Heavy duty tire
Provided is a heavy duty tire 2 that can suppress a decrease in durability due to the provision of a band and can achieve improvement of uneven wear resistance. The tire 2 includes a reinforcing layer 20 and a tread 4 . The tread 4 has shoulder circumferential grooves 34 . The reinforcing layer 20 includes a belt 52 and a band 54 . The belt 52 includes an inner belt ply 74 and an outer belt ply 76 . The band 54 includes a full band 66 . The full band 66 is located between the inner belt ply 74 and the outer belt ply 76 . A distance UFc between the full band 66 and the inner belt ply 74 is longer than a distance SFc between the full band 66 and the outer belt ply 76 at an equator plane of the tire 2.
1 . A heavy duty tire having a nominal aspect ratio of not less than 70%, the tire comprising:
a pair of beads;
a carcass extending on and between the pair of beads;
a reinforcing layer located radially outward of the carcass; and
a tread covering the reinforcing layer and configured to come into contact with a road surface, wherein
the tread has a plurality of circumferential grooves extending continuously in a circumferential direction,
the plurality of circumferential grooves include a shoulder circumferential groove located on each outermost side in an axial direction,
the reinforcing layer includes a belt including a large number of belt cords aligned with each other, and a band including a helically wound band cord,
the belt includes an inner belt ply and an outer belt ply aligned in a radial direction,
a direction of inclination of the belt cords included in the inner belt ply is opposite to a direction of inclination of the belt cords included in the outer belt ply,
the band includes a full band located between the inner belt ply and the outer belt ply,
ends of the inner belt ply, the outer belt ply, and the full band are located axially outward of the shoulder circumferential groove,
a distance UFc between the full band and the inner belt ply is longer than a distance SFc between the full band and the outer belt ply at an equator plane of the tire,
a ratio (UFc/SFc) of the distance UFc between the full band and the inner belt ply to the distance SFc between the full band and the outer belt ply at the equator plane of the tire is not less than 2.0,
a cord density of the full band is not less than 22 ends/50 mm, and
the band includes an edge band, and each narrow buffer layer is between the edge band and the outer belt ply.
2 . The heavy duty tire according to claim 1 , wherein the distance UFc between the full band and the inner belt ply at the equator plane of the tire is not less than 0.6 mm.
3 . The heavy duty tire according to claim 1 , wherein a distance UFs between the full band and the inner belt ply at the end of the full band is not greater than 2.5 mm.
4 . The heavy duty tire according to claim 1 , wherein the distance UFc between the full band and the inner belt ply at the equator plane of the tire is longer than a distance UFs between the full band and the inner belt ply at the end of the full band.
5 . The heavy duty tire according to claim 4 , wherein a ratio (UFc/SFc) is not less than 2.0 and not greater than 3.0.
6 . The heavy duty tire according to claim 5 , wherein a ratio of a cord density of the inner belt ply to a cord density of the outer belt ply is not less than 1.05 and not greater than 1.50.
7 . The heavy duty tire according to claim 1 , wherein a ratio of a cord density of the inner belt ply to a cord density of the full band is not less than 0.65.
8 . The heavy duty tire according to claim 1 , wherein
an angle FU formed between the band cord of the full band and the belt cords of the inner belt ply is not less than 10 degrees and not greater than 25 degrees, and
an angle FS formed between the band cord of the full band and the belt cords of the outer belt ply is not less than 10 degrees and not greater than 25 degrees.
9 . The heavy duty tire according to claim 1 , wherein an angle UE of the belt cords of the inner belt ply with respect to the equator plane of the tire is smaller than an angle SE of the belt cords of the outer belt ply with respect to the equator plane of the tire.
10 . The heavy duty tire according to claim 1 , wherein a cord density of the inner belt ply is higher than a cord density of the outer belt ply.
11 . The heavy duty tire according to claim 1 , wherein
the plurality of circumferential grooves demarcate a plurality of land portions aligned in the axial direction in the tread,
among the plurality of land portions, a land portion located on the equator plane of the tire or a land portion closest to the equator plane is a center land portion,
the center land portion has a transverse sipe traversing the center land portion,
the transverse sipe has a sipe body and a tubular portion located radially inward of the sipe body, and
the tubular portion has a groove width wider than a groove width of the sipe body.
12 . The heavy duty tire according to claim 1 , wherein a ratio (SFs/SFc) of a distance SFs, which is a distance between the band cord and the belt cord of the outer belt ply closest to the end of the full band, to the distance SFc is not less than 0.95 and not greater than 1.05.
13 . The heavy duty tire according to claim 1 , wherein a ratio (UFc/UFs) of the distance UFc to a distance UFs between the full band and the inner belt ply at the end of the full band is not less than 1.05 and not greater than 1.50.
14 . The heavy duty tire according to claim 1 , wherein a wide buffer layer is located between the full band and the inner belt ply.
15 . The heavy duty tire according to claim 1 , wherein a ratio of a cord density of the inner belt ply to a cord density of the outer belt ply is not less than 1.05 and not greater than 1.50.
16 . The heavy duty tire according to claim 15 , wherein a ratio (UFc/UFs) of the distance UFc to a distance UFs between the full band and the inner belt ply at the end of the full band is not less than 1.05 and not greater than 1.50.
17 . The heavy duty tire according to claim 16 , wherein a ratio of a cord density of the inner belt ply to a cord density of the outer belt ply is not less than 1.05 and not greater than 1.50.
18 . A heavy duty tire having a nominal aspect ratio of not less than 70%, the tire comprising:
a pair of beads;
a carcass extending on and between the pair of beads;
a reinforcing layer located radially outward of the carcass; and
a tread covering the reinforcing layer and configured to come into contact with a road surface, wherein
the tread has a plurality of circumferential grooves extending continuously in a circumferential direction,
the plurality of circumferential grooves include a shoulder circumferential groove located on each outermost side in an axial direction,
the reinforcing layer includes a belt including a large number of belt cords aligned with each other, and a band including a helically wound band cord,
the belt includes an inner belt ply and an outer belt ply aligned in a radial direction,
a direction of inclination of the belt cords included in the inner belt ply is opposite to a direction of inclination of the belt cords included in the outer belt ply,
the band includes a full band located between the inner belt ply and the outer belt ply,
ends of the inner belt ply, the outer belt ply, and the full band are located axially outward of the shoulder circumferential groove,
a distance UFc between the full band and the inner belt ply is longer than a distance SFc between the full band and the outer belt ply at an equator plane of the tire,
a wide buffer layer is located between the full band and the inner belt ply, and
the band includes an edge band, and each narrow buffer layer is between the edge band and the outer belt ply.