tire

Abstract

This suppresses the occurrence of irregularities in the tire's circumferential direction on the sidewall. [Solution] A tire having a plurality of independent blocks 20 separated by a plurality of grooves 50 formed on the outer surface 2 of the buttress portion BP, wherein the plurality of blocks 20 form an upper block row 3 consisting of a plurality of upper blocks 30 arranged in the tire circumferential direction on the outer side in the tire radial direction, and a lower block row 4 consisting of a plurality of lower blocks 40 arranged in the tire circumferential direction on the inner side in the tire radial direction than the upper block row 3, and a first raised portion 81 which is lower in height than the lower block 40 is provided in the groove 50 between every pair of lower blocks 40 that are adjacent to each other in the tire circumferential direction so as to connect all of the plurality of lower blocks 40 to each other in the tire circumferential direction.

Description

Technical Field

[0001] The present invention relates to a tire.

Background Art

[0002] Conventionally, a tire is known in which independent blocks partitioned by a plurality of grooves are formed on the outer surface of a buttress portion (hereinafter also referred to as "buttress outer surface") extending from the tread edge toward the inner side in the tire radial direction (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.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the tire described in Patent Document 1, since the rigidity step in the tire circumferential direction in the buttress portion is large, when the tire is filled with internal pressure, unevenness occurs in the circumferential direction on the outer surface of the sidewall portion, and thus the appearance of the tire may be impaired.

[0005] Therefore, an object of the present invention is to provide a tire capable of suppressing the occurrence of unevenness in the tire circumferential direction in the sidewall portion.

Means for Solving the Problems

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

[0007] Please note that the specific number in and

[0004] in the original text should be filled in the translated text according to the actual content. Here, they are represented by asterisks for placeholder purposes.(1) The tire of the present invention is A tire having multiple independent blocks, each separated by multiple grooves, formed on the outer surface of the buttress portion extending radially inward from the tread edge, The aforementioned plurality of blocks form an upper block row consisting of a plurality of upper blocks arranged in the circumferential direction of the tire on the radially outer side of the tire, and a lower block row consisting of a plurality of lower blocks arranged in the circumferential direction of the tire on the radially inner side of the upper block row. A first raised section, lower in height than the lower block, is provided in the groove between every two adjacent lower blocks in the tire circumferential direction, so that all of the aforementioned lower blocks are connected to each other in the tire circumferential direction. According to the tire of the present invention, it is possible to suppress the occurrence of irregularities in the tire circumferential direction on the sidewall portion.

[0008] (2) In the tire described in (1) above, Preferably, a second base portion is provided in the groove between the lower block and the upper block that are adjacent to each other in the tire radial direction, so as to connect at least one of the plurality of lower blocks and at least one of the plurality of upper blocks to each other in the tire radial direction, and the second base portion is lower in height than the lower block and the upper block and narrower in width than the first base portion. In this case, the occurrence of bare rubber in the finished tire can be suppressed without a significant increase in rubber volume.

[0009] (3) In the tire of (1) or (2) above, Preferably, the first raised portion includes an enlarged first raised portion configured to connect the lower blocks and at least one of the upper blocks that are adjacent to each other in the tire circumferential direction. In this case, the occurrence of irregularities in the tire's circumferential direction on the sidewall can be further suppressed.

[0010] (4) In any of the tires described in (1) to (3) above, Preferably, a third raised portion is provided in the groove between two upper blocks that are adjacent to each other in the tire circumferential direction, so as to connect two of the plurality of upper blocks that are adjacent to each other in the tire circumferential direction, and the third raised portion is lower in height than the two upper blocks and narrower in width than the first raised portion. In this case as well, it is possible to suppress the occurrence of bare rubber in the finished tire without a significant increase in rubber volume.

[0011] (5) In the tire described in (4) above, The heights of the first, second, and third base sections are preferably 10 to 60% of the maximum height of the multiple blocks, including the upper and lower blocks. In this case, the effect of each raised section can be fully realized without a significant increase in rubber volume.

[0012] (6) In the tire described in (3) above, The width of the first raised section, excluding the enlarged first raised section, is preferably 50% or more of the length of the smaller of the two sides of the lower block to which the first raised section is connected. In this case, the occurrence of irregularities in the tire's circumferential direction on the sidewall can be suppressed more reliably.

[0013] (7) In the tire described in (2) above, It is preferable that two or more of the second raised sections are provided in the groove between the lower block and the upper block, which are adjacent to each other in the tire radial direction. In this case, the occurrence of bearings in the product tires can be further suppressed.

[0014] (8) In the tire described in (4) above, It is preferable that two or more of the third raised sections are provided in the groove between the two upper blocks that are adjacent to each other in the circumferential direction of the tire. In this case as well, the occurrence of bearings in the finished tire can be further suppressed.

[0015] (9) In any of the tires of (1) to (8) above, it is preferable that the plurality of grooves include a plurality of circumferential grooves extending in the tire circumferential direction and a plurality of radial grooves extending in the tire radial direction in a side view in the tire width direction. In this case, good traction performance in the tire radial direction and the tire circumferential direction can be obtained.

[0016] (10) In any of the tires of (1) to (9) above, it is preferable that the height of the plurality of blocks decreases from the outer side to the inner side in the tire radial direction. In this case, the generation of unevenness in the tire circumferential direction in the sidewall portion can be more effectively suppressed.

Advantages of the Invention

[0017] According to the present invention, it is possible to provide a tire capable of suppressing the generation of unevenness in the tire circumferential direction in the sidewall portion.

Brief Description of the Drawings

[0018] [Figure 1] It is a development view in which a tread surface and a part of a buttress outer surface of a tire according to an embodiment of the present invention are developed on a plane. [Figure 2] It is a side view of the tire of FIG. 1. [Figure 3] It is a partially enlarged side view of a buttress portion and a tread portion of the tire of FIG. 1. [Figure 4] It is a partially enlarged perspective view of a buttress portion and a tread portion of the tire of FIG. 1. [Figure 5] It is another partially enlarged perspective view of a buttress portion and a tread portion of the tire of FIG. 1. [Figure 6] It is a schematic cross-sectional view taken along line A-A of FIG. 1. [Figure 7] It is a schematic cross-sectional view in the tire width direction of a tire half for explaining an arrangement example of a communication device. [Modes for carrying out the invention]

[0019] 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 intended for use on roads with rocks and other obstacles as well as on general roads.

[0020] Hereinafter, embodiments of the tire according to the present invention will be described with reference to the drawings. Common components and parts in each figure are denoted by the same reference numeral. 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 symbol "CD", the tire radial direction by the symbol "RD", and the tire width direction by the symbol "WD". Furthermore, in this specification, the side of the tire closer to the axis of rotation O along the tire's radial direction is referred to as the "inner side in the tire's radial direction," and the side of the tire further away from the axis of rotation O along the tire's radial direction is referred to as the "outer side in the tire's radial direction." In this specification, the side closer to the tire equatorial plane CL along the tire width direction is referred to as the "inner side in the tire width direction," and the side further away from the tire 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 component in the circumferential direction of the tire 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 tire radial direction (or tire width direction)" means extending with a tire radial component (or tire width component) at an angle of less than 45° with respect to the tire radial direction (or tire width direction). That is, "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) and inclination with respect to the tire radial direction (or tire width direction).

[0021] 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.

[0022] 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."

[0023] In this specification, "applicable rim" refers to the standard rim (Measuring Rim in the ETRTO STANDARDS MANUAL, Design Rim in the TRA YEAR BOOK) for the applicable size, which is listed or will be listed in the industrial standards valid in the region where the tire is produced and used, 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 Organisation) in Europe, and the YEAR BOOK of TRA (The Tire and Rim Association, Inc.) in the United States. However, for sizes not listed in these industrial standards, it refers to a rim with a width corresponding to the bead width of a pneumatic tire. "Applicable rim" includes not only current sizes but also sizes that will be listed in the aforementioned industrial 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.

[0024] In this specification, "specified internal pressure" refers to the air pressure (maximum air pressure) corresponding to the maximum load capacity of a single wheel in 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.

[0025] 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 on 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 of the line AA in Figure 1.

[0026] 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 in this embodiment may be of a different type than those described above.

[0027] 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 both sidewall portions SP. Furthermore, as shown in Figures 1 and 2, the tire 10 includes 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, specifically 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) in the sidewall portion SP. 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 also be a directional tire with a configuration such as line symmetry with respect to the tire equatorial plane CL.

[0028] 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. Furthermore, 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 radially inward from the tread edge TE. The outer surface 2 of the buttress is connected to the radially inward side of the tread surface 1.

[0029] First, referring to Figure 1, we will briefly and specifically describe the configuration of the tread portion TP and, consequently, the tread surface 1 (tread pattern) of the tire 10 of this embodiment.

[0030] As shown in Figure 1, the tire 10 has a tread surface 1 with a plurality of independent blocks (center blocks 30C, shoulder blocks 30S) separated 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 circumferential direction of the tire to form three center block rows 3C, and the plurality of shoulder blocks 30S are arranged with spacing between them in the circumferential direction of the tire to form two shoulder block rows 3S, one on each side of the center block rows 3C in the tire width direction.

[0031] The tire 10 of this embodiment has the tread surface 1 configuration (tread pattern) described above, and the edge effect provided by the edges (groove edges) of each block is beneficial in providing traction on rough road surfaces (for example, road surfaces with scattered rocks, etc.). However, the tread pattern of tire 10 may be different from those described above. The configuration of the shoulder block row 3S in the tire 10 of this embodiment will be described in more detail later.

[0032] 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) of the tire 10 of this embodiment will be described in more detail.

[0033] 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, including the first circumferential groove 51 to the second circumferential groove 52 (described later), and a radial groove 6, including 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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 made 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 angle on the acute side of the extension direction of the first circumferential groove 51 and the second circumferential groove 52 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 direction of travel, the angle on the acute side of the extension direction of the first diameter groove 61 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 the outside along the tire width direction.

[0038] In this embodiment, as shown in Figure 3, the multiple blocks 20 form multiple block rows 200, each row of blocks 20 arranged in the circumferential direction of the tire. The multiple blocks 20 in one block row 200 are spaced apart in the circumferential direction of the tire. In the example in Figure 3, the multiple blocks 20 form an upper block row 3 consisting of multiple upper blocks 30 (in this example, multiple first upper blocks 31 and multiple 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 multiple lower blocks 40 (in this example, multiple first lower blocks 41 and multiple 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 some of the multiple blocks 20 that are separated by the first circumferential groove 51, the second circumferential groove 52 and the first radial groove 61 are the multiple upper blocks 30 (31, 32) of the upper block row 3 and the multiple 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.

[0039] With this configuration, the buttress section BP has two block rows 200 (upper block row 3 and lower block row 4), each consisting of multiple blocks 20 arranged in the circumferential direction of the tire. This allows for more effective improvement of traction performance while ensuring protection performance. However, the buttress section BP may have three or more block rows 200, each consisting of multiple 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.

[0040] 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 that 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 and are smoothly connected when viewed from the side in the tire width direction; in other words, they are rounded rather than angular. According to 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 of the tire circumferential direction it inclins inward in the tire radial direction, thereby enabling stronger traction performance.

[0041] As shown in Figure 3, in this embodiment, the upper block row 3 includes a first upper block 31 along the first circumferential groove 51, and a second upper block 32 which at least a portion of which is along the second circumferential groove 52 and 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 extending along the first circumferential groove 51, and a first upper block first groove edge 311 which 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 first groove edge 311 that extends in a direction different from the first circumferential groove 51 with respect to the tire circumferential direction, and inclined inward in the tire radial direction as it approaches one side of the tire circumferential direction, thereby enabling stronger traction performance.

[0042] 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. The two 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 the two groove edges, 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 while also improving the vehicle's appearance.

[0043] As shown in Figure 3, in this embodiment, a second radial groove 62 extending in the tire radial direction is formed between the first lower block 41 and the second lower block 42, and communicates with the longitudinal middle portion of the first circumferential groove 51. With this configuration, the radial edge component of the tire increases by the length of the groove edge in the tire radial direction of the first lower block 41 and the second lower block 42 adjacent to the second diameter 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).

[0044] 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 along 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 along 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 along the second circumferential groove 52, which is connected to one side of the second lower block third groove edge 423 in the tire circumferential direction. With this configuration, the second lower block 42 has a second groove edge 422 that extends in a direction inclined radially inward towards one side of the tire as it approaches one side of the tire circumferential direction, and the second lower block 42 has a third groove edge 423 that extends in a direction inclined radially outward towards one side of the tire as it approaches one side of the tire circumferential direction, and the second lower block 42 has a direction inclined radially inward towards one side of the tire as it approaches one side of the tire circumferential direction, thereby enabling stronger traction performance.

[0045] 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's circumferential direction than the first circumferential groove 51, thereby enabling stronger traction performance.

[0046] 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, and 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 of two halves of the same size, and 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).

[0047] 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 at the inner portion in the tire radial direction. According to 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, thereby effectively ensuring protection performance.

[0048] 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 outer side of the first lower block 41 in the tire radial direction. With this configuration, the radial edge component of the tire increases 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 can be made stronger, especially in the circumferential direction of the tire (in other words, the direction of tire travel).

[0049] 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 at 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.

[0050] Next, the raised section 80 that connects each of the blocks 20 described above in this embodiment will be explained.

[0051] 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 upward from the groove bottom 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 groove bottom).

[0052] In a tire having a plurality of independent blocks 20 arranged in the circumferential direction of the tire in the buttress section BP, the volume change of the buttress section BP in the circumferential direction of the tire is large. Therefore, when the tire is filled with internal pressure, the tire expands unevenly in the circumferential direction, especially in the thin-walled inner region of the buttress section BP, which may cause irregularities in the circumferential direction of the tire on the outer surface of the buttress section BP and consequently the sidewall section SP. Therefore, with the above configuration, a raised section 80 (first raised section 81) is provided in the groove 50 between adjacent lower blocks 40 in the circumferential direction of the tire, so as to connect all of the multiple lower blocks 40 in the circumferential direction of the tire. In other words, the change in height of the land portion arranged in the circumferential direction of the tire is reduced, so the occurrence of irregularities in the sidewall portion SP in the circumferential direction of the tire when the tire 10 is filled with internal pressure can be suppressed. Furthermore, with the above configuration, the rigidity between adjacent lower blocks 40 is reinforced by the raised section 80 (first raised section 81), so protection performance can be more effectively ensured. Moreover, with the above configuration, mud clogging that may occur between adjacent lower blocks 40 when driving on rough roads can be suppressed, and the edge effect of the raised section 80 is added, so traction performance can be more strongly exhibited. Furthermore, with the above configuration, the appearance also exhibits high traction performance, thus improving aesthetics.

[0053] As shown in Figure 3, in this embodiment, the first raised section 81 includes an enlarged first raised section 81a configured to connect the lower blocks 40 (first lower block 41 and second lower block 42) and at least one upper block 30 (first upper block 31 or second upper block 32) that are adjacent to each other in the tire circumferential direction. This configuration makes it possible to further suppress the occurrence of irregularities in the sidewall SP in the tire circumferential direction when the tire 10 is filled with internal pressure, and also improves the appearance.

[0054] 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 in 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 mentioned above, and also improves the appearance.

[0055] 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 can be suppressed more reliably.

[0056] In this embodiment, as shown in Figure 3, a second raised section 82 is provided in the groove 50 (first circumferential groove 51 or second circumferential groove 52) between the lower block 40 and the 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, and the second raised section 82 is lower in height than the lower block 40 and the upper block 30. With this configuration, the presence of the second raised section 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 section 81 is provided.

[0057] In this embodiment, the second base portion 82 is narrower (thinner) than the first base portion 81. This configuration makes it possible to suppress the occurrence of the aforementioned bearing without significantly increasing the rubber volume.

[0058] Furthermore, in this embodiment, two or more (two in the example of Figure 3) second base-raising sections 82 are provided in the groove 50 between the lower block 40 and the upper block 30, which are adjacent to each other in the tire radial direction. In this case, the occurrence of the above-mentioned bearing can be further suppressed, and traction performance is also further improved. However, only one second base-raising section 82 may be provided at the above position. Also, depending on the size of the block 20 to which the second base-raising sections 82 are connected, it is preferable that, for example, four or fewer second base-raising sections 82 are provided at the above position.

[0059] More specifically, in this embodiment, the second base portion 82 includes, as shown in Figure 3, two or more (two in the example in Figure 3) second base portions 82a connecting the first half portion 42a of the second lower block and the first upper block 31, and two or more (two in the example in Figure 3) second base portions 82b connecting the second half portion 42b of the second lower block and the second upper block 32. In this case, the aforementioned effects of the second base portion 82 can be more reliably achieved.

[0060] In this embodiment, as shown in Figure 3, a third raised portion 83 is provided in the groove 50 (fifth diameter groove 65 in this embodiment) between two upper blocks 30 that are adjacent to each other in the tire circumferential direction, so as to connect two of the multiple upper blocks 30 that are adjacent to each other in the tire circumferential direction, and the third raised portion 83 is lower in height than the two upper blocks. This configuration makes it possible to more reliably suppress the occurrence of bearings in the product tires. Furthermore, this configuration can also improve traction performance and appearance, similar to the case where the first raised section 81 and / or the second raised section described above are provided.

[0061] In this embodiment, the third base portion 83 is narrower (thinner) than the first base portion 81. This configuration makes it possible to suppress the occurrence of the aforementioned bearing without significantly increasing the rubber volume.

[0062] In this embodiment, in the radially outer region of the buttress section BP adjacent to the highly rigid crown section 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 circumferential irregularities in the sidewall section 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 part of the thin-walled sidewall section SP where the lower block row 4 and thus the lower block 40 are provided. From this point of view, the third base-raising section 83 connecting the upper blocks 30 in the circumferential direction of the tire does not need to be as wide as the first base-raising section 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 base-raising section 83 connecting adjacent upper blocks 30 in the circumferential direction of the tire is not necessarily great.

[0063] 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, the plurality of lower blocks 40) and a radial position located radially outward from the innermost position in the tire radial direction, separated by a tire radial distance of at least 20%, preferably 30%, of the tire radial distance between the innermost position in the tire radial direction and the tread edge TE. In this embodiment, the innermost position in the tire radial direction among the area occupied by the multiple blocks 20 (multiple lower blocks 40 in this embodiment) can be a tire radial position located radially outward from the tire maximum width position in the sidewall portion SP, in a side view in the tire width direction, separated by a tire radial distance of 10 to 30% of the tire radial distance between the tire maximum width position and the tread edge TE.

[0064] Furthermore, in this embodiment, two or more third base-raising sections 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 section 83 may be provided at the above position. Also, depending on the size of the block 20 to which the third base-raising sections 83 are connected, it is preferable that, for example, four or fewer third base-raising sections 83 are provided at the above position.

[0065] In this embodiment, as shown in Figure 3, the third base-raising portion 83 includes two or more (two in the example in 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.

[0066] In this embodiment, the heights of the first base section 81, the second base section 82, and the third base section 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 sections 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, suppressing the occurrence of bare material in the product tire, improving traction performance, and improving appearance can be reliably obtained by each base section, while having a height of 60% or less avoids 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 sections 81 to 83 be 20 to 50% of the maximum height of the multiple blocks 20.

[0067] 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.

[0068] 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 at least one point 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.

[0069] 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.

[0070] In Figure 3, the second raised section 82 (82a, 82b) and the third raised section 83 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 section 82 (82a, 82b) and the third raised section 83 are connected to the groove wall of the adjacent block 20 and, consequently, to the block 20.

[0071] 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.

[0072] 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 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 block 30) configured in this way, which are adjacent to each other in the circumferential direction of the tire, are repeatedly arranged around the entire circumference in the circumferential direction of the tire. 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 in order, facing one side in the circumferential direction of the tire, 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, 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.

[0073] 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. In addition, since each of the adjacent blocks 20 (first upper block 31 and second upper block 32) has a non-notched area 31d that does not have a notch 9, protection performance is ensured. In this embodiment, the notch 9 is formed on the outermost radial side of the tire in each of the first upper block 31 and the second upper block 32. This allows for a more effective improvement in traction performance.

[0074] 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 is narrow in width and 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, and consequently improving traction performance. Furthermore, with the above configuration, the combination of the narrow groove 7 and the notch 9 improves the appearance. Furthermore, as shown in Figure 3, it is preferable that the opening width of the small-diameter groove 7 is sufficiently smaller (narrower) than the opening width of each of the grooves 50 described above, in order to suppress a significant decrease in the rigidity of the upper block 30 and to still ensure sufficient protection performance.

[0075] 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 of the tire in the circumferential direction. The small-diameter grooves 7 extend from the outermost open 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. According to the above configuration, traction performance can be fully realized, and the reduction in block rigidity caused by 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 extend inward in the tire radial direction beyond the mold division ridges PT, creating a sense of unity in the block and improving its appearance.

[0076] 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) 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 longer than the lengths in the tire radial direction of the other three sides 31e. With this configuration, when viewed from the side in the tire width direction, the two adjacent blocks 20 appear to form one large block, thus improving the appearance while also achieving a good balance between protection and traction performance.

[0077] 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 and traction performance.

[0078] 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.

[0079] 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 have a circular arc shape with a very small radius of curvature when viewed in 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. As can also 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 relative to the tire radial direction in the portion extending inward from the tread edge TE in the tire radial direction, such that the angle of inclination relative to the tire radial direction becomes smaller.

[0080] 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.

[0081] As shown in Figures 1 and 5, the tire 10 of this embodiment has a shoulder block row 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 shoulder block row 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 the tread edge TE. In this embodiment, each shoulder block 30S has substantially the same shape over the entire circumference in the tire circumferential direction.

[0082] 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 width direction of the tire. 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. Note that "viewing 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 radial direction of the tire. By incorporating 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.

[0083] In this embodiment, as can be seen from Figure 5, in a view of the tread surface, the large block 30Sa and the 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 the 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 lateral groove 36G. As shown in Figure 5, in the view of the tread surface, the extension direction of the lateral groove 36G changes at one point during its extension. Furthermore, in order to make the block rigidity of the shoulder block 30S more uniform, the length of the outermost edge 30Sbe in the tire width direction of the small block 30Sb is longer than the length of the outermost edge 30Sae in the tire width direction of the large block 30Sa. Furthermore, the groove edges of the small blocks 30Sb facing the widthwise groove 36G are chamfered, forming the chamfered portion 30Sbc.

[0084] 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. Therefore, 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.

[0085] The foregoing describes exemplary embodiments of the present invention, and various modifications can be made without departing from the scope of the claims.

[0086] The following describes a case where a communication device is provided on a tire. The tire in question may be the tire 10 of the embodiment described above. Figure 7 is a cross-sectional view in the width direction of half of a tire to illustrate an example of the arrangement of a communication device. However, in Figure 7, to avoid complexity, grooves, blocks, etc. on the outer surface of the tire as in the embodiment described above have been omitted. As shown in Figure 7, this tire may be equipped with an RF tag as a communication device CAb. The RF tag comprises an IC chip and an antenna. The RF tag may be positioned, for example, sandwiched between multiple identical or different components that constitute the tire. This makes it easier to attach the RF tag during tire production and improves the productivity of tires equipped with RF tags. In this example, the RF tag may be positioned, for example, sandwiched between a bead filler and another component adjacent to the bead filler. The RF tag may also be embedded in any of the components that constitute the tire. This reduces the load on the RF tag compared to the case where it is sandwiched between multiple components that constitute the tire. This improves the durability of the RF tag. In this example, the RF tag may be embedded in rubber components such as tread rubber or side rubber. Preferably, the RF tag is not placed at a boundary between components with different rigidity in the peripheral length direction, which is the direction along the outer surface of the tire in a cross-sectional view in the tire width direction. By doing so, the RF tag is not placed at a location where strain is likely to concentrate due to the difference in rigidity. Therefore, the load on the RF tag can be reduced. This improves the durability of the RF tag. In this example, preferably, the RF tag is not placed at a boundary between the end of the carcass and a component adjacent to the end of the carcass (e.g., side rubber) in a cross-sectional view in the tire width direction. The number of RF tags is not particularly limited. The tire may have only one RF tag or two or more RF tags. Here, an RF tag is described as an example of a communication device, but a different communication device may be used.

[0087] The RF tag may be placed, for example, on the tire tread. In this way, the RF tag will not be damaged by side cuts of the tire. The RF tag may be placed, for example, in the center of the tread in the tire width direction. The center of the tread is a position where flexing is less likely to concentrate in the tread. In this way, the load on the RF tag can be reduced. This can improve the durability of the RF tag. In addition, differences in communication with the RF tag from both outer sides of the tire in the tire width direction can be suppressed. In this example, the RF tag may be placed, for example, within a range of 1 / 2 of the tread width centered on the tire equatorial plane CL in the tire width direction. The RF tag may be placed, for example, at the tread edge in the tire width direction. If the position of the reader that communicates with the RF tag is predetermined, the RF tag may be placed, for example, at one tread edge close to this reader. In this example, the RF tag may be placed, for example, within a range of 1 / 4 of the tread width with the tread edge as the outer edge in the tire width direction.

[0088] The RF tag may be positioned on the inner side of the tire cavity, for example, beyond the carcass, which includes one or more carcass plies that span between the bead portions. This makes the RF tag less susceptible to damage from impacts applied from outside the tire, such as side cuts or nail punctures. As an example, the RF tag may be positioned in close contact with the inner surface of the carcass facing the inner cavity. As another example, if there is another component on the inner side of the tire cavity beyond the carcass, the RF tag may be positioned, for example, between the carcass and the other component located on the inner side of the carcass facing the inner cavity. An example of another component located on the inner side of the tire cavity beyond the carcass is the inner liner that forms the inner surface of the tire. As yet another example, the RF tag may be attached to the inner surface of the tire facing the inner cavity. By configuring the RF tag to be attached to the inner surface of the tire, it becomes easier to attach the RF tag to the tire and to inspect and replace the RF tag. In other words, the ease of attachment and maintenance of the RF tag can be improved. Furthermore, by attaching the RF tag to the inner surface of the tire, it is possible to prevent the RF tag from becoming the core of a tire failure compared to a configuration in which the RF tag is embedded inside the tire. Also, if the carcass has multiple carcass plies and there are positions where multiple carcass plies overlap, the RF tag may be placed between the overlapping carcass plies.

[0089] The RF tag may be positioned, for example, on the tire tread, outside the belt, which includes one or more belt plies, in the radial direction of the tire. For example, the RF tag may be positioned outside the belt in the radial direction of the tire, in close contact with the belt. Another example is when a reinforcing belt layer is provided, the RF tag may be positioned outside the reinforcing belt layer in the radial direction of the tire, in close contact with the reinforcing belt layer. Yet another example is when the RF tag is embedded in the tread rubber, outside the belt in the radial direction of the tire. By positioning the RF tag outside the belt in the tire tread, communication with the RF tag from the outside of the tire in the radial direction is less likely to be hindered by the belt. Therefore, communication with the RF tag from the outside of the tire in the radial direction of the tire can be improved. Alternatively, the RF tag may be positioned inside the belt in the tire tread, for example. In this way, the outside of the RF tag in the radial direction of the tire is covered by the belt, making the RF tag less susceptible to damage from impacts from the tread surface or nail punctures. As an example, the RF tag may be positioned in the tire tread between the belt and the carcass located radially inward from the belt. Furthermore, if the belt comprises multiple belt plies, the RF tag may be positioned between any two belt plies in the tire tread. In this manner, the outer radial side of the RF tag is covered by one or more belt plies, making the RF tag less susceptible to damage from impacts from the tread surface or nail punctures.

[0090] The RF tag may be placed, for example, in the sidewall or bead portion of the tire. The RF tag may be placed, for example, in the sidewall or bead portion on one side that is close to the reader that can communicate with the RF tag. This improves the communication between the RF tag and the reader. As an example, the RF tag may be placed between the carcass and the side rubber, or between the tread rubber and the side rubber. The RF tag may be placed, for example, between the position of the tire's maximum width and the position of the tread surface in the tire's radial direction. This improves the communication between the RF tag and the outside of the tire in the tire's radial direction compared to a configuration where the RF tag is placed inside the tire's maximum width position in the tire's radial direction. The RF tag may be placed, for example, inside the tire's maximum width position in the tire's radial direction. This places the RF tag near the highly rigid bead portion. Therefore, the load on the RF tag can be reduced. This improves the durability of the RF tag. As an example, the RF tag may be placed adjacent to the bead core in the tire's radial or tire width direction. Strain is less likely to concentrate near the bead core. Therefore, the load on the RF tag can be reduced. This improves the durability of the RF tag. In particular, it is preferable to position the RF tag radially inward from the position of the tire's maximum width, and radially outward from the bead core of the bead portion. By doing so, the durability of the RF tag can be improved, and communication between the RF tag and the reader is less likely to be hindered by the bead core, thereby improving the communication performance of the RF tag. Furthermore, if the side rubber is composed of multiple identical or different rubber members adjacent in the radial direction of the tire, the RF tag may be positioned sandwiched between the multiple rubber members that make up the side rubber.

[0091] The RF tag may be positioned sandwiched between the bead filler and a component adjacent to the bead filler. In this way, the RF tag can be positioned in a location where strain is less likely to concentrate due to the placement of the bead filler. Therefore, the load on the RF tag can be reduced. This improves the durability of the RF tag. The RF tag may also be positioned sandwiched between, for example, the bead filler and the carcass. The portion of the carcass that sandwiches the RF tag together with the bead filler may be located on the outside in the tire width direction relative to the bead filler, or on the inside in the tire width direction. If the portion of the carcass that sandwiches the RF tag together with the bead filler is located on the outside in the tire width direction relative to the bead filler, the load on the RF tag due to impacts and damage from the outside of the tire in the tire width direction can be further reduced. This improves the durability of the RF tag. The bead filler may also have a portion that is positioned adjacent to the side rubber. In such cases, the RF tag may be positioned sandwiched between the bead filler and the side rubber. Furthermore, the bead filler may have a portion positioned adjacent to the rubber chafer. In such cases, the RF tag may be positioned sandwiched between the bead filler and the rubber chafer.

[0092] The RF tag may be positioned, for example, sandwiched between a rubber chafer and a side rubber. In this way, the RF tag can be positioned in a location where strain is less likely to concentrate due to the placement of the rubber chafer. Therefore, the load on the RF tag can be reduced. This improves the durability of the RF tag. The RF tag may also be positioned, for example, sandwiched between a rubber chafer and a carcass. In this way, the load on the RF tag due to impacts and damage from the rim can be reduced. Therefore, the durability of the RF tag can be improved.

[0093] The RF tag may be positioned sandwiched between the wire chafer and another component adjacent to the wire chafer on the inner or outer side in the tire width direction. This arrangement makes it less likely for the RF tag's position to change during tire deformation. Therefore, the load on the RF tag during tire deformation can be reduced, thereby improving the durability of the RF tag. The other component adjacent to the wire chafer on the inner or outer side in the tire width direction may be, for example, a rubber component such as a rubber chafer. Alternatively, the other component adjacent to the wire chafer on the inner or outer side in the tire width direction may be, for example, a carcass.

[0094] A belt reinforcing layer may be further provided on the radially outer side of the belt. For example, the belt reinforcing layer may consist of a cord made of polyethylene terephthalate wound continuously in a spiral shape in the circumferential direction of the tire. Here the cord is 6.9 × 10 -2 The belt is treated with adhesive under a tension of N / tex or higher, and its modulus of elasticity at a load of 29.4N measured at 160°C may be 2.5mN / dtex·% or higher. Furthermore, the belt reinforcement layer may be arranged to cover the entire belt or to cover only the ends of the belt. In addition, the winding density per unit width of the belt reinforcement layer may differ at different positions in the width direction. By doing so, road noise and flat spots can be reduced without reducing high-speed durability. [Industrial applicability]

[0095] 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 SUVs (sports utility vehicles) that are expected to be used on roads with rocks and other obstacles as well as on general roads. Contribution to the United Nations-led Sustainable Development Goals (SDGs)

[0096] The SDGs have been proposed to realize a sustainable society. One embodiment of the present invention is considered to be a technology that can contribute to "No. 12: Responsible Consumption and Production" and "No. 13: Take urgent action to combat climate change and its impacts." [Explanation of Symbols]

[0097] 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 the first upper block, 312: First upper block, second groove edge, 31a: First upper block, first half, 31b: Second half of the first upper block, 31c: Notched region, 31d: Unnotched region, 31e: radial side, 32: second upper block, 321: first groove edge of second upper block, 322: Second upper block, second groove edge, 32a: Second upper block, first half, 32b: Second upper block, second half; 32c: Notched region; 32d: Unnotched region. 32e: radial protrusion, 40: Lower block, 41: First lower block, 411: First groove edge of the first lower block, 412: First upper block, second groove edge, 42: Second lower block, 421: Second lower block, first groove edge, 422: Second lower block, second groove edge, 423: Second lower block, third groove edge, 424: Second lower block, fourth groove edge, 42a: Second lower block, first half; 42b: Second lower block, second half; 50:Groove, 5:Peripheral groove, 51:First circumferential groove, 52:Second circumferential groove, 6: radial groove, 61: 1st radial groove, 62: 2nd radial groove, 63: 3rd radial groove, 64: 4th diameter groove, 65: 5th diameter groove, 7: Small diameter groove, 80: Raised base section, 81: First raised base section, 81a: Enlarged first raised base section (first raised base section), 82, 82a, 82b: Second base-raising section, 83: Third base-raising section 9: Notch, 9f: Notched surface, N9: Unnotched surface 9u: Outer end of the notch in the tire radial direction, 9d: Inner end of the 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 the large block in the tire width direction, 30Sb: Small block, 30Sbe: Outermost edge of the small block in the tire width direction, 30Sbc: Chamfered part of small block, 5M: Main groove, 6S: Sub-groove, BP: Buttress section, CA: Communication device, CD: Tire circumferential direction, CL: Tire equatorial plane, IF: Tire inner surface, O: Tire rotation axis, PT: Mold division section protrusion, RD: Tire radial direction, SP: Sidewall section, TE: Tread edge, TP: Tread section, WD: Tire width direction

Claims

1. A tire having multiple independent blocks, each separated by multiple grooves, formed on the outer surface of the buttress portion extending radially inward from the tread edge, The aforementioned plurality of blocks form an upper block row consisting of a plurality of upper blocks arranged in the circumferential direction of the tire on the radially outer side of the tire, and a lower block row consisting of a plurality of lower blocks arranged in the circumferential direction of the tire on the radially inner side of the upper block row. A tire in which, in order to connect all of the aforementioned lower blocks to each other in the circumferential direction of the tire, a first raised portion is provided in the groove between every two adjacent lower blocks in the circumferential direction of the tire, and is lower in height than the lower block.

2. The tire according to claim 1, wherein a second raised portion is provided in the groove between the lower block and the upper block that are adjacent to each other in the radial direction of the tire, so as to connect at least one of the plurality of lower blocks and at least one of the plurality of upper blocks to each other in the radial direction of the tire, the second raised portion being lower in height than the lower block and the upper block and narrower in width than the first raised portion.

3. The tire according to claim 1, wherein the first raised portion includes an enlarged first raised portion configured to connect the lower blocks and at least one upper block that are adjacent to each other in the circumferential direction of the tire.

4. The tire according to claim 2, wherein a third raised portion is provided in the groove between two upper blocks that are adjacent to each other in the tire circumferential direction, so as to connect two of the plurality of upper blocks that are adjacent to each other in the tire circumferential direction, the third raised portion being lower in height than the two upper blocks and narrower in width than the first raised portion.

5. The tire according to claim 4, wherein the heights of the first raised section, the second raised section, and the third raised section are 10 to 60% of the maximum height of the plurality of blocks, including the upper block and the lower block.

6. The tire according to claim 3, wherein the width of the first raised portion, excluding the enlarged first raised portion, is 50% or more of the length of the smaller of the two sides of the lower block to which the first raised portion is connected.

7. The tire according to claim 2, wherein two or more of the second bottom-raising portions are provided in the groove between the lower block and the upper block, which are adjacent to each other in the radial direction of the tire.

8. The tire according to claim 4, wherein two or more of the third raised portions are provided in the groove between the two upper blocks that are adjacent to each other in the circumferential direction of the tire.

9. The tire according to any one of claims 1 to 8, wherein the plurality of grooves include, in a side view in the tire width direction, a plurality of circumferential grooves extending in the tire circumferential direction and a plurality of radial grooves extending in the tire radial direction.

10. The tire according to any one of claims 1 to 8, wherein the height of the plurality of blocks decreases from the outer side to the inner side in the radial direction of the tire.

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