A cable distribution box convenient for maintenance

Abstract

The present invention relates to the technical field of cable protection, and discloses a cable distribution box convenient for maintenance, including a box body. A protection part is installed in the middle of the interior of the box body and is used for urgently absorbing the thermally expanded air caused by an arc. A switching part is installed on one side of the interior of the box body and is used for automatically switching the heat dissipation and air intake directions under the high heat and high pressure state inside the cable distribution box. Emergency arc protection is adopted. When an arc is generated due to faults such as short circuit and overload in the cable distribution box, the airbag of the protection part quickly absorbs the thermally expanded air, preventing the pressure from rising excessively and the arc from spreading. The airbag squeezes the adjusting block, releasing the locking of the locking part on the switching part, and the switching part and the heat dissipation part act. The cooling fan extracts external air into the box, and at the same time drives the diffusion of the retained nitrogen. Nitrogen can reduce the arc temperature, dilute oxygen, and inhibit gas ionization, effectively extinguishing the arc, avoiding damage to other cables and equipment caused by the arc, and reducing the fault risk and losses.

Description

Technical Field

[0001] The present invention relates to the technical field of cable protection, and particularly to a cable distribution box that is convenient for maintenance. Background Art

[0002] A cable distribution box is an important part of the power cable system. It is used to branch power cables to meet the power consumption needs of different users. During actual operation, the cable distribution box may face various faults, such as short circuits, overloads, overvoltages, etc. If these faults cannot be handled in time, they may cause cable damage, power outages, and even safety accidents such as fires, seriously affecting the stable operation of the power system and the normal power consumption of users.

[0003] According to Chinese Patent Publication No. CN213213102U, this patent provides an arc suppression grounding complete set of devices, including an oil tank and an arc suppression coil placed in the oil tank. It also includes a grounding transformer, which is electrically connected to the arc suppression coil through a cable. A plurality of tap joints are also electrically connected to the arc suppression coil. The tap joints penetrate the oil tank and are located outside the oil tank. The grounding transformer is placed in the oil tank. The cable is a three-core cable with a metal protective layer. The Z-shaped grounding transformer has a neutral point, which is convenient for connecting the arc suppression coil. And the zero-sequence current directions in the two half windings on the same column of the Z-shaped grounding transformer are opposite, so the zero-sequence reactance is very small and does not produce a choking effect on the zero-sequence current. When the neutral point of the Z-shaped grounding transformer is connected to the arc suppression coil, the compensation current of the arc suppression coil can flow freely, and the use effect is good.

[0004] For the existing cable distribution box protection device, when a cable fault occurs in the distribution box, power-off protection is usually carried out by a circuit breaker protection switch. However, cable faults are usually accompanied by current breaking through the aging insulation layer and emitting electric arcs. The spread of the electric arcs in the distribution box will further expand the scope of harm, leading to the risk of synchronous damage and faults of other cables and equipment. Therefore, a cable distribution box that is convenient for maintenance is proposed to solve the above-mentioned problems. Summary of the Invention

[0005] (I) Technical Problems to be Solved

[0006] Aiming at the deficiencies of the prior art, the present invention provides a cable distribution box that is convenient for maintenance, and solves the problem that the electric arcs emitted by cable faults will further spread in the distribution box, leading to the risk of synchronous damage and faults of other cables and equipment.

[0007] (II) Technical Solutions

[0008] To achieve the above object, the present invention provides the following technical solution: A cable distribution box convenient for maintenance, including a box body, a protection part is installed in the middle of the interior of the box body, which is used to absorb the hot expansion air caused by an emergency arc, a switching part is installed on one side of the interior of the box body, which is used to automatically switch the heat dissipation and air intake directions under the high heat and high pressure state inside the cable distribution box, a heat dissipation part is arranged on the switching part, which retains nitrogen in the box by the membrane separation method and guides the air to be discharged, a locking part is installed in the protection part, which is used to lock and release the switching part, and a ventilation part is arranged on the outer wall of the box body, which is used for heat replacement between the air and the inside of the cable distribution box.

[0009] Preferably, the protection part includes a protection shell. Both sides of the top of the protection shell are inclined plane structures and are symmetrically arranged. Through holes are opened on both inclined planes of the protection shell. An airbag is fixedly connected to the inner wall of each through hole. An adjusting block is slidably connected to the inner wall of the protection shell. A tension spring is elastically connected between the top of the adjusting block and the top of the inner wall of the protection shell. Both sides of the top of the adjusting block are inclined plane structures and are attached to the outer wall of the airbag through the inclined planes. An equipment cabin is integrally arranged at the bottom of the front of the protection shell.

[0010] Preferably, the protection shell is fixedly connected to the middle of the inner wall of the box body. Four membrane frames are symmetrically installed on both sides of the outer wall of the protection shell. A polymer membrane is installed between the inner walls of the four membrane frames.

[0011] Preferably, the locking part includes two sliding channels. The two sliding channels are fixedly connected to one side of the inner wall of the protection shell. A U-shaped clamping block is slidably connected between the two sliding channels. A second spring is elastically connected between the bottom of the outer wall of the U-shaped clamping block and the top of the outer wall of the equipment cabin. A sliding hole is opened on one side of the outer wall of the protection shell, and the sliding hole is aligned with the U-shaped clamping block.

[0012] Preferably, the number of the locking parts is four in total. Every two locking parts are respectively arranged on one side of the inner wall of the protection shell, and the four locking parts are symmetrically arranged with each other.

[0013] Preferably, the switching part includes a heat preservation board. The heat preservation board is slidably connected to the inner wall of the box body. Both sides of the top of the heat preservation board are fixedly connected with sliding arms. The ends of the two sliding arms are fixedly connected with L-shaped plates. An air exchange hole is opened on the top of the L-shaped plate. A baffle is fixedly connected to the end face of the L-shaped plate. The tops of the L-shaped plate and the baffle are both attached to the top of the inner wall of the box body. A groove is opened on the top of the heat preservation board. Two clamping arms are fixedly connected to the side wall of the heat preservation board. Sliding sleeves are slidably sleeved on the two clamping arms. A first spring is movably sleeved on each of the two sliding sleeves.

[0014] Preferably, the heat dissipation part includes a support plate which is fixedly connected to one side of the inner wall of the box body. A heat dissipation fan is installed on one side of the top of the support plate. A film hole is formed on the other side of the top of the support plate. A polymer film is installed on the inner wall of the film hole. An exhaust frame is fixedly connected to the middle of the top of the support plate. The end of the L-shaped plate is attached between the outer wall of the exhaust frame and the top of the inner wall of the box body. Side grooves are formed on both sides of the support plate. The inner wall of the groove is attached to the two side grooves. Sliding grooves are formed on both sides of the bottom of the exhaust frame. The two sliding arms are respectively slidably connected to the inner walls of the two sliding grooves. The bottoms of the two sliding arms are attached to the top of the support plate.

[0015] Preferably, there are two switching parts and two heat dissipation parts respectively. The other switching part and heat dissipation part are installed on the other side of the inner wall of the box body. The two switching parts are symmetrically arranged with each other. The two heat dissipation parts are symmetrically arranged with each other. The four sliding sleeves are respectively fixedly connected to both sides of the outer wall of the protective shell and are aligned with the four sliding holes. The four clamping arms are respectively inserted into the four sliding holes and are clamped with the four U-shaped clamping blocks. Every two same-side first springs are respectively elastically connected between the outer wall of the protective shell and the heat preservation board.

[0016] Preferably, the air exchange part includes two side air exchange openings which are respectively formed at the bottoms of both sides of the outer wall of the box body. Through holes are formed at the tops of both sides of the outer wall of the box body. Upper air exchange openings are formed at both sides of the top of the box body. The two baffles respectively block the two upper air exchange openings. The two baffles are respectively slidably connected to the inner walls of the two through holes.

[0017] Preferably, cable insulator assemblies are installed on both sides of the inner wall of the box body. The cable wires in the cable insulator assemblies all pass through the polymer films in the film racks on the same side movably. Each side of the cable insulator assemblies is respectively located between the heat preservation board on the same side and the outer wall of the protective shell. A box door is installed on the front of the box body. The box door is a double-leaf door. Front air exchange openings are formed on each side panel of the box door.

[0018] (III) Beneficial effects

[0019] Compared with the prior art, the invention provides a cable distribution box which is convenient for maintenance and has the following beneficial effects:

[0020] 1. The cable distribution box that is easy to maintain adopts emergency arc protection. When an arc is generated due to faults such as short circuit or overload inside the cable distribution box, the airbag in the protection part quickly absorbs the thermally expanded air, preventing excessive pressure rise and arc diffusion. The airbag squeezes the adjustment block, releasing the locking of the switching part by the locking part. The switching part and the heat dissipation part act. The cooling fan extracts external air into the box, and at the same time drives the diffusion of the retained nitrogen. Nitrogen can reduce the arc temperature, dilute oxygen, and inhibit gas ionization, effectively extinguishing the arc and avoiding damage to other cables and equipment caused by the arc, reducing the fault risk and losses.

[0021] 2. The cable distribution box that is easy to maintain adopts efficient heat dissipation and gas management. Using the membrane separation method, a polymer membrane is used to retain nitrogen in the box and separate and discharge other gases. During normal operation, hot air rises through the polymer membrane, and nitrogen is separated and retained, enhancing the insulation performance inside the box. At the same time, the hot air is guided by the cooling fan to exchange heat with cold air and is discharged from the side ventilation opening, achieving a good heat dissipation effect and ensuring the stable operation of the equipment at an appropriate temperature.

[0022] 3. The cable distribution box that is easy to maintain adopts fault indication and convenient maintenance. In the emergency protection state, the baffle will extend to the outside of the box body. Maintenance personnel can quickly judge whether the cable distribution box has had a fault by observing the state of the baffle, and then take targeted maintenance measures, saving the time for fault troubleshooting and improving the maintenance efficiency. The box door adopts a double-door design and there is a front ventilation opening on the door panel, which is convenient for maintenance personnel to enter and operate, and also helps with ventilation and heat dissipation, improving the convenience of maintenance.

[0023] 4. The cable distribution box that is easy to maintain adopts an optimized structural design. The components such as the protection part, switching part, heat dissipation part, locking part, and ventilation part are reasonably arranged and cooperate with each other. Structures such as the heat preservation board, sliding arm, L-shaped plate, and baffle of the switching part realize different ventilation and protection functions under normal and fault states respectively. The support plate, cooling fan, membrane holes, and exhaust frame of the heat dissipation part work together to ensure heat dissipation and gas discharge. The locking part precisely controls the action of the switching part, and the multiple ventilation openings of the ventilation part optimize the air circulation path. The overall structural design improves the reliability and stability of the cable distribution box. Description of the Drawings

[0024] Figure 1 It is a schematic diagram of the overall structure of a cable distribution box that is easy to maintain proposed by the present invention;

[0025] Figure 2 It is an internal view of the box body of a cable distribution box that is easy to maintain proposed by the present invention;

[0026] Figure 3 It is a schematic diagram of the structure of the protection part of a cable distribution box that is easy to maintain proposed by the present invention;

[0027] Figure 4 The connection diagram of the switching part and the heat dissipation part of a cable distribution box that is convenient for maintenance proposed by the present invention;

[0028] Figure 5 The structural schematic diagram of the switching part of a cable distribution box that is convenient for maintenance proposed by the present invention;

[0029] Figure 6 The structural schematic diagram of the heat dissipation part of a cable distribution box that is convenient for maintenance proposed by the present invention;

[0030] Figure 7 The structural schematic diagram of the locking part of a cable distribution box that is convenient for maintenance proposed by the present invention;

[0031] Figure 8 The structural schematic diagram of the air exchange part of a cable distribution box that is convenient for maintenance proposed by the present invention.

[0032] In the figure: 1. Box body; 2. Protection part; 21. Protection shell; 22. Through hole; 23. Airbag; 24. Adjusting block; 25. Pulling spring; 26. Equipment cabin; 3. Switching part; 31. Heat preservation board; 32. Sliding arm; 33. L-shaped plate; 34. Air exchange hole; 35. Baffle; 36. Groove; 37. Clamping arm; 38. Sliding sleeve; 39. Spring I; 4. Heat dissipation part; 41. Support plate; 42. Heat dissipation fan; 43. Membrane hole; 44. Exhaust frame; 45. Side groove; 46. Sliding groove; 5. Locking part; 51. Slideway; 52. U-shaped clamping block; 53. Spring II; 54. Sliding hole; 6. Air exchange part; 61. Side air exchange port; 62. Through hole in the plate; 63. Upper air exchange port; 7. Membrane frame; 8. Cable insulator assembly; 9. Box door; 10. Front air exchange port. Specific embodiments

[0033] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0034] Please refer to Figure 1-8, the present invention provides a technical solution: a cable distribution box convenient for maintenance, including a box body 1. The protection part 2 of this case is installed in the middle of the interior of the box body 1 and is used to urgently absorb the hot-expanded air caused by the arc. The switching part 3 of this case is installed on one side of the interior of the box body 1 and is used to automatically switch the heat dissipation and air intake directions under the high-temperature and high-pressure state inside the cable distribution box. The heat dissipation part 4 of this case is arranged on the switching part 3, retains nitrogen in the box by the membrane separation method and guides the air to be discharged. The locking part 5 of this case is installed in the protection part 2 and is used to lock and release the switching part 3. The air exchange part 6 of this case is arranged on the outer wall of the box body 1 and is used for heat replacement between the air and the inside of the cable distribution box.

[0035] In the present invention, in order to urgently handle the large amount of energy released by the arc discharge phenomenon, the protection part 2 of this case includes a protective shell 21. The two sides of the top of the protective shell 21 are both inclined surface structures and are symmetrically arranged. Through holes 22 are opened on the inclined surfaces on both sides of the protective shell 21. An airbag 23 is fixedly connected to the inner wall of each through hole 22. An adjusting block 24 is slidably connected to the inner wall of the protective shell 21. A tension spring 25 is elastically connected between the top of the adjusting block 24 and the top inner wall of the protective shell 21. The two sides of the top of the adjusting block 24 are both inclined surface structures and are attached to the outer wall of the airbag 23 through the inclined surfaces. The airbag 23 will adaptively change according to the gas expansion intensity and pressure intensity in the box, so as to absorb the gas expansion and squeeze the adjusting block 24. The bottom of the front of the protective shell 21 is integrally provided with an equipment cabin 26. The protective shell 21 is fixedly connected to the middle of the inner wall of the box body 1. Four membrane frames 7 are symmetrically installed on both sides of the outer wall of the protective shell 21. A polymer membrane is installed between the inner walls of the four membrane frames 7. When the cable in the box works, heat will be continuously generated, thus increasing the temperature of the air in the box. According to the principle that hot gas has a large volume and a small density and thus rises, it prompts the air to pass upward through the polymer membrane for filtration, separating and retaining nitrogen. The accumulation of nitrogen in the box can further enhance the insulation performance, moisture-proof and anti-corrosion effects, and delay the aging of the insulating material.

[0036] In this embodiment, in order to further address the potential risks and hazards brought by high temperature, high pressure and arc radiation in the box, the locking part 5 of this case includes two slideways 51. The two slideways 51 are fixedly connected to one side of the inner wall of the protective shell 21. A U-shaped clamping block 52 is slidably connected between the two slideways 51. A second spring 53 is elastically connected between the bottom of the outer wall of the U-shaped clamping block 52 and the top of the outer wall of the equipment cabin 26. A sliding hole 54 is opened on one side of the outer wall of the protective shell 21, and the sliding hole 54 is aligned with the U-shaped clamping block 52. There are a total of four locking parts 5, and every two locking parts 5 are respectively arranged on one side of the inner wall of the protective shell 21, and the four locking parts 5 are symmetrically arranged with each other. After the adjusting block 24 descends to a certain extent, it will squeeze the U-shaped clamping block 52 to automatically release the clamping connection.

[0037] It should be noted that in order to urgently respond to the high temperature and high pressure inside the box and the arc radiation, and thus automatically switch the direction of the incoming and outgoing airflows, the switching part 3 of this case includes a heat preservation board 31. The heat preservation board 31 is slidably connected to the inner wall of the box body 1. Both sides of the top of the heat preservation board 31 are fixedly connected with sliding arms 32. The ends of the two sliding arms 32 are fixedly connected with an L-shaped plate 33. An air exchange hole 34 is opened at the top of the L-shaped plate 33. A baffle 35 is fixedly connected to the end face of the L-shaped plate 33. The tops of the L-shaped plate 33 and the baffle 35 are both in contact with the top of the inner wall of the box body 1. A groove 36 is opened at the top of the heat preservation board 31. Two clamping arms 37 are fixedly connected to the side wall of the heat preservation board 31. Sliding sleeves 38 are slidably sleeved on both clamping arms 37. The clamping arms 37 can slide along the sliding sleeves 38 without problems of shaking and falling off. Spring one 39 is movably sleeved on both sliding sleeves 38.

[0038] In order to achieve the effects of automatic exhaust heat dissipation and blowing arc extinguishing, the heat dissipation part 4 of this case includes a support plate 41. The support plate 41 is fixedly connected to one side of the inner wall of the box body 1. A heat dissipation fan 42 is installed on one side of the top of the support plate 41. A film hole 43 is opened on the other side of the top of the support plate 41. A polymer film is installed on the inner wall of the film hole 43. An exhaust frame 44 is fixedly connected to the middle of the top of the support plate 41. The end of the L-shaped plate 33 is attached between the outer wall of the exhaust frame 44 and the top of the inner wall of the box body 1. Side grooves 45 are opened on both sides of the support plate 41. The inner wall of the groove 36 is in contact with the two side grooves 45. Sliding grooves 46 are opened on both sides of the bottom of the exhaust frame 44. The two sliding arms 32 are respectively slidably connected to the inner walls of the two sliding grooves 46. The bottoms of the two sliding arms 32 are both in contact with the top of the support plate 41.

[0039] In order to further handle the cable line fault problems in multiple groups of partitions inside the box, there are two switching parts 3 and two heat dissipation parts 4 in this case. Another switching part 3 and heat dissipation part 4 are installed on the other side of the inner wall of the box body 1. The two switching parts 3 are symmetrically arranged with each other. The two heat dissipation parts 4 are symmetrically arranged with each other. The four sliding sleeves 38 are respectively fixedly connected to both sides of the outer wall of the protection shell 21 and are aligned with the four sliding holes 54. The four clamping arms 37 are respectively inserted into the four sliding holes 54 and are clamped with the four U-shaped clamping blocks 52. Every two spring ones 39 on the same side are respectively elastically connected between the outer wall of the protection shell 21 and the heat preservation board 31.

[0040] It should be noted that the effect of emergency protection for cable faults is achieved by changing the direction of air inlet and outlet. The air exchange part 6 of this case includes two side air exchange openings 61, which are respectively opened at the bottoms of both sides of the outer wall of the box body 1. Through holes 62 are opened at the tops of both sides of the outer wall of the box body 1. Upper air exchange openings 63 are opened at both sides of the top of the box body 1. Two baffle plates 35 respectively block the two upper air exchange openings 63. The two baffle plates 35 are respectively slidably connected to the inner walls of the two through holes 62. Cable insulator assemblies 8 are installed on both sides of the inner wall of the box body 1. The cable lines in the cable insulator assemblies 8 all pass through the polymer film in the membrane frame 7 on the same side movably. Each cable insulator assembly 8 on each side is respectively located between the heat preservation plate 31 on the same side and the outer wall of the protective shell 21. A box door 9 is installed on the front of the box body 1. The box door 9 is a double-leaf door. Front air exchange openings 10 are opened on each side plate of the box door 9.

[0041] Working principle: When the cable insulator assembly 8 inside the box body 1 is working normally, the air outlet of the cooling fan 42 is set downward. Air enters the inside of the box body 1 from the front air exchange opening 10 at the box door 9 and slowly heats up through the power loss inside the box and the heat generated by the contact resistance. The hot air rises inside the box body 1 and successively passes through the polymer film in the membrane frame 7 and the membrane holes 43. Nitrogen is separated based on the different permeation rates of different gases by the membrane separation method, so that nitrogen adheres to and stays on one side of the polymer film, while other gases are drawn by the cooling fan 42 through the exhaust frame 44 and enter between the heat preservation plate 31 and the inner wall of the box body 1. At this time, the heat preservation plate 31 can further isolate the high temperature inside the box body 1, so that the hot air gradually cools and settles between the heat preservation plate 31 and the inner wall of the box body 1 and the cold air entering from the side air exchange opening 61, and then is discharged from the side air exchange opening 61, realizing the heat dissipation effect when the cable branch box is working normally.

[0042] When faults such as short circuit, overload, and partial discharge occur, the cable distribution box will heat up rapidly in a short time, causing the pressure inside the box body 1 to increase and the hot air to expand. At this time, the airbag 23 absorbs the expanded hot air under high pressure and squeezes the adjustment block 24 to slide downward, then presses the U-shaped latch 52 to descend along the slideway 51, further releasing the clamping of the clamping arm 37. The elastic force of the first spring 39 pushes the heat insulation plate 31 to approach and abut against the inner wall side of the box body 1. At this time, the groove 36 slides along the side groove 45 of the support plate 41, and the sliding arm 32 slides along the chute 46, driving the L-shaped plate 33 to fit the exhaust frame 44 and block the air from passing through. The baffle 35 slides along the through-hole plate 62 and extends out of the box body 1. The air exchange hole 34 is aligned with the upper air exchange port 63 to achieve communication, and the cooling fan 42 extracts the external air and enters the box body 1 downward. Since the heat insulation plate 31 is attached to the inner wall of the box body 1 at this time, the heat dissipation channel between the heat insulation plate 31 and the inner wall of the box body 1 disappears. The air can only enter the box body 1 from the upper air exchange port 63 and cannot be discharged from the side air exchange port 61, and can only be discharged from the front air exchange port 10. At the same time, the entering air will blow the nitrogen gas retained on each polymer film, causing the nitrogen gas to diffuse and cover. According to the thermal principle, when the nitrogen gas diffuses to the arc area, it can quickly take away heat, rapidly reducing the arc temperature. After the nitrogen gas diffuses, it will dilute the air in the cable box, reducing the oxygen content. Nitrogen has a high electronegativity and can capture free electrons in the arc to form negative ions, thus inhibiting the ionization process of the gas. The current conduction ability in the arc decreases, and the arc will gradually extinguish, thereby achieving emergency protection and avoiding the potential risk of further damage to other adjacent equipment caused by high temperature, high pressure, and arc radiation.

[0043] In the emergency protection state, sufficient preparation time is provided for maintenance personnel. When arriving at the scene, the fault problems existing in the cable distribution box can be judged by whether the baffle 35 extends outside the box body 1, and then targeted maintenance measures can be taken. Through the coordinated work of multiple components, the functions of efficient heat dissipation, emergency protection, and easy maintenance are realized, effectively solving the problems existing in the existing cable distribution box, which is of great significance for ensuring the stable operation of the power system and reducing fault losses.

[0044] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or also elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the said element.

Claims

1. A cable distribution box convenient for maintenance, characterized in that Including: A box body (1); A protection part (2), installed in the middle inside the box body (1), for urgently absorbing the thermally expanded air caused by an electric arc; A switching part (3), installed on one side inside the box body (1), for automatically switching the heat dissipation and air intake directions under the high heat and high pressure state inside the cable branch box; The switching part (3) includes a heat preservation board (31), the heat preservation board (31) is slidably connected to the inner wall of the box body (1), both sides of the top of the heat preservation board (31) are fixedly connected with sliding arms (32), the ends of the two sliding arms (32) are fixedly connected with an L-shaped plate (33), a ventilation hole (34) is opened at the top of the L-shaped plate (33), a baffle (35) is fixedly connected to the end face of the L-shaped plate (33), the tops of the L-shaped plate (33) and the baffle (35) are both attached to the top of the inner wall of the box body (1), a groove (36) is opened at the top of the heat preservation board (31), two clamping arms (37) are fixedly connected to the side wall of the heat preservation board (31), sliding sleeves (38) are slidably sleeved on the two clamping arms (37), and a first spring (39) is movably sleeved on each of the two sliding sleeves (38); A heat dissipation part (4), arranged on the switching part (3), retaining nitrogen in the box by the membrane separation method and guiding the air to be discharged; The heat dissipation part (4) includes a support plate (41), the support plate (41) is fixedly connected to one side of the inner wall of the box body (1), a heat dissipation fan (42) is installed on one side of the top of the support plate (41), a membrane hole (43) is opened on the other side of the top of the support plate (41), a polymer membrane is installed on the inner wall of the membrane hole (43), an exhaust frame (44) is fixedly connected to the middle of the top of the support plate (41), the end of the L-shaped plate (33) is attached between the outer wall of the exhaust frame (44) and the top of the inner wall of the box body (1), side grooves (45) are opened on both sides of the support plate (41), the inner wall of the groove (36) is attached to the two side grooves (45), sliding grooves (46) are opened on both sides of the bottom of the exhaust frame (44), the two sliding arms (32) are respectively slidably connected to the inner walls of the two sliding grooves (46), and the bottoms of the two sliding arms (32) are both attached to the top of the support plate (41); A locking part (5), installed in the protection part (2), for locking and releasing the switching part (3); A ventilation part (6), arranged on the outer wall of the box body (1), for replacing the air and the heat inside the cable branch box.

2. The cable distribution box easy to maintain according to claim 1, characterized in that: The protection part (2) includes a protective shell (21). Both sides of the top of the protective shell (21) are inclined plane structures and are symmetrically arranged. Through holes (22) are provided on the inclined planes on both sides of the protective shell (21). An airbag (23) is fixedly connected to the inner wall of each through hole (22). An adjusting block (24) is slidably connected to the inner wall of the protective shell (21). A tension spring (25) is elastically connected between the top of the adjusting block (24) and the top of the inner wall of the protective shell (21). Both sides of the top of the adjusting block (24) are inclined plane structures and are in contact with the outer wall of the airbag (23) through the inclined planes. The bottom of the front of the protective shell (21) is integrally provided with an equipment cabin (26).

3. The cable distribution box convenient for maintenance according to claim 2, characterized in that: The protective shell (21) is fixedly connected to the middle of the inner wall of the box body (1). Four film racks (7) are symmetrically installed on both sides of the outer wall of the protective shell (21). A polymer film is installed between the inner walls of the four film racks (7).

4. The cable distribution box convenient for maintenance according to claim 3, characterized in that: The locking part (5) includes two slideways (51). The two slideways (51) are fixedly connected to one side of the inner wall of the protective shell (21). A U-shaped clamping block (52) is slidably connected between the two slideways (51). A second spring (53) is elastically connected between the bottom of the outer wall of the U-shaped clamping block (52) and the top of the outer wall of the equipment cabin (26). A sliding hole (54) is provided on one side of the outer wall of the protective shell (21). The sliding hole (54) is arranged in alignment with the U-shaped clamping block (52).

5. The cable distribution box convenient for maintenance according to claim 4, wherein: There are four locking parts (5) in total. Every two locking parts (5) are respectively arranged on one side of the inner wall of the protective shell (21). The four locking parts (5) are symmetrically arranged with each other.

6. The cable distribution box convenient for maintenance according to claim 5, characterized in that: There are two switching parts (3) and two heat dissipation parts (4) respectively. The other switching part (3) and heat dissipation part (4) are installed on the other side of the inner wall of the box body (1). The two switching parts (3) are symmetrically arranged with each other. The two heat dissipation parts (4) are symmetrically arranged with each other. The four sliding sleeves (38) are respectively fixedly connected to both sides of the outer wall of the protective shell (21) and are arranged in alignment with the four sliding holes (54). The four clamping arms (37) are respectively inserted into the four sliding holes (54) and are clamped with the four U-shaped clamping blocks (52). Every two same-side first springs (39) are respectively elastically connected between the outer wall of the protective shell (21) and the heat preservation board (31).

7. The cable distribution box convenient for maintenance according to claim 6, characterized in that: The ventilation part (6) includes two side ventilation openings (61). The two side ventilation openings (61) are respectively provided at the bottoms of both sides of the outer wall of the box body (1). Through plate holes (62) are provided at the tops of both sides of the outer wall of the box body (1). Upper ventilation openings (63) are provided at the tops of both sides of the box body (1). The two baffle plates (35) respectively block the two upper ventilation openings (63). The two baffle plates (35) are respectively slidably connected to the inner walls of the two through plate holes (62).

8. The cable distribution box easy to maintain according to claim 7, characterized in that: On both sides of the inner wall of the box body (1), cable insulator assemblies (8) are installed. The cable lines in the cable insulator assemblies (8) all pass through the polymer film in the same-side film rack (7) movably. Each cable insulator assembly (8) on each side is respectively located between the outer walls of the same-side heat preservation plate (31) and the protective shell (21). A box door (9) is installed on the front of the box body (1). The box door (9) is a double-leaf door, and front ventilation openings (10) are formed on each side plate of the box door (9).

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