Pneumatic tire

Patent metadata

Field	Value
Publication number	US-9849730-B2
Application number	US-201314405146-A
Country	US
Kind code	B2
Filing date	Jun 7, 2013
Priority date	Jul 13, 2012
Publication date	Dec 26, 2017
Grant date	Dec 26, 2017

Abstract

A pneumatic tire includes a carcass layer, a belt layer that is disposed on the outer side in the tire radial direction of the carcass layer, and a tread rubber that is disposed on the outer side in the tire radial direction of the belt layer. The pneumatic tire also includes at least three circumferential main grooves extending in the tire circumferential direction, and a plurality of land portions that are defined by these circumferential main grooves. The belt layer includes an inner-side cross belt and outer-side cross belt having belt angles of not less than 51° and not more than 80° as absolute values with respect to the tire circumferential direction, the belt angles having mutually opposite signs, and a circumferential reinforcing layer having a belt angle that satisfies a range of ±5° with respect to the tire circumferential direction.

First claim

What is claimed is:

1. A pneumatic tire having a carcass layer, a belt layer disposed on an outer side in a tire radial direction of the carcass layer, a tread rubber disposed on an outer side in the tire radial direction of the belt layer, at least three circumferential main grooves extending in a tire circumferential direction, and a plurality of land portions defined by the circumferential main grooves, wherein
the belt layer includes:
an inner-side cross belt and outer-side cross belt having belt angles of not less than 51° and not more than 80° as absolute values with respect to a tire circumferential direction, the belt angles having mutually opposite signs; and
a circumferential reinforcing layer having a belt angle satisfying a range of ±5° with respect to the tire circumferential direction;
wherein a width Wb 2 of a wider cross belt of the inner-side cross belt and the outer-side cross belt, and a cross-sectional width Wca of the carcass layer have a relationship such that 0.73≦Wb 2 /Wca≦0.89.

2. The pneumatic tire according to claim 1 , wherein the circumferential reinforcing layer is disposed between the inner-side cross belt and the outer-side cross belt.

3. The pneumatic tire according to claim 1 , wherein a distance Gcc from a tread profile to a tire inner circumferential surface along a tire equatorial plane, and a distance Gsh from a tread edge to the tire inner circumferential surface have a relationship such that Gsh/Gcc≦1.20.

4. The pneumatic tire according to claim 1 , wherein, upon a wear end surface WE of the circumferential main groove being drawn when viewed as a cross-section from a tire meridian direction,
a distance Dcc on the tire equatorial plane from the circumferential reinforcing layer to the wear end surface WE and a distance De from an end portion of the circumferential reinforcing layer to the wear end surface WE have a relationship such that 0.95≦De/Dcc≦1.05.

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

6. The pneumatic tire according to claim 1 , wherein a tread width TW and a total tire width SW have a relationship such that 0.83≦TW/SW≦0.95.

7. The pneumatic tire according to claim 1 , wherein a radius Ya at a highest position of the carcass layer and a radius Yd of the carcass layer at the end portion of the circumferential reinforcing layer have a relationship such that 0.95≦Yd/Ya≦1.02.

8. The pneumatic tire according to claim 1 , wherein moduli E 2 , E 3 at 100% elongation of coating rubbers of the inner-side cross belt and outer-side cross belt, and a modulus Es at 100% elongation of a 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.

9. The pneumatic tire according to claim 1 , wherein a breaking elongation λs of a coating rubber of the circumferential reinforcing layer satisfies a range of λs≧200%.

10. The pneumatic tire according to claim 1 , wherein breaking elongations λ 2 , λ 3 of coating rubbers of the inner-side cross belt and outer-side cross belt satisfy ranges of λ 2 ≧200% and κ 3 ≧200%.

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

12. The pneumatic tire according to claim 11 , wherein a breaking elongation λbc of the belt cushion satisfies a range of λbc≧400%.

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

14. The pneumatic tire according to claim 1 , further comprising a supplemental belt disposed on an outer side in the tire radial direction of the outer-side cross belt, wherein
a laminate constituted by the inner-side cross belt, the outer-side cross belt, the circumferential reinforcing layer, and the supplemental belt is disposed adjacent to the carcass layer.

Assignees

• Yokohama Rubber Co Ltd

Inventors

• Hamanaka Hideki
• Iga Koshi
• Kotoku Koichi

Classifications

• B60C2009/283

  characterised by belt curvature · CPC title

• B60C3/04

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

• B60C11/0083

  characterised by the curvature of the tyre tread · CPC title

• B60C2009/2016

  comprising cords at an angle of 10 to 30 degrees to the circumferential direction · CPC title

• B60C2009/2064

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