Design And Analysis Of The Exterior Milling Parallel Machine Tool

The research of parallel mechanism belongs to a new branch of theory of multi-loop and multi-D.O.F. mechanism. However, the appearance of Parallel Machine Tool is accompanied with the development of the theoretical research and computer software and hardware technique for parallel mechanism. It is the combination among theory of mechanism, robotics techniques, numerical control techniques and mechanical structure techniques. The larger is the proportion of NC machining parts with surface in all, the higher is the requirements for precision and efficiency of NC machining, and the appearance of parallel machine tool is catering for the era requirement. Parallel machine tool overcomes the disadvantages of traditional NC machine tool such as small stiffness-weight and low bearing capability etc. possesses many merits such as big stiffness-weight, fast response speed, wide adaptability, high machining precision and easy multi-axis linkage etc. and is very suitable for machining free-form surfaces.This paper analyzes the domestic and international situation about parallel machine tool related. Some basic problems about PMT are studied from practical application angle, and elementary conclusions are made. the respective characteristics of RPY angle system and Euler angle system are studied as they are used for posture description of mobile platform, and four kinds of parallel mechanism are given.The whole distribution of Parallel Machine Tool were given .Designed the main machine replacement parts by given parameter. Various calibration methods for the errors in the Parallel Machine Tool structural parameters were examined. An indirect measurement calibration method, based on progressive approaching techniques has been introduced. The fundamental principle and calculation formulas of the proposed calibration method were presented. Comparisons using different calibration methods on a parallel simulation platform with moving base have shown that conventional calibration methods based on precise measurement do not work effectively for large scale Parallel Machine Tool, and that the proposed indirect calibration method can, in fact, improve the structural precision of the Parallel Machine Tool effectively, if used as overall calibration after the Parallel Machine Tool being installed.Make use of ANSYS software, Investigations are made on the stiffness analysis of the main machine replacement parts for parallel machine tool. Analysis the stress and strain of each machine replacement parts. And improved the structure design based on the analysis results. Provide reliable theoretical foundation for Parallel Machine Tool design and development.