Slow-melt fuse and fuse element

Abstract

The utility model provides a kind of slow-melting fuse, comprising: first shell;Second shell, cooperate to first shell and fixed, including sink and limiting portion;Fusing element, comprising: a pair of installation portion, from the first shell and second shell two ends outwardly extend, slow-melting fuse is installed to load;Fusing portion, between a pair of installation portion, when current overload, realize fusing;Wherein, limiting portion and fusing element abut, prevent the torsion of fusing element when assembling fuse.The utility model further provides a kind of fusing element, comprising: a pair of installation portion;Fusing portion, it connects a pair of installation portion, comprising: being provided with slow-melting portion;And weak area being arranged adjacent slow-melting portion, it is configured as when current overload, realize fusing.Compared with prior art, by limiting portion, prevent fusing element spin twist, improve product service life.In addition, setting weak area can also effectively control fusing position, guarantee controllability and consistency of fusing.

Description

Technical Field

[0001] This utility model relates to the field of electrical safety protector technology, and in particular to a slow-blow fuse and a fuse element. Background Technology

[0002] With the increasing electrification and intelligence of automobiles, the number and power of electrical equipment installed in vehicles are also continuously increasing. Low-voltage loads such as lighting, ECUs, sensors, and entertainment systems are widely distributed throughout the vehicle system, placing higher demands on the safety and stability of the power supply. To prevent overload or short-circuit current from damaging the wiring, vehicle low-voltage electrical systems are generally equipped with fuses of various specifications as electrical protection devices, including bolt-type slow-blow fuses.

[0003] Existing bolt-type slow-blow fuses typically consist of upper and lower molded housings and a fusible element, secured within an electrical box by bolts. However, when the bolt passes through the fusible element and is secured with a nut, lateral shear force is generated, which can easily cause the fusible element to rotate, resulting in deformation within the housing. Deformation or even breakage of the fusible element will affect the fuse's performance. Secondly, even if the fusible element in the existing technology has a weak point, the location of the melting point may still be random, making it difficult to control the area that is melted.

[0004] Therefore, there is an urgent need for a slow-blow fuse that can improve the problems of component torsion and uncontrollable melting position in the existing technology, thereby improving the reliability, safety and controllability of the fuse. Utility Model Content

[0005] One objective of this invention is to address at least one aspect of the aforementioned problems and defects existing in the prior art.

[0006] To address the aforementioned problems, this utility model discloses a slow-blow fuse, comprising: a first housing; a second housing fitted to and fixed to the first housing, the second housing including a recess and a limiting portion disposed in the recess; and a fusing element disposed between the first housing and the second housing, including: a pair of mounting portions extending outward from both sides of the first housing and the second housing and configured to mount the slow-blow fuse to a load; and a fusing portion located between the pair of mounting portions and configured to achieve fusing when the current is overloaded; wherein the limiting portion is configured to abut against the fusing element to prevent the fusing element from twisting during assembly of the slow-blow fuse.

[0007] According to an exemplary embodiment of the present invention, each of the pair of mounting portions includes a first side located inside the first housing and the second housing and a second side extending to the outside of the first housing and the second housing opposite to the first side, wherein the limiting portion includes a pair of limiting posts respectively disposed at opposite corners of the sink, and each of the pair of limiting posts abuts against the first side of the corresponding mounting portion of the pair of mounting portions.

[0008] According to an exemplary embodiment of the present invention, the second housing further includes a support portion disposed in the settling tank, which is configured to support the fused portion that has sagged due to melting.

[0009] According to an exemplary embodiment of the present invention, the support portion includes a raised rib.

[0010] According to an exemplary embodiment of the present invention, the fuse portion includes: a slow-melting portion; and a weak region disposed adjacent to the slow-melting portion, the weak region being configured to achieve fuse breaking when the current is overloaded.

[0011] According to an exemplary embodiment of the present invention, the first housing includes a welded portion, and the second housing includes a welded mating portion, wherein the welded portion and the welded mating portion are fixed by ultrasonic welding.

[0012] According to an exemplary embodiment of the present invention, both the welding portion and the welding mating portion include at least one welding groove and / or at least one welding protrusion.

[0013] According to an exemplary embodiment of the present invention, both sides of the first housing and the second housing are provided with recessed assembly positions.

[0014] According to an exemplary embodiment of the present invention, the fused portion has an S-shaped or Z-shaped structure.

[0015] According to an exemplary embodiment of the present invention, the first housing is at least partially made of a transparent material.

[0016] This utility model also discloses a fusing element for a slow-blow fuse, characterized in that the fusing element includes: a pair of mounting portions; a fusing portion disposed between the pair of mounting portions and configured to connect the pair of mounting portions, wherein the fusing element includes: a slow-blow portion; and a weak area disposed adjacent to the slow-blow portion, which is configured to achieve fusing when the current is overloaded.

[0017] In the foregoing exemplary embodiments of this utility model, compared with the prior art, by providing a limiting part on the second housing, the fusible element is effectively limited when tightened by bolts, preventing the fusible element from twisting; by providing a supporting part to support the drooping fusible part after melting, the wall of the second housing is prevented from being burned or damaged; the housing is also provided with an assembly position to avoid interference from the nut, effectively improving the reliability, safety and service life of the fuse. In addition, the weak area provided on the fusible element can effectively control the melting position, ensuring the controllability and consistency of melting. Attached Figure Description

[0018] The features, advantages, and other aspects of the various embodiments of this utility model will become more apparent from the accompanying drawings and the following detailed description. Several embodiments of this utility model are shown herein by way of example and not limitation, in the drawings:

[0019] Figure 1 This is a schematic diagram of a slow-blow fuse according to an embodiment of the present invention;

[0020] Figure 2 This is an exploded view of a slow-blow fuse according to an embodiment of the present invention;

[0021] Figure 3 This is a schematic diagram of the fuse element structure of a slow-blow fuse according to an embodiment of the present invention;

[0022] Figure 4 This is a schematic diagram of the second housing structure of a slow-blow fuse according to an embodiment of the present invention;

[0023] Figure 5 This is a schematic diagram of the first housing structure of a slow-blow fuse according to an embodiment of the present invention. Detailed Implementation

[0024] The technical solution of this utility model will be further described in detail below through embodiments and in conjunction with the accompanying drawings. In this specification, the same or similar reference numerals indicate the same or similar components. The following description of the embodiments of this utility model with reference to the accompanying drawings is intended to explain the overall inventive concept of this utility model and should not be construed as a limitation thereof.

[0025] The terms “comprising,” “including,” and similar terms as used herein should be understood as open-ended terms, meaning “including / including but not limited to,” implying that other content may also be included. The term “based on” means “at least partially based on.” The term “one embodiment” means “at least one embodiment”; the term “another embodiment” means “at least one additional embodiment,” and so on.

[0026] Although the terms “first,” “second,” etc., may be used herein to describe a variety of different elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, without departing from the scope of this disclosure, a first element may be referred to as a second element, and a second element may be referred to as a first element. The term “and / or” includes a combination of multiple related items or any one of multiple related items.

[0027] As mentioned earlier, existing bolt-type slow-blow fuses generate lateral shear forces during bolt installation, which can easily cause the fuse element to rotate, deform, or even break. Secondly, the location of the fuse element's melting point is uncontrollable, making it difficult to control the area being melted, resulting in randomness in the melting location each time.

[0028] To address this problem, this invention proposes a slow-blow fuse and fuse element that can prevent the fuse element from twisting and effectively control the melting position, thereby improving the product performance. The following description uses an exemplary slow-blow fuse of this invention as an example.

[0029] Figure 1 A schematic diagram of a slow-blow fuse according to an embodiment of the present invention is shown; Figure 2 An exploded view of a slow-blow fuse according to an embodiment of the present invention is shown; Figure 3 A schematic diagram of the fuse element structure of a slow-blow fuse according to an embodiment of the present invention is shown. (Referring to...) Figures 1 to 4 The slow-blow fuse 100 includes a first housing 10, a second housing 20, and a fusing element 30 at least partially disposed between the first housing 10 and the second housing 20. The fusing element 30 includes a pair of mounting portions 31 and a fusing portion 32 disposed between the pair of mounting portions 31. The fusing portion 32 is configured to melt when there is an overload. When the fusing element 30 is fully assembled with the first housing 10 and the second housing 20, the fusing portion 32 is enclosed by the closed housing formed by the first housing 10 and the second housing 20. The pair of mounting portions 31 extend outward from both sides of the first housing 10 and the second housing 20, respectively, and are configured to mount the slow-blow fuse 100 to a load (not shown in the figure). The first housing 10 and the second housing 20 effectively prevent external dust, liquids, and other factors from contacting the fusing portion 32 and interfering with its performance, providing reliable protection for the fusing portion 32 and extending its service life.

[0030] In one embodiment, each of the pair of mounting portions 31 includes a mounting hole 311. The mounting hole 311 is configured to connect the slow-blow fuse 100 to a load (not shown) via a threaded connection, i.e., by screwing a bolt into the mounting hole 311 and securing it with a nut.

[0031] In one embodiment, the fuse portion 32 is provided with a slow-melting portion 321 and a weak region 322 adjacent to the slow-melting portion 321, and is configured such that when the current is overloaded, the fuse portion 32 is melted in the weak region 322. In one embodiment, the fuse portion 32 is made of copper; in another embodiment, the fuse portion 32 may also be made of other materials with good conductivity and a high melting point. In one embodiment, the slow-melting portion 321 may be a circular hole with a tin bead. Since the melting point of tin is lower than that of the fuse portion 32, it can prevent the fuse portion 32 from being accidentally melted under conditions of large instantaneous current, such as when the load is started. In another embodiment, the slow-melting portion 321 may also be made of other metals or alloys with lower melting points and better metallurgical compatibility.

[0032] When the current is overloaded, according to Joule's law, the continuous overload current causes the temperature of the fuse part 32 to rise, causing the solder ball in the slow melting part 321 to completely melt into liquid tin and penetrate into the fuse part 32. According to the metallurgical effect, this accelerates the melting of the fuse part 32 and cuts off the circuit to protect the load.

[0033] Because the weak point 322 is adjacent to the slow-blow section 321 and its width is smaller than the width of other areas on the fuse section 32, the weak point 322 will be preferentially melted compared to other areas on the fuse section 32. Therefore, when the current is overloaded, the slow-blow fuse 100 can precisely control the fuse section 32 to melt in the weak point 322. It is understood that the cross-sectional area of ​​the fuse section 32 can be adjusted according to different rated currents to ensure accurate and reliable melting.

[0034] In one embodiment, the fuse element 32 has an S-shaped or Z-shaped structure, which provides a longer current flow path compared to a straight or linear fuse element. This results in more uniform heat distribution, more controllable temperature rise, and a reduced likelihood of accidental melting. Secondly, the slow-blow fuse 100 is subjected to stress during installation. A linear fuse element is prone to breakage due to stress concentration at both ends of the mounting section. The S-shaped or Z-shaped fuse element 32 can disperse stress and is less likely to break when bolts or nuts are tightened, thereby improving the mechanical strength and fatigue resistance of the fuse element 32.

[0035] Figure 4 A schematic diagram of the second housing structure of a slow-blow fuse according to an embodiment of the present invention is shown; Figure 5 A schematic diagram of the first housing structure of a slow-blow fuse according to an embodiment of the present invention is shown. (Referring to...) Figures 1 to 5 The second housing 20 includes a recess 21 and a limiting part 22 disposed in the recess 21, wherein the limiting part 22 is configured to abut against the fusible element 30 to prevent the fusible element 30 from twisting when the slow-blow fuse 100 is assembled.

[0036] In one embodiment, each of the pair of mounting portions 31 includes a first side 312 located within the first housing 10 and the second housing 20, and a second side 313 extending outside the first housing 10 and the second housing 20 opposite to the first side 312. The limiting portion 22 includes a pair of limiting posts 221 respectively disposed diagonally at the countersink 21. Each of the pair of limiting posts 221 abuts against the first side 312 of the corresponding mounting portion in the pair of mounting portions 31. When the fusible element 30 is mounted on the second housing 20, the height of the limiting post 221 is slightly higher than the mounting plane of the fusible element 30. When the slow-blow fuse 100 is installed onto a load, the rotation of the bolts during installation and tightening may generate lateral shear forces, causing the fusible element 30 to twist and affecting its fusing performance. The limiting post 221 can effectively limit the fusible element 30, preventing the fusible element 30 from being twisted and the fusible part 32 from being twisted off when the slow-blow fuse 100 is installed with bolts, thereby improving the stability of the fusing performance and service life of the fusible element 30.

[0037] In one embodiment, the second housing 20 further includes a support portion 24 disposed in the sink 21, which is configured to support the fused portion 32 that has sagged due to melting, preventing the fused portion 32 from directly contacting the wall 212 at the bottom of the second housing 20 and damaging the second housing 20.

[0038] In one embodiment, the support portion 24 includes a raised rib 241. When the fuse element 30 is mounted on the second housing 20, the rib 241 is located below the fuse portion 32 in the fuse element 30. When the fuse element 30 is working normally, i.e., the current is not overloaded, there is a certain gap between the rib 241 and the fuse portion 32. When the current is overloaded, after the fuse element 30 is melted in the weak area 322, its fracture point is prone to sagging due to gravity. Since the rib 241 is located below the fuse portion 32, the sagging fracture point will first contact the rib 241. The fracture point has a high temperature at the moment of melting, and the rib 241 can absorb a certain amount of heat from the fracture point, thereby preventing the high-temperature fracture point from directly contacting the bottom wall 212 of the second housing 20 and burning the second housing 20, causing damage to the housing. In addition, the support portion 24 can also disperse the heat generated by the fuse portion 32 at the moment of melting, avoiding excessive local heating of the second housing 20, improving the service life of the second housing 20 and the safety of the overall structure.

[0039] In one embodiment, the first housing 10 includes a welded portion 14, and the second housing 20 includes a welded mating portion 25. The welded portion 14 and the welded mating portion 25 are fixed together by ultrasonic welding. Ultrasonic welding generates frictional heat through high-frequency vibration, melting and bonding the contact surfaces of the welded portion 14 and the welded mating portion 25. The first housing 10 and the second housing 20, after ultrasonic welding, can form a robust integral structure that remains stable during long-term use, is not easily loosened, and improves the assembly strength of the housing while providing good sealing performance.

[0040] In one embodiment, both the welding portion 14 and the welding mating portion 25 include at least one welding groove 42 and / or at least one welding protrusion 41.

[0041] In one embodiment, the welding protrusion 41 includes a welding block 411 and a welding post 412, and the welding groove 42 includes a welding groove seat 421 corresponding to the welding block 411 and a welding hole 422 corresponding to the welding post 412. In one embodiment, the welding block 411 and the welding groove seat 421 are disposed at the long side edges of the first housing 10 and the second housing 20, and the welding post 412 and the welding hole 422 are disposed at the short side edges of the first housing 10 and the second housing 20.

[0042] When assembling the slow-blow fuse 100, firstly, the fuse element 30 is placed on the second housing 20 by passing the welding post 412 on the second housing 20 through the through hole 33 located on a pair of mounting portions 31 in the fuse element 30. Secondly, the first housing 10 is covered onto the second housing 20 by passing the welding post 412 on the first housing 20 through the through hole 33 and inserting it into the welding hole 422 on the second housing 20, and by inserting the welding block 411 into the welding groove seat 412. Finally, the first housing 10 is welded to the second housing 20, wherein the welding post 412 of the first housing 10 is welded to the welding hole 422 of the second housing 20, and the welding block 411 of the first housing 10 is welded to the welding groove seat 421 of the second housing 20. At the same time, the welding post 412 of the second housing 20 is welded to the welding hole 422 of the first housing 10, and the welding block 411 of the second housing 20 is welded to the welding groove seat 421 of the first housing 10.

[0043] In one embodiment, the housing 100 is made of nylon material; in another embodiment, it may also be made of thermoplastic material with good insulation, abrasion resistance and high mechanical strength.

[0044] In one embodiment, the first housing 10 has a pair of first mounting positions 13 on both sides, and the second housing 20 has a pair of second mounting positions 23 on both sides that correspond spatially to the pair of first mounting positions 13 of the first housing 10. Both the first mounting positions 13 and the second mounting positions 23 are concave arc-shaped, which can prevent the nut from interfering with the first housing 10 and the second housing 20 during installation, thus avoiding local crushing and improving the service life of the first housing 10 and the second housing 20.

[0045] In one embodiment, the first housing 10 is at least partially made of a transparent material. During the use of the slow-blow fuse 100, the melting state of the internal fuse element 30 can be observed through the first housing 10, and the current overload situation can be determined.

[0046] In the foregoing exemplary embodiments of this utility model, compared with the prior art, by providing a limiting part in the second housing, the fusible element is effectively limited when tightened by bolts, preventing the fusible element from twisting; secondly, by providing a supporting part to support the drooping fusible part after melting, the wall of the second housing is prevented from being burned or damaged; and the housing is also provided with an assembly position to avoid interference from the nut, effectively improving the reliability, safety and service life of the fuse. In addition, the weak area provided on the fusible element near the slow melting part can effectively control the melting position, ensuring the controllability and consistency of melting.

[0047] The above description is merely an optional embodiment of the present utility model and is not intended to limit the embodiments of the present utility model. For those skilled in the art, the embodiments of the present utility model can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the embodiments of the present utility model should be included in the protection of the embodiments of the present utility model.

[0048] While embodiments of the present invention have been described with reference to several specific examples, it should be understood that the embodiments of the present invention are not limited to the specific embodiments disclosed. The embodiments of the present invention are intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. The scope of the appended claims is to be interpreted in the broadest sense, thereby encompassing all such modifications and equivalent structures and functions.

Claims

1. A slow-blow fuse, comprising: First shell; A second housing is fitted to and fixed to the first housing, the second housing including a recess and a limiting part disposed in the recess; A fusible element, disposed between the first housing and the second housing, includes: A pair of mounting portions extending outward from both sides of the first housing and the second housing, and configured to mount the slow-blow fuse to a load; A fuse element is located between the pair of mounting portions and is configured to fuse in the event of a current overload. The limiting portion is configured to abut against the fusible element to prevent the fusible element from twisting during the assembly of the slow-blow fuse.

2. The slow-blow fuse according to claim 1, characterized in that, Each of the pair of mounting portions includes a first side located inside the first housing and the second housing and a second side extending to the outside of the first housing and the second housing opposite to the first side. The limiting portion includes a pair of limiting posts respectively disposed at opposite corners of the settling tank. Each of the pair of limiting posts abuts against the first side of the corresponding mounting portion of the pair of mounting portions.

3. The slow-blow fuse according to claim 1, characterized in that, The second housing also includes a support portion disposed in the settling tank, which is configured to support the sag of the fused portion due to melting.

4. The slow-blow fuse according to claim 3, characterized in that, The supporting portion includes protruding ribs.

5. The slow-blow fuse according to claim 1, characterized in that, The fuse portion includes: It is equipped with a slow-melting section; and A weak zone is provided adjacent to the slow-melting section, which is configured to achieve melting when the current is overloaded.

6. The slow-blow fuse according to claim 1, characterized in that, The first housing includes a welded portion, and the second housing includes a welded mating portion, wherein the welded portion and the welded mating portion are fixed by ultrasonic welding.

7. The slow-blow fuse according to claim 6, characterized in that, Both the welded portion and the welded mating portion include at least one weld groove and / or at least one weld protrusion.

8. The slow-blow fuse according to claim 1, characterized in that, Both the first housing and the second housing have recessed mounting positions on both sides.

9. The slow-blow fuse according to claim 1, characterized in that, The fuse section has an S-shaped or Z-shaped structure.

10. The slow-blow fuse according to claim 1, characterized in that, The first housing is at least partially made of a transparent material.

11. A fusing element for a slow-blow fuse, characterized in that, The fusible element includes: A pair of installation parts; A fusible link, disposed between the pair of mounting portions and configured to connect the pair of mounting portions, includes: It is equipped with a slow-melting section; and A weak zone is provided adjacent to the slow-melting section, which is configured to achieve melting when the current is overloaded.

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