Stable and reliable drop-out fuse

Abstract

The utility model relates to the field of electric power facilities, in particular to a stable and reliable drop-out fuse, which comprises an insulator, an upper terminal, a lower terminal, a fuse tube, an upper static contact and a lower static contact. A fuse is arranged in the fuse tube, an upper moving contact is arranged at the upper end of the fuse tube, a lower moving contact is arranged at the lower end of the fuse tube, and the lower moving contact is movably connected to the lower static contact through a trunnion; the lower moving contact is also provided with an elastic wire pressing plate which assists in tensioning the fuse wire. The lower moving contact is provided with a first line pressing terminal, the lower static contact is provided with a second line pressing terminal, and the lower end of the fuse is led out from the fuse tube, penetrates through the first line pressing terminal and then is connected with the second line pressing terminal. And an insulating sheath is arranged at a position where the fuse wire is connected with the elastic wire pressing plate. The sheath is additionally arranged at the contact position of the tail end of the fuse wire and the fuse wire pressing plate to form insulation isolation, so that current does not pass through two sides of the trunnion by the fuse wire, and the heating defect caused by poor contact between the trunnion and the lower static contact is avoided.

Description

Technical Field

[0001] This utility model relates to the field of power facilities, and in particular to a stable and reliable drop-out fuse. Background Technology

[0002] like Figures 1 to 3 The diagram shows an existing drop-out fuse, whose structure mainly includes an insulator 1, an upper terminal 2, a lower terminal 3, and a fuse tube 4. The upper terminal 2 and lower terminal 3 are fixed to the insulator 1. An upper stationary contact 5 is provided on the upper terminal 2; a lower stationary contact 6 is provided on the lower terminal 3; a fuse 7 is provided in the fuse tube 4. The fuse tube 4 has an outer wall made of phenolic paper or epoxy glass cloth, and an arc-suppressing tube made of asbestos material is fitted inside the tube. Its function is to suppress the arc and prevent the arc from burning out the fuse tube. An upper moving contact 8 is provided at the upper end of the fuse tube 4, and a lower moving contact 9 is provided at the lower end. The lower moving contact 9 is movably connected to the lower stationary contact 6 via a trunnion 901. The upper stationary contact 5 is provided with an upper stationary contact spring plate 501 that presses against the upper moving contact 8; the lower moving contact 9 is rotatably connected to the lower end of the fuse tube 4, and the lower moving contact 9 is connected to the upper moving contact 8 through the fuse 7. The fuse 7 tightens the upper moving contact 8 and the lower moving contact 9. At the same time, the lower moving contact 9 is also provided with an elastic pressure plate 902 to help tighten the fuse 7.

[0003] Drop-out fuses have the following functions: (1) Short circuit protection: When a short circuit current passes through the fuse wire, the fuse wire will melt quickly and generate an electric arc. The steel paper tube inside the fuse tube generates a large amount of gas under the action of the electric arc. Since the upper end of the fuse tube is sealed, the gas is sprayed out to the lower end and blows out the electric arc. (2) Automatic drop-out: As the fuse wire melts, the upper and lower moving contacts of the fuse tube lose the tension of the fuse wire. Under the action of the fuse tube's own weight and the upper stationary contact spring, the fuse tube drops quickly, breaking the circuit and disconnecting the faulty section of the line or equipment. Safety isolation: Drop-out fuses have a clear disconnection point and have the function of a disconnecting switch, creating a safe working environment for the maintenance section of the line and equipment.

[0004] The problem with the above-mentioned drop-out fuse structure is that the trunnion of the lower moving contact 9 does not make good contact with the lower stationary contact, resulting in excessive contact resistance, which easily causes overheating and affects the stability of the fuse. Utility Model Content

[0005] Based on the above problems, the purpose of this utility model is to provide a stable and reliable drop-out fuse. The technical solution adopted by this utility model is as follows:

[0006] This utility model provides a stable and reliable drop-out fuse, including an insulator, an upper terminal, a lower terminal, and a fuse tube; an upper stationary contact is provided on the upper terminal, and a lower stationary contact is provided on the lower terminal; a fuse tube contains a fuse, an upper moving contact is provided at the upper end of the fuse tube, and a lower moving contact is provided at the lower end of the fuse tube, the lower moving contact being movably connected to the lower stationary contact via a trunnion;

[0007] The upper stationary contact is provided with an upper stationary contact spring sheet that presses against the upper moving contact; the lower moving contact is rotatably connected to the lower end of the fuse tube, and the lower moving contact is connected to the upper moving contact through the fuse. The fuse binds the upper moving contact and the lower moving contact together. The lower moving contact is also provided with an elastic pressure plate to help tension the fuse.

[0008] The lower moving contact is provided with a first pressure terminal, and the lower stationary contact is provided with a second pressure terminal. The lower end of the fuse is led out from the fuse tube, passes through the first pressure terminal, and connects to the second pressure terminal. An insulating sleeve is provided at the position where the fuse contacts the elastic pressure plate.

[0009] Preferably, the first crimp terminal includes a terminal block, a connecting plate is provided at the bottom of the terminal block, a mounting hole is provided on the connecting plate, a through wire hole is provided on the side wall of the terminal block, and a threaded hole is provided at the top of the terminal block, in which a set screw is provided.

[0010] Preferably, the structure of the second pressure terminal is the same as that of the first pressure terminal.

[0011] Compared with the prior art, the beneficial technical effects of this utility model are as follows:

[0012] In this invention, a protective sleeve is added to the contact position between the fuse tail end and the fuse pressure plate to form an insulation barrier, so that the current does not pass through the trunnion on both sides, thus eliminating the defect of overheating due to poor contact between the trunnion and the lower stationary contact. Attached Figure Description

[0013] The present invention will be further described below with reference to the accompanying drawings.

[0014] Figure 1 A front view of an existing drop-out fuse in its assembled state;

[0015] Figure 2 This is an enlarged view of the lower structure of an existing drop-out fuse.

[0016] Figure 3 An enlarged view of the upper structure of an existing drop-out fuse;

[0017] Figure 4This is a front view of the drop-out fuse in the disassembled state in an embodiment of this utility model;

[0018] Figure 5 This is a front view of the drop-out fuse in its assembled state according to an embodiment of this utility model;

[0019] Figure 6 This is a schematic diagram of the structure of the first pressure terminal in an embodiment of this utility model.

[0020] Explanation of reference numerals in the attached diagram: 1. Insulator; 2. Upper terminal; 3. Lower terminal; 4. Fuse tube; 5. Upper stationary contact; 501. Stationary contact spring sheet; 6. Lower stationary contact; 7. Fuse; 8. Upper moving contact; 9. Lower moving contact; 901. Trunnion; 902. Elastic pressure plate; 10. First pressure terminal; 1001. Terminal block; 1002. Connecting plate; 1003. Mounting hole; 1004. Wire hole; 1005. Threaded hole; 1006. Set screw; 11. Second pressure terminal; 12. Insulating sleeve; Detailed Implementation

[0021] To make the technical problems, technical solutions and beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments.

[0022] like Figure 4 and 5 As shown, this embodiment discloses a stable and reliable drop-out fuse, including an insulator 1, an upper terminal 2, a lower terminal 3, and a fuse tube 4. An upper stationary contact 5 is provided on the upper terminal 2, and a lower stationary contact 6 is provided on the lower terminal 3. A fuse 7 is provided in the fuse tube 4. An upper moving contact 8 is provided at the upper end of the fuse tube 4, and a lower moving contact 9 is provided at the lower end of the fuse tube 4. The lower moving contact 9 is movably connected to the lower stationary contact 6 via a trunnion 901. An upper stationary contact spring plate 501 is provided on the upper stationary contact 5, which presses against the upper moving contact 8. The upper stationary contact spring plate 501 applies a compressive force to the upper stationary contact 5. The lower moving contact 9 is rotatably connected to the lower end of the fuse tube 4. The lower moving contact 9 is connected to the upper moving contact 8 via the fuse 7. The fuse 7 secures the upper moving contact 8 and the lower moving contact 9 together. An elastic pressure plate 902 is also provided on the lower moving contact 9 to assist in tensioning the fuse 7. The elastic pressure plate 902 applies tension to the fuse 7 via a torsion spring. The above technical content pertains to the existing structure of drop-out fuses and will not be described in detail here.

[0023] The improvement of the drop-out fuse in this embodiment is as follows: a first pressure terminal 10 is provided on the lower moving contact 9, a second pressure terminal 11 is provided on the lower stationary contact 6, and the lower end of the fuse 7 is led out from the fuse tube 4, passes through the first pressure terminal 10, and is connected to the second pressure terminal 11; an insulating sleeve 12 is provided at the position where the fuse 7 is connected to the elastic pressure plate 902.

[0024] By setting the insulating sleeve 12, the current in the fuse 7 is prevented from passing through both sides of the trunnion 901, thus eliminating the defect of overheating due to poor contact between the trunnion and the lower stationary contact 6. In particular, after the first pressure terminal 10 presses the fuse 7, the upper moving contact 8 and the lower moving contact 9 can be tightened together.

[0025] like Figure 6 As shown, the first crimping terminal 10 includes a terminal block 1001. A connecting plate 1002 is provided at the bottom of the terminal block 1001. The connecting plate 1002 is provided with a mounting hole 1003, which is fixed to the lower moving contact 9 and the lower stationary contact 6 by bolts. A through wire hole 1004 is provided on the side wall of the terminal block 1001, and a threaded hole 1005 is provided on the top of the terminal block 1001. The threaded hole 1005 communicates with the through wire hole 1004. A set screw 1006 is provided in the threaded hole 1005. When the fuse 7 passes through the through wire hole 1004, rotating the set screw 1006 can press the fuse 7 into the terminal block 1001.

[0026] In this embodiment, the structure of the second wire terminal 11 is the same as that of the first wire terminal 10.

[0027] The embodiments described above are merely preferred embodiments of the present utility model and are not intended to limit the scope of the present utility model. Various modifications and improvements made to the technical solutions of the present utility model by those skilled in the art without departing from the spirit of the present utility model should fall within the protection scope defined by the claims of the present utility model.

Claims

1. A stable and reliable drop-out fuse, comprising an insulator (1), an upper terminal (2), a lower terminal (3), and a fuse tube (4); an upper stationary contact (5) is provided on the upper terminal (2), and a lower stationary contact (6) is provided on the lower terminal (3); a fuse (7) is provided in the fuse tube (4), an upper moving contact (8) is provided at the upper end of the fuse tube (4), and a lower moving contact (9) is provided at the lower end of the fuse tube (4), wherein the lower moving contact (9) is movably connected to the lower stationary contact (6) via a trunnion (901); The upper stationary contact (5) is provided with an upper stationary contact spring plate (501) that presses against the upper moving contact (8); the lower moving contact (9) is rotatably connected to the lower end of the fuse tube (4), the lower moving contact (9) is connected to the upper moving contact (8) through the fuse (7), the fuse (7) fastens the upper moving contact (8) and the lower moving contact (9), and the lower moving contact (9) is also provided with an elastic pressure plate (902) to help tension the fuse (7); Its features are: The lower moving contact (9) is provided with a first pressure terminal (10), and the lower stationary contact (6) is provided with a second pressure terminal (11). The lower end of the fuse (7) is led out from the fuse tube (4), passes through the first pressure terminal (10), and is connected to the second pressure terminal (11). An insulating sleeve (12) is provided at the position where the fuse (7) contacts the elastic pressure plate (902).

2. The stable and reliable drop-out fuse according to claim 1, characterized in that: The first crimp terminal (10) includes a terminal block (1001), a connecting plate (1002) is provided at the bottom of the terminal block (1001), a mounting hole (1003) is provided on the connecting plate (1002), a through wire hole (1004) is provided on the side wall of the terminal block (1001), a threaded hole (1005) is provided at the top of the terminal block (1001), and a set screw (1006) is provided in the threaded hole (1005).

3. The stable and reliable drop-out fuse according to claim 1, characterized in that: The structure of the second wire terminal (11) is the same as that of the first wire terminal (10).

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