tire

Abstract

The present disclosure provides a tire having first and second regions provided on the outer tire surface, the first region having a uneven surface formed by disposing raised portions throughout the entire region, the second region having a uneven surface formed by disposing a plurality of ridges in parallel throughout the entire region, and the second region being disposed adjacent to the first region, wherein a minimum separation distance between the peaks of the raised portions in the first region is shorter than the minimum separation distance between the peaks of two adjacent ridges in the second region.

Description

[Technical Field]

[0001] The present disclosure relates to tires. [Background technology]

[0002] Conventionally, tires have been known that have letters, symbols, figures, patterns, etc. on their outer surface in a manner that makes them identifiable from the outside. This type of tire is described in Patent Document 1. Patent Document 1 also describes a tire that has asymmetric thin stripes between a first portion that is a portion surrounding the letters and a second portion that is the letters themselves. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2002-522294 Summary of the Invention [Problem to be solved by the invention]

[0004] The tire of Patent Document 1 aims to make the characters easier to see by providing asymmetric thin stripes on the first and second parts, thereby creating optical contrast between the first and second parts at multiple viewing angles and multiple lighting angles.

[0005] However, the tire of Patent Document 1 still has room for improvement in terms of making specific areas, such as character portions, more easily visible from the surroundings.

[0006] The present disclosure aims to provide a tire that can improve the visibility of specific areas on the tire's outer surface. [Means for solving the problem]

[0007] A tire according to a first aspect of the present disclosure has, on its outer surface, a first region consisting of an uneven surface formed by arranging convex portions over the entire area, and a second region consisting of an uneven surface formed by arranging a plurality of ridges in parallel over the entire area and arranged adjacent to the first region, and the minimum distance between the peaks of the convex portions in the first region is smaller than the minimum distance between the peaks of two adjacent ridges in the second region. [Effects of the Invention]

[0008] According to the present disclosure, a tire can be provided that can improve the visibility of specific areas on the outer surface of the tire. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a cross-sectional view of a tire according to an embodiment of the present disclosure in a reference state, taken along a cross section parallel to the tire width direction. [Figure 2] FIG. 2 is a side view of the tire shown in FIG. [Figure 3] FIG. 3 is an enlarged view showing a part of FIG. 2. [Figure 4] 4 is an enlarged view of a portion of the letter "D" in FIG. 3 and its vicinity, and a further enlarged view of that portion. [Figure 5] FIG. 5 is a cross-sectional view taken along the line II-II in FIG. 4. [Figure 6] FIG. 5 is a cross-sectional view taken along the line III-III in FIG. 4. [Figure 7] FIG. 5 is a cross-sectional view taken along the line II in FIG. 4. [Figure 8] 5A and 5B are diagrams showing modified examples of the first and second regions shown in FIG. [Figure 9] 5 is a diagram showing another modified example of the second region shown in FIG. 4. FIG. [Figure 10] FIG. 10 is a diagram showing a configuration in which ridges having a higher protrusion height than the ridges of each segment region are provided at the boundaries of the plurality of segment regions in the second region shown in FIG. 9. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of a tire according to the present disclosure will be described with reference to the drawings. In each drawing, the same reference numerals are used to designate common members, parts, and orientations.

[0011] The tire according to the present disclosure includes both pneumatic tires and non-pneumatic tires. In the present embodiment, a pneumatic tire will be described as an example of the tire according to the present disclosure.

[0012] Unless otherwise specified below, the dimensions, length relationships, positional relationships, etc. of each element are measured under the standard conditions in which a pneumatic tire is mounted on an applicable rim, inflated to the specified internal pressure, and in an unloaded state.

[0013] Here, "applicable rim" refers to the standard rim specified in the following standards according to the tire size ("Design Rim" in the TRA Year Book below, and "Measuring Rim" in the ETRTO Standards Manual below). These standards are determined by the industrial standards in effect in the region where the tire is produced or used, such as the "Year Book" of The Tire and Rim Association, Inc. (TRA) in the United States, the "Standards Manual" of The European Tyre and Rim Technical Organisation (ETRTO) in Europe, and the "JATMA Year Book" of the Japan Automobile Tire Manufacturers Association (JATMA) in Japan. Note that the above "applicable rim" includes not only current sizes but also sizes that may be included in the above industrial standards in the future. Examples of sizes that may be included in the above industry standards in the future include sizes listed as "FUTURE DEVELOPMENTS" in the 2013 edition of the ETRTO. However, sizes not listed in the above industry standards refer to rims with a width that corresponds to the bead width of a pneumatic tire.

[0014] "Specified tire pressure" refers to the air pressure (maximum air pressure) corresponding to the maximum load capacity of a single tire for the applicable size and ply rating as set forth in the JATMA Yearbook, etc., and for sizes not specified in the industry standards, refers to the air pressure (maximum air pressure) corresponding to the maximum load capacity specified for each vehicle on which the tire is to be fitted. "Maximum load" as described below refers to the maximum tire load capacity specified in the JATMA or other standards for the applicable size tire, or, for sizes not specified in the industry standards, the load corresponding to the maximum load capacity specified for each vehicle on which the tire is to be fitted.

[0015] FIG. 1 is a diagram showing a pneumatic tire 1 (hereinafter simply referred to as "tire 1") according to this embodiment. Specifically, FIG. 1 is a cross-sectional view of the tire 1 in a cross section parallel to the tire width direction A in a reference state in which the tire 1 is mounted on an applicable rim 2, inflated to a specified internal pressure, and in an unloaded state. Hereinafter, this cross section will be referred to as a "tire width direction cross section." Note that the tire 1 according to this embodiment has a symmetrical configuration with respect to the tire equatorial plane CL, and therefore FIG. 1 shows a tire width direction cross section on only one side in the tire width direction A across the tire equatorial plane CL. However, the tire may have an asymmetrical configuration with respect to the tire equatorial plane CL.

[0016] <Applicable rim 2> The applicable rim 2 of this embodiment shown in Figure 1 comprises a rim seat portion 2a to which a bead member 3 (described later) of the tire 1 is attached on the outside in the tire radial direction B, and a rim flange portion 2b that protrudes outward in the tire radial direction B from both ends of the rim seat portion 2a in the tire width direction A.

[0017] <Tire 1> As shown in FIG. 1, a tire 1 includes a tread portion 1a and a pair of tire side portions 1b extending inward in a tire radial direction B from both ends of the tread portion 1a in the tire width direction A. The tire side portion 1b includes a pair of sidewall portions 1b1 extending inward in the tire radial direction B from both ends of the tread portion 1a in the tire width direction A, and a pair of bead portions 1b2 provided at the inner ends of each sidewall portion 1b1 in the tire radial direction B. The tire 1 of this embodiment is a tubeless radial tire for passenger cars. Here, the "tread portion 1a" refers to a portion sandwiched between tread edges TE on both sides in the tire width direction A. The "bead portion 1b2" refers to a portion in the tire radial direction B where a bead member 3, described later, is located. The "sidewall portion 1b1" refers to a portion between the tread portion 1a and the bead portion 1b2. The term "tread edge TE" refers to the outermost position in the tire width direction of the contact patch when the tire is mounted on the applicable rim described above, inflated to the specified internal pressure described above, and subjected to the maximum load.

[0018] The tire outer surface is composed of an outer surface 31 (hereinafter referred to as the "tread outer surface 31") of the tread portion 1a, which is the outer surface of the tread portion 1a, on the outside in the tire radial direction B, and an outer surface 32 (hereinafter referred to as the "tire side outer surface 32") of the tire side portion 1b, which is the outer surface of the tire side portion 1b. The tire side outer surface 32 includes an outer surface 32a (hereinafter referred to as the "sidewall outer surface 32a") of the sidewall portion 1b1 in the tire width direction A, and an outer surface 32b (hereinafter referred to as the "bead outer surface 32b") of the bead portion 1b2 in the tire width direction A.

[0019] The tire 1 includes a bead member 3 , a carcass 4 , a belt 6 , a tread rubber 7 , a side rubber 8 , and an inner liner 9 .

[0020] [Bead member 3] The bead member 3 is embedded in the bead portion 1b2. The bead member 3 includes a bead core 3a and a rubber bead filler 3b located outside the bead core 3a in the tire radial direction B. The bead core 3a includes a plurality of bead wires covered with rubber. The bead wires may be, for example, steel cords. The steel cords may be, for example, steel monofilaments or may be configured as twisted wires.

[0021] [Carcass 4] The carcass 4 straddles the pair of bead portions 1b2, more specifically, the bead cores 3a of the pair of bead members 3, and extends in a toroidal shape.

[0022] The carcass 4 may be composed of one or more carcass plies (one in this embodiment) in which carcass cords are arranged at an angle of, for example, 75° to 90° with respect to the tire circumferential direction C (see FIG. 1, etc.). This carcass ply includes a ply main body 4a located between a pair of bead cores 3a and ply turn-up portions 4b that are continuous with both ends of the ply main body 4a and are formed by turning back around the bead cores 3a from the inside to the outside in the tire width direction A. In this embodiment, a bead filler 3b is disposed between the ply main body 4a and the ply turn-up portion 4b, tapering from the bead cores 3a to the outside in the tire radial direction B. The carcass cords of the carcass ply may be, for example, metal cords such as steel cords, or organic fiber cords made of polyester, nylon, rayon, aramid, or the like. The number of carcass plies may also be two or more.

[0023] [Belt 6] The belt 6 includes one or more belt layers (two layers in this embodiment) disposed on the outer side of the crown portion of the carcass 4 in the tire radial direction B. Each belt layer of the belt 6 in this embodiment includes a rubber-coated belt cord. Each belt layer may be an inclined belt layer or a circumferential belt layer. The inclined belt layer is composed of a belt ply including belt cords arranged at an angle of more than 10° and not more than 40° with respect to the tire circumferential direction C (see FIG. 1). The circumferential belt layer is composed of a belt ply including belt cords arranged along the tire circumferential direction C (see FIG. 1) (at an angle of not more than 10°, preferably not more than 5° with respect to the tire circumferential direction C). The belt cords in each belt layer may be metal cords such as steel cords, or organic fiber cords made of polyester, nylon, rayon, aramid, or the like. Although the belt 6 in this embodiment includes two belt layers, the belt 6 may be a single-layer belt, or a belt 6 including three or more belt layers.

[0024] [Tread rubber 7 and side rubber 8] The tread rubber 7 forms a tread outer surface 31. In this embodiment, a tread pattern is formed on the tread outer surface 31, including circumferential grooves 7a extending in the tire circumferential direction C (see FIG. 1, etc.) and widthwise grooves (not shown) extending in the tire widthwise direction A. The side rubber 8 forms a tire side outer surface 32 of the tire side portion 1b. The side rubber 8 is continuous with the outer end of the tread rubber 7 in the tire widthwise direction A.

[0025] [Inner liner 9] The inner liner 9 is laminated on the inner surface of the carcass 4. The inner liner 9 can be made of, for example, a butyl-based rubber having low air permeability. Note that butyl-based rubber refers to butyl rubber and its derivative, halogenated butyl rubber.

[0026] Next, further features of the tire 1 will be described.

[0027] FIG. 2 is a side view of the tire 1 in the reference state described above. Specifically, FIG. 2 is a view of the tire side portion 1b of the tire 1 in the reference state, viewed from the outside in the tire width direction A to the front. FIG. 3 is an enlarged view of a portion of FIG. 2. As shown in FIGS. 2 and 3, a marking 10 including letters, symbols, figures, or patterns is formed on the tire side outer surface 32 of the tire 1. Note that, although the marking 10 in this embodiment is formed on the sidewall outer surface 32a of the tire side outer surface 32, the marking 10 may also be formed in another position on the tire outer surface. However, in consideration of external visibility and durability, it is preferable that the marking 10 be formed on the tire side outer surface 32.

[0028] As shown in FIGS. 2 and 3, the mark 10 includes a plurality of mark elements 11 formed at different positions in the tire circumferential direction C on the tire side outer surface 32, which is the outer surface of the tire.

[0029] Specifically, the mark 10 of this embodiment is a character mark consisting of only seven letters, "ABCDEFG." That is, the mark 10 of this embodiment has seven letter portions, "A" to "G," as multiple mark elements 11. Note that the mark may include at least one of a figure, a symbol such as a barcode, and a pattern in addition to or instead of the letters of this embodiment.

[0030] The letter portions "A" to "G" as the multiple mark elements 11 of the mark 10 of this embodiment are formed at different positions in the tire circumferential direction C on the tire side outer surface 32. More specifically, the letter portions "A" to "G" as the multiple mark elements 11 of the mark 10 of this embodiment are formed at positions spaced apart in the tire circumferential direction C. In addition, in the first region X1 in which each mark element 11 of the mark 10 of this embodiment is located, a convex portion 50 (see FIG. 4) is arranged over the entire area. Also, in the second region X2 adjacent to each mark element 11 of the mark 10 of this embodiment, a plurality of ridges 26 (see FIG. 4) as one form of convex portion are arranged in parallel over the entire area. This will be described in detail later (see FIGS. 4 to 7).

[0031] In addition to the first region X1, the second region X2 of this embodiment is adjacent to a third region X3, which is a flat surface without any irregularities. Specifically, the periphery of the first region X1 of this embodiment is surrounded by the second region X2. The periphery of the second region X2 is surrounded by the third region X3, which is also a flat surface. That is, the second region X2 of this embodiment is adjacent to the first region X1 on the inside and to the third region X3 on the outside. Note that the flat surface means a surface without any irregularities, and may be a flat surface or a curved surface. The surface roughness of the flat surface is preferably 1 to 15 Rz (Rt).

[0032] As shown in Fig. 2, two marks 10 are provided on the tire side outer surface 32 of this embodiment at positions facing each other in the tire radial direction B across the tire center axis O (see Fig. 2). In this embodiment, separate second regions X2 are arranged at the positions of the two marks 10 provided on the tire side outer surface 32, but the second regions X2 may be connected in a ring shape. In addition, the tire side outer surface 32 may have other markings formed by projections and recesses or printing.

[0033] Next, the first region X1 and the second region X2 will be described in detail. The right diagram of Fig. 4 is an enlarged view showing the vicinity of a part of the letter "D" as the mark element 11 in Fig. 3 (within the dashed rectangular frame in Fig. 3). The left diagram of Fig. 4 also shows a further enlarged view of a part of the letter "D" in the right diagram of Fig. 4 (within the dashed rectangular frame in Fig. 4). As shown in Fig. 4, the first region X1 in which the letter "D" as the mark element 11 is located is composed of an uneven surface formed by arranging convex portions 50 (see Fig. 4) over the entire area. As shown in Fig. 4, the second region X2 located around the letter "D" is composed of an uneven surface formed by arranging multiple ridges 26 (see Fig. 4) in parallel over the entire area. Note that Figure 4 illustrates the letter "D" and its surroundings as the mark element 11, but the first area X1 in which the other letter parts are located and the surrounding second area X2 have the same configuration, and so their explanation will be omitted here.

[0034] The first region X1 includes a base portion 12 and a protrusion portion 50 protruding from the base portion 12. In this embodiment, the protrusion portion 50 includes a unit pattern of a predetermined shape that is repeatedly arranged. The unit pattern in this embodiment is repeatedly arranged at a predetermined interval. By using the unit pattern, the entire first region X1 can be easily filled regardless of the area of the first region X1. Specifically, the protrusion portion 50 in this embodiment includes two unit patterns: a first unit pattern 13 and a second unit pattern 14. The protrusion portion 50 in this embodiment further includes a connecting portion 60 that connects the first unit pattern 13 and the second unit pattern 14. As will be described in detail later, each of the first unit pattern 13 and the second unit pattern 14 in this embodiment is composed of an asterisk protrusion having six extension portions extending in different directions from a relay point in a planar view. As will be described in detail later, some of the extension portions of the first unit pattern 13 and the second unit pattern 14 in this embodiment are connected to each other via the connecting portion 60.

[0035] The base portion 12 forms a reference surface for each mark element 11, and the first unit pattern 13, the second unit pattern 14 and the connecting portion 60 protrude from the base portion 12 as a reference.

[0036] The first unit pattern 13 includes extension portions 16 that protrude from the base portion 12 and extend in multiple directions from a relay point 15 in a plan view. Specifically, the first unit pattern 13 of this embodiment is configured with an asterisk protrusion as described above. The asterisk protrusion as the first unit pattern 13 of this embodiment includes extension portions 16 of the same shape that extend linearly in different directions from a center point O1 that serves as the relay point 15. More specifically, the asterisk protrusion as the first unit pattern 13 of this embodiment includes six extension portions 16 that extend in different directions from the center point O1 that serves as the relay point 15: a first extension portion 16a, a second extension portion 16b, a third extension portion 16c, a fourth extension portion 16d, a fifth extension portion 16e, and a sixth extension portion 16f. Hereinafter, when the six extension portions 16 are described without distinction, they will be simply referred to as "extension portions 16."

[0037] 4, the first extending portion 16a and the second extending portion 16b extend in opposite directions from a center point O1 serving as a relay point 15, and the first extending portion 16a and the second extending portion 16b form a shape that extends continuously in a straight line. Hereinafter, for convenience of explanation, the first extending portion 16a and the second extending portion 16b will be collectively referred to as a "first straight portion 17a."

[0038] 4, the third extending portion 16c and the fourth extending portion 16d extend in opposite directions from the center point O1 serving as the relay point 15, and the third extending portion 16c and the fourth extending portion 16d form a shape that extends continuously in a straight line. Hereinafter, for convenience of explanation, the third extending portion 16c and the fourth extending portion 16d will be collectively referred to as the "second straight portion 17b."

[0039] 4, the fifth extending portion 16e and the sixth extending portion 16f extend in opposite directions from the center point O1 serving as the relay point 15, and the fifth extending portion 16e and the sixth extending portion 16f form a shape that extends continuously in a straight line. For ease of explanation, the fifth extending portion 16e and the sixth extending portion 16f will hereinafter be collectively referred to as the "third straight portion 17c."

[0040] In this manner, the asterisk protrusion serving as the first unit pattern 13 of this embodiment is composed of a first linear portion 17a, a second linear portion 17b, and a third linear portion 17c that intersect at the center point O1 serving as the relay point 15.

[0041] The six extending portions 16 form an angle of 60° between adjacent extending portions 16. In other words, the six extending portions 16 extend radially from a center point O1 serving as a relay point 15.

[0042] 5 is a diagram showing cross sections perpendicular to the extension direction of the first linear portion 17a, the second linear portion 17b, and the third linear portion 17c of the first unit pattern 13 of this embodiment. Specifically, the cross section is taken along the line II-II in FIG. 4. As shown in FIG. 5, in the asterisk protrusion serving as the first unit pattern 13, the first linear portion 17a, the second linear portion 17b, and the third linear portion 17c are each formed into a substantially isosceles triangle shape having a flat apex. Hereinafter, the apex of the first linear portion 17a will be referred to as the "first apex 18a," the apex of the second linear portion 17b as the "second apex 18b," and the apex of the third linear portion 17c as the "third apex 18c."

[0043] The height from the base 12 to each of the first apex 18a, the second apex 18b, and the third apex 18c (hereinafter referred to as "protrusion height H1") is set to 0.1 mm or more and 1.0 mm or less. It is more preferable that the protrusion height H1 be set within the range of 0.2 mm or more and 0.8 mm or less.

[0044] As shown in Fig. 5, in the asterisk protrusion serving as the first unit pattern 13 of this embodiment, the base portion 12 between the first linear portion 17a and the second linear portion 17b is flat. As shown in Fig. 5, the base portion 12 between the second linear portion 17b and the third linear portion 17c is curved. By making the base portion 12 curved, reflection of incident light is suppressed, the contrast with the outside of the marking element 11 is increased, and visibility is improved.

[0045] In a cross-sectional view (see FIG. 5 ) perpendicular to the extending direction of each of the first to third linear portions 17a to 17c, a width W1, which is the distance between the side wall surfaces on both sides of the first side wall surface 19a, the second side wall surface 19b, and the third side wall surface 19c, which is the hypotenuse of the isosceles triangle of the first linear portion 17a, the second linear portion 17b, and the third linear portion 17c, increases from the top toward the base portion 12. The first side wall surface 19a, the second side wall surface 19b, and the third side wall surface 19c form an angle θ1 with respect to an imaginary perpendicular plane F1 relative to the base portion 12. The angle θ1 is preferably within a range of 5° to 30°, and more preferably within a range of 15° to 25°. If the angle θ1 is greater than 30°, a greater proportion of the light reflected by the first side wall surface 19a to the third side wall surface 19c will return to the outside from between the extension portions 16, resulting in less improvement in visibility. In other words, the light is reflected, reducing the difference in contrast with the outside of the marking element 11, resulting in less improvement in the visibility of the marking element 11. On the other hand, if the angle θ1 is less than 5°, the extension portions 16 will be more likely to collapse. Therefore, in consideration of the effect of suppressing the reflected light of light incident between the extension portions 16 from returning to the outside from between the extension portions 16 and the durability of the extension portions 16, it is preferable that the angle θ1 be 5° to 30°.

[0046] Furthermore, the protrusion height H1 of the extension 16 is preferably 0.8 to 6 times the maximum width W1max (the distance between the bases of the side wall surfaces of the base 12) at the base position of the isosceles triangle. If the protrusion height H1 is less than 0.8 times the maximum width W1max, a greater proportion of light reflected by the first to third side wall surfaces 19a to 19c returns to the outside from between the extension 16, resulting in less improvement in visibility. In other words, the light is reflected, reducing the difference in contrast with the outside of the marking element 11, resulting in less improvement in visibility. On the other hand, if the protrusion height H1 is greater than 6 times the maximum width W1max, the first to third side wall surfaces 19a to 19c will be at an angle close to perpendicular to the base 12, making the extension 16 more likely to tip over. Therefore, taking into consideration the effect of suppressing the reflected light of light incident between the extension portions 16 from returning to the outside from between the extension portions 16 and the durability of the extension portions 16, it is preferable that the protrusion height H1 is 0.8 to 6 times the maximum width W1max, which is the length of the base side.

[0047] The second unit pattern 14 of this embodiment includes extension portions 21 that protrude from the base portion 12 and extend in multiple directions from relay points 20 in a plan view. The second unit pattern 14 of this embodiment is an asterisk protrusion that has the same shape and size as the first unit pattern 13, but is inclined at a different angle from the asterisk protrusion of the first unit pattern 13 in a tire side view (see FIGS. 2 to 4). Specifically, as shown in FIG. 4, the asterisk protrusion of the second unit pattern 14 is inclined at an angle obtained by rotating the asterisk protrusion of the first unit pattern 13 by 30° around a center point O1.

[0048] Specifically, the asterisk protrusion as the second unit pattern 14 of this embodiment includes extending portions 21 of the same shape that extend linearly in different directions from a center point O2 that serves as a relay point 20. More specifically, the asterisk protrusion as the second unit pattern 14 of this embodiment includes a first extending portion 21a, a second extending portion 21b, a third extending portion 21c, a fourth extending portion 21d, a fifth extending portion 21e, and a sixth extending portion 21f as six extending portions 21 that extend in different directions from the center point O2 that serves as a relay point 20. Hereinafter, when the six extending portions 21 are described without distinction, they will be simply referred to as "extending portions 21."

[0049] 4, the first extending portion 21a and the second extending portion 21b extend in opposite directions from a center point O2 serving as the relay point 20, and the first extending portion 21a and the second extending portion 21b form a shape that extends continuously in a straight line. For ease of explanation, the first extending portion 21a and the second extending portion 21b will hereinafter be collectively referred to as a "first straight portion 22a."

[0050] 4, the third extending portion 21c and the fourth extending portion 21d extend in opposite directions from a center point O2 serving as a relay point 20, and form a shape that extends continuously in a straight line by the third extending portion 21c and the fourth extending portion 21d. Hereinafter, for convenience of explanation, the third extending portion 21c and the fourth extending portion 21d will be collectively referred to as a "second straight portion 22b."

[0051] 4, the fifth extending portion 21e and the sixth extending portion 21f extend in opposite directions from the center point O2 serving as the relay point 20, and form a shape that extends continuously in a straight line by the fifth extending portion 21e and the sixth extending portion 21f. Hereinafter, for convenience of explanation, the fifth extending portion 21e and the sixth extending portion 21f will be collectively referred to as the "third straight portion 22c."

[0052] In this manner, the asterisk protrusion serving as the second unit pattern 14 of this embodiment is made up of the first linear portion 22a, the second linear portion 22b, and the third linear portion 22c, which intersect at the center point O2 serving as the relay point 20.

[0053] The six extending portions 21 form an angle of 60° between adjacent extending portions 21. In other words, the six extending portions 21 extend radially from a center point O2 serving as a relay point 20.

[0054] 6 is a diagram showing cross sections perpendicular to the extension direction of the first linear portion 22a, the second linear portion 22b, and the third linear portion 22c of the second unit pattern 14 of this embodiment. Specifically, the cross section is taken along the line III-III in FIG. 4. As shown in FIG. 6, in the asterisk protrusion serving as the second unit pattern 14, the first linear portion 22a, the second linear portion 22b, and the third linear portion 22c are each formed into a substantially isosceles triangular shape having a flat apex. Hereinafter, the apex of the first linear portion 22a will be referred to as the "first apex 23a," the apex of the second linear portion 22b will be referred to as the "second apex 23b," and the apex of the third linear portion 22c will be referred to as the "third apex 23c."

[0055] The protrusion height H1, which is the height from the base portion 12 to each of the first apex 23a, the second apex 23b, and the third apex 23c, is set to 0.1 mm or more and 1.0 mm or less, similar to the protrusion height H1 of the first unit pattern 13. It is more preferable that the protrusion height H1 be set within the range of 0.2 mm or more and 0.8 mm or less.

[0056] As shown in Fig. 6, in the asterisk protrusion serving as the second unit pattern 14 of this embodiment, the base portion 12 between the first linear portion 22a and the second linear portion 22b is flat. As shown in Fig. 6, the base portion 12 between the second linear portion 22b and the third linear portion 22c is curved. By making the base portion 12 curved, reflection of incident light is suppressed, the contrast with the outside of the marking element 11 is increased, and visibility is improved.

[0057] The first side wall surface 24a, which constitutes the hypotenuse of the isosceles triangle of the first linear portion 22a, the second side wall surface 24b, which constitutes the hypotenuse of the isosceles triangle of the second linear portion 22b, and the third side wall surface 24c, which constitutes the hypotenuse of the isosceles triangle of the third linear portion 22c, are configured so that a width W1, which is the distance between the side wall surfaces on both sides, increases from the top side toward the base portion 12 in a cross-sectional view perpendicular to the extending direction of each of the first linear portion 22a to the third linear portion 22c (see FIG. 6). The first side wall surface 24a, the second side wall surface 24b, and the third side wall surface 24c form an angle θ1 with respect to a virtual perpendicular plane F1 relative to the base portion 12. For the same reasons as the angle θ1 of the first unit pattern 13, the angle θ1 is preferably within a range of 5° to 30°, and more preferably within a range of 15° to 25°.

[0058] Furthermore, in the extension portion 21, for the same reasons as the protrusion height H1 in the first unit pattern 13, it is preferable that the protrusion height H1 is 0.8 to 6 times the maximum width W1max (the distance between the bases of the side wall surfaces in the base portion 12) at the base position of the isosceles triangle.

[0059] As shown in FIG. 4, the above-described first unit patterns 13 and second unit patterns 14 are arranged so as to fill the entire first region X1, which is the position of each mark element 11.

[0060] Specifically, the first unit patterns 13 of each of the multiple mark elements 11 of this embodiment are arranged in multiple locations along the tire radial direction B (at an angle of 10° or less with respect to the tire radial direction B). Also, the second unit patterns 14 of each of the multiple mark elements 11 of this embodiment are arranged in multiple locations along the tire radial direction B (at an angle of 10° or less with respect to the tire radial direction B).

[0061] Furthermore, the first unit patterns 13 of each of the multiple mark elements 11 of this embodiment are arranged in a direction substantially perpendicular to the tire radial direction B. Furthermore, the second unit patterns 14 of each of the multiple mark elements 11 of this embodiment are arranged in a direction substantially perpendicular to the tire radial direction B.

[0062] In this way, by regularly arranging the first unit patterns 13 and the second unit patterns 14 in a predetermined direction, the arrangement of the first unit patterns 13 and the second unit patterns 14 can be simplified even for first unit patterns 13 and second unit patterns 14 that do not have anisotropy. Not limited to the configuration of this embodiment, when using unit patterns that do not have anisotropy, it is preferable to use a repeating pattern formed by regularly arranging unit patterns. In this way, even when unit patterns that do not have anisotropy are used, it is possible to easily fill a large area with unit patterns.

[0063] 4, the tip of the first extending portion 16a of the asterisk protrusion as the first unit pattern 13 is located at a position sandwiched between the third extending portion 21c and the fifth extending portion 21e of the asterisk protrusion as the adjacent second unit pattern 14. In addition, the tip of the second extending portion 16b of the asterisk protrusion as the first unit pattern 13 is located at a position sandwiched between the fourth extending portion 21d and the sixth extending portion 21f of the asterisk protrusion as the adjacent second unit pattern 14.

[0064] 4, the tip of the first extending portion 21a of the asterisk protrusion as the second unit pattern 14 is located at a position sandwiched between the fourth extending portion 16d and the sixth extending portion 16f of the asterisk protrusion as the adjacent first unit pattern 13. Furthermore, the tip of the second extending portion 21b of the asterisk protrusion as the second unit pattern 14 is located at a position sandwiched between the third extending portion 16c and the fifth extending portion 16e of the asterisk protrusion as the adjacent first unit pattern 13.

[0065] In adjacent first unit patterns 13 and second unit patterns 14, the distance (hereinafter referred to as "distance P") between center point O1 serving as relay point 15 and center point O2 serving as relay point 20 is 0.2 mm or more and 3.0 mm or less. In the first unit pattern 13, the length from the tip of the first extending portion 16a to the tip of the second extending portion 16b, the length from the tip of the third extending portion 16c to the tip of the fourth extending portion 16d, and the length from the tip of the fifth extending portion 16e to the tip of the sixth extending portion 16f are all equal and are the longest lengths of the first unit pattern 13 in a side view of the tire. This length is hereinafter referred to as "linear extension length L." The linear extension length L is set to be longer than the distance P.

[0066] The length from the tip of the first extension portion 21a to the tip of the second extension portion 21b, the length from the tip of the third extension portion 21c to the tip of the fourth extension portion 21d, and the length from the tip of the fifth extension portion 21e to the tip of the sixth extension portion 21f are the longest lengths of the second unit pattern 14 when viewed from the side of the tire, and are the same length as the linear extension length L of the first unit pattern 13.

[0067] If the spacing P is less than 0.2 mm, the extensions 16 and 21 are too short, making it difficult to ensure the moldability of the first and second unit patterns 13 and 14 during manufacturing. On the other hand, if the spacing P exceeds 3.0 mm, the influence of reflected light from the base portion 12 is significant, making it difficult for the first and second unit patterns 13 and 14 to create contrast with their surroundings. The first and second unit patterns 13 and 14 are densely arranged to minimize the influence of reflected light from the base portion 12, and the spacing P is set to 1.0 mm or less, more preferably 0.8 mm or less. This further reduces the reflected light from the base portion 12, making the mark element 11 appear darker, further increasing the contrast of the mark element 11 with its surroundings and improving its visibility. However, adjacent first and second unit patterns 13 and 14 are not continuous in areas where the connecting portion 60 (described later) is not present, but are spaced apart.

[0068] The mark element 11 of this embodiment includes the first unit pattern 13 and the second unit pattern 14, but only one of the unit patterns may be formed in multiples on the base portion 12. However, by using multiple types of unit patterns as in this embodiment, it becomes easier to densely arrange the unit patterns so as to reduce the area of the base portion 12. This makes it easier to realize a mark element 11 with higher visibility.

[0069] In addition, each of the first unit pattern 13 and the second unit pattern 14 in this embodiment is composed of an asterisk protrusion, but the number of extension portions extending in different directions from the relay point is not limited to six, but may be two or more, and preferably three or more. By providing multiple extension portions, it becomes easier to arrange the unit patterns densely so as to reduce the area of the base portion 12.

[0070] The connecting portion 60 in this embodiment connects adjacent first unit patterns 13 and second unit patterns 14. In this embodiment, any first unit pattern 13 is connected to at least one adjacent second unit pattern 14 via the connecting portion 60. More specifically, in this embodiment, the sixth extending portion 16f of any first unit pattern 13 is connected to the fifth extending portion 21e of the adjacent second unit pattern 14 via the connecting portion 60. Furthermore, in this embodiment, the third extending portion 16c of any first unit pattern 13 is connected to the fourth extending portion 21d of the adjacent second unit pattern 14 via the connecting portion 60. However, the extending portion 16 of the first unit pattern 13 and the extending portion 21 of the second unit pattern 14 connected by the connecting portion 60 are not limited to the configuration in this embodiment, and different extending portions 16, 21 may be connected to each other.

[0071] The connecting portion 60 in this embodiment has a linear configuration formed by extending one of the extending portions 16 of the first unit pattern 13 or one of the extending portions 21 of the second unit pattern 14. However, the connecting portion 60 may have a bent shape that is bent at a predetermined angle, such as 90°, and is formed by extending and connecting one of the extending portions 16 of the first unit pattern 13 and one of the extending portions 21 of the second unit pattern 14. Furthermore, the connecting portion 60 is not limited to a linear or bent shape, and may have a curved shape, for example, an arc shape.

[0072] The multiple first unit patterns 13 arranged along the tire radial direction B are continuous via the connecting portions 60 and the second unit patterns 14 connected by these connecting portions 60. In other words, the multiple second unit patterns 14 arranged along the tire radial direction B are continuous via the connecting portions 60 and the first unit patterns 13 connected by these connecting portions 60. In other words, the first unit patterns 13 and the second unit patterns 14 are connected by the connecting portions 60 and are continuous in a zigzag pattern in the tire radial direction B. The first unit patterns 13 and the second unit patterns 14 are continuous from one end on the inner side to the other end on the outer side in the tire radial direction B.

[0073] By providing the connecting portion 60, the first unit pattern 13 and the second unit pattern 14 are connected, the first unit pattern 13 and the second unit pattern 14 support each other, the collapse of each unit pattern of the first unit pattern 13 and the second unit pattern 14 is suppressed, and the durability of each unit pattern can be improved.

[0074] Furthermore, by connecting the first unit patterns 13 and the second unit patterns 14 in a straight line (the tire radial direction B in this embodiment) as in the connecting portion 60 of this embodiment, rubber flow can be improved during vulcanization molding of the tire 1 using a mold, compared to a configuration in which adjacent first unit patterns 13 and second unit patterns 14 are connected in different directions by connecting portions at irregular positions and there is no linear connection. In other words, the continuous grooves on the inner surface of the mold, which correspond to the shapes of the first unit patterns 13, the second unit patterns 14, and the connecting portion 60, allow air to escape to the outside of each marking element 11 during vulcanization molding. This makes it difficult for air to accumulate in the mold during vulcanization molding, improving rubber flow and reducing the occurrence of defective products.

[0075] Furthermore, in each mark element 11 of this embodiment, adjacent first unit patterns 13 and second unit patterns 14 are regularly connected in a predetermined direction by connecting portions 60, which makes it difficult for variations in the shade of black to occur within each mark element 11, and each mark element 11 can appear uniformly black. However, if only consideration is given to visibility, the convex portions 50 do not need to be provided with connecting portions 60. In other words, from the perspective of visibility, adjacent first unit patterns 13 and second unit patterns 14 may be arranged at a distance from each other. From the perspective of achieving both visibility and the above-mentioned rubber flowability, it is preferable that adjacent first unit patterns 13 and second unit patterns 14 are regularly connected in a predetermined direction by connecting portions 60.

[0076] In this embodiment, the multiple first unit patterns 13 arranged in a direction substantially perpendicular to the tire radial direction B are not continuous via the connecting portions 60 and the second unit patterns 14 connected by these connecting portions 60. Also, the multiple second unit patterns 14 arranged in a direction substantially perpendicular to the tire radial direction B are not continuous via the connecting portions 60 and the first unit patterns 13 connected by these connecting portions 60. This makes it possible to further optimize the air flow during vulcanization molding, and to more efficiently allow air to escape to the outside of each marking element 11. As a result, it is possible to further improve the rubber flow during vulcanization molding, and to further reduce the occurrence of defective products.

[0077] Next, the second region X2 surrounding the mark element 11 will be described in detail. Multiple ridges 26 are arranged in parallel throughout the entire second region X2. Specifically, as shown in the right diagram of FIG. 4, the second region X2 includes a base portion 25 and multiple ridges 26 protruding from the base portion 25. While each ridge 26 in this embodiment extends linearly, it may also extend in a curved manner (see FIG. 8). By arranging multiple ridges 26 in the second region X2 in this manner, the second region X2 can appear brighter at a predetermined viewing angle and a predetermined lighting angle than when the second region X2 is a flat surface. This further enhances the contrast with the first region X1 in which the mark element 11 is located. In other words, the visibility of the mark element 11 can be further improved.

[0078] Furthermore, in this embodiment, the multiple ridges 26 extend in parallel. That is, in this embodiment, the ridges 26 extending in the same direction are arranged around any of the letter portions "A" to "G" serving as the mark elements 11. This makes it possible to uniformize the reflection of light in the second region X2 regardless of the position of the mark elements 11. That is, even if the mark elements 11 are spaced apart, the reflection of light in the second region X2 around each mark element 11 is uniform, thereby suppressing variations in visibility among the multiple mark elements 11 that are spaced apart. That is, because the multiple ridges 26 in the second region X2 extend in parallel, it is possible to suppress variations in visibility among the multiple first regions X1 that are spaced apart.

[0079] FIG. 7 is a diagram showing cross sections perpendicular to the extension direction of the first linear portion 22a of the second unit pattern 14 in the first region X1 and the ridge 26 in the second region X2. Specifically, it is a cross-sectional view taken along the line II in FIG. 4. As shown in FIG. 7, in the asterisk protrusion serving as the second unit pattern 14, the first apex 23a of the first linear portion 22a is formed by a flat apex, as described above (see FIG. 6). In contrast, the cross-sectional shape of the ridge 26 perpendicular to the extension direction is an approximately isosceles triangle, and the apex 27 of the ridge 26 is pointed. Note that, as shown in FIG. 7, the protruding height H1 of the convex portion 50 in the first region X1 is higher than the protruding height H2 of the ridge 26 in the second region X2. This makes the first region X1 appear darker, further enhancing the contrast with the second region X2 and improving the visibility of the first region X1. 7, the maximum width W2max, which is the length of the base of the ridge 26, is longer than the maximum width W1max of the first linear portion 22a. Note that, although the apex 27 of the ridge 26 in this embodiment is configured as a pointed apex, this configuration is not limited thereto. In other words, the apex 27 of the ridge 26 may be a flat apex.

[0080] In a cross-sectional view (see FIG. 7 ) perpendicular to the extension direction of the ridge 26, the sidewall surfaces 28 of the ridge 26 have a width W2, which is the distance between the two sidewall surfaces 28, that increases from the apex 27 toward the base 25. The sidewall surfaces 28 form an angle θ2 with an imaginary perpendicular plane F2 relative to the base 25. The angle θ2 is preferably greater than 30° and less than 75°, and more preferably greater than 30° and less than 60°. When the angle θ2 is 30° or less, the proportion of light reflected by the sidewall surfaces 28 returning to the outside from between the ridges 26 decreases. In other words, light reflection becomes difficult, the difference in contrast with the first region X1 where the marking element 11 is located becomes smaller, and the improvement in visibility of the first region X1 is reduced. On the other hand, when the angle θ2 is greater than 75°, the surface approaches a flat surface, making it difficult to appear bright even at a predetermined viewing angle and a predetermined lighting angle. Therefore, in order to make it easier for the reflected light of light incident between the ridges 26 to return to the outside from between the ridges 26 and to make the light appear particularly bright at a specified viewing angle and a specified illumination angle, it is preferable that the angle θ2 be greater than 30° and less than or equal to 75°.

[0081] Next, the relationship between the first region X1 and the second region X2 will be described. The first region X1 and the second region X2 have a relationship in which the minimum distance D1 between the apexes 50a of the convex portions 50 in the first region X1 is smaller than the minimum distance D2 between the apexes 27 of two adjacent ridges 26 in the second region X2.

[0082] As described above, the convex portion 50 in the first region X1 of this embodiment includes the first unit pattern 13, the second unit pattern 14, and the connecting portion 60. Here, the minimum separation distance D1 between the apexes 50a of the convex portions 50 in the first region X1 of this embodiment is 0.1 to 0.2 mm. Specifically, in the convex portion 50 of this embodiment, the minimum separation distance D1 is achieved at a position where the extension portion of one of the first unit pattern 13 and the second unit pattern 14 is disposed between two extension portions of the other unit pattern. As shown in the left diagram of FIG. 4 , an example of the minimum separation distance D1 in this embodiment is the distance between the apex at the tip of the first extension portion 16a of the first unit pattern 13 and the apex of the third extension portion 21c of the second unit pattern 14. In this embodiment, the apex at the tip of the first extension portion 16a of the first unit pattern 13 is part of the flat first apex 18a of the first linear portion 17a, as shown in FIG. 5. Similarly, the apex of the third extension portion 21c of the second unit pattern 14 is part of the flat second apex 23b of the second linear portion 22b, as shown in FIG. 6. Thus, the minimum separation distance D1 between the flat apexes may be the distance between the closest points of the apexes. While the apex 50a of the convex portion 50 in this embodiment is flat, it may also be pointed, like a ridge formed by the intersection of two surfaces.

[0083] In addition, the minimum separation distance D2 between the peaks 27 of two adjacent ridges 26 in the second region X2 of this embodiment is greater than 0.5 mm and not greater than 1.5 mm. Note that although the peaks 27 of the ridges 26 of this embodiment are pointed and not flat, they may be flat. If the peaks 27 of the ridges 26 are flat, the minimum separation distance D2 may be the distance between the closest points of the peaks.

[0084] Thus, the minimum distance D1 between the apexes 50a of the convex portions 50 in the first region X1 is smaller than the minimum distance D2 between the apexes 27 of two adjacent ridges 26 in the second region X2. This configuration reduces light reflection in the first region X1 compared to the second region X2. Therefore, the first region X1 tends to appear darker than the second region X2. In contrast, the second region X2 has multiple ridges 26 arranged in parallel. Therefore, the second region X2 appears brighter at a predetermined viewing angle and a predetermined lighting angle than a flat surface. This enhances the optical contrast between the adjacent first region X1 and second region X2 at a predetermined viewing angle and a predetermined lighting angle, thereby improving the visibility of one of the first region X1 and the second region X2 relative to the other. This improves the visibility of a specific region on the tire outer surface. In other words, this embodiment improves the visibility of the marking element 11 formed by the first region X1 from the outside.

[0085] Furthermore, as shown in FIG. 4, in this embodiment, the minimum separation distance D3 is smaller than the minimum separation distance D2 between the apexes 27 of two ridges 26 in the second region X2. In this embodiment, the minimum separation distance D3 refers to the minimum separation distance from the reference position SP to the apex of a unit pattern adjacent to the reference unit pattern SU. The reference unit pattern SU refers to any unit pattern in the first region X1 (in this embodiment, the first unit pattern 13 or the second unit pattern 14), and the reference position SP refers to any position of the apex of the reference unit pattern SU. In this embodiment, the minimum separation distance D3 is 0.5 mm or less. The left diagram in FIG. 4 shows an example of the minimum separation distance D3. Note that if the apex is flat, the minimum separation distance D3 may be the distance between the closest points of the apexes.

[0086] In this way, by configuring the minimum separation distance D3 in the first region X1 to be smaller than the minimum separation distance D2 in the second region X2, the density of the convex portions 50 in the first region X1 can be made higher than the density of the ridges 26 in the second region X2. This allows the area of the base portion 12 in the first region X1 to be reduced, and the amount of light reflected by the base portion 12 in the first region X1 to be reduced. This makes the first region X1 appear darker, further enhancing the contrast between the light of the adjacent first region X1 and second region X2. In other words, the visibility of one of the first region X1 and second region X2 relative to the other can be further improved.

[0087] In other words, the total extension length of the apexes 50a of the convex portions 50 in the first region X1 is longer than the total extension length of the apexes 27 of the ridges 26 in the second region X2 per unit area. In this embodiment, the total extension length of the apexes 50a of the convex portions 50 in the first region X1 per unit area is the sum of the total extension length of the first apexes 18a to 18c of the first unit pattern 13, the total extension length of the first apexes 23a to 23c of the second unit pattern 14, and the extension length of the connecting portion 60. In addition, in this embodiment, the total extension length of the apexes 27 of the ridges 26 in the second region X2 per unit area is the sum of the total extension length of the apexes 27 of each ridge 26. In this manner, the convex portions 50 in the first region X1 are arranged more densely than the ridges 26 in the second region X2. This reduces the area of the base portion 12 of the first region X1, thereby reducing the amount of light reflected by the base portion 12 of the first region X1. The unit area for comparing the total extension length is not particularly limited, but can be an area that includes the tops 27 of multiple ridges 26, such as a square of 5 mm square or 10 mm square.

[0088] Furthermore, in this embodiment, the maximum width of the bases of the extensions 16 and 21 in the first region X1 is smaller than the minimum width of the bases of the ridges 26 in the second region X2. In other words, the extensions 16 and 21 in this embodiment are narrower than the ridges 26. This makes it easier to fill the first region X1 with unit patterns (first unit patterns 13 and second unit patterns 14 in this embodiment), thereby further reducing the area of the base portion 12. Note that the bases of the extensions 16 and 21 in this embodiment have a substantially constant width regardless of their position in the extension direction. Furthermore, the bases of the ridges 26 in this embodiment also have a substantially constant width regardless of their position in the extension direction. In other words, the maximum width of the bases of the extensions 16 and 21 in this embodiment is the "maximum width W1max" shown in FIG. 7, and the minimum width of the bases of the ridges 26 in the second region X2 in this embodiment is the "maximum width W2max" shown in FIG. 7.

[0089] 4, in a plan view of the first region X1, the maximum linear length M of the base portion 12 is preferably smaller than the minimum separation distance D2 of the second region X2. This can further reduce the amount of light reflected by the base portion 12 in the first region X1.

[0090] As described above, the convex portions 50 in the first region X1 are arranged more densely than the ridges 26 in the second region X2, and therefore cracks are less likely to occur in the first region X1 than in the second region X2. Therefore, even if a crack occurs in the second region X2 along the ridge 26, the first region X1 can suppress the progression of the crack. In particular, in this embodiment, the convex portions 50 arranged in the first region X1 are composed of the first unit patterns 13 and second unit patterns 14, which are not anisotropic. Therefore, the first region X1 of this embodiment can suppress the progression of a crack along the extension direction of the ridge 26, regardless of the extension direction of the ridge 26 in the second region X2.

[0091] In this embodiment, the position of the mark element 11 is configured as the first region X1, and the position adjacent to the mark element 11 is configured as the second region X2, but this configuration is not limited to this. In other words, it is sufficient that the first region X1 and the second region X2 are disposed adjacent to each other, and there are no particular limitations on the positions of the first region X1 and the second region X2 on the tire outer surface and the types of markings expressed in the first region X1 and the second region X2.

[0092] However, when the first region X1 and the second region X2 are provided on the tire side outer surface 32 as in this embodiment, it is preferable that the second region X2 be adjacent to the first region X1 at least on both sides in the tire circumferential direction C. This can improve the visibility of the first region X1 sandwiched between the second regions X2 in the tire circumferential direction C. When the first region X1 is a plurality of marking elements 11 arranged at intervals in the tire circumferential direction C as in this embodiment, it is particularly preferable that the second region X2 be provided on both sides in the tire circumferential direction C of each first region X1 representing each marking element 11. This can improve the visibility of each marking element 11, and as a result, the visibility of the entire marking 10 can be improved.

[0093] Furthermore, when the first region X1 and the second region X2 are provided on the tire side outer surface 32 as in this embodiment, it is preferable that the second region X2 be adjacent to the first region X1 on at least one side in the tire radial direction B in addition to both sides in the tire circumferential direction C of the first region X1. This can further improve the visibility of the first region X1.

[0094] Furthermore, as in this embodiment, it is preferable that the first region X1 is surrounded by the second region X2, and that the first region X1 is adjacent to the second region X2 over the entire periphery, thereby further increasing the visibility of the first region X1.

[0095] The tire according to the present disclosure is not limited to the specific configuration shown in the above-described embodiment, and various modifications and variations are possible without departing from the scope of the claims. In the above-described embodiment, the convex portion 50 in the first region X1 includes the first unit pattern 13, the second unit pattern 14, and the connecting portion 60, but this configuration is not limited thereto. FIG. 8 shows modified examples of the convex portion 50 in the first region X1 and the ridge 26 in the second region X2. As shown in FIG. 8, the convex portion 50 in the first region X1 may be composed of multiple ridges 51. The cross-sectional shape of the ridge 51 shown in FIG. 8, which is substantially perpendicular to the extension direction, is an isosceles triangle, and the apex 52 is pointed, but may also be flat. In the above-described embodiment, the ridge 26 in the second region X2 extends linearly, but this configuration is not limited thereto. As shown in FIG. 8, the ridge 26 in the second region X2 may extend in a curved shape.

[0096] Fig. 9 is a diagram showing a modified example of the second region X2. The configurations of the first region X1 and the third region X3 shown in Fig. 9 are the same as those of the above-described embodiment shown in Figs. 1 to 7, and therefore description thereof will be omitted here.

[0097] 9 is formed of an uneven surface formed by arranging multiple ridges 26 in parallel across the entire area, similar to the embodiment described above. However, the second region X2 shown in FIG. 9 differs from the second region X2 of the embodiment described above in that it includes multiple types of segment regions in which the separation distance between two adjacent ridges 26 is different.

[0098] Specifically, the second region X2 shown in FIG. 9 includes two types of segment regions X2a and X2b as multiple types of segment regions. Hereinafter, for ease of explanation, the two types of segment regions X2a and X2b will be referred to as the "first segment region X2a" and the "second segment region X2b" to distinguish them from one another. In the second region X2 shown in FIG. 9, a plurality of first segment regions X2a and a plurality of second segment regions X2b are arranged adjacent to one another. More specifically, the second region X2 shown in FIG. 9 is filled with a plurality of first segment regions X2a and a plurality of second segment regions X2b.

[0099] The first segment region X2a includes a plurality of first ridges 26a arranged in parallel. The second segment region X2b includes a plurality of second ridges 26b arranged in parallel. As shown in Fig. 9, the first ridges 26a and the second ridges 26b extend substantially parallel to each other.

[0100] The minimum separation distance D2a between the apexes of two adjacent first ridges 26a in the first segment region X2a is smaller than the minimum separation distance D2b between the apexes of two adjacent second ridges 26b in the second segment region X2b. In the example shown in FIG. 9, the first ridges 26a and the second ridges 26b extend linearly. In the example shown in FIG. 9, the first ridges 26a in the first segment region X2a are arranged at equal intervals. In the example shown in FIG. 9, the second ridges 26b in the second segment region X2b are also arranged at equal intervals. Therefore, the minimum separation distance D2a is the separation distance between the apexes of two adjacent first ridges 26a in a cross section perpendicular to the extension direction of the first ridges 26a, and is the arrangement pitch of the first ridges 26a. The above-mentioned minimum separation distance D2b is the separation distance between the tops of two adjacent second ridges 26b in a cross section perpendicular to the extension direction of the second ridges 26b, and is the arrangement pitch of the second ridges 26b.

[0101] In this way, the second region X2 may include a plurality of segment regions (first segment region X2a and second segment region X2b in the example shown in FIG. 9) in which the ridges 26 are spaced apart from one another by different distances.

[0102] The second region X2 shown in FIG. 9 includes only two types of segment regions (the first segment region X2a and the second segment region X2b), but may include three or more types of segment regions.

[0103] The first segment region X2a and the second segment region X2b shown in Fig. 9 have substantially the same shape and size of their outer edge contours. Specifically, the first segment region X2a and the second segment region X2b shown in Fig. 9 have substantially rectangular outer edge contours. However, two sides extending in the longitudinal direction of the rectangular outer edge contour are concavely curved. Furthermore, two sides extending in the lateral direction of the rectangular outer edge contour are convexly curved.

[0104] However, the shape and size of the outer edge contour of each of the first segment region X2a and the second segment region X2b may be different.Furthermore, the outer edge contour of each of the first segment region X2a and the second segment region X2b does not have to be rectangular as described above.

[0105] The minimum separation distance D2a between two adjacent first ridges 26a in the first segment region X2a shown in Fig. 9 may be, for example, 0.6 mm, but is not limited to this length. The minimum separation distance D2b between two adjacent second ridges 26b in the second segment region X2b shown in Fig. 9 may be, for example, 1.0 mm, but is not limited to this length. The minimum separation distances D2a and D2b may be set appropriately within a range of, for example, more than 0.5 mm and not more than 1.5 mm.

[0106] The protruding height of the first ridge 26a in the first segment region X2a may be equal to or different from the protruding height of the second ridge 26b in the second segment region X2b. However, it is preferable that the protruding heights of the first ridge 26a and the second ridge 26b are both lower than the protruding height H1 in the first region X1 (see FIGS. 5 to 7). The protruding heights of the first ridge 26a and the second ridge 26b can both be 0.15 mm, for example.

[0107] Alternatively, a separate ridge may be provided to form the boundary between the multiple segment regions of the second region X2 (the first segment region X2a and the second segment region X2b in the example shown in FIG. 9). In this case, the protrusion height of the ridges arranged in parallel in each segment region (the first ridge 26a and the second ridge 26b in the example shown in FIG. 9) is made higher than the ridges forming the above-mentioned boundary, so that the ridges arranged in parallel in each segment region (the first ridge 26a and the second ridge 26b in the example shown in FIG. 9) form an uneven surface across the entire second region X2. In this way, the ridges arranged in parallel in each segment region may cross the ridges forming the above-mentioned boundary.

[0108] Fig. 10 shows an example in which a boundary ridge 70 is provided at the boundary between the first segment region X2a and the second segment region X2b of the second region X2 shown in Fig. 9. The upper diagram in Fig. 10 shows an enlarged view of a portion of the first segment region X2a and the second segment region X2b. The lower diagram in Fig. 10 shows a cross-sectional view taken along line IV-IV in the upper diagram in Fig. 10. The protruding height H3 of the boundary ridge 70 shown in Fig. 10 is higher than the protruding heights H4 and H5 of the first ridges 26a and the second ridges 26b arranged in parallel in the first segment region X2a and the second segment region X2b. [Industrial Applicability]

[0109] The present disclosure relates to tires. [Explanation of symbols]

[0110] 1: tire, 1a: tread portion, 1b: tire side portion, 1b1: sidewall portion, 1b2: bead portion, 2: applicable rim, 2a: rim seat portion, 2b: rim flange portion, 3: bead member, 3a: bead core, 3b: bead filler, 4: carcass, 4a: ply main body portion, 4b: ply folded portion, 6: belt, 7: tread rubber, 7a: circumferential groove, 8: side rubber, 9: inner liner, 10: mark, 11: mark element, 12: base portion of first unit pattern, 13: first unit pattern (unit pattern), 14: second unit pattern (unit pattern), 15: relay point of first unit pattern, 16: extension portion of first unit pattern, 16a: first extension portion of first unit pattern 16b: second extension portion of first unit pattern, 16c: third extension portion of first unit pattern, 16d: fourth extension portion of first unit pattern, 16e: fifth extension portion of first unit pattern, 16f: sixth extension portion of first unit pattern, 17a: first straight portion of first unit pattern, 17b: second straight portion of first unit pattern, 17c: third straight portion of first unit pattern, 18a: first apex of first unit pattern, 18b: second apex of first unit pattern, 18c: third apex of first unit pattern, 19a: first side wall surface of first unit pattern, 19b: second side wall surface of first unit pattern, 19c: third side wall surface of first unit pattern, 20: relay point of second unit pattern, 21: extension portion of second unit pattern, 21a: first extension portion of second unit pattern, 21b: second extension portion of second unit pattern, 21c: third extension portion of second unit pattern, 21d: fourth extension portion of second unit pattern, 21e: fifth extension portion of second unit pattern, 21f: sixth extension portion of second unit pattern, 22a: first straight portion of second unit pattern, 22b: second straight portion of second unit pattern, 22c: third straight portion of second unit pattern, 23a: first apex of second unit pattern, 23b: second apex of second unit pattern, 23c: third apex of second unit pattern, 24a: first side wall surface of second unit pattern, 24b: second side wall surface of second unit pattern, 24c: third side wall surface of second unit pattern, 25: base portion of second unit pattern, 26: ridge, 26a: first ridge, 26b: second ridge, 27: ridge top; 28: ridge sidewall;31: tread outer surface, 32: tire side outer surface, 32a: sidewall outer surface, 32b: bead outer surface, 50: convex portion, 50a: convex portion crest, 51: ridge, 52: ridge crest, 60: connecting portion, 70: boundary ridge, A: tire width direction, B: tire radial direction, C: tire circumferential direction, CL: tire equatorial plane, D1: minimum spacing distance between crests of convex portions in the first region, D2: minimum spacing distance between crests of ridges in the second region, D2a: minimum spacing distance between crests of first ridges in first segment regions in the second region, D2b: minimum spacing distance between crests of second ridges in second segment regions in the second region, D3: minimum spacing distance from a reference position in the first region to a crest of a unit pattern adjacent to a reference unit pattern, F1: imaginary vertical plane with respect to a base portion of the first region, F2: imaginary vertical plane with respect to a base portion of the second region H1: protruding height of straight portion of first region, H2: protruding height of ridge of second region, H3: protruding height of boundary ridge of second region, H4: protruding height of first ridge of first segment region of second region, H5: protruding height of second ridge of second segment region of second region, L: straight line extension length, M: maximum straight line length of base portion of first region, O: tire center axis, O1: center point of first unit pattern, O2: center point of second unit pattern, W1: width of straight portion of first region, W2: width of ridge of second region, P: distance between center points of first unit pattern and second unit pattern, SP: reference position, SU: reference unit pattern, TE: tread edge, X1: first region, X2: second region, X2a: first segment region, X2b: second segment region, X3: third region, θ1: angle of base portion of first region relative to imaginary vertical plane, θ2: angle of base portion of second region relative to imaginary vertical plane

Claims

1. On the outer surface of the tire, on the outer side of the tire side, a first region having an uneven surface formed by arranging convex portions over the entire region; a second region having an uneven surface formed by arranging a plurality of ridges in parallel over the entire area, the second region being arranged adjacent to the first region over the entire periphery thereof; a minimum distance between the tops of the convex portions in the first region is smaller than a minimum distance between the tops of two adjacent ridges in the second region; The second region is a plurality of first segment regions each including a plurality of first ridges arranged in parallel; a plurality of second segment regions each including a plurality of second ridges arranged in parallel; a minimum distance between apexes of two adjacent first ridges of the plurality of first ridges in each of the plurality of first segment regions is smaller than a minimum distance between apexes of two adjacent second ridges of the plurality of second ridges in each of the plurality of second segment regions; The plurality of first segment regions and the plurality of second segment regions are arranged alternately in the tire circumferential direction and the tire radial direction.

2. The tire according to claim 1 , wherein the convex portions in the first region include a unit pattern of a predetermined shape that is repeatedly arranged.

3. The tire according to claim 2 , wherein the unit pattern includes a plurality of extension portions extending in different directions from a relay point in a plan view.

4. When any one of the unit patterns in the first region is a reference unit pattern and any one of the positions of the apex of the reference unit pattern is a reference position, The tire according to claim 2 or 3, wherein a minimum distance from the reference position to a vertex of a unit pattern adjacent to the reference unit pattern is smaller than the minimum distance between vertices of the two adjacent ridges in the second region.

5. 5. The tire according to claim 1, wherein the first ridges of each of the first segment regions in the second region and the second ridges of each of the second segment regions in the second region extend in parallel.

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