OIL RING FOR INTERNAL COMBUSTION ENGINE

摘要

Disclosed is a high-quality oil ring for an internal combustion engine, with which oil consumption can be stably reduced over an extended period of time, and upper and lower rails can be shaped with low costs and a high degree of precision. An oil ring for an internal combustion engine is employed, in which, in a vertical cross-section shape in the sliding direction of a first rail and a second rail that constitute an oil ring main body, at least one of the rails forms a concave step in a corner part of a sliding surface provided in an outer circumferential sliding protrusion that comes into contact in a sliding manner with a wall surface inside a cylinder of said rail, and a wall surface of the concave step comprises an arc-shaped surface having a radius of curvature of 0.02 mm to 0.08 mm.