包含刀具-工件多重交互与速度效应的铣削颤振稳定性分析

Stability analysis of milling chatter with tool-workpiece multiple interactions and velocity effects

为研究刀具-工件多重交互与速度效应对铣削颤振稳定性的影响,建立了包含刀具-工件多重交互与速度效应的铣削动力学模型,阐明了无刀轴倾角状态下再生效应、过程阻尼、刀具结构模态耦合与速度效应的耦合作用对铣削颤振稳定性的影响规律,研究了不同径向浸入比下刀具-工件交互与速度效应对铣削稳定性的影响。结果表明,与只考虑再生效应的铣削动力学模型相比,当同时考虑再生效应、过程阻尼与刀具结构模态耦合时,得到的稳定性叶瓣图中颤振区域发生明显变化;当主轴转速较低时,刀具-工件之间的多重交互效应是影响铣削颤振稳定性的主要因素,速度效应对极限切深的影响可忽略不计;随着主轴转速升高,速度效应对极限切深的影响逐渐增大,稳定性叶瓣图中稳定区域呈逐渐减小趋势;在一定范围内,随着铣刀后刀面磨损带的增加,铣削极限切深逐渐增大;主轴转速一定时,径向浸入比相对较小的情况下过程阻尼对铣削稳定性的影响更加明显。采用铣削试验进行验证,结果表明,与传统动力学模型相比,构建的铣削动力学模型能够更加可靠地预测实际铣削状态。

Here,to study effects of tool-workpiece multiple interactions and velocity effect on milling chatter stability,a milling dynamic model including tool-workpiece multiple interactions and velocity effect was established.Influence laws of regeneration effect,process damping,tool structure modal coupling and velocity effect on milling chatter stability under the condition of no tool axis inclination angle were clarified,and effects of tool-workpiece interaction and velocity effect on milling stability under different radial immersion ratios were studied.The results showed that compared with the milling dynamic model only considering regenerative effect,chatter region in stability lobe diagram changes obviously when simultaneously considering regenerative effect,process damping and tool structure modal coupling;when the spindle’s rotating speed is lower,tool-workpiece multiple interaction effects are the main factor affecting milling chatter stability,influence of speed effect on limit cutting depth can be negligible;with increase in spindle rotating speed,influence of speed effect on limit cutting depth gradually increases,and stable region in stability lobe diagram gradually decreases;within a certain range,with increase in wear land of milling cutter flank,milling limit cutting depth gradually increases;when spindle speed is constant,process damping affects milling stability more obviously under the condition of relatively smaller radial immersion ratio;compared with traditional dynamic model,the established milling dynamic model here can more reliably predict actual milling state.