Muffler for internal combustion motor vehicles

Abstract

A muffler has a housing provided with irregularly arranged ridges computed by an FEM computer program. The ridges are regularly bounded, simple geometric figures, such as circles, circular rings, circular ring segments, rectangles or trapezoids. The size and position of the ridges are selected in such a way that the lowest resonance frequency of the muffler housing is greater than or equal to the dominant excitation frequency of the internal combustion engine over its entire rpm range.

1 . A muffler for an internal combustion motor vehicle, comprising: 
 a muffler housing;    an intake pipe attached to the housing; and    an exhaust pipe attached to the housing, the muffler housing having irregularly arranged ridges computed by an FEM computer program, the ridges being regularly bounded, simple geometric figures, the muffler housing further having a lowest resonance frequency at least equal to a dominant excitation frequency of the internal combustion engine over the engine's entire rpm range.    
   
   
       2 . The muffler in accordance with  claim 1 , and further comprising at least one of the group consisting of internal walls and internal pipes.  
   
   
       3 . The muffler in accordance with  claim 1 , wherein the ridges are uniformly elevated.  
   
   
       4 . The muffler in accordance with  claim 1 , wherein the geometric figures of ridges are formed as at least one of the group consisting of circles, circular segments, circular rings, and circular ring segments.  
   
   
       5 . The muffler in accordance with  claim 1 , wherein the ridges are formed as polygons.  
   
   
       6 . The muffler in accordance with  claim 5 , wherein the ridges are formed as rectangles.  
   
   
       7 . The muffler in accordance with  claim 1 , wherein the ridges are formed as characters of any desired character sets.  
   
   
       8 . The muffler in accordance with  claim 1 , wherein at least two of the ridges penetrate one another.  
   
   
       9 . The muffler in accordance with  claim 1 , wherein at least two of the ridges are arranged in series.  
   
   
       10 . The muffler in accordance with  claim 1 , wherein the ridges are at least partially elevated.  
   
   
       11 . The muffler in accordance with  claim 1 , wherein the muffler housing has a single layer wall.  
   
   
       12 . The muffler in accordance with  claim 1 , wherein the muffler housing has a wall with a thickness of less than 1 mm.  
   
   
       13 . The muffler in accordance with  claim 1 , wherein the muffler housing has a wall consisting of two shells.  
   
   
       14 . The muffler in accordance with  claim 1 , wherein the muffler housing has a wall wound from one piece of sheet metal.  
   
   
       15 . The muffler in accordance with  claim 1 , wherein parallel rectangular ridges are provided as mounts for a partition.