Induction coil device and induction cooking hob having an induction coil device

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Induction cooking hobs face issues with non-uniform gaps between induction coils and hob plates, and thermal variations affect the alignment of induction coil devices, requiring careful selection of support structure stiffness.

Innovation Solution

The introduction of a spring assembly and spacer elements within the induction coil device, which forces the support frame towards the hob plate, ensuring precise alignment and compensating for thermal deformations, along with the use of an aluminum shield plate for electromagnetic radiation shielding and a thermal insulation layer for improved heat insulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If screwing is used to fix the support frame to the support structure, then the induction coil device can be assembled, but the gap between induction coils and hob plate becomes non-uniform

Engineering Contradiction:
Improveassembly methodVSAvoidgap uniformity
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

A spring assembly is introduced as an intermediary element between the support frame and the support structure. This spring assembly acts as a mediator that absorbs positioning errors and thermal deformations, ensuring uniform gaps between the induction coils and the hob plate while maintaining ease of assembly through screwing.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The spring assembly allows for dynamic adjustment of the support frame position by changing the compression state of the spring. This parameter change capability enables the system to compensate for manufacturing tolerances and thermal expansions, maintaining uniform gaps without requiring precise initial positioning.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If the support structure stiffness is carefully selected to mitigate gap differences, then gap uniformity improves, but device complexity increases

Engineering Contradiction:
Improvegap uniformityVSAvoidsupport structure design
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The spring assembly serves as a buffer between the support structure and the support frame, decoupling the relationship between support structure stiffness and gap uniformity. This intermediary allows a wide range of support structure stiffness values to achieve acceptable gap uniformity, reducing design complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The spring assembly introduces dynamic compliance to the otherwise rigid support structure. This dynamic element allows the system to adapt to thermal deformations and manufacturing variations automatically, eliminating the need for carefully controlled static stiffness values.

Inventive Principle:
Principle #15Dynamics

3Ease of operation

If thermal variations occur in the support structure, then the relative position of induction coil devices changes with respect to the hob plate, but using rigid fixing methods increases assembly simplicity

Engineering Contradiction:
Improveassembly simplicityVSAvoidrelative position stability
Core Design Contradiction:
Ease of operationVSStability of the object's composition

Solution Approach 1:

The spring assembly is designed to accommodate thermal expansion and contraction of the support structure. As the support structure undergoes thermal variations, the spring compresses or extends accordingly, maintaining the relative position of the induction coil devices with respect to the hob plate while keeping the assembly simple and rigid.

Inventive Principle:
Principle #37Thermal expansion

Solution Approach 2:

The spring assembly introduces dynamic compliance that allows the support frame to move slightly in response to thermal variations. This dynamic adjustment capability maintains stable relative positioning without requiring complex thermal compensation mechanisms or flexible fixing methods.

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

This solution achieves uniform gaps between induction coils and the hob plate, maintains alignment despite thermal variations, and eliminates the need for carefully choosing support structure stiffness, while enhancing heat insulation and electromagnetic shielding.

Implementation Method 1

a spring assembly having one or more spring elements configured to interact with the support structure and the support frame and to force the support frame towards the hob plate

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

any thermal deformations of the support structure are compensate by the spring assembly

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 3

one or more induction coil devices being arranged between the hob plate and the support structure

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 4

Induction cooking hobs are known for the cooking of food products by means of thermal conditioning of the food products

Methodology Applied
Scientific EffectInduction heating: Induction Heating

Implementation Method 5

each induction coil device may also comprise an aluminum shield plate. By providing for the aluminum shield plate it is possible to shield the electromagnetic radiation generated by the induction coils

Methodology Applied
Scientific EffectElectromagnetic shielding: Faraday Cage

Implementation Method 6

a thermal insulation layer, in particular being coupled to the respective support frame. By providing for the thermal insulation layer it is possible to improve heat insulation

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Data Source

PatentEP4090134A1Induction coil device and induction cooking hob having an induction coil device
Publication Date: 2022.11.16 ELECTROLUX APPLIANCES
  • EP4090134A1 patent drawingFigure 1
  • EP4090134A1 patent drawingFigure 2~4
  • EP4090134A1 patent drawingFigure 5~6

AI summary

There is described an induction coil device (4) for an induction cooking hob (1) having a hob plate (2) and a support structure (3). The induction coil device (4) is designed to be interposed between the hob plate (2) and the support structure (3) and comprises at least one induction coil (10), a support frame (11) carrying the induction coil (10), a spring assembly (12) having one or more spring elements (13) configured to interact with the support structure (3) and the support frame (11) and to force the support frame (11) towards the hob plate (2); and a plurality of spacer elements (14) mounted to and protruding from the support frame (11) and designed to abut against the hob plate (2).