Steering Column Rigidity via Bifurcated Arm and Segmented Outer Column
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Solution Overview
Problem
Existing steering apparatuses with tilt and telescopic adjustment mechanisms suffer from reduced rigidity and play when fixed in position, leading to compromised operation feeling due to uneven tightening forces and lack of continuous circumferential support.
Innovation Solution
A steering apparatus with a bifurcated arm unit, a divided outer column, and a linking portion forming a truss-like skeletal structure, providing uniform tightening and increased rigidity through a bifurcated arm portion and circumferential support, which enhances the stability and rigidity of the steering column.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a slot is provided in the outer column along the axial direction to enable telescopic sliding, then the telescopic adjustment is enabled, but the rigidity of the steering column decreases and play occurs in the gap
Solution Approach 1:
The outer column is divided into an upper outer column and a lower outer column that are coupled together. The slot is provided only in the lower outer column, while the upper outer column remains intact and continuous. This segmentation allows the lower part to accommodate telescopic movement while the upper part maintains structural rigidity and continuous circumferential support.
2Device complexity
If the slot is closed at the central side like a dead end, then the structure is simplified, but the pushing pressure weakens gradually and is practically not generated in the central zone
Solution Approach 1:
The outer column is segmented into upper and lower portions with the slot confined to the lower portion. This creates a distinct functional zones: the lower outer column with the slot accommodates the tightening mechanism and allows controlled movement, while the upper outer column provides continuous support. The segmentation ensures uniform pushing pressure distribution along the inner column without the gradual weakening that occurs in dead-end slot configurations.
3Ease of operation
If a gap is provided between the outer column and inner column to facilitate sliding, then telescopic movement is enabled, but play occurs when the steering column is fixed and holding force decreases
Solution Approach 1:
The outer column is divided into upper and lower segments with different functional characteristics. The lower outer column contains the slot and interfaces with the tightening mechanism, while the upper outer column provides continuous circumferential support to the inner column. This segmentation allows the gap to be minimized in the upper region where continuous support is needed, reducing play while still enabling telescopic movement through the lower region.
Solution Approach 2:
Different regions of the outer column are given different structural qualities. The upper outer column has continuous circumferential walls that provide strong holding force and minimize play, while the lower outer column has the slot provision that facilitates sliding. This local differentiation of structural properties optimizes both telescopic adjustment and fixed position stability.
Data Source
AI summary
A steering apparatus includes a fixed bracket, an outer column, an arm unit, an inner column, a steering shaft, and a tightening tool. The outer column includes a main holding body portion, a divided portion, and a tightening portion. The arm unit includes by a bifurcated arm portion that extends axially outward in a substantially bifurcated shape at the axial front side of the main holding body portion and a linking portion formed between the arms of the bifurcated arm portion. The inner column is held by the outer column. The steering shaft is pivotally supported by the linking portion. Two tightening plate pieces of the tightening portion are disposed inside two fixed side portions of the fixed bracket and tightenably connected by the tightening tool.