Steering Apparatus Guide Groove for Electrical Connectivity

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Solution Overview

Problem

The existing steering apparatuses face challenges in ensuring a reliable electrifying path for electrical components installed in the steering wheel, as low friction material coatings applied to reduce clamping friction interfere with electrification through contact surfaces and spline-fitted portions, making it difficult to maintain electrical connectivity during secondary collisions.

Innovation Solution

The steering apparatus incorporates a guide groove in the outer column for the electrifying lead, along with a conductive fixing means and a guide member attached to the inner column, allowing for a shorter electrifying lead and reduced space requirements, while also applying a low friction material coating to absorb secondary collision energy without compromising electrical connectivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If low friction material coating is applied to reduce clamping friction force, then secondary collision energy absorption is improved, but electrical conductivity through contact surfaces is deteriorated

Engineering Contradiction:
Improvesecondary collision energy absorptionVSAvoidelectrical connectivity
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The patent divides the outer column into multiple sections: a coated section with low friction material for reducing clamping friction during collision, and an uncoated conductive section for maintaining electrical connectivity. This segmentation allows each section to fulfill its specific function without interference from the other.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The low friction material coating is applied selectively to specific regions of the outer column where friction reduction is most beneficial for collision energy absorption, while leaving other regions uncoated to maintain electrical conductivity. This local application of different material properties resolves the contradiction between friction reduction and electrical connectivity.

Inventive Principle:
Principle #3Local quality

2Object-generated harmful factors

If resin coating is applied to spline-fitted portion to prevent backlash noises, then noise emission is reduced, but electrical conductivity through spline-fitted portion is deteriorated

Engineering Contradiction:
Improvebacklash noisesVSAvoidelectrical connectivity
Core Design Contradiction:
Object-generated harmful factorsVSReliability

Solution Approach 1:

The spline-fitted portion of the steering shaft is divided into a coated section for noise reduction and an uncoated conductive section for electrical connectivity. This segmentation enables the resin coating to be applied only where needed for preventing backlash noises, while preserving electrical pathways.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Resin coating is applied locally to specific regions of the spline-fitted portion where noise reduction is most effective, while leaving other regions uncoated to maintain electrical conductivity through the steering shaft.

Inventive Principle:
Principle #3Local quality

3Volume of moving object

If electrifying lead is routed through coated contact surfaces, then space for disposing electrifying lead is reduced, but electrical conductivity is deteriorated

Engineering Contradiction:
Improvespace for disposing electrifying leadVSAvoidelectrical connectivity
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

The electrifying lead routing path is segmented into regions passing through uncoated conductive sections of the outer column and steering shaft, ensuring electrical connectivity is maintained while still achieving compact space utilization through the structured routing arrangement.

Inventive Principle:
Principle #1Segmentation

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

This configuration ensures a reliable electrifying path from the steering wheel to the vehicle body, facilitating easy fitting and maintaining electrical component functionality during telescopic adjustments and secondary collisions, while reducing frictional forces for impact absorption.

Implementation Method 1

a low friction material treatment instanced by coating is applied over an outer peripheral surface of the inner column or an inner peripheral surface of the outer column, thereby reducing the clamping friction force

Methodology Applied
Scientific EffectFriction reduction through low friction material coating: Lubrication

Implementation Method 2

an energy absorbing means provided between the inner column and the outer column absorbs the secondary collision energy

Methodology Applied
Scientific EffectEnergy absorption through deformation: Deformation

Data Source

PatentEP3162657B1Steering apparatus
Publication Date: 2018.10.24 NSK LTD
  • EP3162657B1 patent drawingFigure 1
  • EP3162657B1 patent drawingFigure 2
  • EP3162657B1 patent drawingFigure 3

AI summary

A steering apparatus (2) is disclosed, which includes: a steering shaft (3) having a conductive property and transferring a steering force; an outer column (10) having a conductive property and supporting the steering shaft (3) rotatably; an inner column (11) having a conductive property, being fitted in the outer column (10) to enable a relative movement in an axial direction supporting the steering shaft (3) rotatably together with the outer column (10); a bracket (12) having a conductive property, retaining the outer column (10) and being fixed to a vehicle body; and an electrifying lead (17) having a conductive property and configuring a part of an electrifying path leading to the vehicle body from the inner column (11).