| 摘要 |
PURPOSE:To prevent the shearing deformation of a carcass cord so as to prevent the separation thereof by making the twist angle of the cord to be 31.3 deg.-39.3 deg. to the axis line of the cord as measured from the acute angle side. CONSTITUTION:A pneumatic tire 1 is made up of a pair of bead part 1 situated on the right and left sides, a side wall part 2, and a tread part 3. A two-layer belt layer 4, in which each cord crosses each other at an angle of 10 deg.-35 deg. to the circumferential direction of a tire, is arranged on a carcass layer K in the tread part 3. Fiber cords made of polyamid belonging to the aromatic compound are used as carcass cords 10 forming the carcass layer K. And a twist-angle theta of this cord 10 is set at in the range of 31.3 deg.-39.3 deg. to the axis line of the cord as measured from the acute angle side. Owing to this range of angle, even when the force F normal to the axis line is applied to the carcass, it is difficult for the carcass 10 to be deformed, thereby preventing the separation of the carcass cord from occurring. |
