Fuel Filter Drain Fitting Crimped Connection Anti-Rotation
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Solution Overview
Problem
Existing fuel filter cartridges face manufacturing cost and complexity issues due to the need for precise tolerances in press-fitting drain fittings, which can lead to loose connections and operational failures, such as rotation and displacement during draining.
Innovation Solution
A crimped connection is used to attach the drain fitting to the filter cartridge housing, with an anti-rotation feature and a crimping recess, allowing for a more secure and flexible joint that reduces manufacturing complexity and cost, while maintaining secure attachment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a press-fit connection is used to attach the drain fitting to the housing, then the manufacturing process is simpler, but the connection reliability deteriorates due to loosening and rotation during operation
Solution Approach 1:
The connection interface is segmented into distinct functional zones: a crimping zone with radial flexibility for secure attachment, and an axial zone maintaining looseness to prevent rotation. The crimping recess divides the drain fitting's outer surface into a crimpable peripheral portion and a non-crimpable axial portion, allowing differential behavior in different directions.
Solution Approach 2:
Different mechanical properties are applied to different locations of the drain fitting. The peripheral portion is made crimpable with radial flexibility for secure attachment, while the axial portion maintains structural integrity to prevent rotation. The housing similarly has a crimpable portion with specific local geometry that receives and secures the crimped fitting.
2Reliability
If close tolerances are maintained on the drain fitting and housing for press-fit connection, then the connection reliability improves, but the manufacturing cost and complexity increase
Solution Approach 1:
The connection mechanism changes from relying on precise dimensional parameters (close tolerances) to relying on a geometric transformation parameter (crimping deformation). The crimping process transforms the housing's crimpable portion from a loose fit state to a secured state through plastic deformation, eliminating the need for tight manufacturing tolerances.
Solution Approach 2:
The drain fitting is preliminarily inserted into the housing in a loose condition before the crimping operation. This preliminary positioning ensures proper alignment and engagement of the crimping features, while the subsequent crimping action secures the connection. The anti-rotation feature is also preliminarily formed on the drain fitting to prevent rotation during the crimping process.
3Device complexity
If the drain fitting is loosely fitted into the housing, then the manufacturing complexity is reduced, but the connection reliability deteriorates due to potential loosening over time
Solution Approach 1:
The connection transitions from a static loose fit to a dynamically secured state through the crimping process. The housing's crimpable portion is designed to deform plastically during crimping, creating a permanent mechanical interlock that prevents loosening. The crimping recess geometry ensures that the deformed material locks the drain fitting in place while maintaining the ability to prevent rotation.
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 crimped connection provides a more secure and stable attachment of the drain fitting, reducing the likelihood of loosening and rotation, and simplifies the manufacturing process, ensuring effective water drainage and reduced operational issues.
Implementation Method 1
a crimped portion (38) of the housing (20) is formed into the crimping recess (34) of the drain fitting (28) to thereby form a crimped connection (30) between the drain fitting (28) and the housing (20)
Implementation Method 2
The anti-rotation feature of the drain fitting (28) resists rotation of the drain fitting (28) with respect to the housing (20)
Data Source
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AI summary
In a fluid filter cartridge, and a method for manufacturing a fluid filter cartridge, a drain fitting is attached by a crimped joint to a housing of the filter cartridge. The drain fitting is loosely fitted into the housing, prior to forming the crimped joint. The drain fitting has an outer periphery thereof which includes a crimping recess therein and the housing includes a crimped portion thereof which is formed into the crimping recess of the drain fitting to form the crimped connection. The crimping recess further includes anti-rotation features in the form of raised ribs about which the crimped portion of the housing is formed for resisting rotation of the drain fitting with respect to the housing.