Design And Key Parts Analysis Of Longitudinal Seam Welding Machine Based On Multi-Field Synergy

At present,most of the research on longitudinal seam welding machines in China is concentrated on small general-purpose welding machines,and there is relatively little research on longitudinal seam welding machines suitable for large weldments.This paper aims at the welding manufacturing of large thin-walled components and the problem of large residual stress and deformation of the welded parts after welding.Taking the welded parts with extreme manufacturing requirements,such as the nuclear main pump can,as a typical weldment,a longitudinal seam welding machine based on multi-field synergy was designed.The multi-field follow-up welding control device was used to cooperate with the fixture to realize the integrated control of welding residual stress and deformation and meet the extreme manufacturing of large thin-walled components.At the same time,the finite element analysis software was used to analyze the mechanical properties of the longitudinal seam welding machine and the key components of the follow-up welding control device to demonstrate the feasibility and rationality of the designed longitudinal seam welding machine.The main research contents and conclusions are as follows:First,the overall structure design of the longitudinal seam welding machine was completed.According to the system analysis method,the longitudinal seam welding machine was divided into four subsystems and the components of each subsystem were designed.A multi-field device that cooperates with the ultrasonic impact device,the welding chiller and fixture was designed to achieve comprehensive control of the multi-dimensional residual stress and deformation after welding.The structure of the frame and the layout of the parts and components were determined,and a scissor auxiliary supporting mechanism was designed to reduce the deformation generated during the clamping of the weldment.Secondly,the ANSYS Workbench finite element software was used to perform finite element analysis on the key components of the welding machine.The stress and deformation of each component under the external static load were analyzed,and it was verified that it meets the requirements of stiffness and strength.The natural frequency and vibration mode were obtained by modal analysis of key components.The modal analysis of ultrasonic horn with three different diameter tool heads was carried out,and the reasonable diameter of tool head was determined to be 5mm.Finally,the structure of the mandrel was optimized.Based on the response surface optimization algorithm,the size parameters of the diameter of the mandrel,the diameter of the bolt hole and the diameter of the end of the mandrel were improved.After optimization,the maximum stress and deformation of the mandrel were respectively reduced by 58.5% and 46.5%.The overall optimization results were good.