JP2020199820A - Pneumatic tire - Google Patents

Abstract

To provide a pneumatic tire which further improves on-ice/snow performance and suppresses breakage of a block and bottom cracking of a groove bottom of a sipe.SOLUTION: In a pneumatic tire in which inside land parts (12A and 12B) inside an outermost side circumferential groove (11o) of a tread 7 are divided into two lines of division land parts (12p and 12q) by a circumferential narrow groove (13), and blocks (15P and 15Q) divided by width direction grooves (14) of the division land parts (12p and 12q) are deviated from each other in a tire circumferential direction and are positioned in a zigzag form, two outside width direction sipes (16a and 16z) among at least three width direction sipes concentrated at a central part in the tire circumferential direction of the blocks (15P and 15Q) are opened on both of side faces in the tire width direction of the blocks (15P and 15Q), and both ends of an inside width direction sipe (16m) between the two outside width direction sipes (16a and 16z) are within the blocks (15P and 15Q).SELECTED DRAWING: Figure 2

Description

The present invention relates to a pneumatic tire, and more particularly to a pneumatic tire having performance on ice and snow.

In studless tires that take performance on ice and snow into consideration, the traction pattern in which the land portion that is divided by the circumferential groove on the tire tread and is connected in the circumferential direction is divided into multiple blocks by the width direction groove and a sipe is formed in each block well known.

The sipe can improve the traction property by eliminating the water film formed between the road surface and the tire by absorbing water and by cutting the road surface water film by the edge portion of the sipe and directly contacting the road surface.

By increasing the number of sipes formed in the block, the edge component in the block increases, and the performance on ice and snow can be improved.
However, as the number of sipes increases, the divided blocks divided by the sipes in the block become smaller, the rigidity is low, the vehicle is deformed when the vehicle is running, and the divided blocks on the outer side in the tire circumferential direction are particularly likely to be damaged.

Therefore, two sipes are concentrated and formed in the central portion of the block in the tire circumferential direction to secure the edge component due to the sipes, and the block is formed by the two sipes concentrated in the central portion on the outer side of the two tire circumferential directions. There is an example in which the outer dividing block is divided into a small central dividing block, and the outer dividing block is made as large as possible to maintain rigidity and prevent damage during vehicle running (see Patent Document 1).

Japanese Unexamined Patent Publication No. 2008-149768

For the pneumatic tire disclosed in Patent Document 1, in order to further improve the performance on ice and snow, the number of sipes for the block may be increased and the edge component may be increased. However, while increasing the number of sipes, the outer side The challenge is to maintain a large divided block and suppress block loss.
Further, depending on the increased sipes, the rigidity of the dividing block becomes low, and the deformation becomes large at the time of touchdown, which may cause bottom cracking at the groove bottom of the sipes.

The present invention has been made in view of the above points, and an object of the present invention is to provide a pneumatic tire that further improves the performance on ice and snow and suppresses block breakage and cracking of the groove bottom of the sipe. ..

In order to achieve the above object, the present invention
The tread of the tire is divided by a plurality of circumferential grooves extending in the tire circumferential direction to form a land portion connected in a plurality of circumferential directions.
The inner land portion of the land portion located inside the outermost circumferential groove in the tire width direction of the circumferential groove in the tire width direction has a tire width due to a circumferential narrow groove extending in the tire circumferential direction. Divided in the direction into two rows of divided land areas,
The divided land portion is divided into a plurality of blocks by a plurality of widthwise grooves extending in the tire width direction.
The two rows of divided land portions adjacent to each other with the circumferential groove in between are staggered so that the blocks formed therein are displaced from each other in the tire circumferential direction and some of them are alternately overlapped in the tire circumferential direction. In pneumatic tires
At least three widthwise sipes extending in the tire width direction are formed in the block concentrated in the central portion of the block in the tire circumferential direction.
The outermost two outer width sipe of at least three width sipe are open on both sides of the block in the tire width direction.
The inner width sipe sandwiched between the two outer width sipe provides a pneumatic tire characterized in that both ends thereof are within the block.

According to this configuration, at least three widthwise sipes extending in the tire width direction are concentrated in the central portion of the block in the tire circumferential direction in the block partitioned by a plurality of widthwise grooves in the divided land portion. Therefore, at least three widthwise sipes are used to increase the edge component to further improve the performance on ice and snow, and at least three widthwise sipes concentrated in the center divide the block into two large outer divisions in the tire circumferential direction. It can be divided into a large block and a small inner division small block between them, and the outer division large block can be made as large as possible to maintain rigidity and suppress loss during vehicle running.

Further, the two outer width direction sipes are open on both side surfaces in the tire width direction of the block, but the inner width direction sipes formed in the inner dividing small block sandwiched between the two outer width direction sipes are Since both ends are inside the inner dividing block and closed, the inner dividing small block between the two outer width direction sipes is not further divided by the inner width direction sipes, so that the inner dividing small block is not further divided. Even if the deformation of the tire is large, the bottom crack of the groove bottom of the inner width direction sipe is suppressed.

In a preferred embodiment of the invention
The inner width direction sipe is deeper in the tire radial direction than the outer width direction sipe.

According to this configuration, the inner width direction sipe formed in the inner dividing small block sandwiched between the two outer width direction sipes is deeper in the tire radial direction than the outer width direction sipe, so that the contact pressure is high. When added, the side wall portions on both sides facing each other via the inner width direction sipe of the inner dividing small block are deformed so as to buckle, and the outer dividing large block on the kicking side is contacted and pressed at an intermediate depth to kick the same. The ground pressure at the stepping edge of the outer dividing block on the exit side can be increased to enhance the edge effect, and the performance on ice and snow can be improved.

In a preferred embodiment of the invention
The circumferential groove extends in a zigzag shape in the tire circumferential direction while swinging in the tire width direction.
The block is bent so that the center in the tire circumferential direction matches the zigzag shape of the circumferential groove.
The inner width direction sipe is formed at a bent portion of the block.

According to this configuration, the center of the tire circumferential direction is bent according to the zigzag shape of the circumferential groove, and an inner width direction sipe is formed at this bent portion, so that the outer side of the two tire circumferential directions is formed. Since the outer divided large blocks of the above are divided into an appropriate size almost evenly and the rigidity is maintained, it is possible that one outer divided large block becomes smaller than the other and the rigidity decreases, causing a defect when the vehicle is running. Absent.
In addition, since the inner dividing small block has a bent portion and the inner width direction sipe is located at the bent portion of the inner dividing block and both ends are closed, both side surfaces of the inner dividing small block are continuous without being divided. It maintains rigidity and has an edge component, which contributes to performance on ice and snow.

In a preferred embodiment of the invention
The block is bent at the center in the tire circumferential direction so that the side surface on the circumferential groove side of the zigzag shape protrudes.

According to this configuration, the block is bent at the center in the tire circumferential direction so that the side surface of the zigzag shape on the circumferential groove side protrudes, so that the block is adjacent to both sides of the inner width direction sipe located at the bent portion. Since the outer width direction sipe has an opening on the side surface on the circumferential groove side where the block protrudes, the water absorbed at the time of touchdown can be easily discharged to the circumferential groove, and the drainage property can be improved. ..

In the present invention, at least three widthwise sipes extending in the tire width direction are formed concentrated in the central portion of the block in the tire circumferential direction in the block partitioned by a plurality of widthwise grooves in the divided land portion. Therefore, at least three sipes are used to further increase the edge component to further improve the performance on ice and snow, and at least three sipes concentrated in the center make the block into two large outer dividing large blocks in the tire circumferential direction and a small inner side. It can be divided into small divided blocks, and the large outer divided block can be made as large as possible to maintain rigidity and suppress loss during vehicle running.

Further, the two outer width direction sipes are open on both side surfaces in the tire width direction of the block, but the inner width direction sipes formed in the inner dividing block sandwiched between the two outer width direction sipes are. Since both ends are inside the inner dividing small block and closed, the inner dividing small block between the two outer width direction sipes is not further divided by the inner width direction sipes, so that the inner dividing small block is not further divided. Even if the deformation of the tire is large, the bottom crack of the groove bottom of the inner width direction sipe is suppressed.

It is a tire width direction sectional view of the pneumatic tire which concerns on one Embodiment of this invention. It is a partial plan view of the tread of the same pneumatic tire. It is a partially enlarged plan view of the inner land part of the tread. It is a partial cross-sectional view of the same inner land part by the IV-IV arrow view of FIG.

Hereinafter, an embodiment according to the present invention will be described with reference to FIGS. 1 to 4.
FIG. 1 is a tire width direction cross-sectional view (cross-sectional view when cut in a plane including a tire rotation center axis) of a pneumatic tire 1 which is a heavy-duty radial tire for trucks and buses according to the present embodiment.

The pneumatic tire 1 has a toroidal shape in which both side edges are wound around a pair of left and right bead rings 2 and 2 formed by winding a metal wire in a ring shape to bulge outward in the tire radial direction. A carcass ply 3 is formed.

An air-permeable inner liner portion 4 is formed on the inner surface of the carcass ply 3.
A plurality of belts 6 are wound around the outer periphery of the crown portion of the carcass ply 3 to form a belt layer 5, and the tread 7 is formed so as to cover the outer side in the tire radial direction.
The belt layer 5 is formed by stacking belts 6 in a plurality of layers, and each belt 6 is formed by coating a belt cord with rubber for a belt to form a belt.

A sidewall portion 8 is formed on the outer surface of both side portions of the carcass ply 3.
The bead portion 9 that covers the annular end portion that is wound around the bead ring 2 of the carcass ply 3 and is folded back is continuous with the inner liner portion 4 on the inside and continuous with the sidewall portion 8 on the outside.

FIG. 2 is a partial plan view of the tread 7, showing a portion of the tread in contact with the road surface when the tire touches the ground, and tire contact ends E and E on both sides which are the maximum width positions in the tire width direction in contact with the road surface. Shows the interval.
With reference to FIGS. 1 and 2, the tread 7 has two circumferential grooves 11i and 11o extending in the tire circumferential direction on both sides of the central tire equator line Le in the tire width direction in the tire width direction. It is formed at approximately equal intervals.

The four circumferential grooves 11o, 11i, 11i, 11o are the inner peripheral grooves 11i, 11i on the inner side in the tire width direction near the tire equator line Le, and the outermost outermost grooves in the inner peripheral direction groove 11i in the tire width direction. It is composed of an outer circumferential groove 11o.
The circumferential grooves 11i and 11o both extend in a zigzag shape in the tire circumferential direction while swinging in the tire width direction.

Land portions 12C, 12B, 12A, 12B, 12C are formed by being partitioned by the four circumferential grooves 11o, 11i, 11i, 11o and extending in the circumferential direction of the five tires.
Three inner land portions 12B, 12A, and 12B are partitioned inside the tire width direction with the tire equator line Le between the outermost circumferential grooves 11o and 11o on both sides in the tire width direction.
The shoulder land portion 12C is defined in the tire shoulder region outside the tire width direction from the outermost circumferential groove 11o.

The inner land portions 12A and 12B are divided in the tire width direction by the circumferential groove 13 extending in a zigzag shape in the tire circumferential direction while swinging in the tire width direction center in the tire width direction, respectively, and are divided into two rows of land portions 12p and 12q. Is formed.

The divided land portions 12p and 12q are divided into a plurality of blocks 15P and 15Q by a plurality of widthwise grooves 14 extending in the tire width direction provided at equal intervals in the tire circumferential direction, respectively.
The groove 14 in the width direction has a large groove width, and the depth in the tire radial direction is about half the depth of the circumferential grooves 11i and 11o.

In the two rows of divided land portions 12p and 12q adjacent to each other with the circumferential groove 13 in between, the blocks 15P and 15Q formed therein are displaced from each other in the tire circumferential direction, and some of them are alternately overlapped in the tire circumferential direction. It is located in a staggered pattern.

In the blocks 15P and 15Q, the center in the tire circumferential direction is bent according to the zigzag shape of the circumferential groove 11i (or the circumferential groove 11o) and the circumferential fine groove 13.
The blocks 15P and 15Q are bent at the center in the tire circumferential direction so that the side surfaces 15Ps and 15Qs on the side of the zigzag-shaped circumferential groove 11i (or circumferential groove 11o) protrude (see FIG. 3).

Three widthwise sipes 16a, 16m, 16z extending in the tire width direction are formed concentrated on the bent portion in the center of the tire circumferential direction of the blocks 15P and 15Q.
The width direction sipes 16a, 16m, 16z are notches with a groove width of less than 1.0 mm.

Of the width direction sipes 16a, 16m, 16z, the two outermost outer width direction sipes 16a, 16z are double-sided opening sipes that are open on both side surfaces of the blocks 15P, 15Q in the tire width direction.
That is, the outer width direction sipes 16a and 16z have one end opened in the circumferential groove 11i (or the circumferential groove 11o) and the other end open in the circumferential narrow groove 13 and the circumferential groove 11i (or the circumferential groove 11o). 11o) and the circumferential groove 13 are communicated with each other.

On the other hand, the inner width direction sipe 16m between the outer width direction sipe 16a and 16z is a double-sided closed sipe with both ends inside the blocks 15P and 15Q.
As shown in FIG. 4, the tire radial depths of the outer width direction sipes 16a and 16z are substantially the same as those of the width direction groove 14, and the inner width direction sipes 16m are tires of the outer width direction sipes 16a and 16z. Deeper than the radial depth.

With reference to FIG. 3, the block 15P has a long outer block length (the length of the block in the tire circumferential direction) due to the outer width direction sipes 16a, 16z, which are open sipes on both sides. It is divided into a small inner division block 15Pm with a short block length between the outer division large block 15Pa and 15Pz.
Then, an inner width direction sipe 16 m, which is a closed sipe on both sides, is formed in the inner divided small block 15 Pm.

Similarly, the block 15Q has a block length between the outer divided large blocks 15Qa and 15Qz and the outer divided large blocks 15Qa and 15Qz, which have long outer block lengths in the tire circumferential direction due to the outer width direction sipes 16a and 16z which are open sipes on both sides. It is divided into short and small inner division small blocks 15Qm.
Then, an inner width direction sipe 16 m, which is a closed sipe on both sides, is formed in the inner divided small block 15Qm.

Here, since the width direction sipes 16a, 16m, 16z are narrow cuts with a groove width of less than 1.0 mm, the blocks on both sides of the width direction sipes 16a, 16m, 16z are pressed and deformed and come into contact with each other at the time of touchdown. be able to.

That is, at the time of touchdown, the outer division large block 15Pa, the inner division small block 15Pm, the outer division large block 15Pz and the outer division large block 15Qa, the inner division small block 15Qm, and the outer division large are divided by two widthwise sipes 16a and 16z. The blocks 15Qz are pressed and deformed and are in contact with each other, and the blocks 15P and the blocks 15Q can be integrated into one to increase the rigidity.
The inner divided small blocks 15Pm and 15Qm have higher rigidity because the tread sides of the side wall portions 15Pma and 15Pmz (see FIG. 4) on both sides of the inner width direction sipe 16m, which are closed sipe on both sides when touching the ground, are in contact with each other.

Further, the circumferential groove 13 has a groove width equal to or slightly larger than the width sipe 16a, 16m, 16z, and is integrated into one on each side of the circumferential groove 13 at the time of touchdown and is positioned in a staggered manner. The block 15P and the block 15Q are pressed and deformed and continuously mesh with each other, so that the rigidity in the tire circumferential direction can be improved.

With reference to FIG. 2, the shoulder land portion 12C on the outer side in the tire width direction from the outermost circumferential groove 11o is formed with the inner shoulder land portion 12Ci on the inner side in the tire width direction by the circumferential fine groove 21 extending linearly in the tire circumferential direction. It is divided into the outer shoulder 12Co on the outer side in the tire width direction.
The inner shoulder land portion 12Ci has a wider width in the tire width direction and higher rigidity than the outer shoulder land portion 12Co.

The inner shoulder land portion 12Ci is divided into a plurality of inner blocks 23 by inner width direction lug grooves 22 extending in the tire width direction provided at equal intervals in the tire circumferential direction.
The depth of the inner width direction lug groove 22 in the tire radial direction is half the depth of the outermost circumferential groove 11o in the tire radial direction.

The inner block 23 is formed with a narrow groove 24 in the inner width direction extending in the tire width direction at the center in the tire circumferential direction.
The inner width direction narrow groove 24 is a double-sided opening sipe having one end open to 11o and the other end to open to the circumferential fine groove 21, and the depth in the tire radial direction is the same as that of the inner width direction lug groove 22. ..

Therefore, the inner block 23 is divided into small blocks having a short block length by the inner width direction groove 24.
The groove width of the inner width direction narrow groove 24 is slightly larger than that of the sipe, but when the tire touches the ground, the small blocks on both sides of the inner width direction fine groove 24 are pressed and deformed to come into contact with each other.

The outer shoulder land portion 12Co is partitioned outward in the tire width direction by the circumferential groove 21 of the shoulder land portion 12C, and a plurality of outer shoulder land portions 12Co are provided by the outer width direction lug grooves 32 extending in the tire width direction at equal intervals in the tire circumferential direction. It is partitioned into outer blocks 33.
The outer side of the outer block 33 in the tire width direction is the tire ground contact end E.

The outer width direction lug groove 32 has a large groove width, and the depth in the tire radial direction is substantially the same as the depth in the tire radial direction of the inner width direction lug groove 22.
The outer width direction lug groove 32 is formed at the same position as the inner width direction lug groove 22 in the tire circumferential direction.
Therefore, since the inner width direction lug groove 22 and the outer width direction lug groove 32 in the shoulder land portion 12C are formed at the same positions in the tire circumferential direction, the drainage property of the shoulder land portion 12C is improved.

In one embodiment of the pneumatic tire according to the present invention described in detail above, the following effects are obtained.
The inner land portions 12A and 12B located inside in the tire width direction from the outermost circumferential groove 11o in the tread 7 of the pneumatic tire 1 have the tire width due to the circumferential groove 13 with reference to FIGS. 2 and 3. It is divided in the direction into two rows of divided land portions 12p and 12q, and the divided land portions 12p and 12q are divided into blocks 15P and 15Q by a plurality of widthwise grooves 14.

In the block 15P (15Q), three widthwise sipes 16a, 16m, 16z extending in the tire width direction are concentrated in the central portion of the block 15P (15Q) in the tire circumferential direction, so that they are concentrated in the central portion. Block 15P (15Q) by two outer width direction sipes 16a, 16z, large outer division large block 15Pa, 15Pz (15Qa, 15Qz) with long outer block length in the two tire circumferential directions and small inner block with short block length Divided into small blocks 15 Pm (15 Qm).

Since three width direction sipes 16a, 16m, 16z, which are side-opening sipes extending in the tire width direction, are formed in one block 15P (15Q), the edge component is increased and the performance on ice and snow is further improved compared to the two width direction sipes. Can be made to.
At the time of touchdown, the outer division large blocks 15Pa, 15Pz (15Qa, 15Qz) divided into outer width direction sipes 16a, 16z and the inner division small blocks 15Pm (15Qm) between them can be in contact with each other to increase the rigidity.

However, the inner dividing small block 15Pm (15Qm) is formed with a sipe 16m in the inner width direction, and when the ground pressure is concentrated on the inner dividing small block 15Pm (15Qm) having low rigidity, the inner dividing small block 15Pm ( 15Qm) is large and easily deformed.

In the pneumatic tire 1, as shown in FIG. 3, the inner width direction sipes 16m formed in the inner dividing small block 15Pm (15Qm) have both ends within the inner dividing small block 15Pm (15Qm). The inner dividing small block 15Pm (15Qm) between the two outer width direction sipes 16a and 16z is not further divided by the inner width direction sipe 16m, so that the inner dividing small block 15Pm (15Qm) is not further divided. ) Is large, the bottom crack of the groove bottom of the inner width direction sipe 16 m is suppressed.

Further, as shown in FIGS. 2 and 3, the block 15P (15Q) is divided into two large outer dividing large blocks 15Pa in the tire circumferential direction by three widthwise sipes 16a, 16m, 16z concentrated in the central portion. It is divided into 15Pz (15Qa, 15Qz) and small inner division small blocks 15Pm (15Qm), and the outer division large blocks 15Pa, 15Pz (15Qa, 15Qz) are made as large as possible to maintain rigidity and suppress defects during vehicle running. be able to.

As shown in FIG. 4, the inner width direction sipe 16m formed in the inner dividing small block 15Pm (15Qm) sandwiched between the two outer width direction sipe 16a, 16z is obtained from the outer width direction sipe 16a, 16z. Since the depth in the tire radial direction is deep, when ground pressure is applied, the side wall portions 15Pma and 15Pmz (see FIG. 4) facing each other via the inner width direction sipe 16m of the inner dividing small block 15Pm (15Qm) buckle. It is transformed into a large block 15Pa, 15Pz (15Qa, 15Qz) on the kicking side and pressed at an intermediate depth, and the large block 15Pa, 15Pz (15Qa, 15Qz) on the kicking side is pressed. The ground contact pressure of the stepping edge portion can be increased to enhance the edge effect, and the performance on ice and snow can be improved.

As shown in FIG. 2, the block 15P (15Q) is bent at the center of the tire circumferential direction in accordance with the zigzag shape of the circumferential grooves 11i and 11o, and an inner width direction sipe 16 m is formed at the bent portion. Therefore, the outer divided large blocks 15Pa, 15Pz (15Qa, 15Qz), which are concentrated on the inner width direction sipe 16m and are divided by the adjacent outer width direction sipe 16a, 16z, are divided into an appropriate size substantially evenly and the rigidity is increased. Since it is maintained, one of the outer divided large blocks does not become smaller than the other, the rigidity is lowered, and a defect does not occur when the vehicle is running.

Further, since the inner dividing small block 15Pm (15Qm) has a bent portion and the inner width direction sipe 16m is located at the bending portion of the inner dividing block and both ends are closed, the inner dividing small block 15Pm (15Qm) Both sides are not divided and continuously maintain rigidity and have an edge component, which contributes to performance on ice and snow.

As shown in FIG. 3, the blocks 15P and 15Q are bent at the center in the tire circumferential direction so that the side surfaces 15Ps and 15Qs on the circumferential grooves 11i and 11o sides of the zigzag shape protrude. The outer width direction sipes 16a and 16z adjacent to both sides of the inner width direction sipe 16m located at are provided with openings on the side surfaces of the blocks 15P and 15Q on the protruding circumferential groove 11i and 11o side, so that water absorbed at the time of touchdown is provided. Can be easily discharged into the circumferential grooves 11i and 11o, and the drainage property can be improved.

Although the pneumatic tire according to the embodiment of the present invention has been described above, the embodiment of the present invention is not limited to the above embodiment, and is carried out in various embodiments within the scope of the gist of the present invention. It includes things.

For example, the inner width direction sipes sandwiched between the two outer width direction sipes 16a and 16z of the blocks 15P and 15Q are not limited to one, and two or more inner width direction sipes are formed in order to increase the edge component. You may.
Further, in the present embodiment, the number of circumferential grooves formed in the tread extending in the circumferential direction is four, but the number is not limited to four.

The pneumatic tire of the present invention can be applied not only to truck / bus tires but also to passenger car tires.

1 ... pneumatic tire, 2 ... bead ring, 3 ... carcass ply, 4 ... inner liner part, 5 ... belt layer, 6 ... belt, 7 ... tread, 8 ... sidewall part, 9 ... bead part,
11i ... Inner circumferential groove, 11o ... Outermost circumferential groove,
12A, 12B ... inner land part, 12C ... shoulder land part, 12Ci ... inner shoulder land part, 12Co ... outer shoulder land part,
12p, 12q ... Divided land, 13 ... Circumferential groove, 14 ... Width groove,
15P ... block, 15Pa, 15Pz ... outer division large block, 15Pm, 15Pn ... inner division small block,
15Q ... block, 15Qa, 15Qz ... outer division large block, 15Qm, 15Qn ... inner division small block,
16a, 16z ... outer width direction sipe, 16m ... inner width direction sipe, 15Pma, 15Pmz ... side wall part,
21 ... Circumferential groove,
22 ... Inner width direction lug groove, 23 ... Inner block, 24 ... Inner width direction narrow groove,
32 ... outer width direction lug groove, 33 ... outer block.

Claims (4)

The tread of the tire is divided by a plurality of circumferential grooves (11i, 11o) extending in the tire circumferential direction to form a land portion (12A, 12B, 12C) connected in a plurality of circumferential directions.
Inner land of the land portion (12A, 12B, 12C) located inside the tire width direction from the outermost outermost circumferential groove (11o) in the tire width direction of the circumferential grooves (11i, 11o). The portion (12A, 12B) is divided in the tire width direction by the circumferential groove (13) extending in the tire circumferential direction to form a two-row divided land portion (12p, 12q).
The divided land portion (12p, 12q) is divided into a plurality of blocks (15P, 15Q) by a plurality of width direction grooves (14) extending in the tire width direction.
In the two rows of the divided land portions (12p, 12q) adjacent to each other with the circumferential groove (13) in between, the blocks (15P, 15Q) formed in each row are displaced from each other in the tire circumferential direction, and a part of the tire is used. In pneumatic tires that are staggered so that they overlap alternately in the circumferential direction.
In the block (15P, 15Q), at least three widthwise sipes (16a, 16m, 16z) extending in the tire width direction are formed concentrated in the central portion of the block (15P, 15Q) in the tire circumferential direction.
Of the at least three widthwise sipes (16a, 16m, 16z), the two outermost outer widthwise sipes (16a, 16z) are opened on both sides of the block (15P, 15Q) in the tire width direction.
The inner width direction sipe (16m) between the two outer width direction sipe (16a, 16z) is a pneumatic tire characterized in that both ends thereof are inside the block. The pneumatic tire according to claim 1, wherein the inner width direction sipe (16 m) is deeper in the tire radial direction than the outer width direction sipe (16a, 16z). The circumferential groove (11i, 11o) extends in a zigzag shape in the tire circumferential direction while swinging in the tire width direction.
The block (15P, 15Q) is bent so that the center in the tire circumferential direction matches the zigzag shape of the circumferential groove (11i, 11o).
The pneumatic tire according to claim 1 or 2, wherein the inner width direction sipe (16 m) is formed at a bent portion of the block (15P, 15Q). The block (15P, 15Q) is characterized in that the center in the tire circumferential direction is bent so that the side surface (15Ps, 15Qs) on the circumferential groove (11i, 11o) side of the zigzag shape protrudes. The pneumatic tire according to claim 3.

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