Cogged V-belt

A cogged V-belt, comprising:

• a cog portion in which a plurality of cog ridges and cog valleys are alternately provided along a belt longitudinal direction, provided at least on a belt inner peripheral side, and
• having a belt thickness H of 19 to 36 mm and a cog height H1 of 14 to 19 mm,
• wherein the cog valley has a cross-sectional shape in a cross section in the belt longitudinal direction, comprising:
• a bottom portion formed by combining a plurality of continuous arcs;
• and
• side walls of the cog valley inclined with respect to a belt thickness direction,
• wherein the plurality of arcs includes:
• a first arc that passes through the deepest portion of the cog valley, has a diameter larger than a virtual circle tangent to three points of the deepest portion and the side walls on both sides of the cog valley, and has a curvature radius R1 of 7.5 to 9.5 mm;
• and
• a second arc that connects the first arc and an extension line of a side wall in a curved shape so as to be tangent to the first arc and the extension line of the side wall, and has a curvature radius R2 of 1.5 to 2.8 mm.