Bending Die with Diode Laser Bars for Brittle Material Forming

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Solution Overview

Problem

Bending processes for brittle materials like magnesium, titanium, and high-strength steels often result in material breakage or cracking due to insufficient plastic deformability, as these materials have low elongation at break and high yield strength ratios, making them difficult to form using conventional bending methods.

Innovation Solution

A bending die equipped with diode laser bars that provide uniform high-energy radiation along the forming zone, allowing for local heating of the workpiece to increase its formability, combined with adjustable contact elements and beam shaping to ensure efficient radiation distribution and safety.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional bending methods are used on brittle materials, then the bending process is simple and direct, but the materials break or crack due to insufficient plastic deformability

Engineering Contradiction:
Improvesuccess rate of bending processVSAvoidcomplexity of bending process
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by heating the workpiece to elevated temperatures (e.g., 100-500°C or higher depending on material) before bending. This temperature parameter change fundamentally alters the material's mechanical properties, increasing plastic deformability and reducing the yield point ratio, thereby enabling successful bending of brittle materials without cracking or breakage.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements preliminary action by performing heating treatment on the workpiece before the actual bending operation. This preparatory step modifies the material state in advance, making it more ductile and suitable for subsequent forming operations, thus preventing failures during bending.

Inventive Principle:
Principle #10Preliminary action

2Force

If laser heating is used to improve material formability, then the stress required for plastic deformation is reduced, but the device complexity and cost increase due to optical elements

Engineering Contradiction:
Improvestress required for plastic deformationVSAvoidcomplexity of radiation distribution system
Core Design Contradiction:
ForceVSDevice complexity

Solution Approach 1:

The patent applies segmentation by replacing a single complex optical system with multiple simpler radiation sources (e.g., multiple laser diodes or LED bars) distributed along the heating zone. Each radiation source independently illuminates a segment of the workpiece, collectively achieving uniform heating without requiring complex beam shaping optics.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent substitutes complex optical-mechanical beam distribution systems with a simpler array of independent radiation sources. This replacement eliminates the need for precision optical elements (lenses, mirrors, beam splitters) and their associated alignment mechanisms, significantly reducing device complexity while maintaining effective heating.

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

3Use of energy by moving object

If a single concentrated laser beam is used for heating, then the energy density is high, but the uniformity of heating along the bending line is poor

Engineering Contradiction:
Improveenergy density of radiationVSAvoiduniformity of heating along bending line
Core Design Contradiction:
Use of energy by moving objectVSManufacturing precision

Solution Approach 1:

The patent segments the concentrated beam into multiple distributed radiation sources positioned along the bending line. Each source provides localized high energy density, while the collective arrangement ensures uniform heat distribution across the entire heating zone, eliminating the non-uniformity problem of single-beam systems.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by positioning multiple radiation sources at different locations along the bending line, with each source optimized for its local zone. This ensures that every segment of the workpiece receives appropriate energy density, achieving both high local heating efficiency and overall uniformity.

Inventive Principle:
Principle #3Local quality

4Manufacturing precision

If complex optical elements are used to distribute radiation, then the beam power can be distributed evenly, but the quality requirements for optical elements become extremely high and cost increases

Engineering Contradiction:
Improveevenness of beam power distributionVSAvoidmanufacturing cost and quality control
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent replaces complex optical distribution systems with segmented radiation sources, each emitting directly onto its target zone. This eliminates the need for high-precision optical elements and their stringent quality control requirements, significantly reducing manufacturing cost and complexity while achieving even beam power distribution.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent uses simpler, more cost-effective radiation sources (such as laser diodes or LED bars) that can be easily manufactured and replaced if needed, replacing expensive, high-precision optical components that require stringent quality control and are difficult to manufacture.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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

The solution enables the bending of brittle materials by reducing the stress required for plastic deformation, preventing cracks and breakage, while also simplifying the setup and maintenance of the bending die, enhancing operational safety and reducing production downtime.

Implementation Method 1

local heating of the workpiece in the area of a forming zone by means of laser radiation

Methodology Applied
Scientific EffectLaser radiation heating: Laser

Implementation Method 2

the stress required to initiate plastic deformation can be reduced in this heated area

Methodology Applied
Scientific EffectThermal energy transfer: Heating

Data Source

PatentEP2448688B1Device and method for bending a workpiece
Publication Date: 2014.12.17 TRUMPF MASCHEN AUSTRIA
  • EP2448688B1 patent drawingFigure 1~2
  • EP2448688B1 patent drawingFigure 3~4
  • EP2448688B1 patent drawingFigure 5~6

AI summary

The invention relates to a snaker (3), particularly a V-shaped snaker (13), comprising a tool base body (7) with a contact surface (10) for contacting the workpiece (2) to be bent by a bending punch (5), a groove-shaped bending recess (11) in the contact surface (10) and at least one radiation exit opening (17) in the bending recess (11) and extending along thereof, which is configured to discharge high-energy radiation (18) onto a workpiece (2) bearing against the contact surface (10) in order to heat the deformation zone of the workpiece (2). An arrangement of diode laser bars (20) is fixed in the interior of the tool base body (7) for producing the radiation (18). Said diode laser bars (20) are arranged at least approximately uniformly along the longitudinal direction (17) of the bending recess (11) behind the radiation exit opening (17) in the tool base body (7).