Filter Cartridge Mechanical Interference Joining Without Spin Welding
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Solution Overview
Problem
Conventional fuel filters face challenges with spin welding, requiring complex equipment setup, difficult weld joint geometries, and material variations, leading to production delays and costly failures.
Innovation Solution
A fuel filter assembly method that eliminates spin welding by using mechanical interference, such as axial retention mechanisms and anti-rotation features, to securely attach plastic components without the need for threading or spin welding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If spin welding is used to join plastic components, then strong and reliable joints can be achieved, but the process requires complex equipment setup, challenging weld joint geometries, and is sensitive to material variations leading to production delays and failures
Solution Approach 1:
The patent replaces the spin welding process (a thermal/mechanical joining process requiring complex equipment) with a mechanical interference fit system. The tapered outer surface of the end closure engages with the corresponding tapered inner surface of the canister, creating a secure mechanical connection without requiring spin welding equipment. This substitution eliminates the complex equipment setup and operation while maintaining joint reliability through the interference fit geometry.
Solution Approach 2:
The patent changes the joining mechanism from thermal welding to mechanical interference. By designing the end closure with a tapered outer surface and the canister with a corresponding tapered inner surface, the connection parameters are changed to rely on geometric interference and friction rather than thermal fusion. This parameter change eliminates sensitivity to material variations that affect spin welding while maintaining strong joints.
2Reliability
If spin welding is used to join plastic components, then secure attachment can be achieved, but production delays and costly failures occur due to process challenges
Solution Approach 1:
The patent replaces spin welding with a mechanical interference fit system that is simpler and faster to implement. The tapered surfaces allow for direct assembly without requiring the complex spin welding process, thereby eliminating production delays and costly failures while maintaining secure attachment. The mechanical interference fit can be assembled with simple tools or even by hand in many cases.
3Productivity
If mechanical interference fit is used instead of spin welding, then production delays and costs are reduced, but the attachment method must ensure secure and rotation-resistant connections
Solution Approach 1:
The patent employs asymmetric tapered surfaces for the interference fit. The tapered outer surface of the end closure matches the tapered inner surface of the canister, creating an asymmetric geometry that provides both secure attachment and resistance to rotation. This asymmetric design ensures that the connection is not only strong in axial loading but also resistant to rotational forces, thereby maintaining connection security while improving productivity.
Solution Approach 2:
The patent uses curved tapered surfaces for the interference fit mechanism. The continuous curved geometry of the tapered surfaces distributes contact stresses evenly and provides smooth engagement during assembly. This curvature ensures secure attachment while allowing for easy alignment and assembly, thereby maintaining connection security while improving production efficiency.
Data Source
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AI summary
A filter cartridge that includes a canister configured to hold a filter element. The canister has a canister body with an open end and an end closure. The end closure has a central annular element locating feature, and an annular frame portion circumscribing the central annular element locating feature. The canister body and end closure have cooperating geometry for retaining the end closure to the open end of the canister. The cooperating geometry includes an axial retention mechanism for maintaining an attachment between the canister and the end closure. The axial retention mechanism is configured to maintain the attachment solely via mechanical interference.