Electric pole tensioning and supporting device with adjustable slight diameter

Abstract

The invention provides an electric pole tensioning and supporting device with the adjustable tip diameter, and belongs to the technical field of electric poles, the electric pole tensioning and supporting device comprises a trailer outer frame, an electric pole production assembly with the adjustable tip diameter is arranged on the inner side of the trailer outer frame, and a detection supporting assembly is arranged below the electric pole production assembly with the adjustable tip diameter. The trailer outer frame is used as a carrier, and adjustable mold, automatic mold closing, static mold demolding, mobile detection and inclined discharging are integrated on the same mobile platform; the multi-stage expansion piece is linked with the motor to realize the stepless adjustment of the tapered rod slightly-diameter and the quick die change; precise positioning in the whole process is guaranteed by means of a sliding rod and a guide groove; after demolding, the rod body directly falls into the detection supporting assembly, tensioning detection and automatic discharging are completed in the same equipment, tensioning machine fixing and multiple times of hoisting are omitted, and the beneficial effects that transition is convenient and fast, model changing is rapid, production and use are achieved, a conical rod is compatible, and operation is safe are achieved.

Description

Technical Field

[0001] This invention relates to the field of electric pole technology, and more particularly to an adjustable pole tensioning support device. Background Technology

[0002] Pole tensioning and support devices are widely used in power engineering, primarily for supporting and tensioning power line poles or towers to ensure their stability and reliability during installation and operation. They are commonly used in transmission lines, communication lines, and other facilities, providing additional support and tension control, especially in situations with challenging terrain or environmental conditions.

[0003] Currently, traditional pole production uses a "fixed platform + decentralized equipment" model: after the steel bars are cut to a fixed length, they need to be hoisted into a fixed mold and bolted in place; after the concrete is centrifuged or vibrated, it is then lifted by a crane to a tilting platform for demolding; subsequently, it is transported to an independent tensioning machine for mechanical testing. The entire process involves dispersed equipment, large floor space, and mold replacement requires complete disassembly and assembly. When the diameter of the tapered pole changes, a complete set of molds is required, making adjustment time-consuming and lengthy. Multiple hoisting operations can easily cause the pole to collide, and the separation of the tensioning station from the production station leads to slow process coordination, resulting in low overall efficiency and high safety hazards. Summary of the Invention

[0004] To address the aforementioned problems, this invention proposes an adjustable pole tensioning support device.

[0005] This invention is achieved through the following technical solution:

[0006] This invention proposes an adjustable pole tensioning support device, including a trailer outer frame, an adjustable pole production assembly with an adjustable diameter is provided inside the trailer outer frame, and a detection support assembly is provided below the adjustable pole production assembly with an adjustable diameter.

[0007] Furthermore, the adjustable diameter pole production assembly includes a first telescopic joint located at the four corners of the bottom inner side of the trailer's outer frame. Two first telescopic joints form a group, and the output ends of the two groups of first telescopic joints are respectively provided with connecting plates. A second telescopic joint is provided on the opposite side wall of the two connecting plates, and the output end of the second telescopic joint is provided with a first limiting plate.

[0008] Furthermore, a second limiting plate is provided on both sides between the two first limiting plates. The two ends of the second limiting plate pass through the two first limiting plates. A sliding rod is provided on the second limiting plate that passes through the first limiting plates. The two ends of the sliding rod are respectively connected to the upper and lower inner walls of the trailer's outer frame. A third telescopic device is provided on the opposite side wall of the two second limiting plates. A third limiting plate is provided at the output end of the third telescopic device. A fourth telescopic device is provided on both sides of the opposite side wall of the two third limiting plates.

[0009] Furthermore, two sets of pole mold blocks are provided between the two third limiting plates. The two sets of pole mold blocks are spliced ​​together, and injection holes are provided on the two sets of pole mold blocks. Each set of pole mold blocks is composed of multiple pole molds spliced ​​together. The cross-section of the pole mold is arc-shaped. The two fourth telescopic devices on the third limiting plates are connected to the pole mold blocks on one side of the third limiting plates. Mold auxiliary installation components are provided on the first limiting plate.

[0010] Furthermore, the mold auxiliary installation component includes a receiving groove formed in the first limiting plate and a first drive motor set on the first limiting plate. The inner wall of the receiving groove is provided with two sets of guide grooves, each set of guide grooves having multiple grooves. The two sets of guide grooves are symmetrical about the first drive motor. A turntable is rotatably arranged inside the receiving groove, and the output end of the first drive motor is connected to the turntable.

[0011] Furthermore, two sets of first push-pull plates are rotatably connected to the turntable, with multiple first push-pull plates in each set. The positions of the two sets of first push-pull plates correspond to the positions of the two sets of guide grooves. A first guide plate is provided inside the guide groove. The two sets of first push-pull plates on the turntable are rotatably connected to the first guide plates inside the two sets of guide grooves.

[0012] Furthermore, the two first limiting plates have openings on opposite side walls, which communicate with guide grooves. The first guide plates are connected to clamping plates via sliders. The clamping plates press against the first limiting plates, and the sliders on the clamping plates are slidably connected to the openings on the first limiting plates.

[0013] Furthermore, the detection support assembly includes a movable frame disposed at the bottom inner side of the trailer's outer frame. A flip plate is rotatably disposed on the upper end face of the movable frame. A storage groove is formed on one side of the upper end face of the movable frame. A limiting groove is formed at the bottom inner side of the storage groove. A threaded rod is rotatably disposed on the inner side of the limiting groove. A limiting block is slidably disposed on the inner side of the limiting groove. The limiting block is threaded onto the threaded rod. A third drive motor is disposed at one end of the movable frame. The output end of the third drive motor is connected to the threaded rod.

[0014] Furthermore, a push plate is rotatably provided on the upper end face of the limiting block. The push plate is located inside the storage groove. The end of the push plate away from the limiting block is rotatably connected to the lower end face of the flipping plate. A fixing frame is provided on the upper end face of the flipping plate. A discharge port is opened on the lower side of one end of the fixing frame.

[0015] Furthermore, two second guide plates are rotatably connected to the upper inner sides of the fixed frame, with their opposite ends pressed together. Two second drive motors are provided on one side wall of the fixed frame, and each of the two second drive motors is connected to one of the two second guide plates. The two second guide plates have equally spaced notches, and the notches on the two second guide plates are staggered. Two second push-pull plates are provided on both inner sides of the fixed frame, and the positions of the multiple second push-pull plates on both inner sides of the fixed frame correspond to the positions of the notches on the two second guide plates above them. A fifth telescopic device is provided on the second push-pull plate, and the fifth telescopic device is provided on the outer wall of the fixed frame.

[0016] The beneficial effects of this invention are:

[0017] Compared to the traditional "dispersed platform + multiple hoisting" mode, this invention uses a trailer outer frame as a carrier to integrate adjustable molds, automatic mold closing, static mold demolding, moving detection, and tilting material discharge into the same mobile platform; through multi-stage telescopic joints and motor linkage, stepless adjustment of the tapered rod tip diameter and rapid mold changing are achieved; with the help of sliding rods and guide grooves, accurate positioning is ensured throughout the process; after demolding, the rod directly falls into the detection support assembly, and tensioning detection and automatic material discharge are completed in the same equipment, eliminating the need for a fixed tensioning machine and multiple hoisting operations, achieving the beneficial effects of convenient site transfer, rapid model change, ready-to-use production, compatibility with tapered rods, and safe operation. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0019] Figure 2 This is a perspective view of the pole production assembly and testing support assembly of the present invention;

[0020] Figure 3 This is a perspective view of the detection support component of the present invention;

[0021] Figure 4 This is an exploded view of the detection support component of the present invention;

[0022] Figure 5 For the present invention Figure 4 Enlarged view of point A in the middle;

[0023] Figure 6 This is a partial cross-sectional view of the first limiting plate of the present invention from a first perspective.

[0024] Figure 7 This is a partial cross-sectional view of the first limiting plate of the present invention from a second perspective.

[0025] The attached figures are labeled as follows:

[0026] In the diagram: 1. Trailer outer frame; 2. Pole production assembly; 21. First expansion joint; 22. Connecting plate; 23. Second expansion joint; 24. First limiting plate; 25. Second limiting plate; 26. Third expansion joint; 27. Third limiting plate; 28. Fourth expansion joint; 29. ​​Pole mold block; 210. Mold auxiliary installation assembly; 211. Receiving groove; 212. Guide groove; 213. Turntable; 214. First drive motor; 215. First push-pull plate 216. First guide plate; 217. Clamping plate; 3. Detection support assembly; 31. Moving frame; 32. Flipping plate; 33. Storage slot; 34. Limiting slot; 35. Threaded rod; 36. Limiting block; 37. Push plate; 38. Fixing frame; 39. Discharge port; 310. Second guide plate; 311. Second drive motor; 312. Notch; 313. Fifth telescopic device; 314. Second push-pull plate; 315. Third drive motor; 4. Slide rod. Detailed Implementation

[0027] To more clearly and completely illustrate the technical solution of the present invention, the present invention will be further described below in conjunction with the accompanying drawings.

[0028] Please refer to Figure 1 - Figure 7 The present invention proposes an adjustable pole tensioning support device, including a trailer outer frame 1, an adjustable pole production assembly 2 with an adjustable diameter is provided on the inner side of the trailer outer frame 1, and a detection support assembly 3 is provided below the adjustable pole production assembly 2.

[0029] The trailer outer frame 1 allows for the movement of the pole during production.

[0030] The adjustable diameter pole production assembly 2 includes a first telescopic joint 21 located at the four corners of the bottom inner side of the trailer outer frame 1. Two first telescopic joints 21 form a group. The output ends of the two groups of first telescopic joints 21 are respectively provided with connecting plates 22. A second telescopic joint 23 is provided on the opposite side wall of the two connecting plates 22. The output end of the second telescopic joint 23 is provided with a first limiting plate 24.

[0031] A second limiting plate 25 is provided on both sides between the two first limiting plates 24. The two ends of the second limiting plate 25 pass through the two first limiting plates 24. A sliding rod 4 is provided on the second limiting plate 25 that passes through the first limiting plates 24. The two ends of the sliding rod 4 are respectively connected to the upper and lower inner walls of the trailer outer frame 1. A third telescopic device 26 is provided on the opposite side wall of the two second limiting plates 25. A third limiting plate 27 is provided at the output end of the third telescopic device 26. A fourth telescopic device 28 is provided on both sides of the opposite side wall of the two third limiting plates 27.

[0032] The sliding rod 4 passes through the second limiting plate 25, forming an upper and lower guide system, which makes the second limiting plate 25 stable during use.

[0033] Two sets of pole mold blocks 29 are provided between the two third limiting plates 27. The two sets of pole mold blocks 29 are spliced ​​together. The two sets of pole mold blocks 29 are provided with injection holes. Each set of pole mold blocks 29 is composed of multiple pole molds spliced ​​together. The cross-section of the pole mold is arc-shaped. The two fourth telescopic devices 28 on the third limiting plate 27 are connected to the pole mold block 29 on one side of the third limiting plate 27. The first limiting plate 24 is provided with a mold auxiliary installation assembly 210.

[0034] The trailer outer frame 1 integrates the pole production component 2 and the testing support component 3 into a movable whole, allowing the towing vehicle to directly reach the site for "production and use," eliminating the need for fixed platforms and multiple hoisting trips, significantly shortening the construction preparation cycle; the first expansion joint 21, the second expansion joint 23, the third expansion joint 26, and the fourth expansion joint 28 form a three-dimensional adjustable frame; the arc-shaped pole mold block 29 is pushed and pulled separately by the fourth expansion joint 28, and when replacing it, only the corresponding arc segment needs to be replaced and the stroke reset, achieving "easy mold replacement," and no need to spare a whole set of molds for changes in the tip diameter of the tapered pole; after the pole body is formed, the first expansion joint 21 moves down as a whole, and the third expansion joint 26 moves in the opposite direction to "static mold removal of the pole," and the formed pole falls to the testing support component 3 under its own weight, without the need for a crane to unload, reducing the risk of collision.

[0035] The mold auxiliary installation component 210 includes a receiving groove 211 formed in the first limiting plate 24 and a first drive motor 214 set on the first limiting plate 24. The inner wall of the receiving groove 211 is provided with two sets of guide grooves 212, each set of guide grooves 212 having multiple grooves. The two sets of guide grooves 212 are symmetrical about the first drive motor 214. A turntable 213 is rotatably arranged inside the receiving groove 211, and the output end of the first drive motor 214 is connected to the turntable 213.

[0036] Two sets of first push-pull plates 215 are rotatably connected to the turntable 213. Each set of first push-pull plates 215 consists of multiple plates. The positions of the two sets of first push-pull plates 215 correspond to the positions of the two sets of guide grooves 212. A first guide plate 216 is provided inside the guide groove 212. The two sets of first push-pull plates 215 on the turntable 213 are rotatably connected to the first guide plates 216 inside the two sets of guide grooves 212.

[0037] The two first limiting plates 24 have openings on opposite sides of their walls, which communicate with the guide groove 212. The first guide plate 216 is connected to a clamping plate 217 via a slider. The clamping plate 217 presses against the first limiting plate 24, and the slider on the clamping plate 217 is slidably connected to the opening on the first limiting plate 24.

[0038] The connecting plate 22 is equipped with a controller, which controls the operation of the motor and the expansion joint of the adjustable pole production assembly 2.

[0039] In the mold auxiliary installation component 210, the first drive motor 214 synchronously drives the first guide plate 216 via the turntable 213 and the first push-pull plate 215, causing the clamping plate 217 to slide along the guide groove 212, automatically completing the centering alignment and pre-clamping of the tapered mold, ensuring uniform mold gap, eliminating manual straightening errors, thus enabling the production of tapered poles and facilitating quick changeover.

[0040] The detection support assembly 3 includes a movable frame 31 located at the bottom inner side of the trailer outer frame 1. A flip plate 32 is rotatably mounted on the upper surface of the movable frame 31. A storage groove 33 is provided on one side of the upper surface of the movable frame 31. A limiting groove 34 is provided at the bottom inner side of the storage groove 33. A threaded rod 35 is rotatably mounted inside the limiting groove 34. A limiting block 36 is slidably mounted inside the limiting groove 34. The limiting block 36 is threaded onto the threaded rod 35. A third drive motor 315 is provided at one end of the movable frame 31. The output end of the third drive motor 315 is connected to the threaded rod 35.

[0041] The mobile frame 31 is equipped with a controller, which is used to control the operation of the third drive motor 315.

[0042] A push plate 37 is rotatably mounted on the upper end face of the limiting block 36. The push plate 37 is located inside the receiving groove 33. The end of the push plate 37 away from the limiting block 36 is rotatably connected to the lower end face of the flip plate 32. A fixing frame 38 is provided on the upper end face of the flip plate 32. A discharge port 39 is opened on the lower side of one end of the fixing frame 38.

[0043] The upper inner sides of the fixed frame 38 are rotatably connected to two second guide plates 310. The opposite ends of the two second guide plates 310 are pressed together. Two second drive motors 311 are provided on one side wall of the fixed frame 38. The two second drive motors 311 are respectively connected to the two second guide plates 310. The two second guide plates 310 are provided with equally spaced notches 312. The notches 312 on the two second guide plates 310 are staggered. The inner sides of the fixed frame 38 are provided with second push-pull plates 314. The positions of the multiple second push-pull plates 314 on the inner sides of the fixed frame 38 correspond to the positions of the notches 312 on the two second guide plates 310 above them. The second push-pull plates 314 are provided with fifth telescopic devices 313. The fifth telescopic devices 313 are provided on the outer wall of the fixed frame 38.

[0044] The notch 312 is designed to prevent motion conflicts caused by the flipping of the second push-pull plate 314 and the second guide plate 310.

[0045] The mobile frame 31 can be pulled out as a whole from the trailer outer frame 1; the third drive motor 315 drives the threaded rod 35 to rotate, the limit block 36 drives the push plate 37 to tilt the flip plate 32 to the required angle, and the rod slides out from the discharge port 39 along the inclined surface of the fixed frame 38 to realize automatic on-site discharge, eliminating the need for forklifts or secondary hoisting; the two sets of second guide plates 310 inside the fixed frame 38 are synchronously or differentially flipped under the control of the second drive motor 311, which can adapt to the support requirements of different tapers of the tapered rod; the notch 312 and the second push-pull plate 314 are staggered, and the fifth telescopic device 313 pushes the second push-pull plate 314 through the notch 312 to abut against the rod, and the tension test is completed on the same mobile platform. After the test, the material is discharged immediately, and the process is tightly connected.

[0046] Working principle:

[0047] First, the trailer outer frame 1 is placed on a tractor (large truck or transport vehicle, etc.). Then, the trailer outer frame 1 is transported to the target location. Next, the steel bars required for the pole to be produced are placed between two first limiting plates 24. Then, the second telescopic device 23 moves the first limiting plates 24 toward the steel bars until the two first limiting plates 24 press against both ends of the steel bars. At this point, the position of the steel bars is limited by the clamping of the first limiting plates 24. Then, the third telescopic device 26 moves the pole mold block 29 toward the steel bars until the opposite side walls of the two sets of pole mold blocks 29 are pressed together, and the steel bars are located at the splicing point. The process begins by filling the assembled pole mold block 29 with raw material, which is then injected through the injection hole until the mold block 29 is full. Once the pole is formed, the first telescopic device 21 lowers the mold block 29 containing the formed pole, positioning it above the fixed frame 38. Then, the third telescopic device 26 moves the mold block 29 in the opposite direction of the formed pole. The formed pole then falls onto the second guide plate 310 inside the fixed frame 38. Simultaneously, the second drive motor is activated. 311. The second drive motor 311 drives the second guide plate 310 to rotate, causing the second guide plate 310 to tilt downwards. At this time, the pole will move along the inclined surface of the second guide plate 310 to the bottom inside the fixed frame 38 until the pole falls to the bottom inside the fixed frame 38. When the pole falls to the bottom inside the fixed frame 38, the fifth telescopic device 313 drives the second push-pull plate 314 to move towards the pole inside the fixed frame 38. Since the second push-pull plates 314 inside the fixed frame 38 are staggered, the second push-pull plates 314 pressing against the pole perform tension testing on the pole. After the pole passes the test, the moving frame 314 is moved. 1. Pull out from the inside of the trailer outer frame 1 and move it to the target position. Then start the third drive motor 315. The third drive motor 315 drives the threaded rod 35 to rotate. The threaded rod 35 drives the limit block 36 to move along the limit groove 34. The limit block 36 drives one end of the push plate 37 to move. The movement of one end of the push plate 37 pushes the flip plate 32 to flip. When the flip plate 32 flips to the appropriate angle, the fifth telescopic device 313 drives the second push-pull plate 314 away from the pole. At this time, the pole will slide out from the discharge port 39 along the inclined surface of the fixed frame 38. At this time, the staff can install the pole.

[0048] When it is necessary to produce tapered poles, the pole mold block 29 is removed from the fourth telescopic device 28, and then the two sets of tapered pole mold blocks 29 are spliced ​​together and placed between the two first limiting plates 24. At this time, the second telescopic device 23 drives the first limiting plates 24 to press against the two ends of the spliced ​​pole mold blocks 29. Then, the first drive motor 214 is started, which drives the turntable 213 to rotate. The turntable 213 pulls the first guide plate 216 through the first push-pull plate 215. The first guide plate 216 drives the clamping plate 217 to move towards the spliced ​​pole mold blocks 29. When the clamping plate 217 presses against the pole mold block 29, it centers the clamping plate 217 that is spliced ​​together and applies a squeezing force to the spliced ​​pole mold block 29 to prevent the spliced ​​pole mold block 29 from separating. When the pole mold block 29 is centered and clamped stably, the telescopic length is adjusted by activating the fourth telescopic device 28 to adapt to the taper of the pole mold block 29. Then, the output end of the fourth telescopic device 28 is rotated and connected to the pole mold block 29 on one side to complete the installation of the pole mold block 29. Then, the first drive motor 214 is activated in reverse to bring the clamping plate 217 to its initial position. Then, the pole is produced according to the above method.

[0049] The replacement of pole mold blocks 29 with different diameters can be done in accordance with the above method.

[0050] Of course, the present invention may have many other embodiments. Based on this embodiment, other embodiments obtained by those skilled in the art without any creative effort are all within the scope of protection of the present invention.

Claims

1. An adjustable pole tensioning support device, comprising a trailer outer frame, characterized in that, An adjustable-diameter pole production assembly is provided on the inner side of the trailer's outer frame, and a detection support assembly is provided below the adjustable-diameter pole production assembly.

2. The adjustable diameter pole tensioning support device according to claim 1, characterized in that, The adjustable diameter pole production assembly includes a first telescopic joint located at the four corners of the bottom inner side of the trailer's outer frame. Two first telescopic joints form a group, and the output ends of the two groups of first telescopic joints are respectively provided with connecting plates. A second telescopic joint is provided on the opposite side wall of the two connecting plates, and the output end of the second telescopic joint is provided with a first limiting plate.

3. The adjustable diameter pole tensioning support device according to claim 2, characterized in that, A second limiting plate is provided on both sides between the two first limiting plates. The two ends of the second limiting plate pass through the two first limiting plates. A sliding rod is provided on the second limiting plate that passes through the first limiting plates. The two ends of the sliding rod are respectively connected to the upper and lower walls of the inner side of the trailer's outer frame. A third telescopic device is provided on the opposite side wall of the two second limiting plates. A third limiting plate is provided at the output end of the third telescopic device. A fourth telescopic device is provided on both sides of the opposite side wall of the two third limiting plates.

4. The adjustable diameter pole tensioning support device according to claim 3, characterized in that, Two sets of pole mold blocks are arranged between the two third limiting plates. The two sets of pole mold blocks are spliced ​​together. The two sets of pole mold blocks are provided with injection holes. Each set of pole mold blocks is composed of multiple pole molds. The cross-section of the pole mold is arc-shaped. The two fourth telescopic devices on the third limiting plates are connected to the pole mold blocks on one side of the third limiting plates. The first limiting plate is provided with a mold auxiliary installation component.

5. The adjustable diameter pole tensioning support device according to claim 4, characterized in that, The mold auxiliary installation component includes a receiving groove formed in the first limiting plate and a first drive motor set on the first limiting plate. The inner wall of the receiving groove is provided with two sets of guide grooves, each set of guide grooves having multiple grooves. The two sets of guide grooves are symmetrical about the first drive motor. A turntable is rotatably arranged inside the receiving groove, and the output end of the first drive motor is connected to the turntable.

6. The adjustable diameter pole tensioning support device according to claim 5, characterized in that, Two sets of first push-pull plates are rotatably connected to the turntable. Each set of first push-pull plates consists of multiple plates. The positions of the two sets of first push-pull plates correspond to the positions of the two sets of guide grooves. A first guide plate is provided inside the guide groove. The two sets of first push-pull plates on the turntable are rotatably connected to the first guide plates inside the two sets of guide grooves.

7. The adjustable diameter pole tensioning support device according to claim 6, characterized in that, The two first limiting plates have openings on opposite sides of their walls, which communicate with guide grooves. The first guide plates are connected to clamping plates via sliders. The clamping plates press against the first limiting plates, and the sliders on the clamping plates are slidably connected to the openings on the first limiting plates.

8. The adjustable diameter pole tensioning support device according to claim 1, characterized in that, The detection support assembly includes a movable frame disposed at the bottom inner side of the trailer's outer frame. A flip plate is rotatably disposed on the upper surface of the movable frame. A storage groove is formed on one side of the upper surface of the movable frame. A limiting groove is formed at the bottom inner side of the storage groove. A threaded rod is rotatably disposed inside the limiting groove. A limiting block is slidably disposed inside the limiting groove. The limiting block is threaded onto the threaded rod. A third drive motor is disposed at one end of the movable frame. The output end of the third drive motor is connected to the threaded rod.

9. The adjustable diameter pole tensioning support device according to claim 8, characterized in that, The upper end face of the limiting block is rotatably provided with a push plate, which is located inside the receiving groove. The end of the push plate away from the limiting block is rotatably connected to the lower end face of the flipping plate. The upper end face of the flipping plate is provided with a fixing frame, and a discharge port is opened on the lower side of one end of the fixing frame.

10. The adjustable diameter pole tensioning support device according to claim 9, characterized in that, The upper inner sides of the fixed frame are rotatably connected to two second guide plates, with their opposite ends pressed together. Two second drive motors are provided on one side wall of the fixed frame, and each of the two second drive motors is connected to one of the two second guide plates. The two second guide plates have equally spaced notches, and the notches on the two second guide plates are staggered. The inner sides of the fixed frame are provided with second push-pull plates, and the positions of the multiple second push-pull plates on the inner sides of the fixed frame correspond to the positions of the notches on the two second guide plates above them. A fifth telescopic device is provided on the second push-pull plate, and the fifth telescopic device is provided on the outer wall of the fixed frame.

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