Research On Welding Seam Tracking And Welding Foot Automatic Adjustment System Of Gondola Car

With the upgrading of industrial robots,the welding method has been changed from manual welding to automatic welding,which is widely used in the field of vehicle manufacturing and shipbuilding.In fact,every welding system is designed for a specific welding process.This paper designs a set of CNC intelligent gantry cutting and welding system based on a series of problems in the process of repairing and welding of a company's C64 K gondola car,such as large car body size and wide welding range.At the same time,the principle of linear interpolation is used for teaching-playback,so as to realize the welding seam tracking.In addition,in the welding process,a set of automatic adjustment device for welding torch swing was designed to avoid the arc extinguishing phenomenon due to the large gap of the welding seam and the misalignment of high and low edges during the welding process,and the welding quality of this type of weld was effectively improved through the real-time swing of the welding torch.The specific research content is as follows:(1)In order to solve the problems of large car body size and wide welding range,this paper designs a CNC intelligent gantry cutting and welding system with six degrees of freedom,which includes: three-direction movement of XYZ,Z-axis flipping degrees of freedom in the Z direction,the degree of freedom of shaft rotation in the Z direction and the degree of freedom of rotation of the gun head.Then,according to the equipment required by the system and the parameter requirements of some equipment,cooperate with a company in Chengdu to improve the existing equipment to meet the required CNC intelligent gantry cutting and welding system,and then use the teaching-playback to complete the welding seam tracking process.(2)Aiming at the problem of arc extinguishing caused by large weld gap or even high and low edges,this paper designs an automatic welding foot adjustment system.First,send the weld unevenness information detected by the laser displacement sensor to the STM32 microcontroller.Then,according to the information to determine whether to send out a pulse signal to control the stepper motor.Next,according to the process requirements,the swing of the welding gun is realized through the rotation angle and speed of the stepping motor,so that the new plate and the base material are better fused.Finally,according to the needs of the actual problem,the hardware with the optimal parameters is selected and MDK is used as the software development environment,each function is modularized and the code is written,and then the software and hardware design and realization of the automatic adjustment device for welding torch swing are completed.(3)Based on the completed CNC intelligent gantry cutting and welding system,the teaching-playback cutting and welding experiments were carried out.Experiments show that the scheme of completing cutting and welding by teaching and reproducing is effective.It not only solves the problems of large car body size and wide welding range,but also satisfies the process requirements.In addition,the parameter matching experiment of the automatic adjustment device for welding gun swing was also completed.The experiment proves that the real-time swing of the weld-ing torch can solve the problem of arc extinguishing caused by the large weld gap or even the high and low misalignment during the welding process,and the fast walking speed matches the fast swing speed to obtain good welding quality.