Motor Vehicle Cover Retaining Hook and Latching Mechanism
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Solution Overview
Problem
Existing motor vehicle bumper covers require tools for opening and can detach during painting processes due to temperature-induced loss of prestressing force, leading to aesthetic and functional issues.
Innovation Solution
A plastic molded cover with a complementary contour, featuring retaining hooks, latching elements, and additional locking mechanisms that ensure secure closure without prestress, allowing easy assembly and disassembly, and maintaining the cover's closed position during high-temperature processes without the need for tools.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the cover is held in its closed position using conventional fastening elements during painting, then the cover remains fixed, but the high temperatures cause loss of prestressing force leading to loosening of the cover
Solution Approach 1:
The patent changes the physical state of the locking element from elastic to plastic through temperature-dependent material behavior. During painting, the locking element undergoes plastic deformation that prevents loosening, while during normal operation it maintains elastic properties for reversible locking/unlocking
Solution Approach 2:
The locking element transitions between different mechanical states (elastic and plastic) depending on temperature conditions. The system dynamically adapts its behavior: elastic during assembly and normal operation, plastic during painting to prevent loosening
2Ease of operation
If the cover is made easily removable for assembly, then assembly is simple, but the cover may detach unintentionally during operation
Solution Approach 1:
The fastening system is segmented into multiple independent locking elements distributed around the cover perimeter. This provides both easy assembly through simple insertion and high retention reliability through multiple simultaneous locking points
Solution Approach 2:
The locking elements automatically engage when the cover is inserted and automatically disengage when appropriate force is applied. The system is self-regulating, requiring no external assistance for assembly or release
3Reliability
If the cover is held with prestress against the opening, then the cover remains securely closed, but the temperature-dependent loss of prestressing force causes loosening during painting
Solution Approach 1:
The locking mechanism transitions from relying on elastic prestress (which is temperature-sensitive) to plastic deformation (which is temperature-insensitive). This eliminates the energy loss problem during painting while maintaining secure closure during normal operation
Solution Approach 2:
The locking element undergoes preliminary plastic deformation during the painting process to set a new reference state. This preliminary action prevents subsequent loosening that would otherwise occur due to thermal effects
Data Source
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AI summary
A device, having a plastic molded part (1), in particular an add-on part and/or trim part for a motor vehicle, comprises a cover (2) for closing an opening (3) in a wall (4) of the plastic molded part (1). The cover (2) has a first rim (6) and a second rim (7), substantially opposite of the first rim (6), wherein the cover (2) has at least one retaining hook (9), which engages behind the opening (3) in the closed position of the cover (2), on the inner side (8) facing the opening (3) in the region of the first rim (6), and the cover (2) further has at least one detent element (10) on the inner side (8) in the region of the second rim (7), said detent element being latched in the closed position of the cover (2) to at least one detent counter element (11), fixedly attached to the wall (4). The cover (2) has at least one further additional detent element (12) on the inner side (8) in the region of the first rim (6), said element interacting with at least one additional detent counter element (13) at the wall (4), so that the cover (2) is held in the closed position at least substantially without prestress with respect to the opening (3).