Flexible Ferromagnetic Shielding for Cables

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Solution Overview

Problem

Existing magnetic shielding technologies are inadequate for complex-shaped magnetic sources, such as electrical cables with curvatures, as they lead to breaks in ferromagnetic material layers, compromising the effectiveness of magnetic field channeling and shielding performance.

Innovation Solution

A device comprising a first sheet of ferromagnetic material deployed between a space to be protected and a magnetic source, with additional sheets of electrically conductive diamagnetic or paramagnetic material on either side of the ferromagnetic material to enhance shielding, particularly using high relative magnetic permeability ferromagnetic alloys like amorphous iron-based alloys and aluminum for improved attenuation across various frequencies.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If ferromagnetic material layers are used to shield complex-shaped magnetic sources, then magnetic field channeling effectiveness is improved, but the material layers break when cables undergo curvatures, compromising shielding performance

Engineering Contradiction:
Improveshielding performanceVSAvoidintegrity of ferromagnetic material layers
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent replaces rigid ferromagnetic material layers with flexible ferromagnetic wires or ribbons that can bend and deform without breaking. These flexible elements maintain magnetic field channeling effectiveness while adapting to cable curvatures and complex geometries, resolving the contradiction between shielding performance and structural integrity under deformation.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The patent changes the physical form parameter of the ferromagnetic material from continuous layers to discrete flexible wires or ribbons. This parameter change allows the material to maintain its magnetic shielding function while gaining mechanical flexibility to accommodate cable movements and curvatures without breaking.

Inventive Principle:
Principle #35Parameter changes

2Object-affected harmful factors

If traditional magnetic shielding materials are used, then magnetic field attenuation is achieved, but the device becomes heavy and expensive

Engineering Contradiction:
Improvemagnetic field attenuationVSAvoiddevice weight
Core Design Contradiction:
Object-affected harmful factorsVSWeight of moving object

Solution Approach 1:

The patent creates a composite shielding structure by combining multiple types of ferromagnetic materials (wires and ribbons) with different properties. This composite approach achieves effective magnetic field attenuation across various frequencies while optimizing the weight and cost characteristics compared to using single heavy traditional shielding materials.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent applies different ferromagnetic materials (wires versus ribbons) in different locations and orientations within the shielding structure. This local differentiation allows optimization of magnetic field attenuation in specific directions and frequency ranges while minimizing overall weight and material cost.

Inventive Principle:
Principle #3Local quality

3Reliability

If ferromagnetic material sheets are wrapped around cables, then magnetic shielding is provided, but the shielding is not appropriate for complex-shaped magnetic sources including connection terminals and electronic power equipment

Engineering Contradiction:
Improvemagnetic shielding effectivenessVSAvoidadaptability to complex geometries
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent segments the continuous ferromagnetic shielding material into discrete wires or narrow ribbons that can be individually positioned and arranged. This segmentation allows the shielding structure to conform to complex geometries including cables, connection terminals, and electronic power equipment, providing versatile adaptability while maintaining magnetic shielding effectiveness.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent employs flexible ferromagnetic wires and ribbons that can dynamically adapt their configuration to match the geometry of the magnetic source. This dynamic flexibility allows the shielding to effectively wrap around and conform to complex shapes and movements, unlike rigid traditional shielding sheets.

Inventive Principle:
Principle #15Dynamics

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 provides effective magnetic field reduction across a wide frequency range, including low frequencies, with a focus on lightness and cost-effectiveness, suitable for applications in vehicles and other mobile objects, while minimizing weight and mass.

Implementation Method 1

a first sheet of ferromagnetic material deployed between said space and said source

Methodology Applied
Scientific EffectFerromagnetism: Ferromagnetism

Implementation Method 2

a first sheet of electrically conductive material of a diamagnetic or paramagnetic nature which is deployed between said first sheet of ferromagnetic material and said space to be protected

Methodology Applied
Scientific EffectEddy currents: Eddy Currents

Data Source

PatentEP2721913B1Device for protecting a space adjacent to a magnetic source, and method for manufacturing such a device
Publication Date: 2019.01.23 RENAULT SA
  • EP2721913B1 patent drawingFigure 1~2
  • EP2721913B1 patent drawingFigure 3
  • EP2721913B1 patent drawingFigure 4

AI summary

To protect a space adjacent to a magnetic source from magnetic energy radiated by the source, a device includes one or two sheets of ferromagnetic material. Each sheet extends between the space and the source. The device further includes one or two sheets of a diamagnetic or paramagnetic electrically-conductive material, one of which extends between the sheet and the space being protected, and the other additional sheet extending between the sheet of ferromagnetic material and the magnetic source.