Gas Sensor Press-Fit Assembly Eliminates Welding Fumes
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Solution Overview
Problem
The existing gas sensor manufacturing methods face issues with fumes generated during welding, which adhere to the protective cover and casing, reducing measurement accuracy, increasing failure rates, and increasing manufacturing costs due to the need for precise welding and additional management man-hours.
Innovation Solution
A gas sensor manufacturing method that connects the casing and protective cover without welding joints, using press-fitting to ensure accurate alignment and gas flow, preventing fume adhesion and reducing manufacturing complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If welding is used to connect the inner member and distal end portion of the casing, then connection strength is improved, but fumes are generated and adhere to the components, reducing measurement accuracy and increasing failure rate
Solution Approach 1:
The patent removes the welding process from the connection method between the protective cover and casing. By eliminating welding, fume generation is prevented, thus avoiding adhesion to the sensor element and maintaining measurement accuracy while still achieving secure connection through alternative means.
Solution Approach 2:
The patent replaces the thermal welding process with a mechanical connection system. The protective cover is connected to the casing through mechanical engagement features such as ribs, grooves, or snap-fitting mechanisms, which provide sufficient connection strength without generating harmful fumes.
2Strength
If welding is used to connect the outer member and casing, then connection strength is improved, but fumes adhere to the connection portion, reducing connection accuracy
Solution Approach 1:
The patent eliminates welding from the connection process between the outer member and casing. By removing this thermal process, fume adhesion to connection surfaces is prevented, ensuring accurate alignment and proper fit of connection features.
Solution Approach 2:
The patent employs preliminary positioning features such as alignment ribs, guide pins, or pre-formed engagement structures that ensure accurate connection between components before final assembly. This mechanical guidance system maintains connection accuracy without requiring welding.
3Strength
If welding is used to connect the inner member and distal end portion of the casing, then connection strength is improved, but manufacturing cost and management man-hours increase
Solution Approach 1:
The patent removes welding operations from the manufacturing process. This elimination reduces equipment requirements, lowers operational costs, decreases management overhead, and simplifies quality control while maintaining adequate connection strength through mechanical means.
Solution Approach 2:
The patent changes the connection method from a high-complexity thermal process (welding) to a simpler mechanical process. This parameter change in the manufacturing approach reduces cost, time, and management requirements while achieving the necessary connection strength for sensor functionality.
Data Source
AI summary
In a method for manufacturing a gas sensor, a casing for holding a sensor element and a protective cover are connected to each other so that a distal end portion of the sensor element is covered with the protective cover. A first gas chamber, a sensor element chamber, and a second gas chamber into which gas is introduced from the outside are formed between the protective cover and the casing. In the gas introduction portion including the first gas chamber, the sensor element chamber, and the second gas chamber, there is no joint portion formed by welding.