HIGH-VOLTAGE FUSE

Abstract

A high-voltage fuse includes a temperature fuse device and a high-voltage breaking device that are connected in parallel, wherein the high-voltage breaking device includes a fuse link, and the fuse link is an n-shaped structure with parallel segments at both ends thereof; and a resistance value of the temperature fuse device is lower than a resistance value of the fuse link, and a melting point of the temperature fuse device is lower than a melting point of the fuse link. The high-voltage fuse can realize an over-temperature fusing function. Due to the n-shaped fuse link, the electric arc may be cut off quickly to perform high-voltage breaking and protect the safety of the circuitry.

Claims

1. A high-voltage fuse, comprising a temperature fuse device and a high-voltage breaking device, wherein the temperature fuse device and the high-voltage breaking device are connected in parallel; the high-voltage breaking device comprises a fuse link, the fuse link is an n-shaped structure, and parallel segments of the fuse link are arranged at both ends of the fuse link, respectively; and a resistance value of the temperature fuse device is lower than a resistance value of the fuse link, and a melting point of the temperature fuse device is lower than a melting point of the fuse link.

2. The high-voltage fuse according to claim 1, wherein, the high-voltage breaking device further comprises a breaking insulating stopper provided between the parallel segments of the fuse link.

3. The high-voltage fuse according to claim 1, wherein, the temperature fuse device comprises a plurality of fusible alloys, and a surface of each fusible alloy of the plurality of fusible alloys is coated with a fluxing agent.

4. The high-voltage fuse according to claim 3, wherein,-a the plurality of fusible alloys are connected in parallel.

5. The high-voltage fuse according to claim 4, wherein, one fusible alloy of the plurality of fusible alloys has a lowest resistivity and a lowest melting point in the plurality of fusible alloys.

6. The high-voltage fuse according to claim 3, wherein, the each fusible alloy is an n-shaped structure, parallel segments of the each fusible alloy are arranged at both ends of the each fusible alloy, respectively, and a fusing insulating stopper is provided between the parallel segments of the each fusible alloy.

7. The high-voltage fuse according to claim 1, further comprising a left electrode piece, a right electrode piece and an insulating casing, wherein, a first end of the temperature fuse device is connected to the left electrode piece, and a second end of the temperature fuse device is connected to the right electrode piece; a first end of the high-voltage breaking device is connected to the left electrode piece, and a second end of the high-voltage breaking device is connected to the right electrode piece; the temperature fuse device and the high-voltage breaking device are packaged in the insulating casing; and the left electrode piece and the right electrode piece are extended out of the insulating casing as lead-out ends.

8. The high-voltage fuse according to claim 7, wherein, the insulating casing, the left electrode piece, the right electrode piece and the high-voltage breaking device enclose a breaking cavity, and the insulating casing, the left electrode piece, the right electrode piece and the temperature fuse device enclose a fusing cavity.

9. The high-voltage fuse according to claim 8, wherein, the breaking cavity is filled with an arc-extinguishing medium.

10. The high-voltage fuse according to any one of claim 7, wherein, each of the left electrode piece and the right electrode piece comprises an L-shaped connecting portion, and the L-shaped connecting portion and the temperature fuse device are vertically welded.

11. The high-voltage fuse according to claim 4, wherein, the each fusible alloy is an n-shaped structure, parallel segments of the each fusible alloy are arranged at both ends of the fusible alloy, respectively, and a fusing insulating stopper is provided between the parallel segments of the each fusible alloy.

12. The high-voltage fuse according to claim 5, wherein, the each fusible alloy is an n-shaped structure, parallel segments of the each fusible alloy are arranged at both ends of the fusible alloy, respectively, and a fusing insulating stopper is provided between the parallel segments of the each fusible alloy.

13. The high-voltage fuse according to claim 8, wherein, each of the left electrode piece and the right electrode piece comprises an L-shaped connecting portion, and the L-shaped connecting portion and the temperature fuse device are vertically welded.

14. The high-voltage fuse according to claim 9, wherein, each of the left electrode piece and the right electrode piece comprises an L-shaped connecting portion, and the L-shaped connecting portion and the temperature fuse device are vertically welded.

15. The high-voltage fuse according to claim 7, wherein, the right electrode piece and the left electrode piece are in a mirror image relationship.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention is further described below in conjunction with the following accompanying drawings.

[0024] FIG. 1 is a circuit schematic diagram of a high-voltage fuse according to the present invention;

[0025] FIG. 2 is an exploded schematic diagram of a high-voltage fuse according to Embodiment 1 of the present invention;

[0026] FIG. 3 is a schematic longitudinal sectional diagram of the high-voltage fuse according to Embodiment 1 of the present invention;

[0027] FIG. 4 is a schematic cross-sectional diagram of a temperature fuse device of the high-voltage fuse according to Embodiment 1 of the present invention;

[0028] FIG. 5 is a schematic cross-sectional diagram of a high-voltage breaking device of the high-voltage fuse according to Embodiment 1 of the present invention; and

[0029] FIG. 6 is an exploded schematic diagram of a high-voltage fuse according to Embodiment 2 of the present invention.

IN THE FIGURES

[0030] 101 Temperature fuse device

[0031] 102 High-voltage breaking device

[0032] 103 First pin

[0033] 104 Second pin

[0034] 201 Outer casing

[0035] 201a Fusing cavity

[0036] 201b Breaking cavity

[0037] 202 Cover plate

[0038] 203 Breaking insulating stopper

[0039] 204 Right electrode piece

[0040] 204a Right L-shaped connecting portion

[0041] 204b Right-side hole

[0042] 205 Fusible alloy

[0043] 206 Left electrode piece

[0044] 206a Left L-shaped connecting portion

[0045] 206b Left-side hole

[0046] 207 Alloy wire

[0047] 208 Fluxing agent

[0048] 209 Quartz sand

[0049] 210 Epoxy resin

[0050] 211 Right soldering tin

[0051] 212 Left soldering tin

[0052] 301 Outer casing

[0053] 302 Cover plate

[0054] 302a Breaking insulating stopper

[0055] 303 Breaking insulating stopper

[0056] 304 Right electrode piece

[0057] 304a Right boss

[0058] 304b Right-side hole

[0059] 305 Fusible alloy

[0060] 306 Left electrode piece

[0061] 306a Left boss

[0062] 306b Left-side hole

[0063] 307 Alloy wire

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0064] The present invention is specifically described below with reference to the accompanying drawings.

Embodiment 1

[0065] As shown in FIG. 1, the temperature fuse device 101 and the high-voltage breaking device 102 are connected in parallel, wherein the temperature fuse device 101 performs an over-temperature fusing function, and the high-voltage breaking device 102 includes an n-shaped alloy wire to perform a high-voltage breaking function. Moreover, the first pin 103 and the second pin 104 are connected to two parallel points and lead out, respectively. Because the resistance value and melting point of the high-voltage breaking device 102 are higher than those of the temperature fuse device 101, when a rated current is passed, most of the current-carrying capacity is mainly realized by the temperature fuse device 101. At an instant when the temperature fuse device 101 achieves over-temperature fusing, the high-voltage breaking device 102 remains in an on-state, and the current flows through the high-voltage breaking device 102. The current carrying capacity of the alloy wire of the high-voltage breaking device 102 is set to be less than the rated current, and when the current passes through the alloy wire, with the increase of heat, the alloy wire fuses by itself, and an arc inevitably occurs during the breaking process. Due to the arrangement of parallel segments formed by the n-shaped structure, a high electric field strength exists, electrons repel each other, and an electric arc is elongated to accelerate the recombination and diffusion of free electrons and positive ions, which can quickly cut off the electric arc, perform high-voltage breaking, and protect the safety of the circuitry.

Embodiment 2

[0066] As shown in FIGS. 2, 3, 4, and 5, two separate cavities, i.e. the fusing cavity 201a and the breaking cavity 201b, are formed by the outer casing 201, the cover plate 202 and the epoxy resin 210.

[0067] The right electrode piece 204 and the left electrode piece 206 are provided. The right electrode piece 204 and the left electrode piece 206 are in a mirror image relationship, and are provided at an interval directly opposite to each other, and are extended out of the outer casing 201 as lead-out ends. The right L-shaped connecting portion 204a and the right-side hole 204b are provided at one end of the right electrode piece 204, respectively, and correspondingly, the left L-shaped connecting portion 206a and the left-side hole 206b are provided at one end of the left electrode piece 206, respectively.

[0068] In the fusing cavity 201a, the fusible alloy 205 coated with the fluxing agent 208 is provided between the right L-shaped connecting portion 204a and the left L-shaped connecting portion 206a to form the electrical connection between the right electrode piece 204, the fusible alloy 205 and the left electrode piece 206, thereby constituting a temperature fuse device.

[0069] In the breaking cavity 201b, the n-shaped alloy wire 207 is provided between the right-side hole 204b and the left-side hole 206b. One end of the alloy wire 207 is fixed to the right electrode piece 204 through the right soldering tin 211, and the other end of the alloy wire 207 is fixed to the left electrode piece 206 through the left soldering tin 212, thereby forming the electrical connection between the right electrode piece 204, the alloy wire 207 and the left electrode piece 206, and constituting the main body of the high-voltage breaking device. In the breaking cavity 201b, the quartz sand 209 is filled around the alloy wire 207. The breaking insulating stopper 203 is provided between parallel segments of the n-shaped alloy wire 207 to increase the electrical clearance and creepage distance between the right electrode piece 204 and the left electrode piece 206 after the alloy wire 207 is disconnected.

[0070] When applied to protection of a new energy passenger car heater, the high-voltage fuse is connected in series with a heating circuit. Under normal conditions, the fusible alloy 205 assumes the main current-carrying function. When the relay of the heating circuit fails and the heating circuit cannot be disconnected, the heater continues to operate and the temperature rises abnormally. When the temperature reaches the softening temperature of the fluxing agent 208, the fluxing agent 208 changes from a solid state to a liquid state and starts to activate the surface oxide layer of the fusible alloy 205. When the temperature reaches the fusing temperature of the fusible alloy 205, the fusible alloy 205 shrinks and moves toward the right L-shaped connecting portion 204a and the left L-shaped connecting portion 206a under the tension of the fluxing agent 208, thereby cutting off the temperature fuse device. All of the current flows through the alloy wire 207 and exceeds the current-carrying capacity of the alloy wire 207. The alloy wire 207 promotes the increase of heat due to its own high resistance to cause the temperature to reach the melting point of the alloy wire 207, and then the alloy wire 207 fuses by itself. An electric arc is inevitably generated during the breaking process. Due to the arrangement of the parallel segments formed by the n-shaped structure, a high electric field strength exists, electrons repel each other, the electric arc is elongated to accelerate the recombination and diffusion of free electrons and positive ions,. Additionally, the quartz sand 209 can absorb the impact of arc gasification and separate the electric arc. Therefore, the electric arc is quickly cut off, the high-voltage breaking is performed, and the safety of the circuitry is protected.

Embodiment 3

[0071] As shown in FIG. 6, two separate cavities formed by the outer casing 301 and the cover plate 302 are provided with the right electrode piece 304 and the left electrode piece 306, respectively. The right electrode piece 304 and the left electrode piece 306 are in a mirror image relationship, and are provided at an interval directly opposite to each other, and the right electrode piece 304 and the left electrode piece 306 are exposed to the outer casing 301 from opposite ends. The right boss 304a and a right-side hole 304b are provided at one end of the right electrode piece 304, respectively, and the left boss 306a and correspondingly, the left-side hole 306b are provided at one end of the left electrode piece 306, respectively.

[0072] In one of the cavities of the outer casing 301, the n-shaped fusible alloy 305 coated with the fluxing agent is provided between the right boss 304a and the left boss 306a to form the electrical connection between the right electrode piece 304, the fusible alloy 305 and the left electrode piece 206, thereby constituting a temperature fuse device. Moreover, in this cavity, the fusing insulating stopper 302a is provided on the cover plate 302, thereby increasing the creepage distance and electrical clearance after the fusible alloy 305 is disconnected.

[0073] In another one of the cavities of the outer casing 301, the n-shaped alloy wire 307 is provided between the right-side hole 304b and the left-side hole 306b. One end of the alloy wire 307 is fixed to the right-side hole 304b on the right electrode piece 304 through the soldering tin, and the other end of the alloy wire 307 is fixed to the left-side hole 306b on the left electrode piece 306 through the soldering tin, thereby forming the electrical connection between the right electrode piece 304, the alloy wire 307 and the left electrode piece 306, and constituting the main body of the high-voltage breaking device. Moreover, in this cavity, the quartz sand is filled around the alloy wire 307. The breaking insulating stopper 303 is provided between parallel segments of the n-shaped alloy wire 307 to increase the electrical clearance and creepage distance between the right electrode piece 304 and the left electrode piece 306 after the alloy wire 307 is disconnected.

[0074] When applied to protection of an electric bus heater, the high-voltage fuse is connected in series with a heating circuit. Under normal conditions, the fusible alloy 305 assumes the main current-carrying function. When the relay of the heating circuit fails and the heating circuit cannot be disconnected, the heater continues to operate and the temperature rises abnormally. When the temperature reaches the softening temperature of the fluxing agent, the fluxing agent changes from a solid state to a liquid state and starts to activate the surface oxide layer of the fusible alloy 305. When the temperature reaches the fusing temperature of the fusible alloy 305, the fusible alloy 305 shrinks and moves toward the right boss 304a and the left boss 306a on both sides under the tension of the fluxing agent, thereby cutting off the temperature fuse device. All of the current flows through the alloy wire 307 and exceeds the current-carrying capacity of the alloy wire 307. The alloy wire 207 promotes the increase of heat due to its own high resistance, to cause the temperature reach the melting point of the alloy wire 307, and then the alloy wire 207 fuses by itself. An electric arc is inevitably generated during the breaking process. Due to the arrangement of the parallel segments formed by the n-shaped structure, a high electric field strength exists, electrons repel each other, the electric arc is elongated to accelerate the recombination and diffusion of free electrons and positive ions. Additionally, the quartz sand can absorb the impact of arc gasification and separate the electric arc. Therefore, the electric arc is quickly cut off, the high-voltage breaking is performed, and the safety of the circuitry is protected.

[0075] It should be understood that the embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the embodiments, for those skilled in the art, it is still possible to make other changes or modifications in different forms or equivalently replace some of the technical features on the basis of the above description. However, any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present invention shall fall within the scope of protection of the present invention.