Workpiece Behavior in the Milling Process of a Shaft : Influence of Cutting Forces and Workpiece Behavior on Tool Attitudes

摘要

The development of a CNC lathe having a milling spindle significantly improved the productivity of circular shafts with a straight groove and/or a plane surface on an outside surface of a workpiece. However, in the case of milling of shafts with a large length and a small diameter, workpiece deflection induced by cutting forces causes deterioration of surface quality and chatter vibration. This investigation deals with an analysis of workpiece behavior and optimization of the machining conditions for ball-end milling a shaft with a small flexural rigidity in the direction of perpendicular to the shaft axis. In this report, cutting forces during milling for various tool attitudes are calculated by using the cutting model and an energy method. Then, the workpiece deflection is analyzed on the basis of calculated results of cutting forces, and the trajectory of workpiece axis during abovementioned milling process is discussed. As the results, it is clarified that tool attitudes in which deflection and machining error of the shaft can be small.