PASSENGER VEHICLE PNEUMATIC RADIAL TIRE

• US 20170305199A1
• Filed: 09/08/2015
• Published: 10/26/2017
• Est. Priority Date: 10/08/2014
• Status: Active Grant

• Current Assignee: Bridgestone Corporation
• Original Assignee: Bridgestone Corporation
• Inventors: HATANAKA, Shintaro, KUWAYAMA, Isao
• Granted Patent: US 10,486,473 B2
• Time in Patent Office: Days
• CPC Class Codes: B60C 11/0008 characterised by the tread rubber
• CPC Class Codes: B60C 11/03 Tread patterns
• CPC Class Codes: B60C 11/0306 Patterns comprising block rows or discontinuous ribs
• CPC Class Codes: B60C 11/032 Patterns comprising isolated recesses
• CPC Class Codes: B60C 11/0332 by the footprint-ground contacting area of the tyre tread
• CPC Class Codes: B60C 11/1236 with special arrangements in the tread pattern
• CPC Class Codes: B60C 2011/0016 Physical properties or dimensions
• CPC Class Codes: B60C 2011/0025 Modulus or tan delta
• CPC Class Codes: B60C 2011/0341 Circumferential grooves
• CPC Class Codes: B60C 2011/0353 characterised by width
• CPC Class Codes: B60C 3/04 characterised by the relative dimensions of the section, e.g. low profile B60C3/06 takes precedence
• CPC Class Codes: Y02T 10/86 Optimisation of rolling resistance, e.g. weight reduction

Abstract

When a tire is attached to a rim and set to an internal pressure of 250 kPa or more, a ratio SW/OD of the tire is 0.26 or less in the case where SW of the tire is less than 165 (mm), and SW and OD satisfy a relationship 2.135×SW+282.3≦OD in the case where SW is 165 (mm) or more. The tread rubber has dynamic storage modulus E′ of 6.0 MPa to 12.0 MPa, and loss tangent tan δ of 0.05 to 0.15. In at least one land portion, sipes are arranged with a predetermined pitch length L, and a land portion width W, a tire widthwise sipe component total length Ws of the sipes, the pitch length L, and a tire circumferential sipe component total length Ls of the sipes satisfy relationships 0.4W≦Ws≦1.2W and 0.6L≦Ls≦3L.

Claims

1. A passenger vehicle pneumatic radial tire comprising:

a carcass composed of a carcass ply of a radially arranged cord toroidally extending between a pair of bead portions;

a tread rubber provided on a tire radial outer side of the carcass;

at least two circumferential main grooves continuously extending in a tire circumferential direction in a tread surface; and

a plurality of land portions in the tread surface, each of which is defined by adjacent two circumferential main grooves of the at least two circumferential main grooves or by a tire widthwise outermost circumferential main groove of the at least two circumferential main grooves and a tread ground contact edge,

wherein when the tire is attached to a rim and set to an internal pressure of 250 kPa or more, a ratio SW/OD between a sectional width SW and an outer diameter OD (mm) of the tire is 0.26 or less in the case where the sectional width SW of the tire is less than 165 (mm), and the sectional width SW and the outer diameter OD (mm) of the tire satisfy a relationship

2.135×

SW+282.3≦

OD

in the case where the sectional width SW of the tire is 165 (mm) or more,

the tread rubber has dynamic storage modulus E′

at 30°

C. of 6.0 MPa to 12.0 MPa, and loss tangent tan δ

at 60°

C. of 0.05 to 0.15, and

in at least one of the plurality of land portions, a plurality of sipes are arranged with a predetermined pitch length L (mm) measured along the tire circumferential direction, and a land portion width W (mm) of the land portion, a tire widthwise sipe component total length Ws (mm) of the sipes within one pitch area of the pitch length L (mm) in the land portion, the pitch length L (mm), and a tire circumferential sipe component total length Ls (mm) of the sipes within one pitch area of the pitch length L (mm) in the land portion satisfy relationships

0.4W≦

Ws≦

1.2W and 0.6L≦

Ls≦

3L.

2. The passenger vehicle pneumatic radial tire according to claim 1,

wherein the land portion width W (mm), the tire widthwise sipe component total length Ws (mm), the pitch length L (mm), and the tire circumferential sipe component total length Ls (mm) satisfy relationships

0.6W≦

Ws≦

1.2W and L≦

Ls≦

3L.

3. The passenger vehicle pneumatic radial tire according to claim 1,

wherein in the land portion in which the sipes are arranged, at least one small hole is provided within one pitch area of the pitch length L (mm), and

an opening area S (mm²) of the small hole to the tread surface is 0.1≦

S≦

4.

4. The passenger vehicle pneumatic radial tire according to claim 3,

wherein in the land portion in which the sipes are arranged, the pitch length L (mm) and the number N of small holes provided within one pitch area of the pitch length L (mm) satisfy a relationship

0.1≦

N/L≦

0.3.

5. The passenger vehicle pneumatic radial tire according to claim 2,

wherein in the land portion in which the sipes are arranged, at least one small hole is provided within one pitch area of the pitch length L (mm), and

an opening area S (mm²) of the small hole to the tread surface is 0.1≦

S≦

4.

6. The passenger vehicle pneumatic radial tire according to claim 5,

wherein in the land portion in which the sipes are arranged, the pitch length L (mm) and the number N of small holes provided within one pitch area of the pitch length L (mm) satisfy a relationship

0.1≦

N/L≦

0.3.