Exhaust System Of An Internal Combustion Engine

An exhaust system (1) for an internal combustion engine and comprising:

• at least one first high acoustic attenuation path (P1) having a first inlet opening (2);
• at least one second low acoustic attenuation path (P2) having a second inlet opening (3);
• and
• at least one control valve (4), which is arranged at the second inlet opening (3) of the second path (P2) for controlling the flow of the exhaust gases along the second path (P2),
• the exhaust system (1) is characterized in that the control valve (4) comprises:
• a baffle (12) which forms a wall of an exhaust gas passage pipe when is in a closing position of the second inlet opening (3);
• a shaft (13) which is mounted to rotate about a rotation axis (14) and supports the baffle (12) in order to rotate the baffle (12) itself between the closing position of the second inlet opening (3) and an opening position of the second inlet opening (3);
• and
• an elastic body (15), which is mechanically coupled to the shaft (13) to push the baffle (12) towards the closing position with an elastic force calibrated according to the area of the baffle (12) struck by the exhaust gases and to the working pressure of the exhaust gases, so that when the exhaust gas pressure exceeds a predetermined threshold value, the pneumatically originated force generated by the pressure of the exhaust gases on the baffle (12) is higher than the elastic force generated by the elastic body (15) and the baffle (12) moves to the opening position.