Tilt Steering Device Noise Reduction via Buffer Member

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Solution Overview

Problem

Existing tilt steering apparatuses experience unpleasant noise and durability issues during steering wheel height adjustment, and they often compromise operational feeling and smoothness.

Innovation Solution

A tilt steering apparatus with a metal-driven side cam, a buffer member made of softer material, and stoppers to prevent collision between the convex engaging portion and the vertically long holes, along with crank-shaped stepped surfaces and low-rigidity portions to regulate rotation and absorb shocks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a metal-driven side cam is used to maintain durability, then strength is improved, but collision noise occurs during rotation

Engineering Contradiction:
Improvedurability of driven-side camVSAvoidcollision noise
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

A buffer member made of softer material (synthetic resin or rubber) is introduced as an intermediary between the metal convex engaging portion of the driven-side cam and the metal vertically long hole. This buffer member absorbs collision impacts and prevents direct metal-to-metal contact, thereby eliminating collision noise while preserving the durability of the metal cam components.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The buffer member is pre-installed on the convex engaging portion of the driven-side cam before operation. This softer material layer is positioned in advance to cushion and absorb any collision impacts that may occur during rotation, preventing noise generation before it can happen.

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

2Object-affected harmful factors

If stoppers are added to prevent collision, then noise is reduced, but device complexity increases

Engineering Contradiction:
Improvecollision noiseVSAvoidstructural complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The noise prevention function is merged with the existing buffer member that is already part of the tilt mechanism. The buffer member simultaneously serves as both a cushioning element for noise reduction and a structural component of the adjustment mechanism, thereby preventing collision noise without adding separate stopper components.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The buffer member is designed to perform multiple functions: it acts as a cushioning element to prevent collision noise, serves as a structural connector between the driven-side cam and the adjustment rod, and maintains the operational smoothness of the tilt mechanism. This multi-functionality avoids increasing device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Object-affected harmful factors

If softer material is used for buffer member, then noise is reduced, but rotational stability decreases

Engineering Contradiction:
Improvecollision noiseVSAvoidrotational stability
Core Design Contradiction:
Object-affected harmful factorsVSStability of the object's composition

Solution Approach 1:

The driven-side cam assembly uses a composite structure where a softer material (synthetic resin or rubber) is combined with metal components. The softer buffer member reduces collision noise, while the metal driven-side cam and vertically long hole provide structural strength and rotational stability. This composite approach allows both noise reduction and stability maintenance.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

Different parts of the driven-side cam assembly have different material properties optimized for their specific functions: the buffer member at the convex engaging portion is made of softer material for noise reduction, while the main body of the driven-side cam and the vertically long hole remain metal for structural stability. This local differentiation of material quality achieves both noise reduction and rotational stability.

Inventive Principle:
Principle #3Local quality

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

Prevents unpleasant noise and maintains durability, improving the operational feeling of the adjustment lever while ensuring smooth height adjustment of the steering wheel.

Implementation Method 1

a buffer member made of softer material, and that is attached to the convex engaging portion

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP2873589B1Tilt steering device
Publication Date: 2019.03.06 NSK LTD
  • EP2873589B1 patent drawingFigure 1
  • EP2873589B1 patent drawingFigure 2
  • EP2873589B1 patent drawingFigure 3

AI summary

Construction of a tilt steering apparatus is provided that is capable of preventing the occurrence of unpleasant noise during height adjustment of a steering wheel 1, and maintains sufficient durability and smooth operation. The tilt steering apparatus of the present invention is provided with stoppers 65 in at least two locations in a buffer member 21c that are rotationally symmetric about the center axis of an adjustment rod 14, and that when a driven-side cam 15b is rotated as the axial dimension of a cam apparatus 47 is expanded or contracted, controls rotation of the driven-side cam 15b so that a convex engaging portion 39c does not collide with the front-side edge or rear-side edge of a vertically long hole 35b