Three-phase common-box metal closed power transmission line structure

Abstract

The invention belongs to the technical field of power transmission and transformation, and discloses a three-phase common-box metal closed power transmission line structure which comprises a metal shell, basin-type insulators are arranged at the left end and the right end of the metal shell, and metal conductors are fixedly arranged on the sides, close to the metal shell, of the basin-type insulators. And the surface of the metal conductor is fixedly sleeved with a glass fiber plate, the bottom of the glass fiber plate is provided with an insulating plate I, and one side, close to the metal shell, of the insulating plate I is provided with a rotating shaft. The metal conductor can drive the glass fiber plate to move when moving, so that the glass fiber plate is stably supported through the roller, the condition of abrasion between the metal conductor and the glass fiber plate is avoided, and the situation that the roller is damaged in the long-time use process is avoided by lubricating the rotating shaft. And the condition that the glass fiber plate is inconvenient to move due to abrasion and blockage among the insulating plate I, a roller and a rotating shaft is avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of power transmission and transformation, and specifically relates to a three-phase common box metal-enclosed power transmission line structure. Background Art

[0002] With the rapid development of my country's economy, the pace of urban construction is accelerating. Overhead transmission lines are facing difficulties in laying in some urban areas. At the same time, ordinary cables have many disadvantages in some special applications due to their limited transmission capacity and high failure rate. In addition, ordinary fully insulated conductors are not suitable for long-distance laying due to their rigid structure and limited single-circuit current. In order to solve these problems, the existing structural design of placing the conductor in a metal shell, supporting both ends with basin insulators, and then sealing the metal shell, and then filling the metal shell with insulating gas is particularly necessary for application in 10kV transmission occasions. It can improve the reliability and safety of power transmission while reducing the impact on the environment.

[0003] However, this structure also has some problems. During operation, the conductor will experience temperature changes due to the heat generated by the current and the change of the external ambient temperature. If the conductor is fixed in the metal shell and the shell does not provide enough expansion space, the thermal expansion and contraction of the conductor will be restricted, resulting in wear between the conductor and the supporting structure, which will cause damage to the conductor. In addition, the movement of the conductor in the metal shell is not smooth enough, which will have a certain impact on power transmission.

[0004] Therefore, in order to improve the performance of this power transmission structure, it is necessary to consider the wear problem between the conductor and the supporting structure and the improvement of the smoothness of the conductor's movement in the metal shell. This will help promote the development of power transmission technology and provide better support for my country's urban construction and economic development. Summary of the invention

[0005] The object of the present invention is to provide a three-phase common-box metal-enclosed transmission line structure to solve the problems raised in the above-mentioned background technology.

[0006] In order to achieve the above-mentioned purpose, the present invention provides the following technical solutions: a three-phase common box metal-enclosed transmission line structure, comprising a metal shell, wherein the left and right ends of the metal shell are provided with pot-type insulators, a metal conductor is fixedly provided on the side of the pot-type insulator close to the metal shell, a glass fiber board is fixedly sleeved on the surface of the metal conductor, an insulating plate 1 is provided at the bottom of the glass fiber board, a rotating shaft is provided on the side of the insulating plate 1 close to the metal shell, a roller is movably sleeved on the surface of the rotating shaft, a storage box is fixedly connected to the top of the metal shell, and the bottom end of the storage box A flow tube is fixedly connected, and an oil filling tube is fixedly connected to the bottom end of the flow tube, a mounting tube is fixedly connected to the bottom of the metal shell, a movable spring is fixedly connected to the inner cavity of the mounting tube, a movable head is fixedly connected to the side of the movable spring close to the metal shell, a movable rod is fixedly connected to the side of the movable head close to the movable spring through the mounting tube, a blocking rod is fixedly connected to the side of the top of the movable rod close to the oil filling tube, the blocking rod is located in the inner cavity at the connection between the flow tube and the oil filling tube, the oil filling tube is located above the rotating shaft, and the bottom of the inner cavity of the metal shell is fixedly connected to a limited position rail.

[0007] Preferably, an equipotential ring is fixedly connected to the right side of the glass fiber board, a filter ring is fixedly connected to the top of the inner wall of the equipotential ring, the equipotential ring and the filter ring are provided with a capture cavity, and a sticky ring is fixedly connected to the inner wall of the equipotential ring.

[0008] Preferably, the roller is located in the inner cavity of the limiting rail, and the moving head is located on the moving path of the roller.

[0009] Preferably, a blocking block is inserted at the top of the storage box, the storage box is connected to the inner cavities of the flow tube and the oil injection tube, and the moving head is located below the oil injection tube.

[0010] Preferably, the top of the fiberglass board is fixedly connected to an insulating board 2, the inner cavity of the insulating board 2 is provided with two springs, the insulating board 2 is fixedly connected to a nylon slider and an ejector pin through the two springs, and the nylon slider and the ejector pin are fitted with the inner wall of the metal shell.

[0011] Preferably, a support frame is fixedly connected to the bottom end of the metal shell, and an air pump is fixedly connected to the top end of the metal shell.

[0012] Preferably, the moving head is located in the inner cavity of the limiting rail, and one end of the moving head close to the movable rod is located at the center of the inner cavity of the movable spring.

[0013] Preferably, the equipotential ring and the filter ring are closed at a side away from the glass fiber board, and the metal conductor is located in the middle of the filter ring.

[0014] Preferably, three circular holes are opened in the middle of the glass fiber board, and contact sleeves are fixedly sleeved in the three circular holes.

[0015] Preferably, a blocking plate is fixedly connected to the top of the movable rod, a two-color warning plate is fixedly connected to the side of the flow tube away from the metal shell, the blocking plate is in contact with the surface of the two-color warning plate, and the moving head is in contact with the metal shell.

[0016] The beneficial effects of the present invention are as follows:

[0017] 1. The present invention drives the glass fiber board to move when the metal conductor expands and contracts due to heat and cold during use, thereby driving the roller to move in the inner cavity of the limit rail. When the roller moves to the moving head, the moving head is pressed to push the movable rod and the blocking rod away from the oil filling pipe, thereby allowing the flow pipe and the oil filling pipe to pass through, and then the lubricating oil drips from the flow pipe and the oil filling pipe to the rotating shaft, so that the metal conductor can drive the glass fiber board to move when moving, thereby stably supporting the glass fiber board through the roller, avoiding the wear between the metal conductor and the glass fiber board, and lubricating the rotating shaft to avoid the wear and jamming between the insulating board, the roller and the rotating shaft during long-term use of the roller, resulting in inconvenience in moving the glass fiber board.

[0018] 2. In the process of production and installation of metal parts such as metal shells, the present invention will generate some metal particles. When the metal conductor is conductive, the metal particles will be moved between the metal shell and the metal conductor by the electric field force, which will affect the insulation performance. An equipotential structure is formed between the glass fiber board and the equipotential ring, so that the electric field strength in the capture cavity is zero. Therefore, in the process of movement of the glass fiber board, the equipotential ring is driven to move, and the floating metal particles enter the inner cavity of the capture cavity through the filter ring. Since the electric field strength of the capture cavity is low, the metal particles no longer float, and the floating metal particles are captured by the capture cavity, and the metal particles are adsorbed by the sticky ring, thereby preventing the floating metal particles from affecting the insulation performance.

[0019] 3. When the insulating gas in the inner cavity of the metal shell leaks, the air pressure in the inner cavity of the metal shell decreases, and the resistance of the moving head to the air pressure in the inner cavity of the metal shell decreases. Therefore, the elastic force of the movable spring causes the moving head to enter one end of the inner cavity of the metal shell, thereby driving the movable rod to move in the direction of the moving head, and then driving the blocking plate to move on the surface of the two-color warning plate, causing the warning color of the two-color warning plate to leak out, thereby prompting the operation and maintenance personnel that the metal shell is leaking, and then the air pump is used to replenish insulating air into the inner cavity of the metal shell, thereby avoiding the lack of insulating gas, which affects the insulation performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the structural connection of the present invention;

[0021] Figure 2 This is a schematic diagram of the connection of the structural glass fiber board of the present invention;

[0022] Figure 3 For the present invention Figure 2 The connection diagram at A is enlarged;

[0023] Figure 4 This is a schematic diagram of the connection of the structure installation cylinder of the present invention;

[0024] Figure 5 This is a schematic diagram of the sticky ring connection of the structure of the present invention;

[0025] Figure 6 This is a schematic diagram of the oil injection pipe connection of the structure of the present invention;

[0026] Figure 7 For the present invention Figure 6 The connection diagram at B is enlarged;

[0027] Figure 8 A schematic diagram of a connection of a structural insulation board according to the present invention;

[0028] Fig. 9 This is a schematic diagram of the ejector pin connection structure of the present invention.

[0029] In the figure: 1. Metal shell; 2. Basin insulator; 3. Metal conductor; 4. Fiberglass board; 5. Insulation board one; 6. Roller; 7. Support frame; 8. Insulation board two; 9. Nylon slider; 10. Ejector pin; 11. Rotating shaft; 12. Air pump; 13. Storage box; 14. Blocking block; 15. Flow tube; 16. Oil filling tube; 17. Mounting cylinder; 18. Movable spring; 19. Moving head; 20. Movable rod; 21. Blocking rod; 22. Limit rail; 23. Equipotential ring; 24. Filter ring; 25. Capture chamber; 26. Sticky ring; 27. Two-color warning plate; 28. Blocking plate. DETAILED DESCRIPTION

[0030] 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.

[0031] like Figures 1 to 9As shown, the embodiment of the present invention provides a three-phase common box metal-enclosed transmission line structure, including a metal shell 1, a pot-type insulator 2 is arranged at the left and right ends of the metal shell 1, a metal conductor 3 is fixedly arranged on the side of the pot-type insulator 2 close to the metal shell 1, a glass fiber board 4 is fixedly sleeved on the surface of the metal conductor 3, an insulating plate 5 is arranged on the bottom of the glass fiber board 4, a rotating shaft 11 is arranged on the side of the insulating plate 5 close to the metal shell 1, a roller 6 is movably sleeved on the surface of the rotating shaft 11, a storage box 13 is fixedly connected to the top end of the metal shell 1, a flow pipe 15 is fixedly connected to the bottom end of the storage box 13, and the flow pipe 1 5 is fixedly connected with an oil filling pipe 16 at the bottom, a mounting cylinder 17 is fixedly connected with the bottom of the metal shell 1, a movable spring 18 is fixedly connected with the inner cavity of the mounting cylinder 17, a movable head 19 is fixedly connected with the side of the movable spring 18 close to the metal shell 1, a movable rod 20 is fixedly connected through the mounting cylinder 17 on the side of the movable head 19 close to the movable spring 18, a blocking rod 21 is fixedly connected with the side of the top of the movable rod 20 close to the oil filling pipe 16, the blocking rod 21 is located in the inner cavity at the connection between the flow pipe 15 and the oil filling pipe 16, the oil filling pipe 16 is located above the rotating shaft 11, and a limited position rail 22 is fixedly connected to the bottom of the inner cavity of the metal shell 1;

[0032] The working principle and beneficial effects of the above technical solution are as follows: the metal conductor 3 is installed in the inner cavity of the glass fiber board 4, and then the roller 6 is aligned with the limit rail 22, and then the metal conductor 3 is placed in the inner cavity of the metal shell 1, and then the pot-type insulator 2 is installed at both ends of the metal shell 1 to make the metal shell 1 sealed, and then the air pump 12 is used to fill the inner cavity of the metal shell 1 with insulating gas, so that the metal conductor 3 is insulated by the insulating gas in the inner cavity of the metal shell 1, and then the blocking block 14 is pulled out from the top of the storage box 13, and then the lubricating oil is input into the inner cavity of the storage box 13, and the lubricating oil in the inner cavity of the storage box 13 is input into the inner cavity of the flow tube 15;

[0033] When the metal conductor 3 is in use, it expands and contracts due to heat, which drives the glass fiber board 4 to move, thereby driving the roller 6 to move in the inner cavity of the limit rail 22. When the roller 6 moves to the moving head 19, the moving head 19 is pressed, thereby pushing the movable rod 20 and the blocking rod 21 away from the oil filling pipe 16, thereby allowing the flow pipe 15 and the oil filling pipe 16 to pass through, and then the lubricating oil drips from the flow pipe 15 and the oil filling pipe 16 to the rotating shaft 11, so that the metal conductor 3 can drive the glass fiber board 4 to move when moving, so that the glass fiber board 4 is stably supported by the roller 6, and the wear between the metal conductor 3 and the glass fiber board 4 is avoided. In addition, by lubricating the rotating shaft 11, it is avoided that the roller 6 will wear and jam between the insulating board 5, the roller 6, and the rotating shaft 11 during long-term use, which makes it inconvenient to move the glass fiber board 4.

[0034] like Figure 5 As shown, in one embodiment, an equipotential ring 23 is fixedly connected to the right side of the glass fiber board 4, a filter ring 24 is fixedly connected to the top of the inner wall of the equipotential ring 23, the equipotential ring 23 and the filter ring 24 are provided with a capture cavity 25, and an adhesive ring 26 is fixedly connected to the inner wall of the equipotential ring 23;

[0035] The working principle and beneficial effects of the above technical solution are as follows: during the production and installation process of metal parts such as the metal shell 1, some metal particles will be generated. When the metal conductor 3 is conductive, the metal particles will be moved between the metal shell 1 and the metal conductor 3 by the electric field force, which will affect the insulation performance. An equipotential structure is formed between the glass fiber board 4 and the equipotential ring 23, so that the electric field strength in the inner cavity of the capture chamber 25 is zero. Therefore, in the process of the movement of the glass fiber board 4, the equipotential ring 23 is driven to move, and the floating metal particles enter the inner cavity of the capture chamber 25 through the filter ring 24. Since the electric field strength of the capture chamber 25 is relatively low, the metal particles no longer float, and the floating metal particles are captured by the capture chamber 25, and the metal particles are adsorbed by the sticky ring 26, thereby avoiding the floating metal particles from affecting the insulation performance.

[0036] like Figure 4 As shown, in one embodiment, the roller 6 is located in the inner cavity of the limiting rail 22, and the moving head 19 is located on the moving path of the roller 6;

[0037] The working principle and beneficial effects of the above technical solution are: the roller 6 is located in the inner cavity of the limiting rail 22, so that the roller 6 can move along the limiting rail 22, and the moving head 19 is located on the moving path of the roller 6, so that the roller 6 can press the moving head 19 during the movement.

[0038] like Fig. 9 As shown, in one embodiment, a blocking block 14 is inserted into the top of the storage box 13, the storage box 13 is connected with the inner cavity of the flow tube 15 and the oil injection tube 16, and the moving head 19 is located below the oil injection tube 16;

[0039] The working principle and beneficial effects of the above technical solution are as follows: through the blocking block 14 at the top of the storage box 13, the blocking block 14 can be pulled out, and then the lubricating oil is added to the inner cavity of the storage box 13, and then the blocking block 14 is inserted again to seal the storage box 13, and then the moving head 19 is located below the oil filling pipe 16, so that when the roller 6 presses the moving head 19, the lubricating oil at the oil filling pipe 16 drips onto the rotating shaft 11.

[0040] like Fig. 9As shown, in one embodiment, the top of the glass fiber board 4 is fixedly connected with an insulating plate 2 8, the inner cavity of the insulating plate 2 8 is provided with two springs, and the insulating plate 2 8 is respectively fixedly connected with a nylon slider 9 and an ejector pin 10 through the two springs, and the nylon slider 9 and the ejector pin 10 are in contact with the inner wall of the metal shell 1;

[0041] The working principle and beneficial effects of the above technical solution are as follows: the glass fiber board 4 is limited by the fitting of the nylon slider 9 and the ejector pin 10 with the metal shell 1, and then all non-charged metal parts on the glass fiber board 4 are connected to the metal shell 1 at the same potential through the equipotential ring 23.

[0042] like Figure 1 As shown, in one embodiment, the bottom end of the metal shell 1 is fixedly connected to a support frame 7, and the top end of the metal shell 1 is fixedly connected to an air pump 12;

[0043] The working principle and beneficial effects of the above technical solution are as follows: by setting the support frame 7, the metal shell 1 can be stably installed, and then through the air pump 12 at the top of the metal shell 1, the insulating gas can be injected into the inner cavity of the metal shell 1 through the air pump 12 to achieve insulation. The insulating gas is preferably pure nitrogen.

[0044] like Figure 6 As shown, in one embodiment, the moving head 19 is located in the inner cavity of the limiting rail 22, and one end of the moving head 19 close to the movable rod 20 is located at the center of the inner cavity of the movable spring 18;

[0045] The working principle and beneficial effects of the above technical solution are as follows: the moving head 19 is located in the inner cavity of the limiting rail 22, so that the roller 6 can stably press the moving head 19, and then the end of the moving head 19 close to the movable rod 20 is located at the center of the inner cavity of the movable spring 18, so that the movable spring 18 can stably drive the moving head 19 to reset.

[0046] like Figure 4 As shown, in one embodiment, the equipotential ring 23 and the filter ring 24 are closed on one side away from the glass fiber board 4, and the metal conductor 3 is located in the middle of the filter ring 24;

[0047] The working principle and beneficial effect of the above technical solution are: by avoiding the equipotential ring 23 and the filter ring 24 away from the side of the glass fiber board 4, the metal particles can fall into the inner cavity of the capture cavity 25 and be adhered by the adhesive ring 26.

[0048] like Figure 2 As shown, in one embodiment, three circular holes are opened in the middle of the glass fiber board 4, and contact sleeves are fixedly sleeved in the three circular holes;

[0049] The working principle and beneficial effects of the above technical solution are: the glass fiber board 4 is machined without mold casting, and the metal conductor 3 is supported by the circular hole, and the electric field structure is optimized to adapt to gas insulation.

[0050] like Figure 7 As shown, in one embodiment, a blocking plate 28 is fixedly connected to the top of the movable rod 20, a two-color alert plate 27 is fixedly connected to the side of the flow tube 15 away from the metal shell 1, the blocking plate 28 contacts the surface of the two-color alert plate 27, and the moving head 19 fits the metal shell 1;

[0051] The working principle and beneficial effects of the above technical solution are as follows: under normal conditions, the blocking plate 28 blocks half of the two-color alert plate 27, and the color of the portion of the two-color alert plate 27 blocked by the blocking plate 28 is red;

[0052] When the insulating gas in the inner cavity of the metal shell 1 leaks, the air pressure in the inner cavity of the metal shell 1 decreases, and the resistance of the moving head 19 to the air pressure in the inner cavity of the metal shell 1 decreases. Therefore, the elastic force of the movable spring 18 causes the moving head 19 to enter one end of the inner cavity of the metal shell 1, thereby driving the movable rod 20 to move in the direction of the moving head 19, and then driving the blocking plate 28 to move on the surface of the two-color warning plate 27, and the warning color of the two-color warning plate 27 leaks, thereby reminding the operation and maintenance personnel that the metal shell 1 is leaking, and then the insulating air is replenished into the inner cavity of the metal shell 1 through the air pump 12, thereby avoiding the lack of insulating gas, which affects the insulation performance.

[0053] Working principle and use process: install the metal conductor 3 in the inner cavity of the glass fiber board 4, then align the roller 6 with the limit rail 22, then put the metal conductor 3 into the inner cavity of the metal shell 1, then install the pot-type insulator 2 at both ends of the metal shell 1 to make the metal shell 1 sealed, then use the air pump 12 to fill the insulating gas into the inner cavity of the metal shell 1, so that the metal conductor 3 is insulated by the insulating gas in the inner cavity of the metal shell 1, then pull out the blocking block 14 from the top of the storage box 13, then input the lubricating oil into the inner cavity of the storage box 13, and the lubricating oil in the inner cavity of the storage box 13 is input into the inner cavity of the flow tube 15;

[0054] At this time, the nylon slider 9 and the ejector pin 10 are attached to the inner wall of the metal shell 1, so that the metal conductor 3 in the inner cavity of the glass fiber board 4 is supported by the roller 6, the nylon slider 9 and the ejector pin 10, and all non-charged metal parts of the glass fiber board 4 are connected to the metal shell 1 at the same potential through the equipotential ring 23;

[0055] When the metal conductor 3 is in use, it expands and contracts due to thermal expansion and contraction. At this time, the rolling of the roller 6 causes the glass fiber board 4 to move along with the expansion and contraction of the metal conductor 3, thereby providing a stable support for the metal conductor 3. When the roller 6 moves to the moving head 19, the moving head 19 is pressed to drive the movable rod 20 to move. When the movable rod 20 moves, the blocking rod 21 is driven away from the oil injection pipe 16, thereby connecting the flow pipe 15 and the oil injection pipe 16. Then, the lubricating oil in the inner cavity of the storage box 13 can be injected into the rotating shaft 11 by gravity through the flow pipe 15 and the oil injection pipe 16, thereby lubricating the rotating shaft 11.

[0056] Since the glass fiber board 4 and the equipotential ring 23 are equipotential structures, the capture chamber 25 is a space with zero electric field strength. As the glass fiber board 4 drives the movement of the equipotential ring 23, the metal particles that are floating in the inner cavity of the metal shell 1 due to the electric field force come into contact with the filter ring 24, and the metal particles enter the inner cavity of the capture chamber 25. Since the electric field strength in the inner cavity of the capture chamber 25 is relatively low, the metal particles no longer float, and are adhered to by the adhesive ring 26.

[0057] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0058] 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 three-phase metal-enclosed power transmission line structure, comprising a metal shell (1), characterized in that: The left and right ends of the metal shell (1) are provided with pot-type insulators (2); a metal conductor (3) is fixedly provided on the side of the pot-type insulator (2) close to the metal shell (1); a glass fiber board (4) is fixedly sleeved on the surface of the metal conductor (3); an insulating plate (5) is provided at the bottom of the glass fiber board (4); a rotating shaft (11) is provided on the side of the insulating plate (5) close to the metal shell (1); a roller (6) is movably sleeved on the surface of the rotating shaft (11); a storage box (13) is fixedly connected to the top end of the metal shell (1); a flow pipe (15) is fixedly connected to the bottom end of the storage box (13); an oil filling pipe (16) is fixedly connected to the bottom end of the flow pipe (15); A mounting cylinder (17) is fixedly connected to the bottom of the metal shell (1), a movable spring (18) is fixedly connected to the inner cavity of the mounting cylinder (17), a movable head (19) is fixedly connected to the side of the movable spring (18) close to the metal shell (1), a movable rod (20) is fixedly connected to the side of the movable head (19) close to the movable spring (18) passing through the mounting cylinder (17), a blocking rod (21) is fixedly connected to the top of the movable rod (20) close to the oil injection pipe (16), the blocking rod (21) is located in the inner cavity at the connection between the flow pipe (15) and the oil injection pipe (16), the oil injection pipe (16) is located above the rotating shaft (11), and a limit rail (22) is fixedly connected to the bottom of the inner cavity of the metal shell (1).

2. A three-phase metal-enclosed transmission line structure according to claim 1, characterized in that: An equipotential ring (23) is fixedly connected to the right side of the glass fiber board (4), a filter ring (24) is fixedly connected to the top of the inner wall of the equipotential ring (23), a capture cavity (25) is provided in the equipotential ring (23) and the filter ring (24), and an adhesive ring (26) is fixedly connected to the inner wall of the equipotential ring (23).

3. A three-phase common box metal-enclosed transmission line structure according to claim 1, characterized in that: The roller (6) is located in the inner cavity of the limiting rail (22), and the moving head (19) is located on the moving path of the roller (6).

4. A three-phase metal-enclosed transmission line structure according to claim 1, characterized in that: A blocking block (14) is inserted at the top of the storage box (13), the storage box (13) is connected to the inner cavities of the flow tube (15) and the oil injection tube (16), and the moving head (19) is located below the oil injection tube (16).

5. A three-phase common box metal-enclosed transmission line structure according to claim 2, characterized in that: The top of the glass fiber board (4) is fixedly connected to an insulating board 2 (8), the inner cavity of the insulating board 2 (8) is provided with two springs, and the insulating board 2 (8) is respectively fixedly connected to a nylon slider (9) and an ejector pin (10) through the two springs, and the nylon slider (9) and the ejector pin (10) are in contact with the inner wall of the metal shell (1).

6. A three-phase common box metal-enclosed transmission line structure according to claim 2, characterized in that: The bottom end of the metal shell (1) is fixedly connected to a support frame (7), and the top end of the metal shell (1) is fixedly connected to an air pump (12).

7. A three-phase common box metal-enclosed transmission line structure according to claim 2, characterized in that: The moving head (19) is located in the inner cavity of the limiting rail (22), and one end of the moving head (19) close to the movable rod (20) is located at the center of the inner cavity of the movable spring (18).

8. A three-phase common box metal-enclosed transmission line structure according to claim 2, characterized in that: The equipotential ring (23) and the filter ring (24) are closed at a side away from the glass fiber board (4), and the metal conductor (3) is located in the middle of the filter ring (24).

9. A three-phase metal-enclosed power transmission line structure in one box according to claim 2, characterized in that: Three circular holes are provided in the middle of the glass fiber board (4), and contact sleeves are fixedly sleeved in the three circular holes.

10. A three-phase common box metal-enclosed transmission line structure according to claim 2, characterized in that: A blocking plate (28) is fixedly connected to the top of the movable rod (20), a double-color warning plate (27) is fixedly connected to the side of the flow tube (15) away from the metal shell (1), the blocking plate (28) is in contact with the surface of the double-color warning plate (27), and the moving head (19) is in contact with the metal shell (1).

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