Ceramic Spacer for Gas Sensor Heat Insulation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional gas sensors face challenges in suppressing heat transmission to seal members, leading to thermal deterioration, especially when the casing is shortened, and existing solutions like mica spacers lack strength and durability.
Innovation Solution
A gas sensor design incorporating a ceramic spacer with a concave portion between the connector and seal member, which reduces heat transmission from the connector to the seal member, ensuring strength and heat resistance while preventing thermal deterioration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the casing is shortened to reduce sensor length, then the gas sensor size is reduced, but heat transmission to the seal member increases causing thermal deterioration
Solution Approach 1:
An insulating member made of heat-resistant material is inserted between the seal member and the connector to suppress heat transmission. This intermediary component blocks the thermal path from the heat source (exhaust gas/piping) to the seal member, allowing the casing to be shortened without causing thermal deterioration of the seal member.
2Object-affected harmful factors
If a mica insulating member is used as spacer, then heat transmission to seal member is suppressed, but the spacer lacks strength and may detach under vibration
Solution Approach 1:
The insulating member is made of a heat-resistant material that combines both insulating properties and mechanical strength. This composite material approach allows the spacer to suppress heat transmission while maintaining sufficient strength to withstand vibrations and mechanical stresses during operation.
3Object-affected harmful factors
If a resin member with low thermal conductivity is used, then heat transmission is reduced, but heat resistance is insufficient
Solution Approach 1:
The insulating member is made of a heat-resistant material with specific thermal conductivity properties that balance heat transmission suppression and heat resistance. By carefully selecting materials with appropriate thermal parameters, the spacer effectively reduces heat flow to the seal member while maintaining structural integrity at elevated temperatures.
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 ceramic spacer effectively suppresses heat transmission to the seal member, reducing thermal deterioration and ensuring the strength of the spacer, thereby maintaining the gas sensor's performance and longevity.
Implementation Method 1
a ceramic spacer (7) intervening between the seal member (6) and the connector (5) in the outer tube (4)... suppresses heat transmission to the seal member (6)
Data Source
AI summary
A gas sensor includes: a sensor element including a sensing part on a side of one end portion thereof; a casing; and a connector disposed in the casing to electrically connect the sensor element to an outside, wherein the casing includes: an outer tube including a main portion in which a reference gas is included and a sealing portion being an end portion having a smaller diameter than the main portion, another end portion of the sensor element protruding to the main portion, a rubber seal member fitted into the sealing portion to seal the outer tube, and a spacer intervening between the seal member and the connector in the outer tube. The spacer includes a concave portion in an end surface on a side having contact with the connector, and has contact with the connector in the end surface except for the concave portion.