Gas Sensor Element Porous Protection Layer Thermal Shock
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Solution Overview
Problem
Conventional gas sensor elements with protection layers formed by dipping processes face issues of excess thickness and increased heat capacity, leading to wasteful power consumption and prolonged activation times, while spraying processes result in slurry waste and prolonged working times.
Innovation Solution
A gas sensor element with a porous protection layer that includes spaces between the element body and the protection layer, specifically at the vertexes, allowing condensed water to evaporate and reducing the thickness and heat capacity of the protection layer, while maintaining adequate contact areas to prevent adhesion issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the protection layer is formed by a dipping process to ensure sufficient thickness at vertexes, then the element body is protected from thermal shock, but the protection layer thickness increases excessively and heat capacity increases, leading to wasteful power consumption and prolonged activation time
Solution Approach 1:
The patent applies different thicknesses of protection layer to different regions of the element body. The vertex regions have reduced thickness compared to the central regions, allowing sufficient protection where needed while minimizing overall material usage and heat capacity. This local differentiation resolves the contradiction between ensuring protection at critical points and minimizing overall heat capacity.
Solution Approach 2:
The protection layer is segmented into regions of different thicknesses, with thinner layers at vertexes and thicker layers at central regions. This segmentation allows the design to provide adequate protection at critical locations while reducing the total volume and heat capacity of the protection layer, thereby lowering power consumption requirements.
2Reliability
If the protection layer is formed by a dipping process to ensure sufficient thickness at vertexes, then the element body is protected from thermal shock, but the activation time increases due to increased heat capacity
Solution Approach 1:
By providing different thicknesses of protection layer at different locations, the patent minimizes the overall heat capacity while maintaining sufficient protection at vertexes. This reduces the time required to heat the element body to operating temperature, thereby decreasing activation time without compromising reliability.
Solution Approach 2:
The segmented protection layer with varying thickness reduces the total thermal mass of the system. The thinner regions at vertexes contribute less to heat capacity while still providing adequate protection, enabling faster heating and shorter activation times.
3Use of energy by moving object
If the protection layer thickness is reduced to decrease heat capacity and power consumption, then energy efficiency improves, but the protection layer may become too thin to prevent direct adhesion of condensed water at vertexes
Solution Approach 1:
The patent provides sufficient protection layer thickness specifically at vertex regions to prevent direct adhesion of condensed water, while using thinner layers in other regions to minimize overall heat capacity. This localized quality differentiation ensures reliability at critical points while maintaining energy efficiency.
Solution Approach 2:
The protection layer is segmented into functionally different regions: vertex regions with sufficient thickness for adhesion prevention and other regions with reduced thickness for minimizing heat capacity. This segmentation resolves the contradiction between energy efficiency and protection reliability.
4Use of energy by moving object
If a spraying process is used to apply slurry only at particular portions needing additional thickness, then the overall protection layer volume and heat capacity are reduced, but slurry is wasted and working time increases
Solution Approach 1:
The patent incorporates spaces during the formation process itself, preventing the need for subsequent spraying operations. By designing the mold or forming process to create spaces at vertexes, the protection layer is formed with the correct thickness distribution in a single step, eliminating slurry waste and reducing working time while maintaining low heat capacity.
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 reduces the heat capacity of the protection layer, preventing breakage from thermal shock and improving adhesion between the protection layer and the element body, while minimizing slurry waste and process duration.
Implementation Method 1
The protection layer has a certain thickness for allowing condensed water to evaporate before reaching the element body
Implementation Method 2
a volatile solvent disposing step of disposing a volatile solvent on an outer surface of the element body in a region where the space is to be formed... and a heat treatment step of performing heat treatment on the element body on which the green protection layer is formed, thereby forming the protection layer, wherein the volatile solvent is volatilized in a period from start of the solvent disposing step to end of the heat treatment step
Data Source
AI summary
A gas sensor element has a protection layer smaller in heat capacity than a conventional protection layer formed by a dipping process. A gas sensor includes the gas sensor element. The gas sensor element is manufactured by a method of manufacturing. The gas sensor element includes at least one space formed between a protection layer and an element body. The space is positioned over at least one of four vertexes of a forward end of the element body at a location at which the thickness of the protection layer is likely to become small. Therefore, it is possible to restrain breakage of the vertexes of the forward end of the element body which could otherwise result from thermal shock stemming from adhesion of water. The protection layer of the gas sensor element can be reduced in thickness and thus in heat capacity as compared with a conventional protection layer.