| 摘要 |
PURPOSE:To improve the durability of a run flat, in a tire of prescribed flatness ratio, by specifying the rubber performance and arrangement of a crescent- shaped reinforcing liner and a bead filler to form a carcass in two layers, and specifying the arrangement of its inner and outer layer. CONSTITUTION:A crescent-shaped reinforcing liner 8 is formed out of rubber in which dynamic elastic modulus E at 20 deg.C is more than 16 MPa, the ratio between dynamic elastic modulus E at 20 deg.C and 100 deg.C is 0.80, or more, 100% modulus is 60 kg/cm<2> or more and regular less at 100 deg.C is less than 0.35 so as to lap both ends to be arranged with a belt layer 6 and a bead filler 9 in a tire of less than flatness ratio 50%. The bead filler 9 is formed out of rubber with 60 - 80 JIS-A hardness, and the height (h) from a rim base B is set to less than 35 mm. An inner carcass layer 5-1 is turned back from the inside to the outside, and its end is set higher than the height (h) to be held between the inner and outer carcass layers 5-1 and 5-2. It is thus possible to improve the durability of a run flat. |
