Sound absorber comprising two parts delimiting a hollow space

Abstract

The invention relates to a sound absorber, especially for motor vehicles, comprising a molded part ( 1 ) made of thermoplastic material and at least one second part ( 2 ) which with the molded part ( 1 ) defines a hollow space ( 7 ). In order to achieve that such a sound absorber has good media resistance and a high heat resistance with the same or improved acoustic efficiency, it is proposed that a plurality of pin-shaped or spike-shaped spacers ( 4 ), which project into the hollow space ( 7 ) and are directed towards the second part ( 2 ) are formed on the molded part ( 1 ), wherein the molded part ( 1 ) is provided with a plurality of recesses ( 6 ) on the outside which each extend into a spacer ( 4 ).

1 . A sound absorber comprising a molded part ( 1 ) made of thermoplastic material and at least one second part ( 2 ,  9 ) which with the molded part ( 1 ) delimits a hollow space ( 7 ), wherein a plurality of pin-shaped or spike-shaped spacers ( 4 ), which project into the hollow space ( 7 ) and are directed towards the second part ( 2 ) are formed on the molded part ( 1 ), wherein the molded part ( 1 ) has a plurality of recesses ( 6 ) on the outside which each extend into a spacer ( 4 ).  
   
   
       2 . The sound absorber according to  claim 1 , wherein the outside ( 5 ) of the molded part ( 1 ) having the recesses ( 6 ) lies exposed.  
   
   
       3 . The sound absorber according to  claim 1 , wherein the recesses ( 6 ) are closed towards the hollow space ( 7 ).  
   
   
       4 . The sound absorber according to  claim 1 , wherein the molded part ( 1 ) is produced by deep drawing of a thermoplastic plastic film.  
   
   
       5 . The sound absorber according to  claim 1 , wherein the molded part ( 1 ) is made of PET film.  
   
   
       6 . The sound absorber according to  claim 1 , wherein the second part ( 2 ,  9 ) is formed of a heavy layer, a non-woven fabric layer, a foam layer and/or an acoustically effective textile layer.  
   
   
       7 . The sound absorber according to  claim 1 , wherein the average outside diameter of the respective spacer ( 4 ) is smaller than its average length.  
   
   
       8 . The sound absorber according to  claim 1 , wherein the molded part ( 1 ) is formed as cassette-shaped or dish-shaped.  
   
   
       9 . The sound absorber according to  claim 1 , wherein the depth of the molded part ( 1 ) is greater than the respective length of the spacers ( 4 ).  
   
   
       10 . The sound absorber according to  claim 1 , wherein the molded part ( 1 ) has a circumferential fixing flange ( 3 ).  
   
   
       11 . The sound absorber according to  claim 1 , wherein the spacers ( 4 ) and the recesses ( 6 ) are formed as non-uniformly distributed over the surface of the molded part ( 1 ).  
   
   
       12 . The sound absorber according to  claim 1 , wherein the recesses ( 6 ) have different inside diameters.  
   
   
       13 . The sound absorber according to  claim 1 , wherein the recesses ( 6 ) have different depths and/or the spacers ( 4 ) have different lengths.  
   
   
       14 . The sound absorber according to  claim 1 , wherein areas with spacers ( 4 ) of different length are formed on the molded part ( 1 ), wherein the spacers ( 4 ) in the different areas each have the same length.  
   
   
       15 . The sound absorber according to  claim 1 , wherein the hollow space ( 7 ) in the area between the spacers ( 4 ) is partially provided with acoustically effective material.