Research On Swing Arc Parameters And Weld Tracking Method Of Narrow Gap MAG Welding

With the development of economy and science and technology,medium and thick plates are used more and more widely in the fields of building bridges,nuclear power generation,military and national defense,and narrow gap welding is widely used in the processing process.Compared with the usual way of welding medium and thick plates in the past,narrow gap welding is one of the efficient welding methods.Its advantages include less arc heat input,high welding efficiency,less filler wire,and good mechanical properties in the weld area.However,since the angle between the welding wire and the side wall in the narrow gap welding process is close to vertical,it is easy to cause the heat input of the side wall metal to be low,resulting in the phenomenon that the side wall is not completely fused.Tracking must not only make the sidewalls completely fuse,but also meet the accuracy problem of weld tracking.In view of the above problems,this paper conducts a systematic research on the influence of swing parameters and welding process parameters on the forming quality of narrow gap groove welds to narrow gap weld tracking methods.According to the requirements of the swing arc sensor system,the overall scheme of the experimental platform is designed.The swing arc sensor is designed by using the transmission mechanism to drive the overall swing of the welding torch,which can control the swing width,swing frequency and side stop time of the welding torch.A narrow-gap MAG welding oscillating arc seam tracking system was built to complete the motion control of the welding torch,communication data transmission,man-machine interface parameter adjustment,and real-time acquisition and processing of arc signals,which is necessary for subsequent research projects.Prepared experimental conditions.Use simufact.welding software to create a heat source model of a narrow-gap swing arc,and analyze the temperature field distribution under different swing parameters to compare its heat conduction energy distribution in a narrow-gap environment.The temperature field distribution changes of the narrow gap groove under different swing widths and the influence on the thermal cycle curve at the center point and side wall points of the weld are studied.Use a high-speed camera to observe the arc shape and droplet transition form under different swing amplitudes,analyze the changes brought about by the swing amplitude change to the arc shape and droplet transition form;propose a multi-stage filtering method to collect the current signal during welding After processing by this method,the change law of the current signal under different swing widths is analyzed;the characteristics of the weld profile and surface topography under different swing widths are compared,and the change law of the weld formation with the change of the swing width is analyzed.Considering the influence of the swing width of the welding gun on the above factors,the optimal swing width of the welding gun for narrow gap groove welding can be determined.For narrow gap grooves,an improved method of current area integration and comparison on both sides is proposed.After the experiments of extracting several sets of deviations,it shows that the accuracy of extracting weld deviations meets the requirements.A fuzzy PID parameter adaptive adjustment method is proposed to correct the welding seam tracking process.The welding seam tracking method is applied to the experimental platform.The feasibility of the method is tested through experiments.It can achieve fast correction response,stable welding seam tracking,and Precise narrow gap welding.