Pneumatic tire

Abstract

A pneumatic tire 1 includes a carcass 6 extending between bead cores of bead portions via a tread portion 2 and sidewall portions, and a belt layer 7 arranged on an outer side in a tire radial direction of the carcass 6 and inside the tread portion 2. The pneumatic tire 1 has a noise damper 20 arranged on an inner cavity surface of the tread portion 2. Glass transition temperature of the noise damper 20 is in a range of from −55 degrees Celsius to −45 degrees Celsius.

1 . A pneumatic tire comprising a carcass extending between bead cores of bead portions via a tread portion and sidewall portions, and a belt layer arranged on an outer side in a tire radial direction of the carcass and inside the tread portion, wherein
 a porous noise damper is arranged on an inner cavity surface of the tread portion, and   glass transition temperature of the noise damper is in a range of from −55 degrees Celsius to −45 degrees Celsius.   
     
     
         2 . The pneumatic tire according to  claim 1 , wherein
 density of the noise damper is in a range of from 10 to 40 kg/m3.   
     
     
         3 . The pneumatic tire according to  claim 1 , wherein
 volume V 1  of the noise damper is in a range of from 0.4% to 30% of total volume V 2  of a tire inner cavity.   
     
     
         4 . The pneumatic tire according to  claim 1 , wherein
 tensile strength of the noise damper is in a range of from 70 to 115 kPa.   
     
     
         5 . The pneumatic tire according to  claim 1 , further comprising a dumping rubber body having a width W 1  in a tire axial direction in a range of from 60% to 130% of a width W 2  in the tire axial direction of the belt layer and provided inside the tread portion. 
     
     
         6 . The pneumatic tire according to  claim 5 , wherein the damping rubber body is arranged between the carcass and the belt layer. 
     
     
         7 . The pneumatic tire according to  claim 5  further comprising a band layer arranged on an outer side in the tire radial direction of the belt layer and inside the tread portion, wherein the damping rubber body is arranged between the belt layer and the band layer. 
     
     
         8 . The pneumatic tire according to  claim 5  further comprising a band layer arranged on an outer side in the tire radial direction of the belt layer and inside the tread portion, wherein
 the damping rubber body is arranged on an outer side in the tire radial direction of the band layer. 
 
     
     
         9 . The pneumatic tire according to  claim 1 , wherein
 thickness in the tire radial direction of the damping rubber body is not less than 0.3 mm.   
     
     
         10 . The pneumatic tire according to  claim 1 , wherein
 relationship between hardness H1 of the damping rubber body and hardness H2 of a tread rubber arranged on an outer side in the tire radial direction of the belt layer is 0.5≤H1/H2≤1.0.   
     
     
         11 . The pneumatic tire according to  claim 1 , wherein
 a loss tangent tan δ at 0 degree Celsius of a tread rubber arranged on an outer side in the tire radial direction of the belt layer is not less than 0.4, and   the loss tangent tan δ at 70 degrees Celsius of the tread rubber is not more than 0.2.   
     
     
         12 . The pneumatic tire according to  claim 1 , wherein
 a tread rubber arranged on an outer side in the tire radial direction of the belt layer is a rubber composition body having a value not less than 20, the value being calculated by (1.4×carbon black content (phr)+silica content (phr))/sulfur content (phr).