Pulse Arc Welding Wire Feed Timing for One-Droplet Transfer
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Solution Overview
Problem
Conventional pulse arc welding techniques struggle to maintain the one-droplet-per-pulse transfer mode due to variations in welding conditions, leading to deteriorated welding quality.
Innovation Solution
A method for controlling pulse arc welding that involves adjusting the feed speed of the welding wire by changing it from reverse to forward and back at specific preceding periods relative to the current phases, ensuring consistent one-droplet-per-pulse transfer mode through precise timing and current modulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional pulse arc welding techniques are used with simple feed speed control, then the welding process is easy to operate, but the one-droplet-per-pulse transfer mode cannot be maintained under varying welding conditions, leading to deteriorated welding quality
Solution Approach 1:
The feed speed is made dynamic by changing it at different stages of the pulse cycle. The feed speed increases during the peak rising period, is maintained during the peak period, and decreases during the peak falling period. This dynamic adjustment ensures the one-droplet-per-pulse transfer mode is maintained under varying welding conditions, improving welding quality without requiring overly complex control systems.
Solution Approach 2:
The feed speed is increased before the peak current is applied (during the peak rising period) to prepare for droplet formation. This preliminary action ensures that the wire feed is synchronized with the current application, facilitating consistent one-droplet-per-pulse transfer mode establishment before the main welding action occurs.
2Manufacturing precision
If the feed speed is changed frequently to maintain one-droplet-per-pulse transfer mode, then welding quality is improved, but the control system complexity increases
Solution Approach 1:
The feed speed control follows a periodic pattern synchronized with the pulse cycle. The feed speed increases during the peak rising period, maintains a higher value during the peak period, and decreases during the peak falling period. This periodic adjustment pattern ensures consistent droplet formation while using a relatively simple control logic that repeats with each pulse cycle.
Solution Approach 2:
The control system monitors welding conditions and adjusts the feed speed accordingly to maintain the one-droplet-per-pulse transfer mode. By using feedback from the welding process parameters, the system can make necessary feed speed adjustments without requiring overly complex control algorithms, achieving consistent droplet formation with manageable system complexity.
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 ensures high welding quality by maintaining the one-droplet-per-pulse transfer mode, stabilizing droplet formation and detachment, and achieving consistent bead appearance and weld penetration shape, despite variations in welding conditions.
Implementation Method 1
applying a welding current by repeating a pulse cycle including: a peak rising period of applying a peak rising current that increases from a base current to a peak current
Data Source
Figure 1
Figure 2(A)~2(C)
AI summary
A method for controlling pulse arc welding involving feeding a welding wire (1) and applying a welding current (Iw) by repeating a pulse cycle including: a peak rising period (Tu) of applying a peak rising current (Iu) increasing from a base current (Ib) to a peak current (Ip); a peak period (Tp) of applying the peak current (Ip); a peak falling period (Tk) of applying a peak falling current (Ik) decreasing from the peak current (Ip) to the base current (Ib); and a base period (Tb) of applying the base current (Ib). The feed speed (Fw) of the welding wire (1) is changed such that it beings to change from a reverse-feeding peak value (Wr) toward a forward-feeding peak value (Ws) at a point earlier by a first preceding period (Ta1r) than the start of the peak rising period (Tu). Then, the feed speed (Fw) reaches the forward-feeding peak value (Ws) at a point earlier than an end of the peak rising period (Tu), and beings to change from the forward-feeding peak value (Ws) toward the reverse-feeding peak value (Wr) at a point earlier by a second preceding period (Ta2r) than the start of the peak falling period (Tk), and reaches the reverse-feeding peak value (Wr) at a point earlier than an end of the peak falling period (Tk).