A small surface mount fuse

Abstract

This application relates to the field of surface mount fuse technology, and particularly to a miniature surface mount fuse. The miniature surface mount fuse includes a housing, a fusible element, and a package. The housing includes a cover plate and a base box, with the cover plate closing onto the opening of the base box to form a closed arc-extinguishing cavity. The package is disposed on the upper surface of the cover plate and the inner wall of the base box. Extended portions on both sides of the fusible element extend along the current direction and protrude from the housing. Several pressure relief sections are provided at the opening of the base box, penetrating from the inner wall surface of the side wall to its outer wall surface. The extended portions cover the pressure relief sections. Blocking bosses are provided at both ends of the inner wall of the base box corresponding to the positions of the pressure relief sections. The extended portions are interference-fitted between the blocking bosses and extend along the housing. This application, through structural design, ensures the overall structural stability, safety, and operational reliability of the miniaturized fuse, providing a safer and more reliable protection solution for battery management systems in industries such as electric bicycles (electric motorcycles).

Description

Technical Field

[0001] This application relates to the field of surface mount fuse technology, and in particular to a small surface mount fuse. Background Technology

[0002] Surface mount fuses, as a new type of component, provide circuit protection by fixing the two ends of the fusible element in the circuit. Traditional surface mount fuses have significant shortcomings, making it difficult to meet the demands of industries such as electric bicycles (electric motorcycles) for compact and highly reliable battery management systems (BMS). Specifically:

[0003] If a surface mount fuse is too large, it cannot fit into a compact space layout. To meet the requirements of a compact space, the overall size of the surface mount fuse needs to be reduced. However, traditional surface mount fuses with small size have insufficient safety, operational reliability and stability. In particular, the internal pressure caused by the rapid melting of the fuse element in a small space area increases dramatically, causing the surface mount fuse to be unable to withstand the pressure. This damages the stability of the device structure, thereby compromising the safety and breaking performance reliability of the surface mount fuse, posing potential safety hazards, and ultimately failing to adequately protect the safety of the battery management system. Utility Model Content

[0004] To address the problems mentioned in the background section, this application provides a miniature surface mount fuse, the technical solution of which is as follows:

[0005] This small surface mount fuse includes a housing, a fusible element, and a package. The housing includes a cover plate and a base box. The cover plate closes to the opening of the base box to form a closed arc-extinguishing cavity. The package is disposed on the upper surface of the cover plate and the inner wall of the base box. The outer extensions on both sides of the fusible element extend along the current direction and protrude from the housing. The opening of the base box is provided with several pressure relief sections, which penetrate from the inner wall surface of the side wall to its outer wall surface. The outer extensions cover the pressure relief sections. The inner wall of the base box is provided with blocking bosses at both ends corresponding to the positions of the pressure relief sections. The outer extensions are interference-fitted between the blocking bosses and extend along the housing.

[0006] In some embodiments, the melting section of the melt is located within the arc-extinguishing cavity, and the melt has a W-shaped structure; the thickness of the melt is equal to the thickness of the blocking boss.

[0007] In some embodiments, the inner wall of the base box is provided with a step for limiting the cover plate, and the distance from the step to the upper surface of the base box is greater than the thickness of the cover plate.

[0008] In some embodiments, the cover plate is provided with clearance grooves on both the left and right sides; the clearance grooves are matched with the width of the extension portion so that the extension portion passes through the clearance grooves to expose the outer shell.

[0009] In some embodiments, the clearance groove is provided with an insert block in the middle; the middle region of the extension is provided with a clearance hole adapted to the insert block, so that the insert block is inserted into the clearance hole.

[0010] In some embodiments, the melting part of the melt is located within the arc-extinguishing cavity, and the outer extension is connected to both sides of the melting part; the outer extension extends upward and bends to form two bending structures, and the bending structures have a snap-fit ​​part for fitting and snapping onto the bottom box.

[0011] In some embodiments, the bending structure includes a long section and a short section spaced apart side by side, and an intermediate section connected between the long section and the short section; one end of the long section is connected to the fusible part, and the other end extends from the cover plate to expose the outer shell and is connected to the intermediate section; the long section, the short section and the intermediate section together form the snap-fit ​​part.

[0012] In some embodiments, the long section is provided with inwardly recessed clearance surfaces at both ends; the front and rear ends of the left and right sides of the cover plate form inserts; the two sides of the blocking boss abut against the inserts and the long section respectively; the bottom box opening is provided with an upwardly protruding flange higher than the cover plate, and the outer wall surfaces of the left and right side walls of the flange are provided with clearance grooves, which match the short section so that the short section is fitted into the clearance groove.

[0013] In some embodiments, the inner wall surfaces at both ends of the clearance groove are provided with protruding locking blocks, and the front and rear ends of the short section are provided with locking grooves, the locking grooves matching the protruding locking blocks so that the protruding locking blocks are fitted into the locking grooves.

[0014] In some embodiments, the bottom box corresponding to both ends of the clearance hole is provided with a blocking protrusion, which abuts against the inner wall surfaces of the front and rear ends of the clearance hole, so that the blocking protrusion is embedded in the gap between the insert and the clearance hole; and / or the blocking protrusion is located on the bottom box corresponding to the front and rear sides of the extension portion, and abuts against the outer wall surfaces of the front and rear ends of the extension portion, so that the blocking protrusion is embedded in the gap between the extension portion and the insert, and the extension portion is interference-fitted between the blocking protrusions.

[0015] The miniature surface mount fuse provided in this application has the following advantages:

[0016] This application, through structural design, ensures the overall structural stability, safety, and operational reliability of the miniaturized fuse, providing a safer and more reliable protection solution for battery management systems (BMS) in industries such as electric bicycles (electric motorcycles).

[0017] Other features and beneficial effects of this application will be set forth in the following description, and some of the technical features and beneficial effects may be obvious from the description or learned by practicing this application. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, some of the drawings in the following description are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 Schematic diagram of the structure of the miniature surface mount fuse provided in Embodiment 1 of this application Figure 1 ;

[0020] Figure 2 Schematic diagram of the structure of the miniature surface mount fuse provided in Embodiment 1 of this application Figure 2 ;

[0021] Figure 3 This is a schematic diagram of the cover plate structure of the small patch fuse provided in Embodiment 1 of this application;

[0022] Figure 4 Schematic diagram of the fusible element structure of the miniature patch fuse provided in Embodiment 1 of this application Figure 1 ;

[0023] Figure 5 Schematic diagram of the fusible element structure of the miniature patch fuse provided in Embodiment 1 of this application Figure 2 ;

[0024] Figure 6 This is a schematic diagram of the base box structure of the small surface mount fuse provided in Embodiment 1 of this application;

[0025] Figure 7 Schematic diagram of the structure of the miniature surface mount fuse provided in Embodiment 1 of this application Figure 3 ;

[0026] Figure 8 for Figure 7 Section AA;

[0027] Figure 9 This is a schematic diagram of the internal structure of the small patch fuse provided in Embodiment 1 of this application;

[0028] Figure 10 This is a simplified schematic diagram of the mating structure of the blocking boss and the fusible element in the small patch fuse provided in Embodiment 1 of this application.

[0029] Figure label:

[0030] 1. Cover plate; 2. Melt; 3. Base box; 101. Clearance groove; 102. Sealing material; 103. Insert block; 201. Narrow diameter; 202. Clearance hole; 203. Clearance notch; 204. Slot; 205. Fuse section; 206. Extension section; 2061. Long section area; 2062. Middle section area; 2063. Short section area; 301. Partition wall; 302. Arc extinguishing cavity; 303. Protruding locking block; 304. Pressure relief section; 305. Blocking boss; 306. Clearance through groove; 307. Flange; 308. Step. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. The technical features designed in the different implementations of this application described below can be combined with each other as long as they do not conflict with each other. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0032] In the description of this application, it should be understood that the terms "center," "lateral," "upper," "lower," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more. Additionally, the term "comprising" and any variations thereof mean "at least comprising."

[0033] This application provides as follows: Figure 1-10 The technical solution of the miniature surface mount fuse shown in the embodiment is as follows:

[0034] The miniature surface mount fuse includes a housing, a fusible element 2, and an encapsulation component. The housing includes a cover plate 1 and a base box 3. The cover plate 1 closes to the opening of the base box 3 to form a closed arc-extinguishing cavity 302. The encapsulation component is disposed on the upper surface of the cover plate 1 and the inner wall of the base box 3. The extension portions 206 on both sides of the fusible element 2 extend along the current direction and protrude from the housing. The opening of the base box 3 is provided with several pressure relief portions 304, which penetrate from the inner wall surface of the side wall to its outer wall surface. The extension portions 206 cover the pressure relief portions 304. The inner wall of the base box 3 is provided with blocking bosses 305 at both ends corresponding to the positions of the pressure relief portions 304. The extension portions 206 are interference-fitted between the blocking bosses 305 and extend along the housing. Optionally, the encapsulation component is a sealing material (including but not limited to epoxy resin, etc.) coated on the cover plate 1, which is then cured to achieve overall sealing of the fuse.

[0035] like Figure 1-9 As shown, the miniature surface mount fuse provided in this embodiment has an arc-extinguishing cavity 302 inside the housing. This cavity is filled with an arc-extinguishing medium. When the fuse melts, the arc-extinguishing medium can quickly extinguish the generated arc, thereby improving the fuse's safety and operational reliability. Due to the reduced size of the miniature surface mount fuse, structural design optimization is required to improve its safety and operational reliability.

[0036] When the mass of the material is constant, miniaturization of the surface mount fuse results in a smaller internal volume, leading to faster and greater pressure accumulation. In this embodiment, several pressure relief sections 304 are provided on the base box 3 (the pressure relief sections 304 are located at the opening of the base box 3, preventing leakage of the arc-extinguishing medium in the pressure relief chamber 302). These multiple pressure relief sections 304 extend from the inner wall to the outer wall of the sidewall, dispersing the internal pressure of the fuse and assisting in the rapid dispersion and release of pressure accumulated in the small volume space, thereby improving overall performance and ensuring structural stability. It can be seen that this embodiment improves pressure release capability by adding pressure relief sections 304, preventing the outer casing from bursting due to excessive internal pressure during breakage. This provides effective pressure relief when the fusible element 2 breaks, improving product safety and operational reliability during breakage.

[0037] Meanwhile, this embodiment employs designs such as "the cover plate 1 covering the opening of the bottom box 3 to form a closed arc-extinguishing cavity 302, with the encapsulation component disposed on the upper surface of the cover plate 1 and the inner wall of the bottom box 3," "the extended portions 206 on both sides of the fusible element 2 extending along the current direction and protruding from the outer shell," and "the extended portions 206 covering the pressure relief portion 304," which ensures the components cooperate effectively, resulting in a more compact overall fuse structure. When the sealing material is applied to the cover plate 1 and cured to form the encapsulation component, the sealing material flows, permeates, and fixes the overall structure of the cover plate 1 and the outer shell, further enhancing the adhesion between components and the stability of the overall structure. Therefore, in addition to the design of the extended portions 206 and the pressure relief portion 304, the impact of the sealing material's permeability on other components must also be considered.

[0038] like Figure 9-10 As shown, in this embodiment, blocking bosses 305 are provided at both ends of the pressure relief section 304. After the cover plate 1 is installed, a sealing material is applied to the entire surface of the cover plate 1, and the blocking bosses 305 form a structure that prevents fluid penetration. This design can effectively prevent the sealing material from seeping into the pressure relief section 304 and blocking it, ensuring the reliability and stability of the pressure relief, and further enhancing the overall performance and safety of the fuse.

[0039] Through the above structural design, this embodiment ensures the overall structural stability, safety, and operational reliability of the miniaturized fuse, providing a safer and more reliable protection solution for battery management systems (BMS) in industries such as electric bicycles (electric motorcycles).

[0040] Optionally, the bottom box 3 has an upwardly protruding flange 307 at its opening, which is higher than the cover plate 1. The flange 307 has a plurality of pressure relief portions 304, each including multiple pressure relief ports. Further optionally, a plurality of pressure relief ports are equally spaced on the left and right sidewalls of the flange 307, and the pressure relief ports extend from the inner wall surface of the sidewall to its outer wall surface.

[0041] Multiple pressure relief ports are arranged side by side at equal intervals along the left and right side walls of the bottom box 3. The multiple and distributed pressure relief ports facilitate the rapid and directional release of internal pressure of the fuse, preventing the casing from bursting due to internal overpressure during breakage. They effectively relieve pressure when the fuse element 2 breaks, ensuring structural stability and improving product safety and operational reliability.

[0042] Optionally, the inner wall of the bottom box 3 is provided with a step 308 for limiting the cover plate 1. The distance from the step 308 to the upper surface of the bottom box 3 is greater than the thickness of the cover plate 1, providing sufficient space for applying the sealing material.

[0043] like Figure 2 , Figure 9As shown, the step 308 is designed to support the cover plate 1, and the distance from the step 308 to the upper surface of the bottom box 3 is greater than the thickness of the cover plate 1, so that there is a groove-shaped space above the cover plate 1 to accommodate more sealing material to form a package, thereby improving the convenience of the packaging operation and the packaging effect.

[0044] Optionally, the cover plate 1 has clearance grooves 101 on both the left and right sides; the clearance grooves 101 match the width of the extension portion 206 so that the extension portion 206 passes through the clearance grooves 101 and protrudes from the outer shell. Optionally, the width of the extension portion 206 is slightly larger than the width of the clearance grooves 101 so that the two are interference-fitted, thereby ensuring sealing.

[0045] like Figure 2-3 As shown, the cover plate 1 is provided with a relief groove 101. During assembly, the extension 206 passes through the relief groove 101 to expose the outer shell. The relief groove 101 is used to accommodate the assembly of the melt 2 and the outer shell, further ensuring the compactness and stability of the overall structure.

[0046] Optionally, the relief groove 101 has a protruding insert 103 in the middle; the middle region of the extension 206 has a relief hole 202 adapted to the insert 103, so that the insert 103 can be inserted into the relief hole 202.

[0047] like Figure 2-3 As shown, the protruding insert 103 in the middle of the cover plate 1 is designed to fit into the clearance holes 202 on both sides of the melt 2, so that the sealing material can better penetrate and fix the overall structure of the cover plate 1, the melt 2 and the shell, increase the bonding force between the encapsulation component and the cover plate 1, and improve the stability of the overall structure.

[0048] Optionally, the fusion-breaking portion 205 of the melt 2 is located within the arc-extinguishing cavity 302, and the outer extension portion 206 is connected to both sides of the fusion-breaking portion 205. The outer extension portion 206 extends upward and bends to form two bending structures, and the bending structures have a latching portion for fitting and snapping onto the bottom box 3. Optionally, the bending structure includes a long section 2061 and a short section 2063 spaced apart and side by side, and an intermediate section 2062 connecting the long section and the short section. One end of the long section 2061 is connected to the fusion-breaking portion 205, and the other end extends from the cover plate 1, protruding from the outer shell, and is connected to the intermediate section 2062. The long section 2061, the short section 2063, and the intermediate section 2062 together form the latching portion.

[0049] like Figure 2 As shown, the snap-fit ​​design facilitates the snap-fit ​​of the outer extension 206 of the melt 2 onto the bottom box 3, resulting in a more compact overall product structure and better overall structural stability.

[0050] Optionally, the long section 2061 has inwardly recessed clearance surfaces 203 at both ends; the clearance groove (101) has a protruding insert (103) in the middle; the two sides of the blocking boss 305 abut against the insert 103 and the long section 2061 respectively; the outer walls of the left and right sidewalls of the flange 307 are provided with clearance grooves 306, which match the short section 2063 so that the short section 2063 is fitted into the clearance groove 306.

[0051] like Figure 3-4 As shown, the melt 2 has clearance surfaces 203 on both sides. The insert blocks 103 at the front and rear ends of the cover plate 1 are designed to fit into the clearance surfaces 203 on both sides of the melt 2, so that the sealing material can better penetrate and fix the overall structure of the cover plate 1, the melt 2 and the shell, increase the bonding force between the encapsulation component and the cover plate 1, and improve the stability of the overall structure.

[0052] Figure 1-3 As shown, the design of the short section 2063 being embedded in the clearance slot 306 allows the outer extension 206 to be more accurately and securely attached to the bottom box 3, achieving precise positioning between components, making the overall product structure more compact, and improving the overall structural stability.

[0053] Optionally, the inner wall surfaces at both ends of the clearance groove 306 are provided with protruding locking blocks 303, and the short section area 2063 is provided with locking grooves 204 at both ends. The locking grooves 204 match the protruding locking blocks 303 so that the protruding locking blocks 303 are fitted into the locking grooves 204.

[0054] Figure 1 , 4 As shown, the melt 2 is provided with a slot 204, and the bottom box 3 is provided with a protruding locking block 303. Through the locking cooperation between the slot 204 and the protruding locking block 303, the precise positioning between the components is achieved, ensuring that axial alignment and radial limiting can be achieved during the assembly process.

[0055] Optionally, each of the bottom boxes 3 corresponding to both ends of the clearance hole 202 is provided with a blocking protrusion 305, which abuts against the inner wall surfaces of the front and rear ends of the clearance hole 202, so that the blocking protrusion 305 is embedded in the gap between the insert block 103 and the clearance hole 202; and / or the blocking protrusion 305 is located on the bottom boxes 3 corresponding to the front and rear sides of the extension portion 206, and abuts against the outer wall surfaces of the front and rear ends of the extension portion 206, so that the blocking protrusion 305 is embedded in the gap between the extension portion 206 and the insert block 103, and the extension portion 206 is interference-fitted between each of the blocking protrusions 305. Optionally, the thickness of the melt 2 is equal to the thickness of the blocking protrusion 305 to prevent liquid encapsulation from flowing into the pressure relief portion 304. Optionally, a plurality of the pressure relief ports are arranged side by side at intervals along the front-back direction below the buckle portion, and the pressure relief ports are distributed on the front and back sides of the clearance hole 202, so that the extension portion 206 covers the pressure relief portion 304.

[0056] The clearance hole 202 is located between the two pressure relief parts 304, and the two end faces of the clearance hole 202 are engaged with the outer surfaces of the blocking protrusions 305 at the ends of the two pressure relief parts 304. Similarly, as Figure 10 As shown, because the outer wall surfaces of the blocking boss 305 and the outer wall surfaces of the extension 206 are tightly abutted and attached to the sides of the cover plate 1, the blocking boss 305 forms a structure that prevents fluid penetration. This design effectively prevents the sealing material from seeping into the pressure relief part 304 through the clearance hole 202 or the gap between the extension 206 and the blocking boss 305, ensuring the reliability and stability of the pressure relief and further enhancing the overall performance and safety of the fuse.

[0057] Optionally, the bottom surface of the arc-extinguishing cavity 302 is provided with a partition wall 301 extending in the front-rear direction; the central region of the fusion-breaking portion 205 is mounted above the partition wall 301, and its two side regions are separated by the partition wall 301. Optionally, the partition wall 301 extends from the front inner wall surface of the arc-extinguishing cavity 302 to its rear inner wall surface.

[0058] like Figure 8 As shown, the arc-extinguishing cavity 302 is also equipped with a partition wall 301. When in use, the arc-extinguishing medium in the arc-extinguishing cavity 302 can quickly absorb and dissipate the arc energy generated during the melting process, while the partition wall 301 effectively blocks the arc diffusion path, confining the arc to a local area of ​​the arc-extinguishing cavity 302, avoiding multi-area reignition or energy superposition, and further improving the safety and reliability of the fuse.

[0059] Optionally, the fusion-breaking portion 205 of the melt 2 is located within the arc-extinguishing cavity 302, and the melt 2 has a W-shaped structure. Further optionally, the central region of the fusion-breaking portion 205 protrudes upward to form an inverted U-shaped structure, thus making the melt 2 a W-shaped structure. The inverted U-shaped structure of the fusion-breaking portion 205 is mounted above the partition wall 301, and its two side regions are separated by the partition wall 301. A plurality of holes are spaced side-by-side along the front-back direction at the inverted U-shaped structure, and the holes extend along the left-right direction, forming narrow passages 201 between the holes for current to pass through. Further optionally, the holes are spaced side-by-side at equal intervals so that the width of the narrow passages 201 is equal, and the width of the narrow passages 201 is less than the width of the holes. Further optionally, the holes are oblong.

[0060] like Figure 4 , Figure 8 As shown, the fuse section 205 of the melt 2 adopts a design with multiple narrow diameters 201. This design effectively disperses the current density and reduces the local temperature rise by optimizing the current path distribution, so that the fuse section 205 can achieve rapid separation during the fusing process, thereby achieving high breaking capacity while maintaining high rated current.

[0061] In summary, the embodiments of this application, through the above-described structural optimization design, have the following mechanisms of action and beneficial effects:

[0062] The above-described embodiments of this application overcome the shortcomings of existing fuses, such as large size, insufficient rated current, and insufficient breaking capacity. A miniature surface mount fuse is provided that combines the advantages of small size, high rated current, and strong breaking capacity. Through innovative structural design, miniaturization, high rated current (100A class), and high breaking capacity (1.5kA@125VDC) are synergistically optimized. Its key technologies and technical specifications are as follows:

[0063] 1. Miniaturized design:

[0064] The fuse measures 9.5 x 5.0 x 2.9 mm (length x width), significantly smaller than traditional fuses, perfectly fitting the compact space layout of the electric motorcycle BMS; by optimizing the internal structural layout and adopting a compact design, it achieves a significant reduction in size while maintaining high performance.

[0065] 2. High breaking capacity:

[0066] The melt 2 has multiple narrow diameters 201 inside. This design optimizes the current path distribution, effectively disperses the current density, and reduces local temperature rise, thereby achieving high breaking capacity while maintaining a high rated current. Specifically, the specifications of this embodiment are a rated current of 100A and a breaking capacity of up to 1.5kA@125VDC, which can effectively cope with extreme situations such as short circuits and ensure the safety of the battery management system.

[0067] 3. Optimized arc extinguishing performance:

[0068] The outer shell is equipped with an arc-extinguishing cavity 302 and a partition wall 301. The arc-extinguishing cavity 302 is filled with a high-efficiency arc-extinguishing medium, which can quickly absorb and dissipate the arc energy. The partition wall 301 effectively blocks the arc diffusion path and confines the arc to a local area.

[0069] Furthermore, multiple pressure relief ports are added below the melt 2 in the outer shell. The pressure relief ports adopt a multiple design and distribution to achieve rapid and directional pressure release, avoid the outer shell from bursting due to internal overpressure when it breaks, and play an effective pressure relief role when the melt 2 breaks, thereby improving the safety and performance of the product.

[0070] 4. Compared with the prior art, the specific core advantages and specific indicators of the embodiments of this application are shown in Table 1 below:

[0071] Table 1

[0072]

[0073] 5. Overall structural stability:

[0074] This embodiment of the application utilizes the clearance groove 101 and insert block 103 on the cover plate 1, the clearance hole 202, clearance notch 203, blocking boss (305), and slot 204 on the fuse 2, and the clearance through groove 306 and raised locking block 303 on the outer shell, etc., to achieve precise positioning and stable assembly between components. Through the above structural design, in conjunction with the sealing material applied to the entire surface of the cover plate 1 to form an encapsulation, the fuse is completely sealed, increasing the bonding force between components and the overall structural stability, while ensuring that the sealing material does not block the pressure relief part, thus improving pressure relief stability.

[0075] In summary, through the above-mentioned key innovative design optimizations, the fuses in this application have advantages such as miniaturization, high breaking capacity, excellent arc extinguishing performance, and environmental adaptability, providing a safer and more reliable protection solution for battery management systems (BMS) in industries such as electric bicycles (electric motorcycles).

[0076] Furthermore, those skilled in the art should understand that although many problems exist in the prior art, each embodiment or technical solution of this application can be improved in only one or a few aspects, without necessarily solving all the technical problems listed in the prior art or background art simultaneously. Those skilled in the art should understand that any content not mentioned in a claim should not be construed as a limitation on that claim.

[0077] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A miniature surface mount fuse, characterized in that: Includes the outer casing, melt (2), and encapsulation components; The outer casing includes a cover plate (1) and a bottom box (3). The cover plate (1) covers the opening of the bottom box (3) to form a closed arc-extinguishing cavity (302) in the outer casing. The encapsulation component is disposed on the upper surface of the cover plate (1) and the inner wall of the bottom box (3). The extension portions (206) on both sides of the melt (2) extend along the current direction and expose the outer casing. The bottom box (3) has several pressure relief sections (304) at its opening, and the pressure relief sections (304) extend from the inner wall surface of the side wall to its outer wall surface; the extension (206) covers the pressure relief sections (304). The inner wall of the bottom box (3) is provided with blocking protrusions (305) at both ends corresponding to the pressure relief part (304); the extension part (206) is interference-fitted between the blocking protrusions (305) and extends along the outer shell.

2. The miniature patch fuse according to claim 1, characterized in that: The melting part (205) of the melt (2) is located in the arc-extinguishing cavity (302), and the melt (2) has a W-shaped structure; The thickness of the melt (2) is equal to the thickness of the blocking boss (305).

3. The miniature patch fuse according to claim 1, characterized in that: The inner wall of the bottom box (3) is provided with a step (308) for limiting the cover plate (1), and the distance from the step (308) to the upper surface of the bottom box (3) is greater than the thickness of the cover plate (1).

4. The miniature patch fuse according to claim 1, characterized in that: The cover plate (1) is provided with clearance grooves (101) on both the left and right sides; the clearance grooves (101) are matched with the width of the extension (206) so that the extension (206) passes through the clearance grooves (101) and exposes the outer shell.

5. The miniature patch fuse according to claim 4, characterized in that: The clearance groove (101) is provided with a plug (103) in the middle; the extension (206) is provided with a clearance hole (202) in the middle region that is adapted to the plug (103) so that the plug (103) can be inserted into the clearance hole (202).

6. The miniature patch fuse according to claim 5, characterized in that: The melt-breaking portion (205) of the melt (2) is located inside the arc-extinguishing cavity (302), and the extension portion (206) is connected to both sides of the melt-breaking portion (205). The extension portion (206) extends upward and bends to form two bend structures, the bend structures having a snap-fit ​​portion for attaching to the bottom box (3).

7. The miniature patch fuse according to claim 6, characterized in that: The bending structure includes long section (2061) and short section (2063) spaced apart side by side, and an intermediate section (2062) connecting the long section and the short section. One end of the long section (2061) is connected to the fuse part (205), and the other end extends from the cover plate (1) to expose the outer shell and is connected to the middle section (2062); the long section (2061), the short section (2063) and the middle section (2062) together form the buckle part.

8. The miniature patch fuse according to claim 7, characterized in that: The long section (2061) has inwardly recessed clearance surfaces (203) at both ends; the front and rear ends of the cover plate (1) form inserts (103); the two sides of the blocking boss (305) abut against the inserts (103) and the long section (2061) respectively. The bottom box (3) has an upward protrusion (307) at the opening, which is higher than the cover plate (1). The outer wall surfaces of the left and right side walls of the flange (307) are provided with clearance grooves (306). The clearance grooves (306) match the short section area (2063) so that the short section area (2063) is fitted into the clearance grooves (306).

9. The miniature patch fuse according to claim 8, characterized in that: The inner wall surfaces at both ends of the clearance groove (306) are provided with protruding locking blocks (303), and the front and rear ends of the short section area (2063) are provided with locking grooves (204). The locking grooves (204) match the protruding locking blocks (303) so that the protruding locking blocks (303) are embedded in the locking grooves (204).

10. The miniature patch fuse according to claim 6, characterized in that: The bottom box (3) corresponding to both ends of the clearance hole (202) is provided with the blocking boss (305), which abuts against the inner wall surface of the front and rear ends of the clearance hole (202) so that the blocking boss (305) is embedded in the gap between the insert (103) and the clearance hole (202); and / or the blocking boss (305) is located on the bottom box (3) corresponding to the front and rear sides of the extension (206) and abuts against the outer wall surface of the front and rear ends of the extension (206) so that the blocking boss (305) is embedded in the gap between the extension (206) and the insert (103), and the extension (206) is interference-fitted between the blocking bosses (305).

Images