Sound insulation members of a railroad vehicle, and production methods of sound insulation members

Abstract

The invention provides sound insulation members having enhanced sound insulating properties without increasing the thickness of the sound insulation members. The object is achieved by a sound insulation member having disposed inside a pouch-shaped film 1 with a resin coating a flat sound absorption material 2 formed of foamed porous material or fiber material and having its inner space communicated, and filling a filler gas 3 having a sound impedance that differs from air. According to the present invention, since the present sound insulation member is filled with gas having sound impedance that differs from air, the present sound insulation member has superior sound insulating properties since it reflects sound on the sealed surface and also absorbs the sound by the sound absorption material disposed therein.

1 . A railroad vehicle having a vehicle body formed of metal and a sound insulation member disposed on a side of the vehicle body facing an inner side of the vehicle, wherein 
 the sound insulation member comprises a sealing container, a sound absorption material disposed inside the sealing container, and a gas filled inside the sealing container having a density or sound velocity different from that of atmospheric air.    
   
   
       2 . A railroad vehicle having a vehicle body formed of metal and a sound insulation member disposed on a side of the vehicle body facing an inner side of the vehicle, wherein 
 the sound insulation member comprises a pouched member formed of a metal foil, a sound absorption material covered by the pouched member, and a gas filled inside the pouched member having a density or sound velocity different from that of atmospheric air.    
   
   
       3 . The railroad vehicle according to claims  1  or  2 , wherein 
 the sound insulation member has a trapezoidal cross-sectional shape, and multiple sound insulation members are arrayed with slanted trapezoidal edges fit against one another.    
   
   
       4 . The railroad vehicle according to claims  1  or  2 , wherein 
 the sound insulation member has an uneven surface provided at least on a surface facing the inner side of the vehicle.    
   
   
       5 . The railroad vehicle according to claims  1  or  2 , wherein 
 the sound absorption material is either a foamed porous material or a fiber material having its inner space communicated.    
   
   
       6 . The railroad vehicle according to claims  1  or  2 , wherein 
 the gas contains either 90% or more helium or 90% or more carbon dioxide.    
   
   
       7 . The railroad vehicle according to claims  1  or  2 , wherein 
 the sound absorption material is flat shaped and having an uneven surface formed to one surface thereof.    
   
   
       8 . The railroad vehicle according to any one of claims  1  or  2 , wherein 
 the gas sealed inside the member has a pressure lower than atmospheric pressure.    
   
   
       9 . A sound insulation member comprising a pouched member formed of a metal foil having a resin coating, and a foamed porous material or a fiber material enclosed in the pouched member, wherein 
 a gas is filled in the pouched member and airtightly sealed therein.    
   
   
       10 . The sound insulation member according to  claim 9 , wherein 
 the foamed porous material or the fiber material is a solid, flat-shaped material.    
   
   
       11 . The sound insulation member according to  claim 9 , wherein 
 the metal foil is an aluminum foil having a thickness of 6 μm or greater.    
   
   
       12 . The sound insulation member according to  claim 9 , wherein 
 the foamed porous material or the fiber material includes polyurethane, melamine urethane, polyester, carbon fiber polyurethane or glass wool.    
   
   
       13 . The sound insulation member according to  claim 9 , wherein 
 the foamed porous material or the fiber material is flat-shaped and has an uneven surface.    
   
   
       14 . The sound insulation member according to  claim 9 , wherein 
 the foamed porous material or the fiber material is flat-shaped, and either an upper surface or a lower surface thereof has a wider surface area than the opposite surface.    
   
   
       15 . The sound insulation member according to  claim 9 , wherein 
 the gas is of reduced-pressure atmosphere having a pressure 1×10 3  Pa or more lower than atmospheric pressure.    
   
   
       16 . The sound insulation member according to  claim 9 , wherein 
 the foamed porous material or the fiber material has a trapezoidal cross-sectional shape.    
   
   
       17 . A railroad vehicle characterized in comprising the sound insulation member according to  claim 9 .  
   
   
       18 . A method for producing a sound insulation member comprising: 
 forming a pouched member having one portion opened with a metal foil coated with resin;    enclosing a member having a sound absorption function and a gas having a density or sound velocity different from that of atmospheric air in the pouched member;    sealing the opened portion of the pouched member via heat seal; and    disposing backing plates on upper and lower sides of the heat seal surface and welding the metal foils with the backing plates.    
   
   
       19 . A method for producing a sound insulation member comprising: 
 forming a cylindrical member by heat-sealing a metal foil along a longitudinal direction;    inserting a sound absorption material having a sound absorption function to the cylindrical member; and    sealing both ends of the cylindrical member via heat seal.