| 摘要 |
<p>A pneumatic tire comprising a carcass (1) composed of at least one cord ply extending between a pair of bead portions (3), an inner liner (5) adhered to the inner surface of the carcass, and a rubber reinforcing layer (6) made of a rubber composition different from and having a Shore A hardness higher than that of the inner liner and disposed at a lower part of the bead portion including a bead toe portion (7) and a bead heel portion (8) to form an outermost bead rubber at least at that region of the bead portion which comes into contact with a rim (10). In the tire, the rubber reinforcing layer is divided into an axially inside portion (6a) inclusive of the bead toe portion and an axially outside portion (6b) at a boundary surface (11) located in an area between the bead toe portion and a position corresponding to 1/2 of the height (h) of a rim flange, and the axially outside portion extends beyond the height of the rim outwardly in the radial direction of the tire, and the rubber of the axially inside portion has a smaller Shore A hardness and abrasion resistllnce index and a higher breaking energy after heat deterioration as compared with the axally outside portion.</p> |
