Pneumatic tire

Abstract

The present invention includes a run-flat tire comprising a plurality of turbulence generation ridges which extend on a surface of a tire side portion in a tire-radial direction and which are arranged at a pitch in a tire-circumferential direction and relationship Si>So is satisfied. Si is the sum of sidewall areas of all the turbulence generation ridges located at the inner side, in the tire-radial direction, of a maximum width position of the pneumatic tire. So is the sum of sidewall areas of all the turbulence generation ridges located at the outer side, in the tire-radial direction, of the tire maximum width position.

1 . A pneumatic tire comprising a plurality of turbulence generation ridges which extend on a surface of a tire side portion in a tire-radial direction and which are arranged at a pitch in a tire-circumferential direction,
 wherein a relationship Si>So is satisfied where Si is the sum of sidewall areas of all the turbulence generation ridges located at the inner side, in the tire-radial direction, of a maximum width position of the pneumatic tire and   So is the sum of sidewall areas of all the turbulence generation ridges located at the outer side, in the tire-radial direction, of the tire maximum width position, and wherein So is zero.   
     
     
         2 . The pneumatic tire according to  claim 1  wherein the number of the turbulence generation ridges located at the inner side, in the tire-radial direction, of the tire maximum width position is larger than the number of the turbulence generation ridges located at the outer side, in the tire-radial direction, of the tire maximum width position. 
     
     
         3 . The pneumatic tire according to  claim 1  wherein the turbulence generation ridges located at the inner side, in the tire-radial direction, of the tire maximum width position are equidistantly arranged in the tire-circumferential direction. 
     
     
         4 . The pneumatic tire according to  claim 3  wherein the turbulence generation ridges located at the inner side, in the tire-radial direction, of the tire maximum width position and equidistantly arranged in the tire-circumferential direction satisfy 1.0≦p/h≦50.0 where h is a maximum height of each of the turbulence generation ridges from the surface of the tire side portion, and p is a pitch between positions of each adjacent two of the turbulence generation ridges, the positions each being a point having the maximum height h. 
     
     
         5 . The pneumatic tire according to  claim 1  wherein a largest area of a portion which is in a region located in the surface of the tire side portion and located at the outer side, in the tire-radial direction, of the tire maximum width position, and in which no turbulence generation ridges are formed is an area having an angle of 90° or smaller around a tire rolling axis. 
     
     
         6 . The pneumatic tire according to  claim 1  wherein at least one of an end portion, on the inner side in the tire-radial direction, of each turbulence generation ridge and an end portion, on the outer side in the tire-radial direction, of the turbulence generation ridge is formed to have a height gradually decreasing toward the at least one end portion. 
     
     
         7 . The pneumatic tire according to  claim 6  wherein a top surface of the end portion of each of the turbulence generation ridges is formed as a sloping surface that is sloping with respect to the surface of the tire side portion. 
     
     
         8 . The pneumatic tire according to  claim 7  wherein an angle formed by a tangent to the sloping surface and the surface of the tire side portion is within a range from 10° to 40°. 
     
     
         9 . The pneumatic tire according to  claim 1  wherein a maximum height of each of the turbulence generation ridges is within a range from 1 mm to 5 mm measured from the surface of the tire side portion. 
     
     
         10 . The pneumatic tire according to  claim 1  wherein the tire side portion includes a reinforcement rubber that has a crescent-shaped cross-section taken in the tire-radial direction.