Ring net box with protection function

Abstract

The invention relates to a ring main unit with a protection function, which relates to the technical field of intelligent power grids and comprises a box body and two box doors rotatably mounted on two edges of the front side of the box body. The top surface of the box body is rotatably connected with a protection plate, the protection plate can be overturned towards the direction close to the box door to be in a horizontal maintenance state attached to the top surface of the box body and can be overturned towards the direction away from the box door to be in a horizontal application state attached to the top surface of the box body, and the box body is provided with a rotating part for overturning and switching the two states of the protection plate; the protection plate can protrude out of the top face of the box body when in the horizontal maintenance state, and the protruding part of the protection plate can protect workers at the moment. According to the tool, workers are effectively prevented from being wetted, do not need to hold an umbrella, and can freely operate the tool with two hands for maintenance action.

Description

Technical Field

[0001] This application relates to the technical field of smart grids, and in particular to a ring main unit with protective functions. Background Technology

[0002] Currently, in power distribution systems, ring main units (RMS) are key equipment, undertaking important tasks such as distributing electrical energy and controlling circuit switching. They are widely used in urban power grids, industrial and mining enterprises, and other scenarios. They are usually installed outdoors to adapt to different spatial layouts and usage needs. The stable operation of RMS is crucial to ensuring the continuity and reliability of power supply, and is directly related to the normal production and life of various users. However, the complex and ever-changing outdoor environmental conditions bring a series of challenges to the use and maintenance of RMS, especially when dealing with special weather conditions. Existing designs are clearly insufficient in ensuring the convenience of workers' operations.

[0003] In related technologies, a ring main unit includes a housing and two doors rotatably mounted on the two sides of the front side of the housing. Electrical components are fixedly installed inside the housing, and these electrical components are the core parts that realize the function of the ring main unit. These include various devices such as circuit breakers, load switches, and fuses, which cooperate closely with each other to complete key operations such as power distribution, precise control, and effective protection. Through the orderly operation of these electrical components, the ring main unit can play an important role in the power distribution system and meet the power demand in different scenarios.

[0004] In the aforementioned technologies, when ring main units are installed outdoors, workers have to use umbrellas to avoid getting wet during maintenance in the rain. However, using an umbrella occupies one hand, which greatly inconveniences the operation of tools and maintenance actions. Some delicate maintenance operations that originally required both hands become extremely difficult because one hand is occupied. For example, when replacing small electrical components or making wiring connections, single-handed operation is not only inefficient, but may also lead to a decline in maintenance quality due to inaccurate operation, and may even cause safety hazards. There is room for improvement. Summary of the Invention

[0005] The purpose of this application is to provide a ring network box with protective functions to solve the problem in the above-mentioned related technologies where it is inconvenient for workers to carry an umbrella with one hand for maintenance on rainy days.

[0006] The ring main body box with protective function provided in this application adopts the following technical solution: A protective ring mesh box includes a box body and two doors rotatably mounted on the front two sides of the box body. A protective plate is rotatably connected to the top surface of the box body. The protective plate can be flipped towards the door to a horizontal maintenance state that is flush with the top surface of the box body, and flipped away from the door to a horizontal application state that is flush with the top surface of the box body. The box body is provided with a rotating component for switching between the two states of the protective plate. When the protective plate is in the horizontal maintenance state, it can protrude from the top surface of the box body, and the protruding part of the protective plate can protect the workers.

[0007] By adopting the above technical solution, the protective plate rotatably connected to the top of the enclosure can flexibly switch states. When it is flipped towards the enclosure door to a horizontal maintenance state, the part protruding from the top of the enclosure can shield the workers from rain, effectively preventing them from getting wet. This allows workers to operate tools and perform maintenance actions freely with both hands without the need for an umbrella. Whether it is replacing small electrical components or connecting wiring, these delicate operations can be completed more accurately and efficiently. While ensuring the convenience of workers, this improves the quality and safety of maintenance, ensuring that the ring main unit can be maintained smoothly even in special weather conditions.

[0008] Optionally, the rotating component is two rotating rods rotatably mounted on the left and right side edges of the protective plate; the two rotating rods can drive the protective plate to flip.

[0009] By adopting the above technical solution, when it is necessary to switch the state of the protective plate, the staff only needs to stand on the ground and operate the rotating rod directly; the rotating rod rotates around its rotation axis, thereby driving the protective plate to complete the flipping action. The whole process does not require additional tools or complicated operating procedures, which greatly saves operating time and labor costs and improves work efficiency.

[0010] Optionally, several heat dissipation meshes are provided on both the left and right sides of the enclosure. A limiting member is provided on the outside of the enclosure. Two support rods are rotatably connected to the ends of the two rotating rods away from the protective plate. When the protective plate is in maintenance mode, the two support rods can rotate towards each other to a parallel, stowed state; when the protective plate is in use mode, they can rotate away from each other to a coaxial, horizontally supported state. Support plates located below the two support rods are rotatably connected to the left and right sides of the enclosure away from the door. The support plates have clearance notches. When the two support rods are in a horizontally supported state, the support plates can rotate towards the rotating rods to a vertical state. The clearance notches on the support plates allow the heat dissipation meshes to be inserted. The limiting member is detachably connected to the support plate at this time.

[0011] By adopting the above technical solution, the support rod can rotate flexibly on the protective plate in the application state. In the application state, it rotates in opposite directions to the horizontal support state, and cooperates with the support plate connected to the bottom. The support plate rotates to the vertical state, and its clearance notch allows the heat dissipation mesh to be inserted. This does not affect heat dissipation, but also provides stable support for the support rod, enhancing the stability of the protective plate in the application state.

[0012] Optionally, the limiting member is a limiting block fixed on the support plate near the top surface of the support rod, and limiting slots are respectively opened on the bottom surface of the two support rods; the limiting block can be inserted into the limiting slot when the two support rods are in a horizontal support state.

[0013] By adopting the above technical solution, when the support rod is in a horizontal support state, the limiting block is inserted into the limiting slot, which effectively prevents the support rod from accidentally shaking or shifting due to external force in the horizontal support state, and ensures that the support rod can continuously and stably provide support for the protective plate.

[0014] Optionally, the side edges of the two limiting blocks near the support rod are chamfered.

[0015] By adopting the above technical solution, the chamfer changes the contact surface between the limiting block and the support rod from a sharp right angle to a smooth slope, which greatly reduces the resistance caused by collision during the process of the two approaching and docking.

[0016] Optionally, both support plates can rotate to a horizontal position when both support rods are in the retracted state, and the clearance notch can then be used by workers to place maintenance tools.

[0017] By adopting the above technical solution, staff no longer need to worry about tool storage when carrying out maintenance work. They do not need to find additional storage locations or operate tools by hand, thus avoiding the loss or damage of tools due to improper storage.

[0018] Optionally, sliding plates are provided on both the left and right sides of the box. The sliding plates can slide up and down along the sides of the box and are fixed. A fixing notch is provided on the side of the sliding plate near the box. When the two support rods are in the retracted state, they can be placed into the fixing notch. At this time, the sliding plates can prevent the two support rods from moving.

[0019] By adopting the above technical solution, this design not only ensures the stability of the support rod in its stored state and reduces the risk of damage to the box or other components caused by the swaying of the support rod, but also makes the structure of the entire device more compact and orderly.

[0020] Optionally, two guide notches are provided on the side of the housing, and a fixing plate located in the guide notch is fixed on the side of each of the two sliding plates near the housing. Two fixing rods passing through the two guide notches are fixed on the opposite sides of the fixing plate. After passing through the guide notches, the two fixing rods can be fixedly connected to the side of the sliding plate near the housing. An elastic element is provided on the side of the fixing plate near the sliding plate. Several fixing grooves are provided on the inner wall of the housing. The elastic element can continuously engage and disengage from the fixing grooves during the sliding of the sliding plate.

[0021] By adopting the above technical solution, during the sliding process of the sliding plate, the elastic element continuously engages and disengages from the fixing groove. This provides a certain resistance during sliding, giving the sliding process a certain sense of segmentation, which makes it easier for the staff to accurately control the sliding position. After sliding to the appropriate position, the elastic element can automatically position and fix the plate without any additional operation, making it convenient and quick.

[0022] Optionally, the fixing plate has a mounting groove on the side near the sliding plate for inserting an elastic element. The elastic element includes a spring and a fixing protrusion. One end of the spring presses one side of the fixing protrusion so that a part of the fixing protrusion protrudes out of the opening of the mounting groove. The protruding part of the fixing protrusion is an arc surface, and the arc length corresponding to the arc surface of the protruding part is a minor arc.

[0023] By adopting the above technical solution, when the sliding plate slides, the arc surface of the fixed protrusion contacts the inner wall of the box. Due to the arc surface design and the fact that the arc length is a minor arc, it can retract into the mounting groove more smoothly when squeezed, reducing the friction with the inner wall of the box, making the sliding process of the sliding plate easier and smoother, and reducing the difficulty of operation. When it slides to the fixed groove position, the elastic force of the spring can make the fixed protrusion pop out quickly and lock into the fixed groove, achieving precise positioning and fixing, ensuring that the sliding plate stays stably in the required position.

[0024] Optionally, a fixing block is provided at the end of the fixing plate, and a fixing block is fixed on the inner wall of the box door. A fixing slot is provided on the fixing block, and the fixing block can slide down with the sliding plate and be engaged in the fixing slot when the box door is closed.

[0025] By adopting the above technical solution, this snap-fit ​​connection structure is simple yet highly reliable. The tight fit between the fixed block and the fixed slot effectively prevents the cabinet door from opening accidentally when subjected to external forces (such as wind or collisions), greatly enhancing the stability of the cabinet door closure, ensuring the safety of electrical components inside the cabinet, and preventing dust, rainwater, etc. from entering the cabinet due to the opening of the cabinet door and affecting the normal operation of the equipment.

[0026] In summary, this application includes at least one of the following beneficial technical effects: 1. The protective plate rotatably connected to the top of the enclosure can be flexibly switched. When it is flipped towards the enclosure door to a horizontal maintenance position, the part protruding from the top of the enclosure can shield the workers from rain, effectively preventing them from getting wet. This allows workers to operate tools and perform maintenance actions freely with both hands without the need for an umbrella. Whether it is replacing small electrical components or making delicate operations such as wiring connections, it can be completed more accurately and efficiently. While ensuring the convenience of workers, it also improves the quality and safety of maintenance, ensuring that the ring main unit can be maintained smoothly even in special weather conditions. 2. When the sliding plate slides, the arc surface of the fixed protrusion contacts the inner wall of the box. Due to the arc surface design and the fact that the arc length is a minor arc, it can retract into the mounting groove more smoothly when squeezed, reducing the friction with the inner wall of the box. This makes the sliding process of the sliding plate easier and smoother, reducing the difficulty of operation. When it slides to the fixed groove position, the spring force can make the fixed protrusion pop out quickly and lock into the fixed groove, achieving precise positioning and ensuring that the sliding plate stays stably in the required position. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram illustrating the overall structure of the enclosure and protective panel installation and assembly in an embodiment of this application; Figure 2 This is a schematic diagram illustrating the overall structure of the rotating rod and the protective plate installation and cooperation in an embodiment of this application; Figure 3 This is a cross-sectional structural diagram illustrating the installation and cooperation of the rotating rod and the support rod in an embodiment of this application; Figure 4 yes Figure 3 A magnified view of part A in the middle; Figure 5 This is a partially enlarged schematic diagram illustrating the installation and cooperation of the sliding plate and the housing in an embodiment of this application; Figure 6 This is a cross-sectional structural diagram illustrating the installation and cooperation of the sliding plate and the fixed plate in an embodiment of this application; Figure 7 This is a cross-sectional structural diagram illustrating the installation and cooperation of the fixing protrusion and the fixing plate in an embodiment of this application; Figure 8 This is a cross-sectional structural diagram illustrating the installation and cooperation of the fixing plate and the fixing block in an embodiment of this application.

[0029] In the diagram, 1. Box body; 11. Box door; 111. Fixing block; 1111. Fixing slot; 12. Heat dissipation mesh; 13. Guide notch; 14. Fixing groove; 2. Protective plate; 3. Rotating component; 31. Rotating rod; 311. Support rod; 3111. Limiting slot; 4. Limiting component; 41. Limiting block; 411. Chamfer; 5. Support plate; 51. Clearance notch; 6. Sliding plate; 61. Fixing notch; 7. Fixing plate; 71. Fixing rod; 72. Mounting groove; 73. Fixing block; 8. Elastic component; 81. Spring; 82. Fixing protrusion. Detailed Implementation

[0030] The present application will be further described in detail below with reference to all the accompanying drawings.

[0031] Example: Reference Figure 1 and Figure 2 A protective ring mesh box includes a box body 1 and two doors 11 rotatably mounted on the front two sides of the box body 1. A protective plate 2 is rotatably connected to the top surface of the box body 1. The protective plate 2 can be flipped towards the door 11 to a horizontal maintenance state that is flush with the top surface of the box body 1, and flipped away from the door 11 to a horizontal application state that is flush with the top surface of the box body 1. A rotating component 3 is provided on the box body 1 to switch the two states of the protective plate 2. When the protective plate 2 is in the horizontal maintenance state, a part of the protective plate 2 will protrude from the top surface of the box body 1. At this time, the protruding part of the protective plate 2 can protect the workers who are working and effectively prevent rainwater from getting on the workers.

[0032] Reference Figure 1 and Figure 2 The rotating component 3 consists of two rotating rods 31 rotatably mounted on the left and right sides of the protective plate 2. When it is necessary to switch the state of the protective plate 2, the staff only needs to stand on the ground and then directly operate the rotating rods 31. The rotating rods 31 will rotate around their rotation axis, thereby driving the protective plate 2 to complete the flipping action. The whole operation process is simple and easy.

[0033] Reference Figure 1 and Figure 2 Several heat dissipation meshes 12 are provided on both the left and right sides of the box body 1. Limiting parts 4 are provided on the outside of the box body 1. The ends of the two rotating rods 31 away from the protective plate 2 are rotatably connected to two support rods 311. When the protective plate 2 is in the maintenance state, the two support rods 311 can rotate towards each other to a parallel storage state, and when the protective plate 2 is in the application state, they can rotate away from each other to a coaxial horizontal support state. Support plates 5 are rotatably connected to the left and right sides of the housing 1 away from the door 11, and are located below the two support rods 311. The support plates 5 have clearance notches 51. When the two support rods 311 are in a horizontal support state, the support plates 5 can rotate to a vertical state in the direction close to the rotating rods 31. At this time, the clearance notches 51 on the support plates 5 can be used to insert the heat dissipation mesh 12, effectively preventing external dust, debris and other objects from entering the heat dissipation mesh 12 and avoiding affecting the heat dissipation effect. At the same time, the limiting member 4 is detachably connected to the support plate 5 at this time, further ensuring the stability of the support plate 5 in the vertical state.

[0034] Reference Figure 3 and Figure 4 The limiting component 4 is a limiting block 41 integrally formed on the top surface of the support plate 5 near the support rod 311. Limiting slots 3111 are respectively opened on the bottom surface of the two support rods 311. When the two support rods 311 are in a horizontal support state, the limiting block 41 can be inserted into the limiting slot 3111. Through the cooperation between the limiting block 41 and the limiting slot 3111, the support plate 5 is effectively prevented from shaking or shifting due to external factors.

[0035] Reference Figure 4 The two limiting blocks 41 have chamfered edges near the side edges of the support rod 311. In practical applications, when the limiting block 41 is inserted into the limiting slot 3111, the chamfer 411 can play a good guiding role, guiding the limiting block 41 to be smoothly inserted into the limiting slot 3111.

[0036] Reference Figure 5 Both support plates 5 can rotate to a horizontal position when the two support rods 311 are in the retracted state; when the staff is performing equipment maintenance operations, they can place commonly used maintenance tools, such as screwdrivers and multimeters, in the clearance notch 51.

[0037] Reference Figure 5 Sliding plates 6 are slidably installed on both the left and right sides of the housing 1. The sliding plates 6 can slide up and down along the side of the housing 1 and are fixed. A fixing notch 61 is opened on the side of the sliding plate 6 near the housing 1. When the two support rods 311 are in the retracted state, they can be inserted into the fixing notch 61. At this time, the sliding plate 6 can effectively prevent the two support rods 311 from moving, avoiding safety hazards or affecting the normal use of the equipment due to accidental movement of the support rods 311.

[0038] Reference Figure 5 , Figure 6 and Figure 7Two guide notches 13 are provided on the side of the housing 1. Two sliding plates 6 are fixedly installed on the side of the housing 1 with fixed plates 7 located in the guide notches 13. Two fixed rods 71 ​​that pass through the two guide notches 13 are fixedly connected to the opposite sides of the fixed plates 7. After the two fixing rods 71 ​​pass through the guide notch 13, they can be fixedly connected to the side of the sliding plate 6 near the box 1. An elastic element 8 is provided on the side of the fixing plate 7 near the sliding plate 6. Several fixing grooves 14 are opened on the inner wall of the box 1. An installation groove 72 for the elastic element 8 to be inserted is opened on the side of the fixing plate 7 near the sliding plate 6. The elastic element 8 includes a spring 81 and a fixing protrusion 82. One end of the spring 81 presses one side of the fixing protrusion 82 so that a part of the fixing protrusion 82 protrudes out of the opening of the installation groove 72. The protruding part of the fixing protrusion 82 is an arc surface, and the arc length corresponding to the arc surface of the protruding part is the minor arc. During the sliding process of the sliding plate 6, the elastic element 8 can continuously engage and disengage from the fixing groove 14; when the sliding plate 6 slides to the position that needs to be fixed, the fixing protrusion 82 will engage into the corresponding fixing groove 14 due to the elastic force of the spring 81, thereby positioning the sliding plate 6; when it is necessary to continue sliding the sliding plate 6, a certain external force is applied, and the arc surface design of the fixing protrusion 82 will allow the fixing protrusion 82 to smoothly disengage from the fixing groove 14 and continue the sliding process.

[0039] Reference Figure 8 The end of the fixing plate 7 is integrally formed with a fixing block 73 in the vertical direction. The inner wall of the box door 11 is fixed with a fixing block 111, and a fixing slot 1111 is provided on the fixing block 111. During the operation of closing the box door 11, as the sliding plate 6 slides down, the fixing block 73 will move down synchronously with the sliding plate 6. When the slide reaches a specific position, the fixing block 73 can engage in the fixing slot 1111, locking the sliding plate 6 and the door 11 to prevent the door 11 from being accidentally opened without human intervention. When it is necessary to unlock the door 11, the operator can slide the sliding plate 6 upwards, and the fixing block 73 will disengage from the fixing slot 1111 under the action of external force, releasing the locking state between the sliding plate 6 and the door 11. At this time, the door 11 can be opened normally for subsequent operation or maintenance.

[0040] The implementation principle of this application embodiment is as follows: In the horizontal application state, the operator can operate the protective plate 2 to flip away from the door 11 until the protective plate 2 is attached to the top surface of the box 1; at the same time, the rotating rod 31 drives the support rod 311 to rotate to the horizontal support state, and then the support plate 5 is rotated to the vertical position. At this time, the clearance notch 51 on the support plate 5 can be used to insert the heat dissipation mesh 12, effectively preventing external dust and other objects from entering the heat dissipation mesh 12 and ensuring the heat dissipation effect of the equipment; in the horizontal maintenance state, the operator can flip the protective plate 2 towards the door 11. At this time, the protruding part of the protective plate 2 can shield the operator from rain; and after the support plate 5 is rotated to the horizontal state, the surface of the support plate 5 can be used to place maintenance tools, which facilitates the operator to carry out equipment maintenance operations.

[0041] Unless otherwise defined, the terms or scientific terms used in this application shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," "third," and similar words used in this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. The terms "a" or "one," and similar words do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms "comprising," "including," and similar words mean that the element or object preceding "comprising" encompasses the element or object listed following "comprising" or "including," and their equivalents, but do not exclude other elements or objects. "Above," "below," "left," "right," etc., are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0042] The embodiments described in this specific implementation are preferred embodiments of this application and are not intended to limit the scope of protection of this application. Identical components are represented by the same reference numerals. Therefore, all equivalent changes made to the structure, shape, and principle of this application should be covered within the scope of protection of this application.

Claims

1. A protective ring mesh box, comprising a box body (1) and two doors (11) rotatably mounted on the front sides of the box body (1); characterized in that, A protective plate (2) is rotatably connected to the top surface of the box (1). The protective plate (2) can be flipped towards the box door (11) to a horizontal maintenance state that is in contact with the top surface of the box (1), and flipped away from the box door (11) to a horizontal application state that is in contact with the top surface of the box (1). The housing (1) is provided with a rotating component (3) that allows for switching between two states of the protective plate (2); when the protective plate (2) is in a horizontal maintenance state, it can protrude from the top surface of the housing (1), and the protruding part of the protective plate (2) can protect the staff at this time.

2. A ring main unit with protective function according to claim 1, characterized in that, The rotating component (3) consists of two rotating rods (31) rotatably mounted on the left and right sides of the protective plate (2); the two rotating rods (31) can drive the protective plate (2) to flip.

3. A ring main unit with protective function according to claim 2, characterized in that, The box (1) has several heat dissipation meshes (12) on both the left and right sides. The box (1) is provided with a limiting member (4). The ends of the two rotating rods (31) away from the protective plate (2) are rotatably connected to two support rods (311). When the protective plate (2) is in maintenance state, the two support rods (311) can rotate towards each other to a parallel storage state, and when the protective plate (2) is in application state, they can rotate away from each other to a coaxial horizontal support state. The box body (1) is rotatably connected to the left and right sides away from the box door (11) by a support plate (5) located below the two support rods (311). The support plate (5) has a clearance notch (51). When the two support rods (311) are in a horizontal support state, the support plate (5) can rotate to a vertical state in the direction close to the rotating rod (31). The clearance notch (51) on the support plate (5) can be used to insert the heat dissipation mesh (12). The limiting member (4) is detachably connected to the support plate (5) at this time.

4. A ring main unit with protective function according to claim 3, characterized in that, The limiting member (4) is a limiting block (41) fixed on the top surface of the support plate (5) near the support rod (311). Limiting slots (3111) are respectively opened on the bottom surface of the two support rods (311). The limiting block (41) can be inserted into the limiting slot (3111) when the two support rods (311) are in a horizontal support state.

5. A ring main unit with protective function according to claim 4, characterized in that, The two limiting blocks (41) have chamfered edges (411) on the side edges near the support rod (311).

6. A ring main unit with protective function according to claim 3, characterized in that, Both support plates (5) can rotate to a horizontal state when the two support rods (311) are in the retracted state, and the clearance notch (51) can be used by staff to place maintenance tools.

7. A ring main unit with protective function according to claim 3, characterized in that, Sliding plates (6) are slidably provided on both the left and right sides of the box (1). The sliding plates (6) can slide up and down along the side of the box (1) and be fixed. A fixing notch (61) is provided on the side of the sliding plate (6) near the box (1). When the two support rods (311) are in the storage state, they can be placed into the fixing notch (61). At this time, the sliding plate (6) can prevent the two support rods (311) from moving.

8. A ring main unit with protective function according to claim 7, characterized in that, Two guide notches (13) are provided on the side of the box (1). The two sliding plates (6) are fixedly provided with fixing plates (7) located in the guide notches (13) on the side of the box (1). Two fixing rods (71) passing through the two guide notches (13) are fixedly provided on the opposite sides of the fixing plates (7). After the two fixing rods (71) pass through the guide notch (13), they can be fixedly connected to the side of the sliding plate (6) near the box (1). The side of the fixing plate (7) near the sliding plate (6) is provided with an elastic element (8). Several fixing grooves (14) are opened on the inner wall of the box (1). The elastic element (8) can continuously enter and exit the fixing groove (14) during the sliding process of the sliding plate (6).

9. A ring main unit with protective function according to claim 8, characterized in that, The fixed plate (7) has an installation groove (72) on its side near the sliding plate (6) for inserting the elastic element (8). The elastic element (8) includes a spring (81) and a fixing protrusion (82). One end of the spring (81) presses one side of the fixing protrusion (82) so that a part of the fixing protrusion (82) protrudes out of the opening of the installation groove (72). The protruding part of the fixing protrusion (82) is an arc surface, and the arc length corresponding to the arc surface of the protruding part is a minor arc.

10. A ring main unit with protective function according to claim 8, characterized in that, The end of the fixing plate (7) is provided with a fixing block (73), and the inner wall of the box door (11) is fixed with a fixing block (111). The fixing block (111) is provided with a fixing slot (1111). When the box door (11) is closed, the fixing block (73) can slide down with the sliding plate (6) and be inserted into the fixing slot (1111).

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