A small fuse based on multi-layer composite arc extinguishing and double-sensitive triggering

Abstract

The application discloses a small fuse based on multi-layer composite arc extinguishing and double-sensitive triggering, and relates to the technical field of fuses.The fuse comprises a base, an internal combined unit, an external mounting unit and an arc extinguishing processing unit.The fuse has a buckle type fast mounting terminal structure, is compatible with two modes of vertical plugging and horizontal surface mounting, and has multi-layer arc extinguishing measures, so that the arc extinguishing capacity is effectively improved.The fuse has a simulated serpentine hollow design, can prolong the melting path under the same volume, and improve the breaking capacity.The PTC thermistor is integrated at the end, can trigger the fuse in advance when the temperature is abnormal, supports the temperature and current double triggering conditions, realizes double circuit breaking protection, and has a fuse identification which is convenient for maintenance personnel to identify, indicates that the internal fuse ring is fused after the indicating slide rod is popped out from the upper end of the cover, and the internal fuse ring is convenient for dismounting and replacing.

Description

Technical Field

[0001] This invention relates to the field of fuse technology, and in particular to a small fuse based on multi-layer composite arc extinguishing and dual-sensitive triggering. Background Technology

[0002] Miniature fuses belong to the field of circuit protection device technology and are widely used in low-voltage scenarios such as electronic equipment, household appliances, and automotive circuits. They are used to quickly disconnect the circuit in case of overload or short circuit to protect downstream equipment and are an important electrical component.

[0003] Traditional miniature fuses mostly use a single fuse wire structure, which has problems such as limited breaking capacity, difficulty in further reducing size, and short life due to excessive temperature rise. In existing technologies, some improvement solutions improve performance by increasing the number of metal layers or optimizing the packaging materials, but they still face defects such as the contradiction between breaking speed and size, non-recovery after melting, and limited installation methods, making it difficult to meet the protection requirements of high-density integrated electronic devices. To address this, we propose a miniature fuse based on multi-layer composite arc extinguishing and dual-sensitive triggering. Summary of the Invention

[0004] The technical problem this invention aims to solve is to overcome existing defects and provide a miniature fuse based on multi-layer composite arc extinguishing and dual-sensitive triggering. Through a simulated serpentine hollow design of the fuse ring, the fusible element path can be extended within the same volume, improving breaking capacity. Furthermore, by integrating a PTC thermistor at the end, it can trigger the fuse prematurely when the temperature is abnormal, thus supporting dual triggering conditions of temperature and current, achieving dual circuit protection. It also features multi-level arc extinguishing measures, effectively improving arc extinguishing capability. After the cover is installed and fixed, two mounting blocks clamp the outer side of the straight section in the middle of the fuse ring, and the inner grooves are used to clamp and form a small... In a closed space, the heat generated by the melting of the molten metal induces a solid gas-generating material to produce a non-conductive gas to extinguish the electric arc. The arc-extinguishing coating and the filling of quartz sand also contribute to the effective arc extinguishing effect. In addition, it has a fuse indicator that is easy for maintenance personnel to identify. When the solid gas-generating material inside the mounting block generates gas, the gas pressure will exert an upward thrust on the thin sheet, which will drive the indicator slide rod upward. After the indicator slide rod pops out from the top of the cover, it indicates that the internal fuse ring has melted. After melting, the fuse ring can be easily replaced by loosening the fixing bolts at the mounting block, which can effectively solve the problems in the background technology.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a small fuse based on multi-layer composite arc extinguishing and dual-sensitive triggering, comprising a base, an internal assembly unit, an external mounting unit, and an arc extinguishing processing unit;

[0006] Base: It is a rectangular plate, and a cover with the same width and height is inserted on the top of the base;

[0007] Internal assembly unit: includes ceramic brackets, fuse ring, fuse element end, and PTC thermistor. The upper end of the base is fixedly connected to two sets of ceramic brackets, each set of ceramic brackets includes two arc-shaped slots. The openings of the two sets of ceramic brackets are opposite each other, and the openings of the two ceramic brackets on adjacent sides face the same direction. The fuse ring has a snake-shaped structure, and the curved ends of the left and right parts of the fuse ring are centrally symmetrical. The left and right parts of the fuse ring are integrally fixedly connected by a longitudinal straight section in the middle. The middle straight section of the fuse ring has two rows of teeth, with equal spacing between each row of teeth. Each tooth is coated with a nano zinc oxide arc-quenching coating. The fuse ring has a double-layer arc structure, and the fuse ring as a whole is approximately circular. The ends of the double-layer arc structure are connected by bends at the corners. The outermost end of the fuse ring is fixedly connected to a straight fuse element end, and a PTC thermistor is embedded in both the front and rear fuse element ends.

[0008] External mounting units: installed at both the front and rear ends of the base;

[0009] Arc extinguishing unit: installed on the underside of the cover.

[0010] The ceramic holder is used for mounting and securing the fuse ring. The simulated serpentine hollow design of the fuse ring extends the fusible path within the same volume, improving breaking capacity. Equally spaced teeth in the straight section of the fuse ring define the precise location for fusing. The two fuse element ends are used for electrical connection to the outer metal contacts. Integrated PTC thermistors at the ends trigger fusing prematurely when temperatures are abnormal, supporting both temperature and current triggering conditions for dual circuit protection.

[0011] Furthermore, the internal assembly unit also includes a surrounding plate, insertion holes, insertion posts, and screws. A rectangular surrounding plate is fixedly connected to the upper edge of the base. Circular insertion holes are provided at the four corners of the upper end of the base, extending upwards through a portion of the corner of the surrounding plate, thus forming a quarter-circle fan-shaped concave structure at the corner of the surrounding plate. Vertical insertion posts are fixedly connected to the four corners of the lower end of the cover. Each insertion post is inserted into the corresponding insertion hole, and the circumferential side of the insertion post fits tightly against the fan-shaped groove at the corner of the surrounding plate. Screws are embedded at the four corners of the upper end of the cover, passing through the insertion posts and threadedly connected to the bottom of the insertion holes. The surrounding plate can form a tight seal with the edge of the cover after it is inserted. When the insertion post is inserted into the insertion hole, tightening the screws secures the base and the cover. When installing the cover, the circumferential side of the insertion post fits tightly against the fan-shaped groove at the corner of the surrounding plate, making it easier to align the insertion post with the insertion hole.

[0012] Furthermore, the internal assembly unit also includes a sealing gasket, which is fixedly installed on the inner side of the lower end of the cover, and the sealing gasket is vertically aligned with the upper end of the surrounding plate. After the cover is installed, the sealing gasket can be pressed between the cover and the surrounding plate, thereby achieving a good sealing effect, preventing internal quartz sand leakage, and preventing external moisture from entering.

[0013] Furthermore, the external mounting unit includes metal contacts and slots. A square metal contact is inserted into both the front and rear sides of the enclosure, and slots are formed on each side edge of the metal contact. The metal contacts are used for electrical connection with external devices, and the slots are used to lock the metal contacts into place with the external devices.

[0014] Furthermore, the external mounting unit also includes mounting brackets and metal clamps. Two U-shaped mounting brackets are installed at the center of the inner side of the enclosure. Two metal clamps are fixedly connected to the inner end of the metal tab. The fuse tip is inserted into the middle side of the U-shaped mounting bracket. The two metal clamps pass through the enclosure and are inserted into the mounting brackets, clamping the fuse tip on both sides. The mounting brackets are used for mounting and supporting the metal clamps and fuse tip, and the metal clamps and fuse tip are inserted and assembled inside the mounting brackets.

[0015] Furthermore, the external mounting unit also includes threaded holes and fixing bolts. The threaded holes are provided on both sides of the mounting bracket and on the outer side of the metal clamp. The threaded holes penetrate the side of the mounting bracket, and the fixing bolts pass through the mounting bracket and are pressed against the inside of the metal clamp. The fixing bolts can secure the metal clamp to the end of the fuse element, and by loosening the fixing bolts, it is easy to replace the fuse ring after it has melted.

[0016] Furthermore, the arc extinguishing unit includes mounting clamps and solid gas-generating material. The lower end of the cover is fixedly connected with a number of ceramic brackets equal to the number of ceramic brackets at the lower base, and the ceramic brackets fixedly connected to the cover and the ceramic brackets fixedly connected to the base are vertically aligned in pairs. The middle side of the lower end of the cover is fixedly connected with two mounting clamps, and each of the two mounting clamps has a groove on its opposite side. The solid gas-generating material is placed inside the groove. After the cover is installed and fixed, the two mounting clamps are clamped on the outside of the middle straight section of the fuse ring, and a small closed space is formed by clamping with the inner groove. The mounting clamp is used to hold the solid gas-generating material, and the inner groove is used to clamp and form a small closed space. When the fuse breaks, hot gas is generated in the closed space, which induces the solid gas-generating material to generate non-conductive gas to extinguish the arc. In addition, the ceramic holder separates each ring of the fuse ring by a sufficient distance, which can divide the arc energy by multiple gaps. The nano zinc oxide arc-extinguishing coating coated at the toothed part of the middle section of the fuse ring can play an arc-extinguishing role, thus realizing a multi-layer arc-extinguishing measure.

[0017] Furthermore, the arc-extinguishing unit also includes a marking slide rod and a thin plate. The marking slide rod is inserted into the interior of one of the mounting blocks, with its upper end flush with the end face of the cover. A horizontal thin plate is fixedly connected to the upper middle part of the marking slide rod. When the gas-generating material in the space inside the mounting block generates gas, the gas pressure exerts an upward thrust on the thin plate, which in turn moves the marking slide rod upward. Once the marking slide rod pops out from the top of the cover, it indicates that the internal fuse ring has melted.

[0018] Furthermore, the arc-extinguishing unit also includes quartz sand, which fills the space enclosed by the base, the surrounding plate, and the cover. By filling with quartz sand, the gaps between the sand grains are used to divide the arc path and absorb arc heat, which helps to realize the multi-level arc-extinguishing function.

[0019] Furthermore, the slot assembly includes a central long slot and two short slots on the left and right, with the long and short slots perpendicular to each other. By creating slots of different lengths and directions, the metal contacts can be vertically inserted and engaged with the positioning posts on the chip board, thus supporting both vertical insertion and horizontal mounting modes and adapting to high-density PCB layouts.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: This miniature fuse based on multi-layer composite arc extinguishing and dual-sensitive triggering has the following advantages:

[0021] 1. By using the simulated serpentine hollow design of the fuse ring, the fuse path can be extended within the same volume, thus improving the breaking capacity; and by integrating and installing a PTC thermistor at the end, the fuse can be triggered in advance when the temperature is abnormal, thereby supporting dual triggering conditions of temperature and current, and realizing dual circuit protection for the circuit.

[0022] 2. It features multi-level arc extinguishing measures. Two mounting blocks clamp the outer side of the straight section in the middle of the fuse ring, and the inner grooves form a small closed space. When melting occurs, hot gas is generated in the closed space, which induces the solid gas-generating material to produce non-conductive gas to extinguish the arc. In addition, the ceramic holder separates each ring of the fuse ring by a sufficient distance, which can divide the arc energy by multiple gaps. The nano zinc oxide arc-extinguishing coating coated at the toothed edge of the middle section of the fuse ring can play an arc-extinguishing role. By filling with quartz sand, the gaps between the sand grains are used to divide the arc path and absorb the arc heat, which helps to realize the multi-level arc extinguishing function.

[0023] 3. It features a snap-on quick-installation terminal structure, compatible with both vertical insertion and horizontal mounting modes, and has a fuse indicator for easy identification by maintenance personnel. When the gas-generating material inside the mounting clip generates gas, the gas pressure will exert an upward thrust on the thin sheet, which will then drive the indicator slide rod upward. After the indicator slide rod pops out from the top of the cover, it indicates that the internal fuse ring has melted; and the internal fuse ring is easy to disassemble and replace.

[0024] 4. This invention, through the simulated serpentine hollow design of the fuse ring, can extend the molten metal path within the same volume, thereby improving breaking capacity. Furthermore, by integrating a PTC thermistor at the end, it can trigger the fuse to blow prematurely when the temperature is abnormal, thus supporting dual triggering conditions of temperature and current, achieving dual circuit protection. It also features multi-level arc-extinguishing measures, effectively improving arc-extinguishing capability. After the cover is installed and fixed, two mounting blocks clamp the outer side of the straight section in the middle of the fuse ring, and the inner grooves form a small enclosed space. The heat generated by the melting of the molten metal induces solid-state combustion. The gas material generates non-conductive gas to extinguish the electric arc. The arc-extinguishing coating and the filling of quartz sand also provide effective arc extinguishing. In addition, it has a snap-on quick-installation terminal structure, compatible with both vertical plug-in and horizontal mounting modes, and has a fuse indicator that is easy for maintenance personnel to identify. When the gas-generating solid material inside the mounting block generates gas, the gas pressure will exert an upward thrust on the thin sheet, which will drive the indicator slide rod upward. After the indicator slide rod pops out from the top of the cover, it indicates that the internal fuse ring has melted. The internal fuse ring is easy to disassemble and replace. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the external structure of the present invention;

[0026] Figure 2 This is a schematic diagram of the internal structure of the present invention;

[0027] Figure 3 This is a schematic diagram of the lower structure of the cover in this invention;

[0028] Figure 4 For the present invention Figure 2 Enlarged view of the structure at point A in the middle;

[0029] Figure 5 This is a schematic diagram of the structure of the metal connector in this invention.

[0030] Explanation of reference numerals in the attached figures:

[0031] 1. Base, 2. Cover, 3. Internal assembly unit, 31. Ceramic bracket, 32. Fuse ring, 33. Fuse end, 34. Enclosure, 35. Socket, 36. Plug, 37. Screw, 38. PTC thermistor, 39. Sealing gasket, 4. External mounting unit, 41. Mounting bracket, 42. Metal connector, 43. Metal clamp, 44. Threaded hole, 45. Fixing bolt, 46. Slot assembly, 5. Arc extinguishing unit, 51. Mounting clamp, 52. Solid gas generating material, 53. Marking slide bar, 54. Thin sheet, 55. Quartz sand. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] Please see Figures 1-5 This embodiment provides a technical solution: a small fuse based on multi-layer composite arc extinguishing and dual-sensitive triggering, including a base 1, an internal assembly unit 3, an external mounting unit 4, and an arc extinguishing processing unit 5;

[0034] Base 1: It is a rectangular plate, and a cover 2, which is also a cuboid and has the same width and height, is inserted on the top of the base 1.

[0035] Internal assembly unit 3 includes a ceramic holder 31, a fuse ring 32, a fuse element end 33, and a PTC thermistor 38. The upper end of the base 1 is fixedly connected to two sets of ceramic holders 31, each set containing two arc-shaped slots. The openings of the two sets of ceramic holders 31 face each other, and the openings of two adjacent sets of ceramic holders 31 face the same direction. The fuse ring 32 has a snake-shaped structure, and the curved ends of the left and right parts of the fuse ring 32 are centrally symmetrical. The left and right parts of the fuse ring 32 pass through a central longitudinal... The straight section is fixedly connected in one piece, and two rows of teeth are opened in the middle straight section of the fuse ring 32. The spacing of each row of teeth is equal. A nano zinc oxide arc-quenching coating is coated in each tooth. The fuse ring 32 has a double-layer arc structure and the fuse ring 32 is approximately circular in shape. The ends of the double-layer arc structure are connected by the bends at the corners. A straight fuse body end 33 is fixedly connected to the outermost end of the fuse ring 32, and a PTC thermistor 38 is embedded in both the front and rear fuse body ends 33.

[0036] External mounting unit 4: installed at both the front and rear ends of the base 1;

[0037] Arc extinguishing unit 5: installed on the lower side of cover 2.

[0038] The ceramic holder 31 is used for mounting and securing the fuse ring 32. The simulated serpentine hollow design of the fuse ring 32 can extend the fusible path within the same volume, thereby improving the breaking capacity. By opening equidistant teeth in the middle straight section of the fuse ring 32, the specific location of the fuse can be formed. The two fuse body ends 33 at the front and rear are used for electrical connection with the outer metal contact plate 42. By integrating and installing a PTC thermistor at the end, the fuse can be triggered in advance when the temperature is abnormal, thereby supporting dual triggering conditions of temperature and current, and realizing dual circuit protection.

[0039] The internal assembly unit 3 also includes a surrounding plate 34, a socket 35, a post 36, and a screw 37. A rectangular surrounding plate 34 is fixedly connected to the upper edge of the base 1. Circular sockets 35 are provided at the four corners of the upper end of the base 1. The sockets 35 extend upward through a portion of the corner of the surrounding plate 34, thus forming a quarter-circle fan-shaped concave structure at the corner of the surrounding plate 34. Vertical posts 36 are fixedly connected to the four corners of the lower end of the cover 2. Each post 36 is inserted into the socket 35, and the circumferential side of the post 36 fits tightly with the fan-shaped groove at the corner of the surrounding plate 34. Screws 37 are embedded at the four corners of the upper end of the cover 2. The screws 37 pass through the posts 36 and are threaded to the bottom of the socket 35. After the cover 2 is inserted, the enclosure 34 can form a tight seal with the edge of the cover 2. When the insertion post 36 is inserted into the insertion hole 35, the base 1 and the cover 2 can be fastened by tightening the screw 37. When the cover 2 is installed, the circumferential side of the insertion post 36 fits tightly with the fan-shaped groove at the corner of the enclosure 34, which makes it easier for the insertion post 36 to be aligned with the insertion hole 35.

[0040] The internal assembly unit 3 also includes a sealing gasket 39. A sealing gasket 39 is fixedly installed on the inner side of the lower end of the cover 2, and the sealing gasket 39 is vertically aligned with the upper end of the enclosure 34. After the cover 2 is installed, the sealing gasket 39 can be pressed between the cover 2 and the enclosure 34, thereby achieving a good sealing effect, preventing leakage of internal quartz sand 55, and preventing the entry of external moisture.

[0041] The external mounting unit 4 includes metal contacts 42 and slot groups 46. A square metal contact 42 is inserted into both the front and rear sides of the enclosure 34, and slot groups 46 are formed on each side edge of the metal contact 42. The metal contacts 42 are used for electrical connection with external devices, and the slot groups 46 are used to realize the snap-fit ​​between the metal contacts 42 and the external devices.

[0042] The external mounting unit 4 also includes mounting brackets 41 and metal clamps 43. Two U-shaped mounting brackets 41 are installed in the middle of the inner side of the enclosure 34. Two metal clamps 43 are fixedly connected to the inner end of the metal connector 42. The fuse end 33 is inserted into the middle side of the U-shaped mounting brackets 41. The two metal clamps 43 pass through the enclosure 34 and are inserted into the mounting brackets 41, clamping the fuse end 33 on the left and right sides. The mounting brackets 41 are used for mounting and supporting the metal clamps 43 and the fuse end 33. The metal clamps 43 and the fuse end 33 are inserted and combined inside the mounting brackets 41.

[0043] The external mounting unit 4 also includes threaded holes 44 and fixing bolts 45. Threaded holes 44 are provided on both sides of the mounting block 41 and on the outer side of the metal clamp 43. The threaded holes 44 penetrate the side of the mounting block 41, and the fixing bolts 45 pass through the mounting block 41 and are pressed against the inside of the metal clamp 43. The fixing bolts 45 can be used to fasten the metal clamp 43 to the fuse end 33, and by loosening the fixing bolts 45, it is easy to replace the fuse ring 32 after it has melted.

[0044] The arc extinguishing unit 5 includes mounting clamps 51 and solid gas-generating material 52. The lower end of the cover 2 is fixedly connected with ceramic brackets 31 in the same number as the ceramic brackets 31 at the lower base 1. The ceramic brackets 31 fixedly connected to the cover 2 are vertically aligned with the ceramic brackets 31 fixedly connected to the base 1. The middle side of the lower end of the cover 2 is fixedly connected with two mounting clamps 51 on the left and right. Each of the two mounting clamps 51 has a groove on its opposite side. Solid gas-generating material is placed inside the groove. After the cover 2 is installed and fixed, the two mounting clamps 51 are clamped on the outside of the middle straight section of the fuse ring 32 and a small closed space is formed by clamping with the inner groove. The mounting clamp 51 is used to hold the solid gas-generating material 52 and forms a small closed space by clamping it with the inner groove. When the fuse breaks, hot gas is generated in the closed space, which induces the solid gas-generating material 52 to generate non-conductive gas to extinguish the arc. In addition, the ceramic holder 31 separates each ring of the fuse ring 32 by a sufficient distance, which can divide the arc energy by multiple gaps. The nano zinc oxide arc-extinguishing coating coated at the toothed part of the middle section of the fuse ring 32 can play an arc-extinguishing role, thereby realizing a multi-layer arc-extinguishing measure.

[0045] The arc extinguishing unit 5 also includes a marking slide rod 53 and a thin plate 54. The marking slide rod 53 is inserted inside one of the mounting blocks 51. The upper end of the marking slide rod 53 is flush with the end face of the cover 2. A horizontal thin plate 54 is fixedly connected to the upper middle part of the marking slide rod 53. When the gas-generating solid material 52 in the space inside the mounting block 51 generates gas, the gas pressure exerts an upward thrust on the thin plate 54, thereby causing the marking slide rod 53 to move upward. Once the marking slide rod 53 pops out from the upper end of the cover 2, it indicates that the internal fuse ring 32 has melted.

[0046] The arc extinguishing unit 5 also includes quartz sand 55, which fills the space enclosed by the base 1, the surrounding plate 34, and the cover 2. By filling with quartz sand 55, the gaps between the sand grains are used to divide the arc path and absorb the arc heat, which helps to realize the multi-level arc extinguishing function.

[0047] The card slot assembly 46 includes a central long card slot and two short card slots on the left and right, with the long card slot and the short card slots having perpendicular opening directions. By opening card slots of different lengths and directions, the metal contact 42 can be vertically inserted and engaged with the limiting posts on the chip board, thus being compatible with both vertical insertion and horizontal mounting modes and adapting to high-density PCB layouts.

[0048] The working principle of a miniature fuse based on multi-layer composite arc extinguishing and dual-sensitive triggering provided by the present invention is as follows: In the present invention, the ceramic holder 31 is used for the installation and locking of the fuse ring 32. The surrounding plate 34 can form a close seal with the edge of the cover 2 after the cover 2 is inserted. When the insert 36 is inserted into the socket 35, the base 1 and the cover 2 can be fastened by tightening the screw 37. When the cover 2 is installed, the circumferential side of the insert 36 fits tightly with the fan-shaped groove at the corner of the surrounding plate 34, which makes it easier for the insert 36 to align with the socket 35. After the cover 2 is installed, the sealing gasket 39 can be pressed between the cover 2 and the surrounding plate 34, thereby achieving a good sealing effect, preventing the leakage of internal quartz sand 55, and preventing the entry of external moisture. The fuse ring 32 is a double-layered arc-shaped serpentine simulation structure. The left and right parts of the fuse ring 32 are integrally connected by a longitudinal straight section in the middle. The outermost end of the fuse ring 32 is fixedly connected to a straight fuse element end 33, and a PTC thermistor 38 is embedded in both the front and rear fuse element ends 33. Through the simulated serpentine hollow design of the fuse ring 32, the fuse path can be extended within the same volume, thereby improving the breaking capacity. By opening equidistant teeth in the middle straight section of the fuse ring 32, the specific location of the fuse can be formed. The front and rear fuse element ends 33 are used to make electrical connections with the outer metal contact 42. By integrating the PTC thermistor at the end, the fuse can be triggered in advance when the temperature is abnormal, thereby supporting dual triggering conditions of temperature and current, and realizing dual circuit protection. When the molten metal melts, an electric arc is generated, which can cause secondary short circuits and other hazards. This invention has multi-level arc extinguishing measures. Two mounting blocks 51 are clamped on the outer side of the middle straight section of the fuse ring 32, and a small closed space is formed by the inner groove. When melting occurs, hot gas is generated in the closed space, which induces the solid gas-generating material 52 to generate non-conductive gas to extinguish the arc. In addition, the ceramic holder 31 separates each ring of the fuse ring 32 by a sufficient distance, which can divide the arc energy by multiple gaps. The nano zinc oxide arc extinguishing coating coated at the toothed edge of the middle section of the fuse ring 32 can play an arc extinguishing role. By filling with quartz sand 55, the gaps between the sand grains are used to divide the arc path and absorb the arc heat, which helps to realize the multi-level arc extinguishing function. This invention also features a fuse indicator that is easy for maintenance personnel to identify. When the gas-generating solid material 52 inside the mounting block 51 generates gas, the gas pressure will exert an upward thrust on the sheet 54, which will then drive the indicator slide rod 53 to move upward. After the indicator slide rod 53 pops out from the top of the cover 2, it indicates that the internal fuse ring 32 has melted. Furthermore, the internal fuse ring 32 is easy to disassemble and replace. At the mounting block 41, the metal clamp 43 can be fastened to the fuse body end 33 by the fixing bolt 45. And by loosening the fixing bolt 45, it is easy to replace the fuse ring 32 after it has melted.In addition, it also features a snap-on quick-installation terminal structure. The slot group 46 includes a middle long slot and two short slots on the left and right. The opening direction of the long slot and the short slot is perpendicular. By opening slots of different lengths and directions, the metal contact 42 can be vertically inserted and snapped into the limiting post on the chip board, thus being compatible with both vertical insertion and horizontal mounting modes and adapting to high-density PCB layouts.

[0049] It is worth noting that the solid gas-generating material 52 disclosed in the above embodiments uses phenolic resin, which is more suitable for small fuses.

[0050] The above are merely embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A miniature fuse based on multi-layer composite arc extinguishing and dual-sensitive triggering, characterized in that: It includes a base (1), an internal assembly unit (3), an external mounting unit (4), and an arc extinguishing unit (5); Base (1): It is a rectangular plate. A cover (2) with the same width and height is inserted on the top of the base (1). Internal assembly unit (3): includes ceramic card holder (31), fuse ring (32), fuse end (33) and PTC thermistor (38). The upper end of the base (1) is fixedly connected to two sets of ceramic card holders (31) on the left and right. Each set of ceramic card holders (31) includes two arc-shaped card slots. The openings of the two sets of ceramic card holders (31) are opposite to each other. The openings of the two ceramic card holders (31) on the adjacent side face the same direction. The fuse ring (32) has a snake-shaped structure, and the curved ends of the left and right parts of the fuse ring (32) are centrally symmetrical. The left and right parts of the fuse ring (32) are connected to each other. The fuse ring (32) is fixedly connected in a vertical section in the middle, and two rows of teeth are provided in the middle section of the fuse ring (32). The spacing of each row of teeth is equal. A nano zinc oxide arc-quenching coating is coated in each tooth. The fuse ring (32) is a double-layer arc structure, and the fuse ring (32) is approximately circular in shape. The ends of the double-layer arc structure are connected by the bends at the corners. The outermost end of the fuse ring (32) is fixedly connected to a straight fuse body end (33), and a PTC thermistor (38) is embedded in both the front and rear fuse body ends (33). External mounting unit (4): installed at both ends of the base (1); Arc extinguishing unit (5): installed on the underside of the cover (2).

2. A miniature fuse based on multi-layer composite arc extinguishing and dual-sensitive triggering as described in claim 1, characterized in that: The internal assembly unit (3) also includes a surrounding plate (34), a socket (35), a post (36), and a screw (37). The upper edge of the base (1) is fixedly connected to a rectangular surrounding plate (34). The four corners of the upper end of the base (1) are provided with circular sockets (35). The sockets (35) face upward and penetrate a portion of the corner of the surrounding plate (34), thereby forming a quarter-circle fan-shaped concave structure at the corner of the surrounding plate (34). The four corners of the lower end of the cover (2) are fixedly connected with vertical posts (36). Each post (36) is inserted into the socket (35), and the circumferential side of the post (36) fits tightly with the fan-shaped groove at the corner of the surrounding plate (34). The four corners of the upper end of the cover (2) are embedded with screws (37). The screws (37) pass through the posts (36) and are threaded to the bottom of the socket (35).

3. A miniature fuse based on multi-layer composite arc extinguishing and dual-sensitive triggering according to claim 2, characterized in that: The internal assembly unit (3) also includes a sealing gasket (39), and a sealing gasket (39) is fixedly installed on the inner side of the lower end of the cover (2), with the sealing gasket (39) vertically corresponding to the upper port of the enclosure (34).

4. A miniature fuse based on multi-layer composite arc extinguishing and dual-sensitive triggering according to claim 2, characterized in that: The external mounting unit (4) includes a metal tab (42) and a slot group (46). A square metal tab (42) is inserted into both the front and rear sides of the enclosure (34), and the slot group (46) is provided on each side edge of the metal tab (42).

5. A miniature fuse based on multi-layer composite arc extinguishing and dual-sensitive triggering according to claim 4, characterized in that: The external mounting unit (4) also includes mounting brackets (41) and metal clamps (43). Two U-shaped mounting brackets (41) are installed in the middle of the inner side of the enclosure (34). The inner end of the metal connector (42) is fixedly connected to two metal clamps (43) on the left and right. The fuse end (33) is inserted into the middle side of the U-shaped mounting bracket (41). The two metal clamps (43) pass through the enclosure (34) and are inserted into the mounting bracket (41). The two metal clamps (43) are clamped on the left and right sides of the fuse end (33).

6. A miniature fuse based on multi-layer composite arc extinguishing and dual-sensitive triggering according to claim 5, characterized in that: The external mounting unit (4) also includes threaded holes (44) and fixing bolts (45). The threaded holes (44) are provided on the left and right sides of the mounting block (41) and on the outward side of the metal clamp (43). The threaded holes (44) penetrate the side of the mounting block (41), and the fixing bolts (45) pass through the mounting block (41) and are pressed against the inside of the metal clamp (43).

7. A miniature fuse based on multi-layer composite arc extinguishing and dual-sensitive triggering according to claim 1, characterized in that: The arc extinguishing unit (5) includes mounting clamps (51) and solid gas-generating material (52). The lower end of the cover (2) is fixedly connected with ceramic brackets (31) equal in number to those at the lower base (1). The ceramic brackets (31) fixedly connected to the cover (2) and the ceramic brackets (31) fixedly connected to the base (1) are vertically aligned. The middle side of the lower end of the cover (2) is fixedly connected with two mounting clamps (51). The opposite side of the two mounting clamps (51) is provided with a groove. The solid gas-generating material is placed inside the groove. After the cover (2) is installed and fixed, the two mounting clamps (51) are clamped on the outside of the middle straight section of the fuse ring (32) and a small closed space is formed by clamping with the inner groove.

8. A miniature fuse based on multi-layer composite arc extinguishing and dual-sensitive triggering according to claim 7, characterized in that: The arc extinguishing unit (5) also includes a marking slide (53) and a thin plate (54). The marking slide (53) is inserted into the interior of one of the mounting blocks (51). The upper end of the marking slide (53) is flush with the end face of the cover (2). The thin plate (54) is fixedly connected to the upper part of the middle of the marking slide (53).

9. A miniature fuse based on multi-layer composite arc extinguishing and dual-sensitive triggering according to claim 2, characterized in that: The arc extinguishing unit (5) also includes quartz sand (55), and the space enclosed by the base (1), the surrounding plate (34) and the cover (2) is filled with the quartz sand (55).

10. A miniature fuse based on multi-layer composite arc extinguishing and dual-sensitive triggering according to claim 4, characterized in that: The card slot group (46) includes a middle long card slot and two short card slots on the left and right, with the opening direction of the long card slot and the short card slot perpendicular to each other.

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