Design And Process Experiment Of Teaching Type Special Welding Machine For Radiator

In this thesis,according to the actual production situation,the research on teaching type special welding machine for radiator was carried out.The special welding machine adopts carbon dioxide arc welding to realize the automatic welding of tubesheet of radiator.This topic mainly included mechanical design and electrical design of special welding machine.Focus on the image processing of soldering seam and the research of teaching mode,and on this basis,the welding process experiment was carried out.In this study,the teaching mode guided by the camera was used and CPU226 H was used as the control core.The USB camera was placed in a fixed distance before welding gun and moved together.The image acquisition program was used to collect weld images,and upload image to PC,relying on the written VB image processing program to real-time image processing and identify the position information of the tubesheet soldering seam.The data was transmitted to CPU226 H by serial port.The process of teaching welding was realized by using the onestroke teaching mode and the two-stroke teaching mode.In order to meet the hardware requirements of teaching special machine,based on the existing equipment,the mechanical and electrical parts have been reformed accordingly including welding toolings,welding gun fixtures,mechanical zeroes detection,camera installation and so on.In the study,two teaching modes were presented: two-stroke teaching mode and one-stroke teaching mode.In the two-stroke teaching mode,firstly,the camera and the welding gun completed a stroke by manually control,the identified position information of the soldering seam was stored in the controller,the welding gun was back to the original point before automatic welding;one-stroke method used a position difference between the camera and the welding gun,welding at the same time of recognition,the teaching welding was completed in one stroke.In the image processing program,soften,binaryzation of automatic threshold,edge extraction,improved Hough transformation processing modules were designed.Through the experiment,the image processing combination algorithm was found,and the size information of the tubesheet soldering seam was extracted,which satisfied the requirements of the camera teaching.The relevant data of the soldering seam was transferred to the slave computer PLC by the free port communication program.Using the instructions of linear interpolation and circular interpolation in the motion library of CPU226 H,the welding programs of two teaching modes were written,and the requirements of teaching design were achieved through debugging.Welding process experiment by using teaching type special welding machine for radiator,checking the welding quality of the radiator welding joint to verify the welding effect of the special welding machine.Research showed that the teaching mode of the camera is practicable,and the image processing process can satisfy the teaching requirements well.The designed onestroke method has the advantages of high efficiency and no strict requirement for the initial position of the gun body,and achieves the teaching goal well.Some of these ideas and methods have some referential significance for tubesheet heat exchanger.