Pneumatic tire

Patent metadata

Field	Value
Publication number	US-11400762-B2
Application number	US-201716318685-A
Country	US
Kind code	B2
Filing date	Jun 30, 2017
Priority date	Jul 19, 2016
Publication date	Aug 2, 2022
Grant date	Aug 2, 2022

Abstract

A pneumatic tire includes: a center lug groove extending in a lateral direction in a center land portion, the center lug groove connecting to two main groves at both ends; an outer middle lug groove extending in the lateral direction in an outer middle land portion, the outer middle lug groove connecting to two main groves at both ends; and an inner middle lug groove extending in the lateral direction in an inner middle land portion, the inner middle lug groove including an end connecting to the main groove of the two main grooves located inward in the lateral direction and the other end terminating within the inner middle land portion; and the center lug groove and the outer middle lug groove each including a central region in a length direction including a sipe portion, the sipe portion including a sipe with a chamfered opening portion.

First claim

The invention claimed is:

1. A pneumatic tire with a designated mounting direction with respect to a vehicle, the pneumatic tire comprising:
a plurality of main grooves formed in a tread surface extending in a tire circumferential direction;
a center land portion defined on both sides in a tire lateral direction by the main grooves;
a middle land portion located on either side of the center land portion in the tire lateral direction, the middle land portion being defined by the main groove defining the center land portion and the main groove outwardly adjacent in the tire lateral direction to the main groove defining the center land portion;
a center lug groove extending in the tire lateral direction formed in the center land portion, the center lug groove including ends on both sides connecting to two of the main grooves defining the center land portion;
an outer middle lug groove extending in the tire lateral direction formed in an outer middle land portion, of the two middle land portions, located on a vehicle mounting direction outer side, the outer middle lug groove including ends on both sides connecting to two of the main grooves adjacent to the outer middle land portion; and
an inner middle lug groove extending in the tire lateral direction formed in an inner middle land portion, of the two middle land portions, located on a vehicle mounting direction inner side, the inner middle lug groove including an end connecting to the main groove located toward the vehicle mounting direction outer side of the two main groves defining the inner middle land portion and the other end terminating within the inner middle land portion, wherein
the center lug groove and the outer middle lug groove each includes a sipe portion at a central region in a length direction, the sipe portion including a sipe with a chamfered opening portion, the chamfered opening portion being formed in a groove bottom of the center lug groove and the outer middle lug groove, respectively, such that, along a length of the sipe, a sipe width decreases from the chamfered opening portion formed in the groove bottom toward a sipe bottom radially inward of the groove bottom,
the inner middle land portion comprises a straight, circumferential auxiliary groove extending without intersection by lug grooves,
a sipe depth of the sipe, a groove depth of the center lug groove, and a groove depth of the middle lug groove being the same, and
the outer middle lug groove, the center lug groove, and the inner middle lug groove are disposed in a communicating manner.

2. The pneumatic tire according to claim 1 , wherein
the middle land portion includes a middle sipe extending in the tire lateral direction,
the center land portion includes a center sipe extending in the tire lateral direction,
the middle sipe includes an end communicating with the main groove defining an inner end portion of the middle land portion on the vehicle mounting direction inner side and the other end terminating within the middle land portion, and
the center sipe includes an end communicating with the main groove defining an inner end portion of the center land portion on the vehicle mounting direction inner side and the other end terminating within the center land portion.

3. The pneumatic tire according to claim 1 , wherein
the tread surface includes a tread pattern with an asymmetrical pattern in the tire lateral direction, and
a difference in groove area ratio between two sides of a tire equatorial plane in the tire lateral direction is 2% or less.

4. The pneumatic tire according to claim 1 , wherein
the circumferential auxiliary groove extends in the tire circumferential direction, and
the inner middle lug groove is disposed inward from the circumferential auxiliary groove in the tire lateral direction.

5. The pneumatic tire according to claim 4 , wherein
the main grooves are disposed four side by side in the tire lateral direction, and
shoulder land portions are located outwardly adjacent to the middle land portions in the tire lateral direction interposing the main grooves,
the four main grooves extending in the tire circumferential direction with a constant groove width, oscillating in the tire lateral direction.

6. The pneumatic tire according to claim 5 , wherein
the shoulder land portions each include a shoulder lug groove extending in the tire lateral direction, and
the shoulder lug groove includes an inner end portion in the tire lateral direction terminating within the shoulder land portion.

7. The pneumatic tire according to claim 6 , wherein
the shoulder land portions each include a communicating sipe, the communicating sipe connects an inner end portion of the shoulder lug groove in the tire lateral direction and the main groove defining an inner end portion of the shoulder land portion in the tire lateral direction.

8. The pneumatic tire according to claim 7 , wherein
the shoulder lug groove includes a predetermined region, from an inner end portion in the tire lateral direction outward in the tire lateral direction, configured with a chamfered sipe with a chamfered opening portion.

9. The pneumatic tire according to claim 8 , wherein
the shoulder land portion includes a plurality of the shoulder lug grooves, and
the plurality of shoulder lug grooves all include the chamfered sipe.

10. The pneumatic tire according to claim 9 , wherein
the shoulder land portion includes a shoulder sipe extending in the tire lateral direction and communicating with the main groove defining an inner end portion of the shoulder land portion in the tire lateral direction, and
the shoulder lug groove and the shoulder sipe are alternately disposed in the tire circumferential direction.

11. The pneumatic tire according to claim 10 , wherein
the shoulder land portion includes a recessed portion at an outer end of the shoulder land portion in the tire lateral direction, and
the shoulder sipe includes an outer end portion in the tire lateral direction terminating at the recessed portion.

12. The pneumatic tire according to claim 11 , wherein
the shoulder land portion includes a recessed portion at an outer end of the shoulder land portion in the tire lateral direction,
the recessed portions are disposed in two rows in the tire lateral direction,
a laterally inner row including two recessed portions are arranged in the tire circumferential direction,
a laterally outer row including three recessed portions are arranged in the tire circumferential direction, and
the laterally outer row has a larger diameter than the laterally inner row.

13. The pneumatic tire according to claim 1 , wherein
the main grooves are disposed four side by side in the tire lateral direction, and
shoulder land portions are located outwardly adjacent to the middle land portions in the tire lateral direction interposing the main grooves,
the four main grooves extending in the tire circumferential direction with a constant groove width, oscillating in the tire lateral direction.

14. The pneumatic tire according to claim 13 , wherein
the shoulder land portion includes a recessed portion at an outer end of the shoulder land portion in the tire lateral direction,
the recessed portions are disposed in two rows in the tire lateral direction,
a laterally inner row including two recessed portions are arranged in the tire circumferential direction,
a laterally outer row including three recessed portions are arranged in the tire circumferential direction, and
the laterally outer row has a larger diameter than the laterally inner row.

15. The pneumatic tire according to cl

Assignees

• Yokohama Rubber Co Ltd

Inventors

• Kuriyama Masatoshi

Classifications

• B60C2011/0353

  characterised by width · CPC title

• B60C2011/1213

  sinusoidal or zigzag at the tread surface · CPC title

• B60C11/03

  Tread patterns · CPC title

• B60C11/13

  characterised by the groove cross-section, e.g. for buttressing or preventing stone-trapping · CPC title

• B60C11/00

  Tyre tread bands; Tread patterns; Anti-skid inserts · CPC title