pneumatic tire

Abstract

To provide a pneumatic tire capable of reducing the weight and rolling resistance of the tire while maintaining good handling stability and improving the delamination resistance performance. In the pneumatic tire of the present invention, two carcass plies including a plurality of carcass cords are spanned between a pair of bead portions, a bead core and a bead filler are disposed on each bead portion, and the carcass A pneumatic tire in which at least two belt layers are arranged on the outer peripheral side of the carcass is characterized in that both ends of the inner carcass ply are folded around each bead core from the inner side to the outer side of the tire, and the inner carcass The terminal end of the turned-back portion of the carcass is arranged between the inner peripheral side belt layer and the main body portion of the inner peripheral side carcass ply, and on the other hand, both ends of the outer peripheral side carcass ply are arranged so that they are smaller than the inner peripheral side. The turned-back portion of the side carcass ply extends outward in the tire width direction at least to a position where it overlaps with the bead filler, and both ends of the outer peripheral side carcass ply end at each bead portion without going around each bead The core turns back.

Description

technical field [0001] The present invention relates to a pneumatic tire including a multi-layer carcass ply, and more specifically, to a pneumatic tire capable of reducing the weight and rolling resistance of the tire while maintaining good steering stability, and improving delamination resistance. Background technique [0002] Pneumatic tires employ a reinforced structure in which multiple layers of carcass plies are bridged between a pair of bead portions in order to maintain a high internal pressure. For example, a pneumatic tire having a so-called 2-1F locked carcass structure has been proposed (for example, refer to Patent Document 1): three layers of carcass plies are bridged between a pair of bead portions, and two layers of inner peripheral side carcass plies are provided. The ends are folded back around the bead cores from the inside to the outside of the tire, and both ends of one outer carcass ply are arranged on the outer side in the tire width direction of the ...

AI Technical Summary

Problems solved by technology

[0004] However, pneumatic tires are often exposed to severe usage environments such as a high load state due to overloading and / or a high internal pressure state for ensuring load capacity, so if the end of the carcass ply is often arranged at the bead portion or The parts of the sidewall that are prone to deflection are prone to delamination failures starting from these ends

In addition, in the case where three carcass plies are used, the weight of the tire increases, and thus, there is also a problem that the rolling resistance of the tire increases.

[0005] In addition, the above-mentioned problems can be overcome by reducing the number of layers of the carcass ply, but in this case, the rigidity of the tire as a whole decreases, resulting in a decrease in steering stability.

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