机床进给系统动态特性分析-机械制造及其自动化专业论文.docx

华 华 中 科 技 大 学 硕 士 学 位 论 文 华 华 中 科 技 大 学 硕 士 学 位 论 文 万方数据 万方数据 万方数据 万方数据 Abstract Modern CNC is developing constantly in the direction of the high precision and high speed, which makes it to challenging to guarantee manufacturing accuracy in heavy load. Therefore, it is significant to study CNC’s dynamic performance in operation state. Taking CNC milling machine as the research object, this thesis proposed a dynamical model concerning the complicated dynamic performance of movable joint interface. The electro-mechanical co-simulation, rigid-flexible couple and discrete feed system are combined to establish a dynamic characteristic analysis platform to predict the dynamic performance of CNC. Main contributions of this dissertation are shown as follows: Firstly, based on Hertz contact theory and the structural characteristics of feed system movable joint interface, the dynamic parameters of ball linear guide way, bearing and ball screw were distinguished. The influences of pre-tightening force, centrifugal force and gyro torque were considered. The influence relation of speed and force to contact deformation was obtained. Secondly, the structure of lead screw and guide rail were divided by the self- development module. Besides, the kinematic pairs were custom designed according to the dynamic performance of movable joint interface. Examples showed that the discrete feed system is more realistic comparing to the traditional joint model. Finally, a dynamic characteristics analysis platform for whole machine was established, combining the rigid-flexible couple and electro-mechanical co-simulation techniques. Dynamic error in the progress of triangular moving without load and milling round boss wave was analyzed. Comparing with traditional modeling method, the dynamic error obtained by new method was more reasonable. Influences of control system, structure elastic and movable joint interface to dynamic characteristics was discussed. According to the above research, a fea