Laser Welding Head Monitoring With Multi-Wavelength Feedback

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing laser welding devices face challenges in effectively monitoring the welding quality, particularly due to the difficulty in adapting to changing operating conditions and maintaining precise alignment of the laser beam, which affects the accuracy and efficiency of the welding process.

Innovation Solution

The laser welding device incorporates a monitoring system that detects and evaluates radiation reflected from the workpiece in multiple wavelength ranges, including visible light and infrared, allowing for continuous quality assessment and adjustment of the laser beam's focus and power to improve welding quality. Additionally, a galvanometer scanner and movable optical fibers enable flexible beam alignment and adjustment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single wavelength detection method is used for monitoring welding quality, then the device complexity is reduced, but the measurement precision and reliability of welding quality assessment deteriorates

Engineering Contradiction:
Improvemonitoring device structureVSAvoidwelding quality monitoring accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The monitoring device segments the radiation detection into multiple wavelength ranges (first wavelength range and second wavelength range) using separate detector arrangements. This allows independent optimization of detection for each wavelength band, improving overall measurement precision while keeping each detector module relatively simple in structure

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The monitoring device is designed with multi-functionality by incorporating detector arrangements that can detect radiation across different wavelength ranges simultaneously. This universal detection capability enables comprehensive welding quality assessment without requiring multiple separate devices, thus improving measurement precision without proportionally increasing device complexity

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Ease of operation

If the laser beam alignment is not adjusted for changing operating conditions, then the ease of operation is maintained, but the manufacturing precision of the weld joint deteriorates

Engineering Contradiction:
Improvelaser welding operation simplicityVSAvoidweld joint quality
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The monitoring device provides real-time feedback on welding quality by detecting radiation in multiple wavelength ranges. This feedback mechanism enables automatic or operator-guided adjustment of laser beam alignment and parameters, maintaining manufacturing precision while preserving ease of operation through intelligent control assistance

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system incorporates dynamic adjustment capabilities that allow the laser beam parameters and alignment to be adapted in real-time based on changing operating conditions. This dynamic responsiveness ensures consistent weld quality without requiring complex manual realignment procedures, balancing ease of operation with manufacturing precision

Inventive Principle:
Principle #15Dynamics

3Manufacturing precision

If real-time multi-wavelength monitoring is implemented, then the manufacturing precision of weld quality assessment is improved, but the use of energy and device complexity increase

Engineering Contradiction:
Improveweld quality assessment accuracyVSAvoidmonitoring device energy consumption
Core Design Contradiction:
Manufacturing precisionVSUse of energy by moving object

Solution Approach 1:

The monitoring device implements continuous real-time detection across multiple wavelength ranges throughout the welding process. This continuous multi-wavelength monitoring ensures consistent high-precision weld quality assessment without interruption, maintaining manufacturing precision while optimizing energy usage through sustained efficient operation rather than intermittent high-power bursts

Inventive Principle:
Principle #20Continuity of useful 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 solution enhances the monitoring and adjustment capabilities, leading to improved welding quality by allowing real-time assessment and regulation of the welding process, reducing porosity and ensuring precise alignment of the laser beam, thus improving the overall efficiency and accuracy of the welding process.

Implementation Method 1

a sensor arrangement through which radiation, which is reflected from a workpiece struck by the laser beam(s) emerging from the laser welding head

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 2

at least one optical fiber opens, through which at least one laser beam generated by an external radiation source can be supplied to the laser welding head

Methodology Applied
Scientific EffectOptical fiber transmission: Optical Fibre

Implementation Method 3

at least one laser beam generated by an external radiation source

Methodology Applied
Scientific EffectLaser: Laser

Data Source

PatentEP4292749A1Laser welding device and method of monitor, with a laser welding head and a monitoring device
Publication Date: 2023.12.20 FRITZ STEPPER GMBH & CO KG
  • EP4292749A1 patent drawingFigure 1
  • EP4292749A1 patent drawingFigure 2
  • EP4292749A1 patent drawingFigure 3

AI summary

The invention relates to a laser welding device with a laser welding head, in particular for a tool of a machine tool, which has a housing into which at least one optical fiber (3) opens, through which a laser beam (L) generated by an external radiation source can be supplied to the laser welding head, that a beam conditioning unit (5) with an inlet region (5a) and an outlet region (5b) is arranged in the housing, wherein at least one laser beam exiting from the fiber end (3a) of the at least one optical fiber (3) is directed to the inlet region (5a) of the beam conditioning unit (5) and at least one laser beam (L1, L2) exits from the outlet region (5b) of the beam conditioning unit (5), which is guided out of the housing of the laser welding head through an outlet opening (7), and that the laser welding device has a monitoring device (110) with a sensor arrangement (120) through which radiation (S),The monitoring device (110) is designed to detect the radiation reflected from a workpiece (W) exposed to the laser beam(s) (L1, L2) emitted from the laser welding head. It is further designed to detect and evaluate the radiation (S) reflected from the workpiece (W) in at least two wavelength ranges.