Outdoor drop-out current-limiting fuse

Abstract

The utility model relates to the technical field of protection switch equipment, and discloses an outdoor drop-type current-limiting fuse which comprises a fuse body, one end of the fuse body is provided with an upper copper contact cap, and the other end of the fuse body is provided with a separation device. The fuse body comprises an epoxy tube and a support column, the support column is located in the epoxy tube, a fuse wire is wound on the surface of the support column, the epoxy tube is further filled with a quartz sand layer, the quartz sand layer wraps the surface of the fuse wire, one end of the epoxy tube is provided with an upper copper cap, and the other end of the epoxy tube is provided with a lower copper cap. An impact trigger is arranged in the lower copper cap; the outdoor drop-type current-limiting fuse has relatively high ultraviolet resistance and can be used outdoors for a long time; the weight is light, the size is small, and an insulating rod can be used for direct operation; by adopting the separable design, the outdoor drop-out fuse is completely consistent with the use of the existing outdoor drop-out fuse, and the contact part can be repeatedly used, so that the use cost is saved.

Description

Technical Field

[0001] The utility model relates to the technical field of protective switch equipment, in particular to a drop-out current-limiting fuse for outdoor use. Background Art

[0002] The drop-out fuse is the most commonly used short-circuit protection switch for 10kV distribution line branch lines and distribution transformers.

[0003] The drop-out fuse is installed on the branch line of the 10kV distribution line to reduce the scope of power outage. Because it has an obvious disconnection point and has the function of an isolating switch, it creates a safe working environment for the maintenance section lines and equipment. It is installed on the distribution transformer and can be used as the main protection of the distribution transformer.

[0004] Indoor high-voltage current limiters have the advantages of large breaking current, fast fault clearing speed, and small thermal shock to the main transformer. However, they are currently mostly used in switch cabinets. If they are to be used on overhead lines, the following problems need to be solved:

[0005] 1. Overhead lines are almost all exposed to sunlight, and indoor current limiters need to solve the UV resistance problem before they can be used outdoors.

[0006] 2. High-voltage current limiters used indoors generally use a striker to trigger the load switch, but when used on overhead line drop-out fuses, it is necessary to solve the problem of how the striker can trigger the fuse carrier to drop.

[0007] 3. The current-limiting fuse used indoors requires a large breaking current, and is large in size and weight. If it is to be used on an outdoor drop-out fuse, it needs to be further lightweight to ensure that it can be replaced with an insulating rod. Utility Model Content

[0008] The technical problem to be solved by the utility model is to provide an outdoor drop-out current-limiting fuse in view of the deficiencies of the above-mentioned prior art.

[0009] To achieve the above-mentioned purpose, the technical solution of the utility model is: an outdoor drop-out current-limiting fuse, comprising a fuse body, one end of which is provided with an upper copper contact cap, and the other end of which is provided with a separation device;

[0010] The fuse body comprises an epoxy tube and a support, wherein the support is located inside the epoxy tube, a fuse is wound on the surface of the support, the epoxy tube is also filled with a quartz sand layer, and the quartz sand layer is wrapped around the surface of the fuse, an upper copper cap is provided at one end of the epoxy tube, and a lower copper cap is provided at the other end, and an impact trigger is provided inside the lower copper cap;

[0011] The separation device includes a fuse tube seat, a fuse tube mounting hole matched with the lower copper cap is opened on the fuse tube seat, a hanging stress bracket is provided below the fuse tube seat, a contact piece is provided on the hanging stress bracket, a matching locking piece is provided on the contact piece, a trigger tongue matched with the impact trigger is provided at one end of the fuse tube seat, a coil spring is provided on the trigger tongue, and the locking piece is matched with the trigger tongue.

[0012] Furthermore, a hanging limiter is provided below the hanging stress bracket.

[0013] Furthermore, the interior of the melting tube installation hole is provided with threads.

[0014] Furthermore, the upper copper cap and the lower copper cap are made of brass.

[0015] Furthermore, the upper copper contact cap and the separation device are both made of silicon aluminum bronze.

[0016] Furthermore, the outer wall of the epoxy tube is coated with a polymer anti-ultraviolet material layer.

[0017] Furthermore, the pillar is made of alumina ceramics and has a plurality of raised pillars on the surface.

[0018] Compared with the prior art, the utility model has the following beneficial effects:

[0019] 1. The fault clearing of the utility model is faster than that of the jet fuse. Taking 50A as an example, when the fault current is greater than 5 times, the fault clearing speed is much faster than that of the jet fuse. The larger the fault current, the faster the speed is than that of the jet fuse. Especially at 10Ir, the jet fuse designed by the technical solution can clear the fault within 60ms, while the jet fuse needs about 300ms, which is nearly 5 times faster.

[0020] 2. Since quartz sand participates in arc extinguishing, the breaking capacity is greatly improved. The maximum breaking current of the jet type fuse is ≤16kA, and the breaking current of the drop-type current-limiting fuse designed in this scheme can reach 20kA.

[0021] 3. The drop-out current-limiting fuse of the utility model has current-limiting capability, which can effectively reduce the thermal shock of the fault on the main transformer and the line when breaking a large fault current. Taking 50A as an example, the expected fault current is 20kA, and the fault current can be limited to within 5.07kA.

[0022] 4. The utility model has strong anti-ultraviolet ability and can be used outdoors for a long time; it is light in weight and small in size, and can be directly operated with a link rod; it adopts a detachable design, which is completely consistent with the existing outdoor drop-type fuse, and the contact part can be reused, saving the cost of use. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The utility model is a schematic diagram of an outdoor drop-out current-limiting fuse.

[0024] Figure 2 The utility model is a side view of an outdoor drop-out current-limiting fuse.

[0025] Figure 3 It is a schematic diagram of the interior of the fuse body of the utility model.

[0026] Figure 4 It is a front view of the separation device of the utility model.

[0027] Figure 5 It is a schematic diagram of the separation device of the utility model.

[0028] In the figure: 1. fuse body; 11. epoxy tube; 12. support; 13. fuse; 14. quartz sand layer; 15. upper copper cap; 16. lower copper cap; 17. impact trigger; 2. upper copper contact cap; 3. separation device; 31. fuse holder; 32. fuse mounting hole; 33. hanging stress bracket; 34. contact piece; 35. locking piece; 36. trigger tongue; 37. coil spring; 38. hanging limiter. DETAILED DESCRIPTION

[0029] The utility model is now described in further detail in conjunction with the accompanying drawings. The accompanying drawings are simplified schematic diagrams, which only illustrate the basic structure of the utility model in a schematic manner, and therefore only show the components related to the utility model.

[0030] Please refer to Figure 1-Figure 5 , an outdoor drop-type current-limiting fuse comprises a fuse body 1, one end of the fuse body 1 is provided with an upper copper contact cap 2, and the other end is provided with a separation device 3. The current-limiting fuse consists of an upper copper contact cap 2, a fuse body 1, and a separation device 3. When in use, the upper copper contact cap 2 contacts the base, the fuse body 1 realizes the inverse time fuse protection function, and the separation device 3 triggers the entire current-limiting fuse to fall from the base after the fuse body 1 is actuated. Among them, the fuse body 1 uses quartz sand as the arc extinguishing material, and is structurally compatible with the jet-type drop fuse to form a drop-type current-limiting fuse, which can be directly installed on the base of the jet-type fuse. When the fault current flows through the current-limiting drop fuse, the drop-type current-limiting fuse melts and falls, forming an obvious disconnection. The function is consistent with the jet-type drop fuse.

[0031] The fuse body 1 comprises an epoxy tube 11 and a pillar 12, wherein the pillar 12 is located inside the epoxy tube 11, a fuse 13 is wound on the surface of the pillar 12, and the epoxy tube 11 is also filled with a quartz sand layer 14, wherein the quartz sand layer 14 is wrapped around the surface of the fuse 13, an upper copper cap 15 is provided at one end of the epoxy tube 11, and a lower copper cap 16 is provided at the other end, wherein an impact trigger 17 is provided inside the lower copper cap 16. It should be noted that the epoxy tube 11 is an epoxy resin tube, and the outer layer is coated with an anti-ultraviolet coating; the fuse 13 is wound on the pillar 12, and then placed in the epoxy tube 11, the upper copper cap 15 is first fixed at one end of the epoxy tube 11, and a large amount of quartz sand is added to form a quartz sand layer 14 in the epoxy tube 11, so that the quartz sand layer 14 is tightly wrapped around the fuse 13, and the lower copper cap 16 is fixed to the other end of the epoxy tube 11 after the quartz sand layer 14 is filled.

[0032] The separation device 3 includes a fuse holder 31, on which a fuse installation hole 32 matching the lower copper cap 16 is provided, a hanging stress bracket 33 is provided below the fuse holder 31, on which a contact 34 is provided, on which a matching locking member 35 is provided, and one end of the fuse holder 31 is provided with a trigger tongue 36 matching the impact trigger 17, on which a coil spring 37 is provided, and the locking member 35 matches the trigger tongue 36. It should be noted that the locking member 35 is locked with the contact member 34, and the trigger tongue 36 has a coil spring 37. When the fuse is blown, the striker of the impact trigger 17 pops out and hits the trigger tongue 36, which causes the locking member 35 to separate from the contact 34, and the coil spring 37 releases energy to push the entire fuse to fall from the base. The hanging stress bracket 33 plays a supporting role and can greatly improve the strength of the drop-out fuse during the disassembly and assembly process; the contact piece 34 has horizontal stripes to increase the mechanical strength of the contact piece 34.

[0033] A hanging stopper 38 is also provided below the hanging stress bracket 33. The hanging stopper 38 plays a role of limiting, ensuring that the entire current-limiting fuse does not swing left and right during the disassembly and assembly process.

[0034] The interior of the melting tube installation hole 32 is provided with threads. The use of threads can increase the contact area and reduce the contact resistance.

[0035] It should be noted that the upper copper cap 15 and the lower copper cap 16 are machined according to the dimensions of the drawing and are made of brass.

[0036] The upper copper contact cap 2 and the separation device 3 are both made of silicon aluminum bronze, and a metal plating layer is added to the contact part with the base to reduce the contact resistance.

[0037] The outer wall of the epoxy tube 11 is coated with a polymer anti-ultraviolet material with a thickness of 0.1-0.5 mm. The entire epoxy tube 11 can be selected to have a diameter between 38-58 mm and a length between 100 mm-230 mm.

[0038] The pillar 12 is made of aluminum oxide ceramics with seven protruding columns, so that metal fuses such as copper and silver are used as melts and are evenly wound on the pillar 12. The protruding columns of the pillar 12 support the fuse 13, so that there is a gap between the fuse 13 and the ceramic column.

[0039] The ceramic pillar 12 with the fuse 13 wound around it is placed in the epoxy tube 11, and a copper cap 15 is pressed on one end of the epoxy tube 11. The other end of the epoxy tube 11 with the copper cap pressed is filled with quartz sand, and then the lower copper cap 16 with a striker is pressed onto the other end of the fuse. The copper caps on both sides are interference fit with the epoxy tube 11 to ensure sealing.

[0040] After the entire fuse is manufactured, the copper contact caps 2 and the separation device 3 are installed at both ends, and after the entire current limiting fuse is assembled, it is installed on the base to form a consistent and complete drop-out current limiting fuse. The base uses an existing standard base.

[0041] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention of the utility model.

Claims

1. A drop-out current-limiting fuse for outdoor use, comprising a fuse body (1), characterized in that: One end of the fuse body (1) is provided with an upper copper contact cap (2), and the other end is provided with a separation device (3); The fuse body (1) comprises an epoxy tube (11) and a support (12), wherein the support (12) is located inside the epoxy tube (11), a fuse (13) is wound around the surface of the support (12), the epoxy tube (11) is further filled with a quartz sand layer (14), the quartz sand layer (14) is wrapped around the surface of the fuse (13), an upper copper cap (15) is provided at one end of the epoxy tube (11), and a lower copper cap (16) is provided at the other end, and a strike trigger (17) is provided inside the lower copper cap (16); The separation device (3) comprises a fuse tube seat (31), a fuse tube mounting hole (32) matched with a lower copper cap (16) is formed on the fuse tube seat (31), a hanging stress bracket (33) is provided below the fuse tube seat (31), a contact piece (34) is provided on the hanging stress bracket (33), a matching locking piece (35) is provided on the contact piece (34), a trigger tongue piece (36) matched with an impact trigger (17) is provided at one end of the fuse tube seat (31), a coil spring (37) is provided on the trigger tongue piece (36), and the locking piece (35) is matched with the trigger tongue piece (36).

2. The outdoor drop-out current-limiting fuse according to claim 1, characterized in that: A hanging stopper (38) is also provided below the hanging stress bracket (33).

3. The outdoor drop-out current-limiting fuse according to claim 1, characterized in that: The interior of the melting tube installation hole (32) is provided with threads.

4. The outdoor drop-out current-limiting fuse according to claim 1, characterized in that: The upper copper cap (15) and the lower copper cap (16) are made of brass.

5. The outdoor drop-out current-limiting fuse according to claim 1, characterized in that: The upper copper contact cap (2) and the separation device (3) are both made of silicon aluminum bronze.

6. The outdoor drop-out current-limiting fuse according to claim 1, characterized in that: The outer wall of the epoxy tube (11) is coated with a polymer anti-ultraviolet material layer.

7. The outdoor drop-out current-limiting fuse according to claim 1, characterized in that: The pillar (12) is made of aluminum oxide ceramics and has a plurality of protruding pillars on the surface.

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