A traveling chassis and an aerial work platform capable of expanding a bridge in place

Abstract

The present invention relates to the technical field of aerial work equipment, and particularly relates to a traveling chassis and an aerial work platform capable of expanding the bridge in place. The traveling chassis includes a main frame, a wheel assembly, and two front and rear axle units. The axle unit includes two symmetrical half-bridge structures respectively rotatably connected to the main frame, and a wheel assembly is rotatably connected to one end of each half-bridge structure away from the main frame; the axle unit further includes a first pushing device and a second pushing device. The first pushing device can push the half-bridge structure to swing relative to the main frame in the horizontal direction, and the second pushing device can push the wheel assembly to rotate relative to the half-bridge structure in the horizontal direction until the rolling direction of the wheel assembly is substantially consistent with the tangential direction of the swing of the half-bridge structure. By pushing the wheel assembly and rotating it until its rolling direction is consistent with the tangential direction of the swing of the half-bridge structure, the wheel assembly rolls synchronously during the swinging process, thereby realizing the in-place bridge expansion of the traveling chassis.

Description

Technical Field

[0001] The present invention relates to the technical field of aerial work equipment, and particularly relates to a traveling chassis and an aerial work platform capable of expanding a bridge in place. Background Art

[0002] The tire-type chassis of a self-propelled aerial work platform bears the mass of the whole vehicle and drives the whole vehicle to move. When the whole vehicle is moving, considering the passability problem, the width of the tire-type chassis is limited. When the whole vehicle is performing aerial work, considering the stability of the whole vehicle, it is necessary to increase the overall width of the tire-type chassis to improve the stability of its support for the whole vehicle. To balance the above two situations, the currently common method is to add a bridge expansion function to the tire-type chassis, that is, the tire-type chassis is in a narrower state during walking to ensure passability, and the tire-type chassis is in a wider state after bridge expansion during aerial work to improve the support stability.

[0003] For example, a compact aerial vehicle chassis bridge expansion system disclosed in the patent with the application number CN201210108101.1 includes a vehicle frame and tire assemblies installed at the four corners of the frame. Bridge expansion mechanisms are provided between the tire assemblies and the vehicle frame to move the tire assemblies away from or close to the vehicle frame along the axial direction of the tire assemblies. A telescopic vertical support mechanism is provided on the vehicle frame. When the bridge expansion system in this patent expands the bridge, the bridge expansion driving mechanism drives the bridge expansion mechanism to move and extend, so that the tire assemblies move outwards and expand, improving the stability of the chassis support. In the above process, the tire assemblies need to overcome the sliding friction with the ground, which not only requires a higher driving force for the bridge expansion driving mechanism, but also causes damage to the tires and the ground, and also generates noise. Another example is an aerial work vehicle bridge expansion mechanism disclosed in the patent with the application number CN201821880951.2, which includes a vehicle frame, a front telescopic bridge assembly, and a rear telescopic bridge assembly. The vehicle frame is connected to the front telescopic bridge assembly through a floating shaft, and the vehicle frame is connected to the rear telescopic bridge assembly through a floating shaft, and the floating shaft is fixed; the front telescopic bridge assembly includes a front cross arm, a first left telescopic shaft, a first right telescopic shaft, a steering knuckle, a front telescopic shaft oil cylinder, a cross rod oil cylinder, and a steering oil cylinder; the rear telescopic bridge assembly includes a rear cross arm, a second left telescopic shaft, a second right telescopic shaft, and a rear telescopic shaft oil cylinder. This patent can control the telescoping of the front axle and the rear axle through hydraulic pressure, and control the maximum and minimum positions of the telescoping of the front axle and the rear axle through mechanical limits. This function realizes bridge expansion during walking by receiving an electrical signal when the oil cylinder is resisted during walking and then giving a corresponding bridge expansion feedback. However, when the work vehicle stops in place, bridge expansion cannot be realized. Summary of the Invention

[0004] The present invention makes improvements to address the problems existing in the above-mentioned prior art. That is, the technical problem to be solved by the present invention is to provide a traveling chassis capable of expanding a bridge in place, which includes a main frame, a wheel assembly, and two front and rear axle units. The axle unit includes two symmetrical left and right half-bridge structures that are respectively rotatably connected to the main frame, and the wheel assembly is rotatably connected to one end of each half-bridge structure away from the main frame; the axle unit further includes a first pushing device and a second pushing device. The first pushing device can push the half-bridge structure to swing relative to the main frame in the horizontal direction, and the second pushing device can push the wheel assembly to rotate relative to the half-bridge structure in the horizontal direction until the rolling direction of the wheel assembly is substantially consistent with the tangential direction of the swing of the half-bridge structure.

[0005] As a preference of the present invention, the wheel assembly includes a wheel carrier, a tire mounted on the wheel carrier, and a hydraulic motor for driving the tire. The hydraulic motor is connected to a bypass valve through a pipeline. After the bypass valve is opened, it can bypass the oil circuit of the hydraulic motor and enable the hydraulic motor to rotate under the action of an external force.

[0006] As a preference of the present invention, the half-bridge structure includes a support swing arm. The first pushing device includes two left and right first push rods that respectively act on the same-side half-bridge structures. One end of the first push rod is rotatably connected to the main frame, and the other end is rotatably connected to the swing end of the support swing arm. The first push rod, the support swing arm, and the main frame form a triangular structure, and the first push rod pushes the swing of the support swing arm by telescoping.

[0007] As a preference of the present invention, the half-bridge structure further includes a mounting bracket installed at the swing end of the support swing arm. The wheel assembly is rotatably connected to the mounting bracket through the wheel carrier; the second pushing device includes two left and right second push rods that respectively act on the same-side wheel assemblies. One end of the second push rod is rotatably installed on the mounting bracket, and the other end is rotatably connected to the wheel carrier. The second push rod pushes the rotation of the wheel assembly by telescoping.

[0008] As a preference of the present invention, the mounting bracket includes an inner extension part, an outer extension part, and an intermediate connection part located between the two. The swing end of the support swing arm is rotatably connected to the intermediate connection part, the wheel assembly is installed on the outer extension part, and one end of the second push rod is rotatably connected to the inner extension part.

[0009] Preferably, in the present invention, the half-bridge structure further includes a parallel swing arm with one end rotatably connected to the main frame and the other end rotatably connected to the inner protruding portion of the mounting bracket. The parallel swing arm is parallel to the support swing arm, and the support swing arm, the parallel swing arm, the mounting bracket, and the main frame enclose a parallelogram structure. There is a rotational connection between the swinging end of the mounting bracket and the support swing arm.

[0010] Preferably, in the present invention, the axle unit further includes a first angle sensor, a second angle sensor, and a bridge expansion controller. The first angle sensor can detect the swinging angle of the support swing arm and transmit it to the bridge expansion controller. The second angle sensor can detect the rotational angle of the wheel assembly and transmit it to the bridge expansion controller. The bridge expansion controller is electrically connected to the first push rod and the second push rod, and a first module is provided in the bridge expansion controller to make the swinging angle of the support swing arm match the rotational angle of the wheel assembly by controlling the first push rod and the second push rod.

[0011] Preferably, the inner protruding portion of the mounting bracket has an abutting surface facing away from the wheel assembly, and a buffer pad is provided on the abutting surface.

[0012] Preferably, the first driving device further includes a swing oil cylinder, and the swing oil cylinder provides power for the first push rod; the second driving device further includes a steering oil cylinder, and the steering oil cylinder provides power for the second push rod.

[0013] An aerial work platform includes the traveling chassis.

[0014] Beneficial effects:

[0015] In-situ bridge expansion is achieved. Moreover, during the bridge expansion process, the movement form of the wheel assembly is rolling, and the friction between it and the ground is rolling friction. Compared with sliding friction, rolling friction is easier to overcome. Therefore, the thrust requirement for the first driving device during the bridge expansion process is lower, and the cost is controlled. In addition, the rolling of the wheel assembly also avoids its own wear and the generation of noise. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is the overall structural schematic diagram of the straight-arm aerial work platform;

[0017] Figure 2 is the structural schematic diagram of the turntable;

[0018] Figure 3 is the structural schematic diagram of the intermediate support frame;

[0019] Figure 4Schematic diagram of the partition dividing the storage groove into an upper groove and a lower groove;

[0020] Figure 5 Schematic diagram of the components in the storage groove;

[0021] Figure 6 Schematic diagram of the rear baffle;

[0022] Figure 7 Schematic diagram of the positional relationship of the half-bridge structure, the first push rod and the wheel assembly;

[0023] Figure 8 Schematic diagram of the overall structure of the traveling chassis;

[0024] Figure 9 Schematic diagram of the structure of the half-bridge structure;

[0025] Figure 10 Schematic diagram of the structure of the mounting bracket;

[0026] Figure 11 Schematic diagram of the structure of the wheel assembly;

[0027] Figure 12 Schematic diagram of the lifting arm assembly for the aerial work field;

[0028] Figure 13 Schematic diagram of the overall structure of the lifting arm assembly;

[0029] Figure 14 Schematic diagram of the luffing connection device when the small arm body is fully retracted;

[0030] Figure 15 Schematic diagram of the first cavity, the second cavity and the third cavity;

[0031] Figure 16 Schematic diagram of the small arm body swinging from the fully retracted state to the maximum deployment angle relative to the large arm body;

[0032] Figure 17 Schematic diagram of the luffing connection device when the small arm body is deployed to the maximum swing angle;

[0033] Figure 18 Schematic diagram of the connection between the working platform and the small arm body;

[0034] Figure 19 Schematic diagram of the fourth cavity, the fifth cavity and the sixth cavity;

[0035] Figure 20 Schematic diagram of the leveling connection device when the second telescopic push rod extends to the maximum stroke;

[0036] Figure 21 Schematic diagram of the leveling connection device when the second telescopic push rod is fully retracted;

[0037] In the figure: a, traveling chassis; b, lifting arm assembly; c, turntable; 12, intermediate support frame; 121, storage groove; 1211, lower groove; 1212, upper groove; 122, bottom plate; 1221, bearing part; 123, side plate; 1231, tail wing part; 124, partition; 1241, avoidance opening; 125, rear baffle; 126, reinforcing rib plate; 1261, avoidance groove; 13, side mounting frame; 131, side mounting plate; 14, lifting push rod; 151, first rotating support rod; 152, second rotating support rod; 1, main frame; 2, wheel assembly; 21, wheel frame; 22, tire; 23, hydraulic motor; 3, axle unit; 4, half-bridge structure; 41, support swing arm; 42, mounting bracket; 43, parallel swing arm; 421, inner extending part; 422, intermediate connecting part; 423, outer extending part; 424, abutting surface; 51, first push rod; 52, second push rod; 6, boom body; 61, boom body assembly; 7, forearm body; 71, forearm body assembly; 72, swing head assembly; 8, luffing connection device; 81, first telescopic push rod; 82, first transmission rod; 83, first guiding swing rod; 91, first cavity; 92, second cavity; 93, third cavity; 94, fourth cavity; 95, fifth cavity; 96, sixth cavity; 10, working platform; 101, platform head assembly; 11, leveling connection device; 111, second telescopic push rod; 112, second transmission rod; 113, second guiding swing rod. Specific embodiments

[0038] The following specific embodiments are only explanations of the present invention, and they do not limit the present invention. After reading this specification, those skilled in the art can make modifications to this embodiment without creative contributions as needed, but as long as they are within the scope of the claims of the present invention, they are protected by the patent law.

[0039] Embodiment 1:

[0040] A driving chassis capable of expanding the bridge in place according to the present invention includes a main frame 1, a wheel assembly 2, and two front and rear axle units 3. The axle unit 3 includes two symmetrical half-bridge structures 4 that are respectively rotatably connected to the main frame 1, and the wheel assembly 2 is rotatably connected to one end of each half-bridge structure 4 away from the main frame 1. To achieve the bridge expansion function, the two front and rear axle units 3 need to be able to expand the bridge respectively, that is, the left and right half-bridge structures 4 in one axle unit 3 can move away from and close to each other. Therefore, the axle unit 3 further includes a first pushing device and a second pushing device. The first pushing device can push the half-bridge structure 4 to swing relative to the main frame 1 in the horizontal direction, and the second pushing device can push the wheel unit to rotate relative to the half-bridge structure 4 in the horizontal direction until the rolling direction of the wheel assembly 2 is substantially consistent with the tangential direction of the swing of the half-bridge structure 4. When expanding the bridge, first, the second pushing device is used to push the wheel assembly 2 and make it rotate until its rolling direction is substantially consistent with the tangential direction of the swing of the half-bridge structure 4, and then the first pushing device is started to push the half-bridge structure 4 to swing outward relative to the main frame 1, that is, the left and right half-bridge structures 4 in one axle unit 3 swing away from each other. During the swinging process, the wheel assembly 2 rolls forward synchronously, thereby realizing the in-place bridge expansion of the driving chassis. In the above bridge expansion process, the movement form of the wheel assembly 2 is rolling, and the friction between it and the ground is rolling friction. Compared with sliding friction, rolling friction is easier to overcome. Therefore, the thrust requirement for the first pushing device is lower during the bridge expansion process, and the cost is controlled. Moreover, the rolling of the wheel assembly 2 also avoids its own wear and the generation of noise.

[0041] The traveling chassis is mainly used in the field of aerial work platform vehicles. In this field, four-wheel drive is usually selected to ensure the passability of the aerial work platform vehicle. Therefore, in this embodiment, it is preferred that the wheel assembly 2 includes a wheel carrier 21, a tire 22 mounted on the wheel carrier 21, and a motor for driving the tire 22 to achieve four-wheel drive. During bridge expansion, in one implementation, while the first pushing device pushes the half-bridge structure 4 to swing, the motor drives the tire 22 to roll forward, further reducing the requirement for the thrust of the first pushing device during the bridge expansion movement and reducing the cost of the first pushing device. However, the combination of two different forms of power will make it difficult to control the total bridge expansion power. Moreover, the wheel assembly 2 itself is rolling forward. As long as the resistance of the tire 22 in the wheel assembly 2 to rotate under external force is small, then relying only on the thrust of the first thrust device for bridge expansion will not have a very high requirement for the magnitude of its thrust. Therefore, in this embodiment, it is preferred that the motor is a hydraulic motor 23, and the hydraulic motor 23 is connected to a bypass valve through a pipeline. After the bypass valve is opened, it can bypass the oil circuit of the hydraulic motor 23 and enable the hydraulic motor 23 to rotate under external force; during bridge expansion, open the bypass valve to bypass the A port and B port in the hydraulic motor 23. Then, when the hydraulic motor 23 does not start itself, its main shaft can rotate under external force. In this way, while the half-bridge structure 4 swings, it can push the tire 22 to roll without relying on the power of the hydraulic motor 23, reducing the cost. Moreover, only by the thrust of one first pushing device to swing the half-bridge structure 4, it is also easier to control the entire bridge expansion process. Of course, usually, a speed reducer is also provided between the hydraulic motor 23 and the tire 22, and the brake of the speed reducer needs to be released during bridge expansion.

[0042] Under normal circumstances, the bridge expansion movement of the axle unit 3 is that the left and right half-bridge structures 4 swing away from each other simultaneously. One implementation of the first pushing device can be to push the left and right half-bridge structures 4 to swing simultaneously, and another implementation is to push the left and right half-bridge structures 4 to swing separately. However, in this embodiment, the left and right half-bridge structures 4 have a high degree of independence and less structural connection with each other. Therefore, the second implementation is preferably adopted above, which can also meet the independent swing of the half-bridge structure 4. Specifically, in this embodiment, it is preferred that the half-bridge structure 4 includes a support swing arm 41, and the first pushing device includes two first push rods 51 that act on the same-side half-bridge structures 4 respectively. One end of the first push rod 51 is rotatably connected to the main frame 1, and the other end is rotatably connected to the swing end of the support swing arm 41. The swing end is the end far from the main frame 1. The first push rod 51, the support swing arm 41, and the main frame 1 form a triangular structure. Therefore, by making the first push rod 51 expand and contract, the support swing arm 41 can be pushed to swing. Of course, during this process, the first push rod 51 itself also swings accordingly. This not only enables the swing angle range of the support swing arm 41 to be larger, but also makes the structural stability higher, which helps to improve the bridge expansion stability and also helps to improve the support strength of the support swing arm 41 for the entire driving chassis.

[0043] Before bridge expansion, it is necessary to first use the second driving device to drive the wheel assembly 2 to rotate until the rolling direction of the wheel assembly 2 is generally consistent with the swing tangential direction of the half-bridge structure 4. The left wheel assembly 2 in the axle unit 3 is installed on the left half-bridge structure 4, and the right wheel assembly 2 is installed on the right half-bridge structure 4. The traveling chassis in this embodiment has two usage states before and after bridge expansion. One is the normal traveling posture before bridge expansion. At this time, to ensure passability and make the traveling chassis as narrow as possible, the half-bridge structure 4 as a whole is generally in a front-to-back extension state in this state. The ends of the two half-bridge structures 4 far from the main frame 1 are close to each other, and the two wheel assemblies 2 are also close to each other, and the traveling chassis is in the narrowest state as a whole; the other is the stopped state after bridge expansion. At this time, the left and right half-bridge structures 4 in the axle unit 3 swing away from each other by a large angle, and the left and right wheel assemblies 2 are far from each other. If a set of structures of the second driving device acts on the left and right wheel assemblies 2 at the same time, when expanding the bridge in the above normal traveling posture, due to the left and right half-bridge structures 4 being too close, interference may occur during the process of rotating them to make their rolling directions generally consistent with the swing tangential direction, resulting in failure to rotate in place; and in the posture after the above bridge expansion, the distance between the left and right wheel assemblies 2 is relatively large, and the second driving device itself requires a large stroke, resulting in increased costs. Therefore, in this embodiment, it is preferably that the half-bridge structure 4 further includes a mounting bracket 42 installed at the swing end of the support swing arm 41. The wheel assembly 2 is rotatably connected to the mounting bracket 42 through the wheel frame 21; the second driving device includes two second push rods 52 respectively acting on the wheel assemblies 2 on the same side. One end of the second push rod 52 is rotatably installed on the mounting bracket 42, and the other end is rotatably connected to the wheel frame 21. The second push rod 52 drives the rotation of the wheel assembly 2 by telescoping. The mounting bracket 42 is both for installing the second push rod 52, so that the left and right second push rods 52 operate independently, and only the stroke needs to be ensured so that the rotatable angle range of the wheel assembly 2 meets the requirements, with low cost; and it is also for installing the wheel assembly 2, so that the left and right wheel assemblies 2 still maintain a certain distance when approaching each other, avoiding interference between them during rotation.

[0044] For further improvement, it is preferred that the mounting bracket 42 includes an inner protruding portion 421, an outer protruding portion 423 and an intermediate connecting portion 422 located therebetween. The swinging end of the support 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 frame 21 of the wheel assembly 2. Therefore, the mounting bracket 42 not only ensures the stable installation of the second push rod 52, but also the second push rod 52 straddles the mounting bracket 42, and the length of the mounting bracket 42 in the horizontal direction is used to effectively ensure the telescopic stroke of the second push rod 52. Moreover, when the left and right wheel assemblies 2 approach each other before bridge expansion, there are two mounting brackets 42 spaced between them, further ensuring that the two wheel assemblies 2 will not interfere with each other during rotation.

[0045] During the bridge expansion process, it is necessary to ensure that the rolling direction of the tire 22 in the wheel assembly 2 is generally consistent with the tangential direction of the swing of the swing end of the support swing arm 41. This is achieved by controlling the angular relationship between the wheel assembly 2 and the support swing arm 41. However, the presence of the mounting bracket 42 will affect the angular relationship between the wheel assembly 2 and the support swing arm 41. There are two implementation methods here. The first is that the mounting bracket 42 is fixedly connected to the support swing arm 41. Then, during the bridge expansion process, the mounting bracket 42 will not affect the angular relationship between the wheel assembly 2 and the support ring swing arm. However, the mounting bracket 42 is only fixed on the support swing arm 41, and its stability is relatively low. The second is that the mounting bracket 42 is rotatably connected to the support swing arm 41. Then, during the bridge expansion process, the mounting bracket 42 may rotate relative to the support swing arm 41, resulting in the angular relationship between the wheel assembly 2 and the support swing arm 41 being affected. Of course, by setting an angle sensor, a controller, etc. to control the rotation angle of the wheel assembly 2, the influence of the mounting bracket 42 can still be eliminated. However, too many variables will lead to a complex algorithm, increased costs, and a decrease in the accuracy of actual angle matching, which has an adverse effect on the bridge expansion. Considering the problems faced by the above two implementation methods comprehensively, in this embodiment, further improvements are made. 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 support swing arm 41, and the support swing arm 41, the parallel swing arm 43, the mounting bracket 42, and the main frame 1 enclose a parallelogram structure. There is a rotatable connection between the mounting bracket 42 and the swing end of the support swing arm 41. In this way, the half-bridge structure 4 is an integral body composed of the support swing arm 41, the parallel swing arm 43, and the mounting bracket 42. Among them, the support swing arm 41 is the main functional structure, and the parallel swing arm 43 swings synchronously with the support swing arm 41. The presence of the parallel swing arm 43 can not only share the support function of the support swing arm 41 for the entire running chassis, improve the overall strength and bearing capacity of the half-bridge structure 4, but also improve the installation firmness of the mounting bracket 42 in the half-bridge structure 4, and at the same time improve the smoothness of the mounting bracket 42 during the movement of the half-bridge structure 4, thereby ensuring the accuracy and measurability of the positional relationship between the wheel assembly 2 and the support swing arm 41. Due to the parallelogram structure of the above half-bridge structure 4 and the presence of four rotatable connection parts thereon, during the bridge expansion process, the support swing arm 41 and the parallel swing arm 43 maintain parallel synchronous swinging, and the mounting bracket 42 is always parallel to the connection line between the two rotatable connection parts of the half-bridge structure 4 on the main frame 1. These two rotatable connection parts are the rotatable connection parts of the support swing arm 41 and the parallel swing arm 43 with the main frame 1. In short, this makes the overall position direction of the mounting bracket 42 determined. During the bridge expansion process, the mounting bracket 42 is translated as a whole, so the mounting bracket 42 will not affect the position accuracy of the wheel assembly 2.Therefore, during the bridge expansion process, as long as the two variables of the swing angle of the support swing arm 41 and the rotation angle of the wheel assembly 2 are controlled, it can be ensured that the rolling direction of the wheel assembly 2 is generally consistent with the swing tangent of the half-bridge structure 4, thereby realizing the smooth bridge expansion.

[0046] For the control of the swing angle of the support swing arm 41 and the rotation angle of the wheel assembly 2, real-time precise monitoring and feedback are required, so it needs to be realized through a control system. Specifically, in this embodiment, it is preferably 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 support swing arm 41 and transmit it to the bridge expansion controller. The second angle sensor can detect the rotation angle of the wheel assembly 2 and transmit it to the bridge expansion controller. The bridge expansion controller is electrically connected to the first push rod 51 and the second push rod 52, and a first module for making the swing angle of the support swing arm 41 match 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 actual experiments, it can be known that under the condition of always keeping the rolling direction of the wheel assembly 2 generally consistent with the swing tangent of the half-bridge structure 4, the rotation angle of the wheel assembly 2 corresponding to each swing angle of the support swing arm 41. This mapping relationship needs to be written into the first module. Based on this, in the actual bridge expansion process, the first module can be used to realize real-time control so that the above two angles can always be corresponding, thereby realizing the smooth bridge expansion.

[0047] In this embodiment, the traveling chassis is preferably as narrow as possible in the normal traveling posture to ensure passability. Therefore, in the normal traveling posture, the two half-bridge structures 4 on the left and right are close to each other, reducing the width of the traveling chassis. Moreover, this also enables the width of the traveling chassis to meet the loading requirements of the width dimensions of common freight containers, flatbed trucks and other transport vehicles, facilitating transportation and reducing transportation costs. When the traveling chassis is used on an aerial work platform to form a whole vehicle, the two half-bridge structures 4 being close to each other can reduce the width of the whole vehicle, enabling the whole vehicle to meet the width dimension requirements of common freight containers, flatbed trucks and other transport vehicles, facilitating transportation and reducing transportation costs.

[0048] After the two half-bridge structures 4 approach each other, a small gap can be left between them, or they can be abutted against each other to minimize the width as much as possible. When they are abutted against each other, not only is the left-right width of the driving chassis relatively narrow, but also the two half-bridge structures 4 support each other, thereby ensuring the overall stability of the axle unit 3. When the driving chassis changes from the bridge-expanding posture to the normal driving posture, the left and right half-bridge structures 4 swing towards each other until they are abutted against each other. Therefore, in this embodiment, it is preferred 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 be abutted against each other through the abutting surface 424, and a buffer pad is provided on the abutting surface 424 to reduce the damage and noise caused by collisions. Further, it is preferred that the first pushing device further includes a swing oil cylinder, and the swing oil cylinder provides power for the first push rod 51; the second pushing device further includes a steering oil cylinder, and the steering oil cylinder provides power for the second push rod 52. By adopting the power form of the oil cylinder, it is ensured that sufficient large driving force can be provided for the first push rod 51 and the second push rod 52, and the smooth realization of the bridge-expanding operation is ensured.

[0049] The driving chassis can be used in existing aerial work platform vehicles, or can also be used in the aerial work platform vehicles in Embodiment 2 and Embodiment 3 below. An aerial work platform of the present invention includes the driving chassis.

[0050] Embodiment 2:

[0051] A lifting arm assembly of the present invention includes a boom body 6, a forearm body 7, and a luffing connection device 8. The boom body 6 can also swing by itself. Therefore, the swinging end thereof is the lifting end, and the end of the forearm body 7 mounted on the boom body 6 is the fulcrum end. The lifting end of the boom body 6 is rotatably connected to the fulcrum end of the forearm body 7. The luffing connection device 8 includes 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 boom body 6, and the front end is rotatably connected to the rear end of the first transmission rod 82. The first transmission rod 82 is located between the boom body 6 and the forearm body 7, and the front end is rotatably connected to the fulcrum end of the forearm body 7. The luffing connection device 8 drives the forearm body 7 to rotate relative to the boom body 6. Therefore, the boom body 6 can be regarded as a stationary reference datum during motion analysis. During the process of the first transmission rod 82 being pushed to move, both the front end and the rear end thereof are movable relative to the boom body 6. So the whole first transmission rod 82 generates a change in direction and displacement, and the forearm body 7 swings following the displacement of the front end of the first transmission rod 82. Specifically, the first telescopic push rod 81 performs telescopic motion, driving the rear end of the first transmission rod 82 to generate synchronous displacement along the same path. At the same time, the first transmission rod 82 changes direction, pulling or pushing the forearm body 7 to make it swing relative to the boom body 6. Since the whole first transmission rod 82 is not restricted by the rest, the amplitude and range of its overall change in direction and displacement are very large. In this way, the range of displacement of the rear end of the first transmission rod 82 rotatably connected to the forearm body 7 is very large, and then the angle range of swing of the forearm body 7 is relatively large, realizing a wide luffing of the forearm body 7 relative to the boom body 6, so that the lifting arm assembly can be applied to various complex environments and reduce the working blind area. Moreover, when not in use, the boom body 6 and the forearm body 7 can be completely pulled back to a state where the forearm body 7 is substantially parallel to the boom body 6, as Figure 1 shown in the state, improving the compactness, reducing the space occupied by the lifting arm assembly, and reducing the storage space cost. Especially when using common transport carriers such as freight containers for transportation, when the lifting arm assembly is in Figure 1 the retracted state, its total length and height can meet the requirements of container loading, facilitating transportation and reducing the transportation cost. At the same time, the lifting arm assembly is mainly used for being mounted on an aerial work vehicle for use. The improvement of the compactness in the overall retracted state of the lifting arm assembly is also beneficial to ensuring the passing performance of the aerial work vehicle, and reducing the length of the aerial work vehicle, so that the total length and total height of the aerial work vehicle can meet the requirements of container loading of common transport carriers such as freight containers, facilitating transportation and reducing the transportation cost. During the movement of the first transmission rod 82, in addition to the displacement along its own telescopic path, the front end of the first telescopic push rod 81 also generates displacement in the vertical direction following the rear end of the first transmission rod 82. Therefore, the rear end of the first telescopic push rod 81 is rotatably connected to the boom body 6, enabling the first telescopic push rod 81 to swing relative to the boom body 6 in the vertical direction.

[0052] Since the movement trajectory of the first transmission rod 82 is difficult to determine, in some cases of the above solution, the pushing of the small arm body 7 can be successfully achieved, but in some other cases, it cannot be achieved, resulting in insufficient reliability. Therefore, in this embodiment, it is preferred that the luffing connection device 8 further includes a guiding member, which is rotatably connected to the first transmission rod 82 and can limit the displacement path of the first transmission rod 82. During the process of the first transmission rod 82 being pushed by the first telescopic push rod 81, the path of the rotating connection part between the first transmission rod 82 and the guiding member is limited and determined by the guiding member, so that the overall movement trajectory of the first transmission rod 82 is determined. However, the rotation of the first transmission rod 82 relative to the guiding member still occurs, causing its own direction change. Still, the displacement of the front end of the first transmission rod 82 superimposes two forms, namely the overall displacement and the direction change of the first transmission rod 82, and the wide luffing swing of the small arm body 7 relative to the large arm body 6 can still be achieved. Specifically, it is preferred that the guiding member is a first guiding swing rod 83. The upper end of the first guiding swing rod 83 is rotatably connected to the lifting end of the large arm body 6, and the lower end is rotatably connected to the middle part of the first transmission rod 82. The first guiding swing rod 83 swings relative to the large arm body 6, and the lower end of the first guiding swing rod 83 is a swinging end with a determined trajectory, so that the movement trajectory of the part of the first transmission rod 82 rotatably connected to the first guiding swing rod 83 is determined. Without considering the rotation of the first transmission rod 82 relative to the first guiding swing rod 83 caused by the direction change, the overall displacement trajectory of the first transmission rod 82 is determined, ensuring that the first transmission rod 82 can always drive the small arm body 7 to swing during the process of the first telescopic push rod 81 pushing the first transmission rod 82. Specifically, Figure 4 The initial state where the small arm body 7 is completely retracted below the large arm body 6 is shown. The small arm body 7 is rotatably connected to the large arm body 6 at the outermost end. The first transmission rod 82 is located in the space between the large arm body 6 and the small arm body 7 and is inclined to support between the small arm body 7 and the large arm body 6. The first guiding swing rod 83 then pulls the first transmission rod 82 to limit its trajectory. 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, and the front end of the first transmission rod 82 tilts obliquely upwards. The first transmission rod 82 changes its direction with the rotating connection part with the guiding swing rod as the fulcrum, thereby pushing the small arm body 7 to swing away from the large arm body 6. At the same time, the whole of the first transmission rod 82 generates a displacement with the swinging trajectory of the rotating connection part with the first guiding swing rod 83 as the overall displacement trajectory, and together with the above-mentioned self-direction change movement, it pushes the small arm body 7 to swing away from the large arm body 6. Generally speaking, during the process of the first transmission rod 82 being pushed outwards by the first telescopic push rod 81, the first transmission rod 82 simultaneously undergoes an overall displacement following the outward swing of the first guiding swing rod 83 and a movement in which the front end continuously tilts upwards due to the rotation relative to the first guiding swing rod 83. After these two movement forms are superimposed, they act on the small arm body 7, enabling the small arm body 7 to generate a wide luffing swing relative to the large arm body 6.Figure 5 It shows the state of the small arm body 7 after swinging from the initial fully retracted state to the maximum angle, compared with Figure 4 It can be seen from the comparison that the maximum swing angle can reach 230°-240°, greatly increasing the working angle range of the lifting arm assembly, being applicable to various complex working conditions, reducing the working blind area; moreover, the luffing connection device 8 can retract the small arm body 7 to a state substantially parallel to the large arm body 6, greatly reducing the total length of the lifting arm assembly when not in use, reducing the space cost and improving the passability.

[0053] Figure 6It shows the state where the forearm body 7 swings relative to the upper arm body 6 to the maximum angle. At this time, the first telescopic push rod 81 is substantially parallel to the first guiding swing rod 83. The rotating connection part of the first guiding swing rod 83 and the upper arm body 6 blocks the first telescopic push rod 81, reaching the limit state and unable to continue pushing. The first guiding swing rod 83 reaches the maximum swing angle, that is, the overall displacement generated by the swing of the first transmission rod 82 following the first guiding swing rod 83 reaches the maximum extent. On the other hand, at this time, the rotation of the first transmission rod 82 relative to the first guiding swing rod 83 has also reached the maximum angle. The front end of the first transmission rod 82 has flipped backward and upward to be close to the rotating connection part of the first guiding swing rod 83 and the upper arm body 6. The fulcrum end of the forearm body 7 abuts against the lifting end of the upper arm body 6, reaching the limit state. Analyzing that both of the two motion forms of the first transmission rod 82 reach the limit state, it can be known that the condition determining the limit state of the first guiding swing rod 83 is determined, and the rotation of the first transmission rod 82 relative to the first guiding swing rod 83 to the limit state is also related to the selection of the rotating connection part of the first transmission rod 82 and the first guiding swing rod 83; the first transmission rod 82 is shaped like a lever. Taking the rotating connection part between it and the first guiding swing rod 83 as the boundary, it can be divided into a force transmission arm part acting on the forearm body 7 and a power arm part pushed by the first telescopic push rod 81. The rotation of the force transmission arm part is considered as the effective work done on the forearm body 7. The closer the rotating connection point of the first guiding swing rod 83 and the first transmission rod 82 is to the front end of the first transmission rod 82, the shorter the length of the above-mentioned force transmission arm part, and the longer the length of the above-mentioned power arm part. Then, when rotating the first transmission rod 82 relative to the first guiding swing rod 83 to the same limit state, the longer the maximum stroke that the first telescopic push rod 81 needs to extend. At this time, the proportion of the length of the power arm part in the overall length of the first transmission rod 82 is also larger. This part and the first telescopic push rod 81 extend outside, reducing the structural stability and compactness, and the increase in the maximum stroke of the first telescopic push rod 81 will also lead to an increase in its cost. Therefore, in this embodiment, it is preferably that the distance from the rotating connection point of the first guiding swing rod 83 and the first transmission rod 82 to the rear end of the first transmission rod 82 is less than the distance to the front end of the first transmission rod 82, reducing the requirement for the maximum stroke of the first telescopic push rod 81, and increasing the length proportion of the force transmission arm part of the first transmission rod 82 acting on the forearm body 7, obtaining more effective work on the forearm body 7, reducing the length proportion of the power arm part in the first transmission rod 82, and improving the structural stability and compactness.

[0054] During the telescopic process of the first telescopic push rod 81, there is a change in length, and it is necessary to provide it with a moving space. In this embodiment, it is preferably that the lifting end of the large arm body 6 has a hollow first cavity 91, 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 the retracted state, the small arm body 7 is close to the large arm body 6. At this time, the first telescopic push rod 81 is retracted into the first cavity 91 as a whole, realizing the avoidance of the small arm body 7 and not affecting the complete retraction of the small arm body 7. When it is necessary to push out the small arm body 7, the first telescopic push rod 81 extends out of the first cavity 91 and pushes the first transmission rod 82 outwards.

[0055] The main body of the boom 6 and the main body of the forearm 7 are both long support arms. To facilitate the rotational connection between the two and the arrangement of the luffing connection device 8, in this embodiment, it is preferred that the lifting end of the boom 6 has a boom head assembly 61 for the rotational connection of the first guiding swing rod 83, and the fulcrum end of the forearm 7 has a forearm head assembly 71 for the rotational connection of the front end of the first transmission rod 82. The boom 6 and the forearm 7 are rotationally connected through the boom head assembly 61 and the forearm head assembly 71; a hollow second cavity 92 is formed inside the boom head assembly 61, and a hollow third cavity 93 is formed inside the forearm head assembly 71. The second cavity 92 communicates with the first cavity 91, and the third cavity 93 communicates with the second cavity 92; the first cavity 91, the second cavity 92, and the third cavity 93 provide an activity space for the luffing connection device 8. Specifically, the boom head assembly 61 includes two first support plates on the left and right, and the second cavity 92 is the space sandwiched between the two first support plates. The forearm head assembly 71 includes two second support plates on the left and right, and the third cavity 93 is the space sandwiched between the two second support plates. In this way, the luffing connection device 8 can perform planar motion in a plane perpendicular to the left-right direction within the second cavity 92 and the third cavity 93, thereby driving the forearm 7 to swing relative to the boom 6 in the same plane. Of course, during the actual movement of the luffing connection device 8, part of it will extend outside the first cavity 91, the second cavity 92, and the third cavity 93. The existence of the first cavity 91, the second cavity 92, and the third cavity 93 is mainly to avoid the movement of the luffing connection device 8. Further improvement, it is preferred that the boom 6 points to the boom head assembly 61 along its own extension direction, and the first cavity 91 points to and communicates with the second cavity 92 along the extension direction of the boom 6; the forearm head assembly 71 extends out of one side of the forearm 7 and is located between the forearm 7 and the boom 6. In this way, the boom head assembly 61 is integrated with the main body of the boom 6, making the overall boom 6 still a long support arm structure, and making the boom head assembly 61 a static reference that can represent the main body of the boom 6, serving as a reference for the motion analysis of the luffing connection device 8 and the forearm 7. And the forearm head assembly 71 extending out of one side of the forearm 7 facilitates its rotational connection with the boom head assembly 61. The main body of the forearm 7 is also a long support arm structure. When the forearm 7 is fully retracted, its main body is in a state approximately parallel to the boom 6. In this state, the forearm head assembly 71 must extend out of one side of the main body of the forearm 7 to be rotationally connected with the boom head assembly 61.

[0056] The lifting arm assembly is mainly used in the field of aerial work platforms. A working platform 10 is usually installed at the swinging end of the small arm body 7. During operation, the large arm body 6 and the small arm body 7 jointly lift the working platform 10. However, the working platform 10 needs to always maintain a horizontal state to meet the usage requirements. Therefore, a leveling mechanism for leveling the working platform 10 is usually required. In the above solution, the luffing connection device 8 realizes a wide luffing of the small arm body 7 relative to the large arm body 6. This requires that the leveling angle range of the leveling mechanism is also large enough to correspondingly meet the wide luffing of the small arm body 7, that is, it is necessary to realize the matching of the leveling mechanism and the luffing connection mechanism. Obviously, the existing leveling mechanisms are difficult to meet the requirements. The lifting arm assembly of this embodiment further includes a working platform 10, a leveling connection device 11 and a platform head assembly 101. The working platform 10 is installed on the platform head assembly 101, and the platform head assembly 101 is rotatably connected to the swinging end of the small arm body 7. The leveling connection device 11 includes a second telescopic push rod 111, a second transmission rod 112 and a second guiding swing rod 113. The rear end of the second telescopic push rod 111 is rotatably connected to the small arm body 7, and the front end is rotatably connected to the rear end of the second transmission rod 112. The front end of the second transmission rod 112 is rotatably connected to the platform head assembly 101. The rear end of the second guiding swing rod 113 is rotatably connected to the small arm body 7, and the front end is rotatably connected to the middle of the second transmission rod 112. The second telescopic push rod 111 can drive the overall change of direction and displacement of the second transmission rod 112 to push the platform head assembly 101 to swing relative to the small arm body 7. Figure 9 Showing the above specific structure, the structural principle of the leveling connection device 11 is the same as that of the luffing connection device 8. The overall movement trajectory of the second transmission rod 112 is restricted by the second guiding swing rod 113. The second transmission rod 112 can also rotate relative to the second guiding swing rod 113. The superposition of these two movement forms enables the front end of the second transmission rod 112 rotatably connected to the platform head assembly 101 to generate a wide luffing displacement, so that the rotation angle range of the platform head assembly 101 relative to the small arm body 7 is large. Comparing the positions of the platform head assembly 101 in two extreme states where the second telescopic push rod 111 is fully extended and fully retracted, it can be seen that the rotation angle range of the platform head assembly 101 is also approximately 230°-240°, thus realizing the matching of the luffing range of the platform head assembly 101 and the luffing range of the small arm body 7. No matter what angle the small arm body 7 rotates to, the leveling connection device 11 can rotate the platform head assembly 101 to a certain angle to keep the working platform 10 in a horizontal state.

[0057] For the convenience of installing the platform head assembly 101 and the leveling connection device 11 and providing a moving space for the leveling connection device 11, it is further preferably that the swinging end of the small arm body 7 is provided with a swinging head assembly 72 for the rotational connection of the platform head assembly 101 and the second guiding swing rod 113. A hollow fourth cavity 94 is formed inside the swinging end of the small arm body 7. The second telescopic push rod 111 is located inside the fourth cavity 94 and can extend out. A fifth cavity 95 is formed inside the swinging head assembly 72, and a sixth cavity 96 is formed inside the platform head assembly 101. The fourth cavity 94, the fifth cavity 95 and the sixth cavity 96 provide a moving space for the leveling connection device 11. In this embodiment, it is preferably that both the first telescopic push rod 81 and the second telescopic push rod 111 are powered by an oil cylinder.

[0058] The lifting arm assembly can be used in an existing aerial work platform vehicle or in the aerial work platforms in Embodiment 1 and Embodiment 3 of this specification. A straight-arm type aerial work platform convenient for transportation according to the present invention includes the lifting arm assembly.

[0059] Embodiment 3:

[0060] The present invention relates to a straight-arm type aerial work platform convenient for transportation, which includes a traveling chassis a, a turntable c mounted on the traveling chassis a, and a lifting arm assembly b mounted on the turntable c. The turntable c can rotate relative to the traveling chassis a around a vertical axis, and the lifting arm assembly b can swing relative to the turntable c to achieve lifting. The lifting arm assembly b includes a boom body 6, a jib body 7, and a luffing connection device 8. The luffing connection device 8 can push the jib body 7 to make a wide-range luffing swing relative to the boom body 6. The moving range of the overall center of gravity of the lifting arm assembly b is relatively large, and the stability requirements for the whole vehicle of the work platform are relatively high. Therefore, the traveling chassis a can expand the bridge in place to improve its supporting ability for the turntable c and the lifting arm assembly b, and also improve the stability of the whole vehicle of the work platform. The turntable c includes an intermediate support frame body 12 and side mounting frame bodies 13 fixed on the left and right sides of the intermediate support frame body 12. The intermediate support frame body 12 is for the installation of the lifting arm assembly b, and the side mounting frame bodies 13 are for the installation of various drive systems, control systems, etc. An accommodating groove 121 extending in the front-rear direction and opening upward is formed in the intermediate support frame body 12. The rotating end of the boom body 6 extends into the accommodating groove 121 and is rotatably mounted at the rear part of the intermediate support frame body 12. A lifting push rod 14 located below the boom body 6 is arranged in the accommodating groove 121. The front end of the lifting push rod 14 is rotatably connected below the boom body 6, and the rear end extends into the accommodating groove 121 and is rotatably mounted on the intermediate support frame body 12. The lifting push rod 14 swings the boom body 6 relative to the intermediate support frame body 12 by telescoping. The accommodating groove 121 is surrounded by the solid structure of the intermediate support frame body 12. The rotating end of the boom 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 intermediate support frame body 12, so that stable support of the whole intermediate support frame body 12 can be obtained, and it can always remain stable during the wide-range luffing movement of the jib body 7. Preferably, the lifting push rod 14 is driven by a hydraulic cylinder.

[0061] In this embodiment, the intermediate support frame 12 includes a bottom plate 122 and two left and right side plates 123, the bottom plate 122 and the left and right side plates 123 enclose the storage groove 121, the storage groove 121 is provided with a first rotating support rod 151 for the lifting push rod 14 to be rotatably installed and a second rotating support rod 152 for the large arm body 6 to be rotatably installed, the first rotating support rod 151 and the second rotating support rod 152 are both horizontally erected between the left and right side plates 123. The first rotating support rod 151 and the second rotating support rod 152 are fixed on the intermediate support frame 12, and the structural strength and stability thereof are relatively high, and thus the strength and stability of the supporting effect of the intermediate support frame 12 on the large arm body 6 and the lifting push rod 14 are improved, the first rotating support rod 151 is penetrated in the rotating end of the large arm body 6, so that the large arm body 6 can be rotated, and the second rotating support rod 152 is penetrated in the rear end of the lifting push rod 14, so that the lifting push rod 14 can be rotated. For further improvement, the middle support frame 12 preferably also includes a partition 124 horizontally erected between the left and right side panels 123, the partition 124 divides the storage groove 121 into an upper groove 1212 and a lower groove 1211, the first rotating support rod 151 is located in the lower groove 1211, the second rotating support rod 152 is located in the upper groove 1212, and the partition 124 has an escape opening 1241 that passes through the escape opening 1241, and the lifting push rod 14 can swing into the upper groove 1212 through the escape opening 1241, thereby ensuring the lifting effect of the lifting push rod 14 on the upper arm body 6. The partition 124 not only strengthens the structural strength of the intermediate support frame 12, but also separates the first rotating support rod 151 and the second rotating support rod 152 in the upper groove 1212 and the lower groove 1211, so that the intermediate support frame 12 is subjected to balanced force, the degree of stress concentration at a certain point of the intermediate support frame 12 is reduced, and the service life is improved; and when the upper arm body 6 is in a state of being laid down horizontally as a whole, the partition 124 can play a certain supporting role on the upper arm body 6.

[0062] The boom body 6 moves in the upper slot 1212 and the space above it, and the upper slot 1212 is mainly for the rotating end of the boom body 6 to extend into. Therefore, it is preferred that the left and right side plates 123 have tail fin parts 1231 protruding upward at the rear, the tail fin parts 1231 are located above the partition plate 124, and the upper slot 1212 is surrounded by the left and right tail fin parts 1231 and the partition plate 124. In this way, the upper slot 1212 is only used to accommodate the rotating end of the boom body 6, reducing the material cost of the side plate 123. Thus, the upper slot 1212 is only a small part located at the rear of the middle support frame 12, while the lower slot 1211 is still a long strip-shaped cavity extending in the front-rear direction, formed by the main parts of the side plate 123 except the tail fin parts 1231. Further improvement, it is preferred that the middle support frame 12 further includes a rear baffle 125, the rear baffle 125 is arranged between the left and right side plates 123 and seals the storage slot 121 from the rear. The rear baffle 125 not only improves the structural strength and stability of the middle support frame 12, but also can cover the parts of the first rotating support rod 151 and the second rotating support rod 152, preventing foreign objects from entering and affecting rotation, playing a protective role.

[0063] Further improvement, it is preferred that the middle support frame 12 further includes a reinforcing rib plate 126 arranged in the lower slot 1211. The reinforcing rib plate 126 is upright and fixedly connected to both the side plate 123 and the bottom plate 122 at the same time, playing a role in supporting and strengthening the middle support frame 12. The reinforcing rib plate 126 has an avoidance slot 1261 with an upward opening to avoid interference between the lifting push rod 14 and the reinforcing rib plate 126 during the swinging process. It is preferred that the bottom plate 122 has a bearing part 1221 extending below the side mounting frame 13. The side mounting frame 13 is located on the bearing part 1221 and fixedly connected to the bearing part 1221, improving the compactness and integrity of the side mounting frame 13 and the middle support frame 12, and also improving the installation stability of the side mounting frame 13. Further, it is preferred that the side mounting frame 13 includes a side mounting plate 131 attached and fixed to the side plate 123 of the middle support frame 12. In this way, the side mounting frame 13 clamps the middle support frame 12 from both left and right sides, further improving the structural strength and stability of the middle support frame 12, thereby improving the installation strength and stability of the boom body 6 and the lifting push rod 14 on the middle support frame 12.

[0064] The traveling chassis a adopts the specific implementation manner in Embodiment 1 of this specification.

[0065] The lifting arm assembly b adopts the specific implementation manner in Embodiment 2 of this specification.

[0066] The easy-to-transport straight-arm type aerial work platform of the present invention is a large-scale aerial work equipment. The length of the boom body 6 in the lifting boom assembly b is very long, and together with the length of the forearm body 7, it makes the length and height of the whole straight-arm type aerial work platform very large, and the width is very large after the axle of the driving chassis a is expanded. When transporting it with common transport vehicles such as freight containers and flatbed trucks, the straight-arm type aerial work platform needs to be retracted to the shortest state in terms of length, width and height, so that it can meet the requirements of being loaded into the transport vehicle, especially the freight container, which is convenient for transportation and reduces the transportation cost. Specifically, the whole lifting boom assembly b is retracted to Figure 1 the state shown, and the whole driving chassis a is retracted to Figure 1 the state shown, so that the total length, total width and total height of the easy-to-transport straight-arm type aerial work platform can all meet the requirements of being loaded into the freight container. Further, if the easy-to-transport straight-arm type aerial work platform still cannot meet the requirements of being loaded into the freight container after the above adjustments during loading, the tires in the driving chassis a are replaced with special tires only used for loading and transporting, such as iron tires, whose axial thickness and radial width are smaller than the original tires, and the width and height of the easy-to-transport straight-arm type aerial work platform are reduced by reducing the size of the tires, so that it can meet the loading requirements. The special tires are only used during loading. After the straight-arm type aerial work platform is transported to the destination, the special tires need to be replaced with the original tires for actual use.

[0067] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of various equivalent modifications or substitutions, and these modifications or substitutions should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. An aerial work platform, characterized in that, It includes a traveling chassis, a turntable mounted on the traveling chassis, and a lifting arm assembly mounted on the turntable; the traveling chassis can expand the bridge in place, the lifting arm assembly includes a boom body, a forearm body and a luffing connecting device, and the luffing connecting device can push the forearm body to swing with wide luffing relative to the boom body; the turntable includes an intermediate support frame body and side mounting frame bodies fixed on the left and right sides of the intermediate support frame body, an accommodating groove extending in the front-rear direction and opening upward is formed in the intermediate support frame body, the rotating end of the boom body extends into the accommodating groove and is rotatably mounted on the rear part of the intermediate support frame body, a lifting push rod located below the boom body is arranged in the accommodating groove, the front end of the lifting push rod is rotatably connected below the boom body and the rear end extends into the accommodating groove and is rotatably mounted on the intermediate support frame body, and the lifting push rod pushes the boom body to swing relative to the intermediate support frame body through telescoping. The intermediate support frame body includes a bottom plate and two side plates on the left and right, the bottom plate and the two side plates on the left and right enclose the accommodating groove, a first rotating support rod for rotatably mounting the lifting push rod and a second rotating support rod for rotatably mounting the boom body are arranged in the accommodating groove, and the first rotating support rod and the second rotating support rod are both horizontally spanned between the two side plates on the left and right. The intermediate support frame body further includes a partition plate horizontally spanned between the two side plates on the left and right, the partition plate divides the accommodating groove into an upper groove and a lower groove, the first rotating support rod is located in the lower groove, the second rotating support rod is located in the upper groove, the partition plate has an avoidance opening penetrating up and down, and the lifting push rod can swing into the upper groove through the avoidance opening. The traveling chassis includes a main frame, a wheel assembly, and two front and rear axle units, the axle unit includes two symmetrical half-bridge structures respectively rotatably connected to the main frame, and a wheel assembly is rotatably connected to one end of each half-bridge structure far from the main frame; the axle unit further includes a first pushing device and a second pushing device, the first pushing device can push the half-bridge structure to swing horizontally relative to the main frame, and the second pushing device can push the wheel assembly to rotate horizontally relative to the half-bridge structure until the rolling direction of the wheel assembly is consistent with the tangential direction of the swing of the half-bridge structure. The wheel assembly includes a wheel frame, a tire mounted on the wheel frame, and a hydraulic motor for driving the tire, and the hydraulic motor is connected to a bypass valve through a pipeline, and after the bypass valve is opened, the oil circuit of the hydraulic motor can be bypassed and the hydraulic motor can rotate under the action of an external force.

2. The aerial work platform according to claim 1, characterized in that, The half-bridge structure includes a support swing arm, the first pushing device includes two first push rods respectively acting on the same-side half-bridge structures on the left and right, one end of each first push rod is rotatably connected to the main frame and the other end is rotatably connected to the swing end of the support swing arm, the first push rod, the support swing arm and the main frame form a triangular structure, and the first push rod pushes the swing of the support swing arm through telescoping.

3. The aerial work platform according to claim 2, characterized in that, The half-bridge structure further includes a mounting bracket installed at the swinging end of the support swing arm, and the wheel assembly is rotatably connected to the mounting bracket through the wheel frame; the second pushing device includes two second push rods respectively acting on the wheel assemblies on the same side, one end of each second push rod is rotatably installed on the mounting bracket and the other end is rotatably connected to the wheel frame, and the second push rod drives the rotation of the wheel assembly by telescoping.

4. The aerial work platform according to claim 3, characterized in that, The mounting bracket includes an inner protruding portion, an outer protruding portion and an intermediate connecting portion located between the two. The swinging end of the support swing arm is rotatably connected to the intermediate connecting portion, the wheel assembly is installed on the outer protruding portion, and one end of the second push rod is rotatably connected to the inner protruding portion.

5. The aerial work platform according to claim 4, characterized in that The half-bridge structure further includes a parallel swing arm with one end rotatably connected to the main frame and the other end rotatably connected to the inner protruding portion of the mounting bracket. The parallel swing arm is parallel to the support swing arm, and the support swing arm, the parallel swing arm, the mounting bracket and the main frame enclose a parallelogram structure. There is a rotational connection between the mounting bracket and the swinging end of the support swing arm.

6. The aerial work platform according to claim 5, characterized in 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 swinging angle of the support swing arm and transmit it to the bridge expansion controller. The second angle sensor can detect the rotation angle of the wheel assembly and transmit it to the bridge expansion controller. The bridge expansion controller is electrically connected to the first push rod and the second push rod, and a first module is provided in the bridge expansion controller to make the swinging angle of the support swing arm match the rotation angle of the wheel assembly by controlling the first push rod and the second push rod.

7. The aerial work platform according to claim 4, wherein The inner protruding portion of the mounting bracket has a contact surface facing away from the wheel assembly, and a buffer pad is provided on the contact surface.

8. The aerial work platform according to claim 3, wherein The first pushing device further includes a swinging oil cylinder, and the swinging oil cylinder provides power for the first push rod; the second pushing device further includes a steering oil cylinder, and the steering oil cylinder provides power for the second push rod.

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