Tire

Abstract

To provide a tire in which visibility of an emblem can be improved.SOLUTION: A tire 1 comprises at a tire side part emblems 2 whose vertical directions are specified. The emblems 2 are arranged so that lower sides thereof are directed to outside in a tire radial direction. Further the tire 1 comprises a plurality of emblems 2 and 2 arranged separately in a tire circumferential direction. Each of the plurality of emblems 2 and 2 is arranged so that a lower side thereof is directed to outside in the tire radial direction. The tire 1 comprises, at the tire side part, surface processed areas 3 formed so that a plurality of uneven parts are arranged and smooth areas 4 having smooth surfaces. The whole of the emblems 2 are arranged in the smooth areas 4.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a tire, and more particularly to a tire capable of improving the visibility of a marking. [Background technology]

[0002] Conventionally, marks of tire manufacturers, tire brands, etc. have been affixed to the side portions of tires. Technologies described in Patent Documents 1 and 2 are known as tires having such a configuration. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2023-8359 A [Patent Document 2] Publication No. 60-130107 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, small-diameter tires have been developed to be fitted to vehicles with lowered floors to expand the interior space. The small size of such small-diameter tires poses the challenge of improving the visibility of markings such as side brands. In particular, when such small-diameter tires are fitted to vehicles with covers (so-called "spats" or "skirts") that cover the sides of the wheels in the wheel housings, the visible area of ​​the tire side is very narrow, so there is also the challenge of ensuring the appropriate visibility of the tire markings.

[0005] Therefore, the present invention has been made in consideration of the above, and has an object to provide a tire that can improve the visibility of tire markings. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the tire of the present invention is a tire having a marking on the tire side portion whose up-down direction is defined, and is characterized in that the marking is arranged with its lower side facing outward in the radial direction of the tire. Effect of the Invention

[0007] In the tire according to the present invention, when the tire is mounted on a vehicle having a cover in the wheelhouse that covers the side of the wheel, the visibility of the markings on the tire is improved. Specifically, in a vehicle having the cover, the vertically upper area of ​​the tire side is covered by the cover, and only a part of the area on the road surface side is exposed. In this case, the marking is arranged with its lower side facing outward in the tire radial direction, so that the marking appears without being inverted, which has the advantage of improving the visibility of the marking from outside the vehicle. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a cross-sectional view in the tire meridian direction showing a tire according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a plan view showing a tire side portion of the tire shown in FIG. [Diagram 3] FIG. 3 is an enlarged view showing the markings on the tire side portion shown in FIG. [Figure 4] FIG. 4 is a cross-sectional view of the mark shown in FIG. [Diagram 5] FIG. 5 is an enlarged view showing the surface-treated region of the tire side portion shown in FIG. [Figure 6] FIG. 6 is a cross-sectional view taken along line B of the surface-processed region shown in FIG. [Figure 7] FIG. 7 is a table showing the results of performance tests of the tire according to the embodiment of the present invention. [Figure 8] FIG. 8 is a table showing the results of performance tests of the tire according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The present invention will be described in detail below with reference to the drawings. Note that the present invention is not limited to the embodiments. The components of the embodiments include those that can be substituted and are obvious substitutes while maintaining the identity of the invention. The multiple modified examples described in the embodiments can be arbitrarily combined within the scope of what is obvious to those skilled in the art.

[0010] [tire] 1 is a cross-sectional view in the tire meridian direction showing a tire 1 according to an embodiment of the present invention. The figure shows a cross-sectional view of one side region in the tire radial direction of the tire 1 mounted on a rim 10. In this embodiment, a pneumatic radial tire for passenger cars will be described as an example of a tire.

[0011] In the figure, the tire meridian cross section is defined as a cross section of the tire cut by a plane including the tire rotation axis (not shown). The tire equatorial plane CL is defined as a plane that passes through the midpoint of the tire section width DW defined by JATMA and is perpendicular to the tire rotation axis. The tire width direction is defined as a direction parallel to the tire rotation axis, and the tire radial direction is defined as a direction perpendicular to the tire rotation axis. Point T is the tire ground contact edge, and point Ac is the maximum tire width position.

[0012] The tire 1 has an annular structure centered on the tire rotation axis, and includes a pair of bead cores 11, 11, a pair of bead fillers 12, 12, a carcass layer 13, a belt layer 14, a tread rubber 15, a pair of sidewall rubbers 16, 16, a pair of rim cushion rubbers 17, 17, and an inner liner 18 (see Figure 1).

[0013] The pair of bead cores 11, 11 are formed by winding one or more bead wires made of steel in an annular shape in multiple layers, and are embedded in the bead portions to form the cores of the left and right bead portions. The pair of bead fillers 12, 12 are disposed on the outer periphery of the pair of bead cores 11, 11 in the tire radial direction, respectively, to reinforce the bead portions. The bead filler 12 has a rubber hardness Hs_bf of 55 to 105, a modulus M_bf [MPa] at 100[%] elongation of 2.0 to 13.0, and a loss tangent tanδ_bf of 0.03 to 0.30, and preferably has a rubber hardness Hs_bf of 70 to 100, a modulus M_bf [MPa] at 100[%] elongation of 3.0 to 12.0, and a loss tangent tanδ_bf of 0.05 to 0.25.

[0014] The carcass layer 13 has a single-layer structure consisting of one carcass ply or a multi-layer structure consisting of multiple carcass plies stacked together, and is toroidally stretched between the left and right bead cores 11, 11 to form the tire framework. Both ends of the carcass layer 13 are wound back and secured to the outside in the tire width direction so as to envelop the bead cores 11 and the bead fillers 12. The carcass ply of the carcass layer 13 is formed by covering multiple carcass cords made of inorganic fibers (e.g., steel, carbon fiber, glass fiber) or organic fibers (e.g., aramid, nylon, polyester, rayon, etc.) with coating rubber and rolling them, and has a cord angle (defined as the inclination angle of the carcass cords in the longitudinal direction with respect to the tire circumferential direction) of 80 degrees or more and 100 degrees or less.

[0015] The belt layer 14 is formed by laminating a plurality of belt plies 141 to 144, and is disposed by being wrapped around the outer periphery of the carcass layer 13. In the configuration of FIG. 1, the belt plies 141 to 144 are each composed of a pair of cross belts 141, 142, a belt cover 143, and a pair of belt edge covers 144, 144.

[0016] The pair of cross belts 141, 142 are formed by covering a plurality of belt cords made of steel or organic fiber material with coating rubber and rolling them, and have a cord angle (defined as the inclination angle of the belt cords in the longitudinal direction with respect to the tire circumferential direction) of 15 degrees or more and 55 degrees or less in absolute value. The pair of cross belts 141, 142 have cord angles of opposite signs to each other, and are layered with the longitudinal directions of the belt cords crossing each other (so-called cross-ply structure). The pair of cross belts 141, 142 are layered and arranged on the outer side of the carcass layer 13 in the tire radial direction.

[0017] The belt cover 143 and the pair of belt edge covers 144, 144 are configured by covering a belt cover cord made of steel or organic fiber material with coating rubber, and have a cord angle of 0 degrees or more and 10 degrees or less in absolute value. The belt cover 143 and the belt edge cover 144 are, for example, strip materials configured by covering one or more belt cover cords with coating rubber, and are configured by winding the strip materials spirally multiple times in the tire circumferential direction around the outer circumferential surfaces of the cross belts 141, 142. The belt cover 143 is disposed to cover the entire area of ​​the cross belts 141, 142, and the pair of belt edge covers 144, 144 are disposed to cover the left and right edge portions of the cross belts 141, 142 from the outside in the tire radial direction.

[0018] The tread rubber 15 is disposed on the outer periphery in the tire radial direction of the carcass layer 13 and the belt layer 14 to form a tread portion of the tire 1. The tread rubber 15 also includes a cap tread 151 and an under tread 152.

[0019] The cap tread 151 is made of a rubber material having excellent ground contact characteristics and weather resistance, and is exposed to the tread surface over the entire tire ground contact area to form the outer surface of the tread portion. The cap tread 151 has a rubber hardness Hs_cap of 50 to 80, a modulus M_cap [MPa] at 100[%] elongation of 1.0 to 4.0, and a loss tangent tanδ_cap of 0.03 to 0.36, and preferably has a rubber hardness Hs_cap of 58 to 76, a modulus M_cap [MPa] at 100[%] elongation of 1.5 to 3.2, and a loss tangent tanδ_cap of 0.06 to 0.29.

[0020] Rubber hardness Hs is measured at a temperature of 20°C in accordance with JIS K6253.

[0021] The modulus (breaking strength) is measured by a tensile test at a temperature of 20°C using a dumbbell-shaped test piece in accordance with JIS K6251 (using No. 3 dumbbell).

[0022] The loss tangent tan δ is measured using a viscoelasticity spectrometer manufactured by Toyo Seiki Seisakusho Co., Ltd. under the conditions of a temperature of 60°C, a shear strain of 10%, an amplitude of ±0.5%, and a frequency of 20 Hz.

[0023] The undertread 152 is made of a rubber material having excellent heat resistance, and is sandwiched between the cap tread 151 and the belt layer 14 to form a base portion of the tread rubber 15. The undertread 152 has a rubber hardness Hs_ut of 47 to 80, a modulus M_ut [MPa] at 100[%] elongation of 1.4 to 5.5, and a loss tangent tanδ_ut of 0.02 to 0.23, and preferably has a rubber hardness Hs_ut of 50 to 65, a modulus M_ut [MPa] at 100[%] elongation of 1.7 to 3.5, and a loss tangent tanδ_ut of 0.03 to 0.10.

[0024] Moreover, the difference in rubber hardness Hs_cap-Hs_ut is in the range of 3 to 20, and preferably in the range of 5 to 15. The difference in modulus M_cap-M_ut [MPa] is in the range of 0 to 1.4, and preferably in the range of 0.1 to 1.0. The difference in loss tangent tanδ_cap-tanδ_ut is in the range of 0 to 0.22, and preferably in the range of 0.02 to 0.16.

[0025] A pair of sidewall rubbers 16, 16 are disposed on the outer side of the carcass layer 13 in the tire width direction to form left and right sidewall portions. In the configuration of FIG. 1, the outer end of the sidewall rubber 16 in the tire radial direction is disposed in the lower layer of the tread rubber 15 and sandwiched between the end of the belt layer 14 and the carcass layer 13. However, this is not limited thereto, and the outer end of the sidewall rubber 16 in the tire radial direction may be disposed in the outer layer of the tread rubber 15 and exposed to the buttress portion of the tire (not shown). In this case, a belt cushion (not shown) is sandwiched between the end of the belt layer 14 and the carcass layer 13.

[0026] In addition, the sidewall rubber 16 has a rubber hardness Hs_sw of 48 to 65, a modulus M_sw [MPa] at 100% elongation of 1.0 to 2.4, and a loss tangent tanδ_sw of 0.02 to 0.22, and preferably has a rubber hardness Hs_sw of 50 to 59, a modulus M_sw [MPa] at 100% elongation of 1.2 to 2.2, and a loss tangent tanδ_sw of 0.04 to 0.20.

[0027] The pair of rim cushion rubbers 17, 17 extend from the tire radially inner side to the tire widthwise outer side of the turn-up parts of the left and right bead cores 11, 11 and the carcass layer 13 to form the rim fitting surface of the bead part. In the configuration of FIG. 1, the tire radially outer end of the rim cushion rubber 17 is inserted into the lower layer of the sidewall rubber 16 and is sandwiched between the sidewall rubber 16 and the carcass layer 13. The rim cushion rubber 17 has a rubber hardness Hs_rc of 60 to 80, a modulus M_rc [MPa] at 100[%] elongation of 2.0 to 7.0, and a loss tangent tanδ_rc of 0.09 to 0.35, and preferably has a rubber hardness Hs_rc of 65 to 75, a modulus M_rc [MPa] at 100[%] elongation of 3.0 to 6.0, and a loss tangent tanδ_rc of 0.11 to 0.30.

[0028] The inner liner 18 is an air permeation prevention layer disposed on the tire cavity surface and covering the carcass layer 13, suppressing oxidation due to exposure of the carcass layer 13 and preventing leakage of air filled in the tire. The inner liner 18 may be composed of, for example, a rubber composition containing butyl rubber as a main component, or may be composed of a thermoplastic resin or a thermoplastic elastomer composition in which an elastomer component is blended into a thermoplastic resin.

[0029] In FIG. 1, the tire outer diameter OD [mm] is in the range of 200≦OD≦660, and preferably in the range of 250 [mm]≦OD≦580 [mm]. By applying this small-diameter tire, the effect of improving the load performance described below can be significantly obtained. In addition, the tire total width SW [mm] is in the range of 100≦SW≦400, and preferably in the range of 105 [mm]≦SW≦340 [mm]. With such a small-diameter tire 1, for example, the floor surface of a small vehicle can be lowered to expand the interior space. In addition, by providing such a small-diameter tire with a mark 2 described below, the visibility of the mark 2 is effectively improved.

[0030] The outer diameter OD of a tire is measured with the tire mounted on a specified rim, pressurized to a specified internal pressure, and under no load.

[0031] The total tire width SW is measured as the straight-line distance between the sidewalls (including all parts such as patterns and lettering on the side of the tire) when the tire is mounted on a specified rim, pressurized to the specified internal pressure, and unloaded.

[0032] The specified rim refers to the "applicable rim" specified by JATMA, the "design rim" specified by TRA, or the "measuring rim" specified by ETRTO. The specified internal pressure refers to the "maximum air pressure" specified by JATMA, the maximum value of the "tire load limits at various cold inflation pressures" specified by TRA, or the "inflation pressures" specified by ETRTO. The specified load refers to the "maximum load capacity" specified by JATMA, the maximum value of the "tire load limits at various cold inflation pressures" specified by TRA, or the "load capacity" specified by ETRTO. However, in JATMA, for passenger car tires, the specified internal pressure is 180 kPa, and the specified load is 88% of the maximum load capacity.

[0033] Further, the tire total width SW [mm] and the tire outer diameter OD [mm] are in the range of 0.23≦SW / OD≦0.84, and preferably in the range of 0.25≦SW / OD≦0.81.

[0034] It is also preferable that the tire outer diameter OD and the tire total width SW satisfy the following formula (1), where A1min=-0.0017, A2min=0.9, A3min=130, A1max=-0.0019, A2max=1.4, A3max=400, and preferably A1min=-0.0018, A2min=0.9, A3min=160, A1max=-0.0024, A2max=1.6, A3max=362.

[0035]

number

[0036] The tire 1 is assumed to use a rim 10 having a rim diameter of 5 inches to 16 inches (i.e., 125 mm to 407 mm). The rim diameter RD [mm] is in the range of 0.50≦RD / OD≦0.74 with respect to the tire outer diameter OD [mm], and preferably in the range of 0.52≦RD / OD≦0.71. The lower limit ensures that the rim diameter RD is secured, and in particular that the installation space for the in-wheel motor can be secured. The upper limit ensures that the internal volume V of the tire, which will be described later, is secured, and the load capacity of the tire is secured.

[0037] The inner diameter of the tire is equal to the rim diameter RD of the rim 10.

[0038] The tire 1 is expected to be used at an internal pressure higher than the standard, specifically, at an internal pressure of 350 kPa to 1200 kPa, and preferably 500 kPa to 1000 kPa. The lower limit suppresses deformation of the tire side when loaded, improving the visibility of the marking 2, which will be described later, and the upper limit ensures safety during the internal pressure filling operation.

[0039] The tire 1 is assumed to be mounted on a vehicle that travels at a low speed, such as a small shuttle bus. The maximum speed of the vehicle is 100 [km / h] or less, preferably 80 [km / h] or less, and more preferably 60 [km / h] or less. The tire 1 is assumed to be mounted on a vehicle with 6 to 12 wheels. This allows the tire to exhibit its load capacity appropriately.

[0040] The aspect ratio of the tire, that is, the ratio SH / DW of the tire section height SH [mm] to the tire section width DW [mm], is in the range of 0.16≦SH / DW≦0.85, and preferably in the range of 0.19≦SH / DW≦0.82.

[0041] The tire section height SH is half the distance between the tire outer diameter and the rim diameter, and is measured with the tire mounted on a specified rim, with a specified internal pressure applied, and in an unloaded state.

[0042] The tire section width DW is measured as the straight-line distance between the sidewalls (excluding any patterns or lettering on the side of the tire) when the tire is mounted on a specified rim, pressurized to the specified internal pressure, and unloaded.

[0043] Further, the tire contact width TW is in the range of 0.50≦TW / SW≦0.85 relative to the tire total width SW, and preferably in the range of 0.60≦TW / SW≦0.80.

[0044] The tire contact width TW is measured as the maximum straight-line distance in the axial direction of the tire at the contact surface between the tire and a flat plate when the tire is mounted on a specified rim, pressurized to a specified internal pressure, and placed perpendicular to a flat plate in a stationary state and subjected to a load corresponding to a specified load.

[0045] Furthermore, the tire internal volume V [m^3] is in the range of 4.0≦(V / OD)×10^6≦60, preferably 6.0≦(V / OD)×10^6≦50, relative to the tire outer diameter OD [mm]. This optimizes the tire internal volume V. Specifically, the lower limit ensures the tire internal volume and the tire's load capacity. In particular, small-diameter tires are expected to be used under high internal pressure and high load, so it is preferable that the tire internal volume V is sufficiently ensured. The upper limit prevents the tire from becoming too large due to the tire internal volume V being too large.

[0046] Further, the tire internal volume V [m^3] is in the range of 0.5≦V×RD≦17 relative to the rim diameter RD [mm], and preferably in the range of 1.0≦V×RD≦15.

[0047] [Carcass layer] 1, as described above, the carcass layer 13 is made of a single carcass ply and is disposed in a toroidal shape spanning between the left and right bead cores 11, 11. In addition, both ends of the carcass layer 13 are wrapped back and secured to the outside in the tire width direction so as to encase the bead cores 11 and the bead fillers 12.

[0048] In addition, the strength Tcs [N / 50mm] per 50 [mm] of the width of the carcass ply constituting the carcass layer 13 is in the range of 17≦Tcs / OD≦120 with respect to the tire outer diameter OD [mm], and preferably in the range of 20≦Tcs / OD≦120. In addition, the strength Tcs [N / 50mm] of the carcass layer 13 is in the range of 30≦Tcs / SW≦260 with respect to the tire total width SW [mm], and preferably in the range of 35≦Tcs / SW≦220. In this configuration, the load capacity of the carcass layer 13 is appropriately ensured in a small diameter tire, so that the tire has both durability and low rolling resistance. Specifically, the above lower limit suppresses tire deformation during use under high load, and ensures durability of the tire. In addition, use at high internal pressure is possible, and the rolling resistance of the tire is reduced. In particular, in small-diameter tires, which are expected to be used under high internal pressure and high load, the tire durability and rolling resistance reduction effects described above are significantly achieved. The above upper limit suppresses the deterioration of rolling resistance caused by an increase in the mass of the carcass layer.

[0049] The strength Tcs [N / 50mm] of the carcass ply is calculated as follows. That is, the carcass ply that is stretched across the left and right bead cores 11, 11 and extends over the entire inner circumference of the tire is defined as the effective carcass ply. The strength Tcs [N / 50mm] of the carcass ply is calculated as the product of the strength [N / cord] of each carcass cord constituting the effective carcass ply and the number of carcass cords [cords / 50mm] per width of 50 [mm] on the entire circumference of the tire and on the tire equatorial plane CL. The strength of the carcass cord is measured by a tensile test at a temperature of 20 [°C] in accordance with JIS K1017. For example, in a configuration in which one carcass cord is formed by twisting a plurality of wires, the strength of one twisted carcass cord is measured, and the strength Tcs of the carcass layer 13 is calculated. In addition, in a configuration in which the carcass layer 13 has a multi-layer structure (not shown) formed by laminating a plurality of effective carcass plies, the above-mentioned strength Tcs is defined for each of the plurality of effective carcass plies.

[0050] For example, in the configuration of Fig. 1, the carcass layer 13 has a single layer structure made of a single carcass ply (reference numerals omitted in the figure), and the carcass ply is configured by arranging carcass cords made of steel covered with a coating rubber at a cord angle of 80 degrees or more and 100 degrees or less with respect to the tire circumferential direction (not shown). The carcass cords made of steel have a cord diameter φcs [mm] in the range of 0.15 ≦ φcs ≦ 1.10, preferably 0.25 ≦ φcs ≦ 0.60, and an end count Ecs [pieces / 50mm] in the range of 25 ≦ Ecs ≦ 80, preferably 50 ≦ Ecs ≦ 80, thereby realizing the strength Tcs [N / 50mm] of the carcass layer 13 described above. The carcass cords are formed by twisting a plurality of wires together, and the wire diameter φcss [mm] is in the range of 0.12 ≦ φcss ≦ 0.24, preferably 0.14 ≦ φcss ≦ 0.22. It is more preferable that the wire diameter φcss [mm] of the carcass cord is in the range of 0.30≦φcss / φcs≦0.90 with respect to the cord diameter φcs [mm] of the carcass cord. The carcass cord may be made of inorganic fibers other than steel (e.g., carbon fiber, glass fiber, etc.).

[0051] Furthermore, without being limited to the above, the carcass ply may be constituted by a carcass cord made of an organic fiber material (such as aramid, nylon, polyester, rayon, etc.) covered with a coating rubber. In this case, the carcass cord made of the organic fiber material has a cord diameter φcs [mm] in the range of 0.60≦φcs≦0.90 and an end count Ecs [pieces / 50 mm] in the range of 40≦Ecs≦70, thereby realizing the strength Tcs [N / 50 mm] of the carcass layer 13 described above. In addition, carcass cords made of organic fiber materials such as high-strength nylon, aramid, and hybrids can be adopted within the scope of obviousness to those skilled in the art.

[0052] Furthermore, the carcass layer 13 may have a multi-layer structure (not shown) formed by laminating a plurality of carcass plies, for example, two carcass plies, which can effectively increase the load carrying capacity of the tire.

[0053] Moreover, the total strength TTcs [N] of the carcass layer 13 is in the range of 300≦TTcs / OD≦3500, and preferably in the range of 400≦TTcs / OD≦3000, relative to the tire outer diameter OD [mm]. This ensures the overall load capacity of the carcass layer 13.

[0054] The total strength TTcs [N] of the carcass layer 13 is calculated as the product of the strength per carcass cord [N / cord] and the total number of carcass cords in the entire carcass layer 13. Therefore, the total strength TTcs [N] of the carcass layer 13 increases with an increase in the strength Tcs [N / 50mm] of each carcass ply, the number of carcass plies laminated, the circumferential length of the carcass ply, etc.

[0055] It is also preferable that the total strength TTcs [N] of the carcass layer 13 satisfies the following formula (4) with respect to the tire outer diameter OD [mm] and the distance SWD [mm], where Dmin=2.2, Dmax=40, preferably Dmin=4.3, Dmax=40, more preferably Dmin=6.5, Dmax=40, and even more preferably Dmin=8.7, Dmax=40. Furthermore, it is preferable that Dmin=0.02×P, where P [kPa] is the specified tire internal pressure.

[0056]

number

[0057] [Tire side] Fig. 2 is a plan view showing a tire side portion of the tire shown in Fig. 1. This figure shows a plan view of the tire 1 as seen from the axial direction.

[0058] As shown in FIG. 2, the tire 1 includes a mark 2, a surface-treated region 3, and a smooth region 4 on the tire side.

[0059] The mark 2 is composed of letters, figures, symbols, or a combination of these, and includes a trademark that functions as an identification mark particularly indicating the tire manufacturer, tire brand, etc. A plurality of marks 2 are arranged spaced apart in the tire circumferential direction. For example, in the configuration of FIG. 2, a mark consisting of a combination of the character string "YOKOHAMA" indicating the tire manufacturer and a logo with a stylized "Y", which is the initial letter of the name, is stamped on the surface of the tire side. A pair of marks 2, 2 are arranged in opposing positions in the tire circumferential direction. The mark 2 will be explained in detail later.

[0060] The surface-treated area 3 is a surface-treated area formed of an array of multiple concave-convex portions, and is formed on the surface of the tire side portion. This surface-treated area 3 has a function of enhancing the design of the tire side portion by being composed of multiple fine concave-convex portions densely arranged. For example, in the configuration of FIG. 2, the surface-treated area 3 has an elongated structure extending in the tire circumferential direction, and also has a wavy shape with amplitude in the tire radial direction. In addition, a pair of surface-treated areas 3, 3 is disposed in the area between a pair of marks 2, 2. This enhances the visibility of the mark 2. The surface-treated area 3 will be described in detail later.

[0061] The smooth region 4 is a region having a smooth surface, and is formed on the surface of the tire side portion. Specifically, the smooth region 4 is defined as a region having a continuous smooth surface without grooves or uneven portions and surrounding the above-mentioned mark 2. For example, in the configuration of FIG. 2, a pair of smooth regions 4, 4 are arranged surrounding each of the pair of marks 2, 2. In other words, each of the pair of marks 2, 2 is arranged within the pair of smooth regions 4, 4. By arranging the smooth region 4 surrounding the mark 2, the visibility of the mark 2 is improved compared to a configuration (not shown) in which the mark 2 is arranged within the above-mentioned surface-treated region 3.

[0062] In the configuration of FIG. 2, a unit U consisting of the mark 2, the surface-treated region 3, and the smooth region 4 is formed at least on the tire side portion on the outer side in the vehicle width direction (see FIG. 1) when the tire is mounted on the vehicle. A pair of units U, U are arranged in series in the tire circumferential direction to form an annular structure as a whole. As shown in FIG. 2, a pair of units U, U are arranged on the outer side in the tire radial direction than the tire maximum width position Ac (see FIG. 1). More specifically, a pair of thin ribs 5A, 5B extending in the tire circumferential direction are arranged in the region from the tire ground contact edge T (see FIG. 1) to the tire maximum width position Ac, and a pair of units U, U consisting of the mark 2, the surface-treated region 3, and the smooth region 4 are arranged in the annular region partitioned by the pair of thin ribs 5A, 5B. This enhances the design of the tire side portion. However, this is not limited to this, and the unit U consisting of the mark 2, the surface-treated region 3, and the smooth region 4 may be arranged on the inner side in the tire radial direction than the tire maximum width position Ac (not shown).

[0063] The tire maximum width position Ac is defined as the maximum width position of the tire section width DW (see FIG. 1).

[0064] In addition, the pair of thin ribs 5A, 5B described above have a width of 0.4 mm or more and 0.8 mm or less and a height of 0.1 mm or more and 1.0 mm or less, and function as an exhaust path for residual air during tire vulcanization molding, thereby suppressing the occurrence of vulcanization defects, particularly in the smooth region 4 surrounding the mark 2.

[0065] [Mark] Fig. 3 is an enlarged view showing the mark 2 on the tire side portion shown in Fig. 2. The figure shows a part of the mark 2. Fig. 4 is a cross-sectional view taken along line A of the mark 2 shown in Fig. 3.

[0066] In Fig. 2, mark 2 has a vertical direction. In the configuration in Fig. 2, mark 2 is composed of a combination of the "Y" logo and the character string "YOKOHAMA," so its vertical direction is defined.

[0067] As shown in Fig. 2, the mark 2 is arranged with its lower side facing outward in the tire radial direction. For example, in the configuration of Fig. 2, the entire mark 2 is curved along the curvature of the tire, so that each of the elements 21A-21E (see Fig. 3) constituting the mark 2 is arranged with its up-down direction aligned parallel to the tire radial direction. Each of the multiple marks 2, 2 arranged at a predetermined interval in the tire circumferential direction is arranged with its upper side facing inward in the tire radial direction and its lower side facing outward in the tire radial direction.

[0068] In this configuration, when the tire 1 is mounted on a vehicle having a cover 20 (see FIG. 2; so-called "spats" or "skirt") in the wheel housing that covers the side of the wheel, the visibility of the mark 2 of the tire 1 is improved. Specifically, in a vehicle having the cover 20, the vertically upper area of ​​the tire side is covered by the cover 20, and only a part of the area on the road surface side (not shown; lower in the figure) is exposed. At this time, the mark 2 is arranged with its lower side facing outward in the tire radial direction, so that the mark 2 appears without being inverted, improving the visibility of the mark 2 from outside the vehicle. Also, by arranging multiple marks 2, 2 in the tire circumferential direction, the mark 2 has more opportunities to be exposed, improving the visibility of the mark 2.

[0069] 2, the mark 2 is disposed so as to intersect with the tire maximum width position Ac. In this configuration, the mark 2 is positioned at the outermost position in the tire width direction, and therefore the visibility of the mark 2 is improved. However, this is not limiting, and the entire mark 2 may be disposed outward in the tire radial direction from the tire maximum width position Ac (see FIG. 1) (not shown). As a result, even if the bottom of the cover 20 is long, the entire mark 2 is appropriately exposed near the road surface, and the visibility of the mark 2 is improved.

[0070] Note that the present invention is not limited to the above, and the entire mark 2 may be disposed radially inward of the tire maximum width position Ac, or the mark 2 may be disposed so as to intersect with the tire maximum width position Ac (not shown).

[0071] In the configuration of FIG. 2, the entire mark 2 is disposed in the smooth region 4 as described above. Therefore, the mark 2 is surrounded by the smooth region 4 and does not overlap with the surface-treated region 3. For example, in the configuration of FIG. 2, a pair of marks 2, 2 surrounded by the smooth region 4 and a pair of surface-treated regions are alternately arranged in the tire circumferential direction. In addition, a pair of units U, U consisting of the mark 2, the surface-treated region 3 and the smooth region 4 are disposed in an annular region partitioned by a pair of thin ribs 5A, 5B. This enhances the design of the tire side portion.

[0072] 2, the extension range φ2 [deg] of the mark 2 in the tire circumferential direction is in the range of 25≦φ2≦85, and preferably in the range of 35≦φ2≦75. This ensures the visibility of the mark 2.

[0073] 3, the elements 21A to 21E constituting the mark 2 are spaced apart from one another. In this case, the minimum distance I [mm] between adjacent elements 21A, 21B; 21B, 21C; 21C, 21D; 21D, and 21E is in the range of 0.001≦I / OD≦0.015 with respect to the tire outer diameter OD [mm], and preferably in the range of 0.003≦I / OD≦0.013. This improves the visibility of the mark 2.

[0074] 3, the radial height H2 [mm] of the elements 21A to 21E constituting the mark 2 is in the range of 0.010≦H2 / OD≦0.070 with respect to the tire outer diameter OD [mm], and preferably in the range of 0.020≦H2 / OD≦0.060. The circumferential width W2 [mm] of the elements 21A to 21E constituting the mark 2 is in the range of 0.010≦W2 / OD≦0.100 with respect to the tire outer diameter OD [mm], and preferably in the range of 0.020≦W2 / OD≦0.090. The thickness T2 [mm] of the elements 21B to 21E, which are characters constituting the mark 2, is in the range of 0.001≦T2 / OD≦0.040 with respect to the tire outer diameter OD [mm], and preferably in the range of 0.005≦T2 / OD≦0.030. These improve the visibility of the mark 2.

[0075] The radial height H2 of the elements 21A-21E is measured as the maximum extension length of the elements 21A-21E in the tire radial direction. Similarly, the circumferential width W2 of the elements 21A-21E is measured as the maximum extension length of the elements 21A-21E in the tire circumferential direction. Furthermore, the thickness T2 of the elements 21B-21E, which are characters, is measured as the maximum thickness of the lines representing the characters.

[0076] As shown in FIG. 2, the mark 2 is disposed between a pair of fine ribs 5A and 5B extending in the tire circumferential direction. This reduces the amount of residual air in the region surrounding the mark 2, particularly in the smooth region 4, during tire vulcanization, thereby reducing the occurrence of vulcanization defects in the tire 1. In FIG. 3, the radial height H2 [mm] of the elements 21A to 21E constituting the mark 2 is in the range of 0.30≦H2 / H4≦0.70 with respect to the arrangement interval H4 [mm] of the fine ribs 5A and 5B in the tire radial direction, and preferably in the range of 0.40≦H2 / H4≦0.80. In the configuration of FIG. 3, the mark 2 is spaced apart from the pair of fine ribs 5A and 5B. This improves the visibility of the mark 2.

[0077] 2, as shown in Fig. 3 and Fig. 4, some of the elements constituting the mark 2 (specifically, elements 21B to 21E which are characters) have a surface-processed portion formed by arranging a plurality of concave-convex portions 211, 212. Examples of such surface-processed portions include a serration-processed portion formed by arranging a plurality of fine grooves or fine ribs in parallel, and an uneven portion formed by arranging a plurality of concave or convex portions.

[0078] 3 and 4, for example, the elements 21B-21E of the mark 2 are stamps formed in the smooth region, and have a structure that is concave overall with respect to the plane of the smooth region 4. Furthermore, the elements 21B-21E have a plurality of fine grooves 211 and fine ribs 212 arranged in parallel on their bottom surfaces. This forms the elements 21B-21E with a striped surface finish.

[0079] 4, the sidewall angle θ21 [deg] of the uneven portions 211, 212 in the surface-processed portion of the elements 21B to 21E of the mark 2 is in the range of 10≦θ21≦20, preferably in the range of 12≦θ21≦18. The pitch length P21 [mm] of the uneven portions 211, 212 is in the range of 0.5≦P21≦1.5, preferably in the range of 0.7≦P21≦1.3. The height difference H21 [mm] of the uneven portions 211, 212 is in the range of 0.3≦H21≦1.0, preferably in the range of 0.4≦H21≦0.8. Furthermore, the step H21' [mm] forming the contour line of the elements 21B to 21E is in the range of 1.20≦H21' / H21≦2.50, and preferably in the range of 1.50≦H21' / H21≦2.30, relative to the height difference H21 [mm] of the uneven parts 211, 212. These improve the visibility of the mark 2.

[0080] The sidewall angle θ21 [deg] of the uneven portions 211, 212 is measured as the angle that an imaginary straight line connecting the top edge portion and the bottom raised portion of the uneven portions 211, 212 makes with respect to a direction perpendicular to the side profile of the tire (not shown; in FIG. 4, the surface of the smooth region 4) in a cross-sectional view perpendicular to the longitudinal direction of the uneven portions 211, 212 (see FIG. 4).

[0081] The height difference H21 of the uneven portions 211, 212 is measured as the maximum height difference between the maximum depth position and maximum height position of the uneven portions 211, 212 (in FIG. 4, the height difference between the maximum depth position of the fine groove 211 and the maximum height position of the fine rib 212).

[0082] The step H21' of the uneven portions 211, 212 is measured as the maximum step between the maximum depth position of the uneven portion (fine groove 211 in Figure 4) that forms the contour line of elements 21B to 21E of the mark 2 and the surface of the area surrounding elements 21B to 21E of the mark 2 (the surface of smooth area 4 in Figure 4).

[0083] 3 and 4, the elements 21B-21E of the mark 2 have a structure that is concave as a whole with respect to the plane of the smooth region 4 as described above. However, this is not limited thereto, and the elements 21B-21E of the mark 2 may have a structure that is convex as a whole with respect to the plane of the smooth region 4 (not shown). In this case, it is preferable that the amount of convexity of the elements 21B-21E with respect to the plane of the smooth region 4 is 0.3 mm or more and 1.0 mm or less. This makes it possible to reduce the aerodynamic effect of the mark 2 while ensuring the visibility of the mark 2.

[0084] [Surface processing area] Fig. 5 is an enlarged view showing the surface-treated region 3 of the tire side portion shown in Fig. 2. The figure shows a part of the surface-treated region 3. Fig. 6 is a cross-sectional view taken along line B showing the surface-treated region 3 shown in Fig. 5.

[0085] In Fig. 2, the surface-processed region 3 is an area formed by arranging a plurality of concave and convex portions 311, 312, and its boundary is defined by a virtual line (not shown) surrounding a group of closely-arranged concave and convex portions 311, 312. Examples of such a surface-processed region 3 include a serration-processed region formed by arranging a plurality of fine grooves or fine ribs in parallel, and an uneven-processed region formed by arranging a plurality of concave or convex portions. Such a surface-processed region 3 improves the design of the tire side portion.

[0086] For example, in the configuration of Fig. 2, as shown in Figs. 5 and 6, the surface-processed region 3 has a structure that is concave with respect to the plane of the smooth region 4 (see Fig. 2). The surface-processed region 3 also has a plurality of fine grooves 311 and fine ribs 312 arranged in parallel. This forms the surface-processed region 3 that has been subjected to a striped surface processing. The boundary of the surface-processed region consisting of the plurality of fine grooves 311 and fine ribs 312 is defined by a virtual line (not shown) that connects the ends of adjacent fine grooves 311 and fine ribs 312.

[0087] 2, as described above, the pair of marks 2, 2 and the pair of surface-treated regions are alternately arranged in the tire circumferential direction, and the mark 2 and the surface-treated region 3 are arranged in an annular region defined by a pair of fine ribs 5A, 5B. Therefore, the surface-treated region 3 is located at the same position in the tire radial direction as the mark 2, that is, located at a position overlapping the mark 2 when viewed in the tire circumferential direction. This forms an annular design consisting of the mark 2 and the surface-treated region 3.

[0088] 2, the extension range φ3 [deg] of the surface treated region 3 in the tire circumferential direction is in the range of 1.00≦φ3 / φ2≦4.00 relative to the extension range φ2 [deg] of the marking 2 in the tire circumferential direction, and preferably in the range of 1.50≦φ3 / φ2≦3.50. This balances the extension range φ3 [deg] of the surface treated region 3 with the extension range φ2 [deg] of the marking 2, improving the design of the tire side portion.

[0089] 2, the surface-treated region 3 has a wavy shape with amplitude in the tire radial direction, and one continuous surface-treated region 3 is disposed between adjacent marks 2, 2. This improves the visibility of the mark 2. However, this is not limited to the above, and the surface-treated region 3 may have a band-like shape with no amplitude, or multiple discontinuous surface-treated regions 3 may be disposed between adjacent marks 2, 2 (not shown).

[0090] 5, the pitch length P3 [deg] of the wavy shape of the surface-treated region 3 is in the range of 5≦P3≦30, and preferably in the range of 10≦P3≦20. The radial height H3 [mm] of the surface-treated region 3 is in the range of 0.010≦H3 / OD≦0.070 with respect to the tire outer diameter OD [mm], and preferably in the range of 0.02≦H3 / OD≦0.06. The width W3 [mm] of the surface-treated region 3 having the wavy shape is in the range of 0.010≦W3 / OD≦0.030 with respect to the tire outer diameter OD [mm], and preferably in the range of 0.015≦W3 / OD≦0.025.

[0091] The radial height H3 of the surface-processed region 3 is measured as the maximum extension length of the surface-processed region 3 in the tire radial direction. Also, the width W3 of the surface-processed region 3 having a wavy shape is measured as the maximum width of the lines constituting the wavy shape.

[0092] As shown in Fig. 2, the surface-treated region 3 is disposed between a pair of fine ribs 5A, 5B extending in the tire circumferential direction. In Fig. 5, the radial height H3 [mm] of the surface-treated region 3 is in the range of 0.45 ≦ H3 / H4 ≦ 0.95 with respect to the arrangement interval H4 [mm] of the fine ribs 5A, 5B in the tire radial direction, and preferably in the range of 0.50 ≦ H3 / H4 ≦ 0.90. In the configuration of Fig. 5, the surface-treated region 3 is spaced from the pair of fine ribs 5A, 5B. This improves the visibility of the surface-treated region 3.

[0093] In addition, in the configuration of FIG. 5, polygonal smooth portions 6A, 6B are formed in the region between the surface-processed region 3 and the pair of fine ribs 5A, 5B. These smooth portions 6A, 6B do not have grooves or uneven portions. For example, in the configuration of FIG. 5, the surface-processed region 3 has a wavy shape bent in a step shape, and in the region between the surface-processed region 3 and the pair of fine ribs 5A, 5B, a plurality of hexagonal and wide smooth portions 6A and rectangular and narrow smooth portions 6B are alternately arranged in the tire circumferential direction. These smooth portions 6A, 6B fill the gap between the surface-processed region 3 and the pair of fine ribs 5A, 5B, thereby improving the visibility of the surface-processed region 3. In addition, the angle D6 [deg] (dimension symbol omitted in the figure) of the corners of the hexagonal smooth portion 6A that are in contact with the surface-processed region 3 on two sides is in the range of 0.1≦D6 / OD≦0.3 with respect to the tire outer diameter OD [mm].

[0094] 6, the sidewall angle θ31 [deg] of the uneven parts 311, 312 constituting the surface-processed region 3 has a relationship of 0<θ31-θ21 with respect to the sidewall angle θ21 [deg] of the multiple uneven parts 211, 212 (see FIG. 4) in the surface-processed part of the elements 21B-21E (see FIG. 3) of the mark 2, and preferably has a relationship of 5≦θ31-θ21≦25. This improves the visibility of the elements 21B-21E of the mark 2 relative to the surface-processed region 3. The sidewall angle θ31 [deg] of the uneven parts 311, 312 constituting the surface-processed region 3 is in the range of 25≦θ31≦35, and preferably in the range of 27≦θ31≦33.

[0095] The sidewall angle θ31 [deg] of the uneven portions 311, 312 is measured as the angle between an imaginary straight line connecting the top edge portion and the bottom raised portion of the uneven portions 311, 312 in a cross-sectional view perpendicular to the longitudinal direction of the uneven portions 311, 312 (see Figure 6) and a direction perpendicular to the side profile of the tire (not shown; in Figure 6, the surface of the smooth portion 6A).

[0096] 6, the pitch length P31 [mm] of the uneven parts 311, 312 constituting the surface-processed region 3 is in the range of 0.70≦P31 / P21≦1.30, preferably 0.80≦P31 / P21≦1.20, relative to the pitch length P21 of the uneven parts 211, 212 (see FIG. 4) in the surface-processed part of the elements 21B-21E (see FIG. 3) of the mark 2. This improves the visibility of the elements 21B-21E of the mark 2 relative to the surface-processed region 3. The pitch length P31 [mm] of the uneven parts 311, 312 constituting the surface-processed region 3 is in the range of 0.5≦P31≦1.5, preferably 0.7≦P31≦1.3.

[0097] 6, the height difference H31 [mm] of the uneven parts 311, 312 constituting the surface-processed region 3 is in the range of 0.10≦H31 / H21<1.00, preferably 0.30≦H31 / H21≦0.90, with respect to the height difference H21 [mm] of the uneven parts 211, 212 (see FIG. 4) in the surface-processed part of the elements 21B-21E (see FIG. 3) of the mark 2. This improves the visibility of the elements 21B-21E of the mark 2 relative to the surface-processed region 3. The height difference H31 [mm] of the uneven parts 311, 312 constituting the surface-processed region 3 is in the range of 0.1≦H31≦0.8, preferably 0.2≦H31≦0.6.

[0098] The height difference H31 of the uneven portions 311, 312 is measured as the maximum height difference between the maximum depth position and maximum height position of the uneven portions 311, 312 (in FIG. 6, the height difference between the maximum depth position of the fine groove 311 and the maximum height position of the fine rib 312).

[0099] 6, the step H31' [mm] forming the boundary line of the surface-processed region 3 is approximately equal to the height difference H31 [mm] between the uneven portions 311, 312. In contrast, as described above, the step H21' [mm] forming the contour line of the elements 21B to 21E of the mark 2 is set to be larger than the height difference H21 [mm] between the uneven portions 211, 212 of the elements 21B to 21E. This improves the visibility of the elements 21B to 21E of the mark 2 relative to the surface-processed region 3.

[0100] The step H31' of the uneven portions 311, 312 is measured as the maximum step between the maximum depth position of the uneven portion (narrow groove 311 in Figure 6) that forms the boundary line of the surface-processed region 3 and the surface of the region surrounding the surface-processed region 3 (the surface of the smooth portion 6A in Figure 6).

[0101] [effect] As described above, [1] the tire 1 has the mark 2 with a regulated up-down direction on the tire side portion (see FIG. 2). The mark 2 is arranged with the lower side facing outward in the tire radial direction.

[0102] In this configuration, when the tire 1 is mounted on a vehicle having a cover 20 (see FIG. 2) in a tire house that covers the side surface of the wheel, the visibility of the mark 2 of the tire 1 is improved. Specifically, in a vehicle having the cover 20, the vertically upper area of ​​the tire side is covered by the cover 20, and only a part of the area on the road surface side (not shown; lower in the figure) is exposed. In this case, the mark 2 is arranged with its lower side facing outward in the tire radial direction, so that the mark 2 appears without being inverted, which has the advantage of improving the visibility of the mark 2 from outside the vehicle.

[0103] [2] In the tire 1 described in [1] above, the mark 2 is disposed so as to intersect with the tire maximum width position Ac. In this configuration, the mark 2 is positioned at the outermost position in the tire width direction, which has the advantage of improving the visibility of the mark 2.

[0104] [3] In the tire 1 described in [1] or [2] above, the mark 2 is disposed radially outward of the tire maximum width position Ac (see Figs. 1 and 2). This has the advantage that even if the bottom of the cover 20 of the vehicle described above is long, the entire mark 2 is appropriately exposed near the road surface, improving the visibility of the mark 2.

[0105] [4] In the tire 1 according to any one of the above items [1] to [3], the mark 2 is disposed radially inward of the tire maximum width position Ac (not shown). With this configuration, when the tire 1 is mounted on a vehicle, the mark 2 can be seen at a gentle angle from outside the vehicle, which has the advantage of improving the visibility of the mark 2.

[0106] [5] In the tire 1 according to any one of the above items [1] to [4], the mark 2 is composed of a plurality of elements 21A to 21E arranged at a distance from each other (see Figs. 2 and 3). The minimum distance I [mm] between adjacent elements 21A, 21B; 21B, 21C; 21C, 21D; 21D, 21E is in the range of 0.001≦I / OD≦0.015 with respect to the tire outer diameter OD [mm]. This has the advantage of improving the visibility of the mark 2.

[0107] [6] The tire 1 is the tire 1 according to any one of the above items [1] to [5], further comprising a plurality of marks 2, 2 spaced apart in the tire circumferential direction (see FIG. 2). Each of the plurality of marks 2, 2 is arranged with its lower side facing outward in the tire radial direction. This increases the chance of the mark 2 being exposed when the tire 1 is mounted on a vehicle equipped with the above cover 20, improving the visibility of the mark 2.

[0108] [7] The tire 1 is the tire 1 according to any one of the above [1] to [6], further comprising a pair of fine ribs 5A, 5B extending in the tire circumferential direction on the tire side portion (see FIG. 2). The mark 2 is disposed between the pair of fine ribs 5A, 5B. This reduces residual air in the region surrounding the mark 2, particularly in the smooth region 4, during tire vulcanization molding, and has the advantage of reducing the occurrence of vulcanization defects in the tire 1.

[0109] [8] The tire 1 is the tire 1 according to any one of the above [1] to [7], and includes a surface-treated region 3 formed by arranging a plurality of uneven portions (in FIG. 2, fine grooves 211 and fine ribs 212 shown in FIG. 4) and a smooth region 4 having a smooth surface in the tire side portion (see FIG. 2). The entire mark 2 is disposed in the smooth region 4. This has the advantage that the outline of the mark 2 becomes clear and the visibility of the mark 2 is improved.

[0110] [9] In the tire 1 according to any one of the above items [1] to [8], the extension range φ3 [deg] of the surface-treated region 3 in the tire circumferential direction is in the range of 1.00≦φ3 / φ2≦4.00 relative to the extension range φ2 [deg] of the mark 2 in the tire circumferential direction (see FIG. 2). This provides an advantage that the extension range φ3 [deg] of the surface-treated region 3 is balanced with the extension range φ2 [deg] of the mark 2, improving the design of the tire side portion.

[0111]

[10] The tire 1 is the tire 1 according to any one of the above [1] to [9], and has a surface-processed region 3 in the tire side portion, which is formed by arranging a plurality of uneven portions (in FIG. 2, the fine groove 311 and the fine rib 312 shown in FIG. 6). Also, the elements 21B to 21E constituting the mark 2 have a surface-processed portion formed by arranging a plurality of uneven portions (in FIG. 2, the fine groove 211 and the fine rib 212 shown in FIG. 4) (see FIG. 3 and FIG. 4). Also, the sidewall angle θ31 [deg] of the plurality of uneven portions in the surface-processed region 3 (see FIG. 6) has a relationship of 0<θ31-θ21 with respect to the sidewall angle θ21 [deg] of the plurality of uneven portions in the surface-processed portion of the elements 21B to 21E (see FIG. 4). This has the advantage that the visibility of the elements 21B to 21E of the mark 2 is improved relative to the surface-processed region 3.

[0112]

[11] In addition, in the tire 1 according to any one of the above items [1] to

[10] , the height difference H31 [mm] of the uneven portions 311, 312 constituting the surface-treated region 3 is in the range of 0.10≦H31 / H21<1.00 with respect to the height difference H21 [mm] of the plurality of uneven portions 211, 212 (see FIG. 4) in the surface-treated portion of the elements 21B to 21E (see FIG. 3) of the mark 2. This has the advantage that the visibility of the elements 21B to 21E of the mark 2 is improved relative to the surface-treated region 3.

[0113]

[12] The tire 1 is the tire 1 according to any one of the above items [1] to

[11] , further comprising a pair of bead cores 11, 11, a carcass layer 13 laid across the pair of bead cores 11, 11, and a belt layer 14 disposed radially outward of the carcass layer 13 (see FIG. 1). The tire outer diameter OD [mm] is within a range of 200≦OD≦660, and the tire total width SW [mm] is within a range of 100≦SW≦400 (see FIG. 1). By providing the mark 2 described above to such a small diameter tire, there is an advantage that the visibility of the mark 2 is effectively improved.

[0114]

[13] In the tire 1 described in

[12] above, the strength Tcs [N / 50mm] per 50 mm width of the carcass ply constituting the carcass layer 13 is in the range of 17≦Tcs / OD≦120 relative to the tire outer diameter OD [mm]. This ensures the structural strength of the small-diameter tire, suppressing deformation of the tire side portion under load, and improving the visibility of the mark 2. EXAMPLES

[0115] 7 and 8 are tables showing the results of performance tests of the tire according to the embodiment of the present invention.

[0116] In this performance test, the visibility of the markings was evaluated for multiple types of test tires.

[0117] (1) In the evaluation of the visibility of the mark, a test tire with a tire size of 145 / 80R12 is mounted on a rim with a rim size of 12x4.00B, and an internal pressure of 80% of the JATMA-specified internal pressure and a load of 88% of the JATMA-specified load are applied to the test tire. The test tire is also mounted on all wheels of a low-floor vehicle equipped with a cover 20 (see FIG. 2) that covers the tire side. An evaluator then visually observes the mark 2 on the tire side from a position 8 m away from the vehicle and evaluates its visibility. This evaluation is performed using an index evaluation with the comparative example as the standard (100), and the higher the value, the better.

[0118] The test tires of the comparative example and the example have the configurations shown in Fig. 1 and Fig. 2, and have a pair of units U, U, each of which is composed of a mark 2, a surface-treated region 3, and a smooth region 4, on the tire side. The tire outer diameter OD is 531 [mm], and the tire total width SW is 143 [mm]. The radial height H2 of the elements 21A-21E constituting the mark 2 is 18 [mm], and the radial height H3 of the surface-treated region 3 is 25.5 [mm].

[0119] As the test results show, it is possible to improve the visibility of the markings in the test tires of the examples. [Explanation of symbols]

[0120] 1 tire; 2 mark; 21A, 21B element; 211 fine groove; 212 fine rib; 3 surface treatment area; 311 fine groove; 312 fine rib; 4 smooth area; 5A, 5B fine rib; 6A, 6B smooth part; 10 rim; 11 bead core; 12 bead filler; 13 carcass layer; 14 belt layer; 141, 142 cross belt; 143 belt cover; 144 belt edge cover; 15 tread rubber; 151 cap tread; 152 under tread; 16 sidewall rubber; 17 rim cushion rubber; 18 inner liner; 20 cover

Claims

1. A tire having a mark on the tire side portion with a vertical direction defined, A tire characterized in that the mark is arranged with a downward side facing outward in the tire radial direction.

2. 2. The tire of claim 1, wherein said indicia is positioned across a maximum tire width location.

3. The tire according to claim 1 , wherein the marking is disposed radially outward from a maximum width position of the tire.

4. The tire according to claim 1 , wherein the mark is disposed radially inward from a maximum width position of the tire.

5. 2. The tire according to claim 1, wherein the marking is composed of a plurality of elements arranged at a distance from each other, and the minimum distance I [mm] between adjacent elements is in the range of 0.001≦I / OD≦0.015 with respect to the tire outer diameter OD [mm].

6. The tire according to claim 1 , further comprising a plurality of the marks arranged at intervals in the tire circumferential direction, and each of the plurality of marks is arranged with a downward direction facing outward in the tire radial direction.

7. 2. The tire according to claim 1, further comprising a pair of narrow ribs extending in a tire circumferential direction on a tire side portion, and the marking is disposed between the pair of narrow ribs.

8. 2. The tire according to claim 1, further comprising a surface-processed region having a plurality of projections and recesses arranged therein and a smooth region having a smooth surface in a tire side portion, and the entire marking is disposed in the smooth region.

9. The tire according to claim 1, wherein an extension range φ3 [deg] of the surface treated region in the tire circumferential direction is in a range of 1.00≦φ3 / φ2≦4.00 relative to an extension range φ2 [deg] of the mark in the tire circumferential direction.

10. A surface-processed region having a plurality of concave and convex portions arranged on a tire side portion is provided, The element constituting the mark has a surface-processed portion formed by arranging a plurality of concave and convex portions, and The tire according to claim 1, wherein a sidewall angle θ31 [deg] of the plurality of uneven portions in the surface-treated region has a relationship of 0<θ31-θ21 with respect to a sidewall angle θ21 [deg] of the plurality of uneven portions in the surface-treated portion of the element.

11. A surface-processed region having a plurality of concave and convex portions arranged on a tire side portion is provided, The element constituting the mark has a surface-processed portion formed by arranging a plurality of concave and convex portions, and The tire according to claim 1, wherein a height difference H31 [mm] of the plurality of uneven portions in the surface-treated region has a relationship of 0.10≦H31 / H21<1.00 with respect to a height difference H21 [mm] of the plurality of uneven portions in the surface-treated portion of the element.

12. 2. The tire according to claim 1, comprising: a pair of bead cores; a carcass layer disposed across the pair of bead cores; and a belt layer disposed radially outward of the carcass layer, wherein a tire outer diameter OD [mm] is in the range of 200≦OD≦660; and a tire total width SW [mm] is in the range of 100≦SW≦400.

13. The tire according to claim 12, wherein a strength Tcs [N / 50 mm] per 50 mm width of the carcass ply constituting the carcass layer is in a range of 17≦Tcs / OD≦120 with respect to an outer diameter OD [mm] of the tire.

Images