Pneumatic tire

Patent metadata

Field	Value
Publication number	US-9290064-B2
Application number	US-201313845616-A
Country	US
Kind code	B2
Filing date	Mar 18, 2013
Priority date	Mar 23, 2012
Publication date	Mar 22, 2016
Grant date	Mar 22, 2016

Abstract

In a pneumatic tire, a height from a turned-up edge of a carcass layer is not more than 10 mm, a distance from a tire outer surface to the carcass layer is not less than 50% of the total gauge, a height of the bead filler is from 50% to 80% of a tire cross-section height, a cross-sectional area ratio V B /V R of the bead filler to a side reinforcing layer is not less than 0.4 and not more than 0.6, a hardness Hs B of the bead filler is not less than 65 and not more than 80, and the hardness Hs R of the side reinforcing layer is not less than 75 and not more than 85, a size relationship between the hardness Hs B and the hardness Hs R is Hs B ≦Hs R , a value T B of tan δ is not more than 0.06, and a value T R of tan δ is not more than 0.05.

First claim

What is claimed is:

1. A pneumatic tire comprising at least one layer of carcass layer mounted between a pair of left and right bead portions, the carcass layer being folded from the tire inside to the tire outside around bead cores disposed in each bead portion, a bead filler constituted by a rubber composition being disposed on an outer circumferential side of the bead cores, and a plurality of belt layers being disposed on an outer circumferential side of the carcass layer in a tread portion, a plurality of belt cover layers being disposed on an outer circumferential side of the belt layers, and a falcated cross-section side reinforcing layer being disposed inward in a tire width direction of the carcass layer in side wall portions; wherein
a height H T from a turned-up edge of the carcass layer to an outer edge in a tire radial direction of the bead core is not more than 10 mm;
when fitted to a rim, on an imaginary line L drawn from an outermost edge in the tire radial direction of a region in contact with a rim flange normal to a tire inner surface, a distance G O from a tire outer surface to the carcass layer is not less than 50% of a total gauge G T of the side wall portion on the imaginary line L;
a height H B of the outer edge in the tire radial direction of the bead filler is from 50% to 80% of a tire cross-section height SH;
a ratio V B /V R of a cross-sectional area V B of the bead filler to a cross-sectional area V R of the side reinforcing layer is not less than 0.4 and not more than 0.6;
a hardness Hs B at 20° C. of the rubber composition of the bead filler is not less than 65 and not more than 80;
a hardness Hs R at 20° C. of the rubber composition of the side reinforcing layer is not less than 75 and not more than 85, the hardness Hs B and the hardness Hs R satisfy the relationship Hs B ≦Hs R ;
a dynamic elastic modulus E′ B at 60° C. of the rubber composition of the bead filler is not less than 7.0 MPa and not more than 15.0 MPa;
a dynamic elastic modulus E′ R at 60° C. of the rubber composition of the side reinforcing layer is not less than 7.0 MPa and not more than 15.0 MPa;
a value T B of tan δ at 60° C. of the rubber composition of the bead filler is not more than 0.06;
a value T R of tan δ at 60° C. of the rubber composition of the side reinforcing layer is not more than 0.05; and
the side reinforcing layer is constituted by two types of rubber compositions having different dynamic elastic moduli at 60° C. that are laminated in the tire radial direction; and a dynamic elastic modulus E′ RO at 60° C. of the rubber composition of an outer diameter side side reinforcing layer located on the outer side in the tire radial direction and the dynamic elastic modulus E′ RI at 60° C. of the rubber composition of an inner diameter side side reinforcing layer located on an inner side in the tire radial direction satisfy the relationship E′ RO <E′ RI .

2. The pneumatic tire according to claim 1 , wherein the dynamic elastic modulus E′ B and the dynamic elastic modulus E′ RI satisfy the relationship E′ B ≦E′ RI .

3. The pneumatic tire according to claim 2 , wherein the belt cover layer is constituted by a composite cord comprising two types of organic fibers having differing properties.

4. The pneumatic tire according to claim 3 , wherein the composite cord comprises: an organic fiber having relatively high shrinkage, and low elasticity and an organic fiber having relatively low shrinkage and high elasticity.

5. The pneumatic tire according to claim 3 , wherein the composite cord comprises: an organic fiber having relatively high shrinkage, and low elasticity and an organic fiber having relatively low shrinkage and high elasticity.

6. The pneumatic tire according to claim 1 , wherein the bead filler is constituted by two types of rubber compositions having different dynamic elastic moduli at 60° C. that are laminated in the tire radial direction; and a dynamic elastic modulus E′ BO at 60° C. of the rubber composition of an outer diameter side bead filler located on the outer side in the tire radial direction and a dynamic elastic modulus E′ BI at 60° C. of the rubber composition of an inner diameter side bead filler located on the inner side in the tire radial direction satisfy the relationship E′ BO <E′ BI .

7. The pneumatic tire according to claim 6 , wherein the belt cover layer is constituted by a composite cord comprising two types of organic fibers having differing properties.

8. The pneumatic tire according to claim 7 , wherein the composite cord comprises: an organic fiber having relatively high shrinkage, and low elasticity and an organic fiber having relatively low shrinkage and high elasticity.

9. The pneumatic tire according to claim 6 , wherein the dynamic elastic modulus E′ BO and the dynamic elastic modulus E′ R satisfy the relationship E′ BO ≦E′ R .

10. The pneumatic tire according to claim 9 , wherein the belt cover layer is constituted by a composite cord comprising two types of organic fibers having differing properties.

11. The pneumatic tire according to claim 10 , wherein the composite cord comprises: an organic fiber having relatively high shrinkage, and low elasticity and an organic fiber having relatively low shrinkage and high elasticity.

12. The pneumatic tire according to claim 1 , wherein the belt cover layer is constituted by a composite cord comprising two types of organic fibers having differing properties.

13. The pneumatic tire according to claim 12 , wherein the composite cord comprises: an organic fiber having relatively high shrinkage, and low elasticity and an organic fiber having relatively low shrinkage and high elasticity.

14. A pneumatic tire comprising at least one layer of carcass layer mounted between a pair of left and right bead portions, the carcass layer being folded from the tire inside to the tire outside around bead cores disposed in each bead portion, a bead filler constituted by a rubber composition being disposed on an outer circumferential side of the bead cores, and a plurality of belt layers being disposed on an outer circumferential side of the carcass layer in a tread portion, a plurality of belt cover layers being disposed on an outer circumferential side of the belt layers, and a falcated cross-section side reinforcing layer being disposed inward in a tire width direction of the carcass layer in side wall portions; wherein
a height H T from a turned-up edge of the carcass layer to an outer edge in a tire radial direction of the bead core is not more than 10 mm;
when fitted to a rim, on an imaginary line L drawn from an outermost edge in the tire radial direction of a region in contact with a rim flange normal to a tire inner surface, a distance G O from a tire outer surface to the carcass layer is not less than 50% of a total gauge G T of the side wall portion on the imaginary line L;
a height H B of the outer edge in the tire radial direction of the bead filler is from 50% to 80% of a tire cross-section height SH;
a ratio V B /V R of a cross-sectional area V B of the bead filler to a cross-sectional area V R of the side reinforcing layer is not less than 0.4 and not more than 0.6;
a hardness Hs B at 20° C. of the rubber composition of the bead filler is not less than 65 and not more than 80;
a hardness Hs R at 20° C. of the rubber composition of the side reinforcing layer is not less than 75 and not more than 85, the hardness Hs B and the hardness Hs R satisfy the relationship Hs B ≦Hs R ;
a dynamic elastic modulus E′ B at 60° C. of the rubber composition of the bead filler is not less than 7.0 MPa and not more than 15.0 MPa;

Assignees

• Yokohama Rubber Co Ltd

Inventors

• Horiuchi Kenji

Classifications

• B60C2015/061

  Dimensions of the bead filler in terms of numerical values or ratio in proportion to section height · CPC title

• B60C17/0027

  comprising portions of different rubbers in a single insert · CPC title

• B60C17/00 Primary

  Tyres characterised by means enabling restricted operation in damaged or deflated condition; Accessories therefor · CPC title

• B60C2017/0072

  Thickness · CPC title

• B60C2013/006

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