可控硅整流弧焊机动特性对焊接过程的影响

EFFECT OF DYNAMIC CHRACTERISTICS-OF SCR WELDING RECTIFIER ON THE WELDING PROCESS

摘要:

本研究应用自制的微计算机控制可控硅焊机试验系统进行了一系列焊接工艺试验.试验中,通过改变计算机程序参数的给定值来调节焊机在负载-短路过渡过程中的短路电流峰值I_hd等动特性参数,从而定量研究了可控硅焊机动特性对焊接过程中金属飞溅的影响关系.试验结果表明:可控硅焊机在负载-短路过渡中的短路电流峰值与负载电流之比值(I_hd/I_h)对焊接飞溅率△M有很大影响.在本试验条件下,两者间的定量关系为:当(I_hd/I_h)值为1.6~2.0时,焊接过程中飞溅率△M值最低;当(I_hd/I_h)值高于2.0或低于1.6时,焊接飞溅率△M值则相应显著增加.

Abstract:

A microcomputer controled SCR welding rectifier experimental system designed and made by authors has been applied for a serial welding test.By means of changing the preset value of programming parameters,the dynamic behavior parameter Ihd, which is the output current overshoot of the rectifier on the load-short circuit transition,has been adjusted systematically so as to investigate the effect of the dynamic characteristics of the SCR welding rectifier on the welding spatter quantiatively. The experimental results show that the dynamic criterion (Ihd/Ih),i.e.the ratio of current overshoot Ihd to output loading current of the rectifier,has a great effect on the relative ratio of welding spatter △M.Under the testing condition of this paper, the effect of (Ihd/Ih) on the △M can be conclued as follows:there is a minimum value of △M corresponding to the value 1.6—2.0 of (Ihd/Ih);there is an obviously increasing of △M while the value of (Ihd/Ih) is over 2.0 or below 1.6.