Research On Five-Axis Machining Strategy Of Globoidal Indexing Cam

With the rapid development of production relations in today’s society,a new generation of technological revolution and the deep integration of manufacturing,intelligent production lines need to use more intermittent motion mechanisms to achieve higher accuracy of cyclic indexing.Among the various intermittent motion mechanisms,the globoidal indexing cam mechanism has the performance advantages of higher transmission speed and high indexing accuracy.As the globoidal indexing cam mechanism replaces the traditional intermittent mechanism,this high-speed precision indexing device has a very broad application prospect in all walks of life.However,due to the complexity of the working surface of the curved cam,difficult processing,and the traditional manufacturing methods are difficult to ensure the processing quality.The use of the new five-axis machining technology can solve the processing problem of the curved indexing cam more efficiently.This thesis takes titanium alloy globoidal indexing cam as the main research object,and studies the machining strategy from the aspects of three-dimensional model design,machining process design,tool path planning,etc.The main contents are as follows:(1)Study the classification and meshing rules of the globoidal indexing cam,and derive the parameter equation of the profile according to its motion rule,profile characteristics,and calculate the coordinate points using Matlab.In the 3D modeling software,a three-dimensional model of the globoidal indexing cam is constructed by indirectly modeling the curved surface and then constructing the solid,which improves the modeling efficiency of the globoidal indexing cam.(2)According to the characteristics of the three-dimensional model of the globoidal indexing cam,its processing difficulties are analyzed,and the process of processing the globoidal indexing cam is designed by combining the machine tool’s motion characteristics,tools,fixtures,and processing safety.The machining stages are divided,the negative angle faces of the difficult points of the globoidal indexing cam are studied,and a set of machining schemes suitable for five-axis CNC machining is summarized.In order to solve the problem that the swing angle of the tool axis is too large and unstable at the starting and ending positions of the multi-axis machining of the globoidal indexing cam,the tool axis sequence is optimized in conjunction with the modified sinusoidal motion law of the cam.(3)In order to improve the problem that the deformation of the titanium alloy globoidal indexing cam is greatly affected by the milling force and is prone to deformation,the milling parameters based on the titanium alloy processing are optimized.The milling process of titanium alloy parts was analyzed using a single factor test research method,and the influence of milling parameters on the milling force and its component forces in three directions was analyzed.The milling force model was established,and orthogonal experiments were designed to verify,and the regression equation of the milling force of titanium alloy was fitted from the test data to create an experience model of milling force of titanium alloy.The chaotic particle swarm optimization algorithm is improved by the method of parameter optimization,and a more efficient method of milling parameter optimization is proposed.The improved algorithm is used to optimize the milling parameters with the minimum milling force as the optimization goal.(4)For the five-axis dual-turntable CNC machining center,the motion was solved.The Post Processor software was used to develop a post-positioning CNC code that can output three-axis machining,3+2 axis machining and RTCP function in three machining modes.The processor and CNC code compilation.The VERICUT simulation processing experiment proved that the program processed by the customized post-processor is safe and usable,and finally the processing of the arc indexing cam is completed in the five-axis CNC machining center.