Study On Cylinder Milling CAM System Of Turning Center Based On Cylinder Interpolation

1.IntroductionTurning center is the most popular compound equipment in our country,the most important difference between Turning center and normal lathe is that Turning center can not only realize all the process done by lathe but also can MILL and DRILL on the end face and cylindrical surface,which can highly improve efficiency and precision,particularly,its cylinder mill function can be widely used on cam,screw,oil groove and special-shaped groove manufacturing,shows the quintessence of Lathe-Milling Machining.However,the NC code programming of this function is facing big problems.The popular CAM software we used today, can hardly support cylinder mill,and if treat it as normal milling machining,new problem in post process that is more complex will be imported.Even if using cylinder interpolation instruction to program,complex problems still can not be solved because of its manual programming essence.This difficulties make the Turning centers can not fully develop their actions.To solve the problems,based on the most popular NC system:SIEMENS and FANUC,the article proposed to combine the computer aided programming technology and advanced programming method,developed a CAM system which can support the auto program of cylinder interpolation instruction,so the cylinder mill function can be used easily.As the number of Turning center has been increased year by year in our country,this system is of great significance in actual production.2.Research on cylinder interpolation instructionCylinder interpolation instruction is realized based on the special function:cylinder interpolation.Under this mode,nc system can automatically transform the planar mill NC code to cylinder mill code,which can greatly simplify the design and programming work of cylinder groove.Through the research on the format,using method and process of the cylinder interpolation instruction in the SIEMENS and FANUC system,the article proposed its using principle,and gave an manual programming example as well as its simulation in the software VERICUT in order to verify the principle's correctness.This work wa the process foundation of the CAM system. The article studied on the machining method,tool path mode and precision control on the base of cutter path planning,reseached the process of cylinder curve groove maching,proposed the choosing principle of tools,cutter path and Cutting Parameter.3.Research on the tool path generating method of milling cylinder curve grooveThe use of the cylinder interpolation instruction need the programmer to expand the cylinder curve to planer curve.So the expansion method must be studied.By analyzing the classic cylinder curve such as cam,screw,oil groove,combined with the expansion method of cylinder intersection line,we proposed the rapid cylinder curve expansion method,which solve the dilemma in the using of the instruction.The article chose the flexible step method as the nodes calculation method,for it can simply ensure the equal-error principle.Through studying on the process of cylinder curve groove,the article chose Z-level machining as the main milling mode and the algorithms needed by system programming.Because the Cutter Radius Compensation can not be used in the cross-section under the cylinder interpolation mode,offset curve calculation must be done to avoid overcut phenomenon.Analysing the algorithm of Z-level machining,the article divided it into 3 main parts:Path Interval division,Offset Curve calculation and cutting layer division and derived the main Parameter algorithms.4.Development of the systemOn the foundation of process and algorithms research,the article developed the system on the integral programming environment of VC++6.0,divided it into 4 main mode:input,output,numerical calculation and post-processing.The article studied the operation mechanism as well as the construction plan of the system,constructed the basical structure of the menu.5.Development of the calculation and post-processing modeThe article analysised the basical function of the calculation mode,study on the construction method of the structrue,the generation of the object,the storage of the output and the linkage of the combination curve,provided the algorithm flowchart of the major functions:the algorithm of flexible step method,the Z-level calculation algorithm and the main algorithm of the calculation mode.The article analysised the basical function of the post processing mode,researched on the coordinate transformation and data exchange problem,proposed the main thoughts of the program and provided the algorithm flowchart.6.SimulationThe article used the system generating several NC code of cylinder curve groove mill,constructed the process environment in the software VERICUT and simulated to verify the correctness of the auto programming system.Finally by analyzing the outcome of simulation and consulting related data,the article discussed the theoretical error of cylinder curve groove mill and proposed the method to eliminate it,which provided new subject for further research work.7.ConclusionThe popular CAM software we used today,can hardly support cylinder mill, which greatly reduce the programming efficiency of Turning center.The system my subject developed can fill up the blank,meet the demand of actual production.The development of NC manufacture provides a wider prospect for compound machining as well as its related programming software.The main object of this subject is 2.5or3-axis Turning center,which is the basic structure of Lathe-Milling Machining center.For more complex structure,the NC programming of mill,drill, grind is still a big problem,which is a great challenge to our engineer.Our domestic CAM software market has been occupied by foreign brands such as CATIA,UG,MasterCAM.The Lathe-Milling Machining auto programming software is an important breakthrough..How to solve the programming problem imported by muti-axis and compound machining,need further research by our company and research institution...