pneumatic tires

Abstract

To provide a pneumatic tire which achieves restraint of generation of groove bottom crack of a peripheral groove which partitions a shoulder land into a land body and a sacrifice rib and restraint of wear of the land body after wear of the sacrifice rib.SOLUTION: A tire includes a peripheral groove which extends from a contact area to the inside in a radial direction of the tire and is positioned on the outer side in an axial direction of the tire than a belt end which is on the outermost side in the axial direction of the tire among the belt ends of a plurality of belt plies. The peripheral groove partitions a land into a land body and a sacrifice rib which is positioned on the outer side in the axial direction of the tire than the land body. The sacrifice rib includes a first annular groove on the outer side in the radial direction of the tire than the groove bottom of the peripheral groove. The first annular groove opens on a wall surface of the peripheral groove or a surface of a buttress, terminates within the sacrifice rib and extends in a circumferential direction of the tire to have an annular shape. The surface of the buttress includes a second annular groove which opens on the inner side in the radial direction of the tire than the groove bottom of the peripheral groove. The second annular groove extends to and terminates in the inner side in the axial direction of the tire than the wall surface of the peripheral groove on the inside in the axial direction of the tire.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to pneumatic tires. [Background technology]

[0002] It is known that pneumatic tires used on trucks and buses have high contact pressure at the edges of the land that forms the contact surface, making the land prone to wear.

[0003] Patent Document 1 discloses a tire in which two annular grooves are formed in a buttress on the tire sidewall surface.

[0004] Patent Document 2 discloses a tire having grooves that define a tread and fine groove rows formed in shoulder portions. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2019-99077 [Patent Document 2] Japanese Patent Application Laid-Open No. 2000-6615 Summary of the Invention [Problem to be solved by the invention]

[0006] In a tire having a shoulder land forming a contact patch and a circumferential groove extending radially inward from the contact patch of the shoulder land, where the shoulder land is divided into a land body and a sacrificial rib by the circumferential groove, cracks may occur at the bottom of the circumferential groove. Furthermore, after the sacrificial rib wears, the contact pressure of the land body may increase, accelerating wear of the land body.

[0007] The present disclosure provides a pneumatic tire that suppresses the occurrence of groove bottom cracks in circumferential grooves that separate shoulder land into land bodies and sacrificial ribs, and that suppresses wear of the land bodies after the sacrificial ribs have worn away. [Means for solving the problem]

[0008] a surface of a buttress extending radially inward from an edge of the contact patch, a circumferential groove extending radially inward from the contact patch, going around the tire circumferentially, and positioned axially outward of an axially outermost belt end of the belt plies, the circumferential groove dividing the land into a land body and a sacrificial rib positioned axially outward of the land body, the sacrificial rib having a first annular groove radially outward of a groove bottom of the circumferential groove, the first annular groove opening onto a wall surface of the circumferential groove or onto a surface of the buttress, terminating within the sacrificial rib and extending circumferentially in the tire, the surface of the buttress having a second annular groove opening radially inward of the groove bottom of the circumferential groove, extending circumferentially in the tire, and forming an annular ring, the second annular groove extending axially inward of an axially inner wall surface of the circumferential groove and terminating in the sacrificial rib [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a tire meridian cross-sectional view showing a main part of a pneumatic tire according to a first embodiment. [Figure 2] 1 is a side view of a pneumatic tire according to a first embodiment. [Figure 3] FIG. 2 is an enlarged cross-sectional view of a tire meridian showing a main part of FIG. 1. [Figure 4] FIG. 4 is a tire meridian cross section showing a modified example of the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] [First embodiment] A pneumatic tire according to a first embodiment of the present disclosure will be described below with reference to the drawings. In the drawings, "CD" denotes the tire circumferential direction, "AD" denotes the tire axial direction, and "RD" denotes the tire radial direction. Each drawing shows the shape of a new tire.

[0011] 1 and 2, a pneumatic tire includes a pair of beads (not shown), sidewalls 2 extending from each bead toward the tire radially outer side RD1, and a tread 3 connecting the tire radially outer RD1 ends of the sidewalls 2. Each bead includes an annular bead core (not shown) made of a rubber-coated bundle of steel wire or the like, and a bead filler (not shown) made of hard rubber. The bead is attached to a bead seat of a rim (not shown), and if the air pressure is a predetermined pressure (for example, an air pressure determined by JATMA), the internal tire pressure causes the tire to fit properly against the rim flange, and the tire is fitted to the rim.

[0012] The tire also includes a toroidal carcass 4 extending from the tread 3 through the sidewalls 2 to the beads. The carcass 4 is provided between a pair of beads, with its ends secured in a wound-up state via the bead cores. An inner liner rubber 5 for maintaining air pressure is disposed on the inner circumferential side of the carcass 4.

[0013] A plurality of belt plies 6a, 6b, 6c, and 6d (four in the first embodiment) for reinforcing the carcass 4 and a tread rubber 30 are provided on the outer periphery of the carcass 4 in the tread 3, in this order from the inside to the outside. The plurality of belt plies 6a, 6b, 6c, and 6d are disposed between the carcass 4 and the tread rubber 30. It can also be said that the plurality of belt plies 6a, 6b, 6c, and 6d are disposed between the carcass 4 and a contact patch 33 formed by the tread rubber 30. A plurality of main grooves 31 extending along the tire circumferential direction CD and lands 32 partitioned by the main grooves 31 and continuing in the tire circumferential direction CD are formed on the surface of the tread 3. Since the first embodiment is a rib tire, no blocks separated in the tire circumferential direction CD are formed. In the first embodiment, two main grooves 31 are formed on one side of the tire, for a total of four main grooves 31, but this is not limiting. For example, the total number of main grooves may be three, or five or more.

[0014] In the first embodiment, the main grooves 31 form shoulder lands 32a, quarter lands 32b, and center lands 32c, but the number of lands 32 can be changed as appropriate. The center lands 32c are the lands closest to the tire equatorial plane CL. The shoulder lands 32a are lands formed axially outward of the main groove 31 that is located axially outermost in the tire's axial direction AD1 among the multiple main grooves 31. The quarter lands 32b are lands located between the shoulder lands 32a and the center lands 32c. Depending on the number of main grooves 31, the quarter lands 32b may be omitted.

[0015] Each of the four belt plies 6a, 6b, 6c, and 6d includes a plurality of steel cords arranged in parallel like a blind and coated with rubber. Of the four belt plies 6a, 6b, 6c, and 6d, the cords of the second and third belt plies 6b and 6c, which are positioned from the carcass 4 toward the outer periphery, intersect at an angle in opposite directions relative to the tire axis. The second and third belt plies 6b and 6c are so-called main belts, and sandwich the tread rubber 30 therebetween.

[0016] As shown in Figure 1, the land 32 of the tread 3 forms a contact patch 33. Further axially outward from the contact edge LE of the contact patch 33 on the axially outer side AD1 of the tire, there is a tire sidewall surface 7 formed of sidewall rubber. The tire sidewall surface 7 includes a buttress 70 in the region from the contact edge LE to the maximum tire width portion (not shown). As in the first embodiment, the contact edge LE in a heavy-duty tire corresponds to the ridge line between the contact patch 33 and the tire sidewall surface 7.

[0017] The ground contact edge LE is the outermost end of the ground contact surface 33 in the tire axial direction AD. The contact surface 33 refers to the surface that comes into contact with the road when the 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 standard rim is a rim specified for each tire by the standard that includes the standard on which the tire is based. In the case of JATMA, it is called the standard rim, and in the case of TRA or ETRTO, it is called the "Measuring Rim."

[0018] The normal internal pressure is the pressure specified for each tire by the standard system that includes the standard on which the tire is based. For JATMA, it is the maximum 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."

[0019] The normal load is the load specified for each tire by each standard, including the standard 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 "LOAD CAPACITY."

[0020] FIG. 3 is an enlarged view of a main portion of FIG. 1. As shown in FIGS. 1 to 3, the tire has a circumferential groove 80 extending from the ground contact surface 33 toward the tire radially inner side RD2. The circumferential groove 80 extends around the tire in the tire circumferential direction CD. The circumferential groove 80 (including its groove bottom 80a) is located axially outer than the belt end 60, which is located axially outermost in the tire axial direction AD1, among the belt ends of the multiple belt plies 6a, 6b, 6c, and 6d. The circumferential groove 80 divides the shoulder land 32a into a land main body 34 and a sacrificial rib 35. The sacrificial rib 35 is located axially outer in the tire axial direction AD1 of the land main body 34. The circumferential groove 80 of the first embodiment extends parallel to the tire radial direction.

[0021] The depth of the circumferential groove 80 may be 15 mm or less, or the depth of the circumferential groove 80 may be 80% or more and 100% or less of the depth of the main groove. The width of the circumferential groove 80 in the tire axial direction AD may be 1.5 mm or more and 3.0 mm or less. The circumferential groove 80 may be disposed within 2.0 mm from the ground contact edge LE. The circumferential groove 80 may be arranged axially outward AD1 from a position that is 20% of the axial dimension AD of the shoulder land 32a, from the ground contact edge LE toward the axially inward AD2 of the tire.

[0022] The sacrificial rib 35 has at least one first annular groove 90. The at least one first annular groove 90 is disposed further outward in the tire radial direction than the groove bottom 80a of the circumferential groove 80, RD1. When a plurality of first annular grooves 90 are formed, all of the first annular grooves 90 are disposed further outward in the tire radial direction than the groove bottoms 80a of the circumferential grooves 80, RD1. The first annular groove 90 opens to the surface 7 of the buttress 70 and terminates within the sacrificial rib 35. The first annular groove 90 is formed in an annular shape and extends continuously in the tire circumferential direction CD. The first annular groove 90 allows the sacrificial rib 35 to bend, and the groove bottom of the first annular groove 90 also bears the stress, making it possible to distribute the stress acting on the groove bottom 80a of the circumferential groove 80.

[0023] As shown in Fig. 3, the first annular groove 90 may be disposed at the center C1 of the groove depth of the circumferential groove 80, or may be disposed further inward in the tire radial direction than the center C1 of the groove depth of the circumferential groove 80, RD2. The center C1 is half the groove depth of the circumferential groove 80. This allows the first annular groove 90 to be spaced away from the ground contact patch 33 that comes into contact with the road surface, thereby making it possible to suppress the occurrence of cracks originating from the first annular groove 90. When there are multiple first annular grooves 90, it is preferable that the first annular groove 90 located on the outermost side RD1 in the tire radial direction is disposed at the center C1 of the groove depth of the circumferential groove 80, or may be disposed further inward in the tire radial direction than the center C1 of the groove depth of the circumferential groove 80, RD2.

[0024] The length D2 of the first annular groove 90 in the axial direction AD of the tire is preferably one-third or less of the length D1 of the axial direction AD of the sacrificial rib 35 at the contact patch 33. This is to ensure the rigidity of the sacrificial rib 35 and its durability against external damage. If the length D2 of the first annular groove 90 in the axial direction AD of the tire is greater than one-third of the length D1 of the axial direction AD of the sacrificial rib 35 at the contact patch 33, the rigidity of the sacrificial rib 35 will be impaired, making it vulnerable to external damage.

[0025] At least one first annular groove 90 is provided. The minimum width of each first annular groove 90 is 2 mm. The total width of the first annular groove 90 is preferably 8 mm or less. In the first embodiment, one first annular groove 90 is formed, so the width E1 of the first annular groove 90 can be 2 mm or more and 8 mm or less. In another embodiment, if there are two first annular grooves 90, the width E1 of the first annular groove 90 can be 2 mm or more and 4 mm or less. In another embodiment, if there are three first annular grooves 90, the width E1 of the first annular groove 90 can be 2 mm or more and (8 / 3) mm or less. In another embodiment, if there are four first annular grooves 90, the width E1 of the first annular groove 90 is 2 mm. If the width of the first annular groove 90 is smaller than 2 mm, the effect of dispersing stress is less likely to be achieved, and if the total width of the first annular groove 90 exceeds 8 mm, the rigidity of the sacrificial rib is impaired, reducing its durability against external damage. The width of the first annular groove 90 is measured in the thickness direction. In the first embodiment, the first annular groove 90 has a shape having parallel straight surfaces and curved edges in a tire meridian cross section. The width E1 of the first annular groove 90 is measured along a perpendicular line to the parallel straight surfaces.

[0026] The surface 7 of the buttress 70 has at least one second annular groove 91. The second annular groove 91 opens radially inward RD2 of the tire with respect to the groove bottom 80a of the circumferential groove 80. The second annular groove 91 is formed in a ring shape and extends continuously in the tire circumferential direction. The second annular groove 91 extends and terminates axially inward AD2 of the tire further than a wall surface 80c of the circumferential groove 80 on the axially inward AD2 of the tire. An end 91a of the second annular groove 91 on the axially inward AD2 of the tire is located axially inward AD2 of the wall surface 80c of the circumferential groove 80. As shown in Figure 3, the second annular groove 91 extends further toward the inner side AD2 of the tire axial direction than the wall surface 80c of the circumferential groove 80 on the inner side AD2 of the tire axial direction, so that the ground contact pressure at the end of the land body 34 can be reduced even after the sacrificial rib 35 has worn away, thereby suppressing wear of the land body 34.

[0027] The second annular groove 91 may be 3 mm or more away from the belt end 60, which is axially outermost among the belt ends of the multiple belt plies 6a, 6b, 6c, and 6d, AD1. That is, it is preferable that the shortest distance D3 between the second annular groove 91 and the belt end 60 is 3 mm or more. Even if a crack occurs in the second annular groove 91, it is possible to prevent the crack from reaching the belt ply 6b. Furthermore, it is preferable that the shortest distance D5 between the second annular groove 91 and the carcass 4 is 3 mm or more. Even if a crack occurs in the second annular groove 91, the crack can be prevented from reaching the carcass 4.

[0028] At least one second annular groove 91 is provided. The minimum width of each second annular groove 91 is 2 mm. The total width of the second annular groove 91 is preferably 4 mm or less. In the first embodiment, one second annular groove 91 is formed, and therefore the width E2 of the second annular groove 91 can be 2 mm or more and 4 mm or less. In another embodiment, if there are two second annular grooves 91, the width E2 of the second annular groove 91 is 2 mm. In other words, one or two second annular grooves 91 can be provided. If the width of the second annular groove 91 is less than 2 mm, the stress dispersing effect is not easily achieved. If the total width of the second annular grooves 91 exceeds 4 mm, the rigidity of the sacrificial rib is impaired, and durability against external damage is reduced.

[0029] 1, the first annular groove 90 and the second annular groove 91 are preferably spaced apart by 10 mm or more along the surface 7 of the sidewall 2. In other words, the separation distance D4 between the first annular groove 90 and the second annular groove 91 along the surface 7 of the sidewall 2 is 10 mm or more. This is to ensure the rigidity of the buttress 70 as a whole.

[0030] The orientation of the first annular groove 90 and the second annular groove 91 can be set arbitrarily, but may be an orientation between the first orientation and the second orientation. As shown in Fig. 3, the second orientation is an orientation parallel to the contact surface 33 of the sacrificial rib 35, and has an angle θ of N degrees with respect to the tire axial direction AD. This can also be said to be an orientation in which the end on the axially inner side AD2 of the tire is positioned radially outer side RD1 of the tire than the end on the axially outer side AD1 of the tire. The first orientation is a direction parallel to the tire axial direction AD, and the angle θ with respect to the tire axial direction AD is 0. It can also be said that the end of the axially inner side AD2 of the tire and the end of the axially outer side AD1 of the tire are at the same position in the tire radial direction RD. The angle θ of the first annular groove 90 and the second annular groove 91 relative to the tire axial direction AD can be set to be equal to or greater than 0 degrees and equal to or less than N degrees.

[0031] <Modification of the first embodiment> (1) The first annular groove 90 may be disposed radially outward RD1 of the circumferential groove 80 relative to the center C1 of the groove depth.

[0032] (2) The first annular groove 90 and the second annular groove 91 may be oriented such that the angle θ with respect to the tire axial direction AD is negative. That is, the end of the first annular groove 90 on the axially inner side AD2 may be positioned radially inward RD2 of the tire than the end of the first annular groove 90 on the axially outer side AD1. The same applies to the second annular groove 91.

[0033] (3) In the embodiment shown in Figures 1 to 3, the first annular groove 90 opens to the surface 7 of the buttress 70, but is not limited to this. For example, as in the embodiment shown in Figure 4, the first annular groove 90 may open to the side wall 80b of the circumferential groove 80.

[0034] (4) In the first embodiment, the second annular groove 91 is located radially inward RD2 of the belt end 60 of the belt ends of the multiple belt plies 6a, 6b, 6c, and 6d, which is located axially outermost AD1 of the tire. However, this is not limited to this. For example, the second annular groove 91 may be located radially outward RD1 of the belt end 60 of the multiple belt plies 6a, 6b, 6c, and 6d, which is located axially outermost AD1 of the tire. Furthermore, the second annular groove 91 may be located at the same position in the tire radial direction RD as the belt end 60 of the belt ends of the multiple belt plies 6a, 6b, 6c, and 6d, which is located axially outermost AD1 of the tire.

[0035] (5) The shape of the meridian cross section of the first annular groove 90 and the second annular groove 91 is not limited to a shape that combines a linear main body with a curved end portion. The main body may be curved.

[0036] As described above, like the pneumatic tire of the embodiment shown in FIGS. 1 to 4 , the pneumatic tire includes the carcass 4, the land 32 (shoulder land 32 a) forming the ground contact surface 33, the plurality of belt plies 6 a, 6 b, 6 c, 6 d arranged between the carcass 4 and the ground contact surface 33, the surface 7 of the buttress 70 extending from the end (LE) of the ground contact surface 33 toward the tire radially inner side RD2, and the circumferential groove 80 extending from the ground contact surface 33 toward the tire radially inner side RD2, making one turn in the tire circumferential direction CD, and positioned axially outer side AD1 of the belt end 60 of the plurality of belt plies 6 a, 6 b, 6 c, 6 d, and the circumferential groove 80 connects the land 32 to the land main body 34 and The land body 34 may be partitioned into a sacrificial rib 35 located axially outwardly AD1 of the tire, the sacrificial rib 35 having a first annular groove 90 radially outwardly RD1 of the tire than a groove bottom 80a of the circumferential groove 80, the first annular groove 90 opening to a wall surface 80c of the circumferential groove 80 or a surface 7 of the buttress 70, terminating within the sacrificial rib 35 and extending in the tire circumferential direction CD and having a circular shape, the surface 7 of the buttress 70 having a second annular groove 91 opening radially inwardly RD2 of the tire than the groove bottom 80a of the circumferential groove 80 and extending in the tire circumferential direction CD and having a circular shape, the second annular groove 91 extending axially inwardly AD2 of the tire than a wall surface 80c of the circumferential groove 80 and terminating.

[0037] According to this configuration, the sacrificial rib 35 can bend starting from the first annular groove 90, and since not only the circumferential groove 80 but also the first annular groove 90 bears stress, the stress acting on the groove bottom 80a of the circumferential groove 80 can be dispersed, making it possible to suppress the occurrence of cracks in the groove bottom 80a of the circumferential groove 80. Furthermore, since the second annular groove 91 extends further toward the axially inner side AD2 of the circumferential groove 80 than the wall surface 80c of the circumferential groove 80, the ground contact pressure at the end of the land body 34 can be reduced even after the sacrificial rib 35 has worn, making it possible to suppress wear of the land body 34.

[0038] Although not particularly limited, as in the embodiment shown in FIGS. 1 to 4, the first annular groove 90 may be disposed at the center C1 of the groove depth of the circumferential groove 80 or on the tire radially inner side RD2 of the center C1. According to this configuration, the first annular groove 90 can be located away from the ground contact surface 33 that comes into contact with the road surface, so that the occurrence of cracks that start from the first annular groove 90 can be suppressed.

[0039] Although not particularly limited, as in the embodiment shown in Figures 1 to 4, the length D2 of the first annular groove 90 in the tire axial direction AD may be one-third or less of the length D1 of the sacrificial rib 35 in the tire axial direction AD at the contact surface 33. This configuration ensures the rigidity of the sacrificial rib 35, and ensures durability against external damage.

[0040] Although not particularly limited, as in the embodiment shown in Figures 1 to 4, at least one first annular groove 90 may be provided, the minimum width of each first annular groove 90 may be 2 mm, and the total width of the at least one first annular groove 90 may be 8 mm or less. If the width is small, the effect is less apparent, but by limiting the total width to 8 mm or less, the rigidity of the sacrificial rib can be ensured, and durability against external damage can be ensured.

[0041] Although not particularly limited, as in the embodiment shown in Figures 1 to 4, the second annular groove 91 may be 3 mm or more away from the belt end 60 that is located axially outermost AD1 of the belt ends of the multiple belt plies 6a, 6b, 6c, and 6d. Even if a crack occurs in the second annular groove 91, the crack can be prevented from reaching the belt ply.

[0042] Although not particularly limited, as in the embodiment shown in Figures 1 to 4, at least one second annular groove 91 may be provided, the minimum width of each second annular groove 91 may be 2 mm, and the total width of the at least one second annular groove 91 may be 4 mm or less. If the width is small, the effect is less likely to be seen, but by keeping the total width to 4 mm or less, the rigidity of the sacrificial rib can be ensured, and durability against external damage can be ensured.

[0043] Although not particularly limited, the first annular groove 90 and the second annular groove 91 may be spaced apart from each other by 10 mm or more along the surface 7 of the sidewall 2, as in the embodiment shown in FIGS. According to this configuration, the rigidity of the land body 34 and the sacrificial rib 35 can be ensured.

[0044] Although the embodiments of the present disclosure have been described above with reference to the drawings, the specific configurations should not be considered to be limited to these embodiments. The scope of the present disclosure is defined not only by the description of the above embodiments but also by the claims, and further includes all modifications within the meaning and scope of the claims.

[0045] The structures employed in the above-described embodiments can be employed in any other embodiment. The specific configurations of the components are not limited to the above-described embodiments, and various modifications are possible within the scope of the present disclosure. [Explanation of symbols]

[0046] 32a...shoulder land (land), 33...contact surface, 34...land body, 35...sacrificial rib, 4...carcass, 6a, 6b, 6c, 6d...belt ply, 60...belt end, 7...surface of buttress, 70...buttress, 80...circumferential groove, 90...first annular groove, 91...second annular groove, CD...tire circumferential direction, LE...contact edge (edge ​​of contact surface), AD1...tire axial outer side, AD2...tire axial inner side, RD1...tire radial outer side, RD2...tire radial inner side.

Claims

1. the tire has a carcass, a land that forms a contact patch, a plurality of belt plies that are arranged between the carcass and the contact patch, a surface of a buttress that extends radially inward from an edge of the contact patch, and a circumferential groove that extends radially inward from the contact patch, goes around the tire circumferentially, and is positioned axially outward of an axially outermost belt end of the belt ends of the plurality of belt plies, The circumferential groove divides the land into a land main body and a sacrificial rib located axially outward of the land main body, the sacrificial rib has a first annular groove located radially outward of a groove bottom of the circumferential groove, the first annular groove opening onto a wall surface of the circumferential groove or onto a surface of the buttress, terminating within the sacrificial rib, and extending in the tire circumferential direction, and having an annular shape; a surface of the buttress has a second annular groove that opens radially inward of a groove bottom of the circumferential groove and extends circumferentially of the tire to form a ring, the second annular groove extending axially inward of a wall surface of the circumferential groove that is axially inner than the wall surface of the circumferential groove and terminating therein.

2. The pneumatic tire according to claim 1 , wherein the first annular groove is disposed at a center of the groove depth of the circumferential groove or radially inward of the center.

3. The pneumatic tire according to claim 1 or 2, wherein the axial length of the first annular groove is equal to or less than one-third of the axial length of the sacrificial rib in the contact patch.

4. 4. The pneumatic tire according to claim 1, wherein at least one first annular groove is provided, a minimum width per first annular groove is 2 mm, and a total width of the at least one first annular groove is 8 mm or less.

5. The pneumatic tire according to any one of claims 1 to 4, wherein the second annular groove is spaced 3 mm or more from an axially outermost belt end of the plurality of belt plies.

6. 6. The pneumatic tire according to claim 1, wherein at least one second annular groove is provided, a minimum width per second annular groove is 2 mm, and a total width of the at least one second annular groove is 4 mm or less.

7. 7. The pneumatic tire according to claim 1, wherein the first annular groove and the second annular groove are spaced apart from each other by 10 mm or more along the surface of the sidewall.

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