Laser Beam Welding Path for Stable Lap Fillet Joints
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Solution Overview
Problem
Existing lap fillet welding techniques using laser-beam welding and MIG arc welding result in increased equipment size and complexity, compromising practicality.
Innovation Solution
A laser-beam welding method where the laser beam is applied to overlapping metal plates with the beam position moving in a circular or elliptical locus, first targeting the unmelted zone of one plate and then the other, ensuring sufficient heat transfer and preventing molten metal blow-off due to keyhole pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If composite welding including laser-beam welding and MIG arc welding is performed, then deep weld-penetration is achieved without causing burn through, but the size of welding equipment increases and the welding equipment becomes complicated
Solution Approach 1:
The patent combines laser-beam welding and MIG arc welding into a single integrated welding system. The laser beam and welding wire are supplied simultaneously to the same welding region, merging two separate welding processes into one unified operation. This allows deep weld-penetration to be achieved without burn through while avoiding the need for separate equipment setups, thereby reducing overall equipment complexity and size.
Solution Approach 2:
The patent maintains continuous welding action by supplying both laser beam and welding wire simultaneously to the welding region. The laser beam creates deep penetration while the welding wire continuously fills the molten zone, ensuring uninterrupted welding progress. This continuous action achieves satisfactory welding quality without requiring sequential operations that would increase equipment complexity.
2Manufacturing precision
If composite welding including laser-beam welding and MIG arc welding is performed, then deep weld-penetration is achieved without causing burn through, but the size of welding equipment increases
Solution Approach 1:
The patent integrates laser-beam welding and MIG arc welding components into a single welding apparatus. The laser beam source, welding wire feed mechanism, and power supply are combined into one unified system, allowing deep weld-penetration to be achieved without burn through while avoiding the need for separate equipment installations, thereby reducing overall equipment size.
3Productivity
If laser beam is applied to melted zone, then welding progress is maintained, but molten metal is blown off due to keyhole pressure
Solution Approach 1:
The patent introduces welding wire as an intermediary material that is supplied into the molten zone created by the laser beam. The welding wire acts as a mediator that fills the keyhole and prevents molten metal from being blown off due to keyhole pressure. This allows the laser beam to maintain high energy input for fast welding progress while the welding wire counteracts the harmful blow-off effect, achieving both high productivity and stable welding.
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 method achieves high-quality lap fillet welds with sufficient joint strength without the need for additional welding methods like MIG arc welding, maintaining equipment simplicity and efficiency.
Implementation Method 1
a laser beam is applied from a laser diode to a laser-beam application region including a portion of the upper and a portion of the lower plate
Implementation Method 2
heat transfer and preventing molten metal blow-off
Implementation Method 3
an electric arc is generated at a position rearward of the laser-beam application region in the direction of welding
Implementation Method 4
a zone in the laser-beam application region, where a metallic material has been melted
Data Source
AI summary
While a laser-beam application position is moved along a locus which circularly or elliptically circles around a locus center so as to cross a weld line that is a boundary between a first metal plate and a second metal plate overlapped with each other, the locus center is moved in a direction parallel to a weld line. A moving direction of the laser-beam application position is set such that the laser beam is first applied to the first metal plate and then to the second metal plate when the laser beam passes through an unmelted zone of the first metal plate and the second metal plate. The unmelted zone is located downstream of a range through which the laser beam has already passed in the direction parallel to the weld line.