Research On Modeling And Simulation Method Of Marine Diesel Camshaft Swing Grinding Surface Topography

As a key component of marine diesel engine,the camshaft has high rotational speed,complex force and harsh working environment,and the quality of its working surface is the core factor affecting the efficiency and working life of diesel engine.The camshaft is subjected to the impact load and wear effect brought by the roller when working,which requires it to have high surface hardness,wear resistance,closure,core strength and toughness.The working performance of the camshaft will directly affect the product quality,working efficiency,exhaust emission,energy saving and service life of the marine diesel engine.Marine diesel engine camshaft has a wide working surface,and the traditional camshaft processing method is more suitable for narrow working surface.The choice of grinding process directly affects the formation of cam surface shape,and the poor applicability of processing method and poor surface shape quality greatly restrict the processing of camshaft with different widths.In view of the above problems,this thesis proposes the swing grinding process.Based on the principle of grinding and the principle of spatially analytic geometry,the spatial motion form of swing grinding is solved,the grinding surface model is established,the grinding experiment is set up,the experimental and simulation data are processed,and the model simulation program is visualized.The research work done in this thesis mainly includes:(1)Solving the problem of surface feature distribution characteristics of the grinding layer of complex contours of camshafts.Firstly,the kinematic equations of X-C coupling and constant linear velocity grinding of camshaft are elucidated;secondly,the kinematic equations of X-C coupling and the related velocity calculation equations of camshaft grinding are derived;finally,the classical geometric parameters of contact arc length and maximum undeformed chip thickness of the grinding layer are selected,and the geometric model equations of the grinding layer geometric parameters are derived for conventional grinding and swing grinding methods.(2)To solve the problems of low accuracy,complicated simulation process and nonspecific characterization method of conventional surface profile prediction methods.The surface profile modeling and characterization method of swing grinding camshaft with high speed,high prediction accuracy and targeted characterization method is proposed.The modeling of the prediction model mainly includes modeling of grinding wheel surface abrasive arrangement,modeling of grinding wheel participation,modeling of swing grinding kinematics,and characterization of grinding surface morphology,and the above four aspects are realized by two different methods,making the application of swing grinding more extensive.(3)To solve the problem of process matching of swing grinding geometric parameters and surface morphology.The kinematics of swing grinding camshaft and the geometric parameters of grinding layer were analyzed,and the influence of swing grinding process parameters on surface morphology was analyzed and experimentally verified,and the swing grinding process and comprehensive matching analysis were carried out by combining the constraints between the above two analyses.(4)The GUI interface of the surface profile modeling and simulation platform for swing grinding camshaft is designed in MATLAB to realize the analysis interface combining X-C coupled linkage kinematics with the geometric parameters of the grinding layer of swing grinding cams,the surface profile modeling interface of the grinding wheel during swing grinding and the surface profile modeling interface of the workpiece according to the known cam lift data and grinding process parameters.Based on the principles of spatially analytic geometry,grinding and surface profile measurement,this thesis proposes a swing grinding method for wide face camshafts,and designs a measurement system and data processing application to lay the foundation for the application of matching process parameters in swing grinding,which is of great theoretical value and practical guidance for the improvement of camshaft machining accuracy and process matching.