Abstract: An exhaust system for an internal combustion engine; the exhaust system comprises: at least one an exhaust duct, which originates from the internal combustion engine; at least one exhaust gas treatment device, which is arranged along the exhaust duct; and a silencing device, which is arranged along the exhaust duct downstream of the exhaust gas treatment device. The silencing device comprises a silencing valve, which intercepts the exhaust duct and is movable between a completely open position and a completely closed position. In the completely closed position, the silencing valve has a first free section for the passage of the exhaust gases having a first area other than zero, so that the exhaust gases can flow through the silencing valve even when the silencing valve is in the completely closed position.

Abstract: Road vehicle having: a passenger compartment; an internal combustion engine provided with at least one exhaust duct, which originates from an exhaust manifold and has at least one exhaust gas treatment device; and an exhaust noise transmission device provided with a transmission duct, which originates from the exhaust duct, and with a symposer device, which is arranged inside the transmission duct, is pneumatically insulating and is acoustically permeable; an inlet of the transmission duct being arranged between the exhaust manifold and the exhaust gas treatment device, hence upstream of the exhaust gas treatment device.

Abstract: An exhaust system for an internal combustion engine; the exhaust system comprises: at least one an exhaust duct, which originates from the internal combustion engine; at least one exhaust gas treatment device, which is arranged along the exhaust duct; and a silencing device, which is arranged along the exhaust duct downstream of the exhaust gas treatment device. The silencing device comprises a silencing valve, which intercepts the exhaust duct and is movable between a completely open position and a completely closed position. In the completely closed position, the silencing valve has a first free section for the passage of the exhaust gases having a first area other than zero, so that the exhaust gases can flow through the silencing valve even when the silencing valve is in the completely closed position.

Abstract: An internal combustion engine comprising: a plurality of cylinders; at least one intake manifold, which receives fresh air from the outside; a plurality of intake channels, each connecting a cylinder to the intake manifold; and an intake sound amplification device, which is provided with an amplification pipe, an insulating element sealing the amplification pipe in a tight manner, a plurality of amplification channels, each originating from a corresponding intake channel, and an amplification manifold, which, on one side, is connected to all amplification channels and, on the other side, is connected to the amplification pipe.

Abstract: Road vehicle having: a passenger compartment; an internal combustion engine provided with at least one exhaust duct, which originates from an exhaust manifold and has at least one exhaust gas treatment device; and an exhaust noise transmission device provided with a transmission duct, which originates from the exhaust duct, and with a symposer device, which is arranged inside the transmission duct, is pneumatically insulating and is acoustically permeable; an inlet of the transmission duct being arranged between the exhaust manifold and the exhaust gas treatment device, hence upstream of the exhaust gas treatment device.

Abstract: A pneumatically insulating and acoustically permeable symposer device for a noise transmission duct of an internal combustion engine; the insulating symposer device comprises: an outer casing, which has an inlet opening and an outlet opening; an actuator plate, which is mounted so as to slide longitudinally; an emitter plate, which is mounted so as to slide longitudinally and is rigidly constrained to the actuator plate; an insulating element, which is arranged between the actuator plate and the emitter plate; and a communication duct with an adjusted cross section, which establishes a limited pneumatic communication between an inlet opening arranged upstream of the actuator plate and an intermediate chamber arranged downstream of the actuator plate, so that the inlet chamber and the intermediate chamber have the same static pressure but do not have the same dynamic pressure.

Abstract: An internal combustion engine comprising: a plurality of cylinders; at least one intake manifold, which receives fresh air from the outside; a plurality of intake channels, each connecting a cylinder to the intake manifold; and an intake sound amplification device, which is provided with an amplification pipe, an insulating element sealing the amplification pipe in a tight manner, a plurality of amplification channels, each originating from a corresponding intake channel, and an amplification manifold, which, on one side, is connected to all amplification channels and, on the other side, is connected to the amplification pipe.