An improved seal performance energized fuse

Abstract

This invention discloses an excitation fuse with improved sealing performance, comprising a housing with a cavity, a conductive busbar passing through the housing in a sealed manner, a piston and an ignition device disposed in the housing cavity on one side of the conductive busbar, a displacement channel for the piston's impact end to pass through the conductive busbar at the point where it needs to be disconnected, a sealing plate disposed at the end of the displacement channel facing the piston, the sealing plate being in close contact with the outer periphery of the housing of the displacement channel, and a sealing structure disposed between the sealing plate and the outer periphery of the housing of the displacement channel; the sealing plate having a contoured through hole corresponding to the displacement channel, mimicking the size and shape of the piston's impact end for passage, and an arc-extinguishing chamber disposed on the housing on the other side of the conductive busbar away from the piston, wherein when there are multiple arc-extinguishing chambers, the multiple arc-extinguishing chambers are independently disposed. This invention improves the sealing performance and disconnection reliability of the product by providing a sealing plate with a contoured through hole and a sealing structure.

Description

Technical Field

[0001] This invention belongs to the field of power control and electric vehicles, and relates to excitation fuses in circuit protection, specifically excitation fuses with improved sealing performance. Background Technology

[0002] As a protective device in a circuit system, a fuse generates a rapid increase in heat when an overload or short-circuit current occurs in the circuit. The heat generated is Q = I. 2 RT, where I is the current, R is the resistance, and T is the current-carrying time. When the temperature of the molten material exceeds its own melting point, the molten material will melt and generate an electric arc. Under the action of the arc-extinguishing medium, the electric arc is squeezed and its energy is absorbed. The temperature of the electric arc will decrease and it will be extinguished, thereby breaking the fault current. Since the fault current of a traditional fuse is inversely proportional to the breaking time, that is, when the short-circuit current is large, the breaking time is very short, which can reach the millisecond level, while when the fault current is small, the breaking time will be very long, which can reach the minute or hour level or more.

[0003] With the rapid development of the new energy electric vehicle industry, higher requirements have been put forward for the safety protection of people and vehicles. Not only is it required to break the circuit quickly when a large short-circuit current occurs, but also to quickly cut off the main circuit when there is no current in the circuit, such as when a small or medium fault current occurs, or even when the vehicle body is hit or falls into water, so as to ensure the safety of people and vehicles. At this time, traditional fuses can no longer fully meet the needs of this field, and the emergence of excitation fuses fills this gap.

[0004] Existing ignition fuses consist of an ignition device, a piston, a conductor bus, and an outer housing, typically connected in series in the main circuit. When a fault current occurs, the ignition device is instantaneously triggered, generating a large amount of high-pressure gas. The piston, propelled by the high-pressure gas within a sealed chamber, gains kinetic energy and then strikes the weak point of the conductor bus, causing it to break and thus interrupting the fault current. Because the thrust is generated by the chemical energy of the ignition device, even if there is no current in the circuit, a trigger signal to the ignition device can ensure that the circuit is rapidly disconnected within 2ms.

[0005] However, as the range of electric vehicles continues to increase, the system voltage and battery capacity also increase, and the upper limit of the short-circuit current also increases. Achieving high current interruption in such a short time will result in a very high overvoltage due to the increase in di / dt. The high voltage will generate a strong electric field between the two poles. Conductive particles will pass through the gap between the two poles under the action of the electric field force, causing the two poles at the break point of the already disconnected conductor busbar to break down, thus causing the interruption function to fail. Summary of the Invention

[0006] The purpose of this invention is to add a sealing plate to the excitation fuse to improve the insulation performance between the breaks after the conductor busbar is disconnected, thereby avoiding the possibility of the conductor busbar being broken again after disconnection and improving the operational reliability of the product.

[0007] To achieve the above objectives, the present invention provides an excitation fuse with improved sealing performance, comprising a housing with a cavity, a conductive busbar passing through the housing in a sealed manner, a piston and an ignition device being disposed in the cavity of the housing on one side of the conductive busbar, a displacement channel being provided at the part of the conductive busbar to be disconnected for the impact end of the piston to pass through, a sealing plate being provided at one end of the displacement channel facing the piston, the sealing plate being in close contact with the outer periphery of the housing of the displacement channel, and the sealing plate being sealed to the outer periphery of the housing of the displacement channel; the sealing plate being provided with a conformal through hole corresponding to the displacement channel for the impact end of the piston to pass through, the sealing plate being provided with an arc-extinguishing chamber on the other side of the housing away from the piston, and when there are multiple arc-extinguishing chambers, the multiple arc-extinguishing chambers are independently arranged.

[0008] Preferably, the housing comprises a first housing, a second housing, and a third housing connected in sequence, with a sealing structure between the second housing and the third housing; the conductive busbar is integrally formed and inserted into the second housing, and a displacement channel is provided in the second housing corresponding to the part of the conductive busbar that needs to be disconnected; the piston and ignition device are disposed in the first housing; the sealing plate is disposed at the joint end of the first housing and the second housing, the sealing plate is tightly fitted to the end face of the second housing, and a sealing structure is provided between the end faces of the sealing plate and the second housing in contact; and an independent arc-extinguishing chamber is provided on the third housing corresponding to the displacement channel.

[0009] Preferably, a sealing gasket is provided at one end of the sealing plate facing the piston, and when the piston is displaced to the termination position, the end face at the bottom of the impact end of the piston abuts against the sealing gasket.

[0010] Preferably, a receiving groove is provided on the end face of the second housing facing the first housing, the part of the conductive busbar to be disconnected and the displacement channel are both located in the receiving groove, the sealing plate is disposed in the receiving groove in a shape matching manner, and a sealing structure is provided between the sealing plate and the receiving groove.

[0011] Preferably, at least two disconnectable portions are provided at intervals on the conductive busbars, and a displacement channel is provided at each disconnectable portion. The piston is provided with a corresponding impact end corresponding to the disconnectable portion of the conductive busbar. The sealing plate is provided with the contoured through hole corresponding to the impact end of the piston. The third housing is provided with an independent arc-extinguishing chamber for each displacement channel. A sealing structure is provided between each group of adjacent displacement channels and their corresponding arc-extinguishing chambers, and between the contact surfaces of the second and third housings between the group of displacement channels and their corresponding arc-extinguishing chambers near the outer wall of the housing and the outer wall of the housing.

[0012] Preferably, the sealing structure is an interference fit concave-convex structure.

[0013] Preferably, an annular sealing groove is provided in the receiving groove of the second housing. The part of the conductive busbar to be disconnected and the displacement channel are both located in the sealing groove. The sealing plate is provided in the receiving groove in a shape-matching manner. The sealing plate is provided with an annular sealing ridge corresponding to the sealing groove. The sealing ridge is nested in the sealing groove in an interference fit to form an annular sealing structure between the sealing plate and the second housing. A sealing ridge is provided on the end face of the second housing facing the third housing between the displacement channels and the displacement channel near the outer shell wall of the second housing and the outer shell of the second housing. A sealing groove is provided at the corresponding position on the end face of the third housing facing the second housing. The sealing ridge of the second housing is nested in the sealing groove of the third housing in an interference fit to form an annular sealing structure.

[0014] Preferably, an arc-extinguishing structure is provided in the arc-extinguishing chamber.

[0015] Preferably, the arc-extinguishing structure is a porous structure made of metal.

[0016] Preferably, the arc-extinguishing structure has a groove at one end facing the conductive busbar.

[0017] Preferably, a sleeve is provided between the piston and the housing, the piston and the sleeve are in sealed contact, and one end of the high-pressure gas release of the ignition device is located in the sleeve.

[0018] The present invention provides an excitation fuse with improved sealing performance. By using a sealing plate with a shaped through-hole mimicking the piston's impact end, the piston's impact end can pass through the sealing plate in a completely sealed manner, preventing the arc from entering the piston cavity through the sealing plate after the conductor busbar is disconnected. Simultaneously, the sealing structure between the sealing plate and the second housing, as well as between the second and third housing contact surfaces, achieves insulation sealing between the various breaks on the conductor busbar, preventing mutual interference of arcs at each break point. Furthermore, the piston's impact end and the second housing isolate the independent parts of the conductor busbar separated from the conductor busbar between the two breaks, preventing arc reignition at each break point. Through this structure, the reliability of disconnection is improved. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the external structure.

[0020] Figure 2 This is a schematic diagram of the cross-sectional structure in its initial position.

[0021] Figure 3 This is a schematic diagram of the cross-sectional structure after the action.

[0022] Figure 4 This is a schematic diagram of the structure between the integrally formed second housing and the sealing plate of the conductive busbar.

[0023] Figure 5 This is a schematic diagram of an arc-extinguishing structure with grooves.

[0024] Figure label:

[0025] First housing 10, second housing 11, third housing 12, ignition device 13, sleeve 14, piston 15, conductive busbar 16, conductive busbar to be disconnected part 17, displacement channel 18, sealing plate 19, contoured through hole 20, sealing structure 21, sealing gasket 22, arc extinguishing chamber 23, arc extinguishing structure 24, groove 241. Detailed Implementation

[0026] The present invention provides an excitation fuse with improved sealing performance, comprising a housing with a cavity, a conductive busbar passing through the housing in a sealed manner, a piston and an ignition device being disposed in the cavity of the housing on one side of the conductive busbar, a displacement channel for the impact end of the piston to pass through the portion of the conductive busbar to be disconnected, a sealing plate being disposed at the end of the displacement channel facing the piston, the sealing plate being in close contact with the housing on the outer periphery of the displacement channel, and a sealing arrangement between the sealing plate and the housing on the outer periphery of the displacement channel; the sealing plate being provided with a contoured through hole corresponding to the displacement channel for the impact end of the piston to pass through, the sealing plate being provided with a contoured through hole of the outer periphery of the piston impact end to pass through, and an arc-extinguishing chamber being disposed on the housing on the other side of the conductive busbar away from the piston, wherein when there are multiple arc-extinguishing chambers, the multiple arc-extinguishing chambers are disposed independently of each other.

[0027] The following describes preferred embodiments in detail with reference to the accompanying drawings. The directional terms used are for reference only and do not constitute a limitation on the technical solution of this invention.

[0028] See Figures 1 to 5 The excitation fuse for improving sealing performance of the present invention includes a housing comprising a first housing 10, a second housing 11 and a third housing 12 assembled in sequence.

[0029] The first housing 10 has a through cavity. The ignition device 13 is located in the cavity at one end away from the second housing 11 and the cavity end is sealed. A sleeve 14 is provided in the cavity of the first housing 11. The sleeve 14 is fitted to the inner wall of the cavity of the first housing 10. The gas release end of the ignition device 13 is located in the sleeve 14. A piston 15 is provided in the sleeve 14. The piston 15 is in sealed contact with the sleeve 14. In this embodiment, the sealed contact is achieved by providing a sealing ring on the outer periphery of the piston 15.

[0030] In this embodiment, the piston 15 has two spaced-apart impact ends; in other embodiments, the piston 15 may have multiple impact ends.

[0031] The conductive busbar 16 is integrally formed with the second housing 11. The conductive busbar 16 passes through the second housing 11, with both ends located outside the second housing 11 as connection points for activating the fuse. The two impact ends of the piston 15, corresponding to the positions on the conductive busbar 16, are designated as disconnectable portions 17, spaced apart along the length of the conductive busbar 16. Each disconnectable portion 17 in the second housing 11 has a corresponding displacement channel 18, which extends through both ends of the second housing 11 along the displacement direction of the piston 15. The opening end of the displacement channel 18 facing the first housing is smaller than the opening end facing the third housing. One end of the disconnectable portion 17 has a groove forming a pivot, and the other end has a groove for disconnection, such as a V-shaped groove. The thickness of the conductive busbar at the disconnected groove is less than the thickness at the groove serving as the pivot. The thinnest part of the groove in the part to be disconnected 17 of the conductive busbar is located close to the inner wall of one side of the displacement channel 18. When the conductive busbar is cut off by the impact end of the piston, the disconnected part of the conductive busbar is located at the side wall of the displacement channel 18, so that the side of the impact end of the piston can contact the side wall of the displacement channel, forming a one-sided extrusion shape.

[0032] A receiving groove is provided on the end face of the second housing 11 facing the first housing 10. The displacement channel 18 is located in the receiving groove, and a sealing plate 19 is tightly fitted in the receiving groove. The shape of the sealing plate 19 matches the shape of the receiving groove. At the two impact end positions of the piston 15, the sealing plate 19 is provided with contoured through holes 20 that imitate the shape and size of the impact end of the piston 15. The contoured through holes 20 are provided corresponding to the displacement channel 18. A sealing structure 21 is provided on the end face of the sealing plate 19 and the receiving groove on the outer periphery of each displacement channel 18 and the corresponding contoured through hole 20. The sealing structure 21 includes: a sealing groove on the end face of the second housing 11, and a sealing protrusion on the sealing plate 19. The sealing protrusion of the sealing plate is set in the sealing groove of the second housing 11 in an interference fit to form a sealing structure. The tight-fitting structure 21 completely isolates the two displacement channels. Therefore, the sealing structure 20 is shaped like an inverted figure 8 and is set around the displacement channel 18 and the contoured through hole 20. This prevents the electric arc and conductive particles generated when the conductive plates in the two displacement channels are disconnected from each other, which would affect the reliability of the disconnection. It also prevents the generated conductive particles from escaping between the first and second housings along the gap between the second housing and the sealing plate.

[0033] A sealing gasket 22 is provided at the end of the sealing plate 19 facing the piston 15. The shape of the sealing gasket 22 can be the same as that of the sealing plate or different from that of the sealing plate 19. The through hole on the sealing gasket 22 is the same as the shape of the contoured through hole 20 of the sealing plate 9. After the piston 15 cuts off the conductive busbar 16, the end face of the piston 15 can abut against the sealing gasket 22, which further ensures that the piston 15 and the sealing plate 19 are in close contact, improving the sealing performance of the sealing plate. Since the sealing gasket 22 is made of a soft rubber material, it also has a certain buffering and energy absorption function.

[0034] The third housing 12 has an independent arc-extinguishing chamber 23 corresponding to each displacement channel 18, and the arc-extinguishing chambers 23 corresponding to two adjacent displacement channels are also spaced apart. Each arc-extinguishing chamber 23 contains an arc-extinguishing structure 24. The arc-extinguishing structure is a porous structure, such as a metal wire mesh, which divides the electric arc into multiple smaller arc segments for cooling and extinguishing. (See also...) Figure 5 The arc-extinguishing structure is a porous structure made of metal. A groove 241 can also be provided at one end of the arc-extinguishing structure facing the conductive busbar 16. The groove 241 increases the contact area between the arc-extinguishing structure and the electric arc. The depth of the groove is related to the length of the electric arc stretching when it breaks. By setting the groove 241 on the arc-extinguishing structure 24, the arc-extinguishing ability of the arc-extinguishing structure is improved.

[0035] A sealing structure 20 is provided between the end faces of the third housing 12 and the second housing 11 that are in contact, completely isolating the displacement channels and the arc-extinguishing chambers. The sealing structure 20 includes sealing ridges surrounding the outer periphery of each conductor bar to be disconnected on the end face of the second housing 11 facing the third housing 12, and corresponding sealing grooves surrounding the outer periphery of each arc-extinguishing chamber on the end face of the third housing 12 facing the second housing 11. The sealing ridges are embedded in the sealing grooves with an interference fit to form the sealing structure 20. The sealing grooves between the two arc-extinguishing chambers and the two conductor bars to be disconnected are relatively deep, and the corresponding sealing ridges protrude a relatively large distance, resulting in a better sealing effect of the sealing structure 20. This better isolates the breaks in the two disconnected conductor bars and avoids arc interference.

[0036] See Figure 2 The disconnecting grooves of the two conductive bars to be disconnected 17 are adjacent, and the width of the impact end of the piston 15 is greater than the width of the conductive bar. The opposite sides of the impact end contact the displacement channels on both sides of the conductive bar. Through the cooperation of the sealing structure and the design of the contoured through hole of the sealing plate, when the two conductive bars to be disconnected 17 are disconnected from the two breaks formed by the disconnecting groove, the conductive bar part between them is separated from the conductive bar body and surrounded by the second housing and the two impact ends of the piston. It is completely insulated from the outside and can completely insulate the two breaks of the conductive bar. Moreover, each break is insulated through the impact end of the piston.

[0037] Working principle:

[0038] The ignition device operates according to the trigger signal, driving the piston to move. The piston's impact end passes through the contoured through-hole of the sealing plate, cutting the conductive busbar at the disconnection groove of the part to be disconnected, forming a break. After the conductive busbar is disconnected, the piston's impact end presses against the side wall of the displacement channel, causing it to move. Driven by the piston's impact end, the broken part of the conductive busbar moves along the rotating groove as a pivot into the corresponding arc-extinguishing chamber. The arc is compressed and elongated within the displacement channel and enters the arc-extinguishing structure in the arc-extinguishing chamber, where it is absorbed and divided into small arc segments by the porous structure, reducing its temperature and extinguishing it. When the piston reaches the termination position, the piston's end face is in close contact with the sealing gasket, further sealing the opening of the displacement channel. Simultaneously, the two impact ends of the piston and the second housing insulate the independent conductive busbar portion embedded in the second housing, detached from the conductive busbar body. With the cooperation of the sealing structure, the two breaks of the conductive busbar are insulated, eliminating the possibility of re-conductivity after disconnection and improving the reliability of the conductive busbar after disconnection.

Claims

1. An excitation fuse with improved sealing performance, characterized in that, The device includes a housing with a cavity, a conductive busbar that is sealed within the housing, a piston and an ignition device disposed in the cavity of the housing on one side of the conductive busbar, a displacement channel for the impact end of the piston to pass through at the part of the conductive busbar that needs to be disconnected, a sealing plate disposed at the end of the displacement channel facing the piston, the sealing plate being in close contact with the outer periphery of the housing of the displacement channel, and the sealing plate being sealed to the outer periphery of the housing of the displacement channel; the sealing plate having a contoured through hole corresponding to the displacement channel for the impact end of the piston to pass through, the sealing plate having an arc-extinguishing chamber disposed on the other side of the housing away from the piston, when there are multiple arc-extinguishing chambers, the multiple arc-extinguishing chambers are disposed independently of each other.

2. The excitation fuse according to claim 1, characterized in that, The housing includes a first housing, a second housing, and a third housing that are sequentially spliced ​​together, with a sealing structure provided between the second housing and the third housing; the conductive bus is integrally formed and inserted into the second housing, and a displacement channel is provided in the second housing corresponding to the part of the conductive bus that needs to be disconnected; The piston and ignition device are disposed in the first housing. The sealing plate is disposed at the splicing end of the first housing and the second housing. The sealing plate is tightly fitted to the end face of the second housing. A sealing structure is provided between the end faces of the sealing plate and the second housing. An independent arc extinguishing chamber is provided on the third housing corresponding to the displacement channel.

3. The excitation fuse according to claim 2, characterized in that, A sealing gasket is provided at one end of the sealing plate facing the piston. When the piston is displaced to the termination position, the end face at the bottom of the impact end of the piston abuts against the sealing gasket.

4. The excitation fuse according to claim 3, characterized in that, A receiving groove is provided on the end face of the second housing facing the first housing. The part of the conductive busbar that needs to be disconnected and the displacement channel are both located in the receiving groove. The sealing plate is disposed in the receiving groove in a shape-matching manner. A sealing structure is provided between the sealing plate and the receiving groove.

5. The excitation fuse according to claim 4, characterized in that, At least two disconnectable sections are provided at intervals on the conductive busbars. A displacement channel is provided at each disconnectable section. A piston is provided with a corresponding impact end corresponding to the disconnectable section. The sealing plate is provided with a contoured through hole corresponding to the impact end of the piston. The third housing is provided with an independent arc-extinguishing chamber for each displacement channel. A sealing structure is provided between each group of adjacent displacement channels and their corresponding arc-extinguishing chambers, and between the contact surfaces of the second and third housings between the group of displacement channels and their corresponding arc-extinguishing chambers near the outer wall of the housing and the outer wall of the housing.

6. The excitation fuse according to any one of claims 2 to 5, characterized in that, The sealing structure is an interference fit concave-convex structure.

7. The excitation fuse according to claim 6, characterized in that, An annular sealing groove is provided in the receiving groove of the second housing. The part of the conductive busbar that needs to be disconnected and the displacement channel are both located in the sealing groove. The sealing plate is provided in the receiving groove in a shape-matching manner. The sealing plate is provided with an annular sealing ridge corresponding to the sealing groove. The sealing ridge is nested in the sealing groove in an interference fit to form an annular sealing structure between the sealing plate and the second housing. A sealing ridge is provided on the end face of the second housing facing the third housing between the displacement channels and the outer shell of the second housing near the outer shell wall of the second housing. A sealing groove is provided at the corresponding position on the end face of the third housing facing the second housing. The sealing ridge of the second housing is nested in the sealing groove of the third housing in an interference fit to form an annular sealing structure.

8. The excitation fuse according to any one of claims 1 to 5, characterized in that, An arc-extinguishing structure is provided in the arc-extinguishing chamber.

9. The excitation fuse according to claim 8, characterized in that, The arc-extinguishing structure is a porous structure made of metal.

10. The excitation fuse according to claim 9, characterized in that, The arc-extinguishing structure has a groove at one end facing the conductive busbar.

11. The excitation fuse according to any one of claims 1 to 5, characterized in that, A sleeve is provided between the piston and the housing, and the piston is in sealed contact with the sleeve. One end of the high-pressure gas release of the ignition device is located in the sleeve.

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