Double-Wall Structure

Abstract

A double-wall structure ( 1 ), comprising plate-like bodies ( 2 ) and ( 3 ) disposed oppositely to each other to form an inner room ( 4 ) therebetween, peripheral members ( 5 ) disposed so that the inner room ( 4 ) can be completely or approximately closed, and perforated plates ( 13 ) with a large number of holes ( 8 ) disposed between the plate-like bodies facing each other. The double-wall structure is characterized in that an air layer (A) is interposed between the perforated plates and the peripheral members. Thus, since the double-wall structure can suppress the deterioration of a sound reduction index for sound with specific frequencies, it can stably develop sound insulation performance for sound with the various frequencies.

1 . A double-wall structure comprising:
 a pair of plate-like members disposed in opposition to each other to form an air space therebetween;   a circumferential member disposed in such a manner that the said air space is closed completely or substantially; and   a perforated plate disposed between the said opposed plate-like members in a direction intersecting the plate-like members, the said perforated plate having a multitude of holes,   wherein a layer of air is interposed between the said perforated plate and the said circumferential member.   
   
   
       2 . A double-wall structure according to  claim 1 , wherein the said perforated plate is disposed at an incline to the said circumferential member. 
   
   
       3 . A double-wall structure according to  claim 1 , wherein the said perforated plate is provided in a plural number and a layer of air is interposed between the plural perforated plates. 
   
   
       4 . A double-wall structure according to  claim 2 , wherein the said perforated plate is provided in a plural number and a layer of air is interposed between the plural perforated plates. 
   
   
       5 . A double-wall structure according to  claim 2 , wherein the said perforated plate is disposed so that an end thereof is in contact with the said circumferential member, and in the vicinity of the contacted end a hole is formed in the said circumferential member. 
   
   
       6 . A double-wall structure according to  claim 1 , further comprising a partition member for partitioning the space between the said perforated plate and the said circumferential member. 
   
   
       7 . A double-wall structure according to  claim 6 , wherein a multitude of holes are formed in the said partition member. 
   
   
       8 . A double-wall structure according to  claim 6 , wherein at least one of a thickness of the said perforated plate, a thickness of the said partition member, a diameter or a ratio of the said holes formed in the said perforated plate or the said partition member, and a thickness of the layer of air interposed between the said perforated plate and the said circumferential member, is made different between the spaces partitioned by the said partition member. 
   
   
       9 . A double-wall structure according to  claim 1 , wherein a vibration damping/isolating member is disposed between the said perforated plate and at least one of the said opposed plate-like members. 
   
   
       10 . A double-wall structure according to any of  claim 1 , wherein a foil- or film-like member comprised of a single foil or film, or superimposed foils or films is disposed in place of the said perforated plate. 
   
   
       11 . A double-wall structure according to  claim 10 , wherein a multitude of holes are formed in the said foil- or film-like member(s). 
   
   
       12 . A double-wall structure comprising:
 a pair of plate-like members disposed in opposition to each other to form an air space therebetween;   a circumferential member disposed in such a manner that the said air space is closed completely or substantially; and   a porous member disposed in the vicinity of the said circumferential member.   
   
   
       13 . A double-wall structure according to  claim 4 , wherein the said perforated plate is disposed so that an end thereof is in contact with the said circumferential member, and in the vicinity of the contacted end a hole is formed in the said circumferential member. 
   
   
       14 . A double-wall structure according to  claim 7 , wherein at least one of a thickness of the said perforated plate, a thickness of the said partition member, a diameter or a ratio of the said holes formed in the said perforated plate or the said partition member, and a thickness of the layer of air interposed between the said perforated plate and the said circumferential member, is made different between the spaces partitioned by the said partition member.