| 摘要 |
Tire comprising a tread (40) extending between an outboard axial edge (45) and an inboard axial edge (46), over a width L, in which the tread comprises at least 4 circumferential ribs (411-414) separated by grooves (421-423), in which the circumferential rib (411) adjacent to the outboard axial edge of the tread extends from the outboard axial edge over a width of at least 0.6·L and comprises a portion (411a) with a width of at least 0.1·L made from a first rubber composition and an axially adjacent second portion (411b) made from a second rubber composition, the first rubber composition having values for the elastic modulus at 300% deformation, the Shore A hardness and the complex modulus G* at 60° C. which are respectively comprised between 1.1 and 2.1 times, 0.95 times and 1.20 times, and 1.00 times and 2.10 times the corresponding values of the second rubber composition. |
| 主权项 |
1. A tire adapted to be mounted on a mounting rim of a vehicle wheel and having a predetermined direction of mounting on the vehicle, comprising a tread extending between an outboard axial edge and an inboard axial edge, the inboard axial edge being the edge intended to be mounted on the side facing the body shell of the vehicle when the tire is mounted on the vehicle in the predetermined direction of mounting, the distance between the outboard axial edge and the inboard axial edge of the tread in the new state defining a width L of the tread;
wherein the tread comprises N circumferential ribs, N being a whole number greater than or equal to 4, separated by N−1 circumferential grooves each one comprising two lateral walls, the mean axial distance between the two lateral walls of each groove being greater than or equal to 5 mm and less than or equal to 20 mm; in which wherein the circumferential rib adjacent to the outboard axial edge of the tread extends, in any radial section and over the entire radial depth of the tread, from a first axial position, of which the axial distance with respect to the inboard axial edge of the tread is greater than or equal to 0.95·L, to a second axial position, of which the axial distance with respect to the inboard axial edge of the tread is less than or equal to 0.6·L; wherein the circumferential rib adjacent to the outboard axial edge of the tread comprises a first portion made from a first rubber composition and a second portion axially adjacent to the first portion and made from a second rubber composition different from said first rubber composition; wherein the first portion extends, in any radial section and over the entire radial depth of the tread, from said first axial position to a third axial position of which the axial distance with respect to the inboard axial edge of the tread is less than or equal to 0.85·L, the second portion of the circumferential rib extending from said third axial position to said second axial position; wherein said first and second rubber compositions comprise at least one elastomer and at least one reinforcing filler comprising a carbon black, the carbon black representing a percentage greater than or equal to 50% and less than or equal to 100% of the weight of all of the reinforcing filler, and wherein said first rubber composition has:
an elastic modulus at 300% deformation which is greater than 1.1 times and less than or equal to 2.1 times the elastic modulus at 300% deformation of said second rubber composition;a Shore A hardness which is greater than or equal to 0.95 times and less than or equal to 1.20 times the Shore A hardness of said second rubber composition;a complex modulus G* at 60° C. which is greater than or equal to 1.00 times and less than or equal to 2.10 times the complex modulus G* at 60° C. of said second rubber composition. |
