Patent ID: 8256597

Claim:
A friction clutch configured to be engaged/disengaged by an operation of a clutch operator, comprising: a driving-side rotator having a first plate; a driven-side rotator having a second plate facing the first plate; a pressure plate movable in a predetermined direction to bring the first plate and the second plate into contact with each other when the clutch operator is operated; a cam face formed on a side of the pressure plate opposite to the first plate side and the second plate side; an opposing member having an opposing face that faces the cam face; a centrifugal weight arranged between the cam face and the opposing face; and an urging member for urging the centrifugal weight toward the cam face side via the opposing member, wherein an angular velocity ω represented by the following equation increases when a parameter R increases and the angular velocity ω decreases when the parameter R decreases, ω 2 =(1/m)·[F(tan α+tan β)/R], where the mass of the centrifugal weight is m, the revolution radius that is the distance from the rotation center of the centrifugal weight to the center of gravity of the centrifugal weight is R, the angle formed by a radial line and a tangent line of a point of the cam face being in contact with the centrifugal weight in the vertical cross section containing the rotation center is α, the angle formed by the radial line and a tangent line of a point in the opposing face being in contact with the centrifugal weight in the vertical cross section containing the rotation center is β, and the urging force of the urging member that urges the opposing member in the predetermined direction is F.