Convex Cutting Insert Edges for Lower Exit-Burr Machining

The patent applies curvature to the cutting edge by introducing a convex arc shape with a specific radius of curvature (R1) between the main cutting edge and the corner cutting edge. This curved transition replaces the conventional straight edge geometry, which redistributes the cutting forces and prevents the material from being pushed upward to form burrs. The curved cutting edge smoothly guides the chip flow and ensures complete material separation at the exit point.

The patent applies local quality by introducing curvature only at specific critical locations where burr formation occurs (the transition zones between main and corner cutting edges), while keeping other portions of the cutting insert geometry simple and conventional. The convex arc with radius R1 is localized to the cutting edge profile, whereas the overall insert shape, mounting features, and body geometry remain standard and easy to manufacture.

The patent specifies a particular radius of curvature (R1) for the convex arc, transforming the cutting edge geometry from a qualitative concept to a quantitatively defined parameter. This parameterization allows the curved geometry to be precisely controlled during manufacturing using standard CNC machining capabilities. The specific radius value optimizes the balance between burr reduction effectiveness and manufacturability, ensuring that the curvature is pronounced enough to prevent burrs but gentle enough to be accurately produced.