Wire Harness Ferrite Core Shield Abrion Prevention

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Solution Overview

Problem

Wire harnesses with magnetic cores experience abrasion of braided shields due to friction in vibration environments, leading to reduced shield function and increased electromagnetic noise in information-processing equipment.

Innovation Solution

A wire harness design incorporating a corrugated tube with a braided shield and an electromagnetic wave absorption component featuring a ferrite core and rubber members, restricted by a resin tape movement-restricting member to prevent abrasion and enhance noise reduction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a magnetic core is added to reduce electromagnetic noise, then electromagnetic noise reduction is improved, but friction between the braided shield and magnetic core causes abrasion of the braided shield

Engineering Contradiction:
Improveelectromagnetic noiseVSAvoidbraided shield durability
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

A resin layer is introduced as an intermediary substance between the magnetic core and the braided shield. This resin layer prevents direct contact and friction between the magnetic core and the braided shield, eliminating the abrasion problem while maintaining the electromagnetic noise reduction function of the magnetic core.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The resin layer is applied in advance to the magnetic core before assembling the wire harness. This beforehand cushioning creates a protective barrier that prevents future friction and abrasion between the magnetic core and the braided shield, ensuring long-term reliability.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

2Object-affected harmful factors

If the braided shield is used to reduce electromagnetic noise, then electromagnetic noise reduction is improved, but the braided shield undergoes abrasion in vibration environments

Engineering Contradiction:
Improveelectromagnetic noiseVSAvoidabrasion of braided shield
Core Design Contradiction:
Object-affected harmful factorsVSObject-generated harmful factors

Solution Approach 1:

The resin layer serves as a mediator between the magnetic core and the braided shield, preventing direct friction and abrasion. This allows the braided shield to maintain its electromagnetic noise reduction function without undergoing abrasion in vibration environments.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If the magnetic core and braided shield are in direct contact, then device complexity is reduced, but friction causes shield wire breakage in long-term use

Engineering Contradiction:
Improvestructure simplicityVSAvoidshield function duration
Core Design Contradiction:
Device complexityVSDuration of action of stationary object

Solution Approach 1:

The resin layer is applied beforehand to the magnetic core, creating a protective cushion that prevents future friction and shield wire breakage. This simple addition extends the duration of shield function without significantly increasing device complexity.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The resin layer is applied in advance to the magnetic core before assembling the wire harness. This beforehand cushioning creates a protective barrier that prevents future friction and abrasion, ensuring long-term reliability.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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 effectively reduces electromagnetic noise while preventing abrasion of the braided shield, ensuring reliable shield function and durability in vibration environments.

Implementation Method 1

an electromagnetic wave absorption component (2) having a through-hole (20) for allowing the first to third electric wires (11 to 13) to pass through, is provided around the first to third electric wires (11 to 13)

Methodology Applied
Scientific EffectElectromagnetic wave absorption: Absorption (EM radiation)

Implementation Method 2

it is found that the friction between the braided shield and the magnetic core causes abrasion of the braided shield

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2750149B1Wire harness
Publication Date: 2017.11.29 PROTERIAL LTD
  • EP2750149B1 patent drawingFigure 1A~1B
  • EP2750149B1 patent drawingFigure 2A~2B
  • EP2750149B1 patent drawingFigure 3

AI summary

A wire harness includes an electric wire, a braided shield covering the electric wire, an annular electromagnetic wave absorption component that includes a through-hole for inserting electric wire and absorbs electromagnetic wave emitted from the electric wire, and a movement-restricting member for restricting the electromagnetic wave absorption component from moving in a direction of inserting the electric wire in the through-hole.