Muffler

Abstract

The present invention relates to a muffler for an exhaust system of an internal combustion engine. To be able to suppress at least two different frequencies or frequency ranges in a comparatively inexpensive design, the muffler has a housing in which at least two resonator chambers are separated from one another. At least two branch pipes branch off from an exhaust-carrying pipe in a branch section. These branch pipes open into different resonator chambers. The respective resonator chamber forms a Helmholtz resonator with the respective branch pipe, each resonator differing from the others in their different resonance frequencies.

1 . A muffler for an exhaust of an internal combustion engine, said muffler comprising: 
 a housing;    at least first and second resonator chambers in said housing;    an exhaust-carrying pipe having a branch section; and    at least first and second branch pipes branching off said branch section of said exhaust-carrying pipe, each of said first and second branch pipes opening respectively into one of said first and second resonator chambers in said housing;    wherein said first resonator chamber forms a first Helmholtz resonator with said first branch pipe and said second resonator chamber forms a second Helmholtz resonator with said second branch pipe, and    wherein each of said first and second Helmholtz resonators have different resonance frequencies.    
   
   
       2 . The muffler according to  claim 1 , wherein said exhaust-carrying pipe passes through said housing.  
   
   
       3 . The muffler according to  claim 1 , wherein said pipe passes through at least one of said first and second resonator chambers.  
   
   
       4 . The muffler according to  claim 1 , wherein at least one of said first and second branch pipes passes through at least one of said first and second resonator chambers.  
   
   
       5 . The muffler according to  claim 1 , wherein at least one of said first and second branch pipes are arranged inside said housing.  
   
   
       6 . The muffler according to  claim 1 , wherein at least one of said first and second branch pipes branch off radially from said exhaust-carrying pipe.  
   
   
       7 . The muffler according to  claim 1 , wherein said first and second branch pipes differ from one another with regard to at least one of length and cross-section.  
   
   
       8 . The muffler according to  claim 1 , wherein said first and second branch pipes branch off from said exhaust-carrying pipe essentially in a star pattern in said branch section.  
   
   
       9 . The muffler according to  claim 1 , wherein at least one of said first and second branch pipes passes through a partition separating said first and second resonator chambers from one another.  
   
   
       10 . The muffler according to  claim 1 , wherein at least one of said first and second branch pipes has a section extending parallel to said exhaust-carrying pipe.  
   
   
       11 . The muffler according to  claim 1 , wherein said first and second resonator chambers are arranged axially one after the other in said housing with respect to the longitudinal direction of said housing.  
   
   
       12 . The muffler according to  claim 1 , wherein said first and second resonator chambers differ from one another with regard to their volumes.  
   
   
       13 . The muffler according to  claim 1 , wherein said first and second resonator chambers have the same cross sections in the longitudinal direction of said housing.  
   
   
       14 . The muffler according to  claim 1 , wherein said first and second resonator chambers have different axial extents with regard to the longitudinal direction of said housing.  
   
   
       15 . The muffler according to  claim 1 , wherein said branch section is arranged inside said housing.  
   
   
       16 . The muffler according to  claim 1 , wherein said branch section is arranged inside one of said first and second resonator chambers.  
   
   
       17 . The muffler according to  claim 1 , wherein the longitudinal extent of said branch section in the longitudinal direction of said exhaust-carrying pipe corresponds to the diameter of one of said first and second branch pipes measured in the longitudinal direction of the pipe.  
   
   
       18 . The muffler according to  claim 1 , wherein each of said first and second Helmholtz resonators comprises only one of said first and second resonator chambers and only one of said first and second branch pipes.  
   
   
       19 . The muffler according to  claim 1 , wherein exactly one of said first and second branch pipes is provided for each of said first and second resonator chambers.  
   
   
       20 . The muffler according to  claim 1 , further comprising an absorption chamber arranged in said housing, said absorption chamber communicating with said exhaust-carrying pipe.  
   
   
       21 . The muffler according to  claim 20 , wherein said absorption chamber completely surrounds a longitudinal section of said exhaust-carrying pipe in the circumferential direction.  
   
   
       22 . The muffler according to  claim 20 , wherein said absorption chamber comprises a sleeve surrounding a longitudinal section of said exhaust-carrying pipe, said sleeve being axially parallel to said exhaust-carrying pipe.  
   
   
       23 . The muffler according to  claim 20 , wherein said absorption chamber and/or said sleeve extends in at least one of said first and second resonator chambers or through at least one of said first and second resonator chambers.  
   
   
       24 . The muffler according to  claim 20 , wherein said absorption chamber and/or said sleeve is sealed in an airtight manner with respect to said first and second resonator chambers.  
   
   
       25 . The muffler according to  claim 20 , wherein at least one of said absorption chamber and said sleeve extends through a partition separating said first and second resonator chambers from one another.  
   
   
       26 . The muffler according to  claim 20 , wherein said exhaust-carrying pipe has a perforation in an area communicating with said absorption chamber.  
   
   
       27 . The muffler according to  claim 20 , wherein said absorption chamber is filled with an absorption material.  
   
   
       28 . An exhaust system for an internal combustion engine, comprising at least one muffler, said muffler comprising: 
 a housing;    at least two resonator chambers, separated from one another, in said housing;    an exhaust-carrying pipe having a branch section; and    at least first and second branch pipes branching off said branch section of said exhaust-carrying pipe, each of said first and second branch pipes opening into different one of said first and second resonator chambers,    wherein said first resonator chamber forms a first Helmholtz resonator with said first branch pipe and said second resonator chamber forms a second Helmholtz resonator with said second branch pipe, and    wherein each of said first and second Helmholtz resonators have different resonance frequencies.