Electric Welding Quality Monitoring via Resistance Curves
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current electric welding processes, particularly capacitor discharge welding, face challenges in assessing the quality of connections formed during the doughy phase, as traditional monitoring methods fail to distinguish between liquid and solid state welding processes, leading to misinterpretations and inadequate quality assessments.
Innovation Solution
A method and device for monitoring electric welding processes that record and evaluate the system states, specifically the welding current and voltage, to identify whether the process occurs in a resistance welding or metal vapor pressure welding mode, allowing for accurate differentiation and quality assessment based on the type of bonding mechanism.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional monitoring methods are used to assess welding quality, then the welding process can be monitored, but the quality assessment is inaccurate for doughy phase welding because the methods cannot distinguish between liquid and solid state welding processes
Solution Approach 1:
The patent applies parameter changes by analyzing the electrical resistance progression during welding. Different welding processes (liquid phase vs. doughy phase) exhibit distinct resistance characteristic curves. By monitoring and comparing the resistance progression against reference curves, the system can identify the welding process type and assess quality accurately, resolving the inability of traditional methods to distinguish between process types.
2Measurement precision
If cross-sectional analysis is used to evaluate welding quality, then the joint can be inspected, but misinterpretation occurs because no brittle lens is present in doughy phase welding
Solution Approach 1:
The patent introduces an intermediary evaluation method that uses electrical resistance progression as a mediator to indirectly assess welding quality. Instead of directly examining the joint cross-section (which leads to misinterpretation), the system uses resistance characteristic curves as an intermediary indicator that reliably distinguishes between liquid phase and doughy phase welding, enabling accurate quality assessment without misinterpretation.
3Reliability
If empirical tolerances are set for parameter deviations, then process disturbances can be accounted for, but the tolerances must be larger than necessary and only significant disturbances can be detected
Solution Approach 1:
The patent applies preliminary action by establishing reference resistance characteristic curves from known good welding processes before actual welding. These reference curves serve as a baseline for comparison, enabling the system to detect even minor deviations from the expected process pattern. This eliminates the need for large empirical tolerances, as the system can identify subtle quality issues by comparing against the pre-established reference.
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 reliable detection and qualification of metal plasma formation, ensuring high-quality cohesive joints by identifying the type of welding process, thereby improving the interpretation of recorded system states and allowing for appropriate test procedures to be selected, thus enhancing the assessment of welding quality.
Implementation Method 1
a bond is created between two joining partners, for example, between two sheets of metal to be welded together, through ohmic heating of the joint
Implementation Method 2
In the case of very high current densities, metal vapor is generated in the joining zone, which activates the surfaces of the joining partners
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to a method for carrying out and monitoring an electric welding process for joining a joining partner set (6) consisting of at least two joining partners (2, 4), comprising the steps of: carrying out a welding process to produce a welded joint, wherein an electric welding current (IS) flows by means of two electrodes (12, 14) through a joining area of the at least two joining partners (2, 4) of the joining partner set (6) arranged between the electrodes (12, 14), recording at least one system state of the welding process and identifying the welding process carried out as a function of the course of the at least one system state.