Blind Fastening Device for Automotive Trim Panels
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing fastening devices for panels in automotive vehicles, such as inside trim panels, are not visually discrete and do not provide sufficient resistance to pulling off, especially in critical zones like the airbag deployment area.
Innovation Solution
A fastening device comprising a male member with a spike foot and a female member featuring an elastic cavity and actuating part, allowing for blind mounting and high resistance to pulling off, with a design that includes a butt with cylindrical portions and locking fins for secure engagement and release.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If a traditional fastening device with visible components is used, then the panel can be fastened to the wall, but the device is not visually discrete and affects aesthetics
Solution Approach 1:
The male member with spike foot is nested within the female member's reception cavity, allowing the fastening mechanism to be concealed within the wall aperture rather than protruding externally. The spike foot retracts into the cavity when not in use, making the fastening device visually discrete while maintaining functional complexity internally.
Solution Approach 2:
The elastic part acts as an intermediary between the spike foot and the retention wall, providing a flexible connection that allows the spike to pass through while maintaining engagement. This intermediary element enables the fastening function to be achieved without rigid, visible mechanical connections.
2Strength
If a fastening device with high resistance to pulling off is required, then the panel remains secure under shock, but the device becomes more complex with additional retention mechanisms
Solution Approach 1:
The spike foot features a curved, ogive-shaped profile that narrows from shoulder to distal end, allowing it to flex and engage with the retention wall at an angle. This curved geometry enables the spike to deform elastically under pull-off forces, distributing stress along the curved surface rather than at a single point, thereby increasing resistance to pulling off without requiring additional mechanical retention elements.
Solution Approach 2:
The elastic part changes its physical state from relaxed to deformed under load, allowing the fastening device to adapt its retention characteristics dynamically. When pull-off forces are applied, the elastic part deforms to engage more firmly with the retention wall, increasing resistance automatically without requiring complex mechanical adjustment mechanisms.
3Ease of operation
If a fastening device allowing easy assembly and disassembly is used, then maintenance is simplified, but the resistance to pulling off may be reduced
Solution Approach 1:
The fastening device transitions between two dynamic states: engaged and disengaged. The elastic part and spike foot are designed to flex during engagement, creating a temporary deformation that locks the panel in place. For disassembly, applying force to the actuating part reverses this deformation, allowing the spike to withdraw smoothly. This dynamic behavior enables easy assembly and disassembly while maintaining high resistance to pulling off during normal operation.
Solution Approach 2:
The fastening mechanism operates through periodic cycles of engagement and disengagement. During engagement, the spike foot is thrust into the reception cavity, deforming the elastic part to create a locked state. During disassembly, the actuating part is activated to reverse the deformation and release the lock. This periodic action allows the device to switch between high-strength retention and easy release states as needed.
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 device provides high resistance to pulling off forces, is visually discrete, and allows for easy assembly and disassembly, ensuring the panel remains securely attached to the wall even under shock conditions, such as during airbag deployment.
Implementation Method 1
an elastic part extending across the reception cavity which is configured to bend in contact with the spike, on a thrusting-in movement of the foot into the cavity, and to relax when the spike has passed beyond it
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
This is to fasten a panel (3) to a wall (2). The device (1) comprises a male member (5, 6) to engage on the panel (3) and a female member (45) to engage on the wall (2). For its engagement on the periphery of an aperture (8) of the wall (2) having a contour having two crenels facing each other and two circle arcs facing each other and each extending from one to the other of the crenels, the female member (45) comprises a butt enabling the angular position of the female member (45) to be indexed in relation to the wall (2), in order for an actuating part (75) of the female member (45) to be turned towards an outside edge of the wall (2). The assembly comprises the fastening device (1), the wall (2) and the panel (3). Advantageously, the assembly also comprises a tool capable of insertion between the wall (2) and the panel (3) to reach the actuating part of the female member.