Pneumatic tire

Abstract

The purpose of the present invention is to provide a pneumatic tire for purposes of racing and the like, having a half-radial structured cord location where a nylon fiber cord is used as a carcass cord, the pneumatic tire fully taking advantage of the inherent cord characteristics of the nylon fiber carcass cord and providing excellent operational stability and durability. The pneumatic tire according to the present invention is a half-radial structured pneumatic tire in which the carcass cord is inclined with respect to a tire radial direction and provided with an angle of 55 to 85º with respect to a tire circumferential direction as measured at a center position in a tread width direction, and is characterized in that: the carcass cord has a modulus of elasticity of 3 to 10 GPa; the carcass cord has a twist coefficient α of 1500 to 2500; and the tire has an intermediate elongation difference of not more than 1.0% at 2.0 cN / dtex between a center portion and a side portion of the carcass cord, where the twist coefficient α = N × √T, N is the number of twists per 10 cm in length of the fiber cord, and T is the fineness (dtex) of the fiber cord.

Description

technical field [0001] The present invention relates to pneumatic tires. Background technique [0002] Racing tires that require high handling stability when running at high speeds, some are formed into so-called semi-radial tires, that is, carcass cords that are inclined relative to the radial direction of the tire and measured at the center position in the tread width direction The angle with respect to the tire circumferential direction is 55° to 85°, and in this case, some carcass cords are made of nylon fiber cords. [0003] In the cord arrangement of such a semi-radial structure, there is a problem that, in the case of using a nylon fiber cord as the carcass cord, if the carcass cord is placed (fixed) at the time of tire molding vulcanization, etc. In a state where tension in the compression direction is applied to the carcass cords, the carcass cords cannot fully exhibit their original cord properties after tire molding and vulcanization, and the steering stability a...

AI Technical Summary

Problems solved by technology

[0003] In the cord arrangement of such a semi-radial structure, there is a problem that, in the case of using a nylon fiber cord as the carcass cord, if the carcass cord is placed (fixed) at the time of tire molding vulcanization, etc. In the state where tension in the compression direction is applied to the carcass cord, the carcass cord cannot fully exhibit the original cord characteristics after tire molding and vulcanization, and the steering stability and durability cannot be sufficiently improved.

[0007] However, these proposed pneumatic tires are different from the so-called semi-radial structure tires targeted by the present invention, that is, tires in which the above-mentioned carcass cords are inclined relative to the tire radial direction and measured at the center position in the tread width direction. The angle of the body cord relative to the tire circumferential direction is 55-85°, which does not give any inspiration for the pneumatic tire of the present invention

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