Study On Dynamics Modeling And Simulation Of Helical Milling Operation

As a new type of high-efficient hole-making technology, helicalmilling has been widely used in the high-tech manufacturing fields suchas aeronautics and astronautics for its high efficiency, good surfacequality and long tool life when compared with the traditional drilling. Thehelical feed toolpath, the unique cutting mechanics different fromordinary milling operation and the complicated relationship among thecutting conditions and the machining efficiency and quality make it isdifficult to realize high-efficiency and high-quality helical milling.Therefore, it will have great theoretical and practical value to develop ahigh efficiency oriented enable tool by exploring the technology ofdynamics modeling and simulation for helical milling operation.Based on the analysis of kinematics and cutting mechanics forhelical milling operation, the prediction of three orthogonal cutting forcesfor helical milling operation was implemented by discretizing of helicalcutting edges, applying instantaneous cutting force model on eachdifferential cutting edges, coordinate tranformation, integrating along theaxial direction and summation for each tooth. The cutting force testingsystem is setup and the above-mentioned cutting force prediction modelis validated.Based on the dynamic cutting force modeling for helical millingoperation, referencing the solution of chatter stablity for end milling andits procedure and calculating the average directional cutting forcecooeficients by numerical method, the chatter stability prediction modelwas derived. The model was comfirmed by chatter stability validationtests.An improved Z-map model is proposed to represent the surfacetopography of the machined hole on the basis of the classical Z-mapmodel. The prediction of the surface topography of the machined hole isimplemented by discretizing along the helical tool path and calculatingthe intersection between the side cutting edge and the workpiece alongthe discretized points. With the developed simulation software, the effectof the cutting conditions on the surface roughness is systematicallyanalyzied for felical milling. With the result of dynamic modeling for helical milling operation, ahigh efficient helical milling oriented dynamic simulation software isdeveloped on the platform of Matlab, with which the dynamic cuttingforce, chatter stability and the surface topography of helical milling canbe predicted. The software can provide theorectical guidance forengineering applications.