The Structure Design And Dynamic Analyses For Headstock Of NC Boring And Milling Machine

For NC machine tool, feeding-servo system connecting NC equipment and machine tool is an important part of the NC system. Designing of the feeding-servo system, some operating requirements should be met firstly, and then the accuracy, static and dynamic performance of feeding system and the working precision could be ensured. As we all know, high speed, efficiency and accuracy are main research direction in modern NC machine tool. With increase of the designing requirement of feeding system, it becomes very important in theoretical and practical for improving the performance of NC machine tool to study deeply on structure of feeding system and static-dynamic performance of servo system. The main research contents and results of this thesis are as following:(1) Based on systematic introduction of the feeding mechanical and serve-drive system element of NC machine tool, some motion characteristics of feeding system are analyzed.(2) After analyzing of ball screw driving motion, the friction, rigidity and reverse gap of feeding mechanism of feeding mechanism, the improving measurements for dynamic performance are proposed.(3) With studying motion characteristics of ball screw feeding mechanism, a simple dynamic model is presented.(4) The full-scale model of ball screw, boring shaft and frame are built based on Pro/E software, respectively, and these models are analyzed by using ANSYS software, the free frequency and mode of system are obtained in this thesis.(5) According to mechanical vibration theory, meanwhile a mathematical model of feeding system is built and its dynamics is analyzed, these results provide theoretical basis for dynamic performance analysis of serve system.(6) With the development of TK6915 feeding system model, the curve of systemic performance is obtained by simulation, at the same time, the mechanical parameter, gap, skip area, and other factors influencing on precision nonlinear of system are studied too, moreover, the improved measures are presented. With analyzing variation of static-dynamic performance of feeding system, influence rule of designing variance on dynamic characteristics is given.In generally, the results of the thesis provide theoretical basis for designing, choosing parameter and improving performance of NC machine tool feeding-servesystem.