Gas Sensor Two-Stage Sealing Method
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Solution Overview
Problem
Conventional gas sensor manufacturing methods require high loading for hermetic sealing, which can lead to sensor element cracking or breakage due to improper posture during the sealing process, resulting in defective products.
Innovation Solution
A two-stage sealing method is employed, where the sensor element is initially positioned using a tentative sealing process without applying excessive force, followed by a main sealing process that secures airtightness without using an element positioning member, thereby preventing chip or breakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high loading is applied for hermetic sealing, then sealing reliability is improved, but sensor element damage (crack or break) occurs
Solution Approach 1:
The patent applies preliminary positioning action by using an element positioning member to correctly orient the sensor element before hermetic sealing is performed. This preliminary positioning prevents the sensor element from being in an improper posture during high-load sealing, thereby preventing crack or break while achieving reliable sealing.
2Manufacturing precision
If element positioning member is used for positioning, then sensor element positioning accuracy is improved, but device complexity increases
Solution Approach 1:
The patent introduces an element positioning member as an intermediary component that facilitates correct positioning of the sensor element during assembly. This positioning member acts as a mediator between the sensor element and the sealing jig, ensuring proper orientation without requiring complex positioning mechanisms.
3Productivity
If sensor element is in improper posture during sealing, then sealing efficiency is maintained, but defective product generation increases
Solution Approach 1:
The patent performs preliminary positioning of the sensor element using an element positioning member before the hermetic sealing process. This preliminary action ensures the sensor element is in the correct posture and position, preventing defective products while maintaining sealing efficiency through the subsequent high-load sealing process.
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 approach effectively reduces the generation of defective products by ensuring accurate positioning and hermetic sealing without damaging the sensor element, enhancing the reliability of the gas sensor manufacturing process.
Implementation Method 1
a second compression for the hermetic sealing between the spaces located on one end side and the other end side of the sensor element inside of the tubular body is successively performed subsequent to the first compression performed mainly for purpose of positioning the sensor element
Data Source
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AI summary
Provided is a method for manufacturing a gas sensor capable of securing airtightness without a chip in a sensor element. The method includes a step of obtaining an assembled body constituting the gas sensor, including steps of: causing one end of the sensor element to abut to a positioning member for positioning the sensor element; applying a force F1 to the annularly-mounted members including a powder compact annularly mounted to the sensor element under a state that the sensor element is positioned and thereby compressing the powder compact so as to fix the sensor element inside of the tubular body; applying a force F2 larger than the force F1 to the annularly-mounted members under a state that the sensor element is not positioned and thereby further compressing the powder compact, so as to hermetically seal inside of the tubular body.