JP6358970B2 - Pneumatic tire - Google Patents

Description

  The present invention relates to a pneumatic tire having high wet performance and uneven wear resistance.

  For example, the pneumatic tire disclosed in Patent Document 1 is provided with a penetrating element that crosses a land portion in the tire axial direction. This penetrating element is composed of a sipe extending in a V shape in plan view.

  Since the penetrating element is formed by a sipe having a small width, the sipe walls of the penetrating element facing each other are in close contact with each other when a ground pressure or a lateral force is applied to the land portion. As a result, the land portion has an apparent rigidity and behaves as if it is a rib continuous in the tire circumferential direction.

  On the other hand, the land portion has a rib-like behavior when touching the ground, so that when the drainage is reduced or a large lateral force is applied, the circumferential edge of the land portion is lifted and uneven wear (edge wear) occurs. There was a tendency to be easy.

JP 2014-210499A

  The present invention has been devised in view of the actual situation as described above, and provides a pneumatic tire capable of suppressing uneven wear of land portions without impairing drainage, based on improving the shape of the penetrating element. The main purpose is to do.

  The present invention is a pneumatic tire in which a tread portion is provided with a plurality of main grooves extending continuously in a tire circumferential direction, and a land portion divided into the main grooves. A penetrating element that crosses the land portion is provided, and the penetrating element is disposed on the outer side in the tire axial direction than the first inclined portion and in the plan view, the first inclined portion that is inclined with respect to the tire axial direction and the first inclined portion. The second inclined portion extends in a V shape including a second inclined portion inclined in the opposite direction to the first inclined portion, and the first inclined portion is configured by a first sipe from a tread ground surface to the bottom, and the second inclined portion The portion includes an outer groove portion having a groove width larger than the sipe from the tread ground surface, and a second sipe extending inward in the tire radial direction from the bottom of the outer groove portion, and the second sipe is It is characterized by being continuous with one sipe.

  In the pneumatic tire of the present invention, it is preferable that one groove wall surface of the outer groove portion is continuous with one sipe wall surface of the second sipe.

  In the pneumatic tire of the present invention, it is desirable that the other groove wall surface of the outer groove portion be inclined in a direction of increasing the groove width toward the outer side in the tire radial direction.

  In the pneumatic tire according to the aspect of the invention, it is preferable that the second inclined portion has a smaller tire axial length than the first inclined portion.

  In the pneumatic tire of the present invention, it is desirable that an angle θ2 of the second inclined portion with respect to the tire axial direction is smaller than an angle θ1 of the first inclined portion with respect to the tire axial direction.

  In the pneumatic tire of the present invention, it is preferable that the depth of the outer groove portion is 0.15 to 0.35 times the depth of the second inclined portion.

  In the pneumatic tire of the present invention, the distance in the tire axial direction between the inner end of the outer groove portion in the tire axial direction and the apex where the first inclined portion and the second inclined portion intersect is 3.0 mm or less. Is desirable.

  In the pneumatic tire of the present invention, the mounting direction to the vehicle is specified, and the land portion includes a pair of middle land portions provided on both sides of the tire equator, and the pair of middle land portions are mounted when the vehicle is mounted. It is preferable that an inner middle land portion located on the inner side of the vehicle and an outer middle land portion located on the outer side of the vehicle when the vehicle is mounted, wherein the penetrating element is provided in the outer middle land portion.

  In the pneumatic tire of the present invention, the outer middle land portion is divided into the main grooves on both sides in the tire axial direction, and the outer middle land portion is formed on the inner side in the tire axial direction from the main groove on the outer side in the tire axial direction. It is desirable that non-penetrating elements that extend and terminate in the inner middle land portion are provided, and the non-penetrating elements and the penetrating elements are alternately provided in the tire circumferential direction.

  The pneumatic tire of the present invention is provided with a penetrating element that crosses the land. The penetrating element has a first inclined portion that is inclined with respect to the tire axial direction in plan view, and a second inclined that is disposed on the outer side in the tire axial direction than the first inclined portion and is inclined in a direction opposite to the first inclined portion. It extends in a V shape including the part.

  The 1st inclination part is comprised by the 1st sipe from the tread ground surface to the bottom. The second inclined portion includes an outer groove portion having a groove width larger than the sipe from the tread ground surface, and a second sipe extending inward in the tire radial direction from the bottom of the outer groove portion. Moreover, the second sipe is continuous with the first sipe.

  When such a penetrating element is grounded, the sipe wall surfaces facing each other are in close contact with each other in the first sipe and the second sipe. For this reason, the apparent rigidity of the land portion is increased, and excellent steering stability is obtained. Moreover, even when the first sipe and the second sipe are closed, the outer groove portion of the second inclined portion discharges water below the land portion to the main groove side, and provides excellent wet performance.

  Furthermore, when a lateral force is applied to the land portion, in the conventional penetrating element, due to the high apparent rigidity of the land portion, for example, a part of the ground contact surface may be lifted from the road surface, and a sufficient grip may not be obtained. . However, in the pneumatic tire according to the present invention, the second inclined portion is provided with an outer groove portion wider than the sipe. Such an outer groove portion can absorb the distortion of the ground contact surface and suppress its lifting, and can effectively suppress uneven wear such as edge wear while improving steering stability.

It is an expanded view of the tread part of the pneumatic tire of one embodiment of the present invention. It is an enlarged view of the outer middle land part of FIG. (A) is the sectional view on the AA line of the 1st inclination part of FIG. 2, (b) is the BB sectional view of the 2nd inclination part of FIG. It is an enlarged view of the inner middle land part of FIG. It is an enlarged view of the outer side shoulder land part of FIG. It is an enlarged view of the inner side shoulder land part of FIG. It is an enlarged view of the tread part of the pneumatic tire of a comparative example.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a development view of a tread portion 2 of a pneumatic tire (hereinafter sometimes simply referred to as “tire”) 1 of the present embodiment. The pneumatic tire 1 of this embodiment is suitably used for, for example, a passenger car.

  The tread portion 2 of the present embodiment includes, for example, a tread pattern in which the mounting direction to the vehicle is specified. In the tread portion 2 of the present embodiment, the vehicle outer side A and the vehicle inner side B are designated when the vehicle is mounted. The direction of mounting on the vehicle is displayed by, for example, characters or marks on a sidewall (not shown) or the like.

  As shown in FIG. 1, the tread portion 2 of the tire 1 is provided with a plurality of main grooves 3 extending continuously in the tire circumferential direction and land portions 4 divided into the main grooves 3.

  The main groove 3 includes, for example, a shoulder main groove 5 provided on the tread ground contact Te side and a center main groove 6 provided on the inner side in the tire axial direction of the shoulder main groove 5.

  The “tread grounding end Te” is a flat surface with a normal load applied to a normal tire 1 which is assembled with a normal rim (not shown) and filled with a normal internal pressure, and which is not loaded, with a camber angle of 0 °. This is the contact position on the outermost side in the tire axial direction when the contact is made on the ground.

  The “regular rim” is a rim defined for each tire in the standard system including the standard on which the tire is based. For example, “Standard Rim” for JATMA, “Design Rim” for TRA, For ETRTO, "Measuring Rim".

  “Regular internal pressure” is the air pressure that each standard defines for each tire in the standard system including the standard on which the tire is based. “JAMATA” is the “highest air pressure”, TRA is the table “TIRE LOAD LIMITS AT” The maximum value described in “VARIOUS COLD INFLATION PRESSURES”, “INFLATION PRESSURE” for ETRTO.

  “Regular load” is a load determined by each standard for each tire in the standard system including the standard on which the tire is based. “JATMA” is “Maximum load capacity”, TRA is “TIRE LOAD LIMITS” The maximum value described in “AT VARIOUS COLD INFLATION PRESSURES”, “LOAD CAPACITY” in the case of ETRTO.

  The shoulder main groove 5 and the center main groove 6 of the present embodiment extend linearly, for example. The shoulder main groove 5 and the center main groove 6 may extend in a zigzag shape or a wave shape, for example.

  The shoulder main groove 5 includes, for example, an outer shoulder main groove 5A positioned on the vehicle outer side A when the vehicle is mounted, and an inner shoulder main groove 5B positioned on the vehicle inner side B when the vehicle is mounted.

  The center main groove 6 is provided between the outer shoulder main groove 5A and the inner shoulder main groove 5B. One center main groove 6 of this embodiment is provided on the tire equator C, for example. For example, a pair of center main grooves 6 may be provided on both sides of the tire equator C.

  The groove width W1 of the shoulder main groove 5 and the groove width W2 of the center main groove 6 are preferably, for example, 3.5 to 10.0% of the tread ground contact width TW. In the case of a pneumatic tire for a passenger car, the depth of the shoulder main groove 5 and the depth of the center main groove 6 are preferably 5.0 to 12.0 mm, for example. The tread contact width TW is a distance in the tire axial direction between the tread contact ends Te and Te of the tire 1 in the normal state.

  For example, the inner shoulder main groove 5B has a larger groove width than the outer shoulder main groove 5A. Thereby, the steering stability and wet performance on a dry road surface are improved with a good balance.

  The center main groove 6 has, for example, a larger groove width than the inner shoulder main groove 5B. This makes it easy for water near the tire equator C to be discharged during wet running, and the hydroplaning phenomenon is effectively suppressed.

  The tread portion 2 is provided with the shoulder main groove 5 and the center main groove 6 described above, so that the middle land portion 7 between the shoulder main groove 5 and the center main groove 6 and the tire main groove 5 in the tire axial direction. The outer shoulder land portion 8 is divided.

  The middle land portion 7 includes an outer middle land portion 7A that becomes the vehicle outer side A when the vehicle is mounted, and an inner middle land portion 7B that becomes the vehicle inner side B when the vehicle is mounted.

  FIG. 2 shows an enlarged view of the outer middle land portion 7A. As shown in FIG. 2, the outer middle land portion 7A is provided with a plurality of penetrating elements 10 that cross the land portion.

  The penetrating element 10 includes a first inclined portion 11 and a second inclined portion 12 in a plan view, and extends in a convex V shape on one side in the tire circumferential direction (upper side in FIG. 2).

  The first inclined portion 11 is inclined with respect to the tire axial direction. The first inclined portion 11 of the present embodiment is inclined, for example, from the center main groove 6 to one side in the tire circumferential direction and extends linearly to the apex 14 of the V-shaped penetrating element 10.

  The angle θ1 of the first inclined portion 11 with respect to the tire axial direction is preferably 20 to 30 °. Such a 1st inclination part 11 can exhibit the frictional force by an edge with sufficient balance with respect to a tire peripheral direction and a tire axial direction.

  FIG. 3A shows a cross-sectional view taken along line AA of the first inclined portion 11. As shown in FIG. 3, the first inclined portion 11 includes a first sipe 16 from the tread ground surface 2 s to the bottom 15. In this specification, “sipe” means a cut having a width of 1.5 mm or less, and is distinguished from a drainage groove.

  Such a first inclined portion 11 is useful for increasing the apparent rigidity of the land portion when the contact pressure is applied to the tread contact surface 2s and the sipe wall surfaces facing each other are in close contact with each other.

  As shown in FIG. 2, the second inclined portion 12 is disposed on the outer side in the tire axial direction than the first inclined portion 11. The second inclined portion 12 is inclined in the opposite direction to the first inclined portion 11. The second inclined portion 12 of the present embodiment is inclined, for example, from the apex 14 to the other side in the tire circumferential direction (lower side in FIG. 2) and extends linearly to the outer shoulder main groove 5A.

  FIG. 3B shows a cross-sectional view taken along line BB of the second inclined portion 12 of FIG. As shown in FIG. 3B, the second inclined portion 12 has an outer groove portion 18 and a second sipe 19.

  The outer groove 18 opens at the tread contact surface 2s and extends inward in the tire radial direction. The outer groove portion 18 has a larger groove width than the sipe. Such an outer groove 18 is useful for effectively absorbing water and improving wet performance during wet running.

  The second sipe 19 extends inward in the tire radial direction from the bottom 20 of the outer groove portion 18. In addition, the second sipe 19 is continuous with the first sipe 16 (shown in FIG. 3A and the same hereinafter).

  The penetrating element 10 having the first inclined portion 11 and the second inclined portion 12 (shown in FIG. 2 and the same hereinafter) having the first inclined portion 11 and the second inclined portion 12 as described above, The sipe wall surfaces facing each other closely contact each other. For this reason, the apparent rigidity of the land portion is increased, and excellent steering stability is obtained. Even when the first sipe 16 and the second sipe 19 are closed, the outer groove portion 18 of the second inclined portion 12 discharges water below the land portion to the main groove side, and provides excellent wet performance.

  Furthermore, when a lateral force is applied to the land portion, in the conventional penetrating element, due to the high apparent rigidity of the land portion, for example, a part of the ground contact surface may be lifted from the road surface, and a sufficient grip may not be obtained. . In addition, a part of the edge of the land portion is lifted off the road surface, and the edge may be unevenly worn.

  However, in the pneumatic tire of the present invention, the second inclined portion 12 is provided with the outer groove portion 18 wider than the sipe. Such an outer groove portion 18 can absorb the distortion of the ground contact surface and suppress its lifting, and can effectively suppress uneven wear such as edge wear while improving steering stability.

  One first groove wall surface 21 of the outer groove portion 18 extends linearly in the tire radial direction from the tread ground surface 2 s and is continuous with one sipe wall surface 23 of the second sipe 19. And the other 2nd groove wall surface 22 of the outer side groove part 18 inclines in the direction which expands a groove width toward a tire radial direction outer side.

  The second groove wall surface 22 of the present embodiment is smoothly curved, for example, in the cross section. In addition, the center of the radius of curvature of the curved second groove wall surface 22 is outside the tire. Such a 2nd groove wall surface 22 exhibits the outstanding drainage.

  As shown in FIG. 2, as a more desirable mode, the second groove wall surface 22 of the outer groove portion 18 is, in plan view, the apex 14 side of the penetrating element 10, that is, one side in the tire circumferential direction (upper side in FIG. 2). ). Conventionally, the triangular small piece portion 28 between the second inclined portion 12 and the circumferential edge 29 on the outer side in the tire axial direction of the land portion tends to be easily lifted from the road surface and tends to be unevenly worn. In the present embodiment, the second groove wall surface 22 of the outer groove portion 18 is provided on the apex 14 side of the penetrating element 10, so that the lift of the small piece portion 28 is suppressed, and uneven wear is effectively suppressed.

  As shown in FIG. 3B, the depth d2 of the outer groove 18 is preferably 0.15 of the depth d1 of the second inclined portion 12 in order to improve the wet performance and the uneven wear resistance with a good balance. Times or more, more preferably 0.22 times or more, preferably 0.35 times or less, more preferably 0.28 times or less.

  From the same viewpoint, the width W3 of the outer groove portion 18 on the tread contact surface 2s is preferably 1.5 mm or more, more preferably 1.8 mm or more, preferably 2.5 mm or less, more preferably 2.0 mm. It is as follows.

  As shown in FIG. 2, the second inclined portion 12 desirably has a length L2 in the tire axial direction that is smaller than that of the first inclined portion 11. Specifically, the length L2 of the second inclined portion 12 in the tire axial direction is preferably 0.30 times or more, more preferably 0.35 times or longer than the length L1 of the first inclined portion 11 in the tire axial direction. And preferably 0.45 times or less, more preferably 0.40 times or less. Such a 2nd inclination part 12 can provide the outstanding wet performance, suppressing the edge abrasion of the tire axial direction outer side of a land part.

  For example, the angle θ2 of the second inclined portion 12 with respect to the tire axial direction is preferably smaller than the angle θ1 of the first inclined portion 11 with respect to the tire axial direction. Specifically, the angle θ2 is preferably 18 to 25 °, for example. Such a 2nd inclination part 12 exhibits high wet performance, suppressing the floating of the said small piece part 28 when a lateral force acts on a land part.

  The angle θ3 between the first inclined portion 11 and the second inclined portion 12 is preferably 125 ° or more, more preferably 130 ° or more, preferably 140 ° or less, more preferably 135 ° or less. Such a penetrating element 10 serves to suppress uneven wear near the apex 14 while exhibiting a high edge effect.

  From the same viewpoint, the distance L3 in the tire axial direction between the inner end 17 of the outer groove 18 in the tire axial direction and the apex 14 of the penetrating element 10 is preferably 3.0 mm or less, more preferably 1.5 mm or less. .

  In the outer middle land portion 7A, for example, a plurality of non-penetrating elements 25 communicating with the main groove 3 and terminating in the land portion are provided. In the present embodiment, the penetrating elements 10 and the non-penetrating elements 25 are alternately provided in the tire circumferential direction.

  The non-penetrating element 25 of the present embodiment extends, for example, from the outer shoulder main groove 5A inward in the tire axial direction and terminates in the outer middle land portion 7A. Such a non-penetrating element 25 exhibits excellent wet performance while maintaining the rigidity on the inner side in the tire axial direction of the outer middle land portion 7A.

  For example, the non-penetrating element 25 is formed in a V shape including the third inclined portion 26 and the fourth inclined portion 27.

  The third inclined portion 26 extends from the inner end 25 i in the tire axial direction of the non-penetrating element 25 in the same direction as the first inclined portion 11 of the penetrating element 10. The 3rd inclination part 26 of this embodiment is extended along the 1st inclination part 11, for example.

  The third inclined portion 26 has, for example, the same configuration as the cross-sectional shape of the first inclined portion 11 (shown in FIG. 3A and the same applies hereinafter). That is, it is desirable that the third inclined portion 26 is configured by a sipe from the tread ground surface to the bottom (not shown).

  The 4th inclination part 27 is distribute | arranged to the tire axial direction outer side rather than the 3rd inclination part 26, for example. The fourth inclined portion 27 is inclined in the opposite direction to the third inclined portion 26. As a desirable mode, the 4th inclined part 27 of this embodiment has extended along the 2nd inclined part 12, for example.

  The fourth inclined portion 27 has, for example, the same configuration as the cross-sectional shape of the second inclined portion 12 (shown in FIG. 3B and the same applies hereinafter). That is, the fourth inclined portion 27 includes an outer groove portion having a groove width larger than the sipe from the tread ground surface, and a sipe extending from the bottom of the outer groove portion inward in the tire radial direction (not shown). Such a 4th inclination part 27 is useful for making the rigidity distribution of the tire axial direction outer side of a land part uniform, and suppressing the uneven wear of a land part.

  FIG. 4 shows an enlarged view of the inner middle land portion 7B. The inner middle land portion 7B is provided with a plurality of second penetrating elements 30 that cross the land portion. The second penetrating element 30 provided in the inner middle land portion 7B is a penetrating element 10 provided in the outer middle land portion 7A (shown in FIG. 2 and hereinafter may be referred to as the first penetrating element 10). The shape in plan view is different.

  The second penetrating element 30 includes, for example, a central inclined portion 31 that is inclined with respect to the tire axial direction, and a first side portion 32 and a second side portion 33 that are provided on both sides of the central inclined portion 31 in the tire axial direction. It is out.

  For example, the central inclined portion 31 is inclined with respect to the tire axial direction and extends linearly. Such a central inclined portion 31 exhibits an edge effect in the tire circumferential direction and the tire axial direction.

  In order to further exert the above-described effects, the angle θ4 of the central inclined portion 31 with respect to the tire axial direction is preferably 40 ° or more, more preferably 45 ° or more, preferably 55 ° or less, more preferably 50 ° or less. It is.

  For example, the central inclined portion 31 has the same cross-sectional shape as the first inclined portion 11. That is, the central inclined portion 31 is formed by a sipe from the tread ground surface to the bottom (not shown). In such a central inclined portion 31, the sipe wall surfaces facing each other are in close contact with each other at the time of grounding. For this reason, the apparent rigidity of the inner middle land portion 7B is increased, and excellent steering stability is obtained.

  For example, the first side portion 32 communicates between the center main groove 6 and the central inclined portion 31. For example, the second side portion 33 communicates between the inner shoulder main groove 5 </ b> B and the central inclined portion 31.

  It is desirable that the first side portion 32 and the second side portion 33 each extend along the tire axial direction. As a result, the edge of the second penetrating element 30 and the circumferential edge 34 of the inner middle land portion 7B intersect at a right angle, and an acute-angled small piece portion is not formed. Therefore, the uneven wear resistance performance of the inner middle land portion 7B is enhanced.

  It is desirable that the first side portion 32 and the second side portion 33 each have the same cross-sectional shape as the second inclined portion 12 of the first penetrating element 10. That is, the first side portion 32 and the second side portion 33 have an outer groove portion having a groove width larger than the sipe from the tread ground surface, and a sipe extending inward in the tire radial direction from the bottom of the outer groove portion. (Not shown). The first side portion 32 and the second side portion 33 as described above are useful for suppressing uneven wear of the land portion, like the second inclined portion 12.

  As shown in FIG. 1, the shoulder land portion 8 includes an outer shoulder land portion 8A that becomes the vehicle outer side A when the vehicle is mounted, and an inner shoulder land portion 8B that becomes the vehicle inner side B when the vehicle is mounted.

  FIG. 5 shows an enlarged view of the outer shoulder land portion 8 </ b> A as a diagram for explaining the configuration of the shoulder land portion 8. As shown in FIG. 5, the shoulder land portion 8 is provided with, for example, shoulder lateral grooves 35 and shoulder narrow grooves 37 alternately in the tire circumferential direction.

  The shoulder lateral groove 35 extends, for example, in the tire axial direction from the tread grounding end Te and terminates in the shoulder land portion 8. Thereby, the rigidity inside the tire axial direction of the shoulder land portion 8 is enhanced, and excellent steering stability on a dry road surface is obtained. In addition, such shoulder lateral grooves 35 are useful for reducing pumping noise because air does not flow from the shoulder main grooves 5.

  It is desirable that the angle θ5 of the shoulder lateral groove 35 with respect to the tire axial direction is gradually increased toward the inner side in the tire axial direction, for example. Such a shoulder lateral groove 35 can effectively guide the water in the groove to the tread ground contact Te side during wet running.

  The shoulder narrow groove 37 extends, for example, outward from the shoulder main groove 5 in the tire axial direction and terminates in the shoulder land portion 8. The shoulder narrow groove 37 includes, for example, an inner part 38 and an outer part 39.

  For example, the inner portion 38 communicates with the shoulder main groove 5 and extends along the tire axial direction. Such an inner portion 38 helps to increase wet performance.

  For example, the inner portion 38 preferably has a cross-sectional shape similar to that of the second inclined portion 12. That is, the inner side portion 38 has an outer groove portion having a groove width larger than the sipe from the tread ground surface, and a sipe extending inward in the tire radial direction from the bottom of the outer groove portion (not shown). Like the second inclined portion 12, such an inner portion 38 is useful for suppressing uneven wear on the land portion.

  The outer portion 39 is continuous with, for example, the outer side of the inner portion 38 in the tire axial direction. The outer portion 39 provided in the outer shoulder land portion 8A, for example, terminates in the outer shoulder land portion 8A without reaching the tread ground contact end Te.

  For example, the outer portion 39 preferably has a cross-sectional shape similar to that of the first inclined portion 11. In other words, the outer portion 39 is configured by a sipe from the tread ground surface to the bottom (not shown). Such an outer portion 39 is useful for suppressing uneven wear near the outer end of the shoulder narrow groove 37.

  FIG. 6 shows an enlarged view of the inner shoulder land portion 8B. As shown in FIG. 6, similarly to the outer shoulder land portion 8A (shown in FIG. 5), shoulder lateral grooves 35 and shoulder narrow grooves 37 are alternately provided in the tire circumferential direction on the inner shoulder land portion 8B. .

  It is desirable that the shoulder narrow groove 37 provided in the inner shoulder land portion 8B extends, for example, to the tread ground contact end Te. Such shoulder narrow grooves 37 are useful for suppressing distortion of the ground contact surface between the shoulder lateral grooves 35.

  Although the pneumatic tire of the present invention has been described in detail above, the present invention is not limited to the specific embodiment described above, and is implemented with various modifications.

A pneumatic tire of size 195 / 65R15 having the basic tread pattern of FIG. 1 was prototyped based on the specifications in Table 1. As a comparative example, as shown in FIG. 7, a pneumatic tire in which a penetrating element that does not include an outer groove portion is provided in the outer middle land portion was prototyped. The wet performance and uneven wear resistance performance of each test tire was tested. The common specifications and test methods for each test tire are as follows.
Wearing rim: 15 × 6J
Tire internal pressure: 230kPa
Test vehicle: displacement 2400cc, front-wheel drive vehicle Test tire mounting position: all wheels

<Wet performance>
The test vehicle traveled on an asphalt road surface with a radius of 100 m provided with a puddle having a depth of 5 mm and a length of 20 m, and the lateral acceleration (lateral G) of the front wheels was measured. The result is an average lateral G at a speed of 50 to 80 km / h, and is indicated by an index with the value of the comparative example being 100. It shows that wet performance is excellent, so that a numerical value is large.

<Uneven wear resistance>
After traveling a certain distance with the test vehicle, the wear amount of the circumferential edge on the outer side in the tire axial direction of the outer middle land portion was measured. A result is an index | exponent which sets the value of a comparative example to 100, and shows that the abrasion resistance performance is excellent, so that a numerical value is small.
The test results are shown in Table 1.

  As a result of the test, it was confirmed that uneven wear on the land was suppressed without impairing the wet performance.

2 tread portion 2s tread contact surface 3 main groove 4 land portion 10 penetrating element 11 first inclined portion 12 second inclined portion 16 first sipe 18 outer groove portion 19 second sipe

Claims (9)

A pneumatic tire provided with a plurality of main grooves extending continuously in a tire circumferential direction in a tread portion and a land portion divided into the main grooves,
The land portion is provided with a penetrating element across the land portion,
In the plan view, the penetrating element is disposed on the outer side in the tire axial direction with respect to the first inclined portion that is inclined with respect to the tire axial direction, and is inclined in the direction opposite to the first inclined portion. It extends in a V shape including the second inclined part,
The first inclined portion is composed of a first sipe from the tread ground surface to the bottom,
The second inclined portion includes an outer groove portion having a groove width larger than the sipe from the tread ground surface, and a second sipe extending inward in the tire radial direction from the bottom of the outer groove portion,
The pneumatic tire according to claim 1, wherein the second sipe is continuous with the first sipe.   The pneumatic tire according to claim 1, wherein one groove wall surface of the outer groove portion is continuous with one sipe wall surface of the second sipe.   The pneumatic tire according to claim 2, wherein the other groove wall surface of the outer groove portion is inclined in a direction in which the groove width is increased toward the outer side in the tire radial direction.   The pneumatic tire according to any one of claims 1 to 3, wherein the second inclined portion has a smaller length in the tire axial direction than the first inclined portion.   The pneumatic tire according to any one of claims 1 to 4, wherein an angle θ2 of the second inclined portion with respect to the tire axial direction is smaller than an angle θ1 of the first inclined portion with respect to the tire axial direction.   The pneumatic tire according to any one of claims 1 to 5, wherein a depth of the outer groove portion is 0.15 to 0.35 times a depth of the second inclined portion.   7. The distance in the tire axial direction between the inner end of the outer groove portion in the tire axial direction and the apex at which the first inclined portion and the second inclined portion intersect with each other is 3.0 mm or less. Pneumatic tire described in 2. The direction of mounting on the vehicle is specified,
The land portion includes a pair of middle land portions provided on both sides of the tire equator,
The pair of middle land portions includes an inner middle land portion located inside the vehicle when the vehicle is mounted, and an outer middle land portion located outside the vehicle when the vehicle is mounted,
The pneumatic tire according to claim 1, wherein the penetrating element is provided in the outer middle land portion. The outer middle land portion is divided into the main grooves on both sides in the tire axial direction,
The outer middle land portion is provided with a non-penetrating element extending inward in the tire axial direction from the main groove on the outer side in the tire axial direction and terminating in the inner middle land portion,
The pneumatic tire according to claim 8, wherein the non-penetrating elements and the penetrating elements are alternately provided in a tire circumferential direction.

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