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 tread pattern includes a center main groove extending in a circumferential direction, first and second inclined lug grooves located on respective first and second sides in a lateral direction and extending from the center main groove toward the respective first and second sides in the lateral direction with respect to the circumferential direction, and inner branched lug grooves each branched from a middle of a corresponding one of the first and second inclined lug grooves, inclined identically to an inclination direction of the first and second inclined lug grooves, and connected to the center main groove. The first and second inclined lug grooves include a center portion extending outward from the center main groove in the lateral direction, an outer portion extending inward from a shoulder side in the lateral direction, and a bent portion at which the center and outer portions are bent and connected together.

The present technology relates to a pneumatic tire in which the ratio of the total width SW and the outer diameter OD satisfies SW/OD0.3, and grooves are provided on the tread portion. In the ground contact region of the tread portion, when the groove area ratio in the ground contact area is GR, the ground contact width is W, the region having a width of 50% of the ground contact width W and the tire equatorial plane as center is the center region, the groove area ratio in the center region is GCR, the ground contact region on the outer side in the tire width direction of the center region is the shoulder region, and the groove area ratio in the shoulder region is GSR, the ground contact region of the tread portion is formed to satisfy 10%GR25% and GCR>GSR.

In a pneumatic tire, a pair of first center blocks and two or more second center blocks are alternately arranged in the tire circumferential direction to form a block row of a center land portion. Additionally, the block row of the center land portion is obtained by coupling in a row in the tire circumferential direction and in a zigzag shape via coupling grooves each including a groove bottom portion shallower than first and second inclined lug grooves.

In a pneumatic tire, an inner shoulder land portion includes shoulder lug grooves that extend in the tire lateral direction. Additionally, an inner second land portion includes the through lug groove that extends through the inner second land portion in the tire lateral direction. A center land portion includes a single circumferential narrow groove extending in the tire circumferential direction and center lug grooves that each open at one end portion to the edge portion on the vehicle width direction inner side of the center land portion and terminate at the other end portion, communicating with a circumferential narrow groove. The shoulder lug groove, the through lug groove, and the center lug groove form one communication lug groove extending continuously from a tire ground contact edge toward a tire equatorial plane.

A heavy duty tire can have a tread portion that includes a plurality of circumferential grooves that zigzag, a plurality of lateral grooves connecting between zigzag vertexes of the circumferential grooves, and a plurality of hexagonal blocks formed by the circumferential grooves and the lateral grooves. A groove depth of the circumferential groove can be 21 mm or more. Each of the hexagonal blocks can include a three-dimensional sipe extending across the hexagonal block. The lateral groove can include a raised portion formed by raising a groove bottom of the lateral groove to connect between the hexagonal blocks adjacent to each other in the tire circumferential direction.

The present invention provides a tire for a vehicle comprising: a rotation axis, a midplane at a central position along the rotation axis; a circumferential tread portion around the rotation axis, the circumferential tread portion comprising: a tread pattern exhibiting at least a first pitch pattern and a second pitch pattern each comprising: a center block crossed by the midplane, and two side block alignments, said side block alignments being inclined with respect to one another and extending from the center block; the first pitch pattern including: a first pitch length, a first number of blocks; the second pitch pattern including: a second pitch length which is shorter than the first pitch length, and a third number of blocks which is greater than the first number of blocks.

In regions, divided by the tire equator, on both sides of the tread surface of a tire, the tire includes a grip area along the entire circumference of the tread, the grip area including a plurality of recessed lines, with a shape recessed toward an inner side of the tire from the outline of the tread surface, that extend from the tread edge side in a direction inclined relative to the tire equator and are arrayed in parallel, and a plurality of sipes that extend toward the tire equator in a direction inclined relative to the tire equator, starting in the grip area and terminating before the tire equator. The negative ratio in the grip area is higher than the negative ratio closer to the tire equator than the grip area.

A tire tread (1), for a heavy-duty construction plant vehicle, having an improved compromise between resistance to mechanical attack caused by stony ground and grip on muddy ground. The tread (1) having five rows (41, 42, 43) separated in pairs by a longitudinal cut (51, 52) and distributed, along the transverse direction (YY), in a median row (43), two intermediate rows (42), and two lateral rows (41), the blocks (31, 32, 33) in one and the same row (41, 42, 43) being separated in pairs by a transverse cut (61, 62, 63), each transverse cut in a lateral row (41) is a transverse groove, each transverse cut (62) in an intermediate row (42) with a first transverse groove portion (621) and a second transverse sipe portion (622), and each transverse cut (63) in the median row (43) is a transverse sipe which is offset along the longitudinal direction (XX).

A pneumatic tire having a tread portion and a belt layer, wherein the reinforcing cords in the belt layer are composed of monofilament cords arranged in the tire width direction at least 50 cords/5 cm in the cross section of the belt layer in the tire radial direction. A pneumatic tire that is installed on a standardized rim and satisfies the following (formula 1), where Wt (mm) is the cross-sectional width of the tire and Dt (mm) is the outer diameter of the tire when the internal pressure is 250 kPa:

1500(Dt.sup.2/4)/Wt(formula 1).