精密脉冲TIG焊接中的弧长跟踪技术

A New Arc Length Tracing Method for Precison Pulse TIG Welding

关键词:  脉冲TIG焊  弧长传感  弧长跟踪

Key words:  pulse TIG welding  arc length sensing  arc length tracing

摘要:

在研究小电流脉冲TIG焊接弧压与弧长对应关系的基础上,提出了一种新的基于硬件电路的弧长传感与控制技术,并建立了相应的弧长跟踪系统。工艺试验表明,采用该技术可实现较宽电流范围内的脉冲TIG焊及直流TIG焊的弧长跟踪控制,在平均焊接电流20A,弧长给定为1 mm时的弧长跟踪静态误差为±0.1mm。整个系统控制精度高,动态响应快,运行可靠。该技术较好地解决了常规的弧长跟踪方法所无法解决的复杂曲面薄壁不锈钢试件焊接过程中的弧长跟踪问题,取得了较好的工艺效果。

Abstract:

Based on the investigation of the relationship between the are voltage and the are length in small current pulse TIG welding, a new are length sensing and control method has been put forward and realized with hardware circuits. Then, an arc length tracing system has been established. The experimental results proved that the are length could be controlled over a larger current range both in the pulse TIG welding and in the DC TIG welding.When the average current is 20A and the given tracing length is 1 mm, the static are le ngth tracing error is ±0.1 mm. The developed system has high control accuracy, fast dynamic response, high operation reliability. Adopting this method, the arc length tracing problem, which exists in welding processes of thin stainless components with complicated curved surface, has been solved successfully, while such problem couldn't be satisfactorily solved by the conventional arc length tracing methods.