Steering Device Support Shaft Low-Strength Portion Energy Absorption

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing steering devices require additional components and fine adjustments to achieve desired energy absorption during vehicle collisions, leading to increased complexity and component count.

Innovation Solution

A steering device with a telescopically adjustable steering shaft and column jacket, featuring a support shaft with a low-strength portion that breaks upon load, allowing the lock member to disengage and absorb energy without additional components, and adjustable breakage load for customized energy absorption characteristics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a breakaway plate is added to absorb energy during vehicle collision, then energy absorption capability is improved, but the number of components increases

Engineering Contradiction:
Improveenergy absorption capabilityVSAvoidnumber of components
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the energy absorption function with the existing support shaft by creating a low-strength portion directly on the support shaft. This merges two separate functions (structural support and energy absorption) into a single component, eliminating the need for a separate breakaway plate while maintaining collision protection capabilities.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The support shaft is designed to serve multiple functions: it provides structural support during normal operation and acts as an energy absorption mechanism during vehicle collisions through its low-strength portion. This multi-functional design eliminates the need for dedicated collision protection components.

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

2Reliability

If fine adjustment is performed on the breakaway plate, then energy absorption characteristics are improved, but manufacturing complexity increases

Engineering Contradiction:
Improveenergy absorption characteristicsVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent controls energy absorption characteristics by varying the parameters of the low-strength portion (such as its position, size, and strength) directly on the support shaft. This allows for customized energy absorption profiles through standard manufacturing processes without requiring complex post-production adjustments or specialized components.

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

Enables desired energy absorption during vehicle collisions without increasing the number of components and allows for precise adjustment of absorption characteristics, simplifying the design and reducing costs.

Implementation Method 1

a low-strength portion to be broken when a load acts on the steering shaft and the column jacket

Methodology Applied
Scientific EffectFracture Mechanics: Fracture Mechanics

Implementation Method 2

the support shaft that supports the lock member is broken at the low-strength portion, and the lock member is disengaged from the hole with which the lock member has been engaged in accordance with the breakage

Methodology Applied
Scientific EffectDeformation: Deformation

Data Source

PatentEP2923922B1Steering Device
Publication Date: 2017.05.03 JTEKT CORP
  • EP2923922B1 patent drawingFigure 1
  • EP2923922B1 patent drawingFigure 2
  • EP2923922B1 patent drawingFigure 3

AI summary

A steering device includes: a steering shaft (3) and a column jacket (4) that are telescopically adjustable in an axial direction; a lock plate (42) provided with a plurality of holes (57); a support shaft (39) that extends in a cross direction crossing the axial direction and includes a low-strength portion (74) to be broken when a load acts on the steering shaft (3) and the column jacket (4); and a lock member (40) that advances to the lock plate (42) to be engaged with one of the holes (57). The lock member (40) is disengaged from the one of holes (57) when the support shaft (39) is broken in a state in which the lock member (40) is engaged with the one of the holes (57).