Tire

Abstract

Provided is a tire in which further improvement in rough road traveling performance can be achieved while ensuring excellent block durability. A plurality of shoulder blocks (12) are provided in a shoulder region of a tread portion (1), a plurality of side blocks (13) are provided in a side region that is adjacent to the outer side of the shoulder region in a tire width direction, two or more shoulder blocks (12) adjacent to each other in a tire circumferential direction and one side block (13) disposed on the outer side in the tire width direction are defined as a block group (B), a bent side groove (20) that is terminated in the side block (13) is formed on an extension line of a shoulder lug groove (11) disposed between the pair of shoulder blocks (12) included in the block group (B), and the bent side groove (20) includes a connection portion (21) that extends from the end position of the shoulder lug groove (11) toward the inner side in a tire radial direction, and a reversed portion (22) that is bent to one side in the tire circumferential direction from an end portion in the inner side in the tire radial direction, of the connection portion (21) and extends toward the outer side in the tire radial direction.

Description

tire

[0001] The present invention relates to a tire intended for running on unpaved roads and the like, and more particularly to a tire that enables further improvement in off-road performance while ensuring excellent block durability.

[0002] Tires (e.g., all-terrain tires, all-terrain tires, etc.) designed for running on unpaved roads (uneven terrain, muddy terrain, sandy terrain, rocky areas, etc.) in addition to paved roads are required to have excellent running performance on various road surfaces, and in particular, excellent off-road performance (rough road performance). Such tires have unevenness (e.g., side blocks) not only in the tread portion that contacts the road surface on paved roads, but also in the side region (region between the tread portion and the sidewall portion) that may come into contact with mud, snow, sand, stones, rocks, etc. (hereinafter, collectively referred to as "mud, etc.") on unpaved roads, thereby obtaining traction performance by gripping the mud, etc. (see, for example, Patent Documents 1 and 2). In recent years, tire performance requirements have become more stringent, and further improvements in rough road performance are required. Furthermore, since the side blocks tend to be easily damaged by stones, rocks, foreign objects, etc. on unpaved roads (rough roads), they are also required to have sufficient durability. Therefore, there is a demand for improving rough road performance while ensuring durability (particularly block durability), and achieving a high level of both performances.

[0003] Japanese Patent Publication No. 2017-124733 Japanese Patent Publication No. 2020-044882

[0004] An object of the present invention is to provide a tire that allows further improvement in off-road performance while ensuring excellent block durability.

[0005] The tire of the present invention for achieving the above object includes a tread portion extending in a circumferential direction of the tire and forming an annular shape, and a pair of sidewall portions disposed on both sides of the tread portion, the tire having a surface of the tread portion having a pair of main grooves extending along the tire circumferential direction on both sides of the tire equator, a shoulder region located on the tire widthwise outer side of the main grooves, a plurality of shoulder lug grooves extending from the main grooves toward the tire widthwise outer side and spaced apart in the tire circumferential direction, and a plurality of shoulder blocks partitioned by the main grooves and the shoulder lug grooves and arranged along the tire circumferential direction, and a side region adjacent to the shoulder region on the tire widthwise outer side, the sidewall portion having a plurality of shoulder blocks protruding from the outer surface of the sidewall portion. a pair of shoulder blocks, each of which has a widthwise outer circumferential edge, and ...

[0006] The tire of the present invention provides multiple side blocks in the side region, with one side block positioned on the tire widthwise outer side of a block group consisting of two or more circumferentially adjacent shoulder blocks. Therefore, the block group and the side blocks function as a substantially large block, thereby improving block durability. Meanwhile, the bent side grooves of the above-described structure are provided within the side blocks, thereby improving traction performance through their edge effect. In particular, the bent side grooves include a connecting portion extending radially inward from the end of the shoulder lug groove and a folded portion that bends from the radially inner end of the connecting portion to one side in the tire circumferential direction and extends radially outward (i.e., extending in the opposite direction from the connecting portion). Therefore, their bent shape provides an edge effect in various directions, effectively improving traction performance. Furthermore, because the bent side grooves terminate within the side blocks, a decrease in block rigidity due to the provision of grooves within the blocks is suppressed. These combined effects enable a high level of both block durability and rough-road performance.

[0007] In the present invention, it is preferable to form a first recess adjacent to the other circumferential side of the joint portion, which is recessed from the surface of the side block and raised higher than the bent side groove, and a second recess adjacent to the radially outer side of the turn-up portion, which is recessed from the surface of the side block and raised higher than the bent side groove. By providing the first and second recesses in this manner, the unevenness of the side block surface can be made more complex while maintaining block rigidity compared to when more grooves are added within the side block, which is advantageous for achieving both block durability and rough road performance.

[0008] In this case, the recess depth of the first recess and the second recess relative to the surface of the side block is preferably 0.5 mm to 2.5 mm. The area of ​​the second recess is preferably 10% to 40% of the area of ​​the first recess. Setting the recess depth and size relationship of the recesses in this manner results in a good balance between the shape of each recess and the size of the first recess and the second recess, which is advantageous for achieving both block durability and rough road performance.

[0009] In the present invention, it is preferable that the groove width of the folded portion is smaller than the groove width of the connecting portion, which makes it easier to ensure block rigidity and is advantageous for achieving both block durability and rough road performance.

[0010] In the present invention, the groove depth of the curved side grooves is preferably 0.5 mm to 3 mm. By setting the groove depth and recess amount of each portion in this manner, the curved side grooves and recesses are well balanced, which is advantageous for achieving both block durability and rough road performance.

[0011] In the present invention, the shoulder lug grooves may be provided with groove bottom protrusions that protrude from the groove bottoms. This configuration provides an edge effect due to the groove bottom protrusions, which is advantageous for improving traction performance.

[0012] The tire of the present invention is preferably a pneumatic tire, but may also be a non-pneumatic tire. In the case of a pneumatic tire, the interior thereof can be filled with air, an inert gas such as nitrogen, or other gases.

[0013] Fig. 1 is a meridian cross-sectional view of a tire according to an embodiment of the present invention. Fig. 2 is a perspective view showing the shoulder and side regions of a tire according to an embodiment of the present invention. Fig. 3 is an explanatory diagram schematically showing a block group (shoulder blocks (side surfaces) and side blocks (surface surfaces)) according to the present invention.

[0014] The configuration of the present invention will be described in detail below with reference to the accompanying drawings.

[0015] When the tire of the present invention is a pneumatic tire as shown in Figure 1, it comprises a tread portion 1 that contacts the road surface, a pair of sidewall portions 2 arranged on both sides of the tread portion 1, and a pair of bead portions 3 arranged radially inward of the sidewall portions 2. In Figure 1, the symbol CL indicates the tire equator. Although not depicted in Figure 1 because it is a meridian cross-section, the tread portion 1, sidewall portions 2, and bead portions 3 each extend in the tire circumferential direction and form an annular shape, thereby constituting the basic toroidal structure of a pneumatic tire. The following explanation using Figure 1 will be basically based on the meridian cross-section shape shown, but each tire constituent member also extends in the tire circumferential direction and forms an annular shape.

[0016] A carcass layer 4 is installed between a pair of left and right bead portions 3. The carcass layer 4 includes multiple reinforcing cords extending in the tire radial direction and folded back from the inner side to the outer side in the tire width direction around bead cores 5 arranged in each bead portion 3. A bead filler 6 is arranged on the outer periphery of each bead core 5, and this bead filler 6 is wrapped by the main portion and folded back portion of the carcass layer 4. Meanwhile, multiple belt layers 7 (two layers in FIG. 1 ) are embedded on the outer periphery of the carcass layer 4 in the tread portion 1. Each belt layer 7 includes multiple reinforcing cords inclined with respect to the tire circumferential direction, and the reinforcing cords are arranged so as to cross each other between the layers. In these belt layers 7, the inclination angle of the reinforcing cords with respect to the tire circumferential direction is set, for example, in the range of 10° to 40°. Furthermore, at least one belt reinforcing layer 8 (two layers in FIG. 1 ) is provided on the outer periphery of the belt layer 7. The belt reinforcing layer 8 includes organic fiber cords oriented in the tire circumferential direction. In the belt reinforcing layer 8, the organic fiber cords are set at an angle of, for example, 0° to 5° with respect to the tire circumferential direction.

[0017] Because the present invention relates to the shoulder and side regions of a tire as described below, the basic structure (cross-sectional structure) of the tire is not limited to the general structure described above. Furthermore, the detailed shape of the grooves and blocks formed on the surface of the tread portion 1 (tread pattern) is not particularly limited, except for the shoulder regions described below. The tread pattern in the portions excluding the shoulder regions described below is preferably a block-based pattern suitable for unpaved roads. The present invention can be applied to various types of tires, including non-pneumatic tires, as long as they have regions (regions corresponding to the shoulder and side regions) that may come into contact with mud or the like on the road surface when traveling on unpaved roads.

[0018] As shown in Figures 1 and 2, a pair of main grooves 10 are formed on the surface of the tread portion 1, extending circumferentially around the entire tire on both sides of the tire equator CL. The main grooves 10 preferably have a zigzag shape in which linear sections inclined in one direction relative to the tire circumferential direction and linear sections inclined in the other direction are alternately connected in the tire circumferential direction. The region between the pair of main grooves 10 is the center region (a region in which any tread pattern can be adopted without particular structural limitations in the present invention), and the regions on the outer sides of each main groove 10 in the tire width direction are shoulder regions. The main grooves 10 preferably have a groove width of 3 mm to 30 mm, more preferably 5 mm to 11 mm, and a groove depth of 8 mm to 16 mm, more preferably 10 mm to 15 mm.

[0019] A land portion (shoulder land portion) defined on the outer side of the main groove 10 in the tire width direction is provided with shoulder lug grooves 11 extending outward in the tire width direction from the main groove 10. A plurality of shoulder lug grooves 11 may be provided at intervals in the tire circumferential direction. These shoulder lug grooves 11 define the shoulder land portion into a plurality of blocks (shoulder blocks 12). When the main grooves 10 have a zigzag shape, the shoulder lug grooves 11 may be connected to the bending points of each main groove 10 on the outer side in the tire width direction. The groove width of the shoulder lug grooves 11 is not particularly limited, but is preferably 70% to 98%, more preferably 80% to 95%, of the groove width of the main groove 10. The groove depth of the shoulder lug grooves 11 is not particularly limited, but is preferably 75% to 100%, more preferably 80% to 98% of the groove depth of the main groove 10.

[0020] When the region adjacent to the shoulder region on the outer side in the tire width direction is defined as a side region, multiple side blocks 13 protruding from the outer surface of the sidewall portion 2 are provided in this side region. The protrusion height of each side block 13 from the outer surface of the sidewall 2 is not particularly limited, but can be set to, for example, 1 mm to 10 mm. As shown in Figures 2 and 3 , each side block 13 is positioned outward in the tire width direction at a position corresponding to two or more circumferentially adjacent shoulder blocks 12. For example, in the illustrated example, one side block 13 is positioned outward in the tire width direction from two shoulder blocks 12. In other words, side grooves 14 extending along the tire width direction (tire radial direction) are formed between circumferentially adjacent side blocks 13, and these side grooves 14 are connected to at least every other shoulder lug groove 11 spaced apart in the tire circumferential direction. Between these connected shoulder lug grooves 11 and side grooves 14, one side block 13 and two or more shoulder blocks 12 (and one or more shoulder lug grooves 11 not connected to a side groove 14) are positioned.

[0021] The side blocks 13 are preferably positioned within an appropriate radial range of the tire so that they can adequately contact the road surface when the tire becomes buried in mud or other debris while traveling on unpaved roads. Specifically, the radially innermost ends of the side blocks 13 are preferably located within a range of 20% to 50% of the tire cross-sectional height SH from the tire equator CL toward the tire's radially inward direction. In other words, the distance D from the tire equator CL to the radially innermost ends of the side blocks 13 is preferably 20% to 50% of the tire cross-sectional height SH. Positioning the side blocks 13 within an appropriate radial range of the sidewall portion 2 in this manner effectively improves driving performance on unpaved roads. Furthermore, the side blocks 13 can be appropriately sized, which is advantageous for ensuring block rigidity and improving durability. If the distance D is less than 20% of the tire cross-sectional height SH, the side blocks 13 become too small, making it difficult to maintain good block durability. If the distance D exceeds 50% of the tire cross-sectional height SH, the side blocks 13 become too large, which may affect normal running performance. With regard to the arrangement of the side blocks 13, it is preferable that the boundary between the shoulder region and the side region is located within a range of 20% to 25% of the tire cross-sectional height SH from the tire equator CL toward the tire radially inward, regardless of the presence or absence of the protrusions 17.

[0022] In the illustrated example, a protrusion 15 protruding from the sidewall surface and extending around the entire tire circumference is present at the boundary between the outer side of the shoulder block 12 in the tire width direction and the surface of the side block 13 (the boundary between the shoulder region and the side region). This protrusion 15 is an element formed due to the mold split position, etc., and is therefore not necessarily required. While this protrusion 15 is not an element that needs to be considered in the present invention, because it is an element formed during manufacturing, the shoulder region and side region may be distinguished based on the protrusion 15. In other words, the shoulder region can be considered to be the region adjacent to the protrusion 15 on the inner side in the tire width direction, and the side region can be considered to be the region adjacent to the protrusion 15 on the inner side in the tire radial direction.

[0023] When a combination of two or more shoulder blocks 12 and one side block 13 is defined as block group B, in the present invention, a bent side groove 20 is formed that terminates within the side block 13 on an extension of the shoulder lug groove 11 located between a pair of shoulder blocks 12 included in block group B. This bent side groove 20 has a bent shape that includes a connection portion 21 that extends radially inward from the end position of the shoulder lug groove 12, and a turn-up portion 22 that bends from the radially inner end of the connection portion 21 to one side in the tire circumferential direction and extends radially outward in the tire.

[0024] In the tire of the present invention, the entire tire (block group B) consisting of the shoulder blocks 12 and side blocks 13 functions as a substantial large block, ensuring sufficient block rigidity with sufficient volume, thereby improving block durability. Meanwhile, the bent side grooves 20 with the above-described structure are provided within the side blocks 13, resulting in improved traction performance due to their edge effect. In particular, the bent side grooves 20 include a connecting portion 21 extending radially inward from the end of the shoulder lug groove 11 and a folded portion 20 that bends from the radially inner end of the connecting portion 21 to one side in the tire circumferential direction and extends radially outward (i.e., extending in the opposite direction from the connecting portion 21). Because of their curved shape, they exert an edge effect in various directions, effectively improving traction performance. Furthermore, because the bent side grooves 20 terminate within the side blocks 13, a decrease in block rigidity due to the addition of additional grooves is suppressed. These combined effects enable a high degree of both block durability and rough-road performance.

[0025] If the bent side grooves 20 do not have the bent shape described above and simply extend linearly from the end positions of the shoulder lug grooves 11, for example, the groove length will be insufficient, and traction performance will not be sufficiently improved. If the bent side grooves 20 do not terminate within the blocks, the side blocks will be divided, and block group B consisting of a combination of multiple shoulder blocks 12 and one side block 13 will not be formed, and block durability will not be improved.

[0026] The groove depth of the curved side grooves 20 is preferably 0.5 mm to 3 mm, more preferably 1 mm to 2 mm. Setting the groove depth in this range achieves a good balance between the edge effect of the curved side grooves 20 and the reduction in block rigidity due to the provision of the curved side grooves 20, which is advantageous for achieving both block durability and rough road performance. If the groove depth of the curved side grooves 20 is less than 0.5 mm, the groove depth is too small, making it difficult to ensure a sufficient edge effect. If the groove depth of the curved side grooves 20 exceeds 3 mm, it becomes difficult to ensure sufficient block rigidity. It is preferable that the connection portions 21 and folded portions 22 constituting the curved side grooves 20 have the same groove depth.

[0027] The bent side grooves 20 preferably have a tapered shape, with the groove width gradually narrowing from the end position of the shoulder lug groove 12 toward the terminal end. At the very least, the groove width of the folded-back portion 22 is preferably smaller than the groove width of the connecting portion 21. Even if the folded-back portion 22 approaches the connecting portion 21 due to the bent shape of the bent side grooves 20, the narrow groove width of the folded-back portion 22 ensures block rigidity, which is advantageous for achieving both block durability and rough-road performance. The maximum groove width of the bent side grooves 20 (the groove width at the position where they connect with the shoulder lug grooves 12) is preferably 25 mm or less, more preferably 5 mm to 20 mm. Furthermore, the tip of the bent side grooves 20 (i.e., the tip of the folded-back portion 22) is preferably acute-angled.

[0028] In the present invention, a first recess 31 is preferably provided adjacent to the other circumferential side of the connecting portion 21 (the side opposite to the bending direction of the folded-back portion 22), recessed from the surface of the side block 13 and raised higher than the bent side groove 20. Also, a second recess 32 is preferably provided adjacent to the radially outer side of the folded-back portion 22, recessed from the surface of the side block 13 and raised higher than the bent side groove 20. By providing the first recess 31 and the second recess 32 in addition to the bent side groove 20 in this way, the surface irregularities of the side block 13 can be made more complex while maintaining block rigidity, compared to when more grooves are provided within the side block 13, which is advantageous for achieving both block durability and rough road performance.

[0029] The recess depth of the first recess 31 and the second recess 32 relative to the surface of the side block 13 is preferably 0.5 mm to 2.5 mm, more preferably 0.5 mm to 2 mm. Setting the recess depth in this manner achieves a good balance between the curved side groove 20 and each recess 31, 32, which is advantageous for achieving both block durability and rough road performance. If the recess depth of the first recess 31 and the second recess 32 is less than 0.5 mm, sufficient unevenness is not added to the surface of the side block 13, and the effect of improving traction performance is limited. If the recess depth of the first recess 31 and the second recess 32 exceeds 2.5 mm, the difference in depth between the curved side groove 20 and each recess 31, 32 is substantially eliminated, making it difficult to maintain sufficient block rigidity.

[0030] As described above, the first recess 31 and the second recess 32 are recessed from the surface of the side block 13, but because they are raised higher than the curved side groove 20, the recess amount of each recess is smaller than the depth of the curved side groove 20. In this case, the difference between the recess amount of each recess and the depth of the curved side groove 20 (i.e., the height of each recess from the bottom of the curved side groove 20) is preferably 0 mm to 3 mm, and more preferably 0 mm to 2 mm. This improves the uneven shape formed by each recess and the curved side groove 20, which is advantageous for achieving both block durability and rough road performance.

[0031] Considering the positional relationship between the first recess 31 and the second recess 32, it is preferable that the second recess 32 adjacent to the folded portion 22 has a smaller area than the first recess 31 adjacent to the connecting portion 21 (i.e., the side closer to the shoulder block 12). Specifically, the area of ​​the second recess 32 is preferably 10% to 40%, more preferably 15% to 30%, of the area of ​​the first recess 31. This provides a good balance between the sizes of the first recess 31 and the second recess 32, which is advantageous for achieving both block durability and rough road performance. If the area of ​​the second recess 32 is less than 10% of the area of ​​the first recess 31, the second recess 32 is too small, and the edge effect provided by providing the second recess 32 cannot be fully expected. If the area of ​​the second recess 32 exceeds 40% of the area of ​​the first recess 31, the proportion of the first recess 31 and the second recess 32 in the side block 13 becomes large, making it difficult to maintain sufficient block rigidity.

[0032] The opening area of ​​the curved side groove 20 on the surface of the side block 13 is preferably 5% to 40%, more preferably 10% to 30%, of the surface area of ​​the side block 13 (the entire area including the curved side groove 20, the first recess 31, and the second recess 32). The total area of ​​the first recess 31 and the second recess 32 is preferably 5% to 40%, more preferably 15% to 30%, of the surface area of ​​the side block 13 (the entire area including the curved side groove 20, the first recess 31, and the second recess 32).

[0033] The groove bottom of a shoulder lug groove 11 located between a pair of shoulder blocks 12 included in block group B may be provided with a groove bottom protrusion 33 that protrudes from the groove bottom. Similarly, groove bottom protrusions 33 may also be provided on the groove bottom of other shoulder lug grooves 11 (shoulder lug grooves 11 located between two circumferentially adjacent block groups B). Providing groove bottom protrusions 33 in this manner provides an additional edge effect, which is advantageous for improving traction performance. It also helps prevent stone trapping in the shoulder lug groove 11. The groove bottom protrusions 33 do not protrude across the entire width of the shoulder lug groove 11 bottom, but rather, as shown in the figure, protrude only a portion of the groove bottom of the shoulder lug groove 11. The width of the groove bottom protrusion 33 is preferably 10% to 40%, more preferably 15% to 25%, of the groove width of the shoulder lug groove 11. The protrusion height of the groove bottom protrusion 33 is preferably 0.5 mm to 3 mm, more preferably 1 mm to 2 mm.

[0034] The present invention will be further explained below with reference to examples, but the scope of the present invention is not limited to these examples.

[0035] Fifteen types of pneumatic tires were produced, namely, Conventional Example 1, Comparative Examples 1 and 2, and Examples 1 to 12, each with a tire size of LT265 / 70R17 121 / 118S and a basic structure (cross-sectional structure) as illustrated in FIG. 1 , with the shoulder and side region structures based on those of FIG. 2 . The number of shoulder blocks adjacent to the radially outer side of one side block, the presence or absence of bent side grooves, the groove depth of the bent side grooves, the maximum width of the bent side grooves, the presence or absence of first recesses adjacent to the junctions of the bent side grooves, the presence or absence of second recesses adjacent to the folded-back portions of the bent side grooves, the depression depths of the first and second recesses, the ratio of the area of ​​the second recesses to the area of ​​the first recesses, and the presence or absence of groove bottom protrusions in the shoulder lug grooves were set as shown in Tables 1 and 2.

[0036] The tread pattern in the center region was common to all examples, with one row of blocks arranged between a pair of main grooves on each side of the tire equator.

[0037] In the "Presence or Absence of Bent Side Grooves" column in Tables 1 and 2, the case where no bent side grooves were formed but grooves extending radially inward from the end positions of the shoulder lug grooves and terminating within the side blocks were formed (Comparative Example 2) was described as "Straight Side Grooves." In this case, for convenience, the groove depth and maximum width of the straight side grooves were described in the "Depth of Bent Side Grooves" and "Maximum Width of Bent Side Grooves" columns.

[0038] These pneumatic tires were evaluated for rough road running performance and block durability by the following evaluation methods, and the results are shown in Tables 1 and 2.

[0039] Each test tire was mounted on a wheel with a rim size of 17x8J, and the front tire was inflated to an air pressure of 450 kPa and the rear tire was inflated to an air pressure of 550 kPa. The test vehicle (traction test vehicle) was then fitted with the tire, and a test driver performed a sensory evaluation of the traction (starting performance) on a test road consisting of an unpaved road (gravel road surface). The evaluation results were expressed as an index, with the value of Conventional Example 1 being 100. A higher index value indicates better off-road performance.

[0040] Block durability (cut resistance) Each test tire was mounted on a wheel with a rim size of 17x8J, and the air pressure was set to 350 kPa. The test vehicle (four-wheel drive SUV) was fitted with the tire, and the total length of cuts on the side was measured after driving 1000 km on an off-road endurance road. The evaluation results were expressed as an index, with the reciprocal of the measurement value for Conventional Example 1 being set to 100. The larger the index value, the smaller the total length of the cuts, which means better block durability (cut resistance).

[0041]

[0042]

[0043] As is clear from Tables 1 and 2, the pneumatic tires of Examples 1 to 12 improved rough-road performance and block durability compared to Conventional Example 1, achieving a good balance between these performance characteristics. On the other hand, Comparative Example 1 has a structure in which two shoulder blocks are adjacent to one side block, and therefore, although block durability was improved compared to Conventional Example 1, the absence of curved side grooves did not sufficiently improve rough-road performance. Comparative Example 2 had linear side grooves instead of curved side grooves, and therefore could not sufficiently improve rough-road performance.

[0044] REFERENCE SIGNS LIST 1 tread portion 2 sidewall portion 3 bead portion 4 carcass layer 5 bead core 6 bead filler 7 belt layer 8 belt reinforcing layer 10 main groove 11 shoulder lug groove 12 shoulder block 13 side block 14 side groove 15 protrusion 20 bent side groove 21 connection portion 22 turned-up portion 31 first recess 32 second recess 33 groove bottom protrusion CL tire equator B block group

Claims

1. A tire having a tread portion extending in a circumferential direction and forming an annular shape, and a pair of sidewall portions arranged on either side of the tread portion, the surface of the tread portion having a pair of main grooves extending circumferentially on either side of the tire equator, a shoulder region located on the outer side of the main groove in the tire width direction is provided with a plurality of shoulder lug grooves extending from the main groove toward the outer side in the tire width direction and spaced apart in the tire circumferential direction, and a plurality of shoulder blocks partitioned by the main groove and the shoulder lug groove and arranged along the tire circumferential direction, a plurality of side blocks protruding from an outer surface of the sidewall portion are provided in a side region adjacent to the outer side in the tire width direction of the shoulder region, one side block is arranged at a position in the tire width direction outer side of two or more shoulder blocks adjacent in the tire circumferential direction, and when a combination of these two or more shoulder blocks and one side block is formed as a block group, a bent side groove is formed that terminates within the side block on an extension line of the shoulder lug groove arranged between a pair of shoulder blocks included in the block group, a tire characterized in that the bent side groove includes a connection portion extending radially inward in the tire direction from an end position of the shoulder lug groove, and a turn-up portion bent to one side in the tire circumferential direction from an end portion on the radially inner side of the connection portion and extending radially outward in the tire direction.

2. A tire as described in claim 1, characterized in that a first recess is formed adjacent to the other circumferential side of the connection portion, the first recess being recessed from the surface of the side block and raised higher than the bent side groove, and a second recess is formed adjacent to the radially outer side of the turn-up portion, the second recess being recessed from the surface of the side block and raised higher than the bent side groove.

3. The tire according to claim 2, characterized in that the depression amount of the first recess and the second recess relative to the surface of the side block is 0.5 mm to 2.5 mm.

4. The tire according to claim 2 or 3, characterized in that the area of ​​the second recess is 10% to 40% of the area of ​​the first recess.

5. A tire as described in any one of claims 1 to 4, characterized in that the groove width of the folded-back portion is smaller than the groove width of the connecting portion.

6. A tire according to any one of claims 1 to 5, characterized in that the groove depth of the curved side groove is 0.5 mm to 3 mm.

7. A tire as described in any one of claims 1 to 6, characterized in that the shoulder lug groove has a groove bottom protrusion protruding from the groove bottom.

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