Steering System Buffer Retention Mechanism

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Solution Overview

Problem

In existing steering systems, the buffer material may detach from the bolt shaft and stopper plate during shock events, preventing stable shock absorption.

Innovation Solution

A steering system design featuring a retaining member with paired holding portions and a restriction portion that securely holds the buffer member in place, preventing detachment during telescopic adjustment and shock absorption, utilizing a buffer member with a supported surface and rib for enhanced rigidity and contact stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the buffer material is attached to the bolt shaft or stopper plate to restrict telescopic adjustment range, then the adjustment range is restricted, but the buffer material may detach during shock events and cannot stably absorb shock

Engineering Contradiction:
Improveshock absorption stabilityVSAvoidretaining structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The retaining member is divided into multiple functional segments: paired holding portions that grip the buffer member laterally, a support surface that prevents separation, and a restriction portion that limits movement in the opposite direction. This segmentation allows each part to address specific detachment risks independently, enhancing overall reliability without requiring an overly complex monolithic structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The retaining member acts as an intermediary component between the buffer member and the column structure. It provides multiple retention mechanisms (holding portions, support surface, restriction portion) that collectively secure the buffer member, preventing detachment during shock events while maintaining the telescopic adjustment function.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the buffer member is securely retained with multiple retention mechanisms, then detachment is prevented and shock absorption is stabilized, but the retaining member structure becomes more complex

Engineering Contradiction:
Improvebuffer member retentionVSAvoidretaining member structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Multiple retention functions (holding, supporting, restricting) are merged into a single retaining member component. This integration achieves reliable buffer member retention through coordinated action of different features while avoiding the need for multiple separate retention components, thus limiting the increase in device complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The retaining member serves multiple functions simultaneously: it holds the buffer member laterally through paired holding portions, prevents separation through the support surface, and restricts opposite-direction movement through the restriction portion. This multi-functionality achieves comprehensive retention reliability without proportionally increasing structural complexity.

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

3Reliability

If the support surface prevents separation of the buffer member, then detachment is suppressed, but the retaining member requires additional structural elements

Engineering Contradiction:
Improveseparation preventionVSAvoidsupport surface structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The separation prevention function is extracted as a distinct feature (the support surface) from the overall retaining member structure. This dedicated surface specifically addresses the separation risk by providing a counteracting force, while the rest of the retaining member maintains its retention functions, achieving reliable separation prevention with minimal additional structural elements.

Inventive Principle:
Principle #2Taking out (Extraction)

4Reliability

If the buffer member is held firmly toward the support surface, then detachment during contact is prevented, but the buffer member's deformation capability may be restricted

Engineering Contradiction:
Improvecontact stabilityVSAvoidshock absorption capability
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The paired holding portions apply localized lateral forces to grip the buffer member, while the support surface provides localized support to prevent separation. These localized retention actions secure the buffer member during contact without applying continuous constraining forces that would restrict the buffer member's deformation capability for shock absorption.

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 buffer member is securely retained, preventing detachment and ensuring stable shock absorption by suppressing separation and bending deformation, thereby maintaining effective shock absorption capabilities.

Implementation Method 1

the buffer member contacts the engagement member in a contact direction at a time when the upper jacket is displaced to one sliding end of the specified sliding range

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

the buffer member is unlikely to be detached and can stably absorb a shock at a time of contact

Methodology Applied
Scientific EffectShock absorption: Damping

Data Source

PatentEP3205558B1Steering system
Publication Date: 2019.11.27 JTEKT CORP
  • EP3205558B1 patent drawingFigure 1
  • EP3205558B1 patent drawingFigure 2
  • EP3205558B1 patent drawingFigure 3

AI summary

A steering system includes a column jacket (3) including a lower jacket (8) and an upper jacket (7); an engagement member (42); a retaining member (70); and a buffer member (80) that is retained by the retaining member (70) and contacts the engagement member (42) in a contact direction at a time when the upper jacket (7) is displaced to one sliding end. The retaining member (70) includes a support surface (70b) that supports the buffer member (80); paired holding portions (73) that are respectively disposed on both sides of the buffer member (80) in a circumferential direction of the upper jacket (7) and hold the buffer member (80) toward the support surface (70b); and a restriction portion (74) configured to be engaged with an end (80d) of the buffer member (80) on a side toward which an opposite direction is directed, so as to restrict movement of the buffer member (80) in the opposite direction, the opposite direction being opposite to the contact direction.