Fusing element and fuse

Abstract

The invention discloses a fuse element and a fuse, and belongs to the technical field of fuses. The invention relates to a fuse connector, which comprises a plurality of terminal units and a fusible unit, each terminal unit is provided with a main prong, an auxiliary prong and a gap arranged between the main prong and the auxiliary prong, the gap is used for inserting a male end of an opponent piece, the inner side wall of the main prong is at least provided with upper and lower raised contact points, and the upper and lower raised point positions of the main prong are matched with each other. The convex points are respectively corresponding to convex contact points at the upper part and the lower part of the auxiliary prongs, and each convex point is used for forming electrical contact with a male end inserted into the prong gap; the fusible unit is disposed between the plurality of terminal units, and when an overcurrent condition occurs, the fusible unit is disconnected to cause interruption of current flow between the plurality of terminal units. According to the invention, the problems of poor electric contact stability, contact point heating and finally function loss of the fuse caused by distortion or deformation of the contact point due to uneven stress during insertion operation can be effectively solved.

Description

Technical Field

[0001] The present invention mainly relates to the technical field of fuses, and in particular to a fuse element and a fuse. Background Art

[0002] In the electrical field, fuses are core components to ensure circuit safety. The reliability of their performance directly affects the stable operation of the entire electrical system. At present, fuses in automotive electrical fuse boxes are industry standard parts, mainly to ensure high and stable electrical contact. There are two existing solutions: one is to use a "tongue pressure piece" structure, which achieves electrical contact by pressing in a similar way to an elastic pressure piece, as shown in the attached manual. Figure 1 However, it has many disadvantages. From the perspective of mold manufacturing, the mold manufacturing of this type of product is extremely complicated; in terms of process stability, the performance is poor. The material will heat up during the working process, causing the elasticity of the tongue depressor to gradually weaken, indirectly causing severe heating of the electrical contact point, and ultimately causing the fuse to lose its function or significantly shorten its service life.

[0003] Another product is to provide a certain amount of material interference, similar to the instructions attached Figure 2 (It can be called "female end"), directly inserted into the male end. This type of product has a simple process, but the contact point is an asymmetric three-point contact. When inserted, the "female end" contact point is twisted or deformed, which indirectly leads to unstable electrical contact and heating of the contact point, resulting in loss of function or premature end of life.

[0004] In terms of connection stability, since electrical equipment is subject to various external forces such as vibration and impact during operation, and the three-point structure has a limited number of support points and weak resistance to external forces, the connection between the terminal and the male end is prone to loosening. This looseness will increase contact resistance, causing heat, arcing and other adverse phenomena, which will not only hinder the normal operation of the fuse, but in severe cases may also cause major electrical safety accidents such as fire, posing a great threat to the safety of equipment and personnel.

[0005] In terms of current carrying capacity, the cross-sectional area of ​​the existing terminal structure is relatively small, which will increase resistance and thus limit the current passing capacity. In high-current working scenarios, this structure is difficult to meet actual needs and is easily damaged by overheating, which not only reduces the reliability and service life of the fuse, but also increases the maintenance cost and downtime of the equipment, bringing many inconveniences to production and use.

[0006] From the current distribution point of view, the three-point structure has fewer contact points, resulting in a single and concentrated conduction path for the current on the terminal. Excessive local current density will accelerate the aging of the terminal material, adversely affecting its mechanical and electrical properties, and interfere with the fusing characteristics of the fuse, making it impossible to accurately and timely cut off the circuit when overloaded, which may eventually lead to equipment damage and production interruption, and have a negative impact on the company's production order and economic benefits.

[0007] In terms of heat dissipation performance, the existing terminal structure has a small contact area with the surrounding environment, which is not conducive to heat dissipation. When the fuse is working, especially when it is overloaded or running for a long time, heat is easily accumulated on the terminal, causing the terminal temperature to rise. High temperature will have an adverse effect on the electrical performance of the terminal, such as increasing contact resistance, while reducing the mechanical strength of the terminal and shortening its service life, thereby affecting the performance and stability of the entire fuse and reducing the reliability and safety of the electrical system.

[0008] For a long time, technicians in this field have often been stuck in a fixed mindset when it comes to designing and improving fuse terminals. When trying to improve the "tongue-pressing piece" structure, if you want to transform it into something similar to other existing structures, you need to re-evaluate the feasibility of the solution in all aspects, which involves a series of complex considerations from material selection, structural design to process implementation, and is extremely difficult.

[0009] For the three-point structure, for a long time, technicians in this field have mostly followed traditional ideas in the design of fuse terminals, such as the terminal pins and inclined wall design of the tuning fork terminal slow-blow fuse, the terminal gap gradient design of the tuning fork terminal slow fuse, etc. in the patent document publication No. KR1020110126157A, US20190371558A1 and CN102365701A, which mainly focus on optimizing the current capacity, strain relief and other performance by changing the shape, size or internal structure of the terminal. Under the influence of this traditional idea, technicians in this field mainly focus on the realization of the basic functions of the terminals, and pay insufficient attention to the comprehensive optimization of structural stability, electrical properties and thermal properties. When improving the terminal structure, it is often limited to local fine-tuning of the existing structure, and it is easy to improve in a similar direction, but it is difficult to consider other methods.

[0010] In the existing patent literature, although attention has been paid to the connection between the terminal and the outside, insufficient attention has been paid to the number and distribution of contact points and the uniformity of force and heat. Those skilled in the art may believe that the existing terminal structure design can meet the basic connection requirements, but have not thought deeply about how to further improve the stability and uniformity of the contact to avoid a series of problems caused by poor contact, such as local overheating, resistance fluctuations, and reduced service life.

[0011] In summary, the existing fuse terminal structure has many deficiencies in connection stability, current carrying capacity, current distribution uniformity, heat dissipation performance, compatibility with existing systems and comprehensive performance optimization. A new technical solution is urgently needed to solve these problems in order to improve the performance and reliability of the fuse and meet the needs of modern electrical systems, especially the stringent requirements for stability and safety of fuses in automotive electrical fuse boxes. Summary of the invention

[0012] The present invention aims to provide a fuse element and a fuse, which are mainly used to solve the following problems that occur in the application of existing fuses in automobile electrical fuse boxes: during the insertion operation, the "female end" contact point is twisted or deformed due to uneven force, resulting in poor electrical contact stability and heating of the contact point, which ultimately causes the fuse to lose function or terminate its service life prematurely.

[0013] In order to solve the above technical problems, the technical solution adopted by the present invention is: In the first aspect, the present invention provides a fuse element, which is mainly composed of a plurality of terminal units and fusible units. Each terminal unit is equipped with a main fork and a secondary fork, and a gap is provided between the two forks, and the gap is specifically used to insert the male end of the counterpart. The inner side wall of the fork is carefully provided with raised contact points at key positions, namely the upper and lower parts, and the positions of the upper and lower raised contact points of the main fork are precisely corresponding to the positions of the corresponding raised contact points of the secondary fork. This design is based on the principle of good electrical contact. When the male end is inserted into the gap, the raised contact point can fit closely with the male end to ensure a stable and reliable electrical connection, thereby achieving efficient conduction of current.

[0014] The fusible unit is cleverly placed between multiple terminal units, and it can ensure the smooth flow of current when the circuit is working normally. This is because its conductive arm is firmly connected to the terminal unit, and there is a transition section at the connection between the conductive arm and the terminal unit, and the cross-sectional area gradually increases toward the terminal unit.

[0015] This design is based on the characteristics of current transmission in the conductor, which can effectively reduce the concentration of current at the connection part, reduce the contact resistance, and allow the current to pass smoothly through the fusible unit. Once an overcurrent state occurs in the circuit, the fusible unit will quickly break the circuit, thereby effectively interrupting the current flow between multiple terminal units.

[0016] This is because the bridge section in the fusible unit will melt due to its own heating and the effect of the spherical diffusion part when overcurrent occurs. The bridge section is connected to the conductive arms on both sides and carries current under normal circumstances. However, when overcurrent occurs, the fusible parts in the spherical diffusion part on at least one side will melt first. The melting temperature of the fusible parts is lower than that of the bridge section. After melting, they flow into the bridge section. According to the principle of alloy melting point reduction, the melting point of the bridge section is reduced, thereby accelerating the fusing process, cutting off the circuit in time, and protecting the circuit safety.

[0017] In terms of specific structural parameters, the upper gap defined by the upper raised contact points of the main fork tine and the auxiliary fork tine is defined as L1, and the lower gap defined by the lower raised contact points is defined as L2, wherein the lower gap L2 is less than the upper gap L1, and the absolute value of the difference between the lower gap L2 and the upper gap L1 is carefully designed to be between 0.03mm and 0.08mm. This gap design has an important technical effect. When the male end is inserted, the lower gap L2 first contacts the male end and opens the angle, and then contacts the upper gap L1. The lower gap L2 is slightly smaller than the upper gap L1, which can provide a stable 4-point contact to avoid loose clamping and twisting or deformation of the contact point. The lower gap L2 is small, providing a stable clamping force to ensure good contact pressure between the male end and the fork tine, thereby achieving a reliable electrical connection.

[0018] The upper raised contact point of the fork tine is smoothly connected to the lower raised contact point through two inclined sections. The two inclined sections not only play a connecting role, but also constitute the key part of increasing the cross-sectional area in the terminal unit together with the upper raised contact point and the lower raised contact point.

[0019] From the perspective of electrical principles, according to the law of resistance, an increase in cross-sectional area can effectively reduce resistance. Therefore, in a circuit, lower resistance means that at the same voltage, the terminal can carry a larger current, thereby improving the fuse's ability to operate in a high current environment.

[0020] The angle between the two inclined sections has been precisely calculated and optimized, and its degree range is determined to be 150° to 160°. This angle design is conducive to the insertion and contact of the male end while ensuring structural stability. When the male end is inserted, this angle range can play a good guiding role in the insertion of the male end, allowing the male end to enter between the fork teeth in a specific direction, reducing resistance and deviation during the insertion process, and making the insertion operation smoother and more accurate.

[0021] The right angle can also form a larger contact area between the male end and the fork tines, further reducing the contact resistance and improving the reliability of electrical contact on the basis of four-point contact. At the same time, the larger contact area also helps to disperse the current and reduce the possibility of local overheating.

[0022] In addition, the angle design of the fork tines cooperates with the overall structure to enhance the stability of the fusible element (that is, the fuse structure). When subjected to external forces, the angle design enables the fork tines to better withstand and disperse the force, reducing the risk of deformation. Moreover, the angle design can also affect the elasticity of the fork tines, so that they can produce appropriate elastic deformation after being inserted into the male end, providing a certain buffer and self-adaptation ability, and further ensuring the stability and reliability of the contact.

[0023] The structural design of the fusible unit is also unique. It contains multiple conductive arms and multiple bridge sections. Each conductive arm is specially configured to be tightly and firmly connected to a terminal unit to ensure efficient transmission of current between the terminal unit and the fusible unit. Each bridge section is connected to a conductive arm on both sides. Under normal current conditions, the bridge section can stably carry current; under overcurrent conditions, the bridge section will quickly fuse, thereby reliably interrupting the current flow between the terminal units on both sides and realizing the protection function of the circuit.

[0024] In some achievable methods of the first aspect, at least one side of the bridge section is provided with a spherical diffuser, the spherical diffuser includes an easily fusible component, the melting temperature of which is lower than the melting temperature of the bridge section. When an overcurrent occurs, the easily fusible component will melt first and quickly flow into the bridge section, greatly accelerating the fusing process of the bridge section and significantly improving the response speed of the fuse. The diameter of the spherical diffuser is larger than the width of the bridge section, and this design helps to enhance its role in promoting the fusing of the bridge section; and the spherical diffusers can be symmetrically arranged on both sides of the bridge section to further optimize the fusing effect.

[0025] In some achievable embodiments of the first aspect, the spherical diffuser is composed of two detachable hemispherical parts, which is convenient for operation and replacement during manufacturing and maintenance; at the same time, the spherical diffuser is cleverly arranged at the curved part, one end of which is connected to the bridging section and the other end is connected to the conductive arm. This structural design can effectively guide the flow of current and improve the overall performance of the fusible unit.

[0026] In some achievable embodiments of the first aspect, a transition section is provided at the connection portion between the conductive arm and the terminal unit, and the cross-sectional area of ​​the transition section gradually increases from the side away from the terminal unit toward the terminal unit. This gradual design can effectively reduce the concentration of current at the connection portion, reduce contact resistance, and improve current transmission efficiency.

[0027] In addition, the terminal unit has a thickness of d1, the fusible unit has a thickness of d2, and d2<d1. This thickness difference design is beneficial to heat dissipation and optimization of fusing characteristics while ensuring structural strength.

[0028] In some achievable embodiments of the first aspect, the tine includes an inclined wall segment extending from an upper raised contact point to the arc portion, and a gap between the main tine and the secondary tine extends to the arc portion. This structural design enables the male end to contact the tine more smoothly during insertion, thereby improving the stability and reliability of the connection.

[0029] Generally, the fuse element includes a first terminal unit and a second terminal unit, which have the same structure and are symmetrically distributed. The first terminal unit has a first main fork and a first secondary fork, which have the same structure and are symmetrically distributed; the inner side wall of the first main fork is provided with a first main upper contact point and a first main lower contact point, and the inner side wall of the first secondary fork is provided with a first secondary upper contact point and a first secondary lower contact point. This symmetrical structural design can improve stability while ensuring uniform distribution of current on the terminal unit.

[0030] From the perspective of mechanics, according to the theory of force balance and structural stability in statics, the multi-point support structure can provide more constraints, thereby enhancing the overall stability. In three-dimensional space, four points can determine a unique plane, and can effectively resist translation and rotation in all directions within this plane. When external force acts on the terminal, the four-point structure can form a stable force system through the reaction force of each contact point, so that the terminal remains in a balanced state, reducing the possibility of displacement and deformation. At the same time, due to the existence of symmetry, the force borne by each contact point is equal under ideal conditions, which further ensures the uniformity of force and conforms to the principle of mechanical structure optimization.

[0031] In a second aspect, the present invention provides a fuse comprising a shell and a fuse element arranged inside the shell, the shell having a generally rectangular or box-shaped outline, which can provide a completely enclosed protective environment for the fuse element and effectively prevent external factors from interfering with the fuse element.

[0032] In some achievable embodiments of the second aspect, a notch is provided on the housing at a position corresponding to the fork tine, the notch corresponds precisely to the fork tine gap, and the upper and lower raised contact points of the fork tine are both located within the notch, ensuring that the male end can accurately contact the fork tine. The housing is composed of a first part and a second part, and the first part and the second part are detachably connected, so as to facilitate operation of internal components of the fuse during manufacturing, installation and maintenance.

[0033] In summary, the fuse element and the fuse of the present invention have achieved remarkable technical effects in terms of electrical connection stability, current carrying capacity, overcurrent protection performance, compatibility with different male terminals, reliability of the overall structure and convenience of maintenance through unique structural design and parameter optimization, and can effectively meet the high performance requirements of modern electrical systems for fuses.

[0034] Compared with the prior art, the present invention has the following beneficial effects: (1) The fuse element of the present invention adopts a symmetrical design. For example, the first terminal unit and the second terminal unit have the same structure and are symmetrically distributed. When current passes through, the forces on both sides are basically the same. Under the action of external forces such as electromagnetic force, the symmetrical structure can offset some of the forces, reduce the deformation or displacement of components caused by uneven force, enhance the overall stability, ensure normal operation under various working conditions, and improve reliability and service life; (2) The present invention forms a four-point contact with the male end through the upper and lower raised contact points of the main fork tines and the auxiliary fork tines. Compared with the traditional single-point or two-point contact, it can provide more contact points, make the current distribution more uniform, reduce the current density of a single contact point, thereby reducing the contact resistance and heat generation, and greatly improve the stability and reliability of the contact; (3) In the present invention, the upper raised contact point of the fork tine is connected to the lower raised contact point by two inclined sections at a specific angle (150°-160°), which together constitute a portion with an increased cross-sectional area. According to the resistance law, the resistance is reduced, so that the terminal can carry a larger current at the same voltage, thereby improving the working ability of the fuse in a high current environment; (4) The four-point contact in the present invention provides more conduction paths for the current, and the cross-section gradient design of the transition section (such as the first transition section and the second transition section) at the connection between the conductive arm in the fusible unit and the terminal unit can reduce the current concentration phenomenon, further improve the current transmission efficiency, and ensure the stable and efficient conduction of the current between the components; (5) When an overcurrent occurs in the bridge section of the fusible unit, the fusible components in the spherical diffusion parts on both sides (such as the first spherical diffusion part and the second spherical diffusion part) melt first and flow into the bridge section, thereby lowering the melting point of the bridge section, accelerating the fusing process, and significantly improving the response speed of the fuse, which can cut off the circuit in time and effectively protect the circuit safety; (6) The upper gap L1 defined by the upper raised contact points of the main fork tine and the auxiliary fork tine is larger than the lower gap L2 defined by the lower raised contact points, and the absolute value of the difference between L2 and L1 is between 0.03 mm and 0.08 mm. When the male end is inserted, the lower gap L2 first contacts the opening angle and then contacts the upper gap L1. The lower gap L2 is slightly smaller than the upper gap L1, which can provide a stable four-point contact to avoid loose clamping.

[0035] The present invention will be explained in detail below with reference to the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 The structure of the "tongue-pressing piece" fuse in the fuse box of automobile electrical appliances in the prior art is demonstrated; Figure 2The structure of a three-point fuse in a fuse box of an automobile electrical appliance in the prior art is presented; Figure 3 This is a schematic diagram of the three-dimensional structure of the fuse element in the embodiment of the present invention. This figure shows the complete structure of the fuse element involved in the present invention from a three-dimensional perspective, and clearly presents the spatial position relationship and appearance characteristics of its various parts; Figure 4 yes Figure 3 Schematic diagram of the main structure; Figure 5 yes Figure 3 Schematic diagram of the left view structure; Figure 6 yes Figure 3 Schematic diagram of the structure viewed from above; Figure 7 yes Figure 3 A schematic diagram of a top view structure; Figure 8 The structure in which the fuse element is placed in the fuse housing in the embodiment of the present invention is presented. This figure can clearly show the installation position and layout relationship of the fuse element in the fuse housing, and is an intuitive expression of the assembly relationship between the fuse element and the fuse housing of the present invention; Fig. 9 yes Figure 8 The schematic diagram of the front view structure shows the structure in which the fuse element is placed in the fuse housing from the front view angle; Fig.10 Schematic diagram of the main structure of the fuse in the embodiment of the present invention.

[0037] Description of Figure Numbers: 100. Fuse element; 1. fusible unit; 11. bridge section; 2. first spherical diffusion section; 3. second spherical diffusion section; 21. first curved section; 31. second curved section; 121. first transition section; 131. second transition section; 4. first terminal unit; 41. first position-limiting portion; 411. first arc portion; 42. first main fork tine; 42a. first main upper contact point; 42b. first main lower contact point; 421. first main extension end; 422. first upper inclined wall section; 423. first lower inclined wall section; 43. first secondary fork tine; 43a. first secondary upper contact point; 43b. first secondary lower contact point; 431. first secondary extension end; 44. first fork tine gap; 45. first recess; 5. second terminal unit; 51. second position-limiting portion; 511. second arc portion; 52. second main fork tine; 52a. second main upper contact point; 52b. second main lower contact point; 521. second main extension end; 522. second upper inclined wall section; 523. second lower inclined wall section; 53. second secondary fork tine; 53a. second secondary upper contact point; 53b. second secondary lower contact point; 531. second secondary extension end; 54. second fork tine gap; 55. second recess; 200, shell; 201, first notch; 202, second notch. DETAILED DESCRIPTION

[0038] To facilitate understanding of the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings. Several embodiments of the present invention are given in the drawings, but the present invention can be implemented in different forms and is not limited to the embodiments described in the text. On the contrary, these embodiments are provided to make the content disclosed in the present invention more thorough and comprehensive.

[0039] It should be noted that when an element is referred to as being "fixed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used in this article are for illustrative purposes only.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly connected by technicians in the technical field to which the present invention belongs. The terminology used in the specification of the present invention is for the purpose of describing specific embodiments and is not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0041] Embodiment: The embodiment of the present invention provides a fuse element 100 , which is mainly composed of a first terminal unit 4 , a second terminal unit 5 and a fusible unit 1 .

[0042] The first terminal unit 4 includes a first position-limiting portion 41, which is connected to a first arc portion 411, and the first arc portion 411 is further connected to a first main fork tine 42 and a first secondary fork tine 43. The inner side wall of the first main fork tine 42 is provided with a first main upper contact point 42a and a first main lower contact point 42b, and is connected to the first main extension end 421 through a first upper inclined wall section 422 and a first lower inclined wall section 423, wherein the first upper inclined wall section 422 extends from the first main upper contact point 42a to the first arc portion 411, and the first lower inclined wall section 423 extends from the first main lower contact point 42b to the first arc portion 411, and a first fork tine gap 44 is formed between the first main fork tine 42 and the first secondary fork tine 43, and the first fork tine gap 44 extends to the first arc portion 411, and a first recess 45 is provided on the outer side of the first main fork tine 42 and the first secondary fork tine 43.

[0043] The inner side wall of the first secondary fork tine 43 is provided with a first secondary upper contact point 43a and a first secondary lower contact point 43b, which have the same structure as the first main fork tine 42 and are symmetrically distributed, and are also connected to the first secondary extension end 431 through the corresponding inclined wall section, and the two together constitute a structure for inserting the male end of the counterpart. When the male end is inserted, the first main upper contact point 42a, the first main lower contact point 42b, the first secondary upper contact point 43a and the first secondary lower contact point 43b can fit closely with the male end to form a stable electrical contact to ensure effective conduction of current.

[0044] In the manufacturing process of the fuse element 100, for the terminal unit, we use a high-precision stamping process to ensure that the mold accuracy is controlled within ±0.01mm. Taking the first terminal unit 4 as an example, the design of its first main fork tine 42 and the first secondary fork tine 43 is strictly followed. The height difference between the first main upper contact point 42a of the first main fork tine 42 and the first secondary upper contact point 43a of the first secondary fork tine 43 is stable within 0.05mm, and the surface roughness of these raised points reaches below Ra0.8, which enables a tight fit when in contact with the male end, effectively reducing the contact resistance and ensuring the stable conduction of current. The connection between the inclined section of the fork tine and the raised point adopts a special fillet transition process with a fillet radius of 0.2mm, which effectively avoids stress concentration and greatly enhances the stability of the structure.

[0045] The second terminal unit 5 has the same structure as the first terminal unit 4, and has a second limiting portion 51, a second arc portion 511, a second main fork tooth 52, a second secondary fork tooth 53, a second main upper contact point 52a, a second main lower contact point 52b, a second secondary upper contact point 53a, a second secondary lower contact point 53b, a second main extension end 521, a second secondary extension end 531, a second fork tooth gap 54 and a second recess 55. The positional relationship and function of each part are similar to those of the corresponding parts of the first terminal unit 4. The symmetrical distribution of the two not only ensures the uniform distribution of current on the terminal unit, but also enhances the stability of the overall structure.

[0046] The fusible unit 1 includes a plurality of conductive arms, each of which is firmly connected to a terminal unit, and a transition section is provided at the connection between the conductive arm and the terminal unit, such as a first transition section 121 and a second transition section 131. The cross-sectional area of ​​these transition sections gradually increases from the side away from the terminal unit toward the terminal unit. This design is based on the characteristics of current transmission in the conductor, and can effectively reduce the concentration of current at the connection part, reduce the contact resistance, and thus ensure the efficient transmission of current between the terminal unit and the fusible unit 1.

[0047] Furthermore, in this embodiment, the fusible unit 1 also includes a plurality of bridge sections 11, and the two sides of each bridge section 11 are respectively connected to a conductive arm. Under normal current conditions, the bridge section 11 can stably carry current; and under overcurrent conditions, the bridge section 11 will quickly melt, reliably interrupting the current flow between the terminal units on both sides, thereby realizing the circuit protection function. At least one side of the bridge section 11 is provided with a spherical diffusion portion, such as a first spherical diffusion portion 2 and a second spherical diffusion portion 3, and the spherical diffusion portion includes a fusible component, and its melting temperature is lower than the melting temperature of the bridge section 11.

[0048] When an overcurrent occurs, the easily fusible parts melt first and quickly flow into the bridge section 11. Based on the principle of alloy melting point reduction, the fusing process of the bridge section 11 is greatly accelerated, the response speed of the fuse is significantly improved, and the equipment is protected. The diameter of the spherical diffuser is larger than the width of the bridge section 11, and the spherical diffusers can be symmetrically arranged on both sides of the bridge section 11 to further optimize the fusing effect.

[0049] Specifically, the bridge section is made of copper alloy, and the spherical diffuser set on one side thereof is embedded with an easily fusible component. The spherical diffuser is composed of two detachable hemispheres with a manufacturing accuracy controlled within ±0.02mm. After assembly, its diameter is 0.5mm~1.0mm larger than the width of the bridge section.

[0050] The spherical diffuser is composed of two detachable hemispherical parts, which is convenient for operation and replacement during manufacturing and maintenance; at the same time, the spherical diffuser is arranged at the curved part, such as the first curved part 21 and the second curved part 31, one end of the curved part is connected to the bridging section 11, and the other end is connected to the conductive arm. This structural design can effectively guide the flow of current and improve the overall performance of the fusible unit 1.

[0051] In terms of the fork tooth structure, the upper gap defined by the upper raised contact points of the main fork teeth and the secondary fork teeth is L1, such as the gap defined by the first main upper contact point 42a of the first main fork tooth 42 and the first secondary upper contact point 43a of the first secondary fork tooth 43, and the lower gap defined by the lower raised contact points of the main fork teeth and the secondary fork teeth is L2, such as the gap defined by the first main lower contact point 42b of the first main fork tooth 42 and the first secondary lower contact point 43b of the first secondary fork tooth 43, wherein the lower gap L2 is less than the upper gap L1, and the absolute value of the difference between the lower gap L2 and the upper gap L1 is between 0.03mm and 0.08mm.

[0052] When inserting the male end of the handpiece, the lower gap L2 first contacts the opening angle and then contacts the upper gap L1. The lower gap L2 is slightly smaller than the upper gap L1, which can provide a stable 4-point contact to avoid loose clamping. The lower gap L2 is small, providing a stable clamping force to ensure good contact pressure between the male end and the fork teeth, thereby achieving a reliable electrical connection.

[0053] The upper protrusion point and the lower protrusion point of the fork tine are connected by two inclined sections, such as the first upper inclined wall section 422 and the first lower inclined wall section 423 of the first main fork tine 42. The two inclined sections not only play a connecting role, but also together with the upper protrusion point and the lower protrusion point constitute the part with increased cross-sectional area in the terminal unit. According to the law of resistance, the increase in cross-sectional area can effectively reduce the resistance, so that the terminal can carry a larger current under the same voltage, thereby improving the working ability of the fuse in a high current environment.

[0054] The angle formed by the two inclined sections is in the range of 150° to 160°. This angle design has a positive effect on the insertion and contact of the male end while ensuring the stability of the structure. During the insertion of the male end, this angle range can guide the male end to enter between the fork teeth along a specific direction, reduce the resistance and deviation during insertion, and make the insertion operation smoother and more accurate. The appropriate angle can also promote the formation of a larger contact area between the male end and the fork teeth, further reducing the contact resistance and improving the reliability of electrical contact on the basis of four-point contact. At the same time, the larger contact area helps to disperse the current and reduce the possibility of local overheating.

[0055] In addition, the angle design of the fork tines cooperates with the overall structure to enhance the stability of the fuse element 100. When subjected to external force, the angle design enables the fork tines to better withstand and disperse the force, reduce the risk of deformation, and affect the elasticity of the fork tines, so that they can produce appropriate elastic deformation after being inserted into the male end, provide a certain buffer and self-adaptation ability, and further ensure the stability and reliability of the contact.

[0056] The fuse includes a housing 200, which is made of engineering plastics resistant to high temperatures and having good insulation properties and is manufactured through an injection molding process. The housing 200 has a generally rectangular or box-shaped profile, which can provide a completely enclosed protective environment for the fuse element 100 and effectively prevent external factors from interfering with the fuse element 100. On the housing 200, gaps are provided at positions corresponding to the fork teeth, such as a first gap 201 and a second gap 202, so as to receive the terminals. The first gap 201 corresponds to the upper gap L1 and the lower gap L2 of the first terminal unit 4, the second gap 202 corresponds to the upper gap L1 and the lower gap L2 of the second terminal unit 5, and the upper and lower protrusions of the fork teeth of the first terminal unit 4 and the second terminal unit 5 are both located in the corresponding gaps, ensuring that the male end can accurately contact the fork teeth.

[0057] The housing 200 is composed of a first part and a second part, and the first part and the second part are detachably connected, so as to facilitate operation of the internal components of the fuse during manufacturing, installation and maintenance. It is understandable that in some feasible embodiments, the housing 200 can be composed of multiple parts, and the multiple parts can be matched together by thermal bonding or other forced methods.

[0058] From the temperature distribution simulation data results of the fuse under different current conditions, it can be seen that under relatively stable operating conditions, when the fuse element in the embodiment of the present invention is in rated operation, the temperature of the contact point is close to the ambient temperature. Taking the 10A current as an example, the contact point temperature is 24.4773K, which indicates that the thermal stability at the contact point is good and the heating phenomenon at the contact point is weak. Due to the low heat, the oxidation degree of the contact point will be very light, which has a positive effect on extending the service life of the product.

[0059] When the fuse encounters a large current (such as an impact current), that is, when the current passing through reaches more than 1 times the rated current of the fuse element (for example, 60A or 80A), the main heating points are concentrated in the fuse part. Although such a large current lasts for a short time, basically within 1 second, the temperature of the fuse part rises rapidly. Taking the case of a 60A current, the temperature at the fuse position is as high as 144.574k, while the contact point temperature (76.2501k) is much lower than the softening temperature of the material. From the comparison of simulation data under various current conditions, the heating points are always mainly concentrated in the fuse part, and its temperature is far higher than the contact point temperature. In this case, the contact point is limitedly affected by the large current, and has little effect on the oxidation degree and contact stability of the product, thereby ensuring the stability of product quality and helping to improve the service life of the product.

[0060] Working principle: Under normal working conditions, current flows from the external circuit through the male end of the counterpart into the fuse element 100, first through the contact points between the fork teeth of the first terminal unit 4 and the second terminal unit 5 and the male end (such as the first main upper contact point 42a, the first main lower contact point 42b, the first secondary upper contact point 43a, the first secondary lower contact point 43b, etc.), and then flows into the bridge section 11 of the fusible unit 1 through the conductive arm (with the help of transition sections such as the first transition section 121 and the second transition section 131 to achieve efficient transmission), and then evenly conducts to the fuse body (including the relevant parts of the first terminal unit 4 and the second terminal unit 5). Since the fuse has a certain resistance, heat will be generated when the current flows in the fuse body, but within the normal current range, the generated heat can be dissipated in time and the fuse will not melt.

[0061] When the circuit is overloaded or short-circuited, the current increases sharply, and the resistance heating effect of the fuse body (especially the first main upper contact point 42a, the first main lower contact point 42b, the first auxiliary upper contact point 43a, the first auxiliary lower contact point 43b and other parts) is significantly enhanced, and heat accumulates rapidly. Since the resistance in a narrow area is relatively large, the heat is concentrated faster. When the temperature reaches the melting point of the fuse, these parts are melted first, thereby cutting off the circuit, preventing excessive current from damaging the circuit and equipment, and realizing the protection function.

[0062] Under the overcurrent state, the fusible components in the spherical diffusion parts (such as the first spherical diffusion part 2 and the second spherical diffusion part 3) on both sides of the bridge section 11 in the fusible unit 1 melt first. Because their melting temperature is lower than that of the bridge section 11, they flow into the bridge section 11 after melting, which reduces the melting point of the bridge section 11, thereby accelerating the fusing process and ensuring that the circuit is cut off in time.

[0063] During the insertion of the male end, the male end first contacts the lower gap L2 defined by the lower raised contact point. The lower gap L2 first contacts the opening angle and then contacts the upper gap L1. The lower gap L2 is slightly smaller than the upper gap L1, which can provide a stable 4-point contact. The lower gap L2 is small, providing clamping force to ensure that the male end is in close contact with the fork teeth and achieve a stable electrical connection. The 150° to 160° angle design of the fork teeth guides the insertion direction of the male end, reduces resistance and deviation, increases the contact area, reduces contact resistance, disperses current, enhances structural stability and elastic deformation capacity, and ensures contact reliability.

[0064] In summary, the fuse element 100 and the fuse of the present invention have achieved remarkable technical effects in terms of electrical connection stability, current carrying capacity, overcurrent protection performance, compatibility with different male terminals, reliability of the overall structure and convenience of maintenance, etc., by virtue of their unique structural design and parameter optimization, and can effectively meet the high performance requirements of modern electrical systems for fuses.

[0065] The above is an exemplary description of the present invention in combination with the accompanying drawings. It is obvious that the specific implementation of the present invention is not limited to the above-mentioned method. As long as such non-substantial improvements are made by adopting the method concept and technical solution of the present invention, or the concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A fuse element, characterized in that: include: A plurality of terminal units, each of which has a main tine and a secondary tine, and a gap arranged between the main tine and the secondary tine, the gap being used to insert the male end of the counterpart, the inner side wall of the tine having at least upper and lower raised contact points, and the positions of the upper and lower raised contact points of the main tine respectively correspond to the positions of the upper and lower raised contact points of the secondary tine, and each of the raised contact points is used to form an electrical contact with the male end inserted into the tine gap; and The fusible unit (1) is arranged between the plurality of terminal units. When an overcurrent state occurs, the fusible unit (1) is disconnected, causing the current flow between the plurality of terminal units to be interrupted.

2. The fuse element according to claim 1, characterized in that The upper gap defined by the upper protruding contact points of the main fork tine and the auxiliary fork tine is L1, and the lower gap defined by the lower protruding contact points of the main fork tine and the auxiliary fork tine is L2, wherein the lower gap L2 is less than the upper gap L1.

3. The fuse element according to claim 2, characterized in that: The absolute value of the difference between the lower gap L2 and the upper gap L1 is between 0.03 mm and 0.08 mm.

4. The fuse element according to claim 1, characterized in that: The upper raised contact point and the lower raised contact point of the fork tine are connected via two inclined sections; The inclined section, together with the upper raised contact point and the lower raised contact point, respectively, constitutes a portion of the terminal unit with an increased cross-sectional area.

5. The fuse element according to claim 4, characterized in that: The angle formed between the two inclined sections ranges from 150° to 160°.

6. The fuse element according to claim 1, characterized in that: The fusible unit (1) comprises: a plurality of conductive arms, each conductive arm being configured to be connected to a terminal unit; A plurality of bridge sections (11), both sides of each bridge section (11) are respectively connected to a conductive arm, and in an overcurrent state, the bridge section (11) is fused to interrupt the current flow between the terminal units on both sides.

7. The fuse element according to claim 6, characterized in that: At least one side of the bridge section (11) has a spherical diffusion portion, and the spherical diffusion portion includes an easily fusible component, the melting temperature of the easily fusible component is lower than the melting temperature of the bridge section (11), and when an overcurrent state occurs, the easily fusible component melts first and flows into the bridge section (11), thereby accelerating the fusing of the bridge section (11).

8. The fuse element according to claim 7, characterized in that: The diameter of the spherical diffusion portion is greater than the width of the bridging section (11); and / or, spherical diffusers are symmetrically arranged on both sides of the bridge section (11); And / or, the spherical diffuser is composed of two detachable hemispherical parts; And / or, the spherical diffusion portion is arranged at a curved portion, and one end of the curved portion is connected to the bridging section (11), and the other end is connected to the conductive arm.

9. The fuse element according to claim 6, characterized in that: A transition section is provided at the connection position between the conductive arm and the terminal unit, and the cross-sectional area of ​​the transition section gradually increases from the side away from the terminal unit toward the terminal unit.

10. The fuse element according to claim 1, characterized in that The terminal unit has a thickness d1, the fusible unit (1) has a thickness d2, and d2<d1.

11. The fuse element according to claim 1, characterized in that: The tine includes an inclined wall section extending from the upper raised contact point to the arc portion, and the gap between the primary tine and the secondary tine extends to the arc portion.

12. The fuse element according to any one of claims 1 to 11, characterized in that: include: A first terminal unit (4) and a second terminal unit (5), both having the same structure; The first terminal unit (4) has a first main fork tooth (42) and a first auxiliary fork tooth (43), which have the same structure and are symmetrically distributed; The inner side wall of the first main fork tine (42) is provided with a first main upper contact point (42a) and a first main lower contact point (42b), and the inner side wall of the first secondary fork tine (43) is provided with a first secondary upper contact point (43a) and a first secondary lower contact point (43b).

13. A fuse, characterized in that: include: A housing (200) and a fuse element (100) arranged inside the housing (200), wherein the fuse element (100) is as claimed in any one of claims 1 to 12.

14. The fuse according to claim 13, characterized in that The housing (200) has a generally rectangular or box-shaped profile, and the rectangular or box-shaped profile is used to completely enclose the fuse element (100); And / or, a notch is provided on the housing (200) at a position corresponding to the fork tine, the notch corresponds to the gap between the fork tine, and the upper and lower protrusions of the fork tine are both located in the notch.

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