Bus duct connection type jack box and use method thereof

Abstract

The invention relates to the field of power transmission systems, in particular to a bus duct connection type plug box which comprises a fixing support installed on a wall through screws, a box body arranged on the fixing support, a fire extinguishing mechanism arranged on the top of the box body and used for a bus duct, and a double-door bottom plate arranged at the joint of the box body and the fire extinguishing mechanism. A plurality of sets of top fixing blocks are evenly distributed at the bottom of the double-door bottom plate, a plurality of sets of side fixing blocks are arranged on the surfaces of the inner walls of the two sides of the box body, nylon fixing lines are arranged at the top fixing blocks and the side fixing blocks in a penetrating mode, and the two ends of the nylon fixing lines are fixed to the connecting corners of the bottom plate and the side plates of the box body respectively; a guide sliding rail is arranged at the bottom of the inner side of the back plate of the box body, and a sealing mechanism is arranged on the guide sliding rail. When the bus duct main body is on fire, the fire on the bus duct main body is extinguished through the fire extinguishing powder, so that greater loss caused by fire spreading is prevented, and the safety of equipment is improved.

Description

Technical Field

[0001] The present invention relates to the field of power transmission systems, and in particular to a bus duct connection type plug-in box and a use method thereof. Background Art

[0002] As a key tapping device in power transmission systems, busbar duct junction boxes typically consist of conductive components, plug-in claws, and a metal casing. Busbar ducts are enclosed metal devices made of copper and aluminum conductors. They are primarily used for the centralized transmission and distribution of high-power electrical energy in power systems, replacing traditional cables in indoor low-voltage power distribution scenarios. Their core function is to achieve efficient and safe current transmission through low-impedance conductors, making them particularly suitable for high-current scenarios and commonly used in power supply scenarios such as data centers and industrial plants. The main structure of a traditional plug-in box is usually a metal box covering the outside of the bus duct. When the bus duct is used for a long time or the environment is humid, the contact surface of the plug claws is oxidized, the contact surface of the plug connector is oxidized or the bolts are loose, which will lead to increased contact resistance and Joule heat accumulation causing local burning. Long-term use in a high temperature, dusty or chemically corrosive environment can also easily cause the insulation material on the outside of the line to crack, causing leakage or short circuit. When leakage or short circuit occurs, it is easy for the insulation layer to catch fire due to local heat accumulation. If the circuit fire is not extinguished in time, it will often lead to rapid expansion of the hazard and cause more losses. In order to be able to extinguish the fire in a timely and effective manner, improve safety and reduce the losses caused by the fire, a bus duct connection plug-in box and a method of use thereof are proposed. Summary of the Invention

[0003] In order to solve the technical problems existing in the above-mentioned prior art, the present invention provides a bus duct connection type plug-in box and a method of using the same.

[0004] In order to solve the above technical problems, the present invention provides the following technical solutions: a bus duct connection type plug-in box, comprising a fixing bracket mounted on a wall by screws, a box body disposed on the fixing bracket, a fire extinguishing mechanism for the bus duct disposed on the top of the box body, a double-door bottom plate disposed at the junction of the box body and the fire extinguishing mechanism, and a plurality of groups of top fixing blocks evenly arranged on the bottom of the double-door bottom plate, The inner wall surfaces on both sides of the box are provided with a plurality of side fixing blocks. Nylon fixing lines are provided through the top fixing block and the side fixing blocks, and the two ends of the nylon fixing lines are respectively fixed to the corner positions where the bottom plate and the side plate of the box are connected; A guide rail is provided at the bottom inner side of the back plate of the box body, and a sealing mechanism is provided on the guide rail; Wherein, the sealing mechanism is used to isolate the interior of the box from the external air.

[0005] Preferably, a bottom support plate is provided on the bottom side of the fixing bracket, a support plate is provided at the bottom of the bottom support plate, the box body is placed on the top of the bottom support plate, the back of the box body is connected to the fixing bracket by bolts, and the box body bottom plate is connected to the bottom support plate by bolts.

[0006] Preferably, the box body includes a bottom heat dissipation grille, a top heat dissipation grille and a bus duct body. The bottom heat dissipation grille is opened at the bottom end of the box side panel, and two groups of top heat dissipation grilles are respectively arranged at the top of the box door and the top of the box back panel. The bus duct body is arranged in the middle position of the box body.

[0007] Preferably, the fire extinguishing mechanism includes a storage box and a material cavity, the storage box is fixed to the top of the box body, the interior of the storage box constitutes a material cavity, and the fire extinguishing powder is stored in the material cavity.

[0008] Preferably, the double-door bottom plate includes a bottom plate body and a bottom plate docking tongue and groove. The bottom plate body is arranged at the bottom of the material cavity. The bottom plate body is connected to the bottom edge of the storage box through a rotating shaft. The bottom plate docking tongue and groove is arranged at the splicing position of two groups of bottom plate bodies. The width of the bottom plate body is greater than the height of the top heat dissipation grille.

[0009] Preferably, several groups of the top fixing blocks are evenly arranged on the bottom surface of the bottom plate body, and a through hole connected to the nylon fixing line is provided in the middle of the top fixing block.

[0010] Preferably, the guide rail includes a rail body and a limiting spring piece. Two groups of the rail bodies are arranged on both sides of the bus duct body. The rail body is vertically fixed to the inner surface of the back plate of the box body, and the limiting spring piece is arranged in the side opening of the rail body.

[0011] Preferably, the sealing mechanism includes a slider, a sealing plate and a material receiving trough, the slider is mounted on the side of the slide rail body, the sealing plate is fixed to the side of the slider, the sealing plate fits with the inner surface of the side panel of the box body, the height of the sealing plate is greater than the height of the bottom heat dissipation grille opening, and the material receiving trough is arranged on the top of the sealing plate.

[0012] A method for using a bus duct connection type plug-in box, comprising the following steps: Step A: Install the fixing bracket and the box; Step B: Install the fire extinguishing mechanism; Step C, installing the sealing mechanism; Step D: when the bus duct body is on fire, the fire extinguishing mechanism is activated; Step E: Start the sealing mechanism.

[0013] The step A comprises: Step A1: Determine the installation height of the plug-in box on the wall by measuring, place the fixing bracket on the wall surface where the plug-in box is to be installed, and fix the fixing bracket to the wall with screws; Step A2: Place the box on top of the bottom support plate, install bolts to secure the bottom of the box to the bottom support plate, and install bolts to secure the back of the box to the fixing bracket; Step A3: Install the bus duct body in the box and connect the bus duct body to the circuit to be connected; The step B comprises: Step B1: Fill the fire extinguishing powder into the material cavity, close the bottom plate body, and mate the bottom plate tongue and groove at the joint of the bottom plate body; Step B1: align the bottom of the storage box with the top opening of the box body so that the bottom plate of the double door is located at the junction of the storage box and the box body; Step B2: Pass the nylon fixing line through the side fixing block and the top fixing block, tighten the nylon fixing line, and fix the two ends of the nylon fixing line to the corners where the bottom plate and the side plate of the box are connected; The step C comprises: Step C1: vertically fix the two sets of slide rail bodies to the bottom inner side of the back plate of the box; Step C2: Install the slider connected with the sealing plate and the material receiving trough onto the top of the slide rail body, so that the bottom of the slider abuts against the top of the limiting spring, and the sealing plate fits against the inner surface of the side panel of the box body; The step D comprises: Step D1: When the bus duct body is on fire, the nylon fixing wire inside the box is burned off due to the fire; Step D2: After the nylon fixing wire is burned, the bottom of the base plate body, which was originally supported and fixed by the nylon fixing wire, loses its support. The gravity of the fire extinguishing powder in the material cavity causes the base plate body to flip downward around the rotating axis; Step D3: After the bottom plate body is flipped open downward, the fire extinguishing powder in the material cavity loses its support and falls downward onto the bus duct body, extinguishing the fire on the bus duct body through the fire extinguishing powder; Step D4: The bottom plate body is flipped downward and covers the inner side of the top heat dissipation grille, thereby sealing the top heat dissipation grille with the bottom plate body; The step E comprises, Step E1: When the fire extinguishing mechanism is activated, a portion of the fire extinguishing dry powder falls into the receiving trough, pressing the receiving trough downward; In step E2, after the fire extinguishing powder is received in the receiving trough, gravity increases, pushing the slider downward. The limiting spring is squeezed by the slider and deforms and contracts into the side opening of the slide rail body, causing the slider to drive the sealing plate downward. Step E2: When the sealing plate falls to the bottom of the inner side of the box, it covers the inner side of the bottom heat dissipation grille, and the bottom heat dissipation grille is sealed by the sealing plate.

[0014] Compared with the prior art, the beneficial effects of the present invention are: 1. The present invention is provided with a fixing bracket, a box body, a fire extinguishing mechanism, a double-door bottom plate, a top fixing block, a side fixing block, a nylon fixing wire, a guide rail and a sealing mechanism. When a fire occurs in the bus duct body, the nylon fixing wire inside the box body is burned due to the fire; after the nylon fixing wire is burned, the bottom of the bottom plate body, which was originally supported and fixed by the nylon fixing wire, loses its support. Under the action of the gravity of the fire extinguishing powder in the material cavity, the bottom plate body flips downward around the rotating axis; after the bottom plate body flips downward and opens, the fire extinguishing powder in the material cavity that has lost its support falls downward onto the bus duct body, and the fire on the bus duct body is extinguished by the fire extinguishing powder. Therefore, when a fire occurs in the bus duct, the fire can be automatically extinguished, preventing the fire from spreading and causing greater losses, thereby improving the safety of the equipment; 2. The present invention also provides a sealing mechanism, which includes a slider, a sealing plate and a material receiving trough. When the fire extinguishing mechanism is activated, the bottom plate body flips downward and covers the inner side of the top heat dissipation grille, and the top heat dissipation grille is blocked by the bottom plate body. A part of the fire extinguishing dry powder falls into the material receiving trough, pressing the material receiving trough downward. After the fire extinguishing dry powder is received in the material receiving trough, the gravity increases, pushing the slider downward, and the limiting spring piece is squeezed by the slider and deformed and contracts to the inside of the side opening of the slide rail body, so that the slider drives the sealing plate to fall. When the sealing plate falls to the bottom of the inner side of the box body, it covers the inner side of the bottom heat dissipation grille and blocks the bottom heat dissipation grille through the sealing plate. By blocking the heat dissipation grille, the box body becomes closed when a fire occurs, isolating the inside of the box body from the outside air, so that the fire is quickly weakened due to the reduction of oxygen, thereby improving the fire extinguishing efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention; Figure 2 This is a schematic structural diagram of the door of the present invention in an open state; Figure 3 Schematic diagram of the bottom structure of the present invention; Figure 4 It is a schematic diagram of the internal partial structure of the present invention; Figure 5 It is a partial cross-sectional schematic diagram of the fire extinguishing state of the present invention; Figure 6 This is a schematic diagram of the internal structure of the present invention in a fire extinguishing state; Figure 7 This is a schematic diagram of the local structure of the bottom end of the present invention in a fire extinguishing state; Figure 8 It is a partial schematic diagram of the top of the fire extinguishing state of the present invention; Figure 9 It is a partially expanded schematic diagram of the sealing mechanism of the present invention.

[0016] Figure numerals: 1. Fixed bracket; 11. Bottom support plate; 12. Support plate; 2. Box body; 21. Bottom heat dissipation grille; 22. Top heat dissipation grille; 23. Bus duct body; 3. Fire extinguishing mechanism; 31. Storage box; 32. Material cavity; 4. Double door bottom plate; 41. Bottom plate body; 42. Bottom plate docking tongue and groove; 5. Top fixing block; 6. Side fixing block; 7. Nylon fixing line; 8. Guide rail; 81. Slide rail body; 82. Limiting spring piece; 9. Sealing mechanism; 91. Slider; 92. Sealing plate; 93. Material receiving trough. DETAILED DESCRIPTION

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments, with respect to the above and other technical features and advantages of the present invention. However, the following embodiments are merely preferred embodiments of the present invention and are not exhaustive.

[0018] Example: Figure 1 - Figure 9 As shown, the present invention provides a bus duct connection type plug-in box, comprising a fixing bracket 1 mounted on a wall by screws, a box body 2 is provided on the fixing bracket 1, a fire extinguishing mechanism 3 for the bus duct is provided on the top of the box body 2, a double-door bottom plate 4 is provided at the junction of the box body 2 and the fire extinguishing mechanism 3, and a plurality of groups of top fixing blocks 5 are evenly arranged on the bottom of the double-door bottom plate 4. The inner wall surfaces on both sides of the box body 2 are provided with a plurality of side fixing blocks 6. Nylon fixing lines 7 are provided through the top fixing block 5 and the side fixing block 6, and the two ends of the nylon fixing lines 7 are respectively fixed to the corner positions where the bottom plate and the side plate of the box body 2 are connected; A guide rail 8 is provided at the bottom inner side of the back plate of the box body 2, and a sealing mechanism 9 is provided on the guide rail 8; The sealing mechanism 9 is used to isolate the interior of the box 2 from the external air.

[0019] A bottom support plate 11 is provided on the bottom side of the fixed bracket 1, and a support plate 12 is provided at the bottom of the bottom support plate 11. The box body 2 is placed on the top of the bottom support plate 11. The back of the box body 2 is connected to the fixed bracket 1 by bolts, and the bottom plate of the box body 2 is connected to the bottom support plate 11 by bolts. The connection between the bottom support plate 11 and the fixed bracket 1 is reinforced by the support plate 12 to improve the stability of the bottom support plate 11 supporting the box body 2.

[0020] The box body 2 includes a bottom heat dissipation grille 21, a top heat dissipation grille 22 and a bus duct body 23. The bottom heat dissipation grille 21 is opened at the bottom end of the side panel of the box body 2. Two groups of top heat dissipation grilles 22 are respectively arranged at the top of the box door of the box body 2 and the top of the back panel of the box body 2. The bus duct body 23 is arranged in the middle position of the box body 2. The bottom heat dissipation grille 21 and the top heat dissipation grille 22 form an air flow channel inside the box body 2. The hot air rises and is quickly discharged from the top heat dissipation grille 22, thereby improving the heat dissipation efficiency of the internal components of the box body 1.

[0021] The fire extinguishing mechanism 3 includes a storage box 31 and a material cavity 32 . The storage box 31 is fixed to the top of the box body 2 . The interior of the storage box 31 forms a material cavity 32 . The material cavity 32 stores fire extinguishing powder.

[0022] The double-door bottom plate 4 includes a bottom plate main body 41 and a bottom plate docking groove 42. The bottom plate main body 41 is arranged at the bottom of the material cavity 32. The bottom plate main body 41 is connected to the bottom edge of the storage box 31 through a rotating shaft. The bottom plate docking groove 42 is arranged at the splicing position of the two groups of bottom plate main bodies 41. The width of the bottom plate main body 41 is greater than the height of the top heat dissipation grille 22. After the bottom plate main body 41 is flipped over, the top heat dissipation grille 22 is blocked to reduce the air from entering the interior of the box body 2.

[0023] Several groups of top fixing blocks 5 are evenly arranged on the bottom surface of the bottom plate body 41 , and a through hole connected to the nylon fixing line 7 is provided in the middle of the top fixing block 5 .

[0024] The guide rail 8 includes a rail body 81 and a limiting spring piece 82. Two sets of rail bodies 81 are arranged on both sides of the bus duct body 23. The rail body 81 is vertically fixed to the inner surface of the back plate of the box body 2, and the limiting spring piece 82 is arranged in the side opening of the rail body 81.

[0025] The sealing mechanism 9 includes a slider 91, a sealing plate 92 and a material receiving trough 93. The slider 91 is mounted on the side of the slide rail body 81, and the sealing plate 92 is fixed to the side of the slider 91. The sealing plate 92 fits the inner surface of the side plate of the box body 2. The height of the sealing plate 92 is greater than the height of the opening of the bottom heat dissipation grille 21, and the material receiving trough 93 is set at the top of the sealing plate 92.

[0026] How to use the bus duct connection plug-in box: Measure and determine the installation height of the plug-in box on the wall, place the fixing bracket 1 on the wall surface where the plug-in box is to be installed, and secure the fixing bracket 1 to the wall with screws; place the box 2 on top of the bottom support plate 11, install bolts to secure the bottom of the box 2 to the bottom support plate 11, and install bolts to secure the back of the box 2 to the fixing bracket 1; install the bus duct body 23 in the box 2, and connect the bus duct body 23 to the desired circuit; Fill the material chamber 32 with fire extinguishing powder, close the bottom plate body 41, and mate the bottom plate joint groove 42 at the joint of the bottom plate body 41; align the bottom of the storage box 31 with the top opening of the box body 2, so that the double-door bottom plate 4 is located at the junction of the storage box 31 and the box body 2; pass the nylon fixing line 7 through the side fixing block 6 and the top fixing block 5, tighten the nylon fixing line 7, and fix the two ends of the nylon fixing line 7 to the corner where the bottom plate and the side plate of the box body 2 meet; Fix the two sets of slide rail bodies 81 vertically to the bottom inner side of the back plate of the box body 2 respectively; install the slider 91 connected with the sealing plate 92 and the material receiving groove 93 on the top of the slide rail body 81, so that the bottom of the slider 91 abuts against the top of the limiting spring 82, and the sealing plate 92 fits against the inner surface of the side plate of the box body 2; When a fire occurs in the bus duct body 23, the nylon fixing wire 7 inside the box body 2 is burned off. After the nylon fixing wire 7 is burned off, the bottom of the base plate body 41, which was originally supported by the nylon fixing wire 7, loses its support. Under the action of the gravity of the fire extinguishing powder inside the material cavity 32, the base plate body 41 flips downward around the rotation axis. After the base plate body 41 flips downward and opens, the fire extinguishing powder in the material cavity 32, which has lost its support, falls downward onto the bus duct body 23, and the fire on the bus duct body 23 is extinguished by the fire extinguishing powder. The bottom plate body 41 flips downward and covers the inner side of the top heat dissipation grille 22 , and the top heat dissipation grille 22 is blocked by the bottom plate body 41 .

[0027] When the fire extinguishing mechanism 3 is activated, a portion of the fire extinguishing dry powder falls into the receiving trough 93, pressing the receiving trough 93 downward; after the fire extinguishing dry powder is received in the receiving trough 93, the gravity increases, pushing the slider 91 downward, and the limiting spring piece 82 is squeezed by the slider 91 and deformed and shrinks to the inside of the side opening of the slide rail body 81, so that the slider 91 drives the sealing plate 92 to fall; when the sealing plate 92 falls to the bottom inside the box body 2, it covers the inside of the bottom heat dissipation grille 21, and the bottom heat dissipation grille 21 is blocked by the sealing plate 92.

[0028] The above description is merely a preferred embodiment of the present invention and is intended to be illustrative rather than restrictive of the present invention. Those skilled in the art will appreciate that many changes, modifications, and even equivalents may be made to the present invention within the spirit and scope of the claims, all of which fall within the scope of protection of the present invention.

Claims

1. A bus duct connection type plug-in box, characterized in that: The utility model comprises a fixing bracket (1) mounted on a wall by screws, a box (2) is provided on the fixing bracket (1), a fire extinguishing mechanism (3) for a bus duct is provided on the top of the box (2), a double-door bottom plate (4) is provided at the junction of the box (2) and the fire extinguishing mechanism (3), and a plurality of groups of top fixing blocks (5) are evenly arranged at the bottom of the double-door bottom plate (4). The inner wall surfaces on both sides of the box body (2) are provided with a plurality of side fixing blocks (6). Nylon fixing lines (7) are provided through the top fixing block (5) and the side fixing block (6), and the two ends of the nylon fixing lines (7) are respectively fixed to the corner positions where the bottom plate and the side plate of the box body (2) are connected; A guide rail (8) is provided at the bottom inner side of the back plate of the box body (2), and a sealing mechanism (9) is provided on the guide rail (8); The sealing mechanism (9) is used to isolate the interior of the box (2) from the external air.

2. A bus duct connection type plug-in box according to claim 1, characterized in that: A bottom support plate (11) is provided on the bottom side of the fixing bracket (1), a support plate (12) is provided on the bottom of the bottom support plate (11), the box body (2) is placed on the top of the bottom support plate (11), the back of the box body (2) is connected to the fixing bracket (1) by bolts, and the bottom plate of the box body (2) is connected to the bottom support plate (11) by bolts.

3. The bus duct connection type plug-in box according to claim 1, characterized in that: The box body (2) comprises a bottom heat dissipation grille (21), a top heat dissipation grille (22) and a bus duct body (23); the bottom heat dissipation grille (21) is provided at the bottom end of the side panel of the box body (2); two groups of the top heat dissipation grilles (22) are respectively provided at the top of the box door of the box body (2) and the top end of the back panel of the box body (2); and the bus duct body (23) is provided at the middle position inside the box body (2).

4. The bus duct connection type plug-in box according to claim 1, characterized in that: The fire extinguishing mechanism (3) comprises a storage box (31) and a material cavity (32). The storage box (31) is fixed to the top of the box body (2). The interior of the storage box (31) forms a material cavity (32), and the material cavity (32) stores fire extinguishing powder.

5. The bus duct connection type plug-in box according to claim 1, characterized in that: The double-door bottom plate (4) comprises a bottom plate body (41) and a bottom plate joint groove (42); the bottom plate body (41) is arranged at the bottom of the material cavity (32); the bottom plate body (41) is connected to the bottom edge of the storage box (31) via a rotating shaft; the bottom plate joint groove (42) is arranged at the joint position of two groups of bottom plate bodies (41); the width of the bottom plate body (41) is greater than the height of the top heat dissipation grille (22).

6. The bus duct connection type plug-in box according to claim 1, characterized in that: Several groups of the top fixing blocks (5) are evenly arranged on the bottom surface of the bottom plate body (41), and a through hole connected to the nylon fixing line (7) is provided in the middle of the top fixing block (5).

7. The bus duct connection type plug-in box according to claim 1, characterized in that: The guide rail (8) comprises a rail body (81) and a limiting spring piece (82). Two groups of the rail bodies (81) are respectively arranged on both sides of the bus duct body (23). The rail bodies (81) are vertically fixed to the inner surface of the back plate of the box body (2). The limiting spring piece (82) is arranged in the side opening of the rail body (81).

8. The bus duct connection type plug-in box according to claim 1, characterized in that: The sealing mechanism (9) includes a slider (91), a sealing plate (92) and a material receiving trough (93), wherein the slider (91) is mounted on the side of the slide rail body (81), the sealing plate (92) is fixed to the side of the slider (91), the sealing plate (92) is in contact with the inner surface of the side plate of the box body (2), the height of the sealing plate (92) is greater than the height of the opening of the bottom heat dissipation grille (21), and the material receiving trough (93) is arranged on the top of the sealing plate (92).

9. A method for using a bus duct connection type plug-in box according to any one of claims 1 to 8, characterized in that: The following steps are involved: Step (A), installing the fixing bracket (1) and the box (2); Step (B), installing the fire extinguishing mechanism (3); Step (C), installing the sealing mechanism (9); Step (D): when the bus duct body (23) catches fire, the fire extinguishing mechanism (3) is activated; Step (E), starting of the sealing mechanism (9).

10. The method for using a bus duct connection type plug-in box according to claim 9, characterized in that: The step (A) comprises: Step (A1), determining the installation height of the plug-in box on the wall by measuring, placing the fixing bracket (1) on the wall surface where the plug-in box is to be installed, and fixing the fixing bracket (1) to the wall by screws; Step (A2), placing the box body (2) on top of the bottom support plate (11), installing bolts to fix the bottom of the box body (2) to the bottom support plate (11), and installing bolts to fix the back of the box body (2) to the fixing bracket (1); Step (A3), installing the bus duct body (23) in the box (2), and connecting the bus duct body (23) to the circuit to be connected; The step (B) comprises, Step (B1), filling the fire extinguishing powder into the material cavity (32), closing the bottom plate body (41), and fitting the bottom plate joint tongue and groove (42) at the joint of the bottom plate body (41); Step (B1), docking the bottom of the storage box (31) with the top opening of the box body (2), so that the double-door bottom plate (4) is located at the junction of the storage box (31) and the box body (2); Step (B2), pass the nylon fixing line (7) through the side fixing block (6) and the top fixing block (5), tighten the nylon fixing line (7), and fix the two ends of the nylon fixing line (7) to the corners where the bottom plate and the side plate of the box body (2) are connected; The step (C) comprises, Step (C1), vertically fixing the two sets of slide rail bodies (81) to the bottom inner side of the back plate of the box body (2); Step (C2), inserting the slider (91) connected with the sealing plate (92) and the material receiving trough (93) onto the top of the slide rail body (81), so that the bottom of the slider (91) abuts against the top of the limiting spring (82), and the sealing plate (92) fits against the inner surface of the side plate of the box body (2); The step (D) comprises, Step (D1), when the bus duct main body (23) catches fire, the nylon fixing wire (7) inside the box body (2) is burned due to the fire; In step (D2), after the nylon fixing wire (7) is burned, the bottom of the base plate body (41) originally supported and fixed by the nylon fixing wire (7) loses its support, and the base plate body (41) is turned downward around the rotation axis under the gravity of the fire extinguishing powder inside the material cavity (32); Step (D3), after the bottom plate body (41) is flipped downward and opened, the fire extinguishing powder in the material cavity (32) loses its support and falls downward onto the bus duct body (23), and the fire on the bus duct body (23) is extinguished by the fire extinguishing powder; Step (D4), the bottom plate body (41) is turned downward and covers the inner side of the top heat dissipation grille (22), and the top heat dissipation grille (22) is blocked by the bottom plate body (41); The step (E) comprises, Step (E1), when the fire extinguishing mechanism (3) is activated, a portion of the fire extinguishing dry powder falls into the receiving trough (93), pressing the receiving trough (93) downward; In step (E2), after the fire extinguishing dry powder is received in the receiving trough (93), gravity increases, pushing the slider (91) downward, and the limiting spring (82) is squeezed by the slider (91) to deform and shrink into the side opening of the slide rail body (81), so that the slider (91) drives the sealing plate (92) to fall; In step (E2), the sealing plate (92) falls to the bottom of the inner side of the box body (2) and covers the inner side of the bottom heat dissipation grille (21), thereby sealing the bottom heat dissipation grille (21) through the sealing plate (92).

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