Enhanced active fuse
By integrating the arc-extinguishing method of gas generation by the reinforcing element and the arc-extinguishing method of melting by the heat-absorbing part into the active fuse, combined with the sealing structure, the problems of unstable arc-extinguishing effect and insufficient air tightness are solved, and efficient and reliable circuit protection is achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHANGHAI CHANGYUAN WAYON CIRCUIT PROTECTION CO LTD
- Filing Date
- 2025-05-06
- Publication Date
- 2026-05-26
AI Technical Summary
Existing active fuses have unstable arc extinguishing effects and insufficient reliability under complex operating conditions of high voltage and high current, and their airtightness needs to be optimized.
The system employs a reinforcing element to generate gas under the action of an electric arc, increasing the arc voltage. This is combined with the melting and heat absorption of the heat-absorbing part, and the airtightness is enhanced through the sealing structure on the conductive busbar. Multiple arc extinguishing methods are integrated to improve reliability.
It significantly improves arc extinguishing efficiency and reliability, extends service life, and ensures stable operation under complex working conditions.
Smart Images
Figure CN224288224U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the technical field of circuit protection devices, specifically to an enhanced active fuse suitable for high-voltage circuits in electric vehicles and energy storage systems. Background Technology
[0002] With the increasing popularity of electric and hybrid vehicles, high-voltage electrical systems are being used more and more extensively in vehicles. Active fuses, as a critical circuit protection device, are widely used in automotive high-voltage circuits to ensure rapid circuit disconnection in emergencies, protecting the safety of the vehicle and its passengers.
[0003] Existing active fuses typically use a pyrotechnic starter to drive a punch to cut off the conductor and then use an arc-extinguishing chamber and gas generated by a specific material to extinguish the arc. For example, Chinese patent CN201580007126.4 discloses a pyrotechnic circuit breaker that uses the cooperation of a punch and an impact die to form an arc channel when cutting off the conductor, and uses an ablation-resistant material to increase the arc voltage to extinguish the arc.
[0004] However, this single arc-extinguishing method may suffer from unstable arc-extinguishing effect and insufficient reliability when facing complex operating conditions with high voltage and high current.
[0005] For example, Chinese patent application CN202411799581.X discloses a pyrotechnic circuit breaker, comprising: an igniter, an igniter housing, a piston, a conductive metal bar, and a casing. A vertical channel is formed within the casing. The igniter housing is fixed to one end of the vertical channel. The conductive metal bar extends at least partially into the vertical channel. The piston is movably arranged within the vertical channel. When the igniter is actuated, the piston can move from an initial position near the igniter housing to a final position at the other end of the vertical channel. The igniter housing is characterized by having a ring arm extending into the vertical channel, a piston fitted on the ring arm, and a first protrusion extending into the hollow space inside the ring arm. The first protrusion is circumferentially attached to the inner surface of the ring arm, and the igniter is placed inside the ring arm and opposite the top surface of the first protrusion. A circuitous sealing path and / or insulation path is formed between the break point of the conductive metal busbar and the igniter. The sealing and insulation performance of the pyrotechnic circuit breaker is mainly improved through structural optimization of the piston and igniter housing. The main improvements are: 1. The piston is designed as a combination of an outer wall and a first protrusion, with the outer wall attached to the outer surface of the ring arm of the igniter housing and the first protrusion embedded in the hollow space inside the ring arm; 2. The igniter housing includes a ring arm extending into the vertical channel, with a hollow interior, and the igniter is placed inside the ring arm and opposite the top surface of the first protrusion of the piston.
[0006] The airtightness of pyrotechnic circuit breakers is crucial to their breaking performance and reliability, especially when used in harsh environments such as fluctuating temperature and humidity and vibration. Good airtightness can prevent external moisture, dust, and other impurities from entering, avoiding any impact on the performance and lifespan of the fuse. Therefore, the airtightness design of fuses still needs further optimization. Summary of the Invention
[0007] The purpose of this invention is to provide an enhanced active fuse with multiple arc extinguishing methods and enhanced airtightness, so as to improve the arc extinguishing effect and reliability of the fuse under complex working conditions, and at the same time extend its service life.
[0008] To address the aforementioned technical problems, this utility model provides an enhanced active fuse, comprising a housing, within which, from top to bottom, are sequentially arranged an excitation device, a power module, a conductive busbar, and at least one cooling cavity. The conductive busbar extends to the outside of the housing for connecting to a circuit. At least one cutter is located at the bottom of the power module, the number of cutters corresponding to the number of cooling cavities. When the excitation device is triggered, it drives the power module, causing the cutter to move from its initial position towards the corresponding cooling cavity to cut off the conductive busbar. The portion of the conductive busbar located within the housing has at least one reinforcement body, which generates gas under the action of an electric arc when the conductive busbar is disconnected, thereby increasing the arc voltage. A heat-absorbing part is located within the cooling cavity, which absorbs heat under the action of an electric arc when the conductive busbar is disconnected. The housing and the conductive busbar are fixed together by a coupling body, which covers the conductive busbar. The joint portion of the conductive busbar covered by the coupling body has a sealing structure, which is at least one protrusion, groove, or through hole.
[0009] The reinforcing material can be an organic polymer that can generate gas under the action of an electric arc, an inorganic material that can restore the insulating state after the electric arc is extinguished, or a composite material that has stability and durability at high temperatures. Under the action of an electric arc, it can generate gas to increase the arc voltage and improve the recovery strength of the dielectric after the arc, thereby reducing the possibility of reignition after the arc and realizing arc extinguishing.
[0010] The concave-convex design of the sealing structure allows for a tighter fit between the connector and the busbar, increasing the actual contact area and thus improving the airtightness of the fuse. Simultaneously, the sealing structure provides mechanical interlocking, enhancing the bonding force. Furthermore, the sealing structure helps disperse stress, preventing stress concentration, and provides deformation space for the connector, allowing it to better adapt to material deformation and maintain a stable sealing effect under stress or environmental changes.
[0011] Based on the above scheme, the reinforcement is coated onto the conductive busbar through a secondary coating process.
[0012] Preferably, the reinforcement is made of a composite material containing POM (polyoxymethylene) or PMMA (polymethyl methacrylate). Using materials with low carbon content, such as POM or PMMA, can prevent the generation of excessive carbon particles under the influence of a high-temperature electric arc, which could lead to a decrease in the insulation strength within the cavity.
[0013] Based on the above scheme, the heat-absorbing part is a metal mesh. When the conductor busbar is disconnected, the metal mesh can melt under the action of the electric arc and absorb heat, thereby reducing the temperature of the electric arc. At the same time, the melting and breaking of the high-melting-point metal mesh can change the path of the electric arc, making it more difficult to maintain and accelerating the extinction of the electric arc.
[0014] Based on the above scheme, the cutter is a beveled blade, and the bevel of the cutter is at an angle of 60° to 85° with the moving direction of the power module, so as to achieve progressive cutting of the busbar and reduce cutting stress.
[0015] Based on the above scheme, the joint body includes at least one support part, which can fix the part of the conductive busbar that is not cut by the cutter when the conductive busbar is cut by the power module.
[0016] Based on the above scheme, the joint body and the shell are connected to each other by a connector with a sealing function.
[0017] Preferably, the composite is made of polyamide 66 (PA66) material.
[0018] Based on the above scheme, the protrusion height of the sealing structure is 0.1-1 mm, the width is 0.1-3 mm, the groove depth of the sealing structure is 0.1-1 mm, the width is 0.1-3 mm, and the through hole diameter of the sealing structure is 0.1-3 mm.
[0019] Based on the above scheme, the housing includes an upper housing and a lower housing, with the upper housing being a double-sided structure consisting of a metal outer shell covering a plastic inner shell. The metal outer shell is fixed to the outer surface of the plastic inner shell by welding or riveting to enhance the mechanical strength and thermal conductivity of the upper housing.
[0020] Based on the above scheme, at least one sealing element is provided between the excitation device, the power module and the connecting body and the upper and lower housings to ensure the airtightness of the internal chamber. Beneficial effects
[0021] This invention significantly improves arc extinguishing efficiency by employing two different arc extinguishing methods: gas generation and pressurization arc extinguishing in the reinforcing body and melting and absorbing heat in the heat-absorbing part. At the same time, the sealing structure and connecting parts on the conductive busbar enhance airtightness, thereby improving the arc extinguishing effect and reliability of the fuse under complex operating conditions and extending its service life. Attached Figure Description
[0022] Figure 1 This is a schematic diagram of the structure of this utility model;
[0023] Figure 2 This is a partially enlarged view of the conductive busbar sealing structure of this utility model;
[0024] Figure 3 This is a three-dimensional schematic diagram of the present invention.
[0025] Numbering on the map:
[0026] 1—Conducting busbar;
[0027] 2 – Plastic inner shell; 3 – Metal outer shell;
[0028] 4—Excitation device; 5—Power module;
[0029] 6—Joint;
[0030] 7—Lower housing; 8—Cooling chamber;
[0031] 9—Connector;
[0032] 10—Enhancement;
[0033] 11—Sealed structure;
[0034] 111 – Protrusion; 112 – Groove; 113 – Through hole;
[0035] 12—Support Department. Detailed Implementation
[0036] The specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings.
[0037] like Figure 1 and Figure 2 As shown, the enhanced active fuse of this utility model includes a housing, and inside the housing, from top to bottom, there are an excitation device 4, a power module 5, a conductive bus 1, a joint body 6 made of polyamide 66 (PA66) material and two cooling chambers 8. The housing includes an upper housing and a lower housing 7. The upper housing is a double-sided structure in which a metal outer shell 3 covers a plastic inner shell 2. The metal outer shell 3 is fixed to the outer surface of the plastic inner shell 2 by welding.
[0038] The conductive busbar 1 extends to the outside of the housing for connecting the circuit. The bottom of the power module 5 is provided with two oblique cutters, the number of which corresponds to the number of cooling chambers 8. When the excitation device 4 is triggered, it drives the power module 5 to move the cutters from the initial position toward the corresponding cooling chamber 8. The oblique surface of the cutter is at 85° to the moving direction of the power module, so as to progressively cut the conductive busbar 1. The part of the conductive busbar 1 located inside the housing is provided with a reinforcement 10 made of a composite material containing POM (polyoxymethylene) through a secondary coating process. When the conductive busbar 1 is disconnected, the reinforcement 10 can generate gas under the action of the electric arc to increase the electric arc voltage. A metal mesh is provided in the cooling chamber 8. When the conductive busbar is disconnected, the metal mesh can melt and absorb heat under the action of the electric arc.
[0039] The housing and the conductive busbar 1 are fixed together by a coupling body 6. The coupling body 6 covers the conductive busbar 1 and includes a support part 12. The coupling body 6, the plastic inner shell 2, and the lower housing 7 are connected to each other by a connector 9 with a sealing function. When the conductive busbar 1 is cut by the power module 5, the support part 12 can fix the part of the conductive busbar 1 that is not cut by the cutter. The joint part of the conductive busbar 1 covered by the coupling body 6 is provided with a sealing structure 11. The sealing structure 11 consists of five protrusions 111, five grooves 112, and a through hole 113. The protrusions 111 are 1 mm high and 3 mm wide, the grooves 112 are 1 mm deep and 3 mm wide, and the through hole 113 is 3 mm in diameter.
[0040] Based on the above scheme, two sealing elements are respectively provided between the excitation device 4, the power module 5 and the connecting body 6, and between the plastic inner shell 2 and the lower shell 7.
[0041] When the enhanced active fuse of this invention needs to cut off the circuit, the excitation device 4 is triggered, generating gas to drive the power module 5 to impact the conductive busbar 1 for cutting off the circuit, and simultaneously generating an electric arc at the cutting position. At this time, the reinforcement body 10 covering the conductive busbar 1 generates gas under the action of the electric arc, increasing the gas pressure in the cavity to increase the arc voltage while blowing the arc downward; at the same time, the metal mesh in the cooling cavity 8 melts under the action of the electric arc and absorbs heat to extinguish the arc. The sealing structure 11 on the conductive busbar 1 increases the contact area between the coupling body 6 and the conductive busbar 1, improves the airtightness of the product, prevents gas leakage, and ensures the reliable operation of the fuse.
[0042] In summary, the enhanced active fuse of this utility model significantly improves the arc extinguishing efficiency by integrating two methods: pressurized arc extinguishing with the reinforcing body 10 and arc extinguishing by melting and absorbing heat with the heat-absorbing part. At the same time, the airtightness of the product is enhanced by the sealing structure 11, which improves the arc extinguishing effect and reliability of the fuse under complex working conditions.
Claims
1. An enhanced active fuse, comprising a housing, wherein an excitation device, a power module, a conductive row and at least one cooling cavity are sequentially arranged in the housing from top to bottom, the conductive row extends to the outside of the housing for connecting a circuit, the bottom of the power module is provided with at least one cutter, the number of the cutters corresponds to the number of the cooling cavities, and the excitation device drives the power module to move the cutters from an initial position to the direction of the corresponding cooling cavities to cut off the conductive row when the excitation device is triggered, characterized in that: The portion of the conductive bus located inside the housing is provided with at least one reinforcement. When the conductive bus is disconnected, the reinforcement can generate gas under the action of an electric arc to increase the arc voltage. The cooling chamber is equipped with a heat-absorbing part, which can absorb heat under the action of an electric arc when the conductor bar is disconnected. The housing and the conductive busbar are fixed together by a connector, which covers the conductive busbar. The joint portion of the conductive busbar covered by the connector has a sealing structure, which is at least one protrusion, groove or through hole.
2. The enhanced active fuse of claim 1, wherein: The reinforcement is coated onto the busbar using a secondary encapsulation process.
3. The enhanced active fuse of claim 2, wherein: The reinforcement is made of a composite material containing polyoxymethylene (POM) or polymethyl methacrylate (PMMA).
4. The enhanced active fuse of claim 1, wherein: The heat-absorbing part is a metal mesh, which can melt and absorb heat under the action of an electric arc when the conductor is disconnected.
5. The enhanced active fuse of claim 1, wherein: The cutter is a beveled blade, and the bevel of the cutter is at an angle of 60° to 85° to the moving direction of the power module.
6. The enhanced active fuse of claim 1, wherein: The assembly includes at least one support portion, which can fix the portion of the conductive busbar that is not cut by the cutter when the conductive busbar is cut by the power module.
7. The enhanced active fuse of claim 1, wherein: The joint body and the housing are connected to each other by a connector with a sealing function.
8. The enhanced active fuse of claim 1 or 6 or 7, wherein: The bonding body is made of polyamide 66 (PA66) material.
9. The enhanced active fuse of claim 1, wherein: The height of the protrusion of the sealing structure is 0.1-1 mm, the width is 0.1-3 mm, the depth of the groove of the sealing structure is 0.1-1 mm, the width is 0.1-3 mm, and the diameter of the through hole of the sealing structure is 0.1-3 mm.
10. The enhanced active fuse of claim 1, wherein: The housing includes an upper housing and a lower housing.
11. The enhanced active fuse of claim 10, wherein: At least one seal is provided between the excitation device, the power module and the connecting body and the upper and lower housings respectively.