Plasma-Guided Welding of Hidden Joints Without Precise Positioning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Joining hidden joints, such as hidden T-joints, is challenging due to the need for precise alignment of joining partners and the welding tool, which is difficult to achieve accurately, especially when one partner is covered, leading to incomplete or failed welds. Existing solutions like manual positioning and optical coherence tomography are impractical or excessively costly.
Innovation Solution
A welding device with a positioning surface, a welding tool, and a sensor arrangement that monitors the electrical properties of the plasma generated during welding to guide the tool head along the hidden joint, allowing for accurate path definition and correction without precise initial positioning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If manual positioning of the welding tool is used, then the positioning process can be performed, but the productivity is low and the process must be repeated for each component
Solution Approach 1:
The patent implements a feedback mechanism by monitoring plasma characteristics during welding and using this information to automatically adjust the welding tool's position and path. The sensor arrangement detects plasma properties, and the control device uses this feedback to correct the welding path in real-time, eliminating the need for repeated manual positioning for each component while maintaining high positioning accuracy.
2Measurement precision
If optical coherence tomography (OCT) is used to monitor joint position, then measurement precision is improved, but the device complexity and cost increase significantly
Solution Approach 1:
The patent replaces expensive, complex OCT systems with a simpler, more cost-effective sensor arrangement that monitors plasma characteristics. Instead of using sophisticated optical tomography equipment, the invention employs relatively simple sensors that detect electrical properties of the plasma, significantly reducing device complexity and cost while achieving the necessary measurement precision for welding path guidance.
Solution Approach 2:
The patent substitutes complex optical measurement systems (OCT) with a plasma-based sensing approach. By using the plasma generated during welding itself as the measurement medium and detecting its electrical properties, the system replaces elaborate mechanical/optical positioning systems with a simpler electromagnetic field-based detection method.
3Measurement precision
If photodiode-based path guidance is used, then the welding path can be monitored, but the measurement precision is compromised by contaminants like weld spatter and fumes
Solution Approach 1:
The patent changes the measurement parameter from optical properties (which are sensitive to spatter and fumes) to electrical properties of the plasma. By monitoring electrical characteristics such as conductivity or impedance of the plasma, the system achieves path guidance that is not affected by optical contaminants, maintaining measurement precision even in the presence of weld spatter and fumes.
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
Enables successful and error-free welding of hidden joints by monitoring plasma electrical properties, reducing the need for precise initial positioning and offering a cost-effective solution compared to high-tech methods like OCT, making it suitable for mechanical handling systems and robots.
Implementation Method 1
the formation of a plasma, which is caused during welding by the ionization of a metal vapor resulting from the interaction between the welding tool and the workpiece
Data Source
Figure 1
Figure 2
Figure 3
AI summary
This disclosure describes a welding device (100) for joining a hidden joint on a workpiece (101). The welding device comprises a positioning surface (106) for positioning the workpiece (101). Furthermore, the welding device comprises a welding tool (108) configured to heat a surface of the workpiece (101) comprising the hidden joint by means of a tool head (109), wherein the tool head (109) is movably arranged relative to the positioning surface (106). The welding device also comprises a sensor arrangement (112) configured to determine the characteristics of a plasma generated by the welding tool in an interaction zone (110) between the tool head (109) and the workpiece (101) by determining an electrical property of the plasma and to provide a plasma information signal (119) depending on the determined characteristics of the plasma.Furthermore, the welding device includes a control unit (120) for moving the tool head (109), which receives the plasma information signal (119) and is designed to move the tool head (109) along the hidden joint depending on the plasma information signal (119).