Modeling And Analyzing Of Turning Quality Based On Virtual Machining Principle

The processing quality of parts has an important influence on the performance and reliability of mechanical equipment.With the development of the equipment manufacturing industry,the demand for the processing quality of the parts is increased.Based on a large number of domestic and foreign literature,the influence of any part's error of the machine tool on the processing quality of the workpiece and the modeling method are systematically studied and analyzed by the research of this subject.Studying and mastering the effects and rules of the machine parts' unit pose errors on the processing quality can provided a more direct basis for improving the accuracy design and error compensation of machine tools.The relationship model between the source error of the machine and the processing quality of the parts is established by taking the end and cylindrical surface of the turning part as an example.The modeling work is divided into two parts,based on the principle of virtual machining,a mathematical simulation model is established between the unit pose error of the executive parts(tool and workpiece)and the part's processing quality,at the same time,combination the transfer model between the error source of the lathe process system and the pose error of the executive part.This paper focuses on the first part of the research work,based on multi-body system kinematics and homogeneous coordinate transformation principle to establish the kinematics relationship between the tool and the workpiece,the workpiece is processed by virtual machining through MATLAB,analysis and evaluation the machining quality of the workpiece.The main contents of this paper are as follows:First of all,the research status of cutting machining quality's control at home and abroad and the application and development of virtual machining principles are introduced,the research background,source and significance of this thesis are clarified,the shortcomings of the present stage in the study is analyzed.Based on this,the research ideas and methods of this paper are put forward.Based on a brief introduction to the related theories of workpiece machining quality modeling based on the principle of virtual machining,firstly,the use-method and integrated relationship between direct error model and indirect error model are introduced,the modeling methods of the direct error model are mainly elaborated.The main methods include: machine tool movement and part forming,tool model,and virtual workpiece surface preparation based on MATLAB simulation,andthe correctness of the model.Second,taking the virtual turning of the workpiece end face and cylindrical surface as an example,the machine tool error model created in the previous chapter is used to processing the virtual workpiece surface.According to the relevant national regulations,various error items are compiled using MATLAB.Through the example of error setting,,the result of the error project is calculated by assessment model.Finally,based on the virtual machining modeling and the virtual workpiece processing quality assessment results,the single error factor analysis and multi-factor error analysis are taken as examples to illustrate the analysis method of processing error.finally the visualization software for virtual turning machining quality simulation system based on MATLAB-GUI is completed,and the forming motion model of the machine tool and each error item assessment model are integrated.With this software,simulation and prediction of the turning machining quality under different characteristic parameters can be realized intuitively and efficiently.