High-voltage direct-current thermal fuse

Abstract

A high-voltage direct-current thermal fuse including: a fusible component having two fusible alloy support arms parallel to each other; a fluxing agent; a fusing cavity; and two pins. The fusible component and the fluxing agent are sealed within the fusing cavity. The two pins are respectively connected to the two support arms. Technically, the fluxing agent only needs to have contact with the fusible alloy. Practically, the fluxing agent is usually coated over the fusible alloy. The fusible component in the high-voltage direct-current thermal fuse of the present application is a U-shaped structure having two parallel support arms. A high electric field intensity is generated when an arc is being cut off, as a result, the electrons repel each other, and the arc is lengthened, thereby increasing the speed of cutting off the arc.

Claims

1. A high-voltage direct-current thermal fuse, comprising: a fusible component having fusible alloy support arms, wherein the fusible alloy support arms do not intersect; a fluxing agent; a fusing cavity, wherein the fusible component and the fluxing agent are sealed within the fusing cavity; and pins, wherein the pins are respectively connected to the fusible alloy support arms; wherein n conductive members and n−1 fusible alloy connection segments arranged at intervals are connected between the fusible alloy support arms, and n is a natural number; when n is greater than or equal to 2, each of the n−1 fusible alloy connection segment is arranged between the n conductive members.

2. The high-voltage direct-current thermal fuse according to claim 1, wherein the fusible component has a U-shaped, M-shaped, S-shaped or trapezoid-shaped structure; the fusible alloy support arms and the pins are connected in a one-to-one correspondence manner.

3. The high-voltage direct-current thermal fuse according to claim 2, further comprising an insulation block, wherein the insulation block is arranged between the fusible alloy support arms and separates the pins.

4. The high-voltage direct-current thermal fuse according to claim 2, wherein a fusible alloy connection segment is connected between the fusible alloy support arms.

5. The high-voltage direct-current thermal fuse according to claim 2, wherein the pins are perpendicular to the fusible alloy support arms.

6. The high-voltage direct-current thermal fuse according to claim 1, further comprising an insulation block, wherein the insulation block is arranged between the fusible alloy support arms and separates the pins.

7. The high-voltage direct-current thermal fuse according to claim 6, further comprising a housing and a bottom plate; wherein the insulation block is arranged on the bottom plate; the housing, the bottom plate, the insulation block, and the pins form the fusing cavity.

8. The high-voltage direct-current thermal fuse according to claim 1, wherein a fusible alloy connection segment is connected between the fusible alloy support arms.

9. The high-voltage direct-current thermal fuse according to claim 1, wherein one of the n conductive members is connected between the fusible alloy support arms.

10. The high-voltage direct-current thermal fuse according to claim 1, wherein n conductive members comprise two conductive members and the n−1 fusible alloy connection segments comprise one fusible alloy connection segment arranged between the two conductive members are connected between the fusible alloy support arms.

11. The high-voltage direct-current thermal fuse according to claim 1, wherein when n is greater than or equal to 3, cross-sectional areas of the fusible alloy connection segments differ from one another, and an operating temperature of the fusible alloy connection segment having a smaller cross-sectional area is higher than an operating temperature of the fusible alloy connection segment having a larger cross-sectional area.

12. The high-voltage direct-current thermal fuse according to claim 1, wherein a place at which the fusible alloy support arms, the n−1 fusible alloy connection segments, and the n conductive members are connected is provided with connection holes.

13. The high-voltage direct-current thermal fuse according to claim 1, wherein the pins are perpendicular to the fusible alloy support arms.

14. The high-voltage direct-current thermal fuse according to claim 1, wherein the fusible component comprises a plurality fusible components connected in parallel.

15. The high-voltage direct-current thermal fuse according to claim 14, wherein conductive members having equal electric potential in the plurality of fusible components connected in parallel are integrated into one body.

16. The high-voltage direct-current thermal fuse according to claim 1, wherein the fusible component has a hollow tube structure, and the fluxing agent is placed in the hollow tube structure.

17. The high-voltage direct-current thermal fuse according to claim 1, wherein an external connection part of each pin is wavy at a side near the fusing cavity and is flat at a side away from the fusing cavity.

18. A high-voltage direct-current thermal fuse comprising: a fusible component having fusible alloy support arms, wherein the fusible alloy support arms do not intersect; a fluxing agent; a fusing cavity, wherein the fusible component and the fluxing agent are sealed within the fusing cavity; and pins, wherein the pins are respectively connected to the fusible alloy support arms; wherein a non-metallic partition film is arranged inside the fusing cavity to divide the fusing cavity into an inner cavity and an outer cavity, and the inner cavity and the outer cavity are mutually sealed; the fluxing agent is arranged inside the inner cavity, and a quartz sand is arranged inside the outer cavity.

19. A high-voltage direct-current thermal fuse comprising: a fusible component having fusible alloy support arms, wherein the fusible alloy support arms do not intersect; a fluxing agent; a fusing cavity, wherein the fusible component and the fluxing agent are sealed within the fusing cavity; and pins, wherein the pins are respectively connected to the fusible alloy support arms; wherein the fusible component has a U-shaped, M-shaped, S-shaped or trapezoid-shaped structure; the fusible alloy support arms and the pins are connected in a one-to-one correspondence manner; wherein n conductive members and n−1 fusible alloy connection segments arranged at intervals are connected between the fusible alloy support arms, and n is a natural number; when n is greater than or equal to 2, each of the n−1 fusible alloy connection segment is arranged between n conductive members.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present application will be further described below with reference to the following drawings.

(2) FIG. 1 is a cross-sectional view of the high-voltage direct-current thermal fuse according to Embodiment 1 in the present application;

(3) FIG. 2 is an exploded view of the high-voltage direct-current thermal fuse according to Embodiment 1 in the present application;

(4) FIG. 3 is a cross-sectional view of the high-voltage direct-current thermal fuse according to Embodiment 2 in the present application;

(5) FIG. 4 is an exploded view of the high-voltage direct-current thermal fuse according to Embodiment 2 in the present application;

(6) FIG. 5 is a cross-sectional view of the high-voltage direct-current thermal fuse according to Embodiment 3 in the present application;

(7) FIG. 6 is a cross-sectional view of the high-voltage direct-current thermal fuse according to Embodiment 4 in the present application;

(8) FIG. 7 is a cross-sectional view of the high-voltage direct-current thermal fuse according to Embodiment 5 in the present application; and

(9) FIG. 8 shows one embodiment of the pins according to the present disclosure.

(10) The reference numerals in the drawings are illustrated below: 101 housing 102 bottom plate 1021 insulation block 103 left pin 104 right pin 105 fusible alloy 106 fluxing agent 107 encapsulation adhesive 108 non-metallic partition film 109 quartz sand 201 housing 202 bottom plate 203 left pin 204 right pin 205 first support arm 206 conductive member 207 second support arm 208 fluxing agent 209 encapsulation adhesive 210 non-metallic partition film 211 quartz sand 301 housing 302 bottom plate 303 left pin 304 right pin 305 first support arm 306 first conductive member 307 fusible alloy connection segment 308 second conducive member 309 second support arm 310 fluxing agent 311 encapsulation adhesive 401 connection hole

DETAILED DESCRIPTION OF THE EMBODIMENTS

Embodiment 1

(11) As shown in FIG. 1 and FIG. 2, the high-voltage direct-current thermal fuse includes the non-metallic housing 101, the bottom plate 102, and the insulation block 1021 arranged on the bottom plate 102. The housing 101 and the bottom plate 102 are sealed with the encapsulation adhesive 107. The housing 101, the bottom plate 102, the left pin 103, the right pin 104, and the insulation block 1021 form the fusing cavity, and two fusible components coated with the fluxing agent 106 are hermetically arranged in the fusing cavity. The fusible component is a U-shaped structure having two fusible alloy support arms parallel to each other and fusible alloy connection segments connecting the two support arms. Namely, the fusible component is a U-shaped fusible alloy 105. The left pin 103 and the right pin 104 are perpendicular to the fusible alloy support arms. An end of the left pin 103 is connected to a support arm at a side and the other end of the left pin 103 extends out of the housing 101. One end of the right pin 104 is connected to the other support arm at the other side and the other end of the right pin 104 extends out of the housing 101. The insulation block 1021 is arranged between the parallel support arms and separates the left pin 103 and the right pin 104. The left pin 103, the fusible alloy 105, and the right pin 104 form the fusing component of an electrical connection.

(12) When the high-voltage direct-current thermal fuse is applied in the thermal protection of a power device in high-voltage circuits, when the power device operates in unusual conditions, the temperature would rise abnormally. The heat is transferred to the fluxing agent 106 and the fusible alloy 105 through the left pin 103, the right pin 104, and the housing 101, the temperature transfer the fluxing agent 106 from solid state to liquid state and activate the surface oxide layer of the fusible alloy 105. When the temperature reaches the operating temperature point of the fusible alloy 105, the fusible alloy 105 starts to creep and contract toward the left pin 103 and the right pin 104. When the fusible alloy 105 is broken, a high-voltage arc is generated, and the opening point of the fusible alloy 105 is rapidly eroded by electricity. When the fusible alloy 105 reaches the two parallel support arms after contraction and electrical erosion, the high electric field intensity generated by the breaking of the fusible alloy 105 makes the electrons of the two support arms repel each other, the arc is lengthened, and the arc is rapidly cut off, thus cutting off the circuit. The insulation block 1021 of the bottom plate 102 functions to lengthen the arc and increase the insulation voltage withstanding capability of the left pin 103 and the right pin 104 in the arc extinction.

Embodiment 2

(13) As shown in FIG. 3 and FIG. 4, the high-voltage direct-current thermal fuse includes the non-metallic housing 201, the bottom plate 202, and the insulation block arranged on the bottom plate 202. The housing 201 and the bottom plate 202 are sealed with the encapsulation adhesive 209. The housing 201, the bottom plate 202, the left pin 203, the right pin 204, and the insulation block form the fusing cavity, and two fusible components coated with the fluxing agent 208 are hermetically arranged in the fusing cavity. The fusible component is a U-shaped structure having the first support arm 205 and the second support arm 207 which are made of fusible alloy and are parallel to each other. The first support arm 205 and the second support arm 207 are connected by the conductive member 206. The insulation block is arranged between the first support arm 205 and the second support arm 207 and separates the left pin 203 and the right pin 204. The left pin 203 and the right pin 204 are perpendicular to the first support arm 205 and the second support arm 207. An end of the left pin 203 is connected to the first support arm 205 of the fusible component and the other end of the left pin 203 extends out of the housing 201. An end of the right pin 204 is connected to the second support arm 207 of the fusible component and the other end of the right pin 204 extends out of the housing 201. The left pin 203, the first support arm 205, the conductive member 206, the second support arm 207, and the right pin 204 are electrically connected successively to form a structure with two breaking points.

(14) On reaching the operating temperature, the fusible alloy contracts toward the two pins, and the fusible alloy with an excessive length will have a slower contraction rate. As a result, if the fusible alloy is applied to a high voltage structure, the high voltage cannot be cut off in time. The fusible component may be configured as two fusible alloy segments that are separate and parallel to each other. The conductive member is connected between the two fusible alloy segments as a bridge to form an electrical connection.

(15) The first support arm 205 and the second support arm 207 having the same operating temperature would absorb heat and contract toward the metal members at the two sides at the same time on reaching the operating temperature, thereby ensuring that the breaking point falls within the region of the parallel structure, improving the electric field intensity, accelerating the diffusion speed of the charged ions, shortening the length of the fusible alloy, forming multiple breaking points at the same time, increasing the voltage drop and loss, reducing the energy of the arc, and facilitating to cut off the high voltage circuit.

Embodiment 3

(16) As shown in FIG. 5, the high-voltage direct-current thermal fuse is a variant of Embodiment 1. On the basis of Embodiment 1, on the outer layer of the fusible alloy 105 coated with the fluxing agent 106, the non-metallic partition film 108 is used to divide the fusing cavity into an inner cavity and an outer cavity that are mutually sealed. The quartz sand 109 is arranged in the outer cavity, and the fluxing agent 106 is arranged in the inner cavity. The inner cavity and the outer cavity are partitioned to prevent the fluxing agent 106 from penetrating into the quartz sand 109 at a high temperature, and to prevent the quartz sand 109 from penetrating the fluxing agent 106 to destroy the surface structure of the fusible alloy 105.

(17) When the fusible alloy 105 contracts and melts to break, a high-voltage arc is generated. The arc instantaneously and electrically erodes the opening point of the fusible alloy 105, causing instantaneous gasification and expansion of the fusible alloy which impacts the non-metal partition film 108. Under the action of the impact wave, the non-metal partition film 108 gets fractured, and the quartz sand 109 falls down to cover the fusible alloy 109, thereby interrupting the high-voltage arc, forming multiple breaking points, and extinguishing the arc instantaneously, which can effectively cut off the circuit.

Embodiment 4

(18) As shown in FIG. 6, the high-voltage direct-current thermal fuse is a variant of Embodiment 2. On the basis of Embodiment 2, the partition film structure is used in a double breaking point structure. On the outer layer of the first support arm 205 and the second support arm 207 coated with the fluxing agent 208, the partition film 210 is used to separate the quartz sand 211 and the fluxing agent 208. In the fusing process, the arc is cut off at multiple breaking points to prevent further development of the arc.

Embodiment 5

(19) As shown in FIG. 7, according to the level of the voltage to be cut, the fusible alloy may be configured as more segments, and a conductive member is used as a bridge between every two fusible alloy segments to form a linear electrical connection in sequence.

(20) High-voltage direct-current thermal fuse includes the non-metallic housing 301, the bottom plate 302, and the insulation block arranged on the bottom plate 302. The housing 301 and the bottom plate 302 are sealed with the encapsulation adhesive 311. The housing 301, the bottom plate 302, the left pin 303, the right pin 304, and the insulation block form the fusing cavity, and the fusible component coated with the fluxing agent 310 is hermetically arranged inside the fusing cavity. The fusible component is a U-shaped structure having the first support arm 305 and the second support arm 309 that are made of fusible alloy and are parallel to each other. The first support arm 305 and the second support arm 309 are connected by the first conductive member 306, the fusible alloy connection segment 307, and the second conductive member 308 that are arranged at intervals. The insulation block is arranged between the first support arm 305 and the second support arm 309 and separates the left pin 303 and the right pin 304. The left pin 303 and the right pin 304 are perpendicular to the first support arm 305 and the second support arm 309. An end of the left pin 303 is connected to the first support arm 305 of the fusible component and the other end of the left pin 303 extends out of the housing 301. An end of the right pin 304 is connected to the second support arm 309 of the fusible component and the other end of the right pin 304 extends out of the housing 301. The left pin 303, the first support arm 305, the first conductive member 306, the fusible alloy connection segment 307, the second conductive member 308, the second support arm 309, and the right pin 304 are electrically connected successively to form a multiple breaking point structure. The fluxing agent 310 is coated on the surfaces of the first support arm 305, the fusible alloy connection segment 307, and the second support arm 309. The first support arm 305, the fusible alloy connection segment 307, and the second support arm 309 have the same operating temperature and form a multiple breaking point structure when fusing simultaneously, thereby increasing the voltage drop and loss and reducing the energy of the arc, so the thermal protection can be effectively performed.

(21) FIG. 8 shows one embodiment of the pins. It is shown in the drawing that an external connection part of each pin is wavy at a side near the fusing cavity and is flat at a side away from the fusing cavity.

(22) The present application has been described in detail in the form of embodiments with reference to the drawings. Described embodiments are merely preferred embodiments of the present application and are not intended to limit the present application. Although the present application has been described in detail with reference to the embodiments, for those skilled in the art, the technical solutions described in the foregoing embodiments may be modified, or some of the technical features may be equivalently replaced. Any changes, equivalent substitution, improvement, and so on made without departing from the spirit and principle of this application shall be considered as falling within the scope of this application.