利用电流变液阻尼器改变切削系统特性的研究

为了进一步对先前研制的一种基于电流变液阻尼器的切削颤振抑制结构进行系统的研究,对其静态和动态特性进行了实验和理论研究。结果证明,这种结构可以显著改变车刀刀杆的固有频率、阻尼性能等动态特性和静态特性,在零电场下刀杆的静柔度约0.5μm/N,电场强度为1.5kV/mm时减小到约0.3μm/N,2kV/mm时减小到约0.2μm/N;在零电场时刀杆的加载和卸载曲线是大致重合的,近似一纯弹性体;而在电场强度为1.5kV/mm和2kV/mm时加载与卸载曲线包绕的面积都明显增大;刀杆的阻尼比在3kV/mm时为0.05127,而1.5kV/mm和0kV/mm时分别为0.02882和0.02163。动柔度曲线显示:随着电场强度的增大,结构的阻尼比增大,共振峰值减小。利用这种结构具有可控动态性能这一优点,可以在线对机床车削振动进行有效控制。

Application of Electrorheological Fluid Damper to the Suppression of Turning Chatter

For further systematic study on a kind of cutting chatter suppression structure based on electrorheological fluid damper developed earlier which has been used in turning chatter suppression successfully, the authors made experimental and theoretical study of its static and dynamic properties. All the results show that this kind of electrorheological fluid damper structure can notably change such static and dynamic properties of the cutting tool bar as inherent frequency, damp performances and so on. When the added electric field increases from 0 kV/mm and 1.5 kV/mm to 2 kV/ mm, the static flexibility of the cutting tool bar decreases from about 0.5 μm/N and 0.3 μm/N to 0.2 μm/N respectively, its damp ratio decreases from 0.051 27 and 0.02882 to 0.021 63 respectively; and the encircled area of its loading curve and unloading curve increases while resonance peak value decreases. This kind of structure can efficiently control the vibration of machine tools .