Device for imparting a whirling motion on the flow of air for supplying a turbo-supercharged internal-combustion engine

A device for imparting a whirling motion on the flow of air for supplying a turbo-supercharged internal-combustion engine, of the type with exhaust-gas recirculation (EGR) upstream of the supercharger, said device comprising an elbow-shaped portion of duct for the supply air, with an upstream branch and a downstream branch forming an angle between them;

• and means for partializing the section of passage of the flow of air through said upstream branch, which is able to limit the section of passage of the fluid to an area that constitutes only a fraction of the total section of duct, adjacent to a wall of the duct, in such a way that the downstream branch of the aforesaid elbow portion is reached by a localized tangential flow adjacent to a wall of the duct that is thus forced, as a result of the change in direction from the upstream branch to the downstream branch, to traverse said downstream branch according to a substantially helical path, wherein said partializing means comprise a throttle valve with a vane mounted oscillating about an axis in the upstream branch of the aforesaid elbow portion of duct, and wherein said upstream branch has a squared or rectangular cross section, in that said axis of oscillation of the vane is orthogonal to two opposite walls of the aforesaid upstream branch of the duct, and in that said axis of oscillation is set at a distance from the central axis of said upstream branch in such a way that, when one end of the vane is in contact with a wall of the duct, the opposite end is set at a distance from the facing wall of the duct so as to leave free the aforesaid area of passage.