Amplitude-variable connecting rod and cantilever crane connecting device of overhead working truck

Abstract

The invention discloses a variable-amplitude connecting rod and cantilever crane connecting device of an overhead working truck. The variable-amplitude connecting rod and cantilever crane connecting device comprises a lower arm, an upper arm, a connecting device, a variable-amplitude long connecting rod, a variable-amplitude short connecting rod and an oil cylinder. The variable-amplitude short connecting rod is sequentially hinged to the connecting device, the variable-amplitude long connecting rod and the oil cylinder from top to bottom, through non-concentric arrangement of hinge points of the variable-amplitude long connecting rod, the variable-amplitude short connecting rod and the oil cylinder, unfolding and folding of the upper arm within the range of 180 degrees are achieved, and meanwhile bearing of the oil cylinder is reduced. The connecting device adopts an up-and-down butt-joint cylindrical structure, so that the shear and tension of a welding seam are greatly reduced, and the reliability is remarkably improved; meanwhile, the whole connecting pipeline is bent into a C shape, the C-shaped bending direction of the pipeline can be kept unchanged when the upper arm is unfolded and folded, back-and-forth bending caused by other pipeline arrangement modes is avoided, and the fatigue life of the connecting pipeline is effectively prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of connecting rod mechanisms and connecting devices, and in particular to a luffing connecting rod and boom connecting device for an aerial work vehicle. Background Art

[0002] For aerial work vehicles that use more than two-stage booms for operation, the deployment and retraction of the upper boom is generally achieved through a luffing linkage mechanism, which is usually composed of an upper arm, a lower arm, a long luffing linkage, and a short luffing linkage.

[0003] The luffing connecting rod is generally designed as a structure with a common hinge point between the oil cylinder, the luffing long connecting rod and the luffing short connecting rod, such as Figure 1 However, when the upper arm hinge point P needs to be placed upward and the oil cylinder is built-in, the original arrangement of the long and short connecting rods and the oil cylinder with the hinge point Q will not meet the requirement of the upper arm extending 180°, and the oil cylinder force is very large at this time.

[0004] In addition, for aerial work vehicles that use more than two-stage booms, an eccentric arrangement is usually used between the upper and lower booms to meet the requirements of the upper boom's retraction and expansion. The eccentric arrangement will cause an additional lateral bending moment at the connection. At the same time, since this location is subjected to a large amplitude change force within the amplitude change surface, the force at this location is complex. Traditional designs often use a longitudinal and transverse plate welding structure here. This structure has high requirements for welds and weld cracks often occur.

[0005] At the same time, this structure has holes on the main load-bearing surfaces on both sides, which affects the structural stress, and the pipelines between the upper and lower arms need to be arranged from the outside. When the upper arm is extended and retracted, the pipelines need to bend back and forth with the upper arm. From a reliability perspective, the pipelines and outer bellows have poor fatigue resistance. Summary of the invention

[0006] The problem to be solved by the present invention is to provide a boom connecting rod and arm connecting device for an aerial work vehicle, so as to solve the problems that the existing aerial work vehicle connecting rod mechanism needs to be placed on the upper arm hinge point, and when the oil cylinder is built in, the long and short connecting rods and the oil cylinder share the hinge point and cannot meet the use requirements and the oil cylinder force is too large, and the original connection structure has high welding requirements, the weld is easy to crack, and the pipeline is arranged from the outside and affects the appearance.

[0007] The present invention adopts the following technical scheme: an aerial work vehicle luffing connecting rod and boom connecting device, comprising: a lower arm, an upper arm, a connecting device, a luffing long connecting rod, a luffing short connecting rod and a cylinder.

[0008] The long and short boom-changing links are arranged non-concentrically with the hinge point of the oil cylinder; one end of the long boom-changing link is hinged to the lower arm, and the other end is hinged to the middle section of the short boom-changing link at the second hinge point; one end of the short boom-changing link is hinged to the connecting device at the first hinge point, and the other end is hinged to the oil cylinder at the third hinge point; the third hinge point is arranged on the extension line of the first and second hinge points, and is used to reduce the bearing capacity of the oil cylinder.

[0009] Furthermore, the upper arm is welded through the upper part of the connecting device, the lower arm is hinged to the lower part of the connecting device, and the deployment and recovery range of the upper arm relative to the lower arm is 180°.

[0010] Furthermore, the oil cylinder is installed inside the lower arm, and the end is hinged to the short connecting rod of the variable amplitude. The oil cylinder drives the long connecting rod and the short connecting rod of the variable amplitude to move through telescoping, and drives the upper arm to extend through the connecting device.

[0011] Preferably, the connecting device is butt-jointed with an upper bending plate and a lower bending plate and welded into a straight tube structure with side openings. A first connecting hole is symmetrically arranged on the side of the upper arm. The upper arm passes through the first connecting hole into the connecting device and is connected by welding.

[0012] Preferably, the end of the lower arm of the connecting device is welded to the second lower arm connecting hinge ear plate and the pipeline quick-plug docking plate, and the middle section is welded to the first lower arm connecting hinge ear plate.

[0013] A second connection hole and a third connection hole are formed through the sides of the first lower arm connecting hinge ear plate and the second lower arm connecting hinge ear plate. The connecting device is hinged to the variable amplitude short connecting rod through the second connection hole and is hinged to the lower arm through the third connection hole.

[0014] Preferably, a fourth connecting hole is opened on the side of the connecting device as a pipeline channel, and a fifth connecting hole is correspondingly opened on the pipeline quick-plug docking plate as a pipeline fixing and docking position. The pipeline passes through the wire hole above the lower arm, enters the interior of the connecting device through the fourth connecting hole, and docks with the upper arm pipeline at the position of the fifth connecting hole. The upper arm pipeline enters the device through the wire hole on the side of the upper arm.

[0015] Preferably, the pipeline is bent into a C-shape as a whole, and the bending direction of the C-shape remains unchanged when the upper arm is in the extended and retracted states.

[0016] Compared with the prior art, the present invention adopts the above technical solution and has the following technical effects:

[0017] 1. The boom-changing connecting rod and boom connection device of the aerial work vehicle of the present invention realizes the deployment and recovery of the upper arm within a range of 180 degrees by arranging the long boom-changing connecting rod, the short boom-changing connecting rod and the cylinder hinge point non-concentrically, while reducing the load on the cylinder; by adopting the upper and lower butt-jointed cylindrical structure connection device, the shear and tension of the weld are greatly reduced, and the reliability is significantly improved.

[0018] 2. The connecting pipeline of the boom of the aerial work vehicle of the present invention is bent into a C-shape as a whole, which improves the structural stress compared to the original opening structure on the side of the lower arm. When the upper arm is extended or retracted, the pipeline can maintain the C-shaped bending direction unchanged, avoiding the back and forth bending caused by other pipeline layout methods, and effectively improving the fatigue life of the connecting pipeline. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a structural diagram of the common hinge point of the prior art luffing connecting rod cylinder and the luffing long and short connecting rods;

[0020] Figure 2 This is a structural diagram of the luffing connecting rod and the boom connection device of the aerial work vehicle in the unfolded state of the upper arm of the present invention;

[0021] Figure 3 This is a structural diagram of the luffing connecting rod and the boom connection device of the aerial work vehicle in the retracted state of the upper arm of the present invention;

[0022] Figure 4 This is a schematic diagram of the non-concentric setting of the hinge points of the luffing connecting rod mechanism of the present invention;

[0023] Figure 5 This is a structural diagram of the boom connection device of the present invention;

[0024] Figure 6 This is a structural diagram of the pipeline arrangement of the boom in the deployed and retracted states of the present invention.

[0025] Explanation of the accompanying drawings: 1. lower arm; 2. upper arm; 3. connecting device; 4. long connecting rod for amplitude change; 5. short connecting rod for amplitude change; 6. and oil cylinder; 7. pipeline; 3-1. upper bending plate; 3-2. lower bending plate; 3-3. first lower arm connecting hinge ear plate; 3-4. second lower arm connecting hinge ear plate; 3-5. pipeline quick-connect docking plate; 4-1. first connecting hole; 4-2. second connecting hole; 4-3. third connecting hole; 4-4. fourth connecting hole. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the application is further elaborated in detail below in conjunction with the accompanying drawings. The described embodiments are only a part of the embodiments involved in the present invention. All non-innovative embodiments of other researchers in the field on this embodiment belong to the protection scope of the present invention. At the same time, for the step numbering in the embodiment of the present invention, it is only set for the convenience of explanation, and the order between the steps is not limited in any way. The execution order of each step in the embodiment can be adaptively adjusted according to the understanding of those skilled in the art.

[0027] In one embodiment of the present invention, the boom linkage and boom connection device of the aerial work vehicle comprises: a lower arm 1, an upper arm 2, a connection device 3, a long boom linkage 4, a short boom linkage 5 and a cylinder 6. The structure of the boom linkage and boom connection device of the aerial work vehicle in the unfolded state is as follows Figure 2 As shown in the figure, the structure of the luffing connecting rod and the boom connection device in the upper arm retracted state is as follows Figure 3 shown.

[0028] In particular, in this embodiment, the hinge points of the long luffing connecting rod 4, the short luffing connecting rod 5 and the oil cylinder 6 are arranged non-concentrically. The upper arm 2 is welded through the connecting device 3, the connecting device 3 is hinged to the lower arm 1, and the two ends of the long luffing connecting rod 4 are respectively hinged to the lower arm 1 and the short connecting rod 5; the short luffing connecting rod 5 is respectively hinged to the connecting device 3, the long luffing connecting rod 4 and the oil cylinder 6, and the oil cylinder 6 is installed inside the lower arm 1, and the end is hinged to the short luffing connecting rod 5.

[0029] During operation, the oil cylinder 6 drives the long and short boom-changing connecting rods 4 and 5 to move by extending and retracting, thereby driving the connecting device 3 and the upper arm 2 to extend.

[0030] Implementation principle, such as Figure 4 As shown: the long connecting rod AC, short connecting rod BC and cylinder 6 of the luffing connecting rod mechanism are arranged eccentrically, the luffing short connecting rod BC is extended, and the hinge point is offset so that the cylinder and the short connecting rod BC are hinged at D.

[0031] That is, the long luffing link and the short luffing link are hinged at the second hinge point C, one end of the short luffing link 5 is hinged to the connecting device 3 at the first hinge point B, and the other end is hinged to the cylinder 6 at the third hinge point D, so as to realize the deployment and recovery of the upper arm 2 within the range of 180° and reduce the load of the cylinder 6.

[0032] According to the moment balance equations, there is the following formula:

[0033]

[0034] Assuming that the lever arm of the oil cylinder and the long and short connecting rods share the same hinge point is h', and the lever arm of the oil cylinder is h1, we can get:

[0035] h1>h1′

[0036] It can be seen that after the hinge point is offset to D, the cylinder force arm is greater than the force arm when the hinge point is common. At this time, the load moment is M, the force arm h2 of the short connecting rod relative to the hinge point A, and the force arm h3 of the short connecting rod relative to the hinge point F remain unchanged. According to the above torque balance equations, the bearing capacity of the cylinder is significantly reduced.

[0037] Furthermore, in this embodiment, the connecting device 3 is as follows Figure 5As shown, it includes: an upper bending plate 3-1 and a lower bending plate 3-2, a first lower arm connecting hinge ear plate 3-3, a second lower arm connecting hinge ear plate 3-4 and a pipeline quick-plug docking plate 3-5, which are welded to form a connecting device 3.

[0038] Among them, the upper arm connecting device adopts the upper bending plate 3-1 and the lower bending plate 3-2 to be butt-jointed and welded into a straight tube structure. A hole is punched in the middle of the straight tube structure for butt welding with the upper arm. The straight tube structure is welded to the second lower arm connecting ear plate 3-4 at the end and the first lower arm connecting ear plate 3-3 in the middle.

[0039] In particular, the process holes on the side of the straight tube structure are convenient for welding and assembly operations, and the holes on the lower side of the straight tube structure and the inner side of the upper arm are used for pipeline passages. Compared with the original opening structure on the side of the lower arm, the upper and lower butt-jointed cylindrical structure allows the weld to mainly bear pressure, greatly reducing the shear and tension of the weld, and significantly improving the reliability of the connection device.

[0040] Furthermore, in this embodiment, the connecting device 3 is hinged to the variable amplitude short link 5 through the second connecting hole 4-2, and is hinged to the lower arm 1 through the third connecting hole 4-1. The upper arm 2 penetrates into the connecting device 3 through the first connecting hole 4-1 and is connected together by welding.

[0041] A fourth connection hole 4-4 is opened on the side of the connecting device 3 as a pipeline passage, and a fifth connection hole 4-5 is opened on the pipeline quick-plug docking plate 3-5 as a pipeline fixing and docking position.

[0042] After the pipeline 7 comes out from the wire hole above the lower arm 1, it enters the interior of the connecting device 3 through the fourth connecting hole 4-4 on the connecting device 3, and then docks with the upper arm pipeline at the fifth connecting hole 4-5, wherein the upper arm pipeline enters the interior of the connecting device 3 through the wire hole on the side of the upper arm.

[0043] When in use, the pipeline comes out from the wire hole above the lower arm, enters the interior through the hole on the side of the upper arm straight tube structure, and then enters the upper arm through the side channel of the upper arm. Figure 6 As shown, the pipeline is bent into a C shape as a whole.

[0044] Compared with the original structure with an opening on the side of the lower arm, this embodiment improves the stress of the arm structure, so that the main stress-bearing surfaces of the arm are the left and right sides, and when the upper arm is extended and retracted, the pipeline can maintain the C-shaped bending direction unchanged, avoiding the back-and-forth bending caused by other pipeline arrangements, and effectively improving the fatigue life.

[0045] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A boom and boom connection device for an aerial work vehicle, comprising: The lower arm (1), the upper arm (2), the connecting device (3), the long luffing connecting rod (4), the short luffing connecting rod (5) and the oil cylinder (6) are characterized by: The long variable amplitude connecting rod (4), the short variable amplitude connecting rod (5) and the oil cylinder (6) are arranged non-concentrically with respect to the hinge points; one end of the long variable amplitude connecting rod (4) is hinged to the lower arm (1), and the other end is hinged to the middle section of the short variable amplitude connecting rod (5) at a second hinge point; one end of the short variable amplitude connecting rod (5) is hinged to the connecting device (3) at a first hinge point, and the other end is hinged to the oil cylinder (6) at a third hinge point; the third hinge point is located on the extension line of the first hinge point and the second hinge point, and is used to reduce the bearing capacity of the oil cylinder (6).

2. The aerial work vehicle luffing connecting rod and boom connection device according to claim 1, characterized in that: The upper arm (2) is welded through the upper part of the connecting device (3), the lower arm (1) is hinged to the lower part of the connecting device (3), and the expansion and retraction range of the upper arm (2) relative to the lower arm (1) is 180 degrees.

3. The aerial work vehicle luffing connecting rod and boom connection device according to claim 1, characterized in that: The oil cylinder (6) is installed inside the lower arm (1), and its end is hinged to the short boom connecting rod (5). The oil cylinder (6) drives the long boom connecting rod (4) and the short boom connecting rod (5) to move by telescoping, and drives the upper arm (2) to extend through the connecting device (3).

4. The aerial work vehicle luffing connecting rod and boom connection device according to claim 1, characterized in that: The connecting device (3) is butt-jointed with an upper bending plate (3-1) and a lower bending plate (3-2) and welded to form a straight tube structure with a side opening. The side of the upper arm is symmetrically provided with a first connecting hole (4-1). The upper arm (2) passes through the first connecting hole (4-1) and enters the connecting device (3) and is connected by welding.

5. The boom-changing connecting rod and boom connection device for aerial work vehicles according to claim 4, characterized in that: The end of the connecting device (3) is welded with a second lower arm connecting hinge ear plate (3-4) and a pipeline quick-plug docking plate (3-5), and the middle part is welded with a first lower arm connecting hinge ear plate (3-3); A second connection hole (4-2) and a third connection hole (4-3) are formed through the side surfaces of the first lower arm connecting hinge ear plate (3-3) and the second lower arm connecting hinge ear plate (3-4); the connecting device (3) is hinged to the variable amplitude short connecting rod (5) through the second connection hole (4-2) and is hinged to the lower arm (1) through the third connection hole (4-3).

6. The aerial work vehicle luffing connecting rod and boom connection device according to claim 5, characterized in that: The connecting device (3) has a fourth connecting hole (4-4) on the side thereof as a pipeline passage, and the pipeline quick-plug docking plate (3-5) has a corresponding fifth connecting hole (4-5) on the side thereof as a pipeline fixing and docking position, the pipeline (7) passes through the wire hole on the upper side of the lower arm (1), enters the interior of the connecting device (3) through the fourth connecting hole (4-4), and docks with the upper arm pipeline at the position of the fifth connecting hole (4-5), and the upper arm pipeline enters the interior of the device (3) through the wire hole on the side of the upper arm.

7. The boom-changing connecting rod and boom connection device for aerial work vehicles according to claim 6, characterized in that: The pipeline (7) is bent into a C-shape as a whole, and the bending direction of the C-shape remains unchanged when the upper arm (2) is in the extended or retracted state.

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