Polygonal Tapered Shock-Absorbing Member for Constant Counterforce

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Solution Overview

Problem

Existing shock-absorbing members with bending deformation increase counterforce during a crash, leading to higher automotive body stiffness and cost, and are prone to breakage when impact is not axial, resulting in inefficient energy absorption and stability issues.

Innovation Solution

A shock-absorbing member with a regular polygonal cross-section and tapered shape, where the cross-sectional area decreases towards the distal end, maintaining constant counterforce through deformation and preventing whole member breakage by controlling curvature and volume change.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the shock-absorbing member uses bending deformation with folding back of the outer wall, then shock energy is absorbed, but the counterforce increases gradually leading to higher automotive body stiffness and cost

Engineering Contradiction:

Improveenergy absorptionVSAvoidcounterforce

Core Design Contradiction:

Use of energy by moving objectVSForce

Solution Approach 1:

The patent applies parameter changes by modifying the cross-sectional shape from circular to regular polygonal and introducing a tapered configuration. These geometric parameter changes alter the deformation characteristics, causing the curvature to decrease with increasing stroke while maintaining constant counterforce, thereby resolving the contradiction between energy absorption and counterforce increase

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent utilizes curvature control through the tapered geometric configuration. As the shock-absorbing member deforms, the curvature of the folding-back deformation decreases with increasing stroke due to the tapered shape, which enables constant counterforce while maintaining effective energy absorption

Inventive Principle:

Principle #14Spheroidality (Curvature)

2Use of energy by moving object

If the shock-absorbing member increases counterforce to increase energy absorption, then absorbed energy increases, but the automotive body stiffness must be increased leading to higher cost

Engineering Contradiction:

Improveabsorbed energyVSAvoidautomotive body cost

Core Design Contradiction:

Use of energy by moving objectVSEase of manufacture

Solution Approach 1:

The patent changes the geometric parameters of the shock-absorbing member by using a regular polygonal cross-section with tapered configuration. This parameter change enables the member to maintain constant counterforce throughout deformation, achieving effective energy absorption without requiring increased automotive body stiffness, thus avoiding additional manufacturing costs

Inventive Principle:

Principle #35Parameter changes

3Adaptability or versatility

If the shock power does not act along the axial direction, then the shock-absorbing member comes into contact with attached members during deformation, but the whole shock-absorbing member breaks (crashes)

Engineering Contradiction:

Improvedeformation stabilityVSAvoidmember integrity

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent uses the tapered geometric configuration to control the deformation curvature. This curvature control ensures that during oblique impact, the deformation path is constrained within the member's geometric boundaries, preventing contact with attached members and avoiding catastrophic failure, thus improving both adaptability and reliability

Inventive Principle:

Principle #14Spheroidality (Curvature)

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 enhances energy absorption per unit weight without increasing automotive costs and ensures stable deformation, preventing whole member breakage by maintaining constant counterforce and reducing curvature, thus improving energy absorption efficiency.

Implementation Method 1

the main body portion undergoes eversion deformation when a shock power acts on a distal end of the main body portion so that shock energy is absorbed

Methodology Applied

Scientific EffectEversion deformation: Deformation

Implementation Method 2

bending deformation continuously occurs in which a length of a folded-back portion formed by folding back of the outer wall of the first portion caused by a shock power

Methodology Applied

Scientific EffectBending deformation: Deformation

Data Source

PatentUS9505362B2Shock-absorbing member

Publication Date: 2016.11.29 JFE STEEL CORP

AI summary

Provided is a shock-absorbing member that does not increase the cost of automobile and that can increase the absorbed energy per unit weight of the shock-absorbing member. A shock-absorbing member 1 includes a tubular main body portion 3, a bent portion 5 that is formed continuous with the main body portion 3, and a flange 7 provided at the proximal end of the main body portion 3 via the bent portion 5. The main body portion 3 is caused to undergo eversion deformation by a shock power acting on the distal end of the main body portion 3 so that shock energy is absorbed. The main body portion 3 has regular polygonal cross-section orthogonal to the axial direction, and has a tapered shape that an area of the cross-section orthogonal to the axial direction decreases toward the distal end.