Exhaust system for an internal combustion engine of a motor vehicle as well as motor vehicle

Abstract

An exhaust system for an internal combustion engine of a motor vehicle includes an exhaust-gas line and an associated active silencing device. A sound coupling-in line of the silencing device substantially concentrically surrounds the exhaust-gas line on the outside. A first perforation is provided in an axial portion facing away from a sound line in an area of the exhaust-gas line enclosed by the sound coupling-in line. An axial portion facing the sound line is designed perforation-free at least in a portion. Furthermore, a motor vehicle with such an exhaust system is explained.

1 . An exhaust system for an internal combustion engine of a motor vehicle comprising:
 an exhaust-gas line routing exhaust gas;   an active silencing device that comprises a sound-generating unit which is acoustically coupled to the exhaust-gas line via a sound line and a sound coupling-in line connected downstream thereto, such that sound generated by the sound-generating unit can be introduced into an exhaust gas flow present inside the exhaust-gas line;   wherein the sound coupling-in line substantially concentrically surrounds the exhaust-gas line on an outside and an area of the exhaust-gas line enclosed by the sound coupling-in line has an axial portion facing the sound line and an axial portion connected downstream thereto facing away from the sound line; and   wherein a first perforation is provided in the axial portion facing away from the sound line and the axial portion facing the sound line is designed perforation-free at least in a portion.   
     
     
         2 . The exhaust system of  claim 1  wherein the first perforation runs around a whole periphery of the axial portion of the exhaust-gas line facing away from the sound line. 
     
     
         3 . The exhaust system of  claim 1  wherein openings comprised by the first perforation each have a substantially round cross section. 
     
     
         4 . The exhaust system of  claim 1  wherein, in the area enclosed by the sound coupling-in line upstream of the first perforation, the exhaust-gas line has a second perforation in a peripheral portion facing away from the sound line, wherein a peripheral portion facing the sound line is designed perforation-free. 
     
     
         5 . The exhaust system of  claim 4  wherein at least one radial rib is provided on an outer surface of the exhaust-gas line between the peripheral portion facing away from the sound line and the peripheral portion facing the sound line. 
     
     
         6 . The exhaust system of  claim 4  wherein at least one radial rib is provided on an inner surface of the sound coupling-in line between the peripheral portion facing away from the sound line and the peripheral portion facing the sound line. 
     
     
         7 . The exhaust system of  claim 5  wherein the at least one radial rib comprises a plurality of ribs with one radial rib being provided in each of two border areas between the peripheral portion facing away from the sound line and the peripheral portion facing the sound line. 
     
     
         8 . The exhaust system of  claim 5  wherein the at least one radial rib is shorter in an axial direction of the exhaust-gas line than the sound coupling-in line. 
     
     
         9 . The exhaust system of  claim 4  wherein openings comprised by the second perforation each have a substantially rectangular cross section. 
     
     
         10 . The exhaust system of  claim 5  wherein a radial outer end of the at least one radial rib or radial ribs provided on the outer surface of the exhaust-gas line is or are at a radial distance from the sound coupling-in line, wherein each radial rib radiating from the exhaust-gas line is complemented by a radial rib, pointing radially inwards radiating from the sound coupling-in line, which is at only a small peripheral distance from an associated radial rib radiating from the exhaust-gas line or touches the periphery of same, and the radial inside end of which is at a radial distance from the exhaust-gas line. 
     
     
         11 . The exhaust system of  claim 1  wherein, in an area upstream of the sound coupling-in line, the exhaust-gas line has an axial bend or an axial kink. 
     
     
         12 . The exhaust system of  claim 11  wherein, in the area enclosed by the sound coupling-in line upstream of the first perforation, the exhaust-gas line has a second perforation in a peripheral portion facing away from the sound line, wherein a peripheral portion facing the sound line is designed perforation-free, and wherein the second perforation is arranged downstream of a convex area of the axial bend or of the axial kink. 
     
     
         13 . The exhaust system of  claim 1  wherein a center axis of the sound line runs substantially along a radial direction of the sound coupling-in line. 
     
     
         14 . The exhaust system of  claim 5  wherein the at least one radial rib extends up to the sound coupling-in line. 
     
     
         15 . The exhaust system of  claim 6  wherein the at least one radial rib extends up to the sound coupling-in line. 
     
     
         16 . The exhaust system of  claim 9  wherein a short side of the rectangle is oriented in a peripheral direction and a long side of the rectangle is oriented in an axial direction of the exhaust-gas line. 
     
     
         17 . The exhaust system of  claim 11  wherein the axial bend or axial kink is substantially 90°. 
     
     
         18 . A motor vehicle with an exhaust system of  claim 1 .