Shock-absorbing Steering Device Secondary Collision Protection

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Solution Overview

Problem

Existing impact absorbing steering apparatuses face challenges in preventing the rear section of the steering column from displacing upward during a secondary collision, especially when the housing of an electric power steering apparatus drops away from the vehicle body, which can lead to inadequate protection of the driver and difficulties in maintaining the proper positional relationship with the airbag.

Innovation Solution

The impact absorbing steering apparatus incorporates a support plate section located below the installation plate section on the housing side, which moves above a support plate section fastened to the vehicle body before the force supporting the bracket on the housing side is lost, preventing excessive forward displacement of the steering column and maintaining the proper inclination angle, thereby ensuring the steering wheel does not raise excessively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the housing of the electric power steering apparatus is supported independently from the steering column by a bracket fastened to the vehicle body, then the housing can drop away to the front due to impact load, but the rear section of the steering column may displace upward during secondary collision

Engineering Contradiction:
Improveimpact energy absorptionVSAvoidsteering column position
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent merges the support functions of the steering column and housing into a single integrated bracket structure. The bracket simultaneously supports both the steering column at its rear end and the housing at its front end, causing them to move together as a unified assembly during impact. This eliminates the independent support arrangement that caused the steering column to displace upward while the housing dropped away.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The integrated bracket acts as an intermediary structure that couples the motion of the steering column and housing. By fastening both components to the same bracket assembly that is itself fastened to the vehicle body, the bracket mediates the force transmission and ensures coordinated displacement of both the steering column and housing during impact, preventing the steering column from moving independently upward.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Stability of the object's composition

If the steering column and housing are fastened to the vehicle body by a common bracket, then the steering column position is stabilized, but the housing cannot drop away independently to absorb impact energy

Engineering Contradiction:
Improvesteering column positionVSAvoidimpact energy absorption
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The patent combines the impact absorption function into the unified bracket assembly rather than requiring independent housing displacement. The entire bracket assembly (supporting both steering column and housing) drops away together from the vehicle body during impact, absorbing impact energy while maintaining the relative positional relationship between the steering column and housing, thus stabilizing the steering column position even during impact.

Inventive Principle:
Principle #5Merging (Combining)

3Loss of energy

If the steering column drops away to the front during secondary collision, then impact energy is absorbed, but the steering wheel may raise excessively and fail to protect the driver

Engineering Contradiction:
Improveimpact energy absorptionVSAvoidsteering wheel position
Core Design Contradiction:
Loss of energyVSStability of the object's composition

Solution Approach 1:

By integrating the support of the steering column and housing into a single bracket assembly, the patent ensures that when the assembly drops away to absorb impact energy, the steering column and housing move together as a unified system. This coordinated motion prevents the steering column from dropping excessively while the housing remains in its proper position, thereby preventing the steering wheel from raising and maintaining driver protection.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The integrated bracket structure provides preliminary constraint against excessive steering column displacement. By coupling the steering column support to the housing support, the system pre-establishes a mechanical relationship that prevents the steering column from moving independently in an upward direction that would cause the steering wheel to raise, thereby counteracting the potential harmful effect before it occurs.

Inventive Principle:
Principle #9Preliminary anti-action

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

This design effectively prevents the rear section of the steering column from displacing upward during a secondary collision, maintaining the required load for forward displacement and protecting the driver by keeping the steering wheel in its proper position.

Implementation Method 1

the energy absorbing member plastically deforms, which absorbs the impact energy that is transmitted from the steering wheel (1) to the bracket on the column side (12)

Methodology Applied
Scientific EffectPlastic deformation: Plasticity

Data Source

PatentEP2450255B1Shock-absorbing steering device
Publication Date: 2015.11.11 NSK LTD
  • EP2450255B1 patent drawingFigure 1
  • EP2450255B1 patent drawingFigure 2
  • EP2450255B1 patent drawingFigure 3

AI summary

Construction is achieved wherein the rear section of a steering column 6a can be prevented from displacing upward regardless of the occurrence of a secondary collision, and thus can effectively protect the driver. Capsules 28 are supported by a bracket on the vehicle body side. An installation plate section 14b of a bracket 13 on the housing side is held between a top plate section 29 and bottom plate section 30 of each of the capsules 28 so that the installation plate section 14b can displace in the forward direction during a secondary collision. The top and bottom plate sections 29, 30 extend forward to a position where they can support the installation plate section 14b even when the bracket 13 on the housing side has displaced in the forward direction due to a secondary collision. Alternatively, a suspended arm that functions in the same way is provided on the bracket on the vehicle body side.