具有不同通道变极性等离子弧焊设备研制

研制了一种具有不同通道的新型变极性等离子弧焊设备．采用双电源对主弧正负半波供电，在负半波以水冷铜喷嘴代替钨电极作阳极，既避免了主、维弧相互干涉现象，又降低了钨电极的烧损，使电弧和焊接过程稳定性提高．此外，电流频率、正负半波幅值和导通比的独立可调，能满足铝合金焊接时对金属熔化和阴极清理的不同需要．

Development of VPPAW equipment with different current passage

A new type of variable polarity plasma arc welding (VPPAW) equipment with different current passage is developed. The equipment is supplied with two individual power sources for the positive and negative half cycle of main arc current and the water cooled nozzle replaces the tungsten pole to serve as anode in the negative half cycle. Therefore, not only the interference between main arc and pilot arc can be avoided, but the deterioration of tungsten can also be reduced significantly and the welding arc and process can be made stable. In addition, regulating independently the independent adjustability of current frequency and amplitude as well as that of the firing ratio can meet the different needs of metallic penetration and cathode cleaning action in aluminum welding.