Tire for vehicle wheels and respective tread with self-cleaning function

A tire for vehicle wheels, consisting of an internally hollow and substantially toroidal-shaped structure which extends around an axis of rotation, said structure comprising:

• a pair of axially opposite end flaps with circumferential extension, which are arranged to engage tightly with a rim of a vehicle to allow the tire to be fitted on said rim;
• a circumferential belt structure, which is externally provided with a tread portion and is internally provided with an internal base wall of the tire, wherein a circumferential centerline, perpendicular to said axis of rotation, is placed at the center of said tread portion;
• and
• a pair of opposite sidewalls with circumferential extension along a radial surface, wherein each sidewall extends between a respective end flap and said belt structure,
• wherein said tread portion comprises a plurality of lugs and a plurality of grooves, wherein each groove is interposed between contiguous pairs of lugs and has a circumferential surface, and wherein each groove is placed at a distance from said axis of rotation which is less than the distance of each lug from said axis of rotation,
• wherein each lug comprises:
• at least one upper circumferential surface, which has a predefined curvature;
• at least one radial front surface, which is placed on the front side of a respective lug according to a direction of rotation of the tire;
• at least one radial rear surface, which is placed on the rear side of a respective lug according to said direction of rotation of the tire;
• and
• at least one base surface, which connects each radial front surface and each radial rear surface with a respective adjacent groove,
• wherein each groove is oriented according to a two-dimensional Cartesian reference system along a transverse direction of the groove, which is parallel to said axis of rotation, and along a longitudinal direction of the groove, which is perpendicular to said axis of rotation, and wherein one or more discontinuities are obtained on at least part of said grooves, wherein each discontinuity at least partially crosses the respective groove along a direction substantially parallel to said longitudinal direction,
• wherein each discontinuity further extends, again along a direction substantially parallel to said longitudinal direction, over at least part of the base surface, over at least part of the radial front surface and/or over at least part of the radial rear surface of each lug adjacent to the groove on which said discontinuity is obtained, wherein each discontinuity consists of a step that is provided with a flat wall lying on a radial plane, and wherein said flat wall forms a sharp edge with the surface of said groove, as well as with at least part of the base surface, with at least part of the radial front surface and/or with at least part of the radial rear surface of each lug adjacent to the groove on which said discontinuity is obtained, interrupting the surface continuity in said transverse and/or longitudinal directions both of the grooves, and of the base, front and/or rear surfaces of said lugs.