新型水下焊接电源及送丝机构的研究

研究了一种新型的水下焊接系统。系统中孤焊电源输出阶梯型的外特性，送丝系统采用脉动送丝方式。在单片机控制下，脉动送丝波形与外特性同步调控。在停止送丝阶段，单片机夸电源输出电压为峰值，焊丝在此电压下返烧并形成熔滴。送丝脉冲到来的瞬间，电源输出电压切换为基值。熔滴依靠送丝动量向熔地方向前进，最终向熔池过渡，随着焊炬的移动而彤成一道焊缝。实验结果表明，使用这个系统进行气体保护药芯焊丝水下湿法焊接时，电压、电流波形均匀工整，短路过渡频率受控，焊接过程稳定，水下焊缝成形较为美观。

New type of power source and wire feeding system for underwater welding

A new type of underwater welding system is studied,which includes an oscillating wire feed system and a welding power source with staircase external characteristic.The output waveform of the oscillating wire feed system and the external characteristic are controlled and adjusted by a single-chip microcomputer(SCM)synchronously.When the wire feed is pausing in each oscillating cycle,the output voltage of power source is a peak value and the wire is melted under the welding voltage,forming a droplet metal.When the pulse of wire feed occurs,the output is switched to the base value.The drop of molten metal is then pushed to and then to be transferred to the molten pool eventually.As the torch is moving,a weld seam is formed.It is shown that the output voltage and current of the power source is uniform and stable when the system is used underwater with flux-cored wires.The frequency of short-circuit transfer is well controlled and the welding process is stable which results in good shapes.