Steering Column Telescopic Shaft Retention Mechanism

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Solution Overview

Problem

Existing motor vehicle steering columns with telescopic adjustment mechanisms and energy absorption functions face disengagement issues during assembly, transport, and in-service use, leading to potential damage and safety hazards.

Innovation Solution

A modified telescopic internal shaft with abutment means, including an elastic ring and annular face, limits axial translation to prevent disengagement, ensuring the steering column remains securely locked and assembled without interfering with normal operation or adjustment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the steering column is designed with telescopic adjustment mechanism and energy absorption function, then the adaptability and safety are improved, but the risk of disengagement during assembly, transport, and in-service use increases

Engineering Contradiction:
Improvetelescopic adjustment and energy absorption functionVSAvoiddisengagement risk
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

A retention member is introduced as an intermediary component between the inner and outer tubes. This retention member engages with both tubes to prevent disengagement while allowing the telescopic adjustment and energy absorption functions to operate normally. The retention member acts as a mediator that maintains the connection between the two tubes without interfering with their relative movement.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If the steering column allows axial translation for adjustment and retraction, then the adaptability is improved, but the structural stability decreases

Engineering Contradiction:
Improveaxial translation capabilityVSAvoidstructural stability
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The retention member is designed to be dynamic rather than fixed. It allows axial translation when needed for adjustment and energy absorption, but engages to prevent disengagement when the steering column is stationary. This dynamic behavior enables the system to switch between stable and movable states as required.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The retention member changes its engagement parameter based on the operational state. During normal operation, it maintains engagement to prevent disengagement. During adjustment or impact events, it allows axial movement by changing its engagement state, thus adapting its structural constraint parameter to match the required function.

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

The solution effectively prevents disengagement of the steering column during handling and in-service use, ensuring the column remains securely attached and functional, reducing the risk of damage and enhancing safety.

Implementation Method 1

abutment means which cooperate to limit the axial translation of the upper part relative to the lower part... the abutment means comprise, on the one hand, an annular element carried by the lower end of the tubular upper part of the telescopic shaft, the annular element consisting by an elastic ring

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2380797B1Steering column with telescopic adjustment mechanism and/or energy-absorbing function by retraction
Publication Date: 2013.03.13 JTEKT EUROPE SAS
  • EP2380797B1 patent drawingFigure 1
  • EP2380797B1 patent drawingFigure 2
  • EP2380797B1 patent drawingFigure 3

AI summary

The column (2) has an outer tube (5) mounted on an inner tube (4) in an axially sliding manner. An adjusting mechanism (7) locks/unlocks the column by blocking/releasing the inner tube relative to the outer tube. A telescopic rotary inner shaft (16) is extended inside the inner and outer tubes. Stop units are arranged on lower and upper parts (17, 18) of the shaft. The stop units cooperate with each other to limit axial translation of the upper part relative to the lower part of the shaft in an extension direction of the shaft. The stop units include an annular element that is formed of Circlips type elastic split ring (23) and is in contact with and supported against an annular face (24) of the stop units.