Pneumatic tire

Patent metadata

Field	Value
Publication number	US-12420596-B2
Application number	US-202218573233-A
Country	US
Kind code	B2
Filing date	Mar 28, 2022
Priority date	Jun 30, 2021
Publication date	Sep 23, 2025
Grant date	Sep 23, 2025

Abstract

Provided is a pneumatic tire in which fiber reinforced layers on an outer side of a steel reinforced layer in a width direction each include fiber cords arranged in one direction, the fiber cords being oriented to cross each other between layers, a radially outer end of one of the fiber reinforced layers being radially outward of a turned-up end portion of a carcass layer, a radially outer end portion of another one of the fiber reinforced layers being radially inward of the turned-up end portion and radially outward of a line segment (K). Radially inner end portions of the fiber reinforced layers are inward in the width direction of a line segment (J), and cord angles θA and θB of the fiber reinforced layers satisfy 20°≤|θA|≤45° or 70°≤|θA|≤90°, and 20°≤|θB|≤45° or 70°≤|θB|≤90°.

First claim

The invention claimed is:

1. A pneumatic tire, comprising:
a tread portion extending in a tire circumferential direction and having an annular shape;
a pair of sidewall portions disposed on both sides of the tread portion; and,
a pair of bead portions disposed on inner sides of the sidewall portions in a tire radial direction, a carcass layer being mounted between the pair of bead portions, the carcass layer being turned up around a bead core of each of the bead portions from a tire inner side to a tire outer side, and a steel reinforced layer comprising a plurality of steel cords being disposed in each of the bead portions so as to wrap the carcass layer, first and second organic fiber reinforced layers being disposed on an outer side of the steel reinforced layer in a tire width direction, each of the first and second organic fiber reinforced layers comprising a plurality of organic fiber cords arranged in one direction, and the organic fiber cords constituting the first and second organic fiber reinforced layers being oriented so as to cross each other between layers, a radially outer end portion of the first organic fiber reinforced layer being positioned more on an outer side in the tire radial direction than a turned-up end portion of the carcass layer, and a radially outer end portion of the second organic fiber reinforced layer being positioned more on an inner side in the tire radial direction than the turned-up end portion of the carcass layer and more on the outer side in the tire radial direction than a line segment formed by a horizontal line drawn in the tire width direction from an apex of the bead core protruding farthest to the outer side in the tire radial direction, radially inner end portions of the first and second organic fiber reinforced layers being both positioned more on an inner side in the tire width direction than a line segment formed by a normal line drawn from an apex of the bead core protruding farthest to the inner side in the tire radial direction to a surface of a bead base, and a cord angle θA of the first organic fiber reinforced layer with respect to the tire circumferential direction being in a range 20°≤|0A|≤45° or 70°≤|θA|≤90°, and a cord angle θB of the second organic fiber reinforced layer with respect to the tire circumferential direction being in a range 20°≤|θB|≤45° or 70°≤|θB|≤90°.

2. The pneumatic tire according to claim 1 , wherein a distance Ah from a bead heel apex of the each of the bead portions to the radially outer end portion of the first organic fiber reinforced layer and a distance Ph from the bead heel apex of each of the bead portions to the turned-up end portion of the carcass layer satisfy a relationship Ah-Ph≥5.0 mm.

3. The pneumatic tire according to claim 1 , wherein a crack suppression layer is embedded at a position adjacent to the turned-up end portion of the carcass layer, an end portion of the steel reinforced layer on the outer side in the tire width direction, the radially outer end portion of the first organic fiber reinforced layer, and the radially outer end portion of the second organic fiber reinforced layer, 100% modulus KcM100 of the crack suppression layer is in a range 4.5 MPa≤KcM100≤10.0 MPa, and elongation at break KcEB of the crack suppression layer is in a range 300%≤KcEB.

4. The pneumatic tire according to claim 1 , wherein one of the first and second organic fiber reinforced layers is an inner organic fiber reinforced layer positioned on the inner side in the tire width direction, and the other of the first and second organic fiber reinforced layers is an outer organic fiber reinforced layer positioned on the outer side in the tire width direction, the outer organic fiber reinforced layer is disposed so as to cover a radially inner end portion of the inner organic fiber reinforced layer, and a radially inner end portion of the outer organic fiber reinforced layer is separated from the radially inner end portion of the inner organic fiber reinforced layer by 5 mm or more and is positioned more on the inner side in the tire radial direction than a line segment formed by a horizontal line drawn in the tire width direction from an end portion of the steel reinforced layer on the outer side in the tire width direction.

5. The pneumatic tire according to claim 1 , wherein each of fiber structures of the organic fiber cords constituting the first and second organic fiber reinforced layers is in a range from 800 dtex/2 to 1500 dtex/2.

6. The pneumatic tire according to claim 1 , wherein a distance A measured along a straight line extending through an apex of the bead core protruding farthest to an outer side in a width direction and being parallel to a longest side of the bead core, the distance A being from the apex to a bead heel position, is in a range 2.5 mm≤A≤5.5 mm.

7. The pneumatic tire according to claim 1 , wherein cord inclination directions of the first and second organic fiber reinforced layers with respect to the tire circumferential direction are opposite to each other, and the cord angle θA of the first organic fiber reinforced layer with respect to the tire circumferential direction is in a range 20°≤|θA|≤45°.

8. The pneumatic tire according to claim 7 , wherein a distance Ah from a bead heel apex of the bead portion to the radially outer end portion of the first organic fiber reinforced layer and a distance Ph from the bead heel apex of the bead portion to the turned-up end portion of the carcass layer satisfy a relationship Ah-Ph≥5.0 mm.

9. The pneumatic tire according to claim 8 , wherein a crack suppression layer is embedded at a position adjacent to the turned-up end portion of the carcass layer, an end portion of the steel reinforced layer on the outer side in the tire width direction, the radially outer end portion of the first organic fiber reinforced layer, and the radially outer end portion of the second organic fiber reinforced layer, 100% modulus KcM100 of the crack suppression layer is in a range 4.5 MPa≤KcM100≤10.0 MPa, and elongation at break KcEB of the crack suppression layer is in a range 300%≤KcEB.

10. The pneumatic tire according to claim 9 , wherein one of the first and second organic fiber reinforced layers is an inner organic fiber reinforced layer positioned on the inner side in the tire width direction, and the other of the first and second organic fiber reinforced layers is an outer organic fiber reinforced layer positioned on the outer side in the tire width direction, the outer organic fiber reinforced layer is disposed so as to cover a radially inner end portion of the inner organic fiber reinforced layer, and a radially inner end portion of the outer organic fiber reinforced layer is separated from the radially inner end portion of the inner organic fiber reinforced layer by 5 mm or more and is positioned more on the inner side in the tire radial direction than a line segment formed by a horizontal line drawn in the tire width direction from an end portion of the steel reinforced layer on the outer side in the tire width direction.

11. The pneumatic tire according to claim 10 , wherein each of fiber structures of the organic fiber cords constituting the first and second organic fiber reinforced layers is in a range from 800 dtex/2 to 1500 dtex/2.

12. The pneumatic tire according to claim 11 , wherein a distance A measured along a straight line extending through an apex of the bead core protruding farthest to an outer side in a width direction and being parallel to a longest side of the bead core, the distance A being from the apex to a bead heel position, is in a range 2.5 mm≤A≤5.5 mm.

13. The pneumatic tire according to claim 1 , wherein cord inclination d

Assignees

• Yokohama Rubber Co Ltd

Inventors

• Nishio Koji

Classifications

• B60C2015/0692

  characterised by particular materials of the cords · CPC title

• B60C2015/0685

  Physical properties or dimensions of the cords, e.g. modulus of the cords · CPC title

• B60C2015/0667

  comprising cords at an angle of 60 to 90 degrees to the circumferential direction · CPC title

• B60C2015/0664

  comprising cords at an angle of 30 to 60 degrees to the circumferential direction · CPC title

• B60C2015/066

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