JP7243456B2 - tire - Google Patents

Description

TECHNICAL FIELD The present invention relates to a tire, and more particularly to a tire having a tread portion composed of four land portions.

Patent Literature 1 listed below proposes a tire having a tread portion with a specified mounting direction to a vehicle. The tread portion is formed with an outboard middle land portion, an outboard shoulder land portion, an inboard middle land portion, and an inboard shoulder land portion. JP-A-2003-100001 expects to improve on-snow performance while suppressing a decrease in rigidity of the outer middle land portion by specifying grooves arranged in the outer middle land portion.

JP 2015-120380 A

The tire of Patent Literature 1 tends to lack lateral rigidity in the outer middle land portion, and improvement in steering stability on dry road surfaces has been demanded.

The present invention has been devised in view of the problems described above, and aims to provide a tire having a tread composed of four land portions and exhibiting excellent performance on snow and steering stability on dry road surfaces. This is the main issue.

The present invention provides a tire having a tread portion with a specified mounting direction to a vehicle, wherein the tread portion includes a first tread end positioned outside the vehicle when mounted on the vehicle and a first tread end positioned inside the vehicle when mounted on the vehicle. a second tread edge, and the tread portion includes three main grooves continuously extending in the tire circumferential direction between the first tread edge and the second tread edge; and the three main grooves. The main grooves are composed of a first shoulder main groove arranged between the first tread edge and the tire equator, and the second shoulder main groove of the first shoulder main groove. and a crown main groove adjacent to the tread end side, the land portion including a first middle land portion partitioned between the first shoulder main groove and the crown main groove, the first middle land portion. has the largest width in the tire axial direction among the four land portions, and the first middle land portion includes a plurality of first inclined grooves inclined in a first direction with respect to the tire axial direction and a plurality of each of said first slanted grooves extending from said crown main groove and discontinuing within said first middle land portion, each of said second slanted grooves having opposite ends of said first middle land portion; The end portion of the second inclined groove on the crown main groove side is discontinuous in the land portion and has a smaller depth than the other portion of the second inclined groove.

In the tire of the present invention, it is preferable that the end portion of the first inclined groove on the side of the first shoulder main groove has a smaller depth than the other portion of the first inclined groove.

In the tire of the present invention, the first middle land portion is provided with a plurality of third inclined grooves inclined in a second direction opposite to the first direction, and each of the third inclined grooves It is desirable to communicate with the first inclined groove and the second inclined groove.

In the tire of the present invention, it is preferable that the depth of the third inclined groove gradually increases from the end on the crown main groove side to the end on the first shoulder main groove side.

In the tire of the present invention, the second inclined groove includes a communicating portion with the third inclined groove and an inner portion extending from the end on the crown main groove side to the communicating portion, and the inner portion is the second inclined groove. It is desirable that the depth is less than the rest of the angled groove.

In the tire of the present invention, it is preferable that the inner portion has a constant depth in the longitudinal direction of the second inclined groove.

In the tire of the present invention, the first inclined groove includes a communicating portion with the third inclined groove, and an outer portion extending from the end on the first shoulder main groove side to the communicating portion, and the outer portion It is desirable that the depth of the first slanted groove is smaller than the rest of the groove.

In the tire of the present invention, it is preferable that the depth of the outer portion gradually decreases toward the end on the first shoulder main groove side.

In the tire of the present invention, the tread portion is divided into four land portions, and the first middle land portion has the largest width in the tire axial direction among the four land portions. The middle land part has high rigidity and helps to improve steering stability on dry roads.

The first middle land portion is provided with a plurality of first inclined grooves and a plurality of second inclined grooves that are inclined in a first direction with respect to the axial direction of the tire. Since a large ground pressure acts on the first middle land portion, each inclined groove provided in this land portion provides a large snow column shearing force during running on the snow.

Each of the first inclined grooves extends from the crown main groove and is discontinued within the first middle land portion. Both ends of each of the second inclined grooves are discontinued within the first middle land portion. Moreover, the end portion of the second inclined groove on the crown main groove side has a depth smaller than that of the other portion of the second inclined groove. These inclined grooves maintain the rigidity of the first middle land portion on the side of the crown main groove, thereby improving steering stability on a dry road surface.

1 is a developed view of a tread portion of a tire according to one embodiment of the present invention; FIG. FIG. 2 is an enlarged view of a first middle land portion of FIG. 1; FIG. 3 is a cross-sectional view taken along line AA of FIG. 2; FIG. 3 is a cross-sectional view taken along line BB of FIG. 2; FIG. 3 is a cross-sectional view taken along line CC of FIG. 2; FIG. 3 is a cross-sectional view taken along line DD of FIG. 2; FIG. 2 is an enlarged view of a second middle land portion of FIG. 1; FIG. 2 is an enlarged view of a first shoulder land portion of FIG. 1;

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a developed view of a tread portion 2 of a tire 1 showing one embodiment of the present invention. The tire 1 of the present embodiment is suitably used as, for example, a pneumatic tire for passenger cars. However, the present invention is not limited to such an aspect, and may be used for heavy-duty pneumatic tires and non-pneumatic tires in which the interior of the tire is not filled with pressurized air.

As shown in FIG. 1, a tire 1 of the present invention has a tread portion 2 with a specified mounting direction on a vehicle. The tread portion 2 has a first tread end Te1 positioned on the vehicle outer side when the tire 1 is mounted on the vehicle, and a second tread end Te2 positioned on the vehicle inner side when the tire 1 is mounted on the vehicle. The mounting direction to the vehicle is indicated, for example, by characters or symbols on the sidewall portion (not shown).

In the case of a pneumatic tire, the first tread end Te1 and the second tread end Te2 are the outermost ground contact positions in the tire axial direction when the tire 1 in a normal state is applied with a normal load and is grounded on a flat surface with a camber angle of 0°. be. A normal state is a state in which the tire is mounted on a normal rim, is inflated to a normal internal pressure, and has no load. In this specification, unless otherwise specified, the dimensions of each part of the tire are the values measured in the normal condition.

A "regular rim" is a rim defined for each tire in a standard system including the standard on which the tire is based. If there is, it is "Measuring Rim".

"Regular internal pressure" is the air pressure specified for each tire by each standard in the standard system including the standards on which tires are based. Maximum value described in VARIOUS COLD INFLATION PRESSURES", or "INFLATION PRESSURE" for ETRTO.

"Normal load" is the load defined for each tire by each standard in the standard system including the standard on which the tire is based. AT VARIOUS COLD INFLATION PRESSURES", and for ETRTO, it is "LOAD CAPACITY".

The tread portion 2 includes three main grooves 3 continuously extending in the tire circumferential direction between a first tread end Te1 and a second tread end Te2, and four land areas divided by the three main grooves 3. It consists of part 4.

The main grooves 3 include first shoulder main grooves 5 arranged between the first tread edge Te1 and the tire equator C, and second shoulder main grooves arranged between the second tread edge Te2 and the tire equator C. 6 and a crown main groove 7 disposed between the first shoulder main groove 5 and the second shoulder main groove 6 .

The axial distance La from the tire equator C to the groove centerline of the first shoulder main groove 5 or the second shoulder main groove 6 is preferably, for example, 0.20 to 0.35 times the tread width TW. . The axial distance Lb from the tire equator C to the groove centerline of the crown main groove 7 is preferably, for example, 0.15 times or less the tread width TW. The tread width TW is the axial distance of the tire from the first tread end Te1 to the second tread end Te2 in the normal state.

The crown main groove 7 of the present embodiment is provided closer to the second tread end Te2 than the tire equator C, for example. However, the position of the crown main groove 7 is not limited to such a mode.

Each main groove 3 of the present embodiment extends linearly parallel to the tire circumferential direction, for example. Each main groove 3 may, for example, extend in a wavy shape.

A groove width Wa of each main groove 3 is at least 3.0 mm or more, and preferably, for example, 4.0% to 7.0% of the tread width TW. In this specification, vertical narrow grooves having a groove width of less than 3.0 mm are distinguished from the main grooves 3 . Further, the groove width is the distance between the groove edges in the direction perpendicular to the groove center line. The depth of each main groove 3 is desirably 5 to 10 mm, for example, in the case of pneumatic tires for passenger cars.

The land portion 4 is composed of a first middle land portion 11 , a second middle land portion 12 , a first shoulder land portion 13 and a second shoulder land portion 14 . The first middle land portion 11 is divided between the first shoulder main groove 5 and the crown main groove 7 . The second middle land portion 12 is divided between the second shoulder main groove 6 and the crown main groove 7 . The first shoulder land portion 13 is divided between the first shoulder main groove 5 and the first tread edge Te1. The second shoulder land portion 14 is divided between the second shoulder main groove 6 and the second tread edge Te2.

FIG. 2 shows an enlarged view of the first middle land portion 11. As shown in FIG. As shown in FIG. 2 , the first middle land portion 11 has the largest axial width W1 of the four land portions 4 . As in the present invention, the tread portion 2 composed of four land portions exerts a large ground pressure on the first middle land portion 11 during straight running and turning. has the largest width in the tire axial direction among the four land portions and has high rigidity. Therefore, the first middle land portion 11 of the present invention helps improve steering stability on dry road surfaces. The width W1 of the first middle land portion 11 is preferably, for example, 0.25 to 0.35 times the tread width TW (shown in FIG. 1 and the same applies hereinafter).

The first middle land portion 11 is provided with a plurality of first slanted grooves 16 and a plurality of second slanted grooves 17 that are slanted in a first direction (downward to the right in FIG. 2) with respect to the axial direction of the tire. there is Since a large ground pressure acts on the first middle land portion 11, each inclined groove provided in this land portion provides a large snow column shearing force during running on snow.

Each of the first inclined grooves 16 extends from the crown main groove 7 and discontinues within the first middle land portion 11 . Both ends of each of the second inclined grooves 17 are discontinued within the first middle land portion 11 . Such first inclined grooves 16 and second inclined grooves 17 can maintain the rigidity of the first middle land portion 11 and improve the on-snow performance while maintaining steering stability on dry road surfaces.

Moreover, the end portion of the second inclined groove 17 on the crown main groove 7 side has a smaller depth than the other portion of the second inclined groove 17 . Such second inclined grooves 17 maintain the rigidity of the first middle land portion 11 on the crown main groove 7 side, and improve steering stability on dry road surfaces. In addition, such second inclined grooves 17 can prevent the ends from being clogged with snow, and are useful for enhancing performance on snow.

The first middle land portion 11 of the present embodiment is provided with a plurality of third inclined grooves 18 inclined in a second direction opposite to the first direction (upward to the right in FIG. 2). there is The third slanted groove 18 preferably communicates with the first slanted groove 16 and the second slanted groove 17 . In this specification, one groove communicates with another groove means that these two grooves intersect to form a four-way intersection, and two grooves form a three-way intersection. including.

As a desirable aspect, each of the first inclined groove 16, the second inclined groove 17 and the third inclined groove 18 of this embodiment is curved. It is desirable that the radius of curvature of these inclined grooves is, for example, 30 mm or more.

The first inclined groove 16 crosses, for example, the center position 11c of the first middle land portion 11 in the tire axial direction. The axial length L1 of the first inclined groove 16 is preferably 0.80 to 0.90 times the axial width W1 of the first middle land portion 11, for example.

The first inclined groove 16 is curved, for example, in a convex direction toward one side (lower side in FIG. 2) in the tire circumferential direction from a straight line connecting both ends of the groove center line.

For example, it is desirable that the angle of the first inclined groove 16 with respect to the tire circumferential direction gradually decreases from the crown main groove 7 toward the first shoulder main groove 5 side. It is desirable that the angle of the first inclined groove 16 with respect to the tire circumferential direction is, for example, 30 to 70 degrees.

The width of the first inclined groove 16 is preferably reduced from the crown main groove 7 toward the first shoulder main groove 5 side. Such first inclined grooves 16 help maintain the rigidity of the first middle land portion 11 .

FIG. 3 shows a cross-sectional view of the first inclined groove 16 taken along line AA. As shown in FIG. 3, the end of the first inclined groove 16 on the side of the first shoulder main groove 5 preferably has a smaller depth than the other portions of the first inclined groove 16 . As a result, the rigidity in the vicinity of the end portion is maintained, and the steering stability on dry road surfaces is enhanced.

The first inclined groove 16 includes a portion 16a communicating with the third inclined groove 18, an outer portion 16b extending from an end 16e on the side of the first shoulder main groove 5 to the communicating portion 16a, and a crown main groove 7 side of the communicating portion 16a. and a main body portion 16c. It is desirable that the outer portion 16b has a smaller depth than the other portions of the first slanted groove 16. As shown in FIG. Further, the outer portion 16b has a bottom surface that is inclined with respect to the tire axial direction, and the depth gradually decreases toward the end 16e on the first shoulder main groove 5 side. Such first inclined grooves 16 serve to improve steering stability on dry road surfaces.

As shown in FIG. 2, in this embodiment, the first inclined grooves 16 and the second inclined grooves 17 are alternately provided in the tire circumferential direction.

The second inclined groove 17 preferably crosses, for example, the center position 11c of the first middle land portion 11 in the tire axial direction. In addition, it is desirable that the axial length L2 of the second inclined groove 17 is smaller than the axial length L1 of the first inclined groove 16, for example. It is desirable that the length L2 of the second inclined groove 17 is, for example, 0.60 to 0.75 times the width W1 of the first middle land portion 11 in the axial direction of the tire. Such second inclined grooves 17 serve to improve performance on snow and steering stability on dry road surfaces in a well-balanced manner.

The second inclined grooves 17 are preferably curved in the same direction as the first inclined grooves 16, for example. Moreover, it is desirable that the angle of the second inclined groove 17 with respect to the tire circumferential direction gradually decreases toward the first shoulder main groove 5 side, for example. It is desirable that the angle of the second inclined groove 17 with respect to the tire circumferential direction is, for example, 30 to 70 degrees.

The width of the second inclined groove 17 is reduced from the first shoulder main groove 5 side toward the crown main groove 7 side. Such second inclined grooves 17 serve to improve performance on snow and steering stability on dry road surfaces in a well-balanced manner.

FIG. 4 shows a cross-sectional view of the second inclined groove 17 taken along line BB. As shown in FIG. 4, the second inclined groove 17 includes a communicating portion 17a with the third inclined groove 18, an inner portion 17b extending from an end 17e on the crown main groove 7 side to the communicating portion 17a, and a first shoulder main groove 17a. and a body portion 17c from the end 17f on the groove 5 side to the communicating portion 17a. It is desirable that the inner portion 17b has a smaller depth than the other portions of the second slant groove 17. As shown in FIG. Specifically, the depth d2 of the inner portion 17b is 0.40 to 0.80 times the depth d1 of the body portion 17c. In addition, the inner portion 17b has a constant depth in the longitudinal direction of the second inclined groove 17. As shown in FIG. Such second inclined grooves 17 serve to improve performance on snow and steering stability on dry road surfaces in a well-balanced manner.

As shown in FIG. 2, the third inclined groove 18 of the present embodiment extends, for example, from the first shoulder main groove 5 to the end of the first inclined groove 16 on the crown main groove 7 side. Thereby, the third inclined groove 18 intersects with the first inclined groove 16 and the second inclined groove 17, and crosses the center position 11c.

The third inclined groove 18 is curved in a direction convex to one side in the tire circumferential direction from a straight line connecting both ends of the groove center line. Further, the angle of the third inclined groove 18 with respect to the tire circumferential direction gradually decreases toward the crown main groove 7 side, for example.

The angle of the third inclined groove 18 with respect to the tire circumferential direction is preferably 60 to 85°, for example. Also, the angle θ1 between the first inclined groove 16 and the third inclined groove 18 and the angle θ2 between the second inclined groove 17 and the third inclined groove 18 are 50 to 90°. is desirable. As a result, the snow is strongly compacted at the intersection of the sloped grooves, and a large snow column shearing force is exerted.

It is desirable that the groove width of the third inclined groove 18 gradually decreases from at least the first inclined groove 16 to the second inclined groove 17 . As a more desirable aspect, the groove width of the third inclined groove 18 of this embodiment gradually decreases from the first shoulder main groove 5 to the end portion on the crown main groove 7 side. As a result, while the rigidity of the first middle land portion 11 is maintained, on-snow performance is improved.

FIG. 5 shows a cross-sectional view of the third inclined groove 18 taken along line CC. As shown in FIG. 5, it is desirable that the depth of the third inclined groove 18 gradually increases from the end on the crown main groove 7 side to the end on the first shoulder main groove 5 side, for example. The third inclined groove 18 of the present embodiment includes, for example, a first constant-depth portion 18a and a second constant-depth portion 18c having a constant depth in the longitudinal direction of the groove, and a bottom surface inclined with respect to the axial direction of the tire. includes a first variable depth portion 18b and a second variable depth portion 18d. The first constant depth portion 18 a communicates with the first shoulder main groove 5 . The second constant depth portion 18c is arranged on the crown main groove 7 side of the first constant depth portion 18a. The first variable depth portion 18b is arranged between the first constant depth portion 18a and the second constant depth portion 18c. The second variable depth portion 18d is arranged on the crown main groove 7 side of the second constant depth portion 18c.

The minimum depth d4 of the third inclined groove 18 is 0.40 to 0.60 times the maximum depth d3 of the third inclined groove 18. Such third inclined grooves 18 enhance performance on snow and steering stability on dry road surfaces in a well-balanced manner.

As shown in FIG. 2, a plurality of fourth inclined grooves 19 are provided in the first middle land portion 11 of this embodiment. The fourth inclined groove 19 extends, for example, from the first shoulder main groove 5 while being inclined in the second direction, and discontinues within the first middle land portion 11 . The fourth slanted groove 19 crosses the first slanted groove 16 and the second slanted groove 17 and crosses the center position 11c.

The third inclined grooves 18 and the fourth inclined grooves 19 are alternately provided in the tire circumferential direction. Further, the axial length of the fourth inclined groove 19 is smaller than the axial length of the third inclined groove 18 .

The fourth inclined groove 19 is curved in the same direction as the third inclined groove 18, for example. It is desirable that the radius of curvature of the fourth inclined groove 19 is, for example, 30 mm or more.

The fourth inclined groove 19 extends, for example, at an angle of 60-85° with respect to the tire circumferential direction. The angle of the fourth inclined groove 19 with respect to the tire circumferential direction gradually decreases toward the crown main groove 7 side. Such fourth inclined grooves 19 serve to enhance traction and turning performance on snow.

It is desirable that the width of the fourth inclined groove 19 gradually decreases from the first shoulder main groove 5 toward the crown main groove 7 side. Such fourth inclined grooves 19 serve to maintain the rigidity of the first middle land portion 11 and improve steering stability on dry road surfaces.

FIG. 6 shows a cross-sectional view of the fourth inclined groove 19 taken along line DD. As shown in FIG. 6, the fourth oblique groove 19 includes a communicating portion 19a with the first oblique groove 16, a body portion 19b between the first shoulder main groove 5, and a crown main groove rather than the communicating portion 19a. and a tip portion 19c on the groove 7 side. The body portion 19b has a constant depth in its longitudinal direction. The tip portion 19c has a curved bottom surface, and the depth gradually decreases toward the crown main groove 7 side. The radius of curvature of the bottom surface of the tip portion 19c is, for example, 10 to 30 mm. The front end portion 19c of the fourth inclined groove 19 maintains the rigidity of the first middle land portion 11, thereby enhancing the steering stability on dry road surfaces.

As shown in FIG. 2, it is desirable that the first middle land portion 11 of the present embodiment is provided with a plurality of sipes 25 . As used herein, a sipe means an incision with a width of 1.5 mm or less. Desirably, the width of the sipe is, for example, 0.4 to 1.0 mm. Each sipe 25 helps enhance on-snow performance.

The sipe 25 provided in the first middle land portion 11 is desirably inclined in the second direction, for example. Moreover, it is desirable that the sipe 25 is convexly curved in the same direction as the third inclined groove 18 . Such a sipe 25 maintains the rigidity of the first middle land portion 11 and provides a frictional force by its edge.

The first middle land portion 11 of the present embodiment includes, for example, a plurality of first sipes 26 extending from the first shoulder main groove 5 to the crown main groove 7 and a plurality of first sipes 26 extending from the first shoulder main groove 5 to the first inclined grooves 16. A plurality of second sipes 27 are provided.

The first sipe 26 crosses the end of the second inclined groove 17 on the crown main groove 7 side and the first inclined groove 16 . The second sipe 27 crosses the end of the first inclined groove 16 on the side of the first shoulder main groove 5 and the second inclined groove 17 . Such first sipe 26 and second sipe 27 can prevent snow from clogging the ends of the first slanted groove 16 and second slanted groove 17, and can exhibit excellent on-snow performance over a long period of time. .

A plurality of third sipes 28 are provided in the first middle land portion 11 . The third sipe 28 extends from the crown main groove 7 to the end of the fourth oblique groove 19 . The third sipe 28 helps prevent snow from clogging the end of the fourth inclined groove 19 .

FIG. 7 shows an enlarged view of the second middle land portion 12. As shown in FIG. As shown in FIG. 3, it is desirable that the axial width W2 of the second middle land portion 12 is, for example, 0.10 to 0.20 times the tread width TW.

The second middle land portion 12 is provided with, for example, a plurality of middle lateral grooves 30 . The middle lateral groove 30 , for example, extends from the crown main groove 7 and discontinues within the second middle land portion 12 .

The middle lateral groove 30 includes, for example, a first portion 31 extending obliquely in the first direction from the crown main groove 7 and a second portion 32 connected to the first portion 31 and extending along the tire circumferential direction. The depth of the second portion 32 is preferably smaller than the depth of the first portion 31 . Such a middle lateral groove 30 maintains steering stability on a dry road surface and provides a snow column shearing force in the tire circumferential direction and the tire axial direction during running on snow.

A plurality of first middle sipes 33 and a plurality of second middle sipes 34 are provided on the second middle land portion 12 . The first middle sipe 33 , for example, extends from the crown main groove 7 and discontinues within the second middle land portion 12 . The second middle sipe 34 , for example, extends from the second shoulder main groove 6 and communicates with the middle lateral groove 30 .

The second middle land portion 12 of the present embodiment is provided with cut elements 35 in which a plurality of fine cuts extend between two sipe pieces 36 . The two sipe pieces 36 extend, for example, from the first middle sipe 33 to the first portion 31 of the middle lateral groove 30 while reducing the distance between them. Such cut elements 35 serve to improve the grip performance at the start of use of the tire.

FIG. 8 shows an enlarged view of the first shoulder land portion 13. As shown in FIG. As shown in FIG. 4 , the axial width W3 of the first shoulder land portion 13 is preferably larger than the axial width W2 of the second middle land portion 12 . The axial width W3 of the first shoulder land portion 13 is preferably 0.15 to 0.25 times the tread width TW, for example.

A plurality of shoulder lateral grooves 40 and a plurality of shoulder sipes 41 extending in the tire axial direction are provided in the first shoulder land portion 13 . Such shoulder lateral grooves 40 and shoulder sipes 41 serve to improve on-snow performance.

As shown in FIG. 1 , the second shoulder land portion 14 is provided with shoulder lateral grooves 40 and shoulder sipes 41 similar to those of the first shoulder land portion 13 .

In a preferred embodiment, the second shoulder land portion 14 has a chamfered portion 42 between its tread surface and the side surface on the second shoulder main groove 6 side. In a further preferred embodiment, the outer surface of the chamfered portion 42 is formed with a plurality of fine grooves extending from the tread surface to the side surface. Thereby, the second shoulder main groove 6 can provide a large snow column shear force.

Although the tire of one embodiment of the present invention has been described in detail above, the present invention is not limited to the specific embodiment described above, and can be implemented in various ways.

A trial tire of size 215/60R16 having the basic pattern of FIG. 1 was produced. As a comparative example, a prototype tire was produced in which the depth of the second inclined grooves was constant in the longitudinal direction. The depth of the second slanted groove of the tire of the comparative example is the same as the depth of the body portion of the second slanted groove of the example. It should be noted that the tire of the comparative example has substantially the same pattern as that shown in FIG. 1, except for the above items. Each test tire was tested for snow performance and steering stability on dry roads. Common specifications and test methods for each test tire are as follows.
Mounting rim: 16 x 6.5
Tire internal pressure: 240kPa
Test vehicle: 2500cc displacement, front-wheel drive Tire mounting position: All wheels

<Snow Performance>
Performance when the test vehicle was driven on a snowy road was evaluated by the senses of the driver. The results are scored with the comparative example being 100, and the larger the number, the better the on-snow performance.

<Driving stability on dry road surface>
The steering stability of the test vehicle was evaluated by the driver's sensory perception when the test vehicle was driven on a dry road surface. The results are scored with the comparative example being 100, and the larger the number, the better the steering stability on a dry road surface.
Test results are shown in Table 1.

As a result of the test, it was confirmed that the tires of Examples exhibit excellent performance on snow and steering stability on dry road surfaces.

2 tread portion 3 main groove 4 land portion 5 first shoulder main groove 7 crown main groove 11 first middle land portion 16 first inclined groove 17 second inclined groove Te1 first tread edge Te2 second tread edge

Claims (8)

A tire having a tread portion with a specified orientation for mounting on a vehicle,
The tread portion is
Having a first tread end positioned on the vehicle outer side when mounted on the vehicle and a second tread end positioned on the vehicle inner side when mounted on the vehicle,
The tread portion includes three main grooves continuously extending in the tire circumferential direction between the first tread end and the second tread end, and four land portions separated by the three main grooves. consists of
The main groove includes a first shoulder main groove arranged between the first tread edge and the tire equator, and a crown main groove adjacent to the second tread edge side of the first shoulder main groove,
the land portion includes a first middle land portion divided between the first shoulder main groove and the crown main groove;
The first middle land portion has the largest axial width of the four land portions,
The first middle land portion is provided with a plurality of first inclined grooves and a plurality of second inclined grooves inclined in a first direction with respect to the axial direction of the tire,
each of the first inclined grooves extends from the crown main groove and discontinues within the first middle land portion;
both ends of each of the second inclined grooves are interrupted within the first middle land portion;
The end of the second inclined groove on the crown main groove side has a depth smaller than the other portion of the second inclined groove,
tire. The tire according to claim 1, wherein an end portion of the first inclined groove on the side of the first shoulder main groove has a smaller depth than other portions of the first inclined groove. The first middle land portion is provided with a plurality of third inclined grooves inclined in a second direction opposite to the first direction,
The tire according to claim 1 or 2, wherein each of said third slanted grooves communicates with said first slanted groove and said second slanted groove. 4. The tire according to claim 3, wherein the depth of the third inclined groove gradually increases from the crown main groove side end to the first shoulder main groove side end. The second inclined groove includes a communicating portion with the third inclined groove and an inner portion from the end on the crown main groove side to the communicating portion,
The tire according to claim 3 or 4, wherein the inner portion has a smaller depth than other portions of the second inclined groove. 6. The tire of claim 5, wherein the inner portion is configured with a constant depth along the length of the second angled groove. The first inclined groove includes a communicating portion with the third inclined groove, and an outer portion extending from the end on the first shoulder main groove side to the communicating portion,
The tire according to any one of claims 3 to 6, wherein the outer portion has a smaller depth than other portions of the first inclined groove. 8. The tire of claim 7, wherein the outer portion tapers in depth toward the first shoulder main groove side end.

Images