A fuse

Abstract

This utility model relates to fuses, specifically a fuse comprising a fuse tube, an internal fusible element, and an arc-quenching medium filling the space between the inner wall of the fuse tube and the fusible element; both ends of the fuse tube are provided with terminals connected to the fusible element; each terminal includes a terminal substrate, and the outer surface of the terminal substrate is provided with a surface substrate; the resistivity of the surface substrate is lower than that of the terminal substrate. This utility model, by dividing the terminal into a terminal substrate and a surface substrate, and utilizing the skin effect, ensures that when alternating current is transmitted through the terminal, the current on the terminal mainly passes through the surface of the surface substrate. Since the resistivity of the surface substrate is lower than that of the terminal substrate, the cost of the terminal can be reduced while maintaining current conductivity.

Description

Technical Field

[0001] This utility model relates to fuses, specifically to a type of fuse. Background Technology

[0002] A fuse, commonly known as a "fuse", is an overcurrent protection device widely used in power distribution and control systems, primarily for short-circuit or overload protection.

[0003] Currently, the mainstream type of fuse on the market is the thermal fusion type, which consists of an insulating tube, terminals, a cover plate, a fusible element, and an arc-extinguishing medium, among other auxiliary materials. Its working principle is as follows: Under specified voltage conditions, current flows through the fusible element. Utilizing the thermal effect of the current, when the heat accumulates to a certain level, the current sensing point (the narrowest point) of the fusible element melts and breaks the circuit within a specified time, thus achieving the circuit protection function of safely interrupting fault current. The main function of the arc-extinguishing medium is to absorb the energy released by the arc after the fusible element breaks, ensuring that the energy released when the fuse operates does not overflow and harm other surrounding devices.

[0004] The terminal material of the mainstream hot-melt fuse in the market is copper T2, which has many advantages: copper T2 has excellent conductivity, second only to silver, which can effectively reduce the Joule heat generated when current passes through the terminal and avoid affecting the normal protection function of the fuse due to excessive terminal heating; in addition, copper T2 also has good thermal conductivity, which can quickly conduct away the heat generated when the fuse melts.

[0005] However, as an important non-ferrous metal, copper T2 also has obvious drawbacks: its cost is too high, affecting the production cost of fuses; at the same time, due to its low hardness, it is prone to deformation during production, transportation and installation, and the deformation of the terminals will directly affect the reliability of its connection with external circuits. Utility Model Content

[0006] The purpose of this invention is to solve the technical problems of existing fuses using T2 copper terminals, which are high in cost, have low hardness, and are prone to deformation, and to provide a new type of fuse.

[0007] To solve the above-mentioned technical problems, the technical solution provided by this utility model is as follows:

[0008] A fuse includes a fuse tube, a fusible element inside the fuse tube, and an arc-extinguishing medium filling the space between the inner wall of the fuse tube and the fusible element; both ends of the fuse tube are provided with terminals connected to the fusible element.

[0009] The terminal block includes a terminal substrate, and a surface substrate is provided on the outer surface of the terminal substrate; the resistivity of the surface substrate is lower than that of the terminal substrate.

[0010] Furthermore, the hardness of the surface substrate is lower than that of the terminal substrate.

[0011] Furthermore, the terminal substrate is made of brass; the surface substrate is made of aluminum.

[0012] Furthermore, the outer surface of the terminal substrate is die-cast to form a wiring terminal.

[0013] Furthermore, one of the terminals has multiple sand-filling holes on its side that connect the outside to the inside of the fusible tube;

[0014] A plug is installed inside the sand filling hole.

[0015] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0016] 1. The fuse provided by this utility model divides the terminal into a terminal substrate and a surface substrate. By taking advantage of the skin effect, when AC current is transmitted in the terminal, the current on the terminal actually mainly passes through the surface of the surface substrate. Since the resistivity of the surface substrate is lower than that of the terminal substrate, the cost of the terminal can be reduced while ensuring the current conduction capacity.

[0017] 2. The fuse provided by this utility model has an aluminum substrate 32, which has low resistivity and is close to that of copper T2. Therefore, while ensuring the current conduction capacity, the terminal substrate 31 inside the terminal 3 can be made of brass to reduce costs. At the same time, by replacing copper T2 with a combination of brass and aluminum, the manufacturing cost is reduced while ensuring that the terminal has high conductivity and hardness.

[0018] 3. The fuse provided by this utility model has a terminal substrate with a higher hardness than the surface substrate, which can support the surface substrate and ensure that the terminal block is not easily deformed during production, transportation and installation. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of an embodiment of the present utility model;

[0020] Figure 2 This is a schematic diagram of the internal structure of an embodiment of the present utility model.

[0021] Explanation of reference numerals in the attached drawings: 1-Fuse tube, 2-Fuse body, 3-Terminal, 31-Terminal substrate, 32-Surface substrate, 4-Plug. Detailed Implementation

[0022] The technical solutions of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0023] like Figure 1 and Figure 2 As shown, a fuse can be applied to various scenarios; it includes a fuse tube 1, a fuse element 2 inside the fuse tube 1, and an arc-extinguishing medium is filled between the inner wall of the fuse tube 1 and the fuse element 2; both ends of the fuse tube 1 are provided with terminals 3 connected to the fuse element 2.

[0024] like Figure 1 and Figure 2 As shown, the terminal block 3 includes a terminal substrate 31, and a surface substrate 32 is die-cast on the outer surface of the terminal substrate 31. The terminal substrate 31 is made of brass, and the surface substrate 32 is made of aluminum. The resistivity of the aluminum surface substrate 32 is lower than that of the brass of the terminal substrate 31, and the hardness of the aluminum surface substrate 32 is lower than that of the brass of the terminal substrate 31.

[0025] The surface substrate 32 is die-cast onto the outer surface of the terminal substrate 31 to form an aluminum-clad copper terminal 3; replacing the copper terminal 3 of the copper T2 with the aluminum-clad copper terminal 3 can reduce the production cost of the fuse.

[0026] In addition, due to the skin effect, the current on the terminal 3 actually mainly passes through the surface of the substrate 32. The surface substrate 32 of this application is made of aluminum, which has low resistivity and is close to that of copper T2. Therefore, while ensuring the current conduction capacity, the terminal substrate 31 inside the terminal 3 can be made of brass to reduce costs. Since the hardness of the brass terminal substrate 31 is greater than that of the aluminum surface substrate 32, the brass terminal substrate 31 can support the aluminum surface substrate 32, ensuring that the terminal 3 is not easily deformed during production, transportation and installation.

[0027] like Figure 2 As shown, in order to facilitate the filling of the arc-extinguishing medium into the fused tube 1, a plurality of sand-filling holes are provided on the side of one of the terminals 3 to connect the outside with the inside of the fused tube 1; a plug 4 is installed in the sand-filling hole; after the arc-extinguishing medium is filled into the fused tube 1, the sand-filling hole is sealed by the plug 4 to prevent the arc-extinguishing medium from leaking out of the sand-filling hole.

[0028] The terminal 3 in this application has a lower cost than the copper T2 terminal and stronger electrical and thermal conductivity than the brass terminal.

[0029] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any changes or substitutions within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.

Claims

1. A fuse, comprising a fuse tube (1), wherein a fusible element (2) is disposed inside the fuse tube (1), and an arc-extinguishing medium is filled between the inner wall of the fuse tube (1) and the fusible element (2); both ends of the fuse tube (1) are provided with terminals (3) connected to the fusible element (2); characterized in that: The terminal block (3) includes a terminal substrate (31), and the outer surface of the terminal substrate (31) is provided with a surface substrate (32); The resistivity of the surface substrate (32) is lower than that of the terminal substrate (31).

2. The fuse of claim 1, wherein: The surface substrate (32) has a lower hardness than the terminal substrate (31).

3. The fuse of claim 1, wherein: The terminal substrate (31) is made of brass; the surface substrate (32) is made of aluminum.

4. The fuse of claim 1 or 2 or 3, characterized in that: The terminal (3) is formed by die-casting a surface substrate (32) on the outer surface of the terminal substrate (31).

5. The fuse of claim 1, wherein: One of the terminals (3) has multiple sand-filling holes on its side that connect the outside to the inside of the fusible tube (1); A plug (4) is installed inside the sand filling hole.

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