Pneumatic tire
View Patent ↗A pneumatic tire wherein a distance t from an equatorial plane of a tire to outer circumferential main grooves and a distance b from the equatorial plane of the tire to an edge of a belt edge cushion in the width direction of the tire satisfy 0.85≦t/b≦0.90, in a cross-section in a meridian direction of the tire. Moreover, a distance d, which is half the width of a belt ply having the largest width, and a distance u from the equatorial plane of the tire to narrow grooves, satisfy 0.97≦d/u≦1.03. Furthermore, a distance a, which is half the width of a belt ply in the outermost layer, and a distance t, of outer circumferential main grooves, satisfy 1.15≦a/t≦1.25.
1. A pneumatic tire formed by laminating a plurality of belt plies, comprising:
a belt layer arranged on an outer side of a carcass layer in a radial direction of the pneumatic tire;
a belt edge cushion arranged on an edge of the belt plies;
at least four circumferential main grooves in a tread of the pneumatic tire extending in the radial direction of the pneumatic tire forming and partitioning a plurality of land portions, and further comprising narrow grooves forming narrow ribs on an edge of an outer side of the land portions in a width direction of the tire and arranged on a tread shoulder area land portion;
wherein the at least four circumferential main grooves comprise outer circumferential main grooves located on edge sides of a footprint of the pneumatic tire; and
wherein a cross-section of the pneumatic tire in a tire meridian direction comprises:
a distance t from a tire equatorial plane to the outer circumferential main grooves and a distance b from the tire equatorial plane to the edge of an inner side of the belt edge cushion in the tire width direction such that that 0.85≦t/b≦0.90 is satisfied;
a width d comprising half the width of a largest width belt ply, and a distance u extending from the tire equatorial plane to the narrow grooves such that 0.97≦d/u≦1.03 is satisfied; and
a width a comprising half the width of an outermost layer belt ply, and the distance t, such that 1.15≦a/t≦1.25 is satisfied.
2. A pneumatic tire in accordance with claim 1 , the at least four circumferential main grooves further comprising inner circumferential main grooves located near the tire equatorial plane, and wherein a relationship between a distance s from the equatorial plane of the tire to the inner circumferential main grooves and the distance u from the tire equatorial plane to the narrow grooves satisfies 0.18≦s/u≦0.20.
3. A pneumatic tire in accordance with claim 2 , wherein the relationship between the distance t of the outer circumferential main grooves and the distance u of the narrow grooves satisfies 0.55≦t/u≦0.60.
4. A pneumatic tire in accordance with claim 3 , the plurality of belt plies further comprising intermediate belt plies arranged between the belt plies in the outermost layer and the belt plies having the largest width, and wherein a distance D1 from an outer circumferential main groove floor of the outer circumferential main grooves to the belt plies in the outermost layer, a distance D2 from a narrow groove floor of the narrow grooves to an edge of the intermediate belt plies on the outer side in the tire width direction, and a distance D3 from the groove floor of the narrow grooves to the belt plies that have the largest width, satisfy 0.35≦D1/D2≦0.40 and 0.85≦D2/D3≦1.00.
5. A pneumatic tire in accordance with claim 4 , wherein a relationship between a groove depth G1 of the outer circumferential main grooves and a groove depth G2 of the narrow grooves satisfies 0.80≦G2/G1≦1.00.
6. A pneumatic tire in accordance with claim 5 , wherein a center part of the land portion in the tread shoulder area is sipeless.
7. A pneumatic tire in accordance with claim 6 , wherein the pneumatic tire comprises a heavy duty pneumatic tire.
8. A pneumatic tire in accordance with claim 1 , the plurality of belt plies further comprising intermediate belt plies arranged between the belt plies in the outermost layer and the belt plies having the largest width, and wherein a distance D1 from an outer circumferential main groove floor of the outer circumferential main grooves to the belt plies in the outermost layer, a distance D2 from a narrow groove floor of the narrow grooves to an edge of the intermediate belt plies on the outer side in the tire width direction, and a distance D3 from the groove floor of the narrow grooves to the belt plies that have the largest width, satisfy 0.35≦D1/D2≦0.40 and 0.85≦D2/D3≦1.00.
9. A pneumatic tire in accordance with claim 1 , wherein the relationship between the distance t of the outer circumferential main grooves and the distance u of the narrow grooves satisfies 0.55≦t/u≦0.60.
10. A pneumatic tire in accordance with claim 1 , the plurality of belt plies further comprising intermediate belt plies arranged between the belt plies in the outermost layer and the belt plies having the largest width, and wherein a distance D1 from an outer circumferential main groove floor of the outer circumferential main grooves to the belt plies in the outermost layer, a distance D2 from a narrow groove floor of the narrow grooves to an edge of the intermediate belt plies on the outer side in the tire width direction, and a distance D3 from the groove floor of the narrow grooves to the belt plies that have the largest width, satisfy 0.35≦D1/D2≦0.40 and 0.85≦D2/D3≦1.00.
11. A pneumatic tire in accordance with claim 1 , wherein a relationship between a groove depth G1 of the outer circumferential main grooves and a groove depth G2 of the narrow grooves satisfies 0.80≦G2/G1≦1.00.
12. A pneumatic tire in accordance with claim 1 , wherein a center part of the land portion in the tread shoulder area is sipeless.
13. A pneumatic tire in accordance with claim 1 , wherein the pneumatic tire comprises a heavy duty pneumatic tire.
14. A pneumatic tire, comprising:
a plurality of belt plies comprising intermediate belt plies arranged between outermost belt plies and large width belt plies;
a belt layer arranged on an outer side of a carcass layer in a radial direction of the pneumatic tire;
a belt edge cushion arranged on an edge of the belt plies;
at least two inner circumferential main grooves and at least two outer circumferential main grooves in a tread of the pneumatic tire extending in the radial direction of the pneumatic tire forming and partitioning a plurality of land portions;
narrow grooves forming narrow ribs on an edge of an outer side of the land portions in a width direction of the tire and arranged on a tread shoulder area land portion;
wherein the at least four circumferential main grooves comprise outer circumferential main grooves located on edge sides of a footprint of the pneumatic tire; and
wherein a cross-section of the pneumatic tire in a tire meridian direction comprises:
a distance t from a tire equatorial plane to the outer circumferential main grooves and a distance b from the tire equatorial plane to the edge of an inner side of the belt edge cushion in the tire width direction such that that 0.85≦t/b≦0.90 is satisfied;
a width d comprising half the width of a largest width belt ply, and a distance u extending from the tire equatorial plane to the narrow grooves such that 0.97≦d/u≦1.03 is satisfied;
a width a comprising half the width of an outermost layer belt ply, and the distance t, such that 1.15≦a/t≦1.25 is satisfied; and
a distance s from the equatorial plane of the tire to the inner circumferential main grooves and the distance a such that 0.18≦s/u≦0.20 is satisfied.
15. A pneumatic tire in accordance with claim 14 , wherein a distance D1 from an outer circumferential main groove floor of the outer circumferential main grooves to the belt plies in the outermost layer, a distance D2 from a narrow groove floor of the narrow grooves to an edge of the intermediate belt plies on the outer side in the tire width direction, and a distance D3 from the groove floor of the narrow grooves to the belt plies that have the largest width, satisfy 0.35≦D1/D2≦0.40 and 0.85≦D2/D3≦1.00.
16. A pneumatic tire in accordance with claim 14 , wherein the relationship between the distance t of the outer circumferential main grooves and the distance u of the narrow grooves satisfies 0.55≦t/u≦0.60.
17. A pneumatic tire in accordance with claim 16 , wherein a relationship between a groove depth G1 of the outer circumferential main grooves and a groove depth G2 of the narrow grooves satisfies 0.80≦G2/G1≦1.00.
18. A pneumatic tire in accordance with claim 14 , wherein a relationship between a groove depth G1 of the outer circumferential main grooves and a groove depth G2 of the narrow grooves satisfies 0.80≦G2/G1≦1.00.
19. A pneumatic tire in accordance with claim 14 , wherein a center part of the land portion in the tread shoulder area is sipeless.
20. A pneumatic tire in accordance with claim 14 , wherein the pneumatic tire comprises a heavy duty pneumatic tire.