Research On The NC Process Simulation System And Technology Of NC Milling Bsaed On Virtual Manufacturing

Virtual maching process simulation is an key technique and an important means in Virtual Manufacturing (VM). In order to meet the need for the development of Virtual Manufacturing Technology, NC process simulation is research. In this dissertation, emphases are placed on the function and the construction of NC processing simulation system,the modeling and simulation of end-mills,database of milling cutting,prediction of milling force,parameter optimization. The main research results and creative contributions are summarized as follows. (1)In the aspect of NC processing simulation system, the design and the main function of NC processing simulation system that can predict the processing performance, product quantity and the efficiency are putted forward. The structural diagram and the methods of realizing the main functions are gived. (2) In the aspect of modeling and simulation of milling cutters, by means of differential geometry, an approach for describing the geometrical features of arbitrary contour mills is constructed. Then the unitive geometry model of End-mills is builded. Forecast of the physical change that is disjointed with geometrical simulation in the current NC processing simulation is not accurate. To resolve the problem, the theory and modeling method are put forward that can satisfy the request of the physical simulation. With this concept, helical end mills are modeled. In the course of modeling, universal equation of helicoids of the head is set up. The model can provide the coordinate of the cutting point, the length and shape of the blade for the physical simulation. (3) In the aspects of software and database, the author establishes the application of Object Oriented Database. The procedure can select parameters of the standard cutter and definite nonstandard cutters for three dimension end mills. (4) In the aspect of modeling and simulation of milling force, the author puts forward that the milling force is prescribed by an exponential expression of cutting parameters is practical and effective in the emulational model. .It is brought forward and verified that predicting precision of the polynomial expression of the relation of academic circumferential force and component of milling forces is highter than the linear equation. (5) In the aspects of optimizing the parameters, based on the fruit of parameter optimization, the author has established the mathematical model of the many targets' and intelligent optimization, and made use of the genetic algorithms to optimize the parameters of milling in the example.