Modular ring main unit

Abstract

The application relates to the technical field of power distribution equipment, and particularly discloses a modular ring network box, which comprises a box body and a plurality of drawers, a bus system is arranged in the box body, a plurality of compartments are arranged on the box body, each drawer is in pull-out cooperation with each compartment, the rear end of each drawer is provided with a plug-in part, the plug-in part is in plug-in cooperation with the bus system and is electrically connected with the bus system, a protection mechanism is arranged on each drawer, the protection mechanism comprises a protection part and a connecting part, the connecting part is in sliding cooperation with the side wall of the drawer and is rotatable relative to the rear end of the drawer, the connecting part is in elastic limiting cooperation with the side wall of the drawer, the protection part is located at the rear side of the drawer, a slot hole for avoiding the plug-in part is arranged on the protection part, the protection part is in sliding cooperation and elastic limiting cooperation with the connecting part, the modular ring network box of the application provides protection for the plug-in part during the pull-out and installation operation of the drawer relative to the compartment, positions and guides the push-in direction of the drawer during installation of the drawer, and reduces the installation difficulty of the drawer.

Description

Technical Field

[0001] This invention relates to the field of power distribution equipment technology, and specifically to a modular ring main unit. Background Technology

[0002] Smart distribution networks are a crucial foundation for achieving power line status sensing, fault isolation, load transfer, and power restoration. Ring main units (RMS) serve as switches and sectionalizing devices within ring network power lines, typically located at feeder connections, customer access points, branch lines, and prefabricated switching stations. They are used for line segmentation, interconnection, maintenance isolation, and fault area isolation. With increasing demands for automation, modularization, and rapid operation and maintenance in distribution networks, the functional units within RMS are increasingly adopting modular, withdrawable structures. These units can be configured as switch units, protection units, metering units, or monitoring units according to line operation requirements. They are connected to the busbar system within the RMS via drawers, enabling detachable electrical connections and facilitating rapid replacement during power outages, emergency repairs, or functional upgrades.

[0003] Patent document CN109066441B discloses a low-voltage pull-out switch cabinet, including a cabinet body with an operating surface and a drawer mounted on a drawer slide rail. The front panel of the drawer has a latch, which is composed of a strip groove connecting the front panel of the drawer and an annular groove connecting the strip groove. The length of the strip groove is equal to the diameter of the annular groove. A support plate is provided in front of the operating surface. The support plate moves up and down by a vertical slide rail and moves left and right by a horizontal slide rail. A movable plate that moves in the back-and-forth direction in front of the operating surface is provided on the support plate. A rotatable pull rod is provided in the middle of the movable plate. One end of the pull rod passes through the movable plate and is connected to a connector. The other end of the pull rod is equipped with a handle. When pulling out the drawer, the operator moves the support plate to the front of the corresponding drawer by using the horizontal and vertical slide rails. One hand holds the handle, and the other hand pushes the handle. Under the guidance of the vertical slide rail, the handle is rotated so that the connector extends from the strip groove into the annular groove, and the handle is pulled outward, thereby pulling out the drawer.

[0004] The low-voltage withdrawable switchgear described in the aforementioned patent documents ensures a constant force direction when the drawer is pulled out by setting a pallet that can move in front of the operator. However, this structure mainly focuses on supporting the drawer and facilitating operation when pulling it out, without fully considering the maintenance and safety requirements of withdrawable functional modules in intelligent distribution network ring network power supply equipment. For modular ring network boxes, the connectors at the rear of the drawer are the key parts for forming a reliable electrical connection between the functional module and the bus system. During the processes of drawing out, transferring, temporarily placing, and pushing the drawer back into the compartment, the connectors are usually exposed at the rear of the drawer, making them susceptible to deformation, loosening, or damage to the contact surface due to collisions, swaying, or accidental contact. At the same time, when pushing the drawer back into the compartment, if there is a deviation between the direction of pushing the drawer into the compartment and the connector position of the bus system inside the compartment, the connectors may also experience problems such as misalignment, forced compression, or insufficient contact. These situations not only increase the difficulty of modular maintenance operations but may also affect the electrical connection reliability of the ring network power supply nodes and the power restoration efficiency after fault handling. Therefore, it is necessary to provide a modular ring main unit for smart distribution networks that can protect the connectors during drawer extraction, transfer, and reassembly, and can position and guide the drawer reassembly direction. Summary of the Invention

[0005] This invention provides a modular ring main unit, which aims to solve the problem that the drawers of ring main units in related technologies are prone to collisions during installation and disassembly.

[0006] A modular ring main unit of the present invention includes a housing and several drawers. A busbar system is provided inside the housing. Several compartments are provided on the housing. Each drawer is pulled out and closed with each compartment. A connector is provided at the rear end of each drawer. The connector is plugged into and electrically connected to the busbar system. A protective mechanism is provided on each drawer. The protective mechanism includes a protective component and a connecting component. The connecting component slides against the drawer sidewall and rotates relative to the rear end of the drawer. The connecting component is elastically limited against the drawer sidewall. The protective component is located at the rear of the drawer and has a slot to avoid the connector. The protective component slides against and is elastically limited against the connecting component.

[0007] The beneficial effects are as follows: The drawer forms a separable electrical connection with the busbar system inside the enclosure via the connector, facilitating subsequent maintenance, replacement, and functional expansion. By incorporating a protective mechanism on the drawer, the protective component is positioned at the rear of the drawer after it has been pulled out relative to the compartment, maintaining a distance from the rear end of the drawer. This places the connector between the rear end of the drawer and the protective component, reducing the possibility of direct impact to the connector during drawer removal, transfer, and temporary placement. The connector slides against the drawer sidewall and can rotate relative to the rear end of the drawer, allowing the position of the protective component to be adjusted according to the drawer's removal and reinstallation states. The connector elastically limits the movement of the connector and the sliding and elastically limiting movement of the protective component, ensuring the protective component maintains a stable position while protecting the connector, preventing uncontrolled movement that could affect operation. When the drawer is pushed back into the compartment, the protective component and connector also position and guide the drawer's insertion direction, reducing the risk of drawer misalignment, forced compression of the connector, or incomplete contact of the connector. This improves the maintenance safety of the modular ring main unit, the reliability of busbar connections, and the efficiency of power restoration after fault handling.

[0008] Preferably, the protective component has a connecting groove at its front end, and the connecting component slides into the connecting groove. The protective component is also longitudinally slidably connected to a limiting component. The lower end of the limiting component is connected to the protective component through an elastic element. The limiting component has a limiting groove, and the connecting component is movably inserted into the limiting groove. The lower end of the limiting groove is an inclined surface that slopes upward from front to back. When the connecting component is inserted into the limiting groove, the limiting component squeezes the elastic element. When the elastic element naturally extends, the upper end of the limiting component extends to the upper side of the protective component, and the upper end of the limiting component is movably inserted into the compartment.

[0009] Preferably, the compartment is provided with a insertion slot, and the upper end face of the limiting member is inclined downward from front to back.

[0010] The beneficial effects are as follows: By setting a limiting component, it is convenient to position the insertion direction of the drawer when it is inserted into the compartment. When the connector is inserted into the limiting groove, the limiting component squeezes the elastic component. When the elastic component naturally extends, the upper end of the limiting component extends to the upper side of the protective component. When the operator pushes the protective component into the designated compartment, the limiting component contacts the upper side wall of the compartment and is squeezed back into the protective component. When the protective component moves relative to the compartment until the limiting component is opposite to the insertion groove, the limiting component is inserted into the insertion groove. The position of the protective component and the compartment is relatively fixed, and the subsequent drawer insertion direction is positioned.

[0011] Preferably, the protective component is magnetically engaged with the rear end face of the compartment, the connecting groove is provided with two limiting holes, and the rear side of the connector is provided with an elastic protrusion that is movably inserted into the two limiting holes. When the connector moves to the point where the elastic protrusion is opposite to the front limiting hole, it separates from the limiting component.

[0012] The beneficial effects are as follows: it facilitates the separation of the protective piece from the rear end of the drawer when the drawer is pulled out, and provides protection for the connector. The protective piece magnetically engages with the rear end face of the compartment. When the drawer is pulled out to the outside of the compartment, the protective piece remains in contact with the rear end face of the compartment under the magnetic attraction. The connector moves forward with the drawer until the elastic protrusion on the connector aligns with the rear limiting hole in the connecting groove. At this point, the positions of the connector and the protective piece are relatively fixed. The protective piece moves forward synchronously with the connector, creating a certain gap between the protective piece and the rear end face of the drawer. The connector is located between the protective piece and the drawer, and the protective piece can provide a certain degree of protection for the connector.

[0013] Preferably, the drawer sidewall is provided with a guide groove, the front end of the connector is provided with a guide part, the guide part is slidably engaged with the guide groove, and the guide part is rotatably engaged with the rear end of the guide groove.

[0014] Preferably, the guide portion is provided with an elastic block, and the guide groove is provided with a slot that can be movably inserted into the elastic block. The force required for the elastic block to disengage from the slot is greater than the force required for the elastic protrusion to disengage from the limiting hole.

[0015] Preferably, the rear end of the guide groove is provided with two adjustment grooves, and the elastic block is movably inserted into the two adjustment grooves when the connector rotates relative to the guide groove.

[0016] The beneficial effects are: reducing the difficulty of inserting the drawer into the higher compartment; adjusting the connector so that the front end of the connector is opposite to the rear end of the guide groove; then rotating the connector to create a certain angle between the connector and the guide groove; and maintaining the relative angle between the connector and the guide groove through the cooperation of the elastic block and the adjustment groove; the adjusted drawer is located slightly below the protective part, which reduces the height that the staff can lift the drawer when putting it back into the higher compartment, making the drawer return operation more effortless.

[0017] Preferably, there are two connectors, which slide against the opposite side walls of the drawer respectively. The front end of the protective component is provided with two connecting grooves, and the two connectors slide into the two connecting grooves respectively.

[0018] The beneficial effects are: by setting two connectors, the stability of the drawer during the pulling process is improved, and the drawer is prevented from getting stuck in the compartment due to uneven force during the pulling process.

[0019] Preferably, the drawer is further provided with a roller at the rear end, the roller making rolling contact with the compartment, and the lower end of the compartment is provided with a guide rail, the roller engaging with the guide rail in a rolling manner.

[0020] Preferably, the front end face of the drawer is provided with a handle.

[0021] The beneficial effects of this invention are as follows: it provides protection for the connectors during the drawer's extraction and insertion process, while facilitating the insertion of the drawer relative to the compartment. The protective component slides with the drawer on the rear side. When the drawer is pulled out, a certain distance is created between the protective component and the rear end of the drawer to protect the connectors and prevent them from being bumped or knocked during the drawer's extraction and placement. In addition, the protective mechanism can also position and guide the drawer's insertion direction when it is inserted into the compartment, improving the drawer's insertion accuracy and facilitating the operator's operation. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0023] Figure 2 This is a diagram showing the state of the drawer after it has rotated relative to the connecting piece in this invention.

[0024] Figure 3 This is a diagram showing the horizontal relative positions of the drawer and compartment in this invention.

[0025] Figure 4 This is a diagram showing the state of the drawer being pushed into the compartment in this invention.

[0026] Figure 5 This is a diagram showing the state of the drawer being fully pushed into the compartment in this invention.

[0027] Figure 6 This is a diagram showing the state of the protective mechanism when the connector is fully inserted into the protective component in this invention.

[0028] Figure 7 This is a diagram showing the state of the protective mechanism when the connecting member slides forward relative to the protective member in this invention.

[0029] Figure 8 This is a schematic diagram of the connector in this invention.

[0030] Figure 9 This is a schematic diagram of the guide groove in this invention.

[0031] Figure label: 1. Box body; 11. Compartment; 2. Drawer; 21. Connector; 22. Guide groove; 221. Slot; 222. Adjustment groove; 23. Handle; 24. Roller; 3. Protective component; 31. Connector; 311. Guide part; 312. Elastic block; 313. Elastic protrusion; 32. Limiting component; 321. Limiting groove; 322. Elastic component; 33. Connecting groove; 331. Limiting hole. Detailed Implementation

[0032] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0033] like Figure 1 As shown, a modular ring main unit of the present invention includes a housing 1 and several drawers 2. The housing 1 is used to connect to the ring main power supply line and carry the bus system. The drawers 2 can serve as installation carriers for power distribution functional modules such as switch units, protection units, metering units, or monitoring units. The housing 1 is provided with several compartments 11, and each drawer 2 is pulled out and connected to each compartment 11. The rear end of the drawer 2 is provided with a plug-in component 21, which is plugged into and electrically connected to the bus system. The drawer 2 is provided with a protective mechanism, which provides protection for the plug-in component 21 when the drawer 2 is pulled out relative to the compartment 11, and positions and guides the insertion of the drawer 2 when it is inserted into the compartment 11, so that the plug-in component 21 at the rear end of the drawer 2 can be stably plugged into the corresponding bus system.

[0034] like Figures 6 to 9 As shown, the protective mechanism includes a protective component 3 and a connecting component 31. The connecting component 31 slides against the side wall of the drawer 2 and can rotate relative to the drawer 2 when it is moved to the rear end of the drawer 2. The connecting component 31 also has an elastic limiting fit with the side wall of the drawer 2. Specifically, the side wall of the drawer 2 is provided with a guide groove 22, the length direction of which is parallel to the pull-out direction of the drawer 2. A guide part 311 is fixed to the front end of the connecting component 31, the guide part 311 slides against the guide groove 22, and the guide part 311 rotates against the rear end of the guide groove 22. An elastic block 312 is also elastically connected to the guide part 311. The elastic block 312 can be hemispherical. The guide groove 22 is provided with a slot 221. When the connector 31 slides relative to the guide groove 22 until the elastic block 312 is opposite to the slot 221, the elastic block 312 extends into the slot 221 under the action of elastic force, limiting the relative position of the connector 31 and the side wall of the drawer 2. The rear end of the guide groove 22 is also provided with two adjustment grooves 222. When the guide part 311 rotates relative to the rear end of the guide groove 22, the elastic block 312 moves relative to the two adjustment grooves 222. When the elastic block 312 is opposite to the adjustment grooves 222, it extends into the adjustment grooves 222 under the action of elastic force, limiting the relative angle between the connector 31 and the side wall of the drawer 2.

[0035] The protective component 3 is located on the rear side of drawer 2. To prevent the protective component 3 from interfering with the electrical connection between the connector 21 and the busbar system, the protective component 3 has a slot for avoiding the connector 21. The protective component 3 slides along the direction close to or away from the rear end face of drawer 2. The protective component 3 slides and elastically limits the connection with the connector 31. The front end of the protective component 3 has two connecting grooves 33. The connector 31 and guide groove 22 are each provided with two grooves. The two guide grooves 22 are located on two opposite side walls of drawer 2. The two connectors 31 slide with the two connecting grooves 33 respectively. The connecting grooves 33 have two limiting holes 331. The connector 31 has elastic... The connector 313 is connected to the elastic protrusion 313. When the connector 31 slides relative to the protective member 3, the elastic protrusion 313 is in relative position to the two limiting holes 331. When the elastic protrusion 313 is in relative position to the limiting holes 331, it is inserted into the limiting holes 331 under the action of elasticity, and restricts the relative position of the connector 31 and the protective member 3. The elastic protrusion 313 can be hemispherical, and the elastic coefficient of the elastic protrusion 313 is less than the elastic coefficient of the elastic block 312. That is, the force required for the elastic protrusion 313 to separate relative to the limiting hole 331 is less than the force required for the elastic block 312 to separate relative to the slot 221. The protective member 3 and the rear end face of the compartment 11 are magnetically attracted to each other.

[0036] The initial state of the protective mechanism is when drawer 2 is completely submerged in compartment 11, as shown below. Figure 6 As shown, in the initial state, the protective member 3 simultaneously adheres to the rear end face of the drawer 2 and the rear end face of the compartment 11. The connector 31 is inserted into the connecting groove 33 of the protective member 3. The elastic protrusion 313 on the connector 31 is not opposite to the two limiting holes 331. The elastic protrusion 313 is located behind the two limiting holes 331. The elastic block 312 on the connector 31 is inserted into the slot 221 in the guide groove 22. When the drawer 2 is pulled out of the compartment 11, the protective member 3 remains in contact with the rear end face of the compartment 11 under the magnetic attraction. As the drawer 2 moves forward, when the elastic protrusion 313 on the connector 31 aligns with the rear limiting hole 331 in the connecting groove 33, the positions of the connector 31 and the protective member 3 are relatively fixed. The protective member 3 moves forward synchronously with the connector 31, creating a certain gap between the protective member 3 and the rear end face of the drawer 2. The plug-in member 21 is located between the protective member 3 and the drawer 2. The protective member 3 can provide a certain degree of protection for the plug-in member 21, reducing the possibility of the plug-in member 21 being bumped during the process of pulling out the drawer 2 and when the drawer 2 is pulled out and placed.

[0037] like Figure 6 and Figure 7As shown, a limiting member 32 is also longitudinally slidably connected to the protective member 3. The lower end of the limiting member 32 is connected to the protective member 3 via an elastic member 322, which can be a spring. The limiting member 32 is provided with a limiting groove 321. The connecting member 31 is movably inserted into the limiting groove 321. The lower end of the limiting groove 321 is a sloping surface that slopes upward from front to back. When the connecting member 31 is inserted into the limiting groove 321, the limiting member 32 compresses the elastic member 322. When the elastic member 322 naturally extends, the upper end of the limiting member 32 extends to the protective member 3. On the upper side of component 3, the upper end face of the limiting component 32 is inclined downward from front to back. The front end of the upper side of the compartment 11 is provided with a insertion groove. The upper end of the limiting component 32 is movably inserted into the insertion groove. When the limiting component 32 moves backward relative to the insertion groove, the inclined side of the upper end of the limiting component 32 is squeezed against the insertion groove. The limiting component 32 moves downward relative to the protective component 3. When the elastic protrusion 313 on the connecting component 31 is opposite to the rear limiting hole 331, the connecting component 31 remains inserted into the limiting groove 321 and restricts the limiting component 32 from moving upward relative to the protective component 3.

[0038] When placing drawer 2 back into compartment 11, especially when placing drawer 2 back into compartment 11 at a higher position, to facilitate the operator's operation and to protect the connector 21 during the process of drawer 2 entering compartment 11, the relative positions of the protective component 3, connector 31, and drawer 2 can be pre-adjusted when drawer 2 is placed back. First, the operator pulls the protective component 3 backward, causing the elastic protrusion 313 on connector 31 to engage with the limiting hole 331 on the front side of connecting groove 33. Connector 31 separates from limiting component 32, and limiting component 32 pops out under the elastic force of elastic component 322. Then, connector 31 is pulled to slide relative to the side wall of drawer 2, so that the front end of connector 31 is aligned with the rear end of guide groove 22. Then, connector 31 is rotated to create a certain angle between connector 31 and guide groove 22. Through the cooperation of elastic block 312 and adjusting groove 222, the relative angle between connector 31 and guide groove 22 is maintained. After adjustment, drawer 2 is located slightly below protective component 3, as shown in the specific state. Figure 2 As shown, when the drawer 2 is placed back into the higher compartment 11, the height at which the staff can lift the drawer 2 can be reduced, making the return operation of the drawer 2 easier, and the relative positions of the protective part 3, the connecting part 31 and the drawer 2 are stable.

[0039] The worker continuously pushes the protective piece 3 into the designated compartment 11. The limiting piece 32 contacts the upper side wall of the compartment 11 and is squeezed back into the protective piece 3. When the limiting piece 32 is aligned with the insertion slot, the limiting piece 32 is inserted into the insertion slot, and the position of the protective piece 3 and the compartment 11 is relatively fixed. This fixed position is used to position the subsequent push-in of the drawer 2. Then, the drawer 2 is pushed upward, causing the connecting piece 31 to rotate relative to the guide groove 22 until the elastic block 312 is aligned with another adjusting groove 222. The height of the drawer 2 returns to the same level as the protective piece 3. The specific state is as follows. Figure 3As shown, the drawer 2 is then pushed horizontally backward, and the connector 31 slides relative to the guide groove 22, guiding the drawer 2 into the compartment 11 and preventing it from tilting and squeezing the connector 21 when it is pushed into the compartment 11. When the guide part 311 slides to the front end of the guide groove 22, as shown... Figure 4 As shown, drawer 2 pushes connector 31 forward synchronously, connector 31 slides relative to protective member 3, and pushes limiting member 32 downward when it passes through limiting groove 321 on limiting member 32, so that limiting member 32 disengages from insertion groove. When connector 31 abuts against the rear end of connecting groove 33, it pushes protective member 3 to move backward synchronously, and insertion member 21 extends out from the slot on protective member 3. After drawer 2 moves into place, insertion member 21 is inserted into busbar system, and protective member 3 is magnetically fixed to the rear end face of compartment 11. The state of drawer 2 being fully pushed into compartment 11 is as follows. Figure 5 As shown, in order to reduce the friction when the drawer 2 slides relative to the compartment 11, the rear end of the drawer 2 is also provided with a roller 24, and the lower end of the compartment 11 is provided with a guide rail. The roller 24 rolls in contact with the guide rail. To facilitate operation by the staff, the front end face of the drawer 2 is also fixed with a handle 23.

[0040] The modular ring main unit provided by this invention provides protection for the connectors at the rear of the drawer during the sliding of the drawer relative to the compartment, preventing collisions between the connectors and the electrical connection between the electronic components inside the drawer and the busbar system of the unit. In addition, the protective mechanism can also position and guide the drawer when it is inserted into the compartment, improving the insertion accuracy of the drawer and facilitating the operation of the staff.

[0041] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0042] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0043] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A modular ring main unit, comprising a cabinet (1) and a plurality of drawers (2), a busbar system being arranged in the cabinet (1), a plurality of compartments (11) being arranged on the cabinet (1), each of the drawers (2) being in pullable cooperation with each of the compartments (11), a plug-in connector (21) being arranged at a rear end of each of the drawers (2), the plug-in connector (21) being in plug-in cooperation and electrical connection with the busbar system, characterized in that, The drawer (2) is provided with a protective mechanism, which includes a protective component (3) and a connector (31). The connector (31) slides with the side wall of the drawer (2) and rotates relative to the rear end of the drawer (2). The connector (31) is elastically limited with the side wall of the drawer (2). The protective component (3) is located on the rear side of the drawer (2). The protective component (3) is provided with a slot to avoid the connector (21). The protective component (3) slides with the connector (31) and is elastically limited.

2. A modular ring main unit according to claim 1, characterized in that, The protective component (3) has a connecting groove (33) at its front end. The connecting component (31) is slidably engaged with the connecting groove (33). The protective component (3) is also longitudinally slidably connected with a limiting component (32). The lower end of the limiting component (32) is connected to the protective component (3) through an elastic component (322). The limiting component (32) has a limiting groove (321). The connecting component (31) is movably inserted into the limiting groove (321). The lower end of the limiting groove (321) is an inclined surface that slopes upward from front to back. When the connecting component (31) is inserted into the limiting groove (321), the limiting component (32) squeezes the elastic component (322). When the elastic component (322) extends naturally, the upper end of the limiting component (32) extends to the upper side of the protective component (3). The upper end of the limiting component (32) is movably inserted into the compartment (11).

3. A modular ring main unit according to claim 2, characterized in that, The compartment (11) is provided with a plug slot, and the upper end face of the limiting member (32) is inclined downward from front to back.

4. A modular ring main unit according to claim 2, characterized in that, The protective component (3) is magnetically engaged with the rear end face of the compartment (11). The connecting groove (33) is provided with two limiting holes (331). The rear side of the connector (31) is provided with an elastic protrusion (313) that is movably inserted into the two limiting holes (331). When the connector (31) moves to the point where the elastic protrusion (313) is opposite to the front limiting hole (331), it separates from the limiting component (32).

5. A modular ring main unit according to claim 4, characterized in that, The drawer (2) has a guide groove (22) on its side wall, and the front end of the connector (31) has a guide part (311). The guide part (311) slides with the guide groove (22), and the guide part (311) rotates with the rear end of the guide groove (22).

6. A modular ring main unit according to claim 5, characterized in that, The guide part (311) is provided with an elastic block (312), and the guide groove (22) is provided with a slot (221) that is movably inserted into the elastic block (312). The force required for the elastic block (312) to disengage from the slot (221) is greater than the force required for the elastic protrusion (313) to disengage from the limiting hole (331).

7. A modular ring main unit according to claim 6, characterized in that, The rear end of the guide groove (22) is provided with two adjustment grooves (222). When the connector (31) rotates relative to the guide groove (22), the elastic block (312) is movably inserted into the two adjustment grooves (222).

8. A modular ring main unit according to claim 1, characterized in that, There are two connectors (31), which slide against the opposite side walls of the drawer (2) respectively. The front end of the protective part (3) is provided with two connecting grooves (33), and the two connectors (31) slide with the two connecting grooves (33) respectively.

9. A modular ring main unit according to claim 1, characterized in that, The drawer (2) is also provided with a roller (24) at the rear end. The roller (24) makes rolling contact with the compartment (11). The lower end of the compartment (11) is provided with a guide rail. The roller (24) rolls in cooperation with the guide rail.

10. A modular ring main unit according to claim 1, characterized in that, The front end face of the drawer (2) is provided with a handle (23).

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