably connected to the main frame, and one end of each half-bridge structure, which is far away from the main frame, is rotatably connected with the wheel assemblies; the axle unit further comprises a first pushing device capable of pushing the half-bridge structure to swing in the horizontal direction relative to the main frame, and a second pushing device capable of pushing the wheel assembly to rotate in the horizontal direction relative to the half-bridge structure until the rolling direction of the wheel assembly is substantially consistent with the swing tangential direction of the half-bridge structure. The wheel assembly is pushed and rotated until the rolling direction of the wheel assembly is consistent with the swinging tangential direction of the half-bridge structure, and the wheel assembly synchronously rolls and advances in the swinging process, so that the in-situ bridge expansion of the running chassis is realized.

Description

Traveling chassis capable of expanding bridge in situ and aerial work platform

Technical Field

The invention relates to the technical field of aerial work equipment, in particular to a traveling chassis capable of expanding a bridge in situ and an aerial work platform.

Background

The tire type chassis of the self-walking aerial working platform bears the weight of the whole vehicle and drives the whole vehicle to walk, the width of the tire type chassis is limited in consideration of trafficability problems when the whole vehicle walks, and the whole width of the tire type chassis needs to be increased to improve the stability of the whole vehicle support in consideration of the stability of the whole vehicle when the whole vehicle works aloft. In order to take both of the above two situations into consideration, a common way at present is to add a bridge expansion function to the tire type chassis, that is, the tire type chassis is in a narrower state to ensure trafficability when walking, and the tire type chassis is in a wider state after passing through a bridge expansion to improve support stability when working aloft.

A compact type high-altitude vehicle chassis bridge expansion system disclosed in the patent with the application number of CN201210108101.1 comprises a vehicle frame and tire assemblies arranged at four corners of the vehicle frame, wherein bridge expansion mechanisms enabling the tire assemblies to be far away from or close to the vehicle frame along the axial direction of the tire assemblies are arranged between the tire assemblies and the vehicle frame, and telescopic vertical supporting mechanisms are arranged on the vehicle frame. When the axle expanding system in the patent expands the axle, the axle expanding mechanism is driven by the axle expanding driving mechanism to move and extend, so that the tire assembly moves outwards and expands, the stability of chassis supporting is improved, the tire assembly needs to overcome the sliding friction between the tire assembly and the ground in the process, the requirement on the driving force of the axle expanding driving mechanism is high, the tire and the ground can be damaged, and noise can be caused. Also, as disclosed in patent application No. CN201821880951.2, the bridge expansion mechanism of an aerial work platform includes a frame, a front telescopic bridge assembly, and a rear telescopic bridge assembly, where the frame and the front telescopic bridge assembly are connected by a floating shaft, the frame and the rear telescopic bridge assembly are connected by a floating shaft, and the floating shaft is fixed; the front telescopic bridge assembly comprises a front cross arm, a first left telescopic shaft, a first right telescopic shaft, a steering knuckle, a front telescopic shaft oil cylinder, a tie rod oil cylinder and a steering oil cylinder; the rear telescopic bridge assembly comprises a rear cross arm, a second left telescopic shaft, a second right telescopic shaft and a rear telescopic shaft oil cylinder. This patent can be through the flexible maximum position and the minimum position of hydraulic control front axle and rear axle, controls front axle and the flexible maximum position and the minimum position of rear axle through mechanical spacing, and this function receives the resistance through the hydro-cylinder when the walking and obtains the signal of telecommunication, then gives corresponding bridge expansion feedback and realizes expanding the bridge in the walking, but when the work car stops in situ, can't realize expanding the bridge.

Disclosure of Invention

The invention is to solve the technical problem of providing a running chassis capable of expanding a bridge in situ, which comprises a main frame, wheel assemblies and a front axle unit and a rear axle unit, wherein the axle units comprise a left half-bridge structure and a right half-bridge structure which are symmetrically arranged and respectively rotationally connected to the main frame, and one end of each half-bridge structure, which is far away from the main frame, is rotationally connected with the wheel assemblies; the axle unit further comprises a first pushing device capable of pushing the half-bridge structure to swing in a horizontal direction relative to the main frame, and a second pushing device capable of pushing the wheel assembly to rotate in a horizontal direction relative to the half-bridge structure until a rolling direction of the wheel assembly is substantially coincident with a swing tangential direction of the half-bridge structure.

Preferably, the wheel assembly includes a wheel carrier, a tire mounted on the wheel carrier, and a hydraulic motor for driving the tire, wherein the hydraulic motor is connected to a bypass valve through a pipeline, and the bypass valve can bypass an oil passage of the hydraulic motor and enable the hydraulic motor to rotate under the action of external force after being opened.

Preferably, the half-bridge structure includes a supporting swing arm, the first pushing device includes a left push rod and a right push rod, the left push rod and the right push rod respectively act on the half-bridge structure on the same side, one end of the first push rod is rotatably connected to the main frame, the other end of the first push rod is rotatably connected to a swinging end of the supporting swing arm, the first push rod, the supporting swing arm and the main frame form a triangular structure, and the first push rod pushes the supporting swing arm to swing through extension and contraction.

Preferably, the half-bridge structure further comprises a mounting bracket mounted at the swing end of the supporting swing arm, and the wheel assembly is rotatably connected to the mounting bracket through the wheel carrier; the second pushing device comprises a left second pushing rod and a right second pushing rod which act on the wheel assembly on the same side respectively, one end of the second pushing rod is rotatably installed on the mounting support, the other end of the second pushing rod is rotatably connected with the wheel carrier, and the second pushing rod pushes the wheel assembly to rotate through stretching.

Preferably, the mounting bracket includes an inner protruding portion, an outer protruding portion, and an intermediate connecting portion therebetween, the swing end of the support swing arm is rotatably connected to the intermediate connecting portion, the wheel assembly is mounted on the outer protruding portion, and one end of the second push rod is rotatably connected to the inner protruding portion.

Preferably, the half-bridge structure further includes a parallel swing arm having one end rotatably connected to the main frame and the other end rotatably connected to the inner extension portion of the mounting bracket, the parallel swing arm is parallel to the supporting swing arm, the parallel swing arm, the mounting bracket and the main frame form a parallelogram structure, and the mounting bracket and the swing end of the supporting swing arm are rotatably connected.

Preferably, the axle unit further includes a first angle sensor, a second angle sensor and an axle expansion controller, the first angle sensor is capable of detecting a swing angle of the support swing arm and transmitting the detected swing angle to the axle expansion controller, the second angle sensor is capable of detecting a rotation angle of the wheel assembly and transmitting the detected rotation angle to the axle expansion controller, the axle expansion controller is connected to the first push rod and the second push rod through wires, and a first module is provided in the axle expansion controller and controls the first push rod and the second push rod to match the swing angle of the support swing arm with the rotation angle of the wheel assembly.

Preferably, the inner protruding portion of the mounting bracket has an abutting surface facing away from the wheel assembly, and the abutting surface is provided with a cushion pad.

Preferably, the first pushing device further comprises a swing oil cylinder, and the swing oil cylinder provides power for the first push rod; the second pushing device further comprises a steering oil cylinder, and the steering oil cylinder provides power for the second push rod.

An aerial work platform comprises the running chassis.

Has the advantages that:

the in-situ bridge expansion is realized, the movement form of the wheel assembly is rolling in the bridge expansion process, the friction force between the wheel assembly and the ground is mixed friction, and the rolling friction is easier to overcome compared with sliding friction, so that the requirement on the thrust of the first pushing device in the bridge expansion process is lower, and the cost is controlled; in addition, the rolling of the wheel assembly avoids self abrasion and noise generation.

Drawings

FIG. 1 is a schematic diagram of the general structure of the straight arm aerial work platform;

fig. 2 is a schematic structural view of the turntable;

FIG. 3 is a schematic structural view of the intermediate support frame;

FIG. 4 is a schematic view of the partition dividing the receiving groove into an upper groove and a lower groove;

FIG. 5 is a schematic view of the components in the receiving groove;

FIG. 6 is a schematic view of the tailgate;

FIG. 7 is a schematic diagram of the half-bridge structure, the first push rod and the wheel assembly;

FIG. 8 is a schematic view of the general construction of the running chassis;

fig. 9 is a schematic diagram of the half-bridge structure;

FIG. 10 is a schematic view of the mounting bracket;

FIG. 11 is a schematic view of the wheel assembly;

FIG. 12 is a schematic view of the lift arm assembly as used in the field of aerial work;

FIG. 13 is a schematic view of the overall configuration of the lift arm assembly;

FIG. 14 is a schematic view of the luffing attachment apparatus when the horn is fully retracted;

FIG. 15 is a schematic view of a first chamber, a second chamber, and a third chamber;

FIG. 16 is a schematic view of the forearm being swung relative to the forearm from a fully retracted condition to a maximum deployment angle;

FIG. 17 is a schematic view of the luffing attachment apparatus as the forearm body is deployed to a maximum swing angle;

FIG. 18 is a schematic view of the connection between the work platform and the forearm body;

FIG. 19 is a schematic view of the fourth, fifth and sixth chambers;

FIG. 20 is a schematic view of the leveling linkages when the second telescoping ram is extended to a maximum travel;

FIG. 21 is a schematic view of the leveling linkage when the second telescoping ram is fully retracted;

in the figure: a. a running chassis, b, a lifting arm assembly, c, a rotary table, 12, a middle supporting frame body, 121, an accommodating groove, 1211, a lower groove, 1212, an upper groove, 122, a bottom plate, 1221, a bearing part, 123, a side plate, 1231, a tail wing part, 124, a partition plate, 1241, an avoidance port, 125, a rear baffle, 126, a reinforcing rib plate, 1261, an avoidance groove, 13, a side mounting frame body, 131, a side mounting plate, 14, a lifting push rod, 151, a first rotating support rod, 152, a second rotating support rod, 1, a main frame, 2, a wheel assembly, 21, a wheel frame, 22, a tire, 23, a hydraulic motor, 3, an axle unit, 4, a half-bridge structure, 41, a supporting swing arm, 42, a mounting bracket, 43, a parallel swing arm, 421 and an inner extension part, 422, an intermediate connecting part, 423, an outer extending part, 424, a butting surface, 51, a first push rod, 52, a second push rod, 6, a large arm body, 61, a large arm body component, 7, a small arm body, 71, a small arm body component, 72, a swinging head component, 8, a variable amplitude connecting device, 81, a first telescopic push rod, 82, a first transmission rod, 83, a first guide swinging rod, 91, a first cavity, 92, a second cavity, 93, a third cavity, 94, a fourth cavity, 95, a fifth cavity, 96, a sixth cavity, 10, a working platform, 101, a platform head component, 11, a leveling connecting device, 111, a second telescopic push rod, 112, a second transmission rod, 113 and a second guide swinging rod.

Detailed Description

The following specific examples are given by way of illustration only and not by way of limitation, and it will be apparent to those skilled in the art from this disclosure that various changes and modifications can be made in the examples without inventive faculty, and yet still be protected by the scope of the claims.

The first embodiment is as follows:

the invention discloses a running chassis capable of expanding a bridge in situ, which comprises a main frame 1, a wheel assembly 2 and a front axle unit 3 and a rear axle unit 3, wherein each axle unit 3 comprises a left half-bridge structure 4 and a right half-bridge structure 4 which are symmetrically arranged and respectively rotatably connected to the main frame 1, and one end of each half-bridge structure 4, which is far away from the main frame 1, is rotatably connected with the wheel assembly 2. In order to realize the axle expansion function, the front and rear axle units 3 need to be capable of expanding the axle respectively, namely, the left and right half-bridge structures 4 in one axle unit 3 can be far away from each other and close to each other. The axle unit 3 therefore also comprises first thrust means capable of pushing the half-bridge structure 4 to oscillate in a horizontal direction with respect to the main frame 1, and second thrust means capable of pushing the wheel unit to rotate in a horizontal direction with respect to the half-bridge structure 4 until the rolling direction of the wheel assembly 2 substantially coincides with the oscillation tangential direction of the half-bridge structure 4; when the axle is expanded, the wheel assembly 2 is pushed by the second pushing device and is rotated until the rolling direction of the wheel assembly is substantially consistent with the swinging tangential direction of the half-bridge structures 4, then the first pushing device is started to push the half-bridge structures 4 to swing outwards relative to the main frame 1, namely, the left half-bridge structure 4 and the right half-bridge structure 4 in one axle unit 3 swing oppositely, and the wheel assembly 2 synchronously rolls and advances in a swinging process, so that the in-situ axle expansion of the running chassis is realized. In the bridge expansion process, the motion form of the wheel assembly 2 is rolling, the friction force between the wheel assembly and the ground is mixed friction, and compared with sliding friction, the rolling friction is easier to overcome, so that the thrust requirement on the first pushing device in the bridge expansion process is lower, and the cost is controlled; the rolling of the wheel assembly 2 also avoids wear and noise generation.

The driving chassis is mainly used in the field of aerial platform trucks, and four-wheel drive is usually selected in the field to ensure the trafficability of the aerial platform truck, so the present embodiment preferably includes the wheel carrier 21, the tire 22 mounted on the wheel carrier 21, and a motor for driving the tire 22, so as to realize four-wheel drive. In the case of the bridge expansion, one embodiment is that the motor drives the tire 22 to roll during the process of the first pushing device pushing the half-bridge structure 4 to swing, so as to further reduce the requirement of the bridge expansion motion for the pushing force of the first pushing device and reduce the cost of the first pushing device. However, the combination of the two different forms of power can cause the total axle expanding power to be difficult to master, the wheel assembly 2 itself runs in a rolling mode, and as long as the resistance of the rotation of the tire 22 in the wheel assembly 2 under the action of external force is small, the axle expanding by means of the thrust of the first thrust device only does not have high requirements on the thrust. Therefore, in the present embodiment, it is preferable that the motor is a hydraulic motor 23, and the hydraulic motor 23 is connected to a bypass valve through a pipeline, and the bypass valve can bypass an oil path of the hydraulic motor 23 after being opened, so that the hydraulic motor 23 can rotate under the action of external force; when expanding the bridge, open the bypass valve makes A hydraulic fluid port and the bypass of B hydraulic fluid port in the hydraulic motor 23, then when hydraulic motor 23 self does not start, its main shaft can rotate under the exogenic action, like this in the swing of half-bridge structure 4, just can promote tire 22 and roll, need not the power with the help of hydraulic motor 23, the cost is reduced, and only the thrust through a thrust of a thrust device carries out the swing of half-bridge structure 4 in addition, also is more convenient for control whole bridge process that expands. Of course, a speed reducer is usually provided between the hydraulic motor 23 and the tire 22, and the brake of the speed reducer must be released during axle expansion.

In general, the axle expanding movement of the axle unit 3 is that the left and right half-bridge structures 4 swing away from each other at the same time, and one embodiment of the first pushing device may push the left and right half-bridge structures 4 to swing at the same time, and another embodiment may push the left and right half-bridge structures 4 to swing separately. However, in the present embodiment, the left and right half-bridge structures 4 are highly independent and have less structural relationship with each other, so that the second embodiment is preferable, and the individual swing of the half-bridge structures 4 can be satisfied. Specifically, it is preferable that the half-bridge structure 4 includes a supporting swing arm 41, the first pushing device includes a left push rod 51 and a right push rod 51 acting on the same side of the half-bridge structure 4, one end of the first push rod 51 is rotatably connected to the main frame 1, and the other end of the first push rod 51 is rotatably connected to a swing end of the supporting swing arm 41, the swing end is away from one end of the main frame 1, and the first push rod 51, the supporting swing arm 41 and the main frame 1 form a triangular structure, so that the first push rod 51 is extended and retracted to push the supporting swing arm 41 to swing, and the first push rod 51 itself also swings in the process. Therefore, the swing angle range of the supporting swing arm 41 is large, the structural stability is high, the stability of the bridge is improved, and the supporting strength of the supporting swing arm 41 to the whole running chassis is improved.

Before axle expansion, a second pushing device is needed to push the wheel assembly 2 to rotate until the rolling direction of the wheel assembly 2 is approximately consistent with the swing tangential direction of the half-bridge structure 4, the wheel assembly 2 on the left side in the axle unit 3 is installed on the half-bridge structure 4 on the left side, and the wheel assembly 2 on the right side is installed on the half-bridge structure 4 on the right side. The running chassis of the embodiment has two use states before and after axle expansion, one is a normal running posture before axle expansion, and at the moment, the running chassis is made as narrow as possible in order to ensure trafficability, so that in this state, the whole half-bridge structure 4 is approximately in a front-back extension state, one ends of the two half-bridge structures 4, which are far away from the main frame 1, are close to each other, the two wheel assemblies 2 are also close to each other, and the whole running chassis is in a narrowest state; the other is a stop state after axle expansion, at this time, the left half-bridge structure 4 and the right half-bridge structure 4 in the axle unit 3 deviate from each other by a large swing angle, and the left wheel assembly 2 and the right wheel assembly 2 are far away from each other. If the second pushing device adopts a set of structure to act on the left wheel assembly 2 and the right wheel assembly 2 simultaneously, when the axle is expanded under the normal driving posture, the left half-bridge structure and the right half-bridge structure 4 are too close to each other, and interference may occur in the process that the left half-bridge structure and the right half-bridge structure rotate to the state that the rolling direction of the left half-bridge structure and the right half-bridge structure are basically consistent with the swinging tangential direction, so that the left half-bridge structure and the right half-bridge structure cannot rotate in place; in the above-described attitude after axle expansion, the distance between the left and right wheel assemblies 2 is large, and the second pushing device itself needs a large stroke, resulting in an increase in cost. Therefore, in this embodiment, it is preferable that the half-bridge structure 4 further includes a mounting bracket 42 mounted at the swing end of the supporting swing arm 41, and the wheel assembly 2 is rotatably connected to the mounting bracket 42 through the wheel carrier 21; the second pushing device comprises a left second push rod 52 and a right second push rod 52 which respectively act on the wheel assembly 2 on the same side, one end of the second push rod 52 is rotatably mounted on the mounting bracket 42, the other end of the second push rod 52 is rotatably connected with the wheel carrier 21, and the second push rod 52 pushes the wheel assembly 2 to rotate through extension and retraction. The mounting bracket 42 is used for mounting the second push rods 52, so that the left and right second push rods 52 can independently operate respectively, the range of the rotatable angle of the wheel assembly 2 can be ensured to meet the requirement only by ensuring the stroke of the second push rods, and the cost is low; and the wheel assemblies 2 are mounted, so that a certain distance is kept between the left wheel assembly 2 and the right wheel assembly 2 when the left wheel assembly and the right wheel assembly are close to each other, and the interference between the left wheel assembly and the right wheel assembly is avoided when the left wheel assembly and the right wheel assembly rotate.

In a further improvement, preferably, the mounting bracket 42 includes an inner protruding portion 421, an outer protruding portion 423 and an intermediate connecting portion 422 therebetween, the swing end of the supporting swing arm 41 is rotatably connected to the intermediate connecting portion 422, the wheel assembly 2 is mounted on the outer protruding portion 423, one end of the second push rod 52 is rotatably connected to the inner protruding portion 421, and the other end of the second push rod 52 is rotatably connected to the wheel carrier 21 of the wheel assembly 2. The mounting bracket 42 not only ensures stable mounting of the second push rod 52, but also the second push rod 52 straddles the mounting bracket 42, the length of the mounting bracket 42 in the horizontal direction is utilized to effectively ensure the telescopic stroke of the second push rod 52. And when two wheel assembly 2 on the left and right sides are close to each other before expanding the bridge, have two installing support 42 between the two at the interval, further guarantee that two wheel assembly 2 can not take place to interfere each other when rotating.

During the axle expansion process, it is required to ensure that the rolling direction of the tire 22 in the wheel assembly 2 is substantially consistent with the swing tangential direction of the swing end of the support swing arm 41, which is realized by controlling the angular relationship between the wheel assembly 2 and the support swing arm 41, but the existence of the mounting bracket 42 can affect the angular relationship between the wheel assembly 2 and the support swing arm 41; there are two embodiments, the first is that there is a fixed connection between the mounting bracket 42 and the supporting swing arm 41, so that the mounting bracket 42 does not affect the angular relationship between the wheel assembly 2 and the supporting ring swing arm during the axle expanding process, but the mounting bracket 42 is only fixed on the supporting swing arm 41, and its stability is low; the second is that the mounting bracket 42 is rotatably connected with the supporting swing arm 41, so that the mounting bracket 42 may rotate relative to the supporting swing arm 41 in the axle expanding process, which causes the angle relationship between the wheel assembly 2 and the supporting swing arm 41 to be affected, and certainly, the influence of the mounting bracket 42 can still be eliminated by setting an angle sensor, a controller and the like to control the rotation angle of the wheel assembly 2, but too many variables may cause the algorithm to be complicated, the cost is increased, and the accuracy of actual angle matching is reduced, which may cause adverse effect on axle expanding. In consideration of the problems faced by the above two embodiments, this embodiment is further improved, and preferably, the half-bridge structure 4 further includes a parallel swing arm 43 with one end rotatably connected to the main frame 1 and the other end rotatably connected to the inner extension 421 of the mounting bracket 42, the parallel swing arm 43 is parallel to the supporting swing arm 41, the parallel swing arm 43, the mounting bracket 42 and the main frame 1 form a parallelogram structure, and the mounting bracket 42 and the swing end of the supporting swing arm 41 are rotatably connected. Like this half-bridge structure 4 is a whole by supporting swing arm 41, parallel swing arm 43 and installing support 42 are constituteed, wherein support swing arm 41 is the major function structure, parallel swing arm 43 with support swing arm 41 synchronous oscillation, parallel swing arm 43's existence not only can share and support swing arm 41 to the holistic supporting role in driving the chassis, improve the holistic intensity of half-bridge structure 4 and bearing capacity, and improved the firm degree of installation of installing support 42 in half-bridge structure 4, also make the steadiness of installing support 42 in the 4 motion processes of half-bridge structure simultaneously, and then guarantee that wheel subassembly 2 and the accurate of supporting the position relation between swing arm 41 can be surveyed. Because of the parallelogram structure of the half-bridge structure 4 and the four rotary connecting parts, the supporting swing arm 41 and the parallel swing arm 43 keep parallel synchronous swing in the bridge expansion process, the mounting bracket 42 is always parallel to the connecting line of the half-bridge structure 4 between the two rotary connecting parts on the main frame 1, and the two rotary connecting parts, namely the rotary connecting parts of the supporting swing arm 41, the parallel swing arm 43 and the main frame 1, in a word, the whole position direction of the mounting bracket 42 is determined, and the mounting bracket 42 is wholly translated in the bridge expansion process, so the mounting bracket 42 does not influence the position precision of the wheel assembly 2. Therefore, in the axle expanding process, as long as two variables, namely the swing angle of the supporting swing arm 41 and the rotation angle of the wheel assembly 2, are controlled, the rolling direction of the wheel assembly 2 is basically consistent with the swing tangential direction of the half-bridge structure 4, and smooth axle expanding is further realized.

For the control of the swing angle of the support swing arm 41 and the rotation angle of the wheel assembly 2, real-time accurate monitoring and feedback are required, and therefore need to be achieved by a control system. Specifically, it is preferable in this embodiment that the axle unit 3 further includes a first angle sensor, a second angle sensor, and a bridge expansion controller, the first angle sensor can detect the swing angle of the supporting swing arm 41 and transmit the swing angle to the bridge expansion controller, the second angle sensor can detect the rotation angle of the wheel assembly 2 and transmit the rotation angle to the bridge expansion controller, the bridge expansion controller is connected to the first push rod 51 and the second push rod 52 by wires, and a first module that matches the swing angle of the supporting swing arm 41 with the rotation angle of the wheel assembly 2 by controlling the first push rod 51 and the second push rod 52 is provided in the bridge expansion controller. In practical experiments, it can be known that, under the condition that the rolling direction of the wheel assembly 2 is always kept substantially consistent with the swing tangential direction of the half-bridge structure 4, the rotation angle of the wheel assembly 2 corresponding to each swing angle of the supporting swing arm 41 needs to be written into the first module, and by taking the rotation angle as a reference, the first module can control the two angles to always keep corresponding in real time in the actual axle expansion process, so that smooth axle expansion is realized.

In the embodiment, the running chassis is as narrow as possible in the normal running posture to ensure the trafficability, so that the left half-bridge structure and the right half-bridge structure 4 are close to each other in the normal running posture, the width of the running chassis is reduced, and the width of the running chassis can meet the requirements of transportation carriers such as common freight cabinets, flat cars and the like on width dimension loading, so that the transportation is facilitated, and the transportation cost is reduced; when the running chassis is used on an aerial work platform to form a whole vehicle, the two half-bridge structures 4 are close to each other, so that the width of the whole vehicle can be reduced, the width size requirement of transportation carriers such as common freight cabinets, flat cars and the like can be met, the transportation is convenient, and the transportation cost is reduced.

After being close to each other, the two half-bridge structures 4 can leave a little distance between the two, also can lean on each other to reduce the width as much as possible, and not only make the width about driving chassis narrower under the condition of leaning on each other, still make two half-bridge structures 4 support each other, and then guarantee the holistic stability of axle unit 3. When the chassis is changed from the axle-expanding posture to the normal driving posture, the left and right half-bridge structures 4 swing in opposite directions until abutting against each other, so in this embodiment, it is preferable that the inner protruding portion 421 of the mounting bracket 42 has an abutting surface 424 facing away from the wheel assembly 2, the left and right half-bridge structures 4 in the axle unit 3 can abut against each other through the abutting surface 424, and a cushion pad is disposed on the abutting surface 424, so as to reduce damage and noise caused by collision. Further, preferably, the first pushing device further comprises a swing oil cylinder, and the swing oil cylinder provides power for the first push rod 51; the second pushing device further comprises a steering oil cylinder, and the steering oil cylinder provides power for the second push rod 52. The power form of the oil cylinder is adopted, so that enough driving force is provided for the first push rod 51 and the second push rod 52, and smooth realization of bridge expansion operation is ensured.

The travelling chassis can be used in existing aerial platform trucks, as well as aerial platform trucks in the second and third embodiments below. The invention relates to an aerial work platform which comprises a running chassis.

The second embodiment:

the lifting arm assembly comprises a large arm body 6, a small arm body 7 and a variable amplitude connecting device 8, wherein the large arm body 6 can swing, so that the swinging end of the large arm body is a lifting end, one end, mounted on the large arm body 6, of the small arm body 7 is a fulcrum end, and the lifting end of the large arm body 6 is rotatably connected with the fulcrum end of the small arm body 7. The variable amplitude connecting device 8 comprises a first telescopic push rod 81 and a first transmission rod 82, the rear end of the first telescopic push rod 81 is rotatably connected to the large arm body 6, the front end of the first telescopic push rod 81 is rotatably connected to the rear end of the first transmission rod 82, the first transmission rod 82 is positioned between the large arm body 6 and the small arm body 7, and the front end of the first transmission rod is rotatably connected to the pivot end of the small arm body 7; the amplitude-variable connecting device 8 drives the small arm body 7 to rotate relative to the large arm body 6, so that the large arm body 6 can be regarded as a static reference during motion analysis, and the front end and the rear end of the first transmission rod 82 are movable relative to the large arm body 6 in the process of being pushed to move, so that the first transmission rod 82 changes direction and moves integrally, and the small arm body 7 swings along with the movement of the front end of the first transmission rod 82; specifically, the first telescopic push rod 81 performs telescopic motion to drive the rear end of the first transmission rod 82 to generate synchronous same-path displacement, and meanwhile, the first transmission rod 82 generates direction change to pull or push the small arm body 7 to generate swing relative to the large arm body 6, and because the first transmission rod 82 is not limited by other parts on the whole, the amplitude and range of the whole direction change and displacement are very large, so that the range of the rear end of the rotary connection between the first transmission rod 82 and the small arm body 7, which can be displaced, is very large, the angle range of the small arm body 7, which can swing, is relatively large, the wide amplitude of the small arm body 7 relative to the large arm body 6 is realized, the lifting arm assembly can be suitable for various complex environments, and the work blind area is reduced. When the lifting arm assembly is not used, the large arm body 6 and the small arm body 7 can be completely pulled back, the state that the small arm body 7 is approximately parallel to the large arm body 6 is achieved, as shown in the state of fig. 1, the compactness is improved, the occupied space of the lifting arm assembly is reduced, the storage space cost is reduced, and particularly when common transport vehicles such as freight cabinets and the like are used for transporting, the total length and the height of the lifting arm assembly in the retraction state of fig. 1 can meet the requirements of cabinet loading, the transportation is convenient, and the transportation cost is reduced; simultaneously the lifting arm assembly is mainly used for being installed on the high-altitude operation car for use, the improvement of compactness under the state that the lifting arm assembly is wholly withdrawn is also favorable for guaranteeing the trafficability characteristic of the high-altitude operation car, and the length of the high-altitude operation car is reduced, so that the total length and the total height of the high-altitude operation car can meet the loading requirements of common transport carriers such as freight cabinets and the like, the transportation is convenient, and the transportation cost is reduced. In the process of the movement of the first driving rod 82, the front end of the first telescopic push rod 81 can displace in the up-down direction along with the displacement of the rear end of the first driving rod 82 in the self telescopic path, so that the rear end of the first telescopic push rod 81 is rotatably connected to the boom body 6, and the first telescopic push rod 81 can swing relative to the boom body 6 in the up-down direction.

Because the motion track of the first transmission rod 82 is difficult to determine, in the above-mentioned solution, some conditions can smoothly realize the pushing of the small arm body 7, but some conditions cannot realize the pushing, which results in insufficient reliability. Therefore, in the embodiment, it is preferable that the variable-amplitude connecting device 8 further includes a guide member, the guide member is rotatably connected to the first transmission rod 82, and can limit a displacement path of the first transmission rod 82, and in a process that the first transmission rod 82 is pushed by the first telescopic push rod 81, a path of a rotatably connected portion of the first transmission rod 82 and the guide member is limited and determined by the guide member, so that a running track of the whole first transmission rod 82 is determined, and the first transmission rod 82 still rotates relative to the guide member, so that the first transmission rod 82 changes direction, and the displacement of the front end of the first transmission rod 82 is still superimposed on two forms of displacement and direction change of the whole first transmission rod 82, and the variable-amplitude swing of the small arm 7 relative to the large arm 6 can still be realized. Specifically, preferably, the guide member is a first guide swing rod 83, the upper end of the first guide swing rod 83 is rotatably connected to the lifting end of the upper arm body 6, the lower end of the first guide swing rod 83 is rotatably connected to the middle of the first transmission rod 82, the first guide swing rod 83 swings relative to the upper arm body 6, the lower end of the first guide swing rod 83 is a swinging end, and the trajectory is determined, so that the running trajectory of the part of the first transmission rod 82 rotatably connected with the first guide swing rod 83 is determined, under the condition that the first transmission rod 82 is not considered to change direction and rotates relative to the first guide swing rod 83, the overall displacement trajectory of the first transmission rod 82 is determined, and it is ensured that the first transmission rod 82 can always drive the lower arm body 7 to swing in the process that the first telescopic push rod 81 pushes the first transmission rod 82. Specifically, fig. 4 shows an initial state in which the small arm body 7 is completely retracted below the large arm body 6, the small arm body 7 is rotatably connected to the large arm body 6 through the extreme end, the first transmission rod 82 is located in a space between the large arm body 6 and the small arm body 7 and is obliquely supported between the small arm body 7 and the large arm body 6, the first guide swing rod 83 pulls the first transmission rod 82 to limit the track of the first transmission rod 82, as long as the first telescopic push rod 81 extends outwards, the rear end of the first transmission rod 82 can only move obliquely downwards, the front end of the first transmission rod 82 tilts obliquely upwards, and the first transmission rod 82 changes direction with the rotating connection portion with the guide swing rod as a fulcrum, so as to push the small arm body 7 to swing away from the large arm body 6; meanwhile, the first transmission rod 82 is displaced as a whole by taking the swing track of the rotation connection part with the first guide swing rod 83 as a whole displacement track, and pushes the small arm body 7 to swing away from the large arm body 6 in cooperation with the self direction-changing motion. In summary, in the process that the first transmission rod 82 is pushed outwards by the first telescopic push rod 81, the first transmission rod 82 simultaneously generates the overall displacement swinging outwards along with the first guide swing rod 83 and the movement that the front end continuously tilts upwards relative to the rotation of the first guide swing rod 83, so that the two movement forms are superposed and then act on the small arm body 7, and the small arm body 7 can generate the wide amplitude swing relative to the large arm body 6. FIG. 5 shows the state of the small arm 7 after swinging to the maximum angle from the initial state of complete retraction, and compared with FIG. 4, the maximum swinging angle can reach 230 to 240 degrees, which greatly improves the working angle range of the lifting arm assembly, is suitable for various complex working conditions, and reduces the working blind area; and the amplitude-variable connecting device 8 can retract the small arm body 7 to be in a state of being approximately parallel to the large arm body 6, so that the total length of the lifting arm assembly is greatly reduced when the lifting arm assembly is not used, the space cost is reduced, and the trafficability characteristic is improved.

Fig. 6 shows a state that the small arm body 7 swings to a maximum angle relative to the large arm body 6, at this time, the first telescopic push rod 81 is substantially parallel to the first guiding swing rod 83, the first guiding swing rod 83 blocks the first telescopic push rod 81 through a rotation connection portion of the large arm body 6 and the first guiding swing rod 83, and when the limit state is reached, the first telescopic push rod 81 cannot be pushed continuously, and the first guiding swing rod 83 reaches the maximum swing angle, that is, the whole displacement generated by the first transmission rod 82 following the swing of the first guiding swing rod 83 reaches a maximum degree; on the other hand, at this time, the rotation of the first transmission rod 82 relative to the first guide swing rod 83 also reaches the maximum angle, the front end of the first transmission rod 82 turns over backward and upward to be close to the rotation connection part of the first guide swing rod 83 and the large arm body 6, and the fulcrum end of the small arm body 7 abuts against the lifting end of the large arm body 6 to reach the limit state. Analyzing that the two motion forms of the first transmission rod 82 reach the limit state, determining the condition that the first guide swing rod 83 reaches the limit state, and determining that the first transmission rod 82 rotates to the limit state relative to the first guide swing rod 83 is also related to the selection of the part of the first transmission rod 82, which is in rotational connection with the first guide swing rod 83; the first transmission lever 82 is shaped like a lever and divided into a force transmission arm portion acting on the forearm body 7 and a power arm portion pushed by the first telescopic push rod 81 by using the rotation connection portion of the first transmission lever 83 and the first guide swing rod 83 as a boundary, wherein the rotation of the force transmission arm portion is considered to be effective work acting on the forearm body 7, the closer the rotation connection point of the first guide swing rod 83 and the first transmission lever 82 is to the front end of the first transmission lever 82, the shorter the length of the force transmission arm portion is, and the longer the length of the power arm portion is, the longer the maximum stroke of the first telescopic push rod 81 is required to be extended when the first transmission lever 82 is rotated to the same limit state relative to the first guide swing rod 83, and at this time, the ratio of the length of the power arm portion in the first transmission lever 82 to the entire length is also large, and the portion is extended to the outside as the first telescopic push rod 81, which lowers the structural stability and compactness, and the increase of the maximum stroke of the first telescopic push rod 81 also causes the increase of the cost thereof. Therefore, in the present embodiment, it is preferable that the distance from the pivot connection point of the first guiding swing link 83 and the first transmission link 82 to the rear end of the first transmission link 82 is smaller than the distance to the front end of the first transmission link 82, so as to reduce the requirement for the maximum stroke of the first telescopic push rod 81, improve the length ratio of the force transmission arm portion acting on the small arm body 7 in the first transmission link 82, obtain more effective work on the small arm body 7, reduce the length ratio of the power arm portion in the first transmission link 82, and improve the structural stability and compactness.

The first telescopic push rod 81 has a length change in the telescopic process, and a moving space needs to be provided for the first telescopic push rod 81, in this embodiment, it is preferable that a hollow first cavity 91 is provided in the lifting end of the upper arm body 6, and the first telescopic push rod 81 is located in the first cavity 91 and can extend out; when the small arm body 7 is in a retracting state, the small arm body 7 is close to the large arm body 6, at the moment, the first telescopic push rod 81 is integrally retracted in the first cavity 91, the small arm body 7 is avoided, the complete retraction of the small arm 7 is not affected, and when the small arm 7 needs to be pushed out, the first telescopic push rod 81 extends out of the first cavity 91 to push the first transmission rod 82 outwards.

The body of the large arm body 6 and the body of the small arm body 7 are both long-strip-shaped support arms, and in order to facilitate the rotational connection between the two and the arrangement of the variable amplitude connecting device 8, in this embodiment, it is preferable that the lifting end of the large arm body 6 is provided with a large arm head assembly 61 for rotationally connecting the first guide swing rod 83, the fulcrum end of the small arm body 7 is provided with a small arm head assembly 71 for rotationally connecting the front end of the first transmission rod 82, and the large arm body 6 and the small arm body 7 are rotationally connected through the large arm head assembly 61 and the small arm head assembly 71; a hollow second cavity 92 is formed in the big arm head assembly 61, a hollow third cavity 93 is formed in the small arm head assembly 71, the second cavity 92 is communicated with the first cavity 91, and the third cavity 93 is communicated with the second cavity 92; the first cavity 91, the second cavity 92 and the third cavity 93 provide a movable space for the amplitude-variable connecting device 8. Specifically, the forearm head assembly 61 includes two left and right first support plates, the second cavity 92 is a space clamped between the two first support plates, the forearm head assembly 71 includes two left and right second support plates, and the third cavity 93 is a space clamped between the two second support plates, so that the variable-amplitude connecting device 8 can realize planar motion in a plane perpendicular to the left and right directions in the second cavity 92 and the third cavity 93, and thereby the forearm body 7 is pushed to swing relative to the forearm body 6 in the same plane. Of course, during the actual movement of the variable amplitude connecting device 8, a part of the variable amplitude connecting device extends out of the first cavity 91, the second cavity 92 and the third cavity 93, and the first cavity 91, the second cavity 92 and the third cavity 93 exist mainly for avoiding the movement of the variable amplitude connecting device 8. In a further improvement, preferably, the upper arm body 6 points to the upper arm head assembly 61 along the extending direction thereof, and the first cavity 91 points to and communicates with the second cavity 92 along the extending direction of the upper arm body 6; the small arm head assembly 71 extends out of one side of the small arm body 7 and is positioned between the small arm body 7 and the large arm body 6. The boom head assembly 61 is thus integrated with the body of the boom 6, so that the entire boom 6 is still in the form of a long bar, and the boom head assembly 61 serves as a reference for motion analysis of the luffing attachment device 8 and the boom 7, which can represent the rest of the body of the boom 6. The small arm head assembly 71 extends out of one side of the small arm body 7 to facilitate the rotary connection with the large arm head assembly 61, the small arm body 7 is also of an elongated support arm structure, the body of the small arm body 7 is approximately parallel to the large arm body 6 under the condition that the small arm body 7 is completely retracted, and in the state, the small arm head assembly 71 must extend out of one side of the body of the small arm body 7 to be connected with the large arm head assembly 61 in a rotary mode.

The lifting arm assembly is mainly used in the field of aerial work platforms, a working platform 10 is usually required to be installed at the swinging end of the small arm body 7, the large arm body 6 and the small arm body 7 jointly lift the working platform 10 in the working process, but the working platform 10 can meet the use requirement only by being kept in a horizontal state all the time, and therefore a leveling mechanism for leveling the working platform 10 is usually required to be equipped; in the above scheme, the variable amplitude connecting device 8 realizes the wide amplitude of the swing of the small arm body 7 relative to the large arm body 6, which requires that the leveling angle range of the leveling mechanism is also large enough to correspondingly satisfy the wide amplitude of the small arm body 7, i.e. the matching of the leveling mechanism and the variable amplitude connecting mechanism needs to be realized, and obviously, the existing leveling mechanism cannot satisfy the requirements. The lifting arm assembly of the embodiment further comprises a working platform 10, a leveling connecting device 11 and a platform head assembly 101, wherein the working platform 10 is installed on the platform head assembly 101, and the platform head assembly 101 is rotatably connected with the swinging end of the small arm body 7; leveling connecting device 11 includes second telescopic push rod 111, second transfer line 112 and second direction pendulum rod 113, second telescopic push rod 111 rear end rotates to be connected on the forearm body 7 and the front end rotates to be connected the rear end of second transfer line 112, second transfer line 112 front end rotates to be connected on the platform head subassembly 101, second direction pendulum rod 113 rear end rotates to be connected on the forearm body 7 and the front end rotates to be connected the middle part of second transfer line 112, second telescopic push rod 111 can push through driving the holistic diversion of second transfer line 112 and displacement platform head subassembly 101 for the swing of forearm body 7. Fig. 9 shows the above specific structure, the structural principle of the leveling connection device 11 is consistent with that of the luffing connection device 8, the second guide swing rod 113 limits the motion track of the second transmission rod 112 as a whole, the second transmission rod 112 can rotate relative to the second guide swing rod 113, and the superposition of the two motion forms enables the front end of the second transmission rod 112, which is rotatably connected with the platform head assembly 101, to generate a wide luffing displacement, so that the range of the rotation angle of the platform head assembly 101 relative to the forearm 7 is large, compared with the position of the platform head assembly 101 in two extreme states of complete extension and complete retraction of the second telescopic push rod 111, the range of the rotation angle of the platform head assembly 101 is also approximately 230 ° -240 °, so that the matching between the range of the luffing of the platform head assembly 101 and the range of the forearm 7 is realized, and the leveling connection device 11 can rotate the platform head assembly 101 to a certain angle to keep the working platform 10 horizontal no matter the rotation of the forearm body 7 to any angle.

In order to facilitate the installation of the platform head assembly 101 and the leveling connecting device 11 and provide a movable space for the leveling connecting device 11, it is further preferable that the swing end of the forearm body 7 is provided with a swing head assembly 72 for rotationally connecting the platform head assembly 101 and the second guide swing rod 113, a hollow fourth cavity 94 is formed in the swing end of the forearm body 7, the second telescopic push rod 111 is located in the fourth cavity 94 and can extend out, a fifth cavity 95 is formed in the swing head assembly 72, a sixth cavity 96 is formed in the platform head assembly 101, and the fourth cavity 94, the fifth cavity 95 and the sixth cavity 96 provide a movable space for the leveling connecting device 11. In this embodiment, the first telescopic push rod 81 and the second telescopic push rod 111 are preferably powered by oil cylinders.

The lifting arm assembly can be used in the existing aerial platform vehicle, and can also be used in the aerial platform in the first embodiment and the third embodiment of the specification. The invention relates to a straight arm type aerial work platform convenient to transport, which comprises a lifting arm assembly.

Example three:

the invention relates to a straight arm type aerial work platform convenient to transport, which comprises a running chassis a, a rotary table c arranged on the running chassis a and a lifting arm assembly b arranged on the rotary table c, wherein the rotary table c can rotate relative to the running chassis a around a vertical axis, and the lifting arm assembly b can swing relative to the rotary table c to realize lifting. The lifting arm assembly b comprises a large arm body 6, a small arm body 7 and a variable amplitude connecting device 8, wherein the variable amplitude connecting device 8 can push the small arm body 7 to perform wide variable amplitude swing relative to the large arm body 6, the moving range of the whole gravity center of the lifting arm assembly b is large, and the requirement on the stability of the whole operation platform is high. Therefore, the travelling chassis a can expand the bridge in situ, the supporting capability of the travelling chassis a on the turntable c and the lifting arm assembly b is improved, and the stability of the whole operation platform is also improved. The turntable c comprises a middle supporting frame body 12 and side mounting frame bodies 13 fixed on the left side and the right side of the middle supporting frame body 12, wherein the middle supporting frame body 12 is used for mounting the lifting arm assembly b, and the side mounting frame bodies 13 are used for mounting various driving systems, control systems and the like; be formed with in the middle support frame body 12 and extend and open up the groove 121 of accomodating along the fore-and-aft direction, the rotation end of the big arm body 6 stretches into accomodate in the groove 121 and rotate and install middle support frame body 12 rear portion, it is located to accomodate being provided with in the groove 121 the lifting push rod 14 of big arm body 6 below, the rotation of lifting push rod 14 front end is connected and is stretched into in big arm body 6 below rear end accomodate in the groove 121 and rotate and install on middle support frame body 12, lifting push rod 14 promotes through flexible big arm body 6 for the swing of middle support frame body 12. The accommodating groove 121 is defined by the solid structure of the middle support frame 12, and the rotating end of the large arm body 6 and the rear end of the lifting push rod 14 extend into the accommodating groove 121 and are mounted on the solid structure of the middle support frame 12, so that the whole middle support frame 12 can be stably supported, and the small arm body 7 can be kept stable all the time in the process of wide-amplitude movement. Preferably the lifting ram 14 is driven by a hydraulic ram.

In this embodiment, the middle support frame 12 includes a bottom plate 122 and two left and right side plates 123, the bottom plate 122 and the two left and right side plates 123 enclose the storage groove 121, a first rotating support rod 151 for the lifting push rod 14 to rotate and mount and a second rotating support rod 152 for the upper arm body 6 to rotate and mount are disposed in the storage groove 121, the first rotating support rod 151 and the second rotating support rod 152 are transversely erected left and right between the two left and right side plates 123. First rotation branch 151 and second rotation branch 152 are fixed on middle braced frame body 12, and its structural strength and stability are higher, and then middle braced frame body 12 is to the intensity and the stability of the supporting role of forearm body 6 and lifting push rod 14, and first rotation branch 151 wears to establish in the rotation end of forearm body 6, makes the forearm body 6 rotate, second rotation branch 152 wears to establish in the rear end of lifting push rod 14, makes lifting push rod 14 can rotate. Further improve, preferably middle support frame 12 still includes transversely erects two about baffle 124 between the curb plate 123, baffle 124 will accomodate groove 121 and divide into upper groove 1212 and lower groove 1211, first rotation branch 151 is located in lower groove 1211, second rotation branch 152 is located in upper groove 1212, the last mouth 1241 of dodging that link up from top to bottom that has of baffle 124, lifting push rod 14 can pass through dodge mouth 1241 and swing to in the upper groove 1212, guarantee lifting push rod 14 to the lift effect of forearm body 6. The partition plate 124 not only enhances the structural strength of the middle support frame 12, but also separates the first rotating support rod 151 and the second rotating support rod 152 into the upper groove 1212 and the lower groove 1211, so that the middle support frame 12 is stressed uniformly, the stress concentration degree at a certain position of the middle support frame 12 is reduced, and the service life is prolonged; the partition 124 can also support the boom 6 to a certain extent in a state where the entire boom 6 is laid down in the lateral direction.

The large arm body 6 moves in the upper groove 1212 and the space above the upper groove 1212, and the rotating end of the large arm body 6 mainly extends into the upper groove 1212, so that it is preferable that the left and right side plates 123 have tail wing portions 1231 which are located at the rear and protrude upward, the tail wing portions 1231 are located above the partition plate 124, and the upper groove 1212 is defined by the left and right tail wing portions 1231 and the partition plate 124. Thus, the upper groove 1212 is used only to receive the pivoting end of the upper arm 6, reducing the material cost of the side plate 123. Thus, the upper groove 1212 is only a small portion located at the rear of the middle support frame 12, and the lower groove 1211 is still an elongated cavity extending in the front-rear direction and formed by sandwiching the main body portion of the side plate 123 except the tail portion 1231. Further improve, preferably middle braced frame 12 still includes backplate 125, backplate 125 sets up two about between the curb plate 123 and from the rear shutoff accomodate the groove 121, backplate 125 has both improved middle braced frame 12's structural strength and stability, can cover first rotation branch 151 and second rotation branch 152 position again, avoids the foreign matter to get into the influence and rotates, plays the guard action.

In a further improvement, preferably, the middle supporting frame 12 further includes a reinforcing rib plate 126 disposed in the lower groove 1211, the reinforcing rib plate 126 is upright and is simultaneously fixedly connected to the side plate 123 and the bottom plate 122, so as to support and reinforce the middle supporting frame 12, and the reinforcing rib plate 126 is provided with an avoiding groove 1261 with an upward opening, so as to avoid interference between the lifting push rod 14 and the reinforcing rib plate 126 during the swinging process. Preferably, the bottom plate 122 has a bearing portion 1221 extending below the side attachment frame 13, and the side attachment frame 13 is located on the bearing portion 1221 and is fixedly connected to the bearing portion 1221, so that compactness and integrity of the side attachment frame 13 and the intermediate support frame 12 are improved, and attachment stability of the side attachment frame 13 is also improved. Further, it is preferable that the side attachment frame body 13 includes side attachment plates 131 which are fixedly attached to the side plates 123 of the intermediate support frame body 12, so that the side attachment frame body 13 clamps the intermediate support frame body 12 from both the left and right sides, thereby further improving the structural strength and stability of the intermediate support frame body 12, and further improving the attachment strength and stability of the boom body 6 and the lift push rod 14 to the intermediate support frame body 12.

The running chassis a adopts the specific implementation mode in the first embodiment in the specification.

The lifting arm assembly b adopts the specific implementation mode in the second embodiment in the specification.

The straight arm type aerial work platform convenient to transport is large-scale aerial work equipment, the length of a large arm body 6 in a lifting arm assembly b is very long, and the length of a small arm body 7 is added, so that the length and the height of the whole straight arm type aerial work platform are very large, the width of the straight arm type aerial work platform after a traveling chassis a expands a bridge is very large, and when the straight arm type aerial work platform is transported by using common transport carriers such as a freight cabinet, a flat car and the like, the straight arm type aerial work platform needs to be retracted to the shortest state in length, width and height, so that the straight arm type aerial work platform can meet the container loading requirement in the transport carriers, particularly the freight cabinet, the transportation is convenient, and the transportation cost is reduced. Specifically, the lifting arm assembly b is integrally retracted to the state shown in fig. 1, and the traveling chassis a is integrally retracted to the state shown in fig. 1, so that the total length, the total width and the total height of the straight arm type aerial work platform convenient to transport can meet the container loading requirements of the freight container. Further, if the straight-arm type aerial work platform convenient to transport cannot meet the loading requirement of the freight cabinet after adjustment, tires in the running chassis a are replaced by special tires only used for loading and transporting, such as iron tires, the axial thickness and the radial width of the tires are smaller than those of original tires, and the width and the height of the straight-arm type aerial work platform convenient to transport are reduced by reducing the size of the tires, so that the straight-arm type aerial work platform convenient to transport can meet the loading requirement. The special tires are only used when being assembled in a cabinet, and after the straight arm type aerial work platform is conveyed to a destination, the special tires need to be replaced by original tires for actual use.

While the invention has been described with reference to specific embodiments, the invention is not limited thereto, and various equivalent modifications and substitutions can be easily made by those skilled in the art within the technical scope of the invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. The running chassis capable of expanding the bridge in situ is characterized by comprising a main frame (1), a wheel assembly (2) and a front axle unit and a rear axle unit (3), wherein the axle units (3) comprise a left half-bridge structure and a right half-bridge structure (4) which are symmetrically arranged and respectively rotatably connected to the main frame (1), and one end, far away from the main frame (1), of each half-bridge structure (4) is rotatably connected with the wheel assembly (2); the axle unit (3) further comprises a first urging means capable of urging the half-bridge structure (4) to oscillate in a horizontal direction with respect to the main frame (1), and a second urging means capable of urging the wheel assembly (2) to rotate in a horizontal direction with respect to the half-bridge structure (4) until a rolling direction of the wheel assembly (2) coincides substantially tangentially with an oscillation direction of the half-bridge structure (4).

2. The running chassis capable of expanding a bridge in situ according to claim 1, wherein the wheel assembly (2) comprises a wheel carrier (21), a tire (22) mounted on the wheel carrier (21) and a hydraulic motor (23) for driving the tire (22), the hydraulic motor (23) is connected with a bypass valve through a pipeline, and the bypass valve can bypass an oil path of the hydraulic motor (23) after being opened and enables the hydraulic motor (23) to rotate under the action of external force.

3. The running chassis capable of expanding a bridge in situ according to claim 1, wherein the half-bridge structure (4) comprises a supporting swing arm (41), the first pushing device comprises a left push rod and a right push rod (51) which respectively act on the half-bridge structure (4) on the same side, one end of the first push rod (51) is rotatably connected to the main frame (1), the other end of the first push rod is rotatably connected to the swinging end of the supporting swing arm (41), the first push rod (51), the supporting swing arm (41) and the main frame (1) form a triangular structure, and the first push rod (51) pushes the swinging of the supporting swing arm (41) through telescoping.

4. A vehicle chassis capable of expanding a bridge in situ according to claim 3, wherein the half-bridge structure (4) further comprises a mounting bracket (42) mounted at the swinging end of the supporting swinging arm (41), and the wheel assembly (2) is rotatably connected to the mounting bracket (42) through the wheel carrier (21); the second pushing device comprises a left second pushing rod and a right second pushing rod (52) which respectively act on the wheel assembly (2) on the same side, one end of each second pushing rod (52) is rotatably installed on the installation support (42), the other end of each second pushing rod is rotatably connected with the wheel carrier (21), and the second pushing rods (52) stretch to push the wheel assembly (2) to rotate.

5. The chassis capable of expanding a bridge in situ according to claim 4, wherein the mounting bracket (42) comprises an inner protruding portion (421), an outer protruding portion (423) and an intermediate connecting portion (422) therebetween, the swing end of the supporting swing arm (41) is rotatably connected to the intermediate connecting portion (422), the wheel assembly (2) is mounted on the outer protruding portion (423), and one end of the second push rod (52) is rotatably connected to the inner protruding portion (421).

6. The chassis capable of expanding a bridge in situ according to claim 5, wherein the half-bridge structure (4) further comprises a parallel swing arm (43) rotatably connected to the main frame (1) at one end and rotatably connected to the inner extension portion (421) of the mounting bracket (42) at the other end, the parallel swing arm (43) is parallel to the supporting swing arm (41), the parallel swing arm (43), the mounting bracket (42) and the main frame (1) form a parallelogram structure, and the swing ends of the mounting bracket (42) and the supporting swing arm (41) are rotatably connected.

7. The running chassis capable of expanding a bridge in situ according to claim 6, wherein the axle unit (3) further comprises a first angle sensor capable of detecting a swing angle of the supporting swing arm (41) and transmitting the swing angle to the bridge expansion controller, a second angle sensor capable of detecting a rotation angle of the wheel assembly (2) and transmitting the rotation angle to the bridge expansion controller, and a first module for matching the swing angle of the supporting swing arm (41) with the rotation angle of the wheel assembly (2) by controlling the first push rod (51) and the second push rod (52) is disposed in the bridge expansion controller.

8. A vehicle chassis according to claim 5, wherein the inner extension (421) of the mounting bracket (42) has an abutment surface (424) facing away from the wheel assembly (2), the abutment surface (424) being provided with a cushion.

9. The running chassis capable of expanding a bridge in situ according to claim 4, wherein the first pushing device further comprises a swing oil cylinder, and the swing oil cylinder provides power for the first push rod (51); the second pushing device further comprises a steering oil cylinder, and the steering oil cylinder provides power for the second push rod (52).

10. An aerial work platform comprising a travel chassis as claimed in any one of claims 1 to 9.