Patent ID: 6925986

Claim:
A servo-assisted butterfly valve ( 1 ) for an internal combustion engine comprising: a valve body ( 2 ), a valve seat ( 4 ) defined in the valve body ( 2 ), a butterfly body ( 5 ) adapted to engage the valve seat ( 4 ), a shaft ( 6 ) on which the butterfly body ( 5 ) is keyed and housed by the valve body ( 2 ), an electric actuator ( 3 ) coupled to the shaft ( 6 ) in order to rotate the butterfly body ( 5 ) between an open and a closed position of the valve seat ( 4 ), an elastic body ( 23 ) which is adapted to exert a torque on the shaft ( 6 ) which tends to rotate the butterfly body ( 5 ) towards a limp-home position and an abutment body ( 29 ) which forms an abutment surface for an abutment member ( 28 ) of the elastic body ( 23 ) in order to stop, in the desired limp-home position, the rotation of the butterfly body ( 5 ) caused by the elastic body ( 23 ) in the absence of action by the electric actuator ( 3 ); wherein the abutment body ( 29 ) comprises an eccentric member ( 35 ) which is adapted to rotate with respect to the valve body ( 2 ) with a predetermined eccentricity about an adjustment axis ( 31 ); wherein the elastic body ( 23 ) comprises a first spring ( 24 ) provided with a first projection ( 25 ) coupled mechanically to the shaft ( 6 ) and a second spring ( 26 ) provided with a projection ( 27 ) coupled mechanically to the valve body ( 2 ), the first and second springs ( 24 , 26 ) being connected together by a curved member ( 28 ) which forms the abutment member ( 28 ).