JP7230493B2 - tire - Google Patents

Description

TECHNICAL FIELD The present invention relates to a tire, and more particularly to a tire provided with sipes in a middle land portion.

Patent Document 1 below describes a pneumatic tire having a sipe in a middle land portion. In general, when ground pressure is applied to the land portion, the sipe closes so that the facing sipe walls come into contact with each other, thereby suppressing excessive deformation of the land portion.

JP 2016-13820 A

In recent years, tires are required to have improved noise performance in addition to improved steering stability. The pneumatic tire of Patent Document 1 is expected to improve steering stability due to the above action of the sipes, but there is room for further improvement in noise performance.

SUMMARY OF THE INVENTION The present invention has been devised in view of the problems described above, and a main object of the present invention is to provide a tire capable of exhibiting excellent steering stability and noise performance.

The present invention is a tire having a tread portion, wherein the tread portion includes a crown main groove extending continuously in the tire circumferential direction, and a tire circumferentially continuous portion between the crown main groove and a first tread edge. and a first middle land portion divided between the crown main groove and the first shoulder main groove, wherein the first middle land portion includes the first middle land portion. a plurality of first transverse sipes that completely traverse the land portion and at least one first non-transverse sipe extending from the crown main groove and discontinuous within the first middle land portion; A chamfered portion is provided at the communicating portion with the non-transverse sipe.

In the tire of the present invention, it is preferable that the chamfered portion has an inclined surface continuous with the tread surface of the first middle land portion, the groove wall of the crown main groove, and the sipe wall of the first non-transverse sipe.

In the tire of the present invention, it is desirable that the inclined surface is a curved surface.

In the tire of the present invention, it is preferable that a tread surface side edge between the inclined surface and the tread surface of the first middle land portion is arc-shaped in a tread plan view.

In the tire of the present invention, in a tread plan view, the angle between the edge of the first non-transverse sipe contiguous to the tread side edge and the groove edge of the crown main groove contiguous to the tread side edge is an obtuse angle. is desirable.

In the tire of the present invention, it is desirable that the first non-transverse sipe is inclined at an angle of 15 to 35° with respect to the axial direction of the tire.

In the tire of the present invention, the axial length of the first non-transverse sipe is preferably 0.40 to 0.60 times the axial width of the first middle land portion.

In the tire of the present invention, the tread portion has two crown main grooves extending across the tire equator and a crown land portion divided between the two crown main grooves. The portion is provided with a plurality of crown non-transverse sipes extending from the crown main groove and discontinued within the land portion, and at least one of the crown non-transverse sipes communicates with the first non-transverse sipe via the crown main groove. It is desirable that they are arranged so as to be smooth and continuous.

The tread portion of the tire of the present invention includes a crown main groove extending continuously in the tire circumferential direction, a first shoulder main groove extending continuously in the tire circumferential direction between the crown main groove and a first tread end, A first middle land portion is provided between the crown main groove and the first shoulder main groove. The first middle land portion is provided with a plurality of first transverse sipes that completely cross the land portion and at least one first non-crossing sipe extending from the crown main groove and discontinuous within the land portion. A communicating portion between the crown main groove and the first non-transverse sipe is provided with a chamfered portion.

The first crossing sipe and the first non-crossing sipe can increase the edge component while maintaining the rigidity of the first middle land portion, thereby enhancing steering stability and wet performance.

Further, the first middle land portion of the present invention is relatively easily deformed on the crown main groove side by providing the first transverse sipe and the first non-transverse sipe. Therefore, when a large ground contact pressure acts on the first middle land portion or when a slip angle is applied to the tire, a portion of the outer surface of the chamfered portion can be brought into contact with the ground. Greater real contact area. Therefore, initial responsiveness during turning is enhanced, and excellent steering stability can be expected.

In addition, since the first middle land portion of the present invention is provided with the chamfered portion, it is possible to reduce the hammering sound when the communicating portion touches the ground, thereby improving the noise performance.

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, a second middle land portion, and a first shoulder land portion in FIG. 1; 3 is an enlarged perspective view of the first non-transverse sipe of FIG. 2; FIG. 2. (a) is a cross-sectional view taken along the line AA of FIG. 2, and (b) is a cross-sectional view taken along the line BB of FIG. FIG. 4 is a developed view of a tread portion of a tire according to another embodiment of the present invention; FIG. 3 is a developed view of a tread portion of a tire of a comparative example;

An embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 shows a developed view of a tread portion 2 of a tire 1 of this embodiment. The tire 1 of the present embodiment is suitably used as, for example, a pneumatic tire for passenger cars. However, the tire 1 of the present invention is not limited to such a mode of use.

As shown in FIG. 1, the tread portion 2 of the tire 1 has a crown main groove 3 extending continuously in the tire circumferential direction, and a crown main groove 3 extending continuously in the tire circumferential direction between the crown main groove 3 and the first tread end Te1. and a second shoulder main groove 5 extending continuously in the tire circumferential direction between the crown main groove 3 and the second tread edge Te2.

The first tread end Te1 and the second tread end Te2 are mounted on a regular rim (not shown), are filled with regular internal pressure, and are in a regular state with no load. This is the outermost grounding position in the axial direction of the tire when it is grounded on a flat surface at an angle of 0°.

A "regular rim" is a rim defined for each tire in a standard system that includes standards on which tires are based. For ETRTO, 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".

In this embodiment, one crown main groove 3 is arranged on the tire equator C, for example.

The axial distance L1 from the tire equator C to the groove centerline of the first shoulder main groove 4 or the second shoulder main groove 5 is preferably, for example, 0.20 to 0.30 times 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.

It is desirable that the groove width W1 of each main groove is, for example, 4 to 7% of the tread width TW. The groove depth of each main groove is preferably 5 to 10 mm, for example.

The tread portion 2 is provided with a crown main groove 3, a first shoulder main groove 4 and a second shoulder main groove 5, thereby forming a first middle land portion 6, a second middle land portion 7 and a first shoulder land portion. A portion 8 and a second shoulder land portion 9 are separated.

The first middle land portion 6 is divided between the crown main groove 3 and the first shoulder main groove 4 . The second middle land portion 7 is divided between the crown main groove 3 and the second shoulder main groove 5 . The second middle land portion 7 is adjacent to the first middle land portion 6 with the crown main groove 3 interposed therebetween.

The first shoulder land portion 8 is divided between the first shoulder main groove 4 and the first tread edge Te1. The first shoulder land portion 8 is adjacent to the first middle land portion 6 via the first shoulder main groove 4 . The second shoulder land portion 9 is divided between the second shoulder main groove 5 and the second tread edge Te2. The second shoulder land portion 9 is adjacent to the second middle land portion 7 via the second shoulder main groove 5 .

The tread portion 2 of this embodiment has a substantially point-symmetrical tread pattern. Therefore, the configuration of the first middle land portion 6 described below can be applied to the second middle land portion 7 . Also, the configuration of the first shoulder land portion 8 can be applied to the second shoulder land portion 9 .

FIG. 2 shows an enlarged view of the first middle land portion 6, the second middle land portion 7 and the first shoulder land portion 8. As shown in FIG. As shown in FIG. 2 , the first middle land portion 6 includes a plurality of first transverse sipes 11 that completely traverse the first middle land portion 6 and sipes extending from the crown main groove 3 and within the first middle land portion 6 . There is at least one first non-transversal sipe 13 that terminates at the . The first crossing sipe 11 and the first non-crossing sipe 13 can increase the edge component while maintaining the rigidity of the first middle land portion 6 to improve steering stability and wet performance. In this specification, "sipe" means a cut with a width of less than 2.0 mm.

In this embodiment, the first crossing sipes 11 and the first non-crossing sipes 13 are alternately provided in the tire circumferential direction. In a more desirable aspect, the first crossing sipes 11 and the first non-crossing sipes 13 are arranged at substantially equal intervals in the tire circumferential direction.

An enlarged perspective view of the first non-transverse sipe 13 is shown in FIG. As shown in FIG. 3 , a chamfered portion 25 is provided in the communication portion 13 a between the crown main groove 3 and the first non-transverse sipe 13 . The chamfered portion 25 has an inclined surface 25 a that is continuous with the tread surface of the first middle land portion 6 , the groove wall of the crown main groove 3 and the sipe wall of the first non-transverse sipe 13 .

Since the first middle land portion 6 of the present embodiment is provided with the first crossing sipe 11 and the first non-crossing sipe 13, the crown main groove 3 side is relatively easily deformed. Therefore, when a large ground contact pressure acts on the first middle land portion 6 or when a slip angle is applied to the tire, a portion of the outer surface of the chamfered portion 25 can be brought into contact with the ground. The substantial contact area of the portion 6 is increased. Therefore, initial responsiveness during turning is enhanced, and excellent steering stability can be expected.

In addition, since the first middle land portion 6 of the present invention is provided with the chamfered portion 25, it is possible to reduce the hammering sound when the communication portion 13a touches the ground, thereby improving the noise performance.

In a desirable mode, the inclined surface 25a of the chamfered portion 25 is configured as a curved surface. Further, in the present embodiment, the inclined surface 25a is a curved surface that protrudes outward from the first middle land portion 6. As shown in FIG. Such a chamfered portion 25 can smoothly bring the inclined surface into contact with the ground when the ground contact pressure acting on the first middle land portion 6 increases, and can suppress uneven wear around the chamfered portion 25 .

The maximum depth of the chamfer 25 is, for example, 2.0-4.0 mm, preferably 2.5-3.5 mm.

As shown in FIG. 2, in a plan view of the tread, the tread surface side edge 26 between the inclined surface 25a and the tread surface of the first middle land portion 6 is preferably curved, and more preferably arcuate.

For example, the chamfered portion 25 is preferably arranged at a corner portion where the angle between the groove edge 3e of the crown main groove 3 and the edge 13e of the first non-transverse sipe 13 is an obtuse angle. That is, in a tread plan view, the angle between the edge 13e of the first non-transverse sipe 13 connected to the tread side edge 26 and the groove edge 3e of the crown main groove 3 connected to the tread side edge 26 is an obtuse angle. Such a chamfered portion 25 has a larger slanted surface than that provided at a corner portion with an acute angle, and in addition to the above effects, improvement in wet performance and reduction in rolling resistance can be expected.

In a tread plan view, the axial length L6 of the chamfered portion 25 is, for example, preferably 0.30 times or more, more preferably 0.35 times the axial length L2 of the first non-crossing sipe 13. or more, preferably 0.45 times or less, more preferably 0.40 times or less. Such a chamfered portion 25 can improve steering stability and noise performance in a well-balanced manner.

From the same point of view, the length of the chamfered portion 25 along the groove edge 3e of the crown main groove 3 is preferably 0.90 to 1.50 times the length L6 of the chamfered portion 25 in the axial direction of the tire.

The above-described chamfered portion 25 is provided only on the first non-crossing sipe 13 and not provided on the first crossing sipe 11 . As a result, it is possible to prevent the chamfered portion from excessively reducing the contact area during normal running.

The first non-transverse sipe 13 is, for example, inclined with respect to the tire axial direction. The first non-transverse sipe 13 is slanted in the same direction as the first transverse sipe 11, for example. The angle of the first non-transverse sipe 13 with respect to the tire axial direction is, for example, 15 to 35 degrees. As a more desirable aspect, in this embodiment, the first crossing sipe 11 and the first non-crossing sipe 13 are arranged parallel to each other.

The axial length L2 of the first non-crossing sipe 13 is, for example, preferably 0.40 to 0.60 times the axial width W2 of the first middle land portion 6, and more preferably 0.40 to 0.60 times. 51 to 0.55 times.

The interrupted end 13b in the first middle land portion 6 of the first non-crossing sipe 13 is arranged near the central portion of the block piece 6a divided between the two first crossing sipes 11, for example. desirable. Specifically, the discontinuous end 13b of the first non-crossing sipe 13 is preferably provided at a position where the distance from the centroid of the tread surface of the block piece 6a is less than 5 mm. In a further preferred embodiment, the discontinuous end 13b of the first non-transverse sipe 13 is arranged on the centroid of the tread surface of the block piece 6a. Such a first non-transverse sipe 13 suppresses local deformation of the block piece 6a, and can be expected to improve noise performance and reduce rolling resistance.

The first transverse sipe 11 , for example, extends linearly from the crown main groove 3 to the first shoulder main groove 4 . Further, the first transverse sipe 11 is, for example, inclined in one direction with respect to the tire axial direction. The angle of the first transverse sipe 11 with respect to the axial direction of the tire is preferably 15 to 35 degrees, for example.

FIG. 4(a) shows a cross-sectional view of the first transverse sipe 11 of FIG. 2 taken along the line AA. As shown in FIG. 4( a ), the first transverse sipe 11 is arranged, for example, in an opening 28 that opens at the tread surface of the first middle land portion 6 and inside the opening 28 in the tire radial direction, and and a narrow portion 29 having a width smaller than that of the opening 28 . A width W4 of the opening 28 is, for example, 1.0 to 1.5 mm. A width W5 of the narrow portion 29 is, for example, 0.6 to 1.0 mm. Such a first transverse sipe 11 can be expected to improve wet performance while maintaining the rigidity of the first middle land portion 6 .

FIG. 4(b) shows a cross-sectional view of the first transverse sipe 11 of FIG. 2 taken along the line BB. As shown in FIG. 4(b), the first transverse sipe 11 preferably has a shallow portion 27 with a raised bottom, for example. The shallow bottom portion 27 is desirably raised, for example, at positions other than both ends in the axial direction of the tire. The shallow bottom portion 27 crosses the center of the first middle land portion 6 in the tire axial direction. Such a shallow bottom portion 27 enhances initial response and wear resistance in a well-balanced manner.

In order to further enhance the above effect, the depth d2 of the shallow portion 27 is preferably 0.45 to 0.65 times the maximum depth d1 of the first transverse sipe 11, for example. The axial length L5 of the shallow bottom portion 27 is preferably, for example, 0.55 to 0.70 times the axial width W2 of the first middle land portion 6 (shown in FIG. 2).

As shown in FIG. 2 , the second middle land portion 7 is provided with a plurality of second crossing sipes 12 and a plurality of second non-crossing sipes 14 . The configuration of the first transverse sipe 11 described above can be applied to the second transverse sipe 12 . The configuration of the first non-crossing sipe 13 described above can be applied to the second non-crossing sipe 14 .

Each of the first transverse sipes 11 is arranged so as not to be smoothly continuous with each of the second transverse sipes 12 via the crown main groove 3 . In this specification, "one sipe is smoothly continuous with the other sipe through the main groove" means that one sipe is extended along its longitudinal direction and the other sipe is It means that the minimum circumferential distance of the tire in the main groove is less than 1.0 mm, with respect to the area extending along the longitudinal direction. In addition, when the sipe is bent, the region extends while maintaining the curvature at the end of the sipe on the main groove side.

That is, in the present embodiment, the first transverse sipe 11 is extended in the longitudinal direction toward the second middle land portion 7 side in the first region 21, and the second transverse sipe 12 is longitudinally extended in the second region. The minimum clearance in the tire circumferential direction from the second region 22 extending toward the first middle land portion 6 is at least 1.0 mm or more in the crown main groove 3 . As a desirable aspect, the minimum separation distance in this embodiment is 3.0 to 6.0 mm. Such an arrangement of sipes helps suppress uneven wear of the first middle land portion 6 and the second middle land portion 7 .

Preferably, each of the first non-transverse sipes 13 is not smoothly continuous with each of the second non-transverse sipes 14 through the crown main groove 3 . Specifically, the third region 23 is formed by extending the first non-crossing sipe 13 along its length direction toward the second middle land portion 7 side, and the second non-crossing sipe 14 is extended along its length direction to the third region 23 . The fourth region 24 extending toward the first middle land portion 6 side does not overlap with each other within the crown main groove 3 . Such first non-crossing sipe 13 and second non-crossing sipe 14 can further suppress uneven wear of the first middle land portion 6 and the second middle land portion 7 .

In the crown main groove 3, the minimum circumferential distance between the third region 23 and the fourth region 24 is, for example, 1.0 to 6.0 mm, more preferably 1.0 to 2.0 mm. be. Such first non-crossing sipe 13 and second non-crossing sipe 14 can improve initial response and wear resistance in a well-balanced manner.

In the present embodiment, the chamfered portion 25 continuous with the first non-crossing sipe 13 is provided on one side of the first non-crossing sipe 13 in the tire circumferential direction, and the chamfering portion 25 continuous with the second non-crossing sipe 14 is located at the second non-crossing sipe 13 . It is provided on the other side of the non-crossing sipe 14 in the tire circumferential direction. Further, a region obtained by extending the chamfered portion 25 continuous with the first non-crossing sipe 13 along the length direction of the first non-crossing sipe 13 is the chamfering portion 25 continuous with the second non-crossing sipe 14 . does not overlap with regions extending along the length of Such an arrangement of the chamfered portion 25 can further suppress uneven wear of the first middle land portion 6 and the second middle land portion 7 .

The first shoulder land portion 8 is provided with a first shoulder lateral groove 30 , a first shoulder sipe 31 and a second shoulder sipe 32 .

The first shoulder lateral groove 30 , for example, extends axially inward from the first tread end Te<b>1 and discontinues within the first shoulder land portion 8 .

The axial length L3 of the first shoulder lateral groove 30 is preferably 0.75 to 0.79 times the axial width W3 of the first shoulder land portion 8, for example.

It is desirable that the first shoulder lateral grooves 30 are arranged, for example, at an angle of 0 to 20° with respect to the axial direction of the tire. For example, the angle of the first shoulder lateral groove 30 of the present embodiment with respect to the tire axial direction gradually increases inward in the tire axial direction.

The first shoulder sipe 31 extends axially outward from the first shoulder main groove 4 . The first shoulder sipe 31 of this embodiment extends from the first shoulder main groove 4 to the inner end 30i of the first shoulder lateral groove 30, for example.

Each of the first transverse sipes 11 is arranged so as to be smoothly continuous with each of the first shoulder sipes 31 via the first shoulder main grooves 4 . That is, in the first shoulder main groove 4, a region 17a where the first transverse sipe 11 extends toward the first shoulder land portion 8 and a region 17b where the first shoulder sipe 31 extends toward the first middle land portion 6 side. The minimum tire circumferential separation distance is less than 1.0 mm.

In the present embodiment, as described above, when the first transverse sipe 11, the second transverse sipe 12, and the first shoulder sipe 31 are arranged in association with each other, when the slip angle is given, the first shoulder land portion 8 can The torsional rigidity of the second middle land portion 7 is optimized, and excellent initial responsiveness is exhibited.

Preferably, said minimum distance between said regions 17a and 17b is less than 0.5 mm. In this embodiment, the regions 17a and 17b overlap (that is, the minimum separation distance is 0). In a more desirable embodiment, the region 17a of the first transverse sipe 11 extending along the longitudinal direction toward the first shoulder land portion 8 is aligned with the end portion of the first shoulder sipe 31 on the first shoulder main groove 4 side. Duplicate. Such arrangement of the sipes facilitates the movement of the first middle land portion 6 and the first shoulder land portion 8 together, and is useful for further enhancing the initial responsiveness.

The second shoulder sipe 32, for example, extends axially inward from the first tread end Te1. In this embodiment, the first shoulder lateral grooves 30 and the second shoulder sipes 32 are provided alternately in the tire circumferential direction. The axially inner end 32 i of the second shoulder sipe 32 is cut off within the first shoulder land portion 8 . In a more desirable aspect, the inner end 32i of the second shoulder sipe 32 is located closer to the first tread end Te1 than the inner end 30i of the first shoulder lateral groove 30 is. Such a second shoulder sipe 32 serves to make the rigidity distribution of the first shoulder land portion 8 uniform and to improve initial responsiveness.

The axial length L4 of the second shoulder sipe 32 is preferably 0.75 to 0.95 times the axial length L3 of the first shoulder lateral groove 30, for example.

It is desirable that the region where the first non-crossing sipe 13 is extended along its length direction toward the first shoulder land portion 8 passes near the inner end 32i of the second shoulder sipe 32 . Specifically, it is desirable that the minimum distance between the region and the inner edge 32i is less than 5 mm. As a more desirable aspect, in the present embodiment, the region where the first non-crossing sipe 13 is extended along the length direction toward the first shoulder land portion 8 overlaps the inner end 32i of the second shoulder sipe 32. there is Such an arrangement of the first non-crossing sipe 13 and the second shoulder sipe 32 can make the deformation of each sipe uniform during running, thereby enhancing wear resistance.

FIG. 5 shows a developed view of the tread portion 2 of the tire 1 of another embodiment of the invention. In FIG. 5, the same reference numerals are assigned to elements that are common to the above-described embodiment, and descriptions thereof are omitted here.

The tread portion 2 of this embodiment has two crown main grooves 3 extending across the tire equator C and a crown land portion 10 divided between the two crown main grooves 3 . The crown land portion 10 is provided with a plurality of non-crown-crossing sipes 35 extending from the crown main groove 3 and interrupted within the land portion. Such a crown non-transverse sipe 35 reduces rolling resistance and suppresses hitting noise when the crown land portion 10 touches the ground, thereby helping to improve noise performance.

The crown non-crossing sipe 35 includes, for example, a first crown non-crossing sipe 36 extending from the crown main groove 3 arranged between the tire equator C and the first tread edge Te1, and a tire equator C and the second tread edge Te2. and a second crown non-transverse sipe 37 extending from the crown main groove 3 disposed between. The first non-crossing crown sipes 36 and the second non-crossing sipes 37 are provided alternately in the tire circumferential direction, for example.

In this embodiment, the first non-crossing crown sipe 36 is arranged so as to be smoothly continuous with the first non-crossing sipe 13 arranged in the first middle land portion 6 via the crown main groove 3 . Similarly, the second non-crossing crown sipe 37 is arranged so as to be smoothly continuous with the second non-crossing sipe 14 arranged in the second middle land portion 7 via the crown main groove 3 . Such sipe placement can further enhance wet and noise performance.

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 tire of size 195/65R15 having the basic pattern shown in FIG. As a comparative example, as shown in FIG. 6, a prototype tire was produced in which the non-transverse sipe b provided in the middle land portion a was not provided with a chamfered portion. The tire of the comparative example has substantially the same tread pattern as that shown in FIG. 1, except for the above configuration. Each test tire was tested for handling stability and wear resistance. Common specifications and test methods for each test tire are as follows.
Rim: 15 x 6.0
Tire internal pressure: 200kPa
Test vehicle: 1500cc displacement, front-wheel drive Tire mounting position: All wheels

<Steering stability>
Steering stability (including initial responsiveness during cornering) was evaluated by the driver's senses 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.

<Noise performance>
The test vehicle was run at 40 to 100 km/h on a dry road surface including unevenness, and the maximum sound pressure of noise inside the vehicle was measured at this time. The results are indexed with the sound pressure of the comparative example being 100, and the smaller the numerical value, the smaller the noise inside the vehicle and the better the noise performance.
The results of the tests are shown in Table 1.

As a result of the test, it was confirmed that the tires of Examples exhibited excellent steering stability and noise performance.

2 tread portion 3 crown main groove 4 first shoulder main groove 6 first middle land portion 11 first transverse sipe 13 first non-transverse sipe 25 chamfered portion

Claims (5)

A tire having a tread portion,
The tread portion is
a crown main groove extending continuously in the tire circumferential direction;
a first shoulder main groove extending continuously in the tire circumferential direction between the crown main groove and the first tread end;
a first middle land portion divided between the crown main groove and the first shoulder main groove;
The first middle land portion includes a plurality of first transverse sipes that completely cross the first middle land portion, and at least one first non-crossing sipe extending from the crown main groove and discontinuous within the first middle land portion. sipes are provided,
A chamfered portion is provided in a communicating portion between the crown main groove and the first non-transverse sipe,
The axial length of the first non-crossing sipe is 0.40 to 0.60 times the axial width of the first middle land portion.
tire. A tire having a tread portion,
The tread portion is
a crown main groove extending continuously in the tire circumferential direction;
a first shoulder main groove extending continuously in the tire circumferential direction between the crown main groove and the first tread end;
a first middle land portion divided between the crown main groove and the first shoulder main groove;
The first middle land portion includes a plurality of first transverse sipes that completely cross the first middle land portion, and at least one first non-crossing sipe extending from the crown main groove and discontinuous within the first middle land portion. sipes are provided,
A chamfered portion is provided in a communicating portion between the crown main groove and the first non-transverse sipe,
the chamfered portion has an inclined surface continuous with each of the tread surface of the first middle land portion, the groove wall of the crown main groove, and the sipe wall of the first non-transverse sipe;
The inclined surface is a curved surface,
In a plan view of the tread, a tread surface-side edge between the inclined surface and the tread surface of the first middle land portion is arcuate.
tire. 3. The tread according to claim 2, wherein, in a tread plan view, an angle between the edge of the first non-transverse sipe contiguous to the tread-side edge and the groove edge of the crown main groove contiguous to the tread-side edge is an obtuse angle. tire. A tire according to any one of claims 1 to 3, wherein said first non-transverse sipe is inclined at an angle of 15-35° with respect to the tire axial direction. The tread portion has two crown main grooves extending across the tire equator and a crown land portion divided between the two crown main grooves,
The crown land portion is provided with a plurality of crown non-transverse sipes extending from the crown main groove and interrupted within the land portion,
The tire according to any one of claims 1 to 4, wherein at least one of said crown non-crossing sipes is arranged so as to be smoothly continuous with said first non-crossing sipe via said crown main groove.

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