Prediction of Cutting Process with Curved-Edge End Mill (1st Report, Application of Ball End Milling Process in Energy Approach)

An approach is presented to predict the chip formation and the three components of cutting force in the machining with the curved-edge end mill, which has the tool geometries changing with the cutter height. Those geometrical parameters are defined as the functions of the cutter height. The chip formation in the milling process is modeled as a pilling up of orthogonal cuttings along the cutting edge. The orthogonal cuttings are made in the planes containing the cutting velocities and the chip flow velocities so that chip flows up to a certain direction as a rigid body. The chip flow direction can be given to minimize the cutting energy, which can be given as the sum of the shear energy on shear plane and the friction energy on rake face. The cutting force, then, can be predicted with the chip formation having the minimum cutting energy. The presented approach is applied to the prediction of cutting process in the machining with the insert-ball end mill. The predicted results are verified to be accurate enough in a variety of depth of cut. The change of the chip flow angle and that of the orthogonal cutting model during a rotation of the cutter can be shown in the presented approach.