Flat Electric Wire Multilayer Resin Coating Soot-Free Welding

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Solution Overview

Problem

Conventional high-frequency rectangular wires with insulative enamel films face difficulties in rigid welding due to soot formation during motor assembly, affecting the integrity of the weld.

Innovation Solution

A rectangular wire design featuring a multilayer conductor member with a non-crystalline or crystalline thermoplastic resin layer on the outer periphery, including a second thermoplastic resin with a melting point of 300°C or more, selected from specific polymers like polyetherimide and polyetheretherketone, to facilitate easy welding without soot generation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If an insulative enamel film is formed on the outer periphery of rectangular metallic bodies, then high-frequency property is improved, but welding quality deteriorates due to soot formation

Engineering Contradiction:
Improvehigh-frequency lossVSAvoidwelding quality
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The patent applies composite materials by forming a multilayer coating structure consisting of a first thermoplastic resin layer (non-crystalline or crystalline with amide bond) and a second thermoplastic resin layer (melting point ≥300°C) on the rectangular metallic conductor. This composite structure combines the high-frequency loss reduction capability of thermoplastic resins with the soot-free welding property of the second resin layer, resolving the contradiction between high-frequency performance and welding quality.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent changes the material parameters by selecting specific thermoplastic resins with defined properties: the first resin is chosen from polyetherimide, polyphenylsulfone, polyethersulfone, polyamide 66, polyamide 46, or polyamide 6, while the second resin has a melting point of 300°C or higher. These parameter specifications ensure both low high-frequency loss and clean welding without soot formation.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If a thermoplastic resin layer is formed on the outer periphery of rectangular metallic conductors, then welding ease is improved, but high-frequency property may deteriorate

Engineering Contradiction:
Improvewelding easeVSAvoidhigh-frequency loss
Core Design Contradiction:
Ease of manufactureVSLoss of energy

Solution Approach 1:

The patent uses composite materials with a specific two-layer thermoplastic resin structure where the first layer (non-crystalline or crystalline with amide bond) maintains high-frequency properties by having appropriate dielectric characteristics, while the second layer (melting point ≥300°C) provides easy welding. This composite approach ensures both welding ease and high-frequency performance are achieved simultaneously.

Inventive Principle:
Principle #40Composite materials

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

The solution inhibits high-frequency loss and ensures reliable, soot-free welding, maintaining high-frequency properties and mechanical strength in electrical equipment.

Implementation Method 1

a layer of a non-crystalline resin having no melting point or a crystalline resin having an amide bond

Methodology Applied
Scientific EffectAmide bond: Chemical Bonding

Implementation Method 2

a layer of a second thermoplastic resin having a melting point of 300°C or more on the outer periphery of the multilayer conductor member

Methodology Applied
Scientific EffectMelting point: Melting

Data Source

PatentEP3043356B1Flat electric wire, manufacturing method thereof, and electric device
Publication Date: 2021.09.22 ESSEX FURUKAWA MAGNET WIRE JAPAN CO LTD
  • EP3043356B1 patent drawingFigure 1
  • EP3043356B1 patent drawingFigure 2(a)~2(b)
  • EP3043356B1 patent drawingFigure 3(a)~3(d)

AI summary

A rectangular wire having: a multilayer conductor member constructed by stacking, in a thickness direction, a rectangular metallic conductor that has a layer of a first thermoplastic resin formed on the outer periphery thereof, the first thermoplastic resin being a non-crystalline resin having no melting point or a crystalline resin having an amide bond; and a layer of a second thermoplastic resin having a melting point of 300°C or more on the outer periphery of the multilayer conductor member.