Rectangular Insulated Wire with Multi-Layer Resin Coating
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional insulated wires for electric generators in vehicles face challenges with flex resistance reliability and partial discharge inception voltage, particularly when subjected to bending, leading to cracks reaching the conductor and insufficient high-voltage insulation.
Innovation Solution
A rectangular insulated wire is developed with multiple baked-coating resin layers composed of specific materials like polyester-based resins, polyamide-imide, and polyimide, along with an extruded thermoplastic covering layer, to enhance adhesion strength and prevent crack propagation while maintaining flexibility and high partial discharge inception voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single-layer insulation coating is used, then the structure is simple and manufacturing is easy, but cracks occur during bending and reach the conductor, reducing reliability
Solution Approach 1:
The insulation coating is divided into multiple layers (first baked-coating resin layer and second baked-coating resin layer) with different material compositions. The first layer uses a polyester-based resin with specific hydroxyl groups for adhesion, while the second layer uses a different resin formulation for crack resistance. This segmentation allows each layer to perform its specific function, preventing cracks from reaching the conductor while maintaining manufacturing feasibility.
Solution Approach 2:
The patent employs composite material structures where the first baked-coating resin layer and second baked-coating resin layer are composed of different resin systems. The first layer contains a polyester-based resin with specific hydroxyl groups that provide strong adhesion to the conductor, while the second layer uses a different resin composition that provides superior flexibility and crack resistance. This composite approach resolves the contradiction by combining materials with complementary properties.
2Reliability
If the insulation coating is made thicker to prevent cracks, then reliability improves, but the wire loses flexibility and becomes difficult to form into coils
Solution Approach 1:
Instead of using a single thick coating layer, the patent segments the insulation into multiple thinner layers with different material properties. The first layer provides adhesion and basic protection, while the second layer provides flexibility and crack resistance. This segmentation maintains overall reliability while preserving the flexibility needed for coil formation, as each thin layer can deform without cracking.
Solution Approach 2:
The patent changes the material parameters of each layer to achieve the desired balance. The first layer uses a polyester-based resin with specific hydroxyl groups for adhesion, while the second layer uses a resin with higher elasticity for flexibility. By adjusting the material composition and thickness parameters of each layer, the patent achieves both crack prevention and maintained flexibility for easy coil formation.
3Reliability
If conventional resin materials are used, then manufacturing cost is low, but partial discharge inception voltage is insufficient for high-voltage applications
Solution Approach 1:
The patent uses composite resin materials where the first baked-coating resin layer employs a polyester-based resin with specific hydroxyl groups for adhesion, and the second layer uses a different resin formulation optimized for electrical insulation and partial discharge resistance. This composite material approach achieves high partial discharge inception voltage suitable for high-voltage applications while maintaining manufacturing feasibility through established coating processes.
Solution Approach 2:
The patent changes the chemical composition parameters of the resin materials to achieve superior electrical properties. The first layer uses a polyester-based resin with specific hydroxyl groups, and the second layer uses a resin with different molecular structure and composition that provides higher partial discharge resistance. These parameter changes enable the wire to withstand high-voltage applications while the manufacturing process remains practical.
Data Source
Figure 1A~1B
Figure 2
AI summary
Provided is a rectangular insulated wire that has an improved flex resistance reliability by preventing an occurrence of a crack reaching the conductor while maintaining flexibility and resistance to thermal softening, and also achieve a higher insulating property by having a higher partial discharge inception voltage. The rectangular insulated wire (1) comprises a rectangular conductor (2) having a generally rectangular cross section, a plurality of baked-coating resin layers (3), (4), (5) formed on the rectangular conductor, and an extruded covering layer (6) that is formed to cover the baked-coating resin layer 5 which an outermost layer of the plurality of baked-coating resin layers. The plurality of the baked-coating resin layer is formed of two or more kinds of materials. The plurality of baked-coating resin layers (3), (4), (5) are formed of two or more resins selected from a group consisting of a polyester-based resin including a trihydric or higher alcohol constituent, a polyester imide resin, a polyamide-imide resin and a polyimide resin, respectively.