A telescoping device

Abstract

This utility model discloses a telescopic device comprising a telescopic arm and a drive mechanism. The telescopic arm includes several sequentially nested mechanical arms, with adjacent mechanical arms slidably connected. The outermost mechanical arm has a positioning part on its end face, and the innermost mechanical arm has a stop adapted to the positioning part. The output end of the drive mechanism is fixedly connected to the innermost mechanical arm, driving it to move away from the outermost mechanical arm. Under the action of the positioning part and the stop, it sequentially drives adjacent mechanical arms to slide in the same direction, thereby extending the telescopic arm. The drive mechanism also drives the innermost mechanical arm to move towards the outermost mechanical arm, and under the action of the positioning part and the stop, it sequentially drives adjacent mechanical arms to slide in the same direction, thereby retracting the telescopic arm. This utility model has the advantages of compact structure, long service life, adaptability to complex forces under heavy-load conditions, high structural strength, low power transmission loss, and smooth telescopic operation.

Description

Technical Field

[0001] This utility model relates to the field of drilling construction machinery technology, specifically to a telescopic device. Background Technology

[0002] Telescopic devices, as an important mechanical structure, have wide and crucial applications in many fields. In industrial production, they are commonly found in various large-scale mechanical equipment, such as the booms of cranes and the lifting arms of aerial work platforms, used to meet the needs of lifting, moving, and operating at different heights.

[0003] In existing telescopic devices, some products use simple mechanical connections to achieve telescopic functionality, lacking effective limiting and force transmission structures between adjacent robotic arms. Under heavy loads, when the drive mechanism extends or retracts the robotic arms, misalignment and jamming can easily occur. During the operation of the telescopic device, frequent friction occurs at the sliding connection points between the robotic arms. However, the sliding connection structure design of some existing telescopic devices is unreasonable, lacking effective lubrication and wear-resistant measures.

[0004] The connection between the drive mechanism and the robotic arm of existing telescopic devices is not optimal, resulting in a long power transmission path and significant energy loss. Current technologies often employ chain or belt drives, which suffer energy loss during transmission due to friction and tension. This prevents the power output from the drive mechanism from being efficiently transmitted to the robotic arm, thus reducing the drive efficiency of the telescopic device. This not only increases energy consumption but, under heavy-load conditions, insufficient power transmission can also cause the telescopic device to malfunction, failing to meet actual production needs. Summary of the Invention

[0005] The technical problem to be solved by this utility model is to provide a telescopic device with a compact structure, long service life, adaptability to complex stress under heavy load conditions, high structural strength, low power transmission loss, and smooth telescopic operation.

[0006] To solve the above-mentioned technical problems, the present invention provides a telescopic device, which includes at least a telescopic arm and a drive mechanism. The telescopic arm includes a plurality of mechanical arms that are sequentially nested together. Adjacent mechanical arms are slidably connected, and the end face of the outer mechanical arm is provided with a positioning part, while the inner mechanical arm is provided with a stop that is adapted to the positioning part. The output end of the drive mechanism is fixedly connected to the innermost robotic arm, and is used to drive the innermost robotic arm to move away from the outermost robotic arm. Under the action of the positioning part and the stop, the adjacent robotic arms are sequentially driven to slide in the same direction, thereby extending the telescopic arm. And for driving the innermost robotic arm to move along the direction close to the outermost robotic arm, under the action of the positioning part and the stop, the adjacent robotic arms are sequentially driven to slide in the same direction, thereby causing the telescopic arm to retract.

[0007] In a preferred embodiment, the telescopic arm includes a first robotic arm, a second robotic arm, and a third robotic arm, wherein the free end of the third robotic arm is provided with a mounting portion for mounting external equipment.

[0008] In a preferred embodiment, the first robotic arm is provided with a first cavity adapted to the outer surface of the second robotic arm, and a plurality of liner plates are provided at intervals around the sliding direction of the second robotic arm on the outer surface. One end of each liner plate extends into the first cavity and abuts against the outer surface of the second robotic arm. The second robotic arm is slidably connected to the inner wall of the first cavity through the liner plates. The second robotic arm is provided with a second cavity that is adapted to the outer surface of the third robotic arm, and a plurality of liner plates are provided at intervals around the sliding direction of the third robotic arm on the outer surface. One end of the liner plate extends into the second cavity and abuts against the outer surface of the second robotic arm. The second robotic arm is slidably connected to the inner wall of the second cavity through the liner plate.

[0009] In a preferred embodiment, the cross-section of the first cavity and / or the second cavity perpendicular to the telescopic arm's telescopic direction is a regular polygon.

[0010] In a preferred embodiment, the driving mechanism includes a hydraulic cylinder, which is located in the first cavity and fixedly connected to the first robotic arm, and a piston rod passes through the second cavity and is fixedly connected to the third robotic arm.

[0011] In a preferred embodiment, the liner includes a mounting plate and an abutment block fixedly connected to the mounting plate. The liner is fixedly connected to the outer surface of the first robotic arm via the mounting plate and abuts against the outer surface of the second robotic arm via the abutment block. A lubrication groove is provided on the end face of the abutment block that abuts against the outer surface of the second robotic arm.

[0012] In a preferred embodiment, the abutment block is provided with at least one through hole communicating with the lubrication groove, and the mounting plate is provided with filling holes corresponding to the through holes, the filling holes penetrating the mounting plate and communicating with the through holes.

[0013] In a preferred embodiment, the abutment block uses high-density brass as the substrate, and graphite is embedded in the substrate as a solid lubricant or a surface coating.

[0014] In a preferred embodiment, the second liner plate adopts the same structural design as the first liner plate.

[0015] In a preferred embodiment, the abutment block of the first liner plate and the mounting plate of the second liner plate are offset from each other around the telescopic arm's telescopic direction.

[0016] Compared with the prior art, the telescopic device of this utility model has the following advantages: (1) The telescopic device of this utility model includes at least a telescopic arm and a drive mechanism. The telescopic arm includes several mechanical arms that are nested in sequence, forming the basic structural framework of the telescopic device, which can realize the telescopic function. Through the design of several mechanical arms nested in sequence, a compact storage state and a large telescopic stroke are achieved. The nested structure occupies little space when retracted and can extend step by step when unfolded, meeting the telescopic range requirements of different working scenarios. Adjacent mechanical arms are connected by a sliding connection. The sliding connection ensures that the mechanical arms can move smoothly relative to each other, reducing resistance during the telescopic process. Compared with traditional hinges or gear transmissions, the sliding structure is simpler and more reliable, and is suitable for heavy-duty and high-frequency telescopic scenarios.

[0017] The outer end face of the robotic arm is equipped with a positioning part, and the inner end face of the robotic arm is equipped with a stop that matches the positioning part. During the extension and retraction of the telescopic arm, when the drive mechanism drives the robotic arm to move, the positioning part and the stop cooperate to precisely control the relative position of adjacent robotic arms, preventing misalignment during extension and retraction, ensuring the accuracy and stability of the telescopic arm's movement, avoiding jamming caused by misalignment, and improving the reliability and service life of the telescopic device under heavy loads. At the same time, the direct contact between the stop and the positioning part forms a short-path force transmission, replacing traditional chain / belt drives, reducing energy loss, and improving drive efficiency.

[0018] The output end of the drive mechanism is fixedly connected to the innermost robotic arm, which is used to drive the innermost robotic arm to move away from the outermost robotic arm. Under the action of the positioning part and the stop, it drives the adjacent robotic arms to slide in the same direction in sequence, thereby extending the telescopic arm. It is also used to drive the innermost robotic arm to move towards the outermost robotic arm. Under the action of the positioning part and the stop, it drives the adjacent robotic arms to slide in the same direction in sequence, thereby retracting the telescopic arm. The design of the concentrated point of application of the driving force makes the innermost robotic arm move first. The power is transmitted step by step through the stop, which is more suitable for bearing uneven loads.

[0019] (2) In the telescopic device of this utility model, the first robotic arm is provided with a first cavity adapted to the outer surface of the second robotic arm, and a plurality of liner plates are provided at intervals around the sliding direction of the second robotic arm. One end of the liner plate extends into the first cavity and abuts against the outer surface of the second robotic arm. The second robotic arm is slidably connected to the inner wall of the first cavity through the liner plate. The second robotic arm is provided with a second cavity adapted to the outer surface of the third robotic arm, and a plurality of liner plates are provided at intervals around the sliding direction of the third robotic arm. One end of the liner plate extends into the second cavity and abuts against the outer surface of the second robotic arm. The second robotic arm is slidably connected to the inner wall of the second cavity through the liner plate. On the one hand, the structure of the cavity matches the shape of the outer surface of the robotic arm, ensuring the linear movement of the robotic arm during telescopic movement and avoiding skew or twisting; on the other hand, the spaced liner plates distribute the force of the robotic arm to multiple contact points of the cavity, reducing local stress concentration and extending the structural life. At the same time, the liner plates and the liner plates are independent friction pairs, reducing the sliding resistance.

[0020] The cross-sections of the first cavity and / or the second cavity perpendicular to the telescopic boom's extension direction are regular polygons. On one hand, the straight-edge structure of regular polygons (such as quadrilaterals and hexagons) naturally possesses anti-rotation characteristics, preventing adjacent robotic arms from rotating freely. Under heavy loads or asymmetrical forces (such as eccentric loading on cranes), this effectively prevents misalignment of the robotic arms due to torque, ensuring the stability of the telescopic movement. On the other hand, the sides and corners of regular polygons form clear guiding paths, which, combined with the sliding contact of the liner plates (132 / 142), ensure that the robotic arms can only move in a straight line along the axial direction, avoiding skewness and improving extension accuracy. Each side of the regular polygon forms an independent force transmission path in contact with the liner plate. Compared to the continuous contact surface of a circular cross-section, this results in less local pressure and reduced wear. Under impact loads, the corners of the polygonal cross-section can disperse stress, avoiding the "single-point crushing" risk of a circular cross-section. The moment of inertia of a regular polygon (such as a hexagon) is higher than that of a circle, resulting in stronger bending stiffness and reducing sagging deformation during telescopic boom extension, making it particularly suitable for long-stroke telescopic booms. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the telescopic device of this utility model; Figure 2 This is a side view of the overall structure of an embodiment of the telescopic device of this utility model; Figure 3 for Figure 2 BB-direction sectional view; Figure 4 for Figure 2 A sectional view along the AA direction; Figure 5 This is a schematic diagram of the liner structure of an embodiment of the telescopic device of this utility model; Figure 6for Figure 5 A schematic diagram of the structure in the C direction.

[0022] Explanation of reference numerals in the attached figures: 1-Telescopic arm; 11-Positioning part; 12-Stop block; 13-First robotic arm; 131-First cavity; 132-Liner plate one; 1321-Mounting plate; 1322-Abutting plate; 1323-Lubrication groove; 1324-Through hole; 1325-Filling hole; 1326-Adjusting shim; 133-Centralized lubrication part; 134-Liquid flow channel; 14-Second robotic arm; 141-Second cavity; 142-Liner plate two; 15-Third robotic arm; 151-Mounting part; 2-Drive mechanism; 21-Hydraulic cylinder. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0024] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0025] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation", "connection" and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, an integral connection, or a detachable connection; they can refer to the internal connection of two components; they can refer to a direct connection or an indirect connection through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0026] One type of telescopic device in this embodiment, such as Figure 1 , Figure 2 and Figure 3 As shown, it includes at least a telescopic arm 1 and a drive mechanism 2. The telescopic arm 1 comprises several sequentially nested robotic arms, forming the basic structural framework of the telescopic device, enabling telescopic functionality. Through the sequential nesting design of the robotic arms, a compact storage state and a large telescopic stroke are achieved. The nested structure occupies little space when retracted and can extend step by step when extended, meeting the telescopic range requirements of different operating scenarios.

[0027] Adjacent robotic arms are slidably connected, with a positioning part 11 on the outer end face of the robotic arm and a stop 12 adapted to the positioning part on the inner end face of the robotic arm. During the extension and retraction of the telescopic arm, when the drive mechanism drives the robotic arm to move, the positioning part and the stop cooperate to precisely control the relative position of adjacent robotic arms, preventing misalignment during extension and retraction, ensuring the accuracy and stability of the telescopic arm's movement, avoiding jamming caused by misalignment, and improving the reliability and service life of the telescopic device under heavy loads. At the same time, the direct contact between the stop and the positioning part forms a short-path force transmission, replacing traditional chain / belt drives, reducing energy loss, and improving drive efficiency.

[0028] The output end of the drive mechanism 2 is fixedly connected to the innermost robotic arm, and is used to drive the innermost robotic arm to move away from the outermost robotic arm. Under the action of the positioning part 11 and the stop 12, it sequentially drives the adjacent robotic arms to slide in the same direction, thereby extending the telescopic arm. It is also used to drive the innermost robotic arm to move towards the outermost robotic arm. Under the action of the positioning part 11 and the stop 12, it sequentially drives the adjacent robotic arms to slide in the same direction, thereby retracting the telescopic arm. The design of the concentrated point of application of the driving force makes the innermost robotic arm move first. The power is transmitted step by step through the stop, which is more suitable for bearing uneven loads.

[0029] like Figure 2 and Figure 3 As shown, the telescopic arm 1 in this embodiment includes a first robotic arm 13, a second robotic arm 14 and a third robotic arm 15. The free end of the third robotic arm is provided with a mounting part 151 for mounting external equipment.

[0030] The first robotic arm 13 has a first cavity 131 adapted to the outer surface of the second robotic arm, and a plurality of first liner plates 132 are spaced apart on the outer surface around the sliding direction of the second robotic arm. One end of the first liner plate extends into the first cavity and abuts against the outer surface of the second robotic arm. The second robotic arm is slidably connected to the inner wall of the first cavity through the first liner plate. The second robotic arm 14 has a second cavity 141 adapted to the outer surface of the third robotic arm, and a plurality of second liner plates 142 are spaced apart on the outer surface around the sliding direction of the third robotic arm. One end of the second liner plate extends into the second cavity and abuts against the outer surface of the second robotic arm. The second robotic arm is slidably connected to the inner wall of the second cavity through the second liner plate. On the one hand, the structure of the cavity matches the shape of the outer surface of the robotic arm, ensuring the linear movement of the robotic arm during extension and retraction, and avoiding skew or twisting; on the other hand, the spaced liner plates distribute the force of the robotic arm to multiple contact points of the cavity, reducing local stress concentration and extending the structural life. At the same time, the first and second liner plates act as independent friction pairs, reducing sliding resistance.

[0031] The cross-sections of the first cavity 131 and / or the second cavity 141 perpendicular to the telescopic arm 1's extension direction are regular polygons. On one hand, the straight-edge structure of a regular polygon (such as a quadrilateral or hexagon) naturally possesses anti-rotation characteristics, preventing adjacent robotic arms from rotating freely. Under heavy loads or asymmetrical forces (such as eccentric loading on a crane), this effectively prevents the robotic arm from misaligning due to torque, ensuring the stability of the telescopic movement. On the other hand, the edges and corners of the regular polygon form clear guiding paths, which, combined with the sliding contact of the first and second liner plates, ensure that the robotic arm can only move in a straight line along the axial direction, avoiding skewness and improving extension accuracy. Each edge of the regular polygon forms an independent force transmission path in contact with the liner plate. Compared to the continuous contact surface of a circular cross-section, this results in less local pressure and reduced wear. Under impact loads, the corners of the polygonal cross-section can disperse stress, avoiding the "single-point crushing" risk of a circular cross-section. The moment of inertia of the regular polygon cross-section is higher than that of a circle, resulting in stronger bending stiffness and reducing sagging deformation during telescopic arm extension, making it particularly suitable for long-stroke telescopic arms. In this embodiment, the cross-section adopts a square structure.

[0032] like Figure 3 As shown, the drive mechanism 2 includes a hydraulic cylinder 21, which is located in the first cavity 131 and fixedly connected to the first robotic arm 13. The piston rod passes through the second cavity 141 and is fixedly connected to the third robotic arm. Integrating the hydraulic cylinder 21 directly into the first cavity of the first robotic arm 13 avoids the need for an external drive mechanism to occupy extra space, making the overall structure more compact. The hydraulic system itself has high power density, and combined with the direct drive method, it can achieve fast and precise movements of the telescopic arm.

[0033] In this embodiment, the hydraulic cylinder and the robotic arm are arranged coaxially, and the driving force is transmitted along the centerline of the telescopic arm, avoiding deformation or jamming of the robotic arm caused by asymmetrical force. The cross-sections of the first cavity and the second cavity adopt a regular polygonal structure. After the hydraulic cylinder is built in, the polygonal edges can be used to further restrict the rotation of the hydraulic cylinder, enhancing the overall torsional resistance.

[0034] like Figure 5As shown, the liner 132 includes a mounting plate 1321 and an abutment block 1322 fixedly connected to the mounting plate. The liner 132 is fixedly connected to the outer surface of the first robotic arm through the mounting plate and abuts against the outer surface of the second robotic arm through the abutment block. The end face of the abutment block 1322 that abuts against the outer surface of the second robotic arm is provided with a lubrication groove 1323. On the one hand, the abutment block directly abuts against the outer surface of the second robotic arm, playing a precise limiting and guiding role during the extension and retraction of the telescopic arm. This ensures that the second robotic arm moves along a predetermined trajectory during extension and retraction, preventing deviation or wobbling during movement, thus guaranteeing the accuracy and stability of the extension and retraction and improving the working precision of the telescopic device. On the other hand, during the operation of the telescopic device, frequent relative sliding friction occurs between the abutment block and the second robotic arm. The lubrication groove can store lubricating grease. During relative sliding, the lubricating grease can form a lubricating film between the contact surfaces, effectively reducing the coefficient of friction between the two and reducing the generation of frictional force. This not only reduces energy loss and improves the driving efficiency of the telescopic device, but also significantly reduces the wear of the contact surfaces of the abutment block and the second robotic arm, extending their service life.

[0035] The abutment block is provided with at least one through hole 1324 that communicates with the lubrication groove 1323, and the mounting plate 1321 is provided with filling holes 1325 that correspond one-to-one with the through holes. The filling holes penetrate the mounting plate and communicate with the through holes.

[0036] like Figure 5 As shown, the abutment block 1322 is fitted with at least one adjusting pad 1326 that is fixedly connected to the mounting plate. During the repeated extension and retraction of the telescopic device, the abutment block 1322 will become thinner due to friction, resulting in an increase in the gap between the robotic arms and affecting the motion accuracy. By adjusting the number of adjusting pads, on the one hand, the original mating gap can be quickly restored, avoiding robotic arm wobbling or misalignment caused by wear; on the other hand, it is not necessary to replace the entire abutment block. The wear can be compensated by removing the adjusting pads, so that the abutment block can still tightly abut against the outer surface of the second robotic arm, making full use of the performance of the abutment block material, extending its actual service life, and avoiding material waste due to premature replacement.

[0037] Preferably, the abutment block uses high-density brass as the base material, and graphite is embedded in the base material as a solid lubricant or a surface coating.

[0038] In this embodiment, the second liner 142 and the first liner 132 adopt the same structural design, which reduces the processing, storage and management costs of different types of liners on the one hand; on the other hand, in the multi-layer robotic arm, the first liner and the second liner can be used interchangeably, and there is no need to distinguish the models during assembly, which shortens the installation time.

[0039] like Figure 2As shown, the first robotic arm 13 is equipped with a centralized lubrication section 133 and a fluid flow channel 134 connecting the centralized lubrication section and the filling hole 1325. By adding lubricating material to the centralized lubrication section 133, the lubricating material sequentially passes through the fluid flow channel 134, the filling hole 1325, the through hole 1324, and the lubrication groove 1323 to the contact position between the abutment block and the outer surface of the second robotic arm, effectively reducing the coefficient of friction between the two. When the robotic arms move relative to each other, the reduction in friction significantly reduces the wear of the contact surfaces, while significantly extending the service life of the components and reducing vibration and noise during the movement of the robotic arm.

[0040] like Figure 4 As shown, the abutment block 1322 of liner 132 and the mounting plate 1321 of liner 2 142 are offset around the telescopic arm 1 in the telescopic direction. On the one hand, this optimizes load distribution and improves structural strength. The offset structural design disperses the load to different axial positions, reduces single-point stress, and extends the life of the robotic arm. At the same time, it is equivalent to adding "multi-point support" in the length direction of the telescopic arm, reducing bending deformation of the cantilever section, which is especially suitable for long-stroke heavy-load telescopic arm. On the other hand, when the telescopic arm is subjected to lateral force, the offset liner 1 and liner 2 will generate a counter-torque, suppressing the rotation tendency of the robotic arm. In conjunction with the regular polygonal cross-section, this further enhances the torsional resistance.

[0041] In summary, the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A telescopic device, characterized in that: It includes at least a telescopic arm (1) and a drive mechanism (2). The telescopic arm (1) includes a plurality of mechanical arms that are sequentially nested together. The adjacent mechanical arms are connected by a sliding connection. The end face of the mechanical arm located on the outer side is provided with a positioning part (11), and the mechanical arm located on the inner side is provided with a stop (12) that is adapted to the positioning part. The output end of the drive mechanism (2) is fixedly connected to the innermost mechanical arm, and is used to drive the innermost mechanical arm to move in a direction away from the outermost mechanical arm. Under the action of the positioning part (11) and the stop block (12), the adjacent mechanical arms are sequentially driven to slide in the same direction, thereby extending the telescopic arm. And for driving the innermost robotic arm to move along the direction close to the outermost robotic arm, under the action of the positioning part (11) and the stop (12), the adjacent robotic arms are sequentially driven to slide in the same direction, thereby causing the telescopic arm to retract.

2. The telescopic device according to claim 1, characterized in that: The telescopic arm (1) includes a first mechanical arm (13), a second mechanical arm (14) and a third mechanical arm (15), and the free end of the third mechanical arm is provided with a mounting part (151) for installing external equipment.

3. A telescopic device according to claim 2, characterized in that: The first robotic arm (13) is provided with a first cavity (131) that is adapted to the outer surface of the second robotic arm, and a plurality of liner plates (132) are provided at intervals around the sliding direction of the second robotic arm. One end of the liner plate extends into the first cavity and abuts against the outer surface of the second robotic arm. The second robotic arm is slidably connected to the inner wall of the first cavity through the liner plate. The second robotic arm (14) is provided with a second cavity (141) that is adapted to the outer surface of the third robotic arm, and a plurality of liner plates (142) are provided at intervals around the sliding direction of the third robotic arm. One end of the liner plate extends into the second cavity and abuts against the outer surface of the second robotic arm. The second robotic arm is slidably connected to the inner wall of the second cavity through the liner plate.

4. A telescopic device according to claim 3, characterized in that: The cross section of the first cavity (131) and / or the second cavity (141) perpendicular to the telescopic arm (1) telescopic direction is a regular polygon.

5. A telescopic device according to claim 4, characterized in that: The drive mechanism (2) includes a hydraulic cylinder (21), which is located in the first cavity (131) and fixedly connected to the first robotic arm (13), and the piston rod passes through the second cavity (141) and is fixedly connected to the third robotic arm.

6. A telescopic device according to any one of claims 3-5, characterized in that: The first liner (132) includes a mounting plate (1321) and an abutment block (1322) fixedly connected to the mounting plate. The first liner (132) is fixedly connected to the outer surface of the first robotic arm through the mounting plate and abuts against the outer surface of the second robotic arm through the abutment block. The end face of the abutment block (1322) that abuts against the outer surface of the second robotic arm is provided with a lubrication groove (1323).

7. A telescopic device according to claim 6, characterized in that: The abutment block is provided with at least one through hole (1324) communicating with the lubrication groove (1323), and the mounting plate (1321) is provided with filling holes (1325) corresponding to the through holes. The filling holes penetrate the mounting plate and communicate with the through holes.

8. A telescopic device according to claim 7, characterized in that: The abutment block uses high-density brass as the base, with graphite embedded in the base as a solid lubricant or a surface coating.

9. A telescopic device according to claim 8, characterized in that: The second liner (142) adopts the same structural design as the first liner (132).

10. A telescopic device according to claim 9, characterized in that: The abutting block (1322) of the first liner (132) and the mounting plate (1321) of the second liner (142) are offset from each other around the telescopic arm (1) in the telescopic direction.

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