Arc Welding Current Timing to Minimize Short-Circuit Spatter
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Solution Overview
Problem
Existing arc welding apparatuses face challenges in accurately reducing spatter by prematurely reducing electric current due to irregularities in voltage changes during the transition from short circuit to arc conditions, leading to inadequate spatter reduction.
Innovation Solution
An arc welding apparatus with a state detecting unit to identify the start of short and arc conditions based on voltage, a time detecting unit to set a reference time shorter than the estimated continuation time of the short circuit, and a power control unit to gradually reduce electric current after reaching this reference time, then raise it after the arc condition starts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If electric current is reduced based on constriction detection, then spatter reduction is expected, but the reduction timing may be too late due to detection accuracy variations
Solution Approach 1:
The system performs preliminary action by detecting the start of short circuit condition and initiating current reduction based on elapsed time before the arc condition actually begins. The time detecting unit monitors elapsed time from short circuit start, and when it reaches the reference time (which is shorter than estimated short circuit continuation time), the power control unit starts reducing current. This preliminary current reduction happens proactively before the arc condition starts, ensuring spatter is minimized without waiting for constriction detection that may be delayed by voltage irregularities.
2Object-affected harmful factors
If current reduction timing is advanced to reduce spatter, then spatter is minimized, but power supply may become insufficient for proper welding
Solution Approach 1:
The system applies dynamics by continuously adjusting the electric current based on real-time conditions. During the short circuit condition, the power control unit gradually reduces current from the short circuit current value to a lower arc starting current value as elapsed time approaches the reference time. After the arc condition begins (detected by voltage rise), the system dynamically increases current to the arc welding current value. This dynamic adjustment ensures current is reduced enough to minimize spatter but restored quickly to maintain sufficient power for welding.
Solution Approach 2:
The system changes current parameters at different stages: during short circuit condition, current is reduced from high short circuit current to lower arc starting current; after arc condition begins, current is increased to arc welding current. The time detecting unit uses reference time (shorter than estimated short circuit duration) as a parameter to trigger the reduction, and the state detecting unit detects arc condition start via voltage rise to trigger the increase, ensuring both spatter reduction and adequate power supply.
3Loss of time
If reference time is set shorter than estimated short circuit continuation time, then current reduction occurs before arc start, but detection accuracy must be maintained despite voltage irregularities
Solution Approach 1:
The system uses feedback by continuously monitoring voltage between workpiece and welding consumable through the state detecting unit. The time detecting unit receives feedback on elapsed time from short circuit start, and the state detecting unit provides feedback on arc condition start via voltage rise detection. This feedback mechanism allows the system to accurately determine when to reduce current (when elapsed time reaches reference time) and when to restore current (when arc condition begins), maintaining detection precision despite voltage irregularities during the short circuit condition.
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 allows for precise reduction of electric current before the arc condition begins, effectively minimizing spatter while ensuring sufficient power supply, even with variations in short circuit duration.
Implementation Method 1
a state detecting unit configured to detect a start of the short circuit condition and a start of the arc condition based on a voltage between the workpiece and the welding consumable
Implementation Method 2
an arc welding apparatus that performs welding while repeatedly generating a short circuit condition and an arc condition
Data Source
Figure 1
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AI summary
An arc welding apparatus (A1, A2) includes: a driving unit (41) for advancing and retreating a welding consumable (44) with respect to a workpiece (W) to generate a short circuit condition and an arc condition; a state detecting unit (U2) for detecting respective starts of the short circuit condition and the arc condition based on a voltage between the workpiece and the welding consumable; a time detecting unit (U3) for detecting that an elapsed time from the start of the short circuit condition reaches a reference time (t2, t3) using a time shorter than an estimated continuation time of the short circuit condition as the reference time; and a power control unit (U5) for reducing an electric current between the workpiece and the welding consumable corresponding to a state where the elapsed time reaches the reference time and raising the electric current after the start of the arc condition.