Steering Column Energy Absorption via Nested Jacket and Segmented Rivets
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Solution Overview
Problem
Telescopically adjustable steering columns face challenges in energy absorption during vehicle rear collisions, as existing energy absorption mechanisms, such as energy absorption rivets and straps, can shear and deform, leading to unintended steering wheel position changes due to rearward forces.
Innovation Solution
A steering column assembly with a telescoping mechanism that includes a lower and upper jacket assembly, a telescope actuator assembly, and an energy absorption assembly featuring nested energy absorption straps and a mechanical fastener system, allowing for adaptive energy absorption and controlled movement of the steering column during collisions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If energy absorption rivets and straps are used in the telescope actuator, then energy absorption capability is improved during vehicle impact, but the steering wheel position becomes unstable due to shearing and deformation of fasteners
Solution Approach 1:
The fastening system is segmented into multiple independent fasteners (rivets and straps) distributed at different locations within the telescope actuator. This segmentation allows the energy absorption forces to be distributed across multiple connection points, preventing any single fastener from experiencing excessive stress that would cause shearing or deformation, thereby maintaining steering wheel position stability while preserving energy absorption capability
Solution Approach 2:
The energy absorption rivets and straps are pre-installed and pre-positioned within the telescope actuator assembly before any collision occurs. These fasteners are designed with specific material properties and geometric configurations that allow them to deform in a controlled manner during impact, absorbing energy while maintaining structural integrity and preventing unintended steering wheel movement
2Strength
If the column jacket is made longitudinally collapsible for energy absorption, then safety during impact is improved, but the steering column structure becomes more complex
Solution Approach 1:
The column jacket is designed with nested telescoping sections that can collapse longitudinally during impact. The inner jacket is inserted within the outer jacket, allowing controlled compression and energy absorption through the telescoping mechanism. This nested structure provides effective energy absorption while maintaining a relatively compact and integrated design, avoiding excessive structural complexity
Solution Approach 2:
The column jacket transitions from a static rigid structure to a dynamic collapsible structure that can adapt its stiffness and geometry during impact events. The telescoping sections are designed to remain stable during normal operation but can dynamically collapse in a controlled manner during collision, providing energy absorption without requiring permanently complex structural features
Data Source
AI summary
A steering column assembly includes a lower jacket assembly extending along a steering column axis. Also included is an upper jacket assembly at least partially received within the lower jacket assembly, the upper jacket assembly extendable along the steering column axis relative to the lower jacket assembly. Further included is a telescope actuator assembly configured to translate the upper jacket assembly relative to the lower jacket assembly. Yet further included is a telescope drive bracket of the telescope actuator assembly, the telescope drive bracket operatively coupled to the upper jacket assembly with a mechanical fastener disposed in a bracket slot located within the telescope drive bracket, the mechanical fastener moveable with the upper jacket assembly in a single axial direction along the steering column axis.