Special lifting appliance for lifting pipe joints of large pipe piles and loading and unloading process

Abstract

The invention provides a special lifting appliance for lifting large pipe pile pipe joints and a loading and unloading process, and relates to the technical field of pipe pile pipe joint lifting devices, the special lifting appliance comprises a lifting arm body, and the lifting arm body is of a C-shaped opening structure with the upper end and the lower end being lengthened; the two ends of the leveling ball sliding rod are provided with traction driving levers which synchronously move in the same direction or away from each other, the two sides of the suspension arm body are each symmetrically provided with a pair of flexible stabilizing mechanisms, and a compensation telescopic oil cylinder is further arranged in the suspension arm body. The traction telescopic oil rod, the compensation telescopic oil cylinder, the flexible stabilizing mechanism and the active telescopic oil cylinder communicate with one another through an oil way. Before a pipe body is suspended, the suspension arm body is moved to a counterweight balance position through traction of the traction shifting rod; and effective internal supporting is carried out on pipe body structures with different thicknesses through stretching and retracting of the rubber telescopic rods, so that the overall gravity balance of the suspension mechanism is guaranteed, and the safety in the suspension process is greatly guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of pipe pile and pipe section lifting devices, in particular to a special lifting device and a loading and unloading process for lifting large pipe pile and pipe sections. Background Art

[0002] The prior art discloses a large-diameter reinforced concrete pipe hoisting device based on improving assembly stability, with the publication number "CN221565480U", comprising: a U-shaped steel frame having a hoisting slot opening toward the side; a hoisting seat structure having a plurality of groups, and the plurality of groups of hoisting seat structures are respectively fixedly assembled on the top of the U-shaped steel frame; an extension frame rod, one end of which is transitionally assembled on one side of the U-shaped steel frame; a fixed frame clamp, which is transitionally assembled with the other end of the extension frame rod, and the fixed frame clamp has a clamping end, which is used for detachably clamping the pipe body. The prior art solves the technical problems of low efficiency, poor assembly quality and high safety risks when large-diameter reinforced concrete pipe bodies are assembled and tied with hoisting ropes.

[0003] However, the above-mentioned device still has obvious defects during use: the above-mentioned device needs to be manually pulled and connected, the fixing process is relatively cumbersome, and due to the differences in the length and thickness of the tube body, the above-mentioned device cannot be adjusted specifically according to the length and thickness of the tube body, which is not conducive to ensuring the stability during the suspension process, and production safety accidents may occur due to unbalanced force on the suspension mechanism. Summary of the invention

[0004] The purpose of the present invention is to provide a special lifting device and a loading and unloading process for lifting large pipe pile sections, so as to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions: A special lifting device for lifting large pipe pile sections, comprising a lifting arm body, wherein the lifting arm body is a C-shaped opening structure with elongated upper and lower ends; A leveling ball slide is installed between the upper and lower openings of the boom body in a lifting manner. The leveling ball slide is inserted into the tube body during the lifting process of the tube body. Sliding balls are arranged in a rectangular array on the upper surface of the leveling ball slide. Pulling levers that move toward or away from each other synchronously are provided at both ends of the leveling ball slide. The pulling levers on both sides move toward each other to push the inserted tube body to the counterweight balance position. The pulling levers on both sides slide in translation during the extension and retraction process of the pulling telescopic oil rod. A pair of flexible stabilizing mechanisms are symmetrically installed on both sides of the boom body, and the flexible stabilizing mechanisms include a cylinder sleeve and a rubber telescopic rod. The rubber telescopic rods of the flexible stabilizing mechanisms on both sides perform telescopic movements synchronously in the cylinder sleeve, and the rubber telescopic rods abut against the inner wall of the pipe body to further ensure the stability of the pipe body during lifting; The bottom of the leveling ball slide is fixedly connected to the telescopic arms of several active telescopic cylinders. A compensating telescopic cylinder is also arranged in the boom body. The pulling telescopic oil rod, the compensating telescopic oil cylinder, the flexible stabilizing mechanism and the active telescopic oil cylinder are interconnected through an oil circuit. The oil pushes the corresponding mechanism to perform telescopic movement during the transfer process. In the absence of external force, the oil in the pulling telescopic oil rod, the compensating telescopic oil cylinder and the flexible stabilizing mechanism enters the active telescopic oil cylinder to push the leveling ball slide to move upward. When the leveling ball slide descends under the weight of the pipe body, the oil flows out of the active telescopic oil cylinder and flows in a manner of first pulling the telescopic oil rod, then the flexible stabilizing mechanism and finally the compensating telescopic oil cylinder.

[0006] Preferably, the active telescopic cylinder, the pulling telescopic rod and the compensating telescopic cylinder all include a cylinder body, a piston telescopic arm and an extrusion spring. An extrusion spring is also provided in the flexible stabilizing mechanism. The sequence of their actions can be adjusted by adjusting the stiffness coefficients of the extrusion springs in different mechanisms.

[0007] Preferably, the boom body includes a variable-section empty box lower boom, an arc-shaped empty box end boom and a variable-section empty box upper boom, and the variable-section empty box lower boom, the arc-shaped empty box end boom and the variable-section empty box upper boom are welded and fixed, and the length of the variable-section empty box lower boom is longer than that of the variable-section empty box upper boom.

[0008] Preferably, a pair of hooks are fixedly mounted on the upper boom of the variable-section empty box.

[0009] Preferably, an embedding groove for embedding a leveling ball slide is provided in the middle of the lower hanging arm of the variable-section empty box. The leveling ball slide slides horizontally toward the side close to the embedding groove under the action of the weight of the tube body. Flexible pads are installed on the lower hanging arm of the variable-section empty box and the arc-shaped empty box end arm on both sides of the embedding groove. After the leveling ball slide is lowered to the extreme position, its upper surface is lower than the upper surface of the flexible pad, so that the inner wall of the tube body is in contact with the flexible pad.

[0010] Preferably, pressure sensors are evenly distributed on the bottom of the flexible pad, and the pressure distribution conditions of various parts of the flexible pad are detected by the pressure sensors.

[0011] A loading and unloading process for lifting a large pipe pile section adopts the above-mentioned special lifting device for lifting a large pipe pile section, comprising the following steps: Step 1: Use the crane to lift the boom body to the pipe body to be lifted, insert the lower boom of the variable cross-section empty box into the pipe body, and then drive the boom body to rise slowly through the crane; Step 2: During the rising process of the boom body, the leveling ball slide bar first abuts against the inside of the tube body. As the boom body continues to rise, the leveling ball slide bar is pushed downward under the weight of the tube body. At this time, the active telescopic oil cylinder is compressed, and the oil first enters the pulling telescopic oil rod; Step 3: When the oil first enters the pulling and telescopic oil rod, it pushes the pulling levers at both ends of the leveling ball slide rod to move toward each other. As the pulling levers move toward each other synchronously, the boom body performs follow-up adjustment so that the tube body moves to the counterweight balance position. At this time, the pulling levers at both ends abut against the two ends of the tube body. After this process is completed, the leveling ball slide rod is still in the descending process; Step 4: After the pulling lever clamps and limits the tube body, as the leveling ball slide bar continues to descend, the oil enters the flexible stabilizing mechanism, and the oil pushes the rubber telescopic rod to move away from the cylinder sleeve so that it abuts against the inner wall of the tube body, thereby further limiting the tube body; Step 5: As the leveling ball slide bar continues to descend, the oil inside eventually enters the compensating telescopic cylinder, thereby completing the transfer of the oil inside the leveling ball slide bar. At this time, the leveling ball slide bar enters the embedding groove, the tube body contacts the flexible pad, and is lifted up as the boom body rises.

[0012] Compared with the prior art, the present invention has the following beneficial effects: The present invention utilizes the deadweight of the pipe body to drive the corresponding mechanism to work. Before the pipe body is suspended, the arm body is moved to a counterweight balanced position by pulling the pull rod, and the pipe body structure of different thicknesses is effectively supported internally by the extension and retraction of the rubber telescopic rod, thereby ensuring the overall gravity balance of the suspension mechanism. Combined with the internal support of the rubber telescopic rod, the pipe body is effectively prevented from tipping over and sliding during the lifting process, thereby greatly ensuring the safety of the suspension process. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a three-dimensional schematic diagram of the overall structure of the present invention; Figure 2 It is a three-dimensional schematic diagram of the leveling ball slide rod connection structure of the present invention; Figure 3 It is a side view cross-sectional schematic diagram of the present invention; Figure 4 It is a schematic diagram of the oil circuit connection state of the active telescopic oil cylinder of the present invention; Figure 5 It is a schematic diagram of the oil circuit connection structure between the pulling telescopic oil rod and the active telescopic oil cylinder of the present invention.

[0014] In the figure: 1 boom body, 2 leveling ball slide bar, 3 sliding ball, 4 pulling lever, 5 pulling telescopic oil rod, 6 cylinder sleeve, 7 rubber telescopic rod, 8 active telescopic oil cylinder, 9 compensating telescopic oil cylinder, 10 cylinder body, 11 piston telescopic arm, 12 extrusion spring, 13 variable-section empty box lower boom, 14 arc-shaped empty box end arm, 15 variable-section empty box upper boom, 16 hook, 17 embedded groove, 18 flexible pad. DETAILED DESCRIPTION

[0015] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0016] See also Figure 1-Figure 5 , the present invention provides a technical solution: Embodiment 1: A special lifting device for lifting large pipe pile sections comprises a lifting arm body 1, wherein the lifting arm body 1 is a C-shaped opening structure with elongated upper and lower ends; A leveling ball slide bar 2 is installed between the upper and lower openings of the boom body 1 in a lifting manner. The leveling ball slide bar 2 is inserted into the pipe body during the lifting process of the pipe body. Sliding balls 3 are arranged in a rectangular array on the upper surface of the leveling ball slide bar 2. Pulling levers 4 that move toward or away from each other synchronously are provided at both ends of the leveling ball slide bar 2. The inserted pipe body is pushed to the counterweight balance position by the pull levers 4 on both sides moving toward each other. The pull levers 4 on both sides slide in translation during the extension and retraction process of the pulling telescopic oil rod 5. A pair of flexible stabilizing mechanisms are symmetrically installed on both sides of the boom body 1. The flexible stabilizing mechanisms include a cylinder sleeve 6 and a rubber telescopic rod 7. The rubber telescopic rods 7 of the flexible stabilizing mechanisms on both sides perform telescopic movements synchronously in the cylinder sleeve 6. The rubber telescopic rods 7 abut against the inner wall of the pipe body to further ensure the stability of the pipe body during lifting. The bottom of the leveling ball slide 2 is fixedly connected to the telescopic arms of several active telescopic cylinders 8. A compensating telescopic cylinder 9 is also arranged in the boom body 1. The pulling telescopic oil rod 5, the compensating telescopic oil cylinder 9, the flexible stabilizing mechanism and the active telescopic oil cylinder 8 are interconnected through oil circuits. The oil pushes the corresponding mechanisms to perform telescopic movements during the transfer process. In the absence of external force, the oil in the pulling telescopic oil rod 5, the compensating telescopic oil cylinder 9 and the flexible stabilizing mechanism enters the active telescopic oil cylinder 8, thereby pushing the leveling ball slide 2 to move upward. When the leveling ball slide 2 descends under the weight of the pipe body, the oil flows out of the active telescopic oil cylinder 8 and flows in the manner of first pulling the telescopic oil rod 5, then the flexible stabilizing mechanism, and finally the compensating telescopic oil cylinder 9.

[0017] In this embodiment, the boom body 1 serves as the main structure, which is a C-shaped opening structure with elongated upper and lower ends, including a variable-section empty box lower boom 13, an arc-shaped empty box end boom 14 and a variable-section empty box upper boom 15. The variable-section empty box lower boom 13, the arc-shaped empty box end boom 14 and the variable-section empty box upper boom 15 are welded and fixed, and a pair of hooks 16 are fixedly installed on the variable-section empty box upper boom 15. The hooks 16 are suspended by a traveling hoisting steel cable to tow the entire boom body 1. The length of the variable-section empty box lower boom 13 is longer than that of the variable-section empty box upper boom 15, wherein the upper and lower openings of the boom body 1 are raised between each other. The lowering type is equipped with a leveling ball slide bar 2, and the upper surface of the leveling ball slide bar 2 is arranged in an array with sliding balls 3, so that the tube body and the leveling ball slide bar 2 can slide in translation relatively easily. Pulling rods 4 that move toward or away from each other synchronously are arranged at both ends of the leveling ball slide bar 2. The pulling rod 4 slides in translation during the extension and retraction process of the pulling telescopic oil rod 5. The bottom of the leveling ball slide bar 2 is fixedly connected to the telescopic arms of several active telescopic oil cylinders 8. When the leveling ball slide bar 2 descends under the action of the weight of the tube body, the oil flows out of the active telescopic oil cylinder 8 and first enters the pulling telescopic oil rod 5. Refer to the attached manual Figure 5There are slotted structures on the upper and lower sides of the active telescopic oil cylinder 8, wherein the telescopic arm of the active telescopic oil cylinder 8 is fixedly connected to the leveling ball slide bar 2. By arranging an oil circuit in the leveling ball slide bar 2, the oil in the active telescopic oil cylinder 8 preferentially enters the pulling and telescopic oil rod 5 from the top through the leveling ball slide bar 2 when being pumped out. After the pulling and telescopic oil rod 5 is filled with oil, its rod body contracts inward, at which time the pulling levers 4 on both sides are driven to move toward each other synchronously. Due to the large dead weight of the tube body, it is difficult to move it by the push of the pulling lever 4 alone, but the boom body 1 is in a suspended state. Therefore, when the pulling lever 4 moves toward each other and abuts against the two ends of the tube body, it will push the boom body 1 to adjust its position, thereby moving it to a position where gravity is balanced. At this time, the tube body is suspended again. It can ensure the uniformity of gravity distribution and effectively prevent production safety accidents caused by the pipe falling off during the subsequent suspension process. At the same time, the bottom of the active telescopic cylinder 8 is connected with the flexible stabilizing mechanism and the compensating telescopic cylinder 9 through the oil path opened in the boom body 1. The structural setting of the flexible stabilizing mechanism is similar to that of the telescopic cylinder. The rubber telescopic rod 7 telescopes in the cylinder sleeve 6, so that the rubber telescopic rod 7 abuts against the inner wall of the pipe body, and the pipe body slides during the suspension process. The telescopic process of the rubber telescopic rod 7 is also achieved through the transfer of oil. The leveling ball slide bar 2 descends under the dead weight of the pipe body. Since the pulling levers 4 on both sides have limited and fixed the two ends of the pipe body, the oil can no longer enter the pulling telescopic oil rod 5. As the compression of the expansion cylinder 8 continues, the oil enters the cylinder sleeve 6 and pushes the rubber telescopic rod 7 to extend outward, thereby completing the abutment against the inner wall of the tube body. When the abutment is completed, as the leveling ball slide bar 2 continues to descend, the excess oil eventually enters the compensation telescopic cylinder 9 for storage. It should be noted that the size parameters of the active telescopic cylinder 8 in the figure are relatively small, which is only for illustration. In the design process, the size and number of the active telescopic cylinder 8 are set so that the volume inside can be filled with oil sufficient to achieve the above-mentioned actions, thereby ensuring the normal progress of the above-mentioned operations. Since the boom body 1 needs to perform suspension operations on tubes of different lengths and thicknesses, the telescopic range of the pulling lever 4 and the rubber telescopic rod 7 is not fixed during each suspension process. Therefore, the arrangement of the compensating telescopic oil cylinder 9 can store excess oil, wherein the active telescopic oil cylinder 8, the pulling telescopic oil rod 5 and the compensating telescopic oil cylinder 9 all include a cylinder body 10, a piston telescopic arm 11 and an extrusion spring 12, and the flexible stabilizing mechanism is also provided with an extrusion spring 12. This type of telescopic mechanism driven by oil is relatively common in the prior art and will not be described in detail herein. In order to ensure the working sequence of the above-mentioned devices, the active telescopic oil cylinder 8, the pulling telescopic oil rod 5, the compensating telescopic oil cylinder 9 and the flexible stabilizing mechanism are provided with extrusion springs 12 with different stiffness coefficients. The pulling telescopic oil rod 5 that acts first is provided with an extrusion spring 12 with the lowest stiffness coefficient, while the compensating telescopic oil cylinder 9 is provided with an extrusion spring 12 with the largest stiffness coefficient.This allows different structural actions to proceed smoothly one after another.

[0018] Embodiment 2: An embedding groove 17 is provided in the lower boom 13 of the variable-section empty box. The leveling ball slide bar 2 enters the embedding groove 17 during the descent process, and the tube body is finally placed on the flexible pad 18, thereby ensuring stability during the suspension process.

[0019] An embedding groove 17 for embedding the leveling ball slide 2 is provided in the middle of the lower hanging arm 13 of the variable-section empty box. The leveling ball slide 2 slides horizontally toward the side close to the embedding groove 17 under the action of the inner weight of the tube body. Flexible pads 18 are installed on the lower hanging arm 13 of the variable-section empty box and the arc-shaped empty box end arm 14 on both sides of the embedding groove 17. After the leveling ball slide 2 is lowered to the extreme position, its upper surface is lower than the upper surface of the flexible pad 18, so that the inner wall of the tube body is in contact with the flexible pad 18.

[0020] Embodiment three: Pressure sensors are evenly distributed on the bottom of the flexible pad 18, and the pressure distribution conditions of various parts of the flexible pad 18 are detected by the pressure sensors.

[0021] In this embodiment, by setting up a pressure sensor, the pressure distribution condition at each position can be monitored in real time during the suspension process of the pipe body, which is conducive to timely discovering the uneven gravity distribution condition of the pipe body and further ensuring the safety during the suspension process.

[0022] A loading and unloading process for lifting a large pipe pile section adopts the above-mentioned special lifting device for lifting a large pipe pile section, comprising the following steps: Step 1: Use a crane to lift the boom body 1 to the pipe body to be lifted, and insert the variable-section empty box lower boom 13 into the pipe body, and then drive the boom body 1 to slowly rise by the crane; Step 2: During the rising process of the boom body 1, the leveling ball slide bar 2 first abuts against the inside of the tube body. As the boom body 1 continues to rise, the leveling ball slide bar 2 is pushed downward under the weight of the tube body. At this time, the active telescopic oil cylinder 8 is compressed, and the oil first enters the pulling telescopic oil rod 5; Step 3: When the oil first enters the pulling and telescopic oil rod 5, it pushes the pulling levers 4 at both ends of the leveling ball slide bar 2 to move toward each other. As the pulling levers 4 move toward each other synchronously, the boom body 1 performs follow-up adjustment so that the tube body moves to the counterweight balance position. At this time, the pulling levers 4 at both ends abut against the two ends of the tube body. After this process is completed, the leveling ball slide bar 2 is still in the descending process; Step 4: After the pulling lever 4 clamps and limits the tube body, as the leveling ball slide bar 2 continues to descend, the oil enters the flexible stabilizing mechanism, and the oil pushes the rubber telescopic rod 7 to move away from the cylinder sleeve 6 so that it abuts against the inner wall of the tube body, thereby further limiting the position of the tube body; Step 5: As the leveling ball slide 2 continues to descend, the oil inside eventually enters the compensating telescopic cylinder 9, thereby completing the transfer of the oil inside the leveling ball slide 2. At this time, the leveling ball slide 2 enters the embedding groove, the tube body contacts the flexible pad 18, and is lifted up as the boom body 1 rises.

[0023] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A special lifting device for lifting large pipe pile sections, comprising a lifting arm body, wherein the lifting arm body is a C-shaped opening structure with elongated upper and lower ends; characterized in that: A leveling ball slide is installed between the upper and lower openings of the boom body in a lifting manner. The leveling ball slide is inserted into the tube body during the lifting process of the tube body. Sliding balls are arranged in a rectangular array on the upper surface of the leveling ball slide. Pulling levers that move toward or away from each other synchronously are provided at both ends of the leveling ball slide. The pulling levers on both sides move toward each other to push the inserted tube body to the counterweight balance position. The pulling levers on both sides slide in translation during the extension and retraction process of the pulling telescopic oil rod. A pair of flexible stabilizing mechanisms are symmetrically installed on both sides of the boom body, and the flexible stabilizing mechanisms include a cylinder sleeve and a rubber telescopic rod. The rubber telescopic rods of the flexible stabilizing mechanisms on both sides perform telescopic movements synchronously in the cylinder sleeve, and the rubber telescopic rods abut against the inner wall of the pipe body to further ensure the stability of the pipe body during lifting; The bottom of the leveling ball slide is fixedly connected to the telescopic arms of several active telescopic cylinders. A compensating telescopic cylinder is also arranged in the boom body. The pulling telescopic oil rod, the compensating telescopic oil cylinder, the flexible stabilizing mechanism and the active telescopic oil cylinder are interconnected through an oil circuit. The oil pushes the corresponding mechanism to perform telescopic movement during the transfer process. In the absence of external force, the oil in the pulling telescopic oil rod, the compensating telescopic oil cylinder and the flexible stabilizing mechanism enters the active telescopic oil cylinder to push the leveling ball slide to move upward. When the leveling ball slide descends under the weight of the pipe body, the oil flows out of the active telescopic oil cylinder and flows in a manner of first pulling the telescopic oil rod, then the flexible stabilizing mechanism and finally the compensating telescopic oil cylinder.

2. A special lifting device for lifting large pipe pile sections according to claim 1, characterized in that: The active telescopic cylinder, pulling telescopic rod and compensating telescopic cylinder all include a cylinder body, a piston telescopic arm and an extrusion spring. The flexible stabilizing mechanism is also provided with an extrusion spring. The sequence of their actions can be adjusted by adjusting the stiffness coefficients of the extrusion springs in different mechanisms.

3. A special lifting device for lifting large pipe pile sections according to claim 1 or 2, characterized in that: The boom body includes a variable-section empty box lower boom, an arc-shaped empty box end boom and a variable-section empty box upper boom. The variable-section empty box lower boom, the arc-shaped empty box end boom and the variable-section empty box upper boom are welded and fixed to each other. The length of the variable-section empty box lower boom is longer than that of the variable-section empty box upper boom.

4. A special lifting device for lifting large pipe pile sections according to claim 3, characterized in that: A pair of hooks are also fixedly mounted on the upper boom of the variable-section empty box.

5. A special lifting device for lifting large pipe pile sections according to claim 4, characterized in that: An embedding groove for embedding a leveling ball slide is provided in the middle of the lower hanging arm of the variable-section empty box. The leveling ball slide slides horizontally toward the side close to the embedding groove under the action of the weight of the tube body. Flexible pads are installed on the lower hanging arm of the variable-section empty box and the arc-shaped empty box end arms on both sides of the embedding groove. After the leveling ball slide is lowered to the extreme position, its upper surface is lower than the upper surface of the flexible pad, so that the inner wall of the tube body is in contact with the flexible pad.

6. A special lifting device for lifting large pipe pile sections according to claim 5, characterized in that: Pressure sensors are evenly distributed on the bottom of the flexible pad, and the pressure distribution conditions of various parts of the flexible pad are detected by the pressure sensors.

7. A loading and unloading process for lifting large pipe pile sections, using the special lifting device for lifting large pipe pile sections according to claim 5 or 6, characterized in that: The following steps are involved: Step 1: Use the crane to lift the boom body to the pipe body to be lifted, insert the lower boom of the variable cross-section empty box into the pipe body, and then drive the boom body to rise slowly through the crane; Step 2: During the rising process of the boom body, the leveling ball slide bar first abuts against the inside of the tube body. As the boom body continues to rise, the leveling ball slide bar is pushed downward under the weight of the tube body. At this time, the active telescopic oil cylinder is compressed, and the oil first enters the pulling telescopic oil rod; Step 3: When the oil first enters the pulling and telescopic oil rod, it pushes the pulling levers at both ends of the leveling ball slide rod to move toward each other. As the pulling levers move toward each other synchronously, the boom body performs follow-up adjustment so that the tube body moves to the counterweight balance position. At this time, the pulling levers at both ends abut against the two ends of the tube body. After this process is completed, the leveling ball slide rod is still in the descending process; Step 4: After the pulling lever clamps and limits the tube body, as the leveling ball slide bar continues to descend, the oil enters the flexible stabilizing mechanism, and the oil pushes the rubber telescopic rod to move away from the cylinder sleeve so that it abuts against the inner wall of the tube body, thereby further limiting the tube body; Step 5: As the leveling ball slide bar continues to descend, the oil inside eventually enters the compensating telescopic cylinder, thereby completing the transfer of the oil inside the leveling ball slide bar. At this time, the leveling ball slide bar enters the embedding groove, the tube body contacts the flexible pad, and is lifted up as the boom body rises.

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