JP5282479B2 - Pneumatic tire - Google Patents

Description

  The present invention relates to a pneumatic tire. More specifically, the present invention relates to a pneumatic tire that improves driving stability on a dry road surface and improves uneven wear while ensuring good performance on snow.

  Conventionally, as a pneumatic tire for all seasons, a pneumatic tire is known in which a block is formed by a circumferential groove and a lateral groove in a center region of a tread surface (see, for example, Patent Document 1). A pneumatic tire provided with such a block can exhibit high performance on snow, but on the other hand, the steering stability during running on a dry road surface is lowered, and further, uneven wear is likely to occur on the block.

  On the other hand, as a tread pattern that increases the tread rigidity of the center region and improves the handling stability when driving on dry roads, the lateral groove arranged in the center region of the tread surface of the pneumatic tire with the specified tire mounting direction is It is known that the tire mounting outer end is arranged so as not to communicate with the circumferential main groove, and ribs are formed in the center region (see, for example, Patent Document 2). There is an advantage that every other lateral groove extends so as not to exceed the tire equatorial plane, whereby the tread rigidity in the center region is greatly increased, and the steering stability on the dry road surface can be greatly improved. Also, uneven wear can be improved.

However, if the lateral grooves are arranged in this way, the performance on snow must be lowered, and the steering stability on the dry road surface cannot be improved and uneven wear cannot be improved while ensuring good performance on snow.
JP 2000-280712 A JP 2000-238510 A

  An object of the present invention is to provide a pneumatic tire capable of improving steering stability on a dry road surface and improving uneven wear while ensuring good performance on snow.

In the pneumatic tire of the present invention that achieves the above object, the tire mounting direction is specified, and four circumferential main grooves extending in the tire circumferential direction are provided on the tread surface, and the four circumferential main grooves are used as tires. Comprising two first circumferential main grooves disposed on both sides of the equatorial plane, and two second circumferential main grooves disposed on both outer sides in the tire width direction of the two first circumferential main grooves, A pneumatic tire in which five land rows are formed on the tread surface by the four circumferential main grooves,
The two first circumferential directions have a first lateral groove extending in an arc shape from the inner first circumferential main groove disposed in the inner region located on the tire mounting inner side from the tire equator surface of the tread surface toward the tire mounting outer side. While being arranged at a predetermined interval in the tire circumferential direction in the center land portion between the main grooves, each first lateral groove extends beyond the tire equator surface to the outer region located outside the tire mounting from the tire equator surface of the tread surface. And a first sipe or first lateral groove provided so as to be separated from the outer first circumferential main groove disposed in the outer region, and extending in the tire circumferential direction between the front end portions of the first lateral grooves adjacent to each other in the tire circumferential direction. more width in addition to Rukoto provided a narrow first narrow groove,
A tire ground contact edge toward the outer side in the tire width direction from the position spaced apart from the outer second circumferential main groove to the outer shoulder land portion on the outer side in the tire width direction from the outer second circumferential main groove disposed in the outer region of the tread surface Second lateral grooves extending beyond the tire are arranged at predetermined intervals in the tire circumferential direction, and extend beyond the tire ground contact edge from the outer second circumferential main groove toward the outer side in the tire width direction. Second sipe or second narrow groove narrower than the second lateral groove communicated with the tire is disposed at a predetermined interval in the tire circumferential direction, and the second lateral groove and the second sipe or second narrow groove are alternately arranged in the tire circumferential direction. The distance D1 from the second sipe or second narrow groove to the second lateral groove adjacent to one side in the tire circumferential direction and the second sipe or second narrow groove to the second lateral groove adjacent to the other side in the tire circumferential direction The ratio D1 / D2 to the distance D2 is 0.8 to 1.2 And, and / or,
The tire ground contact edge from the position spaced from the inner second circumferential main groove toward the outer side in the tire width direction on the inner shoulder land portion outside the inner second circumferential main groove arranged in the inner region of the tread surface. The third lateral grooves extending beyond the tire circumferential direction are arranged at predetermined intervals in the tire circumferential direction, and the third lateral grooves adjacent to each other in the tire circumferential direction are spaced from the inner second circumferential main groove toward the outer side in the tire width direction. Two third sipes extending in parallel to the three lateral grooves and extending beyond the tire ground contact edge or a third narrow groove having a narrower width than the third lateral groove are arranged, and one third sipes adjacent to the third lateral groove or A ratio D3 / D4 of the distance D3 to the third narrow groove and the distance D4 between two adjacent third sipes or third narrow grooves is set to 0.8 to 1.2 .

  According to the above-described present invention, by arranging the first lateral groove so as not to communicate with the outer first circumferential main groove, the center land portion has a structure having ribs, so that the tread rigidity of the center region is increased, Steering stability on dry road can be improved. Moreover, the uneven wear resistance of the center land portion can also be improved.

  On the other hand, each first lateral groove extends in a circular arc shape beyond the tire equatorial plane, while the first sipes or first narrows extending in the tire circumferential direction between the front ends of the first lateral grooves adjacent in the tire circumferential direction. By providing the groove, an edge component effective for the on-snow performance can be ensured for a long time, so that the on-snow performance can be exhibited.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 shows an embodiment of the pneumatic tire of the present invention. The pneumatic tire has a designated tire mounting direction when mounted on the vehicle, and is mounted with the right side of the tire equatorial plane 100 being the vehicle outer side.

  The tread surface 1 of the pneumatic tire is provided with four circumferential main grooves 2 extending linearly in the tire circumferential direction 101 at predetermined intervals in the tire width direction. The four circumferential main grooves 2 include two first circumferential main grooves 2A and 2B arranged symmetrically with respect to the tire equatorial plane 100 on both sides of the tire equatorial plane 100, and two first circumferential main grooves. It is composed of two second circumferential main grooves 2C and 2D that are arranged symmetrically with respect to the tire equatorial plane 100 on both outer sides in the tire width direction of the grooves 2A and 2B.

  The two first circumferential main grooves 2A, 2B are the inner first circumferential main groove 2A disposed in the inner region 1X located on the tire mounting inner side than the tire equator surface 100 of the tread surface 1, and the tire of the tread surface 1. The outer first circumferential main groove 2B is arranged in the outer region 1Y located on the outer side of the tire from the equatorial plane 100, and the two second circumferential main grooves 2C, 2D are arranged in the inner region 1X. It is composed of a two circumferential main groove 2C and an outer second circumferential main groove 2D arranged in the outer region 1Y. The circumferential main groove 2 referred to here is a circumferential groove having a width of 10 mm to 50 mm and a depth of 5 mm to 20 mm. These four circumferential main grooves 2 form five land rows on the tread surface 1.

  The five land portion rows include a center land portion 3 between the first circumferential main grooves 2A and 2B, an outer shoulder land portion 4 on the outer side in the tire width direction from the outer second circumferential direction main groove 2D, and an inner second circumferential direction. The inner shoulder land portion 5 outside the main groove 2C in the tire width direction, the outer intermediate land portion 6 between the outer first circumferential main groove 2B and the outer second circumferential main groove 2D, and the inner first circumferential main portion. The inner intermediate land portion 7 is formed between the groove 2A and the inner second circumferential main groove 2C.

  In the center land portion 3, first lateral grooves 8 extending in an arc shape from the inner first circumferential main groove 2 </ b> A toward the tire mounting outer side are arranged in the tire circumferential direction 101 at predetermined intervals. Each first lateral groove 8 extends to the outer region 1Y beyond the tire equator plane 100 while inclining toward one side (the upper side in FIG. 1) in the tire circumferential direction 101. Each of the first lateral grooves 8 is not connected to the outer first circumferential main groove 2B but is separated from the outer first circumferential main groove BD by a predetermined distance so that the center land portion 3 is a rib that continues in the tire circumferential direction 101. Is formed.

  The width of the first lateral groove 8 is gradually narrowed toward the tip. The first lateral groove 8 has an inner groove portion 8A in the inner region 1X and an outer groove portion 8B in the outer region 1Y. As shown in FIG. 2, a bottom raised portion 9 is provided at the groove bottom of the outer groove portion 8B. The depth of the outer groove 8B is made shallower than the depth of the inner groove 8A. Thus, the tread rigidity in the outer region 1Y of the center land portion 3 is increased.

  One first sipe 10 extending in an arc shape in the tire circumferential direction 101 is provided between the front end portions 8x of the first lateral grooves 8 adjacent to each other in the tire circumferential direction 101. Both ends of the first sipe 10 communicate with the distal end portion 8 x of the first lateral groove 8. The first lateral groove 8 and the first sipe 10 extending from the tip 8x thereof are continuously formed by arcs having the same radius of curvature. The first sipe 10 preferably communicates with the distal end portion 8x of the first lateral groove 8 as described above, but may be slightly separated. In addition, the sipe referred to in the present invention is a cut having a width of 0.3 mm to 2 mm.

  The outer shoulder land portion 4 has a second lateral groove 11 extending beyond one tire ground contact end 102 from the position spaced from the outer second circumferential main groove 2D toward the outer side in the tire width direction. Are arranged at predetermined intervals. Thus, the outer side shoulder land part 4 is formed in the rib which continues in the tire circumferential direction 101 by making the 2nd horizontal groove 11 not connect with the outer side 2nd circumferential direction main groove 2D. As a result, the uneven wear resistance and noise performance of the outer shoulder land portion 4 are enhanced.

  The outer shoulder land portion 4 further includes second sipes 12 extending beyond the tire ground contact edge 102 from the outer second circumferential main groove 2D toward the outer side in the tire width direction at predetermined intervals in the tire circumferential direction 101. Has been. The second lateral grooves 11 and the second sipes 12 are alternately arranged in the tire circumferential direction 101, and the second sipes 12 communicate with the second lateral grooves 11 on the outer side in the tire width direction from the tire ground contact end 102. By providing the second sipe 12 in this way, on-snow tracking performance and wet performance are improved.

  The inner shoulder land portion 5 has a third lateral groove 13 extending beyond the other tire ground contact end 103 from the position away from the inner second circumferential main groove 2C toward the outer side in the tire width direction. Are arranged at predetermined intervals. Thus, the inner side shoulder land portion 5 is formed in a rib continuous in the tire circumferential direction 101 by not allowing the third lateral groove 13 to communicate with the inner second circumferential main groove 2C. Thereby, the uneven wear resistance and noise performance of the inner shoulder land portion 5 are enhanced.

Between the third lateral grooves 13 adjacent to each other in the tire circumferential direction 101, 2 extends beyond the tire ground contact end 103 in parallel with the third lateral groove 13 from the inner second circumferential main groove 2 </ b> C toward the outer side in the tire width direction. The third sipe 14 of the book is arranged at a predetermined interval in the tire circumferential direction 101. By providing the third sipe 14 in this manner, the on-snow tracking performance and the wet performance are improved .

  In the outer intermediate land portion 6 and the inner intermediate land portion 7, fourth lateral grooves 15 extending in the tire width direction are arranged at predetermined intervals in the tire circumferential direction 101. The fourth lateral groove 15A of the outer intermediate land portion 6 extends from the outer second circumferential main groove 2D to the outer first circumferential main groove 2B toward the inner side in the tire width direction, and the outer intermediate land portion 6 extends to the block 6A. Is formed. The fourth lateral groove 15A is configured so that the groove width at the end communicating with the outer first circumferential main groove 2B is significantly narrower than other parts, thereby increasing the rigidity of the block 6A.

  The fourth lateral groove 15B of the inner intermediate land portion 7 extends from the inner second circumferential main groove 2C toward the inner first circumferential main groove 2A toward the inner side in the tire width direction, and the inner intermediate land portion 7 is formed into a block 7A. Forming. The fourth lateral groove 15B extends in an arc shape having substantially the same width and the same radius of curvature as the first lateral groove 8, and is connected to the first lateral groove 8 via the inner first circumferential main groove 2A.

  The center land portion 3 is further provided with a plurality (two in FIG. 1) of sipe 16 between the first lateral grooves 8 adjacent to each other in the tire circumferential direction 101 and having both ends communicating with the first lateral grooves 8. The sipe 16 makes the first lateral groove 8 easy to move and makes it easy to discharge snow that has entered the groove. Further, the edge effect by the sipe 16 is exhibited.

  Each block 6A is provided with one sipe 17 extending in the tire width direction in parallel with the fourth lateral groove 15A and having both ends communicating with the circumferential main grooves 2B and 2D. Also in each block 7A, one sipe 18 extends so as to cross the block 7A obliquely. The lateral grooves 8, 11, 13, 15 provided in each land portion are arranged in the tire circumferential direction 101 at the same interval.

  According to the present invention described above, by forming the center land portion 3 on the rib as described above, it is possible to increase the tread rigidity of the center region, and thus it is possible to improve the handling stability when traveling on a dry road surface. Further, by making the center land portion 3 a rib that is less likely to generate uneven wear than the block, it is possible to improve uneven wear.

  In addition, each first lateral groove 8 extends in an arc shape beyond the tire equatorial plane 100, while the first lateral groove 8 extends in the tire circumferential direction 101 between the front end portions 8 x of each first lateral groove 8 adjacent to the tire circumferential direction 101. By providing one sipe 8, an edge component effective for on-snow performance can be ensured for a long time, so that excellent on-snow performance can be obtained.

  In the present invention, the width W of the center land portion 3 is preferably in the range of 20% to 40% of the tire ground contact width TW. If the width W of the center land portion 3 is smaller than 20% of the tire ground contact width TW, the width becomes too narrow, and it becomes difficult to effectively increase the tread rigidity in the center region. If the width W of the center land portion 3 is larger than 40% of the tire ground contact width TW, the first circumferential main grooves 2A and 2B that greatly affect drainage in the center region are located on the outer side in the tire width direction. Getting worse.

  The distance L in the tire width direction between the front end 8x of the first lateral groove 8 and the outer first circumferential main groove 2B is preferably in the range of 15% to 35% of the width W of the center land portion 3. . When the distance L is less than 15% of the width W of the center land portion 3, the rib rigidity is lowered, and it is difficult to effectively increase the tread rigidity in the center region. When the distance L is more than 35% of the width W of the center land portion 3, the first lateral groove 8 is shortened, so that the performance on snow is deteriorated. In addition, the wet performance is reduced.

  Ratio D1 / D2 between the distance D1 from the second sipe 12 to the second lateral groove 11 adjacent to the one side in the tire circumferential direction and the distance D2 from the second sipe 12 to the second lateral groove 11 adjacent to the other side in the tire circumferential direction For example, the range of 0.8 to 1.2 is preferable from the viewpoint of uneven wear resistance of the rib portion between the second lateral grooves 11. Here, the distance D1 and the distance D2 are distances measured from the tire ground contact end 102 on the inner side in the tire width direction.

  For the two third sipes 14, the distance D 3 from the third lateral groove to one third sipes 14 adjacent to the third circumferential groove 101 and the two third sipes 14 adjacent to the tire circumferential direction 101. The ratio D3 / D4 with the distance D4 is preferably in the range of 0.8 to 1.2 from the viewpoint of uneven wear resistance of the rib portion between the third lateral grooves 13.

  In the above-described embodiment, the first sipe 10 extending in the tire circumferential direction 101 is provided between the front end portions 8x of the first lateral grooves 8 adjacent to each other in the tire circumferential direction 101. A first narrow groove having a width smaller than 8 may be provided. Further, a second narrow groove having a width smaller than that of the second lateral groove 11 may be provided in place of the second sipe 12, and a third narrow groove having a width smaller than that of the third lateral groove 13 is disposed in place of the third sipe 14. You may make it do. The width of each narrow groove can be in the range of 2 mm to 5 mm.

  The outer intermediate land portion 6 and the inner intermediate land portion 7 are both formed in the blocks 6A and 7A in the above embodiment, but at least one intermediate land portion may be formed in the block from the viewpoint of wet performance.

  The present invention can be preferably used for all-season pneumatic tires for passenger cars used throughout the year. The tire ground contact ends 102 and 103 referred to in the present invention attach a tire to a standard rim prescribed by JATMA (Japan Automobile Tire Association), apply air pressure corresponding to the maximum load capacity prescribed by JATMA, and It is the grounding end of the tread surface 1 measured under a condition where a load corresponding to 74% of the load capacity is applied. In the case of tires not prescribed by JATMA but prescribed by TRA (American Tire and Rim Association) or ETRTO (European Tire and Rim Association), measurements shall be made in accordance with them.

  FIG. 1 shows the tire size common to 215 / 60R16, and the distance L in the tire width direction between the width W of the center land portion, the tip portion of the first lateral groove, and the outer first circumferential main groove is as shown in Table 1. The present invention tires 1 to 6 (Examples 1 to 6) having the configuration shown in FIG. 3 and the same configuration as the tire 2 of the present invention except that the center land portion has the configuration of FIG. A reference tire (reference example) having the same configuration as the tire 2 of the present invention was prepared as a test tire, except that a comparative tire (comparative example) having a center land portion was formed in a block as shown in FIG. In each test tire, the ratio D1 / D2 and the ratio D3 / D4 are each 1.0.

Each of these test tires is mounted on a rim having a rim size of 16 × 6.5J, mounted on a test vehicle with a displacement of 2500 cc with an air pressure of 200 kPa, and performance on snow, handling stability and uneven wear resistance are as follows. As a result of the evaluation test, the results shown in Table 1 were obtained.
Performance on snow A test vehicle was run on the snow road test course, and a sensory test of performance on snow was conducted by a test driver. The evaluation result is indicated by an index value where the reference tire is 100. The larger this value, the better the performance on snow. The range of the index value 100 ± 2 is the same level as the reference tire.
Steering stability A test vehicle was run on a dry road test course, and a sensory test of steering stability was conducted by a test driver. The evaluation result is indicated by an index value where the reference tire is 100. The larger this value, the better the steering stability on the dry road surface.
Uneven wear resistance After running the test vehicle for 8000 km on the test course, the amount of uneven wear generated in the center land portion was measured. The evaluation result is indicated by an index value where the reference tire is 100. The larger this value, the better the uneven wear resistance.

表１から、本発明タイヤは、雪上性能が基準タイヤと同じレベルにあり、良好な雪上性能を確保しながら、ドライ路面での操縦安定性を高め、かつ耐偏摩耗性を改善できることがわかる。

It can be seen from Table 1 that the tire of the present invention has the same level of snow performance as that of the reference tire, and can improve the steering stability on the dry road surface and improve the uneven wear resistance while ensuring good snow performance.

1 is a partial development view of a tread surface showing an embodiment of a pneumatic tire of the present invention. It is a partial expanded sectional view of the 1st transverse groove. It is a partial front view which shows the tread pattern of the center land part of a comparative tire. It is a partial front view which shows the tread pattern of the center land part of a reference | standard tire.

Explanation of symbols

1 tread surface 1X inner region 1Y outer region 2 circumferential main groove 2A inner first circumferential main groove 2B outer first circumferential main groove 2C inner second circumferential main groove 2D outer second circumferential main groove 3 center land portion 4 outer shoulder land portion 5 inner shoulder land portion 6 outer intermediate land portion 6A block 7 inner intermediate land portion 7A block 8 first lateral groove 8A inner groove portion 8B outer groove portion 8x tip portion 10 first sipe 11 second lateral groove 12 second sipe 13 3rd lateral groove 14 3rd sipe 15 4th lateral groove 16 sipe 100 Tire equatorial plane 101 Tire circumferential direction 102,103 Tire ground contact edge L distance TW Tire ground contact width W width

Claims (11)

The tire mounting direction is designated, and four first circumferential grooves extending in the tire circumferential direction are provided on the tread surface, and the four first circumferential grooves are arranged on both sides of the tire equatorial plane. Directional main grooves and two second circumferential main grooves disposed on both outer sides in the tire width direction of the two first circumferential main grooves, and five land portions are formed by the four circumferential main grooves. A pneumatic tire having rows formed on the tread surface,
The two first circumferential directions have a first lateral groove extending in an arc shape from the inner first circumferential main groove disposed in the inner region located on the tire mounting inner side from the tire equator surface of the tread surface toward the tire mounting outer side. While being arranged at a predetermined interval in the tire circumferential direction in the center land portion between the main grooves, each first lateral groove extends beyond the tire equator surface to the outer region located outside the tire mounting from the tire equator surface of the tread surface. And a first sipe or first lateral groove provided so as to be separated from the outer first circumferential main groove disposed in the outer region, and extending in the tire circumferential direction between the front end portions of the first lateral grooves adjacent to each other in the tire circumferential direction. Providing a narrower first narrow groove ;
A tire ground contact edge toward the outer side in the tire width direction from the position spaced apart from the outer second circumferential main groove to the outer shoulder land portion on the outer side in the tire width direction from the outer second circumferential main groove disposed in the outer region of the tread surface Second lateral grooves extending beyond the tire are arranged at predetermined intervals in the tire circumferential direction, and extend beyond the tire ground contact edge from the outer second circumferential main groove toward the outer side in the tire width direction. Second sipe or second narrow groove narrower than the second lateral groove communicated with the tire is disposed at a predetermined interval in the tire circumferential direction, and the second lateral groove and the second sipe or second narrow groove are alternately arranged in the tire circumferential direction. The distance D1 from the second sipe or second narrow groove to the second lateral groove adjacent to one side in the tire circumferential direction and the second sipe or second narrow groove to the second lateral groove adjacent to the other side in the tire circumferential direction The ratio D1 / D2 to the distance D2 is 0.8 to 1.2 Pneumatic tire. The tire mounting direction is designated, and four first circumferential grooves extending in the tire circumferential direction are provided on the tread surface, and the four first circumferential grooves are arranged on both sides of the tire equatorial plane. Directional main grooves and two second circumferential main grooves disposed on both outer sides in the tire width direction of the two first circumferential main grooves, and five land portions are formed by the four circumferential main grooves. A pneumatic tire having rows formed on the tread surface,
  The two first circumferential directions have a first lateral groove extending in an arc shape from the inner first circumferential main groove disposed in the inner region located on the tire mounting inner side from the tire equator surface of the tread surface toward the tire mounting outer side. While being arranged at a predetermined interval in the tire circumferential direction in the center land portion between the main grooves, each first lateral groove extends beyond the tire equator surface to the outer region located outside the tire mounting from the tire equator surface of the tread surface. And a first sipe or first lateral groove provided so as to be separated from the outer first circumferential main groove disposed in the outer region, and extending in the tire circumferential direction between the front end portions of the first lateral grooves adjacent to each other in the tire circumferential direction. Providing a narrower first narrow groove;
The tire ground contact edge from the position spaced from the inner second circumferential main groove toward the outer side in the tire width direction on the inner shoulder land portion outside the inner second circumferential main groove arranged in the inner region of the tread surface. The third lateral grooves extending beyond the tire circumferential direction are arranged at predetermined intervals in the tire circumferential direction, and the third lateral grooves adjacent to each other in the tire circumferential direction are spaced from the inner second circumferential main groove toward the outer side in the tire width direction. Two third sipes extending in parallel to the three lateral grooves and extending beyond the tire ground contact edge or a third narrow groove having a narrower width than the third lateral groove are arranged, and one third sipes adjacent to the third lateral groove or A pneumatic tire in which a ratio D3 / D4 between a distance D3 to the third narrow groove and a distance D4 between two adjacent third sipes or third narrow grooves is 0.8 to 1.2. The tire ground contact edge from the position spaced from the inner second circumferential main groove toward the outer side in the tire width direction on the inner shoulder land portion outside the inner second circumferential main groove arranged in the inner region of the tread surface. The third lateral grooves extending beyond the tire circumferential direction are arranged at predetermined intervals in the tire circumferential direction, and the third lateral grooves adjacent to each other in the tire circumferential direction are spaced from the inner second circumferential main groove toward the outer side in the tire width direction. Two third sipes extending in parallel to the three lateral grooves and extending beyond the tire ground contact edge or a third narrow groove having a narrower width than the third lateral groove are arranged, and one third sipes adjacent to the third lateral groove or The pneumatic according to claim 1, wherein a ratio D3 / D4 between a distance D3 to the third narrow groove and a distance D4 between two adjacent third sipes or third narrow grooves is 0.8 to 1.2. tire. The pneumatic tire according to any one of claims 1 to 3, wherein a width of the center land portion is 20% to 40% of a tire ground contact width. The distance in the tire width direction between the front end portion of the first lateral groove and the outer first circumferential main groove is 15% to 35% of the width of the center land portion , according to any one of claims 1 to 4. The described pneumatic tire. The first lateral groove extends while inclining to one side in the tire circumferential direction, and a plurality of sipes having both ends communicating with the first lateral groove are provided between the first lateral grooves adjacent to each other in the tire circumferential direction . A pneumatic tire given in any 1 paragraph . The pneumatic tire according to any one of claims 1 to 6, wherein the width of the first lateral groove gradually decreases toward the tip. The pneumatic according to any one of claims 1 to 7 , wherein the first lateral groove has an inner groove portion in an inner region and an outer groove portion in an outer region, and a depth of the outer groove portion is shallower than a depth of the inner groove portion. tire. The pneumatic tire according to any one of claims 2 to 8, wherein the first lateral grooves and the third lateral grooves are arranged at the same interval in the tire circumferential direction. The inner intermediate land portion between the inner first and second circumferential main grooves and the outer intermediate land portion between the outer first and second circumferential main grooves extend in the tire width direction to at least one intermediate land portion. The pneumatic tire according to any one of claims 1 to 9 , wherein the fourth lateral grooves are arranged at predetermined intervals in the tire circumferential direction, and the at least one intermediate land portion is formed in a block. The first sipe extends between tip portions of first lateral grooves adjacent to each other in the tire circumferential direction, a center land portion is formed in a rib, and both ends of the first sipe communicate with the first lateral groove. The pneumatic tire according to any one of 10 .

Images