A tire comprises a tread portion provided with at least one longitudinal groove extending in a tire circumferential direction. The longitudinal groove has a groove bottom surface and a pair of groove wall surfaces extending outwardly in a tire radial direction from the groove bottom surface. The groove bottom surface is provided with a groove bottom protruding portion protruding outwardly in the tire radial direction. At least one of the pair of the groove wall surfaces is provided with a groove wall protruding portion protruding toward a side of a groove center of the longitudinal groove.

A tire comprises a tread portion 2 comprising a shoulder main groove 5 extending on a side of a tread edge Te and comprising inner and outer groove walls 11 and 12. The inner groove wall 11 has an angle 1 with respect to a tread normal line in a cross section of the shoulder main groove 5 periodically increasing and decreasing in a tire circumferential direction so as to comprise concave and convex wall portions 16 and 17 arranged alternately in the tire circumferential direction. The outer groove wall 12 has an angle 2 with respect to a tread normal line in the cross section periodically increasing and decreasing in the tire circumferential direction so as to comprise convex and concave wall portions 22 and 21 arranged alternately in the tire circumferential direction. The angle 2 is larger than the angle 1 in any cross section of the groove.

A tire comprises a tread portion 2 comprising a shoulder main groove 5 extending on a side of a tread edge (Te). The shoulder main groove 5 comprises an inner groove wall 11 having an angle with respect to its tread normal line in a cross section of the shoulder main groove 5 periodically increasing and decreasing in a tire circumferential direction so that the inner groove wall 11 comprises concave wall portions 16 and convex wall portions 17 arranged alternately in the tire circumferential direction. The concave wall portions 16 are provided at inner end portions thereof in a tire axial direction with recess portions 20 locally recessed inwardly in the tire axial direction and having openings at a ground contacting surface of the tread portion 2.

A vehicle tire includes a tread portion provided in the tread surface with a circumferentially continuously extending groove having a bottom and a pair of opposite side walls, wherein at least one of the side walls is provided with protrusions protruding into the groove and arranged in the tire circumferential direction. The protrusion has a gradually increasing part in which the area of the cross section of the protrusion being parallel with the tread surface is gradually increased toward the radially outer side of the tire.

Tire tread (1) comprising groove (2) of depth (P) that opens onto tread surface (10) of the tread in the new state, this groove comprising a plurality of first and second portions of groove, each first portion (21) of groove being delimited by facing walls (211, 212) spaced apart by a maximum width (L1) measured at the tread surface when new, these walls (211, 212) approaching one another such that, at a depth (H11) between 20 and 80% of the total depth (P) of the groove, they are spaced apart by a width (L1) less than the maximum width (L1). Walls (211, 212) diverge from one another down to the depth (P) of the groove such that they are spaced apart from one another by a width (L1). Each second portion (22) of groove is delimited by facing walls (221, 222) spaced apart by a minimum width (L2) measured at the tread surface (10) when new, these walls (221, 222) diverging from one another such that, at a depth (H21) between 20% and 80% of the total depth (P) of the groove, they are spaced apart from one another by a width (L2) greater than the width (L2). Walls (221, 222) then approach one another down to the depth (P) of the groove such that they are spaced apart by a width (L2). Groove (2) is formed by a plurality of first and second portions of groove so as to form a continuous passage (3) between all the portions of groove in order to allow liquid to flow in the groove regardless of the level of wear, this continuous passage (3) being broken down into two elementary passages (31, 32).

The disclosed technology relates generally to a pneumatic tire, and more particularly to a pneumatic tire capable of enhancing running performance on wet surfaces (wet performance) without reducing of running performance on dry surfaces (dry performance) by having an improved groove structure. In one aspect, a pneumatic tire includes a tread, a sidewall and a bead, wherein the tread has a block and a groove formed thereon. First inclined portions inclined toward the bottom of the groove on the side of the groove are alternately installed in a longitudinal direction of the groove.

A pneumatic tire includes rib-shaped land parts adjacent to each other with a circumferential groove therebetween, and raised-row-shaped projections projecting toward each other from both mutually opposed side wall surfaces of the adjacent rib-shaped land parts are provided to extend in the tread circumferential direction. As compared to a raised-row-shaped projection in an outermost-side circumferential groove located on a tire width direction outermost side, a raised-row-shaped projection in an inner adjacent circumferential groove located on tire width direction inner side of and adjacent to the outermost-side circumferential groove is formed at a shallower position near a tread surface between the tread surface and the groove bottom. As a result, it is possible to obtain suitable drainage properties according to the tire width direction positions of the circumferential grooves, while restraining an increase in rolling resistance, and to realize improved wet grip performance owing to an enlarged grounding area.

Pneumatic vehicle tire, in particular a commercial vehicle tire, having a tread which has a profile and has at least one circumferential groove (1) which is encircling in the circumferential direction, is embodied to a profile depth (P.sub.T) and in the cross section, starting at the tread external face, is composed of three adjoining groove portions, one outer groove portion (2) that expands in a funnel-shaped manner toward the outside, one 1 mm to 3 mm wide contracted groove portion, and one inner groove portion (4) which lies radially inward, is expanded in relation to the contracted groove portion (3) and has the largest cross-sectional face of all portions, and which is delimited by two cover flanks (4a), lateral groove flanks (4b, 4b) that adjoin said cover flanks (4a), and a groove base (4c). The lateral groove flanks (4b, 4b) in the expanded groove portion (4), while reducing the mutual spacing thereof from the groove base (4c), run at an angle () of 5 to 25 in relation to the radial direction and in the direction of the circumferential extent of said lateral groove flanks (4b, 4b) run in a wave form

A tire having a circumferential groove having a groove bottom and a pair of groove walls. The groove bottom is provided with groove bottom raised portions protruding radially outwardly from a reference plane 5a. The groove bottom raised portions are a first groove bottom raised portion located on a first side in the width direction of the circumferential groove and a second groove bottom raised portion located on a second side in the width direction. The first and second groove bottom raised portions each has a plurality of repeating units having a first bottom surface extending substantially in the tire radial direction and a second bottom surface inclined with respect to the tire radial direction at a larger angle than the first bottom surface. The inclination direction of the second bottom surfaces of the first groove bottom raised portion is opposite to the inclination direction of the second bottom surfaces of the second groove bottom raised portion.

A pneumatic tire is provided in the tread portion with zigzag middle main grooves 4 and shoulder main grooves 5 to define middle land regions 7 therebetween. The middle main groove is composed of alternately-arranged, oppositely-inclined long first oblique segments 11 and short second oblique segments 12. The middle land regions are provided with middle transverse grooves 20 shallower than the middle main grooves. The first oblique segments are inclined axially outwardly toward the opposite direction to the intended tire rotational direction R. The middle transverse grooves are inclined to the same direction as the first oblique segments or in parallel with the tire axial direction. The axially inner end of each of the middle transverse grooves is connected to one of the second oblique segments so as to include at least a part of an axially outwardly protruding outside corner portion 4A of the middle main groove.