Pulse Arc Welding Current Control for Thin Aluminum Bead Stability
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Solution Overview
Problem
Existing arc welding methods face challenges in controlling the shape of weld beads, especially when using pulse welding with high welding currents on thin aluminum materials, and struggle to apply methods effectively with inert gas shield gases.
Innovation Solution
An arc welding control method that stabilizes pulse welding with a low welding current by controlling the waveform of the welding current and superimposing a second peak current on the base current at a higher frequency, ensuring consistent arc direction and heat input, thereby forming a weld bead with a good appearance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If pulse welding with high welding current is used to control bead shape, then welding efficiency and productivity are improved, but spatters are generated and weld appearance deteriorates
Solution Approach 1:
The patent applies periodic action by using pulse welding with alternating peak current and base current. The peak current pulse causes droplet detachment while the base current maintains the arc, creating a periodic cycle that controls bead formation. This periodic current variation allows efficient welding while reducing spatters compared to continuous high current welding.
Solution Approach 2:
The patent employs dynamics by dynamically adjusting the welding current waveform. The current is varied over time with peak current pulses superimposed on base current, allowing the system to adapt between high current for productivity and low current for spatter control. This dynamic current control optimizes both welding efficiency and weld appearance.
2Reliability
If pulse welding with high welding current is used to maintain arc stability, then arc continuity is improved, but heat input to base material increases causing poor weld bead shape on thin plates
Solution Approach 1:
The patent uses periodic action with alternating peak and base current pulses. The base current maintains arc continuity and stability, while the periodic peak current pulses provide additional heat only when needed for droplet detachment. This periodic structure maintains arc stability while controlling total heat input to prevent excessive melting on thin plates.
Solution Approach 2:
The patent applies parameter changes by varying the welding current parameters over time. The current waveform includes base current for arc maintenance and peak current pulses for droplet control. By changing current magnitude and duration parameters periodically, the system maintains arc stability while precisely controlling heat input for good weld bead shape on thin materials.
3Ease of manufacture
If CO2 gas is used as shield gas to protect weld area, then welding process is simplified, but arc reaction force increases making one-pulse one-drop control difficult
Solution Approach 1:
The patent employs dynamics by dynamically controlling the current waveform to compensate for CO2 gas effects. The peak current pulses are timed and sized to overcome the increased arc reaction force from CO2, enabling droplet detachment despite the challenging gas environment. This dynamic current adjustment maintains ease of operation with CO2 shield gas.
4Manufacturing precision
If welding current is reduced to improve weld appearance on thin plates, then heat input is controlled, but arc stability and droplet detachment become difficult
Solution Approach 1:
The patent uses periodic action with base current maintaining arc stability at lower levels and peak current pulses providing temporary high current for droplet detachment. This periodic structure allows the system to maintain stable arc at low average current for good weld appearance while periodically delivering sufficient current for reliable droplet transfer.
Solution Approach 2:
The patent applies dynamics by dynamically switching between base current and peak current modes. The base current maintains arc stability at low levels for controlled heat input, while dynamic peak current pulses are applied when needed for droplet detachment. This dynamic current management achieves both arc stability and good weld appearance on thin plates.
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 method allows for stable pulse welding with a low welding current, suppressing spatters and irregularities, and produces a weld bead with improved fitness and appearance by maintaining arc directivity and preventing excessive droplet growth.
Implementation Method 1
melting the welding wire using arc heat generated between the welding wire and a base material
Implementation Method 2
a peak current at which a droplet is detached from a welding wire
Data Source
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AI summary
A pulse welding period Tp alternately includes a first peak period Tp1 in which a first peak current Ip1 whose peak value is a first current value IA is caused to flow through a welding wire 18 and a base period Tb in which a base current Ib having a second current value IB is caused to flow through the welding wire 18. During the base period Tb, a second peak current Ip2 whose peak current value is a sum of a second current value IB and a third current value IC and is smaller than the first current value IA is superimposed on the base current Ib at a second pulse frequency Fp2. A second peak period Tp2 in which the second peak current Ip2 is caused to flow once is shorter than the first peak period Tp1. During the first peak period Tp1, a droplet is transferred from the welding wire 18 toward a base material 17.