Arc Welding Control via Dynamic Wire Feeding
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Solution Overview
Problem
Conventional arc welding control methods face challenges in stabilizing welding voltage and reducing spatters, particularly in maintaining a fixed ratio between short-circuit and arc periods, which leads to unstable arcs and increased spatter generation.
Innovation Solution
The method involves controlling the short-circuit current increasing gradient, inflection point, peak current, and base current to adjust the ratio between short-circuit and arc periods, allowing for precise matching of output voltage with set voltage, thereby stabilizing welding voltage and reducing spatters by periodically repeating forward and reverse wire feeding in sine or trapezoidal waveforms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the welding output is increased or decreased by periodically repeating forward feed and reverse feed at a fixed wire feeding speed, then the arc is stabilized and spatters are reduced, but the welding voltage cannot be matched with the set voltage due to fixed arc period
Solution Approach 1:
The patent applies dynamics by making the wire feeding speed variable rather than fixed. The feeding speed is dynamically adjusted based on the welding voltage feedback, allowing the system to adapt the arc period and short-circuit period ratios to achieve both arc stability and precise voltage control. The feeding speed waveform is modified from a conventional fixed pattern to a dynamic pattern that responds to voltage deviations.
Solution Approach 2:
The patent changes the parameter of wire feeding speed dynamically during the welding process. By adjusting the feeding speed amplitude and frequency based on voltage feedback, the system can control the transition between arc and short-circuit states, thereby matching the welding voltage with the set voltage while maintaining arc stability.
2Speed
If a high gain is used to force control the welding voltage within a predetermined time period, then the voltage control response is improved, but large variations in arc length occur leading to unstable arc
Solution Approach 1:
The patent uses dynamic adjustment of wire feeding speed with feedback control to achieve fast voltage response without high gain. The system dynamically modifies the feeding speed waveform based on voltage deviations, providing rapid response while maintaining arc stability through controlled, adaptive changes rather than aggressive high-gain control.
Solution Approach 2:
The patent implements feedback control by monitoring the welding voltage and using this information to adjust the wire feeding speed. The feedback mechanism allows the system to respond to voltage deviations and adjust the arc period and short-circuit period ratios accordingly, achieving fast response without the need for high gain that would cause arc instability.
3Device complexity
If the ratio between short-circuit period and arc period is fixed, then the control system is simple, but the welding voltage cannot be precisely controlled
Solution Approach 1:
The patent makes the ratio between short-circuit period and arc period dynamic rather than fixed. The wire feeding speed is continuously adjusted based on voltage feedback, which automatically modifies the timing and duration of arc and short-circuit periods. This dynamic adjustment enables precise voltage control while keeping the control system relatively simple through feedback-driven adaptation.
Solution Approach 2:
The patent changes the parameters of short-circuit period and arc period dynamically based on voltage feedback. By adjusting the wire feeding speed waveform, the system can vary the duration and frequency of arc and short-circuit states, thereby achieving precise voltage control without requiring a complex multi-parameter 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 enables stable control of welding voltage and reduces spatter generation by dynamically adjusting the short-circuit and arc periods, improving the consistency and quality of the welding process.
Implementation Method 1
Arc welding method and arc welding device... welding by alternately generating a short-circuit state and an arc state
Data Source
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AI summary
An arc welding method of the present invention controls a short-circuit current increasing gradient (di/dt), an inflection point at which the short-circuit current increasing gradient (di/dt) changes, the current in a peak period and in a base period, and the time of the peak period in accordance with a difference between a set voltage and an output voltage. This allows the output voltage to be matched with the set voltage, and stabilizes the arc. Thereby, a stable arc welding method can be implemented, even as a method for outputting a welding current based on a welding voltage.