Optimization Of Tip Dressing Parameters Based On Research Of Electrode Wear Using Servo Gun

Resistance spot welding is the main joint method in vehicle manufacturing industry. Now more and more galvanized steels are used in vehicle manufacturing process because of its good performance on corrosion resistance, which lead to electrodes wear serious. Now a lot of researches have been done on electrode wear using zinc coated and bare steels. However, the zinc of galvanized steels tend to react with electrode during spotting welding under high temperature and pressure, which leads to electrodes wear serious and cost increases. At present tip dress is used to solve this problem. However, no research has been done in this field. Experiments indicate that appropriate tip dressing timing and parameters can increase electrode service life. So it is very necessary to choose tip dressing timing and parameters based on research of galvanized steels wearing process.So this paper did researches on the effect of electrode axial wear, pitting and electrode face diameter on weld quality using servo gun. And put forward an electrode life model using the results getting from the experiment, then optimize tip dressing timing. Finally choose the best tip dressing parameters based on the experiment of tip dress. This paper carried out the following jobs:(1) Experiment study on characteristics of electrode wear in resistance spot welding galvanization steelsExperiment is carried out to determine changing rules of electrode face diameter, axial wear and pitting with increase of welding points. And axial wear is measured using servo gun's axial wear detect function, face diameter and pitting is measured by CCD system.(2)Establish electrode service life modelEstablish electrode life model based on analysis of electrode wearing process. Put forward a new tip dressing method, and after that make sure the life model terminal condition. Then choose tip dressing timing based on the model and terminal condition in order to maximize electrode service life.(3)Study influence of tip dressing parameters on tip dressing qualityPut forward tip dressing evaluation criterion. Evaluate contribution to tip dressing quality between speed of rotation, time, pressure, number of tools and axial misalignment etc. Make sure the relationship of the three main factors, speed of rotation, time, pressure and tip dressing quality, so that the weld quality can be controlled by the three main factors. And optimizing tip dressing parameters will be chosen based on the electrode wear condition. Based on the above researches, electrode service life model is established, and also tip dressing parameters controlling model is put forward in order to optimize tip dressing parameters. The result of research indicates that electrode life extends one time than before using the optimizing tip dressing parameters put forward by this text.