JP7590170B2 - Pneumatic tires - Google Patents

Description

The present invention relates to a pneumatic tire.

The tread of a pneumatic tire is provided with multiple circumferential grooves that extend around the tire, and block pattern tires are also known in which lateral grooves are provided in the land areas partitioned by the circumferential grooves, forming a block row made up of multiple blocks.

In tires with such block patterns, in order to increase the block rigidity in the tire circumferential direction and improve resistance to uneven wear, it has been proposed to provide a bridge that protrudes from the bottom of the lateral groove to connect adjacent blocks in the tire circumferential direction across the lateral groove (see Patent Document 1).

Patent Publication 2010-69956

However, providing a bridge in a lateral groove reduces the groove volume, which reduces snow and soil removal performance.

The present invention was made in consideration of these circumstances, and aims to provide a pneumatic tire that can increase block rigidity in the tire circumferential direction and improve resistance to uneven wear while suppressing deterioration of snow and soil removal performance.

The pneumatic tire of the present invention has a tread having a block row formed by a plurality of main grooves extending in a tire circumferential direction and a plurality of lateral grooves extending in a direction intersecting the main grooves, the lateral grooves including a pair of first lateral groove portions located on both sides in the tire width direction, and a second lateral groove portion located between the pair of first lateral groove portions and having a narrower groove width than the first lateral groove portions, the first lateral groove portion having a first shallow groove portion having a shallower depth than the main grooves, and the second lateral groove portion having a second shallow groove portion having a shallower depth than the first shallow groove portion,
The block row includes a center block row located in a center portion of the tread in a tire width direction and sandwiched between the main grooves,
the first lateral groove portion provided in the center block row inclines toward one side in the tire circumferential direction toward the center of the center block row in the width direction, and then changes its length direction at a bent portion and inclines toward the other side in the tire circumferential direction,
A pneumatic tire in which an outer end in the tire width direction of the first shallow groove portion provided in the center block row is located outer in the tire width direction than the bent portion.

The above pneumatic tire can increase block rigidity in the tire circumferential direction and improve resistance to uneven wear while minimizing deterioration of snow and soil removal performance.

FIG. 1 is a half cross-sectional view of a pneumatic tire according to a first embodiment of the present invention; FIG. 2 is a development view of the tread portion and the buttress portion of the pneumatic tire of FIG. 1. Enlarged view of the main part of Figure 2 AA cross-sectional view of FIG.

One embodiment of the present invention will now be described with reference to the drawings. Figure 1 is a tire meridian cross-section of a pneumatic tire T, and Figure 2 is a development of the pneumatic tire T. Only the right half is shown in Figure 1.

In the figure, the symbol CL indicates the tire equatorial plane, which corresponds to the center in the tire width direction. In this example, the pneumatic tire T is symmetrical with respect to the tire equatorial plane CL.

Here, the tire width direction is the direction parallel to the tire rotation axis, and is indicated by the symbol WD in the drawings. The inner side of the tire width direction WD is the direction approaching the tire equatorial plane CL, and the outer side of the tire width direction WD is the direction moving away from the tire equatorial plane CL. The tire radial direction is the direction perpendicular to the tire rotation axis, and is indicated by the symbol RD in the drawings. The inner side of the tire radial direction RD is the direction moving towards the tire rotation axis, and the outer side of the tire radial direction RD is the direction moving away from the tire rotation axis. The tire circumferential direction is the circumferential direction centered on the tire rotation axis, and is indicated by the symbol CD in the drawings.

Unless otherwise specified, the dimensions of each part of a pneumatic tire in this specification are for a pneumatic tire mounted on a standard rim, inflated to the standard internal pressure, and in a standard, unloaded condition.

In addition, in Figures 1 and 2, the symbol E indicates the contact end when the pneumatic tire is mounted on a standard rim, inflated to the standard internal pressure, placed vertically on a flat road surface, and subjected to a standard load.

A regular rim is a rim that is determined for each tire by the standard system that includes the standard on which the tire is based. For example, for JATMA, it is a standard rim, for TRA, it is a "Design Rim", and for ETRTO, it is a "Measuring Rim". Regular internal pressure is the air pressure that is determined for each tire by each standard in the standard system that includes the standard on which the tire is based. For JATMA, it is the maximum air pressure, for TRA, it is the maximum value listed in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES", and for ETRTO, it is "INFLATION PRESSURE".

The normal load is the load that each standard specifies for each tire in the standard system on which the tire is based. For JATMA, it is the maximum load capacity, for TRA, it is the maximum value listed in the table above, and for ETRTO, it is the "LOAD CAPACITY."

This pneumatic tire T comprises a pair of left and right beads 1, a pair of left and right sidewalls 2 extending radially outward from the beads 1, a tread 3 continuing to the radially outer ends of each of the sidewalls 2, and a pair of left and right buttresses 14 arranged radially inward of the tread 3. The buttresses 14 are boundary regions between the sidewalls 2 and the tread 3, and are provided to connect the sidewalls 2 and the tread 3.

The bead 1 has an annular bead core 1a and a bead filler 1b. A toroidal carcass 4 is provided between the pair of beads 1.

The carcass 4 runs from the tread 3 through the buttress 14 and sidewall 2 to the bead 1 and is secured by the bead core 1a, reinforcing the bead 1, sidewall 2, buttress 14, and tread 3. In this example, the carcass 4 is secured by folding back both ends around the bead core 1a from the inside to the outside in the tire width direction. An inner liner is arranged inside the carcass 4 to maintain air pressure.

The carcass 4 has at least one ply in which organic fiber or steel cords are arranged at a predetermined angle (e.g., 70° to 90°) with respect to the tire circumferential direction CD and covered with topping rubber. In this example, it is composed of two plies. As the organic fiber cords that make up the carcass 4, for example, polyester fiber, rayon fiber, aramid fiber, nylon fiber, etc. are preferably used.

The sidewall rubber 5 is provided on the outside of the carcass 4 (i.e., the outer surface side of the tire) of the sidewall 2.

The tread 3 has a belt layer 6 on the outer side of the carcass 4 in the tire radial direction RD, and a tread rubber 7 is laminated on the outer side of the belt layer 6 in the tire radial direction RD.

The belt layer 6 is composed of multiple belts 8, 9 provided on the inner side of the tread rubber 7 in the tire radial direction RD. The belts 8, 9 are made of belt cords such as steel cords arranged at an inclined angle of, for example, 10° to 35° with respect to the tire circumferential direction CD and covered with rubber. In this example, the belt layer 6 has a two-layer structure having two belts, a first belt 8 and a second belt 9, in that order from the inner side in the tire radial direction RD. Note that the number of belt layers 6 is not limited to two, and may be three or more.

The first belt 8 is the innermost belt arranged on the innermost side in the tire radial direction RD. The first belt 8 is the widest belt (hereinafter, the first belt 8 may be referred to as the "widest belt 8") of the two belts, having the largest width (belt width, i.e., the dimension of the belt in the tire width direction WD). The second belt 9 is the outermost belt arranged on the outermost side in the tire radial direction RD (hereinafter, the second belt 9 may be referred to as the "outer belt 9").

Between the maximum width belt 8 and the carcass 4, a belt under rubber layer 10 is provided, which does not contain cord reinforcing materials such as organic fibers or steel cords, so as to gradually move away from the carcass 4 toward the tire width direction end of the maximum width belt 8 (hereinafter sometimes referred to as the "maximum width belt end 8a").

The outer belt 9 is overlapped on the tire radially outer side of the maximum width belt 8 over the entire tire width direction WD, and the tire width direction end 9a of the outer belt 9 (hereinafter sometimes referred to as the "outer belt end 9a") is also overlapped on the tire radially outer side of the maximum width belt 8.

The tread rubber 7 has a two-layer structure consisting of a cap rubber layer 12 that has a tread surface that comes into contact with the road surface, and a base rubber layer 13 that is arranged on the inner side of the cap rubber layer 12 in the tire radial direction RD. The tread rubber 7 covers the outer end of the sidewall rubber 5 in the tire radial direction.

The cap rubber layer 12 has an outer end in the tire width direction that covers the outer end in the tire width direction of the base rubber layer 13, and terminates on the inner side in the tire radial direction RD than the outer end in the tire width direction of the base rubber layer 13. In other words, the outer end in the tire width direction of the cap rubber layer 12 is located on the outer side in the tire width direction WD and on the inner side in the tire radial direction RD than the outer end in the tire width direction of the base rubber layer 13. As a result, the entire width of the base rubber layer 13 is covered by the cap rubber layer 12 and is not exposed to the outer tire surface.

In the cap rubber layer 12, a number of main grooves 20A, 20A, 20B, 20B extending along the tire circumferential direction CD are formed at intervals in the tire width direction WD. In this example, a pair of center main grooves 20A, 20A are provided on both sides of the tire equatorial plane CL, and a pair of shoulder main grooves 20B, 20B are provided on the outside of the center main grooves 20A, 20A. The four main grooves 20A, 20A, 20B, 20B are zigzag grooves that extend in the tire circumferential direction CD while bending with amplitude in the tire width direction WD.

In the cap rubber layer 12, a plurality of land portions are defined in the tire width direction WD by grooves 20A, 20A, 20B, 20B. In detail, a center land portion 21 is sandwiched between a pair of center main grooves 20A, 20A, a pair of left and right intermediate land portions 22 are sandwiched between the center main groove 20A and the shoulder main groove 20B, and a pair of left and right shoulder land portions 23 are formed between the shoulder main groove 20B and the ground contact edge E.

The center land portion 21 is provided with a plurality of center lateral grooves 24 spaced apart in the tire circumferential direction CD, which extend crossing the center main groove 20A. The center lateral grooves 24 are provided so as to cross the center land portion 21. The center land portion 21 is formed as a center block row in which a plurality of center blocks partitioned by the center lateral grooves 24 are arranged in the tire circumferential direction CD.

As shown in Figures 3 and 4, the center lateral groove 24 includes a pair of first center lateral groove portions 34 provided on both sides in the tire width direction WD, and a second center lateral groove portion 35 provided between the pair of first center lateral groove portions 34.

The pair of first center lateral grooves 34 open into the center main groove 20A at positions where one end of the tire width direction WD is offset from the other in the tire circumferential direction CD. The first center lateral grooves 34 incline toward one side of the tire circumference as they move from the center main groove 20A toward the widthwise center of the center block, and then the length direction of the first center lateral grooves 34 changes at the bend 34a (see FIG. 3), and they incline in the opposite direction toward the other side of the tire circumference.

The second center lateral groove portion 35 is a narrower lateral groove that is narrower than the first center lateral groove portion 34, extends in a direction inclined with respect to the tire width direction WD, and connects a pair of first center lateral groove portions 34.

A pair of the first center lateral groove portion 34 and the second center lateral groove portion 35 is provided with a bridge 37 that connects the lateral side surfaces 21a (see FIG. 3) of the center blocks facing each other across the center lateral groove 24, and shallow groove portions 38, 39 that are shallower than the center main groove 20A are formed at the position where the bridge 37 is provided (see FIG. 4).

Specifically, the bridge 37 protrudes from the groove bottom of the center lateral groove 24, which is at the same height as the groove bottom of the center main groove 20A, to a greater extent in the second center lateral groove portion 35 than in the first center lateral groove portion 34. As a result, the first center lateral groove portion 34 is formed with a first shallow groove portion 38 that is shallower than the center main groove 20A, and the second center lateral groove portion 35 is formed with a second shallow groove portion 39 that is shallower than the first shallow groove portion 38.

Such a bridge 37 may be provided on the outer side in the tire width direction of the bent portion 34a of the first center lateral groove portion 34 so that the outer end in the tire width direction of the first shallow groove portion 38 is located on the outer side in the tire width direction of the bent portion 34a.

In the intermediate land portion 22, a plurality of intermediate lateral grooves 25 are provided at intervals in the tire circumferential direction CD, which extend crossing the center main groove 20A and the shoulder main groove 20B. The intermediate lateral grooves 25 are provided so as to cross the intermediate land portion 22. The intermediate land portion 22 is formed as an intermediate block row consisting of a plurality of intermediate blocks partitioned by the intermediate lateral grooves 25 and arranged in the tire circumferential direction CD.

The intermediate lateral groove 25 comprises a pair of first intermediate lateral groove portions 40 provided on both sides in the tire width direction WD, and a second intermediate lateral groove portion 41 provided between the pair of first intermediate lateral groove portions 40.

The pair of first intermediate lateral grooves 40 open into the main grooves 20A, 20B at positions offset from each other in the tire circumferential direction CD at one end in the tire width direction WD. The first intermediate lateral grooves 40 incline toward one side in the tire circumferential direction as they move from the main grooves 20A, 20B toward the widthwise center of the intermediate block.

The second intermediate lateral groove portion 41 is a narrower lateral groove having a narrower groove width than the first intermediate lateral groove portion 40, extends in a direction inclined with respect to the tire width direction WD, and connects a pair of first intermediate lateral groove portions 40.

A pair of first intermediate transverse groove portions 40 and second intermediate transverse groove portions 41 are provided with bridges 42 that connect the lateral sides 22a (see FIG. 3) of the intermediate blocks that face each other across the intermediate transverse groove 25, and shallow groove portions 43, 44 that are shallower than the center main groove 20A and the shoulder main groove 20B are formed at the positions where the bridges 42 are provided (see FIG. 4).

Specifically, the bridge 42 protrudes from the groove bottom of the intermediate lateral groove 25, which is at the same height as the groove bottoms of the center main groove 20A and shoulder main groove 20B, to a greater extent in the second intermediate lateral groove portion 41 than in the first intermediate lateral groove portion 40. As a result, the first intermediate lateral groove portion 40 has a first shallow groove portion 43 that is shallower than the shoulder main groove 20B, and the second intermediate lateral groove portion 41 has a second shallow groove portion 44 that is shallower than the first shallow groove portion 43.

The groove depth of the first shallow groove portion 38, 43 and the second shallow groove portion 39, 44 may be set, for example, as follows. The groove depth of the first shallow groove portion 38, 43 is preferably 50 to 70% of the groove depth of the center main groove 20A or the shoulder main groove 20B. The groove depth of the second shallow groove portion 39, 44 is preferably 15 to 25% of the groove depth of the center main groove 20A or the shoulder main groove 20B. As an example of the groove depth of the center main groove 20A, the shoulder main groove 20B, the first shallow groove portion 38, 43, and the second shallow groove portion 39, 44, the groove depth of the center main groove 20A and the shoulder main groove 20B can be 8 to 12 mm, the groove depth of the first shallow groove portion 38, 43 can be 4 to 8.4 mm, and the groove depth of the second shallow groove portion 39, 44 can be 1.2 to 3.0 mm.

The center block and intermediate block provided in the center land portion 21 and intermediate land portion 22 are provided with a first sipe 51 and a third sipe 53 extending in the tire width direction WD.

The first sipes 51 are provided at the circumferential center of the center block and intermediate block so as to penetrate the blocks. The first sipes 51 extend in a wavy manner in a direction slightly inclined with respect to the tire width direction WD.

The third sipes 53 are provided on both sides of the first sipes 51 in the tire circumferential direction CD at intervals and inclined in the same direction as the first sipes 51. The third sipes 53 are provided so as to terminate within the center block and intermediate block.

The first sipe 51 and the third sipe 53 are slits with a very small groove width that closes when the pneumatic tire is mounted on a standard rim, inflated to the standard internal pressure, and placed in contact with the road surface and subjected to a standard load, and the first sipe 51 has a larger groove width than the third sipe 53.

The shoulder land portion 23 is provided with multiple shoulder lateral grooves 26 spaced apart in the tire circumferential direction CD, which extend crossing the shoulder main groove 20B. The shoulder lateral grooves 26 open at the ground contact edge E on the outer side in the tire width direction, and terminate within the shoulder land portion 23 on the inner side in the tire width direction without opening into the shoulder main groove 20B.

The shoulder lateral groove 26 includes a first lateral groove portion 27 on the shoulder main groove 20B side (inner side in the tire width direction), a second lateral groove portion 28 that is wider than the first lateral groove portion 27 and is provided on the outer side of the first lateral groove portion 27 in the tire width direction, and a connecting portion 29 that connects the first lateral groove portion 27 and the second lateral groove portion 28. The second lateral groove portion 28 extends from the outer belt end 9a to the inner side in the tire width direction so as to overlap the maximum width belt end 8a and the outer belt end 9a in the tire radial direction RD.

The shoulder lateral groove 26 is provided with a bottom-raised portion 30 that rises from the groove bottom so as to connect the lateral sides 23a, 23a of the shoulder land portion 23 that forms the shoulder lateral groove 26.

Specifically, as shown in FIG. 1, the bottom-raised portion 30 includes a flat portion 31 that rises from the groove bottom 26a of the shoulder lateral groove 26 so that the groove depth is shallower, a root portion 32a that connects the groove bottom 26a (here, the groove bottom of the first lateral groove portion 27) at the tire width direction inner end of the lateral groove 26 and the flat portion 31, and a root portion 32a that connects the groove bottom 26a (here, the groove bottom of the second lateral groove portion 28) at the tire width direction outer end of the lateral groove 26 and the flat portion 31.

The flat portion 31 is arranged parallel to the contour line (profile line) of the tread surface, and the groove depth in the flat portion 31 is constant. The groove depth in the flat portion 31 is shallower than the groove depth at the groove bottom of the first lateral groove portion 27 and the groove depth at the groove bottom of the second lateral groove portion 28.

The shoulder land portion 23 is provided with second sipes 52 and fourth sipes 54 that extend in the tire circumferential direction CD.

The second sipes 52 penetrate the shoulder land portion 23 in the tire circumferential direction CD so as to connect the first lateral groove portions 27 of the shoulder lateral grooves 26 adjacent in the tire circumferential direction CD. The second sipes 52 extend in a wavy manner in the tire circumferential direction CD.

The fourth sipes 54 are provided at intervals in the tire circumferential direction CD on both sides of the second sipes 52 in the tire width direction. The fourth sipes 54 extend in a wavy manner in a direction slightly inclined with respect to the tire width direction WD, and are provided so as to terminate within the shoulder land portion 23.

The second sipe 52 and the fourth sipe 54 are slits with a very small groove width that closes when the pneumatic tire is mounted on a standard rim, inflated to the standard internal pressure, and placed in contact with the road surface and subjected to a standard load. The second sipe 52 has a larger groove width than the fourth sipe 54, and may have the same groove width as the first sipe 51 described above.

The width dimensions of the first sipe 51, the second sipe 52, the third sipe 53 and the fourth sipe 54 may be set, for example, as follows. The width of the first sipe 51 is preferably 0.6 to 1.2 mm. The width of the second sipe 52 is preferably 0.6 to 1.2 mm. The width of the third sipe 53 is preferably 0.3 to 0.6 mm. The width of the fourth sipe 54 is preferably 0.3 to 0.6 mm. In the pneumatic tire T of this embodiment as described above, the second shallow groove portions 39, 44 having a narrow groove width and a shallow groove depth are provided in the tire width direction central portions of the center lateral groove 24 and the intermediate lateral groove 25, so that the block rigidity in the tire circumferential direction CD can be efficiently improved. In addition, the first shallow groove sections 38, 43, which are provided on the widthwise outer side of the second shallow groove sections 39, 44, are wider and deeper than the second shallow groove sections 39, 44, so they are less likely to impede the discharge of snow and soil that has entered the center lateral groove 24 or intermediate lateral groove 25 into the main grooves 20A, 20B, and the bridges 37, 42 provided at the bottom of the grooves can be used to prevent a decrease in snow and soil discharge.

In addition, in the pneumatic tire T of this embodiment, the first center lateral groove portion 34 provided in the center lateral groove 24 is provided with a bent portion 34a whose length direction changes, thereby improving traction performance.

In addition, the outer end of the first shallow groove portion 38 in the shoulder lateral groove 26 is located on the outer side in the tire width direction than the bend 34a, improving the block rigidity in the vicinity of the bend 34a and improving traction.

In addition, the blocks constituting the center land portion 21 and the intermediate land portion 22 formed between the shoulder land portions 23 on both sides in the tire width direction WD are provided with first sipes 51 extending in the tire width direction, and the shoulder land portion 23 is provided with second sipes 52 extending in the circumferential direction. Therefore, when traveling on a road surface with a high friction coefficient, slippage in the center of the blocks constituting the center land portion 21 and the intermediate land portion 22 can be eliminated, heel-and-toe wear occurring on both sides of the tire circumferential direction of the center lateral groove 24 and the intermediate lateral groove 25 can be suppressed, and slippage in the tire width direction and uneven ground contact pressure distribution caused by wiping in the shoulder land portion 23 can be eliminated, and uneven wear occurring in the tire width direction in the shoulder land portion 23 can be suppressed. When traveling on a road surface with a low friction coefficient, the rigidity in the center of the blocks constituting the center land portion 21 and the intermediate land portion 22 and the center of the tire width direction of the shoulder land portion 23 can be reduced to uniformize the ground contact pressure.

In addition, in the pneumatic tire T, the flat portion 31 of the bottom-raised portion 30 that rises from the groove bottom of the shoulder land portion 23 is provided on the tire radially outer side of the outer belt end 9a, so that the rubber thickness can be ensured near the outer belt end 9a, which is prone to distortion when the tire rolls, and the movement of the belt end floating outward in the tire radial direction, known as belt lift, can be suppressed when the tire rolls.

In addition, in the pneumatic tire T, the flat portion 31 of the bottom-raised portion 30 terminates on the inner side in the tire width direction than the maximum width belt end 8a, which prevents an increase in the amount of rubber and a decrease in the drainage performance of the shoulder lateral grooves 26. Moreover, near the maximum width belt end 8a, the tire inner side (carcass 4 side) of the belt layer 6 is curved more toward the tire radially inward than the outer side (tread rubber side), making it easier to ensure the thickness of the tread rubber 7 near the maximum width belt end 8a, so belt lift can be prevented even if there is no flat portion 31 on the tire radially outer side of the maximum width belt end 8a.

In addition, the pneumatic tire T has shoulder land portions 23, 23 each having a first lateral groove portion 27 and a second lateral groove portion 28 that is wider than the first lateral groove portion 27, and a bottom-raised portion 30 is provided at the bottom of the second lateral groove portion 28 to connect the lateral sides 23a, 23a that define the second lateral groove portion 28. This ensures the groove volume of the shoulder land portion 23 and improves drainage performance, while preventing a decrease in land portion rigidity near the second lateral groove portion 28 by the bottom-raised portion 30.

In addition, in the pneumatic tire T, a belt under rubber layer 10 is disposed between the widthwise end of the maximum width belt 8 and the carcass 4, and the maximum width belt end 8a does not come into direct contact with the carcass 4, which contains organic fibers, steel cords, etc., so that the distortion that occurs near the maximum width belt end 8a when the tire rolls can be alleviated, and belt lift can be suppressed.

The above embodiment is presented as an example and is not intended to limit the scope of the invention. This novel embodiment can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention.

For example, in the above embodiment, the center land portion 21 and the shoulder land portion 22 are provided with lateral grooves 24, 25 each having a first shallow groove portion 38, 43 and a second shallow groove portion 39, 44. However, it is also possible to provide the first shallow groove portion and the second shallow groove portion in only one of the land portions of the center land portion 21 and the shoulder land portion 22, and not provide the first shallow groove portion and the second shallow groove portion in the other land portion.

T...tire, 1...bead, 2...sidewall, 3...tread, 4...carcass, 5...sidewall rubber, 6...belt layer, 7...tread rubber, 8...widest belt, 8a...widest belt end, 9...outer belt, 9a...outer belt end, 10...underbelt rubber layer, 12...cap rubber layer, 13...base rubber layer, 14...buttress, 20A...center main groove, 20B...shoulder main groove, 21...center land portion, 22...intermediate land portion, 23...shoulder land portion, 24...center lateral groove, 25...intermediate lateral groove, 26...shoulder lateral groove, 27...first lateral groove, 28...second lateral groove, 29...connection, 30...bottom raised portion, 31...flat portion, 32a...root portion, 32b...root portion, 34...first center lateral groove, 34a...bend portion, 35...second center lateral groove, 37...bridge, 38...first shallow groove, 39...second shallow groove, 40...first intermediate lateral groove, 41...second intermediate lateral groove, 42...bridge, 43...first groove shallow portion, 44...second groove shallow portion, 51...first sipe, 52...second sipe, 53...third sipe, 54...fourth sipe

Claims (2)

A pneumatic tire having a tread having a block row formed by a plurality of main grooves extending in a tire circumferential direction and a plurality of lateral grooves extending in a direction intersecting the main grooves,
The lateral groove includes a pair of first lateral groove portions located on both sides in the tire width direction, and a second lateral groove portion located between the pair of first lateral groove portions and having a groove width narrower than that of the first lateral groove portions,
The first lateral groove portion has a first shallow groove portion having a depth shallower than that of the main groove,
The second lateral groove portion has a second shallow groove portion having a depth shallower than that of the first shallow groove portion,
The block row includes a center block row located in a center portion of the tread in a tire width direction and sandwiched between the main grooves,
the first lateral groove portion provided in the center block row inclines toward one side in the tire circumferential direction toward the center of the center block row in the width direction, and then changes its length direction at a bent portion and inclines toward the other side in the tire circumferential direction,
A pneumatic tire in which an outer end in the tire width direction of the first shallow groove portion provided in the center block row is located outer in the tire width direction than the bent portion. The main grooves include a pair of shoulder main grooves formed on outer sides in the tire width direction,
a pair of shoulder land portions formed between the pair of shoulder main grooves and a ground contact edge on outer sides of the block row in the tire width direction,
the block rows are located on the inner sides of the pair of shoulder land portions,
A first sipe extending in the tire width direction is provided in each block constituting the block row,
The pneumatic tire according to claim 1 , wherein a second sipe extending in the tire circumferential direction is provided in the shoulder land portion.

Images