Nested Energy Absorption Strap Assembly for Compact Steering Columns
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing energy absorption steering column systems face challenges in compact design and occupant safety due to the need for a switching mechanism between high and low energy modes, which often require additional space or undesirable forces.
Innovation Solution
A two-stage energy absorption strap assembly with a first and second energy absorption strap, where the second strap is not directly coupled to the upper jacket, and a locking pin that switches between high and low load modes by extending or retracting to control the energy absorption, allowing for synchronized or translated movement of the straps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a switching mechanism is added to select between high and low energy modes, then energy absorption capability is improved, but device complexity increases
Solution Approach 1:
The patent employs a dynamic switching mechanism that can transition between high and low energy absorption modes based on occupancy detection. The system dynamically adjusts the energy absorption characteristics by engaging or disengaging the auxiliary strap, allowing the steering column to adapt to different safety requirements without permanent structural changes.
Solution Approach 2:
The auxiliary strap serves multiple functions: it provides additional energy absorption in high-energy modes when the vehicle is occupied, and can be disengaged to reduce energy absorption in low-energy modes when unoccupied. This multi-functional component allows a single system to handle varying safety requirements without requiring entirely separate mechanisms for each mode.
2Loss of energy
If the auxiliary strap is made to roll synchronously with the upper jacket, then energy absorption is improved, but space requirements increase
Solution Approach 1:
The auxiliary strap is nested within the steering column structure, surrounding the first energy absorption strap. This nested configuration allows the auxiliary strap to engage and provide additional energy absorption without significantly increasing the external dimensions of the steering column. The strap utilizes the existing internal space efficiently.
Solution Approach 2:
Instead of extending the auxiliary strap in the same dimensional space as the primary strap, the patent positions it in a nested configuration that utilizes the radial dimension. The auxiliary strap surrounds the first strap, effectively using the cross-sectional area rather than requiring additional axial length, thus providing enhanced energy absorption without proportionally increasing overall volume.
3Loss of energy
If the auxiliary strap is directly coupled to the upper jacket, then energy absorption is improved, but force requirements increase
Solution Approach 1:
The locking pin serves as an intermediary mechanism between the auxiliary strap and the upper jacket. Rather than directly coupling the auxiliary strap to the upper jacket, the locking pin engages with apertures in both components, providing a controlled connection that allows the auxiliary strap to contribute to energy absorption while distributing and managing the forces involved through the pin engagement points.
4Ease of operation
If an extra aperture is provided for non-rolling strap travel, then strap movement is enabled, but device complexity increases
Solution Approach 1:
The locking pin mechanism serves multiple functions: it engages with apertures to enable controlled movement of the auxiliary strap, provides the switching mechanism between high and low energy modes, and distributes forces throughout the system. By making this single component multi-functional, the patent avoids the need for separate dedicated features for each function, thereby reducing overall device complexity while maintaining ease of strap movement.
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 enables a compact steering column design with reduced space requirements and enhanced occupant safety by allowing for efficient energy absorption in both high and low load conditions without the need for additional apertures or excessive forces.
Implementation Method 1
a locking pin moveable between an extended position and a retracted position, the locking pin extending through the second energy absorption strap in the extended position, the locking pin withdrawn from the second energy absorption strap in the retracted position
Implementation Method 2
When in the lower energy absorbing state, the switching mechanism disconnects the EA straps so that only the main strap undergoes the rolling action
Data Source
AI summary
An energy absorption strap assembly for a steering column is provided. The assembly includes an upper jacket. The assembly also includes a first energy absorption strap extending from a first end to a second end, the first energy absorption strap operatively coupled to the upper jacket proximate the second end of the first energy absorption strap. The assembly further includes a second energy absorption strap surrounding a portion of the first energy absorptions strap, the second energy absorption strap not directly coupled to the upper jacket.