Heating Element With Low Resistivity Joining Portion

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Solution Overview

Problem

Existing heat generating elements, such as honeycomb structural bodies used for catalyst carriers, face challenges in adjusting their shape to suit various applications and ensuring efficient heat generation.

Innovation Solution

A heat generating element comprising multiple honeycomb structure units with partition walls forming cells for fluid flow, where the units are joined through a first joining portion with a volume resistivity of 1 Ω·cm or less, and optionally a second joining portion with a higher volume resistivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If honeycomb structure units are joined together to form a heat generating element, then the shape can be adjusted to suit different applications, but the heat generation characteristics may be compromised due to high resistance at joining portions

Engineering Contradiction:
Improveshape adjustabilityVSAvoidheat generation characteristics
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

A joining portion with low volume resistivity (1 Ω·cm or less) is introduced as an intermediary between honeycomb structure units with higher volume resistivity (2 Ω·cm or more). This intermediary conducting layer ensures efficient electrical connection and heat generation while allowing modular assembly of different shapes.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The joining portion is designed with locally optimized low resistivity properties specifically at the connection points between honeycomb units, while the main body units maintain their structural integrity and higher resistivity characteristics. This localized quality differentiation resolves the contradiction between shape flexibility and heat generation efficiency.

Inventive Principle:
Principle #3Local quality

2Power

If a joining portion with low volume resistivity is used to ensure good electrical connection, then heat generation efficiency is improved, but the joining portion may become a weak point for current concentration and overheating

Engineering Contradiction:
Improveheat generation efficiencyVSAvoidcurrent concentration and overheating
Core Design Contradiction:
PowerVSObject-affected harmful factors

Solution Approach 1:

The volume resistivity of the joining portion is precisely controlled to be 1 Ω·cm or less, creating an optimal electrical parameter that ensures low resistance connection while distributing current effectively. This parameter optimization prevents both excessive resistance (reducing power) and current concentration (causing overheating).

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The joining portion acts as an intermediary conducting element that mediates between the higher resistivity honeycomb units and the electrical current flow, ensuring uniform current distribution and preventing localized overheating while maintaining efficient heat generation.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Shape

If multiple honeycomb structure units are joined together, then the desired shape and size can be achieved, but the manufacturing complexity increases

Engineering Contradiction:
Improveshape and sizeVSAvoidmanufacturing complexity
Core Design Contradiction:
ShapeVSDevice complexity

Solution Approach 1:

The heat generating element is segmented into multiple standardized honeycomb structure units that can be independently manufactured and then assembled with joining portions. This segmentation allows flexible configuration of different shapes and sizes while maintaining relatively simple manufacturing processes for each modular unit.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The honeycomb structure units are designed as universal modular components that can be assembled in various configurations to create different shapes and sizes. The standardized joining portions provide multi-functional connections that simplify the overall manufacturing process despite the modular complexity.

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 proposed heat generating element achieves excellent heat generation characteristics and allows for easy adjustment of its shape, enhancing its applicability across different applications.

Implementation Method 1

the first joining portion has a volume resistivity that is lower than a volume resistivity of the honeycomb structure unit, and wherein the volume resistivity of the first joining portion is 1 Ω·cm or less

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 2

configured to generate heat by energization

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP4559576A1Heating element
Publication Date: 2025.05.28 NGK INSULATORS LTD
  • EP4559576A1 patent drawingFigure 1
  • EP4559576A1 patent drawingFigure 2
  • EP4559576A1 patent drawingFigure 3

AI summary

Provided is a heat generating element, which has excellent heat generation characteristics, and has a shape that can be easily adjusted. A heat generating element according to an embodiment of the present invention includes a plurality of honeycomb structure units, each of which includes partition walls, and is configured to generate heat by energization, the partition walls defining and forming a plurality of cells that extend from a first end surface to a second end surface, and serve as fluid flow passages. The plurality of honeycomb structure units include a first honeycomb structure unit and a second honeycomb structure unit. The first honeycomb structure unit and the second honeycomb structure unit are joined to each other through intermediation of a first joining portion. The first joining portion has a volume resistivity that is lower than a volume resistivity of the honeycomb structure unit. The volume resistivity of the first joining portion is 1 Ω·cm or less.