Lower contact of a drop-out fuse and drop-out fuse containing the same

Abstract

The lower contact of a drop-out fuse and the drop-out fuse containing the lower contact relate to the field of power facilities. The present invention is to solve the problem that there are many types of existing drop-out fuses and they have no universality. In the present invention, the lower static contact is fixedly connected to the fuse tube by screws. Two lower moving contacts are arranged in mirror symmetry. Both lower moving contacts are perpendicular to the connecting plate. A connecting column is respectively arranged on the outer sides of the ends of the two lower moving contacts. A contact hinge rod and a spring piece hinge rod are connected between the inner sides of the two lower moving contacts. The lower moving contact is hinged to the lower operating ring; a torsion spring is sleeved on the spring piece hinge rod. When the torsion spring is in a compressed state, the front surface of the clamping plate contacts the protrusion of the lower static contact. When the torsion spring is in a free state, the front surface of the clamping plate is separated from the protrusion of the lower static contact. The present invention is applicable to the power system.

Description

Technical Field

[0001] The present invention belongs to the field of power facilities, and particularly relates to a drop-out fuse. Background Art

[0002] Drop-out fuses are commonly used in 10kV distribution lines, the high-voltage side and the low-voltage side of a transformer substation, providing an obvious disconnection point for workers during line or transformer substation work, and also being a safety measure to protect the line and transformer from overload. Usually, three groups of drop-out fuses are installed on the 10kV distribution line, the high-voltage side and the low-voltage side of the transformer. When a fault, overload or maintenance occurs in the line or transformer substation, the drop-out fuse needs to be replaced. Several problems often occur when replacing the fuse:

[0003] (1). Even for the same model of drop-out fuses produced by the same manufacturer, there will be slightly different lengths, which will result in insufficient contact area when the upper contact of the fuse is pushed into the "duckbill" card slot, and then cause the upper contact to overheat and melt, or have loose contact and spark, unable to ensure power supply reliability;

[0004] (2). Due to different construction times of the distribution line and transformer substation, the models of drop-out fuses used cannot be exactly the same. This requires the maintenance construction team to be equipped with various models of fuses to match different lines and transformer substations. This increases the spare parts and materials cost of the maintenance construction unit, and the construction team must carry different models of fuses at all times, which not only occupies the space in the vehicle but also increases the construction burden;

[0005] (3). The fuse wire inside the drop-out fuse tube is fixed by the lower static contact spring piece, a hexagonal screw and two pressure pieces. When replacing the fuse wire, it is necessary to use a wrench to loosen the hexagonal screw, rewind the fuse wire and then tighten it, which is inconvenient to operate.

[0006] (4). The cross-section of the lower contact spring piece is a rectangle, and the fuse wire is tied to the spring piece. Since the fuse wire must always be kept in a taut state, over time it will cause the fuse wire to wear and break, resulting in a power outage accident. Summary of the Invention

[0007] The present invention is to solve the problem that there are many models of existing drop-out fuses and there is no universality, and now provides a drop-out fuse with an adjustable length of the fuse tube.

[0008] A lower contact of a drop-out fuse includes: a lower operating ring, a lower static contact, two lower moving contacts and a spring piece,

[0009] The lower static contact is annular, and a plurality of threaded holes are radially formed in the annular wall of the annular shape. The lower static contact is used for sleeving on the end of the fuse tube of the drop-out fuse and fixedly connecting with the fuse tube through screws passing through the threaded holes. The lower operating ring is fixed on the outer circumferential surface of the lower static contact, and the ring surface of the lower operating ring is coplanar with the main axis of the lower static contact. A protrusion is provided on the lower operating ring in the direction of the lower end of the lower static contact;

[0010] Two lower moving contacts are arranged symmetrically in a mirror image, and the ends are connected by a connecting plate. Threaded holes are formed in the connecting plate, and ingot screws are provided in the threaded holes. Both lower moving contacts are perpendicular to the connecting plate. A connecting column is respectively provided on the outer sides of the ends of the two lower moving contacts. A contact hinge rod and a spring plate hinge rod are connected between the inner sides of the two lower moving contacts. The contact hinge rod is close to the front end of the lower moving contact, and the spring plate hinge rod is close to the connecting plate. A hinge hole is formed in the lower operating ring at a position close to the lower static contact. The contact hinge rod passes through the hinge hole so that the lower moving contact is hinged to the lower operating ring;

[0011] The spring plate includes: a clamping plate, a main plate, a bottom plate and two side plates. The clamping plate and the bottom plate are respectively connected to the upper and lower sides of the main plate. The angle between the clamping plate and the main plate is an obtuse angle and faces the rear side of the main plate. The bottom plate is perpendicular to the main plate and faces the front side of the main plate. The two side plates are respectively vertically fixed on the two side edges of the main plate and both face the front side of the main plate. An opening is formed in each of the two side plates. The spring plate is hung on the spring plate hinge rod through the opening;

[0012] A torsion spring is sleeved on the spring plate hinge rod and the torsion spring is located between the two side plates. One end of the torsion spring is in contact with the front side of the main plate, and the other end of the torsion spring is in contact with the upper surface of the connecting plate. When the torsion spring is in a compressed state, the front surface of the clamping plate is in contact with the protrusion of the lower static contact. When the torsion spring is in a free state, the front surface of the clamping plate is separated from the protrusion of the lower static contact.

[0013] Further, the bottom plate includes two flat plate portions, one side of the two flat plate portions is connected and the included angle is an obtuse angle, and this angle faces the direction of the clamping plate.

[0014] Further, 2 threaded holes are formed in the lower static contact, and the lower static contact is clamped with the fuse tube through an ingot screw passing through the threaded hole.

[0015] Further, an opening or a groove is formed at the junction of the two flat plate portions.

[0016] The drop-out fuse containing the above-mentioned lower contact includes: an upper contact, a lower contact and a fuse tube. The upper contact is fixed at the top end of the fuse tube, and the lower static contact of the lower contact is fixedly connected with the end of the fuse tube through a screw passing through the threaded hole.

[0017] Further, the upper contact part includes an upper moving contact, an upper operating ring, a pressure relief cap, a contact link, a contact torsion spring and an upper static contact; the upper static contact is annular, the upper static contact is sleeved on the top end of the fuse tube, the upper operating ring is fixed on the outer side wall of the upper static contact, and the ring surface of the upper operating ring is coplanar with the main axis of the upper static contact. The pressure relief cap is threadedly connected to the top end of the upper static contact. One end of the contact link is fixed on the outer circumference of the upper static contact and is perpendicular to the main axis of the upper static contact. The contact torsion spring is sleeved on the contact link, and the upper moving contact is sleeved on the other end of the contact link. A gasket is provided between the contact torsion spring and the upper moving contact. One end of the contact torsion spring is fixedly connected to the contact link, and the other end of the contact torsion spring is connected to the upper moving contact.

[0018] The beneficial effects of the present invention are as follows:

[0019] (1). For the lower contact of the drop-out fuse described in the present invention, the position where the lower moving contact is fixed on the fuse tube can be adjusted by tightening and loosening three ingot screws, ensuring that fuse tubes of various lengths can be matched with the line or equipment, and solving the problem that fuses of different models have different lengths and cannot be compatible and universal.

[0020] (2). Since the position of the lower contact on the fuse tube is adjustable, fuses of different models can be compatible with different environments, saving procurement costs, reducing the time for selecting the fuse model, and improving work efficiency.

[0021] (3). Ingot screws are used in all parts where construction workers need to use tools to tighten and loosen the screws. When forgetting to bring tools at the construction site, the screws can be tightened even by hand, which is convenient for operation.

[0022] (4). A through hole is provided at the stress end where the fuse is tied to the elastic piece, reducing the friction surface between the fuse and the spring piece, prolonging the service life of the fuse, and ensuring the power supply quality. Description of the Drawings

[0023] Figure 1 It is the front view of the lower contact of the drop-out fuse described in the first specific embodiment;

[0024] Figure 2 It is for Figure 1 the bottom view;

[0025] Figure 3 It is for Figure 1 the left sectional view;

[0026] Figure 4 It is the structural schematic diagram of the elastic piece;

[0027] Figure 5 It is the front view of the drop-out fuse described in the second specific embodiment;

[0028] Figure 6 It is for Figure 5Rear view;

[0029] Figure 7 Schematic structural diagram of the upper static contact;

[0030] Figure 8 Schematic structural diagram of the upper contact. Specific implementation manner

[0031] Specific implementation manner 1: Refer to Figures 1 to 4 Specifically describe this implementation manner. The lower contact of a drop-out fuse described in this implementation manner includes: a lower operating ring 201, a lower static contact 202, two lower moving contacts 203, and a spring piece 204.

[0032] The lower static contact 202 is circular ring-shaped. A plurality of threaded holes are radially formed on the ring wall of the circular ring. The lower static contact 202 is used to be sleeved on the end of the fuse tube 3 of the drop-out fuse and is fixedly connected to the fuse tube 3 by screws passing through the threaded holes. The lower operating ring 201 is fixed on the outer circumferential surface of the lower static contact 202, and the ring surface of the lower operating ring 201 is coplanar with the main axis of the lower static contact 202. The lower operating ring 201 is provided with a protrusion 216 in the direction of the lower end of the lower static contact 202.

[0033] The two lower moving contacts 203 are arranged in mirror symmetry and are connected at the ends by a connecting plate 209. A threaded hole is formed in the connecting plate 209, and a wing nut 210 is provided in the threaded hole. The two lower moving contacts 203 are both perpendicular to the connecting plate 209. A connecting column 208 is respectively arranged on the outer sides of the ends of the two lower moving contacts 203. A contact hinge rod 207 and a spring piece hinge rod 205 are connected between the inner sides of the two lower moving contacts 203. The contact hinge rod 207 is close to the head end of the lower moving contact 203, and the spring piece hinge rod 205 is close to the connecting plate 209. An articulation hole is formed at the position of the lower operating ring 201 close to the lower static contact 202. The contact hinge rod 207 passes through the articulation hole, so that the lower moving contact 203 is articulated with the lower operating ring 201.

[0034] The spring piece 204 includes: a clamping plate 211, a main plate 212, a bottom plate 213, and two side plates 215. The clamping plate 211 and the bottom plate 213 are respectively connected to the upper and lower sides of the main plate 212. The included angle between the clamping plate 211 and the main plate 212 is obtuse and faces the rear side of the main plate 212. The bottom plate 213 is perpendicular to the main plate 212 and faces the front side of the main plate 212. The two side plates 215 are respectively vertically fixed on both sides of the main plate 212 and both face the front side of the main plate 212. An opening 214 is formed on each of the two side plates 215. The spring piece 204 is hung on the spring piece hinge rod 205 through the opening 214.

[0035] A torsion spring is sleeved on the elastic sheet hinge rod 205, and the torsion spring is located between the two side plates 215. One end of the torsion spring is in contact with the front side of the main board 212, and the other end of the torsion spring is in contact with the upper surface of the connecting plate 209. When the torsion spring is in a compressed state, the front surface of the clamping plate 211 is in contact with the protrusion of the lower static contact 202. When the torsion spring is in a free state, the front surface of the clamping plate 211 is separated from the protrusion of the lower static contact 202.

[0036] Specifically, the bottom plate 213 includes two flat plate portions. One side of the two flat plate portions is connected, and the included angle is an obtuse angle, and this angle faces the direction of the clamping plate 211. That is, a groove is formed, and the fuse 4 is placed in this groove portion. An opening 217 or a slot is provided at the junction of the two flat plate portions. Both the opening 217 and the slot can reduce the friction between the fuse 4 and the bottom groove of the bottom plate 213 and extend the service life of the fuse 4.

[0037] There are 2 threaded holes on the lower static contact 202. The lower static contact 202 is clamped with the fuse tube 3 through the ingot screws passing through the threaded holes. When the ingot screws are loosened, the lower static contact 202 can move back and forth on the fuse tube 3, and the overall position of the lower contact is adjusted. When adjusted to the appropriate position, the ingot screws are tightened so that the ends of the ingot screws are in contact with the fuse tube 3. The three ingot screws jointly clamp the fuse tube, so that the lower contact is fixed on the fuse tube 3.

[0038] Specific Embodiment 2: The drop-out fuse described in this embodiment contains the lower contact of the drop-out fuse described in Specific Embodiment 1. In this embodiment, it includes: an upper contact, a lower contact, and a fuse tube 3.

[0039] The upper contact part includes: an upper moving contact 101, an upper operating ring 102, a pressure relief cap 103, a contact link 104, a contact torsion spring 105, and an upper static contact 107.

[0040] The upper static contact 107 is annular. There is a circle of card slots inside the upper static contact 107 that can be fixed to the top of the fuse tube 3. The upper static contact 107 is sleeved on the top of the fuse tube 3. The upper operating ring 102 is welded to the outer side wall of the upper static contact, and the ring surface of the upper operating ring 102 is coplanar with the main axis of the upper static contact 107. The top of the upper static contact 107 has threads, and the pressure relief cap 103 is fixed to the top of the upper static contact 107 through the threads. One end of the contact link 104 is fixed on the outer circumference of the upper static contact 107 and is perpendicular to the main axis of the upper static contact 107. The contact torsion spring 105 is sleeved on the contact link 104. The upper moving contact 101 is sleeved on the other end of the contact link 104. A gasket 106 is provided between the contact torsion spring 105 and the upper moving contact 101. One end of the contact torsion spring 105 is fixedly connected to the contact link 104, and the other end of the contact torsion spring 105 is connected to the upper moving contact 101.

[0041] The upper contact is a cap-shaped component with a hollow interior. The upper contact is fixed to the top end of the fuse tube 3. The lower static contact 202 of the lower contact is fixedly connected to the end of the fuse tube 3 through a screw passing through a threaded hole.

[0042] In this embodiment, the position of the lower contact on the fuse tube 3 can be adjusted by adjusting the tightness of the screw on the lower static contact 202, so that the distance between the upper and lower contacts is adjustable, so that the fuse is suitable for various environments and various sizes.

[0043] In actual application of this embodiment, the top end of the upper moving contact 101 is pushed into the "duckbill" card slot. The two connecting columns 208 are respectively fixed on the lower support, so that the lower contact is hinged to the support. Unscrew the pressure relief cap 103, put the fuse 4 into the fuse tube 3, and let it pass through the bottom of the fuse tube 3. Move the end of the elastic piece 204 towards the lower static contact 202, so that the front surface of the clamping plate 211 contacts the protrusion of the lower static contact 202. Then, clamp the fuse 4 in the bottom groove of the elastic piece 204, and tighten the fuse 4 with the ingot screw 210, keeping the clamping plate 211 and the protrusion in contact with each other all the time to form an interlocking structure. At this time, the upper and lower moving contacts of the fuse are fixed, and the fuse is in a tensioned state.

[0044] When the fuse 4 melts, the elastic piece 204 loses the restriction of the fuse 4 and returns to its initial position under the elastic force of the torsion spring. At this time, taking the two connecting columns 208 as the axis, the fuse tube 3 drops by its own weight, and the top end of the upper moving contact 101 falls off from the "duckbill" card slot, disconnecting the circuit and cutting off the faulty section of the line or the faulty equipment.

[0045] When the fuse needs to be replaced, use an insulating rod to pull open the upper operating ring 102 to make the upper moving contact fall off from the "duckbill" card slot and cut off the circuit. Then use the insulating rod to lift the lower operating ring 201 to disengage the connecting column 208 from the support, and the drop-type fuse can be removed from the line or equipment.

Claims

1. The lower contact of a drop-out fuse, characterized in that, Comprising: Lower operating ring (201), lower static contact (202), two lower moving contacts (203) and elastic piece (204). The lower static contact (202) is annular. A plurality of threaded holes are radially formed on the annular wall of the annular shape. The lower static contact (202) is used for sleeving on the end of the fuse tube (3) of the drop-out fuse and is fixedly connected to the fuse tube (3) by screws passing through the threaded holes. The lower operating ring (201) is fixed on the outer circumferential surface of the lower static contact (202), and the ring surface of the lower operating ring (201) is coplanar with the main axis of the lower static contact (202). A protrusion (216) is provided on the lower operating ring (201) in the direction of the lower end of the lower static contact (202). The two lower moving contacts (203) are arranged in mirror symmetry and are connected at the ends by a connecting plate (209). Threaded holes are formed in the connecting plate (209), and a wing nut (210) is provided in the threaded holes. The two lower moving contacts (203) are both perpendicular to the connecting plate (209). A connecting column (208) is respectively provided on the outer sides of the ends of the two lower moving contacts (203). A contact hinge rod (207) and an elastic piece hinge rod (205) are connected between the inner sides of the two lower moving contacts (203). The contact hinge rod (207) is close to the head end of the lower moving contact (203), and the elastic piece hinge rod (205) is close to the connecting plate (209). An articulation hole is formed in the lower operating ring (201) at a position close to the lower static contact (202). The contact hinge rod (207) passes through the articulation hole, so that the lower moving contact (203) is articulated with the lower operating ring (201). The elastic piece (204) includes: a clamping plate (211), a main plate (212), a bottom plate (213) and two side plates (215). The clamping plate (211) and the bottom plate (213) are respectively connected to the upper and lower sides of the main plate (212). The included angle between the clamping plate (211) and the main plate (212) is an obtuse angle and faces the rear side of the main plate (212). The bottom plate (213) is perpendicular to the main plate (212) and faces the front side of the main plate (212). The two side plates (215) are respectively vertically fixed on the two side edges of the main plate (212) and both face the front side of the main plate (212). A through hole (214) is formed in each of the two side plates (215). The elastic piece (204) is hung on the elastic piece hinge rod (205) through the through hole (214). A torsion spring is sleeved on the elastic piece hinge rod (205), and the torsion spring is located between the two side plates (215). One end of the torsion spring is in contact with the front side of the main plate (212), and the other end of the torsion spring is in contact with the upper surface of the connecting plate (209). When the torsion spring is in a compressed state, the front surface of the clamping plate (211) is in contact with the protrusion of the lower static contact (202). When the torsion spring is in a free state, the front surface of the clamping plate (211) is separated from the protrusion of the lower static contact (202).

2. The lower contact of a drop-out fuse according to claim 1, characterized in that, The bottom plate (213) includes two flat plate parts. One side of the two flat plate parts is connected and the included angle is an obtuse angle, and this angle faces the direction of the clamping plate (211).

3. The lower contact of a drop-out fuse according to claim 1 or 2, characterized in that, 2 threaded holes are formed in the lower static contact (202). The lower static contact (202) is clamped with the fuse tube (3) by wing nuts passing through the threaded holes.

4. The lower contact of a drop-out fuse according to claim 2, characterized in that, An opening (217) or a groove is formed at the junction of the two flat parts.

5. A drop-out fuse comprising the lower contact according to claim 1 or 2, characterized in that, Comprising: an upper contact, a lower contact and a fuse tube (3), the upper contact is fixed at the top end of the fuse tube (3), and the lower static contact (202) of the lower contact is fixedly connected to the end of the fuse tube (3) by a screw passing through a threaded hole.

6. The drop-out fuse according to claim 5, characterized in that, The upper contact part includes an upper moving contact (101), an upper operating ring (102), a pressure relief cap (103), a contact link (104), a contact torsion spring (105) and an upper static contact (107); The upper static contact (107) is annular, the upper static contact (107) is sleeved on the top end of the fuse tube (3), the upper operating ring (102) is fixed on the outer side wall of the upper static contact (107), and the ring surface of the upper operating ring (102) is coplanar with the main axis of the upper static contact (107), the pressure relief cap (103) is threadedly connected to the top end of the upper static contact (107), one end of the contact link (104) is fixed on the outer circumference of the upper static contact (107) and is perpendicular to the main axis of the upper static contact (107), the contact torsion spring (105) is sleeved on the contact link (104), the upper moving contact (101) is sleeved on the other end of the contact link (104), a gasket (106) is provided between the contact torsion spring (105) and the upper moving contact (101), one end of the contact torsion spring (105) is fixedly connected to the contact link (104), and the other end of the contact torsion spring (105) is connected to the upper moving contact (101).

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