Pneumatic Tire

• US 20150210122A1
• Filed: 04/07/2014
• Published: 07/30/2015
• Est. Priority Date: 05/14/2013
• Status: Active Grant

• Current Assignee: Yokohama Rubber Company Limited
• Original Assignee: Yokohama Rubber Company Limited
• Inventors: Shimizu, Tsuyoto
• Granted Patent: US 9,403,408 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B60C 11/0304 Asymmetric patterns
• CPC Class Codes: B60C 11/0309 further characterised by the groove cross-section
• CPC Class Codes: B60C 11/04 in which the raised area of the pattern consists only of continuous circumferential ribs, e.g. zig-zag B60C11/12, B60C11/13 take precedence
• CPC Class Codes: B60C 11/1259 Depth of the sipe
• CPC Class Codes: B60C 11/13 characterised by the groove cross-section, e.g. for buttressing or preventing stone-trapping
• CPC Class Codes: B60C 11/1307 with special features of the groove walls
• CPC Class Codes: B60C 2011/0341 Circumferential grooves
• CPC Class Codes: B60C 2011/0348 Narrow grooves, i.e. having a width of less than 4 mm
• CPC Class Codes: B60C 2011/0353 characterised by width
• CPC Class Codes: B60C 2011/0355 characterised by depth
• CPC Class Codes: B60C 2011/0369 with varying depth of the groove
• CPC Class Codes: B60C 2011/0395 for linking shoulder blocks
• CPC Class Codes: B60C 5/00 Inflatable pneumatic tyres or inner tubes B60C1/00, B60C9/00 - B60C17/00 take precedence

Abstract

A pneumatic tire includes a tread portion that includes three main grooves extending in the tire circumferential direction, and four rows of land portions defined by each of the main grooves, wherein, in each of two rows of center land portions located on a tire equator side, one narrow groove extending in the tire circumferential direction and a plurality of inclined grooves extending from the narrow groove towards the outer side in the tire width direction are provided, in each of the two rows of shoulder land portions located on shoulder sides, a plurality of lug grooves extending in tire width direction and not connecting to the main grooves is provided, and a distance on the vehicle outer side and a distance on the vehicle inner side from groove edges on shoulder land portion sides of side main grooves to the tire equator are equal.

Claims

1. A pneumatic tire having a vehicle inner/outer orientation designated when mounted on a vehicle, the pneumatic tire comprising a tread portion;

the tread portion including;

three main grooves extending in a tire circumferential direction; and

four rows of land portions defined by each of the main grooves;

one narrow groove and a plurality of inclined grooves being provided in each of two rows of center land portions located on a tire equator side of the tread portion, the one narrow groove extending in the tire circumferential direction, the plurality of inclined grooves extending from the narrow groove towards an outer side in a tire width direction;

a plurality of lug grooves being provided in each of two rows of shoulder land portions located on an outer side in the tire width direction of the tread portion, the plurality of lug grooves extending in the tire width direction and not connecting to the main grooves,

a distance Do on a vehicle outer side and a distance Di on a vehicle inner side from groove edges on shoulder land portion sides of side main grooves located on the outer side in the tire width direction of the main grooves to the tire equator being equal,

a center position of a center main groove of the main grooves being located in a position shifted away from the tire equator to the vehicle inner side, and a length of shift d from the center position of the center main groove to the tire equator being in the range of 5% to 100%, both inclusive, of a width L of the center main groove; and

a width Wo of the center land portion on the vehicle outer side being greater than a width Wi of the center land portion on the vehicle inner side.

2. The pneumatic tire according to claim 1, wherein a ratio Wo/Wi of the width Wo of the center land portion on the vehicle outer side to the width Wi of the center land portion on the vehicle inner side is in the range of 1.02 to 1.35, both inclusive.

3. The pneumatic tire according to claim 2, wherein a ratio Lo/Li of a width Lo of the side main groove on the vehicle outer side to a width Li of the side main groove on the vehicle inner side is in the range of 1.05 to 1.40, both inclusive.

4. The pneumatic tire according to claim 3, wherein an intersection angle between the narrow groove and the inclined grooves in each of the center land portions is in the range of 30°

to 50°

, both inclusive.

5. The pneumatic tire according to claim 4, wherein, in each of the shoulder land portions on the vehicle outer side and the vehicle inner side, a circumferential narrow groove is formed connecting to each of the lug grooves and extending in the tire circumferential direction, and widths of the respective circumferential narrow grooves are equal.

6. The pneumatic tire according to claim 5, wherein, in each of the shoulder land portions on the vehicle outer side and the vehicle inner side, a circumferential narrow groove is formed connecting to each of the lug grooves and extending in the tire circumferential direction, a rib is formed sandwiched between the circumferential narrow groove and the side main groove, and a width Ro of the rib on the vehicle outer side is less than a width Ri of the rib on the vehicle inner side.

7. The pneumatic tire according to claim 6, wherein, in each of the center land portions, a groove depth D of the narrow groove and the inclined grooves provided within a range of 65% to 75%, both inclusive, of the widths Wo, Wi, the widths Wo, Wi being from a tire equator side to the outer side in the tire width direction, is equal to or less than 55% a groove depth GD of the main grooves.

8. The pneumatic tire according to claim 7, wherein, in a meridian cross-section, among groove wall angles of the main grooves with respect to a profile normal line of a tread surface, groove wall angles of the center main groove and the side main groove on the vehicle outer side are greater than a groove wall angle of the side main groove on the vehicle inner side.

9. The pneumatic tire according to claim 1, wherein a ratio Lo/Li of a width Lo of the side main groove on the vehicle outer side to a width Li of the side main groove on the vehicle inner side is in the range of 1.05 to 1.40, both inclusive.

10. The pneumatic tire according to claim 1, wherein an intersection angle between the narrow groove and the inclined grooves in each of the center land portions is in the range of 30°

to 50°

, both inclusive.

11. The pneumatic tire according to claim 1, wherein, in each of the shoulder land portions on the vehicle outer side and the vehicle inner side, a circumferential narrow groove is formed connecting to each of the lug grooves and extending in the tire circumferential direction, and widths of the respective circumferential narrow grooves are equal.

12. The pneumatic tire according to claim 1, wherein, in each of the shoulder land portions on the vehicle outer side and the vehicle inner side, a circumferential narrow groove is formed connecting to each of the lug grooves and extending in the tire circumferential direction, a rib is formed sandwiched between the circumferential narrow groove and the side main groove, and a width Ro of the rib on the vehicle outer side is less than a width R1 of the rib on the vehicle inner side.

13. The pneumatic tire according to claim 1, wherein, in each of the center land portions, a groove depth D of the narrow groove and the inclined grooves provided within a range of 65% to 75%, both inclusive, of the widths Wo, Wi, the widths Wo, Wi being from a tire equator side to the outer side in the tire width direction, is equal to or less than 55% a groove depth GD of the main grooves.

14. The pneumatic tire according to claim 1, wherein, in a meridian cross-section, among groove wall angles of the main grooves with respect to a profile normal line of a tread surface, groove wall angles of the center main groove and the side main groove on the vehicle outer side are greater than a groove wall angle of the side main groove on the vehicle inner side.