Abstract: A sipe includes a first widened and a second widened portion. In a cross section orthogonal to the sipe extending direction, the sipe includes at least one bent portion, at least one bent portion has a widened portion where the width of sipe portions sandwiching the bent portion is increased, and at least one widened portion has a straight line portion, in which an angle formed with a line segment orthogonal to the normal line at the opening center of the sipe on the tread surface is 30° or more, in a wall surface on the major angle side of the bent portion of wall surfaces defining the widened portion.

Abstract: The projection portion includes a straight portion extended linearly in a predetermined direction, a first inclined portion inclined to spread toward an outer side in the predetermined direction from one end of the straight portion, and a second inclined portion inclined to spread toward an outer side in the predetermined direction from another end of the straight portion. A period defined by a length of the projection portion in the predetermined direction is 0.8 times to 2.0 times as large as a sipe depth defined by a length of the sipe between the wheel tread of a block and a bottom of the sipe.

Abstract: A sipe includes a first widened and a second widened portion. In a cross section orthogonal to the sipe extending direction, the sipe includes at least one bent portion, at least one bent portion has a widened portion where the width of sipe portions sandwiching the bent portion is increased, and at least one widened portion has a straight line portion, in which an angle formed with a line segment orthogonal to the normal line at the opening center of the sipe on the tread surface is 30° or more, in a wall surface on the major angle side of the bent portion of wall surfaces defining the widened portion.

Abstract: A pneumatic tire, having a plurality of sipes formed in land portions of a tread thereof so as to each extend in the tire width direction, characterized in that: in a cross section of the land portion orthogonal to the sipe extending direction, provided that an imaginary sipe main line links two ends in the tire radial direction of each sipe, at least two of the sipes are “inclined sipes” each having the sipe main line inclined with respect to the tire radial direction; each inclined sipe has inner bent portions each protruding with respect to the sipe main line with peaks positioned deeper than 20% of the sipe depth; and the sipe main line(s) of at least one of the inclined sipes are inclined in a direction opposite, with respect to the tire radial direction, to the sipe main line of any of the other inclined sipes.

Abstract: A tire mold includes a mold surface for vulcanizing and molding a tire, and a blade for vulcanizing and molding a sipe formed in the mold surface. The blade includes a concave-convex surface in which a plurality of convex portions formed adjacent to each other and a plurality of concave portions formed between the adjacent convex portions adjacent to each other are formed. A length of the concave portion is smaller than a length of the convex portion in a concave-convex surface view. The concave portion is sharp in a depth direction of the concave portion.

Abstract: The projection portion 150 includes a straight portion 152 extended linearly in a predetermined direction, a first inclined portion 151 inclined to spread toward an outer side in the predetermined direction from one end of the straight portion 152, and a second inclined portion 153 inclined to spread toward an outer side in the predetermined direction from another end of the straight portion 152. A period defined by a length of the projection portion 150 in the predetermined direction is 0.8 times to 2.0 times as large as a sipe depth defined by a length of the sipe 100A between the wheel tread of a block 20A and a bottom of the sipe 100A.

Abstract: A pneumatic tire (10), which has, in the surface of the tread (11), lug grooves (15) on one side extending from one axial edge towards the axial center of the tire in such a manner as to intersect with the circumferential direction of the tire and lug grooves (15) on the other side extending in a symmetrically opposite direction from the axial center towards the other axial edge of the tire, has at least one circumferential groove (12) extending circumferentially around the tire. Also, circumferential grooves (12, 13a, 13b) are so formed as to satisfy a relationship of “1?(S/L)?3” where L is the axial length of the central region, which is the region enclosed by two straight parallel lines each passing through the center between the contact width center (CL) and the contact edge with the shoulder regions being the regions axially outside of the parallel lines, and S is the total of the groove areas of the circumferential grooves (12, 13a, 13b) disposed in the central region.

Abstract: Provided is a pneumatic tire including a land portion provided with a sipe, which is capable of simultaneously providing snow performance, dry performance, and wet performance all at high level in a single land portion. The pneumatic tire includes a land portion 2 on a tread portion. The land portion 2 is provided with a sipe 5 having amplitude in a tire circumferential direction and extending in a tire width direction. In a depth direction extending from a land portion surface S toward an inner side in a tire radial direction, sipe 5 includes: a land portion's surface-side part 5a1 bent toward tire circumferential direction from land portion surface S; and a land portion's bottom-side part 5a2 bent in a direction different from a direction of land portion's surface-side part 5a1 or bent toward tire circumferential direction by a displacement different from a displacement of land portion's surface-side part 5a1.

Abstract: A pneumatic tire (10) has, in the surface of the tread (11), a central circumferential groove (12) located at the center of the contact patch width and extending circumferentially around the tire, a plurality of longitudinal grooves (13 (13a, 13b)) formed on the axially outside of the central circumferential groove (12), lug grooves (15), and blocks (16 (16a to 16c)) defined by the central circumferential groove (12), the longitudinal grooves (13), and the lug grooves (15). Each of the lug grooves (15) is formed such that its width in the shoulder region is greater than its width in the central region, and the sum of the groove area of the central circumferential groove (12) and the groove area of the longitudinal grooves (13) is smaller than the area of the lug grooves (15).

Abstract: A pneumatic tire, comprising: a tread surface; a plurality of grooves formed in the tread surface, including a plurality of widthwise grooves each extending from a corresponding tread end on the inner side in the tread width direction and a plurality of circumferential grooves each extending in the tread circumferential direction to intersect the widthwise grooves; blocks demarcated by the plurality of grooves; and a chamfered portion formed at a corner, on the trailing edge side and on the outer side in the tread width direction, of each block.

Abstract: A tire having V-shaped lug grooves displays both improved grip performance on snow and anti-hydroplaning performance. To that end, an absolute value of difference between a lug groove diagonal angle (?LG), which is an angle of diagonal lug grooves (13) in a tread (11) surface with respect to a tire axial direction, and a profile line diagonal angle (?FP), which is an angle of a normal line of a leading-end profile line of a contact patch shape of the tire (10) with respect to the tire axial direction, is set to 0° or more and 60° or less at respective positions in the tire axial direction.

Abstract: A pneumatic tire having enhanced on-ice braking performance achieved by further increasing the amount of water that can be sucked up into sipes. In the pneumatic tire, blocks (26) partitioned by circumferential grooves and lateral grooves are formed in the tread. A sipe (28) is formed in a block (26), and a fine structure (32) having a height in the range of from 1/50 of the sipe width t to less than 1/10 of the sipe width t is formed on a sipe wall surface. This reduces fluid friction coefficient of water relative to the sipe wall surface to a lower level than conventional products. As a result, when water staying on ice comes into contact with the sipe wall surface, the water is more easily sucked up into the sipe. The construction increases the amount of water that can be sucked up into the sipe (28) or the removal amount of water that stays on ice etc., and this enhances braking performance (friction characteristics) on ice.

Abstract: A pneumatic tire (10) has, in the surface of the tread (11), a central circumferential groove (12) located at the center of the contact patch width and extending circumferentially around the tire, a plurality of longitudinal grooves (13 (13a, 13b)) formed on the axially outside of the central circumferential groove (12), lug grooves (15), and blocks (16 (16a to 16c)) defined by the central circumferential groove (12), the longitudinal grooves (13), and the lug grooves (15). Each of the lug grooves (15) is formed such that its width in the shoulder region is greater than its width in the central region, and the sum of the groove area of the central circumferential groove (12) and the groove area of the longitudinal grooves (13) is smaller than the area of the lug grooves (15).

Abstract: A pneumatic tire (10), which has, in the surface of the tread (11), lug grooves (15) on one side extending from one axial edge towards the axial center of the tire in such a manner as to intersect with the circumferential direction of the tire and lug grooves (15) on the other side extending in a symmetrically opposite direction from the axial center towards the other axial edge of the tire, has at least one circumferential groove (12) extending circumferentially around the tire. Also, circumferential grooves (12, 13a, 13b) are so formed as to satisfy a relationship of “1?(S/L)?3” where L is the axial length of the central region, which is the region enclosed by two straight parallel lines each passing through the center between the contact width center (CL) and the contact edge with the shoulder regions being the regions axially outside of the parallel lines, and S is the total of the groove areas of the circumferential grooves (12, 13a, 13b) disposed in the central region.

Abstract: A pneumatic tire, comprising: a tread surface; a plurality of grooves formed in the tread surface, including a plurality of widthwise grooves each extending from a corresponding tread end on the inner side in the tread width direction and a plurality of circumferential grooves each extending in the tread circumferential direction to intersect the widthwise grooves; blocks demarcated by the plurality of grooves; and a chamfered portion formed at a corner, on the trailing edge side and on the outer side in the tread width direction, of each block.

Abstract: A pneumatic tire, having a plurality of sipes formed in land portions of a tread thereof so as to each extend in the tire width direction, characterized in that: in a cross section of the land portion orthogonal to the sipe extending direction, provided that an imaginary sipe main line links two ends in the tire radial direction of each sipe, at least two of the sipes are “inclined sipes” each having the sipe main line inclined with respect to the tire radial direction; each inclined sipe has inner bent portions each protruding with respect to the sipe main line with peaks positioned deeper than 20% of the sipe depth; and the sipe main line(s) of at least one of the inclined sipes are inclined in a direction opposite, with respect to the tire radial direction, to the sipe main line of any of the other inclined sipes.

Abstract: Provided is a pneumatic tire including a land portion provided with a sipe, which is capable of simultaneously providing snow performance, dry performance, and wet performance all at high level in a single land portion. The pneumatic tire includes a land portion 2 on a tread portion. The land portion 2 is provided with a sipe 5 having amplitude in a tire circumferential direction and extending in a tire width direction. In a depth direction extending from a land portion surface S toward an inner side in a tire radial direction, sipe 5 includes: a land portion's surface-side part 5a1 bent toward tire circumferential direction from land portion surface S; and a land portion's bottom-side part 5a2 bent in a direction different from a direction of land portion's surface-side part 5a1 or bent toward tire circumferential direction by a displacement different from a displacement of land portion's surface-side part 5a1.

Abstract: There is provided a pneumatic tire to improve on-ice braking performance.