| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a pneumatic tire achieving low rolling resistance without spoiling other tire performance properties. <P>SOLUTION: The pneumatic tire includes a carcass ply 2, belt layers 3a, 3b, and belt reinforcing layers 4, 5 made of organic fiber cord rubberized layers disposed substantially in parallel to the tire circumferential direction. Where the minimum diameter as a dip cord is R1 (mm) and the maximum diameter is R2 (mm) in the cross section perpendicular to the longitudinal direction of an organic fiber cord constituting the belt reinforcing layers, the circularity of the organic fiber cord defined as R2/R1 satisfies 1.0<R2/R1≤1.3. Where the cord diameter as a dip cord measured according to the JIS Standards of the organic fiber cord is defined to be D (mm) and the number of yarns of the organic fiber cord as a treat of the belt reinforcing layers is defined to be E (number/50 mm), a relation indicated as π×D×(R2/R1)×E<70. <P>COPYRIGHT: (C)2012,JPO&INPIT |
