tire

Abstract

To provide a tire which has improved on-snow traction performance.SOLUTION: In a tire 1, a block 3 is provided on a tread part 2. On a block wall surface 6 of the block 3, first recesses 11 are formed. The first recesses 11 straddle a block tread 5 and the block wall surface 6. The first recesses 11 have a triangular tread opening on the block tread 5, and a triangular wall surface opening on the block wall surface 6. The wall surface opening has a first end 17 which terminates without reaching a groove bottom.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a tire.

Background Art

[0002] Patent Document 1 below describes a pneumatic tire having groove portions provided on a tread surface. Notch portions are formed on the groove walls of the groove portions such that the shape on the tread surface is zigzag.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The notch portions of Patent Document 1 do not have a sufficient effect of compacting the snow on the road surface, and there is room for further improvement in snow traction performance.

[0005] The present invention has been devised in view of the above actual situation, and the main object thereof is to provide a tire capable of further improving snow traction performance.

Means for Solving the Problems

[0006] The present invention relates to a tire having a tread portion, wherein the tread portion is provided with at least one block and grooves that demarcate the block, the block comprises a block tread surface and a block wall surface extending radially inward from the block tread surface to the bottom of the groove, the block wall surface has a plurality of first recesses formed therein, each of the first recesses straddling the block tread surface and the block wall surface, each of the first recesses having a triangular tread opening on the block tread surface and a triangular wall opening on the block wall surface, the wall opening having a first end that terminates without reaching the bottom of the groove. [Effects of the Invention]

[0007] By adopting the above configuration, the tire of the present invention can further improve traction performance on snow. [Brief explanation of the drawing]

[0008] [Figure 1] This is a perspective view of a block showing one embodiment of the tire of the present invention. [Figure 2] Figure 1 is a front view of the block wall surface of the block. [Figure 3] This is a plan view of the tread section. [Figure 4] (A) is an enlarged front view of the block tread in Figure 1, and (B) is a cross-sectional view taken along line AA in Figure 2. [Figure 5] This is a perspective view of the block illustrating the first recess. [Figure 6] This is a front view of the block wall surface of another embodiment. [Figure 7] (A) is a front view of a block wall surface of yet another embodiment, and (B) is a cross-sectional view of (A) along line BB. [Modes for carrying out the invention]

[0009] One embodiment of the present invention will be described below with reference to the drawings. Figure 1 is an enlarged perspective view of a portion of the tread 2 of the tire 1 of this embodiment. The tire 1 of this embodiment is suitably used, for example, as a pneumatic tire for passenger cars that is suitable for driving on snowy roads, particularly compacted snow roads. In addition to pneumatic tires for heavy loads, the present invention may also be applied to non-pneumatic tires in which pressurized air is not filled inside the tire.

[0010] As shown in Figure 1, the tread portion 2 of this embodiment is provided with at least one block 3 and grooves 4 that divide the block 3. In this specification, the grooves 4 are groove-shaped bodies with a groove width of 1.5 mm or more, and are clearly distinguished from notched sipes with a width of 1.5 mm or less.

[0011] Block 3 comprises a block tread surface 5 and a block wall surface 6 extending radially inward from the block tread surface 5 to the groove bottom 4s of the groove 4. The block tread surface 5 and the block wall surface 6 are connected, for example, via a block edge 7.

[0012] The block tread surface 5, in the case of a pneumatic tire, is the surface that contacts the flat surface with a camber angle of 0° when a normal load is applied to the tire 1 in its normal state. The "normal state" refers to the case of a pneumatic tire 1 for which various standards have been defined, where the tire is mounted on a normal rim, filled to the normal internal pressure, and is in an unloaded state. For tires for which various standards have not been defined, or for non-pneumatic tires, the normal state refers to the standard usage state according to the intended use of the tire, and is an unloaded state. In this specification, unless otherwise specified, the dimensions of each part of the tire 1 are values ​​measured in the normal state.

[0013] The aforementioned "standard rim" refers to the rim specified for each tire in the standards system, including the standard on which tire 1 is based. For example, it is the "standard rim" for JATMA, the "Design Rim" for TRA, and the "Measuring Rim" for ETRTO.

[0014] The "normal internal pressure" is the air pressure determined for each tire in the standard system including the standards on which the tire 1 is based. In the case of JATMA, it is the "maximum air pressure"; in the case of TRA, it is the maximum value described in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES"; and in the case of ETRTO, it is the "INFLATION PRESSURE".

[0015] The "normal load" is the load determined for each tire in the standard system including the standards on which the tire 1 is based. In the case of JATMA, it is the "maximum load capacity"; in the case of TRA, it is the maximum value described in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES"; and in the case of ETRTO, it is the "LOAD CAPACITY". In the case of a tire for which various standards are not defined, the "normal load" refers to the maximum load applicable in using the tire, in accordance with the above-mentioned standards.

[0016] A plurality of first recesses 11 are formed in the block wall surface 6. The first recess 11 straddles the block tread surface 5 and the block wall surface 6. The first recess 11 has a triangular tread opening 15 (shown in FIG. 4(A)) on the block tread surface 5. Further, the first recess 11 has a triangular wall surface opening 16 (shown in FIG. 2) on the block wall surface 6. Such a first recess 11 can take in snow and compact it within the first recess 11 when driving on a snowy road. The "triangular shape" includes not only an equilateral triangle but also various triangles such as an isosceles triangle.

[0017] FIG. 2 is a front view of the block wall surface 6. As shown in FIGS. 1 and 2, the wall surface opening 16 has a first end 17 that terminates without reaching the groove bottom 4s. Thereby, compared with a recess (not shown) in which the wall surface opening 16 reaches the groove bottom 4s, the snow can be more strongly compacted. Therefore, the tire 1 of the present invention can further improve the snow traction performance.

[0018] FIG. 3 is a plan view of the tread portion 2 of the present embodiment. As shown in FIG. 3, in the tread portion 2 of the present embodiment, the blocks 3 are arranged in the tire circumferential direction and the tire axial direction. Further, the groove 4 includes a plurality of circumferential grooves 4A that continuously extend in the tire circumferential direction and a lateral groove 4B that extends in the tire axial direction. In the present embodiment, each circumferential groove 4A and each lateral groove 4B extend linearly. Each circumferential groove 4A and each lateral groove 4B can adopt a well-known shape.

[0019] The block 3 includes a crown block 3A located on the tire equator C, a pair of shoulder blocks 3B located on the outermost side in the tire axial direction, and a pair of middle blocks 3C located between the crown block 3A and each shoulder block 3B. The block tread surface 5 of each block 3 is formed with an outer diameter shape that is rectangular. Note that the tread pattern of the tread portion 2 is not limited to such a mode, and various well-known shapes can be adopted.

[0020] In the present embodiment, the first recess 11 is provided on the block wall surface 6 that reaches the groove bottom 4s of the lateral groove 4B. The first recess 11 is provided, for example, on the block wall surfaces 6 on both sides facing each other through the lateral groove 4B. The first recess 11 is provided, for example, on the block wall surface 6 that forms the lateral groove 4B partitioning the crown block 3A, the block wall surface 6 that forms the lateral groove 4B partitioning the shoulder block 3B, and the block wall surface 6 that forms the lateral groove 4B partitioning the middle block 3C. Thereby, snow columns can be effectively sheared using the driving force and the braking force, so that the snow traction performance can be further enhanced. Note that the first recess 11 is not limited to such an arrangement position. The first recess 11 may be provided, for example, on the block wall surface 6 that reaches the groove bottom 4s of the circumferential groove 4A. Such a first recess 11 enhances the snow traction performance during turning travel.

[0021] Figure 4(A) is a partial front view of the block tread 5. Figure 4(B) is a cross-sectional view of line AA in Figure 2, showing a block cross-section perpendicular to the block tread 5. As shown in Figure 4, the tread opening 15 has a second end 18 located away from the block wall 6. The first recess 11 has a ridge line 20 extending from the first end 17 to the second end 18. Thus, the ridge line 20 in this embodiment extends linearly from the first end 17 of the first recess 11, inclined outward in the tire radial direction and away from the block wall 6. As a result, when the block tread 5 makes contact with the ground, the ridge line 20 applies force in the direction of the road surface to the snow taken into the first recess 11, thereby forming a stronger snow column. Furthermore, at the ridge line 20 of the first recess 11 provided on the block wall surface 6 connected to the horizontal groove 4B, a force can be applied to push the snow column in a direction perpendicular to the horizontal groove 4B by utilizing the driving force or braking force, thereby achieving a snow removal effect.

[0022] In a block cross-section that passes through the ridge line 20 and is perpendicular to the block tread surface 5, it is desirable that the angle α1 of the ridge line 20 with respect to the block tread surface 5 be between 20 and 60°. If the angle α1 is 20° or more, the volume within the first recess 11 is secured, and a large snow column can be formed. If the angle α1 is 60° or less, a force in the direction of the road surface can be effectively applied to the snow taken into the first recess 11. In order to effectively exert such effects, it is even more desirable that the angle α1 be 30° or more, and even more desirable that it be 50° or less.

[0023] Figure 5 is a schematic partial perspective view showing block 3 for illustrating the first recess 11. As shown in Figure 5, the tread opening 15 has a pair of first edges 21 that extend tapered from the block wall surface 6 (block edge 7). The wall opening 16 also has a pair of second edges 22 that extend tapered from the block tread surface 5 (block edge 7). The pair of first edges 21 are connected, for example, at a second end 18. The pair of second edges 22 are connected, for example, at a first end 17.

[0024] Each first edge 21 has a length La of 1 to 5 mm. If the length La is excessively large, it may not be possible to firmly compact the snow taken into the first recess 11. If the length La is excessively small, the volume of the snow column will be small, which may reduce traction performance on snow. For this reason, a length La of 2 mm or more is more desirable, and 3 mm or less is even more desirable. From a similar viewpoint, the length Lb of each second edge 22 is preferably 1 mm or more, more preferably 2 mm or more, preferably 5 mm or less, and even more preferably 3 mm or less.

[0025] The minimum distance L1n between adjacent first recesses 11 is preferably 2 mm or less. This allows for the formation of more snow columns, thus enabling high traction performance on snow. In the present invention, the first recesses 11 have triangular tread openings 15 and wall openings 16. Therefore, when arranging the first recesses 11, the minimum distance L1n can be reduced compared to, for example, a design where the tread openings 15 and wall openings 16 are rectangular (not shown). For this reason, the first recesses 11 of this embodiment can exert greater snow column shear force. In the present invention, the minimum distance L1n is set to 0 mm.

[0026] As shown in Figures 1, 2, and 4, the block wall surface 6 has a plurality of second recesses 12 formed on the inside of the first recess 11 in the tire radial direction. In addition, the block wall surface 6 has a plurality of third recesses 13 formed on the inside of the second recesses 12 in the tire radial direction. Each second recess 12 is recessed from a triangular opening 25A formed on the block wall surface 6. Each third recess 13 is recessed from a triangular opening 25B formed on the block wall surface 6. These second recesses 12 appear on the block tread surface 5 after the first recess 11 has worn away, forming snow columns between them and the road surface and exerting shear force. The third recesses 13 appear on the block tread surface 5 after the second recesses 12 have worn away, forming snow columns between them and the road surface and exerting shear force. In this way, the tire 1 of this embodiment improves snow traction performance over a long period of time. The minimum distance L1m in the tire radial direction between the first recess 11 and the second recess 12 is preferably 2mm or less, and more preferably 1mm or less. In this invention, the minimum distance L1m is set to 0mm.

[0027] The second recess 12 is, for example, recessed in a cone shape from the opening 25A. In this embodiment, the second recess 12 is recessed in a triangular pyramidal shape from the opening 25A. The third recess 13 is, for example, recessed in a cone shape from the opening 25B. In this embodiment, the third recess 13 is recessed in a triangular pyramidal shape from the opening 25B. This allows snow to be easily removed from within each of the recesses 12 and 13.

[0028] In a front view of the block wall surface 6, the contour shape of the opening 25A of the second recess 12 is, for example, tapered toward the inside in the tire radial direction. Similarly, the contour shape of the opening 25B of the third recess 13 is, for example, tapered toward the inside in the tire radial direction. Such a second recess 12 can form a stronger snow column after the first recess 11 has worn away. Similarly, the third recess 13 can form a stronger snow column after the second recess 12 has worn away.

[0029] The second recess 12 includes, for example, a second recess end 12t (shown in Figure 4(B)) that is furthest from the block wall surface 6, a second inner end 12i (shown in Figure 2) in the tire radial direction of the opening 25A, and a second ridge line 12j connecting the second recess end 12t and the second inner end 12i. The second ridge line 12j extends continuously inclined outward in the tire radial direction from the second inner end 12i toward the second recess end 12t. As a result, the load from the vehicle acts effectively on the snow taken into the second recess 12 from the second ridge line 12j, making it possible to form a stronger snow column.

[0030] Similarly, the third recess 13 includes, for example, a third recess end 13t (shown in Figure 4(B)) that is furthest from the block wall surface 6, a third inner end 13i (shown in Figure 2) in the tire radial direction of the opening 25B, and a third ridge line 13j connecting the third recess end 13t and the third inner end 13i. The third ridge line 13j extends continuously inclined outward in the tire radial direction from the third inner end 13i toward the third recess end 13t.

[0031] The angle α2 of the second ridge line 12j is, for example, the same as the angle α1 of the ridge line 20 of the first recess 11. In this embodiment, the angle α3 of the third ridge line 13j is the same as the angle α2 of the second ridge line 12j. This is expected to have the effect of allowing the same magnitude of snow column shear force to be exerted in the first recess 11 to the third recess 13. Angle α2 is the angle of the second ridge line 12j with respect to the block tread 5 (or a plane parallel to it) in a block cross section that passes through the second ridge line 12j and is perpendicular to the block tread 5. Angle α3 is the angle of the third ridge line 13j with respect to the block tread 5 (or a plane parallel to it) in a block cross section that passes through the third ridge line 13j and is perpendicular to the block tread 5.

[0032] From a similar perspective, it is preferable that the depth D2 of the second recess 12 be the same length as the depth D1 of the first recess 11. It is also preferable that the depth D3 of the third recess 13 be the same length as the depth D2 of the second recess 12. The depth D1 of the first recess 11 is the shortest distance between the block wall surface 6 (wall opening 16) and the second end 18. The depth D2 of the second recess 12 is the shortest distance between the block wall surface 6 and the end 12t of the second recess. The depth D3 of the third recess 13 is the shortest distance between the block wall surface 6 and the end 13t of the third recess.

[0033] The second recesses 12 are, for example, arranged at a first position e1 (shown in Figure 2) in the tire radial direction. In this embodiment, the second inner end 12i in the tire radial direction of the opening 25A of each second recess 12 is arranged to be in contact with the first position e1. The third recesses 13 are, for example, arranged at a second position e2 in the tire radial direction. The third inner end 13i in the tire radial direction of the opening 25B of each third recess 13 is arranged to be in contact with the second position e2.

[0034] As shown in Figure 2, in a front view of the block wall surface 6, the second recess 12 is misaligned with the first recess 11 and the third recess 13 in the longitudinal direction of the block wall surface 6 (a direction perpendicular to the tire radius direction). This reduces the difference in rigidity of the block 3. Also, in a front view of the block wall surface 6, the first recess 11 and the third recess 13 are located at the same position in the longitudinal direction of the block wall surface 6. In this embodiment, the second recess 12 is misaligned by half a pitch with respect to the first recess 11 and the third recess 13 in the longitudinal direction of the block wall surface 6.

[0035] Block 3 includes a block protrusion 23 surrounded by adjacent first recesses 11 and second recesses 12 located inward in the tire radial direction of these first recesses 11. In this embodiment, the block protrusion 23 has a plurality of triangular surfaces and has a high penetration effect against compacted snow, thereby further improving traction performance on snow. When the first recesses 11 wear away, a block recess 23 surrounded by adjacent second recesses 12 and third recesses 13 located inward in the tire radial direction of these second recesses 12 appears. Also, when the second recesses 12 wear away, a block recess 23 surrounded by adjacent third recesses 13 and a fourth recess 14, which will be described later, located inward in the tire radial direction of these third recesses 12 appears.

[0036] In this embodiment, in a front view of the block wall surface 6, the opening area S1 of the wall opening 16 of the first recess 11 is the same as the opening area S2 of the opening 25A of the second recess 12. Also, the opening area S2 of the opening 25A of the second recess 12 is the same as the opening area S3 of the opening 25B of the third recess 13. Thus, the opening areas S1 to S3 of each recess 11 to 13 are the same. In such a block 3, each of the recesses 11 to 13 itself exhibits the same snow compaction effect, which helps to improve traction performance on snow. In this specification, "the same" includes differences in opening area due to precision errors in tire manufacturing.

[0037] In this embodiment, the block wall surface 6 has a plurality of fourth recesses 14 formed on the inner side of the third recess 13 in the tire radial direction. The fourth recesses 14 are arranged, for example, at a third position e3 (shown in Figure 2) in the tire radial direction. In this embodiment, the fourth recesses 14 are formed in the same shape as the second recess 12. When the third recess 13 wears away, these fourth recesses 14 appear on the block tread surface 5, forming snow columns between them and the road surface and exerting shear force. The block wall surface 6 may also have a plurality of fifth recesses (not shown) formed on the inner side of the fourth recess 14 in the tire radial direction, or a plurality of sixth recesses (not shown) formed on the inner side of the fifth recess in the tire radial direction. It is desirable that the fourth recesses 14, fifth recesses and sixth recesses are formed in the same shape as, for example, the second recess 12 or the third recess 13.

[0038] Figure 6 is a front view of the block wall surface 6 of another embodiment. Components identical to those in this embodiment may be denoted by the same reference numerals and their descriptions may be omitted. As shown in Figure 6, in this embodiment, the block 3 includes an outer block 3r and an inner block 3q adjacent to the outer block 3r in the tire axial direction.

[0039] The volume of the first recess 11r in the outer block 3r is, for example, larger than the volume of the first recess 11q in the inner block 3q. The volume of the second recess 12r in the outer block 3r is, for example, larger than the volume of the second recess 12q in the inner block 3q. The volume of the third recess 13r in the outer block 3r is, for example, larger than the volume of the third recess 13q in the inner block 3q. As a result, when turning under large lateral forces, the outer block 3r deforms more than the inner block 3q, thereby increasing the snow column shear force in the first recess 11r to the third recess 13r located in the outer block 3r. This improves traction performance on snow during turning.

[0040] In the outer block 3r, for example, the opening area of ​​the wall opening 16 of the first recess 11r is the same as the opening area of ​​the opening 25A of the second recess 12r and the opening area of ​​the opening 25B of the third recess 13r. Similarly, in the inner block 3q, for example, the opening area of ​​the wall opening 16 of the first recess 11q is the same as the opening area of ​​the opening 25A of the second recess 12q and the opening 25B of the third recess 13q.

[0041] Figure 7(A) is a front view of the block wall surface 6 of yet another embodiment. Figure 7(B) is a cross-sectional view of Figure 7(A) along line BB. Components identical to those in this embodiment may be denoted by the same reference numerals and their descriptions may be omitted. As shown in Figure 7, in this embodiment, the block wall surface 6 is provided with a plurality of first recesses 11 to third recesses 13, respectively.

[0042] Generally, a tire 1 is manufactured by vulcanizing a green tire placed in a vulcanizing mold (not shown). The vulcanizing mold for manufacturing the tire 1 of the present invention is provided with protrusions that form an inverted pattern of the first recess 11 to the third recess 13, and the first recess 11 to the third recess 13 are formed when the tire 1 is vulcanized. In this way, after vulcanization, the protrusions of the vulcanizing mold engage with the second recess 12 and the third recess 13 of the tire 1. In this embodiment, the length L2 of the second recess 12 in the tire radial direction is smaller than the length L1 of the first recess 11 in the tire radial direction. Also, the length L3 of the third recess 13 in the tire radial direction is smaller than the length L2 of the second recess 12. As a result, the engagement between the second recess 12 and the third recess 13 and the protrusions of the vulcanizing mold is reduced, making it easier to remove the tire 1 from the vulcanizing mold.

[0043] Furthermore, generally, when driving on a compacted snow surface, in the initial stages of wear, the snow trapped in the groove 4 rarely reaches the groove bottom 4s, and the possibility of it being compacted by the groove 4 is small. Moreover, in the final stages of wear, as the depth of the groove 4 decreases, the snow trapped in the groove 4 reaches the groove bottom 4s, and there is a high possibility that it will be strongly compacted by the groove bottom 4s. In this embodiment, in the initial stages of wear, the first recess 11 with a large length L1 can compact the snow, so the snow column shear force is maintained at a high level. Also, in the final stages of wear, the first recess 11 disappears, and only the second recess 12 or the third recess 13 remains. The length L2 of the second recess 12 and the length L3 of the third recess 13 are smaller than the length L1 of the first recess 11, but a strong snow column is formed by the groove 4 itself and the second recess 12 or the third recess 13, so the snow column shear force is maintained at a high level even in the final stages of wear. In order to effectively exert this effect, it is desirable that the third recess 13 be provided so as to appear on the block tread surface 5 when the groove is worn down by 50%.

[0044] While not particularly limited, the length L1 of the first recess 11 is preferably 1.5 mm or more, more preferably 1.8 mm or more, preferably 2.5 mm or less, and even more preferably 2.3 mm or less. The length L2 of the second recess 12 is preferably 1.0 mm or more, more preferably 1.3 mm or more, preferably 2.0 mm or less, and even more preferably 1.8 mm or less. The length L3 of the third recess 13 is preferably 0.5 mm or more, more preferably 0.8 mm or more, preferably 1.5 mm or less, and even more preferably 1.3 mm or less.

[0045] Similarly, the depth D2 of the second recess 12 is made smaller than, for example, the depth D1 of the first recess 11. Also, the depth D3 of the third recess 13 is made smaller than, for example, the depth D2 of the second recess 12. In this embodiment, the width W1 of the first recess 11, the width W2 of the second recess 12, and the width W3 of the third recess 13 are all the same length.

[0046] Although one embodiment of the present invention has been described in detail above, the present invention is not limited to the specific embodiments described above and can be implemented in various modified forms.

[0047] [Note] The present invention includes the following embodiments.

[0048] [Invention 1] A tire having a tread portion, The tread portion is provided with at least one block and grooves that divide the block. The block comprises a block tread surface and a block wall surface extending radially inward from the block tread surface to the bottom of the groove. Multiple first recesses are formed in the block wall surface. Each of the first recesses spans the block tread and the block wall, Each of the first recesses has a triangular tread opening on the block tread and a triangular wall opening on the block wall, The wall opening has a first end that terminates without reaching the bottom of the groove. tire. [2nd Invention] The tire according to the present invention, wherein the groove is a transverse groove extending in the direction of the tire axis. [Invention 3] In a front view of the block tread, the tread opening has a second end located at a position separated from the block wall surface. Each of the first recesses is provided with a ridge extending from the first end to the second end, The tire according to invention 1 or 2, wherein in a block cross section that passes through the aforementioned ridge line and is perpendicular to the block tread surface, the angle of the ridge line with respect to the block tread surface is 20 to 60°. [4th Invention] The tread opening has a pair of first edges that extend tapered from the block wall surface, The tire according to any one of inventions 1 to 3, wherein the first edge has a length of 1 to 5 mm. [5th ​​Invention] The wall opening has a pair of second edges that extend tapered from the block tread, The tire according to any one of inventions 1 to 4, wherein the second edge is 1 to 5 mm in length. [Invention 6] Multiple second recesses are formed on the block wall surface on the inner side of the first recess in the tire radial direction. The tire according to any one of inventions 1 to 5, wherein the second recess is recessed from a triangular opening formed on the block wall surface. [7th Invention] The tire according to the present invention, wherein, in a front view of the block wall surface, the contour shape of the opening is tapered toward the radially inward direction of the tire. [8th Invention] The tire according to claim 6 or 7 of the present invention, wherein the second recesses are arranged at a first position in the radial direction of the tire. [Invention 9] Multiple third recesses are formed on the block wall surface on the inner side of the second recess in the tire radial direction. The tire according to any one of claims 6 to 8 of the present invention, wherein the third recess is recessed from a triangular opening formed on the block wall surface. [Invention 10] In a front view of the block wall surface, the contour shape of the opening of the third recess is tapered toward the radially inward direction of the tire, as described in invention 9. [Invention 11] The tire according to invention 9 or 10, wherein the third recess is arranged at a second position in the radial direction of the tire. [Invention 12] The length of the second recess in the tire radial direction is smaller than the length of the first recess in the tire radial direction. The tire according to any one of claims 9 to 11, wherein the length of the third recess in the tire radial direction is smaller than the length of the second recess in the tire radial direction. [13th Invention] The tire according to any one of inventions 1 to 12, wherein the minimum distance between adjacent first recesses is 2 mm or less. [Invention 14] The groove is a transverse groove extending in the direction of the tire axis, The first recess includes an outer first recess located on the outside in the tire axial direction and an inner first recess located on the inside in the tire axial direction of the outer first recess. The tire according to any one of invention 1 to 13, wherein the volume of the outer first recess is greater than the volume of the inner first recess. [Explanation of symbols]

[0049] 1 tire 2 Tread section 3 blocks 5 Block treads 6 Block wall 11. First recess 15 Tread opening 16 Wall openings 17 1st end

Claims

1. A tire having a tread portion, The tread portion is provided with at least one block and grooves that divide the block. The block comprises a block tread surface and a block wall surface extending radially inward from the block tread surface to the bottom of the groove. Multiple first recesses are formed in the block wall surface. Each of the first recesses spans the block tread and the block wall, Each of the first recesses has a triangular tread opening on the block tread and a triangular wall opening on the block wall, The wall opening has a first end that terminates without reaching the bottom of the groove, Multiple second recesses are formed on the block wall surface on the inner side of the first recess in the tire radial direction. Each of the second recesses is recessed from a triangular opening formed on the block wall surface. tire.

2. The tire according to claim 1, wherein the groove is a transverse groove extending in the direction of the tire axis.

3. In a front view of the block tread, the tread opening has a second end located away from the block wall. Each of the first recesses is provided with a ridge extending from the first end to the second end, The tire according to claim 1, wherein in a block cross section that passes through the ridge line and is perpendicular to the block tread surface, the angle of the ridge line with respect to the block tread surface is 20 to 60°.

4. The tread opening has a pair of first edges that extend tapered from the block wall surface, The tire according to claim 1, wherein each of the first edges has a length of 1 to 5 mm.

5. The wall opening has a pair of second edges that extend tapered from the block tread, The tire according to claim 1, wherein each of the second edges is 1 to 5 mm in length.

6. The tire according to any one of claims 1 to 5, wherein, in a front view of the block wall surface, the contour shape of the opening is tapered toward the radially inward direction of the tire.

7. The tire according to any one of claims 1 to 5, wherein the second recesses are arranged at a first position in the radial direction of the tire.

8. The block wall surface has a plurality of third recesses formed on the inner side of the second recess in the tire radial direction, The tire according to any one of claims 1 to 5, wherein each of the third recesses is recessed from a triangular opening formed on the block wall surface.

9. The tire according to claim 8, wherein, in a front view of the block wall surface, the contour shape of the opening of the third recess is tapered toward the radially inward direction of the tire.

10. The tire according to claim 8, wherein the third recesses are arranged at a second position in the radial direction of the tire.

11. The length of the second recess in the tire radial direction is smaller than the length of the first recess in the tire radial direction. The tire according to claim 8, wherein the length of the third recess in the tire radial direction is smaller than the length of the second recess in the tire radial direction.

12. The tire according to claim 1, wherein the minimum distance between adjacent first recesses is 2 mm or less.

13. A tire having a tread portion, The tread portion is provided with at least one block and grooves that divide the block. The block comprises a block tread surface and a block wall surface extending radially inward from the block tread surface to the bottom of the groove. Multiple first recesses are formed in the block wall surface. Each of the first recesses spans the block tread and the block wall, Each of the first recesses has a triangular tread opening on the block tread and a triangular wall opening on the block wall, The wall opening has a first end that terminates without reaching the bottom of the groove, The groove is a transverse groove extending in the direction of the tire axis, The first recess includes an outer first recess located on the outside in the tire axial direction and an inner first recess located on the inside in the tire axial direction of the outer first recess. The volume of the outer first recess is greater than the volume of the inner first recess. tire.

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