Laser Welding of Planar Plates Without Re-Clamping Errors

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Solution Overview

Problem

Existing methods for welding bipolar plates in fuel cells face challenges such as high production costs, long welding times, and difficulties in maintaining precise positioning due to repeated clamping and warping, particularly with thin materials and complex weld seam configurations, leading to inefficiencies and inaccuracies.

Innovation Solution

A device and method that transports and welds metal plates in a horizontal plane, using multiple simultaneous welding lasers and a position measurement system, with a helical compensation for the polygon effect to ensure precise alignment and reduce re-clamping needs, allowing for efficient and high-quality production.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If bipolar plate halves are welded in a horizontal plane with repeated clamping, then weld coverage can be achieved, but positioning precision deteriorates due to warping and re-clamping errors

Engineering Contradiction:
Improveweld point positioning accuracyVSAvoidrepeated clamping operations
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent inverts the conventional welding approach by welding bipolar plate halves in a vertical plane instead of horizontal plane. The plates are clamped vertically between upper and lower anvil plates, and the laser welds from the side. This inversion eliminates the need for re-clamping and positioning adjustments, maintaining consistent weld point accuracy throughout the process.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The welding process is segmented into multiple simultaneous weld operations. Multiple laser beams weld different sections of the bipolar plate halves at the same time while the workpiece remains in a single fixed position. This segmentation of the welding process across multiple spatial locations eliminates the need for sequential re-clamping operations.

Inventive Principle:
Principle #1Segmentation

2Productivity

If multiple welding lasers operate simultaneously, then productivity increases, but system complexity increases

Engineering Contradiction:
Improvewelding cycle timeVSAvoidmultiple laser coordination system
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

Multiple laser welding systems are merged into a single integrated device that processes bipolar plate halves simultaneously. The multiple lasers are coordinated through a common control system that synchronizes their operation, achieving high productivity while managing system complexity through unified control architecture.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The system maintains continuous welding action by having multiple lasers operate simultaneously without interruption. While one laser completes a weld segment, another laser is already positioned for the next segment, eliminating idle time and maintaining continuous productive action throughout the welding cycle.

Inventive Principle:
Principle #20Continuity of useful action

3Manufacturing precision

If thin bipolar plate materials are welded with conventional methods, then weld seams can be created, but manufacturing precision deteriorates due to warping and positioning difficulties

Engineering Contradiction:
Improveweld seam accuracyVSAvoidthin material handling
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

By inverting the welding orientation to vertical positioning, thin bipolar plate materials are supported rigidly between upper and lower anvil plates throughout the welding process. This vertical configuration prevents warping and maintains positioning accuracy, making thin material welding as controllable as thicker material welding.

Inventive Principle:
Principle #13The other way round (Inversion)

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 significantly reduces cycle times, minimizes contamination, and enhances production efficiency by eliminating the need for repeated clamping, ensuring high accuracy and quality while reducing costs.

Implementation Method 1

the at least two welding lasers (22a, 22b) weld the plate-shaped workpieces (14)

Methodology Applied
Scientific EffectLaser welding: Laser Beam Welding

Implementation Method 2

a position measurement system (9) determines the position of the workpieces (14)

Methodology Applied
Scientific EffectPosition measurement:

Data Source

PatentEP4408603B1Method and device for laser welding planar workpieces
Publication Date: 2025.09.03 ANDRITZ SOUTEC
  • EP4408603B1 patent drawingFigure 1
  • EP4408603B1 patent drawingFigure 2
  • EP4408603B1 patent drawingFigure 3

AI summary

The invention relates to a device (1) and to a method for producing welded, planar workpieces (14, 15), in particular for producing bipolar plates or heat exchanger plates. Standing vertically in a horizontal plane XY, the workpieces (14) are transported by means of a continuously circulating product transport system (2) through a processing area (23a, 23b) and are welded. The workpieces (14) are transported through the processing area at a constant speed and, whilst there, are welded by means of at least two simultaneously working welding lasers (22a, 22b), the position of the workpieces (14) being determined and the at least two welding lasers (22a, 22b) thus being controlled.