A fusing element and a fuse

Abstract

The present invention discloses a fusing element and a fuse, belonging to the technical field of fuses. It includes a plurality of terminal units and a fusible unit. Each terminal unit has a main fork tooth and a secondary fork tooth, and a gap arranged between the two. The gap is used for inserting the male end of a mating part. The inner side wall of the main fork tooth has at least upper and lower raised contact points, and the positions of the upper and lower raised points of the main fork tooth respectively correspond to the positions of the upper and lower raised contact points of the secondary fork tooth. Each raised point is used to form an electrical contact with the male end inserted into the fork tooth gap; the fusible unit is arranged between the plurality of terminal units. When an overcurrent state occurs, the fusible unit opens the circuit, causing an interruption in the current flow between the plurality of terminal units. The present invention can effectively solve the problems that during the insertion operation, due to uneven force, the contact points are distorted or deformed, resulting in poor electrical contact stability, heat generation at the contact points, and ultimately the loss of the fuse function.

Description

Technical Field

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

[0002] In the electrical field, as a core component to ensure circuit safety, the performance of a fuse directly affects the stable operation of the entire electrical system. Currently, the fuses in automotive electrical fuse boxes are industry standard parts, mainly ensuring high and stable electrical contact. There are two existing solutions: one is the "pressing tongue piece" structure, which realizes electrical contact by means of pressing similar to an elastic pressing piece, as shown in the attached Figure 1 description. However, it has many drawbacks. From the perspective of mold manufacturing, the molds for such products are extremely complex; in terms of process stability, it performs poorly. During operation, the material will heat up, causing the elasticity of the pressing tongue piece to gradually weaken, indirectly leading to serious heating of the electrical contact point, ultimately causing the fuse function to be lost or significantly shortening the service life.

[0003] The other product provides a certain material interference, similar to the attached Figure 2 description (which can be called the "female end") and directly inserts it into the male end. This type of product has a simple process, but the contact point is an asymmetric three-point contact. When inserting, the contact points of the "female end" are distorted or deformed, indirectly resulting in unstable electrical contact and heating of the contact points, which may cause the function to be lost or the life to end prematurely.

[0004] In terms of connection stability, since electrical equipment will be subjected to various external forces such as vibration and impact during operation, and due to the limited number of support points of the three-point structure, its resistance to external forces is weak, and it is extremely easy for the connection between the terminal and the male end to become loose. This looseness will increase the contact resistance, causing adverse phenomena such as heating and arcing, which not only hinders the normal operation of the fuse, but may also cause major electrical safety accidents such as fires in severe cases, 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 the resistance and thus limit the current-carrying capacity. In the scenario of high-current operation, this structure is difficult to meet the actual requirements and is easily damaged due to overheating. This 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 perspective of current distribution, the three-point structure has fewer contact points, resulting in a single and concentrated conduction path of current on the terminal. The excessive local current density will accelerate the aging of the terminal material, have an adverse impact on its mechanical and electrical properties, and at the same time interfere with the fusing characteristics of the fuse, making it unable to accurately and timely cut off the circuit during overload, which may ultimately lead to equipment damage and production interruption, causing negative impacts on the production order and economic benefits of the enterprise.

[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 works, especially in the state of overload or long-term operation, heat is extremely easy to accumulate on the terminal, causing the terminal temperature to rise. High temperature will have an adverse impact on the electrical performance of the terminal, such as increasing the contact resistance, and at the same time reducing the mechanical strength of the terminal and shortening its service life, thus affecting the performance and stability of the entire fuse and reducing the reliability and safety of the electrical system.

[0008] For a long time, those skilled in the art have often fallen into a mindset in the design improvement of fuse terminals. When trying to improve the "tongue piece" structure, if it is to be transformed into a structure similar to other existing ones, it is necessary to re-evaluate the feasibility of the solution comprehensively, which involves a series of complex considerations from material selection, structural design to process implementation, and the difficulty is extremely high.

[0009] For the three-point structure, for a long time, those skilled in the art have mostly followed traditional ideas in the design of fuse terminals. For example, in patent documents with publication numbers KR1020110126157A, US20190371558A1, and CN102365701A, such as the terminal pin and inclined wall design of a tuning fork terminal slow-blow fuse, and the design of gradually changing the terminal gap of a tuning fork terminal slow fuse, etc., mainly focus on optimizing performance such as current capacity and strain relief by changing the shape, size or internal structure of the terminal. Under the influence of this traditional idea, those skilled in the art mainly focus on the realization of the basic functions of the terminal, and pay insufficient attention to the comprehensive optimization of structural stability, electrical performance and thermal performance. When improving the terminal structure, they are often limited to local fine-tuning of the existing structure, and are prone to improving along similar directions, and it is very difficult to consider other ways.

[0010] In the existing patent documents, although attention has also been paid to the connection between the terminal and the outside, the importance of aspects such as the number, distribution of contact points, and the uniformity of force and heat is not enough. Those skilled in the art may think that the existing terminal structure design can already meet the basic connection requirements, and do not deeply consider how to further improve the contact stability and uniformity to avoid a series of problems caused by poor contact, such as local overheating, resistance fluctuation, and reduced service life.

[0011] In summary, the existing fuse terminal structures have many deficiencies in aspects such as connection stability, current-carrying capacity, uniformity of current distribution, heat dissipation performance, compatibility with existing systems, and optimization of comprehensive performance. There is an urgent need for a new technical solution to solve these problems in order to improve the performance and reliability of fuses and meet the requirements 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 fusing element and a fuse, mainly for solving the following problems that occur in the application of existing fuses in automotive electrical fuse boxes: during the insertion operation, due to uneven force, the contact points of the "female end" are distorted or deformed, resulting in poor electrical contact stability, heat generation at the contact points, and ultimately causing the fuse function to be lost or the service life to terminate prematurely.

[0013] To solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0014] In the first aspect, the present invention provides a fusing element, mainly composed of a plurality of terminal units and a fusible unit. Each terminal unit is equipped with a main fork tooth and a secondary fork tooth, and there is a gap between the two fork teeth, which is specifically used for inserting the male end of the mating part. The inner side walls of the fork teeth are 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 tooth correspond precisely to the corresponding raised contact points of the secondary fork tooth. Based on the principle of good electrical contact, when the male end is inserted into the gap, the raised contact points can be in close contact with the male end, ensuring the formation of a stable and reliable electrical connection, thereby achieving efficient conduction of current.

[0015] The fusible unit is cleverly arranged between a plurality of terminal units. When the circuit is operating normally, it can ensure the smooth flow of current. This is because its conductive arms are firmly connected to the terminal units, and there is a transition section at the connection part between the conductive arms and the terminal units, and the cross-sectional area gradually increases in the direction of the terminal units.

[0016] This design is based on the characteristics of current transmission in conductors, which can effectively reduce the concentration of current at the connection part, reduce the contact resistance, and enable the current to pass through the fusible unit smoothly. Once an overcurrent state occurs in the circuit, the fusible unit will quickly open the circuit, thereby effectively interrupting the current flow between the plurality of terminal units.

[0017] This is because the bridging segment in the fusible unit will melt due to its own heat generation and the action of the spherical diffusion part when overcurrent occurs. Both sides of the bridging segment are connected to the conductive arms and carry current under normal circumstances. However, when overcurrent occurs, the fusible component in the spherical diffusion part on at least one side melts first. The melting temperature of the fusible component is lower than that of the bridging segment. After melting, it flows into the bridging segment. According to the principle of the melting point reduction of the alloy, the melting point of the bridging segment is reduced, thereby accelerating the melting process and timely cutting off the circuit to protect the circuit safety.

[0018] In terms of specific structural parameters, the upper gap defined by the upper convex contact points of the main fork teeth and the secondary fork teeth is defined as L1, and the lower gap defined by the lower convex contact points is defined as L2. Among them, the lower gap L2 < the upper gap L1, and the absolute value of the difference between the lower gap L2 and the upper gap L1 is carefully designed and is between 0.03 mm and 0.08 mm. This gap design has important technical effects. When the male terminal is inserted, the lower gap L2 contacts the male terminal first and spreads the angle, and then contacts the upper gap L1. The lower gap L2 is slightly smaller than the upper gap L1, which can provide stable four-point contact, avoiding clamping looseness and the phenomenon of distortion or deformation of the contact points. The lower gap L2 is smaller, providing a stable clamping force to ensure a good contact pressure is formed between the male terminal and the fork teeth, thereby achieving a reliable electrical connection.

[0019] The upper convex contact points and the lower convex contact points of the fork teeth are smoothly connected by two inclined segments. These two inclined segments not only play a connecting role but also jointly constitute the key part with an increased cross-sectional area in the terminal unit together with the upper convex contact points and the lower convex contact points.

[0020] From the perspective of electrical principles, according to the resistance law, an increase in the cross-sectional area can effectively reduce the resistance. Thus, in the circuit, a lower resistance means that the terminal can carry a larger current under the same voltage, improving the working ability of the fuse in a high-current environment.

[0021] The included angle formed between the two inclined segments is 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 terminal while ensuring structural stability. When the male terminal is inserted, this angle range can play a good guiding role in the insertion of the male terminal, enabling the male terminal to enter between the fork teeth along a specific direction, reducing the resistance and deviation during the insertion process, and making the insertion operation smoother and more accurate.

[0022] The appropriate angle can also form a larger contact area between the male terminal and the fork teeth. On the basis of four-point contact, it further reduces the contact resistance and improves the reliability of electrical contact. At the same time, the larger contact area also helps to disperse the current and reduce the possibility of local overheating.

[0023] In addition, the angle design of the fork teeth cooperates with the overall structure, enhancing the stability of the fusible element (i.e., the fuse structure). When subjected to external forces, the angle design enables the fork teeth to better withstand and disperse the forces, reducing the risk of deformation. Moreover, the angle design can also affect the elasticity of the fork teeth, enabling them to produce appropriate elastic deformation after being inserted into the male terminal, providing a certain degree of buffering and self - adapting ability, and further ensuring the stability and reliability of the contact.

[0024] The structural design of the fusible unit is also ingenious. It includes multiple conductive arms and multiple bridging segments. Each conductive arm is specially configured to be closely and firmly connected to a terminal unit, ensuring the efficient transmission of current between the terminal unit and the fusible unit. Each bridging segment is connected to a conductive arm on both sides. Under normal current conditions, the bridging segment can stably carry the current; while in the over - current state, the bridging segment will quickly melt, thus reliably interrupting the current flow between the two terminal units on both sides and realizing the protection function of the circuit.

[0025] In some realizable ways of the first aspect, at least one side of the bridging segment is provided with a spherical diffusion part, which includes a fusible component whose melting temperature is lower than that of the bridging segment. When over - current occurs, the fusible component will melt first and quickly flow into the bridging segment, greatly accelerating the fusing process of the bridging segment and significantly improving the response speed of the fuse. The diameter size of the spherical diffusion part is larger than the width size of the bridging segment. This design helps to enhance its promotion effect on the fusing of the bridging segment; and spherical diffusion parts can be symmetrically arranged on both sides of the bridging segment to further optimize the fusing effect.

[0026] In some realizable ways of the first aspect, the spherical diffusion part is composed of two detachable hemispherical parts, which is convenient for operation and replacement during manufacturing and maintenance; at the same time, the spherical diffusion part is cleverly arranged at the bending part, one end of which is connected to the bridging segment and the other end is connected to the conductive arm. This structural design can effectively guide the current flow and improve the overall performance of the fusible unit.

[0027] In some realizable ways of the first aspect, a transition section is provided at the connection part between the conductive arm and the terminal unit. The cross - sectional area of this transition section gradually increases from the side away from the terminal unit towards the terminal unit. This gradient design can effectively reduce the concentration of current at the connection part, reduce the contact resistance, and improve the current transmission efficiency.

[0028] In addition, the terminal unit has a thickness d1, and the fusible unit has a thickness d2, and d2 < d1. This thickness difference design can optimize the heat dissipation and fusing characteristics while ensuring the structural strength.

[0029] In some realizable ways of the first aspect, the fork teeth include an inclined wall section that extends from the upper convex contact point towards the arc section, and the gap between the main fork teeth and the secondary fork teeth extends to the arc section. This structural design enables the male end to come into contact with the fork teeth more smoothly during insertion, improving the stability and reliability of the connection.

[0030] Generally, the fusing 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 tooth and a first secondary fork tooth, which have the same structure and are symmetrically distributed; the inner side wall of the first main fork tooth 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 tooth is provided with a first secondary upper contact point and a first secondary lower contact point. This symmetrical structural design can ensure the uniform distribution of current on the terminal unit while improving stability.

[0031] In terms of mechanical principles, according to the theory of force balance and structural stability in statics, a multi-point support structure can provide more constraint conditions, thereby enhancing the overall stability. In three-dimensional space, four points can determine a unique plane, and within this plane, it can effectively resist translation and rotation in all directions. When an external force acts on the terminal, the four-point structure can form a stable force system through the reaction forces of each contact point, keeping the terminal in a balanced state and reducing the possibility of displacement and deformation. At the same time, due to symmetry, the forces borne by each contact point are equal in an ideal situation, further ensuring the uniformity of force, which conforms to the principle of optimizing mechanical structures.

[0032] In the second aspect, the present invention provides a fuse, which includes a housing and a fusing element arranged inside the housing. The housing has a generally rectangular or box-shaped profile, which can provide a completely enclosed protection environment for the fusing element, effectively preventing external factors from interfering with the fusing element.

[0033] In some realizable ways of the second aspect, on the housing, a notch is provided at a position corresponding to the fork teeth. The notch corresponds precisely to the fork tooth gap, and the upper and lower convex contact points of the fork teeth are both located within the notch, ensuring that the male end can accurately contact the fork teeth. The housing is composed of a first part and a second part, and the connection between the first part and the second part is detachable, facilitating the operation of the internal components of the fuse during manufacturing, installation, and maintenance.

[0034] In summary, through unique structural design and parameter optimization, the fusing element and 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 ends, and the reliability and maintenance convenience of the overall structure, and can effectively meet the high-performance requirements of modern electrical systems for fuses.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] (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;

[0037] (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;

[0038] (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;

[0039] (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;

[0040] (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;

[0041] (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.

[0042] The present invention will be explained in detail below with reference to the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 Shows the structure of the "tongue piece" fuse in the automotive electrical fuse box in the prior art;

[0044] Figure 2 Presents the structure of the three-point fuse in the automotive electrical fuse box in the prior art;

[0045] Figure 3 Is a schematic perspective view 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, clearly presenting the spatial position relationship and external shape characteristics of its various parts;

[0046] Figure 4 Is Figure 3 The front view structure schematic diagram of;

[0047] Figure 5 Is Figure 3 The left view structure schematic diagram of;

[0048] Figure 6 Is Figure 3 The bottom view structure schematic diagram of;

[0049] Figure 7 Is Figure 3 The top view structure schematic diagram of;

[0050] Figure 8 Presents the structure of the fuse element placed in the fuse housing in the embodiment of the present invention. 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;

[0051] Figure 9 Is Figure 8 The front view structure schematic diagram of, showing the structure of the fuse element placed in the fuse housing from the front view angle;

[0052] Figure 10 Is the front view structure schematic diagram of the fuse in the embodiment of the present invention.

[0053] Explanation of the reference numerals in the attached drawings:

[0054] 100. Fuse element;

[0055] 1. Fusible unit; 11. Bridging section; 2. First spherical diffusion part; 3. Second spherical diffusion part; 21. First bending part; 31. Second bending part; 121. First transition section; 131. Second transition section;

[0056] 4. First terminal unit; 41. First limiting part; 411. First arc part; 42. First main fork tooth; 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 tooth; 43a. First secondary upper contact point; 43b. First secondary lower contact point; 431. First secondary extension end; 44. First fork tooth gap; 45. First recess;

[0057] 5. Second terminal unit; 51. Second limiting part; 511. Second arc part; 52. Second main fork tooth; 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 tooth; 53a. Second secondary upper contact point; 53b. Second secondary lower contact point; 531. Second secondary extension end; 54. Second fork tooth gap; 55. Second recess;

[0058] 200. Housing; 201. First notch; 202. Second notch. Detailed implementation mode

[0059] For the convenience of understanding 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. However, 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 disclosure of the present invention more thorough and comprehensive.

[0060] It should be noted that when an element is referred to as "fixedly provided on" another element, it can be directly on the other element or there can be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used in this article are only for the purpose of illustration.

[0061] Unless otherwise defined, all technical and scientific terms used in this article have the same meaning as those commonly understood by those skilled in the technical field to which the present invention belongs. The terms used in the description of the present invention in this article are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used in this article includes any and all combinations of one or more of the related listed items.

[0062] Embodiment: An embodiment of the present invention provides a fusing element 100, which mainly consists of a first terminal unit 4, a second terminal unit 5 and a fusible unit 1.

[0063] The first terminal unit 4 includes a first limiting portion 41. The first limiting portion 41 is connected to a first arc portion 411, and the first arc portion 411 is further connected to a first main fork tooth 42 and a first auxiliary fork tooth 43. On the inner sidewall of the first main fork tooth 42, there are arranged a first main upper contact point 42a and a first main lower contact point 42b, and they are connected to a first main extension end 421 through a first upper inclined wall section 422 and a first lower inclined wall section 423. Among them, the first upper inclined wall section 422 extends from the first main upper contact point 42a towards the first arc portion 411, and the first lower inclined wall section 423 extends from the first main lower contact point 42b towards the first arc portion 411. A first fork tooth gap 44 is formed between the first main fork tooth 42 and the first auxiliary fork tooth 43, and the first fork tooth gap 44 extends to the first arc portion 411. And on the outer sides of the first main fork tooth 42 and the first auxiliary fork tooth 43, there is a first recess 45.

[0064] On the inner sidewall of the first auxiliary fork tooth 43, there are arranged a first auxiliary upper contact point 43a and a first auxiliary lower contact point 43b, which have the same structure as the first main fork tooth 42 and are symmetrically distributed. Similarly, they are connected to a first auxiliary extension end 431 through corresponding inclined wall sections, and the two together form a structure for inserting the male end of the opponent part. When the male end is inserted, the first main upper contact point 42a, the first main lower contact point 42b, the first auxiliary upper contact point 43a, and the first auxiliary lower contact point 43b can be in close contact with the male end, forming a stable electrical contact to ensure the effective conduction of current.

[0065] In the manufacturing process of the fusing element 100, for the terminal unit, we adopt a high-precision stamping process to ensure that the die accuracy is controlled within ±0.01 mm. Taking the first terminal unit 4 as an example, the design of its first main fork tooth 42 and first auxiliary fork tooth 43 strictly follows. The height difference between the first main upper contact point 42a of the first main fork tooth 42 and the first auxiliary upper contact point 43a of the first auxiliary fork tooth 43 is stably within 0.05 mm, and the surface roughness of these raised points reaches below Ra0.8. This enables close contact when contacting the male end, effectively reducing the contact resistance and ensuring the stable conduction of current. The connection part between the inclined section of the fork tooth and the raised point adopts a special fillet transition process with a fillet radius of 0.2 mm, effectively avoiding stress concentration and greatly enhancing the structural stability.

[0066] The second terminal unit 5 has the same structure as the first terminal unit 4, and includes a second limiting portion 51, a second arc portion 511, a second main fork tooth 52, a second auxiliary fork tooth 53, a second main upper contact point 52a, a second main lower contact point 52b, a second auxiliary upper contact point 53a, a second auxiliary lower contact point 53b, a second main extension end 521, a second auxiliary extension end 531, a second fork tooth gap 54, and a second recess 55. The positional relationship and functions of its respective parts are similar to those of the corresponding parts of the first terminal unit 4. Their symmetric distribution not only ensures the uniform distribution of current on the terminal unit, but also enhances the stability of the overall structure.

[0067] The fusible unit 1 includes a plurality of conductive arms, and each conductive arm is firmly connected to a terminal unit. Transition segments are provided at the connection parts between the conductive arms and the terminal unit, such as a first transition segment 121 and a second transition segment 131. The cross-sectional areas of these transition segments gradually increase from the side far away from the terminal unit towards the terminal unit. Based on the characteristics of current transmission in a conductor, this design 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.

[0068] Furthermore, in this embodiment, the fusible unit 1 further includes a plurality of bridging segments 11. Both sides of each bridging segment 11 are respectively connected to a conductive arm. Under normal current conditions, the bridging segment 11 can stably carry current; while in the overcurrent state, the bridging segment 11 will quickly fuse, reliably interrupting the current flow between the two side terminal units and realizing the protection function for the circuit. At least one side of the bridging segment 11 is provided with a spherical diffusion portion, such as a first spherical diffusion portion 2 and a second spherical diffusion portion 3. The spherical diffusion portion contains a fusible component, and its melting temperature is lower than that of the bridging segment 11.

[0069] When an overcurrent occurs, the fusible component melts first and quickly flows into the bridging segment 11. According to the principle of the decrease in the melting point of the alloy, it greatly accelerates the fusing process of the bridging segment 11, significantly improves the response speed of the fuse, and protects the safety of the equipment. The diameter size of the spherical diffusion portion is larger than the width size of the bridging segment 11, and spherical diffusion portions can be symmetrically arranged on both sides of the bridging segment 11 to further optimize the fusing effect.

[0070] Specifically, the bridging segment is made of a copper alloy material, and a fusible component is inlaid in the spherical diffusion portion provided on one side thereof. The spherical diffusion portion is composed of two detachable hemispheres with a manufacturing precision controlled within ±0.02 mm. After assembly, its diameter is 0.5 mm to 1.0 mm larger than the width of the bridging segment.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] In addition, the angular design of the fork teeth cooperates with the overall structure, enhancing the stability of the fusing element 100. When subjected to external forces, the angular design enables the fork teeth to better withstand and disperse the forces, reducing the risk of deformation, and also affects the elasticity of the fork teeth, enabling them to undergo appropriate elastic deformation after insertion into the male terminal, providing a certain degree of buffering and self - adapting ability, and further ensuring the stability and reliability of the contact.

[0077] The fuse includes a housing 200, which is made of an engineering plastic with high temperature resistance and good insulation performance through an injection molding process. The housing 200 has a general rectangular or box - shaped profile, which can provide a completely enclosed protection environment for the fusing element 100, effectively preventing external factors from interfering with the fusing element 100. On the housing 200, notches are provided at positions corresponding to the fork teeth, such as a first notch 201 and a second notch 202, for receiving terminals. The first notch 201 corresponds to the positions of the upper gap L1 and the lower gap L2 of the first terminal unit 4, and the second notch 202 corresponds to the positions of the upper gap L1 and the lower gap L2 of the second terminal unit 5. Moreover, the upper and lower protruding points of the fork teeth of the first terminal unit 4 and the second terminal unit 5 are located within the corresponding notches, ensuring that the male terminal can accurately contact the fork teeth.

[0078] The housing 200 is composed of a first part and a second part, and a detachable connection is adopted between the first part and the second part, facilitating the operation of the internal components of the fuse during manufacturing, installation, and maintenance. It can be understood that in some implementable embodiments, the housing 200 can be composed of multiple parts, and the multiple parts can be fitted together by thermal bonding or other forced means.

[0079] From the results of the temperature distribution simulation data of the fuse under different current - passing conditions, it can be seen that in a relatively stable operating state, when the fusing element in the embodiment of the present invention operates at rated conditions, the temperature at the contact point is close to the ambient temperature. Taking the case of passing 10A current as an example, the temperature at the contact point is 24.4773K at this time, which indicates that the thermal stability at the contact point is good and the heat - generating phenomenon at the contact point is weak. Due to less heat generation, the degree of oxidation at the contact point will be very light, which has a positive effect on extending the service life of the product.

[0080] When the fuse encounters a large current (such as an impact current), that is, when the passing current reaches more than 1 times the rated current of the fusing element (for example, 60A or 80A), the main heat generation point is concentrated in the fusing part. Although the duration of such a large current is short, basically within 1 second, the temperature of the fusing part rises rapidly. Taking the case of passing a 60A current as an example, the temperature at the fusing position is as high as 144.574k, while the temperature of the contact point (76.2501k) is much lower than the softening temperature of the material. From the comparison of the simulation data under various current conditions, the heat generation point is always mainly concentrated in the fusing part, and its temperature far exceeds that of the contact point. In this case, the contact point is limitedly affected by the large current, has little impact on the oxidation degree and contact stability of the product, thus ensuring the stability of the product quality and helping to improve the service life of the product.

[0081] Working principle: In the normal working state, the current flows from the external circuit through the male terminal of the mating part into the fusing element 100. First, it enters through the contact points (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.) between the fork teeth of the first terminal unit 4 and the second terminal unit 5 and the male terminal, and then flows into the bridging section 11 of the fusible unit 1 through the conductive arm (realizing efficient transmission with the help of transition sections such as the first transition section 121 and the second transition section 131), 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 is generated when the current flows through the fuse body. However, within the normal current range, the generated heat can be dissipated in time, and the fuse will not melt.

[0082] When abnormal conditions such as overload or short circuit occur in the circuit, the current increases sharply, and the resistance heating effect of the fuse body (especially the parts 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.) is significantly enhanced, and the heat accumulates rapidly. Given that the resistance is relatively large in the narrow area, the heat is concentrated faster. When the temperature reaches the melting point of the fuse, these parts fuse first, thus cutting off the circuit and preventing the excessive current from damaging the circuit and equipment, realizing the protection function.

[0083] In 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 bridging section 11 in the fusible unit 1 melt first. Because their melting temperature is lower than that of the bridging section 11, after melting, they flow into the bridging section 11, reducing the melting point of the bridging section 11, and then accelerating the fusing process to ensure timely cutting off of the circuit.

[0084] During the insertion process of the male terminal, the male terminal first comes into contact with the lower gap L2 defined by the lower convex 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 stable four-point contact. The smaller lower gap L2 provides a clamping force to ensure close contact between the male terminal and the fork teeth, achieving stable electrical connection. The angle design of the fork teeth from 150° to 160° guides the insertion direction of the male terminal, reduces resistance and deviation, increases the contact area, reduces the contact resistance, disperses the current, enhances the structural stability and elastic deformation ability, and ensures the reliability of the contact.

[0085] In summary, the fuse element 100 and the fuse of the present invention, with their unique structural design and parameter optimization, have achieved remarkable technical effects in terms of electrical connection stability, current-carrying capacity, overcurrent protection performance, compatibility with different male terminals, and the reliability and maintenance convenience of the overall structure, and can effectively meet the high-performance requirements of modern electrical systems for fuses.

[0086] The above description of the present invention with reference to the accompanying drawings is exemplary. Obviously, the specific implementation of the present invention is not limited by the above methods. 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 a male end of a counterpart, the inner side walls of the main tine and the secondary 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 correspond to the positions of the upper and lower raised contact points of the secondary tine, respectively, and each of the raised contact points is used to form an electrical contact with the male end inserted into the gap between the main tine and the secondary tine; and A fusible unit (1) is arranged between the plurality of terminal units, and when an overcurrent state occurs, the fusible unit (1) is disconnected, causing the current flow between the plurality of terminal units to be interrupted; 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.

2. The fuse element according to claim 1, 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.

3. The fuse element according to claim 1, characterized in that: The upper raised contact points and the lower raised contact points of the main fork tine and the auxiliary 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.

4. The fuse element according to claim 3, characterized in that: The angle formed between the two inclined sections ranges from 150° to 160°.

5. 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.

6. The fuse element according to claim 5, 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).

7. The fuse element according to claim 6, 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.

8. The fuse element according to claim 5, 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.

9. 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.

10. The fuse element according to claim 1, characterized in that The primary tine and the secondary tine include 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.

11. The fuse element according to any one of claims 1 to 10, 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).

12. 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 11.

13. The fuse according to claim 12, 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, the shell (200) is provided with a notch at a position corresponding to the main fork tine and the secondary fork tine, the notch corresponds to the gap between the main fork tine and the secondary fork tine, and the upper and lower protrusions of the main fork tine and the secondary fork tine are both located in the notch.

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