Structure Design And Research Of Heavy NC Machine Tool Feed System

This thesis mainly studies how to design the structure of heavy NC machine tool's feed system which is developed by QIQIHAR Heavy CNC Equipment CO., Ltd and puts forward a method for the design of machine tool. The traditional designing mostly depend on experience or adopt analogy to solve problems, however, these methods can not improve the precision and stability any more now and it need more precise calculation which would need tremendous calculations, a long-period design cycle and high cost. With the development of computer technique, the exploitation and practical application of the great engineering software, these problems have been solved completely.According to the constitution characters of heavy NC machine tool feed system the thesis derives the mathematical model of the feed system, analyses the reason why the feed system generates slow speed creeping and calculates the critical velocity of slow speed creeping. The simulation analysis is carried out by applying mechanical system dynamics analysis software ADAMS. It is studied that the error of dynamic and static friction factors between worktable and guide rails, transmission stiffness and worktable mass have effects on the lower speed stability. The research results illustrate that the smaller the error of dynamic and static friction factors between worktable and guide rails, the higher the transmission stiffness, the lower the critical speed and the better machine tool slow velocity stability. The smaller the worktable mass and the less inertia force, the more impossible slow speed creeping, The research applies MATLAB/SIMULINK mathematical model to simulating force signals, then sends signals back to ADAMS model. It makes virtual prototype model in correspondence with actual service conditions.The results of the simulation show that the application of ADAMS and MATLAB is effective for structure design and simulation study. The research has reference value for designing the feed system of heavy NC machine tool and improving machine tool performances.