卧式加工中心动平衡试验研究

Experimental Analyizing on Dynamic Balancing of Horizontal Machining Center

由主轴不平衡引起周期性波动的简谐力学模型分析得知,主轴不平衡引起的振动属于受迫振动,振动最大幅值与主轴转速有关。试验研究发现,不平衡主轴转动时会激发机床固有频率引起共振。加工表面振纹频率与工件的结构固有频率相符,切削时主轴的旋转不平衡会激发工件固有频率,引起颤振。动平衡可明显改善主轴系统的运行性能,平衡后的主轴可用转速得到大幅度的提高。最后,依据ISO等标准将机床主轴分为2个组别4个等级,为该型卧式加工中心的动平衡建立测试规范。

A cyclical swing harmonic force model caused by spindle unbalancing has been developed. It is found through theoretical analyzing that vibration caused by spindle unbalancing belongs to forced vibration, and the vibration am- plitude varies with rotation speed. It is found through experimental analizing that the frequence of machining surface marks is identical to the natural frequency of workpieee, which comes down to rotation unblancing spindle excites the natural fre- quency of workpiece causing machining chatter. The operating performance of spindle system could be observably improved by dynamic balancing, so useable spindle rotation speed is increased. Finally, according to ISO standard, a testing specification for dynamic balancing of horizontal machining center which includes two groups and four grades has been built up.