Three-Stage Hood Bumper for Progressive Impact Absorption
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Solution Overview
Problem
Hood bumpers in vehicles face challenges in effectively managing varying force magnitudes during hood closure and potential impacts, necessitating a solution that provides progressive absorption and deformation to meet safety standards like HIC criteria.
Innovation Solution
A three-stage hood bumper system comprising a retractable plunger, a compressible bumper head, and a collapsible support frame, which absorbs forces through distinct mechanisms: initial plunger compression, bumper head compression, and frame collapse, respectively, to manage forces from normal closure to high-impact events.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single-stage bumper design is used, then the device complexity is reduced, but the ability to effectively manage varying force magnitudes deteriorates
Solution Approach 1:
The bumper is divided into three distinct operational stages with different mechanical characteristics: a first stage with high stiffness for normal closure forces, a second stage with reduced stiffness for moderate impact forces, and a third stage with minimal stiffness for severe impact forces. Each stage is designed to activate at specific force thresholds, allowing the bumper to adapt to varying force magnitudes without requiring a completely different structure for each scenario.
Solution Approach 2:
The bumper transitions from a static, single-stiffness structure to a dynamic, multi-stiffness system that automatically adjusts its mechanical properties based on the applied force. The progression through three distinct stages with decreasing stiffness allows the bumper to dynamically respond to the severity of the impact, providing appropriate protection while maintaining structural integrity for normal operations.
2Reliability
If progressive three-stage absorption is implemented, then the force management effectiveness is improved, but the device complexity increases
Solution Approach 1:
The bumper mechanism is segmented into three distinct functional stages, each with specific stiffness characteristics designed to activate at different force thresholds. This segmentation allows the system to reliably manage forces across a wide range of magnitudes by transitioning through predetermined stages, with each stage contributing to the overall force absorption effectiveness.
Solution Approach 2:
The bumper utilizes changes in stiffness parameters across three operational stages to improve force absorption effectiveness. By designing the bumper to progress from high stiffness in the first stage to reduced stiffness in the second stage, and minimal stiffness in the third stage, the system reliably adapts its mechanical properties based on the applied force magnitude.
3Object-affected harmful factors
If hood deformation is increased to meet HIC criteria, then the safety performance is improved, but the protection capability for engine compartment components deteriorates
Solution Approach 1:
The bumper applies different stiffness characteristics at different stages of deformation to simultaneously satisfy conflicting requirements. The first stage maintains high stiffness to protect components during normal operation, while the second and third stages progressively reduce stiffness to enable sufficient hood deformation for HIC criteria compliance. This local differentiation of mechanical properties allows the bumper to provide both component protection and safety performance.
Solution Approach 2:
The bumper is designed with predetermined stiffness reductions at specific force thresholds to cushion the impact before it reaches critical levels. By planning for progressive stiffness reduction across three stages, the system ensures that sufficient deformation occurs to meet HIC criteria while the initial high-stiffness stage provides beforehand protection for engine compartment components during normal closure events.
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 system effectively absorbs and distributes forces across three magnitude levels, providing progressive deformation to protect vehicle components, aligning with safety standards by ensuring adequate hood deformation during impacts.
Implementation Method 1
a biasing mechanism operably connected to the housing and a plunger operably connected to the biasing mechanism
Implementation Method 2
The plunger is configured to move from an extended position to a compressed position into the internal chamber and compress the biasing mechanism when the force is greater than a first magnitude
Implementation Method 3
The bumper is configured to be compressible when the force is above the second magnitude
Implementation Method 4
The support frame is collapsible from an uncollapsed position to a collapsed position when the force is greater than a third magnitude
Data Source
AI summary
A hood bumper for a vehicle having a hood including: a housing having a wall, a base, an internal chamber, and an opening to the internal chamber. The wall having an interior surface and an exterior surface. the interior surface defines the internal chamber. The hood bumper further including a biasing mechanism operably connected to the housing and a plunger operably connected to the biasing mechanism and configured to receive an exerted force from the hood. The hood bumper further including a bumper head operably connected to the housing and a support frame operably connecting the bumper head to the housing. The plunger is configured to first move into the bumper head to absorb an impact force to the hood, next the bumper head compresses to further absorb the impact force, and then the support frame collapses to even further absorb the impact force.