JP5165975B2 - Pneumatic tire - Google Patents

Description

  The present invention relates to a pneumatic tire, and more particularly, to a pneumatic tire that has improved uneven wear resistance performance of a land portion on the innermost side in the vehicle width direction when the vehicle is mounted.

A performance-balance-oriented summer tire generally employs a block pattern in which a straight main groove extending in the tire circumferential direction and a lug groove that is inclined with respect to the tire circumferential direction are combined (see Patent Document 1). . In order to obtain high performance, the tread pattern is asymmetrical. Note that a pattern with directionality has a problem that rotation is limited and difficult to use, and therefore a pattern with no directionality is often used.
In the case of an asymmetric pattern having no directionality, the lug groove has a relatively large angle with respect to the tire circumferential direction.

  By the way, in order to improve wet hydroplaning performance, that is, drainage performance, it is common to increase the groove area (negative rate) by increasing the circumferential main groove or increasing the groove width. However, when the circumferential main groove is increased, there is a problem that high-frequency noise generated by resonance in the circumferential main groove becomes conspicuous.

Conventional pneumatic tires with an asymmetric pattern with no directivity have lugs with a very small inclination angle with respect to the tire circumferential direction in order to suppress the flow to one side of the vehicle when maneuvering on dry and wet road surfaces. The groove could not be placed.
In a lug groove having a large inclination angle with respect to the circumferential direction, pattern noise and drainage are disadvantageous.

Also, if the lug groove is arranged, it becomes a block pattern, and if it is made a block pattern, it becomes difficult to ensure the driving stability on the dry and wet road surface due to the decrease in block rigidity. If it is large, noise and the like are disadvantageous, so it is difficult to achieve a total balance as a tire.
Therefore, both the drainage and the tire noise are compatible, and further improvement is required.
JP 2004-306906 A

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a pneumatic tire capable of achieving both a drainage property and tire noise and achieving a total balance.

  The invention according to claim 1 is a pneumatic tire having at least three circumferential main grooves in the tread and having a tread pattern that is left-right asymmetric, and is disposed on the outermost side in the vehicle width direction when the vehicle is mounted. A first inclined groove extending from the outermost circumferential main groove in the vehicle width direction toward the inner side in the vehicle width direction and one side in the tire rotating direction and terminating in the land, and an end portion in the land of the first inclined groove The vehicle width from the V-shaped groove formed by the second inclined groove extending toward the other side in the tire rotation direction and the innermost circumferential main groove in the vehicle width direction disposed at the innermost side in the vehicle width direction when the vehicle is mounted A lug groove portion extending inward in the direction and terminating in the land portion, and an L-shaped groove composed of an auxiliary groove portion extending in a direction intersecting the lug groove portion from the land end portion of the lug groove portion in the tread Have It is set to.

Next, the operation of the pneumatic tire according to claim 1 will be described.
In the pneumatic tire according to claim 1, if the tread includes at least three circumferential main grooves, and the tread has three or more circumferential main grooves, the basic drainage performance is ensured. Is done.

  By providing three or more circumferential main grooves in the tread, the tread will be provided with at least two rows of central sections (two rows of land) on the tread center side, which is fundamental on dry and wet road surfaces. Safe handling stability can be ensured. Also, by providing three or more circumferential main grooves in the tread, the tread can be clearly divided into a central area on the center side in the tread width direction and both side areas on the outer side in the tread width direction. It is possible to clearly separate the functions for each area, such as setting the areas on both sides advantageous for uneven wear and the center area advantageous for dry, wet and drainage performance.

  Since the tread has an asymmetric pattern, it is possible to divide functions such as placing importance on wear on the inner side in the vehicle width direction and attaching importance on drainage on the outer side in the vehicle width direction.

  A V-shaped groove is provided on the inner side in the vehicle width direction of the outermost circumferential main groove in the vehicle width direction, and a first inclined groove portion extending from the outermost circumferential main groove is present in the first inclined groove portion. The water in the land portion (that is, the central area) can be efficiently drained into the outer circumferential main groove.

  Further, since the V-shaped groove connected to the outermost circumferential main groove is bent without penetrating the second circumferential main groove from the outermost side, the second circumferential main groove from the outermost side is bent. The turbulent flow in the V-shaped groove caused by the inflow from the groove into the V-shaped groove can be prevented, and the drainage efficiency of the V-shaped groove can be further increased.

Further, the V-shaped groove is bent in the middle to branch a groove having a long total length from the outermost circumferential main groove, and such a long branch groove having a total length is a frequency generated in the circumferential main groove. It is possible to mute the sound in the vicinity of high (for example, 1 kHz).
Thus, the V-shaped groove can contribute to both drainage and tire noise.

  Furthermore, an L-shaped groove is disposed in a land portion (so-called shoulder land portion) on the inner side in the vehicle width direction than the innermost circumferential main groove disposed on the innermost side in the vehicle width direction when the vehicle is mounted. By connecting to the innermost circumferential main groove, high-frequency noise generated in the innermost circumferential main groove can be suppressed. Therefore, even if it is set in a rib shape, the drainage can be secured.

  In this way, by arranging the V-shaped groove on the outside when the tread is mounted on the vehicle and the L-shaped groove on the inside when the tread is mounted on the vehicle, both excellent drainage and noise characteristics can be achieved and a total balance can be achieved. Can do.

  According to a second aspect of the present invention, in the pneumatic tire according to the first aspect, the second inclined groove portion terminates in the land portion.

Next, the operation of the pneumatic tire according to claim 2 will be described.
By terminating the second inclined groove portion constituting the V-shaped groove in the land portion, the land portion (tire central region) on the inner side in the vehicle width direction from the outermost circumferential main groove disposed on the outermost side in the vehicle width direction is terminated. Land rigidity is ensured, and steering stability on dry and wet road surfaces can be ensured.

  Further, the second inclined groove portion is terminated in the land portion, and only one open end to the circumferential main groove of the V-shaped groove is most effective for tire high frequency noise.

  According to a third aspect of the present invention, in the pneumatic tire according to the second aspect, an inclination angle of the first inclined groove portion with respect to the tire circumferential direction is 20 to 70 at an opening end portion of the outermost circumferential main groove. The inclination angle of the second inclined groove portion with respect to the tire circumferential direction is set to be smaller than that of the first inclined portion.

Next, the operation of the pneumatic tire according to claim 3 will be described.
The opening angle of the V-shaped groove to the circumferential main groove, that is, the inclination angle (to the tire circumferential direction) of the opening end portion of the outermost circumferential main groove of the first inclined groove is 20 in consideration of drainage. A range of ˜70 ° is preferable. That is, high drainage is obtained by setting the inclination angle within the range of 20 to 70 °. If the inclination angle is less than 20 °, the rigidity of the land near the opening end is insufficient, and the maneuverability and uneven wear are adversely affected. On the other hand, when this inclination angle exceeds 70 °, the merit for drainage becomes thin.

  Note that the inclination angle of the inclined groove portion of the V-shaped groove is not constant within the groove, and the vicinity of the opening end is a relatively large angle, and the vicinity of the bend (the joint portion between the first inclined groove portion and the second inclined groove portion). In the vicinity), even if it is gradually changed, such as gradually decreasing, it becomes more advantageous for drainage and maneuverability. Further, after bending, the angle is smaller with respect to the tire circumferential direction than before the bending, that is, the angle of the second inclined groove portion with respect to the tire circumferential direction is smaller than that of the first inclined groove portion (an angle close to the tire circumferential direction). By setting to, the land portion where the V-shaped groove is formed is divided in the circumferential direction, the lateral rigidity is optimized while ensuring the land portion rigidity in the front-rear direction, and good balance is achieved on the dry road surface and the wet road surface Maneuverability can be realized.

  The invention according to claim 4 is the pneumatic tire according to any one of claims 1 to 3, wherein the auxiliary groove portion extends in a tire circumferential direction and terminates in a land portion. It is characterized by that.

Next, the operation of the pneumatic tire according to claim 4 will be described.
The L-shaped groove is terminated in a state close to the circumferential direction after being bent, so that the rigidity of the land portion can be secured, and the steering stability on the dry road surface and the wet road surface can be secured. Further, since the L-shaped groove is not connected to another groove different from the circumferential main groove, it is advantageous for reducing high-frequency noise during traveling.

  The invention according to claim 5 is the pneumatic tire according to any one of claims 1 to 4, wherein a pitch length of the V-shaped groove is longer than a pitch length of the L-shaped groove. It is characterized by being set.

Next, the operation of the pneumatic tire according to claim 5 will be described.
When the V-shaped groove on the outer side in the vehicle width direction when the vehicle is mounted is set to have a longer pitch length in the circumferential direction than the L-shaped groove, the V-shaped groove contributes to the improvement of drainage. Since the letter-shaped groove is located on the inner side in the vehicle width direction when the vehicle is mounted than the V-shaped groove, stepped wear, which is a type of uneven wear, is made shorter than the L-shaped groove in the circumferential direction. Can be suppressed. Furthermore, since the groove length of the V-shaped groove and the groove length of the L-shaped groove are greatly changed, the frequency characteristics of high-frequency noise generated during running can be changed for each groove, which is more effective for reducing tire noise. It becomes the target.

  The invention according to claim 6 is the pneumatic tire according to any one of claims 1 to 5, wherein an angle formed by the lug groove portion and the auxiliary groove portion is set to 90 °. It is characterized by.

Next, the operation of the pneumatic tire according to claim 6 will be described.
By setting the angle formed by the lug groove portion and the auxiliary groove portion to 90 °, the rigidity of the land portion on the inner side when the vehicle on which the L-shaped groove is formed can be secured, thereby improving uneven wear resistance.

  As described above, since the pneumatic tire of the present invention has the above-described configuration, it has an excellent effect that it is possible to achieve both improved drainage and reduced tire noise.

Hereinafter, a pneumatic tire 10 according to an embodiment of the present invention will be described in detail with reference to the drawings.
In the tread 12 of the pneumatic tire 10 of the present embodiment, a first circumferential main groove 14 is formed on the outer side of the tire equatorial plane CL when the vehicle is mounted (the arrow direction OUT direction is the outer side when the vehicle is mounted). The second circumferential main groove 16 is formed on the inner side of the CL when the vehicle is mounted (the arrow IN direction is the inner side when the vehicle is mounted), and the third circumferential direction is formed on the inner side of the second circumferential main groove 16 when the vehicle is mounted. A main groove 18 is formed, and the first land portion 20, the first circumferential main groove 14, and the second circumferential main groove 16 are disposed outside the first circumferential main groove 14 when the vehicle is mounted. Between the second land portion 22 and the second circumferential main groove 16 and the third circumferential main groove 18, the third land portion 24 and the third circumferential main groove 18 are mounted on the vehicle. On the inner side, the fourth land portions 26 are partitioned.

  The first land portion 20 includes a first lug groove 28 that traverses the first land portion, and a second lug groove 30 that extends from the ground contact end 12E side to the tire equatorial plane CL side and terminates in the land portion. Are alternately formed in the circumferential direction. Further, the first land portion 20 is formed with a first sipe 32 extending in the circumferential direction and a second sipe 34 that connects the second lug groove 30 and the first circumferential main groove 14. Yes.

  Here, the ground contact edge 12E means that the pneumatic tire 10 is mounted on a standard rim defined in JATMA YEAR BOOK (2007, Japan Automobile Tire Association Standard), and applied size and ply rating in JATMA YEAR BOOK. This is when the maximum load capacity is loaded with 100% internal pressure of the air pressure (maximum air pressure) corresponding to the maximum load capacity (bold load in the internal pressure-load capacity correspondence table). When the TRA standard or ETRTO standard is applied at the place of use or manufacturing, the respective standards are followed.

The second land portion 22 includes a first inclined groove portion 36A that extends from the first circumferential main groove 14 to the inner side when the vehicle is mounted inclining to the left with respect to the tire circumferential direction and terminates in the land portion, From the end portion in the land portion of the first inclined groove portion 36A to the outside when the vehicle is mounted, it is inclined downward to the right in the tire circumferential direction and terminates in the land portion, and the inclination angle with respect to the tire circumferential direction is the first inclined groove portion 36A. A plurality of V-shaped grooves 36 each having a second inclined groove portion 36B set smaller than that are formed at intervals in the tire circumferential direction.
Here, it is preferable to set the inclination angle of the opening end portion of the first inclined groove portion 36A with respect to the tire circumferential direction to 20 to 80 °.

In the second land portion 22, a short third lug groove 40 is formed on an extension line of the first lug groove 28 formed in the first land portion 20.
Further, the second land portion 22 includes a third sipe 42 that connects the intermediate portion of the first inclined groove portion 36A and the first circumferential main groove 14, and an intermediate portion between one end of the second inclined groove portion 36B. A fourth sipe 44 that connects the portion and the second circumferential main groove 16 is formed. The sipe means a groove width such that the groove width becomes zero when the land portion is grounded, or a notched shape having no groove width, and the groove walls facing each other when the land portion is grounded. Since the two members are in close contact with each other, the land portion rigidity is hardly reduced with respect to a groove that does not close when grounded.
As described above, the second land portion 22 is not divided in the circumferential direction by the V-shaped groove 36 but is a rib continuous in the circumferential direction.

  The third land portion 24 is formed with a fifth sipe 46 having one end connected to the third circumferential main groove 18 and the other end terminating in the land portion. A round hole 47 is formed in the end portion. That is, the third land portion 24 is not divided in the circumferential direction by a groove that does not close when grounded, and is a rib that is continuous in the circumferential direction.

  In the fourth land portion 26, two rows of dent rows 50 in which a plurality of dents 48 are arranged along the tire circumferential direction are arranged on the ground contact end 12E side. Note that the two hollow rows 50 are disposed closer to the ground contact end 12 </ b> E than the center in the width direction of the fourth land portion 26.

The shape of the recess 48 when the tread 12 is viewed in plan is not particularly limited, but it is preferable that the opening portion of the tread surface has a straight portion extending along the tire circumferential direction on the tire equatorial plane CL side. As shown in FIG. 1, the recess 48 of the present embodiment has a trapezoidal shape in which the side on the ground contact end side is shorter than the side on the tire equatorial plane CL side.
In the fourth land portion 26, a plurality of L-shaped grooves 52 are arranged on the tire equatorial plane CL side of the recess 48 at intervals in the tire circumferential direction.

The L-shaped groove 52 extends from the third circumferential main groove 18 toward the inner side in the vehicle width direction and terminates in the land portion, and from the end portion in the land portion of the lug groove portion 52A along the tire circumferential direction. It extends in the direction of arrow B and is composed of a circumferential groove 52B that terminates in the land.
The fourth land portion 26 is not divided in the circumferential direction by a groove that does not close when grounded, and is a rib that is continuous in the circumferential direction.

In the present embodiment, the angle formed by the lug groove 52A and the circumferential groove 52B is smaller than 90 °, but may be 90 ° or larger than 90 °.
In the pneumatic tire 10 of the present embodiment, as shown in FIG. 1, the tread 12 has an asymmetric pattern, but there is no designation of the rotation direction.
Further, in the pneumatic tire 10 of the present embodiment, the pitch length of the V-shaped groove 36 is set longer than the pitch length of the L-shaped groove 52.

(Function)
In the pneumatic tire 10 of the present embodiment, a total of three circumferential main grooves including a first circumferential main groove 14, a second circumferential main groove 16, and a third circumferential main groove 18 are provided on the tread 12. Because it is provided, basic drainage performance is secured.

  By providing three main grooves in the tread 12 in the circumferential direction, the tread 12 can be clearly divided in the width direction into a central area 12C on the center side in the tread width direction and both side areas 12S on the outer side in the tread width direction of the central area 12C. The two side sections 12S, which are severe to uneven wear, are advantageously set for uneven wear, and the central section 12C is set to be advantageous for dry, wet, and drainage performance, and the function can be clearly separated.

  Since the second inclined groove portion 36B constituting the V-shaped groove 36 is terminated in the second land portion 22 and the second land portion 22 is a rib, the land of the second land portion 22 is The section rigidity is ensured, and the steering stability on the dry road surface and the wet road surface can be secured. Further, since the third land portion 24 is also a rib, the rigidity of the land portion of the third land portion 24 is ensured, and the steering stability on the dry road surface and the wet road surface can be ensured. That is, since the tread 12 is provided with two rows of ribs of the second land portion 22 and the third land portion 24 in the central area 12C, which greatly contributes to the steering stability performance, the tread 12 is dry. Therefore, high steering stability performance is ensured on the wet road surface.

  In the pneumatic tire 10 of the present embodiment, since the tread 12 has an asymmetric pattern, the function can be separated so that wear is emphasized on the inner side in the vehicle width direction when the vehicle is mounted, and drainage is emphasized on the outer side in the vehicle width direction. It has become.

  Here, the tread 12 is provided with a V-shaped groove 36 on the inner side in the vehicle width direction of the outermost first circumferential main groove 14 in the vehicle width direction when the vehicle is mounted. The first inclined groove portion 36A extending from the water can efficiently drain the water of the second land portion 22 to the outer first circumferential main groove 14 during wet traveling. That is, the water in the central area 12C of the tread 12 can be efficiently drained to the outer first circumferential main groove 14, and the wet hydroplaning performance is improved.

  In the present embodiment, the inclination angle of the inclined groove portion of the V-shaped groove 36 is not constant in the groove, and is inclined at a relatively large angle with respect to the tire circumferential direction in the vicinity of the opening end, In the vicinity of the joint portion between the first inclined groove portion 36A and the second inclined groove portion 36B), it is gradually reduced, which is more advantageous for drainage and maneuverability. Further, after bending, the angle with respect to the tire circumferential direction is smaller than that before the bending, that is, the angle of the second inclined groove portion 36B with respect to the tire circumferential direction is set smaller than that of the first inclined groove portion 36A. The second land portion 22 in which the letter-shaped groove 36 is formed is divided in the circumferential direction, the lateral rigidity is optimized while ensuring the land portion rigidity in the front-rear direction, and the controllability with good balance on the dry road surface and the wet road surface Has been realized.

  Since the V-shaped groove 36 is bent without penetrating the second circumferential main groove 16 on the tire equatorial plane CL side, the V-shaped groove 36 flows into the V-shaped groove 36 from the second circumferential main groove 16. The turbulent flow in the V-shaped groove generated by the above can be prevented, and the drainage efficiency can be further increased.

Further, the V-shaped groove 36 connected to the first circumferential main groove 14 is bent in the middle to branch a groove having a long total length from the first circumferential main groove 14, and the second inclined groove portion 36 </ b> B. Is terminated in the second land portion 22, such a long branch groove having a total length is a noise around the high frequency (for example, 1 kHz) generated in the first circumferential main groove 14. (Resonance sound) can be effectively muted.
That is, the V-shaped groove 36 greatly contributes to both drainage and tire noise.

  Further, since the L-shaped groove 52 is arranged on the inner side in the vehicle width direction from the third circumferential main groove 18 arranged on the innermost side in the vehicle width direction when the vehicle is mounted, the tread 12 has a third circumference. High-frequency noise generated in the direction main groove 18 is suppressed by the L-shaped groove 52, and further, the innermost fourth land portion 26 is set in a rib shape to cope with noise and uneven wear. Nevertheless, drainage inside the vehicle width direction can be secured.

  In addition, since the L-shaped groove 52 is terminated in a state close to the circumferential direction after being bent, the land portion rigidity of the fourth land portion 26 can be secured, and the steering stability on the dry road surface and the wet road surface can be ensured. It can be secured. Further, since the L-shaped groove 52 is not connected to any groove other than the third circumferential main groove 18, it is advantageous for reducing high-frequency noise during traveling.

  Further, the V-shaped groove 36 on the outer side in the vehicle width direction when the vehicle is mounted is set to have a longer pitch length in the circumferential direction than the L-shaped groove 52, so that the V-shaped groove 36 can further improve drainage. Since the L-shaped groove 52 is located on the inner side in the vehicle width direction when the vehicle is mounted than the V-shaped groove 36, the pitch length in the circumferential direction is made shorter than the V-shaped groove 36. Further, stepped wear which is a kind of uneven wear can be suppressed. Furthermore, since the groove length of the V-shaped groove 36 and the groove length of the L-shaped groove 52 are greatly changed, the frequency characteristics of the high-frequency noise generated during running are changed for each groove, so that it is more effective in reducing tire noise. It is a typical composition.

  Thus, by arranging the V-shaped groove 36 on the outer side when the vehicle is mounted and the L-shaped groove 52 on the inner side when the vehicle is mounted, both excellent drainage and noise characteristics can be achieved.

  If the angle of inclination of the opening end portion of the first inclined groove portion 36A of the V-shaped groove 36 is less than 20 °, the rigidity of the land portion near the opening end portion is insufficient, and the maneuverability and uneven wear properties are adversely affected. . On the other hand, when this inclination angle exceeds 70 °, the merit for drainage becomes thin.

[Other Embodiments]
The innermost fourth land portion 26 when mounted on the vehicle is a severe land portion against uneven wear, but the angle formed by the lug groove portion 52A of the L-shaped groove 52 and the circumferential groove portion 52B is set to 90 °. By doing so, the rigidity of the fourth land portion 26 can be secured, and the uneven wear resistance performance of the fourth land portion 26 can be improved.

(Test example)
In order to confirm the effect of the present invention, a pneumatic tire of a conventional example and a pneumatic tire of an example to which the present invention was applied were prepared and subjected to uneven wear resistance tests.

  Example: A pneumatic tire having the tread pattern of the above-described embodiment. The groove depth is 8.3 mm. The groove width of the first circumferential main groove is 8.5 mm, the groove width of the second circumferential main groove is 9.0 mm, and the groove width of the third circumferential main groove is 7.5 mm. The width of the first land portion is 30 mm, the width of the second land portion is 35 mm, the width of the third land portion is 13.2 mm, and the width of the fourth land portion is 32 mm. On the other hand, the inclination angle of the V-shaped groove is 45 ° on the first circumferential main groove side and 30 ° near the bent portion. The circumferential pitch length of the V-shaped groove is 58 mm, and the circumferential pitch length of the L-shaped groove is 28 mm.

Conventional example: A pneumatic tire having the tread pattern shown in FIG. In the tread 100 shown in FIG. 2, reference numerals 102, 104, 106, and 108 are circumferential main grooves, reference numerals 110, 112, 114, 116, and 118 are land portions, reference numerals 120, 122, and 123 are lug grooves, and reference numeral 124. , 126, 127 are sipes, 128 is a bent groove having a substantially L-shape comprising a lug groove portion 128A and a circumferential main groove portion 128B, 130, 132 are depressions in which the tread plan view shape is a triangular shape, Reference numeral 134 denotes a sipe extending from the recess 130 toward the tread end, and reference numeral 100E denotes a ground contact end. The groove depths of the lug groove portion 128A and the circumferential main groove portion 128B are 7.5 mm, the lug groove portion 128A is 3 mm wide and 12 mm long, and the circumferential main groove portion 128B is 4 mm wide and 12 mm long. is there.
The tire size is 195 / 65R15 for both the example and the conventional example.

・ Hydroplaning performance test: Feeling evaluation by a test driver at the critical speed of hydroplaning when passing through a wet road surface with a depth of 5mm. The evaluation is expressed as an index with the conventional example being 100, and the larger the value, the better the performance.

・ Dry road maneuvering stability test: Feeling evaluation of test driver when driving on dry circuit course in various driving modes. The evaluation is expressed as an index with the conventional example being 100, and the larger the value, the better the performance.

-Wet road maneuvering stability performance test: Feeling evaluation of test driver when driving on wet circuit course in various driving modes. The evaluation is expressed as an index with the conventional example being 100, and the larger the value, the better the performance.

・ Tire (pattern) noise test: Test driver's feeling evaluation when driving in various driving modes on a dry general road. The evaluation is expressed as an index with the conventional example being 100, and the larger the value, the better the performance.

・ Ride comfort test: Feeling evaluation of a test driver when driving on a dry general road in various driving modes. The evaluation is expressed as an index with the conventional example being 100, and the larger the value, the better the performance.

-Uneven wear resistance performance test: Amount of step wear between adjacent blocks after traveling 5000 km when traveling on a general road in a dry state in various traveling modes. The index is displayed with the reciprocal of the level difference of the conventional example as 100, and the larger the value, the better the uneven wear resistance.

試験の結果、本発明の適用された実施例の空気入りタイヤは、従来例の空気入りタイヤに対し、全ての性能が向上していることが分かった。

As a result of the test, it was found that the performance of the pneumatic tire of the example to which the present invention was applied was improved with respect to the conventional pneumatic tire.

It is a top view of the tread of the pneumatic tire concerning one embodiment of the present invention. It is a top view of the tread of the pneumatic tire concerning a conventional example.

Explanation of symbols

10 Pneumatic tire 12 Tread 14 First circumferential main groove (outermost circumferential main groove in the vehicle width direction)
16 Second circumferential main groove 18 Third circumferential main groove (the innermost circumferential main groove in the vehicle width direction)
20 1st land part 22 2nd land part 24 3rd land part 26 4th land part 36 V-shaped groove 36A 1st inclined groove part 36B 2nd inclined groove part 52 L-shaped groove 52A Lug groove part 52B Circumferential groove (auxiliary groove)

Claims (6)

A pneumatic tire having at least three circumferential main grooves in a tread and having a tread pattern that is asymmetrical to the left and right,
A first inclined groove portion extending from a vehicle width direction outermost circumferential main groove disposed on the outermost side in the vehicle width direction at the time of vehicle mounting to the vehicle width direction inner side and one side in the tire rotation direction and terminating in the land portion; And a V-shaped groove composed of a second inclined groove portion extending from the end portion in the land portion of the first inclined groove portion toward the other side in the tire rotation direction,
From a vehicle width direction innermost circumferential main groove disposed on the innermost side in the vehicle width direction when the vehicle is mounted, extending from the vehicle width direction inner side to terminate in the land portion, and a land portion of the lug groove portion in the land portion An L-shaped groove composed of an auxiliary groove extending in a direction intersecting with the lug groove;
A pneumatic tire having a tread.   The pneumatic tire according to claim 1, wherein the second inclined groove portion terminates in a land portion. An inclination angle of the first inclined groove portion with respect to the tire circumferential direction is set within a range of 20 to 70 ° at an opening end portion of the outermost circumferential main groove,
The pneumatic tire according to claim 2, wherein an inclination angle of the second inclined groove portion with respect to a tire circumferential direction is set to be smaller than that of the first inclined portion.   The pneumatic tire according to any one of claims 1 to 3, wherein the auxiliary groove portion extends along a tire circumferential direction and terminates in a land portion.   The pneumatic tire according to any one of claims 1 to 4, wherein a pitch length of the V-shaped groove is set longer than a pitch length of the L-shaped groove.   The pneumatic tire according to any one of claims 1 to 5, wherein an angle formed by the lug groove portion and the auxiliary groove portion is set to 90 °.

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