Magnetic Element Core Design for Flux Leakage Reduction

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Solution Overview

Problem

Magnetic elements with combined cores face issues of magnetic flux leakage due to gaps between components, leading to reduced inductance values and potential electromagnetic interference with other electronic parts on the same substrate.

Innovation Solution

A magnetic element design featuring a pot core, a cross-shaped core, and a winding, where the cross-shaped core fits into cutout portions of the pot core, and a bobbin with specific trench structures to secure the winding and cores, minimizing flux leakage and ensuring effective magnetic path contact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a ring core with a lid is mounted on a T-shaped core, then the magnetic element can be assembled with standard components, but gaps between components cause magnetic flux leakage and reduce inductance value

Engineering Contradiction:
Improveassembly of standard componentsVSAvoidinductance value
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The invention merges the ring core and T-shaped core into a single integrated core body with a T-shaped cross section, eliminating gaps between separate components. This unified structure ensures continuous magnetic flux paths and maintains stable inductance values while preserving ease of manufacture through一体化 design.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The invention uses composite magnetic materials with specific permeability ratios (μ1/μ2 between 0.5-2.0) for different regions of the T-shaped core, optimizing magnetic flux distribution. This material composition strategy enhances magnetic path efficiency and reduces flux leakage without requiring complex assembly structures.

Inventive Principle:
Principle #40Composite materials

2Ease of operation

If a cutout is provided in the ring core for pin terminal fitting, then terminal mounting is enabled, but magnetic flux leaks via the cutout

Engineering Contradiction:
Improveterminal mountingVSAvoidmagnetic flux containment
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The invention applies local quality by providing magnetic shielding walls at specific locations around the terminal mounting regions. These localized shielding structures contain magnetic flux in areas where cutouts are necessary for terminal access, while maintaining open structures in regions where flux containment is less critical, thus balancing terminal mounting ease with flux containment.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention introduces magnetic shielding walls as intermediary structures between the terminal cutouts and the magnetic flux paths. These shielding walls act as mediators that redirect and contain magnetic flux away from cutout regions, preventing flux leakage while preserving terminal mounting capabilities.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If gaps exist between T-shaped core and ring core with lid, then component assembly is simplified, but magnetic flux leaks in lateral direction

Engineering Contradiction:
Improvecomponent assemblyVSAvoidmagnetic flux leakage
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The invention merges previously separate T-shaped core and ring core components into a single integrated core body, eliminating lateral gaps that caused magnetic flux leakage. This unified structure maintains simplified assembly processes while effectively containing magnetic flux within the intended paths.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The invention converts the potential harm of gap-induced flux leakage into a benefit by designing the T-shaped cross section with optimized flange widths and thicknesses. The dimensional parameters are specifically configured to maximize magnetic path efficiency while minimizing any potential gap effects, turning a potential weakness into a strength.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 design effectively reduces magnetic flux leakage, maintains inductance values, and prevents electromagnetic interference, while ensuring stable mounting and secure core contact for enhanced magnetic path formation.

Implementation Method 1

a winding (30) having conductivity, and a core member... in which a third core member (22) having a columnar form is provided integrally on a center portion of the bottom wall forming the first core member (11) or on a center portion of the cross shape of the second core member (21)

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

the core member includes a first core member (11) having a bottom wall and a plurality of peripheral walls provided to stand on peripheral side portions of the bottom wall, and a second core member (21) having a plate form which is cross-shaped or substantially cross-shaped

Methodology Applied
Scientific EffectMagnetic flux confinement: Magnetic Field

Data Source

PatentEP2437273B1Magnetic element
Publication Date: 2013.05.01 SUMIDA CORP
  • EP2437273B1 patent drawingFigure 1
  • EP2437273B1 patent drawingFigure 2
  • EP2437273B1 patent drawingFigure 3

AI summary

A problem to be solved is to prevent leakage of magnetic flux in a magnetic element. A magnetic element has a winding (30) having conductivity, and a core member disposed in a state that the winding is wound, in which the core member includes a first core member having a bottom wall (11) and a plurality of peripheral walls (12,13,14,15) provided to stand on peripheral side portions of the bottom wall, and a second core member (21) having a plate shape which is cross-shaped, in which cutout portions (19) for allowing fitting of end portions of the cross shape of the second core member are formed in the peripheral walls of the first core member.