Research And Application Of 3(1/2)(1/2)-axis Method On A 5-axis Machine Tool

With the development of manufacturing, the design of CNC machining parts is increasely complex and precision is increasely higher. Which tilted surface and free surface are more complex,3-axis machining methods can not meet the requirements of rocessing efficiency and accuracy, so methods need to use 5-axis machining,which can make the tool surface and the part surface with a good match. But 5-axis machining also brought some problems:1. For the tilted working plane, method using 5-axis CNC machining algorithm is complex and difficult NC programming. And processing at different slant on the same graph Shique requires repeated programming, code numbers and more data loaded.2. For free-form surface machining, using the method of simultaneous 5-axis machining, in high-speed machining, when the curvature change too fast, the rotation axis servo drive system will limit the feed rate and jitter, which is difficult and effects surface smoothness.For the above deficiencies of 5-axis machining methods, this paper have designed a 3??-axis machining method for three typical 5-axis machine tool based on a fixed axis designed a structure. In 3??-axis machining, two continuous rotations are not synchronized with the X-, Y-, and Z-axis movements to improve its ability and efficiency for machining complex sculptured parts in 3-axis machining and overcome the inherent problems with simultaneous 5-axis machining such as dramatic reductions in feed rate and non-liner error. This paper has mainly studied the 3??-axis method for the tilted working plane and thefree surface.Firstly, this paper have analyzed the structure ofthree typical 5-axis machine tools and the related kinematic model were studied.Secondly, the paper have designed inclined surface 3??-axis machining methods,Setting properties in an inclined plane coordinate system making the space programming problem into plane programing problem.Thirdly, this article discusses the methods of 3??-axis machining path planning method for free surface including the knife contacts the solution and the calculation of tool axis.Finally, experimental verification of the above methods is done.using 3-axis, 5 axis and 3??-axis machining method respectively to machine the same surface , the results of which were compared.The design of this method is simple, reliable, able to simplify the process of NC programming and meet modern numerical control system for high efficiency and high precision requirements.