| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve cross rigidity of a tire, bead durability and comfortableness compatible to each other by forming bead apex in a multi layer structure to which two or more kind of rubber material which have different hardness are laminated in annual ring shape or spiral shape. SOLUTION: This tire is constituted to have a bead apex 8 of two or more kind of rubber material of different hardness between a body part of a carcass and a return part. In this case, the bead apex 8 is formed as a multi layer structure 16 to which a rubber layer of S is laminated in annual ring shape or spiral shape extending from the center of the bead apex P to the outer peripheral surface of the bead apex in a tire tangential cross section and the number of laminated layer of the rubber layer from the center of the bead apex P to the outer periphery surface of the bead apex is 3 or more.</p> |
