伺服焊枪点焊镀锌高强钢的电极磨损在线评价

Online evaluation of electrode wear based on servo gun spot welding of galvanization high strength steel

镀锌高强钢点焊的严重、磨损不确定性电极磨损阻碍其在车身制造中进一步应用,进行点焊过程中电极磨损在线评价,对提高车身点焊质量与电极寿命具有重要意义。首先,分析伺服焊枪的电极轴向磨损检测特性及压痕深度在线提取的可行性,实现基于伺服焊枪技术特性的压痕深度提取;其次,通过镀锌高强钢点焊的电极磨损试验获取压痕深度变化规律。结果表明,镀锌高强钢点焊的电极寿命波动范围较大,压痕深度在电极磨损初期阶段变化速率较大,在后期磨损阶段处于稳定波动;当电极端面直径磨损增加超出40%时,电极寿命结束。根据压痕深度随电极端面直径磨损的变化规律及其对熔核质量影响,提出以压痕深度处于稳定波动阶段作为电极修磨的判定标准,减小不确定性电极磨损对焊点质量的影响。

Serious and uncertainty electrode wear in spot welding galvanization high strength steel encumberes the steel being largely applied in body manufacturing.Online evaluation of electrode wear in spot welding high steel can improve welding quality and electrode life.Firstly,the wear detection characteristic of servo gun electrode axial direction and the feasibility of online measure of indentation depth are analyzed,and online measure of indentation depth based on servo gun technology is achieved.Secondly.electrode wear experiment in spot welding galvanization high strength steel is carried out,the results show that changing speed of indentation depth is higher at earlier electrode wear stage and becomes stable at later stage, the electrode life has large range and is over when the wear increment of electrode end face diameter exceeds 40%.Lastly,indentation depth at stable stage is taken as the standard of electrode wear to reduce the effect of uncertainty electrode wear on welding quality.