Integrated Hood Bump-Stop and Headlamp Bracket for Pedestrian Protection
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Solution Overview
Problem
Conventional hood and headlamp mounting systems in automotive vehicles face issues with high resistance to deformation during collisions, particularly pedestrian impacts, due to the combined break-away resistance of multiple support components, leading to undesirably high acceleration of the impactor.
Innovation Solution
Integration of a single structural element combining hood bump-stop and headlamp support bracket with shear pins that break away at a target force, and a horizontal slot for decoupling in case of eccentric loading, to manage reaction forces effectively during impacts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional hood and headlamp mounting systems use multiple support components with break-away resistance, then the structural strength and robustness are improved, but the acceleration imparted to the impactor during pedestrian collisions increases undesirably
Solution Approach 1:
The mounting system is segmented into multiple independent break-away points (shear pins at mounting locations, horizontal slot above shear pins) that can fail independently. This segmentation allows the structure to provide sufficient strength during normal use while enabling controlled failure modes during impact to limit force transmission to the pedestrian.
Solution Approach 2:
The break-away force parameters are carefully engineered for different components: shear pins are designed with specific shear strengths, the horizontal slot provides eccentric loading decoupling capability, and the bump-stop mounting section has controlled break-away characteristics. These parameter changes create a progressive failure mode that limits impact force while maintaining structural integrity during normal operation.
2Shape
If the hood structure is designed with flat surface closely spaced to headlamps for styling purposes, then the aesthetic appearance is improved, but the stroke zone is reduced leading to higher impact strength and undesirably high acceleration
Solution Approach 1:
The mounting system is segmented into multiple independent break-away points (shear pins at mounting locations, horizontal slot above shear pins) that can fail independently. This segmentation allows the structure to provide sufficient strength during normal use while enabling controlled failure modes during impact to limit force transmission to the pedestrian.
Solution Approach 2:
The integrated bracket acts as an intermediary element between the hood bump-stop and the reinforcement member. It provides a controlled failure path through the shear pins and horizontal slot, mediating the impact force and preventing direct transmission to the pedestrian while allowing the hood to deform appropriately.
3Stability of the object's composition
If multiple support structures are used to hold the hood, then the structural stability and support are improved, but the summing of break-away forces from several components makes it difficult to achieve desired impact response
Solution Approach 1:
The mounting system is segmented into multiple independent break-away points (shear pins at mounting locations, horizontal slot above shear pins) that can fail independently. This segmentation allows the structure to provide sufficient strength during normal use while enabling controlled failure modes during impact to limit force transmission to the pedestrian.
Solution Approach 2:
The mounting system transitions from a static rigid structure to a dynamic system with controlled degrees of freedom. The horizontal slot allows vertical movement of the bracket relative to the reinforcement member, and the shear pins provide controlled rotational movement. This dynamics enables the structure to absorb impact energy through controlled deformation rather than rigid resistance.
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
This solution reduces the acceleration imparted to the impactor during collisions by allowing controlled breakaway of the support structure, enhancing pedestrian head impact performance while maintaining robustness for normal use.
Implementation Method 1
A force greater than a predetermined force applied to the adjustable bumper results in the shear pin breaking off in the bore
Data Source
AI summary
A vehicle apparatus comprises a slider body having a substantially vertical slide slot and a substantially horizontal shear pin. The slider body further includes a headlamp mounting section and a hood bump-stop mounting section. An adjustable bumper is received by the hood bump-stop mounting section with an adjustable height. A reinforcement member is configured to be fixed with respect to a grille opening of the vehicle. The reinforcement member has a bore aligned with the slide slot for receiving a fastening pin and an aperture receiving the shear pin. A force greater than a predetermined force applied to the adjustable bumper results in the shear pin breaking off in the bore and the fastening pin sliding along the slide slot as the slider body moves downward.