| 摘要 |
<p>Provided is a run-flat type pneumatic tire, which is enhanced in the vibration-riding comfortableness of a vehicle in a normal rolling state. The pneumatic tire comprises a tread portion (11), a side wall portion (12) and a bead portion (13), and is equipped with a carcass (2) and an intersecting belt layer (3). The pneumatic tire is constituted such that a reinforcing rubber (4) having a substantially crescent sectional shape in the tire radius direction is arranged in the side wall portion (12) on the inner side in the tire radius direction of the carcass (2), and such that the rigidity of the steel cord per unit width of the intersecting belt layer (3) satisfies a relation expressed by the following formula: (A - 800)/B = 20, (A designates the cord tensile rigidity (Kg) defined by the load at the time of a tension of 1 % X a driven number (cords/50 mm), and B designates the cord bending resistance (g/mm) obtained by a code three-point bending test and defined by the inclination of the stress - bending displacement curve at the forced displacement time of 2 to 6 mm X the driven number (cords/50 mm)).</p> |
