Tire

Abstract

To provide a tire that can improve mud performance, wet performance and heating durability.SOLUTION: A tire 1 includes a first shoulder block 5. The first shoulder block 5 includes: a first part 7 including a first tread 11 which forms a first tread end T1 and a first side wall surface 12 which extends to a tire radial direction inner side from the first tread end T1; and a second part 8 including a second tread 15 which forms a second tread end T2 and a second side wall surface 16 which extends to a tire radial direction inner side from the second tread end T2. The second tread 15 has at least a part including a recess 18, which is recessed to the tire radial direction inner side with respect to the first tread 11, so that the second tread end T2 is positioned on the tire radial direction inner side with respect to the first tread end T1. A recess 19 is formed in the second side wall surface 16. The recess 19 extends in a tire circumferential direction from a shoulder lateral groove 3, and has a bottom 20 in the first shoulder block 5.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a tire. [Background technology]

[0002] Patent Document 1 below describes a pneumatic tire having side protectors arranged circumferentially on the sidewalls. The side protectors include a first protector having a first inclined groove inclined in a first direction and a second protector having a second inclined groove inclined in a second direction. This pneumatic tire is said to exhibit excellent off-road performance in muddy terrain. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2021-003948 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, there has been a demand for improvements not only in mud performance, which is the ability to drive on muddy ground, but also in wet performance and heat resistance.

[0005] The present invention has been devised in view of the above circumstances, and has as its main object to provide a tire that can improve mud performance, wet performance, and heat buildup durability. [Means for solving the problem]

[0006] A tire having a tread portion, the tread portion being formed with a plurality of shoulder lateral grooves and a plurality of shoulder blocks separated by the plurality of shoulder lateral grooves, the plurality of shoulder blocks including at least one first shoulder block, the first shoulder block including a first portion including a first tire circumferential edge and a second portion including a second tire circumferential edge, the first portion including a first tread surface forming a first tread edge and a first sidewall surface extending radially inward from the first tread edge, the second portion including a a second tread surface forming a second tread edge and a second sidewall surface extending radially inward from the second tread edge, wherein the second tread surface includes a recessed portion that is recessed at least partially radially inward from the first tread surface so that the second tread edge is located radially inward from the first tread edge, and the second sidewall surface has a recessed portion that is recessed axially inward from the second sidewall surface, and the recessed portion extends circumferentially from one of the plurality of shoulder lateral grooves adjacent to the second sidewall surface and has a bottom within the first shoulder block. [Effects of the Invention]

[0007] By adopting the above-described configuration, the present invention can improve mud performance, wet performance, and heat resistance. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a tire meridian cross-sectional view of a tread portion of a tire according to one embodiment of the present invention. [Figure 2] FIG. 2 is a partial development view of a tread portion of the tire of FIG. 1. [Figure 3] FIG. 3 is a perspective cross-sectional view of the tread portion shown in FIG. 2. [Figure 4] FIG. 2 is an enlarged view of the vicinity of a first tread edge T1 of FIG. [Figure 5] 2, and FIG. 6B is a cross-sectional view taken along line BB in FIG. [Figure 6] FIG. 2 is a partial development view of a tread portion of the tire of FIG. 1. [Figure 7] FIG. 7 is a perspective cross-sectional view of the tread portion shown in FIG. 6. DETAILED DESCRIPTION OF THE INVENTION

[0009] An embodiment of the present invention will now be described with reference to the drawings. The drawings include exaggerated representations and representations different from the dimensional ratios of the actual structures to facilitate understanding of the present invention. Furthermore, when there are multiple embodiments, the same or common elements are designated by the same reference numerals throughout the specification, and redundant explanations will be omitted.

[0010] 1 is a tire meridian cross-sectional view of a tread portion 2 of one embodiment of a tire 1 of the present invention. The present invention is suitably used, for example, in pneumatic tires for passenger cars (SUVs) that can run on muddy roads. Note that the present invention may also be used, for example, in pneumatic tires for heavy loads and non-pneumatic tires that do not have pressurized air filled inside the tire.

[0011] Fig. 1 shows a tire 1 in a normal state. The "normal state" refers to a state in which the tire 1 is mounted on a normal rim (not shown), inflated to a normal internal pressure, and no load is applied. In this specification, unless otherwise specified, the dimensions of each part of the tire 1 are measured in the normal state.

[0012] The "genuine rim" is a rim that is defined for each tire by the standard system that includes the standard on which the tire is based, such as a "standard rim" for JATMA, a "design rim" for TRA, or a "measuring rim" for ETRTO.

[0013] "Normal internal pressure" is the air pressure specified for each tire by each standard in the standard system, including 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 the "INFLATION PRESSURE."

[0014] Fig. 2 is a partial development view of the tread portion 2 of the tire 1 of Fig. 1. Fig. 3 is a perspective cross-sectional view of the tread portion 2 shown in Fig. 2. As shown in Figs. 1 to 3, the tread portion 2 of this embodiment is formed with a plurality of shoulder lateral grooves 3 and a plurality of shoulder blocks 4 separated by the plurality of shoulder lateral grooves 3. The shoulder lateral grooves 3 of this embodiment are provided on both sides of each shoulder block 4 in the tire circumferential direction. In this specification, the "groove" refers to a recessed groove having a groove width of 1.5 mm or more, and is distinguished from sipes having a width of less than 1.5 mm.

[0015] The multiple shoulder blocks 4 include at least one first shoulder block 5. The first shoulder block 5 includes a first portion 7 including a first tire circumferential edge 5e and a second portion 8 including a second tire circumferential edge 5i. The first tire circumferential edge 5e and the second tire circumferential edge 5i are each formed as a block edge of the first shoulder block 5. The first tire circumferential edge 5e and the second tire circumferential edge 5i each extend in the tire axial direction adjacent to the shoulder lateral grooves 3. Thus, in this embodiment, the shoulder lateral grooves 3 include a first shoulder lateral groove 3A adjacent to the first tire circumferential edge 5e and a second shoulder lateral groove 3B adjacent to the second tire circumferential edge 5i.

[0016] The first portion 7 includes a first tread surface 11 that forms the first tread edge T1 and a first sidewall surface 12 that extends radially inward from the first tread edge T1. The second portion 8 includes a second tread surface 15 that forms the second tread edge T2 and a second sidewall surface 16 that extends radially inward from the second tread edge T2. In this specification, the first tread edge T1 refers to the axially outermost contact point of the tire when the tire 1 in a normal state is in a normal load state and is in contact with the ground on a flat surface with a camber angle of 0 degrees.

[0017] The "normal load" is the load determined for each tire by each standard in the standard system, including the standard on which the tire is based. In the case of JATMA, it is the "maximum load capacity," in the case of TRA, it is the maximum value listed in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES," and in the case of ETRTO, it is the "LOAD CAPACITY."

[0018] A recess 19 is formed in the second sidewall surface 16, recessed axially inward in the tire direction. The recess 19 extends circumferentially from one of the shoulder lateral grooves 3 (second shoulder lateral groove 3B) adjacent to the second sidewall surface 16, and has a bottom 20 within the first shoulder block 5. In this way, the recess 19 is formed in a closed shape within the second sidewall surface 16. Such a recess 19 exerts a large shear force on mud when traveling on muddy ground.

[0019] Fig. 4 is an enlarged view of the vicinity of the first tread edge T1 in Fig. 1. As shown in Figs. 2 to 4, the second tread surface 15 includes a recessed portion 18 that is recessed at least partially radially inward of the first tread surface 11 so that the second tread edge T2 is located radially inward of the first tread edge T1. Such a recessed portion 18 exerts a shear force against mud between the recessed portion 18 and the first tread surface 11 when traveling on muddy ground.

[0020] The second tread edge T2 is, for example, a position that does not contact the flat surface under the normal load condition. Such a second tread edge T2 increases the apparent groove volume of the shoulder lateral groove 3, thereby further improving wet performance. In this case, the axial end that contacts the flat surface under the normal load condition is formed on the recessed portion 18. Note that the second tread edge T2 may be a position that contacts the flat surface under the normal load condition.

[0021] The recessed portions 18 are also connected to the second shoulder lateral grooves 3B. Such recessed portions 18 increase the apparent groove volume of the shoulder lateral grooves 3, allowing mud and water to be smoothly discharged from the shoulder lateral grooves 3. Furthermore, the recessed portions 19 and recessed portions 18 increase the surface area of ​​the first shoulder blocks 5, enhancing their heat dissipation effect. Therefore, the tire 1 of the present invention has excellent mud performance, wet performance, and heat resistance.

[0022] The second tread surface 15 of this embodiment includes a recessed portion 18 and a main portion 17 extending axially inward from the recessed portion 18. The main portion 17 is smoothly connected to the first tread surface 11 in the tire circumferential direction, for example.

[0023] The first tread surface 11 and the recessed portion 18 of the second tread surface 15 are connected via a stepped surface 25. The stepped surface 25 extends, for example, in the tire radial direction and the tire axial direction. Such a stepped surface 25 exerts a large shear force on the mud when traveling on muddy ground.

[0024] Fig. 5(A) is a cross-sectional view taken along line AA in Fig. 2. As shown in Fig. 5(A), the step surface 25 is inclined with respect to a normal n1 of the first tread surface 11, which is erected at the intersection of the step surface 25 and the first tread surface 11. This increases the surface area of ​​the step surface 25, improving heat durability. If the angle α1 between the normal n1 and the step surface 25 becomes too large, the shear force caused by the step surface 25 may decrease. For this reason, the angle α1 is preferably 2 degrees or more, more preferably 5 degrees or more, more preferably 15 degrees or less, and even more preferably 13 degrees or less.

[0025] 4, the radial distance La between the first tread surface 11 and the recessed portion 18 increases continuously toward the second tread edge T2. Such a recessed portion 18 allows mud and water inside the recessed portion 18 to be smoothly discharged from the second tread edge T2 to the outside.

[0026] The separation distance La is preferably 5% or less of the tread width TW (shown in FIG. 1). If the separation distance Lb exceeds 5% of the tread width TW, the contact patch of the first shoulder blocks 5 becomes small, which may result in poor wet performance. To improve mud and wet performance, the maximum value of the separation distance La is preferably 1% or more of the tread width TW, and more preferably 2% or more.

[0027] FIG. 6 is a partial development view of the tread portion 2 of the tire 1 of FIG. 1. FIG. 7 is a perspective cross-sectional view of the tread portion 2 shown in FIG. 6. As shown in FIGS. 4, 6, and 7, the axial length Lb of the recessed portion 18 is preferably 15% or more of the circumferential length Lf of the first shoulder block 5, more preferably 20% or more, and more preferably 30% or less, and even more preferably 25% or less. Because the length Lb is 15% or more of the length Lf, water on the first tread surface 11 and the second tread surface 15 can be smoothly discharged. Because the length Lb is 30% or less of the length Lf, the rigidity of the first shoulder block 5 can be maintained high. In this specification, the length Lf of the first shoulder block 5 is the maximum length above the recessed portion 18. From the same viewpoint, the circumferential length Lc of the recess 18 is preferably 20% or more of the length Lf of the first shoulder block 5, more preferably 30% or more, and is preferably 80% or less, and even more preferably 70% or less.

[0028] The second sidewall surface 16 is located axially more inward than the first sidewall surface 12. In this manner, in this embodiment, the second sidewall surface 16 and the first sidewall surface 12 are connected via the sidewall step surface 27. Such a sidewall step surface 27 also exerts a shear force on mud when traveling on muddy ground. Note that the tire 1 of the present invention is not limited to an embodiment in which the sidewall step surface 27 is provided, and the first sidewall surface 12 and the second sidewall surface 16 may be smoothly connected to form a single surface.

[0029] In this embodiment, side wall step surface 27 is smoothly connected to step surface 25 to form one surface, which allows mud captured in recess 18 to be smoothly discharged to the second side wall surface 16 side.

[0030] 5(B) is a cross-sectional view taken along line BB in FIG. 6. As shown in FIG. 5(B), sidewall step surface 27 is inclined with respect to normal n2 of first sidewall surface 12, which is set at the intersection of sidewall step surface 27 and first sidewall surface 12. This increases the surface area of ​​sidewall step surface 27, improving heat durability. If angle α2 between normal n2 and sidewall step surface 27 becomes too large, the shear force of sidewall step surface 27 may decrease. For this reason, angle α2 is preferably 2 degrees or more, more preferably 5 degrees or more, more preferably 15 degrees or less, and even more preferably 13 degrees or less.

[0031] As shown in Figure 4, the separation distance Ls between the first side wall surface 12 and the second side wall surface 16 is preferably 1 mm or more, more preferably 5 mm or more, more preferably 15 mm or less, and even more preferably 10 mm or less. Because the separation distance Ls is 1 mm or more, the second side wall surface 16 can exert a shear force on the mud. Because the separation distance Ls is 15 mm or less, damage to the first side wall surface 12 can be suppressed. In this specification, the separation distance Ls is the length in the normal direction of the second side wall surface 16.

[0032] 4 and 7, the second side wall surface 16 is raised from the groove bottom 3s of the shoulder lateral groove 3 adjacent to the second side wall surface 16. Such a second side wall surface 16 increases the surface area of ​​the first shoulder block 5, thereby helping to improve heat resistance. In addition, such a second side wall surface 16 forms a groove wall surface 3k between the second side wall surface 16 and the groove bottom 3s of the shoulder lateral groove 3, and the groove wall surface 3k exerts a shear force on mud when traveling on muddy ground.

[0033] The recess 19 includes an outward surface 21 facing outward in the tire axial direction. In a tire meridian cross section passing through the outward surface 21, the angle θ1 between the outward surface 21 and the second sidewall surface 16 is preferably 45 degrees or more, more preferably 60 degrees or more, preferably 120 degrees or less, and even more preferably 90 degrees or less. Because the angle θ1 is 45 degrees or more and 120 degrees or less, a large volume of the recess 19 is ensured, and the rigidity of the first shoulder block 5 near the recess 19 is maintained high. An imaginary line v1 shown in FIG. 4 is a line segment parallel to the second sidewall surface 16. For convenience, the angle θ1 is shown as the angle between the imaginary line v1 and the outward surface 21.

[0034] The recess 19 further includes an inner surface 22 connecting the outward surface 21 and the second side wall surface 16, and an outer surface 23 located radially outward of the inner surface 22 and connecting the outward surface 21 and the second side wall surface 16. The inner surface 22, for example, faces radially outward and extends in the tire axial direction. The outer surface 23, for example, is formed to include a recessed surface 23a that is recessed radially outward. Such an outer surface 23 can increase the amount of mud captured within the recess 19 and increase the shear force thereof. Note that the outer surface 23 is not limited to this configuration, and may, for example, face radially inward and extend substantially parallel to the inner surface 22 (not shown).

[0035] In this embodiment, the recess 19 connects the outward surface 21 and the inner surface 22 via a circular arc 24. The radius of curvature Ra of the circular arc 24 is preferably 1 mm or more, more preferably 2 mm or more, and is preferably 10 mm or less, and even more preferably 8 mm or less. Such a recess 19 maintains high rigidity of the first shoulder block 5.

[0036] As shown in FIG. 4 or FIG. 6 , the circumferential length Ld of the recess 19 is preferably 20% or more of the length Lf of the first shoulder block 5, more preferably 30% or more, and preferably 80% or less, and even more preferably 70% or less. The length Ld of the recess 19 is the maximum circumferential length on the second sidewall surface 16. From the same perspective, the radial length Ha of the recess 19 is preferably 15% or more of the radial length H1 of the second sidewall surface 16, more preferably 20% or more, and preferably 35% or less, and even more preferably 30% or less. The maximum depth da of the recess 19 is preferably 1 mm or more, more preferably 5 mm or more, and preferably 20 mm or less, and even more preferably 15 mm or less. This allows for a large shear force to be exerted on mud when traveling on muddy ground, while maintaining the rigidity of the first shoulder block 5, enabling stable traveling on wet roads. The length Ha is the length of the opening on the second sidewall surface 16. The maximum depth da of the recess 19 is measured in the normal direction of the second side wall surface 16 .

[0037] Although not particularly limited, the radial length Hb between the recess 19 and the second tread edge T2 is preferably 2 mm or more, more preferably 5 mm or more, and is preferably 15 mm or less, and even more preferably 10 mm or less.

[0038] The first sidewall surface 12 is provided with at least one circumferential small groove 28 extending in the tire circumferential direction. The circumferential small groove 28 extends, for example, so as to connect the first tire circumferential end 5e (shown in FIG. 2) and the sidewall step surface 27. In this embodiment, the circumferential small groove 28 extends parallel to the tire circumferential direction. Such a circumferential small groove 28 can further increase the shear force against mud.

[0039] In this embodiment, two circumferential small grooves 28 are provided, spaced apart in the tire radial direction. The circumferential small grooves 28 include a first circumferential small groove 28A adjacent to the first tread edge T1 and a second circumferential small groove 28B located radially inward of the first circumferential small groove 28A. The first circumferential small groove 28A is connected to the recessed portion 19. This allows mud in the first circumferential small groove 28A to be smoothly discharged through the recessed portion 19. In this embodiment, the first circumferential small groove 28A is connected to the inner surface 22 of the recessed portion 19.

[0040] As shown in Fig. 1, the tread portion 2 of this embodiment includes a plurality of shoulder lateral grooves 3 and a plurality of shoulder blocks 4 on both axial ends of the tire across the tire equator C. As a result, the tread portion 2 has first tread edges T1 of first shoulder blocks 5 on both axial ends of the tire. In this specification, the axial length of the first tread edges T1 on both sides is defined as the tread width TW.

[0041] The tread portion 2 includes, for example, a plurality of grooves (not shown) on the axially inner side of the shoulder blocks 4, and a plurality of inner blocks (not shown) separated by the plurality of grooves. Conventionally, various shapes are adopted for the plurality of grooves and the plurality of inner blocks.

[0042] 6 and 7, the multiple shoulder blocks 4 include at least one second shoulder block 6. The second shoulder block 6 is adjacent to the first shoulder block 5 via the shoulder lateral groove 3. In the tread portion 2 of this embodiment, the first shoulder blocks 5 and the second shoulder blocks 6 are arranged alternately in the tire circumferential direction, with the shoulder lateral groove 3 interposed therebetween. In this embodiment, the first shoulder lateral groove 3A and the second shoulder lateral groove 3B are arranged alternately in the tire circumferential direction.

[0043] The second shoulder block 6 has a shape that is symmetrical to the first shoulder block 5 with respect to the groove center line 3c of one of the shoulder lateral grooves 3 (the second shoulder lateral groove 3B). The "shape that is symmetrical to the first shoulder block 5" refers to a configuration in which the second shoulder block 6 includes a first portion 7s that includes the second circumferential edge 6i and a second portion 8s that includes the first circumferential edge 6e. In this manner, the second portion 8s is located closer to the groove center line 3c than the first portion 7s. The "shape that is symmetrical to the first shoulder block 5" also refers to a configuration in which the first portion 7s includes, for example, a first tread surface 11s that forms the first tread edge T1s and a first sidewall surface 12s that extends radially inward from the first tread edge T1s. Furthermore, the second portion 8s refers to a mode including, for example, a second tread surface 15s that forms the second tread edge T2s, and a second sidewall surface 16s that extends radially inward from the second tread edge T2s.

[0044] The "shape of the shoulder block 5 is symmetrical to the axis of the first shoulder block 5" means that the second portion 8s has at least a second sidewall surface 16s with a recess 19s formed therein and a second tread surface 15s with a recess 18s. The groove center line 3c is defined as the tire axial line Y passing through the groove width center position 3t of the shoulder lateral groove 3 on a tire circumferential line passing through the first tread edge T1.

[0045] As shown in FIGS. 2 and 6, the first tread edge T1s is, for example, located at the same position as the first tread edge T1 in the tire axial direction and the tire radial direction. The second tread edge T2s is, for example, located at the same position as the second tread edge T2 in the tire axial direction and the tire radial direction. The first tread surface 11s is, for example, formed so as not to be line-symmetrical with the first tread surface 11. The second tread surface 15s is, for example, formed so as not to be line-symmetrical with the second tread surface 15. The first side wall surface 12s is, for example, formed so as to be line-symmetrical with the first side wall surface 12. The second side wall surface 16s is, for example, formed so as to be line-symmetrical with the second side wall surface 16. The first tread surface 11s may be line-symmetrical with the first tread surface 11, and the second tread surface 15s may be line-symmetrical with the second tread surface 15. Furthermore, the first side wall surface 12s does not have to be formed in a shape that is line-symmetrical with the first side wall surface 12, and the second side wall surface 16s does not have to be formed in a shape that is line-symmetrical with the second side wall surface 16.

[0046] In this embodiment, the recess 19s formed in the second sidewall surface 16s is recessed axially inward. The recess 19s extends circumferentially from the second shoulder lateral groove 3B adjacent to the second sidewall surface 16s and has a bottom 20s within the second shoulder block 6. The recess 19s is formed, for example, in an axisymmetrical shape with the recess 19. Together with the recess 19, the recess 19s exerts shear force on the mud during driving and braking when traveling on muddy ground. Note that the recess 19s does not have to be formed, for example, in an axisymmetrical shape with the recess 19.

[0047] As shown in Figures 6 and 7, the recessed portion 18s of the second tread surface 15s of this embodiment is formed so that at least a portion thereof is recessed radially inward of the first tread surface 11s so that the second tread edge T2s is located radially inward of the first tread edge T1s. This recessed portion 18s exerts a large shear force on mud between the recessed portion 18s and the first tread surface 11s when traveling on muddy ground. The recessed portion 18s is formed, for example, in a shape that is line-symmetrical with the recessed portion 18. The recessed portion 18s does not necessarily have to be formed in a shape that is line-symmetrical with the recessed portion 18.

[0048] The recessed portions 18s are connected to the second shoulder lateral grooves 3B adjacent to the second sidewall surfaces 16s. Such recessed portions 18s increase the apparent groove volume of the shoulder lateral grooves 3, allowing mud and water to be smoothly discharged from the shoulder lateral grooves 3. Furthermore, the recessed portions 19s and the recessed portions 18s increase the surface area of ​​the second shoulder blocks 6, improving their heat dissipation effect.

[0049] 2 and 6, the length Lf of the first shoulder block 5 is preferably at least 20%, more preferably at least 30%, and even more preferably at most 60%, and even more preferably at most 50% of the circumferential distance L1 between the first circumferential end 5e of the first shoulder block 5 and the second circumferential end 6i of the second shoulder block 6. Because the length Lf of the first shoulder block 5 is at least 20% and at most 60% of the distance L1, the circumferential rigidity of the first shoulder block 5 is maintained, ensuring stable mud and wet performance. In this specification, the distance L1 is the maximum length above the recess 18.

[0050] 4, 6, and 7, the tire 1 of this embodiment has circumferential protrusions 30 formed on the radially inner sides of the shoulder blocks 4. The circumferential protrusions 30 extend, for example, in the tire circumferential direction and protrude outward in the tire axial direction. The circumferential protrusions 30 of this embodiment extend continuously in the tire circumferential direction.

[0051] The circumferential protrusion 30 connects, for example, each shoulder lateral groove 3 and each shoulder block 4. In this embodiment, the circumferential protrusion 30 connects each first side wall surface 12, 12s and each second side wall surface 16, 16s of each shoulder block 4. The circumferential protrusion 30 protrudes axially outward from each first side wall surface 12, 12s. Note that raised portions 31 aligned in the tire circumferential direction are provided on the radially inner side of the circumferential protrusion 30. The raised portions 31 are formed in a V-shape so as to connect the first shoulder block 5 and second shoulder block 6 that are adjacent in the tire circumferential direction via the circumferential protrusion 30.

[0052] Although a particularly preferred embodiment of the present invention has been described in detail above, the present invention is not limited to the illustrated embodiment and can be modified and implemented in various ways.

[0053] [Note] The present invention includes the following aspects.

[0054] [Invention 1] A tire having a tread portion, a plurality of shoulder lateral grooves and a plurality of shoulder blocks separated by the plurality of shoulder lateral grooves are formed in the tread portion, the plurality of shoulder blocks includes at least one first shoulder block; the first shoulder block includes a first portion including a first tire circumferential end and a second portion including a second tire circumferential end, the first portion includes a first tread surface that forms a first tread edge and a first sidewall surface that extends radially inward from the first tread edge, the second portion includes a second tread surface that forms a second tread edge and a second sidewall surface that extends radially inward from the second tread edge, the second tread surface includes a recessed portion that is at least partially recessed radially inward of the first tread surface so that the second tread edge is positioned radially inward of the first tread edge, A recessed portion recessed axially inward in the tire direction is formed on the second side wall surface, the recessed portion extends in the tire circumferential direction from one of the shoulder lateral grooves adjacent to the second sidewall surface and has a bottom within the first shoulder block. tire. [Invention 2] the plurality of shoulder blocks includes at least one second shoulder block; the second shoulder block is adjacent to the first shoulder block via one of the plurality of shoulder lateral grooves, The tire according to Invention 1, wherein the second shoulder block has a shape that is line-symmetrical to the first shoulder block with respect to a groove center line of one of the shoulder lateral grooves. [Invention 3] The tire according to Invention 2, wherein the length of the first shoulder block in the tire circumferential direction is 20% to 60% of the distance in the tire circumferential direction between the first circumferential end of the first shoulder block and the first circumferential end of the second shoulder block. [Invention 4] The tire according to any one of the first to third aspects of the present invention, wherein a distance in the tire radial direction between the first tread surface and the recessed portion increases continuously toward the second tread edge side. [Invention 5] 5. The tire according to claim 4, wherein the separation distance is 5% or less of the tread width. [Invention 6] The tire according to any one of inventions 1 to 5, wherein the axial length of the recessed portion is 15% to 30% of the circumferential length of the first shoulder block. [Invention 7] the recessed portion includes an outward surface facing outward in the tire axial direction, In a tire meridian cross section passing through the outward surface, The tire according to any one of Inventions 1 to 6, wherein the angle between the outward surface and the second sidewall surface is 45 to 120 degrees. [Invention 8] The tire according to any one of inventions 1 to 7, wherein the second side wall surface is located axially inward of the first side wall surface. [Invention 9] The tire according to invention 8, wherein the distance between the first side wall surface and the second side wall surface in the tire axial direction is 1 mm or more. [Invention 10] The tire according to any one of claims 1 to 9, wherein the second side wall surface is raised from the groove bottom of the shoulder lateral groove adjacent to the second side wall surface. [Invention 11] The tire according to any one of inventions 1 to 10, wherein the first tread surface and the recessed portion of the second tread surface are connected via a step surface. [Invention 12] 12. The tire according to any one of claims 1 to 11, wherein the length of the recess in the tire circumferential direction is 20% to 80% of the length of the first shoulder block in the tire circumferential direction. [Explanation of symbols]

[0055] 1 tire 3 Shoulder groove 5. First Shoulder Block 7 Part 1 8 Part 2 11 1st tread 12 First side wall 15 Second tread 16 Second side wall 18 Recessed part 19 Recess 20 bottom T1 First tread edge T2 Second tread edge

Claims

1. A tire having a tread portion, a plurality of shoulder lateral grooves and a plurality of shoulder blocks separated by the plurality of shoulder lateral grooves are formed in the tread portion, the plurality of shoulder blocks includes at least one first shoulder block; the first shoulder block includes a first portion including a first circumferential end and a second portion including a second circumferential end, the first portion includes a first tread surface forming a first tread edge and a first sidewall surface extending radially inward from the first tread edge, the second portion includes a second tread surface that forms a second tread edge and a second sidewall surface that extends radially inward from the second tread edge, the second tread surface includes a recessed portion that is at least partially recessed radially inward from the first tread surface so that the second tread edge is located radially inward from the first tread edge, a recessed portion recessed axially inward in the tire direction is formed on the second side wall surface, the recessed portion extends in the tire circumferential direction from one of the shoulder lateral grooves adjacent to the second sidewall surface and has a bottom within the first shoulder block. tire.

2. the plurality of shoulder blocks includes at least one second shoulder block; the second shoulder block is adjacent to the first shoulder block via one of the shoulder lateral grooves, The tire according to claim 1 , wherein the second shoulder block has a shape that is line-symmetrical to the first shoulder block with respect to a groove center line of one of the shoulder lateral grooves.

3. 3. The tire according to claim 2, wherein the length of the first shoulder block in the tire circumferential direction is 20% to 60% of the distance in the tire circumferential direction between the first circumferential end of the first shoulder block and the first circumferential end of the second shoulder block.

4. The tire according to claim 1 , wherein a distance in the tire radial direction between the first tread surface and the recessed portion increases continuously toward the second tread edge.

5. 5. The tire of claim 4, wherein said separation distance is 5% or less of the tread width.

6. 2. The tire according to claim 1, wherein the axial length of the recessed portion is 15% to 30% of the circumferential length of the first shoulder block.

7. the recessed portion includes an outward surface facing outward in the tire axial direction, In a tire meridian cross section passing through the outward surface, The tire according to any one of claims 1 to 6, wherein an angle between the outwardly facing surface and the second sidewall surface is between 45 and 120 degrees.

8. The tire according to claim 1 , wherein the second sidewall surface is located axially inward of the first sidewall surface.

9. 9. The tire of claim 8, wherein the separation distance between the first sidewall surface and the second sidewall surface is 1 mm or greater.

10. The tire according to claim 1 , wherein the second sidewall surface is raised from a groove bottom of the shoulder lateral groove adjacent to the second sidewall surface.

11. The tire according to claim 1 , wherein the first tread surface and the recessed portion of the second tread surface are connected via a stepped surface.

12. 7. The tire according to claim 1, wherein the length of the recess in the tire circumferential direction is 20% to 80% of the length of the first shoulder block in the tire circumferential direction.

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