Gas Sensor Assembly Positioning and Compression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional gas sensors with ceramic sensor elements face issues of breakage during assembly due to improper posture and stress from ceramic supporters, leading to defective products and reduced manufacturing efficiency.
Innovation Solution
A method for manufacturing gas sensors that involves a two-stage compression process for hermetic sealing, using a positioning member to initially position the sensor element and then applying a second force without the member to ensure proper alignment and prevent breakage, along with an inclination inspection to detect potential defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high pressing load (400 kgf or more) is applied by sealing jig for hermetic sealing, then airtightness is secured, but sensor element may break due to stress concentration
Solution Approach 1:
The sensor element is positioned in advance using positioning members (pins or jigs) before the hermetic sealing process begins. This preliminary positioning ensures the element is correctly aligned and supported, distributing the subsequent pressing load evenly across the powder compacts rather than concentrating stress at specific contact points, thereby preventing breakage during sealing
Solution Approach 2:
Positioning members act as intermediaries between the sealing jig and the sensor element. These members transfer and distribute the pressing force through the powder compacts in a controlled manner, mediating the interaction between the high-load sealing process and the fragile sensor element to prevent direct stress concentration on the element
2Productivity
If sensor element is not properly positioned during assembly, then manufacturing efficiency is reduced due to defective products, but implementing complex positioning mechanisms increases device complexity
Solution Approach 1:
The positioning function is segmented into multiple simple positioning members (pins or jigs) distributed at different locations on the sensor element. Each positioning member handles a specific location, and collectively they ensure proper alignment. This segmentation allows using simple, individual components rather than a single complex positioning mechanism
Solution Approach 2:
The positioning members are designed to automatically guide and constrain the sensor element into the correct position during assembly. The sensor element itself, through its interaction with the positioning members, achieves proper alignment without requiring complex external positioning systems or manual adjustment, thereby maintaining manufacturing efficiency
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 method effectively suppresses breakage failures and defective product generation, ensuring accurate assembly and reliable gas sensor performance by constraining the sensor element's position and detecting washer inclination to prevent misalignment.
Implementation Method 1
applying a first force to the annularly-mounted members from the other end side of the sensor element having been positioned through the step a) and thereby compressing the powder compact so as to fix the sensor element inside of the tubular body
Data Source
Figure 1
Figure 2
Figure 3A~3C
AI summary
Provided is a method for manufacturing a gas sensor which suppresses a defective product caused by a defective posture of a sensor element therein. 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 come to abut to a positioning member for positioning the sensor element; and applying a first force 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, and the compression is performed while constraining the sensor element in a predetermined constraining region in the other end side of the sensor element.