Piston ring for a piston of an internal combustion engine, and a method for producing same

Method for the production of a piston ring (30, 130, 230) for a piston (10) of an internal combustion engine, having a ring back (31), an upper ring side (32), a lower ring side (33), and a working surface (42), comprising the following method steps:

• a) making available a ring blank (30′) having a ring back (31′), an upper ring side (32′), a lower ring side (33′), and an outer mantle surface (34′),
• (b) forming an asymmetrically barrel-shaped contour (35) along the outer mantle surface (34′) and forming a projection (36) in the outer mantle surface (34′), in the region of the lower ring side (33′), which projection extends radially outward,
• (c) forming a bevel (37), a convex-shaped radius (37′) or a concave-shaped radius (37″) having an axial height of B=0.10-0.30 mm in the region of the outer mantle surface (34′) between the asymmetrically barrel-shaped contour (35) and the upper ring side (32′),
• (d) coating the outer mantle surface (34′) with a coating material,
• (e) removing the material of the projection (36), thereby exposing the material of the ring blank (30′) in the form of a circumferential surface (41) that makes a transition into the coating (39), and forming an oil stripping edge (40) between the circumferential surface (41) and the lower ring side (33′),
• (f) subsequent machining and/or finish-machining of the coated ring blank (30′) to produce a finished piston ring (30, 130, 230).