Fuse having small projection area

Abstract

This application provides a fuse with a small projected area, including an insulating shell and an insulating base; a first groove is provided in the insulating shell; at least one first connecting part is provided on the insulating base, and at least one second connecting part is provided on the insulating shell; the insulating base and the insulating shell are joined by at least one first connecting part and at least one second connecting part to cover the first groove to form a receiving cavity; a first through hole and a second through hole are provided on the insulating base, a first electrode passes through the first through hole, and a second electrode passes through the second through hole; the first electrode and the second electrode are used to connect in the protected circuit to protect the downstream circuit; the length of the insulating shell in a first direction is at least twice the maximum diameter of the first end face of the insulating shell and the maximum diameter of the second end face of the insulating shell; the first end face is parallel to the second end face, and the first direction is the direction from the first end face to the second end face or from the second end face to the first end face.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of emergency protection devices, and particularly relates to a fuse with a small projection area. BACKGROUND

[0002] At present, under the background of rapid development of the new energy automobile industry, efficient use of the vehicle space has been upgraded from an "optimization item" to a "core competitiveness". The underlying logic of this trend is not only derived from the direct demand of consumers for the available space (such as the seating cabin and storage area) inside the vehicle, but also is coordinated with the development direction of the power battery energy density improvement and the electric drive system integration. When the vehicle's cruising range breaks through the "range anxiety" threshold, the space utilization rate becomes a key indicator for measuring the competitiveness of the product. In this process, the miniaturization process of the on-board charger (OBC), which is one of the core subsystems of the new energy automobile, is particularly crucial. On the one hand, the OBC undertakes the core function of converting alternating current into direct current, and its volume directly affects the layout space of the surrounding components such as the high-voltage distribution box and the battery pack. On the other hand, the improvement of the power density (unit volume output power) of the OBC can effectively reduce the energy consumption of the whole vehicle and indirectly prolong the actual cruising range. Therefore, promoting the OBC to develop in the direction of "lightweight, compact and high integration" has become the technical consensus of the entire new energy automobile industry chain.

[0003] However, in the technical research of OBC miniaturization, one easily overlooked but crucial link, the installation design of the circuit protection device (especially the fuse), is becoming a key bottleneck restricting the volume optimization. SUMMARY

[0004] The application provides a fuse with a small projection area, so as to reduce the area occupied by the fuse on the circuit board and further reduce the size of the circuit board.

[0005] In a first aspect, the application provides a fuse with a small projection area, comprising an insulating shell and an insulating base.

[0006] The insulating shell is provided with a first groove; the insulating base is provided with at least one first combining part, and the insulating shell is provided with at least one second combining part; the insulating base and the insulating shell are combined through the at least one first combining part and the at least one second combining part to cover the first groove to form a containing cavity;

[0007] The insulating base is provided with a first through hole and a second through hole, a first electrode is led out from the first through hole, and a second electrode is led out from the second through hole; the first electrode and the second electrode are used to be connected in a protected circuit to protect the subsequent circuit;

[0008] The length of the insulating shell in a first direction is at least twice the maximum diameter of the first end face of the insulating shell and twice the maximum diameter of the second end face of the insulating shell; the first end face is parallel to the second end face, and the first direction is the direction from the first end face to the second end face or from the second end face to the first end face.

[0009] In conjunction with the first aspect, in one possible embodiment, the fuse with a small projected area further includes an assembly, the insulating base including a first substrate, a first platform extending from a third end face of the first substrate, and a first guardrail extending from the edge of the first platform; at least one first connecting portion is disposed on the first guardrail; a first through hole and a second through hole both penetrate the first platform and the first substrate; at least one second connecting portion is disposed on the shell wall of the insulating housing near the first opening end of the first groove; when the insulating base is combined with the insulating housing, the first platform and the first guardrail are inserted into the first groove, and the fourth end face of the first opening abuts against the first end face; the at least one first connecting portion and the at least one second connecting portion are combined and fixed by the assembly to combine the insulating base and the insulating housing.

[0010] In conjunction with the first aspect, in one possible embodiment, the insulating base includes a first substrate, the at least one first coupling portion being disposed on the first substrate; the at least one second coupling portion extending from the fourth end face of the insulating housing near the first opening of the first groove; the at least one second coupling portion being combined with the at least one first coupling portion to join the insulating base and the insulating housing; both the first through hole and the second through hole penetrating the first substrate.

[0011] In conjunction with the first aspect, in one possible embodiment, the fuse with a small projected area further includes an assembly, the insulating base including a first substrate; a first platform extending from a third end face of the first substrate, a first step between the first platform and the first substrate forming a first joint portion; a second platform extending from a fourth end face of the insulating housing near a first opening of a first groove, a second step between the second platform and the fourth end face forming a second joint portion; the first joint portion and the second joint portion are joined and fixed together by the assembly to join the insulating base and the insulating housing; both the first through hole and the second through hole penetrate the first substrate; or,

[0012] At least one first joint is provided on the edge of the first end face, and at least one second joint is provided on the edge of the fourth end face. The at least one first joint and the at least one second joint are joined and fixed together by the assembly to join the insulating base and the insulating shell. Both the first through hole and the second through hole penetrate the first substrate.

[0013] In conjunction with the first aspect, in one possible embodiment, the insulating base includes a first substrate, a first platform extending from a third end face of the first substrate, a first fence extending from the edge of the first platform, and a first joint extending from the outer wall of the connection between the first platform and the first fence; the at least one second joint is disposed on the shell wall of the insulating housing near the first opening end of the first groove; when the insulating base is combined with the insulating housing, the first platform and the first fence are inserted into the first groove, and the first joint and the second joint are combined to combine the insulating base and the insulating housing; the fourth end face of the first opening abuts against the first end face.

[0014] In conjunction with the first aspect, in one possible embodiment, the assembly includes a ring structure, a rectangular structure, or an irregular structure.

[0015] In conjunction with the first aspect, in one possible embodiment, the seal has a first penetrating cavity that penetrates the sixth and seventh end faces of the seal; a third step is provided on the outer wall of the first end of the insulating shell, and the edge of the first substrate is flush with the third step; the seal is sleeved on the third step through the first penetrating cavity to fix the insulating shell and the first substrate.

[0016] In conjunction with the first aspect, in one possible embodiment, a second groove is provided on the third step. When the seal is fitted onto the third step, a protrusion formed on the inner wall of the first penetration cavity by a narrowing operation is formed so that the protrusion engages with the second groove and fixes the seal to the insulating shell. The narrowing operation refers to the process of narrowing the target area on the seal toward the inside of the first penetration cavity to form the protrusion when the seal is fitted onto the third step.

[0017] In conjunction with the first aspect, in one possible embodiment, the insulating base has a third through hole penetrating the insulating base, the third through hole being used to fill the cavity with arc-extinguishing material.

[0018] In conjunction with the first aspect, in one possible embodiment, a support portion is provided on the fifth end face of the first substrate; the support portion is used to separate the circuit board from the first through hole and the second through hole by a predetermined distance when the fuse with a small projected area is soldered in the protected circuit, so as to provide a soldering distance.

[0019] As can be seen, the fuse with a small projected area in this application includes an insulating shell and an insulating base; the insulating shell has a first groove; the insulating base has at least one first connecting part, and the insulating shell has at least one second connecting part; the insulating base and the insulating shell are joined through the at least one first connecting part and the at least one second connecting part to cover the first groove to form a receiving cavity; the insulating base has a first through hole and a second through hole, through which a first electrode passes and through which a second electrode passes; the first electrode and the second electrode are used to connect in the protected circuit to protect the downstream circuit; the length of the insulating shell in a first direction is at least twice the maximum diameter of the first end face of the insulating shell and the maximum diameter of the second end face of the insulating shell; the first end face is parallel to the second end face, and the first direction is the direction from the first end face to the second end face or from the second end face to the first end face. In this way, by setting the smallest end of the fuse as an insulating base, and setting the first electrode and the second electrode on the insulating base, the fuse can be installed on the circuit board in a vertical manner, reducing the area occupied by the fuse on the circuit board and thus reducing the size of the circuit board; at the same time, by setting the first joint and the second joint on the insulating shell and the insulating base respectively, the connection between the insulating shell and the insulating base is made more secure. Attached Figure Description

[0020] 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, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the structure of the first type of fuse with a small projected area provided in the embodiments of this application;

[0022] Figure 2 This is a schematic diagram of the structure of a metallic conductor provided in an embodiment of this application;

[0023] Figure 3 This is a cross-sectional schematic diagram of the first type of insulating shell and insulating base provided in the embodiments of this application;

[0024] Figure 4 This is a cross-sectional schematic diagram of the second type of insulating shell and insulating base provided in the embodiments of this application;

[0025] Figure 5 This is a cross-sectional schematic diagram of the third type of insulating shell and insulating base provided in the embodiments of this application;

[0026] Figure 6 This is a cross-sectional schematic diagram of the fourth type of insulating shell and insulating base provided in the embodiments of this application;

[0027] Figure 7 This is a cross-sectional schematic diagram of a metal conductor combined with an insulating base according to an embodiment of this application;

[0028] Figure 8 This is a schematic diagram of the structure of a sealing element provided in an embodiment of this application;

[0029] Figure 9 This is a schematic diagram of the structure of a second type of fuse with a small projected area provided in the embodiments of this application. Detailed Implementation

[0030] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0031] The terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, systems, products, or apparatuses.

[0032] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0033] Currently, in the technological breakthroughs of OBC miniaturization, an easily overlooked yet crucial aspect—the installation design of circuit protection devices (especially fuses)—is becoming a key bottleneck restricting size optimization.

[0034] To address the aforementioned problems, this application provides a fuse with a small projected area. This fuse with a small projected area can be applied in circuit protection scenarios. The fuse with a small projected area in this application includes an insulating shell and an insulating base; the insulating shell has a first groove; the insulating base has at least one first connecting portion, and the insulating shell has at least one second connecting portion; the insulating base and the insulating shell are joined through the at least one first connecting portion and the at least one second connecting portion to cover the first groove and form a receiving cavity; the insulating base has a first through hole and a second through hole, through which a first electrode extends and through the second through hole; the first electrode and the second electrode are used to connect in the protected circuit to protect downstream circuits; the length of the insulating shell in a first direction is at least twice the maximum diameter of the first end face and the maximum diameter of the second end face of the insulating shell; the first end face is parallel to the second end face, and the first direction is the direction from the first end face to the second end face or from the second end face to the first end face. In this way, by designating the smallest end of the fuse as an insulating base, and placing the first and second electrodes on the insulating base, the fuse can be vertically mounted on the circuit board, reducing the area occupied by the fuse on the circuit board and thus reducing the size of the circuit board. Simultaneously, by providing a first and second joint on the insulating shell and the insulating base respectively, the connection between the insulating shell and the insulating base is made more robust. This solution is applicable to various scenarios, including but not limited to the applications mentioned above.

[0035] The specific structure will be described in detail below.

[0036] Please see Figures 1-9 This application also provides a fuse 100 with a small projected area, including an insulating housing 10 and an insulating base 20;

[0037] The insulating housing 10 is provided with a first groove 11; the insulating base 20 is provided with at least one first connecting part 21, and the insulating housing 10 is provided with at least one second connecting part 12; the insulating base 20 and the insulating housing 10 are connected through the at least one first connecting part 21 and the at least one second connecting part 12 to cover the first groove 11 to form a receiving cavity 50.

[0038] The insulating base 20 has a first through hole 22 and a second through hole 23. A first electrode 32 passes through the first through hole 22 and a second electrode 33 passes through the second through hole 23. The first electrode 32 and the second electrode 33 are used to connect in the protected circuit to protect the downstream circuit.

[0039] The length of the insulating housing 10 in a first direction is at least twice the maximum diameter of the first end face of the insulating housing 10 and twice the maximum diameter of the second end face of the insulating housing 10; the first end face is parallel to the second end face, and the first direction is the direction from the first end face to the second end face or from the second end face to the first end face.

[0040] In practice, an insulating shell 10 is manufactured by adding 30% glass fiber toughening to high-temperature resistant engineering plastic PA66 and then using injection molding. The insulating shell 10 is cylindrical in shape, with one end being a closed end (the end containing the second end face) and the other end being an open end (the end containing the first opening 111), forming a hollow cavity structure in the middle, namely the first groove 11. The cross-section of the insulating shell 10 parallel to the first end face can be circular, elliptical, square, or other arbitrary shapes, forming a hollow cylindrical body with one open end. The second end face is the sealed bottom of the first groove 11.

[0041] Furthermore, a first joint 21 is formed at the end of the major axis of the elliptical cross section at a specific position on the inner wall surface of the first groove 11 at the opening end of the insulating shell 10; a through hole is formed on the groove wall of the first groove 11 above the first joint 21 in the insulating shell 10, which penetrates the inner wall surface of the first groove 11 of the insulating shell 10, and serves as a sand filling hole for filling the arc extinguishing material of the product.

[0042] The cross-sectional dimensions of the bottom sealed end of the insulating base 20 are the same as those of the insulating shell 10, that is, the insulating base 20 can be inserted into the first groove 11 of the insulating shell 10, and the side wall of the bottom sealed end of the insulating base 20 is flush with the outer wall of the insulating shell 10.

[0043] Furthermore, the insulating shell 10 is formed by sealing the two ends of the second penetration cavity through the first substrate 24 and the second substrate, respectively, with a tubular shell including the second penetration cavity. The sealed second penetration cavity is the receiving cavity 50 in the insulating shell 10. One side of the first substrate 24 that serves as the cavity wall of the receiving cavity 50 is a first end face, and at least one platform extends from the first end face, so that the first substrate 24 can be combined with the tube wall of the tubular shell through at least one platform, thereby increasing the bonding strength between the first substrate 24 and the tubular shell through friction.

[0044] For details, please refer to Figure 2The fuse 100 further includes a molten metal element 31, which is integrally formed with the first electrode 32 and the second electrode 33. The first electrode 32 is disposed at the first end of the molten metal element 31, and the second electrode 33 is disposed at the second end of the molten metal element 31. The molten metal element 31 includes a fusing portion 311, a first connecting portion 312, and a second connecting portion 313. The first connecting portion 312 is connected to the first end of the fusing portion 311 and the first electrode 32, respectively, and the second connecting portion 313 is connected to the second end of the fuse 100 and the second electrode 33, respectively.

[0045] Optionally, the fusing part 311, the first electrode 32, the second electrode 33, the first connecting part 312, and the second connecting part 313 are integrally formed to form a metal conductor 30. The metal conductor 30 is preferably made of T2 copper or oxygen-free copper (other materials are also acceptable, and are not limited here). During manufacturing, the metal material is first prepared into a rectangular metal sheet of a predetermined size. Then, based on the specifications of each component, the fusing part 311, the first electrode 32, the second electrode 33, the first connecting part 312, and the second connecting part 313 are fabricated on the rectangular metal sheet using appropriate manufacturing processes to obtain the metal conductor 30.

[0046] The shape of the metal conductor 30 is not limited, as long as the first electrode 32 and the second electrode 33 can pass through the first through hole 22 and the second through hole 23. The thickness of the fusing portion 311 is less than the thickness of the first connecting portion 312, the second connecting portion 313, the first electrode 32, and the second electrode 33. The fusing portion 311 forms multiple narrow necks with small cross-sectional areas at specific locations through through holes, serving as the first point of fusing under abnormal current. Optionally, the projections of the first and second ends of the fusing portion 311 on any plane do not overlap. Taking a U-shaped structure as an example, the narrow necks are formed on the two vertically downward arms (i.e., the first and second vertical arms) of the U-shaped structure, with a certain misalignment on both sides to ensure that arcing does not occur when an arc is generated. The first electrode 32 and the second electrode 33 extend from the first through hole 22 and the second through hole 23 on the insulating base 20 and are exposed outside the fifth end face 25 of the first substrate 24, for connecting the product to the circuit board of the protected circuit. The first connecting portion 312 and the second connecting portion 313 are respectively inside the first through hole 22 and the second through hole 23 of the insulating base 20, for transitional connection between the fuse portion 311 and the first electrode 32 and the second electrode 33. In addition, the first connecting portion 312 extends obliquely from the first vertical arm of the fuse portion 311 in a direction away from the second vertical arm to the first electrode 32, and then connects to the first vertical arm and the first electrode 32 respectively. Similarly, the second connecting portion 313 extends obliquely from the second vertical arm of the fuse portion 311 in a direction away from the first vertical arm to the second electrode 33, and then connects to the second vertical arm and the second electrode 33 respectively. This arrangement increases the insulation distance between the first electrode 32 and the second electrode 33 without changing the distance between the two vertical arms of the fuse.

[0047] The insulating base 20 can be a multi-layered stepped structure. The first end face and the fifth end face 25 of the first substrate 24 of the insulating base 20 have the same cross-sectional area as the tubular shell parallel to the first end face and the fifth end face 25, but the cross-sectional area of ​​at least one platform decreases layer by layer. It is understood that the insulating base 20 may also be provided with one platform, multiple platforms, or no platform, which can be adjusted according to the actual production situation, and no unique limitation is made here.

[0048] Taking a two-layer platform as an example, at least one platform includes a first platform 26 and a third platform. The first platform 26 is disposed on the first substrate 24, and the third platform is disposed on the first platform 26. The first end face dimension of the first substrate 24 is larger than the dimension of the first platform 26, and the dimension of the first platform 26 is larger than the dimension of the third platform.

[0049] As can be seen, in this embodiment, the first electrode 32 and the second electrode 33 are provided at the end with the smallest area in the fuse 100, so that the fuse 100 can be installed on the circuit board in a vertical manner, reducing the area occupied by the fuse 100 on the circuit board and thus reducing the size of the circuit board; at the same time, the fuse 100 uses the insulating shell 10 as the main body, and various structures are obtained by processing the insulating shell 10, and then the first electrode 32 and the second electrode 33 are connected, further reducing the overall size of the fuse 100.

[0050] In one possible embodiment, please refer to Figure 3 The fuse 100 further includes an assembly 41. The insulating base 20 includes a first substrate 24, a first platform 26 extending from the third end face 27 of the first substrate 24, and a first fence 28 extending from the edge of the first platform 26. At least one first connecting portion 21 is disposed on the first fence 28. The first through hole 22 and the second through hole 23 both penetrate the first platform 26 and the first substrate 24. At least one second connecting portion 12 is disposed on the shell wall of the insulating housing 10 near the first opening 111 of the first groove 11. When the insulating base 20 is combined with the insulating housing 10, the first platform 26 and the first fence 28 are inserted into the first groove 11, and the fourth end face of the first opening 111 abuts against the first end face. The at least one first connecting portion 21 and the at least one second connecting portion 12 are combined and fixed by the assembly 41 to combine the insulating base 20 and the insulating housing 10.

[0051] In this specific implementation, only one platform, designated as the first platform 26, is provided. At least one second connecting portion 12 is provided at a specific height from the opening end of the insulating tube. Simultaneously, at least one first connecting portion 21 can be formed on the first enclosure 28 of the insulating base 20. The first connecting portion 21 can be a through hole penetrating the first enclosure 28, and the second connecting portion 12 can be a through hole penetrating the wall of the first groove 11. When the first platform 26 on the insulating base 20 is inserted into the first groove 11 of the insulating tube from the first opening 111, the openings of the two through holes of the first connecting portion 21 and the second connecting portion 12 coincide. Furthermore, an assembly 41 is prepared, which can be columnar. During installation, the assembly 41 is pressed into the first connecting portion 21 and the second connecting portion 12, so that both ends of the installed assembly 41 are flush with the outer surface of the side wall of the insulating tube. This allows the insulating shell 10 and the insulating base 20 to be joined together, making them less prone to separation and improving the stability of the connection between the insulating shell 10 and the insulating base 20. The assembly 41 is fitted with the first joint 21 and the second joint 12 with an interference fit to improve the bonding strength. It is understood that, in a preferred example, the interference fit between the assembly 41 and the first joint 21 and the second joint 12 has improved the bonding strength between the insulating base 20 and the insulating housing 10.

[0052] It is understood that the assembly 41 can also be a ring structure, a rectangular structure, or an irregular structure, or other types of structures, as long as it can fix the insulating shell 10 and the insulating base 20 with the first connecting part 21 and the second connecting part 12.

[0053] In one possible embodiment, please refer to Figure 4 The insulating base 20 includes a first substrate 24, and at least one first connecting portion 21 is disposed on the first substrate 24; at least one second connecting portion 12 extends from the fourth end face of the insulating housing 10 near the first opening 111 of the first groove 11; the at least one second connecting portion 12 is combined with the at least one first connecting portion 21 to combine the insulating base 20 and the insulating housing 10; the first through hole 22 and the second through hole 23 both penetrate the first substrate 24.

[0054] In a specific implementation, the insulating base 20 may consist only of a first substrate 24, with at least one second connecting portion 12 extending from the fourth end face of the opening end of the insulating tube. At least one first connecting portion 21 is provided on the first substrate 24 of the insulating base 20. The insulating base 20 and the insulating shell 10 are joined by the at least one second connecting portion 12 and the at least one first connecting portion 21. Both the first through hole 22 and the second through hole 23 penetrate the first substrate 24. The second connecting portion 12 may be columnar, wedge-shaped, or other shapes, and the first connecting portion 21 may be a groove adapted to the second connecting portion 12. In some cases, the shapes of the first connecting portion 21 and the second connecting portion 12 may be interchangeable; for example, the first connecting portion 21 may be columnar, wedge-shaped, or other shapes, while the second connecting portion 12 may be a groove. An interference fit is used between the first connecting portion 21 and the second connecting portion 12 to improve the bonding strength between the insulating base and the insulating tube. During installation, the first joint 21 on the insulating tube body is pressed into the second joint 12 on the insulating base 20 to connect the insulating tube body and the insulating base 20, and to ensure that the contact surfaces of the two can be tightly joined.

[0055] In one possible embodiment, please refer to Figure 5 The fuse 100 also includes an assembly 41. The insulating base 20 includes a first substrate 24. A first platform 26 extends from the third end face 27 of the first substrate 24. A first step between the first platform 26 and the first substrate 24 forms the first joint portion 21. A second platform extends from the fourth end face of the insulating housing 10 near the first opening 111 of the first groove 11. A second step between the second platform and the fourth end face forms the second joint portion 12. The first joint portion 21 and the second joint portion 12 are joined and fixed by the assembly 41 to join the insulating base 20 and the insulating housing 10. The first through hole 22 and the second through hole 23 both penetrate the first substrate 24.

[0056] In a specific implementation, a first platform 26 is provided on the insulating base 20, and a second annular platform extending around the first opening 111 extends from the fourth end face of the insulating shell 10.

[0057] During installation, when the fourth end face of the insulating tube body and the first end face of the insulating base 20 are placed at the preset positioning position, the edges of the first platform 26 and the second platform are aligned. At this time, the first joint 21 and the second joint 12 combine to form an annular positioning groove. An interference fit annular positioning wedge (i.e., assembly 41) is fastened on the annular positioning groove. Finally, a sealing member 60 is fastened on the outer wall of the joint between the insulating shell 10 and the insulating base 20 to realize the connection between the insulating tube body and the insulating base 20.

[0058] In another possible embodiment, at least one first connecting portion 21 is provided on the edge of the first end face, and at least one second connecting portion 12 is provided on the edge of the fourth end face. The at least one first connecting portion 21 and the at least one second connecting portion 12 are connected and fixed together by the assembly 41 to connect the insulating base 20 and the insulating shell 10. The first through hole 22 and the second through hole 23 both penetrate the first substrate 24.

[0059] In a specific implementation, at least one first connecting portion 21 is provided at the edge of the first substrate 24 of the insulating base 20 to form at least one first notch on the first substrate 24. The shape of the first notch can be rectangular, circular, elliptical, wedge-shaped, or other shapes, and is not limited to a single shape. At least one second connecting portion 12 is also provided on the insulating shell 10 to form at least one second notch on the fourth end face of the insulating shell 10. The shape of the second notch can be rectangular, circular, elliptical, wedge-shaped, or other shapes, and is not limited to a single shape. During installation, when the fourth end face of the insulating tube is placed with the first end face of the insulating base 20 at a preset positioning position, the first notch (i.e., the first connecting portion 21) and the second notch (i.e., the second connecting portion 12) intersect to form a positioning groove. An interference fit positioning wedge (i.e., assembly 41) is pressed into each positioning groove. Finally, a sealing member 60 is ringed on the outer wall of the joint between the insulating shell 10 and the insulating base 20 to achieve the connection between the insulating tube and the insulating base 20.

[0060] It is understood that the assembly 41 may include a ring structure, a rectangular structure or an irregular structure, or other types of structures, as long as it can fix the insulating shell 10 and the insulating base 20 with the first connecting part 21 and the second connecting part 12.

[0061] In one possible embodiment, please refer to Figure 6 and Figure 7 The insulating base 20 includes a first substrate 24, a first platform 26 extending from the third end face 27 of the first substrate 24, a first fence 28 extending from the edge of the first platform 26, and a first connecting portion 21 extending from the outer wall of the connection between the first platform 26 and the first fence 28; at least one second connecting portion 12 is disposed on the shell wall of the insulating housing 10 near the first opening 111 of the first groove 11; when the insulating base 20 is combined with the insulating housing 10, the first platform 26 and the first fence 28 are inserted into the first groove 11, and the first connecting portion 21 is combined with the second connecting portion 12 to combine the insulating base 20 and the insulating housing 10; the fourth end face of the first opening 111 abuts against the first end face.

[0062] In specific implementation, a wedge-shaped protrusion extends from the outer wall of the connection between the first platform 26 and the first fence 28 of the insulating base 20 as the first connecting part 21. Simultaneously, a wedge-shaped groove, adapted to the first connecting part 21, is formed at a specific position on the inner wall surface of the first groove 11, serving as the second connecting part 12. When the insulating base 20 is inserted into the first groove 11, the first platform 26 and the first fence 28 are also inserted into the first groove 11, and the wedge-shaped protrusion is precisely inserted into the wedge-shaped groove on the side wall of the insulating tube, thereby fixing the insulating base 20 to the insulating tube. This prevents the insulating base 20 from moving laterally within the insulating shell 10; and the step between the first base plate 24 and the first platform 26 abuts against the fourth end face. Combined with the connection of the first connecting part 21 and the second connecting part 12, this prevents the insulating base 20 from moving longitudinally within the insulating shell 10. Ultimately, this allows the insulating shell 10 and the insulating base 20 to be joined together, making them difficult to separate in any direction, thus improving the stability of the connection between the insulating shell 10 and the insulating base 20.

[0063] In one possible embodiment, please refer to Figure 8 It also includes a sealing member 60, on which a first penetrating cavity 61 is formed, penetrating the sixth end face and the seventh end face of the sealing member 60; a third step 13 is provided on the outer wall of the first end of the insulating shell 10, and the edge of the first substrate 24 is flush with the third step 13; the sealing member 60 is sleeved on the third step 13 through the first penetrating cavity 61 to fix the insulating shell 10 and the first substrate 24.

[0064] In a specific implementation, the sealing member 60 is fastened to the third step 13 of the insulating tube body, thereby fixing the first substrate 24 to the insulating shell 10; at the same time, the sealing member 60 is used to block the third through hole 15 for injecting arc-extinguishing material, which is provided on the third step 13 and penetrates into the receiving cavity 50, so as to prevent the arc-extinguishing material filled into the insulating tube body from flowing out through the third through hole 15.

[0065] In one possible embodiment, a second groove 14 is provided on the third step 13. When the sealing member 60 is fitted onto the third step 13, a protrusion formed on the inner wall of the first penetration cavity 61 through a narrowing operation allows the protrusion to engage with the second groove 14, thereby fixing the sealing member 60 to the insulating housing 10. The narrowing operation refers to forming the protrusion by narrowing a target area on the sealing member 60 towards the inside of the first penetration cavity 61 when the sealing member 60 is fitted onto the third step 13. This target area corresponds to the area of ​​the second groove 14.

[0066] In practice, the sealing element 60 is fitted onto the third step 13, covering the second groove 14. Then, pressure is applied to the sealing element 60 at the position corresponding to the second groove 14, causing the outer wall of the sealing element 60 to retract inwards into the second groove 14, forming a protrusion. The second groove 14 limits the protrusion, preventing the sealing element 60 from shifting or falling off during product vibration. Optionally, the sealing clamp is made of an elastic metal material (such as beryllium bronze or stainless steel) to ensure sealing performance and mechanical strength, while also providing electromagnetic shielding for the fuse 100.

[0067] In one possible embodiment, please refer to Figure 9 The insulating base 20 has a third through hole 15 that penetrates the insulating base 20. The third through hole 15 is used to fill the cavity 50 with arc-extinguishing material.

[0068] In specific implementation, the location design of the third through hole 15 in the manufacturing process of fuse 100 has a significant impact on the filling quality and production efficiency of the arc-extinguishing material. When the third through hole 15 is set on the third step 13 as described in the above example, due to the filling principle of the arc-extinguishing material under the action of gravity, in order to ensure that the arc-extinguishing material can flow smoothly into the internal cavity of the insulating shell 10 and to prevent the material from overflowing during the filling process, fuse 100 can only be placed horizontally in the filling process. Vertical placement refers to a placement method with a smaller horizontal projected area, while horizontal placement refers to a placement method with a larger horizontal projected area. This horizontal placement method has particularly prominent drawbacks when the height dimension of fuse 100 is large. Because the horizontal length of fuse 100 increases significantly when placed horizontally, the arc-extinguishing material, after entering from the third through hole 15, needs to flow through a longer horizontal path to reach the other end of fuse 100. During this process, the arc-extinguishing material will generate a large frictional force with the inner wall of the insulating tube, resulting in increased material flow resistance. Meanwhile, during the filling process, the arc-extinguishing material tends to accumulate midway, making it difficult to distribute evenly to the far end of the fuse 100. This makes it difficult to guarantee the filling density of the arc-extinguishing material at the end of the fuse 100, severely affecting the arc-extinguishing performance of the fuse 100. In addition, the long-distance flow of the material also significantly increases the filling time, greatly reducing production efficiency and increasing the quality risks such as material moisture absorption and impurity contamination due to excessively long filling time.

[0069] like Figure 9As shown, in this embodiment, a third through hole 15 is provided at the bottom center of the insulating base 20 as a sand filling hole. This design allows the fuse 100 to be placed vertically when filling with arc-extinguishing material. After the arc-extinguishing material is filled, a sand-stop plug is pressed into the third through hole 15, and then sealing silicone is applied to the sand-stop plug to increase the sealing effect and bonding strength. The advantage of vertical placement is that the arc-extinguishing material can fall directly to the second end face vertically under the action of gravity, minimizing the bending and resistance of the material flow path, and allowing the arc-extinguishing material to fill the internal cavity of the insulating tube more efficiently. At the same time, because the material falls vertically, it can be evenly distributed inside the tube, avoiding local accumulation or insufficient filling, thereby effectively ensuring the uniformity and stability of the filling density. This not only significantly improves production efficiency, but also ensures the consistency and reliability of the arc-extinguishing performance of the fuse 100, providing a strong guarantee for the quality of the fuse 100. Optionally, a fifth through hole can be provided on the second substrate as a sand filling hole. Since the second substrate and the first substrate are substrates facing each other, filling the arc-extinguishing material through the fifth through hole can also achieve the purpose of vertical filling in this embodiment, thereby achieving the same or similar technical effect as the third through hole.

[0070] In one possible embodiment, please refer to the following: Figure 1 and Figure 9 A support portion 29 is provided on the fifth end face 25 of the first substrate 24; the support portion 29 is used to separate the circuit board from the first through hole 22 and the second through hole 23 by a predetermined distance when the fuse 100 with a small projected area is soldered in the protected circuit, so as to provide a soldering distance.

[0071] In a specific implementation, a number of support portions 29 are preset at the bottom of the insulating base 20 so that a certain gap is maintained between the insulating base 20 and the circuit board during welding. This makes it easier for the solder to enter the bottom of the product and cover the entire end electrode, increasing the contact area between the solder and the end electrode, reducing the contact resistance, and improving the welding quality.

[0072] Understandably, the number of support portions 29 can be selected as needed. For example, depending on the type of fixture, one, two, or more support portions 29 can be provided so that the fuse 100 can be isolated from the circuit board through the support portions 29. At the same time, it can also enhance the stability of the fuse 100 during welding and reduce unnecessary displacement of the fuse 100 during welding.

[0073] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can easily conceive of variations or substitutions without departing from the spirit and scope of the present invention, and various modifications and alterations can be made, including combinations of the different functions and implementation steps described above, as well as software and hardware implementation methods, all of which are within the protection scope of the present invention.

Claims

1. A fuse with a small projected area, characterized in that, Includes an insulating housing, an insulating base, molten metal, and seals; The insulating shell is provided with a first groove; the first direction length of the insulating shell is at least twice the maximum diameter of its first end face and the maximum diameter of its second end face, the first end face is parallel to the second end face, and the first direction is the direction from the first end face to the second end face or from the second end face to the first end face. The insulating base has a multi-layered stepped structure, including a first substrate, a first platform and a first fence. The cross-sectional area of ​​the first substrate is greater than the cross-sectional area of ​​the first platform and the cross-sectional area enclosed by the first fence. The cross-sectional area of ​​the first substrate is the same as the cross-sectional area of ​​the insulating shell parallel to the first end face. At least one first joint is provided on the outer peripheral wall of the first fence, and at least one second joint is provided on the inner wall of the insulating shell near the first opening of the first groove, which is adapted to the first joint; when the insulating base is combined with the insulating shell, the first platform and the first fence are inserted into the first groove to cover the first groove and form a receiving cavity, and the fourth end face of the first opening abuts against the first end face of the first substrate. The insulating base has a first through hole and a second through hole that penetrate the first platform and the first substrate. A first electrode passes through the first through hole and a second electrode passes through the second through hole. The first electrode and the second electrode are used to connect in the protected circuit to protect the subsequent circuit. A third step is provided on the outer wall of the first end of the insulating shell, and the edge of the first substrate is flush with the third step; a first penetrating cavity is provided on the sealing member, penetrating its sixth end face and seventh end face, and the sealing member is sleeved on the third step through the first penetrating cavity to fix the insulating shell and the insulating base. A support portion is provided on the fifth end face of the first substrate; the support portion is used to separate the circuit board from the first through hole and the second through hole by a predetermined distance when the fuse with a small projected area is soldered in the protected circuit, so as to provide a soldering distance. The molten metal includes a fused portion, a first connecting portion, and a second connecting portion. The fused portion includes a first pendant arm and a second pendant arm. The first connecting portion extends obliquely from the first pendant arm of the fused portion away from the second pendant arm to the first electrode, so as to connect with the first pendant arm and the first electrode respectively. The second connecting portion extends obliquely from the second pendant arm of the fused portion away from the first pendant arm to the second electrode, so as to connect with the second pendant arm and the second electrode respectively.

2. The fuse with a small projected area according to claim 1, characterized in that, The insulating shell is made of a composite material toughened with glass fiber added to a high-temperature resistant engineering plastic, and is manufactured by injection molding based on the composite material.

3. The fuse with a small projected area according to claim 1, characterized in that, The third step is provided with a second groove. When the sealing member is fitted onto the third step, a protrusion is formed on the inner wall of the first penetration cavity by a narrowing operation, so that the protrusion engages with the second groove and fixes the sealing member to the insulating shell. The narrowing operation refers to the process of narrowing the target area on the sealing member toward the inside of the first penetration cavity to form the protrusion when the sealing member is fitted onto the third step.

4. The fuse with a small projected area according to claim 1, characterized in that, The insulating base has a third through hole that penetrates the insulating base, and the third through hole is used to fill the cavity with arc-extinguishing material.

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