Deformable Head Restraint Bracket for Rear Impact Energy Dissipation
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Solution Overview
Problem
In vehicle seat assemblies, existing head restraints are directly welded to the seat back frame, leading to acceleration of the seat back into the occupant during a rear impact, which can cause harmful energy transfer to the head and neck. This results in inadequate management of impact forces, potentially increasing injury risk.
Innovation Solution
A deformable head restraint bracket system is designed, where a bracket with a tapered projection and support plate is mounted to the seat back frame, allowing the head restraint post to translate towards the seat back frame upon impact, absorbing and dissipating energy through elastic and plastic deformation, and featuring a deformation limit mechanism to control the collapse of the bracket.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the head restraint is directly welded to the seat back frame, then the structural strength and stability are improved, but the harmful impact forces are transferred directly to the occupant during rear impact
Solution Approach 1:
A deformable bracket is introduced as an intermediary component between the head restraint and the seat back frame. This bracket absorbs and dissipates impact energy through controlled deformation, preventing direct force transfer to the occupant while maintaining structural integrity during normal operation
Solution Approach 2:
The bracket is designed with specific material properties and geometric features (such as tapered projections) that allow it to change its mechanical parameters under impact conditions. The bracket transitions from a rigid load-bearing state during normal use to a deformable energy-absorbing state during impact, optimizing both strength and harm reduction
2Loss of energy
If the bracket is designed to deform during impact, then the impact energy management is improved, but the structural stability during normal operation may be compromised
Solution Approach 1:
The bracket is designed with dynamic characteristics that allow it to adapt its structural behavior based on loading conditions. During normal operation, the bracket maintains sufficient rigidity for stability, while during impact it transitions to a controlled deformation mode to dissipate energy, achieving both stability and energy management
3Object-affected harmful factors
If the head restraint post is spaced apart from the seat back frame, then the deformable bracket mechanism is enabled for impact protection, but the device complexity increases
Solution Approach 1:
The connection between the head restraint and seat back frame is segmented into multiple functional components: the deformable bracket, the mounting bracket, and the head restraint post. This segmentation allows each component to perform its specific function while enabling the overall system to achieve impact protection through the deformable bracket mechanism
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 deformable bracket system effectively manages rear impact forces by dissipating energy and decelerating the head restraint, reducing the risk of injury by distributing and absorbing impact forces, while maintaining a compact design.
Implementation Method 1
the bracket deforms as the at least one head restraint post is translated toward the seat back frame
Implementation Method 2
absorbing and dissipating energy through elastic and plastic deformation
Data Source
AI summary
A vehicle seat assembly is provided with a seat back frame. A bracket is provided with a substrate welded to the seat back frame. Two pairs of sidewalls extend from the substrate and are tapered with an enlarged region at an upper distal end. A pair of support plates are each supported by one of the two pairs of sidewalls and spaced apart from the substrate to provide a mounting surface. A pair of spaced apart tubes are each welded to the bracket mounting surface of one of the pair of support plates. A pair of head restraint posts are each received in one of the pair of tubes. A head restraint is supported upon the pair of head restraint posts, so that upon a rear vehicle impact, the bracket deforms as the pair of head restraint posts are translated toward the seat back frame.