Steering Column Shroud Guidance Mechanism for Noise and Collapse
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Solution Overview
Problem
Existing vehicle steering column assemblies fail to provide a reliable interface between the steering column and shroud that allows axial translation without lash or misalignment and prevents audible rattle noise during normal driving conditions, while also enabling energy-absorbing collapsibility during an event.
Innovation Solution
A shroud guidance mechanism featuring a bracket coupled to the upper jacket, an interface feature, and a guiding component between the shroud and grommet, which translates with the steering column during normal operation but decouples during a collapse event to allow forward translation of the shroud, preventing contact with other components and reducing noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the interface feature is rigidly retained to the bracket to prevent lash and misalignment, then alignment precision and noise reduction are improved, but the ability to allow energy-absorbing collapse is worsened
Solution Approach 1:
The interface feature transitions from a static rigid connection to a dynamic system that adapts its state: during normal operation it maintains a rigid retained connection to prevent lash and misalignment, while during energy absorption events it automatically decouples from the bracket to allow controlled collapse. This dynamic behavior resolves the contradiction between maintaining precision alignment and enabling collapse capability.
Solution Approach 2:
The interface feature acts as an intermediary element between the bracket and the shroud/upper jacket assembly. It provides a controlled interface that can transmit forces rigidly when needed for alignment precision while also allowing controlled separation when energy absorption is required, thus mediating between the conflicting requirements of rigid fixation and collapse capability.
2Strength
If the interface feature remains coupled to the bracket during collapse, then structural rigidity is maintained, but energy absorption capability and driver safety are worsened
Solution Approach 1:
The system dynamically adjusts its structural characteristics: during normal driving conditions the interface feature maintains a rigid retained connection providing structural strength, but during energy absorption events it automatically transitions to a decoupled state that enables controlled collapse and energy absorption, thus resolving the contradiction between maintaining rigidity and enabling energy absorption.
3Manufacturing precision
If the shroud is rigidly fixed to the steering column, then misalignment is prevented, but audible rattle noise and lash are not avoided
Solution Approach 1:
The interface feature provides a dynamic connection that maintains precise alignment during normal operation through rigid retention while incorporating compliance elements that eliminate audible rattle noise and lash by allowing controlled movement, thus resolving the contradiction between alignment precision and noise elimination.
Data Source
AI summary
A shroud guidance mechanism for a steering column is provided. The shroud guidance mechanism includes a bracket operatively coupled to an upper jacket. Also included is an interface feature retained to the bracket in a first condition of the steering column. Further included is a shroud operatively coupled to the interface feature and to the upper jacket, the interface feature, the upper jacket and the shroud moveable with each other to decouple the interface feature from the bracket in a second condition of the steering column.