Laser Butt Welding With Rotating Beam and Gap-Based Filler Control
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Solution Overview
Problem
Conventional laser beam welding methods struggle to achieve high-quality butt-welded joints in steel sheets, especially when the gap between the sheets is large or varies in width, leading to instability and reduced mechanical strength in the weld.
Innovation Solution
The method involves controlling the amount of filler supplied to the gap between the steel sheets based on the detected gap width, and delivering the laser beam while rotating it to cross the gap, ensuring the filler and steel sheets are melted and solidified uniformly to form a high-quality weld.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the gap between butted steel sheets is reduced to improve weld quality, then welding precision is improved, but it becomes impossible to eliminate the gap completely due to cutting imperfections and burrs
Solution Approach 1:
Filler material is introduced as an intermediary substance to occupy the gap between steel sheets. The filler bridges the gap created by cutting imperfections and burrs, enabling complete fusion without requiring the gap to be reduced to zero, thus resolving the contradiction between achieving tight gaps and maintaining cutting feasibility
Solution Approach 2:
The invention changes the parameter of gap width from a critical constraint to a controllable variable within a specific range (0.01-5mm). By defining an acceptable gap range rather than requiring zero gap, the system accommodates cutting variations while maintaining weld quality through coordinated filler supply and laser beam weaving
2Manufacturing precision
If a laser beam with small diameter and low output is used to achieve precise welding, then manufacturing precision is improved, but it becomes difficult to accurately direct the beam to the weld
Solution Approach 1:
The laser beam is transformed from a static, fixed-path beam into a dynamic, moving beam through weaving motion. The beam oscillates in the sheet width direction at frequencies of 50-2000 Hz, creating a time-averaged effective beam width that is larger than the physical beam diameter, thereby improving ease of targeting while maintaining precision through controlled motion
Solution Approach 2:
The laser beam employs periodic oscillation (weaving) at controlled frequencies and amplitudes. This periodic motion allows the beam to scan across the gap and accommodate positioning variations, making the welding process more tolerant of alignment errors while maintaining weld quality
3Strength
If filler material is supplied to the gap to ensure complete fusion, then weld strength is improved, but the welding process becomes more complex
Solution Approach 1:
The system incorporates feedback control where the filler supply amount is dynamically adjusted based on real-time detection of gap width. Sensors measure the actual gap between sheets and feed this information to the control system, which then modulates filler delivery to maintain optimal welding conditions, resolving the complexity through intelligent control
Solution Approach 2:
The invention establishes specific parameter ranges for filler supply rate, laser power, and welding speed that are coordinated with each other. By defining these parameter relationships, the system manages complexity through standardized parameter sets rather than requiring complex adaptive control for every variable
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 allows for the stable production of high-quality butt-welded joints with excellent mechanical strength, even under conditions of varying gap widths, thereby improving productivity and reducing welding failures in continuous processing lines.
Implementation Method 1
irradiating a gap between butted steel sheets with a laser beam while supplying filler to the gap, causing the butted portion of the steel sheets and the filler to melt and solidify
Implementation Method 2
causing the butted portion of the steel sheets and the filler to melt and solidify, forming a weld metal
Implementation Method 3
delivering the laser beam while rotating the laser beam so as to cross the gap between the steel sheets
Data Source
AI summary
A laser beam welding method is disclosed that includes irradiating a gap between butted steel sheets with a laser beam while supplying a filler to the gap so as to cause butted portions of the steel sheets and the filler to melt and solidify, and thus form a weld metal, thereby melting and joining the butted steel sheets. The method includes delivering the laser beam while rotating it across the gap between the steel sheets and controlling the ratio of the amount of the filler supplied to the gap per unit time to the volume of the gap between the steel sheets to be welded per unit time to be within a predetermined range. Also disclosed are a welding machine used for the method and a weld joint obtained with the method.