Steering Wheel Position Adjuster Noise Suppression

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Solution Overview

Problem

Conventional position adjustable steering apparatuses generate harsh abnormal noise due to contact between stopper parts on cam surfaces when adjusting the steering wheel position.

Innovation Solution

Incorporation of a sub-arm, receiving side member, and buffer member with specific surface features to prevent direct contact between stopper parts, utilizing a buffer member with projections and inclined surfaces to absorb the impact and reduce noise.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If stopper parts on cam surfaces are used to limit adjustment range, then adjustment range is controlled, but harsh noise is generated due to metal contact

Engineering Contradiction:
Improveadjustment range controlVSAvoidharsh noise
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A buffer member made of elastic material is introduced as an intermediary between the stopper parts on the cam surfaces. When the adjustment lever reaches the adjustment range limit, the buffer member contacts the stopper part first, deforming elastically to absorb impact energy and prevent direct metal-to-metal contact, thereby eliminating harsh noise while maintaining reliable adjustment range control

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The buffer member is pre-installed on the adjustment lever before operation. Its elastic properties provide beforehand cushioning that absorbs impact energy when the adjustment lever contacts the stopper part, preventing harsh noise generation while ensuring the adjustment range is properly controlled

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

2Ease of operation

If cam mechanism is used for position adjustment, then position control is achieved, but metal contact noise occurs during adjustment

Engineering Contradiction:
Improveposition controlVSAvoidmetal contact noise
Core Design Contradiction:
Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The buffer member serves as a mediator between the adjustment lever and the cam mechanism's stopper parts. During position adjustment, the buffer member's elastic deformation absorbs impact energy, preventing direct metal contact between the adjustment lever and cam surfaces, thereby eliminating metal contact noise while preserving smooth position control

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The buffer member changes the physical parameters of the contact interface by introducing elastic deformation. This parameter change transforms the rigid metal-to-metal contact into a compliant contact with energy absorption, eliminating harsh noise while maintaining the cam mechanism's position control functionality

Inventive Principle:
Principle #35Parameter changes

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

Effectively suppresses the generation of harsh noise by ensuring the sub-arm or receiving side member contacts the buffer member before stopper parts on cam surfaces, preventing metal contact noise.

Implementation Method 1

a buffer member 54 made of an elastic material

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3000690B1Position adjusting-type steering device
Publication Date: 2019.03.06 NSK LTD
  • EP3000690B1 patent drawingFigure 1
  • EP3000690B1 patent drawingFigure 2
  • EP3000690B1 patent drawingFigure 3

AI summary

A sub-arm 49 which is rotated together with an adjustment lever 34a is fixed to a base end portion of the adjustment lever 34a. A receiving side member 52 is fixed to an outer surface of one support plate part 23a of a support bracket 22a and a buffer member 54 made of an elastic material is fixed to the receiving side member 52. When the adjustment lever 34a is rotated in a predetermined direction, a tip portion of the sub-arm 49 first contacts the buffer member 54 before step portions of driving and driven cam surfaces 32, 33 contact each other. Therefore, when the adjustment lever 34a is rotated in the predetermined direction (a direction in which an axial dimension of a cam mechanism 31a is contracted) so as to adjust a position of a steering wheel, it is possible to prevent generation of a harsh abnormal noise caused as the step portions of the driving and driven cam surfaces 32, 33 contact each other.