AC Consumable Electrode Welding Control for Stable Negative Polarity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional arc welding with an AC consumable electrode experiences unstable welding status during the electrode negative polarity period, leading to deteriorated welding quality.
Innovation Solution
A control method for arc welding that involves repeating short-circuiting and arc periods, with specific feeding patterns and control strategies, including backward- and forward-feeding the welding wire, and switching between electrode positive and negative polarities, with adjusted peak values, feeding speeds, and control modes to stabilize the welding status during the negative polarity period.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional AC arc welding is performed with cyclically switching electrode polarity, then welding can be performed with both electrode positive and negative polarity periods, but the welding status during electrode negative polarity period becomes unstable and welding quality deteriorates
Solution Approach 1:
The patent applies dynamics by making the wire feeding speed variable and polarity-dependent. During electrode negative polarity period, the wire feeding speed is increased compared to electrode positive polarity period. This dynamic adjustment compensates for the unstable welding status during negative polarity, maintaining stable arc length and welding performance throughout the cyclic polarity switching process
Solution Approach 2:
The patent changes the wire feeding speed parameter based on electrode polarity. Specifically, the wire feeding speed is set to a higher value during electrode negative polarity period and a lower value during electrode positive polarity period. This parameter change addresses the instability during negative polarity by adjusting the feeding characteristics to match the electrical conditions, thereby improving welding status stability and quality
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
The method stabilizes the welding status during the electrode negative polarity period, thereby securing favorable welding quality by preventing unstable arc formation and reducing spatter generation.
Implementation Method 1
cyclically switching an electrode polarity between an electrode positive polarity period and an electrode negative polarity period
Implementation Method 2
arc welding with an AC consumable electrode
Data Source
AI summary
A control method is provided for arc welding with an AC consumable electrode. The method includes: repeating a short-circuiting period and an arc period between a welding wire and a base material; backward-feeding the welding wire backward during the short-circuiting period and forward-feeding the welding wire forward during the arc period; performing the arc welding by cyclically switching between an electrode positive polarity period and an electrode negative polarity period each including at least one arc period; and setting an absolute value of a peak value of the forward-feeding and an absolute value of a peak value of the backward-feeding to be larger during the electrode negative polarity period than during the electrode positive polarity period.