Laser-Treated Polygonal Impact-Absorbing Member

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing impact-absorbing members in vehicles face challenges in reducing deformation while minimizing the area of laser thermal treatment, as current methods do not consider deformation behavior, leading to inefficient energy absorption and increased costs.

Innovation Solution

The impact-absorbing member features a tubular body with polygonal cross-sections, including flat portions and corner portions, where laser thermal treatment is applied to specific areas to deform at angles between 0.1 and 3.0 degrees, strategically positioned to reduce deformation and enhance strength, particularly along diagonal directions and at the end portions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the cross sectional dimensions or wall thickness of the impact-absorbing member are increased to enhance strength, then the strength is improved, but the volume or weight increases leading to deterioration in fuel efficiency and increased damage to opposing vehicle

Engineering Contradiction:
ImprovestrengthVSAvoidweight
Core Design Contradiction:
StrengthVSWeight of stationary object

Solution Approach 1:

The patent applies laser thermal treatment to specific localized regions (flat portions) of the impact-absorbing member rather than uniformly throughout. This creates local quality variations where treated portions have enhanced strength and hardness, allowing the overall structure to maintain lower weight while achieving required strength through strategic reinforcement of high-stress areas

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes the physical and chemical parameters of the material through laser thermal treatment, transforming the microstructure of the steel in treated portions. This parameter change (through heating and self-quenching) increases hardness and strength without requiring an increase in overall dimensions or weight of the impact-absorbing member

Inventive Principle:
Principle #35Parameter changes

2Strength

If laser thermal treatment is applied to enhance strength while suppressing distortion, then the strength is improved, but the area requiring treatment increases leading to higher costs and reduced productivity

Engineering Contradiction:
ImprovestrengthVSAvoidproductivity
Core Design Contradiction:
StrengthVSProductivity

Solution Approach 1:

The patent identifies and treats only the flat portions of the polygonal cross-section with laser thermal treatment, leaving corner portions untreated. This localized approach reduces the total treatment area compared to uniform treatment, thereby reducing costs and processing time while still achieving the required strength enhancement in the most critical regions

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent applies laser thermal treatment partially rather than completely across the entire surface. By treating only the flat portions and not the corner portions, the process achieves sufficient strength enhancement with reduced treatment area, improving productivity and reducing costs while maintaining adequate performance

Inventive Principle:
Principle #16Partial or excessive 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 approach effectively reduces deformation and enhances energy absorption efficiency while minimizing the area treated with laser thermal treatment, resulting in improved resistance to impact forces and reduced material costs.

Implementation Method 1

a laser beam having a high energy density is emitted to an untreated impact-absorbing member to locally heat the impact-absorbing member to a transformation temperature or melting point or more

Methodology Applied
Scientific EffectLaser heating: Laser

Implementation Method 2

the impact-absorbing member is quench hardened through an self cooling mechanism

Methodology Applied
Scientific EffectSelf-cooling mechanism: Cooling

Implementation Method 3

at least one of the plural flat portions has a thermally-treated portion formed by applying a thermal treatment with laser light so as to deform at an angle of not less than 0.1 degrees and not more than 3.0 degrees

Methodology Applied
Scientific EffectThermal deformation: Deformation

Data Source

PatentEP2565489B1Shock-absorbing member
Publication Date: 2016.05.25 NIPPON STEEL & SUMITOMO METAL CORP
  • EP2565489B1 patent drawingFigure 1A~1B
  • EP2565489B1 patent drawingFigure 2A~2C
  • EP2565489B1 patent drawingFigure 3A~3B

AI summary

An impact-absorbing member according to the present invention includes a tubular body having a polygonal shape in cross-section perpendicular to a longitudinal direction of the tubular body, the tubular body including: plural flat portions; and plural corner portions provided between the flat portions, in which at least one of the plural flat portions has a thermally-treated portion formed by applying a thermal treatment with a laser light so as to deform at an angle of not less than 0.1 degrees and not more than 3.0 degrees.