Enclosed high-voltage drop-out fuse

Abstract

This utility model discloses a closed-type high-voltage drop-out fuse, including an insulator, an upper contact seat, a lower contact seat, and a fully enclosed fuse tube. The insulator has an inlet socket and an outlet socket with insulating shells at both ends, which are integrally encapsulated with the insulator. The upper and lower contact seats are integrally encapsulated with the insulator and covered with an insulating material layer. The main fuse wire in the fuse tube is wound around the outer surface of a ceramic quartz column, and quartz sand is filled between the epoxy tube and the ceramic quartz column. This utility model achieves complete insulation and enclosure of all conductor structural components of the high-voltage fuse. Simultaneously, the fuse tube also adopts a fully enclosed structure, achieving overall complete insulation to avoid short circuits or grounding accidents caused by external foreign objects, and preventing explosive ejection when the fuse drops.

Description

Technical Field

[0001] This utility model relates to a high-voltage drop-out fuse, specifically a closed high-voltage drop-out fuse. Background Technology

[0002] High-voltage drop-out fuses are widely used protective devices in power distribution systems, typically installed at the input terminal of transformer platforms. They are primarily used for maintenance interruption on the primary side of the transformer and for short-circuit protection on the high-voltage side. Their basic structure includes a fuse tube, upper contact, lower contact, insulator, mounting bracket, and terminals. The mounting bracket connects to the middle of the insulator, supporting the entire fuse and ensuring grounding safety. Terminals include an input terminal and an output terminal located at the top and bottom of the insulator, respectively. The upper contact is fixed to the upper part of the insulator and electrically connected to the input terminal, while the lower contact is fixed to the lower part of the insulator and electrically connected to the output terminal. The fuse tube, as the core component, is installed between the upper and lower contact terminals. It is filled with an arc-extinguishing medium and contains a fuse wire, forming a conductive path from the input terminal to the upper contact, fuse wire, lower contact, and output terminal. When the current is too high, the fuse wire melts, cutting off the circuit. Simultaneously, the disconnected fuse wire releases the positioning mechanism at the lower end of the fuse tube, causing the fuse tube to drop.

[0003] However, existing high-voltage drop-out fuses still have problems:

[0004] 1. The incoming and outgoing terminals of the fuse, as well as the upper and lower contacts and other power transmission carriers, are all exposed to the air. They are prone to phase-to-phase short circuits due to strong winds, foreign objects, falling branches, or small animal activity. Furthermore, the carbonized residue formed after a fault is difficult to clean, which seriously affects the reliability of the equipment and the efficiency of operation and maintenance.

[0005] 2. Most existing fuses use a jet-type fuse tube structure, which generates a high-temperature electric arc and explosive impact when interrupting fault current, and sprays burning residue downwards. If the fuse is installed in a flammable environment (such as a densely vegetated area), the high-temperature residue may ignite combustibles below, causing secondary accidents such as fires, posing a significant safety defect. Utility Model Content

[0006] This invention proposes a closed-type high-voltage drop-out fuse, the purpose of which is to solve the problem that exposed current-carrying components and the interruption of the fuse can easily cause fires.

[0007] The technical solution of this utility model is as follows:

[0008] A closed-type high-voltage drop-out fuse includes a mounting bracket, an insulator, an inlet end, an outlet end, an upper contact seat, a lower contact seat, and a fuse tube. The mounting bracket is connected to the middle of the insulator. The inlet end and the outlet end are located at the top and bottom of the insulator, respectively. The upper contact seat is fixed to the upper part of the insulator and electrically connected to the inlet end. The lower contact seat is fixed to the lower part of the insulator and electrically connected to the outlet end. The fuse tube is installed between the upper and lower contact seats. A fuse wire and an impactor are installed inside the fuse tube. The impactor's impact post pops out when the fuse wire melts, causing the fuse tube to drop. The inlet end and the outlet end are respectively an inlet socket and an outlet socket with an insulating shell. The inlet socket and the outlet socket are encapsulated as a whole with the insulator.

[0009] The first conductor portion connected to the incoming line socket at the left end of the upper contact base is encapsulated as a single unit with the insulator, and an insulating material layer is provided on the outer surface of the upper contact base; the right end of the upper contact base is provided with an upper contact piece and a first spring for pushing the upper contact piece downward;

[0010] The second conductor portion connected to the outlet socket at the left end of the lower contact base is encapsulated as a single unit with the insulator, and an insulating material layer is provided on the outer surface of the lower contact base; the lower contact base is also provided with a lower contact piece and a first hook for engaging with the positioning shaft at the lower end of the fuse tube; the lower contact piece is electrically connected to the outlet socket through the second conductor portion;

[0011] The fusion tube includes an epoxy tube, and also includes a metal cap and a metal seat respectively installed at the upper and lower ends of the epoxy tube; the metal cap is in contact with the upper contact piece, and the metal seat is electrically connected to the lower contact piece; a hollow ceramic quartz column is installed inside the epoxy tube, and the fusion wire is a main fusion wire wound around the outer surface of the ceramic quartz column; the space between the epoxy tube and the ceramic quartz column is filled with quartz sand.

[0012] The tension wire inside the impactor is connected in parallel with the main fuse between the metal cap and the metal seat.

[0013] As a further improvement to the aforementioned enclosed high-voltage drop-out fuse: the front and rear sides of the upper contact base are provided with downwardly extending first insulating shield plates;

[0014] The lower contact base has a second insulating shield plate extending to the right on both the front and rear sides.

[0015] As a further improvement to the enclosed high-voltage drop-out fuse: the upper contact is located between two first insulating shields, and the lower contact and the first hook are located between two second insulating shields.

[0016] As a further improvement to the enclosed high-voltage drop-out fuse, a gap is left between the first insulating shield and the second insulating shield.

[0017] As a further improvement to the aforementioned enclosed high-voltage drop-out fuse: the impactor also includes a metal housing and a second spring; the metal housing is installed in the inner hole of the metal base and is electrically connected to the metal base; the impact post is a conductor, and its lower end slides in contact with the metal housing to achieve a conductive connection; the second spring is installed in the metal housing and is used to push the impact post downward; the tension wire passes through the second spring, its lower end is connected to the upper end of the impact post, its upper end is fixedly connected to the insulating block in the inner hole of the ceramic quartz post, and is electrically connected to the metal cap through a connecting wire.

[0018] As a further improvement to the aforementioned enclosed high-voltage drop-out fuse: the connecting wire is disposed in the inner hole of the ceramic quartz column.

[0019] As a further improvement to the aforementioned enclosed high-voltage drop-out fuse: the fuse tube also includes a rotating frame and a rotating plate;

[0020] The upper part of the rotating frame is rotatably connected to the metal base, and the metal base is electrically connected to the lower contact piece through the rotating frame made of conductive material;

[0021] The positioning shaft is located at the lower part of the rotating frame; the end of the positioning shaft is used to engage with the first hook facing upward on the lower contact seat.

[0022] The middle part of the rotating plate is rotatably connected to the metal seat and a torsion spring is installed at the connection. The left end of the rotating plate is provided with a downward-facing second hook. Under the action of the torsion spring, the second hook is engaged with and in contact with the middle part of the positioning shaft. The right end of the rotating plate corresponds to the position of the impact column.

[0023] Compared with the prior art, the present invention has the following advantages:

[0024] 1. This utility model achieves full insulation and sealing of all conductor structural components of the high-voltage fuse. After on-site installation, it can achieve overall full insulation without the need for an external insulating sleeve, thereby avoiding short circuits or grounding accidents caused by external foreign objects.

[0025] 2. The fuse tube of this utility model has a fully enclosed structure, with the main fuse located between the ceramic quartz column and the quartz sand. Firstly, in the event of a short-circuit fault, the internal quartz sand can interrupt the arc, preventing explosive ejection. The entire interruption process is free of explosive noise, pollutant generation, and falling flammable materials, thus having no impact on surrounding equipment or the environment. Secondly, the main fuse is not exposed to air and will not age or fail due to external environmental influences, ensuring reliable interruption and arc extinguishing throughout its entire lifespan. Furthermore, the fully enclosed structure effectively avoids fuse failure caused by improper installation, incorrect installation, or substitution with wire by on-site construction personnel. Attached Figure Description

[0026] Figure 1This is a schematic diagram of the structure of the fuse of this utility model;

[0027] Figure 2 for Figure 1 A magnified view of part A in the middle;

[0028] Figure 3 This is a schematic diagram of the structure of this utility model when connected with the inlet plug and outlet plug;

[0029] Figure 4 This is a cross-sectional view of the fusion tube;

[0030] Figure 5 for Figure 4 A magnified view of part B in the middle section;

[0031] Figure 6 This is a schematic diagram of the lower end of the fusion tube in the installed state.

[0032] Figure 7 This is a schematic diagram of the lower end of the fuse tube in the released state.

[0033] The reference numerals in the figures include:

[0034] 1. Mounting bracket; 2. Insulator; 3. Inlet socket; 4. Upper contact base; 4-1. Upper contact piece; 5. Fuse tube; 5-1. Metal cap; 5-2. Epoxy tube; 5-3. Quartz sand; 5-4. Ceramic quartz column; 5-5. Connecting wire; 5-6. Main fuse; 5-7. Metal base; 5-8. Impactor; 5-8-1. Metal housing; 5-8-2. Tensioning wire; 5-8-3. Second spring; 5-8-4. Impact post; 5-9. Rotating frame; 5-10. Positioning shaft; 5-11. Rotating plate; 6. Lower contact base; 7. Outlet socket; 8. Inlet plug; 9. Outlet plug. Detailed Implementation

[0035] The technical solution of this utility model will now be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments.

[0036] like Figure 1 and Figure 3 A closed-type high-voltage drop-out fuse includes a mounting bracket 1, an insulator 2, an inlet terminal, an outlet terminal, an upper contact seat 4, a lower contact seat 6, and a fuse tube 5.

[0037] Mounting bracket 1 is connected to the middle of insulator 2 and is used to mount the fuse on the external mounting bracket.

[0038] The inlet and outlet ends are located at the top and bottom of the insulator 2, respectively. In this embodiment, the inlet and outlet ends are respectively an inlet socket 3 and an outlet socket 7 with insulating shells, which are integrally encapsulated with the insulator 2. During manufacturing, the terminal blocks on the inlet and outlet sides of a conventional fuse are removed. When encapsulating the insulator 2, both ends are encapsulated integrally with the inlet socket 3 and outlet socket 7, or the separately encapsulated sockets are installed in the corresponding positions after the insulator 2 is encapsulated, forming a complete unit with the insulator 2. Figure 2 Correspondingly, insulated plugs (inlet plug 8 and outlet plug 9) are connected to the incoming and outgoing cables. During on-site installation, simply insert the plugs into the sockets and tighten the outer insulating sleeves to complete the electrical connection and achieve fully enclosed protection.

[0039] Furthermore, the upper contact seat 4 is fixed to the upper part of the insulator 2, and the first conductor portion of the left end of the upper contact seat 4 connected to the inlet socket 3 is encapsulated integrally with the insulator 2, and the outer surface of the upper contact seat 4 is provided with an insulating material layer. For example... Figure 2 The upper contact base 4 has an upper contact piece 4-1 and a first spring (hidden inside) for pushing the upper contact piece 4-1 downward. The upper contact base 4 has first insulating shield plates extending downward on the front and rear sides, and the upper contact piece 4-1 is located between the two first insulating shield plates.

[0040] Similarly, such as Figure 1 and Figure 3 The lower contact seat 6 is fixed to the lower part of the insulator 2. The second conductor portion of the left end of the lower contact seat 6, which connects to the outgoing socket 7, is integrally encapsulated with the insulator 2, and the outer surface of the lower contact seat 6 is provided with an insulating material layer. The lower contact seat 6 is also provided with a lower contact piece and a first hook for engaging with the positioning shaft 5-10 at the lower end of the fuse tube 5. The front and rear sides of the lower contact seat 6 are provided with second insulating shield plates extending to the right, and the lower contact piece and the first hook are located between the two second insulating shield plates.

[0041] During manufacturing, the upper guide frame of the traditional fuse is removed. When potting the insulator 2, the first conductor part and the second conductor part are potted together with the insulator 2. At the same time, the upper contact 4 and the lower contact 6 are fully encapsulated with insulating material, leaving only the fusible components (upper contact piece 4-1, lower contact piece, first hook, etc.) connected to the fuse tube 5 exposed.

[0042] Furthermore, a gap is left between the first insulating shield and the second insulating shield to facilitate maintenance personnel to observe the status of the fusible tube 5 installed between the upper contact 4 and the lower contact 6 from different angles. The right side of both sets of first insulating shields and the right side and bottom of both sets of second insulating shields are open, providing sufficient space for the fusible tube 5 to flip and fall.

[0043] Furthermore, such as Figure 4 and Figure 5The fusible tube 5 includes a fuse, an impactor 5-8, and an epoxy tube 5-2. It also includes a metal cap 5-1 and a metal base 5-7 respectively installed at the upper and lower ends of the epoxy tube 5-2. The metal cap 5-1 is in contact with the upper contact piece 4-1. An insulating pull ring is also installed on the metal cap 5-1.

[0044] The epoxy tube 5-2 possesses high strength and high pressure resistance, and houses a hollow ceramic-quartz column 5-4. The fuse is a main fuse 5-6 uniformly wound around the outer surface of the ceramic-quartz column 5-4, with its two ends connected to a metal cap 5-1 and a metal base 5-7, respectively. The main fuse 5-6 is made of pure silver or copper alloy and is designed with multiple breaks for different current specifications. The space between the epoxy tube 5-2 and the ceramic-quartz column 5-4 is filled with quartz sand 5-3.

[0045] The impactor 5-8 includes a metal housing 5-8-1, a tension wire 5-8-2, a second spring 5-8-3, and an impact post 5-8-4. The metal housing 5-8-1 is installed in the inner hole of a metal base 5-7 and is electrically connected to the metal base 5-7. The impact post 5-8-4 is a conductor, with its lower end sliding in contact with the metal housing 5-8-1 to achieve a conductive connection. The second spring 5-8-3 is installed in the metal housing 5-8-1 and is used to push the impact post 5-8-4 downwards. The tension wire 5-8-2 passes through the second spring 5-8-3, its lower end connected to the upper end of the impact post 5-8-4, and its upper end fixedly connected to an insulating block disposed in the inner hole of the ceramic quartz post 5-4. It is also electrically connected to the metal cap 5-1 through a connecting wire 5-5 disposed in the inner hole of the ceramic quartz post 5-4. The metal cap 5-1 is electrically connected to the lower metal seat 5-7 via connecting wire 5-5, tension wire 5-8-2, impact post 5-8-4, and metal shell 5-8-1. This allows the tension wire 5-8-2 and connecting wire 5-5 within the impactor 5-8 to be connected in parallel with the main fuse 5-6 between the metal cap 5-1 and the metal seat 5-7. The tension wire 5-8-2 is made of a low-melting-point alloy material (such as lead-based alloy), with a melting point significantly lower than that of the main fuse 5-6. During normal operation, the tension wire 5-8-2 is in a taut state, the elastic force generated by the second spring 5-8-3 is supported by an insulating block fixed in the inner hole of the ceramic quartz post 5-4, and the connecting wire 5-5 is in a relaxed state.

[0046] Furthermore, such as Figure 5 , Figure 6 and Figure 7The fusible tube 5 also includes a rotating frame 5-9 and a rotating plate 5-11. The upper part of the rotating frame 5-9 is rotatably connected to the metal seat 5-7, and the metal seat 5-7 is electrically connected to the lower contact piece through the conductive rotating frame 5-9. The positioning shaft 5-10 is located at the lower part of the rotating frame 5-9. The end of the positioning shaft 5-10 is used to engage with the upward-facing first hook on the lower contact seat 6. The middle part of the rotating plate 5-11 is rotatably connected to the metal seat 5-7, and a torsion spring is installed at the connection. The left end of the rotating plate 5-11 has a downward-facing second hook. Under the action of the torsion spring, the second hook engages with and remains in contact with the middle part of the positioning shaft 5-10. The right end of the rotating plate 5-11 corresponds to the position of the impact post 5-8-4.

[0047] During operation, due to the high resistance of connecting wire 5-5 and tension wire 5-8-2, the current flows sequentially through the inlet socket 3, upper contact seat 4, metal cap 5-1, main fuse 5-6, metal seat 5-7, rotating frame 5-9, lower contact seat 6, and outlet socket 7. The main fuse 5-6 is inside the epoxy tube 5-2 and is completely isolated from the outside. When the main fuse 5-6 melts due to overload current and generates an arc, the quartz sand 5-3 at the break absorbs the arc energy, melts, and forms a high-resistance state, cutting off and extinguishing the high-voltage arc, thus blocking the fault current. After the main fuse 5-6 is disconnected, the large current in the circuit is cut off. The current will flow through the tension wire 5-8-2, causing the tension wire 5-8-2 to disconnect. This causes the second spring 5-8-3 to eject the impact post 5-8-4, which then impacts the right end of the rotating plate 5-11. This causes the second hook on the left end of the rotating plate 5-11 to disengage from the positioning shaft 5-10, releasing the rotating frame 5-9 (as shown). Figure 7 As shown in the figure, the fuse tube 5 falls naturally under the action of gravity, completing the drop break. Since the current passing through the tension wire 5-8-2 is very small after the main fuse 5-6 is broken, no electric arc will be generated in the impactor, and no burning material will be sprayed out of the fuse tube 5 during the entire breaking process.

[0048] It should be noted that, as will be apparent to those skilled in the art, this utility model is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this utility model. The scope of this utility model is defined by the claims rather than the foregoing description.

Claims

1. A closed-type high-voltage drop-out fuse, comprising a mounting bracket (1), an insulator (2), an inlet end, an outlet end, an upper contact seat (4), a lower contact seat (6), and a fuse tube (5), wherein the mounting bracket (1) is connected to the middle part of the insulator (2), the inlet end and the outlet end are respectively located at the top and bottom ends of the insulator (2), the upper contact seat (4) is fixed to the upper part of the insulator (2) and electrically connected to the inlet end, the lower contact seat (6) is fixed to the lower part of the insulator (2) and electrically connected to the outlet end, the fuse tube (5) is installed between the upper contact seat (4) and the lower contact seat (6), and a fuse wire and an impactor (5-8) are installed inside the fuse tube (5), wherein the impact post (5-8-4) of the impactor (5-8) pops out when the fuse wire melts, causing the fuse tube (5) to drop, characterized in that: The inlet and outlet terminals are respectively an inlet socket (3) and an outlet socket (7) with an insulating shell, and the inlet socket (3) and outlet socket (7) are encapsulated together with the insulator (2); The first conductor part of the upper contact seat (4) connected to the inlet socket (3) on the left end is encapsulated with the insulator (2) as a whole, and the outer surface of the upper contact seat (4) is provided with an insulating material layer; the upper contact seat (4) is provided with an upper contact piece (4-1) and a first spring for pushing the upper contact piece (4-1) downward; The second conductor part of the lower contact (6) connected to the outlet socket (7) at the left end is encapsulated with the insulator (2) as a whole, and the outer surface of the lower contact (6) is provided with an insulating material layer; the lower contact (6) is also provided with a lower contact piece and a first hook for connecting with the positioning shaft (5-10) at the lower end of the fuse tube (5); the lower contact piece is electrically connected to the outlet socket (7) through the second conductor part; The fusion tube (5) includes an epoxy tube (5-2), and also includes a metal cap (5-1) and a metal seat (5-7) respectively installed at the upper and lower ends of the epoxy tube (5-2); the metal cap (5-1) is in contact with the upper contact piece (4-1), and the metal seat (5-7) is electrically connected to the lower contact piece; a hollow ceramic quartz column (5-4) is installed inside the epoxy tube (5-2), and the fusion wire is a main fusion wire (5-6) wound around the outer surface of the ceramic quartz column (5-4); the space between the epoxy tube (5-2) and the ceramic quartz column (5-4) is filled with quartz sand (5-3). The tension wire (5-8-2) inside the impactor (5-8) is connected in parallel with the main fuse (5-6) between the metal cap (5-1) and the metal seat (5-7).

2. The enclosed high-voltage drop-out fuse as described in claim 1, characterized in that: The upper contact seat (4) is provided with downwardly extending first insulating shield plates on the front and rear sides; The lower contact seat (6) has a second insulating shield plate extending to the right on both the front and rear sides.

3. The enclosed high-voltage drop-out fuse as described in claim 2, characterized in that: The upper contact plate (4-1) is located between two first insulating shield plates, and the lower contact plate and the first hook are located between two second insulating shield plates.

4. The enclosed high-voltage drop-out fuse as described in claim 2, characterized in that: There is a gap between the first insulating shield and the second insulating shield.

5. The enclosed high-voltage drop-out fuse as described in claim 1, characterized in that: The impactor (5-8) also includes a metal shell (5-8-1) and a second spring (5-8-3); the metal shell (5-8-1) is installed in the inner hole of the metal seat (5-7) and is electrically connected to the metal seat (5-7); the impact post (5-8-4) is a conductor, and its lower end slides in contact with the metal shell (5-8-1) to achieve a conductive connection; the second spring (5-8-3) is installed in the metal shell (5-8-1) and is used to push the impact post (5-8-4) downward; the tension wire (5-8-2) passes through the second spring (5-8-3), its lower end is connected to the upper end of the impact post (5-8-4), its upper end is fixedly connected to the insulating block in the inner hole of the ceramic quartz post (5-4), and is electrically connected to the metal cap (5-1) through the connecting wire (5-5).

6. The enclosed high-voltage drop-out fuse as described in claim 5, characterized in that: The connecting wire (5-5) is placed in the inner hole of the ceramic quartz column (5-4).

7. The enclosed high-voltage drop-out fuse as described in claim 5, characterized in that: The fusion tube (5) also includes a rotating frame (5-9) and a rotating plate (5-11). The upper part of the rotating frame (5-9) is rotatably connected to the metal base (5-7), and the metal base (5-7) is electrically connected to the lower contact piece through the rotating frame (5-9) made of conductive material; The positioning shaft (5-10) is located at the lower part of the rotating frame (5-9); the end of the positioning shaft (5-10) is used to hook onto the first hook facing upward on the lower contact seat (6); The middle part of the rotating plate (5-11) is rotatably connected to the metal seat (5-7) and a torsion spring is installed at the connection. The left end of the rotating plate (5-11) is provided with a downward-facing second hook. Under the action of the torsion spring, the second hook is engaged with the middle part of the positioning shaft (5-10) and keeps in contact. The right end of the rotating plate (5-11) corresponds to the position of the impact post (5-8-4).

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