Bumper Energy Absorber Layout to Prevent Fastener Interference
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Solution Overview
Problem
The existing impact energy absorbing members, such as crash boxes, can collapse during frontal collisions, leading to inefficient energy absorption due to the separation from the bumper reinforcement, and the fastening mechanism can cause bolts to collide with the energy absorber, reducing its effectiveness.
Innovation Solution
An impact energy absorbing member is designed with a tubular energy absorbing portion and an attachment portion fastened to the bumper reinforcement using bolts and nuts, where the attachment portions are positioned to avoid overlapping with the energy absorbing portion, allowing for effective energy absorption without joint cracking and maintaining the bumper reinforcement's integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the impact energy absorbing member is fastened to the bumper reinforcement using a fastener, then the joining strength is improved, but the fastener may collide with the energy absorbing portion during collapse, reducing energy absorption effectiveness
Solution Approach 1:
The patent positions the fastener in a location that does not overlap with the energy absorbing portion when viewed from the bumper reinforcement toward the energy absorbing member. This spatial arrangement in a different dimension (lateral offset) allows the fastener to secure the member while avoiding collision during axial collapse, thus maintaining both joining strength and energy absorption effectiveness
2Loss of energy
If the energy absorbing member is designed to collapse during collision, then impact energy absorption is improved, but the joined portion may separate from the bumper reinforcement, reducing energy absorption efficiency
Solution Approach 1:
The impact energy absorbing member is divided into distinct functional portions: an energy absorbing portion designed to collapse and an attachment portion that maintains the connection to the bumper reinforcement. This segmentation allows the energy absorbing portion to collapse for energy absorption while the attachment portion remains intact to prevent separation, thus maintaining both energy absorption capability and connection reliability
3Strength
If the fastener extends through the energy absorbing portion, then the attachment is secured, but the energy absorbing portion cannot collapse freely, reducing energy absorption capability
Solution Approach 1:
The fastener is extracted from the energy absorbing portion and positioned in the attachment portion instead. This extraction allows the energy absorbing portion to collapse freely without the fastener interfering with its deformation, while the attachment portion still provides secure fastening to the bumper reinforcement, thus maintaining both attachment security and energy absorption capability
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 configuration ensures that the energy absorbing portion breaks without joint cracking, effectively absorbs collision energy, and maintains the bumper reinforcement's structural integrity during collisions, enhancing energy absorption efficiency and preventing bolt collisions with the absorber.
Implementation Method 1
an energy absorbing portion including an axis that extends in a vehicle front-rear direction, and configured to be collapsed by the load, thereby absorbing impact energy generated when the load is received
Data Source
AI summary
An impact energy absorbing member includes an energy absorbing portion and an attachment portion. The attachment portion is fastened to the bumper reinforcement using a fastener, the fastener extending through the attachment portion and a wall of the bumper reinforcement and including an axis that extends in a direction intersecting an axial direction of the energy absorbing portion. The attachment portion and the energy absorbing portion are in a positional relationship in which the energy absorbing portion does not overlap the fastener when the impact energy absorbing member is viewed in a direction from the bumper reinforcement toward the energy absorbing portion in a vehicle front-rear direction.