| 摘要 |
PURPOSE:To enhance the high-speed durability of the captioned tire by placing the predetermined cushion rubber at the both ends of a breaker consisting of a sheet of pry having the predetermined cord angle and placing the middle belt layer having the predetermined cord angle on the outer side of the middle line of the rubber thickness together with placing sidebelt layers at the both ends of the middlebelt layer. CONSTITUTION:A breaker 7 consisting of a pry having an angle of 5 deg.-45 deg. to the circumferential direction of a tire is formed in the same width as the tread width W of the tire. The width of the upper side pry 7a is made smaller than that of the lower side pry 7b. Cusion rubber 70, which is 40 deg.-75 deg. in JIS hardness and the thickness of which reduces toward the both ends, is arranged between the both ends of the both prys 7a and 7b in order to absorb or alleviate the strain occurring at the end of the pry. In addition, a middle belt layer 11 having the cord angle of 10 deg.-40 deg. is placed at the outside of the breaker 7 along the middle line of the rubber thickness, while side belt layers 12a each having the cord angle of 0 deg.-10 deg. are placed on the both sides of the middle belt layer 11, being neighbored on the upper side pry 7a. With this constitution, durability, road gripping performance, and running performance of the tire at the time of high speed running can be enhanced. |
