Gas Sensor Sealing Structure With Tapered Protrusions
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional gas sensors face damage to the sensor element due to concentrated pressing forces from filling powder, which compresses uniformly and damages the corners with low strength.
Innovation Solution
The gas sensor design includes a tubular holder and sleeve with tapered protrusions surrounding the element holes, distributing the pressing force more evenly along the sensor element, reducing the force at the corners and ensuring effective sealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If filling powder is compressed uniformly between flat surfaces of holder and sleeve, then sealing function is achieved, but pressing force concentrates on corners of sensor element causing damage
Solution Approach 1:
The invention introduces protrusions with tapered surfaces at specific locations where the holder and sleeve contact the filling powder. These protrusions create localized zones with different geometric properties (tapered surfaces) compared to the surrounding flat surfaces. The tapered surfaces redirect the pressing force from the filling powder, causing it to act perpendicular to the taper rather than concentrating at the corners of the sensor element, thus protecting vulnerable areas while maintaining sealing effectiveness.
Solution Approach 2:
The protrusions act as intermediary structures between the filling powder and the sensor element. Instead of the filling powder directly contacting and concentrating force on the sensor element corners, the protrusions intercept and redistribute this force through their tapered geometry. The protrusions mediate the force transmission, converting potentially harmful concentrated corner forces into distributed forces acting on more robust surfaces.
2Reliability
If filling powder is compressed to seal gap between metal shell and sensor element, then sealing is achieved, but corners with low strength are damaged due to uniform pressing forces
Solution Approach 1:
The protrusions create localized zones with tapered surfaces that modify the stress distribution pattern. Where the protrusions contact the filling powder, the pressing force is redirected along the tapered surface at an angle, preventing direct transmission of force to the sensor element corners. This local geometric modification selectively protects vulnerable corner areas while allowing effective sealing in other regions.
Solution Approach 2:
The protrusions serve as intermediary structures that intercept the pressing force from the filling powder before it reaches the sensor element. The tapered surfaces of the protrusions act as force redistribution elements, converting the uniform pressing force into redirected forces that bypass the vulnerable corners, thus eliminating the harmful effect while preserving the sealing function.
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 design prevents damage to the sensor element while maintaining a secure seal between the metal shell and sensor element, ensuring reliable operation.
Implementation Method 1
a protrusion protruding from the flat surface toward the filling powder and surrounding the first element hole or the second element hole. The protrusion is tapered toward the filling powder... when the filling powder is compressed, a pressing force from the filling powder applied to the sensor element near the boundary portion becomes a highest pressing force on a side near the top portion, and becomes a pressing force lower, at the boundary portion
Data Source
AI summary
A gas sensor comprising: a sensor element; a metal shell; a holder having a first element hole; a sleeve having a second element hole; and filling powder, wherein at least one of the holder and the sleeve has a flat surface contacting with the filling powder, and a protrusion protruding from the flat surface toward the filling powder and surrounding the first element hole or the second element hole, the protrusion is tapered toward the filling powder, as seen from a direction D perpendicular to a main surface of the sensor element, and a boundary portion BR where corners parallel to the axial-line-O direction of the sensor element abut on the protrusion is located between a top portion of the protrusion and a base portion.