Gas Sensor Rib Design for Heat Resistance
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Solution Overview
Problem
Conventional gas sensors in internal combustion engines face heat deterioration of ventilation filters due to high temperatures, leading to potential crevice corrosion and compromised waterproof properties, especially when the stepped section increases, forming a narrow crevice that is difficult to drain and prone to moisture leakage.
Innovation Solution
A gas sensor design featuring a rib protruding from the small-diameter section of the atmosphere-side cover, allowing the ventilation filter to be positioned closer to the base end and separated from the high-temperature tip end, thereby reducing heat transmission and ensuring stable ventilation between the atmosphere-side cover and filter cover, preventing corrosion and maintaining heat resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the stepped section is increased to place the ventilation filter closer to the base end, then heat resistance is improved, but crevice corrosion risk increases due to narrow crevice formation
Solution Approach 1:
The atmosphere-side cover is segmented into a large-diameter section and a small-diameter section, creating distinct zones that allow the ventilation filter to be positioned in the narrow crevice region without compromising overall structure. This segmentation enables heat isolation while maintaining drainage pathways.
Solution Approach 2:
A rib structure is introduced as an intermediary element between the stepped section and the ventilation filter. This rib provides structural support and creates a controlled interface that prevents moisture accumulation while allowing the filter to be positioned close to the base end for heat protection.
2Reliability
If the ventilation filter is positioned closer to the base end, then heat deterioration is reduced, but ventilation efficiency may be compromised due to restricted space
Solution Approach 1:
The ventilation pathways are designed to extend in multiple dimensions - both axially along the cover and radially through the wall thickness. This multi-dimensional ventilation approach ensures adequate air supply to the sensing element even when the filter is positioned close to the base end.
Solution Approach 2:
The atmosphere-side cover features localized ventilation openings positioned at specific locations where thermal exposure is lowest. This local quality approach ensures that ventilation occurs through regions optimized for both heat protection and airflow efficiency.
Data Source
AI summary
A gas sensor comprises an atmosphere-side cover, ventilation filter, and filter cover as well as a sensing element and housing. The atmosphere-side cover has i) a first section of a first diameter located on a tip-end side in a axial direction of the housing and fixed on an axially base end of the housing, ii) a second section of a second diameter smaller than the first diameter, the second section being located on an axially base-end side, iii) a stepped section formed between the first and second sections, and iv) a rib protruding outward from the second section and being formed between the stepped section and the second section. The ventilation filter is mounted on the second section and has an axially tip-end section being in contact with an axially base-end section of the rib. The filter cover fixes the ventilation filter between the second section and the filter cover.