Pneumatic tire

Patent metadata

Field	Value
Publication number	US-10166819-B2
Application number	US-201214655856-A
Country	US
Kind code	B2
Filing date	Dec 28, 2012
Priority date	Dec 28, 2012
Publication date	Jan 1, 2019
Grant date	Jan 1, 2019

Abstract

A pneumatic tire is provided with at least three circumferential main grooves extending in a tire circumferential direction, and a plurality of land portions defined by the circumferential main grooves. The belt layer is formed by laminating a pair of cross belts having belt angles, as an absolute value, of not less than 10° and not greater than 45° and of mutually opposite signs, and a circumferential reinforcing layer having a belt angle within a range of ±5° with respect to the tire circumferential direction. In a cross-sectional view in the tire meridian direction, the distance Dcc from the circumferential reinforcing layer to the terminal wear surface on a tire equatorial plane and the distance De from an end portion of the circumferential reinforcing layer to the terminal wear surface have the relationship such that De/Dcc≤0.94.

First claim

What is claimed is:

1. A pneumatic tire comprising:
a carcass layer;
a belt layer disposed outward of the carcass layer in a tire radial direction;
a tread rubber disposed outward of the belt layer in the tire radial direction; at least three circumferential main grooves extending in a tire circumferential direction; and
a plurality of land portions partitioned by the circumferential main grooves,
the belt layer being formed by laminating a pair of cross belts having belt angles, as an absolute value, of not less than 10° and not greater than 45° and of mutually opposite signs, and a circumferential reinforcing layer having a belt angle within a range of ±5° with respect to the tire circumferential direction,
when viewed as a cross-section from a tire meridian direction, when a wear end surface WE of the circumferential main grooves is drawn, a distance Dcc from the circumferential reinforcing layer to the wear end surface WE along a tire equatorial plane and a distance De from an end portion of the circumferential reinforcing layer to the wear end surface WE having a relationship such that De/Dcc≤0.94,
a diameter Ya at a highest position of the carcass layer and a diameter Yd of the carcass layer at a position of the end portion of the circumferential reinforcing layer having a relationship such that 0.95≤Yd/Ya≤1.02,
a distance Gcc from a tread profile to a tire inner circumferential surface along the tire equatorial plane and a distance Gsh from a tread edge to the tire inner circumferential surface having a relationship such that 1.20≤Gsh/Gcc,
the land portion located furthest out in a tire width direction being referred to as a shoulder land portion, a diameter D 1 of the a tread profile along the tire equatorial plane, a diameter D 2 of the tread profile at an edge portion of the shoulder land portion inward in the tire width direction, and a diameter D 3 of the tread profile at an end portion of the circumferential reinforcing layer having a relationship such that D 1 >D 2 , D 1 >D 3 , and 0≤(D 2 −D 3 )/(D 1 −D 3 )≤0.85, and
the circumferential reinforcing layer terminating inward in the tire width direction of an outermost circumferential main groove in the tire width direction.

2. The pneumatic tire according to claim 1 , wherein the diameter Ya at the highest position of the carcass layer and a diameter Yc at a widest position of the carcass layer have a relationship such that 0.80≤Yc/Ya≤0.90.

3. The pneumatic tire according to claim 1 , wherein, when the land portion located furthest out in a tire width direction is referred to as a shoulder land portion, a diameter D 1 of a tread profile along the tire equatorial plane, a diameter D 2 of the tread profile at an edge portion of the shoulder land portion inward in the tire width direction, and a diameter D 3 of the tread profile at an end portion of the circumferential reinforcing layer have a relationship such that D 1 >D 2 , D 1 >D 3 , and −0.65≤(D 2 −D 3 )/(D 1 −D 3 )≤0.85.

4. The pneumatic tire according to claim 1 , wherein a width Ws of the circumferential reinforcing layer and a width Wca of the carcass layer have a relationship such that 0.60≤Ws/Wca≤0.70.

5. The pneumatic tire according to claim 1 , wherein a tread width TW and a cross-sectional width Wca of the carcass layer have a relationship such that 0.82≤TW/Wca≤0.92.

6. The pneumatic tire according to claim 1 , wherein a tread width TW and a total tire width SW have a relationship such that 0.79≤TW/SW≤0.89.

7. The pneumatic tire according to claim 1 , wherein a distance Hcc from the circumferential reinforcing layer to a tread profile along the tire equatorial plane and a distance He from the end portion of the circumferential reinforcing layer to the tread profile have a relationship such that He/Hcc≤0.97.

8. The pneumatic tire according to claim 1 , wherein a difference Dr between a diameter of the circumferential reinforcing layer along the tire equatorial plane and a diameter at the end portion on an outer side of the circumferential reinforcing layer in a tire width direction, and a width Ws of the circumferential reinforcing layer have a relationship such that 0.010≤Dr/Ws≤0.010.

9. The pneumatic tire according to claim 1 , wherein the belt layer comprises a large angle belt having a belt angle, as an absolute value, of not less than 45° and not greater than 70°.

10. The pneumatic tire according to claim 9 , wherein belt cords of the large angle belt are steel wire, and a number of ends in the large angle belt is not less than 15 ends/50 mm and not more than 25 ends/50 mm.

11. The pneumatic tire according to claim 9 , wherein a width Wb 1 of the large angle belt and a width Wb 3 of a narrower cross belt of the pair of cross belts have a relationship such that 0.85≤Wb 1 /Wb 3 ≤1.05.

12. The pneumatic tire according to claim 9 , wherein a breaking elongation λ 1 of a coating rubber of the large angle belt is not less than 200%.

13. The pneumatic tire according to claim 9 , wherein the large angle belt and the cross belt on an inner side in the tire radial direction of the pair of cross belts are disposed adjacent to each other, and
an intercord distance Dc between belt cords of the large angle belt and belt cords of the cross belt is within a range of 0.50 mm≤Dc≤1.50 mm.

14. The pneumatic tire according to claim 1 , wherein a modulus Es at 100% elongation of a coating rubber of the circumferential reinforcing layer is within a range of 4.5 MPa≤Es≤7.5 MPa.

15. The pneumatic tire according to claim 1 , wherein moduli E 2 , E 3 at 100% elongation of a coating rubber of the pair of cross belts and a modulus Es at 100% elongation of the coating rubber of the circumferential reinforcing layer have a relationship such that 0.90≤Es/E 2 ≤1.10 and 0.90≤Es/E 3 ≤1.10.

16. The pneumatic tire according to claim 1 , wherein a breaking elongation λs of a coating rubber of the circumferential reinforcing layer is not less than 200%.

17. The pneumatic tire according to claim 1 , further comprising a belt cushion disposed interposed between the carcass layer and an end portion of the cross belt on an inner side in the tire radial direction of the pair of cross belts, wherein
a modulus Ebc at 100% elongation of the belt cushion is within a range of 1.5 MPa≤Ebc≤3.0 MPa.

18. The pneumatic tire according to claim 17 , wherein a breaking elongation λbc of the belt cushion is not less than 400%.

19. The pneumatic tire according to claim 1 , wherein, when left and right circumferential main grooves disposed furthest out in a tire width direction are referred to as outermost circumferential main grooves, when viewed as a cross-section from the tire meridian direction, the land portions located inward in the tire width direction from the left and right outermost circumferential main grooves have a first profile that protrudes outward in the tire radial direction, and also, the land portions located outward in the tire width direction from the left and right outermost circumferential main grooves, hereinafter, referred to as shoulder land portions, have a second profile that protrudes inward in the tire radial direction in a ground contact patch, and
a distance d in the tire radial direction between an extended line of the first profile in the ground contact patch of the shoulder land portions and the second profile increases toward an outer side in the tire width direction.

20. The pneumatic tire according to claim 1 , wherein belt cords of the circumferential reinforcing layer are steel wire and a number

Assignees

• Yokohama Rubber Co Ltd

Inventors

• Obana Kentaroh

Classifications

• B60C9/1835

  Rubber strips or cushions at the belt edges · CPC title

• B60C3/04

  characterised by the relative dimensions of the section, e.g. low profile (B60C3/06 takes precedence) · CPC title

• B60C9/28 Primary

  characterised by the belt or breaker dimensions or curvature relative to carcass (B60C9/30 takes precedence) · CPC title

• B60C9/20

  built-up from rubberised plies each having all cords arranged substantially parallel · CPC title

• B60C2009/2064

  Modulus; Hardness; Loss modulus or "tangens delta" · CPC title