Gas Sensor Elastic Body Swaging Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Gas sensors with a tapered swaged shape on the rear end of the outer tube face issues such as stress concentration, increased risk of elastic body rupture, deterioration of airtightness, and displacement of the contact point, leading to unstable airtightness and electrical connection loss.
Innovation Solution
A gas sensor design with a constant diameter in the reduced diameter portion of the tubular body and a corresponding constant post-swaging diameter of the elastic body, where the elastic body is swaged from the periphery, ensuring appropriate stress distribution and conversion of deformation into radial deformation to maintain airtightness and prevent contact point displacement, as defined by specific mathematical expressions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the rear end side of the outer tube is swaged to have a tapered shape, then the airtightness of the interior of the outer tube is improved, but stress concentrates on the elastic body causing increased risk of rupture and deterioration of airtightness
Solution Approach 1:
The patent applies local quality by creating a reduced diameter portion with a specific constant diameter in the tubular body, rather than using a uniform tapered shape throughout. This localized structural modification concentrates the stress-reducing effect at the critical swaging region while maintaining the overall tapered configuration for airtightness.
Solution Approach 2:
The patent changes the geometric parameter of the tubular body by introducing a reduced diameter portion with a constant diameter section. This parameter modification alters the stress distribution characteristics, preventing stress concentration that would occur with a continuous tapered shape, thereby protecting the elastic body from rupture while maintaining sealing effectiveness.
2Reliability
If the rear end side of the outer tube is swaged to have a tapered shape, then the airtightness is improved, but the swaged portion varies in diameter making it difficult to control dimensions
Solution Approach 1:
The patent introduces a reduced diameter portion with a constant diameter section in the tubular body, creating a localized region with uniform dimensions. This allows precise control of the swaged portion diameter while maintaining the overall tapered configuration for airtightness, directly addressing the manufacturing precision issue.
Solution Approach 2:
The reduced diameter portion is formed in advance during the manufacturing process, establishing a predetermined constant diameter section before the swaging operation. This preliminary structural preparation ensures that the swaged portion maintains consistent dimensions, making it easier to control manufacturing precision.
3Reliability
If the elastic body is swaged with large compressive force, then the airtightness is improved, but the elastic body deforms and moves in the axial direction causing contact point displacement
Solution Approach 1:
The reduced diameter portion creates a localized structural feature that modifies how compressive forces are transmitted to the elastic body. By concentrating the structural modification at a specific location, the patent reduces overall axial deformation while maintaining effective sealing pressure, thereby preventing contact point displacement.
Solution Approach 2:
The reduced diameter portion acts as a stress-distributing feature that cushions the elastic body against excessive compressive forces during the swaging process. This preliminary structural design prevents over-compression and subsequent axial movement, protecting the electrical connection stability before damage can occur.
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 design effectively reduces the risk of airtightness deterioration, elastic body rupture, and contact point displacement, ensuring stable airtightness and maintaining electrical connections by converting axial deformation into radial deformation within acceptable limits.
Implementation Method 1
an elastic body configured to seal the opening end, the lead wire being inserted into the elastic body
Implementation Method 2
the reduced diameter portion configured to swage a part of the elastic body from a periphery... the gas sensor converts axial deformation into radial deformation
Data Source
AI summary
Provided is a gas sensor that prevents risks such as deterioration of airtightness of the interior of an outer tube, rupture of an elastic body, and occurrence of the displacement of a contact point without swaging a rear end side of the outer tube to have a tapered shape. In the gas sensor according to one aspect of the present invention, a diameter of a reduced diameter portion formed on a rear end side of a tubular body and swaging the elastic body is constant in the axial direction, and a value of a comprehensive parameter which is an index for evaluating the deformation of the elastic body is 0.038 or more and 0.171 or less.