Excitation fuse capable of improving sealing performance

Abstract

The excitation fuse comprises a shell provided with a cavity, a conducting bar is arranged in the shell in a penetrating mode in a sealed mode, a piston and an ignition device are arranged in the cavity of the shell on one side of the conducting bar, and a displacement channel for the impact end of the piston to penetrate through is arranged at the position, needing to be disconnected, of the conducting bar. A sealing plate is arranged at the end, facing the piston, of the displacement channel and makes close contact with the shell on the periphery of the displacement channel, and a sealing structure is arranged between the sealing plate and the shell on the periphery of the displacement channel. The sealing plate is provided with a profiling through hole corresponding to the displacement channel, the profiling through hole allows the impact end of the piston to penetrate through and imitates the peripheral size and shape of the impact end of the piston, arc extinguishing chambers are arranged on the shell on the other side, away from the piston, of the conducting bar, and when the number of the arc extinguishing chambers is multiple, the arc extinguishing chambers are independently arranged. According to the invention, by arranging the sealing plate with the profiling through hole and the sealing structure, the sealing performance and the breaking reliability of the product are improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of electric power control and electric vehicles, and relates to an energized fuse in circuit protection, in particular to an energized fuse with improved sealing performance. BACKGROUND

[0002] As a protection device of circuit system, when an overload or short-circuit current occurs in the circuit, the heat generation of the fuse will increase sharply, heat generation Q = I 2 RT, where I is the current, R is the resistance, and T is the current time. When the temperature of the fuse exceeds the melting point of the fuse itself, the fuse will melt and produce an arc. Under the action of the arc extinguishing medium, the arc is squeezed and the energy is absorbed, and the arc temperature decreases and is extinguished, thereby breaking the fault current. Since the fault current of the traditional fuse is inversely proportional to the breaking time, that is, when the short-circuit current is large, the melting time is very short, which can reach ms level, and when the fault current is small, the melting time is very long, which can reach minutes or hours or more.

[0003] With the rapid development of the new energy electric vehicle industry, higher safety protection requirements for people and vehicles are put forward. Not only is the breaking speed fast when a large short-circuit current occurs, but also the main circuit needs to be quickly cut off when there is no current in the circuit in scenes such as small fault current occurrence and vehicle body being hit or falling into water, so as to ensure the safety of life and property of people and vehicles. At this time, the traditional fuse cannot fully meet the needs of this field, and the emergence of the energized fuse fills this gap.

[0004] The existing energized fuse is composed of an ignition device, a piston, a conductive row, and an external shell, and is usually connected in series in the main circuit. When a fault current occurs, the ignition device will be triggered instantaneously to generate a large amount of high-pressure gas, the piston will be pushed by the high-pressure gas in the closed chamber to obtain kinetic energy, and then will hit the weak breaking point of the conductive row to make the conductive row break, thereby cutting off the fault current. Since the chemical energy of the ignition device is relied on to generate thrust, even if there is no current in the circuit, by triggering a signal to the ignition device, the circuit can be quickly cut off within 2 ms.

[0005] However, with the continuous improvement of the endurance of electric vehicles, the system voltage and battery capacity are continuously increasing, and the upper limit value of the short-circuit current is also increasing. In such a short time, the breaking of large current is realized, and the increase of di / dt will generate a very high overvoltage. The high voltage will generate a strong electric field between the two poles, and the conductive particles will pass through the gap between the two poles under the action of the electric field force, causing the two poles of the broken conductive row to break down and resulting in failure of the breaking function. SUMMARY

[0006] The purpose of the present application is to increase the sealing plate in the incentive fuse, improve the insulation performance between the broken part after the conductive row is broken, thereby avoiding the possibility of the conductive row being broken again after being broken, and improving the working reliability of the product.

[0007] To achieve the above object, the technical scheme provided by the present application is an incentive fuse with improved sealing performance, which comprises a shell provided with a cavity, a conductive row is arranged in the shell in a sealed manner, a piston and an ignition device are arranged in the cavity of the shell on one side of the conductive row, a displacement channel is arranged at the position where the conductive row needs to be broken, and the impact end of the piston passes through the displacement channel, a sealing plate is arranged at one end of the displacement channel towards the piston, the sealing plate is in close contact with the shell on the outer periphery of the displacement channel, and the sealing plate and the shell on the outer periphery of the displacement channel are sealed; the sealing plate is provided with a profiled through hole corresponding to the displacement channel, the profiled through hole is shaped according to the size and shape of the outer periphery of the impact end of the piston, and the impact end of the piston passes through the profiled through hole, the shell on the other side of the conductive row away from the piston is provided with an arc extinguishing chamber, and when the arc extinguishing chamber is multiple, the multiple arc extinguishing chambers are independently arranged.

[0008] Preferably, the shell comprises a first shell, a second shell and a third shell which are sequentially spliced, a sealing structure is arranged between the second shell and the third shell, the conductive row is arranged in the second shell in an integrated manner, the displacement channel is arranged in the second shell corresponding to the position where the conductive row needs to be broken, the piston and the ignition device are arranged in the first shell, the sealing plate is arranged at the splicing end of the first shell and the second shell, the sealing plate is arranged in close contact with the end face of the second shell, a sealing structure is arranged between the end face of the second shell contacted by the sealing plate and the sealing plate, and the independent arc extinguishing chamber is arranged on the third shell corresponding to the displacement channel.

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

[0010] Preferably, a containing groove is arranged on the end face of the second shell towards the first shell, the position where the conductive row needs to be broken and the displacement channel are located in the containing groove, the sealing plate is arranged in the containing groove in a shape-matched manner, and a sealing structure is arranged between the sealing plate and the containing groove.

[0011] Preferably, at least two of the conductive rows are provided with a position to be disconnected at intervals, and a displacement channel is arranged at each of the positions to be disconnected, and the piston is provided with a corresponding impact end corresponding to the position to be disconnected of the conductive row; the sealing plate is provided with a corresponding profiled through hole corresponding to the impact end of the piston; the third shell is provided with an independent arc extinguishing chamber corresponding to each of the displacement channels, and a sealing structure is arranged between each group of adjacent displacement channels and the corresponding arc extinguishing chamber, between a group of displacement channels close to the outer side wall of the shell and the outer side wall of the shell, and between the contact surface of the second shell and the third shell.

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

[0013] Preferably, an annular sealing groove is arranged in the accommodating groove of the second shell, the position to be disconnected of the conductive row and the displacement channel are located in the sealing groove, the sealing plate is arranged in the accommodating groove in a shape matching manner, the sealing plate is provided with an annular sealing convex edge corresponding to the sealing groove, and the sealing convex edge is nested in the sealing groove in an interference fit to form an annular sealing structure between the sealing plate and the second shell; a sealing convex edge is arranged on the end face of the second shell facing the third shell between the displacement channels and between the displacement channels close to the outer side wall of the second shell and the outer shell of the second shell, and a sealing groove is arranged at the corresponding position of the end face of the third shell facing the second shell, and the sealing convex edge of the second shell is nested in the sealing groove of the third shell in an interference fit to form an annular sealing structure.

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

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

[0016] Preferably, a groove is arranged at one end of the arc extinguishing structure facing the conductive row.

[0017] Preferably, a sleeve is arranged between the piston and the shell, the piston is in sealing contact with the sleeve, and the high-pressure gas release end of the ignition device is located in the sleeve.

[0018] The sealing performance improved excitation fuse of the application, by setting the sealing plate with the profiled through hole of the profiled impact end, when the impact end of the piston passes through the sealing plate, it can pass through the sealing plate in the way of completely sealed contact, avoiding the arc after the disconnection of the conducting row from passing through the sealing plate into the cavity where the piston is located, meanwhile, the insulation sealing between each disconnection of the conducting row is realized through the sealed contact between the sealing plate and the second shell and the sealing structure between the contact surface of the second shell and the third shell, preventing the arc at each disconnection from interfering with each other, through the impact end of the piston and the second shell, the independent part separated from the conducting row between the two disconnections of the conducting row is formed to be isolated, avoiding the arc at each disconnection from reigniting, through the above structure, the disconnection reliability is improved. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is the schematic diagram of the appearance structure.

[0020] Figure 2 is the schematic diagram of the cross-sectional structure at the initial position.

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

[0022] Figure 4 is the schematic diagram of the structure between the second shell integrally formed with the conducting row and the sealing plate.

[0023] Figure 5 is the schematic diagram of the arc extinguishing structure with the groove.

[0024] Reference signs:

[0025] First shell 10, second shell 11, third shell 12, ignition device 13, sleeve 14, piston 15, conducting row 16, position where the conducting row needs to be disconnected 17, displacement channel 18, sealing plate 19, profiled through hole 20, sealing structure 21, sealing gasket 22, arc extinguishing chamber 23, arc extinguishing structure 24, groove 241. DETAILED DESCRIPTION

[0026] The sealing performance improved excitation fuse of the application, by setting the sealing plate with the profiled through hole of the profiled impact end, when the impact end of the piston passes through the sealing plate, it can pass through the sealing plate in the way of completely sealed contact, avoiding the arc after the disconnection of the conducting row from passing through the sealing plate into the cavity where the piston is located, meanwhile, the insulation sealing between each disconnection of the conducting row is realized through the sealed contact between the sealing plate and the second shell and the sealing structure between the contact surface of the second shell and the third shell, preventing the arc at each disconnection from interfering with each other, through the impact end of the piston and the second shell, the independent part separated from the conducting row between the two disconnections of the conducting row is formed to be isolated, avoiding the arc at each disconnection from reigniting, through the above structure, the disconnection reliability is improved.

[0027] The preferred embodiments are described below in detail with reference to the drawings. The orientation words involved are only based on the orientation shown in the drawings and do not constitute a limitation on the technical solutions of the present application.

[0028] Referring to Figures 1 to 5 The improved sealing performance of the excitation fuse of the present application includes a first shell 10, a second shell 11 and a third shell 12 which are sequentially spliced.

[0029] A through cavity is provided in the first shell 10, and the ignition device 13 is arranged in the cavity of the first shell 10 and closes the end of the cavity. A sleeve 14 is arranged in the cavity of the first shell 10, and the sleeve 14 is arranged in close contact with the inner wall of the cavity of the first shell 10. The gas release end of the ignition device 13 is located in the sleeve 14. A piston 15 is arranged in the sleeve 14, and the piston 15 is in sealing contact with the sleeve 14. In this embodiment, the sealing contact is achieved by arranging a sealing ring on the outer periphery of the piston 15.

[0030] In this embodiment, the piston 15 has two impact ends arranged at intervals. In other embodiments, the piston 15 can have multiple impact ends.

[0031] The conductive row 16 is integrally formed with the second shell 11. The conductive row 16 is arranged in the second shell 11, and the two ends of the conductive row 16 are located outside the second shell 11 as the connection ends of the excitation fuse. The two impact ends of the piston 15 are respectively arranged at the positions of the conductive row 16 to be disconnected 17. The two conductive row to be disconnected positions 17 are arranged at intervals along the length direction of the conductive row 16. The second shell 11 is respectively arranged with displacement channels 18 at the positions corresponding to each conductive row to be disconnected position 17. The displacement channels 18 pass through the second shell 11 along the displacement direction of the piston 15 and have two ends. The opening end of the displacement channel 18 towards the first shell is smaller in size than the opening end towards the third shell. The one end of the conductive row to be disconnected position 17 is provided with a groove to form a pivot, and the other end is provided with a groove for disconnection, such as a V-shaped groove. The thickness of the conductive row at the disconnection groove is smaller than the thickness at the pivot groove. The thinnest position of the disconnection groove of the conductive row to be disconnected position 17 is arranged adjacent to the inner wall of the displacement channel 18 on one side, so that when the conductive row is cut off by the impact end of the piston, the disconnection position of the conductive row is located at the side wall of the displacement channel 18, and the side surface of the impact end of the piston can contact the side wall of the displacement channel to form a one-sided extrusion form.

[0032] The second shell 11 is provided with a receiving groove on the end face thereof facing the first shell 10, the displacement passage 18 is located in the receiving groove, and the sealing plate 19 is tightly arranged in the receiving groove. The sealing plate 19 has a shape matching the shape of the receiving groove. The sealing plate 19 is provided with a profiled through hole 20 corresponding to the shape and size of the impact end of the piston 15 at the two impact end positions of the piston 15, and the profiled through hole 20 corresponds to the displacement passage 18. The sealing structure 21 is arranged on the end face of the sealing plate 19 and the receiving groove at the outer periphery of each displacement passage 18 and corresponding profiled through hole 20. The sealing structure 21 comprises a sealing groove arranged on the end face of the second shell 11 and a sealing convex rib arranged on the sealing plate 19, and the sealing convex rib of the sealing plate is arranged in the sealing groove of the second shell 11 in an interference fit to form the sealing structure. The sealing structure 21 completely separates the two displacement passages, and therefore, the sealing structure 20 has an inverted 8-shaped structure and is arranged around the displacement passage 18 and the profiled through hole 20 to avoid the mutual interflow of the electric arcs and conductive particles generated by the two displacement passages when the conductive plates in the two displacement passages are disconnected, thereby affecting the reliability of the disconnection and preventing the conductive particles from escaping along the gap between the second shell and the sealing plate to the first shell and the second shell.

[0033] The sealing gasket 22 is arranged on the end of the sealing plate 19 facing the piston 15. The sealing gasket 22 can have the same shape as the sealing plate or can have a shape different from that of the sealing plate 19. The through hole of the sealing gasket 22 has the same shape as the profiled through hole 20 of the sealing plate 9. After the piston 15 cuts off the conductive row 16, the end face of the piston 15 can abut against the sealing gasket 22, and the piston 15 is further tightly contacted with the sealing plate 19 through the sealing gasket 22, thereby improving the sealing performance of the sealing plate. Since the sealing gasket 22 is made of soft rubber material, the sealing gasket 22 also has a certain buffering and energy absorbing effect.

[0034] The third shell 12 is provided with an independent arc extinguishing chamber 23 corresponding to each displacement passage 18, and the arc extinguishing chambers 23 corresponding to the adjacent two displacement passages are also arranged apart from each other. The arc extinguishing structure 24 is arranged in each arc extinguishing chamber 23. The arc extinguishing structure is a porous structure, such as a metal mesh, and the arc is divided into multiple small arcs through the porous arc extinguishing structure, and then the arc is cooled and extinguished. Figure 5 The arc extinguishing structure is a porous structure made of metal material, and a groove 241 can also be arranged on the end of the arc extinguishing structure facing the conductive row 16. The groove 241 increases the contact area between the arc extinguishing structure and the arc, and the depth of the groove is related to the length of the stretched arc during disconnection. The groove 241 arranged on the arc extinguishing structure 24 improves the arc extinguishing capacity of the arc extinguishing structure.

[0035] A sealing structure 20 is arranged between the end face of the third shell 12 and the second shell 11 in contact, completely isolating the displacement channels and the arc extinguishing chambers. The sealing structure 20 includes a sealing ridge arranged on the end face of the second shell 11 towards the third shell 12 around the outer periphery of each conductive row to be disconnected, and a corresponding sealing groove arranged on the end face of the third shell 12 towards the second shell 11 around the outer periphery of each arc extinguishing chamber, corresponding to the sealing ridge of the second shell 11 towards the third shell 12. The sealing ridge is embedded in the sealing groove in an interference fit to form the sealing structure 20. The depth of the sealing groove between the two arc extinguishing chambers and the two conductive rows to be disconnected is relatively deep, and the corresponding sealing ridge protrudes a corresponding distance, so that the sealing effect of the sealing structure 20 is better, and the two disconnected conductive row breaks can be better isolated to avoid arc interference.

[0036] Referring to Figure 2 , the two disconnected conductive row breaks 17 are adjacent, and the impact end of the piston 15 has a width greater than that of the conductive row. The opposite sides of the impact end are in contact with the displacement channels on both sides of the conductive row. Through the cooperation of the sealing structure and the design of the profiled through hole of the sealing plate, when the two disconnected conductive row breaks 17 are disconnected from the disconnected groove to form two breaks, the conductive row part between the two breaks is separated from the conductive row body, surrounded by the two impact ends of the second shell and the piston, and completely insulated from the outside. The two breaks of the conductive row are completely insulated and isolated, and each break is isolated by the impact end of the piston.

[0037] Working principle:

[0038] The ignition device operates according to the trigger signal to drive the piston to displace. The impact end of the piston passes through the profiled through hole of the sealing plate to cut off the conductive row from the disconnected groove of the conductive row to be disconnected to form a break. After the conductive row is disconnected, the impact end of the piston is pressed against the side wall of the displacement channel. Under the drive of the impact end of the piston, the disconnected part of the conductive row enters the corresponding arc extinguishing chamber along the rotating groove as a rotating shaft. The arc is elongated in the displacement channel and enters the arc extinguishing structure in the arc extinguishing chamber. The arc is divided into small arcs by the porous structure in the arc extinguishing structure, the temperature is lowered, and the arc is extinguished. When the piston is displaced to the terminal position, the end face of the piston is in close contact with the sealing gasket to further close the open end of the displacement channel. At the same time, the two impact ends of the piston and the second shell insulate and isolate the independent part of the conductive row from the conductive row body buried in the second shell, and insulate and isolate the two breaks of the conductive row under the cooperation of the sealing structure to eliminate the possibility of re-conducting after disconnection and improve the disconnection reliability of the conductive row after disconnection.

Claims

1. An energized fuse for improved sealing, characterized in that The utility model provides a kind of arc extinguishing device, including the shell provided with cavity, electrically conductive row is arranged in the shell in sealed manner, the cavity of the shell in the electrically conductive row one side is provided with piston and ignition device, the electrically conductive row needs to be arranged with the displacement passage for the impact end of the piston to pass through at the part of being disconnected, the displacement passage is provided with sealing plate towards the one end of the piston, the sealing plate is in close contact with the shell of the displacement passage periphery, and sealing is arranged between the sealing plate and the shell of the displacement passage periphery;The sealing plate is provided with the through hole of the profiled pass-through hole corresponding the displacement passage for the impact end of the piston to pass through, and the profiled pass-through hole is shaped according to the size and shape of the periphery of the impact end of the piston;The shell of the electrically conductive row away from the other side of the piston is provided with arc extinguishing chamber, when the arc extinguishing chamber is multiple, multiple arc extinguishing chambers are independently arranged.

2. The energized fuse of claim 1, wherein, The shell includes first shell, second shell and third shell spliced in sequence, sealing structure is arranged between the second shell and the third shell;The electrically conductive row is arranged in the second shell in one-piece manner, and the displacement passage is arranged in the second shell corresponding to the part of the electrically conductive row to be disconnected; The piston and ignition device are arranged in the first shell, the sealing plate is arranged at the splicing end of the first shell and the second shell, the sealing plate is arranged in close contact with the end face of the second shell, sealing structure is arranged between the end face of the second shell contacted by the sealing plate, and the third shell is provided with independent arc extinguishing chamber corresponding to the displacement passage.

3. The energized fuse of claim 2, wherein, Sealing pad is arranged at the one end of the sealing plate towards the piston, and the end face at the bottom of the impact end of the piston is in contact with the sealing pad when the piston is displaced to the terminal position.

4. The energized fuse of claim 3, wherein, End face of the second shell towards the first shell is provided with accommodating groove, the part of the electrically conductive row to be disconnected and the displacement passage are located in the accommodating groove, the sealing plate is arranged in the accommodating groove in shape matching manner, and sealing structure is arranged between the sealing plate and the accommodating groove.

5. The energized fuse of claim 4, wherein, At least two electrically conductive row parts to be disconnected are arranged on the electrically conductive row at intervals, the displacement passage is arranged at each electrically conductive row part to be disconnected, and the piston is provided with corresponding impact end corresponding to the electrically conductive row part to be disconnected;The sealing plate is provided with the profiled pass-through hole corresponding to the impact end of the piston respectively;The third shell is provided with independent arc extinguishing chamber corresponding to each displacement passage respectively, and sealing structure is arranged between the contact surface of the second shell and the third shell between each group of displacement passages and the arc extinguishing chambers corresponding thereto, and between the displacement passage and the arc extinguishing chamber corresponding thereto close to the outer lateral wall of the shell and the outer lateral wall of the shell.

6. The energizing fuse of any one of claims 2 to 5, wherein, The sealing structure is the concave-convex structure of interference fit.

7. The energized fuse of claim 6, wherein, An annular sealing groove is arranged in the accommodating groove of the second shell, the electrically conductive row needs to be disconnected part and the displacement channel are located in the sealing groove, the sealing plate is arranged in the accommodating groove in a shape matching manner, the sealing plate is provided with an annular sealing convex edge corresponding to the sealing groove, and the sealing convex edge is nested in the sealing groove in an interference manner to form the annular sealing structure between the sealing plate and the second shell.

8. The energized fuse of any one of claims 1 to 5, wherein, An arc extinguishing structure is arranged in the arc extinguishing chamber.

9. The energized fuse of claim 8, wherein, The arc extinguishing structure is a porous structure made of metal.

10. The energized fuse of claim 9, wherein, An end of the arc extinguishing structure towards the electrically conductive row is provided with a groove.

11. The energized fuse of any one of claims 1 to 5, wherein, A sleeve is arranged between the piston and the shell, the piston is in sealing contact with the sleeve, and a high-pressure gas release end of the ignition device is located in the sleeve.

Images