A multi-link lifting boom and a knuckle boom truck

Abstract

This utility model provides a multi-link lifting boom and a boom lifter, belonging to the field of engineering machinery technology. The technical solution of the multi-link lifting boom includes a main boom and a folding boom, as well as a multi-link luffing mechanism. The multi-link luffing mechanism includes a first link, a second link, and a luffing cylinder. The first link has a first end and a second end, and the second link has a third end and a fourth end. The fixed end of the luffing cylinder is hinged to the main boom at a second hinge point. The movable end of the luffing cylinder is hinged to the first and third ends at a third hinge point, and the second end is hinged to the main boom at a fourth hinge point, located away from the folding boom. The fourth end is hinged to the folding boom at a fifth hinge point, located closer to the main boom. This utility model places the fourth hinge point away from the folding boom and the fifth hinge point closer to the main boom, effectively utilizing the space in the hinge area between the main boom and the folding boom, thus reducing the folded size of the boom.

Description

Technical Field

[0001] This utility model relates to the field of engineering machinery technology, and in particular to a multi-link lifting boom and articulated boom truck. Background Technology

[0002] Aerial work platforms are increasingly used in construction, power, and municipal maintenance. Articulated boom lifts, as an important type of aerial work machinery, have become core equipment in aerial work scenarios due to their flexible boom luffing capabilities and adaptability to complex working conditions. The demand for articulated boom lifts with heights exceeding several meters continues to grow, especially in high-rise building construction and large equipment installation.

[0003] Currently, the boom systems of high-meter articulated boom trucks generally adopt a linkage-type folding boom structure, achieving lifting and ascending functions through the articulated combination of the main boom and the folding boom. Specifically, the main boom is usually a telescopic structure, while the folding boom uses a telescopic design with a boom tube. The two are connected by a main shaft hinge and rely on an independent luffing cylinder to drive the main boom's luffing motion. Traditional luffing mechanisms are mainly single-link or double-link structures, transmitting the driving force of the luffing cylinder to the main boom and the folding boom to achieve boom angle adjustment. However, in high-meter applications, when the main boom extension length increases and full load operation is performed, the pressure that the main boom luffing cylinder must withstand rises sharply, easily exceeding the system's allowable pressure threshold, leading to hydraulic system overflow and directly affecting the normal luffing motion of the main boom. Therefore, a larger-sized luffing linkage structure is generally used.

[0004] However, since the luffing linkage structure needs to be arranged in the limited space between the main boom and the folding boom, the hinge point position and structural dimensions of the linkage mechanism are strictly limited when the boom system is in the folded storage state. Utility Model Content

[0005] This invention addresses the problem that in current high-meter-long articulated boom trucks, the limited space between the main boom and the folding boom restricts the structural dimensions of existing luffing linkages, making it difficult to effectively reduce cylinder pressure within a compact space. A multi-link lifting boom and articulated boom truck are proposed.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] This utility model provides a multi-link lifting boom, including a main boom and a folding boom, and also includes a multi-link luffing mechanism. One end of the main boom is hinged to one end of the folding boom at a first hinge point. The multi-link luffing mechanism is connected between the main boom and the folding boom. The multi-link luffing mechanism includes a first link, a second link, and a luffing cylinder. The first link has a first end and a second end opposite to each other along its extension direction. The second link has a third end and a fourth end opposite to each other along its extension direction. The fixed end of the luffing cylinder is hinged to the main boom at a second hinge point. The movable end of the luffing cylinder is hinged to the first end and the third end at a third hinge point. The second end is hinged to the end of the main boom near the first hinge point at a fourth hinge point, and the fourth hinge point is located on the side away from the folding boom. The fourth end is hinged to the end of the folding boom near the first hinge point at a fifth hinge point, and the fifth hinge point is located on the side close to the main boom.

[0008] Furthermore, the width of the first link gradually increases from the middle position to both ends along its extension direction.

[0009] Furthermore, the boom also includes a first hinge shaft and a first bushing, with a first opening at the second end and a second opening at the main boom. The first hinge shaft passes through the first opening and the second opening so that the second end is hinged to the main boom. The axis of the first hinge shaft forms a fourth hinge point. The first bushing is sleeved on the first hinge shaft and passes through at least the second opening.

[0010] Furthermore, the first bushing is provided with a first shoulder, the diameter of which is larger than the diameter of the first opening and the second opening, and the first shoulder is located between the first connecting rod and the main arm.

[0011] Furthermore, the boom also includes a first reinforcing plate, which has a first through hole through which the first bushing passes. The diameter of the first through hole is smaller than the diameter of the first shoulder. The first reinforcing plate is disposed between the first connecting rod and the main boom, and the first shoulder is disposed between the first connecting rod and the first reinforcing plate.

[0012] Furthermore, the first link includes a symmetrical first branch and a second branch, which are located on both sides of the main arm.

[0013] Furthermore, the fourth end of the second link has a barb structure, and the barb is oriented towards the folding arm.

[0014] Furthermore, the boom also includes a second hinge shaft and a second bushing, a third opening at the fourth end, a fourth opening at the folding arm, the second hinge shaft passing through the third and fourth openings so that the fourth end is hinged to the folding arm, the axis of the second hinge shaft forming a fifth hinge point, and the second bushing being fitted on the second hinge shaft and passing through at least the fourth opening.

[0015] Furthermore, the second bushing is provided with a second shoulder, the diameter of which is larger than the diameters of the third and fourth openings, and the second shoulder is located between the second connecting rod and the folding arm.

[0016] Furthermore, the boom also includes a second reinforcing plate, which has a second through hole through which the second bushing passes. The diameter of the second through hole is smaller than the diameter of the second shoulder. The second reinforcing plate is disposed between the second connecting rod and the folding arm, and the second shoulder is disposed between the second connecting rod and the second reinforcing plate.

[0017] Furthermore, the second link includes a connecting plate and symmetrical first and second sub-plates. The first and second sub-plates are respectively disposed on both sides of the folding arm. One end of the first and second sub-plates is hinged to the folding arm at the fifth hinge point. The connecting plate connects the first and second sub-plates, so that the connecting plate, the first sub-plate, and the second sub-plate form a box structure with a cavity.

[0018] This utility model also provides a boom lift, which includes a multi-link lifting boom according to any one of the above.

[0019] As can be seen from the above technical solutions, the advantages of this utility model are:

[0020] This invention utilizes a first connecting rod, a second connecting rod, and a luffing cylinder, hinged between the main boom and the folding boom. The fourth hinge point of the first connecting rod to the main boom is located on the side away from the folding boom, while the fifth hinge point of the second connecting rod to the folding boom is located on the side closer to the main boom. This effectively utilizes the space in the hinge area between the main boom and the folding boom, reducing the boom's folded size. Furthermore, the driving force of the luffing cylinder is distributed to the main boom and the folding boom through the multi-link structure formed by the first and second connecting rods, effectively solving the overflow problem in the hydraulic system of high-meter articulated boom trucks. Attached Figure Description

[0021] To more clearly illustrate the technical solution of this utility model, the drawings used in the description will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the folded state of the multi-link lifting boom in one embodiment of the present invention;

[0023] Figure 2 This is a schematic diagram of the unfolded state of the multi-link lifting boom in one embodiment of the present invention;

[0024] Figure 3This is a schematic diagram of the connection structure between the first connecting rod and the main arm in one embodiment of this utility model;

[0025] Figure 4 This is a schematic diagram of the structure of the second connecting rod in one embodiment of the present invention.

[0026] Explanation of key figure labels:

[0027] 100. Main boom; 110. Second opening; 200. Folding boom; 210. Fourth opening; 300. Multi-link luffing mechanism; 310. First link; 311. First end; 312. Second end; 3121. First opening; 313. First branch link; 314. Second branch link; 320. Second link; 321. Third end; 322. Fourth end; 3221. Third opening; 323. First dividing plate; 324. Second dividing plate; 325. Connecting plate; 330, Luffing cylinder; 331, Fixed end; 332, Movable end; 410, First hinge point; 420, Second hinge point; 430, Third hinge point; 440, Fourth hinge point; 450, Fifth hinge point; 510, First hinge shaft; 520, First bushing; 521, First shoulder; 530, First reinforcing plate; 531, First through hole; 540, Second hinge shaft; 550, Second bushing; 551, Second shoulder; 560, Second reinforcing plate. Detailed Implementation

[0028] To make the objectives, features, and advantages of this utility model more apparent and understandable, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings of the specific embodiments. Obviously, the embodiments described below are only some embodiments of this utility model, and not all embodiments. Based on the embodiments in this patent, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this patent.

[0029] Example 1

[0030] Please see Figures 1-4A multi-link lifting boom includes a main boom 100 and a folding boom 200, and also includes a multi-link luffing mechanism 300. One end of the main boom 100 is hinged to one end of the folding boom 200 at a first hinge point 410. The multi-link luffing mechanism 300 is connected between the main boom 100 and the folding boom 200. The multi-link luffing mechanism 300 includes a first link 310, a second link 320, and a luffing cylinder 330. The first link 310 has a first end 311 and a second end 312 opposite each other along its extension direction. The second link 320 has a third end 321 and a fourth end 322 opposite each other along its extension direction. 22. The fixed end 331 of the luffing cylinder 330 is hinged to the main boom 100 at the second hinge point 420. The movable end 332 of the luffing cylinder 330 is hinged to the first end 311 and the third end 321 at the third hinge point 430. The second end 312 is hinged to the end of the main boom 100 near the first hinge point 410 at the fourth hinge point 440, and the fourth hinge point 440 is located on the side away from the folding arm 200. The fourth end 322 is hinged to the end of the folding arm 200 near the first hinge point 410 at the fifth hinge point 450, and the fifth hinge point 450 is located on the side near the main boom 100.

[0031] In this embodiment, as Figure 1 , Figure 2As shown, the main boom 100 is a telescopic structure, and the folding boom 200 is a telescopic structure with a boom tube. One end of the main boom 100 and one end of the folding boom 200 are hinged at the first hinge point 410 to form a rotatable connection, thus constituting the main frame of the boom system. The extension directions of the main boom 100 and the folding boom 200 are approximately parallel. A multi-link luffing mechanism 300 is connected between the main boom 100 and the folding boom 200. The multi-link luffing mechanism 300 includes a first link 310, a second link 320, and a luffing cylinder 330. The first link 310 and the second link 320 are both rectangular rod structures. The two ends of the first link 310 extending along its own direction form a first end 311 and a second end 312, respectively. The two ends of the second link 320 extending along its own direction form a third end 321 and a fourth end 322, respectively. The fixed end 331 of the luffing cylinder 330 is hinged to the main boom 100. Connecting to the second hinge point 420, on the connection of the first link 310, the second end 312 of the first link 310 is hinged to the main arm 100 on the side away from the folding arm 200 to form a fourth hinge point 440, and this fourth hinge point 440 is located on the main arm 100 near the first hinge point 410. On the connection of the second link 320, the fourth end 322 of the second link 320 is hinged to the folding arm 200 on the side near the main arm 100 to form a fifth hinge point. 450, and the fifth hinge point 450 is also located on the folding arm 200 near the first hinge point 410, wherein the extension direction of the first link 310 intersects the extension of the second link 320, and the first end 311 of the first link 310, the third end 321 of the second link 320 and the movable end 332 of the luffing cylinder 330 are hinged at the third hinge point 430, wherein the third hinge point 430 is located between the main arm 100 and the folding arm 200.

[0032] When the boom lift needs to perform aerial work, the multi-link lifting boom operates as follows: The hydraulic system drives the piston rod of the luffing cylinder 330 to extend and retract, causing the movable end 332 to move linearly, displacing the third hinge point 430. This displacement forces the first link 310 to rotate around the fourth hinge point 440. Since the fourth hinge point 440 is located outside the main boom 100, the rotation of the first link 310 generates a component force towards the outside of the main boom 100. The movement of the first link 310 is transmitted to the second link 320 through the third hinge point 430. The second link 320 rotates around the fifth hinge point 450, thereby transmitting the force to the folding boom 200, causing the folding boom 200 to rotate relative to the main boom 100 around the first hinge point 410. Through the extension and retraction control of the luffing cylinder 330 and the coordinated action of the first link 310 and the second link 320, the angle between the main boom 100 and the folding boom 200 is adjusted. When the luffing cylinder 330 extends, the boom system unfolds; when the luffing cylinder 330 retracts, the boom system folds and is stored away.

[0033] In the above structure, by setting a first connecting rod 310, a second connecting rod 320, and a luffing cylinder 330, and hinged between the main boom 100 and the folding boom 200, the fourth hinge point 440 of the first connecting rod 310 and the main boom 100 is set on the side away from the folding boom 200, and the fifth hinge point 450 of the second connecting rod 320 and the folding boom 200 is set on the side closer to the main boom 100. This effectively utilizes the space of the hinge area between the main boom 100 and the folding boom 200, avoids the interference problem of traditional mechanisms in the folded state, and significantly reduces the storage size of the boom system. In addition, the driving force of the luffing cylinder 330 is distributed and transmitted to the main boom 100 and the folding boom 200 through the multi-link structure formed by the first connecting rod 310 and the second connecting rod 320. Compared with the traditional single-link mechanism, this effectively solves the overflow problem of the hydraulic system of high-meter-span articulated boom trucks.

[0034] In the specific structure of the first link 310, the width of the first link 310 gradually increases from the middle position to both ends along its own extension direction.

[0035] In this embodiment, as Figure 1 , Figure 3 As shown, the outline dimensions of the first link 310 are a gradually changing structure. Specifically, along the extension direction of the first link 310, the width of the first link 310 gradually increases from the middle position to both ends, making the width at the middle position the smallest. The specific proportion is optimized and determined according to the boom size and load requirements. In addition, at the first end 311 and the second end 312, the increase in the width of the first link 310 is accompanied by a thickness gradient change, with the end thickness being thicker than the middle, and a transition fillet is provided to reduce stress concentration.

[0036] In the above structure, the first link 310 is designed with a gradually changing external dimension. This allows the gradually wide first link 310 to form a compact nest with the main boom 100 and the folding arm 200 when the boom is folded, avoiding spatial interference caused by links of equal width. When the boom is extended, the narrower middle section of the first link 310 effectively avoids interference with the folding arm 200 and the portion of the main boom 100 near the first hinge point 410. The wider ends increase the load-bearing area of ​​the hinge joint, reducing pressure per unit area, minimizing deformation of the hinge hole, and improving bending resistance.

[0037] Specifically, the boom also includes a first hinge shaft 510 and a first bushing 520. The second end 312 has a first opening 3121, and the main boom 100 has a second opening 110. The first hinge shaft 510 passes through the first opening 3121 and the second opening 110, so that the second end 312 is hinged to the main boom 100. The axis of the first hinge shaft 510 forms a fourth hinge point 440. The first bushing 520 is fitted onto the first hinge shaft 510 and passes through at least the second opening 110. The first bushing 520 has a first shoulder 521, the diameter of which is larger than the diameters of the first opening 3121 and the second opening 110, and the first shoulder 521 is located between the first connecting rod 310 and the main boom 100.

[0038] In this embodiment, as Figure 3 As shown, the first hinge shaft 510 is a cylindrical shaft with a diameter determined by calculation based on the boom load. Threads or grooves are provided at both ends of the shaft for installing limit nuts or retaining rings. The first bushing 520 is fitted onto the outer surface of the first hinge shaft 510. The first bushing 520 is a lubrication-free bushing structure with a self-lubricating material (such as polytetrafluoroethylene PTFE or copper-based powder metallurgy) in the inner layer. The length of the first bushing 520 is greater than the wall thickness of the main boom 100 to ensure that it completely passes through the second opening 110. A circular first opening 3121 is made at the second end 312 of the first connecting rod 310, and a second opening 110 is made at the corresponding position of the main arm 100. The first bushing 520 passes through the second opening 110 from the outside of the main arm 100. The first shoulder 521 is close to the outside of the main arm 100. The second end 312 of the first connecting rod 310 is hinged to the outside of the first bushing 520. The first hinge shaft 510 passes through the first connecting rod 310, the first bushing 520 and the main arm 100 in sequence from the outside. Both ends are fixed with limit nuts or snap rings.

[0039] In the above structure, by sleeved with a first bushing 520 on the first hinge shaft 510, the friction coefficient of the hinge part is reduced, ensuring smooth rotation and making the boom move smoothly without jamming. In addition, the first shoulder 521 can distribute the concentrated load to a larger area, effectively reducing the local stress at the edge of the second opening 110 of the main boom 100, and preventing the crack propagation caused by stress concentration at the second opening 110. The protective function of the first bushing 520 avoids direct contact between the first hinge shaft 510 and the main boom 100, reducing wear and improving service life.

[0040] In addition, the boom also includes a first reinforcing plate 530, which has a first through hole 531 through which the first bushing 520 passes. The diameter of the first through hole 531 is smaller than the diameter of the first shoulder 521. The first reinforcing plate 530 is disposed between the first connecting rod 310 and the main boom 100, and the first shoulder 521 is disposed between the first connecting rod 310 and the first reinforcing plate 530.

[0041] In this embodiment, as Figure 3 As shown, the first reinforcing plate 530 is a plate-like structure, circular or square in shape, with an outer diameter or side length larger than the diameter of the first shoulder 521. Its thickness is determined according to the structural strength requirements of the main arm 100 and the first connecting rod 310. A first through hole 531 is provided at the center of the first reinforcing plate 530, with a diameter slightly larger than the outer diameter of the first bushing 520, forming a clearance fit to ensure that the first bushing 520 can pass through smoothly. The first reinforcing plate 530 is disposed between the first connecting rod 310 and the main arm 100, and is located between the first shoulder 521 and the first connecting rod 310. One side of the first reinforcing plate 530 abuts against the outer surface of the main arm 100, and the other side abuts against the first shoulder 521.

[0042] First, the first reinforcing plate 530 is attached to the main arm 100 so that the first through hole 531 corresponds to the second opening 110. Then, the first hinge shaft 510, which is fitted with the first bushing 520, is passed through the first through hole 531 and the second opening 110 in sequence, so that the first hinge shaft 510 passes through the first connecting rod 310, the first reinforcing plate 530, the first bushing 520 and the main arm 100 in sequence from the outside. The two ends are fixed with limit nuts or snap rings.

[0043] By incorporating the first reinforcing plate 530, the connection area between the main boom 100 and the first connecting rod 310 is increased, effectively dispersing the stress at the hinge point and improving the overall strength and reliability of the structure. The first reinforcing plate 530, in conjunction with the first shoulder 521, enhances the support for the first bushing 520, reducing deformation of the first bushing 520 during luffing and further improving the stability of the hinge point. Furthermore, the first reinforcing plate 530 effectively prevents external impurities and dust from entering the hinge point, reducing wear and corrosion on the first bushing 520 and the first hinge shaft 510.

[0044] The first link 310 includes a first branch link 313 and a second branch link 314 that are symmetrically positioned, with the first branch link 313 and the second branch link 314 located on both sides of the main arm 100.

[0045] In this embodiment, as Figure 3As shown, the first connecting rod 310 is a double connecting rod structure, including a first branch rod 313 and a second branch rod 314. The first branch rod 313 and the second branch rod 314 are respectively hinged on opposite sides of the main arm 100 and are symmetrically distributed about the center line of the main arm 100. One end of the first branch rod 313 and the second branch rod 314 along their own extension direction forms a first end 311, and the other end forms a second end 312. Both the first branch rod 313 and the second branch rod 314 are provided with through holes to form a first opening 3121. When connected, the first hinge shaft 510 passes through the first branch rod 313, the main arm 100 and the second branch rod 314 in sequence, thereby hinged the first connecting rod 310 at the fourth hinge point 440. In order to improve the strength and rigidity of the first branch rod 313 and the second branch rod 314, some reinforcing ribs can be provided on their surfaces.

[0046] By configuring the first connecting rod 310 as a symmetrical first branch rod 313 and second branch rod 314, a uniform supporting force is formed on both sides of the main boom 100, avoiding structural damage caused by excessive force on one side. This better balances the forces experienced by the main boom 100 during luffing, reducing structural deformation and vibration caused by uneven force distribution. The symmetrical branch rod structure improves the stability and reliability of the boom system. The first branch rod 313 and second branch rod 314 each bear a portion of the load, thus increasing the overall load-bearing capacity of the first connecting rod 310. The first branch rod 313 and second branch rod 314 are located on both sides of the main boom 100, making full use of the space on both sides of the main boom 100 and avoiding potential spatial interference problems when connecting rods are placed above or below the main boom 100.

[0047] In the specific structure of the second link 320, the fourth end 322 of the second link 320 is a barb structure, and the barb direction is towards the folding arm 200.

[0048] In this embodiment, as Figure 2 , Figure 4 As shown, the fourth end 322 of the second link 320 is a barb structure, which is curved overall. The bending angle of the barb is designed according to the motion requirements and spatial layout of the boom system, and the bending direction of the barb is set towards the folding arm 200, so that the barb structure can form a better coordinated movement with the folding arm 200, avoiding motion interference problems caused by improper connection point position, and further ensuring that the boom can achieve a wider range of amplitude.

[0049] Setting the fourth end 322 as a barbed structure makes the connection point between the second link 320 and the folding arm 200 more flexible, providing greater freedom of movement during boom luffing, and significantly increasing the maximum elevation angle of the folding arm 200. This expands the boom's operating range, enabling the articulated boom truck to operate in more complex conditions. Furthermore, the barbed structure effectively disperses and transmits force during boom movement, making the connection between the second link 320 and the folding arm 200 more stable.

[0050] Specifically, the boom also includes a second hinge shaft 540 and a second bushing 550. The fourth end 322 has a third opening 3221, and the folding arm 200 has a fourth opening 210. The second hinge shaft 540 passes through the third opening 3221 and the fourth opening 210, so that the fourth end 322 is hinged to the folding arm 200. The axis of the second hinge shaft 540 forms a fifth hinge point 450. The second bushing 550 is fitted onto the second hinge shaft 540 and passes through at least the fourth opening 210. The second bushing 550 has a second shoulder 551, the diameter of which is larger than the diameters of the third opening 3221 and the fourth opening 210, and the second shoulder 551 is located between the second connecting rod 320 and the folding arm 200.

[0051] In this embodiment, as Figure 4 As shown, the second hinge shaft 540 is a cylindrical shaft with a diameter determined by calculation based on the boom load. Threads or grooves are provided at both ends of the shaft for installing limit nuts or retaining rings. The second bushing 550 is fitted onto the outer surface of the second hinge shaft 540. The second bushing 550 is a lubrication-free bushing structure with a self-lubricating material (such as polytetrafluoroethylene PTFE or copper-based powder metallurgy) in the inner layer. The length of the second bushing 550 is greater than the wall thickness of the folding arm 200 to ensure complete passage through the fourth opening 210. A circular third opening 3221 is made at the fourth end 322 of the second connecting rod 320, and a fourth opening 210 is made at the corresponding position of the folding arm 200. The second bushing 550 passes through the fourth opening 210 from the outside of the folding arm 200, and the second shoulder 551 is close to the outside of the folding arm 200. The fourth end 322 of the second connecting rod 320 is hinged to the outside of the second bushing 550. The second hinge shaft 540 passes through the second connecting rod 320, the second bushing 550 and the folding arm 200 in sequence from the outside, and is fixed at both ends with limit nuts or snap rings.

[0052] In the above structure, by fitting a second bushing 550 onto the second hinge shaft 540, the friction coefficient of the hinge part is reduced, ensuring smooth rotation and making the boom move smoothly without jamming. In addition, the second shoulder 551 can distribute the concentrated load to a larger area, effectively reducing the local stress at the edge of the fourth opening 210 of the folding arm 200, and preventing crack propagation caused by stress concentration at the fourth opening 210. The protective function of the second bushing 550 avoids direct contact between the second hinge shaft 540 and the folding arm 200, reducing wear and improving service life.

[0053] In addition, the boom also includes a second reinforcing plate 560, which has a second through hole through which the second bushing 550 passes. The diameter of the second through hole is smaller than the diameter of the second shoulder 551. The second reinforcing plate 560 is disposed between the second connecting rod 320 and the folding arm 200, and the second shoulder 551 is disposed between the second connecting rod 320 and the second reinforcing plate 560.

[0054] In this embodiment, as Figure 2 , Figure 4 As shown, the second reinforcing plate 560 is a plate-like structure, circular or square in shape, with an outer diameter or side length larger than the diameter of the second shoulder 551. Its thickness is determined according to the structural strength requirements of the folding arm 200 and the second connecting rod 320. A second through hole is provided at the center of the second reinforcing plate 560, with a diameter slightly larger than the outer diameter of the second bushing 550, forming a clearance fit to ensure that the second bushing 550 can pass through smoothly. The second reinforcing plate 560 is positioned between the second connecting rod 320 and the folding arm 200, and is located between the second shoulder 551 and the second connecting rod 320. One side of the second reinforcing plate 560 abuts against the outer surface of the folding arm 200, and the other side abuts against the second shoulder 551.

[0055] First, the second reinforcing plate 560 is attached to the folding arm 200 so that the second through hole corresponds to the fourth opening 210. Then, the second hinge shaft 540, which is fitted with the second bushing 550, is passed through the second through hole and the fourth opening 210 in sequence, so that the second hinge shaft 540 passes through the second connecting rod 320, the second reinforcing plate 560, the second bushing 550 and the folding arm 200 in sequence from the outside. The two ends are fixed with limit nuts or snap rings.

[0056] By adding a second reinforcing plate 560, the connection area between the folding arm 200 and the second connecting rod 320 is increased, effectively dispersing the stress at the hinge point and improving the overall strength and reliability of the structure. The second reinforcing plate 560 works in conjunction with the second shoulder 551 to enhance the support for the second bushing 550, reducing deformation of the second bushing 550 during luffing and further improving the stability of the hinge point. Furthermore, the second reinforcing plate 560 effectively prevents external impurities and dust from entering the hinge point, reducing wear and corrosion on the second bushing 550 and the second hinge shaft 540.

[0057] Specifically, the second link 320 includes a connecting plate 325 and symmetrical first and second sub-plates 323 and 324. The first and second sub-plates 323 and 324 are respectively disposed on both sides of the folding arm 200. One end of the first and second sub-plates 323 and 324 are hinged to the folding arm 200 at the fifth hinge point 450. The connecting plate 325 connects the first and second sub-plates 323 and 324, so that the connecting plate 325, the first and second sub-plates 323 and 324 form a box structure with a cavity.

[0058] In this embodiment, as Figure 4 As shown, the second connecting rod 320 includes a first plate 323 and a second plate 324 with identical structures. The first plate 323 and the second plate 324 are respectively disposed on both sides of the folding arm 200. The first plate 323 and the second plate 324 are symmetrical flat plate structures. At the end near the folding arm 200, the first plate 323 and the second plate 324 are respectively provided with a third opening 3221 for installing the second hinge shaft 540 to achieve hinge connection with the folding arm 200. The connecting plate 325 is a rectangular plate, the width of which matches the distance between the first plate 323 and the second plate 324. The connecting plate 325 is connected to the inner edges of the first plate 323 and the second plate 324 by welding or other connection methods, so that the first plate 323, the second plate 324 and the connecting plate 325 form a box structure with a cavity.

[0059] In the above structure, by forming a box structure with a cavity by the first plate 323, the second plate 324 and the connecting plate 325, the structural strength of the second connecting rod 320 is enhanced, the torsional stiffness is improved, and the weight of the second connecting rod 320 is reduced. The symmetrically arranged first plate 323 and second plate 324 evenly transmit the load to both sides of the folding arm 200, avoiding stress concentration caused by unilateral force.

[0060] Example 2

[0061] This utility model also provides a boom lift, which includes a multi-link lifting boom according to any one of the above.

[0062] In this embodiment, the articulated boom lift mainly consists of a chassis frame, a slewing platform, a multi-link lifting boom, a hydraulic control system, and a work platform. The slewing platform is mounted above the chassis frame and achieves 360° rotation via a slewing bearing (turntable bearing). A boom hinge seat is located on the platform, hinged to the lower end of the main boom 100, forming the slewing fulcrum of the boom system. This hinge seat, in conjunction with a slewing motor, drives the boom to rotate horizontally. The main boom 100 is a telescopic structure with an integrated telescopic cylinder, allowing the extension length to be controlled by a hydraulic system. The folding boom 200 is a telescopic folding boom with a boom cylinder, and a work platform is installed at its end. The platform is equipped with an angle sensor and a collision avoidance device.

[0063] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A multi-link lifting boom, comprising a main boom (100) and a folding boom (200), characterized in that, It also includes a multi-link luffing mechanism (300), one end of the main boom (100) is hinged to one end of the folding arm (200) at a first hinge point (410). The multi-link luffing mechanism (300) is connected between the main boom (100) and the folding arm (200). The multi-link luffing mechanism (300) includes a first link (310), a second link (320), and a luffing cylinder (330). The first link (310) has a first end (311) and a second end (312) along its own extension direction. The second link (320) has a third end (321) and a fourth end (322) along its own extension direction. The fixed end (331) of the luffing cylinder (330) is connected to... The main boom (100) is hinged to the second hinge point (420). The movable end (332) of the luffing cylinder (330) is hinged to the first end (311) and the third end (321) at the third hinge point (430). The second end (312) is hinged to the end of the main boom (100) near the first hinge point (410) at the fourth hinge point (440), and the fourth hinge point (440) is located on the side away from the folding arm (200). The fourth end (322) is hinged to the end of the folding arm (200) near the first hinge point (410) at the fifth hinge point (450), and the fifth hinge point (450) is located on the side near the main boom (100).

2. The multi-link lifting boom according to claim 1, characterized in that, The width of the first link (310) gradually increases from the middle position to both ends along its own extension direction.

3. The multi-link lifting boom according to claim 2, characterized in that, It also includes a first hinge shaft (510) and a first bushing (520), the second end (312) is provided with a first opening (3121), the main arm (100) is provided with a second opening (110), the first hinge shaft (510) passes through the first opening (3121) and the second opening (110) so that the second end (312) is hinged to the main arm (100), the axis of the first hinge shaft (510) forms the fourth hinge point (440), and the first bushing (520) is sleeved on the first hinge shaft (510) and passes through at least the second opening (110). And / or, the first bushing (520) is provided with a first shoulder (521), the diameter of the first shoulder (521) is greater than the diameter of the first opening (3121) and the second opening (110), and the first shoulder (521) is disposed between the first connecting rod (310) and the main arm (100).

4. A multi-link lifting boom according to claim 3, characterized in that, It also includes a first reinforcing plate (530), which has a first through hole (531) through which the first bushing (520) passes. The diameter of the first through hole (531) is smaller than the diameter of the first shoulder (521). The first reinforcing plate (530) is disposed between the first connecting rod (310) and the main arm (100), and the first shoulder (521) is disposed between the first connecting rod (310) and the first reinforcing plate (530).

5. A multi-link lifting boom according to any one of claims 2-4, characterized in that, The first link (310) includes a first branch link (313) and a second branch link (314) that are symmetrically positioned, with the first branch link (313) and the second branch link (314) located on both sides of the main arm (100).

6. A multi-link lifting boom according to claim 1, characterized in that, The fourth end (322) of the second link (320) is a barb structure, and the barb direction is towards the folding arm (200).

7. A multi-link lifting boom according to claim 6, characterized in that, It also includes a second hinge shaft (540) and a second bushing (550), the fourth end (322) is provided with a third opening (3221), the folding arm (200) is provided with a fourth opening (210), the second hinge shaft (540) passes through the third opening (3221) and the fourth opening (210) so that the fourth end (322) is hinged to the folding arm (200), the axis of the second hinge shaft (540) forms the fifth hinge point (450), and the second bushing (550) is sleeved on the second hinge shaft (540) and passes through at least the fourth opening (210). And / or, the second bushing (550) is provided with a second shoulder (551), the diameter of which is greater than the diameter of the third opening (3221) and the fourth opening (210), and the second shoulder (551) is disposed between the second connecting rod (320) and the folding arm (200).

8. A multi-link lifting boom according to claim 7, characterized in that, It also includes a second reinforcing plate (560), which has a second through hole through which the second bushing (550) passes. The diameter of the second through hole is smaller than the diameter of the second shoulder (551). The second reinforcing plate (560) is disposed between the second connecting rod (320) and the folding arm (200), and the second shoulder (551) is disposed between the second connecting rod (320) and the second reinforcing plate (560).

9. A multi-link lifting boom according to any one of claims 6-8, characterized in that, The second connecting rod (320) includes a connecting plate (325) and a symmetrical first sub-plate (323) and a second sub-plate (324). The first sub-plate (323) and the second sub-plate (324) are respectively disposed on both sides of the folding arm (200). One end of the first sub-plate (323) and the second sub-plate (324) are hinged to the folding arm (200) at the fifth hinge point (450). The connecting plate (325) connects the first sub-plate (323) and the second sub-plate (324) so ​​that the connecting plate (325), the first sub-plate (323) and the second sub-plate (324) form a box structure with a cavity.

10. A boom lift truck, characterized in that, Including a multi-link lifting boom as described in any one of claims 1-9.

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