Adjustable Steering Column Layout to Reduce Resonance

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Solution Overview

Problem

Existing electrically adjustable steering systems cause driver discomfort due to resonance and have limited telescopic adjustable length, primarily because the heavy electric motor is fixed to the steering jacket, leading to low natural frequency and vibration issues.

Innovation Solution

The system incorporates a top bracket-mounted motor with a steering jacket comprising overlapping first to third jacket members, allowing for increased telescopic adjustable length and reduced resonance by fixing the motor to the vehicle body side, enabling separate expansion and contraction of the jacket members.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the electric motor is fixed to the steering jacket, then the telescopic mechanism can be compact, but the natural frequency of the steering jacket decreases causing resonance and driver discomfort

Engineering Contradiction:

Improvetelescopic mechanism compactnessVSAvoiddriver discomfort from resonance

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

The electric motor is extracted from the steering jacket and repositioned to the vehicle body side. This separation removes the heavy motor mass from the steering jacket, preventing the motor's weight from lowering the jacket's natural frequency and causing resonance that leads to driver discomfort.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

A connection rod serves as an intermediary element to transmit the driving force from the motor (located on the vehicle body side) to the steering jacket. This allows the motor to control the telescopic mechanism without being physically attached to the steering jacket, maintaining both compact functionality and structural integrity.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Stability of the object's composition

If the steering shaft and steering jacket use a pair of shafts and jackets structure, then the structure is stable, but the telescopic adjustable length is limited

Engineering Contradiction:

Improvestructural stabilityVSAvoidtelescopic adjustable length

Core Design Contradiction:

Stability of the object's compositionVSLength of moving object

Solution Approach 1:

The steering shaft is divided into multiple segments (first shaft member, second shaft member, third shaft member) that can telescopically extend relative to each other. Similarly, the steering jacket is segmented into multiple jacket members. This segmentation allows the steering column to achieve greater telescopic adjustable length while maintaining structural stability through the interconnected segmented structure.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS11345387B2Electrically adjustable steering

Publication Date: 2022.05.31 NSK LTD

AI summary

In an electrically adjustable steering of the present embodiment, a first telescopic actuator is disposed between a top bracket or a mount bracket on a vehicle body side and a steering jacket. The steering jacket includes a plurality of jacket members that overlap each other so as to be able to expand and contract in an axial direction. A motor of the first telescopic actuator is fixed to the top bracket or the mount bracket on the vehicle body side.