Research On CAD Technology For Variable Pitch Solid End Mills

When using conditional equal pitch end mills during high speed milling process, due to the same cutting feed of each cutting tooth, the milling force waveform of each cutting tooth is identical, causing self-excited vibration in milling system, which not only leads to poor surface finish, low accuracy and processing efficiency, but also decreases tool life and even causes damage to the machine tools. While variable pitch end mills have the ability to suppress chatter vibration in milling effectively.Using3D CAD model of cutting tools, structure optimization of cutting tools, cutting process simulation and CNC machining programs automatically generating become much easier. As a result, it becomes a bottleneck for improving cutting tools design quality to establish the3D CAD model of variable pitch solid end mills fast and accurately. In this paper, a parameterized computer aided design system for variable pitch solid end mills based on UG platform is designed and put into practice. Research contents are as follows.The classification and structural features of variable pitch solid end mills are analyzed. The mathematical models for helix angle, helical line and helicoid of cylindrical end mills have been established on the basis of theoretical studies results of complex revolving tools.Dynamic model of milling and chatter suppressing mechanism are analyzed. The optimization algorithm for optical pitch angles for solid end mills are analyzed and included in the paper, which has been proposed by Budak.Variable pitch solid end mills computer aided design system is designed in theory, which contains module of pitch variation optimization, design wizard, parametric modelling and database for variable pitch solid end mills.On the basis of the theoretical research results, the variable pitch solid end mills computer aided design system is developed in practice on UG NX7.0platform using development tools of Visual Studio2005, SQL Server2005and UG development APIs and tools, which is called VPSEM-CADS.