Lighting Device Assembly Locking Plate Airbag Safety
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Solution Overview
Problem
Lighting devices fixed to trim elements in motor vehicles, such as reading lights on roof linings, are prone to ejection during airbag deployment due to the stress caused by airbag deployment, which can lead to safety concerns.
Innovation Solution
A lighting device assembly that includes a luminous housing with interlocking members engaging with a fixing ring, which is sandwiched between a locking plate and the trim element, ensuring that the locking fingers remain in contact with the locking plate during deformation, maintaining the assembly's robustness. The assembly features a locking plate and locking fingers that prevent movement away from the locking plate, and a compact design that pinches the trim element for enhanced stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the lighting device is fixed directly to the trim element using interlocking members, then the assembly is simple and compact, but the lighting device may be ejected during airbag deployment due to trim element deformation
Solution Approach 1:
A locking plate is introduced as an intermediary component between the trim element and the lighting device housing. The locking plate has a rigid structure that prevents deformation during airbag deployment, and it provides stable engagement surfaces for the locking fingers. This mediator transfers the fixing load from the deformable trim element to the rigid locking plate, ensuring reliable retention of the lighting device under stress conditions.
2Device complexity
If the locking fingers rest on the trim element, then the assembly structure is simple, but the locking fingers may lose contact during trim element deformation
Solution Approach 1:
The locking plate serves as a stable intermediary that maintains contact with the locking fingers regardless of trim element deformation. The locking plate's rigid structure ensures it does not deform during airbag deployment, providing consistent engagement surfaces for the locking fingers. This guarantees stable locking contact even when the trim element undergoes significant deformation.
Solution Approach 2:
The locking plate is pre-installed on the trim element before the lighting device is attached. This preliminary action ensures that the rigid locking plate is already in position to absorb deformation stresses, so that when the lighting device is installed and the locking fingers engage, the stable contact surface is already prepared and will maintain engagement during subsequent deformation events.
3Adaptability or versatility
If the locking plate is made of deformable material like the trim element, then the assembly is flexible, but the locking plate will deform during airbag deployment and fail to maintain locking
Solution Approach 1:
The locking plate is made of rigid material (metal or hard polymer) specifically at the regions that contact the locking fingers and bear locking loads, while other portions of the lighting device housing may remain deformable. This local quality differentiation ensures that the critical locking interface maintains stability during airbag deployment, while the overall assembly can still have flexible components for other functions.
Data Source
Figure 1
Figure 2~3
AI summary
The invention relates to an assembly (10) of a lighting device (20) and a trim element of a motor vehicle. The trim element has a flat receiving portion (32) with an opening. The lighting device (20) comprises a light housing (21) equipped with a mounting portion (22) having engagement members (23) that, through the opening (34), engage with engagement members (41) of a retaining ring (40) bearing against a face of the receiving portion (32) opposite the housing. The housing (22) rests on a locking plate (50) applied against the receiving portion (32) around the perimeter of its opening. The retaining ring (40) includes at least two locking fingers (42) passing through the opening towards the housing, a free end (43) of each locking finger (42) bearing against the locking plate (50).