| 摘要 |
PURPOSE:To improve a bead part durability by placing the wall thickness change part of the inner liner covering the winding part of an extreme strength layer to the upper part of the upper end of the winding part and making the thickness of the inner liner at the upper end of the winding part a given one in the tire for a truck and bus etc. CONSTITUTION:A wall thickness change part 7c in which a wall thickness is gradually decreasing is provided to an inner liner 6, and a lower part 7B and upper part 7A are continuously formed without providing a state difference. The height H7b from the bead base L of the lower end 7b of the part 7C continuing to the part 7B is set to 12 times or more the upper end height H5a of a winding part 5A. Similarly the height H7a of an upper end 7a continuing to the part 7A is set to 1.4 times or more H5a. And the wall thickness difference at an upper end 7a and the end 7b is set to 0.5-1.0 time the wall thickness W7a of the end 7a, and the wall thickness W7c at the position of 90% of the height H5a is set to 0.9-1.2 times the thickness W7a of the end 7a respectively. Thus durability can be improved. |
