tire

Abstract

A tire 10 has a plurality of mutually independent blocks 31, 32 on an outer surface 2 of a buttress portion BP, wherein: the plurality of blocks 31, 32 are partitioned in the tire circumferential direction by radial grooves 64 that extending at least in the tire radial direction; each of the plurality of blocks 31, 32 comprises a cutout region 31c, 32c that has a cutout 9 extending in the tire circumferential direction on the outer surface, and a non-cutout region 31d, 32d that is adjacent to the cutout region 31c, 32c in the tire circumferential direction and that does not have a cutout 9 on the outer surface; and the cutouts 9 in the cutout regions 31c, 32c of at least one pair of two blocks 31, 32 that are adjacent to one another in the tire circumferential direction, among the plurality of blocks 31, 32, face one another with the radial groove 64 therebetween.

Description

Tire

[0001] This application claims priority based on Japanese Patent Application No. 2024-190137 filed in Japan on October 29, 2024, the entire content of which is incorporated herein by reference. The present invention relates to a tire.

[0002] Conventionally, a tire in which a plurality of mutually independent blocks are formed on the outer surface of a buttress portion extending from the tread edge toward the inner side in the tire radial direction (hereinafter also referred to as the "buttress outer surface") is known (for example, Patent Document 1). According to the conventional tire, due to the configuration of the buttress portion, the traction performance of the tire and the protection performance for the sidewall portion (hereinafter simply referred to as "protection performance") for protecting the sidewall portion from foreign object collisions and the like can be exhibited.

[0003] International Publication No. 2013 / 125246

[0004] However, in the tire described in Patent Document 1, since the shapes of the blocks in the buttress portion are the same, there is still room for further improvement, particularly in terms of improving traction performance.

[0005] Therefore, an object of the present invention is to provide a tire that can improve traction performance while ensuring protection performance.

[0006] The means for achieving the above object are as follows.

[0007] (1) The tire of the present invention is a tire having a plurality of mutually independent blocks on the outer surface of a buttress portion extending from the tread edge toward the inner side in the tire radial direction, wherein the plurality of blocks are partitioned in the tire circumferential direction by at least radial grooves extending in the tire radial direction, each of the plurality of blocks includes a notch region having a notch extending in the tire circumferential direction on the outer surface and a non-notch region adjacent to the notch region in the tire circumferential direction and not having the notch on the outer surface, and in at least one set of two blocks adjacent to each other in the tire circumferential direction among the plurality of blocks, the notches in the notch regions face each other across the radial groove.

[0008] According to the present invention, it is possible to provide a tire that can improve traction performance while ensuring protective performance.

[0009] This is an unfolded view of a tire according to one embodiment of the present invention, showing a portion of the tread surface and buttress outer surface laid out in a plane. This is a side view of the tire in Figure 1. This is a partially enlarged side view of the buttress and tread portions of the tire in Figure 1. This is a partially enlarged perspective view of the buttress and tread portions of the tire in Figure 1. This is another partially enlarged perspective view of the buttress and tread portions of the tire in Figure 1. This is a schematic cross-sectional view taken along line A-A in Figure 1.

[0010] The tire according to the present invention can be suitably used as any type of tire, including passenger car tires and truck / bus tires, and is particularly suitable for use as a passenger car tire, and among them, as a tire for an SUV (sports utility vehicle) that is expected to be used on roads with rocks and the like, as well as on general roads.

[0011] Hereinafter, embodiments of the tire according to the present invention will be described with reference to the drawings. Common members and parts in each figure are denoted by the same reference numerals. In this specification, "tire circumferential direction" refers to the direction in which the tire rotates around the tire's axis of rotation (axis line) O, "tire radial direction" refers to the direction perpendicular to the tire's axis of rotation O, and "tire width direction" refers to the direction parallel to the tire's axis of rotation O. In some drawings, the tire circumferential direction is indicated by the reference numeral "CD", the tire radial direction by the reference numeral "RD", and the tire width direction by the reference numeral "WD". Furthermore, in this specification, the side of the tire closer to the tire's axis of rotation O along the tire radial direction is referred to as the "inner side in the tire radial direction", and the side of the tire further from the tire's axis of rotation O along the tire radial direction is referred to as the "outer side in the tire radial direction". Also, in this specification, the side of the tire closer to the tire's equatorial plane CL along the tire width direction is referred to as the "inner side in the tire width direction", and the side of the tire further from the tire's equatorial plane CL along the tire width direction is referred to as the "outer side in the tire width direction". Furthermore, in this specification, "extending in the circumferential direction of the tire" means extending with a circumferential component at an angle of 45° or less with respect to the circumferential direction of the tire. That is, "extending in the circumferential direction of the tire" means that it may extend in a direction along the circumferential direction of the tire (i.e., at an angle of 0° with respect to the circumferential direction of the tire, without inclination with respect to the circumferential direction of the tire), or it may extend at an angle of more than 0° and 45° or less with respect to the circumferential direction of the tire, inclined with respect to the circumferential direction of the tire. Furthermore, in this specification, "extending in the radial direction (or tire width direction) of the tire" means extending with a radial component (or tire width direction) at an angle of less than 45° with respect to the radial direction (or tire width direction) of the tire. In other words, "extending in the tire radial direction (or tire width direction)" means that it may extend in a direction along the tire radial direction (or tire width direction) (i.e., at an angle of 0° with respect to the tire radial direction (or tire width direction) and without inclination with respect to the tire radial direction (or tire width direction)), or it may extend at an inclination angle of more than 0° but less than 45° with respect to the tire radial direction (or tire width direction).

[0012] Although a detailed explanation will be omitted, the tire of the embodiment described below can be a general tire structure, for example, which comprises a carcass having a radial structure carcass ply made of, for example, organic fiber cord or steel cord that extends from one bead portion through the tread portion to the other bead portion, and a belt having a belt layer made of, for example, steel cord that is placed between the carcass and the tread rubber of the tread portion.

[0013] Unless otherwise specified, the positional relationships and dimensions of each element shall be measured under standard conditions, with the tire mounted on the applicable rim, filled to the specified internal pressure, and unloaded. Furthermore, the outer circumference of the tire that comes into contact with the road surface when the tire is mounted on the applicable rim, filled to the specified internal pressure, and under maximum load shall be called the "tread surface" (however, it may be referred to as the "tread face" below), and the edges at both ends of the tread surface in the tire width direction shall be called the "tread edges."

[0014] In this specification, "Applicable Rim" refers to the standard rim for the applicable size (Measuring Rim in ETRTO's STANDARDS MANUAL, Design in TRA's YEAR BOOK) which is an industrial standard valid in the region where the tire is produced and used, and which is described or will be described in the future in publications such as the JATMA YEAR BOOK of JATMA (Japan Automobile Tire Manufacturers Association) in Japan, the STANDARDS MANUAL of ETRTO (The European Tyre and Rim Technical Organization) in Europe, and the YEAR BOOK of TRA (The Tire and Rim Association, Inc.) in the United States. This refers to the rim, but in the case of sizes not listed in these industry standards, it refers to a rim with a width corresponding to the bead width of a pneumatic tire. "Applicable rims" include current sizes as well as sizes that will be listed in the aforementioned industry standards in the future. An example of "sizes that will be listed in the future" is the size listed as "FUTURE DEVELOPMENTS" in the ETRTO 2013 edition.

[0015] In this specification, "specified internal pressure" refers to the air pressure (maximum air pressure) corresponding to the maximum load capacity of a single wheel for the applicable size and ply rating as described in the aforementioned industrial standards such as the JATMA YEAR BOOK. For sizes not listed in the aforementioned industrial standards, it refers to the air pressure (maximum air pressure) corresponding to the maximum load capacity specified for each vehicle on which the tire is mounted. Furthermore, in this specification, "maximum load" refers to the load corresponding to the maximum load capacity of a tire of the applicable size as described in the aforementioned industrial standards, or, for sizes not listed in the aforementioned industrial standards, the load corresponding to the maximum load capacity specified for each vehicle on which the tire is mounted.

[0016] Figure 1 is an unfolded view of a tire according to one embodiment of the present invention, showing a portion of the tread surface and buttress outer surface laid out in a plane. Figure 2 is a side view of the tire in Figure 1. Figures 3 to 5 are a partially enlarged side view, a partially enlarged perspective view, and another partially enlarged perspective view of the buttress and tread portions of the tire in Figure 1, respectively, and Figure 6 is a schematic cross-sectional view taken along line A-A in Figure 1.

[0017] The tire 10 of this embodiment is configured as a passenger car tire. More specifically, the tire 10 is configured as an SUV (Sports Utility Vehicle) tire intended for use on roads with rocks and / or sand, as well as on general roads. Even more specifically, the tire 10 of this embodiment is a pneumatic radial tire for passenger cars. However, the tire 10 of this embodiment may be a tire of a different type than those described above.

[0018] The tire 10 of this embodiment comprises sidewall portions SP on both sides in the tire width direction and a tread portion TP spanning between the two sidewall portions SP. Furthermore, as shown in Figures 1 and 2, the tire 10 also comprises a buttress portion BP extending radially inward from the tread end TE of the tread portion TP. As shown in Figure 2, the buttress portion BP is a part of the sidewall portion SP, and is the radially outer end region of the sidewall portion SP, more specifically, the region radially outward from at least the maximum tire width position (not shown) on the sidewall portion SP. Note that, as shown in Figure 1, the tire 10 of this embodiment is a non-directional tire with a point-symmetric configuration with respect to a point on the tire equatorial plane CL. However, the tire 10 may be a directional tire with a configuration such as line symmetry with respect to the tire equatorial plane CL.

[0019] In the tire 10 of this embodiment, as shown in Figures 1 and 5, a plurality of independent blocks, each separated by a plurality of grooves, are formed on the tread surface 1, which is the outer surface of the tread portion TP. Also in the tire 10 of this embodiment, as shown in Figures 1 to 5, a plurality of independent blocks 20, each separated by a plurality of grooves 50, are formed on the outer surface 2 of the buttress portion BP, which extends inward in the tire radial direction from the tread end TE. The outer surface 2 of the buttress is connected to the inner side of the tread surface 1 in the tire radial direction.

[0020] First, with reference to Figure 1, the configuration of the tread portion TP and, consequently, the tread surface 1 (tread pattern) of the tire 10 of this embodiment will be explained more specifically and briefly.

[0021] As shown in Figure 1, the tire 10 has a plurality of independent blocks (center blocks 30C, shoulder blocks 30S) on the tread surface 1, which are divided by four main grooves 5M extending in the circumferential direction of the tire, and sub-grooves 6S extending between the main grooves 5M and between the main grooves 5M and the tread edge TE. The shoulder blocks 30S are blocks formed at both ends of the tread surface 1 in the tire width direction, and the center blocks 30C are blocks formed further inward in the tire width direction than the shoulder blocks 30S. The plurality of center blocks 30C are arranged with spacing between them in the tire circumferential direction to form three center block rows 3C, and the plurality of shoulder blocks 30S are arranged with spacing between them in the tire circumferential direction to form two shoulder block rows 3S, one on each side of the center block rows 3C in the tire width direction.

[0022] The tire 10 of this embodiment has the tread surface 1 configuration (tread pattern) described above, and is therefore beneficial in providing traction performance on rough road surfaces (for example, road surfaces with scattered rocks, etc.) due to the edge effect of the edges (groove edges) of each block. However, the tread pattern of the tire 10 may be other than that described above. The configuration of the shoulder block row 3S in the tire 10 of this embodiment will be described in more detail later.

[0023] Next, with reference to Figures 3 to 4 and Figure 6, the configuration of the buttress portion BP and, consequently, the buttress outer surface 2 (buttress pattern) in the tire 10 of this embodiment will be described in more detail.

[0024] As described above, in the tire 10 of this embodiment, as shown in Figure 3, a plurality of independent blocks 20, each separated by a plurality of grooves 50, are formed on the outer surface 2 of the buttress. Here, in this specification, "independent blocks" refers to adjacent blocks 20 that are connected by a raised section 80 (described later) or a narrow mold division section projection PT (described later), which is lower than the block height, which is the height from the bottom of the groove that separates the block 20. In this embodiment, as shown in Figure 3, the plurality of grooves 50 on the outer surface 2 of the buttress include a circumferential groove 5, which includes the first circumferential groove 51 to the second circumferential groove 52 (described later), and a radial groove 6, which includes the first radial groove 61 to the fifth radial groove 65 (described later). Here, "circumferential groove" refers to a groove that extends in the circumferential direction of the tire, and "radial groove" refers to a groove that extends in the radial direction of the tire.

[0025] In the tire 10 of this embodiment, as shown in Figure 3, at least a portion of the multiple blocks 20 on the outer surface 2 of the buttress are separated by a first circumferential groove 51, a second circumferential groove 52, and a first diameter groove 61. That is, at least a portion of the multiple blocks 20 are separated by the fact that the first circumferential groove 51, the second circumferential groove 52, and the first diameter groove 61 are repeatedly arranged in the circumferential direction of the tire. In Figure 3, for ease of understanding, the extended portions and directions of the first circumferential groove 51, the second circumferential groove 52, and the first diameter groove 61 are indicated by thick solid arrows.

[0026] The first circumferential groove 51 is a circumferential groove that extends in the tire circumferential direction from the inner side of the multiple blocks 20 in the tire radial direction, and inclined outward in the tire radial direction as it approaches one side in the tire circumferential direction (approximately the right side in Figure 3; the same applies hereinafter). The second circumferential groove 52 is a circumferential groove that is connected to the first circumferential groove 51 and extends in the tire circumferential direction as it approaches one side in the tire circumferential direction. Furthermore, the first radial groove 61 is a radial groove that is connected to the second circumferential groove 52 and extends in the tire radial direction so as it approaches one side in the tire radial direction.

[0027] As described above, in the tire 10 of this embodiment, at least some of the multiple blocks 20 of the buttress portion BP are partitioned by the repeated arrangement of first circumferential grooves 51, second circumferential grooves 52, and first diameter grooves 61, each extending in a different direction, in the circumferential direction of the tire. Therefore, a large traction effect is obtained in both the circumferential and radial directions of the tire due to the edge effect of the blocks 20 adjacent to these grooves 50 (51, 52, 61), particularly the groove edges, and the multiple blocks 20 partitioned by the grooves 50 (51, 52, 61) also ensure protection performance for the sidewall portion SP. Furthermore, with the above configuration, the multiple blocks 20 that appear to form one large block as a whole, partitioned by the first circumferential grooves 51, second circumferential grooves 52, and first diameter grooves 61, are repeatedly arranged in the circumferential direction of the tire, thus improving the appearance of the buttress portion BP.

[0028] In this embodiment, as shown in Figure 3, the length of the first circumferential groove 51 in the longitudinal direction (extension direction) and thus its length in the tire circumferential direction is longer than the length of the second circumferential groove 52 in the longitudinal direction (extension direction) and thus its length in the tire circumferential direction. Furthermore, from the viewpoint of improving traction performance in the tire radial direction, the acute angle that the extension directions of the first circumferential groove 51 and the second circumferential groove 52 make with respect to the tire circumferential direction, as viewed from the side in the tire width direction, is preferably 40° or less, and more preferably 30° or less. Moreover, from the viewpoint of improving traction performance in the tire circumferential direction and thus in the tire travel direction, the acute angle that the extension direction of the first diameter groove 61 makes with respect to the tire radial direction, as viewed from the side in the tire width direction, is preferably 40° or less, and more preferably 30° or less. The same applies to the second diameter grooves 62 to the fifth diameter grooves 65, which will be described later. Here, in this specification, "side view in the tire width direction" means visually inspecting the tire from outside the tire along the tire width direction.

[0029] In this embodiment, as shown in Figure 3, the plurality of blocks 20 form a plurality of block rows 200, each of which a plurality of blocks 20 are arranged in the circumferential direction of the tire. The plurality of blocks 20 in one block row 200 are spaced apart in the circumferential direction of the tire. In the example of Figure 3, the plurality of blocks 20 form an upper block row 3 consisting of a plurality of upper blocks 30 (in this example, a plurality of first upper blocks 31 and a plurality of second upper blocks 32, respectively, which will be described later) arranged in the circumferential direction of the tire on the radially outer side of the tire, and a lower block row 4 consisting of a plurality of lower blocks 40 (in this example, a plurality of first lower blocks 41 and a plurality of second lower blocks 42, respectively, which will be described later) arranged in the circumferential direction of the tire on the radially inner side of the upper block row 3. At least a portion of the plurality of blocks 20 that are separated by the first circumferential groove 51, the second circumferential groove 52 and the first radial groove 61 described above are the plurality of upper blocks 30 (31, 32) of the upper block row 3 and the plurality of lower blocks 40 (41, 42) of the lower block row 4. In other words, the upper block row 3 and the lower block row 4 are separated by a first circumferential groove 51, a second circumferential groove 52, and a first diameter groove 61, which are sequentially connected.

[0030] With this configuration, the buttress section BP has two block rows 200 (upper block row 3 and lower block row 4), each consisting of a plurality of blocks 20 arranged in the circumferential direction of the tire, so that traction performance can be improved more effectively while ensuring protection performance. However, the buttress section BP may have three or more block rows 200, each consisting of a plurality of blocks 20 arranged in the circumferential direction of the tire. However, from the viewpoint of manufacturing efficiency, appearance, etc., it is preferable that there are two block rows 200 as in the example above.

[0031] As shown in Figure 3, in this embodiment, the lower block row 4 includes a first lower block 41 along the first circumferential groove 51, and a second lower block that at least a portion of which also follows the first circumferential groove 51 and is adjacent to one side of the first lower block 41 in the tire circumferential direction. Furthermore, in a side view in the tire width direction, the first lower block 41 includes a first groove edge 411 of the first lower block that extends along the first circumferential groove 51, and a second groove edge 412 of the first lower block that is connected to one side of the first groove edge 411 in the tire circumferential direction and extends so as to inclined inward in the tire radial direction as it approaches one side in the tire circumferential direction. Here, in this specification, "groove edge" such as "first groove edge" and "second groove edge" refers to the edge of the outer surface of the block, in other words, the boundary portion between the outer surface of the block and the groove wall facing the groove of the block. Furthermore, when a block "follows" a groove such as the first circumferential groove, it means that the entire block is adjacent to the groove. In this embodiment, as shown in Figure 3, it is preferable that the adjacent groove edges in each block have a very small radius of curvature when viewed from the side in the tire width direction, and are smoothly connected; in other words, they are rounded rather than angular. With the above configuration, the first lower block 41 has a first lower block second groove edge 412 that is inclined in a direction different from that of the first circumferential groove 51 with respect to the tire circumferential direction, and extends so as to one side in the tire circumferential direction that it is inclined inward in the tire radial direction, thereby enabling stronger traction performance.

[0032] As shown in Figure 3, in this embodiment, the upper block row 3 includes a first upper block 31 that follows the first circumferential groove 51, and a second upper block 32 that at least a portion follows the second circumferential groove 52 and is adjacent to one side of the first upper block 31 in the tire circumferential direction. Furthermore, in a side view in the tire width direction, the first upper block 31 includes a first upper block second groove edge 312 that extends along the first circumferential groove 51, and a first upper block first groove edge 311 that is connected to the other side of the first upper block second groove edge 312 in the tire circumferential direction (approximately the left side in Figure 3; the same applies hereinafter) and extends so as to be inclined inward in the tire radial direction as it approaches one side in the tire circumferential direction. With this configuration, the first upper block 31 has a different inclination direction with respect to the tire circumferential direction than the first circumferential groove 51, and includes a first upper block first groove edge 311 that extends so as to be inclined inward in the tire radial direction as it approaches one side in the tire circumferential direction, thus enabling stronger traction performance.

[0033] As shown in Figure 3, in this embodiment, in a side view in the tire width direction, the second groove edge 412 of the first lower block and the first groove edge 311 of the first upper block face each other. Both groove edges (412, 311) face each other across the first circumferential groove 1. More specifically, the second groove edge 412 of the first lower block and the first groove edge 311 of the first upper block have a configuration in which a short groove is formed between them, intersecting the first circumferential groove 51 midway through the groove, and having a different inclination direction with respect to the tire circumferential direction from the first circumferential groove 51. This configuration allows for more effective traction performance and improves appearance.

[0034] As shown in Figure 3, in this embodiment, a second radial groove 62 extending in the tire radial direction and communicating with the longitudinal middle portion of the first circumferential groove 51 is formed between the first lower block 41 and the second lower block 42. With this configuration, the radial edge component of the tire increases by the length of the radial groove edges of the first lower block 41 and the second lower block 42 adjacent to the second radial groove 62, so that traction performance can be made stronger, especially in the circumferential direction of the tire (in other words, the direction of tire travel).

[0035] As shown in Figure 3, in this embodiment, the second lower block 42, in a side view in the tire width direction, includes a second lower block first groove edge 421 extending along the first circumferential groove, a second lower block second groove edge 422 extending from one side of the second lower block first groove edge 421 in the tire circumferential direction and inclined inward in the tire radial direction as it approaches that side, a second lower block third groove edge 423 extending from one side of the second lower block second groove edge 422 in the tire circumferential direction and inclined outward in the tire radial direction as it approaches that side, and a second lower block fourth groove edge 424 extending from one side of the second lower block third groove edge 423 in the tire circumferential direction and along the second circumferential groove 52. With this configuration, the second lower block 42 has a second groove edge 422 that extends in a direction inclined in the radial direction of the tire as it approaches one side of the tire circumferential direction, and the inclination of the second lower block 422 differs from that of the first circumferential groove 51 with respect to the tire circumferential direction. Furthermore, the second lower block 42 has a third groove edge 423 that extends in a direction inclined outward in the radial direction of the tire as it approaches one side of the tire circumferential direction, with respect to the tire circumferential direction, and the inclination of the second groove edge 423 differs from that of the second circumferential groove 52 with respect to the tire circumferential direction. As a result, traction performance can be enhanced.

[0036] As shown in Figure 3, in this embodiment, the length of the second groove edge 422 of the second lower block is longer than the length of the third groove edge 423 of the second lower block. With this configuration, the second groove edge 422 compensates for edge components that have a different orientation with respect to the tire circumferential direction from the first circumferential groove 51, thereby enabling stronger traction performance.

[0037] As shown in Figure 3, in this embodiment, the second lower block 42 includes a first half 42a of the second lower block, which has a first groove edge 421 and a second groove edge 422 of the second lower block, and a second half 42b of the second lower block, which has a third groove edge 423 and a fourth groove edge 424 of the second lower block. A third diameter groove 63 extending in the tire diameter direction is formed between the first half 42a and the second half 42b of the second lower block. In this specification, the term "half" of a block, such as "first half of the second lower block," does not necessarily mean one half of a block divided into two equal-sized parts; each half may be of a different size. According to the above configuration, the radial edge component of the tire increases by the length of the groove edge in the tire radial direction of the first half 42a and the second half 42b of the second lower block adjacent to the third diameter groove 63, so that traction performance can be made stronger, especially in the circumferential direction of the tire (in other words, the direction of tire travel).

[0038] As shown in Figure 3, in this embodiment, the third diameter groove 63 terminates within the second lower block 42. More specifically, the third diameter groove 63 opens outward in the tire radial direction of the second lower block 42 (i.e., on the side of the first circumferential groove 51 and the second circumferential groove 52) and terminates inward in the tire radial direction within the second lower block 42. In other words, the first half 42a and the second half 42b of the second lower block are connected and integrated in the inner portion in the tire radial direction. With the above configuration, the reduction in block rigidity of the second lower block 42 due to the provision of the third diameter groove 63 can be suppressed, and thus protection performance can be effectively ensured.

[0039] As shown in Figure 3, in this embodiment, a fourth diameter groove 64 is formed between the first upper block 31 and the second upper block 32, extending in the tire radial direction on the extension of the third diameter groove 63, and a fifth diameter groove 65 is formed between the second upper block 32 and the first upper block 31, extending in the tire radial direction on the tire radially outer side of the first lower block 41. With this configuration, the tire radial edge component is increased by the length of the groove edge in the tire radial direction of the first upper block 31 and / or the second upper block 32 adjacent to the fourth diameter groove 64 and / or the fifth diameter groove 65, so that traction performance in the tire circumferential direction (in other words, the tire direction of travel) can be made stronger.

[0040] In Figure 3, the symbol "PT" represents a mold division ridge that extends continuously in the circumferential direction of the tire and may inevitably occur in conjunction with the division (split position) of the tire vulcanization mold during tire manufacturing. In this embodiment, the fourth diameter groove 64 and the fifth diameter groove 65 extend from the first circumferential groove 51 and / or the second circumferential groove 52, across the mold division ridge PT, and open to the tread edge TE. As a result, the traction performance improvement effect in the circumferential direction of the tire by the fourth diameter groove 64 and the fifth diameter groove 65 can be fully realized.

[0041] Next, the raised section 80 that connects each of the blocks 20 described above in this embodiment will be explained.

[0042] In this embodiment, as shown in Figure 3, a first raised section 81 is provided in the groove 50 (first diameter groove 61 and second diameter groove 62 in this embodiment) between any two adjacent lower blocks 40 (first lower block 41 and second lower block 42 in this embodiment) in the tire circumferential direction, so that all of the multiple lower blocks 40 are connected to each other in the tire circumferential direction. Here, in this specification, "raised section" refers to a rubber portion that connects adjacent blocks 20 across either groove 50 (circumferential groove 5, diameter groove 6), extending from the bottom of the groove 50 upward in the groove depth direction, and is formed to be lower in height than the block height of any of the blocks 20 (the height of the groove 50 in the groove depth direction from the bottom of the groove 50).

[0043] In a tire provided with a plurality of independent blocks 20 arranged in the tire circumferential direction in the buttress portion BP, since the volume change in the tire circumferential direction of the buttress portion BP is large, when the tire is filled with internal pressure, in the region on the inner side in the tire radial direction where the buttress portion BP has a particularly thin thickness, the tire expands unevenly in the tire circumferential direction, and unevenness may occur in the tire circumferential direction on the outer surface of the buttress portion BP and thus the sidewall portion SP. Therefore, according to the above configuration, a bottom raising portion 80 (first bottom raising portion 81) is provided in the groove 50 between the lower blocks 40 adjacent to each other in the tire circumferential direction so as to connect all of the plurality of lower blocks 40 in the tire circumferential direction. In other words, since the change in the height of the land portions arranged in the tire circumferential direction is reduced, the occurrence of unevenness in the tire circumferential direction of the sidewall portion SP when the tire 10 is filled with internal pressure can be suppressed. Further, according to the above configuration, since the rigidity between the adjacent lower blocks 40 is reinforced by the bottom raising portion 80 (first bottom raising portion 81), the protection performance can be ensured more effectively. Furthermore, according to the above configuration, for example, clogging that may occur between the adjacent lower blocks 40 during traveling on a rough road can be suppressed, and the edge effect by the bottom raising portion 80 is also added, so that the traction performance can be exerted more strongly. Also, according to the above configuration, since the tire exhibits an appearance with high traction performance, the appearance property is improved.

[0044] As shown in FIG. 3, in the present embodiment, the first bottom raising portion 81 includes an enlarged first bottom raising portion 81a configured to connect the lower blocks 40 (first lower block 41 and second lower block 42) adjacent to each other in the tire circumferential direction and at least one upper block 30 (first upper block 31 or second upper block 32). According to this configuration, the occurrence of unevenness in the tire circumferential direction of the sidewall portion SP when the tire 10 is filled with internal pressure can be suppressed more, and the appearance property is also further improved.

[0045] In this embodiment, more specifically, the enlarged first raised portion 81a connects the first lower block 41, the second lower block 42, and the radial projection 32e formed on the non-notched half portion 32d of the second upper block 32, which will be described later. This configuration further suppresses the occurrence of irregularities in the sidewall portion SP described above, and also further improves the appearance.

[0046] In this embodiment, as shown in Figure 3, the width of the first raised portion 81, excluding the enlarged first raised portion 81a, is preferably 50% or more of the length of the smaller of the two sides (groove edges) of the lower block 40 (first lower block 41 and second lower block 42) to which the first raised portion 81 is connected, in a side view in the tire width direction. Here, in this specification, the "width" of the raised portion 80 refers to the width measured in a direction perpendicular to the direction in which the raised portion 80 connects adjacent blocks 20, in a side view in the tire width direction. Also, as shown in Figure 3, in this embodiment, the smaller of the two sides (groove edges) of the lower block 40 to which the first raised portion 81 is connected is the side (groove edge) of the first lower block 41 to which the first raised portion 81 is connected (excluding the second groove edge 412 of the first lower block). In this case, the occurrence of irregularities in the sidewall portion SP described above can be suppressed more reliably.

[0047] In this embodiment, as shown in Figure 3, a second raised portion 82 is provided in the groove 50 (first circumferential groove 51 or second circumferential groove 52) between a lower block 40 and an upper block 30 that are adjacent to each other in the tire radial direction, so as to connect at least one of the plurality of lower blocks 40 and at least one of the plurality of upper blocks 30 to each other in the tire radial direction. This second raised portion 82 is lower in height than the lower block 40 and the upper block 30. With this configuration, the presence of the second raised portion 82, which becomes a recess on the vulcanization mold side during tire manufacturing, improves the flow of rubber during tire manufacturing (vulcanization), and consequently allows air to escape to the outside, thereby suppressing the occurrence of bares (air pockets) in the finished tire. Furthermore, with this configuration, traction performance and appearance can also be improved, similar to the case where the first raised portion 81 described above is provided.

[0048] In addition, in the present embodiment, the second bottom raising portion 82 is narrower (thinner) than the first bottom raising portion 81. According to this configuration, without a large increase in the rubber volume, the occurrence of the above-mentioned bear can be suppressed.

[0049] Also, in the present embodiment, two or more (two in the example of FIG. 3) second bottom raising portions 82 are provided in the groove 50 between the lower block 40 and the upper block 30 adjacent to each other in the tire radial direction. In this case, the occurrence of the above-mentioned bear can be further suppressed, and the traction performance is also further improved. However, only one second bottom raising portion 82 may be provided at the above position. Further, the second bottom raising portion 82 is preferably provided, for example, in four or less at the above position, although it also depends on the size of the block 20 to which the second bottom raising portion 82 is connected.

[0050] More specifically, in the present embodiment, as shown in FIG. 3, the second bottom raising portion 82 includes two or more (two in the example of FIG. 3) second bottom raising portions 82a that connect the second lower block first half portion 42a and the first upper block 31, and two or more (two in the example of FIG. 3) second bottom raising portions 82b that connect the second lower block second half portion 42b and the second upper block 32. In this case, the above-mentioned effects by the second bottom raising portion 82 can be more surely exhibited.

[0051] In the present embodiment, as shown in FIG. 3, between the two upper blocks 30 adjacent to each other in the tire circumferential direction among the plurality of upper blocks 30 so as to connect them in the tire circumferential direction, a third bottom raising portion 83 having a height lower than that of the two upper blocks is provided in the groove 50 (the fifth radial groove 65 in the present embodiment). According to this configuration, the occurrence of bears in the product tire can be more surely suppressed. Further, according to this configuration, the traction performance and the appearance can also be improved as in the case where the above-mentioned first bottom raising portion 81 and / or second bottom raising portion is provided.

[0052] In addition, in the present embodiment, the third bottom raising portion 83 is narrower (thinner) than the first bottom raising portion 81. According to this configuration, without a large increase in the rubber volume, the occurrence of the above-mentioned bear can be suppressed.

[0053] In this embodiment, in the radially outer region of the buttress portion BP adjacent to the highly rigid crown portion including the tread rubber, carcass, and belt, where the upper block row 3 and thus the upper block 30 are provided, even when the tire is filled with internal pressure, the aforementioned circumferential irregularities in the sidewall portion SP due to the presence of multiple independent blocks 20 are less likely to occur compared to the radially inner region adjacent to or near the main portion of the thin sidewall portion SP where the lower block row 4 and thus the lower block 40 are provided. From this point of view, the third bottom-raising portion 83 connecting the upper blocks 30 in the circumferential direction of the tire does not need to be as wide as the first bottom-raising portion 81 connecting the lower blocks 40 in the circumferential direction of the tire. Furthermore, from viewpoints other than suppressing the occurrence of bearings as described above, it can be said that the need to provide a third bottom-raising portion 83 connecting adjacent upper blocks 30 in the circumferential direction of the tire is not necessarily great.

[0054] Conversely, in a side view in the tire width direction, it is preferable to provide a raised section (for example, a raised section similar to the first raised section 81 or the third raised section 83) between adjacent blocks in the tire circumferential direction, between the innermost position in the tire radial direction of the area occupied by the plurality of blocks 20 (in this embodiment, a plurality of lower blocks 40) and a radial position located radially outward from the innermost position in the tire radial direction, separated by a radial distance of at least 20%, preferably 30%, of the radial distance between the innermost position and the tread edge TE. In this embodiment, the innermost position in the tire radial direction of the area occupied by the plurality of blocks 20 (in this embodiment, a plurality of lower blocks 40) can be a radial position located radially outward from the maximum tire width position in the sidewall section SP, separated by a radial distance of 10 to 30% of the radial distance between the maximum tire width position and the tread edge TE, in a side view in the tire width direction.

[0055] Furthermore, in this embodiment, two or more third base-raising portions 83 (two in the example of Figure 3) are provided in the groove 50 (fifth diameter groove 65 in this embodiment) between two upper blocks 30 adjacent to each other in the circumferential direction of the tire. In this case, the occurrence of the above-mentioned bearing can be further suppressed, and traction performance is also further improved. However, only one third base-raising portion 83 may be provided in the above position. Also, depending on the size of the block 20 to which the third base-raising portions 83 are connected, it is preferable that, for example, four or fewer third base-raising portions 83 are provided in the above position.

[0056] In this embodiment, as shown in Figure 3, the third base-raising portion 83 includes two or more (two in the example of Figure 3) third base-raising portions 83 that connect one side of the second upper block 32 in the tire circumferential direction (specifically, the radial projection 32e of the second upper block 32) and the other side of the first upper block 31 in the tire circumferential direction. However, no third base-raising portion is provided between one side of the first upper block 31 in the tire circumferential direction and the other side of the second upper block 32 in the tire circumferential direction. In this case, the aforementioned effects of the third base-raising portion 83 can be achieved while suppressing a large increase in rubber volume.

[0057] In this embodiment, the heights of the first base portion 81, the second base portion 82, and the third base portion 83 are preferably 10 to 60% of the maximum height of the multiple blocks 20, including the upper block 30 and the lower block 40. By having the heights of the first to third base portions 81 to 83 be 10% or more of the maximum height of the multiple blocks 20, the effects of suppressing the occurrence of irregularities in the sidewall portion, suppressing the occurrence of bare material in the product tire, improving traction performance, and improving appearance can be reliably obtained by each base portion, while having a height of 60% or less does not result in a large increase in rubber volume and consequently a large increase in tire weight. From a similar viewpoint, it is more preferable that the heights of the first to third base portions 81 to 83 be 20 to 50% of the maximum height of the multiple blocks 20.

[0058] In this embodiment, as described above, the plurality of grooves 50 include, in a side view in the tire width direction, a plurality of circumferential grooves 5 extending in the tire circumferential direction and a plurality of radial grooves 6 extending in the tire radial direction. With this configuration, good traction performance can be obtained in both the tire radial direction and the tire circumferential direction.

[0059] In this embodiment, the height of the multiple blocks 20 decreases as you move from the outside to the inside in the radial direction of the tire. That is, the height of the multiple blocks 20 as a whole decreases at least at one or more points along the way as you move from the outside to the inside in the radial direction of the tire, and does not change in a way that increases. In this embodiment, the height of the multiple blocks 20 decreases continuously as you move from the outside to the inside in the radial direction of the tire. This configuration makes it possible to more effectively suppress the occurrence of irregularities in the sidewall portion SP mentioned above.

[0060] In this embodiment, the height, width, and shape of the first raised sections 81, the enlarged first raised sections 81a, the second raised sections 82a, the second raised sections 82b, and the third raised sections 83 are the same around the entire circumference of the buttress section BP, excluding the enlarged first raised section 81a. In addition, in this embodiment, all the raised sections 80, including the various raised sections, are the same height. In this case, the design and manufacture of the tire including the raised sections 80 become easier. However, for example, the height of at least some of the raised sections 80 may differ from the height of other raised sections 80.

[0061] In Figure 3, the second raised portion 82 (82a, 82b) and the third raised portion 83 may appear to be separated from the edge of the adjacent block 20 to which they are connected. However, in this embodiment, the groove wall adjacent to the groove 50 of the block 20 is slightly inclined with respect to the groove depth direction and extends in that direction. Thus, the second raised portion 82 (82a, 82b) and the third raised portion 83 are connected to the groove wall of the adjacent block 20 and, consequently, to the block 20.

[0062] Next, referring mainly to Figures 3 to 4 and Figure 6, the upper block row 3 in this embodiment will be explained, focusing on the notches 9 provided in each upper block 30 that constitute the upper block row 3, which will be described later. Note that in Figure 6, the internal structure of the tire is omitted to avoid complexity.

[0063] As shown in Figures 3 and 4, in this embodiment, the multiple upper blocks 30 of the buttress section BP are divided in the circumferential direction of the tire by diameter grooves 6 (in this embodiment, the fourth diameter groove 64 and the fifth diameter groove 65) that extend at least in the radial direction of the tire. Furthermore, in this embodiment, each of the multiple upper blocks 30 (in this embodiment, the first upper block 31 and the second upper block 32) includes notched regions 31c, 32c having notches 9 extending in the circumferential direction of the tire on their outer surface, and non-notched regions 31d, 32d adjacent to the notched regions 31c, 32c in the circumferential direction of the tire and not having notches 9 on their outer surface (i.e., the outer surface is a non-notched surface N9). Moreover, in this embodiment, in at least one pair of upper blocks 30 that are adjacent to each other in the circumferential direction of the tire, the notches 9 in the notched regions 31c, 32c face each other across the diameter groove 6 (in this embodiment, the fourth diameter groove 64). In this embodiment, two blocks 20 (upper blocks 30) configured in this manner, adjacent to each other in the tire circumferential direction, are repeatedly arranged around the entire circumference in the tire circumferential direction. In other words, as shown in Figures 3 and 4, when the four halves of the adjacent first upper block 31 and second upper block 32, each having notched regions 31c, 32c or non-notched regions 31d, 32d, are referred to as the first half 31a of the first upper block, the second half 31b of the first upper block, the first half 32a of the second upper block, and the second half 32b of the second upper block, respectively, with respect to one side in the tire circumferential direction, then the second half 31b of the first upper block and the first half 32a of the second upper block are notched regions 31c, 32c, and the first half 31a of the first upper block and the second half 32b of the second upper block are non-notched regions 31d, 32d. In this specification, "notch" refers to a portion of the outer surface of block 20 that has been indented as if it had been cut out toward the inside (meat side) of block 20.

[0064] According to the above configuration, the notches 9 of adjacent blocks 20 (first upper block 31 and second upper block 32) in the circumferential direction of the tire face each other. For example, when driving on rough roads, it becomes possible to grip large rocks, etc., between the notches 9, and traction performance can be achieved regardless of the direction of rotation of the tire, thereby improving traction performance. Furthermore, since the adjacent blocks 20 (first upper block 31 and second upper block 32) each have a non-notched region 31d that does not have a notch 9, protection performance is ensured. In this embodiment, the notches 9 are formed on the outermost part in the radial direction of the tire of each of the first upper block 31 and the second upper block 32. This makes it possible to improve traction performance more effectively.

[0065] In this embodiment, the notched region 31c and the non-notched region 31d of each upper block 30 are separated by a narrow groove 7 that extends in the tire diameter direction. With this configuration, the notched region 31c can be flexibly deformed, making it easier to push mud in when gripping it with the notch, for example, and thereby improving traction performance. Furthermore, with the above configuration, the combination of the narrow groove 7 and the notch 9 improves the appearance. As shown in Figure 3, it is preferable that the opening width of the narrow groove 7 is sufficiently smaller (narrower) than the opening width of each groove 50 described above, in order to suppress a large decrease in the rigidity of the upper block 30 and still ensure sufficient protection performance.

[0066] As described above, in this embodiment, mold division ridges PT, corresponding to the divisions (split positions) of the tire vulcanization mold used to manufacture the tire 10, are formed on the outer surface 2 of the buttress portion BP along the entire circumference in the tire circumferential direction. The small-diameter grooves 7 extend from the outermost opening end in the tire radial direction of the buttress portion BP (i.e., the tread end TE), beyond the mold division ridges PT, inward in the tire radial direction, and terminate within the upper block 30. In other words, the notched and non-notched regions of each upper block 30 are connected and integrated in the inner portion in the tire radial direction. With the above configuration, traction performance can be fully demonstrated, and the reduction in block rigidity due to the provision of small-diameter grooves 7 can be suppressed, thereby effectively ensuring protection performance. Furthermore, since the mold division ridges PT hinder the sense of unity of a single block, the small-diameter grooves 7 extending beyond the mold division ridges PT inward in the tire radial direction creates a sense of unity in the block, improving its appearance.

[0067] In this embodiment, as shown in Figure 3, in a side view in the tire width direction, of the four sides (i.e., groove edges) 31e extending in the tire radial direction of two blocks 20 (in this embodiment, the first upper block 31 and the second upper block 32) that are adjacent to each other in the tire circumferential direction, the length in the tire radial direction of one side 31e (in this embodiment, the side 31e on one side of the second upper block 32 in the tire circumferential direction) that constitutes the non-notched region of one block 20 (in this embodiment, the second upper block 32) is made longer than the lengths in the tire radial direction of the other three sides 31e. With this configuration, in a side view in the tire width direction, the two adjacent blocks 20 appear to form one large block, improving appearance while also achieving a sufficient balance between protection performance and traction performance.

[0068] In this embodiment, as shown in Figure 3, of two blocks 20 adjacent to each other in the tire circumferential direction (i.e., the first upper block 31 and the second upper block 32), the length of the notched region 31c (and thus the notch 9) of one block (in this example, the first upper block 31) in the tire circumferential direction is made longer than the length of the non-notched region 31d (and thus the non-notched surface N9) of the one block (first upper block 31) and the notched region 32c (and thus the notch 9) of the other block (in this example, the second upper block 32) in the tire circumferential direction. This configuration also allows for a sufficient balance between protection performance and traction performance.

[0069] In this embodiment, as shown in Figures 4 and 6, the notched surface 9f of the notch 9 is a curved surface that exhibits a curved shape in a cross-sectional view in the tire width direction. In this case, it is possible to suppress the occurrence of cracks, breakage, chipping, and other failures in the notched surface 9f and consequently the block 20 that may occur if any part of the notched surface 9f is angular.

[0070] Furthermore, as shown in Figure 6, the outer end 9u and inner end 9d of the notch 9 in the tire radial direction in this embodiment are arc-shaped with a very small radius of curvature in a cross-sectional view in the tire width direction; in other words, they are rounded rather than angular. In this case as well, it is possible to suppress failures such as cracking, breaking, and chipping in the block 20. Also, as can be seen from Figure 6, in this example, in a cross-sectional view in the tire width direction, the outer surface of the non-notched region having a non-notched surface N9 changes its angle of inclination with respect to the tire radial direction in the portion extending inward from the tread edge TE in the tire radial direction, so that the angle of inclination with respect to the tire radial direction becomes smaller.

[0071] Next, referring mainly to Figure 5, the shoulder block row 3S of the tread portion TP and, consequently, the tread surface 1 of the tire 10 of this embodiment will be described.

[0072] As shown in Figures 1 and 5, the tire 10 of this embodiment has a row of shoulder blocks 3S formed at both ends of the tread surface 1 in the tire width direction, with a plurality of shoulder blocks 30S arranged apart from each other in the tire circumferential direction. Each shoulder block 30S in the row of shoulder blocks 3S is configured to be separated from each other in the tire circumferential direction by a sub-groove 6S extending in the tire width direction. That is, each shoulder block 30S is demarcated by a main groove 5M extending in the tire circumferential direction, a sub-groove 6S extending in the tire width direction, and a tread edge TE. In this embodiment, each shoulder block 30S has substantially the same shape over the entire circumference in the tire circumferential direction.

[0073] In this embodiment, as shown in Figure 5, each shoulder block 30S is composed of a large block 30Sa and a small block 30Sb that has a smaller area than the large block 30Sa when viewed from the tread surface. The large block 30Sa and the small block 30Sb are separated by a circumferential groove 35G that extends in the circumferential direction of the tire and a widthwise groove 36G that communicates with the circumferential groove 35G and extends in the tire width direction. The groove widths of both the circumferential groove 35G and the widthwise groove 36G are smaller than the groove widths of the main groove 5M and the sub-groove 6S. "View from the tread surface" refers to visually inspecting the tread surface from directly above the tread surface on the outside of the tire, along the tire diameter direction. By providing the shoulder block 30S with the above configuration, it is possible to ensure appropriate block rigidity of the shoulder block 30S while increasing the edge components in the tire width direction and tire circumferential direction due to the groove edges of the block, thereby improving traction performance in both directions.

[0074] In this embodiment, as can be seen from Figure 5, in the view of the tread surface, the large block 30Sa and small block 30Sb of the shoulder block 30S have a substantially polygonal shape, and the opposing sides (groove edges) of the large block 30Sa and small block 30Sb are parallel to each other. Furthermore, in order to maintain high block rigidity of the shoulder block 30S, the groove depth of the circumferential groove 35G is shallower than the groove depth of the widthwise groove 36G. As shown in Figure 5, in the view of the tread surface, the extension direction of the widthwise groove 36G changes at one point during its extension. Furthermore, in order to make the block rigidity of the shoulder block 30S closer to uniform, the length of the outermost edge 30Sbe of the small block 30Sb in the tire width direction is longer than the length of the outermost edge 30Sae of the large block 30Sa in the tire width direction. In addition, the groove edge of the small block 30Sb facing the widthwise groove 36G is chamfered, forming a chamfered portion 30Sbc.

[0075] As shown in Figure 5, in this embodiment, the sub-grooves 6S on the tread surface 1 are connected to the fourth diameter groove 64 or the fifth diameter groove on the buttress outer surface 2. Also, the shoulder blocks 30S on the tread surface 1 are connected to the first upper block 31 or the second upper block 32 on the buttress outer surface 2. Furthermore, the large blocks 30Sa on the tread surface 1 are connected to the first half 31a of the first upper block or the first half 32a of the second upper block on the buttress outer surface 2. Moreover, the small blocks 30Sb on the tread surface 1 are connected to the second half 31b of the first upper block or the second half 32b of the second upper block on the buttress outer surface 2. In addition, the widthwise grooves 36G on the tread surface 1 are connected to the small diameter grooves 7 on the buttress outer surface 2. Consequently, these grooves and / or blocks ensure more reliable traction and protection, and the sense of continuity and unity between the tread surface 1 and the tread portion TP and the buttress outer surface 2 and the buttress portion BP is enhanced, resulting in improved appearance.

[0076] The foregoing describes exemplary embodiments of the present invention, and various modifications can be made without departing from the scope of the claims.

[0077] The tire according to the present invention can be suitably used as any type of tire, including passenger car tires and truck / bus tires, and is particularly suitable for use as a passenger car tire, and among them, as a tire for an SUV (sports utility vehicle) that is expected to be used on roads with rocks and the like, as well as on general roads.

[0078] 10: Tire, 1: Tread surface, 2: Buttress outer surface, 20: Block, 200: Block row, 3: Upper block row, 4: Lower block row, 30: Upper block, 31: First upper block, 311: First groove edge of first upper block, 312: Second groove edge of first upper block, 31a: First half of first upper block, 31b: Second half of first upper block, 31c: Notched area, 31d: Non-notched area, 31e: Radial side, 32: Second upper block, 321: First groove edge of second upper block, 322: Second groove edge of second upper block, 32a: First half of second upper block, 32b: Second half of second upper block, 32c: Notched area, 32d: Non-notched area, 32e: Radial projection, 40: Lower block, 41: First lower block, 411: First groove edge of the first lower block, 412: Second groove edge of the first upper block, 42: Second lower block, 421: First groove edge of the second lower block, 422: Second groove edge of the second lower block, 423: Third groove edge of the second lower block, 424: Fourth groove edge of the second lower block, 42a: First half of the second lower block, 42b: Second half of the second lower block, 50: Groove, 5: Circumferential groove, 51: First circumferential groove, 52: Second circumferential groove, 6: Diameter groove, 61: First diameter groove, 62: Second diameter groove, 63: Third diameter groove, 64: Fourth diameter groove, 65: Fifth diameter groove, 7: Small diameter groove, 80: Raised bottom section, 81: First raised bottom section, 81a: Enlarged first bottom-raising section (first bottom-raising section), 82, 82a, 82b: Second bottom-raising section, 83: Third bottom-raising section, 9: Notch, 9f: Notched surface, N9: Non-notched surface, 9u: Outer end of notch in the tire radial direction, 9d: Inner end of notch in the tire radial direction, 30C: Center block, 3C: Center block row, 30S: Shoulder block, 3S: Shoulder block row, 30Sa: Large block, 30Sae: Outermost edge of large block in the tire width direction, 30Sb: Small block, 30Sbe: Outermost edge of small block in the tire width direction, 30Sbc: Chamfered part of small block, 5M: Main groove, 6S: Sub-groove, BP: Buttress section, CD: Tire circumferential direction, CL: Tire equatorial plane, IF: Inner surface of tire, O: Tire rotation axis, PT: Molded section projection, RD: Tire radial direction, SP: Sidewall, TE: Tread edge, TP: Tread, WD: Tire width direction

Claims

1. A tire having a plurality of independent blocks on the outer surface of a buttress portion extending radially inward from the tread edge, wherein the plurality of blocks are divided in the circumferential direction of the tire by at least radial grooves extending in the radial direction of the tire, each of the plurality of blocks consists of a notched region having a notch extending in the circumferential direction of the tire on its outer surface, and a non-notched region adjacent to the notched region in the circumferential direction of the tire and not having the notch on its outer surface, and in at least one pair of blocks that are adjacent to each other in the circumferential direction of the tire, the notches in the notched region face each other across the radial groove.

2. The tire according to claim 1, wherein the notched region and the non-notched region are separated by a narrow groove that is narrow in width and extends in the radial direction of the tire.

3. On the outer surface of the buttress portion, mold division ridges corresponding to the division portions of the tire vulcanizing mold used to manufacture the tire are formed over the entire circumference in the tire circumferential direction, and the small diameter groove extends from the outermost opening end in the tire radial direction of the buttress portion, beyond the mold division ridges, inward in the tire radial direction, and terminates within the block, as described in claim 2.

4. In a side view in the tire width direction, of the two blocks adjacent to each other in the tire circumferential direction, the length in the tire radial direction of one of the four sides extending in the tire radial direction of one of the blocks is longer than the length in the tire radial direction of the other three sides.

5. The tire according to any one of claims 1 to 3, wherein the length in the tire circumferential direction of the notched region of one of the two blocks adjacent to each other in the tire circumferential direction is longer than the length in the tire circumferential direction of the non-notched region of the one block and the notched region of the other block.

6. The tire according to any one of claims 1 to 3, wherein the notched surface of the notch is a curved surface that exhibits a curve in a cross-sectional view in the tire width direction.

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