Laser-Welded Reinforcement Strip Bending for Joined Metal Bodies

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Solution Overview

Problem

The existing methods for joining metal members by welding, especially when one member is bent, result in increased costs and reduced yield due to the need for specialized tools and processes to conform the reinforcing steel strip to the bent shape.

Innovation Solution

A method and apparatus that allow for the bending of the second metal member during welding, using a laser welding process with a specific irradiation pattern and bending technique to form a joint with increased density and strength, eliminating the need for special devices and improving yield.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a steel strip is bonded to a bent ridge portion by welding, then the ridge portion can be reinforced, but it requires punching or cutting the steel strip from a wide steel plate which increases cost and reduces yield

Engineering Contradiction:
Improveridge portion reinforcementVSAvoidsteel plate yield
Core Design Contradiction:
StrengthVSLoss of substance

Solution Approach 1:

The steel strip is bent to match the contour of the ridge portion before welding. This preliminary shaping action allows the strip to conform to the bent surface without requiring complex punching or cutting operations from a wide steel plate, thereby reducing material waste and improving yield while maintaining reinforcement effectiveness

Inventive Principle:
Principle #10Preliminary action

2Shape

If a steel strip is punched or cut from a wide steel plate to conform to a bent shape, then the strip can fit the ridge portion, but cost increases and yield decreases

Engineering Contradiction:
Improvesteel strip contour conformityVSAvoidmanufacturing cost
Core Design Contradiction:
ShapeVSEase of manufacture

Solution Approach 1:

The steel strip is bent to the required contour before welding operations. This preliminary forming step creates the necessary shape conformity without requiring expensive punching or cutting processes, thereby reducing manufacturing cost while achieving the required geometric fit to the bent ridge portion

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention replaces complex mechanical punching or cutting operations with a simpler bending process. By using forming operations instead of subtractive manufacturing, the process becomes more cost-effective while achieving the same geometric conformity to the bent ridge portion

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Shape

If the second metal member is bent during welding, then specialized devices are needed which increases device complexity, but the invention achieves bending without special devices by using higher welding set density

Engineering Contradiction:
Improvemetal member bendingVSAvoidwelding apparatus complexity
Core Design Contradiction:
ShapeVSDevice complexity

Solution Approach 1:

The invention changes the welding parameters by increasing the density of the welding set (number of welding points or welding speed). This parameter adjustment allows the second metal member to be bent during welding without requiring specialized bending devices, as the higher welding density provides sufficient thermal control to accommodate the bending deformation

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The welding process itself performs the bending function without requiring separate specialized devices. By adjusting the welding set density, the thermal field from welding naturally accommodates and induces the bending of the second metal member, making the welding apparatus self-sufficient for both joining and shaping operations

Inventive Principle:
Principle #25Self-service

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 enables efficient welding of bent metal members without specialized equipment, reducing costs and increasing the joint strength between the metal members, suitable for processing vehicle frame components like B pillars through hot stamping.

Implementation Method 1

a first metal member and a second metal member are joined by laser welding

Methodology Applied
Scientific EffectLaser heating: Laser

Implementation Method 2

the laser beam is moved in a direction along a width direction of the second metal member while the second metal member is bent, so that the joint portion has a density of a welding set higher than a main body portion

Methodology Applied
Scientific EffectMelting: Melting

Data Source

PatentEP3677376B1Method of and apparatus for manufacturing a joined body, and joined body
Publication Date: 2022.10.05 KOBE STEEL LTD
  • EP3677376B1 patent drawingFigure 1~2
  • EP3677376B1 patent drawingFigure 3A~3B
  • EP3677376B1 patent drawingFigure 4

AI summary

Provided is a manufacturing method for a joint body having a first metal member 2 and a second metal member 3 joined together by welding. With a density of the welding set higher than a density of the welding of other portions, the second metal member 3 is bent within a plane by changing a positional relation of the second metal member 3 relative to the first metal member 2 in plan view.