Motion Analysis And Processing Application Research Of Four-axis Numerical Control Machine Tool

NC machine tool can realize different movement by controlling of different movement shafts and linkage shaft in order to achieve the processing of different shapes parts. Because the numbers of controlling axes and linkage axes are different, corresponding motion trail are different, and the complexity of processing components are also different. The motion style of the four-axis NC machining tool becomes more complex than the three-axis NC machining tool as the rotating axis control is added, which limits the practical use efficiency. In this thesis, taking the four-axis vertical NC machining center as object, motion paths and machining application is studied to assist the auto part programming to increase the practical efficiency.The typical motion trajectories of four axes coordinated machining tool are analyzed, and the trajectory models are built with the UG software, the built models can provide guidance for modeling of parts with same shape factors. The mathematical model of the motion trajectories of different axis combination of the four axis vertical machining center are analyzed specially and the trajectory curves are given. Then the basic elements and features of the parts suitable for four-axis machining are presented. The virtual machining experiments verify that the models have guiding significance for part modeling and machining.The general geometry model of the milling tool is built, focusing on the ball-nose end mill, the S-type geometry blade equations are built. Based on analyzing of the tool path planning principles, the tool path of the four-axis coordinated machine tool is constructed, the turbofan axis with revolution surfaces is taken as typical part and is modeled according to the above studied.To improve the reliability of the complex part programming and avoid the impact or interference among the tools, axes and fixtures, the virtual four-axis vertical machining center is built, the programming and virtual machining of the turbofan axis is finished. Thus the programmer can simulate the machining environment of the whole machine tool on the computer and check the NC program without running on the practical machine tool, which can save programming time, improve efficiency and avoid the possibility of damaging the part or even the machine tool.Normal error model is established and the calculating method is given. During the calculating process, to determine the intersection point of the normal line through a random point of the theoretical curved surface with the practical curve surfaced, the tangent plane projection analysis method is presented, which can effectively analyze the errors between the practical machined curved surface and the theoretical curved surface.