时变金属切削过程颤振的研究

A Study of the Chatter in Time-Varying Metal Cutting

本文根据时变金属切削过程的概念,采用对信号分段的AR模型描述其时变性,并用于第二汽车制造厂Mx-4车床颤振的研究.文中对时变金属切削过程颤振的AR谱特性、颤振模态的阻尼率、时变系统的特征根这三个方面都进行了深入的研究,指出了时变金属切削过程颤振的特点,提出了颤振状态下的机床切削系统仍然是稳定系统的观点.文中的分析结果较好地解释了Mx-4车床颤振的一些特有现象.

The concept of the chatter in time-varying metal cutting is proposed and AR models based on the sectioned time series are introduced to de-scribe the time variability. The models have been applied to an investigation on the chatter in a type Mx-4 lathe. An in-depth study has been made on the AR spectrum, the chatter modal damping ratio and the characteristic root of a time-varying system. It is pointed out that, for the time-varying chatter, its time interval is quite short compared with ordinary chatter and the chatter will wither away owing to the variability of certain system parameters. It is also shown that, under steady chatter, the machine cutting system is still stable. The peculiar phenomena of the chatter in the Mx-4 lathe are convincingly explained by the results of investigation.