JP2007045334A5 - - Google Patents

Claims (5)

In heavy duty flat pneumatic radial tire of arranging the steel cord belt layers of a plurality plies on the outer circumference of the car mosquito scan layer, the steel cord belt layer, as well as placed directly on the carcass layer, the cord angle with respect to the tire circumferential direction At least one ply of a 0 degree belt layer that is substantially 0 degrees, and disposed at the outer peripheral side of the 0 degree belt layer, and at least a substantially balanced angle with a cord angle in the range of 45 to 65 degrees with respect to the tire circumferential direction. A heavy-load flat pneumatic radial tire comprising a two-ply bias belt layer and a protective belt layer made of a steel cord having a cord angle of 15 to 30 degrees with respect to the tire circumferential direction and being arranged on the outer peripheral side of the bias belt layer . The width of the 0-degree belt layer is 75 to 85% of the total tire width, the width of the bias belt layers with narrower than the 0 ° belt layer, in claim 1 which is 60 to 80% of the total tire width The flat pneumatic radial tire for heavy loads described. The flat pneumatic radial tire for heavy loads according to claim 2 , wherein the width of the protective belt layer is narrower than that of the bias belt layer and is 25 to 70% of the total tire width. The flat pneumatic radial tire for heavy loads according to any one of claims 1 to 3 , wherein the two-plies of the 0 degree belt layer and the bias belt layer are arranged, and one ply of the protective belt layer is arranged. The flat pneumatic radial tire for heavy loads according to any one of claims 1 to 4 , wherein the flatness of the tire is 60% or less.