Tandem双丝气保焊引弧控制方法的研究

Research on Arc Ignition Control Method of Tandem Dual-Wire Arc Welding

研究分析了相位匹配、恒频率、变频率三种情况对Tandem双丝引弧性能的影响。为保证前后丝能正常顺利的引弧,即弧长合适、不发生断弧等现象,焊接时,前丝应先于后丝或与后丝同时引弧。前丝采用变频率方式引弧顺畅,待进入稳定焊接后切换为恒频率方式;采用恒频率引弧,弧长调整慢,恢复到正常弧长所需时间长。后丝如果与前丝同时引弧,后丝采用与前丝同相位同频率的控制方法,引弧顺畅,飞溅小;采用不同相位同频率方式,后丝有产生断弧的风险。如果前丝已进入稳定焊接,后丝再引弧,此时后丝采用同相位模式,会发生频繁断弧,焊接效果很差;采用不同相位模式,通过实时调整前后丝脉冲频率比,引弧顺畅,飞溅小。

The influence of phase matching, constant frequency and variable frequency on the performance of Tandem twin wire arc ignition was studied and analyzed. In order to ensure that the front and rear wires can start the arc normally and smoothly, that is, the arc length is appropriate, and there is no arc breaking phenomenon, during welding, the front wire should be ignited prior or at the same time with the rear wire. The arc ignition of the front wire is smooth by adopting variable frequency mode. When entering the stable welding, it is switched to the constant frequency mode. Adopt constant frequency arc ignition, arc length adjustment is slow, it needs long time to reach normal arc length. If the rear wire and the front wire are ignited at the same time, the rear wire adopts the same control method of the front wire with the same phase and frequency, the arc ignition is smooth, the splash is small;using different phase and same frequency mode, the rear wire has the risk of arc breaking. If the front wire has entered the stable welding, then the rear wire is ignited, the rear wire adopts same phase with the front wire, there will be frequent arc breakage and the welding effect is poor;using different phase modes, the pulse frequency ratio of the front and rear wires is adjusted in real time, the arc ignition is smooth and the splash is small.