| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a pneumatic radial tire achieving keeping of tire durability and low rolling resistance while arranging belt layers obtained by aligningly winding a plurality single steel wires. <P>SOLUTION: In the pneumatic radial tire in which the plurality of belt layers 8 obtained by aligningly winding the plurality of single steel wires 10 are disposed, the respective single steel wires 10 are twisted around the axes thereof, a plurality of wire assemblies 12 constituted of 2-4 pieces of the single steel wires 10 are formed within the belt layers 8, the single steel wires 10 are arranged so as to be aligned in the face direction of the belt layers 8 in the respective assemblies 12, at least two kinds of single steel wires 10i with different wire diameter are used as the single steel wires 10 composing the respective assemblies 12, and the maximum value d<SB POS="POST">max</SB>and the minimum value d<SB POS="POST">min</SB>of the wire diameter have the relation of 0.28 mm≤d<SB POS="POST">max</SB>≤0.40 mm, 0.15 mm≤d<SB POS="POST">min</SB>≤0.35 mm, and 1.05≤d<SB POS="POST">max</SB>/d<SB POS="POST">min</SB>≤2.00. <P>COPYRIGHT: (C)2013,JPO&INPIT |
