Laser Butt Welding Gap Measurement for Variable Sheet Metal Seams
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Solution Overview
Problem
Current methods for butt welding sheet metal parts, particularly in body construction, face challenges in maintaining high welding quality due to varying gap situations and geometries, leading to issues like seam cracks and reduced productivity, as existing systems struggle to accurately measure and adapt to different gap widths and positions, especially in complex geometries like V-shaped gaps.
Innovation Solution
The method combines reflected light and transmitted light techniques to measure gap width and real gap geometry, allowing for precise estimation of missing volume and optimal control of the welding process, including the use of cored wire, to ensure high-quality welds and improved productivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If conventional laser welding processes are used with stationary welding tools, then welding automation is achieved, but welding quality deteriorates due to varying gap situations and geometries
Solution Approach 1:
The patent implements dynamic gap measurement and evaluation during the welding process, allowing the system to adapt to varying gap situations in real-time. The measurement device captures gap geometry data continuously, and the control unit adjusts welding parameters dynamically based on the evaluated gap conditions, transforming a static welding process into a dynamic adaptive one.
Solution Approach 2:
The patent establishes a feedback loop where gap dimensions are measured during welding, evaluated by the control unit, and used to adjust the welding process. The system continuously monitors gap situations and provides feedback to optimize welding parameters, ensuring consistent weld quality despite variations in gap geometry.
2Adaptability or versatility
If filler wire is added to close variable gaps, then gap closure capability improves, but device complexity increases
Solution Approach 1:
The patent primarily adjusts welding parameters (power, speed, focus position) based on evaluated gap conditions to achieve successful welding without filler wire. The system changes process parameters dynamically according to gap measurements, providing adaptability through parameter optimization rather than physical system modifications.
3Manufacturing precision
If precise mechanical positioning is used to maintain seam path accuracy, then positioning precision improves, but manufacturing complexity increases
Solution Approach 1:
The patent replaces complex mechanical positioning systems with an optical measurement and evaluation system. Instead of relying on mechanical precision to maintain seam path accuracy, the system uses light-based measurement devices to detect gap geometry and control units to calculate optimal seam paths, substituting mechanical complexity with optical and computational approaches.
4Difficulty of detecting and measuring
If incident light method is used to measure gap width, then measurement capability is provided, but measurement precision deteriorates for complex geometries
Solution Approach 1:
The patent transitions from one-dimensional gap width measurement to three-dimensional gap geometry evaluation. The measurement device captures spatial information about the gap structure, and the control unit evaluates the complete gap geometry including depth, shape, and orientation, providing comprehensive dimensional analysis rather than simple width measurement.
Solution Approach 2:
The patent introduces a control unit as an intermediary that processes raw measurement data and evaluates gap geometry. This intermediary layer analyzes the captured light patterns, calculates gap dimensions and shape characteristics, and provides interpreted gap information, mediating between the measurement device and the welding control system.
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 enhances welding quality and productivity by accurately determining gap geometry, reducing the need for additional material and improving seam quality, thereby addressing the limitations of existing methods in handling variable gaps and ensuring reliable welds.
Implementation Method 1
gap situations such as A-, V-, parallel, zero gap or a mixture of these occur. One well-known method for determining gap dimensions is the incident light method. This involves shining light onto the gap via a light source. This light is then reflected by the metal surface and evaluated by a camera
Implementation Method 2
the sheet metal blanks are joined to form a welded sheet metal blank by means of a welding laser
Implementation Method 3
In the other method, metal sheets are fed to a stationary welding tool and welded
Data Source
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AI summary
The invention relates to a method for butt welding flat sheet metal plates (1, 2) in a welding machine, wherein: two sheet metal plates (1, 2) are placed on a conveyor unit (37) by feed means and secured using holding means; two edges (4, 5) of two sheet metal plates (1, 2) to be welded together are butted against one another so as to form as small a gap as possible and welded together using a welding laser (6); and the gap width (7) of the gap is measured and the welding process is controlled using the measured values. According to the invention, the gap width (7) is measured by means of a reflected light method, and the real gap width (9) is measured by means of a transmitted light method, such that the error surface (8) or the error volume in the gap can be better estimated.