Noise reducing device, manufacturing method for the noise reducing device, and pneumatic tire having the noise reducing device

Abstract

Provided are: a noise reduction device with an improved adhesion of objects formed of a porous material and with a reduced processing time; a method of manufacturing the noise reduction device; and a pneumatic tire including the noise reduction device. The noise reduction device of the present invention includes: objects formed of a porous material; a band member for attaching the objects to the inner surface of a tire at two positions spaced at substantially equal intervals in the tire circumferential direction; and locking members formed of a thermoplastic resin. The band member is formed of a thermoplastic resin. Each object is disposed at a predetermined position in the tire circumferential direction, between the band member and the corresponding locking members. The locking members are bonded to the band member through the objects by thermal fusion.

What is claimed is: 
     
         1 . A pneumatic tire comprising a noise reduction device in a cavity portion thereof, the noise reduction device comprising:
 a pair of objects formed of a porous material;   a band member formed of a thermoplastic resin for attaching the objects to the inner surface of a tire at two positions spaced at substantially equal intervals in the tire circumferential direction; and   locking members formed of a thermoplastic resin;   wherein each object is disposed at a predetermined position in the tire circumferential direction, between the band member and the locking members,   the locking members are bonded to the band member through the objects by thermal fusion, and   a constituent material of the band member and a constituent material of the locking members are same thermoplastic resin.   
     
     
         2 . The pneumatic tire according to  claim 1 , wherein the constituent material of the band member and the constituent material of the locking members are polypropylene. 
     
     
         3 . The pneumatic tire according to  claim 2 , wherein the porous material of the objects is polyurethane foam. 
     
     
         4 . The pneumatic tire according to  claim 2 , wherein each locking member has a plate shape. 
     
     
         5 . The pneumatic tire according to  claim 2 , wherein each locking member has a cylindrical shape with a bottom. 
     
     
         6 . The pneumatic tire according to  claim 5 , wherein through holes are formed in each object at positions where the object is locked by the locking members. 
     
     
         7 . The pneumatic tire according to  claim 6 , wherein the objects are held in the state of being compressed by the locking members when the locking members are bonded to the band member via the through holes by thermal fusion. 
     
     
         8 . The pneumatic tire according to  claim 2 , wherein an edge portion of each object is retained by a fastener formed of a thermoplastic resin, and then the fastener is bonded to the band member by thermal fusion. 
     
     
         9 . The pneumatic tire according to  claim 2 , wherein
 the width of each locking member is 90 to 300% of the width of the band member,   the width of a thermal-fusion-bonding portion where each locking member is bonded to the band member by thermal fusion is made narrower than the width of the band member, and   non-fusion-bonding portions, each having a width equivalent to 5 to 20% of the width of the band member, are left on both sides of the thermal-fusion-bonding portion.   
     
     
         10 . The pneumatic tire according to  claim 9 , wherein
 the thermal-fusion-bonding portions of the locking members and the band member are arranged at intervals in the tire circumferential direction, and   the relation between the interval H and the width W of each object is 0.2W≦H≦4W.   
     
     
         11 . The pneumatic tire according to  claim 1 , wherein the porous material of the objects is polyurethane foam. 
     
     
         12 . The pneumatic tire according to  claim 1 , wherein each locking member has a plate shape. 
     
     
         13 . The pneumatic tire according to  claim 1 , wherein each locking member has a cylindrical shape with a bottom. 
     
     
         14 . The pneumatic tire according to  claim 13 , wherein through holes are formed in each object at positions where the object is locked by the locking members. 
     
     
         15 . The pneumatic tire according to  claim 14 , wherein the objects are held in the state of being compressed by the locking members when the locking members are bonded to the band member via the through holes by thermal fusion. 
     
     
         16 . The pneumatic tire according to  claim 1 , wherein an edge portion of each object is retained by a fastener formed of a thermoplastic resin, and then the fastener is bonded to the band member by thermal fusion. 
     
     
         17 . The pneumatic tire according to  claim 1 , wherein
 the width of each locking member is 90 to 300% of the width of the band member,   the width of a thermal-fusion-bonding portion where each locking member is bonded to the band member by thermal fusion is made narrower than the width of the band member, and   non-fusion-bonding portions, each having a width equivalent to 5 to 20% of the width of the band member, are left on both sides of the thermal-fusion-bonding portion.   
     
     
         18 . The pneumatic tire according to  claim 17 , wherein
 the thermal-fusion-bonding portions of the locking members and the band member are arranged at intervals in the tire circumferential direction, and   the relation between the interval H and the width W of each object is 0.2W≦H≦4W.