Geared Rack Steering Column for Axial Sensing During Vertical Articulation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing steering column assemblies with absolute position sensors face challenges in accurately sensing the displacement of the lower jacket relative to the column mounting bracket due to simultaneous movements in multiple planes, particularly during stow functions, which require a geared rack to interface with the sensor while accommodating vertical articulations.
Innovation Solution
A geared rack is operatively coupled to the column mounting bracket and rotatable with the lower jacket, maintaining contact with an absolute position sensor to accurately detect the axial position of the steering column assembly, even during vertical articulations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a geared rack is fixed to the column mounting bracket to detect axial position, then position sensing accuracy is improved, but the system cannot accommodate vertical articulation movements of the lower jacket
Solution Approach 1:
The geared rack is made rotatable rather than fixed, allowing it to dynamically adapt its orientation. The rack rotates with the lower jacket during vertical articulation while maintaining its engagement with the absolute position sensor, enabling both accurate axial position detection and accommodation of rake movements.
Solution Approach 2:
The motion detection function is separated into two independent components: the geared rack handles vertical articulation (rake) movements through rotation, while the absolute position sensor with cogged wheels handles axial (fore/aft) position detection. This segmentation allows each component to specialize in one degree of freedom without interference.
2Length of moving object
If the lower jacket translates axially relative to the column mounting bracket during stow function, then stow displacement is increased, but the geared rack must simultaneously accommodate both axial and vertical movements
Solution Approach 1:
The geared rack is designed to rotate dynamically as the lower jacket articulates vertically during stow functions. This rotational capability allows the rack to maintain proper engagement with the absolute position sensor while accommodating large stow displacements and simultaneous vertical movements without increasing mechanical complexity.
3Adaptability or versatility
If the hand wheel is repositioned further away from the driver for stow mode, then versatility of vehicle use is improved, but position sensing accuracy may be compromised due to increased movement ranges
Solution Approach 1:
The sensing system is segmented into two independent measurement channels: the absolute position sensor with geared rack measures axial (fore/aft) telescope position, while a separate sensor measures vertical (rake) position. This segmentation allows the system to accurately track large displacement ranges enabled by versatile stow functions without compromising measurement precision in either degree of freedom.
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 ensures precise detection of the steering column's axial position, accommodating both telescopic and vertical movements, enhancing the accuracy and reliability of position sensing in axially adjustable steering systems.
Implementation Method 1
a geared rack operatively coupled to the column mounting bracket, the geared rack correspondingly rotatable with the lower jacket, wherein the geared rack is in contact with a gear wheel of the position sensor
Data Source
AI summary
An axially adjustable steering column assembly includes an upper jacket. The assembly also includes a lower jacket, wherein the upper jacket is received within the lower jacket and is telecopingly adjustable therein, the lower jacket having a position sensor operatively coupled thereto. The assembly further includes a column mounting bracket, wherein the lower jacket translates and rotates relative to the column mounting bracket. The assembly yet further includes a geared rack operatively coupled to the column mounting bracket, the geared rack correspondingly rotatable with the lower jacket, wherein the geared rack is in contact with a gear wheel of the position sensor to detect the axial position of the axially adjustable steering column assembly.