Steering Column Tilt Adjustment Impact Absorption Stability

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Solution Overview

Problem

Existing steering systems face instability in impact absorption during secondary collisions due to varying positions resulting from tilt adjustments, which affects the timing and effectiveness of impact absorption.

Innovation Solution

A steering system with a position fixing mechanism that includes an elongate engaged member and fixing members to stabilize the column jacket's position during tilt adjustments, ensuring consistent impact absorption by breaking a fixing member during secondary collisions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If tilt adjustment is allowed to vary the column jacket position, then ease of operation is improved, but stability of impact absorption deteriorates

Engineering Contradiction:
Improvetilt adjustmentVSAvoidimpact absorption stability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The engaged member is divided into multiple engagement positions along its length, allowing the column jacket to be tilted to different positions while maintaining stable impact absorption at each position through engagement with the engaged member at different locations

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The position fixing mechanism is pre-configured with multiple engagement positions before tilt adjustment occurs. When tilt adjustment is needed, the system can engage at the appropriate pre-positioned location, ensuring stable impact absorption is established in advance regardless of the final tilt position

Inventive Principle:
Principle #10Preliminary action

2Reliability

If the column jacket position is fixed during tilt adjustment, then stability of impact absorption is improved, but ease of operation deteriorates

Engineering Contradiction:
Improveimpact absorption stabilityVSAvoidtilt adjustment
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The system dynamically adapts by providing multiple engagement positions along the engaged member. During tilt adjustment, the column jacket can move freely until it reaches a desired position, at which point the position fixing mechanism engages at the appropriate location, providing stability without restricting the adjustment process

Inventive Principle:
Principle #15Dynamics

3Adaptability or versatility

If the engaging member engages with the engaged member at different positions, then adaptability is improved, but manufacturing precision deteriorates

Engineering Contradiction:
Improvetilt position variabilityVSAvoidimpact absorption timing consistency
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The engaged member is segmented into multiple engagement positions, each designed to provide stable impact absorption. This segmentation allows the system to adapt to different tilt positions while maintaining consistent performance through the distributed engagement points

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different portions of the engaged member are designed with specific local characteristics optimized for engagement at each position. This allows the system to accommodate position variability while maintaining manufacturing precision through localized feature optimization

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

The system achieves stable impact absorption regardless of the column jacket's position from tilt adjustments, ensuring consistent and effective energy absorption during secondary collisions.

Implementation Method 1

Impact energy is absorbed by friction between the buffer shaft and the peripheral portion of the excess area

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

Impact energy is absorbed by friction between the buffer shaft and the peripheral portion of the excess area and by deformation between the buffer shaft and the peripheral portion of the vertically long groove

Methodology Applied
Scientific EffectDeformation: Deformation

Data Source

PatentEP3239017B1Steering system
Publication Date: 2019.08.21 JTEKT CORP
  • EP3239017B1 patent drawingFigure 1
  • EP3239017B1 patent drawingFigure 2
  • EP3239017B1 patent drawingFigure 3

AI summary

A column jacket (6) can pivot in a tilt direction around an end of a steering shaft (3) along with the steering shaft (3). When the column jacket (6) is pivoted in the tilt direction, an engaging member (45,72) moves in the tilt direction along with the column jacket (6). A position fixing mechanism (86,87) has a pair of fixing members (30,78) located adjacent to opposite ends of an engaged member (34,43,71) in a longitudinal direction to fix the position of the engaged member (34,43,71) in the tilt direction. The position fixing mechanism (86,87) fixes the position of the column jacket (6) in the tilt direction by engaging the engaged member (34,43,71) with the engaging member (45,72). At a time of a secondary collision, the engaged member (34,43,71) engaged with the engaging member (45,72) breaks a front fixing member (30A).