Low-voltage direct-current explosion-proof distribution box

Abstract

The invention relates to the technical field of distribution boxes, in particular to a low-voltage direct-current anti-explosion distribution box which comprises a box body, a box cover and an anti-explosion gap and further comprises flange bolts, wiring ports and knob sets, the box cover is arranged on the surface of the box body, the anti-explosion gap is formed between the box cover and the box body, and a plurality of electric appliance sets are arranged on the inner wall of the box cover and are connected with the flange bolts. An isolation bin is fixedly installed on the inner wall of the box cover, a rubber film and an injection port are arranged on the surface of the isolation bin, a butt joint port is slidably installed on the inner wall of the box cover, a small groove is formed in the surface of the butt joint port, a plurality of first connecting pipes are arranged on the surface of the butt joint port, a front cavity is formed in the isolation bin, and the front cavity is filled with cleaning gas. The front cavity communicates with the small groove through a first connecting pipe, the front cavity makes contact with the rubber film, and memory alloy is arranged between the box cover and the butt joint port, communication of the anti-explosion gap and the small groove is controlled through deformation of the memory alloy, and clean gas is discharged out of the anti-explosion gap to guarantee circulation of the anti-explosion gap.

Description

Technical Field

[0001] The invention relates to the technical field of distribution boxes, in particular to a low-voltage direct current explosion-proof distribution box. Background Art

[0002] With the improvement of industrialization level and the advancement of science and technology, the safety issues of power systems have become increasingly prominent. Especially in some special environments, such as places with explosive gas or dust, the safe operation of power systems faces severe challenges, and explosion-proof distribution boxes have become the preferred product to ensure circuit safety.

[0003] Among the existing types of explosion-proof distribution boxes, the most commonly used is the flameproof type. Flameproof distribution boxes are widely used in dangerous environments where flammable and explosive substances exist because of their wide applicability, ready-to-install, good performance, and low maintenance costs. For example, in dangerous working areas in the petroleum, chemical, pharmaceutical, coal mining and other industries, there are often large amounts of flammable and explosive gases in these working areas, and explosion-proof distribution boxes are needed to ensure the safety of the workers. The explosion-proof distribution box uses a high-strength alloy material as the shell to separate the circuit devices inside the distribution box from the external dangerous working environment. An explosion-proof gap is designed between the distribution box and the protective cover. When the circuit devices inside the distribution box generate electric sparks or high temperatures, it may cause an explosion inside the distribution box, and a huge shock wave will be generated during the explosion. The role of the explosion-proof gap is that when an explosion occurs inside the distribution box, the shock wave can flow through the explosion-proof gap to the outside of the distribution box for pressure relief, preventing the huge pressure generated during the explosion from destroying the surface structure of the distribution box and causing greater explosion damage. In addition, the high-temperature gas generated during the explosion will exchange heat with the surrounding metal shell when passing through the explosion-proof gap, and reach the outside of the distribution box after cooling to a certain temperature. In a hazardous environment, the temperature of the cooled explosion gas is not enough to ignite or detonate the combustible gas in the hazardous environment, thereby preventing the explosion from spreading. Therefore, in order to effectively control the explosion hazard of circuit devices, the surface of the explosion-proof distribution box cannot be completely closed, and the existence of an explosion-proof gap is necessary. However, since the metal gaps are in a static state for a long time, the metal atoms will penetrate each other and metal adhesion will occur. Especially in a high-temperature working environment, the thermal motion of the metal atoms will intensify, which is more likely to cause adhesion. The size and length of the explosion-proof gap have strict standards. If the metal around the explosion-proof gap is adhered, it will affect the structure of the explosion-proof gap, resulting in a significant decrease in the explosion-proof performance of the explosion-proof distribution box. Summary of the invention

[0004] The purpose of the present invention is to provide a low-voltage DC explosion-proof distribution box, which solves the problem that metal adhesion occurs around the explosion-proof gap after long-term use and destroys the structure of the explosion-proof gap. By arranging an isolation chamber in the box body, whenever the temperature inside the box body rises, the clean gas stored in the isolation chamber will shuttle in the explosion-proof gap to maintain the fluidity of the explosion-proof gap.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A low-voltage DC explosion-proof distribution box comprises a box body, a box cover and an explosion-proof gap, and also comprises flange bolts, a wiring port and a knob group, wherein the box cover is arranged on the surface of the box body, the explosion-proof gap is arranged between the box cover and the box body, a plurality of electrical appliance groups are arranged on the inner wall of the box cover, an isolation chamber is fixedly installed on the inner wall of the box cover, a rubber membrane and an injection port are arranged on the surface of the isolation chamber, a docking port is slidably installed on the inner wall of the box cover, a small groove is opened on the surface of the docking port, a plurality of first connecting pipes are arranged on the surface of the docking port, a front cavity is arranged inside the isolation chamber, the front cavity is filled with clean gas, the front cavity is connected with the small groove through the first connecting pipe, the front cavity is in contact with the rubber membrane, a memory alloy is arranged between the box cover and the docking port, the connection between the explosion-proof gap and the small groove is controlled by the deformation of the memory alloy when heated, and the clean gas in the front cavity is discharged from the explosion-proof gap to ensure the fluidity of the explosion-proof gap.

[0007] Preferably, a large groove is formed on the surface of the docking interface, a plurality of second connecting pipes are arranged on the surface of the docking interface, a rear cavity is arranged in the isolation chamber, and the rear cavity is connected with the large groove through the second connecting pipes.

[0008] In the above scheme, the explosion-proof gap and the rear cavity are connected through a large groove, so that the gas outside the box can enter the rear cavity through the large groove and be separated from the electrical equipment group in the box. Without changing the fluidity of the explosion-proof gap, the external dangerous gas will not enter the box through the explosion-proof gap and directly contact the electrical equipment group. Even if the electronic components generate high temperature or short circuit occurs, it is not easy to cause an explosion inside the box.

[0009] Preferably, inclined blocks are slidably installed on all four sides of the inner wall of the box cover, and the side of the inclined block close to the docking interface is set as an inclined surface, and a fixing ring is fixedly installed on the inner side of the isolation chamber, and four groups of air pipes and piston cylinders are set on the surface of the box cover, and the air pipes pass through the box cover and are connected to the surface of the isolation chamber, and the piston cylinder is connected with the rear cavity through the air pipe, and a piston rod is sleeved inside the piston cylinder, and a slide plate is sleeved on the end of each piston rod close to the box cover, and each slide plate corresponds to and is close to the flange bolt on one side of the box cover, and inclined grooves are provided at both ends of the slide plate, and a guide block is fixedly installed on the surface of the box cover close to the inclined groove, and the surface of the guide block is in contact with the inner wall of the inclined groove, and the cross-sectional diameter of the guide block is equal to the width of the inclined groove, and a friction plate is slidably installed on the surface of the slide plate, and the side of the friction plate close to the flange bolt is set as a rough surface, and a transition spring is arranged between the friction plate and the slide plate.

[0010] In the above scheme, a fixing ring is arranged near the inner side of the isolation chamber, and an inclined block is arranged on the outer side. The inclined block moves after being squeezed by the docking interface, squeezing the rear cavity part in the isolation chamber. When the rear cavity is squeezed, the internal gas flows into the piston cylinder through the air pipe, and the piston rod is pushed to move under the action of air pressure. The slide plate is arranged at a position close to the bolt flange. After the slide plate moves, the friction plate can tighten the flange bolts to avoid loosening of the flange bolts when an explosion occurs inside the box, thereby improving the stability of the flange bolts and avoiding loosening of the bolts that may affect the structure of the explosion-proof gap. The position where the slide plate is arranged will not hinder the installation and disassembly of the flange bolts, and is convenient for use.

[0011] Preferably, the docking port is rectangular, and its surface is completely in contact with the box body and the box cover.

[0012] In the above scheme, the docking port is set to a rectangular frame with the same shape as the inside of the box body and the box cover, which is convenient for movement inside the box, ensures the fit between the docking port and the explosion-proof gap, improves air tightness, and at the same time, the use of a frame design will not affect the wiring of the electrical group in the box.

[0013] Preferably, the magnitude of the elastic force between the memory alloy and the abutment interface is α, the magnitude of the friction force on the surface of the abutment interface is β, and α>β.

[0014] In the above scheme, the interface surface is subjected to a certain friction force, and the tension generated on the interface when the memory alloy is deformed is set to be greater than the friction force borne by the interface surface, so that the interface can be stably driven to move.

[0015] Preferably, the isolation chamber and the rubber membrane as a whole can be slightly deformed, are made of silicone rubber material, and the thickness of the rubber membrane is smaller than the overall thickness of the isolation chamber.

[0016] In the above scheme, the isolation chamber needs to isolate and store the internal gas, so it needs to have a certain structural strength. The silicone rubber material has good mechanical properties and can withstand high temperatures. In response to the increase in temperature inside the box, a part of the surface of the isolation chamber is dug out to form a rubber film. The rubber film is easier to deform when subjected to pressure than other parts of the surface of the isolation chamber, and the pressure of the high-temperature gas inside the box is converted into pressure on the clean gas in the front cavity, so that the clean gas can be stably discharged from the explosion-proof gap after being squeezed.

[0017] Preferably, the isolation chamber is arranged in a rectangular shape on the inner wall of the box cover, and there is a certain distance between the surface and the electrical appliance group.

[0018] In the above solution, the isolation chamber is arranged around the inner wall of the box cover while ensuring its own capacity, and does not contact the electrical device group, thereby ensuring the heat dissipation efficiency of the electrical device group.

[0019] Preferably, the friction plate is kept parallel to the slide plate, and the bottoms of both are in contact with the surface of the box cover.

[0020] In the above scheme, when the slide plate moves obliquely, the lateral force and longitudinal force generated by its own movement are transmitted to the surface of the friction plate, so that when the friction plate contacts the flange bolts, the flange bolts have a certain movement tendency, thereby locking the flange bolts to prevent loosening. The bottom of the slide plate and the friction plate are both in contact with the surface of the box cover, ensuring stability during movement.

[0021] Preferably, the cleaning gas filled in the front chamber is an inert gas, specifically nitrogen.

[0022] In the above scheme, nitrogen is relatively easy to produce. As the filler in the front cavity, it also has the characteristics of high stability and is not easy to react when it comes into contact with external dangerous gases through the explosion-proof gap, thereby ensuring safety and stability in use.

[0023] Preferably, the length of the inclined block is a, the width of the rear cavity is b, the width of the fixing ring is c, and a=b=c.

[0024] In the above scheme, the width of the rear cavity is consistent with the size of the inclined block and the fixed ring. When the inclined block moves, it cooperates with the limiting effect of the fixed ring to directly convert the movement of the inclined block into extrusion of the rear cavity, making the extrusion force of the rear cavity from all sides more uniform.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. The present invention provides a front cavity and a small groove. When the temperature inside the box rises, the internal gas expands due to the temperature increase, and the pressure increases. The high-temperature gas expands and squeezes the front cavity, so that the clean gas in the front cavity is squeezed and quickly discharged to the outside of the box through the small groove and the explosion-proof gap. The operation of the electrical group will generate a large amount of heat energy. Whenever the temperature inside the box rises, the clean gas in the front cavity will shuttle in the explosion-proof gap, unblocking the explosion-proof gap, avoiding metal adhesion between the box and the box cover after long-term use, changing the structure of the explosion-proof gap, and avoiding affecting the explosion-proof efficiency of the explosion-proof gap.

[0027] 2. In the present invention, the rear chamber is provided to separate the dangerous gas entering the box through the explosion-proof gap from the electrical group to avoid contact between the two. Even if the electrical group generates high temperature or a short circuit occurs due to operation, it is not easy to explode inside the box, thereby ensuring the operating stability of the electrical group and reducing the possibility of explosion inside the box.

[0028] 3. In the present invention, when the temperature inside the box rises, it proves that there is an explosion risk. By arranging a slide plate and a friction plate, whenever the temperature inside the box rises, the slide plate will drive the friction plate to move together, so that the rough surface of the friction plate contacts the outer wall of the flange bolt, and the slide plate tilts and moves according to a specified moving path, so that the friction plate provides an external force in a tightening direction to the flange bolt when contacting the outer wall of the flange bolt, thereby tightening the flange bolt to prevent the flange bolt from loosening in an impending explosion, and to prevent the loosening of the flange bolt from affecting the structure of the explosion-proof gap, thereby ensuring the explosion-proof function of the explosion-proof gap. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the structure of the present invention;

[0030] Figure 2 It is a schematic diagram of the internal structure of the present invention;

[0031] Figure 3 It is a schematic diagram of the side cross-sectional structure of the present invention;

[0032] Figure 4 This is a schematic diagram of the cross-sectional structure of the isolation chamber of the present invention;

[0033] Figure 5 This is a schematic diagram of the motion state of the docking interface of the present invention;

[0034] Figure 6 This is a schematic diagram of the motion state of the docking interface of the present invention;

[0035] Figure 7 This is a schematic diagram of the position structure of the slide plate and the friction plate of the present invention;

[0036] Figure 8 For the present invention Figure 7 Enlarged schematic diagram of part A in the middle.

[0037] Fig. 9 It is a schematic diagram of the motion state of the inclined block and the rear cavity of the present invention.

[0038] Fig.10 It is a schematic diagram of the motion state of the inclined block and the rear cavity of the present invention.

[0039] In the figure: 1. box body; 2. box cover; 3. explosion-proof gap; 4. flange bolt; 5. wiring port; 6. knob group; 7. electrical group; 8. isolation chamber; 9. rubber membrane; 10. injection port; 11. docking port; 12. small groove; 13. first connecting pipe; 14. front cavity; 15. memory alloy; 16. large groove; 17. second connecting pipe; 18. rear cavity; 19. oblique block; 20. fixing ring; 21. air pipe; 22. piston cylinder; 23. piston rod; 24. slide plate; 25. oblique groove; 26. guide block; 27. friction plate; 28. transition spring. DETAILED DESCRIPTION

[0040] 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.

[0041] Please refer to Figure 1 to Figure 2. The present invention provides a low-voltage DC explosion-proof distribution box, and the technical solution is as follows:

[0042] As an embodiment of the present invention, reference Figures 1 to 5A low-voltage DC explosion-proof distribution box includes a box body 1, a box cover 2 and an explosion-proof gap 3, and also includes a flange bolt 4, a wiring port 5 and a knob group 6. The box cover 2 is arranged on the surface of the box body 1, and the explosion-proof gap 3 is arranged between the box cover 2 and the box body 1. A plurality of electrical groups 7 are arranged on the inner wall of the box cover 2. An isolation chamber 8 is fixedly installed on the inner wall of the box cover 2. The isolation chamber 8 is rectangular and arranged on the inner wall of the box cover 2, and there is a certain distance between the surface and the electrical group 7. A rubber membrane 9 and an injection port 10 are arranged on the surface of the isolation chamber 8. The isolation chamber 8 and the rubber membrane 9 can be slightly deformed as a whole and are made of silicone rubber material. The thickness of the rubber membrane 9 is less than the overall thickness of the isolation chamber 8. The silicone rubber material provides mechanical strength for the isolation chamber 8 while ensuring that the isolation chamber 8 can withstand the long-term damage of the electrical group 7 inside the box body 1. Due to the high temperature generated by the working environment, the surface of the isolation chamber 8 is not designed to be smooth. Instead, a part of the largest contact surface with the box body 1 is dug out to form a rubber membrane 9. Since the thickness of the rubber membrane 9 is less than the overall thickness of the isolation chamber 8, it is more likely to deform. When the gas temperature inside the box body 1 increases, the gas pressure will increase. The gas pressure directly acts on the surface of the rubber membrane 9, causing the rubber membrane 9 to deform under the action of pressure and sink into the front cavity 14, thereby transmitting the air pressure change inside the box body 1 to the front cavity 14 and squeezing the gas in the front cavity 14. A docking port 11 is slidably installed on the inner wall of the box cover 2. The docking port 11 is rectangular in shape, and the surface is completely in contact with the box body 1 and the box cover 2. Because the explosion-proof gap 3 is set at the junction of the box body 1 and the box cover 2, if you want to use the docking port 11 to In order to be connected with the isolation chamber 8, it is necessary to make the docking port 11 contact with the explosion-proof gap 3 on each side, so the docking port 11 is set to a rectangular frame with the same shape as the inner part of the box cover 2, so that it can be ensured that the docking port 11 can be docked with the entire explosion-proof gap 3 after moving, and a small groove 12 is opened on the surface of the docking port 11, and the small groove 12 runs through the entire outer wall of the docking port 11. After the docking port 11 is moved, the small groove 12 completely wraps the explosion-proof gap 3 to ensure the uniform transmission of gas between the explosion-proof gap 3 and the explosion-proof gap 3. A plurality of first connecting pipes 13 are arranged on the surface of the docking port 11, and a front cavity 14 is arranged inside the isolation chamber 8. The front cavity 14 is filled with clean gas. The clean gas filled in the front cavity 14 is an inert gas, specifically nitrogen. The clean gas circulates in the explosion-proof gap 3 and passes through a long After working for a period of time, the fluidity of the explosion-proof gap 3 can be guaranteed. Nitrogen, which is an inert gas, is selected as the filler of the front chamber 14, because nitrogen is relatively easy to prepare and convenient to use. The clean gas can be filled into the front chamber 14 through the injection port 10, and the chemical property is stable. When flowing to the outside through the explosion-proof gap 3, the dangerous gas diffused around the explosion-proof gap 3 is pushed away. Even if an explosion occurs inside the box 1, the high-temperature gas generated by the explosion will not be exposed to the high-concentration dangerous gas for the first time when the pressure is relieved through the explosion-proof gap 3. Nitrogen is not easy to react with dangerous gases. It is safer and more stable to use nitrogen to push away the dangerous gas. The front chamber 14 is connected to the small groove 12 through the first connecting pipe 13. The front chamber 14 is in contact with the rubber membrane 9, and the inner side of the rubber membrane 9 is completely in contact with the inside of the front chamber 14.The uniform deformation of the surface can be converted into a stable extrusion of the interior of the front cavity 14. A memory alloy 15 is arranged between the box cover 2 and the docking interface 11. The memory alloy 15 is twisted into a spring shape by plastic means, one end of which is fixed to the inner wall of the box cover 2, and the other end is connected to the docking interface 11. When the memory alloy 15 contacts the high temperature generated inside the box body 1, it recovers to its original shape due to its own shape memory characteristics. During the recovery process, it will pull the docking interface 11 to move. The elastic force between the memory alloy 15 and the docking interface 11 is α, and α>β. The surface of the docking interface 11 is subjected to The friction force is β, the surface of the docking interface 11 will be completely in contact with the inner wall of the box body 1 or the box cover 2, and the size of the contact surface is constant, and the friction force on the surface is also constant. It is only necessary to set the elastic force of the docking interface 11 when the memory alloy 15 is restored to be greater than the friction force on the surface of the docking interface 11, so that the memory alloy 15 can drive the docking interface 11 to move when it is deformed, and the connection between the explosion-proof gap 3 and the small groove 12 is controlled by the deformation of the memory alloy 15 when it is heated, and the clean gas in the front cavity 14 is discharged from the explosion-proof gap 3 to ensure the flowability of the explosion-proof gap 3.

[0043] As an embodiment of the present invention, reference Figure 4 and Figure 6 A large groove 16 is provided on the surface of the docking port 11, and a plurality of second connecting pipes 17 are provided on the surface of the docking port 11. A rear cavity 18 is provided in the isolation chamber 8, and the rear cavity 18 is connected to the large groove 16 through the second connecting pipe 17. A large groove 16 is provided next to the small groove 12. When the docking port 11 does not move, the large groove 16 always maintains communication with the explosion-proof gap 3, and the dangerous gas outside the box body 1 will directly enter the rear cavity 18 through the large groove 16. If the large groove 16 and the rear cavity 18 are not provided, due to the existence of the explosion-proof gap 3, the dangerous gas outside the box body 1 will enter the inside of the box body 1 through the explosion-proof gap 3 and directly contact with the running electrical group 7. When the electrical group 7 is in high-load operation, the high temperature generated on the surface makes the dangerous gas more likely to explode. Therefore, a large groove 16 is provided to guide the dangerous gas entering the box body 1 through the explosion-proof gap 3 to the rear cavity 18, and separate it from the electrical group 7, thereby ensuring the stability of the operation of the electrical group 7 and reducing the possibility of explosion inside the box body 1.

[0044] As an embodiment of the present invention, reference Figures 7 to 10, inclined blocks 19 are slidably installed around the inner wall of the box cover 2, and the side of the inclined block 19 close to the docking port 11 is set as an inclined surface. When the docking port 11 moves to squeeze the inclined block 19, the inclined block 19 squeezes the rear cavity 18 part of the isolation chamber 8. The inclined block 19 is set in the middle position close to each side of the isolation chamber 8. When the surface of the isolation chamber 8 is squeezed, it is ensured that each surface of the isolation chamber 8 is subjected to uniform linear extrusion. A fixing ring 20 is fixedly installed on the inside of the isolation chamber 8. The length of the inclined block 19 is a, the width of the rear cavity 18 is b, the width of the fixing ring 20 is c, and a=b=c. The fixing ring 20 is set on one side of the inner wall of the isolation chamber 8. Through the limit of the fixing ring 20, When the isolation chamber 8 is squeezed by the inclined block 19, one side of the inner wall cannot move, and the squeezing force of the inclined block 19 on the isolation chamber 8 is completely converted into deformation of one side of the outer wall of the isolation chamber 8. The gas in the rear chamber 18 is efficiently transmitted by concentrated squeezing. Four groups of air pipes 21 and piston cylinders 22 are arranged on the surface of the box cover 2. The air pipes 21 penetrate the box cover 2 and are connected to the surface of the isolation chamber 8. The piston cylinder 22 is connected to the rear chamber 18 through the air pipes 21. A piston rod 23 is sleeved inside the piston cylinder 22. A slide plate 24 is sleeved on one end of each piston rod 23 close to the box cover 2. Each slide plate 24 corresponds to and is close to the flange bolt 4 on one side of the box cover 2. Both ends of the slide plate 24 are provided with inclined grooves 25, a guide block 26 is fixedly installed on the surface of the box cover 2 near the inclined groove 25, the surface of the guide block 26 contacts the inner wall of the inclined groove 25, and the cross-sectional diameter of the guide block 26 is equal to the width of the inclined groove 25, and a friction plate 27 is slidably installed on the surface of the slide plate 24, the friction plate 27 is parallel to the slide plate 24, and the bottom is in contact with the surface of the box cover 2, and the side of the friction plate 27 close to the flange bolt 4 is set as a rough surface, and the moving path of the slide plate 24 is limited by the guide block 26 and the inclined groove 25. When the slide plate 24 moves, the mutual extrusion between the guide block 26 and the inclined groove 25 will push the slide plate 24 to move in the direction of the inclined groove 25, so that the slide plate 24 can The plate 27 applies a vertical thrust and a horizontal thrust at the same time. After the slide plate 24 moves, the vertical thrust makes the rough surface of the friction plate 27 contact with the surface of the flange bolt 4. When the rough surface of the friction plate 27 contacts with the surface of the flange bolt 4, the horizontal thrust of the slide plate 24 on the friction plate 27 makes the friction plate 27 have a movement trend in the tightening direction of the flange bolt 4, and applies a horizontal thrust in the tangential direction of the outer wall of the flange bolt 4. The flange bolt 4 is tightened by the friction between the plate 24 and the flange bolt 4, so as to avoid the flange bolt 4 from loosening due to the violent impact force when an explosion occurs inside the box 1, and to avoid the size of the explosion-proof gap 3 from being changed, so as to ensure the explosion-proof efficiency of the explosion-proof gap 3. A transition spring 28 is arranged between the friction plate 27 and the slide plate 24. The transition spring 28 makes the friction plate 27 in a semi-fixed state on the surface of the slide plate 24. The elastic force of the transition spring 28 is combined with the horizontal thrust of the friction plate 27 on the flange bolt 4, so that the friction plate 27 maintains a movement trend in the tangential direction of the outer wall of the flange bolt 4. Even if no actual movement occurs, the flange bolt 4 can be tightened by applying a horizontal thrust.

[0045] Working principle: When the box 1 is working normally, the large groove 16 on the surface of the interface 11 is connected to the explosion-proof gap 3. Figure 3 As described above, the dangerous gas outside the box body 1 that permeates around the explosion-proof gap 3 can pass through the explosion-proof gap 3 and enter the rear cavity 18 through the large groove 16 for isolation. Through the setting of the rear cavity 18, the dangerous gas that originally enters the box body 1 and directly contacts the electrical group 7 is separated from the electrical group 7. Even if the electrical group 7 generates high temperature or a short circuit during operation, it is not easy to explode, thereby reducing the possibility of explosion inside the box body 1 and ensuring the safe operation of the equipment.

[0046] Because the operating power and current intensity of the electrical group 7 will change according to the actual working conditions, the large amount of high temperature generated by the electrical group 7 under long-term high-power operation is likely to cause combustion and explosion inside the box 1. Whenever the temperature inside the box 1 rises, it is necessary to connect the internal environment of the box 1 with the explosion-proof gap 3 in advance to ensure that the explosion-proof gap 3 can play a flameproof role when an explosion occurs inside the box 1. When the temperature inside the box 1 rises, the heat will be transferred to the memory alloy 15, so that the surface temperature of the memory alloy 15 will rise. After heating, the memory alloy 15 will restore its shape and shrink. The shrinking memory alloy 15 drives the docking interface 11 to move, such as Figure 5 As shown, until the small groove 12 on the surface of the docking interface 11 completely covers the explosion-proof gap 3, so that the explosion-proof gap 3 and the small groove 12 are connected. At the same time, the gas in the internal environment of the box body 1 expands under the principle of thermal expansion and contraction. Since the internal volume of the box body 1 remains unchanged, the pressure of the gas increases when it expands. The increased gas pressure acts on the surface of the rubber membrane 9, squeezing the rubber membrane 9 to deform concavely toward the inside of the front cavity 14. The concave rubber membrane 9 squeezes the clean gas in the front cavity 14. When the small groove 12 and the explosion-proof gap 3 are connected, the clean gas quickly flows from the front cavity 14 to the explosion-proof gap 3 through the first connecting pipe 13 and the small groove 12 under the squeezing force of the rubber membrane 9, and is discharged to the outside of the box body 1 after passing through the explosion-proof gap 3. As long as the operation of the electrical group 7 causes the internal temperature of the box body 1 to rise, the gas in the front chamber 14 will quickly flow out through the explosion-proof gap 3, and the fluidity of the explosion-proof gap 3 is ensured by the clean gas shuttling through the explosion-proof gap 3, thereby avoiding the metal adhesion phenomenon around the explosion-proof gap 3 after the box body 1 has been working for a long time, and maintaining the explosion-proof efficiency of the explosion-proof gap 3. Moreover, when the clean gas in the front chamber 14 is discharged, it will instantly push the dangerous gas diffused around the explosion-proof gap 3, forming a buffer zone between the explosion-proof gap 3 and the external environment. Even if an explosion occurs inside the box body 1, when the pressure is relieved through the explosion-proof gap 3, the high-temperature and high-pressure gas generated by the explosion will not contact the external dangerous gas for the first time, thereby improving the explosion-proof efficiency of the explosion-proof gap 3.

[0047] When the docking port 11 continues to move so that the small groove 12 is away from the explosion-proof gap 3, as shown in FIG. Figure 6As shown, at this time, the small groove 12 and the large groove 16 are blocked by the box cover 2, closing the gas passages in the front chamber 14 and the rear chamber 18, and the explosion-proof gap 3 is directly connected to the inside of the box body 1. At this time, if the high temperature or short circuit of the electrical group 7 inside the box body 1 causes an explosion, the box body 1 will directly relieve pressure and explosion-proof through the explosion-proof gap 3. Moreover, the docking port 11 will contact the inclined block 19 during the movement, squeezing the inclined surface of the inclined block 19. After being squeezed, the inclined block 19 will move toward the isolation chamber 8. When the fixed ring 20 limits one side of the isolation chamber 8, the inclined block 19 squeezes the surface of the isolation chamber 8 to cause the rear chamber 18 to shrink and deform, as shown in FIG. Fig. 9 and Fig.10 As shown, the gas in the squeezed rear chamber 18 enters the piston cylinder 22 through the air pipe 21, and pushes the piston rod 23 to move under the action of the gas pressure. After the piston rod 23 moves, the slide plate 24 moves. Since the surface of the slide plate 24 is provided with an inclined groove 25, as shown in FIG. Figure 8 As shown, the inclined groove 25 contacts the guide block 26 on the surface of the box cover 2. When the slide plate 24 moves, the inclined groove 25 and the guide block 26 limit the moving path of the slide plate 24, and the slide plate 24 moves in the inclined direction of the inclined groove 25. During the movement, the slide plate 24 drives the friction plate 27 to move in the direction of the flange bolt 4, and at the same time applies a vertical force and a horizontal thrust to the friction plate 27. The vertical force makes the rough surface of the friction plate 27 close to the outer wall of the flange bolt 4, and the horizontal thrust makes the rough surface contact the outer wall of the flange bolt 4 so that the flange bolt 4 has a movement tendency to rotate in the tightening direction. The flange bolt 4 is tightened by the horizontal thrust, so as to avoid the flange bolt 4 from loosening and affecting the size of the explosion-proof gap 3 when an explosion occurs inside the box body 1, thereby ensuring the explosion-proof efficiency of the explosion-proof gap 3.

[0048] 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 low voltage DC explosion-proof distribution box, comprising a box body (1), a box cover (2) and an explosion-proof gap (3), characterized in that: The box cover (2) is provided on the surface of the box body (1), the explosion-proof gap (3) is provided between the box cover (2) and the box body (1), a plurality of electrical groups (7) are provided on the inner wall of the box cover (2), an isolation chamber (8) is fixedly installed on the inner wall of the box cover (2), a rubber membrane (9) and an injection port (10) are provided on the surface of the isolation chamber (8), a docking port (11) is slidably installed on the inner wall of the box cover (2), a small groove (12) is provided on the surface of the docking port (11), and a A plurality of first connecting pipes (13) are arranged, a front chamber (14) is arranged inside the isolation chamber (8), the front chamber (14) is filled with clean gas, the front chamber (14) is connected with the small groove (12) through the first connecting pipe (13), the front chamber (14) is in contact with the rubber membrane (9), a memory alloy (15) is arranged between the box cover (2) and the docking port (11), the memory alloy (15) is deformed when heated to control the connection between the explosion-proof gap (3) and the small groove (12), and the clean gas in the front chamber (14) is discharged from the explosion-proof gap (3) to ensure the fluidity of the explosion-proof gap (3).

2. A low voltage DC explosion-proof distribution box according to claim 1, characterized in that: A large groove (16) is provided on the surface of the docking port (11), a plurality of second connecting pipes (17) are provided on the surface of the docking port (11), a rear cavity (18) is provided in the isolation chamber (8), and the rear cavity (18) is connected to the large groove (16) through the second connecting pipe (17).

3. A low voltage DC explosion-proof distribution box according to claim 1, characterized in that: The inner wall of the box cover (2) is slidably mounted with inclined blocks (19) all around, and the side of the inclined block (19) close to the docking port (11) is set as an inclined surface. A fixing ring (20) is fixedly mounted on the inner side of the isolation chamber (8). Four groups of air pipes (21) and piston cylinders (22) are arranged on the surface of the box cover (2). The air pipes (21) penetrate the box cover (2) and are connected to the surface of the isolation chamber (8). The piston cylinder (22) is connected to the rear cavity (18) through the air pipes (21). A piston rod (23) is sleeved inside the piston cylinder (22). A slide plate (24) is sleeved on one end of each piston rod (23) close to the box cover (2). Each slide plate (24) is sleeved on the inner side of the piston cylinder (22). The plates (24) respectively correspond to and are close to the flange bolts (4) on one side of the box cover (2). Both ends of the slide plate (24) are provided with oblique grooves (25). A guide block (26) is fixedly installed on the surface of the box cover (2) close to the oblique groove (25). The surface of the guide block (26) contacts the inner wall of the oblique groove (25), and the cross-sectional diameter of the guide block (26) is equal to the width of the oblique groove (25). A friction plate (27) is slidably installed on the surface of the slide plate (24). The side of the friction plate (27) close to the flange bolt (4) is set as a rough surface, and a transition spring (28) is arranged between the friction plate (27) and the slide plate (24).

4. A low voltage DC explosion-proof distribution box according to claim 1, characterized in that: The docking port (11) is arranged in a rectangular shape, and its surface is completely in contact with the box body (1) and the box cover (2).

5. A low voltage DC explosion-proof distribution box according to claim 1, characterized in that: The magnitude of the elastic force between the memory alloy (15) and the docking interface (11) is α, the magnitude of the friction force on the surface of the docking interface (11) is β, and α>β.

6. A low voltage DC explosion-proof distribution box according to claim 1, characterized in that: The isolation chamber (8) and the rubber membrane (9) are slightly deformable as a whole and are made of silicone rubber material, and the thickness of the rubber membrane (9) is smaller than the overall thickness of the isolation chamber (8).

7. A low voltage DC explosion-proof distribution box according to claim 1, characterized in that: The isolation chamber (8) is arranged in a rectangular shape on the inner wall of the box cover (2), and there is a certain distance between the surface and the electrical equipment group (7).

8. A low voltage DC explosion-proof distribution box according to claim 1, characterized in that: The cleaning gas filled in the front chamber (14) is an inert gas, specifically nitrogen.

9. A low voltage DC explosion-proof distribution box according to claim 3, characterized in that: The friction plate (27) is kept parallel to the slide plate (24), and the bottoms of the friction plates (27) are in contact with the surface of the box cover (2).

10. A low voltage DC explosion-proof distribution box according to claim 3, characterized in that: The length of the inclined block (19) is a, the width of the rear cavity (18) is b, the width of the fixing ring (20) is c, and a=b=c.

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