The Research On Virtual Prototype Of Large CNC Portal-type Milling Machine

Large CNC Portal-type milling machine is indispensable equipment in machinerymanufacturing. To design and manufacture CNC planer type milling machine with highaccuracy and efficiency is the long-cherished wish of manufacturer at home and abroad.The gantry framework is the key component of the milling machine. It plays a decisive rolein the performance of the milling machine. This article applies virtual prototype technologyto design and analyze milling machine and gantry framework. For the design of CNCmilling machine we have done meaningful attempt.This article uses the three-dimensional modeling software Pro/E to establish theoverall model of Large CNC Portal-type milling machine and parameterized digital modelof the portal-type frame, to realize the series design for gantry framework and to make thestatic analysis，modal test and harmonic response analysis of virtual prototype through thefinite element analysis software. The finite element model of gantry framework is built onANSYS Workbench directly, and the manual operation is used to optimize mesh qualityand reduces elements number.Static simulation analysis on the gantry framework，the deformation and stressdistribution is calculated to determine the stiffness and strength to meet the requirementsof CNC milling machine, which is of great significance for the design work. What’s more,the static analysis based on ANSYS offers bases for the renovation and design of themachine.The gantry framework are selected for the modal simulation to attain the modalfrequency and mode shape separately，and analysis of the first10order mode shapes toillustrate the modal frequencies and mode shapes effect on the dynamic characteristics ofthis gantry framework.Harmonic response analysis on the gantry framework, how much response amplitudeto get of the gantry frame section is calculated when Machine tool working on thecomplicated spatial loads. By analysis and calculation the structure of the sustaineddynamic characteristics can be predicted, then validate whether its design can restrain ornot the harmful effects caused by resonance, fatigue and other forced vibration.The whole CAD model which is established by Pro/E import to ADAMS, and proceedparameter setting and adjust, add motion joints and motor drive. The virtual prototype ofthe same performance compared to physical prototype is formed. The reasonableness of its structural design，as well as the deformation requirements of the upright column in motionhave been verified，through the rigid body and rigid-flexible mix body kinematic analysisof portal-type milling machine.The research has gained some feasible findings, and provided valid references forstructural design, assembly, modal test, static analysis, harmonic response analysis andkinematic analysis of gantry framework, also for mastering and optimizing dynamicperformance of gantry framework and vibration absorption designing for gantry framework,and for the series, parameterization, optimal design and modular design of gantry frame.Besides, to improve the machining accuracy of large gantry milling machine provides animportant way.