Excitation fuse with compact structure

Abstract

The invention relates to circuit protection in the field of electric power control and electric automobiles, in particular to a compact-structure excitation fuse which comprises a shell, an excitation source, a piston and at least one conducting bar for circuit protection, and a melt is connected to the conducting bar for circuit protection in parallel. A first cavity and at least one second cavity filled with an arc extinguishing medium are arranged in the shell, and the second cavity is positioned on the peripheral side of the first cavity in the displacement direction of the piston; the excitation source and the piston are sequentially arranged in the first cavity, the conducting bar for circuit protection penetrates through the first cavity, and the melt is arranged in the arc extinguishing medium in the second cavity in a penetrating mode. When the excitation source acts to drive the piston to move to cut off the conducting bar for circuit protection, the melt is fused in the arc extinguishing medium. The fuse is compact in structure and smaller in size.

Description

Technical Field

[0001] The present invention relates to circuit protection in the fields of power control and electric vehicles, specifically to an excitation fuse for circuit protection, which can be used in scenarios of single-circuit protection, multi-circuit protection, and current interruption required for complex internal structures of products. Background Art

[0002] Currently, there is already a relatively mature excitation fuse product on the market, including an excitation source, a piston, a conductive bar, and a fuse element connected in parallel to the conductive bar, arranged in sequence. The excitation source and the piston are sequentially arranged in an upper housing, the conductive bar is arranged between the upper housing and the lower housing, and the fuse element and the fuse element housing are arranged below the lower housing. A hollow part is arranged in the upper housing, the excitation source is arranged at the top of the hollow part, and the piston is arranged in the hollow part below the excitation source. A displacement space for the piston to displace after breaking the conductive bar is arranged on the lower housing. The excitation source is an electronic ignition device, which can be heated according to the received trigger electrical signal, increasing the temperature, undergoing a chemical reaction, and releasing high-pressure gas as a driving force. The modular excitation fuse disclosed in Chinese Patent 2021210930360 has the above structure.

[0003] The working principle is as follows: The excitation fuse is connected in series in the circuit. For example, when used in new energy vehicles, when the vehicle is in a normal working state, the current flows through the conductive bar of the excitation fuse, and the product can be regarded as a conductor. When the vehicle is in an abnormal working state and needs to cut off the circuit, the vehicle control system sends a trigger electrical signal to the excitation source, and the electronic ignition device triggers to generate high-pressure gas as a driving force, pushing the piston downward to break the pre-break of the conductive bar, forming a physical break. Then the current flows through the fuse element connected in parallel to the conductive bar, and the fuse element melts, completely cutting off the circuit. Although the performance of this excitation fuse has been improved compared with that of the thermal fuse, there are still the following deficiencies: The space utilization efficiency is insufficient, the product size is relatively large, and the weight is also relatively large; due to the large size of the existing excitation fuse, the copper bars are mostly single-circuit copper bars and cannot adapt to some more complex situations. Summary of the Invention

[0004] The purpose of the present invention is to rationalize the use of the space of the fuse product, make the structure of the fuse product more compact, improve the space utilization rate of the product, and reduce the product volume.

[0005] To achieve the above object, the technical solution provided by the present invention is a structurally compact incentive fuse, comprising: a housing, an excitation source, a piston, and at least one conductive busbar for circuit protection, wherein a fuse element is connected in parallel to the conductive busbar for circuit protection; a first cavity and at least one second cavity are provided in the housing; the excitation source and the piston are sequentially arranged in the first cavity, and the signal receiving end of the excitation source is located outside the housing; the conductive busbar for circuit protection passes through the first cavity and is located on the displacement path of the piston, and both ends of the conductive busbar for circuit protection are connection ends and are respectively located outside the housing; the piston can move along the first cavity from an initial position to a termination position under the driving force released by the excitation source; the second cavity is located on the outer peripheral side of the first cavity in the displacement direction of the piston, and an arc extinguishing medium is filled in the second cavity, and the fuse element is arranged in the arc extinguishing medium in the second cavity; when the excitation source acts according to the received trigger signal to release the driving force and drives the piston to displace to cut off the conductive busbar for circuit protection, the fuse element fuses in the arc extinguishing medium.

[0006] Preferably, the fuse element is preferentially arranged in the second cavity outside the first cavity between the end of the piston close to the excitation source and the conductive busbar for circuit protection.

[0007] The term "preferably" here means that when arranging the fuse element, first arrange the fuse element in the second cavity outside the first cavity between the end of the piston close to the excitation source and the conductive busbar for circuit protection, and ensure insulation between the fuse elements connected in parallel to each conductive busbar for circuit protection; however, when arranging the fuse element in the second cavity outside the first cavity between the end of the piston close to the excitation source and the conductive busbar for circuit protection cannot meet the insulation requirement between the fuse elements, then arrange the fuse elements that cannot meet the insulation requirement in the second cavity between the conductive busbar for circuit protection and the bottom of the second groove.

[0008] Preferably, the housing includes an excitation source sheath, an upper housing, and a lower housing that are butt-jointed in sequence; hollow portions that penetrate through both ends are respectively provided at corresponding positions on the excitation source sheath and the upper housing, and a second groove for the displacement of the piston is provided on the end face where the lower housing is butt-jointed with the upper housing. After docking, the hollow portions of the excitation source sheath and the upper housing and the second groove of the lower housing communicate to form the first cavity; a second cavity is provided on the upper housing around the outer side of the hollow portion of the upper housing, or a second cavity is respectively provided on the upper housing around the outer side of the hollow portion of the upper housing and on the lower housing around the outer periphery of the second groove of the lower housing; the second cavity in the upper housing is located outside the first cavity between the end of the piston close to the excitation source and the conductive busbar for circuit protection, and the second cavity in the lower housing is located outside the first cavity between the end of the first cavity close to the end position of the piston displacement and the conductive busbar for circuit protection; the excitation source is arranged at the top of the hollow portion of the excitation source sheath and closes the top, the initial position of the piston is arranged in the hollow portion of the upper housing, and the conductive busbar for circuit protection penetrates between the upper housing and the lower housing; the melt penetrates through the second cavity.

[0009] Preferably, the second cavity includes a first groove. When the first groove is located in the upper housing, the first groove is sealed by the excitation source sheath or the melt cover plate; when the first groove is located in the lower housing, the first groove is sealed by the upper housing or the melt cover plate.

[0010] Preferably, the first groove has an annular structure, and a plurality of support columns are arranged at intervals along the circumferential direction at the bottom of the first groove. Limiting columns are provided at positions corresponding to the support columns on the excitation source sheath, the upper housing, or the melt cover plate; when the excitation source sheath, the upper housing, or the melt cover plate seals the first groove, the limiting columns are butt-jointed with the support columns, and the melt is positioned between the support columns and the limiting columns.

[0011] Preferably, when the first groove has an annular structure, the melt has an arc-shaped structure matching the annular structure. The melt includes an arc-shaped main body and connecting ends located at both ends of the arc-shaped main body and integrally formed with the arc-shaped main body. A positioning portion is integrally formed at a position corresponding to the support column on the inner or outer side of the arc-shaped main body, and the positioning portion is located between the contact surfaces of the support column and the limiting column; the connecting end of the melt passes through the through hole at the bottom of the first groove and then bends towards the side of the corresponding conductive busbar for circuit protection and makes conductive contact with the corresponding conductive busbar for circuit protection.

[0012] Preferably, when the first groove is located in the upper housing, through holes for both ends of the melt to pass through are formed at the bottom of the first groove; fixing bumps are provided at positions corresponding to or near the through holes on the excitation source sheath or the melt cover plate; after the excitation source sheath or the melt cover plate seals the first groove, the fixing bumps are inserted into the through holes at the bottom of the first groove to fix the melt passing through the through holes between the fixing bumps and one side of the through holes; or the fixing bumps press the melt between two adjacent support columns near the through holes.

[0013] Preferably, when there are two or more circuit protection conductive bars, the circuit protection conductive bars are arranged at an insulating interval; the melts connected in parallel on two of the circuit protection conductive bars are respectively arranged in the second cavity on the upper housing, and the melts connected in parallel on the remaining circuit protection conductive bars are arranged in the second cavity on the lower housing.

[0014] Preferably, when there are two or more melts arranged in one second cavity, the melts are arranged vertically, or inside and outside, or arranged in sequence; when the second cavity is an annular structure surrounding the piston, the melts are symmetrically arranged in the second cavities on both sides of the piston.

[0015] Preferably, when there are three circuit protection conductive bars, the first circuit protection conductive bar, the second circuit protection conductive bar, and the third circuit protection conductive bar are located between the upper housing and the lower housing in a mutually insulated and spaced manner; among them, the first circuit protection conductive bar and the second circuit protection conductive bar are arranged in the same plane at an insulating interval, the third circuit protection conductive bar is arranged in another plane, and the third circuit protection conductive bar is arranged at the insulating interval position directly opposite to the insulating interval between the first circuit protection conductive bar and the second circuit protection conductive bar; the melts connected in parallel on the first circuit protection conductive bar and the second circuit protection conductive bar are respectively located in the second cavity on the upper housing, and the melt connected in parallel on the third circuit protection conductive bar is located in the second cavity on the lower housing.

[0016] Preferably, when the circuit protection conductive bar is two or three and is applied to a three-phase circuit, the circuit protection conductive bar is respectively arbitrarily connected to one phase of the three-phase circuit, and the piston simultaneously cuts off two or three circuit protection conductive bars.

[0017] Preferably, when the circuit protection conductive bar is two and is applied to a three-phase circuit, a connecting conductive bar is further included; the connecting conductive bar is located beside the displacement path of the piston.

[0018] Preferably, the conductive bars for circuit protection have the same length.

[0019] Preferably, one end or both ends of the conductive bars for circuit protection are conductively connected with independent connection ends to extend their lengths, so that the conductive bars for circuit protection have the same length; the conductive bars for connection are arranged on the lower housing through insert molding.

[0020] In the compact-structured excitation fuse of the present invention, by arranging the parallel fuses in the space on the outer peripheral side of the displacement path required for the piston to disconnect the conductive bar, that is, the space on the outer peripheral side of the piston in the upper housing and the space on the outer peripheral side of the space for the piston to displace in the lower housing. The product space is fully utilized, the product space utilization rate is improved, the product structure is more compact, the product volume is miniaturized, and it can adapt to various application environments.

[0021] Due to the compact product space of the present invention, it can be designed into a single-way or multi-way breaking structure in a smaller space. For example, it can be designed into a two-way on-off structure, which can be applied to the protection of three-phase circuits and avoid faults caused by mutual interference of circuits after a single-phase fuse melts.

[0022] The compact-structured excitation fuse of the present invention can be provided with two-way, three-way, and four-way conductive bars. When there are more than three ways, through staggered setting and fully utilizing the space on the outer peripheral side of the displacement path required for the piston to disconnect the conductive bar to arrange parallel fuses, so that the excitation fuse product can achieve multi-way protection in a limited space.

[0023] The current flows through both ends of the conductive copper bar connected in series in the protection system loop, which will not cause adverse effects on the fuse. And because the cross-section of the conductive copper bar is large and the resistance is small, it has good current impact resistance;

[0024] The overall fuse is partially sealed and has no ventilation holes, which can prevent foreign objects from contaminating the fracture and can also prevent the high-temperature arc from spraying out of the housing and damaging the surrounding devices, improving the protection level. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a schematic structural diagram before the operation of the present invention. When the fuse part overlapping with the piston and the guide cylinder is in section, it should be shielded by the piston and the guide cylinder. For the convenience of understanding the setting method of the fuse, it is shown in the figure.

[0026] Figure 2 is Figure 1 a schematic structural diagram of the fuse melting after the conductive bar is disconnected after the operation.

[0027] Figure 3 is a front sectional view of the two-way conductive bars for circuit protection.

[0028] Figure 4 is a left sectional view of the two-way conductive bars for circuit protection.

[0029] Figure 5 It is a schematic structural diagram of the melt cover plate.

[0030] Figure 6 It is a schematic structural diagram of the melt.

[0031] Figure 7 It is a partial sectional view of the three-dimensional structure of the product.

[0032] Figure 8 It is a front view schematic diagram of the excitation fuse provided with a conductive bar for three-way circuit protection.

[0033] Figure 9 It is a left view schematic diagram of the excitation fuse provided with a conductive bar for three-way circuit protection.

[0034] Figure 10 It is a schematic structural diagram of the piston when provided with a conductive bar for three-way circuit protection.

[0035] Figure 11 It is a schematic structural diagram of the excitation source sheath and the upper housing of the excitation fuse with a conductive bar for two-way circuit protection and a conductive bar for one-way connection.

[0036] Figure 12 It is Figure 11 a schematic three-dimensional structure diagram of

[0037] Figure 13 It is Figure 11 a schematic three-dimensional structure diagram of the lower housing that mates with

[0038] Figure 14 It is Figure 12 and Figure 13 a schematic top view structure diagram after assembly.

[0039] Excitation source sheath 1, upper housing 2, first groove 201, support arm 2011, guide cylinder 202, piston slideway 2021, melt cover plate 203, limit post 2031, limit bump 2032, fixed bump 2033, annular sleeve 2035, lower housing 3, second groove 301, bottom protection plate 4, excitation source 5, connector 501, signal connector 502, piston 6, limit bump 601, impact end 602, insulating isolation end 603, insulating partition 604, conductive bar for circuit protection 7, insulating partition 701, insulating isolation layer 702, first conductive bar for circuit protection 71, first connection end 711, first connection end 712, connection point 714 at one end of the first conductive bar for circuit protection 71,

[0040] The second conductive bar 72 for circuit protection, the second connection end 721, the second connection end 722, the connection part 723 at one end of the second conductive bar 72 for circuit protection, the third conductive bar 73 for circuit protection, the third conductive bar 74 for circuit connection, the third connection end 741, the third connection end 742, the fuse link 8, the arc-shaped main body 801, the connection end 802, and the positioning part 803. Detailed implementation mode

[0041] The structure-compact excitation fuse of the present invention includes: a housing, an excitation source, a piston, and at least one conductive bar for circuit protection, and a fuse link is connected in parallel on the conductive bar for circuit protection; a first cavity and at least one second cavity are arranged in the housing; the excitation source and the piston are sequentially arranged in the first cavity, and the signal receiving end of the excitation source is located outside the housing; the conductive bar for circuit protection passes through the first cavity and is located on the displacement path of the piston, and both ends of the conductive bar for circuit protection are connection ends and are respectively located outside the housing; the piston can move along the first cavity from the initial position to the end position under the driving force released by the excitation source; the second cavity is located on the outer periphery of the first cavity in the displacement direction of the piston, and an arc extinguishing medium is filled in the second cavity, and the fuse link is arranged in the arc extinguishing medium in the second cavity; when the excitation source acts according to the received trigger signal to release the driving force and drives the piston to displace and cut off the conductive bar for circuit protection, the fuse link fuses in the arc extinguishing medium.

[0042] For the above technical solutions, preferred embodiments are now given for specific description.

[0043] Embodiment 1

[0044] This embodiment is the basic principle structure of the present invention. Refer to Figures 1 to 2 , and includes an excitation source sheath 1, an upper housing 2, a lower housing 3, a bottom protection plate 4, an excitation source 5, a piston 6, a conductive bar 7 for circuit protection, and a fuse link 8.

[0045] The excitation source sheath 1, the upper housing 2, and the lower housing 3 are butt - jointed in sequence. The bottom protection plate 4 is arranged at the bottom of the lower housing 3 to protect the lower housing 3, forming a complete housing. The butt - jointed housing is fixed by bolt connection. Seals are arranged at the butt - joint surfaces of the excitation source sheath 1, the upper housing 2, and the lower housing 3, and silica gel is filled. Silica gel is filled between the lower housing 3 and the bottom protection plate 4, so that the butt - jointed housing forms a completely sealed structure, which will not allow external pollutants to contaminate the product interior, nor will it allow the arc generated during breaking to spray outside the housing, improving the safety performance of the product. The excitation source 5 is arranged in the excitation source sheath 1, the piston 6 is arranged in the upper housing 2, the conductive busbar 7 for circuit protection penetrates through the contact surface between the upper housing 2 and the lower housing 3, and the fuse 8 is arranged in the upper housing 2 and is connected in parallel with the conductive busbar 7 for circuit protection. The resistance of the fuse 8 is much larger than the resistance of the conductive busbar 7 for circuit protection. Under normal operating conditions, both ends of the conductive busbar 7 for circuit protection are connected in series to the main circuit, and the current flows through the conductive busbar 7 for circuit protection. Since the resistance of the fuse 8 is much larger than the resistance of the conductive busbar 7 for circuit protection, the current flowing through the fuse 8 can be ignored.

[0046] The excitation source sheath 1 is provided with a hollow part that penetrates through its upper and lower ends. The excitation source 5 is arranged in the upper part of the hollow part, and the upper part of the hollow part of the excitation source sheath 1 is closed.

[0047] The excitation source 5 is a gas - generating device. When receiving a trigger signal, the excitation source ignites and releases high - pressure gas as a driving force. The signal receiving end of the excitation source 5 is located outside the housing and can be connected to the signal sending end outside the housing. The driving - force release end of the excitation source 5 is located in the hollow part of the excitation source sheath. A circumferential limiting step is provided on the inner wall of the hollow part on the outer peripheral side of the driving - force release end of the excitation source 5, and the limiting step and the side wall of the excitation source 5 form a circumferential limiting mounting ring.

[0048] The upper housing 2 is provided with a hollow part that penetrates through its upper and lower ends corresponding to the hollow part of the excitation source sheath 1. First grooves 201 are spaced apart on the outer peripheral side of the hollow part of the upper housing 2. A ring - shaped guide cylinder 202 is formed between the first grooves 201 and the hollow part of the upper housing 2. The guide cylinder 202 protrudes from the end face of the upper housing 2 at one end of the excitation source sheath 1. A fuse cover plate 203 is arranged at the open end of the first groove 201. The fuse cover plate 203 closes the first groove 201 to form a sealed arc - extinguishing chamber, and the closed arc - extinguishing chamber is the second cavity. A filling hole is provided on the fuse cover plate, and arc - extinguishing medium, such as quartz sand, is filled into the arc - extinguishing chamber through the filling hole. The filling hole is closed by a sealing plug. A through - hole for the fuse 8 to pass through is provided at the bottom of the first groove 201. The fuse 8 is arranged in the arc - extinguishing medium in the first groove 201, and its two ends pass through the through - holes on the first groove 201 and are connected in parallel with the conductive busbar 7 for circuit protection.

[0049] In this embodiment, the first groove in the upper housing 2 is sealed by a melt cover plate. In other embodiments, the first groove can be sealed by an excitation source sheath. When the excitation source sheath is used for sealing, the structure of the excitation source sheath at the position corresponding to the first groove of the arc extinguishing chamber is substantially the same as the structure of the melt cover plate corresponding to the first groove.

[0050] After the upper housing 2 is docked with the excitation source sheath 1, the end of the guide cylinder 202 extends into the hollow part of the excitation source sheath 1 and is nested in the limit mounting ring outside the excitation source 5, so that the hollow part in the excitation source sheath 1 and the hollow part in the guide cylinder 202 of the upper housing 2 are communicated; at the same time, by nesting the guide cylinder 202 in the limit mounting ring, the excitation source 5 is supported, and the position of the excitation source 5 is limited by the structure of the hollow part where the excitation source 5 is located and the structural shape of the excitation source 5.

[0051] The piston 6 is arranged in the guide cylinder 202 of the upper housing 2. A sealing ring is arranged between the contact surfaces of the piston 6 and the guide cylinder 202, and a sealed cavity is formed between the driving force release end of the excitation source 5 and the piston 6. The piston 6 is limited in its initial position in the guide cylinder 202 by the sealing ring. Piston slides 2021 are arranged on the opposite inner walls of the guide cylinder 202, and limit ridges are arranged on the opposite sides of the piston 6. The limit ridges of the piston 6 are slidably arranged in the piston slides to ensure that the piston 6 makes a linear displacement along the guide cylinder. One end of the piston 6 facing the conductive busbar 7 for circuit protection is the impact end. When the piston 6 is driven by the driving force released by the excitation source 5, the piston 6 makes a linear displacement along the guide cylinder 202.

[0052] The lower housing 3 is provided with a second groove 301 at one end facing the upper housing 2. After the lower housing 3 is docked with the upper housing 2, the second groove 301 is communicated with the hollow part of the guide cylinder 202 of the upper housing 2, providing a displacement space for the piston 6 after disconnecting the conductive busbar 7 for circuit protection. The second groove 301 after docking, the hollow part of the guide cylinder 202 of the upper housing 2 and the hollow part of the excitation protection sleeve 1 form a first cavity, and a second cavity is arranged around the first cavity at the upper housing.

[0053] The conductive bar 7 for circuit protection is disposed between the contact surfaces where the upper housing 2 and the lower housing 3 are butted, and both ends of the conductive bar 7 for circuit protection are located outside the housing. A mechanical disconnection weak point is provided on the conductive bar 7 for circuit protection at the second groove 301 to form a pre-fracture. The mechanical disconnection weak point penetrates the width of the conductive bar 7 and is a groove structure or a structure with reduced mechanical strength, provided on one or both sides of the conductive bar 7, such as U-shaped or V-shaped grooves, or a structure with reduced thickness, etc. In this embodiment, it is a V-shaped groove, and opposite V-shaped grooves are respectively formed on both sides of the conductive bar 7 for circuit protection, which can ensure current conduction and the timeliness of breaking the copper bar. The mechanical disconnection weak point on the conductive bar 7 for circuit protection is correspondingly arranged opposite to the impact end of the piston 6. When the piston 6 is displaced by impact, the impact end of the piston 6 can disconnect the conductive bar 7 for circuit protection from the mechanical disconnection weak point of the conductive bar 7 for circuit protection, and then the impact end of the piston 6 enters the second groove 301 of the lower housing 3.

[0054] In this embodiment, by disposing the arc extinguishing chamber on the outer periphery of the piston located in the upper housing, the melt 8 is disposed in the arc extinguishing chamber on the outer peripheral side of the piston 6 of the upper housing 2, avoiding the existing structure in which the arc extinguishing chamber is designed below the second groove 301 of the lower housing 3. Without changing the volume size of the upper housing, the volume size of the lower housing 3 is reduced, making the product structure more compact and the volume smaller.

[0055] The working principle of this embodiment:

[0056] Under normal working conditions, current flows through the conductive bar 7 for circuit protection. Since the resistance of the melt 8 is much greater than that of the conductive bar 7 for circuit protection, the current flowing through the melt 8 can be ignored.

[0057] When there is an overload, short circuit or abnormal condition, the excitation source 5 acts according to the received trigger signal, releases the driving force, drives the piston 6 to displace and cut off the conductive bar 7 for circuit protection, forming a fracture on the conductive bar 7 for circuit protection. After the conductive bar 7 for circuit protection is disconnected, the current flowing through the conductive bar 7 for circuit protection then flows through the melt 8. The melt 8 heats up due to the flowing current, and then the melt 8 melts from the narrow neck. Since the narrow neck of the melt 8 is located in the arc extinguishing medium, the arc generated after the melt 8 melts is extinguished by the arc extinguishing medium.

[0058] Embodiment 2

[0059] See Figures 3 to 7, A structure optimized based on Embodiment 1. A connector 501 with an electrostatic ring is sleeved on the outer periphery of the signal receiving end of the excitation source 5 located outside the excitation source sheath 1, which is used to press the excitation source 5 and limit its position. At the same time, since the electrostatic ring can eliminate static electricity, it can avoid the malfunction of the excitation source 5 caused by static electricity generated during the storage and transportation of the product. A signal connector 502 is inserted into the signal receiving end of the excitation source 5, and it can be conveniently connected to an external trigger signal circuit through the signal connector 502.

[0060] On the inner wall of one end of the guiding cylinder 202 facing the excitation source 5, the opposite sides are designed as inclined surface structures. Correspondingly, on the outer periphery of one end of the piston 6 facing the excitation source 5, two inclined surface-shaped limiting protrusions 601 extend outward respectively. After the end of the guiding cylinder 202 of the upper housing 2 is inserted into the limiting mounting ring of the excitation source sheath 1, an inclined surface-shaped limiting groove is formed at the inner wall of the excitation source sheath where the guiding cylinder 202 and the limiting mounting ring are located, and the limiting protrusions 601 of the piston 6 are just located in the inclined surface-shaped limiting groove formed at the inner wall of the excitation source sheath where the guiding cylinder 202 and the limiting mounting ring are located, forming a limit on the initial position of the piston 6. When the piston 6 is driven by the driving force released by the excitation source 5, the limiting protrusions 601 at the piston 6 will disconnect, releasing the limit on the initial position of the piston 6.

[0061] The conductive busbar 7 for circuit protection is a two-way conductive busbar for circuit protection, that is, two conductive busbars for circuit protection, which can be respectively connected to different circuits. The two-way conductive busbars 7 for circuit protection are arranged at intervals on the same plane between the upper housing 2 and the lower housing 3. An insulating partition 701 is arranged between the two conductive busbars for circuit protection on the contact surface between the upper housing 2 and the lower housing 3. The insulating partition 701 can be arranged on the end face of the upper housing 2 or on the end face of the lower housing 3. No insulating partition is arranged between the two conductive busbars for circuit protection located at the hollow part.

[0062] On the end face of the piston 6 facing the conductive busbar 7 for circuit protection, impact ends 602 corresponding to the mechanically weak disconnection parts of the two-way conductive busbars 7 for circuit protection are respectively arranged. An insulating isolation end 603 is arranged between the two impact ends 602, and the insulating isolation end protrudes from the two impact ends 602. When the piston 6 is in the initial position, the insulating isolation end 603 of the piston is located between the two conductive busbars for circuit protection, and the two impact ends 602 are located on one side of the surface of the conductive busbar 7 for circuit protection. The impact end 602 is a symmetric three-step structure, the bottom of which is a plane, and the middle step part protrudes from the bottom and has a higher strength, which is convenient for concentrating force to cut the copper bar.

[0063] After the piston 6 is driven to cut off the conductive bars for circuit protection, the insulating isolation end 603 of the piston 6 is located between the two conductive bars for circuit protection and contacts the insulating partition 701, completely insulating and isolating the break points of the two conductive bars for circuit protection, avoiding arc flashover, so that the two conductive bars for circuit protection will not affect each other after being disconnected, and improving the breaking reliability.

[0064] The distances between the two impact ends of the piston 6 from the two conductive bars for circuit protection can be the same or different. When the distances between the two impact ends of the piston 6 from the corresponding conductive bars for circuit protection are the same, the piston 6 disconnects the two conductive bars for circuit protection 7 simultaneously and cuts off the two circuits connected thereto at the same time; when the distances between the two impact ends of the piston 6 from the corresponding conductive bars for circuit protection are different, the piston 6 disconnects the two conductive bars for circuit protection 7 successively and cuts off the two circuits connected thereto successively. Whether the two conductive bars for circuit protection 7 are disconnected simultaneously or successively is designed according to the usage requirements.

[0065] In this embodiment, the first groove 201 is a circular ring structure formed around the guide cylinder 202. At the bottom of the first groove 201, a plurality of support columns are arranged at intervals along its circumferential direction. A plurality of support arms 2011 are arranged at intervals on the inner wall of the first groove 201. The height of the support arms 2011 is lower than the height of the first groove 201 and is used to support the melt cover plate 203. Limiting grooves are arranged at intervals on the inner wall of the open end of the first groove 201. Through holes for the melt 8 to pass through are respectively formed at opposite sides along the length direction of the conductive bar for circuit protection at the bottom of the first groove 201, and screw holes are respectively formed on both sides of the through holes at the bottom of the first groove 201. When the melts 8 of the two conductive bars for circuit protection are both placed in the first groove of the upper shell 2, the two melts 8 are respectively arranged oppositely in the first grooves on both sides of the piston, that is, one melt occupies half of the space of the first groove, and the two melts 8 are insulated from each other.

[0066] Both ends of the melt 8 respectively pass through the through holes at the bottom of the first groove and are in conductive contact with the conductive bar for circuit protection 7. After both ends of the melt 8 are in conductive contact with the conductive bar for circuit protection 7, both ends of the melt 8 are pressed against the conductive bar for circuit protection 7 by bolts passing through the screw holes to ensure conductive contact between the melt 8 and the conductive bar for circuit protection.

[0067] The melt cover plate 203 has an annular sleeve 2035 that can be tightly sleeved around the outer periphery of the guide cylinder 202. On the end face of the melt cover plate 203 opposite to the support column, a limit post 2031 is correspondingly provided. The limit post 2031 is integrally connected to the annular sleeve 2035. The limit post 2031 is butt-jointed with the support column, and the melt 8 placed between the butt-joint surfaces of the limit post 2031 and the support column can be tightly pressed and positioned. At the position of the limit groove on the inner wall of the opening end of the first groove 201 corresponding to the outer peripheral edge of the melt cover plate 203, a limit projection 2032 is provided. The limit projection 2032 can be nested into the limit groove at the opening end of the first groove to position the melt cover plate 203.

[0068] At the position of the through hole through which the melt 8 passes at the bottom of the melt cover plate 203 relative to the first groove 201, a fixing projection 2033 protruding from the end face of the melt cover plate 203 is provided. The fixing projection 2033 can be inserted into the through hole at the bottom of the first groove 201 to fix the connecting end 802 of the melt 8 between the through hole and the fixing projection 2033.

[0069] In other embodiments, at the position of the through hole through which the melt 8 passes at the bottom of the melt cover plate 203 near the first groove 201, a fixing projection 2033 protruding from the end face of the melt cover plate 203 is provided. The fixing projection 2033 can be inserted between two adjacent support columns at a position near the through hole at the bottom of the first groove 201 to press the melt between the two support columns. The through hole at the bottom of the first groove 201 is only for the melt 8 to pass through.

[0070] The melt 8 has an arc-shaped structure and is composed of an arc-shaped main body 801 and connecting ends 802 located at both ends of the arc-shaped main body 801. The arc-shaped main body 801 is the melt body, and positioning portions 803 are respectively formed by extending the support columns corresponding to the first groove on the inner side thereof. The positioning portions 803 can widen the width of the arc-shaped main body 801, making it more convenient for the positioning portions 803 to be between the support columns on the first groove that are clamped and the limit posts of the melt cover plate. The positioning portions are provided on the inner side of the arc-shaped main body 801, and the arc-shaped main body 801 is not easily deformed during installation. A number of narrow necks are provided on the arc-shaped main body 801. In other embodiments, the positioning portions 803 can also be provided on the outer side of the arc-shaped main body 801.

[0071] The connecting ends 802 are integrally formed at both ends of the arc-shaped main body 801, and their width is greater than that of the arc-shaped main body 801 to improve the connection strength of the melt. After being bent, the connecting ends 802 pass through the through hole at the bottom of the first groove 201 and then are bent toward the side of the circuit protection conductive busbar 7 corresponding to them and are in conductive contact with the surface of the circuit protection conductive busbar 7.

[0072] When the melt 8 is threaded through the first groove 201, the positioning portion 803 at the arcuate body 801 of the melt 8 is placed on the top end surface of the support portion of the first groove 201. The end surface of the limit post 2031 of the melt cover plate 203 presses and positions the positioning portion of the melt 8 between the support post and the limit post, realizing the fixation of the melt 8. The connection ends 802 at both ends of the melt 8 pass through the through holes of the first groove 201 and then bend towards the side of the conductive busbar 7 for circuit protection corresponding to them and make conductive contact with the conductive busbar 7 for circuit protection. The fixing bumps 2033 on the melt cover plate 203 are inserted into the through holes at the bottom of the first groove 201 to fix the connection ends 802 of the melt 8 between one side of the through hole of the first groove 201 and the fixing bumps 2033. The connection ends 802 of the melt 8 are pressed on the surface of the conductive busbar 7 for circuit protection by bolts to ensure conductive contact.

[0073] Since the conductive busbars 7 for circuit protection are arranged in two paths, therefore, each path of the conductive busbars 7 for circuit protection is connected in parallel with a melt 8. Two melts 8 are relatively insulated in the first groove 201, and the two melts 8 respectively occupy half of the space of the first groove 201; the two connection ends 802 of the two melts 8 respectively pass through the through holes at the bottom of the first groove, and the connection ends 802 of the two melts 8 are fixed on the opposite side walls of the through holes and are insulated and isolated by the fixing bumps 2033. After the connection ends of the two melts 8 pass through the through holes, they respectively bend towards the direction of the conductive busbars for circuit protection corresponding to them, and the connection ends 802 of the bent melts 8 are then pressed on the conductive busbars for circuit protection between the upper housing and the lower housing.

[0074] The structure of the circular first groove 201 around the guide cylinder and the arcuate melt 8 in this embodiment can make better use of space, making the product structure more compact and the volume smaller.

[0075] The working principle of this embodiment:

[0076] The two paths of conductive busbars for circuit protection are respectively connected to one path of the circuit. When used in a three-phase circuit, the two paths of conductive busbars for circuit protection are respectively connected to one phase of the circuit.

[0077] Under normal working conditions, the current flows through the conductive busbar 7 for circuit protection. Since the resistance of the melt 8 is much greater than the resistance of the conductive busbar 7 for circuit protection, the current flowing through the melt 8 can be ignored.

[0078] When there is overload, short circuit or abnormal situation, the excitation source 5 acts according to the received trigger signal, releases the driving force, drives the piston 6 to displace and simultaneously cuts off the two circuit protection conductive bars 7 or successively cuts off the two circuit protection conductive bars 7, forming a break on the circuit protection conductive bar 7. After the circuit protection conductive bar 7 is disconnected, the current flowing through the circuit protection conductive bar 7 flows through the fuse 8. The fuse 8 generates heat as the current flows through it, resulting in an increase in temperature. Then the fuse 8 melts from the narrow neck. Since the narrow neck of the fuse 8 is located in the arc extinguishing medium, the arc generated after the fuse 8 melts is extinguished by the arc extinguishing medium.

[0079] When used in a three-phase circuit, the two circuit protection conductive bars 7 cut off any two phases simultaneously.

[0080] Embodiment 3

[0081] See Figures 8 to 10 Based on Embodiment 2, an additional circuit protection conductive bar 7 is added, forming three circuit protection conductive bars 7, namely the first circuit protection conductive bar 71, the second circuit protection conductive bar 72, and the third circuit protection conductive bar 73. The three circuit protection conductive bars 7 are arranged in an inverted product shape on the end face between the upper housing 2 and the lower housing 2. A receiving groove is provided at the center position of the end face where the lower housing 3 is docked with the upper housing 2, and the width of the receiving groove is greater than the width of the circuit protection conductive bar 7. The first circuit protection conductive bar 71, the second circuit protection conductive bar 72, and the third circuit protection conductive bar 73 are arranged in parallel at intervals in an insulated manner. Among them, the first circuit protection conductive bar 71 and the second circuit protection conductive bar 72 are in the same plane and are located on both sides of the receiving groove respectively. The distance between the first circuit protection conductive bar 71 and the second circuit protection conductive bar 72 is the insulated interval position. The third circuit protection conductive bar 73 is located in the receiving groove, that is, the third circuit protection conductive bar 73 is arranged facing the insulated interval position between the first circuit protection conductive bar 71 and the second circuit protection conductive bar 72. The third circuit protection conductive bar 73 is pressed on the end face of the lower housing 3 by the upper housing 2. The protruding part of the upper housing 2 that presses the third circuit protection conductive bar 73 in the receiving groove forms an insulating isolation layer 702, insulating and isolating the first circuit protection conductive bar 71, the second circuit protection conductive bar 72, and the third circuit protection conductive bar 73 that are pressed by the contact surface of the upper and lower housings.

[0082] On the end face of the piston 6 facing the conductive bars for circuit protection, three impact ends 602 are respectively provided corresponding to the three conductive bars 7 for circuit protection. From left to right, they are the first impact end, the second impact end, and the third impact end. The first impact end and the third impact end are respectively located on both sides of the second impact end, and the end face of the second impact end protrudes from the end faces of the first impact end and the third impact end. On both sides adjacent to the first impact end and the third impact end respectively in the direction of the conductive bars for circuit protection, insulating partitions 604 are respectively extended. When the piston 6 is in the initial position, insulating partitions are inserted between the first conductive bar for circuit protection and the third conductive bar for circuit protection, and insulating partitions are also inserted between the second conductive bar for circuit protection and the third conductive bar for circuit protection. The insulating partitions cooperate with the insulating partitions to achieve the insulating isolation of the first conductive bar 71 for circuit protection, the second conductive bar 72 for circuit protection, and the third conductive bar 73 for circuit protection between the upper housing and the lower housing, and avoid the mutual influence of the arcs generated when the conductive bars for circuit protection are disconnected. In this embodiment, the lengths of the three impact ends of the piston 6 are set according to the disconnection time of the three conductive bars for circuit protection. When the three conductive bars for circuit protection need to be disconnected simultaneously, the distances between the end faces of the three impact ends 602 of the piston 6 and the corresponding conductive bars for circuit protection are the same; when they need to be disconnected successively, the distance between the conductive bar for circuit protection that needs to be disconnected first and the corresponding impact end of the piston 6 is less than the distance between the conductive bar for circuit protection that needs to be disconnected later and the corresponding impact end of the piston 6.

[0083] The first conductive bar 71 for circuit protection and the second conductive bar 72 for circuit protection are on the same plane between the upper housing 2 and the lower housing 3. The interval distance between the first conductive bar 71 for circuit protection and the second conductive bar 72 for circuit protection is greater than the width of the third conductive bar 73 for circuit protection. The third conductive bar 73 for circuit protection and the first conductive bar 71 for circuit protection and the second conductive bar 72 for circuit protection are located on different planes. The third conductive bar 73 for circuit protection is arranged facing the gap between the first conductive bar 71 for circuit protection and the second conductive bar 72 for circuit protection. The arrangement of the first conductive bar 71 for circuit protection, the second conductive bar 72 for circuit protection, and the third conductive bar 73 for circuit protection is in an inverted product shape.

[0084] The fuse 8 connected in parallel on the first conductive bar 71 for circuit protection and the second conductive bar 73 for circuit protection is arranged in the arc extinguishing chamber (i.e., the second cavity) formed by the first groove 201 and the fuse cover plate 203 as in Embodiment 2. The fuse 8 connected in parallel on the third conductive bar 7 for circuit protection penetrates through the arc extinguishing chamber (i.e., the second cavity) of the lower housing 3, and the arc extinguishing chamber is filled with an arc extinguishing medium. Structure of the second cavity of the lower housing: A first groove is provided on the outer peripheral side of the second groove, and the first groove is closed by the upper housing or the fuse cover plate to form a second cavity (i.e., the arc extinguishing chamber), and the arc extinguishing medium is filled in the second cavity.

[0085] The shape of the fuse 8 connected in parallel on the third conductive bar 7 for circuit protection is the same as that of the arc-shaped fuse 8 in Embodiment 2. The arc extinguishing chamber of the lower housing 3 is arranged on the outer side in the piston displacement direction of the second groove 301 of the lower housing 3, and is an arc-shaped groove structure or an annular structure. The arc extinguishing chamber of the lower housing 3 can be sealed by the upper housing 2 or a fuse cover plate can be additionally provided for sealing. The two ends of the fuse 8 connected in parallel on the third conductive bar 7 for circuit protection penetrate through the arc extinguishing chamber or the fuse cover plate and then are in conductive contact with the third conductive bar 7 for circuit protection. Whether the arc extinguishing chamber of the lower housing is sealed by the upper housing or by the fuse cover plate, the fuse 8 penetrating through the arc extinguishing chamber of the lower housing is fixed by the upper housing or the fuse cover plate. When sealed by the upper housing, the structure of the upper housing at the position corresponding to the arc extinguishing chamber is substantially the same as the structure of the fuse cover plate at the position corresponding to the arc extinguishing chamber.

[0086] When the fuse 8 is placed in the arc extinguishing chamber of the lower housing, that is, placed in the second cavity between the conductive bar for circuit protection and the bottom of the second groove (the arc extinguishing chamber surrounding the outer periphery of the second groove that forms part of the first cavity), it saves space in the height direction (piston displacement direction) of the product. At the same time, the chamber wall of the second chamber provided on the lower housing and the arc extinguishing medium filled therein can withstand the air pressure during breaking, making the housing wall of the lower housing not easily cracked, enabling the housing wall of the lower housing to be made thinner and saving the material of the lower housing.

[0087] Working principle of this embodiment;

[0088] The three conductive bars for circuit protection are respectively connected to one circuit, and a total of three circuits are connected. It can also be applied in a three-phase circuit and be respectively connected to one phase of the three-phase circuit.

[0089] Under normal working conditions, the current flows through the conductive bar 7 for circuit protection. Since the resistance of the fuse 8 is much greater than that of the conductive bar 7 for circuit protection, the current flowing through the fuse 8 can be ignored.

[0090] When there is overload, short circuit or abnormal condition, the excitation source 5 acts according to the received trigger signal, releases the driving force, drives the piston 6 to displace and simultaneously cuts off the three-way circuit protection conductive busbar 7 or successively cuts off the three-way circuit protection conductive busbar 7, forming a break on the circuit protection conductive busbar 7. After the circuit protection conductive busbar 7 is disconnected, the current flowing through the circuit protection conductive busbar 7 flows through the fuse 8. The fuse 8 generates heat as the current flows through it, causing the temperature to rise, and then the fuse 8 melts from the narrow neck. Since the narrow neck of the fuse 8 is located in the arc extinguishing medium, the arc generated after the fuse 8 melts is extinguished by the arc extinguishing medium.

[0091] When applied to a three-phase circuit, the three-way circuit protection conductive busbars are cut off simultaneously.

[0092] Embodiment 4

[0093] See Figures 11 to 14 , on the basis of Embodiment 2, an additional circuit connection conductive busbar 74 is added to form two circuit protection conductive busbars and one circuit connection conductive busbar, which are respectively the first circuit protection conductive busbar 71, the second circuit protection conductive busbar 72, and the third circuit connection conductive busbar 74. The difference from the three-way circuit protection conductive busbars in Embodiment 3 is that the three-way circuit protection conductive busbars in Embodiment 3 can all be disconnected by the piston 6. In the three-way circuit protection conductive busbars of Embodiment 4, the first circuit protection conductive busbar 71 and the second circuit protection conductive busbar 72 are arranged according to the setting method of the two-way circuit protection conductive busbars in Embodiment 2 and will be disconnected by the piston 6. The third circuit connection conductive busbar 74 is arranged beside the displacement path of the piston 6 and will not be disconnected by the piston 6.

[0094] In this embodiment, the first circuit protection conductive busbar 71 and the second circuit protection conductive busbar 72 are arranged on the displacement path of the piston. An insulating partition is provided between the contact surfaces of the upper housing and the lower housing between the first circuit protection conductive busbar 71 and the second circuit protection conductive busbar 72. The portions of the first circuit protection conductive busbar 71 and the second circuit protection conductive busbar 72 between the contact surfaces between the upper housing and the lower housing are of planar structure.

[0095] The first circuit protection conductive busbar 71 and the second circuit protection conductive busbar 72 are respectively connected in parallel with a fuse 8. The fuse 8 is arranged in the same way as in Embodiment 2 and is respectively located in the second cavity outside the piston 6 in the upper housing 2.

[0096] Since the fuse in this embodiment needs to be applied to a three-phase circuit, it is required that the first circuit protection conductive busbar 71, the second circuit protection conductive busbar 72, and the third circuit connection conductive busbar 74 have the same length, so as to avoid the phase difference between phases when connected to the three-phase circuit.

[0097] Since it is necessary to keep the lengths of the first circuit protection conductive bar 71, the second circuit protection conductive bar 72, and the third circuit connection conductive bar 74 the same, and to make the fuse product structure compact and conform to the three-phase circuit usage scenario, therefore, in this embodiment, in order to keep the lengths of the first circuit protection conductive bar 71, the second circuit protection conductive bar 72, and the third circuit connection conductive bar 74 the same, corresponding connection ends are separately manufactured to conductively connect to one end or both ends of the first circuit protection conductive bar 71, the second circuit protection conductive bar 72, and the third circuit connection conductive bar 74 located between the upper housing and the lower housing, so as to extend their lengths, make the three conductive bars have the same length, and make the positions of the respective connection ends convenient for connection to the three-phase circuit. When the separate connection ends are connected to one end or both ends of the first circuit protection conductive bar 71, the second circuit protection conductive bar 72, and the third circuit connection conductive bar 74, they are conductively connected by bolts. In this embodiment, the structure of the lower housing 3 is different from the external structures of Embodiments 1 to 3.

[0098] The connection parts at both ends of the first circuit protection conductive bar 71 (where one connection part 714 and the connection end at the other end are not shown) are respectively conductively connected to the first connection ends (711, 712) by bolts, and the first connection ends (711, 712) are respectively located on both sides outside the housing. The first connection end 712 is a straight plate structure, and the first connection end 711 is a special-shaped structure. The connection part at the end of the first circuit protection conductive bar 71 that is not shown is conductively connected to the first connection end 712 by a conductive bolt, and the connection part 714 at the other end is conductively connected to the first connection end 711 by a conductive bolt.

[0099] The second circuit protection conductive bar 72 is a special-shaped structure. The part of the second circuit protection conductive bar 72 located between the contact surfaces of the upper housing and the lower housing is a flat structure. The connection part 723 at one end of the flat structure is conductively connected to the second connection end 721 by a conductive bolt. The second connection end 721 is a special-shaped structure. The second connection end 721 and the first connection end 711 are located on the same side outside the housing. The other end of the second circuit protection conductive bar 72 extends to form a special-shaped second connection end 722, which is located on the same side of the housing as the first connection end 712.

[0100] The third circuit connection conductive bar 74 is an integral structure and is arranged on the lower housing 3 by means of insert molding. The two third connection ends (741, 742) of the third circuit connection conductive bar 74 are respectively located on both sides outside the housing. The third connection end 741 and the first connection end 711 and the second connection end 721 are located on the same side outside the housing. The third connection end 742 and the first connection end 712 and the second connection end 722 are located on the other side outside the housing. Each connection end located outside the housing is a flat structure.

[0101] By adding flat connection ends or connection ends with special-shaped structures, the three-way conductive bars can be made of equal length. When connected to a three-phase circuit, the phase difference between each phase can be avoided. When connecting to a three-phase circuit, the two-way conductive bars for circuit protection and the one-way conductive bar for circuit connection can be arbitrarily connected to any one phase respectively.

[0102] In this embodiment, the connection end with a special-shaped structure can facilitate heat dissipation. At the same time, the connection end with a special-shaped structure can make the three-way conductive bars for circuit protection of equal length, save the space occupancy rate, and make the structure more compact.

[0103] The working principle of this embodiment;

[0104] The three-way conductive bars of this embodiment are respectively connected to one phase in a three-phase circuit. The first-way conductive bar 71 and the second-way conductive bar 72 for circuit protection that can be disconnected by the piston 6 can be connected to any one phase.

[0105] When overload, short circuit or abnormal conditions occur, the excitation source 5 acts according to the received trigger signal, releases the driving force, drives the piston 6 to displace, and the piston 6 simultaneously cuts off the first-way conductive bar 71 and the second-way conductive bar 72 for circuit protection, that is, simultaneously cuts off any two phases in the three-phase circuit and cuts off the three-phase circuit.

[0106] In the above embodiments, the fuse element connected in parallel with the conductive bar for circuit protection is preferably arranged at the second cavity on the outer periphery of the piston in the upper housing; or, the fuse element connected in parallel with the conductive bar for circuit protection is arranged in the second cavity in the lower housing, rather than arranging the arc extinguishing chamber below the second groove of the lower housing 3 in the prior art, making the fuse structure more compact and smaller in volume.

[0107] When there are three-way conductive bars for circuit protection, the three-way conductive bars for circuit protection are arranged in a staggered manner, and the fuse element connected in parallel with the third-way conductive bar for circuit protection is arranged on the outer periphery of the second groove of the lower housing, and the fuse elements connected in parallel with the other two groups of conductive bars for circuit protection are arranged on the outer periphery of the piston of the upper housing, making full use of the existing space, making the product structure compact and smaller in volume.

[0108] In the above embodiments, the entire product assembly is connected by bolts.

[0109] In the above embodiments, the piston is in sealed cooperation with the inner wall of the hollow part of the upper housing, and a sealing structure is formed by using a sealing ring.

[0110] In the above embodiments, the excitation source sheath, the upper housing, the lower housing, and the piston are all made of insulating materials. The arc extinguishing medium filled in the second cavity is a solid arc extinguishing medium or a liquid arc extinguishing medium, such as solid quartz sand and liquid arc extinguishing gel.

[0111] In each of the above embodiments, a plurality of narrow necks are provided on the melt, and the narrow necks are located in the arc extinguishing medium. The melt may be the arc-shaped structure in the above embodiments or other structures, such as a linear strip structure, a wavy structure, etc.

[0112] In addition to the arrangement methods in the above embodiments, the arrangement method of the melt in the second cavity may also be other arrangement methods: when multiple melts are provided in the second cavity, the melts may be arranged at intervals in the height direction of the second cavity, or at intervals inside and outside. For example, when the second cavity is an arc-shaped or circular ring-shaped structure, the melt is arranged on the inner side of the second cavity close to the piston, and the melt is arranged on the outer side of the second cavity far from the piston; or, they are arranged in sequence in the second cavity. For example, when the second cavity is a circular ring-shaped structure, a plurality of melts are arranged in sequence along the circumference of the circular ring-shaped structure.

[0113] In each of the above embodiments, the excitation source sheath, the upper shell, and the lower shell are designed to be sealed without air vents, and the parts that cooperate with each other are all provided with sealing rings and silicone filling, and the sealing performance is excellent. It can not only prevent foreign objects from polluting the fracture surface, but also prevent the high-temperature arc from spraying out of the shell and damaging the surrounding devices.

[0114] In each of the above embodiments and other embodiments, it is preferably to place the melt connected in parallel to the conductive bar for circuit protection in the second cavity between the conductive bar for circuit protection and the end of the piston close to the excitation source, such as the second cavity provided in the upper shell. Such an arrangement can be more conducive to the compactness of the product structure and reduce the volume of the product. The second cavity and the arc extinguishing medium filled therein can withstand a part of the gas pressure released by the excitation source, reduce the wall thickness of the shell, save volume and materials at the same time.

[0115] The second cavity provided on the lower shell, that is, between the conductive bar for circuit protection and the lower shell at the bottom of the second groove, the second cavity is arranged around the second groove. The melt passes through the second cavity provided in the lower shell, and in the piston displacement direction, that is, the height direction of the product, the height of the product is reduced, making the product structure more compact and the volume smaller. The second cavity and the arc extinguishing medium filled therein can withstand a part of the gas pressure released by the excitation source, reduce the wall thickness of the lower shell, save volume and materials at the same time.

Claims

1. A compact excitation fuse, characterized in that: include: A housing, an excitation source, a piston, and at least one circuit protection conductive bar, wherein a melt is connected in parallel to the circuit protection conductive bar; a first cavity and at least one second cavity are arranged in the housing; the excitation source and the piston are arranged in the first cavity in sequence, and a signal receiving end of the excitation source is located outside the housing; the circuit protection conductive bar passes through the first cavity and is located on the displacement path of the piston, and both ends of the circuit protection conductive bar are connection ends, which are respectively located outside the housing; the piston can move from an initial position to a terminal position along the first cavity under the driving force released by the excitation source; The second cavity is located at the outer peripheral side of the first cavity in the displacement direction of the piston, the second cavity is filled with an arc extinguishing medium, and the melt penetrates the arc extinguishing medium in the second cavity; When the excitation source releases the driving force according to the received trigger signal and drives the piston to move and cut off the circuit protection conductive bar, the fuse melts in the arc extinguishing medium.

2. The compact excitation fuse according to claim 1, characterized in that: The melt is preferably disposed in the second cavity outside the first cavity between the end of the piston close to the excitation source and the circuit protection conductive bar.

3. The compact excitation fuse according to claim 2, characterized in that: The shell comprises an excitation source sheath, an upper shell and a lower shell that are connected in sequence; a hollow portion with two ends passing through is respectively opened at corresponding positions on the excitation source sheath and the upper shell, and a second groove for the displacement of the piston is opened on the end surface where the lower shell and the upper shell are connected, and the hollow portion of the excitation source sheath and the upper shell and the second groove of the lower shell after the connection are connected to form the first cavity; a second cavity is opened on the outer side of the hollow portion of the upper shell on the upper shell, or, two hollow portions are respectively opened on the upper shell around the outer side of the hollow portion of the upper shell and on the outer circumference of the second groove of the lower shell on the lower shell a second cavity; the second cavity in the upper shell is located outside the first cavity between one end of the piston close to the excitation source and the circuit protection conductive bar, and the second cavity in the lower shell is located outside the first cavity between the end of the first cavity close to the piston displacement termination position and the circuit protection conductive bar; the excitation source is arranged at the top of the hollow part of the excitation source sheath and the top is closed, the initial position of the piston is arranged in the hollow part of the upper shell, and the circuit protection conductive bar is penetrated between the upper shell and the lower shell; the melt is penetrated in the second cavity.

4. The compact excitation fuse according to claim 3, characterized in that: The second cavity includes a first groove, and when the first groove is located in the upper shell, the first groove is sealed by the excitation source sheath or the melt cover plate; when the first groove is located in the lower shell, the first groove is sealed by the upper shell or the melt cover plate.

5. The compact excitation fuse according to claim 4, characterized in that: The first groove is annular in structure, a plurality of support columns are arranged at intervals along the circumferential direction at the bottom of the first groove, and a limiting column is arranged at the position corresponding to the support column on the excitation source sheath, the upper shell or the melt cover plate; When the excitation source sheath, the upper shell or the melt cover plate is sealed on the first groove, the limiting column is butted against the supporting column, and the melt is positioned between the supporting column and the limiting column.

6. The compact excitation fuse according to claim 5, characterized in that: When the first groove is in a circular ring structure, the melt is an arc structure matching the circular ring structure, the melt includes an arc-shaped main body, and connecting ends located at both ends of the arc-shaped main body and integrally formed with the arc-shaped main body, a positioning portion is integrally formed on the inner or outer side of the arc-shaped main body corresponding to the position of the support column, and the positioning portion is located between the contact surface of the support column and the limit column; the connecting end of the melt passes through the through hole at the bottom of the first groove and is bent toward the side of the corresponding circuit protection conductive bar, and is in conductive contact with the corresponding circuit protection conductive bar.

7. The compact excitation fuse according to claim 6, characterized in that: When the first groove is located in the upper shell, through holes for the two ends of the melt to pass through are opened at the bottom of the first groove; a fixing protrusion is arranged on the excitation source sheath or the melt cover plate at a position corresponding to the through hole or near the through hole; when the excitation source sheath or the melt cover plate seals the first groove, the fixing protrusion is inserted into the through hole at the bottom of the first groove to fix the melt passing through the through hole between the fixing protrusion and one side of the through hole; or, the fixing protrusion presses the melt between the two adjacent support columns near the through hole.

8. The compact excitation fuse according to any one of claims 3 to 7, characterized in that: When there are more than two circuit protection conductive bars, each circuit protection conductive bar is arranged with insulation intervals; wherein the fuses connected in parallel on two circuit protection conductive bars are respectively arranged in the second cavity on the upper shell, and the fuses connected in parallel on the remaining circuit protection conductive bars are arranged in the second cavity on the lower shell.

9. The compact excitation fuse according to claim 8, characterized in that: When more than two melts are arranged in one of the second cavities, the melts are arranged up and down, or inside and outside, or arranged in sequence; when the second cavity is a circular ring structure surrounding the piston, the melts are symmetrically arranged in the second cavities on both sides of the piston.

10. The compact excitation fuse according to claim 8, characterized in that: When there are three circuit protection conductive bars, the first circuit protection conductive bar, the second circuit protection conductive bar and the third circuit protection conductive bar are located between the upper shell and the lower shell in a mutually insulated and spaced manner; wherein the first circuit protection conductive bar and the second circuit protection conductive bar are arranged on the same plane in an insulated and spaced manner, the third circuit protection conductive bar is arranged on another plane, and the third circuit protection conductive bar is arranged at an insulated and spaced position directly opposite to the first circuit protection conductive bar and the second circuit protection conductive bar; the parallel-connected fuses on the first circuit protection conductive bar and the second circuit protection conductive bar are respectively located in the second cavity on the upper shell, and the parallel-connected fuse on the third circuit protection conductive bar is located in the second cavity on the lower shell.

11. The compact excitation fuse according to claim 8, characterized in that: When the circuit protection conductive bars are two or three in number and are used in a three-phase circuit, the circuit protection conductive bars are connected to any one phase of the three-phase circuit, and the piston simultaneously cuts off the two or three circuit protection conductive bars.

12. The compact excitation fuse according to claim 11, characterized in that: When the circuit protection conductive bar is two-way and is used in a three-phase circuit, it also includes a connecting conductive bar; the connecting conductive bar is located beside the displacement path of the piston.

13. The compact excitation fuse according to any one of claims 11 or 12, characterized in that: The circuit protection conductive bars have the same length.

14. The compact excitation fuse according to claim 13, characterized in that: One end or both ends of the circuit protection conductive bar are conductively connected with independent connection ends to extend its length, so that the lengths of the circuit protection conductive bars are the same; the connection conductive bar is arranged on the lower shell by buried mold injection molding.

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