The Design And Performance Analysis Of Welding Torch Regulating Mechanism Based On Parallel Mechanism

With the development of the West-East gas pipeline project,China has entered a peak period of pipeline construction.Numerous existing pipelines are approaching their service life and need to be replaced.There is a great demand for long pipelines,especially those with a large diameter.Due to the restrictions on the structural size of large-diameter pipes,they are normally welded with steel.Therefore,welding process imposes an immediate influence on the quality and service life of the pipes.Taking the company XX for example,this paper analyzed the original equipment,the welding method and the welding technology.This paper studied the causes of unqualified products in welding processes.Key technologies used for welding large-diameter pipelines was summarized.Finally,based on a comprehensive analysis the quality of spiral welded pipes fabricated in the company,the paper located the major problem,which was derived from the fixed welding equipment based on serial mechanism.Focusing on the innovation cost,equipment stiffness and operability,the paper proposed parallel mechanism to improve the performance of the original welding equipment in order to solve the above problem.The main research contents of the paper are as follows.Through the research of spiral welded pipe production line and key technology in the welding process of large-diameter spiral welded pipe,the paper argued that the design of welding torch regulating mechanism was improper and the adjustment accuracy of equipment was low.These factors affected the quality of welded pipes to some extent,leading to weld misalignment and irregular weld bead.For this,this paper put forward a new type of torch regulating mechanism based on parallel mechanism.The design of welding torch regulating mechanism based on parallel mechanism was modeled using the analysis method of the space mechanism kinematic.First,the mechanism type selection was determined with the method of calculating the motion equations.Then,it built a model by D-H method and used the closed vector method mechanism solution.It set up agency relationship between input and output.Finally,the welding performance of parallel welding equipment were analyzed.The paper built a simulation model in SolidWorks package for welding torch regulating mechanism.A simulation analysis for mechanism kinematics,dynamics,and natural frequency was conducted using ADAMS and ANSYS software,respectively.The stability of parallel welding torch regulating mechanism was verified.