| 摘要 |
<p>A heavy-duty radial tire including a carcass and four steel cord belts bearing most of stress of the tire. The carcass and the belts cross each other. An outer side belt (25) layer of two belt layers of different cord diameters which are defined by the belts being divided into the two belt layers, the outer side belt layer being a belt layer of the two belt layers which is disposed at an outer circumferential side of the tire in a radial direction thereof; and an inner side belt layer (21) disposed further toward an inner circumferential side of the tire in the radial direction thereof than the outer side belt layer. A difference between belt cord angles of respective belts of the outer side belt layers is less than or equal to 5 DEG . A difference between belt cord angles of respective belts of the inner side belt layers is less than or equal to 5 DEG . Further, 1 < PHI out/ PHI in </= 2.5, and alpha in- alpha out >/= 5 DEG and ( alpha out+ alpha in)/2 </= 23 DEG , wherein: PHI out = belt cord diameter of the outer side belt layer; alpha out = average value of absolute values of belt cord angles, defined by an equatorial plane of the tire, of the outer side belt layers; PHI in = belt cord diameter of the inner side belt layer; and alpha in = average value of absolute values of belt cord angles, defined by the equatorial plane of the tire, of the inner side belt layers. <IMAGE></p> |
