Tire with specified belt layers of 1X4 steel cords

Patent metadata

Field	Value
Publication number	US-11780266-B2
Application number	US-201716090401-A
Country	US
Kind code	B2
Filing date	Feb 9, 2017
Priority date	Apr 5, 2016
Publication date	Oct 10, 2023
Grant date	Oct 10, 2023

Abstract

A plurality of belt layers 7 are superimposed in a radial direction. The belt layers 7 include a plurality of steel cords 10 arranged in parallel in a row and rubber 11. The steel cords 10 have a 1×4 structure in which four filaments 20 are twisted, and when a center-to-center distance between the steel cords 10 in at least two of the belt layers 7 adjacent in the radial direction is T, and an average diameter of virtual circumscribed circles of the steel cords 10 having the 1×4 structure is D, 1.25≤T/D≤2.25.

First claim

The invention claimed is:

1. A tire comprising a plurality of belt layers superimposed in a radial direction,
wherein the belt layers include a plurality of steel cords arranged in parallel in a row and rubber that covers the steel cords, and
wherein the steel cords have a 1×4 structure in which four filaments are twisted, and when a center-to-center distance between the steel cords in at least two of the belt layers adjacent in the radial direction is T, and an average diameter of virtual circumscribed circles of the steel cords is D, T/D is in a range of greater than or equal to 1.34 and less than or equal to 2.04,
wherein the average diameter D is 0.72 mm, and the center-to-center distance T is greater than or equal to 0.96 mm and less than or equal to 1.47 mm,
wherein in the at least two of the belt layers, a steel cord breaking load×ends/50 mm is greater than or equal to 15,000 N/50 mm and less than or equal to 40,000 N/50 mm, and
wherein cornering power for the tire over the range for the T/D increases as a value of the T/D decreases.

2. The tire according to claim 1 , wherein the elastic modulus E* of the rubber is greater than or equal to 5 MPa and less than or equal to 20 MPa.

3. The tire according to claim 1 , wherein, in each cross-sectional view of a plane perpendicular to a longitudinal direction of each of the steel cords, the central portion surrounded by the four filaments is filled with the rubber.

4. The tire according to claim 1 , wherein, in at least one filament of the four filaments of each of the steel cords, bent portions and non-bent portions are repeatedly formed along a longitudinal direction of the filament.

5. The tire according to claim 4 , wherein a repetition pitch of the bent portions and the non-bent portions of the at least one filament is greater than or equal to 2.2 mm and less than or equal to 7.0 mm.

6. The tire according to claim 4 ,
wherein when the at least one filament is placed on a plane, a height from the plane to the bent portions, at a far side from the plane, is defined as a bending height, and
wherein the bending height of each of the at least one filament is 0.2-fold or more and 0.8-fold or less of a diameter of the filament.

7. The tire according to claim 1 , wherein the cornering power for the tire over the range for the T/D increases linearly as the value of the T/D decreases.

Assignees

• Sumitomo Electric Tochigi Co Ltd
• Sumitomo Electric Industries
• Sumitomo Rubber Ind

Inventors

• Matsuoka Akifumi
• Saito Kazuhiko
• Takamura Shinei
• Suzuki Masumi
• Fujisawa Koji

Classifications

• B60C9/0057 Primary

  Reinforcements comprising preshaped elements, e.g. undulated or zig-zag filaments · CPC title

• B60C9/00

  Reinforcements or ply arrangement of pneumatic tyres (inserts having reinforcing means B60C5/08; bead structure, e.g. turnup or overlap construction, B60C15/00) · CPC title

• B60C9/0007

  Reinforcements made of metallic elements, e.g. cords, yarns, filaments or fibres made from metal · CPC title

• B60C9/20

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

• B60C9/2006 Primary

  consisting of steel cord plies only · CPC title