Fuel Canister Filter Retaining Projections for Assembly Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing canisters for adsorbing and desorbing vapor from fuel systems face issues with filter displacement due to static electricity, leading to assembly failures and complex management in automated lines, and press fitting causes edge turn-ups that complicate assembly.
Innovation Solution
A canister design featuring a tentative filter engaging projection within the adsorbent chamber to securely hold the filter in place during assembly, using a combination of ring-shaped projections and ultrasonic welding to prevent displacement and ensure proper installation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the filter is loosely fitted in the adsorbent chamber to facilitate proper installation, then the ease of installation is improved, but the filter may be displaced due to static electricity or other forces
Solution Approach 1:
The retaining structure is divided into multiple discrete retaining projections distributed around the adsorbent chamber. Each projection independently holds a portion of the filter, collectively providing stable positioning while allowing easy installation. This segmentation approach prevents filter displacement without requiring a continuous complex structure.
Solution Approach 2:
The retaining projections are pre-formed on the adsorbent chamber before filter installation. These projections create preliminary engagement points that guide and secure the filter during the installation process, preventing displacement before welding occurs. The preliminary structure prepares the chamber to automatically hold the filter in the correct position.
2Reliability
If press fitting is used to prevent filter displacement, then the filter position stability is improved, but the circumferential edge of the filter may turn up causing assembly problems
Solution Approach 1:
Instead of applying uniform press fitting force around the entire filter circumference, the retaining projections provide localized support at specific points. This localized approach prevents filter displacement without causing circumferential edge turn-up, as the force is distributed through discrete contact points rather than continuous compression.
Solution Approach 2:
Rather than forcing the filter into position through press fitting (applying force to move the filter), the retaining projections work by preventing movement in the opposite direction. The projections engage the filter and prevent it from being lifted or displaced, using a passive restraint approach instead of active forcing.
3Strength
If the filter is welded directly after installation to ensure secure attachment, then the strength of attachment is improved, but assembly failures occur if the filter is displaced during the process
Solution Approach 1:
The retaining projections are prepared in advance on the adsorbent chamber to provide immediate engagement with the filter upon installation. This preliminary retaining structure ensures the filter remains precisely positioned throughout the welding process, eliminating the risk of displacement that would cause assembly failures. The precision is established before the welding operation begins.
Solution Approach 2:
The retaining projections provide a protective cushioning effect by preemptively preventing filter displacement. This protective measure is in place before any harmful displacement can occur, ensuring the filter remains stable during the vulnerable installation and welding phases. The projections act as a preventive safeguard against assembly failures.
Data Source
AI summary
A canister includes a canister case having an adsorbent chamber, an adsorbent housed in the adsorbent chamber of the canister case, a filter disposed between the adsorbent chamber and a port mounted on an end wall of the adsorbent chamber, and a tentative filter engaging projection provided in the adsorbent chamber. The filter is loosely fitted within the adsorbent chamber and then welded on the end wall of the adsorbent chamber. The tentative filter engaging projection tentatively holds the filter loosely fitted within the adsorbent chamber in a welding step of the filter.