Pneumatic tire

Patent metadata

Field	Value
Publication number	US-9499012-B2
Application number	US-201414406522-A
Country	US
Kind code	B2
Filing date	Jan 10, 2014
Priority date	Jan 23, 2013
Publication date	Nov 22, 2016
Grant date	Nov 22, 2016

Abstract

In a pneumatic tire, the groove width of the connecting subsidiary grooves changes midway. The relationship between the groove width (W 1 ) connecting to the circumferential main groove on the outer side in the tire width direction and the groove width (W 2 ) connecting to the circumferential main groove on the inner side in the tire width direction satisfies the range of 0.30≦W 1 /W 2 ≦0.70. The relationship between the groove length (L 1 ) on the tread surface having a region of groove width (W 1 ) and the groove length (L 2 ) on the tread surface having a region of groove width (W 2 ) satisfies the range of 0.25≦L 2 /L 1 ≦0.65. Sipes are provided on the tread surface of the block-like land portions. The respective end portions of the sipes connect to a position where the groove width (W 1 ) of the connecting subsidiary grooves changes to the groove width (W 2 ).

First claim

What is claimed is:

1. A pneumatic tire including, on a tread surface of a tread portion, at least four rib-like land portions extending in a tire circumferential direction formed by at least three circumferential main grooves extending along the tire circumferential direction, and subsidiary grooves provided at intervals in the tire circumferential direction and connecting to each of the circumferential main grooves, forming block-like land portions at least in the rib-like land portions between the circumferential main groove closest to a tire equator line and the circumferential main groove located adjacent to said circumferential main groove, wherein
a groove width of the subsidiary grooves changes midway, a relationship between a groove width (W 1 ) of a first opening of the subsidiary groove with respect to the circumferential main groove on an outer side in a tire width direction and a groove width (W 2 ) of a second opening of the subsidiary groove with respect to the circumferential main groove on an inner side in the tire width direction satisfies a range of 0.30≦W 1 /W 2 ≦0.60, a relationship between a groove length (L 1 ) on the tread surface having a region of the groove width (W 1 ) and a groove length (L 2 ) on the tread surface having a region of the groove width (W 2 ) satisfies a range of 0.25≦L 2 /L 1 ≦0.65, and sipes are provided on the tread surface of the block-like land portions, respective end portions of the sipes connecting to a position where the groove width (W 1 ) of the subsidiary groove changes to the groove width (W 2 ), and to a portion in a section of the subsidiary groove having the groove width (W 1 ) between the subsidiary grooves located adjacent to each other in the tire circumferential direction; and
a relationship between a groove depth (G 1 ) of the circumferential main groove closest to the tire equator line and a groove depth (D 1 ) in the section of the subsidiary groove having the groove width (W 1 ) satisfies a range of 0.30≦D 1 /G 1 ≦0.70, and a relationship between the groove depth (G 1 ) of the circumferential main groove closest to the tire equator line and a groove depth (D 2 ) in a section of the subsidiary groove having the groove width (W 2 ) satisfies a range of 0.50≦D 2 /G 1 ≦0.70.

2. The pneumatic tire according to claim 1 , wherein the sipe connects to an intersecting portion connecting to the circumferential main groove in the section of the subsidiary groove having the groove width (W 1 ), and a relationship between a sipe depth (H 1 ) of the sipe at the intersecting portion and a groove depth (G 2 ) of the circumferential main groove to which the sipe connects satisfies a range of 0.15≦H 1 /G 2 ≦0.30.

3. The pneumatic tire according to claim 2 , wherein a circumferential narrow groove extending along the tire circumferential direction is formed between each of the circumferential main grooves on an outermost side in the tire width direction and each ground contact edge, and a relationship between a distance (S 1 ) in the tire width direction from the tire equator line to the ground contact edge and a distance (S 2 ) in the tire width direction from the tire equator line to a center of the circumferential narrow groove satisfies a range of 0.7≦S 2 /S 1 ≦0.9.

4. The pneumatic tire according to claim 3 , wherein a circumferential narrow groove extending along the tire circumferential direction is formed between each of the circumferential main grooves on the outermost side in the tire width direction and each ground contact edge, and a relationship between a groove width (A 1 ) of the circumferential main groove closest to the tire equator line and a groove width (A 2 ) of the circumferential main groove located on the outer side in the tire width direction of said circumferential main groove satisfies a range of 1.05≦A 2 /A 1 ≦1.15, and a relationship between the groove width (A 1 ) of the circumferential main groove closest to the tire equator line and a groove width (A 3 ) of the circumferential narrow groove satisfies a range of 0.20≦A 3 /A 1 ≦0.35.

5. The pneumatic tire according to claim 4 , wherein a rib-like land portion is provided on the tire equator line, formed between the two circumferential main grooves closest to the tire equator line, and a relationship between a land portion width (B 1 ) on the tread surface of the rib-like land portion and the groove width (Al) of the circumferential main groove closest to the tire equator line satisfies a range of 2.5≦B 1 /A 1 ≦3.0.

6. The pneumatic tire according to claim 5 , wherein the pneumatic tire is a small truck tire with a regular inner pressure of 575 kPa or less.

7. The pneumatic tire according to claim 2 , wherein a circumferential narrow groove extending along the tire circumferential direction is formed between each of the circumferential main grooves on the outermost side in the tire width direction and each ground contact edge, and a relationship between a groove width (Al) of the circumferential main groove closest to the tire equator line and a groove width (A 2 ) of the circumferential main groove located on the outer side in the tire width direction of said circumferential main groove satisfies a range of 1.05≦A 2 /A 1 ≦1.15, and a relationship between the groove width (Al) of the circumferential main groove closest to the tire equator line and a groove width (A 3 ) of the circumferential narrow groove satisfies a range of 0.20≦A 3 /A 1 ≦0.35.

8. The pneumatic tire according to claim 2 , wherein a rib-like land portion is provided on the tire equator line, formed between the two circumferential main grooves closest to the tire equator line, and a relationship between a land portion width (B 1 ) on the tread surface of the rib-like land portion and the groove width (Al) of the circumferential main groove closest to the tire equator line satisfies a range of 2.5≦B 1 /A 1 ≦3.0.

9. The pneumatic tire according to claim 2 , wherein the pneumatic tire is a small truck tire with a regular inner pressure of 575 kPa or less.

10. The pneumatic tire according to claim 1 , wherein a circumferential narrow groove extending along the tire circumferential direction is formed between each of the circumferential main grooves on an outermost side in the tire width direction and each ground contact edge, and a relationship between a distance (S 1 ) in the tire width direction from the tire equator line to the ground contact edge and a distance (S 2 ) in the tire width direction from the tire equator line to a center of the circumferential narrow groove satisfies a range of 0.7≦S 2 /S 1 ≦0.9.

11. The pneumatic tire according to claim 1 , wherein a circumferential narrow groove extending along the tire circumferential direction is formed between each of the circumferential main grooves on the outermost side in the tire width direction and each ground contact edge, and a relationship between a groove width (Al) of the circumferential main groove closest to the tire equator line and a groove width (A 2 ) of the circumferential main groove located on the outer side in the tire width direction of said circumferential main groove satisfies a range of 1.05≦A 2 /A 1 ≦1.15, and a relationship between the groove width (Al) of the circumferential main groove closest to the tire equator line and a groove width (A 3 ) of the circumferential narrow groove satisfies a range of 0.20≦A 3 /A 1 ≦0.35.

12. The pneumatic tire according to claim 1 , wherein a rib-like land portion is provided on the tire equator line, formed between the two circumferential main grooves closest to the tire equator line, and a relationship between a land portion width (B 1 ) on the tread surface of the rib-like land portion and t

Assignees

• Yokohama Rubber Co Ltd

Inventors

• Nemoto Masayuki

Classifications

• B60C11/1236

  with special arrangements in the tread pattern · CPC title

• B60C2011/0353

  characterised by width · CPC title

• B60C2011/0388

  provided at the equatorial plane · CPC title

• B60C2011/0372

  with particular inclination angles · CPC title

• B60C11/03 Primary

  Tread patterns · CPC title