Muffler for an exhaust system

Abstract

A muffler for an exhaust system has a muffler housing with an inlet chamber fluidically connected an outlet chamber. The inlet chamber has an inlet pipe for supplying an exhaust gas stream into the inlet chamber, and the outlet chamber has an outlet pipe for discharging the exhaust gas stream from the outlet chamber, wherein the inlet pipe and the outlet pipe each have a first pipe portion and a second pipe portion. The inlet pipe and the outlet pipe in the respective first pipe portions are circumferentially impermeable to the exhaust gas stream and are circumferentially porous in the respective second pipe portions. The first pipe portions each have a predetermined length, such that a λ/4 resonator is formed between the respective first pipe portions and walls of the muffler housing associated with the respective first pipe portions.

1 . A muffler for an exhaust system, comprising:
 a muffler housing having an inlet chamber fluidically connected to an outlet chamber;   wherein the inlet chamber has an inlet pipe to supply an exhaust gas stream into the inlet chamber, and the outlet chamber has an outlet pipe to discharge the exhaust gas stream from the outlet chamber;   wherein the inlet pipe and the outlet pipe each have a first pipe portion a second pipe portion;   wherein the inlet pipe and the outlet pipe are impermeable to the exhaust gas stream in respective first pipe portions and are porous in respective second pipe portions; and   wherein the first pipe portions each have a predetermined length such that a λ/4 resonator is formed between the respective first pipe portion and an inner wall of the muffler housing associated with the respective first pipe portion.   
     
     
         2 . The muffler according to  claim 1 , wherein a ratio of a porosity in the second pipe portion of the inlet pipe is three to six times a porosity in the second pipe portion of the outlet pipe. 
     
     
         3 . The muffler of  claim 1 , wherein a ratio of a length of the second pipe portion of the inlet pipe to a length of the second pipe portion of the outlet pipe is in a range of 1 to 2. 
     
     
         4 . The muffler according to  claim 1 , wherein the inlet pipe and/or the outlet pipe have an axial end associated with the inlet chamber or the outlet chamber, which axial end is at least partially sealed. 
     
     
         5 . The muffler according to  claim 1 , wherein an exhaust gas aftertreatment element that treats at least one pollutant contained in the exhaust gas stream is arranged between the inlet chamber and the outlet chamber. 
     
     
         6 . The muffler according to  claim 5 , wherein the inlet pipe is a mixing pipe that mixes the exhaust gas stream with a treatment chemical. 
     
     
         7 . The muffler according to  claim 1 , wherein the inlet chamber and/or the outlet chamber have multiple partial chambers which are delimited from one another by a partition wall through which the exhaust gas stream can flow. 
     
     
         8 . The muffler according to  claim 7 , wherein the partition wall has one or more connecting pipes which fluidically connect the partial chambers to one another. 
     
     
         9 . The muffler according  claim 4 , wherein the axial end of the outlet pipe associated with the outlet chamber is tulip-shaped. 
     
     
         10 . The muffler according to  claim 1 , wherein at least one inner wall of the muffler housing is lined at least partially with a sound-absorbing material.