Research And Design On Numerical Control Welding Machine Of Saddle-shaped Weld Seam

Full automatic welding of saddle-shaped weld seam of high quality has been always adifficult problem and a research hot spot in the process of the pressure vessel’s shellmanufacture. With large production of the high quality pressure vessels, increasingrequirement of the welding quality and productivity, the demand of the complex spacecurve welding seam automatic welding machines is increasingly urgent.This paper designes a numerical control welding machine which can realize all sortsof saddle-shaped weld seams. The welding system realizes body posture adjustment byfive separate shafts, and positioning chuck clamps welding tube to make it located.Welding mechanism achieves saddle-shaped curve movement and welding gun poseadjustment by five linkage shafts. Using the conductive slip ring and the pipe rotary joint,the problems about winding wire and pipeline during the welding process are solved, anda welding gun with optical fiber sensor is designed. The main structures of the weldingmachine are analysed and improved by the finite element.A huge mass of date and engineering practice proved that the noncoincidencebetween actual weld seam trajectory and ideal weld seam trajectory is the main factorinfluencing the precision of welding gun tracking weld seam. In order to get the actualweld seam trajectory, and improving the precision of welding gun tracking weld seam, theprinciple of structured light detection is applied to developing a trajectory detectingsystem of saddle-shaped weld seam. And the constitution of the system and hardware aredesigned and selected, also the mathematical model of detecting the saddle-shaped weldseam trajectory based on the detection principle is set up. According to all sorts of thesaddle-shaped weld seam characteristics, using B-spline curve constant speed interpolationalgorithm and the new solder joint paramete curve fitting method to realize the reasonablematching of welding parameters, thequality of the weld is improved.The automatic welding numerical control system of saddle-shaped weld seam isdesigned based on the PC. And the designs of the numerical control system function, theactuators hardware of welding machine, the detecting system of welding quality dataacquisition hardware, the matching with welding parameters control system hardware, and the mian function process of numerical control system are completed.