Mathematic Modeling And Machining Method Of Changed Angle And Variable Pitch Spiral Groove

Changed angle and variable pitch spiral groove which is on the rocket engine nozzle outside surface is a new kind of cooling channel. The type of nozzle is used to adjust rocket's pose. It is a very difficult problem in aerospace manufacturing to machining it. In order to resolve the puzzle, this thesis concentrates on the research of its mathematic modeling, machining method, data processing, dynamic simulating.With the theory of kinematics, the universal model of changed angle and variable pitch spiral groove on any turning surface is researched. the theory that spiral angle and pitch are the function of nozzle section radius is established and the mathematic models of spiral groove which generatrices are linear, arc, multinomial are built.According to peculiarity of spiral groove and with the principle of motion synthesis of spiral groove machining,a stick cutter milling method which five axes can simultaneously interpolate is researched and developed.CAD/CAM automatic programming and Pro/Engineer software which has powerful solid modeling and machining simulating function are chosen because of complicated machining track and tool path of spiral groove.The mathematic model of changed angle and variable pitch spiral groove is such complicated curve integral equation that it is impossible to build 3D model directly for Pro/Engineer.Simpson interpolation is researched to do data processing.The course is realized by Matlab.The CAD model of changed angle and variable pitch spiral groove is complicated. According to a typical workpiece, 3D surface modeling is researched and CAD modeling is resolved. In order to improve both of the machining accuracy and efficiency, milling methods and tool path planning are researched and realized in the simulating trial. The optimized tool path generation is resolved.Generating CL document is transferred to NC codes to be used in the practice.NC programming of spiral groove is resolved.