| 摘要 |
PURPOSE:To improve the high-speed durability while reduce the vibration of a tire by spirally winding a composite cord having both low elastic area on the lower portion and high elastic area on the upper portion, of an inflection point in which high-elastic filaments and low-elastic filaments are entwined, continuously in the circumferential direction of a tire and forming a band layer. CONSTITUTION:A band layer 7 placed outside in the radial direction of a belt layer 6 is formed by winding one or a plurality of composite cords 12 formed by entwining high-elastic filaments 10 and low-elastic filaments 11. The high- elastic filament 10 is formed by using aromatic polyamide fiber, polyvinyl alcohol fiber with above 15-g/d strength, etc., having an elastic modulus EH of above approx. 1000kg/mm<2>, while forming the low-elastic filament 11 by using nylon fiber, etc., with an elastic modulus EL of below approx. 1000kg/mm<2>. The inflection point of a stress-elongation curve is set in a position of 2-7% elongation while setting EH/EL to be 2-10. By this structure, high-speed durability can be improved while reducing vibration. |
