Pneumatic tire

Patent metadata

Field	Value
Publication number	US-10173477-B2
Application number	US-201314436006-A
Country	US
Kind code	B2
Filing date	Oct 29, 2013
Priority date	Nov 12, 2012
Publication date	Jan 8, 2019
Grant date	Jan 8, 2019

Abstract

A tire includes a pair of beads, a carcass, chafers, an insulation, and cushion layers. Each bead includes a core positioned inward of the bead in a radial direction. At an inside of the core in the radial direction, the insulation is laminated on the chafers so as to be located outward of the chafers in the radial direction. Each cushion layer is laminated on the insulation so as to be located outward of the insulation in the radial direction. The insulation and the cushion layer are formed from respective crosslinked rubbers different from each other. A compressive elastic modulus Eα* of the crosslinked rubber of the cushion layer is smaller than a compressive elastic modulus Eβ* of the crosslinked rubber of the insulation.

First claim

The invention claimed is:

1. A pneumatic tire comprising:
a pair of beads;
a carcass extending along and inward of a tread and sidewalls and on and between one of the beads and the other bead;
chafers positioned near the beads and abutted on a rim;
an inner liner located inward of the carcass;
an insulation interposed between the carcass and the inner liner in an axial direction; and
cushion layers, wherein
each of the beads includes a core positioned inward of the bead in a radial direction,
at an inside of the core in the radial direction, the insulation is laminated on the chafers so as to be located outward of the chafers in the radial direction,
each of the cushion layers is laminated on the insulation so as to be located outward of the insulation in the radial direction,
the insulation and the cushion layer are formed from respective crosslinked rubbers different from each other,
a compressive elastic modulus Eα* of the crosslinked rubber of the cushion layer is smaller than a compressive elastic modulus Eβ* of the crosslinked rubber of the insulation,
a lower part of the insulation extends from an inner side toward an outer side in the axial direction,
the lower part of the insulation is interposed between the cushion layer and the chafer in the radial direction, and
wherein the cushion layers are formed of a crosslinked rubber, and the cushion layers are located radially inward of the carcass ply without extending axially beyond an axial maximum width of the turn-up portion of the carcass ply.

2. The tire according to claim 1 , wherein a thickness L, in the radial direction, from the chafer to the core is equal to or greater than 4 mm and equal to or less than 8 mm.

3. The tire according to claim 1 , wherein, at the inside of the core in the radial direction, a ratio (Lα/L) of a thickness Lα of the cushion layer to a thickness L, in the radial direction, from the chafer to the core is equal to or greater than 0.5.

4. The tire according to claim 1 , wherein a ratio (Eα*/Eβ*) of the compressive elastic modulus Eα* of the crosslinked rubber of the cushion layer to the compressive elastic modulus Eβ* of the crosslinked rubber of the insulation is equal to or greater than 0.5.

5. The tire according to claim 1 , wherein, when a fastening force of the tire mounted to a rim ranges from 3 (kN) to 4 (kN), a gradient of a change of fastening forces with respect to a change of amounts of compressive deformation is equal to or greater than 1.5 (kN/mm) and equal to or less than 2 (kN/mm).

6. The tire according to claim 1 , wherein,
the core is formed by winding a bead wire in a circumferential direction, and
the bead wire is wound so as to be stacked in both the radial direction and an axial direction.

7. The tire according to claim 1 , wherein a compression set of the crosslinked rubber of the cushion layer is equal to or less than 30%.

8. The tire according to claim 2 , wherein, at the inside of the core in the radial direction, a ratio (Lα/L) of a thickness Lα of the cushion layer to a thickness L, in the radial direction, from the chafer to the core is equal to or greater than 0.5.

9. The tire according to claim 2 , wherein a ratio (Eα*/Eβ*) of the compressive elastic modulus Eα* of the crosslinked rubber of the cushion layer to the compressive elastic modulus Eβ* of the crosslinked rubber of the insulation is equal to or greater than 0.5.

10. The tire according to claim 2 , wherein, when a fastening force of the tire mounted to a rim ranges from 3 (kN) to 4 (kN), a gradient of a change of fastening forces with respect to a change of amounts of compressive deformation is equal to or greater than 1.5 (kN/mm) and equal to or less than 2 (kN/mm).

11. The tire according to claim 2 , wherein,
the core is formed by winding a bead wire in a circumferential direction, and
the bead wire is wound so as to be stacked in both the radial direction and an axial direction.

12. The tire according to claim 2 , wherein a compression set of the crosslinked rubber of the cushion layer is equal to or less than 30%.

13. The tire according to claim 1 , wherein the inner liner has a portion interposed between the insulation and the chafers.

14. The tire according to claim 1 , wherein the lower part of the insulation has a distal end directly joining to the chafers, and interposed between the cushion layer and the chafer in the radial direction.

15. The tire according to claim 2 , wherein the thickness L is from the bottom of the core to a point where the clinch intersects with the chafer.

16. The tire according to claim 15 , wherein, at the inside of the core in the radial direction, a ratio (Lα/L) of a thickness Lα of the cushion layer to a thickness L, in the radial direction, from the chafer to the core is equal to or greater than 0.5.

17. The tire according to claim 15 , wherein a ratio (Eα*/Eβ*) of the compressive elastic modulus Eα* of the crosslinked rubber of the cushion layer to the compressive elastic modulus Eβ* of the crosslinked rubber of the insulation is equal to or greater than 0.5.

18. The tire according to claim 15 , wherein, when a fastening force of the tire mounted to a rim ranges from 3 (kN) to 4 (kN), a gradient of a change of fastening forces with respect to a change of amounts of compressive deformation is equal to or greater than 1.5 (kN/mm) and equal to or less than 2 (kN/mm).

19. The tire according to claim 15 , wherein,
the core is formed by winding a bead wire in a circumferential direction, and
the bead wire is wound so as to be stacked in both the radial direction and an axial direction.

Assignees

• Sumitomo Rubber Ind

Inventors

• Ueda Kenji

Classifications

• B60C2015/0614

  characterised by features of the chafer or clinch portion, i.e. the part of the bead contacting the rim · CPC title

• B60C15/06

  Flipper strips, fillers, or chafing strips {and reinforcing layers for the construction of the bead} · CPC title

• B60C2015/0617

  comprising a cushion rubber other than the chafer or clinch rubber · CPC title

• B60C5/00

  Inflatable pneumatic tyres or inner tubes (B60C1/00, B60C9/00 - B60C17/00 take precedence) · CPC title

• Y10T152/10828

  Chafer or sealing strips · CPC title