Steering Column Lock Mechanism with Independent Friction Plates

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Solution Overview

Problem

Existing position adjustable steering column devices cannot independently set retaining forces in the tilt and telescopic directions, leading to reduced retaining forces during a second collision, causing potential slippage and reduced impact absorption.

Innovation Solution

A steering column device with separate tilt and telescopic friction plates on each side of the tilt bracket, utilizing a lock mechanism with a fastening shaft and cam mechanism to achieve independent locking and increase retaining forces by enhancing frictional engagement through washers and cam followers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the same number of tilt friction plates and telescopic friction plates are used, then the structure is simplified, but the retaining force in tilt direction and telescopic direction cannot be set independently

Engineering Contradiction:

ImprovestructureVSAvoidindependent retaining force setting

Core Design Contradiction:

Device complexityVSAdaptability or versatility

Solution Approach 1:

The friction plates are segmented into separate tilt friction plates and telescopic friction plates, with different numbers of plates in each direction. This allows independent control of retaining forces while maintaining structural organization through separate stacking arrangements for each direction.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different local configurations are applied to different directions: the tilt direction has a specific number of tilt friction plates while the telescopic direction has a different number of telescopic friction plates. This local differentiation enables independent optimization of retaining forces for each direction without affecting the other.

Inventive Principle:

Principle #3Local quality

2Device complexity

If fewer tilt friction plates are provided, then the structure is simplified, but the retaining force in tilt direction becomes small causing slippage during second collision

Engineering Contradiction:

Improvenumber of friction platesVSAvoidretaining force

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The friction plates utilize dynamic friction characteristics during collision events. The stackable configuration allows the friction plates to engage dynamically during tilt and telescopic movements, generating sufficient frictional force to prevent slippage even with a reduced number of plates through optimized friction engagement.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The retaining force is optimized by changing the friction parameters through the arrangement and material properties of the friction plates. By adjusting the number, position, and friction characteristics of individual plates, sufficient retaining force is achieved without requiring a large number of plates, balancing simplicity and reliability.

Inventive Principle:

Principle #35Parameter changes

3Ease of manufacture

If friction plates are stacked in the same configuration for both directions, then manufacturing is simplified, but the retaining force cannot be independently optimized for each direction

Engineering Contradiction:

ImprovemanufacturingVSAvoidindependent retaining force optimization

Core Design Contradiction:

Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The friction plate system is segmented into separate tilt friction plates and telescopic friction plates with different stacking configurations. This segmentation allows independent manufacturing optimization for each direction while maintaining overall manufacturing efficiency through standardized plate designs and assembly procedures.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different local stacking configurations are implemented: tilt friction plates are stacked in one arrangement while telescopic friction plates are stacked in another. This local quality differentiation enables independent retaining force optimization for each direction while using standardized manufacturing processes for the individual plate components.

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

Enables independent setting of retaining forces in both tilt and telescopic directions, maintaining high retaining forces during a second collision and improving impact absorption by generating stick-slip forces, while simplifying the structure and reducing manufacturing costs.

Implementation Method 1

both of the friction plates are fastened and frictionally engaged with each other, thus increasing a binding force of both of the brackets

Methodology Applied

Scientific EffectFriction: Friction

Implementation Method 2

generating stick-slip forces, while simplifying the structure and reducing manufacturing costs

Methodology Applied

Scientific EffectStick-slip phenomenon: Stick-slip Phenomenon

Data Source

PatentUS8746740B2Steering column device

Publication Date: 2014.06.10 JTEKT CORP

AI summary

A steering column device includes a tilt bracket that is fixed to a vehicle body, and a telescopic bracket that is fixed to a column jacket. A lock mechanism includes a fastening shaft that is inserted through a first side plate and a second side plate of the tilt bracket, and a third side plate and a fourth side plate of the telescopic bracket, and achieves tilt locking and telescopic locking by fastening the third and fourth side plates by using the first and second side plates. Tilt friction plates and telescopic friction plates are provided separately from each other on right and left sides of the tilt bracket, respectively.