Abstract
By using a CNC lathe having a tool (milling) spindle, machining of a shaft which has a flat surface or a straight groove on the peripheral surface can be performed with one machine tool. However, when milling a workpiece having a small flexural rigidity, deflections and vibrations of the workpiece caused by the cutting force deteriorate the machining accuracy and surface roughness at the grooved portion. In this report, in order to analyze the behavior of workpiece deflection and the mechanism of machined surface generation when slot milling is performed on a shaft using a ball end mill, cutting forces are predicted by applying a cutting model and an energy method proposed in previous papers. The results obtained for the milling process when the tool was fed perpendicular to the center line of a shaft are shown. The variation of geometrical quantities such as the tool-workpiece contact region, distribution of the undeformed chip thickness along the cutting edge, and the area of cutting cross-section and cutting forces relative to the tool location on the workpiece, are identified.
