217results about How to "Improve wetting performance" patented technology

A pneumatic tire achieving good on-ice performance and good wet performance at the same time is provided. A pair of first main grooves extending in the circumferential direction of the tire is provided in the center region of a tread. A pair of second main grooves extending in the circumferential direction of the tire is provided on both the outer sides of the pair of first main grooves. First luggrooves and second lug grooves are alternately arranged in the circumferential direction of the tire such that the first lug grooves extend inward in the lateral direction of the tire from each shoulder end of the tread and communicate with the corresponding one of the first main grooves and further such that the second lug grooves extend inward in the lateral direction of the tire from the shoulder end of the tread and do not communicate with the corresponding one of the first main grooves. A center rib is arranged to extend between the pair of first main grooves. A shoulder block row composed of blocks is arranged between each second main groove and the corresponding one of the shoulder ends, and an intermediate shoulder block row composed of blocks is arranged between the second main groove and the adjacent one of the first main grooves. In the intermediate shoulder block row are arranged long blocks having a circumferential length equivalent to the length of two blocks of the shoulder block row.

Provided is a run-flat tire which has an excellent run-flat performance as well as a high high-speed straight running stability in the non-punctured state, a high steering stability on both of a dry road surface and a wet road surface and a good fuel efficiency. A run-flat tire which comprises at least two cross belt layers formed by rubberizing a steel cord and a tread rubber located successively, wherein a reinforcing rubber is provided inside a carcass. The above-described steel cord has a single twisted structure or a core / single layered sheath structure consisting of 6 to 10 steel strands having a strand diameter of 0.10 to 0.20 mm. The density of the implanted steel cords is 40 cords / 50 mm or more and the distance between the adjacent steel cords in the belt layer is 0.3 mm or longer. Moreover, the dynamic storage modulus E' (MPa) at 30 DEG C of the tread rubber and tand at 60 DEG C of the same respectively satisfy the relationships represented by the formulae: 5.0<=E' and 0.050<=tand<=0.240.

The invention provides a heavy duty tire, comprising: a shoulder rib (A1) (shoulder rib (A5)) which is provided to a tread shoulder section; a second rib (A2) (second rib (A4)) which is adjacent to the shoulder rib (A1) with a circumferential groove (110) (circumferential groove (116)) interposed therebetween and is provided further toward the tire equator side than the shoulder rib (A1); and an uneven wear absorbing rib (B1) (uneven wear absorbing rib (B2)) provided within the circumferential groove (110) and located further toward the inside in the tire radial direction than the tread surfaces of the shoulder rib (A1) and of the second rib (A2). Circumferential narrow grooves (10, 12) having a smaller width than the circumferential grooves (110, 116) are formed in the second ribs (A2, A4). Each circumferential narrow groove (10, 12) is formed in such a manner that, when the tire is mounted on the vehicle, the circumferential groove (10, 12) is located on the outer side of the tire with reference to the center of the second rib (A2, A4) in the tread width direction.

The present invention provides a tire in which wet performance can be improved without sacrificing steering stability. A tire (1) has designated installation direction on a vehicle. An outboard shoulder land region (8) is provided with outboard shoulder sipes (26). The outboard shoulder sipe (26) comprises a deep bottom part (27) and a shallow bottom part (28) with a depth smaller than the deep bottom part (27). The shallow bottom part (28) comprises a first part (30) extending axially inwardly from the axially inner end (27i) of the deep bottom part (27) towards a tire equator C, a second part (31) extending axially outwardly from the outboard shoulder main groove (4) to wards an outboard tread edge (To), and a third part (32) connecting the first part (30) and the second part (31). The first part (30), the second part (31) and the third part (32) have different angles with respect to the tire axial direction.