Vehicle Hood Reinforcement Structure for Lower Head Impact Acceleration
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Solution Overview
Problem
Existing vehicle hood designs fail to effectively reduce Head Injury Criterion (HIC) values and ensure repeatable performance by lacking strategically structured and positioned reinforcements to absorb or redirect the momentum of impacting objects, often relying on complex release mechanisms or rigid outer surfaces that increase damage.
Innovation Solution
A vehicle hood assembly with an inner reinforcement structure positioned between the outer and inner hood structures, featuring a rib structure and rear flange to absorb or redirect the momentum of impacting objects, preventing contact with rigid fascia features and reducing HIC values by altering the acceleration trajectory.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a complex release mechanism with airbag assemblies or springs is used to offset the acceleration of impacting objects, then the acceleration of impacting objects can be reduced, but the device complexity and weight increase substantially
Solution Approach 1:
The patent extracts and eliminates the complex release mechanism (airbag assemblies, springs) from the hood structure, replacing it with a simplified reinforcement bar architecture that achieves the same safety function through structural geometry rather than active mechanical systems
Solution Approach 2:
The reinforcement structure is segmented into discrete bars with specific geometric configurations (lengths, positions, orientations) that work together to control deformation patterns and redirect impacting objects, replacing the monolithic complex mechanism with modular structural elements
2Stability of the object's composition
If the outer surface of the hood is made rigid to maintain structural integrity during vehicle movement, then the hood remains a rigid body, but impacting objects experience increased damage due to higher acceleration
Solution Approach 1:
The patent applies local quality by introducing reinforcement bars at specific locations and orientations within the hood structure, creating zones of controlled stiffness that guide deformation in safe patterns while maintaining overall structural integrity, rather than making the entire hood uniformly rigid or flexible
Solution Approach 2:
The hood assembly functions as a composite structure combining the outer hood surface, inner hood structure, and reinforcement bars into an integrated system with tailored mechanical properties that balance rigidity for vehicle operation with controlled deformability for impact safety
3Strength
If the inner support structure is made stiff to maintain hood rigidity, then the hood remains structurally sound, but it cannot deform adequately to reduce HIC values below threshold
Solution Approach 1:
The reinforcement bar structure provides dynamic characteristics by allowing controlled deformation during impact while maintaining structural integrity, enabling the hood to transition from a static rigid structure to a dynamic system that adapts its stiffness during impact events to meet HIC requirements
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 effectively reduces the likelihood of damage to both the vehicle hood and impacting objects by redirecting the momentum of impacting objects, thereby meeting safety criteria without the need for complex release mechanisms or rigid outer surfaces, ensuring the HIC values remain below threshold limits.
Implementation Method 1
redirect an impacting object's acceleration away from rigid fascia feature
Implementation Method 2
deform in a manner that reduces damage experienced by objects that impact the hood assembly
Data Source
AI summary
Systems and methods are presented herein for providing a reinforcement structure to reduce a Head Impact Criteria value associated with an object impacting a hood assembly that comprises the reinforcement structure. The reinforcement structure is arranged between an outer hood structure and an inner hood structure. The reinforcements structure comprises a main reinforcement and a reinforcement extension configured to extend laterally away from the main reinforcement. The reinforcement extension comprises a rib structure configured to accommodate an upper profile of a rigid front fascia feature and a rear flange configured to extend rearward over the rigid front fascia feature. The reinforcement extension is structured to be stiff enough to deform in a manner that reduces the amount of time an impacting structure reaches a peak acceleration value while also reducing the achievable peak acceleration value.