车削大螺距螺杆振动特性分析及振动抑制措施

Large-pitch Screw Vibration Characteristics Analysis and Vibration Suppression Method

大螺距螺纹螺杆在车削加工过程中,由于工件轴向长度大,使得工件刚性较差,柔性较大,极易造成切削振动加剧。研究振动抑制方法,是减小切削振动对工件表面质量影响的关键,本文针对大螺距螺杆的振动特性进行了研究。首先通过有限元软件ANSYS Workbench对工件不同位置进行了模态分析,其次根据大螺距螺杆切削过程中不同位置的振动模态频率变化规律,提出了移动支撑随刀具切削位置变化的振动抑制措施,提高切削过程稳定性。然后结合大螺距螺杆结构特点,进行了车削大螺距螺杆专用跟刀架设计。最后通过谐响应分析对比有无跟刀架约束位移响应的变化,进一步证实了施加跟刀架约束可以提高工件的刚性,减小切削时的振动。

In the turning process of large-pitch screw,due to the large axial length of the workpiece,the rigidity of the workpiece is poor,the flexibility is large,and the cutting vibration is easily caused.The vibration suppression method is studied to reduce the influence of cutting vibration on the surface quality of the workpiece.The key of this paper is to study the vibration characteristics of large pitch screws.Firstly,the modal analysis of the different positions of the workpiece was carried out by the finite element software ANSYS Workbench.Secondly,according to the variation law of the vibration mode frequency at different positions during the cutting process of the large pitch screw,the vibration suppression measures of the moving support changing with the cutting position of the tool were proposed.Then,the design of the special tool holder for turning large pitch screw was carried out,which was combined with the characteristics of the large pitch screw structure.Finally,it is further confirmed that the application of the tool holder constraint can improve the rigidity of the workpiece and reduce the vibration by harmonic response comparison analyzing the change of displacement response before and after applying the constraint of the tool holder.