Chatter Characteristic Analysis Of Parallel Machine Tool

Chatter is an important factor to affect the stability of the high-speed machining, which influences the machining quality and precision greatly. Parellel machine tool is possible to be a high-speed machine tool in the future. Research shows that the dynamic characteristic of parallel machine tool has high consistency in several different positions. Therefore, to analysis the chatter characteristic from the inherent structure of parallel machine tool is of great signifiance to develop the machines which is fit for high speed machining, forecast and control chatter.This subject mainly studies flutter consistency problem of the parallel machine tool in several positions in the working space.Firstly, this paper analysed the basic mechanism of regenerative chatter detailedly, understood chatter stability theory of Autintas deeply and programed to draw the flutter stability limit diagram which has a function that once cutting parameters and modal parameters are obtained, this program can draw the chatter stability limit diagram to estimate the machining stability.Secondly, the paper established the entity models of the major components based on parallel machine tool EXE700 in the ProE. Then put the assembled into ANSYS and established the finite element model of parallel machine tool in several locations in the workspace and done with the kinematic pair with the method of coupling.Thirdly, this paper found the main mode of vibration to influence machining by the modal analysis of the finite element model. Then solved the response of the tip of machine tool under the unit harmonic force on the basis of the modal analysis and extracted the modal parameters of the tip of machine tool in the vertical direction from the frequency response curve by using the method of curve-fitting. After that this paper computed the stability limit diagram in different positions according to a certain cutting condition and compared their consistency.At last, this paper has done the vibration test on machine tool tip point and extracted modal parameters in each position with LMS.Test.Lab and calculated flutter stability limit diagram in order to test the results in the finite element.The above research and analysis, the paper obtained some preliminary conclusion to provide the theory and the method for the further research.