阅读说明：本技术 轮胎 (Tyre for vehicle wheels ) 是由 木寅龙太 大场亮 石飞泰将 于 2019-05-14 设计创作，主要内容包括：本发明提供一种轮胎。提供能够提高干燥路面上的操纵稳定性和雪上性能的轮胎。轮胎具有指定了向车辆安装的朝向的胎面部(2)。胎面部(2)具有外侧胎面端(To)、内侧胎面端(Ti)和外侧中间陆地部(7)。在外侧中间陆地部(7)设有从第1纵向边缘(7a)延伸并且在外侧中间陆地部(7)内中断的外侧中间横槽(15)、从外侧中间横槽(15)的中断端延伸至第2纵向边缘(7b)的第1外侧中间刀槽(16)、以及从第1纵向边缘(7a)延伸并且在比外侧中间横槽(15)的中断端靠第2纵向边缘(7b)侧的位置中断的第2外侧中间刀槽(17)。在外侧中间陆地部(7)上没有设置从第2纵向边缘(7b)向第1纵向边缘(7a)侧延伸并且到达外侧中间陆地部(7)的轮胎轴向上的中心位置的横槽。(The invention provides a tire. Provided is a tire capable of improving steering stability on a dry road surface and on-snow performance. The tire has a tread portion (2) in which the direction of mounting to the vehicle is specified. The tread portion (2) has an outer tread end (To), an inner tread end (Ti) and an outer intermediate land portion (7). The outer intermediate land portion (7) is provided with an outer intermediate lateral groove (15) extending from the 1 st longitudinal edge (7a) and interrupted in the outer intermediate land portion (7), a 1 st outer intermediate sipe (16) extending from the interrupted end of the outer intermediate lateral groove (15) to the 2 nd longitudinal edge (7b), and a 2 nd outer intermediate sipe (17) extending from the 1 st longitudinal edge (7a) and interrupted at a position closer to the 2 nd longitudinal edge (7b) than the interrupted end of the outer intermediate lateral groove (15). A lateral groove extending from the 2 nd longitudinal edge (7b) to the 1 st longitudinal edge (7a) side and reaching a center position of the outer intermediate land portion (7) in the tire axial direction is not provided in the outer intermediate land portion (7).)

1. A tire having a tread portion that specifies an orientation for mounting to a vehicle, wherein the tread portion has:

An outer tread end located on an outer side of the vehicle when mounted to the vehicle;

An inner tread end located on an inner side of the vehicle when mounted to the vehicle; and

An outer intermediate land portion disposed between the outer tread end and a tire equator,

The outer middle land portion has: a 1 st longitudinal edge extending in the tire circumferential direction on the inner tread end side, a 2 nd longitudinal edge extending in the tire circumferential direction on the outer tread end side, and a tread surface between the 1 st longitudinal edge and the 2 nd longitudinal edge,

The outer middle land part is provided with: an outer-side intermediate lateral groove extending from the 1 st longitudinal edge and interrupted in the outer-side intermediate land portion, a 1 st outer-side intermediate sipe extending from an interrupted end of the outer-side intermediate lateral groove to the 2 nd longitudinal edge, and a 2 nd outer-side intermediate sipe extending from the 1 st longitudinal edge and interrupted at a position closer to the 2 nd longitudinal edge side than the interrupted end of the outer-side intermediate lateral groove,

the outer intermediate land portion is not provided with a lateral groove extending from the 2 nd longitudinal edge toward the 1 st longitudinal edge and reaching a center position in the tire axial direction of the outer intermediate land portion.

2. the tire according to claim 1, wherein,

The tread portion has: an outer shoulder main groove continuously extending in a tire circumferential direction on the outer tread end side of the outer intermediate land portion; and an outboard shoulder land portion divided between the outboard shoulder main groove and the outboard tread end,

and the outer tire shoulder land part is provided with an outer tire shoulder transverse groove extending from the outer tire shoulder main groove to the outer tire tread end.

3. The tire according to claim 2, wherein,

The outboard shoulder cross slot includes: a 1 st groove portion extending from the outer shoulder main groove; and a 2 nd groove portion connected to the 1 st groove portion to extend to the outer tread end with a groove width larger than that of the 1 st groove portion.

4. The tire according to claim 3,

The length of the 1 st groove portion in the tire axial direction is greater than the length of the outer middle lateral groove in the tire axial direction.

5. Tire according to any one of claims 2 to 4,

and the land part of the outer tire shoulder is provided with a chamfer part formed by sinking the corner part between the tread and the side surface.

6. The tire according to claim 5,

The chamfered portion is connected with the outer shoulder transverse groove.

7. the tire according to claim 5 or 6,

A region in which the chamfered portion is extended in the tire axial direction intersects with the 2 nd outer intermediate sipe.

8. The tire according to claim 3 or 4,

the groove width of the 1 st groove part is smaller than that of the outer middle transverse groove.

9. The tire according to claim 8,

The groove width of the 2 nd groove part is larger than that of the outer middle transverse groove.

10. The tire according to claim 9,

the 2 nd groove portion has a depth greater than the 1 st groove portion.

11. The tire according to claim 1, wherein,

The tread portion has an inner intermediate land portion disposed between the inner tread end and a tire equator,

the inner intermediate land portion has:

A 1 st longitudinal edge extending in the tire circumferential direction on the inner tread end side;

a 2 nd longitudinal edge extending in the tire circumferential direction on the outer tread end side; and

A tread located between the 1 st longitudinal edge and the 2 nd longitudinal edge,

An inner intermediate lateral groove extending from the 1 st longitudinal edge and interrupted in the inner intermediate land portion is provided on the inner intermediate land portion,

The ratio Li/Wi of the length Li in the tire axial direction of the inner intermediate lateral groove to the width Wi in the tire axial direction of the inner intermediate land portion is larger than the ratio Lo/Wo of the length Lo in the tire axial direction of the outer intermediate lateral groove to the width Wo in the tire axial direction of the outer intermediate land portion.

12. The tire according to claim 11,

the length Li of the inner middle transverse slot is greater than the length Lo of the outer middle transverse slot.

13. The tire according to claim 11 or 12,

And a 1 st inner middle knife groove extending from the interrupted end of the inner middle transverse groove to the 2 nd longitudinal edge is arranged on the inner middle land part.

14. The tire according to claim 13, wherein,

A region in which the 1 st inner intermediate sipe extends toward the outer tread end intersects a region in which the outer intermediate lateral groove extends toward the inner tread end.

15. Tire according to any one of claims 11 to 14,

The inner intermediate land portion is not provided with a lateral groove that extends from the 2 nd longitudinal edge to the 1 st longitudinal edge side and reaches a center position in the tire axial direction of the inner intermediate land portion.

16. Tire according to any one of claims 11 to 15,

The medial intermediate transverse slot and the lateral intermediate transverse slot each extend with a fixed slot width.

17. Tire according to any one of claims 11 to 16,

The outer intermediate lateral groove reaches a center position in the tire axial direction of the outer intermediate land portion.

18. Tire according to any one of claims 11 to 17,

And a chamfer part formed by sinking the corner between the tread and the side surface of the outer middle land part is arranged on the 1 st longitudinal edge side of the outer middle land part.

19. The tire according to claim 18,

And a chamfer part formed by sinking the corner between the tread and the side surface of the inner middle land part is arranged on the 1 st longitudinal edge side of the inner middle land part.

20. the tire according to claim 19,

The length in the tire circumferential direction of the chamfered portion provided in the inner intermediate land portion is greater than the length in the tire circumferential direction of the chamfered portion provided in the outer intermediate land portion.

Technical Field

The present invention relates to a tire, and more particularly, to a tire that can be preferably implemented as an all-weather tire.

Background

All-weather tires are required to have basic running performance not only on dry roads but also on snow roads. In order to improve the running performance on slippery snow roads, tires are required to have a large snow column shearing force and a road surface scraping effect. The snow column shear force is obtained by pressing and shearing snow on a road surface with the transverse grooves. Therefore, in order to improve the on-snow performance, it is effective to provide a plurality of long lateral grooves in the tread portion. Furthermore, the traction force is improved by scraping the edges of the lateral grooves or the cutter grooves against the compacted snow covered road. As a related technique, there is the following patent document 1.

Patent document 1: japanese laid-open patent publication No. 2015-013604

The lateral grooves and sipes provided in the tread portion contribute to improvement of on-snow performance, but tend to lower the pattern rigidity of the tread portion and further deteriorate the steering stability on a dry road surface.

disclosure of Invention

The present invention has been made in view of the above-described problems, and a main object thereof is to provide a tire capable of improving steering stability on a dry road surface and on-snow performance.

the present invention is a tire having a tread portion in which an orientation of mounting to a vehicle is designated, wherein the tread portion has: an outer tread end located on an outer side of the vehicle when mounted to the vehicle; an inner tread end located on an inner side of the vehicle when mounted to the vehicle; and an outer intermediate land portion disposed between the outer tread end and a tire equator, the outer intermediate land portion having a 1 st longitudinal edge extending in a tire circumferential direction on the inner tread end side, a 2 nd longitudinal edge extending in the tire circumferential direction on the outer tread end side, and a tread surface between the 1 st longitudinal edge and the 2 nd longitudinal edge, the outer intermediate land portion being provided with an outer intermediate lateral groove extending from the 1 st longitudinal edge and interrupted in the outer intermediate land portion, a 1 st outer intermediate sipe extending from an interrupted end of the outer intermediate lateral groove to the 2 nd longitudinal edge, and a 2 nd outer intermediate sipe extending from the 1 st longitudinal edge and interrupted at a position closer to the 2 nd longitudinal edge side than the interrupted end of the outer intermediate lateral groove, the outer intermediate land portion being provided with no intermediate sipe extending from the 2 nd longitudinal edge to the 1 st longitudinal edge and reaching the outer longitudinal edge side A lateral groove at the center of the lateral middle land part in the tire axial direction.

In the tire of the present invention, it is preferable that the tread portion has: an outer shoulder main groove continuously extending in a tire circumferential direction on the outer tread end side of the outer intermediate land portion; and an outer shoulder land portion divided between the outer shoulder main groove and the outer tread end, the outer shoulder land portion being provided with an outer shoulder lateral groove extending from the outer shoulder main groove to the outer tread end.

In the tire of the present invention, it is preferable that the outer shoulder lateral groove includes: a 1 st groove portion extending from the outer shoulder main groove; and a 2 nd groove portion connected to the 1 st groove portion to extend to the outer tread end with a groove width larger than that of the 1 st groove portion.

In the tire of the present invention, it is preferable that the length of the 1 st groove portion in the tire axial direction is longer than the length of the outer middle lateral groove in the tire axial direction.

In the tire according to the present invention, it is preferable that the outer shoulder land portion is provided with a chamfered portion formed by recessing a corner portion between the tread surface and the side surface

In the tire of the present invention, it is preferable that the chamfered portion is connected to the outer shoulder lateral groove.

In the tire of the present invention, it is preferable that a region of the chamfered portion extending in the tire axial direction intersects with the 2 nd outer intermediate sipe.

In the tire of the present invention, it is preferable that the groove width of the 1 st groove portion is smaller than the groove width of the outer middle lateral groove.

In the tire of the present invention, it is preferable that the groove width of the 2 nd groove portion is larger than the groove width of the outer middle lateral groove.

in the tire of the present invention, it is preferable that the 2 nd groove portion has a depth larger than that of the 1 st groove portion.

in the tire of the present invention, it is preferable that the tread portion has an inner intermediate land portion disposed between the inner tread end and a tire equator, the inner intermediate land portion having: a 1 st longitudinal edge extending in the tire circumferential direction on the inner tread end side; a 2 nd longitudinal edge extending in the tire circumferential direction on the outer tread end side; and a tread surface located between the 1 st longitudinal edge and the 2 nd longitudinal edge, an inner intermediate lateral groove extending from the 1 st longitudinal edge and interrupted in the inner intermediate land portion being provided on the inner intermediate land portion, a ratio Li/Wi of a length Li in a tire axial direction of the inner intermediate lateral groove to a width Wi in the tire axial direction of the inner intermediate land portion being larger than a ratio Lo/Wo of a length Lo in the tire axial direction of the outer intermediate lateral groove to a width Wo in the tire axial direction of the outer intermediate land portion.

In the tire of the present invention, it is preferable that the length Li of the inner middle lateral groove is larger than the length Lo of the outer middle lateral groove.

In the tire of the present invention, it is preferable that a 1 st inner intermediate sipe extending from an interrupted end of the inner intermediate lateral groove to the 2 nd longitudinal edge is provided in the inner intermediate land portion.

in the tire of the present invention, it is preferable that a region in which the 1 st inner intermediate sipe extends toward the outer tread end side intersects a region in which the outer intermediate lateral groove extends toward the inner tread end side.

in the tire of the present invention, it is preferable that no lateral groove extending from the 2 nd longitudinal edge to the 1 st longitudinal edge side and reaching a center position of the inner intermediate land in the tire axial direction is provided in the inner intermediate land.

In the tire of the present invention, it is preferable that the inner middle lateral groove and the outer middle lateral groove each extend with a constant groove width.

In the tire of the present invention, it is preferable that the outer intermediate lateral groove reaches a center position in the tire axial direction of the outer intermediate land portion.

In the tire of the present invention, it is preferable that a chamfered portion recessed from a corner between a tread surface and a side surface of the outer intermediate land portion is provided on the 1 st longitudinal edge side of the outer intermediate land portion.

In the tire of the present invention, it is preferable that a chamfered portion recessed from a corner between a tread surface and a side surface of the inner intermediate land portion is provided on the 1 st longitudinal edge side of the inner intermediate land portion.

in the tire of the present invention, it is preferable that the length in the tire circumferential direction of the chamfered portion provided in the inner intermediate land portion is larger than the length in the tire circumferential direction of the chamfered portion provided in the outer intermediate land portion.

Drawings

Fig. 1 is a development view of a tread portion of a tire according to an embodiment of the present invention.

Fig. 2 is an enlarged view of the outer intermediate land portion and the inner intermediate land portion of fig. 1.

Fig. 3A is a sectional view taken along line a-a of fig. 2, fig. 3B is a sectional view taken along line B-B of fig. 2, and fig. 3C is a sectional view of a 2 nd outer intermediate sipe in another embodiment.

fig. 4 is a cross-sectional view taken along line C-C of fig. 2.

fig. 5 is an enlarged view of the outboard shoulder land portion of fig. 1.

FIG. 6 is an enlarged view of the inboard shoulder land portion of FIG. 1.

Fig. 7 is an enlarged view of an outer middle land portion of the tire of the comparative example.

Fig. 8 is an enlarged view of the outer middle land portion and the inner middle land portion of the tire of the embodiment.

Detailed Description

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

Fig. 1 is a development view showing a tread portion 2 of a tire 1 according to an embodiment of the present invention. The tire 1 of the present embodiment is configured as a pneumatic tire, for example. In the present embodiment, an all-weather tire intended to be mounted on a passenger car or an SUV is shown as a preferable embodiment.

as shown in fig. 1, a tire 1 of the present invention has a tread portion 2 in which a direction of mounting to a vehicle is designated. The tread portion 2 of the tire 1 of the present embodiment has a tread pattern that is asymmetric in the left and right. The tread portion 2 has an outer tread end To located on the vehicle outer side when the tire 1 is mounted on the vehicle and an inner tread end Ti located on the vehicle inner side when the tire 1 is mounted on the vehicle. The direction of attachment to the vehicle is indicated by characters or symbols on the side wall (not shown), for example.

In the case of a pneumatic tire, the outer tread end To and the inner tread end Ti are ground contact positions that are most outward in the axial direction of the tire when a standard load is applied To the tire 1 in a standard state and ground is in a plane at a camber angle of 0 °. The standard state is a state in which the tire rim is assembled to a standard rim, the standard internal pressure is filled, and no load is applied. In the present specification, unless otherwise specified, the dimensions and the like of each portion of the tire are values measured in the standard state.

The "standard Rim" is a Rim specified for each tire in a specification system including a specification under which the tire is based, and is, for example, "standard Rim" in the case of JATMA, "Design Rim" in the case of TRA, or "Measuring Rim" in the case of etro.

The "standard internal PRESSURE" is an air PRESSURE specified for each TIRE in a specification system including specifications under which the TIRE is based, and is "the highest air PRESSURE" in case of JATMA, the maximum value described in the table "TIRE LOAD list AT variation color establishment PRESSURES" in case of TRA, and "establishment PRESSURE" in case of etro.

The "standard LOAD" is a LOAD specified for each TIRE in a specification system including specifications to be followed by the TIRE, and is "maximum LOAD CAPACITY" in case of JATMA, maximum values described in a table "TIRE LOAD conditions AT variance stability requirements" in case of TRA, and "LOAD CAPACITY" in case of ETRO.

The tread portion 2 of the present embodiment is provided with, for example, a plurality of main grooves 3 continuously extending in the tire circumferential direction. The main tank 3 includes, for example: an outer shoulder main groove 4 disposed on the outermost tread end To side; an inner shoulder main groove 5 disposed on the innermost tread end Ti side; and a crown main groove 6 disposed therebetween. In the present embodiment, one crown main groove 6 is provided on the tire equator C. Thereby, the tread portion 2 is divided into 4 land portions. In another mode, the tread portion 2 may be divided into 5 land portions by, for example, the outer shoulder main groove 4 and the inner shoulder main groove 5, and two crown main grooves 6 sandwiching the tire equator C.

The distance L1 in the tire axial direction from the groove center line of the outer shoulder main groove 4 or the inner shoulder main groove 5 to the tire equator C is preferably, for example, 0.15 to 0.25 times the tread width TW. The tread width TW is a distance in the tire axial direction from the outer tread end To the inner tread end Ti in the standard state.

Each main groove 3 extends linearly, for example. The main grooves 3 may extend, for example, in a zigzag pattern. The groove width W1 of the main groove 3 is preferably 4.0% to 7.0% of the tread width TW, for example. The groove depth of the main groove 3 is preferably 5.0 to 12.0mm, for example. This can improve the steering stability on a dry road surface and the on-snow performance in a well-balanced manner.

The tread portion 2 of the present embodiment is divided into an outer middle land portion 7, an inner middle land portion 8, an outer shoulder land portion 9, and an inner shoulder land portion 10. The outer intermediate land portion 7 is disposed between the tire equator C and the outer tread end To, specifically, is divided between the crown main groove 6 and the outer shoulder main groove 4. The inner intermediate land portion 8 is disposed between the tire equator C and the inner tread end Ti, specifically, is divided between the crown main groove 6 and the inner shoulder main groove 5. The outer shoulder land portion 9 is divided between the outer shoulder main groove 4 and the outer tread end To. The inner-shoulder land portion 10 is divided between the inner-shoulder main groove 5 and the inner tread end Ti.

Fig. 2 shows an enlarged view of the outer intermediate land portion 7 and the inner intermediate land portion 8. As shown in fig. 2, the outer intermediate land portion 7 has: a 1 st longitudinal edge 7a extending in the tire circumferential direction on the inner tread end Ti side; a 2 nd longitudinal edge 7b extending in the tire circumferential direction on the outer tread end To side; and a tread between the 1 st longitudinal edge 7a and said 2 nd longitudinal edge 7 b. Similarly, the inner intermediate land portion 8 has: a 1 st longitudinal edge 8a extending in the tire circumferential direction on the inner tread end Ti side; a 2 nd longitudinal edge 8b extending in the tire circumferential direction on the outer tread end To side; and a tread between the 1 st longitudinal edge 8a and the 2 nd longitudinal edge 8 b.

The outer intermediate land portion 7 is provided with an outer intermediate lateral groove 15, a 1 st outer intermediate sipe 16, and a 2 nd outer intermediate sipe 17. The outboard intermediate lateral groove 15 extends from the 1 st longitudinal edge 7a and is interrupted within the outboard intermediate land portion 7. The 1 st lateral intermediate sipe 16 extends from the interrupted end of the lateral intermediate lateral groove 15 to the 2 nd longitudinal edge 7 b. The 2 nd outside middle sipe 17 extends from the 1 st longitudinal edge 7a and is interrupted at a position closer to the 2 nd longitudinal edge 7b than the interrupted end of the outside middle lateral groove 15. In the present specification, the term "sipe" refers to a slit having a width of less than 1.5mm, and in a preferred embodiment, the sipe has a width of, for example, 0.5 to 1.0 mm.

The outer intermediate transverse grooves 15 can provide snow column shear when driving on snow. Further, since the outer middle lateral groove 15 extends from the 1 st longitudinal edge 7a and is interrupted in the outer middle land portion 7, it is possible to prevent a decrease in rigidity of the outer middle land portion 7 on the 2 nd longitudinal edge 7b side, thereby suppressing deterioration in steering stability.

The 1 st outer intermediate sipe 16 is a narrow slit, and can suppress excessive reduction in rigidity of the land portion, and can increase the amount of snow entering the outer intermediate lateral groove by facilitating opening of the outer intermediate lateral groove 15. The 2 nd outer intermediate sipe 17 can facilitate appropriate movement of the land portion between the 2 nd outer intermediate lateral groove 15 on the 1 st longitudinal edge 7a side and the 2 nd outer intermediate sipe 17 while maintaining the rigidity of the 2 nd longitudinal edge 7b side of the outer intermediate land portion 7, and can strongly fix snow entering the outer intermediate lateral groove 15. As described above, in the present invention, the arrangement of the 1 st outer intermediate sipe 16 and the 2 nd outer intermediate sipe 17 increases the snow column shearing force of the outer intermediate lateral groove 15, and excellent on-snow performance can be obtained.

No lateral groove extending from the 2 nd longitudinal edge 7b toward the 1 st longitudinal edge 7a side and reaching the center position in the tire axial direction of the outer intermediate land portion 7 is provided in the outer intermediate land portion 7. Normally, such a groove greatly reduces the rigidity of the land portion in the vicinity of the 2 nd longitudinal edge 7b, and by not providing such a groove, the rigidity of the outer middle land portion 7 can be maintained, and excellent steering stability can be exhibited.

In a preferred mode, no lateral groove extending from the 2 nd longitudinal edge 7b and exceeding 0.25 times the width Wo of the outer intermediate land portion 7 is provided in the outer intermediate land portion 7. As a more preferable mode, in the present embodiment, the lateral grooves extending from the 2 nd longitudinal edge 7b are not provided in the outer intermediate land portion 7, and only the sipes are connected to the 2 nd longitudinal edge 7 b. Further, no chamfered portion recessed from a corner between the tread surface and the side surface of the land portion is provided at the 2 nd longitudinal edge 7 b. Such an outer middle land portion 7 has higher rigidity in the vicinity of the 2 nd longitudinal edge 7b, and more excellent steering stability can be expected.

The ratio Lo/Wo of the width Wo of the outer intermediate land portion 7 in the tire axial direction to the length Lo of the outer intermediate lateral groove 15 in the tire axial direction is preferably, for example, 0.40 to 0.60. The outer intermediate lateral groove 15 of the present embodiment reaches, for example, the center position of the outer intermediate land portion 7 in the tire axial direction. Such an outer middle lateral groove 15 can improve steering stability and snow performance on a dry road surface in a relatively well-balanced manner.

The outer intermediate lateral groove 15 is preferably inclined with respect to the tire axial direction, for example. The angle of the outer intermediate lateral groove 15 with respect to the tire axial direction is preferably less than 30 °, for example, 15 to 25 °. A large traction force on the snow can be expected for such outer intermediate lateral grooves 15.

The outer intermediate transverse groove 15 preferably extends, for example, with a constant groove width. The constant groove width extension includes a difference between the maximum groove width and the minimum groove width of the lateral groove being less than 5% of the maximum groove width. The groove width W2 of the outer intermediate lateral grooves 15 is preferably 0.25 to 0.40 times the groove width W1 of the main groove 3, for example.

The 1 st outer intermediate sipe 16 is preferably inclined in the same direction as the outer intermediate lateral groove 15 with respect to the tire axial direction, for example. Further, the angle of the 1 st outer intermediate sipe 16 with respect to the tire axial direction is preferably less than 30 °.

FIG. 3A shows a cross-sectional view taken along line A-A of the lateral middle lateral groove 15 and the 1 st lateral middle sipe 16 of FIG. 2. As shown in FIG. 3A, the depth d2 of the 1 st outer middle sipe 16 is preferably 0.50 to 0.70 times the depth d1 of the outer middle lateral groove 15. Such a 1 st outer intermediate sipe 16 can prevent the rigidity of the outer intermediate land portion 7 from being lowered, and can improve the on-snow performance.

As shown in fig. 2, for example, the 2 nd outer intermediate sipe 17 is interrupted at a position closer to the 2 nd longitudinal edge 7b side than the center position of the outer intermediate land portion 7 in the tire axial direction. The length L2 in the tire axial direction of the 2 nd outer intermediate sipe 17 is, for example, 0.65 to 0.85 times the width Wo in the tire axial direction of the outer intermediate land portion 7. The length L2 of the 2 nd outer middle sipe 17 is preferably 1.40 to 1.60 times the length Lo of the outer middle lateral groove 15 in the tire axial direction. This makes it easier for the land portion pieces between the outer middle lateral grooves 15 and the 2 nd outer middle sipes 17 to move, and when the vehicle travels on snow, the snow in the outer middle lateral grooves 15 is strongly compressed, and a large snow column shear force can be obtained.

the 2 nd outer intermediate sipe 17 is inclined, for example, in the same direction as the outer intermediate lateral groove 15 with respect to the tire axial direction. The angle of the 2 nd outer intermediate sipe 17 with respect to the tire axial direction is, for example, 10 to 30 °.

FIG. 3B illustrates a cross-sectional view taken along line B-B of the 2 nd outer intermediate sipe 17 of FIG. 2. As shown in fig. 3B, the 2 nd outside intermediate sipe 17 has, for example: a shallow bottom portion 17a formed by raising the bottom of the groove at the end portion on the 1 st longitudinal edge 7a side; and a tapered portion 17b whose depth gradually decreases toward the 2 nd longitudinal edge 7b side interrupt end. The depth d4 of the shallow bottom 17a is 0.70 to 0.90 times the maximum depth d3 of the 2 nd outer middle sipe 17. Since excessive opening of the 2 nd outer middle sipe 17 having the shallow bottom portion 17a and the tapered portion 17b is suppressed, it is possible to prevent reduction in steering stability on a dry road surface.

FIG. 3C illustrates a cross-sectional view of another embodiment of the 2 nd outside intermediate sipe 17. As shown in fig. 3C, the depth of the 2 nd outer intermediate sipe 17 of this embodiment gradually decreases from the 1 st longitudinal edge 7 a-side end portion toward the interruption end portion. The ratio d5/d3 of the minimum depth d5 to the maximum depth d3 of the 2 nd outer middle sipe 17 is, for example, 0.20 to 0.40. Since the rigidity in the tire circumferential direction of the outer intermediate land portion 7 in which such a 2 nd outer intermediate sipe 17 is arranged gradually increases toward the 2 nd longitudinal edge 7b side, the steering response at the time of cornering can be made linear.

As shown in fig. 2, a chamfered portion 18 recessed by a corner between the tread surface and the side surface of the land portion is provided on the 1 st longitudinal edge 7a side of the outer intermediate land portion 7. The chamfered portion 18 of the present embodiment is connected to the outer intermediate lateral groove 15, for example. Such chamfered portions 18 are for suppressing one-sided wear of the outer intermediate land portion 7. The chamfered portions 18 contribute to integrating snow in the outer intermediate lateral grooves 15 with snow in the crown main groove 6 during snow travel, and further can suppress snow from clogging in the outer intermediate lateral grooves 15.

The inner intermediate land portion 8 is provided with an inner intermediate lateral groove 20 extending from the 1 st longitudinal edge 8a and interrupted in the inner intermediate land portion 8. The inner intermediate transverse groove 20 can provide snow column shear when driving on snow. Further, the inner intermediate lateral groove 20 prevents a decrease in rigidity of the inner intermediate land portion 8 on the 2 nd longitudinal edge 8b side, suppressing deterioration in steering stability.

The ratio Li/Wi of the length Li in the tire axial direction of the inner intermediate lateral grooves 20 to the width Wi in the tire axial direction of the inner intermediate land portions 8 is preferably larger than the ratio Lo/Wo of the length Lo in the tire axial direction of the outer intermediate lateral grooves 15 to the width Wo in the tire axial direction of the outer intermediate land portions 7. This ensures the length of the lateral groove in the inner middle land portion 8 on which a relatively large ground contact pressure acts, and thus exhibits excellent on-snow performance.

Further, such arrangement of the lateral grooves can relatively increase the rigidity of the outer middle land portion 7. This makes it possible to obtain a tire having a large self-aligning torque (hereinafter, sometimes referred to as "SAT"). For example, when tires having a large SAT are mounted on all the wheels of an FF car, the tire yaw stiffness of the front wheels (hereinafter, sometimes referred to as "CP") is relatively reduced by the SAT, and the CP of the front wheels and the CP of the rear wheels approach each other. Therefore, in a passenger car in which the tire of the present invention is mounted on all the wheels, when a steering angle is applied to the front wheel, the cornering force of the front wheel and the cornering force of the rear wheel are easily shifted to a substantially balanced stable state, and excellent steering stability can be exhibited.

The ratio Li/Wi is more preferably 0.70 to 0.90, for example. The length Li of the inner intermediate lateral grooves 20 is preferably longer than the length Lo of the outer intermediate lateral grooves 15. This can further improve the on-snow performance.

no lateral groove extending from the 2 nd longitudinal edge 8b to the 1 st longitudinal edge 8a side and reaching a center position in the tire axial direction of the inner intermediate land portion 8 is provided on the inner intermediate land portion 8. In a preferred form, no transverse groove extending from the 2 nd longitudinal edge 8b and exceeding 0.25 times the width Wo of the inner intermediate land portion 8 is provided on the inner intermediate land portion 8. As a more preferable mode, in the present embodiment, the lateral groove extending from the 2 nd longitudinal edge 8b is not provided in the inner intermediate land portion 8, and only the sipe is connected to the 2 nd longitudinal edge 8 b. Further, no chamfered portion recessed from a corner between the tread surface and the side surface of the land portion is provided at the 2 nd longitudinal edge 7 b. Such an inner land portion 8 can further improve steering stability on a dry road surface.

The inner intermediate lateral grooves 20 are preferably inclined in the same direction as the outer intermediate lateral grooves 15, for example. The angle of the inner intermediate transverse grooves 20 with respect to the axial direction of the tire is preferably less than 30 °, for example, 15 ° to 25 °. Such an inner intermediate transverse groove 20 enables a more balanced improvement of the traction and cornering performance on snow.

The medial transverse slot 20 preferably extends a slot width. The groove width W3 of the inner intermediate lateral groove 20 is preferably 0.25 to 0.40 times the groove width W1 of the main groove 3, for example.

The inside intermediate land portion 8 is provided with a 1 st inside intermediate sipe 21 and a 2 nd inside intermediate sipe 22.

The 1 st medial intermediate sipe 21 extends, for example, from the interrupted end of the medial intermediate lateral groove 20 to the 2 nd longitudinal edge 8 b. The 1 st inside intermediate sipe 21 is preferably inclined, for example, in the same direction as the inside intermediate lateral groove 20 with respect to the tire axial direction. The angle of the 1 st inside intermediate sipe 21 with respect to the tire axial direction is preferably, for example, less than 30 °.

preferably, a region of the 1 st inside intermediate sipe 21 extending toward the outside tread end To in the longitudinal direction thereof intersects with a region of the outside intermediate lateral groove 15 extending toward the inside tread end Ti in the longitudinal direction thereof in the crown main groove 6. Such arrangement of the lateral grooves and the sipes facilitates appropriate opening of the lateral grooves, thereby contributing to improvement in on-snow performance.

The 2 nd medial intermediate sipe 22 extends, for example, from the 1 st longitudinal edge 8a to the 2 nd longitudinal edge 8 b. Such a 2 nd inside intermediate sipe 22 can improve traction on snow.

The 2 nd inside intermediate sipe 22 is preferably inclined, for example, in the same direction as the inside intermediate lateral groove 20 with respect to the tire axial direction. The angle of the 2 nd inside intermediate sipe 22 with respect to the tire axial direction is, for example, 10 ° to 30 °.

FIG. 4 illustrates a cross-sectional view taken along line C-C of the 2 nd inside intermediate sipe 22. As shown in fig. 4, the 2 nd inside middle sipe 22 preferably has a shallow bottom 22a at both ends in the tire axial direction. The depth d7 of the shallow bottom 22a is, for example, 0.70 to 0.90 times the maximum depth d6 of the 2 nd inner middle sipe 22. Such a 2 nd inside intermediate sipe 22 can suppress a decrease in steering stability, and can improve on-snow performance.

As shown in fig. 2, a chamfered portion 23 formed by recessing a corner between the tread surface and the side surface of the land portion is provided on the 1 st longitudinal edge 7a side of the inner intermediate land portion 8. The chamfered portion 23 of the present embodiment is connected to the inner intermediate lateral groove 20, for example. Such chamfered portion 23 can suppress one-sided wear of the inner intermediate land portion 8. Further, the length in the tire circumferential direction of the chamfered portion 23 provided to the inner intermediate land portion 8 is larger than the length in the tire circumferential direction of the chamfered portion 18 provided to the outer intermediate land portion 7. This reduces the difference in the progress of wear between the inner intermediate land portion 8 and the outer intermediate land portion 7 due to the difference in the ground contact pressure.

Fig. 5 shows an enlarged view of the outboard shoulder land portion 9. As shown in fig. 5, the outer shoulder land portion 9 is provided with an outer shoulder lateral groove 25, a 1 st outer shoulder sipe 26, and a 2 nd outer shoulder sipe 27.

The outer-shoulder lateral groove 25 extends, for example, from the outer-shoulder main groove 4 To the outer tread end To. The outer shoulder lateral grooves 25 are inclined in the same direction as the outer middle lateral grooves 15 with respect to the tire axial direction, for example. The angle of the outboard shoulder lateral groove 25 with respect to the tire axial direction is preferably, for example, 10 ° to 30 °.

The outboard shoulder lateral groove 25 of the present embodiment includes: a 1 st groove portion 25a extending from the outer shoulder main groove 4; and a 2 nd groove portion 25b continuous with the 1 st groove portion 25a and extending To the outer tread end To with a groove width larger than that of the 1 st groove portion 25 a. In a more preferred embodiment, one edge of the 1 st groove portion 25a and one edge of the 2 nd groove portion 25b are smoothly continuous.

The groove width W4 of the 1 st groove portion 25a is preferably smaller than the groove width W2 of the outer intermediate lateral groove 15 (as shown in fig. 2), for example. The groove width W5 of the 2 nd groove portion 25b is preferably larger than the groove width W2 of the outer intermediate lateral groove 15, for example. The groove width W5 of the 2 nd groove portion 25b is preferably 1.70 to 2.00 times the groove width W4 of the 1 st groove portion 25a, for example. Such an outer shoulder lateral groove 25 can improve the steering stability and the on-snow performance on a dry road surface in a relatively well-balanced manner.

The length L3 of the 1 st groove portion 25a in the tire axial direction is, for example, 0.35 to 0.55 times the width W6 of the outer shoulder land portion 9 in the tire axial direction. Further, the length L3 in the tire axial direction of the 1 st groove portion 25a is preferably larger than the length Lo in the tire axial direction of the outer intermediate lateral groove 15 (as shown in fig. 2).

The 2 nd groove portion 25b preferably has a depth larger than that of the 1 st groove portion 25a, for example. The depth of the 2 nd groove 25b is preferably 1.5 to 2.0 times the depth of the 1 st groove 25a, for example. Such an outer shoulder lateral groove 25 prevents a decrease in rigidity of the land portion by the 1 st groove portion 25a, and exhibits excellent on-snow performance by the 2 nd groove portion 25 b.

The 1 st outer shoulder sipe 26 is, for example, a closed sipe having both ends interrupted in the outer shoulder land portion 9. In the present embodiment, two 1 st outer shoulder sipes 26 are provided between two outer shoulder lateral grooves 25 adjacent in the tire circumferential direction.

The length of the 1 st outer shoulder sipe 26 in the tire axial direction is preferably, for example, larger than the length of the 1 st groove portion 25a of the outer shoulder lateral groove 25 in the tire axial direction.

The 2 nd outer shoulder sipe 27 extends from the outer tread end To toward the tire equator C side, and is interrupted in the outer shoulder land portion 9. In the present embodiment, two 2 nd outer shoulder sipes 27 are provided between two outer shoulder lateral grooves 25 adjacent in the tire circumferential direction. In a preferred mode, the 2 nd outside shoulder sipe 27 and the 1 st outside shoulder sipe 26 do not overlap in the tire axial direction. Such a 2 nd outer shoulder sipe 27 contributes to improving the swimming performance on snow while maintaining the rigidity of the land portion.

A chamfered portion 28 formed by recessing a corner between a tread surface and a side surface of the land portion is provided on the outer shoulder main groove 4 side of the outer shoulder land portion 9. The chamfered portion 28 of the present embodiment is connected to the outer shoulder lateral groove 25, for example. Such chamfered portions 28 form a large snow column together with the outer shoulder lateral grooves 25, and can improve on-snow performance.

As shown in fig. 1, it is preferable that a region where the chamfered portion 28 provided on the outer shoulder land portion 9 is extended in the tire axial direction intersects with the 2 nd outer intermediate sipe 17. Such a disposition of the chamfered portion 28 contributes to suppression of one-sided wear of the outer shoulder land portion 9.

Fig. 6 shows an enlarged view of the inboard shoulder land portion 10. As shown in fig. 6, the inner shoulder land portion 10 is provided with an inner shoulder lateral groove 30, a 1 st inner shoulder sipe 31, and a 2 nd inner shoulder sipe 32.

The inner-shoulder lateral groove 30 extends, for example, from the inner-shoulder main groove 5 to the inner tread end Ti. The inner shoulder lateral groove 30 is inclined in the same direction as the inner middle lateral groove 20 with respect to the tire axial direction, for example. The angle of the inner shoulder lateral groove 30 with respect to the tire axial direction is preferably, for example, 10 ° to 30 °.

preferably, the groove width W7 of the inner shoulder lateral groove 30 is at least greater than the groove width W4 (shown in fig. 5) of the 1 st groove portion 25a of the outer shoulder lateral groove 25. In a more preferred form, the groove width W7 of the inboard shoulder transverse groove 30 is greater than either of the groove width W2 (shown in fig. 2) of the outboard intermediate transverse groove 15 and the groove width W3 (shown in fig. 2) of the inboard intermediate transverse groove 20. Such an inner shoulder lateral groove 30 contributes to the exertion of excellent on-snow performance.

The inner-shoulder lateral groove 30 preferably has a shallow bottom portion 40 with a raised groove bottom at the end portion on the inner-shoulder main groove 5 side, for example. The length of the shallow bottom portion 40 in the tire axial direction is preferably smaller than the length of the 1 st groove portion 25a (shown in fig. 5) of the outer shoulder lateral groove 25 in the tire axial direction. The depth of the shallow bottom 40 is, for example, 0.55 to 0.70 times the maximum depth of the inner shoulder lateral groove 30.

The 1 st inboard shoulder sipe 31 extends from the inboard shoulder main groove 5 toward the inboard tread end Ti side, for example, and is interrupted in the inboard shoulder land portion 10. In the present embodiment, two 1 st inboard shoulder sipes 31 are provided between two adjacent inboard shoulder lateral grooves 30 in the tire circumferential direction. The length L4 of the 1 st inboard shoulder sipe 31 in the tire axial direction is, for example, 0.75 to 0.90 times the width W8 of the inboard shoulder land portion 10 in the tire axial direction.

The 2 nd inside shoulder sipe 32 extends from the inside tread end Ti toward the tire equator C side, and is interrupted in the inside shoulder land portion 10. In the present embodiment, two 2 nd inside-shoulder sipes 32 are provided between two adjacent inside-shoulder lateral grooves 30 in the tire circumferential direction. In a preferred mode, the 2 nd and 1 st inboard shoulder sipes 32 and 31 do not overlap in the tire axial direction. Such a 2 nd inner shoulder sipe 32 can improve the swimming performance on snow while maintaining the rigidity of the inner shoulder land portion 10.

The inner shoulder land portion 10 is provided on the inner shoulder main groove 5 side with a chamfered portion 33 formed by recessing the corner between the tread surface and the side surface of the land portion. The chamfered portion 33 of the present embodiment is connected to the inboard shoulder lateral groove 30 and the 1 st inboard shoulder sipe 31, for example. Such chamfered portions 33 can suppress the one-sided wear of the inner shoulder land portions 10.

Although the preferred embodiments of the tire of the present invention have been described above in detail, the present invention is not limited to the specific embodiments described above, and can be implemented in various modified forms.