基于蜂窝芯圆盘刀切削齿的系统稳定性研究

Research on System Stability Based on Honeycomb Core Disc Cutter

从圆盘刀超声振动切削Nomex蜂窝芯加工原理出发,将圆盘刀超声加工系统简化成双自由度弹簧-质量-阻尼系统并建立了圆盘刀超声振动动力学模型,推导了圆盘刀加工系统临界稳定成立的条件式。在理论分析的基础上,基于MATLAB/SIMULINK搭建了圆盘刀系统动力学仿真模型,并开展了颤振仿真试验,研究得出了切削齿数对系统稳定性的影响规律:在低转速范围内,随着刀具切削齿数量逐渐增大时,加工系统稳定性逐渐降低;在高转速范围内,加工系统的稳定性随着刀具切削齿数量的增大反而逐渐增强。采用控制变量法在转速为1 500 r/min等加工条件下通过使用所设计的3种不同齿数的圆盘刀现场加工Nomex蜂窝芯得到的零件表面质量对比分析表明,大齿数Z=36的圆盘刀加工得出的零件表面质量更高,系统稳定性更好,与仿真结果一致,从而很好地验证了已建立的超声振动动力学模型与稳定性条件式。

Starting from the principle of ultrasonic vibration cutting of Nomex honeycomb core,the disc cutter ultrasonic machining system is simplified into a double-degree-of-freedom spring-mass-damping system and the ultrasonic vibration dynamics model of the disc cutter is established.The conditional formula that the system is critically stable.Based on the theoretical analysis,the dynamic simulation model of the disc cutter system was built based on MATLAB/SIMULINK,and the flutter simulation test was carried out.The influence of the number of cutting teeth on the stability of the system was obtained:in the low speed range,as the number of cutting teeth increases,the stability of the machining system gradually decreases.In the high speed range,the stability of the machining system gradually increases as the number of cutting teeth increases.Using the control variable method to compare the surface quality of the parts obtained by in-situ processing Nomex honeycomb cores using three different tooth count disc cutters under the processing conditions of 1500r/min,the disc cutter with large teeth number Z=36 is shown.The surface quality of the parts obtained by machining is higher,the system stability is better,and the simulation results are consistent,which proves the established ultrasonic vibration dynamics model and stability condition.