A thermal fuse

By employing a composite structure of aluminum alloy base layer, stainless steel layer and silver metal layer in the fusible link, the problems of precious metal waste and poor stability are solved, and a fusible link design with high conductivity and high stability is achieved.

CN224519861UActive Publication Date: 2026-07-17ZHANGZHOU YABAO ELECTRONICS
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Utility models(China)
Current Assignee / Owner
ZHANGZHOU YABAO ELECTRONICS
Filing Date
2025-07-15
Publication Date
2026-07-17

AI Technical Summary

Technical Problem

The metal casing of existing thermal fuses is mostly made of brass alloy, which results in an excessive amount of precious metal silver and poor stability. It is easy to loosen and deviate, leading to poor contact and affecting the yield rate.

Method used

A composite structure consisting of an aluminum alloy base layer, a stainless steel layer, and a silver metal layer is adopted, combined with a nickel metal layer as a transition layer to optimize conductivity and stability, reduce the amount of silver used, and improve connection stability.

Benefits of technology

The amount of precious metals used has been reduced, and the conductivity and stability have been improved, ensuring the reliability and breaking reliability of the thermal fuse in high-temperature environments.

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Abstract

The utility model provides a kind of thermal fuse, including metal outer shell, first connecting wire, second connecting wire, sealing resin, insulating terminal, circuit breaking spring, star spring piece, elastic support and thermal fuse block, wherein metal outer shell is with aluminium alloy as base layer, outer surface is provided with stainless steel layer, inner surface is provided with silver metal layer, compared with traditional copper shell, the excellent electrically conductive heat performance of shell body is guaranteed, and it also has high strength, high toughness and light weight and other characteristics, at the same time, by stainless steel as surface layer, relative improvement resistance, reduce the amount of silver electroplated to outer surface when electroplating, reduce the amount of silver, ensure the reliability of thermal fuse through the excellent nature of silver inside, and ensure the connection stability of star spring piece through support.
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Claims

1. A thermal fuse comprising a metal outer case, a first connecting wire, a second connecting wire, a sealing resin, an insulating terminal, a star-shaped spring piece, and a thermal fuse block, characterized in that, The hot melt block is adapted to be disposed at the bottom of the inner cavity of the metal outer shell. The insulating terminal is fixedly disposed at one end of the inner cavity near the opening and sealed and fixed by sealing resin. The right side of the star-shaped spring abuts against the hot melt fuse through an elastic support member, and the left side abuts against the insulating terminal through a circuit breaking spring. The connecting end of the first connecting wire passes through the insulating terminal from the opening end and abuts against the star-shaped spring. The connecting end of the second connecting wire is fixedly connected to the right end of the metal outer shell. The metal outer shell includes an aluminum alloy base layer in the middle, a stainless steel layer on the outer surface, and a silver metal layer on the inner surface; the outer peripheral end of the star-shaped spring abuts against the silver metal layer, so that the first connecting line can be electrically connected to the silver metal layer through the star-shaped spring.

2. A thermal fuse according to claim 1, characterized in that A nickel metal layer is also provided between the aluminum alloy base layer and the silver metal layer.

3. A thermal fuse according to claim 1, characterized in that The thickness of the metal outer shell is 0.25-0.60 mm.

4. A thermal fuse according to claim 1, characterized in that... The aluminum alloy base layer is any one of 1050 aluminum alloy layer, 1070 aluminum alloy layer, 1100 aluminum alloy layer, 3003 aluminum alloy layer, 3004 aluminum alloy layer, and 5052 aluminum alloy layer.

5. A thermal fuse according to claim 1, wherein The stainless steel layer is any one of 304 stainless steel, 316 stainless steel, or 202 stainless steel.

6. A thermal fuse according to claim 1, characterized in that The inner cavity is provided with a slot near the opening end, and the end of the insulating terminal abuts against the bottom of the slot.

7. A thermal fuse according to claim 1, characterized in that The elastic support includes a support spring and support plates connected to both ends of the support spring.

8. A thermal fuse according to claim 1, characterized in that The bottom end of the metal outer shell is provided with a connection port, and a connecting block is provided between the hot melt block and the bottom of the inner cavity. The connecting end of the second connecting line passes through the connection port and connects to the connecting block, and is electrically connected to the silver metal layer through the connecting block.

9. A thermal fuse according to claim 1, wherein The first connecting line has a silver-plated area at one end near the star-shaped spring, and the surface of the silver-plated area is provided with a silver-plated layer. The silver-plated area accounts for less than 20% of the surface area of ​​the first connecting line.

10. A thermal fuse according to claim 1, characterized in that The first connecting line extends radially to one end near the star-shaped spring to form an end.