| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a pneumatic tire capable of improving durability and capable of reducing rolling resistance while maintaining lateral rigidity. <P>SOLUTION: In the pneumatic tire wherein carcass layers 4A and 4B are constituted by an organic fiber cord, a casing structure having a bead filler 6 on an outer peripheral side of a bead core 5 is provided, and an air pressure corresponding to the maximum load capacity is in a range of 350 to 650 kPa, the bead filler 6 is constituted by a plurality of rubber layers 6a and 6b stacked along the tire radial direction, and relationship among a cross section area S<SB>1</SB>, hardness Hs<SB>1</SB>and a loss tangent tanδ<SB>1</SB>of the rubber layer 6a on the outermost peripheral side, and a cross section area S<SB>2</SB>, hardness Hs<SB>2</SB>and a loss tangent tanδ<SB>2</SB>of the rubber layer 6b on the inner most peripheral side, and a ratio of a bead filler height BFH with respect to a tire cross section height SH is expressed as follows; (1) (S<SB>1</SB>×tanδ<SB>1</SB>)/[(S<SB>1</SB>×tanδ<SB>1</SB>)+(S<SB>2</SB>×tanδ<SB>2</SB>)]=0.25 to 0.40; (2) (S<SB>1</SB>×Hs<SB>1</SB>)/[(S<SB>1</SB>×Hs<SB>1</SB>)+(S<SB>2</SB>×Hs<SB>2</SB>)]=0.35 to 0.50; (3) BFH/SH=0.25 to 0.60; (4) Hs<SB>2</SB>-Hs<SB>1</SB>=10 to 25; (5) tanδ<SB>1</SB>≤0.1; and tanδ<SB>2</SB>-tanδ<SB>1</SB>≤0.1. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
