Induction Heating Coil Unit with Shared Ferrite for Nonmagnetic Materials

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Solution Overview

Problem

Existing heating coil units for induction cooking struggle to efficiently heat nonmagnetic materials like aluminum and copper without generating excessive heat or increasing in size, as they require high currents or increased coil turns.

Innovation Solution

A heating coil unit comprising first and second heating coils, along with a plurality of ferrites, including a shared ferrite that surrounds adjacent portions of both coils, which enhances magnetic field distribution and prevents magnetic saturation, allowing for efficient heating of nonmagnetic materials without excessive heat generation or size increase.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If a large current is applied to a heating coil or the number of turns of the heating coil is increased to heat nonmagnetic materials, then the heating power is improved, but the heating coil itself is raised to high temperature and increased in size

Engineering Contradiction:
Improveheating powerVSAvoidcoil temperature
Core Design Contradiction:
PowerVSTemperature

Solution Approach 1:

The invention divides the heating coil into multiple independent coils (first heating coil, second heating coil, etc.) arranged in a lattice pattern. Each coil can be independently controlled and contributes to the overall heating power, allowing the system to achieve high heating power without requiring a single coil to operate at excessively high temperatures or currents.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Multiple heating coils are combined in a lattice arrangement with their respective ferrite cores working together to generate the magnetic field needed for heating nonmagnetic materials. The combined effect of multiple coils achieves the required heating power while distributing the thermal load across multiple components rather than concentrating it in a single coil.

Inventive Principle:
Principle #5Merging (Combining)

2Power

If a large current is applied to a heating coil or the number of turns of the heating coil is increased to heat nonmagnetic materials, then the heating power is improved, but the heating coil unit increases in size

Engineering Contradiction:
Improveheating powerVSAvoidcoil unit size
Core Design Contradiction:
PowerVSVolume of moving object

Solution Approach 1:

The heating coil unit is segmented into multiple smaller coils arranged in a lattice structure, each with its own ferrite core. This segmentation allows the system to achieve high heating power through combined output from multiple compact units rather than requiring a single large coil, thus maintaining a compact overall size while delivering high power.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention changes the configuration parameters of the heating system by using multiple coils with fewer turns each, rather than a single coil with many turns. This parameter change allows the system to achieve the required inductance and heating power while maintaining a more compact size, as each individual coil can be smaller and the ferrite cores provide magnetic flux concentration.

Inventive Principle:
Principle #35Parameter changes

3Power

If multiple heating coils are used to achieve high heating power, then the heating capability for nonmagnetic materials is improved, but the device complexity increases

Engineering Contradiction:
Improveheating powerVSAvoidcoil unit structure
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The heating coil unit is segmented into multiple identical or similar modular coils arranged in a lattice pattern, each with its own ferrite core. This modular segmentation allows for standardized manufacturing and assembly, reducing the actual complexity despite the increased number of components. Each module can be independently manufactured and then assembled into the final lattice structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Multiple heating coils are designed with identical or similar structures, allowing them to perform the same heating function. This universality simplifies the design process, as a single coil design can be replicated multiple times, and reduces manufacturing complexity through standardization. The lattice arrangement of identical modules creates a system that achieves high power while maintaining design simplicity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 enables effective inductive heating of nonmagnetic materials while minimizing heat generation and size expansion, achieving high heating power with efficient magnetic field conversion and reduced risk of ferrite overheating.

Implementation Method 1

a heating coil unit of an induction heating cooker including first and second heating coils

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

a ferrite is disposed between the heating coils and functions as a magnetic shielding means so that a magnetic field generated from one heating coil does not affect the other heating coil

Methodology Applied
Scientific EffectMagnetic shielding: Magnetic Field

Data Source

PatentEP3579661B1Heating coil unit and induction heating cooker including the same
Publication Date: 2021.08.25 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP3579661B1 patent drawingFigure 1
  • EP3579661B1 patent drawingFigure 2
  • EP3579661B1 patent drawingFigure 3

AI summary

PROBLEM TO BE SOLVED: To enable a heating coil unit of an induction heating cooker including first and second heating coils to achieve a heating power capable of inductively heating a cooking container made of a nonmagnetic material while suppressing heat generation and an increase in size. SOLUTION: A heating coil unit 16 has first and second heating coils 22, 24 and a plurality of ferrites 26 to 36. The plurality of ferrites includes a shared ferrite 34 opened upward and surrounding both an adjacent portion 22a of the first heating coil 22 and an adjacent portion 24a of the second heating coil 24 adjacent to each other.