Arc Welding Transition Control for Stable Droplet Transfer
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Solution Overview
Problem
Conventional arc welding methods experience instability and spatter generation when switching between pulse arc welding and short-circuit transfer arc welding due to the transfer of droplets, leading to an unstable welding state.
Innovation Solution
An arc welding method that alternates between pulse arc welding and short-circuit transfer arc welding by ensuring no droplet transfer during the final pulse cycle of the pulse arc welding period, with increased wire feeding speed to a forward-feeding peak value at the start of the short-circuit transfer arc welding period, and switching to pulse arc welding during the arc period of short-circuit transfer arc welding when arcing reoccurs at a low current level.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional arc welding methods switch between pulse arc welding and short-circuit transfer arc welding, then the welding process can control heat input and produce scale-like beads, but spatters are generated and the welding state becomes unstable due to droplet transfer during switching
Solution Approach 1:
The patent applies preliminary action by controlling the wire feeding speed and arc current in advance during the pulse arc welding period to ensure that a droplet is properly formed and detached before switching to short-circuit transfer arc welding. This prevents spatter generation during the transition by preparing the droplet transfer condition beforehand, thus maintaining welding state stability while preserving bead appearance quality.
2Productivity
If droplet transfer is allowed during pulse arc welding period, then welding efficiency is improved, but spatter increases and welding state becomes unstable during switching to short-circuit transfer arc welding
Solution Approach 1:
The patent implements periodic action by dividing the welding process into distinct pulse arc welding periods and short-circuit transfer arc welding periods with specific switching conditions. During the pulse arc welding period, parameters are controlled to complete droplet formation and detachment cyclically, ensuring that switching occurs at optimal moments. This periodic control maintains welding efficiency while minimizing spatter by synchronizing droplet transfer with the welding cycle.
3Reliability
If wire feeding speed is increased during short-circuit transfer arc welding, then droplet transfer is improved, but the risk of non-melted wire portions being short-circuited increases
Solution Approach 1:
The patent applies feedback control by continuously monitoring the arc voltage and current during short-circuit transfer arc welding and dynamically adjusting the wire feeding speed accordingly. When the arc length and droplet formation conditions are optimal, the feeding speed is increased to improve droplet transfer. When conditions indicate potential short-circuiting of non-melted wire, the feeding speed is reduced, thus maintaining reliable droplet transfer while preventing harmful short-circuits.
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 stabilizes the welding state by preventing non-melted wire portions from being short-circuited, reducing spatter generation, and optimizing heat input for improved bead appearance, ensuring smooth transitions between welding periods.
Implementation Method 1
performing pulse arc welding with a welding wire being fed in a forward direction during a first period; performing short-circuit transfer arc welding with the welding wire being fed in the forward direction and a reverse direction during a second period
Implementation Method 2
switching the first period to the second period is performed in a manner such that no transfer of a molten droplet of the welding wire occurs during a final pulse cycle of the first period
Data Source
AI summary
An arc welding method includes the following steps. Pulse arc welding is performed with the welding wire being fed in a forward direction during a first period. Short-circuit transfer arc welding is performed with the welding wire being fed in the forward direction and the reverse direction during a second period. The first period and the second period are alternately switched. The switching of the first period to the second period is performed in a manner such that no transfer of a molten droplet of the welding wire occurs during the final pulse cycle of the first period.