Accuracy Analysis And Accuracy Stable Research Of Direct-drive A/C Axis Bi-rotary Milling Head

Direct-drive A/C axis bi-rotary milling head is the core component of high-grade CNCmilling machine, which has the advantage of simple structure, short transmission chain, andhigh accuracy so on. The machining accuracy of CNC milling machine is directly affected bythe accuracy of mechanical bi-rotary milling head. Therefore, it is the focus on the study of thedouble pendulum for the study of CNC milling machine. In this thesis, the A/C doublependulum angle milling head is studied to analyze the error precision hotspot of CNC machinetools. It based on Angle milling head as the research object, the independent research anddevelopment of the error precision of milling head and keep the reliability modeling andprecision analysis are studied, mainly divided into the following sections:(1) The structure of the A/C axis double pendulum Angle milling is detailedly studiedand decomposed, simultaneously the error sources between components and the major errorbetween all the parts milling are analyzed in detail.(2) The topological structure of double pendulum angle milling head and low-order bodyarrays are established based on multi-body system theory. The motion error model of doublependulum angle milling head is established according to the ideal and the actual movement ofthe characteristic matrix.(3) The double pendulum Angle milling head is detected by RL10type laserinterferometer, the detection scheme of positioning error and repeat positioning error of thedouble pendulum Angle milling head is designed, whose results is calculated and analyzed tofinally get the actual position error of milling head.(4) There are many kinds of reasons that the influence of precision retaining ability ofmilling head, such as vibration, environment temperature, lubrication effect and sportswear,etc. In this thesis, according to the time of this year, time interval of fault condition of over theaccuracy is showed, which is met by the Weibull distribution characteristics, to estimate theMTBF. At the same time, the MATLAB software simulation is adopted to predict themaintenance cycle of milling head, as the foundation of improving precision retaining ability.In a word, the motion error model of the A/C axis double pendulum angle milling head isestablished to analyze position error detection and to study precision retaining ability based on the degradation data, which is of great importance to improve the machining accuracy ofindependent research and development of numerical control equipment.