PLC及触摸屏控制系统在薄壁方管焊接中的设计和应用

Application of PLC and touch screen on control system of thin wall rectangle tube welding

采用路径示教、记忆跟踪、参数控制等技术,建立了方管密排焊的TIG自动焊PLC控制系统;介绍了PLC及触摸屏组成的控制系统工作原理、系统构成和软件设计。该系统能根据间隙变化使电流线性调节,并用电弧静特性来匹配电流电压关系,从而获得了稳定的电弧长度,避免了因电流电压特性处于下降段,当电流随间隙减小而减小,工件却向上挠曲,造成钨极扎进焊缝的现象。实验表明,该系统不仅能使焊接生产顺利进行,而且得到均匀一致的焊缝宽度。

The automatic PLC control system of TIG welding for rectangle tube densely welding is developed in this paper,including the techniques of path teaching,memory tracking,parameters matching and parameters controlling.And the working principles,system structure and software designing are also introduced.The linear control of current is applied according to the relationship between the gap and the welding current.And in order to control the arc length to avoid tungsten electrode plunging into welding seam, another strategy is applied according to the static characteristic of arc,Experiment shows that the welding process can proceed smoothly and get homogeneous width of welding it＇s seam ,while the welding reduces according to the gap becomes narrow and the welding seam appears upwards bend deformation.