| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a pneumatic tire for an automobile which is largely reduced in tire weight and rolling resistance.SOLUTION: In a pneumatic tire in which a carcass layer 4 is bridged between bead parts 3, at least one layer of reinforcing layers 8 is arranged at an external peripheral side of the carcass layer 4, and a tread rubber layer 9 is laminated on an external peripheral side of the reinforcing layer 8, a first region A is segmented between a pair of first boundary lines L1, a second region B is segmented between the first boundary line L1 and a second boundary line L2, and a third region C is segmented to a bead toe 31 side rather than the second boundary line L2. When cross section areas (mm) of the regions are set as SA, SB and SC, and also when peripheral lengths (mm) along tire internal faces of the first region A to the third region C are set as a, b and c, relationships of 7.5≤SA/a≤11.5, 2.0≤SB/b≤6.0 are satisfied with respect to ratios of SA/a, SB/b, and at least one layer of the reinforcing layers 8 includes a reinforcing layer 8A in the circumferential direction in which a plurality of pieces of reinforcing cords are aligned substantially in parallel along the tire circumferential direction.</p> |
