Scheme Design And PerformanceAnalysis Of High Precision Ten-roller Ttraightener For Tube

With the characteristics of lightweight,sufficient stiffness,toughness,and strength,the thin-walled tube is widely used from industrial,aerospace,defense and other high-tech fields to cans,household appliances and other fields of life.Straightening is an important process in its finished process which can be used to eliminate defects such as bending,buckling that were produced in the processes of forging,machining,transportation and so on.Most of the traditional ways are through trial correction,determininmg the amount of reduction,straightening force,and then repeat the process of bending straightening untill it qualified.To a large extent,the straightening accuracy and products qualification rate leveller are ensured by the experience of the workers,This is likely to cause an increase in the rate of waste and the fact that the material is still not straight.In this paper,a new high precision straightening machine was designed according to the characteristicsof the thin-walled tube and the practical problems during the straightening process.Fristly,the shape of the second and fourth pairs of straightening roller are designed with concave-convex shape,so the pipe is flexed in the roll moment and between the rolls,and a very long plastic deformation area can be obtained under the smaller pressure.Then the press down system is controlled automaticly by the servo.The straightening forces calculated based on the theory,areapplied to the frame.The workbench analysis software is used to analyze the deformation of the frame and the distribution of stress and strain and the stiffness and strength of the frame are checked.On the other hand,the obtained deformation can be used to provide a numerical basis to remedy the variable quantity by the servo mechanism,so as to ensure the high precision and efficiency of the straightener.Secondly,dynamic analysis for the straightening process was used to obtain the contact condition between the thin-walled tube and straightening roller and The distribution of stress and strain is during the stage of biting,stabilizing and throwing out.The influence of different diameter and wall thickness on the pressure and bending capacity is analyzed.At the same time,the rationality of the straightening parameter,the roll type and the straightener's overall design are also verified.Thin walled tube straightening process is a complex nonlinear problem,The finite element software can be used to simulate the elastoplastic deformation of the tube in the process of straightening.To a great extent,it has made up for the shortcomings of the traditional research methods.The theories of straightening are enriched and improved,and it also has certain guiding significance and data accumulation for the design of thin-walled tube straightening equipment.