Gas Sensor Element Heating Element Positioning
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Solution Overview
Problem
Existing gas sensor elements for internal combustion engines face challenges such as slow activation, mechanical fragility, and increased size due to thick insulating layers, which affect durability and thermal efficiency, and complex electrode layouts can lead to defects and inefficiencies in measuring exhaust gas components like oxygen.
Innovation Solution
A gas sensor element design featuring a solid electrolyte body with a heating element positioned between the insulating ceramic member and the cylindrical ceramic base, utilizing a high thermal conductivity insulating ceramic member for rapid activation and mechanical support, while maintaining electric insulation and protecting the heating element from gases, with a specific insulating interval to optimize size and durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a thick insulating layer is used to protect the heating element from gases, then the heating element is protected and electric insulation is maintained, but the sensor size increases and thermal efficiency decreases
Solution Approach 1:
The heating element is repositioned from a planar configuration to a three-dimensional space between the insulating ceramic member and cylindrical ceramic base. This spatial rearrangement allows the heating element to be protected by insulating structures without requiring a thick insulating layer, thereby reducing sensor size while maintaining protection.
Solution Approach 2:
The heating element is nested within the structure formed by the insulating ceramic member and cylindrical ceramic base. This nesting arrangement allows multiple functional layers (insulation, heating, structural support) to be compactly integrated, reducing overall sensor size while maintaining the protective function.
2Reliability
If a thick insulating layer is used to maintain electric insulation, then electric insulation is maintained, but activation time increases
Solution Approach 1:
The heating element is positioned in a three-dimensional space between ceramic members rather than behind a thick planar insulating layer. This allows heat to reach the solid electrolyte body through shorter thermal paths via conduction through the ceramic members, reducing activation time while maintaining electric insulation through the ceramic structures.
Solution Approach 2:
The insulating ceramic member and cylindrical ceramic base act as intermediary structures that simultaneously provide electric insulation and thermal conduction pathways. These ceramic intermediaries allow heat to bypass the need for thick insulating layers while maintaining electrical isolation between the heating element and gas-exposed surfaces.
3Power
If the heating element is exposed to gases for direct heating, then heating efficiency improves, but the heating element deteriorates due to gas exposure
Solution Approach 1:
The insulating ceramic member and cylindrical ceramic base serve as intermediary protective structures between the heating element and the exhaust gases. These intermediaries allow thermal energy to be transferred to the solid electrolyte body while preventing direct contact between the heating element and corrosive gases, thereby maintaining both heating efficiency and element durability.
Solution Approach 2:
The heating element is nested within the protective structure of the ceramic members, allowing it to function without direct gas exposure. This nested arrangement enables the heating element to maintain high efficiency through close proximity to the solid electrolyte body while being protected from gas-induced deterioration by the surrounding ceramic structures.
4Adaptability or versatility
If complex electrode layouts are used to measure multiple exhaust gas components, then measurement capability improves, but manufacturing precision decreases due to defects
Solution Approach 1:
The sensor is segmented into distinct functional modules: the solid electrolyte body for oxygen measurement, the insulating ceramic member for structural support and insulation, and the cylindrical ceramic base with reference gas chamber. This segmentation allows each component to be manufactured and assembled separately, simplifying the overall manufacturing process and reducing defects compared to complex integrated electrode layouts.
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 quick activation of the gas sensor element, enhances durability, and reduces size, improving thermal efficiency and mechanical strength, while maintaining stability and accuracy in measuring exhaust gas components.
Implementation Method 1
a solid electrolyte body which is disposed in a through hole formed in an insulating ceramic member and conducts to at least a given ion
Implementation Method 2
a heating element which is disposed on one of opposed surfaces of the insulating ceramic member on a same side as the solid electrolyte body and works to activate the solid electrolyte body
Implementation Method 3
utilizing a high thermal conductivity insulating ceramic member for rapid activation
Data Source
AI summary
A gas sensor element includes an insulating ceramic base, a solid electrolyte body, and a heating element. The solid electrolyte body is disposed in an opening of the insulating ceramic base and has a measuring electrode affixed to one of major surfaces thereof and a reference electrode affixed to the other major surface. The measuring electrode is exposed to gas to be measured. The reference electrode is exposed to a reference gas. The heating element works to activate the solid electrolyte body and is mounted on one of opposed surfaces of the insulating ceramic base on the same side as the major surface of the solid electrolyte body on which the reference electrode is disposed. Specifically, the insulating ceramic base is located between the solid electrolyte body and the heating element, thereby ensuring a desired degree of electric insulation between the heating element and the reference electrode.