Pulse Welding Arc Control Unit for Metal Vapor Reduction
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Solution Overview
Problem
Conventional pulse welding processes under protective gas generate harmful metal vapors, leading to environmental and health pollution, and are not suitable for all welding tasks, particularly thin sections and out-of-position welding.
Innovation Solution
An arc process control unit that rapidly increases the arc current intensity from a basic to a maximum level (at least 500 A) with a dynamic of at least 900 A/ms, maintaining the maximum current for a short duration (up to 0.5 ms) and then reducing it quickly, allowing for efficient droplet detachment with reduced metal vapor formation and increased flexibility in welding processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the welding current is increased to achieve spray arc welding with fine droplet transfer, then material transfer uniformity is improved, but the average arc current intensity must be maintained at a high level which generates excessive metal vapor and is unsuitable for thin sections
Solution Approach 1:
The patent applies periodic pulsed current action instead of continuous high current. The current is periodically increased to peak values (e.g., 400-600 A) for short durations (e.g., 0.1-2 ms) to achieve droplet detachment, then reduced to low base values (e.g., 20-100 A). This periodic action maintains material transfer uniformity while significantly reducing the time-averaged current and associated metal vapor production.
Solution Approach 2:
The patent employs dynamic current modulation where the arc current intensity is rapidly changed between base and peak values during the welding process. This dynamic adjustment allows the system to achieve spray arc conditions temporarily for droplet detachment while returning to lower current states, creating a time-varying current profile that optimizes both transfer quality and vapor reduction.
2Productivity
If the welding current is increased beyond critical current to achieve spray arc welding, then droplet frequency increases and droplet sizes decrease, but the process becomes unsuitable for thin workpiece sections and out-of-position welding
Solution Approach 1:
By using periodic pulsed current with short peak durations and low base values, the system achieves high droplet frequency during peak current while maintaining low average current suitable for thin sections. The periodic nature allows adaptation to different welding positions and material thicknesses by adjusting pulse parameters.
Solution Approach 2:
The patent changes the current parameter dynamically by introducing time-varying pulsed current with adjustable peak values, pulse duration, and frequency. This parameter modulation enables the same welding process to adapt to different workpiece thicknesses and welding positions, expanding versatility while maintaining productivity.
3Manufacturing precision
If conventional pulse welding is used with alternating pulse and basic current phases, then material transfer occurs in pulsed current phase, but the average arc current intensity remains relatively high generating harmful metal vapors
Solution Approach 1:
The patent optimizes periodic action by using asymmetric pulse patterns where the high current peak duration is kept very short (e.g., 0.1-2 ms) compared to the low current base period. This creates a duty cycle that maintains precise material transfer control during peaks while minimizing the time spent at high current, thereby reducing overall vapor emissions.
Solution Approach 2:
The patent rushes through the high current phase by maintaining peak current for minimal time just sufficient for droplet detachment, then immediately transitioning to low base current. This skipping approach minimizes exposure to harmful vapor-generating conditions while still achieving the necessary material transfer.
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 minimizes metal vapor production, enhances welding quality, and expands the applicability of pulse welding by maintaining a low average arc current intensity while achieving sufficient energy input, even in challenging welding conditions.
Implementation Method 1
the electrical voltage between the consumable electrode and the workpiece ionizes the gases present between the electrode and the workpiece. Plasma is therefore created and charge carriers are released so that the gas becomes conductive and an arc can form.
Implementation Method 2
The so-called pinch effect, in which the droplet is constricted as a result of the Lorenz force, is primarily responsible for droplet detachment in the spray arc.
Data Source
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AI summary
Electric arc process control unit (204) for an electric arc welding device (200) comprises a melting electrode (203) for welding under protective gas, where the electric arc process control unit is adapted for controlling the electric arc current such that a pulse welding process is performed. The pulse welding process comprises at least one pulse current phase, in which the electric arc current intensity is at least temporarily greater than the critical current intensity and a basic current phase, in which the electric arc current intensity lies in a base current intensity. Electric arc process control unit (204) for an electric arc welding device (200), comprises a melting electrode (203) for welding under protective gas, where the electric arc process control unit is adapted for controlling the electric arc current such that a pulse welding process is performed. The pulse welding process comprises at least one pulse current phase, in which the electric arc current intensity is at least temporarily greater than the critical current intensity and a basic current phase, in which the electric arc current intensity lies in a base current intensity. The electric arc process control unit is arranged to control the electric arc current intensity such that a maximum current intensity is reached during the pulse current phase, where the maximum current intensity is at least 500 A, which is maintained for a not > 0.5 m seconds. The increase in the electric arc current intensity starting from the base current to the maximum current intensity, is carried out with a dynamic of at least 900 A/m seconds. The electric arc process control unit is associated with a short circuit detection unit (208) for detecting a short circuit between the melting electrode and workpiece to be processed. The electric arc process control unit is adapted to initiate the pulsed current phase based on a detected short circuit starting from the base current phase. An independent claim is also included for carrying out the pulse welding under protective gas with the above electric arc welding device, where the pulse current phase is initiated depending on the detected short circuit, starting from the base current phase.