Research On The Impact Of The Spindle System On Cutting Stability

Studies have shown that the main factor affecting the quality and accuracy ofprocessing in the milling machining center is the relative displacement between the tooltip and the parts in the process. In the actual cutting process，it tends to produce relativevibration between the tool tip and the parts. Therefore studying vibration causes wouldbecome the key to improve the quality and accuracy of processing. According to causes，the vibration is divided into two aspects: forced vibration caused by the externalenvironment， and chatter caused by self-excited vibration in the process. The studiesin avoiding and reducing the impact of the forced vibration have been more mature，and the studies in the chatter caused by self-excited vibration become the main directionin recent years. The major factor of producing self-excited vibration is the driving forcefrom the machine in the process， which is inevitable， and therefore the most effectiveway would be to adjust the cutting parameters to avoid the formation of a chatter.In order to accurately forecast the cutting stable region， in addition to have aclearer understanding of the chatter formation mechanism， we should treat thedynamic characteristics of the machine as more important object of study. Firstly， thispaper introduces the math modeling for the entire spindle system， separately studiesthe general mathematical modeling method on each parts of the spindle. On this basis，mathematical models on the bearing and the spindle are verified and analyzed on staticand dynamic characteristics. And ultimately this paper establishes the generalmathematical modeling method of the entire spindle system based on finite elementtheory， which has been verified. Secondly， in order to predict the stability of themilling， the paper introduces the concept of average teeth， and discusses in detailin prediction methods for milling stability combined with the chatter mechanism， thencalculates the milling stability region based on the frequency response function of thetip point， and ultimately obtains the effects of the axial force， radial force and speedon the entire spindle system characteristics and milling stability region.