Abstract:
PROBLEM TO BE SOLVED: To provide a pneumatic radial tire equipped with a good maneuvering stability, durability, and cost performance required of a high performance radial tire designed for application to a high performance passenger car. SOLUTION: The pneumatic radial tire includes a carcass 1 as a skeleton which stretches toroidally between a pair of bead parts 11 and is structured so that at least one belt layer 2 formed by lining with rubber the steel cords consisting of a plurality of steel element wires is laid on the outside in radial direction of the crown part of the carcass. The bending rigidity Ec of the steel cords in the condition embedded in the belt layer ranges between 49 and 196 Pa, being 1.0-1.27 times as large as the cord bending rigidity Er in the condition of cords solely not embedded in the belt layer. COPYRIGHT: (C)2007,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide a steel cord for reinforcing a rubber article, excellent in fatigue durability by improving rubber penetration property, and especially applicable as a belt-reinforcing material of a high performance passenger car radial tire, etc. SOLUTION: This steel cord for reinforcing the rubber article consists of a core arranging 2 pieces of core wires 1 in parallel without stranding them and 5-7 pieces of sheath wires 2 stranded around the core, and the cord cross section shape is approximately elliptical. The diameter dc (mm) of the core wire 1 satisfies 0.05≤dc
Abstract:
PROBLEM TO BE SOLVED: To provide a pneumatic tire in which it is prevented that water is spread from flaw into the interior when a tread part suffer an external flaw such as cut flaw and development of crack from belt end is suppressed and durability is enhanced. SOLUTION: The pneumatic tire 7 is equipped with a belt 13 obtained by covering a plurality of reinforcing elements 12 parallel arranged over both width ends 11 with rubber on the outer periphery of a crown part 10 of a carcass 9. Each reinforcing element 12 is an open cord and a profile shape P3 of a virtual cross section perpendicular to the extending direction is changed along the extending direction between nearly circle and nearly ellipse in which the short axis extends to the thickness direction of the belt. When the diameter of the reinforcing element in the thickness direction of the belt 13 is defined as a vertical diameter (a) and the diameter of the reinforcing element in the direction perpendicular to the thickness direction of the belt 13 is defined as a transverse diameter (b) and a ratio (a/b) of the vertical diameter (a) to the transverse diameter (b) is defined as a flat ratio and the reinforcing element 12 is divided into both ends 15 and a central part 16, in the both ends 15, maximum value of the transverse diameter (b) is smaller and minimum value of a flat ratio (a/b) is larger, compared with the central part 16. COPYRIGHT: (C)2005,JPO&NCIPI