JP5797412B2 - Pneumatic tire - Google Patents

Description

  The present invention relates to a pneumatic tire, and more particularly, to a pneumatic tire suitably used for a heavy-duty vehicle.

  In recent years, as can be seen from the fact that wearing of M + S tires (Mud & Snow tires) has become mandatory in some European countries in winter, tires with high winter wet performance are required.

  Incidentally, some pneumatic tires used in heavy-duty vehicles such as trucks, buses, and trailers have the tread described in Patent Document 1. In this pneumatic tire, a plurality of main grooves and land portions are formed in the tread, and narrow grooves and sipes are formed in the land portions to ensure wet performance.

  However, even in the tread described in Patent Document 1, the wet performance is not sufficient and further improvement is required. On the other hand, when the edge component is increased in order to improve the wet performance, the progress of wear is accelerated and the life of the tire is shortened.

JP 2000-168317 A

  The present invention has been made in view of the above facts, and an object thereof is to provide a pneumatic tire having high wet performance while suppressing shortening of the tire life.

The pneumatic tire according to claim 1 of the present invention is formed in a tire tread and has a plurality of circumferential grooves extending along the tire circumferential direction, and a plurality of land portions that are partitioned by the circumferential grooves and extend in the tire circumferential direction. A width direction narrow groove that traverses in the tire width direction a first land portion row that is shallower than the row and the circumferential portion, and both ends of the land portion row in the tire width direction are partitioned by the circumferential groove; A groove bottom sipe formed on the groove bottom of the width direction narrow groove along the width direction narrow groove, and shallower than the circumferential groove, and one end in the tire width direction of the land portion row is adjacent to a tire shoulder A wide narrow groove extending in the tire width direction and having one end opened in the circumferential groove and the other end terminating in the shoulder land portion row, and one end formed in the shoulder land portion row. Is connected to the other end of the wide narrow groove, and the other end is Includes a narrow fine grooves narrower than the wide thin groove extending in de end, a, between the wide narrow grooves adjacent to each other in the tire circumferential direction, the tire width direction narrower than the wide thin groove And the width direction narrow groove adjacent to each other in the tire circumferential direction is formed by forming a narrow groove extending in the direction of the shoulder width direction groove formed in at least one of the sipes. The number of the shoulder width direction grooves formed between a pair of the wide narrow grooves adjacent to each other in the tire circumferential direction is wider than the interval between the first land portion rows adjacent to the shoulder land portion rows. to be formed, the have multi than the number of the width-direction narrow grooves located between the width-direction narrow grooves having an open end into the circumferential groove on the extension of each said wide narrow groove.

  In the pneumatic tire according to claim 1, wide narrow grooves and narrow narrow grooves are formed in the shoulder land portion. In the shoulder land portion, the wide narrow groove on the side close to the tire equatorial plane has one end opened to the circumferential groove, so that drainage can be secured and wet performance can be improved. Moreover, since the shoulder side on which uneven wear is likely to occur is a narrow narrow groove that is narrower than the wide narrow groove, a decrease in rigidity is suppressed, and uneven wear can be suppressed. Therefore, shortening of the tire life can be suppressed.

Note that the circumferential groove, the width direction narrow groove, the wide width narrow groove, and the narrow width narrow groove here are groove widths such that the groove walls are not separated from each other even when the tire tread is grounded and the groove is not closed. It is what has. On the other hand, the groove bottom sipe is such that the sipe wall surfaces come into contact with each other and close when the tire tread is grounded.
Here, the tire tread is brought into contact with a pneumatic tire by attaching it to a standard rim specified in JATMA YEAR BOOK (Japan Automobile Tire Association Standard, 2010 edition), and the maximum size and ply rating applicable to JATMA YEAR BOOK. This is when 100% internal pressure of the air pressure (maximum air pressure) corresponding to the load capacity (internal pressure-load capacity correspondence table) is filled and 70% of the maximum load is applied. When the TRA standard or ETRTO standard is applied at the place of use or manufacturing, the respective standards are followed.

As described above, the width of the wide narrow grooves formed in the shoulder land portion is widened to be smaller than the number of width direction narrow grooves formed in the first land portion, thereby maintaining the rigidity of the shoulder land portion. Thus, uneven wear can be more reliably suppressed.
Further, in this way, by forming the shoulder width direction groove narrower than the wide narrow groove in the shoulder land portion, it is possible to improve the wet performance by increasing the edge component while ensuring the tire rigidity. .
Furthermore, by increasing the number of shoulder width direction grooves formed within the same distance from the number of width direction narrow grooves, the edge component on the shoulder side is secured while ensuring the rigidity of land portions other than the shoulder land portions. Increase the traction performance.

In the pneumatic tire according to claim 2 of the present invention, circumferential narrow grooves extending in the tire circumferential direction are formed in the first land portion row to connect the narrow narrow grooves adjacent in the tire circumferential direction. It is characterized by that.

  Thus, by forming the circumferential narrow groove in the first land portion, it is possible to improve drainage and improve wet performance.

  The circumferential narrow groove here has a groove width such that the groove walls are not separated from each other even when the tire tread is grounded and the groove is not closed.

  As described above, according to the pneumatic tire of the present invention, high wet performance can be obtained while suppressing shortening of the tire life.

It is a top view of the tread of the pneumatic tire concerning the embodiment of the present invention. (A) of the tread shown in FIG. 1 is an AA sectional view, and (B) is a BB sectional view. (A) of the tread shown in FIG. 1 is a DD cross-sectional view, and (B) is a CC cross-sectional view. It is EE sectional drawing of the tread shown in FIG. It is a top view of the tread of the pneumatic tire concerning a comparative example.

  Hereinafter, a pneumatic tire 10 according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 shows a tread 12 of a pneumatic tire 10. An arrow S in the figure indicates the tire circumferential direction, and an arrow W indicates the tire width direction.

  The tread end 12E of the tread 12 has a pneumatic tire 10 mounted on a standard rim defined in JATMA YEAR BOOK (Japan Automobile Tire Association Standard, 2010 edition), and applicable size / prior rating in JATMA YEAR BOOK. 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.

  In the tread 12 of the pneumatic tire 10 of the present embodiment, four circumferential grooves extending along the tire circumferential direction are formed. Of these, the pair of grooves arranged on the most shoulder side is referred to as shoulder circumferential grooves 22 and 26, and the pair of grooves formed on the tire equatorial plane CL side is referred to as center circumferential grooves 24 and 25. The shoulder circumferential grooves 22 and 26 and the center circumferential grooves 24 and 25 are formed in a zigzag shape having an amplitude in the tire width direction. The groove widths W0 of the shoulder circumferential grooves 22, 26 and the center circumferential groove 24 are substantially the same, and the groove depth H0 is also substantially the same. The tread 12 includes a plurality of land portion rows extending in the tire circumferential direction S by the shoulder circumferential grooves 22 and 26 and the center circumferential groove 24.

  A first shoulder land row 32 is formed on the shoulder side (left side in FIG. 1) from the shoulder circumferential groove 22. A second shoulder land portion row 38 is formed on the shoulder side (the right side in FIG. 1) from the shoulder circumferential groove 26. A first land portion row 34 is formed between the shoulder circumferential groove 22 and the center circumferential groove 24, and a second land portion row 36 is formed between the shoulder circumferential groove 26 and the center circumferential groove 25. Is formed. A central land portion row 35 is formed on the tire equatorial plane CL between the center circumferential groove 24 and the center circumferential groove 25.

  In the first land portion row 34, width direction narrow grooves 40 are formed at predetermined intervals in the tire circumferential direction. The width direction narrow groove 40 is formed so as to extend from one end to the other end in the tire width direction of the first land portion row 34 and opens to the shoulder circumferential groove 22 and the center circumferential groove 24. . The width direction narrow groove 40 has an inflection point so that a convex portion 40A that protrudes in the tire circumferential direction is formed from one end to the other end of the first land portion row 34 in the tire width direction. Yes. The width direction narrow groove 40 is narrower than the shoulder circumferential direction groove 22 and the center circumferential direction groove 24 and is formed with a shallow groove depth.

  A groove bottom sipe 42 is formed at the groove bottom of the width direction narrow groove 40. The groove bottom sipe 42 is formed so as to extend from one end to the other end in the tire width direction of the first land portion row 34 along the extending direction of the width direction narrow groove 40.

  Here, as shown in FIG. 2A, the groove width W1 of the widthwise narrow groove 40 is narrower than the groove width W0 of the shoulder circumferential groove 22, and the groove depth H1 of the widthwise narrow groove 40 is the shoulder circumference. The direction groove 22 is formed shallower than the groove depth H0. The groove width W1 of the width direction narrow groove 40 is such a groove width that the groove walls are separated even when the tread 12 is grounded and the groove is not closed, and is about 2.0 mm to 5.0 mm. . Moreover, the groove depth H1 of the width direction narrow groove 40 is about 1.5 mm to 3.5 mm.

  On the other hand, the groove width W2 of the groove bottom sipe 42 is such that when the tread 12 is grounded, the sipe wall surfaces come into contact with each other and close, and is about 0.7 mm to 1.5 mm. The groove depth H2 (depth from the tread surface to the groove bottom) of the groove bottom sipe 42 is preferably set to 50% to 90% of the groove depth H0 of the shoulder circumferential groove 22 when new. By setting within this range, the rubber flow component in the tire circumferential direction is appropriately blocked by the groove bottom sipe 42, thereby preventing slipping when kicking out and suppressing wear. When the groove depth H2 of the groove bottom sipe 42 is less than 50% of the groove depth H0 of the shoulder circumferential groove 22, the slipping at the time of kicking cannot be effectively suppressed, and the groove depth H2 exceeds 90%. This is because the rigidity of the block is reduced.

  Between the narrow grooves 40 adjacent to each other in the tire circumferential direction, circumferential narrow grooves 43 extending in the tire circumferential direction are formed. The circumferential narrow groove 43 is formed so as to connect adjacent widthwise narrow grooves 40. The circumferential narrow groove 43 is bent so as to be zigzag in the tire circumferential direction.

  As shown in FIG. 2B, the groove width W3 of the circumferential narrow groove 43 is narrower than the groove width W0 of the shoulder circumferential groove 22, and the groove depth H3 of the circumferential narrow groove 43 is the shoulder circumferential groove. The groove depth is shallower than the groove depth H0. The groove width W3 of the circumferential narrow groove 43 is such a groove width that the groove walls are separated even when the tread 12 is grounded and the groove is not closed, and is about 1.0 mm to 3.0 mm. .

  In the second land portion row 36, width direction narrow grooves 44 are formed at predetermined intervals in the tire circumferential direction. The width direction narrow grooves 44 are formed so as to extend from one end to the other end in the tire width direction of the second land portion row 36 and open to the shoulder circumferential groove 26 and the center circumferential groove 24. . About the structure of the width direction narrow groove 44, the convex part 44A, the groove bottom sipe 46, and the circumferential direction narrow groove 47 currently formed in the 2nd land part row | line 36, it is formed in the 1st land part row | line | column 34, respectively. This is the same as the width direction narrow groove 40, the convex portion 40A formed in the width direction narrow groove 40, the groove bottom sipe 42, and the circumferential direction narrow groove 43.

  A wide narrow groove 50 extending in the tire width direction is formed in the first shoulder land portion row 32. The wide narrow groove 50 has one end opening in the shoulder circumferential groove 22 and the other end terminating in the first shoulder land portion row 32.

  A narrow narrow groove 52 extending in the tire width direction is formed in the first shoulder land portion row 32 on the tire shoulder side of the wide narrow groove 50. One end of the narrow narrow groove 52 reaches the tread end 12E, and the other end is connected to the other end of the wide narrow groove 50 in the first shoulder land portion row 32.

  As shown in FIG. 3, the groove width W <b> 4 of the wide narrow groove 50 is wider than the groove width W <b> 5 of the narrow thin groove 52. The groove width W4 of the wide narrow groove 50 can be about 2.0 mm to 5.0 mm, and the groove width W5 of the narrow thin groove 50 can be about 1.0 mm to 3.0 mm.

  The groove width W4 of the wide narrow groove 50 and the groove width W5 of the narrow narrow groove 52 are narrower than the groove width W0 of the shoulder circumferential groove 22, and the groove depth H4 of the wide narrow groove 50 and the narrow narrow groove 52 are narrow. The groove depth H <b> 5 is shallower than the groove depth H <b> 0 of the shoulder circumferential groove 22. The groove width W4 of the wide narrow groove 50 and the groove width W5 of the narrow narrow groove 52 are such that when the tread 12 is grounded, the groove walls are separated from each other and the groove is not closed.

  A shoulder width direction narrow groove 54 is formed between the wide narrow grooves 50 adjacent to each other in the tire circumferential direction of the first shoulder land portion row 32. One end of the shoulder width direction narrow groove 54 opens to the shoulder circumferential groove 22 and the other end reaches the tread end 12E. Two shoulder width direction narrow grooves 54 are formed between adjacent wide narrow grooves 50. As shown in FIG. 3, the groove width W <b> 6 of the shoulder width direction narrow groove 54 is narrower than that of the wide narrow groove 50. Further, the groove width W6 of the shoulder width direction narrow groove 54 is such that the groove walls are not separated from each other even when the tread 12 is grounded, and the groove is not closed.

  In the present embodiment, the shoulder width direction narrow groove 54 has a groove width that does not close even when the tread 12 is grounded, but the shoulder width direction narrow groove 54 is a so-called sipe, that is, The groove width may be a groove width that closes when the tread 12 is grounded. The shoulder width direction narrow groove 64 to be described later may be sipe similarly.

  A wide narrow groove 60 extending in the tire width direction is formed in the second shoulder land portion row 38. The wide narrow groove 60 has one end opening in the shoulder circumferential groove 26 and the other end terminating in the second shoulder land portion row 38. The configuration of the wide narrow groove 60, the narrow narrow groove 62, and the shoulder width direction narrow groove 64 formed in the second shoulder land portion row 38 is the wide narrow groove formed in the first shoulder land portion row 32, respectively. The configurations of the groove 50, the narrow narrow groove 52, and the shoulder width direction narrow groove 54 are the same.

  As shown in FIG. 4, a central narrow groove 66 extending in the tire width direction is formed in the central land portion row 35. The central narrow groove 66 is linear, and one end opens in the center circumferential groove 24 and the other end opens in the center circumferential groove 25. A groove bottom sipe 68 is formed at the groove bottom of the central narrow groove 66. The groove bottom sipe 68 is formed so as to extend from one end to the other end in the tire width direction of the central land portion row 35 along the extending direction of the central narrow groove 66.

  The groove width W7 of the central narrow groove 66 is narrower than the groove width W0 of the shoulder circumferential groove 22, and the groove depth H7 of the central narrow groove 66 is shallower than the groove depth H0 of the shoulder circumferential groove 22. . The groove width W7 of the central narrow groove 66 is such a groove width that the groove walls are not separated even when the tread 12 is grounded and the groove is not closed, and is about 2.0 mm to 5.0 mm. The groove depth H7 of the central narrow groove 66 is about 1.5 mm to 3.5 mm.

  On the other hand, the groove width W8 of the groove bottom sipe 68 is such that the sipe wall surfaces come into contact with each other and close when the tread 12 is grounded, and is about 0.7 mm to 1.5 mm. The groove depth H8 (depth from the tread surface to the groove bottom) of the groove bottom sipe 68 is preferably set to 50% to 90% of the groove depth H0 of the shoulder circumferential groove 22 when new. By setting within this range, the rubber flow component in the tire circumferential direction is appropriately blocked by the groove bottom sipe 68, thereby preventing slippage during kicking and suppressing wear. When the groove depth H8 of the groove bottom sipe 68 is less than 50% of the groove depth H0 of the shoulder circumferential groove 22, the slipping at the time of kicking cannot be effectively suppressed, and the groove depth H8 exceeds 90%. This is because the rigidity of the block is reduced.

  The central narrow groove 66 formed in the central land portion row 53, the width direction narrow groove 40 formed in the first land portion row 34, and the width direction narrow groove 44 formed in the second land portion row 36 are substantially the same. They are formed at a predetermined interval P1 in the tire circumferential direction at the same pitch. The opening of the central narrow groove 66 to the center circumferential groove 24 is formed at a position extending from the opening of the width narrow groove 40 to the center circumferential groove 24. The opening of the central narrow groove 66 to the center circumferential groove 25 is formed at a position extending from the opening of the width narrow groove 44 to the center circumferential groove 25.

  The wide narrow grooves 50 formed in the first shoulder land portion row 32 and the wide narrow grooves 60 formed in the second shoulder land portion row 38 are formed at a predetermined interval P2 in the tire circumferential direction. The interval P2 is twice the interval P1. Therefore, the number of the wide narrow grooves 50 and 60 is smaller than the number of the width-direction narrow grooves 40 and 44. Moreover, the opening part to the shoulder circumferential direction groove | channel 22 of the wide narrow groove 50 is comprised in the position extended from the opening to the shoulder circumferential direction groove | channel 22 of the width direction fine groove 40, and the shoulder circumferential direction of the wide narrow groove 60 The opening to the groove 26 is formed at a position extending from the opening to the shoulder circumferential groove 26 of the width direction narrow groove 44.

  Further, the interval P3 between the wide narrow groove 50 formed in the first shoulder land portion row 32 and the shoulder width direction narrow groove 54 adjacent in the circumferential direction, and the interval P4 between the adjacent shoulder width direction narrow grooves 54 are as follows. , Narrower than the interval P1. Two shoulder width direction narrow grooves 54 are formed between the adjacent wide narrow grooves 50, and the width direction narrow grooves 40, 44 are formed within the same interval as the interval between the adjacent wide narrow grooves 50. The number is one except for the width-direction narrow grooves 40 and 44 at both end portions corresponding to the wide narrow groove 50.

  In the pneumatic tire 10 of the present embodiment, the wide narrow groove 50 formed near the tire equatorial plane CL of the first shoulder land portion row 32 is open to the shoulder circumferential groove 22, thus ensuring drainage. The wet performance can be improved. Further, since the narrow narrow groove 52 formed on the tire shoulder side is narrower than the wide narrow groove 50, a decrease in rigidity of the first shoulder land portion row 32 is suppressed, and uneven wear can be suppressed. Therefore, shortening of the tire life can be suppressed. Similarly, with respect to the second shoulder land portion row 38, the wide narrow groove 60 can ensure drainage and improve wet performance. In addition, the narrow narrow groove 62 suppresses a decrease in rigidity of the second shoulder land portion row 38, thereby suppressing uneven wear.

  Further, in the pneumatic tire 10 of the present embodiment, the interval P2 between the wide narrow grooves 50 adjacent in the tire circumferential direction is the interval P1 between the wide narrow grooves 40 adjacent in the tire circumferential direction, and the width narrow grooves 44 Therefore, the rigidity of the first shoulder land portion row 32 and the second shoulder land portion row 38 can be maintained, and uneven wear can be suppressed.

Further, in the pneumatic tire 10 of the present embodiment, the shoulder width direction narrow grooves 54 and 64 narrower than the wide narrow grooves 50 and 60 are formed between the wide narrow grooves 50 and 60 adjacent to each other in the tire circumferential direction. Therefore, it is possible to improve the wet performance by suppressing the increase of the negative rate and increasing the edge component while ensuring the tire rigidity.

  Further, in the pneumatic tire 10 of the present embodiment, the number of the shoulder width direction narrow grooves 54 and 64 is larger than the number of the width direction narrow grooves 40 and 44 formed within the same distance, whereby the first land. The traction performance can be improved by increasing the edge components of the first shoulder land portion row 32 and the second shoulder land portion row 38 while ensuring the rigidity of the portion row 34 and the second land portion row 36.

  Further, in the pneumatic tire 10 of the present embodiment, the circumferential narrow groove 43 is formed in the first land portion row and the circumferential narrow groove 47 is formed in the second land portion row 36, thereby improving drainage. The wet performance can be improved. Moreover, the traction performance can be further improved by forming the circumferential narrow grooves 43 and 47 in a zigzag shape in the tire circumferential direction.

  Further, in the present embodiment, the width direction narrow groove 40 is bent so that the convex portion 40A is formed between one end and the other end of the first land portion row 34 in the tire width direction. As a result, the turning performance and braking performance can be improved. The same applies to the width direction narrow groove 44.

  The width direction narrow grooves 40 and 44 are not necessarily bent, and may be linear. Moreover, the shape bent in a zigzag may be sufficient.

  In the present embodiment, the two center circumferential grooves 24 and 25 are formed between the shoulder circumferential grooves 22 and 26, but only one circumferential groove may be formed.

  In order to confirm the effect of the present invention, the tire of the comparative example and the tire of the example to which the present invention was applied were prepared, and the wet turning performance, the wet brake performance, and the wear resistance performance were tested with an actual vehicle.

  As shown in FIG. 5, the tire tread 90 of the comparative example includes a pair of shoulder circumferential grooves 91 on the most shoulder side and a center circumferential groove 92 on the tire equatorial plane CL. A center side land portion row 95 is formed between the shoulder circumferential groove 91 and the center circumferential groove 92, and a shoulder land portion row 94 is formed outside the shoulder circumferential groove 91 in the tire width direction. Yes. The center side land portion row 95 is formed with first narrow grooves 96A and 96B extending in the tire width direction from the center circumferential groove 92 to the shoulder circumferential groove 91 at predetermined intervals in the tire circumferential direction. In the shoulder land portion row 94, second narrow grooves 98 extending in the tire width direction from the shoulder circumferential groove 91 to the tread end 90E are formed at predetermined intervals in the tire circumferential direction.

The test conditions of the examples and comparative examples are as follows.
Vehicle used: Truck (2-D)
Applicable rim: 7.50 × 22.5
Test air pressure: 900KPa
Load: Regular load

(Wet turning performance test)
The road surface of the test course was wet Belgian, and the turning acceleration was evaluated when new and worn (4 mm remaining). The evaluation of turning acceleration shows the index of the comparative example as 100 when it is new and worn (4 mm remaining). The index of the turning acceleration evaluation indicates that the turning performance is higher as the numerical value is higher.

  As shown in the test results in Table 1, the tire of the example to which the present invention is applied obtains a high turning performance on the wet road surface both when new and worn, as compared with the tire of the comparative example. I was able to.

(Wet brake performance)
The road surface of the test course was wet asphalt, and the brake performance was evaluated by the deceleration index when new and worn (4 mm remaining). The index shows 100 as the index of the comparative example when new and worn (4 mm remaining). The index indicates that the higher the value, the higher the braking performance.

  As shown in the test results of Table 2, the tire of the example to which the present invention is applied obtains high braking performance on the wet road surface both when new and worn as compared with the tire of the comparative example. I was able to.

(Abrasion resistance)
The road surface of the test course was dry asphalt, and the wear resistance performance was evaluated by the wear life index. In the evaluation, in the new tire, the distance traveled until the groove disappeared first was indicated by an index. The wear life index is shown as 100 as a comparative example. The wear life index indicates that the higher the numerical value, the higher the wear resistance performance.

  As shown in the test results of Table 3, it is clear that the tire of the example to which the present invention was applied has higher wear resistance than the tire of the comparative example.

DESCRIPTION OF SYMBOLS 10 Pneumatic tire 12 Tread 22 Shoulder circumferential groove 24 Center circumferential groove 25 Center circumferential groove 26 Shoulder circumferential groove 32 First shoulder land row 34 First land portion row 35 Central land portion row 36 Second land portion row 38 Second shoulder land row 40 Width direction narrow groove 42 Groove bottom sipe 43 Circumferential direction narrow groove 44 Width direction narrow groove 46 Groove bottom sipe 47 Circumferential direction narrow groove 50 Wide width narrow groove 52 Narrow width narrow groove 53 Central land portion row 54 Shoulder width direction narrow groove 60 Wide width narrow groove 62 Narrow width narrow groove 64 Shoulder width direction narrow groove 66 Center narrow groove 68 Groove bottom sipe

Claims (2)

A plurality of circumferential grooves formed in the tire tread and extending along the tire circumferential direction;
A plurality of land portion rows partitioned by the circumferential grooves and extending in the tire circumferential direction;
A widthwise narrow groove that is shallower than the circumferential groove and that traverses the first land portion row of the land portion row in the tire width direction at both ends in the tire width direction defined by the circumferential groove;
A groove bottom sipe formed along the width direction narrow groove at the groove bottom of the width direction narrow groove;
One end in the tire width direction is shallower than the circumferential groove, and one end in the tire width direction is formed in a shoulder land portion row adjacent to the tire shoulder, one end is open to the circumferential groove, and the other end is the shoulder land portion. A wide narrow groove extending in the tire width direction terminating in the row;
A narrow narrow groove that is formed in the shoulder land portion row, has one end connected to the other end of the wide narrow groove and the other end reaching the tread end, and narrower than the wide narrow groove.
With
Between the wide narrow grooves adjacent to each other in the tire circumferential direction, a narrow groove that is narrower than the wide narrow groove and extends in the tire width direction, and a shoulder width direction groove formed of at least one of sipes are formed. And
The interval between the wide narrow grooves adjacent in the tire circumferential direction is wider than the interval between the wide narrow grooves adjacent in the tire circumferential direction, and is formed between the pair of wide narrow grooves adjacent in the tire circumferential direction. The number of the shoulder width direction grooves formed is formed in the first land portion row adjacent to the shoulder land portion row, and has an opening end to the circumferential groove on an extension line of each of the wide narrow grooves. A pneumatic tire that is larger in number than the number of the width direction narrow grooves between the width direction narrow grooves . Wherein the first land row, according to claim 1, characterized in that, the circumferential narrow groove extending in the tire circumferential direction for connecting the width-direction narrow grooves adjacent to each other in the tire circumferential direction is formed Pneumatic tire.

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