A high efficiency approach to line contact rotatory milling based on feature surface

Point contact machining has been widely applied in surface machining recently. However, the point contact area, the contact area between the cutter and the workpiece, is small and often leads to low efficient machining. Moreover, inequable curvature of the contact point in the contact area also results in different cutting speed at every bit of the cutting blade, these two defects together may result in surface quality deterioration. To overcome these defects, a new method of line contact rotatory milling based on feature face is presented in this paper. And in this new method, peripheral edges of the cutter are in contact with the theoretical profile of a workpiece, and rotation of the principal axis seat imitates turning. By analyzing the theoretical profile of a feature workpiece, the machining contrail can be directly achieved by means of this new machining method and machine tool, which require the cutter axis always moves on the equidistant surface, a distance of cutter semidiameter from the machined surface. That is, this machining method replaces arc interpolation with direct arc feeding and the arc interpolation error can been theoretically avoided. To explain this method, the ruled feature surface widely used in surface machining is adopted and its equation is studied, a new method of line contact rotatory milling based on the ruled feature surface and the milling model is proposed. Aiming at the developable ruled feature surface such as conical surface, column and plane, twisted ruled surface, free curved surfacean and so on, the implementation form of the maching feather face and the need for motion are presented by studying their feather equations and analyzing their machining methods. It is a novel efficient NC machining approach that combines the high efficiency of line contact machining with low roughness of turning.