Overcurrent Cutoff Unit With Reduced Diameter Fuse Portion
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Solution Overview
Problem
The existing overcurrent cutoff solutions require an increase in manufacturing steps and components due to the need for ultra-fine and long fuse portions, which complicates the formation and increases the number of components involved.
Innovation Solution
An overcurrent cutoff unit is designed with a conductive core wire coated in insulating material, featuring a terminal connection portion, core wire connection portion, and a coating holding portion, where the fuse portion is formed by reducing the core wire diameter, and optionally covered with a sleeve to prevent breakage and heat transfer, using a combination of copper and steel wires to enhance fusing efficiency and reduce size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an ultra-fine and long fuse portion is formed in the relay terminal to cut off overcurrent, then the overcurrent cutoff reliability is improved, but the number of manufacturing steps increases
Solution Approach 1:
The patent combines the fuse portion formation with the existing wire coating removal process. The coating is removed to expose the core wire, and during this same process, the core wire diameter is reduced to form the fuse portion. This merging of operations eliminates the need for separate fuse portion formation steps, thereby improving manufacturing efficiency while maintaining overcurrent cutoff reliability.
Solution Approach 2:
The patent applies local quality by creating a fuse portion with reduced core wire diameter only in the specific region where overcurrent cutoff is needed, while maintaining the original wire structure elsewhere. This localized modification allows the wire to serve dual purposes: maintaining electrical connectivity where needed and providing overcurrent protection where the fuse portion is located.
2Reliability
If the fuse portion is made long to account for heat transfer to the mold resin member, then the overcurrent cutoff reliability is improved, but the device complexity increases
Solution Approach 1:
The patent merges the fuse portion with the wire structure itself, eliminating the need for separate overcurrent cutoff components. The wire's own structure is modified to include the fuse portion, which simplifies the overall device structure while maintaining the necessary overcurrent protection functionality.
Solution Approach 2:
The wire serves dual functions: it provides electrical connectivity and simultaneously provides overcurrent protection through its integrated fuse portion. The wire essentially protects itself by having the fuse portion formed from its own core wire, eliminating the need for separate protection components and reducing device complexity.
3Reliability
If the core wire diameter is reduced to form the fuse portion, then the overcurrent cutoff efficiency is improved, but the fuse portion strength decreases making it prone to breakage
Solution Approach 1:
The patent applies local quality by creating the fuse portion with reduced diameter only in the specific region where overcurrent cutoff is needed, while maintaining the original wire structure and strength elsewhere. This localized modification allows the wire to serve dual purposes: maintaining electrical connectivity where needed and providing overcurrent protection where the fuse portion is located.
Solution Approach 2:
The coating is removed in advance to expose the core wire before the fuse portion is formed. This preliminary action allows for precise control of the fuse portion formation process and enables subsequent protective measures to be applied to the exposed fuse portion to prevent breakage while maintaining its low-strength, high-fusibility characteristics.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design effectively cuts off overcurrents while minimizing the number of manufacturing steps and components, allowing for a more compact and cost-effective overcurrent cutoff solution.
Implementation Method 1
when an overcurrent flows through the terminal connection portion, the overcurrent from the terminal connection portion can be cut off due to fusing of the fuse portion in which the diameter of the core wire is reduced
Implementation Method 2
a wire in which a conductive core wire is coated with an insulating coating
Data Source
AI summary
A voltage detection unit includes a wire in which a conductive core wire is coated with an insulating coating that is insulative, a terminal connection portion to be connected to an electrode terminal, a core wire connection portion of a connecting piece that is provided continuously with the terminal connection portion and connected to the core wire that is exposed from the insulating coating at a terminal of the wire, and a second coating holding portion that is provided side by side with the core wire connection portion in an extending direction of the wire and holds the insulating coating of the wire, and the wire arranged between the core wire connection portion and the second coating holding portion includes a fuse portion in which a diameter of the core wire is reduced in a state of being exposed from the insulating coating.