Gas Sensor Protective Member Shielding Filter from Impact
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Solution Overview
Problem
Conventional oxygen sensors are vulnerable to external impacts and water ingress due to the exposure of filter members, leading to potential damage and abnormal sensor output or short-circuiting.
Innovation Solution
A gas sensor design featuring a protective member that covers the air vent of the plug member, providing air permeability while preventing direct exposure of the filter member to the outside environment, and includes a locking mechanism to prevent rotation and ensure safe assembly, ensuring the filter member is not directly exposed to external impacts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the filter member is directly exposed to the outside environment through the air vent, then air permeability is secured, but the filter member becomes susceptible to external impact and water ingress
Solution Approach 1:
A protective member is introduced as an intermediary component between the external environment and the filter member. This protective member covers the air vent while containing openings that allow air passage, thereby mediating between the need for air permeability and the need to protect the filter member from external impacts and water ingress.
Solution Approach 2:
The protective member is designed with multiple separate openings rather than a single large opening. This segmentation allows air to pass through multiple small paths while making the protective member more resistant to external impacts, as the distributed structure can better withstand and distribute impact forces.
2Reliability
If the protective member is added to cover the air vent, then the filter member is protected from external impact, but the device complexity increases
Solution Approach 1:
The protective member is integrated with the existing plug member structure. The protective member is fitted into the plug member, combining the functions of sealing, air venting, and protection into a single integrated assembly, thereby reducing the overall device complexity despite adding protective functionality.
Solution Approach 2:
The protective member serves multiple functions simultaneously: it protects the filter member from external impacts, prevents water ingress, maintains air permeability through its openings, and can also serve as a mounting structure for the filter member. This multi-functionality reduces the need for additional separate components.
3Reliability
If the opening of the protective member is made smaller than the air vent, then the filter member is better protected, but air permeability may be reduced
Solution Approach 1:
The protective member features localized openings positioned strategically to maintain air flow paths. The openings are distributed in specific locations and patterns that preserve adequate air permeability while the overall protective structure maintains its protective function. The local quality of the openings allows air passage without compromising the global protective function.
Solution Approach 2:
The protective member can be designed with a porous structure or multiple small openings that collectively provide sufficient air permeability. This porous approach allows air to pass through the protective member effectively while maintaining the protective function, as the porous structure can withstand external impacts better than large single openings.
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 protective member effectively shields the filter member from external impacts and water ingress, maintaining air permeability and preventing damage, thus ensuring the reliability and accuracy of the gas sensor's operation.
Implementation Method 1
a filter member (87) having air permeability and waterproofness
Implementation Method 2
The atmosphere communication hole of the plug member is provided with a filter member for introducing the atmosphere into the outer casing, but which prevents water droplets or the like from entering the outer casing
Implementation Method 3
a first protective member (100) that covers the air vent (91) of the plug member (9) so as to protect the filter member (87)
Implementation Method 4
The detecting element detects oxygen in the exhaust gas by an electromotive force generated between the subject electrodes according to a difference in oxygen partial pressure between the exhaust gas and the reference gas (atmosphere)
Data Source
AI summary
A gas sensor having an axis including a detecting element; a metal shell; an outer cylinder; and a plug member, as defined herein, and the gas sensor includes a first protective member that covers an air vent of the plug member so as to protect the filter member, the protective member having a ventilation portion having an opening smaller than an opening of the air vent and at least partially overlapping the air vent in the axial direction, and at least one of the outer cylinder and the plug member is provided with a locking portion that limits rotation of the protective member around the axis.