| 摘要 |
<p>A pneumatic tire having four circumferential grooves has optimal groove angles and rib cross-sectional shapes to achieve an optimal contact pressure at an edge portion of each rib. A optimal contact pressure at an edge portion of each rib depends on the relative ratio between a contact pressure at an edge portion of each rib and a contact pressure at the center position of each rib, and therefore, to achieve the optimum contact pressure of the tire, contact pressure distribution at a normal pressure and a 100% load is set as follows: center rib edge contact pressure/center rib center contact pressure is not less than 0.80 and not more than 1.00, second rib inner edge contact pressure/second rib center contact pressure is not less than 0.80 and not more than 1.00, second rib outer edge contact pressure/second rib center contact pressure is not less than 0.75 and not more than 0.95, shoulder rib inner edge contact pressure/shoulder rib center contact pressure is not less than 0.80 and not more than 0.95, and shoulder rib outer edge contact pressure/shoulder rib center contact pressure is not less than 0.85 and not more than 1.00.</p> |
