60results about How to "Improve snow performance" patented technology

Groove widths of center main grooves are larger than groove widths of inner and outer main grooves. Plurality of lateral grooves are formed at intervals in a tire circumferential direction so as to define inner shoulder blocks belonging to an inner shoulder row. A first raised portion connecting a pair of inner shoulder blocks to each other is formed in the lateral grooves every one other on an inner main groove side. A depth of the lateral groove in the first raised portion is smaller than the depth of the lateral groove in other portions. A second raised portion is formed on the outer main groove in a region defined by an imaginary line connecting an outer intermediate block and an outer shoulder block. A depth of the outer main groove in the second raised portion is smaller than that of the outer main groove in other portions.

A pneumatic tire includes first and second pairs of main grooves extending in the tire circumferential direction; and auxiliary grooves disposed in land portions located between the first and second main grooves which open to the corresponding first main groove or the corresponding second main groove and terminate within the corresponding land portion. Each of the auxiliary grooves includes a first auxiliary groove that extends from the opening portion to the bent portion and a second auxiliary groove that extends from the bent portion to the terminating end. A length a of the first auxiliary groove and a length b of the second auxiliary groove have the relationship 0.3a<b<0.8a. The angle θ made by the first auxiliary groove and the second auxiliary groove at the bent portion is in the range 0°<θ<90°.

Provided is a pneumatic tire which is capable of securing a driving stability on dry road surfaces and concurrently of improving snow performance without worsening its pattern noise. The pneumatic tire includes four main grooves each extending in its tread part in a tire circumferential direction, and the four main grooves partition the tread part into: a center land part; paired intermediate land parts located with the center land part being interposed in between; and paired shoulder land parts located with the center land part and the paired intermediate land parts being interposed in between. Each of the intermediate land parts and the shoulder land parts includes multiple V-shaped grooves each configured of: a thick groove part extending in a tire width direction; and a thin groove part extending in the tire circumferential direction. The V-shaped grooves are arranged in a way that each paired V-shaped grooves are opposed to each other in the tire circumferential direction with a connecting groove part being interposed between vertices of the respective paired V-shaped grooves. Each thick groove part communicates with the main grooves or the outside of a ground contacting area. Each thin groove part terminates within the land part.

Provided is a pneumatic tire having high snow road performance. Provided is a pneumatic tire, the direction of mounting of which to a vehicle is specified. A tread section has formed therein an outer shoulder main groove which extends in a zigzag pattern, an outer middle main groove, outer shoulder lateral grooves, and outer middle lateral grooves. As a result, outer shoulder lands and outer middle lands are formed on the tread section. The outer shoulder lands are provided with outer shoulder lug grooves, and the outer middle lands are provided with outer middle lug grooves. The outer shoulder lateral grooves and the outer middle lug grooves are smoothly connected through the outer shoulder main groove. The outer middle lateral grooves and the outer shoulder lug grooves are smoothly connected through the outer shoulder main groove.

A pneumatic tire is configured such that: paired first main grooves extending in a tire circumferential direction are provided on the two sides of a tire equator line in a tread portion, respectively; a distance between a center position of each first main groove and the tire equator line is set at 8% to 20% of a ground contact width W; a first land portion is defined between these first main grooves; multiple sub-grooves each having a curved shape are formed in each of both edge portions of the first land portion at intervals in the tire circumferential direction; one end of each sub-groove is opened to the corresponding first main groove, and the other end of the sub-groove is terminated inside the first land portion; a rib portion continuously extending in the tire circumferential direction is formed in an area of the first land portion on the tire equator line; and a relation between a length (L) of a center line of each sub-groove and a pitch length (P) of the sub-grooves in the tire circumferential direction satisfies 1.1×P≦L≦2.0×P.

A tire tread is provided with a crown main groove, and outboard and inboard shoulder main grooves to divide the tread portion into an outboard crown land portion, an inboard crown land portion, an outboard shoulder land portion and an inboard shoulder land portion. The inboard shoulder land portion is provided with inboard shoulder lateral grooves connecting an inboard tread edge and the inboard shoulder main groove. The outboard shoulder land portion is provided with outboard shoulder lateral grooves extending axially inwardly from an outboard tread edge and terminating within the outboard shoulder land portion. The inboard crown land portion is provided with inboard crown lateral grooves extending from the inboard shoulder main groove and terminating within the inboard crown land portion. The outboard crown land portion is provided with outboard crown lateral grooves extending from the crown main groove and terminating within the outboard crown land portion.

On the surface of a tread portion (1), one central main groove (2) extends in a tire circumferential direction (C) at a pattern center, and a pair of outer main grooves (4a, 4b) extend in the tire circumferential direction (C) each at a position between the central main groove (2) and a respective one of two tread ends (3a, 3b). The central main groove (2) and the outer main grooves (4a, 4b) define central land portions (5a, 5b), and the outer main grooves (4a, 4b) and the tread ends (3a, 3b) define outer land portions (6a, 6b). Among the central land portions (5a, 5b) and the outer land portions (6a, 6b), first circumferential narrow grooves (7a, 7b) are provided only in the central land portions (5a, 5b), extend in the tire circumferential direction (C), have a narrower opening width and a shallower depth than those of the central main groove (2), and have a first groove wall (8) on the side of the outer main groove (4a, 4b) and a second groove wall (9) on the side of the central main groove (2) such that an intersection angle (θ1) between a tread surface (10) and the first groove wall (8) is larger than an intersection angle (θ2) between the tread surface (10) and the second groove wall (9).

A pneumatic tire includes first and second pairs of main grooves extending in the tire circumferential direction; and auxiliary grooves disposed in land portions located between the first and second main grooves which open to the corresponding first main groove or the corresponding second main groove and terminate within the corresponding land portion. Each of the auxiliary grooves includes a first auxiliary groove that extends from the opening portion to the bent portion and a second auxiliary groove that extends from the bent portion to the terminating end. A length a of the first auxiliary groove and a length b of the second auxiliary groove have the relationship 0.3a<b<0.8a. The angle θ made by the first auxiliary groove and the second auxiliary groove at the bent portion is in the range 0°<θ<90°.