Research On 3D Dynamic Simulation Technology For Special Helical Pole Machining Process

The technology of manufacture about helical rotor is vital to the manufacture of various helical poles, such as helic-borer and helic-pump. Since 1994, the CNC Research Center in Shenyang University of Technology has pursued research on the technology of manufacture about complex special helical pole. It firstly put forward the non-instantaneous pole envelope method in China, and pursued systemic research on the theory of envelope method and NC programming method, then acquired a lot of achievements, based on which, this paper researched on the simulation of machining process of special helical pole, and developed the three-dimension graphic dynamic simulation system on basis of non-instantaneous pole envelope method.This paper analyzed and discussed the interrelated theory of computer graphics, visual simulation method, non-instantaneous pole envelope method about CNC machine and the three-dimension graphics modeling method. With triangle graphic element as the main modeling tool we established the simulation model of machining special helical pole. This paper emphatically researched on the problem of calculating the intersection point between workpiece that rotated with variational angle velocity and milling cutter that moved with complicated track and rotated with high speed. Method of expressing special helical pole in PC by defining a height buffer area and discretizing curve surface for milling cutter are proposed, based on which a new algorithm of calculating the intersection between workpiece and milling cutter are argued. The problem of transformation and storage of data on the machining process was resolved as well on basis of the relative movement state of the workpiece and milling cutter, which largely reduced the calculation in the simulation.In order to improve the quality of graphics, this paper also discussed further the problem of display the dynamic manufacture process with three-dimension graphics. It described the algorithms of display the workpiece under particular expression method and milling cutter withbetter graphics reality sense. Eventually by use of C++ and OpenGL, simulation for the whole machining process of a special helical pole is realized, which is satisfying on machining velocity and effect.Furthermore, this paper researched on other interrelated issue, such as interference judgment and curve interpolation, and resolved them on the simplified model. By the algorithms mentioned above, a integrated simulation system for special helical pole machining process is developed. It makes control manufacture combines with the whole complex screw pole manufacture process such as parameters input, selection of milling cutter, interference judgment, interpolation computing, three-dimension simulation and numeral code, in order for the guide of theory research and manufactural practice.