Tire
A pneumatic tire includes circumferential grooves, lug grooves, land portions defined by the circumferential grooves and the lug grooves, and a narrow groove in the land portions that extends in a circumferential direction. At least one of the circumferential grooves that defines the land portions in which the narrow groove is disposed has an amplitude in a width direction while extending in the circumferential direction to be formed in zigzag shape including long and short portions having relatively different lengths. The narrow groove has one or more bent portions where an extension direction changes in the land portions to include a long portion and a short portion having relatively different lengths. The long portion of the narrow groove has an inclination direction in the width direction with respect to the circumferential direction in a direction opposite to the long portion of the at least one of the circumferential grooves.
1 . A tire, comprising:
a plurality of circumferential grooves extending in a tire circumferential direction;
a plurality of lug grooves extending in a tire width direction;
a plurality of land portions defined by the circumferential grooves and the lug grooves; and
only a single one of a circumferential narrow groove that extends in the tire circumferential direction and is disposed in one of the land portions, the circumferential narrow groove having a narrower groove width in the tire width direction than a groove width of each of the circumferential grooves;
a zigzag circumferential groove is disposed having an amplitude in the tire width direction while extending in the tire circumferential direction to be formed in a zigzag shape comprising a long portion and a short portion having different lengths,
the circumferential narrow groove having only two bent portions where an extension direction changes in the one of the land portions to comprise a plurality of long portions and a short portion having different lengths,
one of the long portions of the circumferential narrow groove opens to one of the lug grooves and has an inclination direction in the tire width direction with respect to the tire circumferential direction in a direction opposite to the long portion of the zigzag circumferential groove, wherein
one end of the lug grooves opens to the zigzag circumferential groove and another end of the lug grooves opens to a shoulder circumferential groove provided on an outermost side in the tire width direction,
an inclination direction of the one end to the another end of the lug grooves in the tire width direction with respect to the tire circumferential direction and an inclination direction of the short portion of the circumferential narrow groove in the tire width direction with respect to the tire circumferential direction are the same,
the land portion including the circumferential narrow groove is disposed between the shoulder circumferential groove and the zigzag circumferential groove inward of the shoulder circumferential groove in the tire width direction,
the shoulder circumferential groove extends in the tire circumferential direction to be formed in a linear shape,
the short portion of the circumferential narrow groove is between the only two bent portions and the long portions are connected to each of two ends of the short portion, and
the circumferential narrow groove has a groove width in a range of from 1.5 mm or more to 4 mm or less.
2 . The tire according to claim 1 , wherein the circumferential narrow groove has plural ends, one end opening to the one of the lug grooves and an other end opening to an other one of the lug grooves.
3 . The tire according to claim 1 , wherein the circumferential narrow groove has a change point of a groove depth at least at one location in the one of the land portions.
4 . The tire according to claim 1 , wherein at least one of the long portions of the circumferential narrow groove has an inclination in the tire width direction with respect to the tire circumferential direction in a range from 5° or more to 45° or less.
5 . The tire according to claim 1 , wherein the long portion of the zigzag circumferential groove has an inclination in the tire width direction with respect to the tire circumferential direction in a range from 5° or more to 30° or less.
6 . The tire according to claim 1 , wherein at least one bent portion among the only two bent portions comprised in the circumferential narrow groove has a bend angle of 90° or more.
7 . The tire according to claim 1 , wherein a total length of the long portions comprised in the circumferential narrow groove is in a range from 60% or more to 90% or less of a whole length of the circumferential narrow groove.
8 . The tire according to claim 1 , wherein at least one bent portion among the only two bent portions of the circumferential narrow groove is disposed in a range of 40% of a maximum width of the one of the land portions in the tire width direction with a center in the tire width direction of the one of the land portions in which the circumferential narrow groove is disposed as a center.
9 . The tire according to claim 1 , wherein
the zigzag circumferential groove has the groove width in a range from 3.5 mm or more to 12 mm or less.
10 . The tire according to claim 1 , wherein
at least some of the plurality of land portions intersect the tire equatorial plane.
11 . The tire according to claim 1 , wherein in the land portions, a plurality of sipes extending in the tire width direction are disposed.
12 . The tire according to claim 11 , wherein the sipes are inclined with respect to the tire circumferential direction in a direction opposite to the inclination direction of the long portions of the circumferential narrow groove in the tire width direction with respect to the tire circumferential direction.
13 . A tire, comprising:
a plurality of circumferential grooves extending in a tire circumferential direction;
a plurality of lug grooves extending in a tire width direction;
a plurality of land portions defined by the circumferential grooves and the lug grooves; and
only a single one of a circumferential narrow groove that extends in the tire circumferential direction and is disposed in one of the land portions, the circumferential narrow groove having a narrower groove width in the tire width direction than a groove width of each of the circumferential grooves;
a zigzag circumferential groove among the circumferential grooves that define the one of the land portions in which the circumferential narrow groove is disposed having an amplitude in the tire width direction while extending in the tire circumferential direction to be formed in a zigzag shape comprising a long portion and a short portion having different lengths,
the circumferential narrow groove having only two bent portions where an extension direction changes in the one of the land portions to comprise a plurality of long portions and a short portion having different lengths,
one of the long portions of the circumferential narrow groove opens to one of the lug grooves and has an inclination direction in the tire width direction with respect to the tire circumferential direction in a direction opposite to the long portion of the zigzag circumferential groove, wherein
one end of the lug grooves opens to the zigzag circumferential groove and another end of the lug grooves opens to a zigzag shoulder circumferential groove provided on an outermost side in the tire width direction,
an inclination direction of the one end to the another end of the lug grooves in the tire width direction with respect to the tire circumferential direction and an inclination direction of the short portion of the circumferential narrow groove in the tire width direction with respect to the tire circumferential direction are the same,
the land portion including the circumferential narrow groove is disposed between the zigzag shoulder circumferential groove and the zigzag circumferential groove inward of the shoulder circumferential groove in the tire width direction,
the short portion is between the only two bent portions, and the long portions are connected to each of the two ends of the short portion, and
the circumferential narrow groove has a groove width in a range of from 1.5 mm or more to 4 mm or less.
14 . The tire according to claim 13 , wherein
at least some of the plurality of land portions intersect the tire equatorial plane.
15 . The tire according to claim 13 , wherein the circumferential narrow groove has one end opening to one of the lug grooves and another end opening to another one of the lug grooves.
16 . The tire according to claim 15 , wherein the circumferential narrow groove has a change point of a groove depth at least at one location in the one of the land portions.
17 . The tire according to claim 16 , wherein at least one of the long portions of the circumferential narrow groove has an inclination in the tire width direction with respect to the tire circumferential direction in a range from 5° or more to 45° or less.
18 . The tire according to claim 17 , wherein the long portion of the zigzag circumferential groove has the inclination in the tire width direction with respect to the tire circumferential direction in a range from 5° or more to 30° or less.
19 . The tire according to claim 18 , wherein at least one bent portion among the only two bent portions comprised in the circumferential narrow groove has a bend angle of 90° or more.
20 . The tire according to claim 19 , wherein in the circumferential narrow groove, the long portion comprises a plurality of long portions and a total length of the long portions comprised in the circumferential narrow groove is in a range from 60% or more to 90% or less of a whole length of the circumferential narrow groove.
21 . The tire according to claim 20 , wherein the at least one bent portion among the only two bent portions of the circumferential narrow groove is disposed in a range of 40% of a maximum width of the one of the land portions in the tire width direction with a center in the tire width direction of the one of the land portions in which the circumferential narrow groove is disposed as a center.
22 . The tire according to claim 21 , wherein
the zigzag circumferential groove has the groove width in a range from 3.5 mm or more to 12 mm or less,
in the land portions, a plurality of sipes extending in the tire width direction are disposed, and
the sipes are inclined with respect to the tire circumferential direction in a direction opposite to the inclination direction of the long portion of the circumferential narrow groove in the tire width direction with respect to the tire circumferential direction.