Sound-absorbing shielding element

Abstract

A sound-absorbing shielding element, in particular for fitting into a motor vehicle, comprises a layered construction which has a support plate, an acoustically effective porous absorber layer and at least one acoustically effective first microperforated sheet which is arranged on a first side of the absorber layer. An acoustically effective second microperforated sheet is arranged on the first side of the absorber layer.

1 . A sound-absorbing shielding element, comprising
 a layered construction having:
 a support plate, 
 an acoustically effective porous absorber layer having a first side and a second side opposite the first side, 
 an acoustically effective first microperforated sheet arranged on the first side of the absorber layer, 
 an acoustically effective second microperforated sheet arranged on the first side of the absorber layer. 
   
     
     
         2 . The shielding element of  claim 1 , wherein the first microperforated sheet and the second microperforated sheet are immediately adjacent to one another. 
     
     
         3 . The shielding element of  claim 2 , wherein the second microperforated sheet is immediately adjacent to the absorber layer. 
     
     
         4 . The shielding element of  claim 1 , wherein the layered construction further has a third microperforated sheet arranged on the second side of the absorber layer. 
     
     
         5 . The shielding element of  claim 1 , wherein the first side of the absorber layer faces away from the support plate. 
     
     
         6 . The shielding element of  claim 1 , wherein the first microperforated sheet is a heat sealing sheet. 
     
     
         7 . The shielding element of  claim 4 , comprising a sequence of layers in the following order: the support plate, the third microperforated sheet, the absorber layer, the second microperforated sheet and the first microperforated sheet. 
     
     
         8 . The shielding element of  claim 7 , wherein the first microperforated sheet is a heat sealing sheet. 
     
     
         9 . The shielding element of  claim 1 , wherein the first side of the absorber layer faces the support plate. 
     
     
         10 . The shielding element of  claim 1 , wherein the first microperforated sheet has a thickness within a range of approximately 20 μm to approximately 150 μm. 
     
     
         11 . The shielding element of  claim 1 , wherein the first microperforated sheet has a thickness within a range of approximately 40 μm to approximately 60 μm. 
     
     
         12 . The shielding element of  claim 1 , wherein the second microperforated sheet has a thickness within a range of approximately 20 μm to approximately 150 μm. 
     
     
         13 . The shielding element of  claim 1 , wherein the second microperforated sheet has a thickness within a range of approximately 40 μm to approximately 60 μm. 
     
     
         14 . The shielding element of  claim 1 , wherein the first microperforated sheet has a perforation with holes which have an individual diameter within a range of approximately 50 μm to approximately 200 μm. 
     
     
         15 . The shielding element of  claim 1 , wherein the first microperforated sheet has a perforation with holes which have an individual diameter within a range of approximately 80 μm to approximately 100 μm. 
     
     
         16 . The shielding element of  claim 1 , wherein the second microperforated sheet has a perforation with holes which have an individual diameter within a range of approximately 50 μm to approximately 200 μm. 
     
     
         17 . The shielding element of  claim 1 , wherein the second microperforated sheet has a perforation with holes which have an individual diameter within a range of approximately 80 μm to approximately 100 μm. 
     
     
         18 . The shielding element of  claim 1 , wherein the first microperforated sheet has a perforation with holes which have a surface covering within a range of approximately 20 to approximately 80 holes per cm 2 . 
     
     
         19 . The shielding element of  claim 1 , wherein the first microperforated sheet has a perforation with holes which have a surface covering within a range of 40 to approximately 60 holes per cm 2 . 
     
     
         20 . The shielding element of  claim 1 , wherein the second microperforated sheet has a perforation with holes which have a surface covering within a range of approximately 20 to approximately 80 holes per cm 2 . 
     
     
         21 . The shielding element of  claim 1 , wherein the second microperforated sheet has a perforation with holes which have a surface covering within a range of 40 to approximately 60 holes per cm 2 . 
     
     
         22 . A sound-absorbing shielding element, comprising
 a layered construction having:
 a support plate, 
 an acoustically effective porous absorber layer, 
 an acoustically effective first microperforated sheet arranged on the first side of the absorber layer, 
 an acoustically effective second microperforated sheet arranged between the absorber layer and the first microperforated sheet, and 
 an acoustically effectice third microperforated sheet arranged between the support plate and the absorber layer. 
   
     
     
         23 . The shielding element of  claim 22 , wherein the second microperforated sheet is immediately adjacent to the first microperforated sheet and to the absorber layer. 
     
     
         24 . The shielding element of  claim 23 , wherein the first microperforated sheet is a heat sealing sheet made of aluminium.