Gas Sensor Protector with Dual Opening Configuration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Gas sensors in intake passages of internal combustion engines face challenges with clogging due to soot and moisture ingress, leading to degraded detecting precision and potential fracturing or cracking of the detecting element.
Innovation Solution
A gas sensor design featuring a protector with a dual opening configuration, where the second opening at the bottom portion is larger than the largest imaginary circle that can fit inside the first opening, and the second opening is positioned to face the downstream side of the intake passage, allowing for rapid gas exchange and minimizing moisture intrusion, while the first opening is smaller to prevent soot accumulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the gas releasing portion is made large to prevent clogging, then soot blockage is suppressed, but water intrusion increases causing detecting element damage
Solution Approach 1:
The gas releasing portion is divided into multiple smaller openings distributed across the bottom surface of the protector, rather than one large opening. This segmentation allows sufficient gas exchange while reducing individual opening size to prevent soot blockage and minimizes water intrusion risk through each small opening
Solution Approach 2:
The bottom surface of the protector is designed with specific local properties - a hydrophobic coating is applied to the bottom surface where gas releases, creating a water-repellent local quality that prevents water intrusion while allowing gas to pass through the multiple small openings
2Object-affected harmful factors
If the gas releasing portion is made small to prevent water intrusion, then detecting element protection is improved, but clogging occurs reducing detecting precision
Solution Approach 1:
The gas releasing portion is divided into multiple smaller openings distributed across the bottom surface of the protector, rather than one large opening. This segmentation allows sufficient gas exchange while reducing individual opening size to prevent soot blockage and minimizes water intrusion risk through each small opening
Solution Approach 2:
A heating element is provided that heats the bottom surface of the protector to a temperature sufficient to evaporate condensed water and burn off soot particles. This thermal treatment prevents water intrusion and maintains detecting precision by keeping the openings clear of soot accumulation
3Object-affected harmful factors
If the protector opening faces the upstream side to prevent water intrusion, then detecting element protection is improved, but gas exchange efficiency decreases
Solution Approach 1:
The protector is designed with asymmetric features - the bottom surface has a specific orientation and geometry that exploits gravitational and aerodynamic effects to prevent water intrusion while maintaining gas exchange efficiency, regardless of the opening's directional orientation
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
This configuration effectively suppresses clogging and fracturing, maintaining the detecting element's precision and preventing water coverage, thereby enhancing the sensor's responsiveness and longevity.
Implementation Method 1
a gas sensor having a detecting element in which the intensity of the electromotive force or the resistance value varies with the concentration of NOx (nitrogen oxides), oxygen, and the like
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A gas sensor including a detecting element (10); and a protector having a tube portion (130) surrounding the detecting portion, and a bottom portion (132) the protector having a first opening (140) disposed at the tube portion and a second opening (150) at the bottom portion. The bottom portion includes first (1321) and second (1322) bottom wall portions, the second bottom wall portion (1322) protrudes toward the leading end side, and at least a part of the inner face thereof is located at the leading end side with respect to the outer face of the first bottom wall portion. The second opening (150) is provided on a side opposite the inner space of the tube portion in a communication passage formed by the inner face of the second bottom wall portion, and an opening area of the second opening is larger than an area of the largest imaginary circle that can be placed inside the first opening.