Miniature distribution box for extension power supply point of low-voltage overhead line

Abstract

The invention discloses a small distribution box for a low-voltage overhead line extension power supply point, and relates to the technical field of electric power auxiliary tools, the small distribution box comprises a connection box and a distribution box, the connection box is internally provided with a wiring terminal, a first wire inlet and a first wire outlet, the first wire inlet is connected with a busbar, the busbar is connected with an overhead low-voltage line through a parallel groove clamp, and the first wire outlet is connected with a second wire outlet. The first wire outlet is connected with a cable, the distribution box is connected with the connection box through the cable, a second wire inlet, a wire inlet switch, a second wire outlet and a wire outlet switch are arranged in the distribution box, the cable is connected with the distribution box through the second wire inlet, and the second wire outlet is provided with a load wire connected with a load. According to the device, the connecting box is installed on the low-voltage tower, the connecting box and the distribution box are connected through the cable necklace, the other end of the connecting box is connected with the low-voltage wire through the busbar, when a new load line is connected in the later period, fire can be directly connected from the distribution box, and the line does not need to be led again from a low-voltage overhead line; when a fault occurs, maintenance can be performed at a low position, and the number of times of pole climbing operation is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of electric power auxiliary tools, and particularly relates to a small distribution box for an extended power supply point of a low-voltage overhead line. Background Art

[0002] In the power distribution system, as a crucial support structure for power lines, there are often multiple meter box down-leads on one pole tower. With the accelerating urbanization process and the increasing power demand, the number of meter boxes on a single pole tower is continuously increasing, and the connection lines between the meter box incoming cables and the low-voltage conductors become extremely complex and dense, making the lines at the connection points rather chaotic. In addition, since the meter box incoming cables are exposed to the natural environment for a long time and are affected by harsh conditions such as wind, sun, rain, and snow pressure, over time, the cable sheaths gradually become severely aged and even cracked, and the metal conductors inside the cables are easily exposed, posing a short-circuit risk.

[0003] In the power system, it is often necessary to connect new loads. Whenever a new load needs to be connected, workers are required to climb the pole and lay new down-leads along the pole tower. However, there are significant safety hazards during pole climbing operations. Workers need to perform delicate operations in a high-altitude environment, and any carelessness may lead to safety accidents such as falling. Especially on pole towers with complex lines and narrow spaces, the difficulty and risk of pole climbing operations increase exponentially.

[0004] In summary, the current layout method of the meter box down-leads on the pole tower has many drawbacks, which not only affect the safe and stable operation of the power system but also pose great safety hazards to the operation and maintenance personnel. Therefore, to solve the above problems, it is necessary to design a small distribution box for an extended power supply point of a low-voltage overhead line to measure and judge the deformation amount of the expansion joint. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to address the deficiencies in the prior art and design a small distribution box for extending the power supply point of a low-voltage overhead line. This small distribution box for extending the power supply point of a low-voltage overhead line has a simple structure, including a connection box and a distribution box. The connection box serves as an intermediate node, connecting the low-voltage overhead line and the distribution box, transmitting the electricity on the low-voltage overhead line to the distribution box, and then transmitting it to the load through the distribution box to complete the power supply to the load. Specifically, during installation, the connection box is installed on the low-voltage pole. The connection box and the distribution box are connected by a cable. The other end of the connection box is connected to the low-voltage conductor through a busbar. When a new load line is connected later, it can be directly connected to the fire inside the distribution box without leading a wire from the low-voltage overhead line again; when a fault occurs, it can be repaired at a low place, reducing the number of pole climbing operations and lowering the safety risk of the staff's work, solving the problem that the layout method of the lead wire from the meter box on the current pole has many drawbacks, which not only affects the safe and stable operation of the power system but also brings great potential safety hazards to the operation and maintenance personnel.

[0006] The solution adopted by the present invention to solve its technical problem is as follows:

[0007] A small distribution box for extending the power supply point of a low-voltage overhead line,

[0008] characterized in that,

[0009] it includes a connection box and a distribution box,

[0010] The connection box is provided with a terminal block, a first inlet and a first outlet,

[0011] The terminal block connects the first inlet and the first outlet,

[0012] The first inlet is connected with a busbar, and the busbar is connected to the overhead low-voltage line through a parallel groove clamp,

[0013] The first outlet is connected with a cable, and the end of the cable extends into the connection box to connect the first outlet,

[0014] The distribution box is connected to the connection box through a cable,

[0015] The distribution box is provided with a second inlet, an inlet switch, a second outlet and an outlet switch,

[0016] The cable is connected to the distribution box through the second inlet,

[0017] The inlet switch is used to control the on-off of the cable and the distribution box,

[0018] The second outlet is provided with a load line connecting to the load,

[0019] The outlet switch is used to control the on-off of the load line and the distribution box.

[0020] As a preferred embodiment of the present invention,

[0021] The parallel groove clamp includes a fixing plate, an adjusting rod and an adjusting plate,

[0022] The fixing plate is provided with a first fixing hole,

[0023] The adjusting rod is welded to the side of the fixing plate through the fixing hole,

[0024] External threads are provided on the outer side of the adjusting rod,

[0025] The adjusting plate is sleeved on the side of the adjusting rod,

[0026] The adjusting plate and the fixing plate are arranged in parallel, and the overhead low-voltage line is fixed between the adjusting plate and the fixing plate.

[0027] A first nut is provided at the free end of the adjusting plate,

[0028] A wiring board is welded to the side of the fixing plate,

[0029] The wiring board is provided with a connection hole,

[0030] The busbar is fixed to the side of the connection board through the connection hole and a second bolt.

[0031] As a preferred embodiment of the present invention,

[0032] One side of the busbar connected to the first inlet is connected with an inlet board, and the angle between the inlet board and the busbar is an acute angle.

[0033] As a preferred embodiment of the present invention,

[0034] The fixing plate is provided with a second fixing hole, a reinforcing rod is welded to the second reinforcing hole, the reinforcing rod and the adjusting rod are arranged in parallel, and a second nut is provided at the free end of the reinforcing rod.

[0035] As a preferred embodiment of the present invention,

[0036] A cover plate corresponding to the first inlet is provided on the side of the connection box.

[0037] As a preferred embodiment of the present invention,

[0038] First wire nose is provided at both ends of the cable, and the cable is connected to the distribution box and the connection box through the first wire nose.

[0039] As a preferred embodiment of the present invention,

[0040] One end of the cable is provided with a cable lug for connection to a connection box, and the second inlet is provided with a terminal clamp for connection to the cable.

[0041] As a preferred embodiment of the present invention,

[0042] One end of the busbar connected to the first inlet is provided with a prefabricated hole, the first inlet is provided with a first bolt, and the bolt passes through the prefabricated hole.

[0043] As a preferred embodiment of the present invention,

[0044] The busbar is cylindrical.

[0045] As a preferred embodiment of the present invention,

[0046] The busbar is made of a copper bar.

[0047] Compared with the prior art, the present invention has the following beneficial effects:

[0048] 1. The device of the present invention provides a small distribution box for extending the power supply point of a low-voltage overhead line. Its structure is simple, including a connection box and a distribution box. The connection box serves as an intermediate node, connecting the low-voltage overhead line and the distribution box, transmitting the electricity on the low-voltage overhead line to the distribution box, and then transmitting it to the load through the distribution box to complete the power supply to the load.

[0049] The connection box is installed on the low-voltage pole tower. The connection box is connected to the distribution box through a cable. The other end of the connection box is connected to the low-voltage conductor through a busbar and a parallel groove clamp. When a new load needs to be added after long-term use, the new load line can be directly connected to the power source inside the distribution box when accessing, without leading a wire from the low-voltage overhead line again; when a fault occurs, it can be repaired at a low place, reducing the number of pole climbing operations and reducing the safety risk of the staff.

[0050] 2. A water bay is formed between the inlet board and the busbar. In rainy and snowy weather, water cannot flow along the inlet board into the connection box, preventing rainwater from entering the connection box, reducing the failure rate caused by rainwater intrusion and the frequent maintenance and repair work of the operation and maintenance personnel due to dealing with rainwater intrusion failures, reducing the operation and maintenance cost, and improving the overall operation efficiency of the power system.

[0051] 3. The busbar is cylindrical, and it is difficult for rainwater to stagnate or accumulate on the surface, avoiding the retention of rainwater at the corners to form a water film or penetration channel.

[0052] 4. The first outlet is arranged inside the connection box, and the end of the cable is placed inside the connection box to prevent the cable from aging later.

[0053] 5. A cover plate is arranged on the side of the connection box to cover the end of the busbar, protecting the end of the busbar and improving the rainproof performance of the device of the present invention. Description of the Drawings

[0054] Figure 1 Schematic diagram of a small distribution box for the extended power supply point of a low - voltage overhead line proposed by the present invention;

[0055] Figure 2 Schematic diagram of a parallel groove clamp of a small distribution box for the extended power supply point of a low - voltage overhead line proposed by the present invention;

[0056] Figure 3 Schematic diagram of a parallel groove clamp of a small distribution box for the extended power supply point of a low - voltage overhead line proposed by the present invention.

[0057] Description of the reference numerals:

[0058] 1. Connection box,

[0059] 1 - 1. Cover plate,

[0060] 2. Distribution box,

[0061] 2 - 1. Second inlet,

[0062] 2 - 2. Inlet switch,

[0063] 2 - 3. Second outlet,

[0064] 2 - 4. Outlet switch,

[0065] 3. Busbar,

[0066] 3 - 1. Inlet board,

[0067] 3 - 2. Second bolt,

[0068] 4. Parallel groove clamp,

[0069] 4 - 1. Fixed plate,

[0070] 4 - 2. Adjusting rod,

[0071] 4 - 3. Adjusting plate,

[0072] 4 - 4. First nut,

[0073] 4 - 5. Wiring board,

[0074] 4 - 6. Reinforcing rod,

[0075] 4 - 7. Second nut,

[0076] 5. Low - voltage overhead line,

[0077] 6. Cable. Detailed implementation manners

[0078] The specific embodiments of the present invention will be described below in conjunction with the accompanying drawings and embodiments:

[0079] It should be noted that the structures, colors, ratios, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those familiar with this technology to understand and read, and are not used to limit the limiting conditions under which the present invention can be implemented. Any modification of the structure, change in the proportional relationship, or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope covered by the technical content disclosed in the present invention.

[0080] At the same time, in the description of the present invention, it should be understood that the orientation or positional relationships indicated by terms such as "one end", "the other end", "the middle part", "above", "one side", "the top", "inside", "the front part", "the center", "both ends", etc. are based on the orientation or positional relationships shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention.

[0081] In addition, the terms "first", "second", "third", "fourth" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first", "second", "third", "fourth" may explicitly or implicitly include at least one of such features.

[0082] In the present invention, unless otherwise clearly specified and limited, terms such as "installation", "setting", "connection", "fixation", "swivel connection", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or directly designed as an integral body; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. It can be the communication inside two elements or the interaction relationship between two elements. Unless otherwise clearly limited, for those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0083] As Figures 1-3 shown, the present invention proposes a small distribution box for the extended power supply point of a low-voltage overhead line, which includes a connection box 1 and a distribution box 2. The connection box 1 serves as an intermediate node, and its structure is similar to the existing distribution box structures on the market. It only needs to complete the power transmission, and existing devices on the market can be directly selected during production. The distribution box serves as the power supply for the load. The low-voltage overhead line and the distribution box 2 are connected through the connection box, and the electric energy on the low-voltage overhead line is transmitted to the distribution box 2, and then transmitted to the corresponding load through the distribution box 2 to complete the power supply for the load.

[0084] The core design point of the device of the present invention is to design a small distribution box as an intermediate connection point to connect the low-voltage high-altitude conductor and the distribution box 2. A connection box 1 with a structure similar to the internal circuit structure of the distribution box 2 is installed on the low-voltage pole. The connection box 1 and the distribution box 2 are connected by a cable 6. The other end of the connection box 1 is connected to the low-voltage conductor through a busbar 3. The busbar 3 adopts an advanced process, is not easy to age, and has a long service life.

[0085] With the development of society, when new loads need to be added, the new load line can be directly connected to the power supply from the inside of the distribution box 2 when accessing the circuit, without leading a wire from the low-voltage overhead line again. And the rear-end load line often fails due to long-term use, improper use or the influence of the external natural environment. When a failure occurs, maintenance is required. When using the device of the present invention, maintenance can be carried out at a low place, reducing the number of pole climbing operations, thereby reducing the safety risk of the staff's work, reducing the cost generated by pole climbing operations, and shortening the working time of the traditional meter box installation operation.

[0086] The connection box 1 is provided with a terminal block, a first inlet and a first outlet. A set of inlet and outlet ports are arranged in the connection box 1, corresponding to connecting the low-voltage high-altitude conductor and the distribution box 2. The terminal block connects the first inlet and the first outlet, and the first inlet and the first outlet are connected through the terminal block. The first inlet is connected with a busbar 3. The busbar 3 is connected to the overhead low-voltage line 5 through a parallel groove clamp 4. The first outlet is connected with a cable 6, ensuring that the current of the low-voltage high-altitude line is transmitted to the cable 6 connected to the first outlet through the busbar 3 and the terminal block. The end of the cable 6 extends into the connection box 1 to connect the first outlet. The distribution box 2 is connected to the connection box 1 through the cable 6, and the current received by the connection box 1 from the low-voltage overhead line is transmitted to the distribution box 2 through the cable 6.

[0087] The first outlet is arranged in the connection box 1. If the cable 6 wants to connect to the first outlet, it needs to extend into the inside of the connection box 1 and then connect to the first outlet. The end of the cable 6 is placed inside the connection box 1 to prevent the cable 6 from aging later.

[0088] Preferably, an insulating layer is provided on the surface of the busbar 3 to ensure the insulation performance of the busbar 3 and protect the safety of the staff during the work process.

[0089] The insulating layer can adopt insulating materials with high thermal conductivity and high voltage resistance, such as epoxy resin, silicone rubber or ceramic coating, etc. Electrical isolation is provided through the insulating layer to prevent the busbar 3 from directly contacting the surrounding conductors or metal enclosures, ensuring the insulation performance of the busbar 3.

[0090] Furthermore, a hydrophobic layer is provided on the outer side of the insulating layer, which can be made of fluoropolymer (such as PTFE), silicone resin or nano-hydrophobic coating, etc. Specifically, the surface tension of the busbar 3 is reduced through the microscopic rough structure, enabling water droplets to roll off quickly, reducing the residence time of moisture on the surface of the busbar 3, avoiding electrochemical corrosion, and improving the waterproof performance of the busbar 3.

[0091] An insulating layer and a hydrophobic layer are provided on the surface layer of the busbar 3. The insulating layer isolates the current, and the hydrophobic layer prevents moisture penetration from causing insulation failure, while ensuring the insulation performance and waterproof performance of the busbar 2, significantly reducing the short-circuit risk of the busbar 3.

[0092] The distribution box 2 is provided with a second inlet 2-1, an inlet switch 2-2, a second outlet 2-3 and an outlet switch 2-4. The inlet switch 2-2 corresponds to the second inlet 2-1, and the outlet switch 2-4 corresponds to the second outlet 2-3, respectively controlling the on-off of the power input and output ends of the distribution box 2, providing a prerequisite for power-off maintenance of the distribution box 2 and the load end.

[0093] The cable 6 is connected to the distribution box 2 through the second inlet 2-1 to complete the connection between the connection box 1 and the distribution box 2. The inlet switch 2-2 is used to control the on-off of the cable 6 and the distribution box 2, controlling the power input of the distribution box 2. The second outlet 2-3 is provided with a load line connecting to the load to supply power to the rear-end load, and the outlet switch 2-4 is used to control the on-off of the load line and the distribution box 2, controlling the power output of the distribution box 2.

[0094] By providing a set of inlet and outlet ports and their corresponding switches inside the distribution line, corresponding to the connection box 1 and the load, the power supply to the rear-end load is completed.

[0095] The first inlet, the second inlet, the first outlet, the second outlet, the inlet switch and the outlet switch are all provided inside their corresponding connection box or distribution box. When the cable, busbar and load line are connected to the connection box or distribution box, their ends need to be inserted into the box body, which plays a protective role for the ends of the cable, busbar and load line.

[0096] The parallel groove clamp 4 includes a fixing plate 4-1, an adjusting rod 4-2 and an adjusting plate 4-3. The fixing plate 4-1 is provided with a first fixing hole. The adjusting rod 4-2 is welded to the side of the fixing plate 4-1 through the fixing hole. The adjusting rod 4-2 is perpendicular to the fixing plate 4-1. External threads are provided on the outer side of the adjusting rod 4-2. The adjusting plate 4-3 is sleeved on the side of the adjusting rod 4-2 and can move up and down according to the size of different cables 6. The adjusting plate 4-3 is parallel to the fixing plate 4-1. The overhead low-voltage line 5 is fixed between the adjusting plate 4-3 and the fixing plate 4-1 to fix the parallel groove clamp 4 on the overhead low-voltage line 5.

[0097] Preferably, grooves are provided on the sides of the fixed plate 4-1 and the adjusting plate 4-3 that come into contact with the low-voltage overhead line, so that the parallel groove clamp 4 is wrapped around the outside of the low-voltage overhead line, can closely adhere to the low-voltage overhead line, but will not damage the line insulation layer at the same time, making the connection between the low-voltage overhead line and the parallel groove clamp 4 more stable.

[0098] Furthermore, insulating pads made of other materials such as rubber pads can be provided inside the grooves provided on the fixed plate 4-1 and the adjusting plate 4-3. While providing friction, they can also deform according to the wire size, so that the grooves can closely adhere to the low-voltage overhead line. When the low-voltage overhead line is affected by natural forces such as wind and rain, the parallel groove clamp 4 will not easily fall off.

[0099] A first nut 4-4 is provided at the free end of the adjusting plate 4-3. The first nut 4-4 is threadedly connected to the adjusting rod 4-2. The first nut 4-4 can move up and down along the adjusting rod 4-2, playing a limiting role on the adjusting rod 4-2 to ensure that the adjusting plate 4-3 closely adheres to the low-voltage overhead line, fixing the position of the adjusting plate 4-3 and ensuring the stability of the fixation of the parallel groove clamp 4.

[0100] A wiring board 4-5 is welded to the side of the fixed plate 4-1. The wiring board 4-5 is provided with connection holes. The busbar 3 is fixed to the side of the connection board through the connection holes and the second bolt 3-2. A wire nose is provided at the end of the busbar 3. The plate-like structure of the wire nose is in close contact with the wiring board 4-5. The connection between the busbar 3 and the parallel groove clamp 4 is completed by passing the second bolt 3-2 through the wire nose and the wiring board 4-5.

[0101] An inlet board 3-1 is connected to the side of the busbar 3 that connects to the first inlet. The angle between the inlet board 3-1 and the busbar 3 is an acute angle. Compared with the busbar 3, the inlet board 3-1 bends upward, forming a drip bay similar to a concave shape between the inlet board 3-1 and the busbar 3. Water cannot flow along the inlet board 3-1 into the connection box 1 during rainy and snowy weather, effectively preventing rainwater from entering the connection box 1 and effectively reducing the failure rate caused by rainwater intrusion.

[0102] Water cannot flow along the inlet board 3-1 into the distribution box 2. The electrical components in the distribution box 2 are better protected, and the service life and reliability are significantly improved. In addition, it also reduces the frequent inspections and maintenance work of the operation and maintenance personnel due to handling rainwater intrusion faults, reduces the operation and maintenance costs, and improves the overall operation efficiency of the power system.

[0103] The fixing plate 4-1 is provided with a second fixing hole, and a reinforcing rod 4-6 is welded to the second reinforcing hole. The reinforcing rod 4-6 and the adjusting rod 4-2 are arranged in parallel. The reinforcing rod 4-5 and the fixing plate 4-1 adopt the same structure. The reinforcing rod 4-6 and the adjusting rod 4-2 are fixed on both sides of the low-voltage overhead line to ensure the stability of the connection between the parallel groove clamp 4 and the low-voltage overhead circuit. Similarly, a second nut 4-7 is provided at the free end of the reinforcing rod 4-6, and the first nut 4-4 and the second nut 4-7 cooperate to fix the adjusting plate 4-3 to ensure the stability of the fixing of the parallel groove clamp 4.

[0104] A cover plate 1 - 1 corresponding to the first line inlet is arranged on the side of the connection box 1 , which further improves the rainproof performance of the device of the present invention.

[0105] Both ends of the cable 6 are provided with a first line nose, and the cable 6 is connected to the distribution box 2 and the connection box 1 through the first line nose.

[0106] The contact area between the cable lug and the cable 6 is much larger than the contact area when the cable 6 is directly connected, which helps to reduce contact resistance, reduce power loss, and improve conductive efficiency. In addition, the cable lug connects the cable 6 and the distribution box 2 and the cable 6 and the connection box 1, which can greatly simplify the construction process, reduce complex operations such as on-site welding or crimping, and improve construction efficiency. At the same time, the cable lug is usually designed to be easy to install and disassemble, which is convenient for maintenance and replacement when necessary.

[0107] One end of the cable 6 is provided with a wire nose and connected to the connection box 1 , and the second line inlet 2 - 1 is provided with a wiring clamp and connected to the cable 6 .

[0108] The connection box 1 is installed at a higher position and is more affected by external forces such as gravity and wind. The wire nose is tightly combined with the cable 6 by crimping, has high mechanical strength, and can effectively prevent the cable 6 from falling off due to external pulling.

[0109] The terminal clamp is compatible with a variety of cable specifications and has a simple structure. It does not require special tools or processes. The initial investment and replacement costs are lower than those of the wire nose.

[0110] The connection between the connection box 1 and the cable 6 emphasizes reliability, and the connection between the distribution box 2 and the cable 6 focuses on the convenience of maintenance. In view of the differences in temperature, humidity, vibration, etc. at different altitudes, an appropriate connection method is selected to effectively extend the service life of the equipment.

[0111] A prefabricated hole is provided at one end where the busbar 3 is connected to the first inlet, and a first bolt is provided at the first inlet. The bolt passes through the prefabricated hole to fix the busbar 3 on the first inlet, thereby completing the connection between the busbar 3 and the connection box 1.

[0112] The busbar 3 is cylindrical. The surface of the cylindrical busbar 3 is smooth and arc-shaped. After rainwater contacts it, due to the action of gravity, it quickly slides along the tangent direction and is difficult to stagnate or accumulate on the surface. Compared with the traditional rectangular busbar 3, the cylindrical busbar has no sharp corners, avoiding the retention of rainwater at the edges and corners to form a water film or a penetration channel. In addition, the wind resistance coefficient of the cylindrical cross-section is low, which can reduce the probability of rainwater directly impacting the surface of the busbar 3 in strong winds or heavy rains and reduce the risk of splashing water.

[0113] The busbar 3 is made of copper busbar.

[0114] 1. The resistivity of copper is only 1 / 1.68 that of aluminum (copper: 1.7×10⁻ 8 Ω·m, aluminum: 2.8×10⁻ 8 Ω·m). Under the same cross-sectional area, the current-carrying capacity of the copper busbar is higher and the loss is lower;

[0115] 2. The electrical conductivity of copper is less affected by temperature. At high temperatures, the attenuation of the electrical conductivity of copper is lower than that of aluminum;

[0116] 3. The tensile strength of copper is 200 - 300 MPa, and the tensile strength of aluminum is 150 - 200 MPa. The tensile strength of copper is higher than that of aluminum;

[0117] 4. Copper is easy to form a dense oxide film in the air, which can prevent further corrosion and is suitable for humid or sulfur-containing environments.

[0118] The busbar 3 connects the low-voltage overhead line and the connection box 1 and needs to be exposed to the air for a long time. The dense oxide film formed by copper in the air can effectively prevent the further corrosion of the busbar 3 by the air and can extend the service life of the busbar 3.

[0119] As another implementation mode of the present invention, the busbar 3 can be made of aluminum busbar.

[0120] 1. The price of aluminum is only 1 / 3 - 1 / 4 that of copper. Using aluminum busbar for the large-current busbar 3 can greatly reduce the material cost;

[0121] 2. The density of aluminum is 2700 kg / m³, and the density of copper is 8900 kg / m³. The density of aluminum is 1 / 3.3 of the density of copper, which is convenient for installation and transportation;

[0122] 3. The thermal conductivity coefficient of aluminum is 237 W / m·K, and the thermal conductivity coefficient of copper is 401 W / m·K. Combined with the lightweight design, the heat dissipation efficiency of aluminum is higher;

[0123] 4. The thermal expansion coefficients of aluminum and many insulating materials are similar, which can reduce the cracking risk caused by thermal stress.

[0124] The price of aluminum is lower than that of copper. Using aluminum bars can greatly reduce the manufacturing cost of the device of the present invention. Moreover, the aluminum bars have a low thermal conductivity and a high heat dissipation efficiency. The bus bar 3 of the device of the present invention is installed outdoors, and preferably, aluminum bars more suitable for outdoor use are selected.

[0125] As another embodiment of the present invention, the bus bar 3 can be made of a structure with a copper material on the surface layer and an aluminum material on the inner layer, which can reduce the cost as much as possible while taking into account the performance. Making the surface layer with copper material can improve the electrical conductivity and anti-corrosion performance of the bus bar 3, and making the inner layer with aluminum material with low density can reduce the weight of the bus bar 3.

[0126] The preferred embodiments of the present invention have been described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those of ordinary skill in the art, various changes can be made without departing from the gist of the present invention.

[0127] Many other changes and modifications can be made without departing from the concept and scope of the present invention. It should be understood that the present invention is not limited to specific embodiments, and the scope of the present invention is defined by the appended claims.

Claims

1. A small distribution box for extending the power supply point of a low-voltage overhead line, Characterized in that, It includes a connection box (1) and a distribution box (2), The connection box (1) is provided with terminal blocks, a first inlet and a first outlet, The terminal block connects the first inlet and the first outlet, The first inlet is connected with a busbar (3), and the busbar (3) is connected to the overhead low-voltage line (5) through a parallel groove clamp (4), The first outlet is connected with a cable (6), and the end of the cable (6) extends into the connection box (1) to connect the first outlet, The distribution box (2) is connected to the connection box (1) through the cable (6), The distribution box (2) is provided with a second inlet (2-1), an inlet switch (2-2), a second outlet (2-3) and an outlet switch (2-4), The cable (6) is connected to the distribution box (2) through the second inlet (2-1), The inlet switch (2-2) is used to control the on-off of the cable (6) and the distribution box (2), The second outlet (2-3) is provided with a load line connecting the load, The outlet switch (2-4) is used to control the on-off of the load line and the distribution box (2).

2. The small distribution box for extending the power supply point of a low-voltage overhead line according to claim 1, Characterized in that, The parallel groove clamp (4) includes a fixing plate (4-1), an adjusting rod (4-2) and an adjusting plate (4-3), The fixing plate (4-1) is provided with a first fixing hole, The adjusting rod (4-2) is welded to the side of the fixing plate (4-1) through the fixing hole, The outer side of the adjusting rod (4-2) is provided with an external thread, The adjusting plate (4-3) is sleeved on the side of the adjusting rod (4-2), The adjusting plate (4-3) and the fixing plate (4-1) are arranged in parallel, and the overhead low-voltage line (5) is fixed between the adjusting plate (4-3) and the fixing plate (4-1), The free end of the adjusting plate (4-3) is provided with a first nut (4-4), A wiring board (4-5) is welded to the side of the fixing plate (4-1), The wiring board (4-5) is provided with a connection hole, The busbar (3) is fixed to the side of the connecting plate through the connection hole and a second bolt (3-2).

3. The small distribution box for extending the power supply point of a low-voltage overhead line according to claim 2, Characterized in that, One side of the busbar (3) connected to the first inlet is connected with an inlet board (3-1), and the angle between the inlet board (3-1) and the busbar (3) is an acute angle.

4. The small distribution box for extending the power supply point of a low-voltage overhead line according to claim 1, Characterized in that, The fixing plate (4-1) is provided with a second fixing hole, a reinforcing rod (4-6) is welded to the second reinforcing hole, the reinforcing rod (4-6) is arranged in parallel with the adjusting rod (4-2), and the free end of the reinforcing rod (4-6) is provided with a second nut (4-7).

5. The small distribution box for extending the power supply point of a low-voltage overhead line according to claim 4, Characterized in that, A cover plate (1-1) corresponding to the first inlet is provided on the side of the connection box (1).

6. A small distribution box for a low-voltage overhead line extended power supply point as claimed in claim 1, characterized in that, both ends of the cable (6) are provided with first cable lugs, and the cable (6) is connected to the distribution box (2) and the connection box (1) through the first cable lugs.

7. A small distribution box for a low-voltage overhead line extended power supply point as claimed in claim 6, characterized in that, one end of the cable (6) is provided with a cable lug and is connected to the connection box (1), and the second inlet (2-1) is provided with a terminal clamp and is connected to the cable (6).

8. A small distribution box for a low-voltage overhead line extended power supply point as claimed in claim 7, characterized in that, one end of the busbar (3) connected to the first inlet is provided with a prefabricated hole, the first inlet is provided with a first bolt, and the bolt passes through the prefabricated hole.

9. A small distribution box for a low-voltage overhead line extended power supply point as claimed in claim 1, characterized in that, the busbar (3) is cylindrical.

10. A small distribution box for a low-voltage overhead line extended power supply point as claimed in claim 1, characterized in that, the busbar (3) is made of copper busbar.

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