Molded Fastener Clip Assembly for High-Extraction Panel Attachment
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Solution Overview
Problem
Conventional fastener devices fail to provide adequate attachment of body panels to vehicle chassis with varying curvature or thickness, leading to issues like buzzing, rattling, and poor tolerance for production variations, while offering equal insertion and extraction forces.
Innovation Solution
A fastener clip assembly is molded onto a component using an injection mold, transferring its contour to the blade, with inward and outward projections engaging corresponding depressions and projections on the blade for enhanced securement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If conventional fastener devices are used to attach body panels to chassis, then the attachment can be made with simple structure, but the insertion force and extraction force are approximately equal which does not provide adequate attachment
Solution Approach 1:
The fastener device is segmented into multiple independent arms (typically four) that can engage with the slot at different positions. Each arm can independently provide engagement force, allowing the fastener to accommodate variations in slot position and sheet metal thickness while maintaining high extraction force through cumulative engagement of multiple arms.
Solution Approach 2:
The fastener arms are designed to be flexible and movable during insertion, allowing them to adapt to the slot position and sheet metal thickness variations. Once inserted, the arms become rigid to provide high extraction force. This dynamic behavior allows the fastener to achieve high extraction force without requiring a complex rigid structure.
2Adaptability or versatility
If conventional fasteners with stepped arms are used, then the fastener can engage the slot, but only at discrete step positions which limits adaptability to production tolerances
Solution Approach 1:
The fastener arms are designed to be flexible during insertion, allowing continuous adjustment of engagement position along the slot rather than being restricted to discrete stepped positions. This dynamic flexibility enables the fastener to accommodate production tolerances in slot position and sheet metal thickness without requiring precise manufacturing of fixed step positions.
Solution Approach 2:
The fastener design allows the engagement parameters (position, depth, angle) to vary within a range to accommodate production tolerances. The flexible arms can engage the slot at different positions along its length, providing adaptability to variations in slot position and sheet metal thickness without requiring high manufacturing precision for fixed engagement points.
3Object-affected harmful factors
If conventional fasteners are used, then the structure is simple, but buzzing and rattling occur due to movement within step size range
Solution Approach 1:
The fastener arms are designed with different properties at different locations: the engagement portions are rigid to prevent movement and noise, while the connection portions to the body are flexible to allow insertion and accommodate misalignment. This local differentiation of rigidity and flexibility reduces noise without requiring a completely complex structure.
Solution Approach 2:
The fastener arms transition from a flexible state during insertion to a rigid state during operation. Once the arms engage the slot, they become rigid to prevent movement and eliminate buzzing and rattling. This dynamic rigidification eliminates noise without requiring permanently complex noise-damping structures.
4Adaptability or versatility
If conventional fasteners are used, then manufacturing is simple, but the fastener does not accommodate variations in sheet metal thickness and production tolerances
Solution Approach 1:
The fastener design allows key parameters such as arm length, arm thickness, and engagement depth to vary within specified ranges to accommodate production tolerances in body panels and chassis. This parametric flexibility enables the same fastener design to work across different sheet metal thicknesses without requiring complex adjustment mechanisms or multiple fastener variants.
Solution Approach 2:
The flexible arms can adapt their engagement depth and angle during insertion to accommodate variations in sheet metal thickness and slot position. This dynamic adaptation allows the fastener to maintain proper engagement across a range of tolerances without requiring precise manufacturing or complex adjustment mechanisms.
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 solution ensures stable attachment with high extraction resistance, minimizing noise and accommodating production variations, by using projections and depressions for secure engagement.
Implementation Method 1
blade 210 is molded onto component 400 using fastener clip 100 as part of the injection mold for the blade
Implementation Method 2
engagement of one portion of the hole in the chassis with one of the arms may not provide suitable frictional engagement
Data Source
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AI summary
A method comprising inserting a fastener clip inside an injection mold cavity to use as part of the injection mold cavity. The fastener clip is inserted into the injection mold cavity where a blade is to be formed on a plastic component. The fastener clip is configured to engage and couple to the blade and to the plastic component and to engage and couple to a slot in a structure. Also included is injecting flowing plastic into the fastener clip and the injection mold to form the lade. At least a portion of a contour of a surface of the blade follows a contour of an inner surface of the fastener clip. A fastener clip comprising a pair of laterally offset legs joined at a head portion, wherein the legs form a clip opening at an opposite end of the head portion, wherein the pair of legs are configured to spring back to an original position based at least in part on the pair of legs being pushed together, a pair of outward projections extending outward from the pair of legs, a pair of inward projections correspondingly extending inward from the pair of legs, wherein the fastener clip attaches to a slot in a structure based at least upon: the fastener clip being pushed into the slot, the pair of legs compressing for the outward projections to clear the slot, the pair of legs decompressing, the pair of outward projections engaging an inner part of the slot, and contact forces generated between the pair of outward projections and the inner part of the slot.