Tire

Abstract

A tire (1) according to the present invention is provided with a mark (2) that defines the vertical direction in a sidewall section. The marker (2) is disposed so that the lower side faces the outside in the radial direction of the tire. In addition, the tire (1) is provided with a plurality of marks (2, 2) arranged at intervals in the circumferential direction of the tire. Each of the plurality of markers (2, 2) is disposed so that the lower side faces the outside in the radial direction of the tire. In addition, the tire (1) is provided with a surface-processed region (3) in which a plurality of uneven portions are arranged, and a smooth region (4) having a smooth surface in a sidewall portion. In addition, the whole mark (2) is arranged in the smooth area (4).

Description

tire Technical Field

[0001] This invention relates to a tire, and more specifically, to a tire that improves the visual recognizability of markings. Background Technology

[0002] Conventionally, tire manufacturers and brands are marked on the sidewalls of tires. The technology described in Patent Documents 1 and 2 is known as a tire with this configuration.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2023-8359

[0006] Patent Document 2: Japanese Patent Publication No. 60-130107 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] However, in recent years, the industry has developed small-diameter tires that are installed on vehicles with lowered floors to increase interior space. Due to their smaller size, these small-diameter tires present the challenge of improving the visual legibility of branding and other markings on the tire sidewalls. In particular, when these small-diameter tires are installed on vehicles with sidewall covers (so-called "spats" or "skirts") within the tire house, the area of ​​the tire sidewall that can be visually identified is very narrow, thus necessitating appropriate measures to ensure the visual legibility of tire markings.

[0009] Therefore, the present invention was made in view of the above-mentioned problems, and its object is to provide a tire that can improve the visual recognition of tire markings.

[0010] Methods for solving problems

[0011] To achieve the above objectives, the tire of the present invention has markings on the sidewall portion that define the vertical direction, characterized in that the markings are arranged downwards toward the radially outward side of the tire.

[0012] Invention Effects

[0013] In the tire of the present invention, when the tire is mounted in a vehicle having an outer cover that covers the sidewall of the wheel, the visual recognizability of the tire markings is improved. Specifically, in a vehicle having the aforementioned outer cover, the area above the vertical direction of the tire sidewall is covered by the outer cover, with only a portion of the road surface exposed. In this case, by arranging the markings with their lower surface facing radially outward from the tire, the markings are displayed without being reversed, thereby improving the visual recognizability of the markings from outside the vehicle. Attached Figure Description

[0014] Figure 1 is a cross-sectional view of the tire along the radial direction according to an embodiment of the present invention.

[0015] Figure 2 is a top view of the sidewall of the tire shown in Figure 1.

[0016] Figure 3 is an enlarged view showing the markings on the tire sidewall as shown in Figure 2.

[0017] Figure 4 is a cross-sectional view from the A-angle of the label shown in Figure 3.

[0018] Figure 5 is an enlarged view of the surface-processed area of ​​the tire sidewall shown in Figure 2.

[0019] Figure 6 is a cross-sectional view from view B of the surface-processed area shown in Figure 5.

[0020] Figure 7 is a graph showing the performance test results of the tire according to an embodiment of the present invention.

[0021] Figure 8 is a graph showing the performance test results of the tire according to an embodiment of the present invention. Detailed Implementation

[0022] The present invention will now be described in detail with reference to the accompanying drawings. It should be noted that the present invention is not limited to this embodiment. Furthermore, the constituent elements of this embodiment include elements that are replaceable while maintaining the identity of the invention, and the replacement is obvious. Moreover, the various modifications described in this embodiment can be arbitrarily combined within the scope that is obvious to those skilled in the art.

[0023] [tire]

[0024] Figure 1 is a cross-sectional view showing the radial direction of a tire 1 according to an embodiment of the present invention. This figure shows a cross-sectional view of a single-sided region of the 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.

[0025] In this diagram, the tire radial section is defined as the section cut across the tire in a plane including the tire's axis of rotation (not shown). Furthermore, the tire equatorial plane CL is defined as a plane passing through the midpoint of the tire's section width DW as defined by JATMA and perpendicular to the tire's axis of rotation. Additionally, the tire width direction is defined as parallel to the tire's axis of rotation, and the tire radial direction is defined as perpendicular to the tire's axis of rotation. Furthermore, point T represents the tire's contact patch, and point Ac represents the tire's maximum width position.

[0026] Tire 1 has an annular structure centered on the tire rotation axis, and includes a pair of bead cores 11, 11, a pair of sidewall cores 12, 12, a carcass layer 13, a belt layer 14, tread rubber 15, a pair of sidewall rubbers 16, 16, a pair of rim cushioning rubbers 17, 17, and an inner liner 18 (see Figure 1).

[0027] A pair of bead cores 11, 11 are formed by repeatedly winding one or more bead wires made of steel in a loop and embedding them in the bead portion to form the cores of the left and right bead portions. A pair of sidewall cores 12, 12 are respectively disposed on the radial outer periphery of the tire of the pair of bead cores 11, 11 to reinforce the bead portion. In addition, the sidewall core 12 has a rubber hardness Hs_bf of 55 or more and 105 or less, a modulus M_bf [MPa] at 100% elongation of 2.0 or more and 13.0 or less, and a loss tangent tanδ_bf of 0.03 or more and 0.30 or less, preferably having a rubber hardness Hs_bf of 70 or more and 100 or less, a modulus M_bf [MPa] at 100% elongation of 3.0 or more and 12.0 or less, and a loss tangent tanδ_bf of 0.05 or more and 0.25 or less.

[0028] The carcass layer 13 has a single-layer structure formed by a single carcass ply or a multi-layer structure formed by stacking multiple carcass ply layers, and is arranged in a ring between the left and right bead cores 11, 12 to form the tire skeleton. Furthermore, the two ends of the carcass layer 13 are rolled back and secured to the outside of the tire width direction, enclosing the bead core 11 and the sidewall core 12. Additionally, the carcass ply of the carcass layer 13 is constructed by covering multiple carcass cords made of inorganic fibers (e.g., steel, carbon fiber, glass fiber) or organic fiber materials (e.g., aramid, nylon, polyester, rayon, etc.) with overlay rubber and then rolling them, and has a cord angle of 80 degrees or more and 100 degrees or less (defined as the angle of inclination of the length direction of the carcass cord relative to the tire circumference).

[0029] The belt layer 14 is formed by stacking multiple belt ply layers 141 to 144 and is arranged around the outer periphery of the carcass layer 13. In the configuration of FIG1, the belt ply layers 141 to 144 are composed of a pair of cross belts 141, 142, a belt cover layer 143, and a pair of belt edge cover layers 144, 144.

[0030] A pair of cross belts 141 and 142 are constructed by rolling multiple belt cords made of steel or organic fiber material over a layer of rubber, and have a cord angle of 15 degrees or more and 55 degrees or less (defined as the angle of inclination of the length direction of the belt cords relative to the tire circumference). Furthermore, the pair of cross belts 141 and 142 have cord angles of different signs, causing the length directions of the belt cords to intersect and overlap (a so-called oblique structure). The pair of cross belts 141 and 142 are stacked on the radially outer side of the tire carcass layer 13.

[0031] The belt cover layer 143 and the pair of belt edge cover layers 144, 144 are constructed by covering belt cover cords made of steel or organic fiber material with rubber coating, and have cord angles of 0 degrees or more and 10 degrees or less in absolute terms. Furthermore, the belt cover layer 143 and the belt edge cover layer 144 are, for example, strip-shaped profiles formed by covering one or more belt cover cords with rubber coating, and are constructed by repeatedly and spirally winding these strip-shaped profiles around the outer periphery of the cross belts 141, 142 along the tire circumference. Moreover, the belt cover layer 143 is configured to cover the entire area of ​​the cross belts 141, 142, and the pair of belt edge cover layers 144, 144 are configured to cover the left and right edges of the cross belts 141, 142 from the radially outer side of the tire.

[0032] The tread rubber 15 is disposed on the radial outer periphery of the tire carcass layer 13 and the belt layer 14 to form the tread portion of the tire 1. In addition, the tread rubber 15 has a crown tread 151 and a base tread 152.

[0033] The crown tread 151 is made of a rubber material with excellent ground contact characteristics and weather resistance, and is exposed throughout the entire area of ​​the tire contact surface, forming the outer surface of the tread portion. Furthermore, the crown tread 151 has a rubber hardness Hs_cap of 50 or more and 80 or less, a modulus M_cap [MPa] at 100% elongation of 1.0 or more and 4.0 or less, and a loss tangent tanδ_cap of 0.03 or more and 0.36 or less; preferably, it has a rubber hardness Hs_cap of 58 or more and 76 or less, a modulus M_cap [MPa] at 100% elongation of 1.5 or more and 3.2 or less, and a loss tangent tanδ_cap of 0.06 or more and 0.29 or less.

[0034] The rubber hardness Hs was determined at a temperature of 20 °C according to JIS K6253.

[0035] Modulus (fracture strength) is determined according to JIS K6251 (using a No. 3 dumbbell) by tensile testing at 20°C using a dumbbell-shaped test piece.

[0036] The loss tangent tanδ was measured using a viscoelastic spectrometer manufactured by Toyo Seiki Co., Ltd., under conditions of 60°C, 10% shear strain, ±0.5% amplitude, and 20 Hz frequency.

[0037] The base tread 152 is made of a heat-resistant rubber material and is sandwiched between the crown tread 151 and the belt layer 14, forming the base part of the tread rubber 15. Furthermore, the base tread 152 has a rubber hardness Hs_ut of 47 or more and 80 or less, a modulus M_ut [MPa] at 100% elongation of 1.4 or more and 5.5 or less, and a loss tangent tanδ_ut of 0.02 or more and 0.23 or less. Preferably, it has a rubber hardness Hs_ut of 50 or more and 65 or less, a modulus M_ut [MPa] at 100% elongation of 1.7 or more and 3.5 or less, and a loss tangent tanδ_ut of 0.03 or more and 0.10 or less.

[0038] Furthermore, the difference in rubber hardness, Hs_cap - Hs_ut, is in the range of 3 or more and 20 or less, preferably in the range of 5 or more and 15 or less. Furthermore, the difference in modulus, M_cap - M_ut [MPa], is in the range of 0 or more and 1.4 or less, preferably in the range of 0.1 or more and 1.0 or less. Furthermore, the difference in loss tangent, tanδ_cap - tanδ_ut, is in the range of 0 or more and 0.22 or less, preferably in the range of 0.02 or more and 0.16 or less.

[0039] A pair of sidewall rubbers 16, 16 are respectively 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 FIG1, the radially outer end of the sidewall rubber 16 is disposed on the lower layer of the tread rubber 15 and sandwiched between the end of the belt layer 14 and the carcass layer 13. However, it is not limited to this; the radially outer end of the sidewall rubber 16 may also be disposed on the outer layer of the tread rubber 15 and exposed in the tire shoulder reinforcement portion (not shown). In this case, the belt layer separator rubber (not shown) is sandwiched between the end of the belt layer 14 and the carcass layer 13.

[0040] Furthermore, the sidewall rubber 16 has a rubber hardness Hs_sw of 48 or more and 65 or less, a modulus M_sw [MPa] of 100% elongation of 1.0 or more and 2.4 or less, and a loss tangent tanδ_sw of 0.02 or more and 0.22 or less. Preferably, it has a rubber hardness Hs_sw of 50 or more and 59 or less, a modulus M_sw [MPa] of 100% elongation of 1.2 or more and 2.2 or less, and a loss tangent tanδ_sw of 0.04 or more and 0.20 or less.

[0041] A pair of rim cushioning rubbers 17, 17 extend radially inward from the inner side of the tire at the roll-back portion of the left and right bead cores 11, 11 and the carcass layer 13, towards the outer side in the tire width direction, forming the rim mating surface of the bead portion. In the configuration of FIG1, the radially outer end of the rim cushioning rubber 17 is inserted into the lower layer of the sidewall rubber 16, thereby being sandwiched between the sidewall rubber 16 and the carcass layer 13. Furthermore, the rim cushioning rubber 17 has a rubber hardness Hs_rc of 60 or more and 80 or less, a modulus M_rc [MPa] at 100% elongation of 2.0 or more and 7.0 or less, and a loss tangent tanδ_rc of 0.09 or more and 0.35 or less, preferably having a rubber hardness Hs_rc of 65 or more and 75 or less, a modulus M_rc [MPa] at 100% elongation of 3.0 or more and 6.0 or less, and a loss tangent tanδ_rc of 0.11 or more and 0.30 or less.

[0042] The inner liner 18 is an air-permeable layer disposed on the inner surface of the tire cavity and covering the carcass layer 13. It inhibits oxidation of the carcass layer 13 due to exposure and also prevents leakage of air filled in the tire. Furthermore, the inner liner 18 may be made of, for example, a rubber composition with butyl rubber as the main component, or a thermoplastic resin or a thermoplastic elastomer composition in which elastomer components are blended into a thermoplastic resin.

[0043] Furthermore, in Figure 1, the tire outer diameter OD [mm] is in the range of 200 ≤ OD ≤ 660, preferably in the range of 250 [mm] ≤ OD ≤ 580 [mm]. By using this small-diameter tire, the improved load-bearing performance described later can be significantly achieved. Furthermore, the total tire width SW [mm] is in the range of 100 ≤ SW ≤ 400, preferably in the range of 105 [mm] ≤ SW ≤ 340 [mm]. Using this small-diameter tire 1, for example, the floor of a small vehicle can be lowered, thereby increasing the interior space. Furthermore, by equipping this small-diameter tire with the marking 2 described later, the visual recognizability of the marking 2 is effectively improved.

[0044] The tire outer diameter (OD) is measured by mounting the tire on a specified rim and applying a specified internal pressure, while the tire is in an unloaded state.

[0045] The total tire width (SW) is measured as the straight-line distance between the sidewalls (including all parts such as the tire tread and lettering) when the tire is mounted on a specified rim, subjected to a specified internal pressure, and placed under no-load conditions.

[0046] The specified rim refers to the "applied rim" as specified by JATMA, the "design rim" as specified by TRA, or the "measuring rim" as specified by ETRTO. Furthermore, the specified internal pressure refers to the "maximum tire pressure" as specified by JATMA, the maximum value of the "tire load limits at various cold inflation pressures" as specified by TRA, or the "inflation pressure" as specified by ETRTO. Similarly, the specified load refers to the "maximum load capacity" as specified by JATMA, the maximum value of the "tire load limits at various cold inflation pressures" as specified by TRA, or the "load capacity" as 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.

[0047] Furthermore, the total tire width SW [mm] relative to the tire outer diameter OD [mm] is in the range of 0.23≤SW / OD≤0.84, preferably in the range of 0.25≤SW / OD≤0.81.

[0048] Furthermore, the tire outer diameter OD and the total tire width SW preferably satisfy the following formula (1). Wherein, A1min=-0.0017, A2min=0.9, A3min=130, A1max=-0.0019, A2max=1.4, A3max=400, preferably A1min=-0.0018, A2min=0.9, A3min=160, A1max=-0.0024, A2max=1.6, A3max=362.

[0049] [Formula 1]

[0050]

[0051] In the tire 1 described above, it is assumed that a rim 10 with a rim diameter of 5 inches or more and 16 inches or less (i.e., 125 mm or more and 407 mm or less) is used. Furthermore, the rim diameter RD (mm) relative to the tire outer diameter OD (mm) is in the range of 0.50 ≤ RD / OD ≤ 0.74, preferably in the range of 0.52 ≤ RD / OD ≤ 0.71. This lower limit ensures the rim diameter RD, and in particular, ensures the installation space for the hub motor. This upper limit ensures the tire's internal volume V, which will be described later, thereby ensuring the tire's load-bearing capacity.

[0052] It should be noted that the inner diameter of the tire is equal to the rim diameter RD of the rim 10.

[0053] Furthermore, it is assumed that the tire 1 described above is used at an internal pressure higher than the specified internal pressure, specifically above 350 kPa and below 1200 kPa, preferably above 500 kPa and below 1000 kPa. The lower limit suppresses sidewall deformation under applied load, improving the visual visibility of the marking 2 described later, while the upper limit ensures the safety of the internal pressure filling operation.

[0054] Furthermore, it is assumed that the aforementioned tire 1 is installed on a vehicle that travels at low speeds, such as a minibus. 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. Furthermore, it is assumed that the aforementioned tire 1 is installed on a vehicle with 6 to 12 wheels. Thus, the load-bearing capacity of the tire is appropriately utilized.

[0055] Furthermore, the aspect ratio of the tire, i.e. the ratio of the tire section height SH [mm] to the tire section width DW [mm], SH / DW, is in the range of 0.16≤SH / DW≤0.85, preferably in the range of 0.19≤SH / DW≤0.82.

[0056] The tire section height SH is the distance of half the difference between the tire's outer diameter and the rim diameter. It is measured by mounting the tire on a specified rim, applying a specified internal pressure, and placing it under no-load conditions.

[0057] The tire section width (DW) is the straight-line distance between the sidewalls (excluding tread patterns, lettering, etc. on the tire sidewalls) when the tire is mounted on a specified rim and subjected to a specified internal pressure and is in an unloaded state.

[0058] Furthermore, the tire contact width TW relative to the total tire width SW is in the range of 0.50≤TW / SW≤0.85, preferably in the range of 0.60≤TW / SW≤0.80.

[0059] Regarding tire contact width (TW), it is measured as the maximum straight-line distance along the tire axial direction on the contact surface between the tire and the flat plate when the tire is mounted on a specified rim and a specified internal pressure is applied, and the tire is placed perpendicular to the flat plate in a stationary state and a load corresponding to the specified load is applied.

[0060] Furthermore, the tire internal volume V [m^3] relative to the tire outer diameter OD [mm] is preferably within the range of 4.0 ≤ (V / OD) × 10^6 ≤ 60, and more preferably within the range of 6.0 ≤ (V / OD) × 10^6 ≤ 50. This optimizes the tire internal volume V. Specifically, by limiting the tire internal volume as described above, the tire's load-bearing capacity is ensured. Especially in small-diameter tires, since they are assumed to be used under high internal pressure and high load, it is preferable to sufficiently ensure the tire internal volume V. By limiting the tire internal volume as described above, tire enlargement caused by excessively large tire internal volume V is suppressed.

[0061] Furthermore, the tire internal volume V[m^3] relative to the rim diameter RD[mm] is in the range of 0.5≤V×RD≤17, preferably in the range of 1.0≤V×RD≤15.

[0062] [Peripheral layer]

[0063] In the configuration shown in Figure 1, as described above, the carcass layer 13 is composed of a single layer of carcass ply, which is arranged in a ring between the left and right bead cores 11, 11. Furthermore, the two ends of the carcass layer 13 are rolled back and secured to the outside of the tire width direction in a manner that wraps around the bead core 11 and the sidewall core 12.

[0064] Furthermore, the strength Tcs [N / 50mm] of each 50mm width of the carcass ply constituting the carcass layer 13, relative to the tire outer diameter OD [mm], is in the range of 17 ≤ Tcs / OD ≤ 120, preferably in the range of 20 ≤ Tcs / OD ≤ 120. Additionally, the strength Tcs [N / 50mm] of the carcass layer 13, relative to the total tire width SW [mm], is in the range of 30 ≤ Tcs / SW ≤ 260, preferably in the range of 35 ≤ Tcs / SW ≤ 220. With this configuration, the load-bearing capacity of the carcass layer 13 is appropriately ensured in a small-diameter tire, thus offering the advantage of balancing tire durability and low rolling resistance. Specifically, by using the aforementioned lower limits, tire deformation under high loads is suppressed, thereby ensuring tire durability. Furthermore, it allows for use under high internal pressures, reducing tire rolling resistance. Especially in small-diameter tires, since they are assumed to be used under high internal pressure and high load, the aforementioned tire durability and rolling resistance reduction effects are significantly achieved. This upper limit suppresses the deterioration in rolling resistance caused by the increase in the mass of the tire carcass layers.

[0065] The strength Tcs [N / 50mm] of the carcass ply is calculated as follows: The carcass ply extending across the entire inner circumference of the tire, mounted on the left and right bead cores 11, 11, is defined as the effective carcass ply. Furthermore, the strength [N / ply] of each carcass cord constituting the effective carcass ply is calculated as the product of the number of carcass cords embedded per 50mm width on the tire's circumference and equatorial plane CL [ply / 50mm], and this product is taken as the strength Tcs [N / 50mm] of the carcass ply. The strength of the carcass cord is determined by a tensile test at 20°C according to JIS K1017. For example, in a carcass ply composed of multiple twisted monofilaments, the strength of a single twisted carcass cord is measured, thereby calculating the strength Tcs of the carcass ply 13. Furthermore, in the configuration where the carcass layer 13 has a multi-layer structure (not shown) formed by stacking multiple effective carcass plies, the aforementioned strength Tcs is defined for each of the multiple effective carcass plies.

[0066] For example, in the configuration of Figure 1, the carcass layer 13 has a single-layer structure formed by a single carcass ply (reference numerals omitted in the figure). Furthermore, the carcass ply is composed of carcass cords made of steel and covered with overlay rubber arranged at a cord angle of 80 degrees or more and 100 degrees or less relative to the tire circumference (illustration omitted). In addition, by having the cord diameter φcs (mm) of the aforementioned carcass cords made of steel in the range of 0.15 ≤ φcs ≤ 1.10, preferably in the range of 0.25 ≤ φcs ≤ 0.60, and the number of embedded cords Ecs (cords / 50 mm) in the range of 25 ≤ Ecs ≤ 80, preferably in the range of 50 ≤ Ecs ≤ 80, the strength Tcs (N / 50 mm) of the aforementioned carcass layer 13 is achieved. Furthermore, the carcass cord is formed by twisting multiple monofilaments together, and its monofilament diameter φcss [mm] is in the range of 0.12 ≤ φcss ≤ 0.24, preferably in the range of 0.14 ≤ φcss ≤ 0.22. Moreover, the monofilament diameter φcss [mm] of the carcass cord is more preferably in the range of 0.30 ≤ φcss / φcs ≤ 0.90 relative to the cord diameter φcs [mm]. It should be noted that the carcass cord can also be composed of inorganic fibers other than steel (e.g., carbon fiber, glass fiber, etc.).

[0067] Furthermore, the carcass ply is not limited to the above-described configuration and can also be composed of carcass cords made of organic fiber materials (e.g., aramid, nylon, polyester, rayon, etc.) coated with rubber. In this case, the strength Tcs [N / 50mm] of the carcass layer 13 is achieved by having the carcass cords made of the aforementioned organic fiber materials with a cord diameter φcs [mm] in the range of 0.60 ≤ φcs ≤ 0.90 and an embedded number Ecs [strips / 50mm] in the range of 40 ≤ Ecs ≤ 70. Furthermore, carcass cords made of high-strength organic fiber materials such as nylon, aramid, or blended materials can be used to a extent readily apparent to those skilled in the art.

[0068] Furthermore, the carcass layer 13 may also have a multi-layer structure consisting of multiple layers, such as two carcass plies, stacked together (illustration omitted). This effectively improves the tire's load-bearing capacity.

[0069] Furthermore, the total strength TTcs [N] of the carcass layer 13 relative to the tire outer diameter OD [mm] is in the range of 300 ≤ TTcs / OD ≤ 3500, preferably in the range of 400 ≤ TTcs / OD ≤ 3000. This ensures the overall load-bearing capacity of the carcass layer 13.

[0070] The total strength TTcs[N] of the carcass layer 13 is calculated by multiplying the strength of each carcass cord [N / cord] by the total number of embedded carcass cords in the entire carcass layer 13. Therefore, the total strength TTcs[N] of the carcass layer 13 increases with the increase of the strength Tcs[N / 50mm] of each carcass cord, the number of carcass cord layers, the circumference of the carcass cord, etc.

[0071] Furthermore, the total strength TTcs[N] of the carcass layer 13 preferably satisfies the following formula (2) with respect to the tire outer diameter OD[mm] and the distance SWD[mm]. Wherein, 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. Moreover, it is preferable that, using the specified tire internal pressure P[kPa], Dmin=0.02×P.

[0072] [Formula 2]

[0073]

[0074] [Side of the tire]

[0075] Figure 2 is a top view of the sidewall of the tire shown in Figure 1. This figure shows a top view of tire 1 viewed axially.

[0076] As shown in Figure 2, the tire 1 has markings 2, a surface processing area 3, and a smooth area 4 on the sidewall.

[0077] Logo 2 consists of words, graphics, or symbols, or combinations thereof, and in particular includes trademarks that function as identification marks for tire manufacturers, tire brands, etc. Furthermore, multiple logos 2 are spaced apart along the tire's circumference. For example, in the configuration of Figure 2, a logo consisting of the string "YOKOHAMA" representing the tire manufacturer and a design based on its first letter "Y" is engraved on the tire sidewall surface. Additionally, a pair of logos 2, 2 are positioned opposite each other along the tire's circumference. Logo 2 will be described in detail later.

[0078] Surface-processed area 3 is a surface-processed area formed by arranging multiple protrusions and recesses on the tire sidewall surface. This surface-processed area 3 is composed of a densely arranged array of tiny protrusions and recesses, thereby enhancing the design of the tire sidewall. For example, in the configuration of Figure 2, surface-processed area 3 has an elongated structure extending circumferentially along the tire and a wavy shape with amplitude in the tire's radial direction. Furthermore, a pair of surface-processed areas 3, 3 are positioned in the area between a pair of markings 2, 2. This improves the visual recognizability of marking 2. Surface-processed area 3 will be described in detail later.

[0079] Smooth region 4 is a region with a smooth surface formed on the sidewall surface of the tire. Specifically, smooth region 4 is defined as a region with a continuous smooth surface without grooves or unevenness that surrounds the aforementioned mark 2. For example, in the configuration of FIG2, a pair of smooth regions 4, 4 are arranged to surround a pair of marks 2, 2 respectively. In other words, a pair of marks 2, 2 are respectively arranged within a pair of smooth regions 4, 4. By arranging the smooth region 4 to surround the mark 2, the visual recognizability of the mark 2 is improved compared to the configuration in which the mark 2 is arranged within the aforementioned surface-processed region 3 (illustration omitted).

[0080] Furthermore, in the configuration shown in Figure 2, the unit U, consisting of the marking 2, the surface-processed area 3, and the smooth area 4, is formed at least on the tire sidewall on the outer side of the vehicle width direction (see Figure 1) when the tire is mounted on the vehicle. Additionally, a pair of units U, U are linearly arranged in the tire circumferential direction and have an overall annular structure. Furthermore, as shown in Figure 2, the pair of units U, U are positioned further radially outward than the tire's maximum width position Ac (see Figure 1). More specifically, a pair of thin stripe patterns 5A, 5B extending circumferentially are arranged in the area from the tire contact patch T (see Figure 1) to the tire's maximum width position Ac, and the pair of units U, U, consisting of the marking 2, the surface-processed area 3, and the smooth area 4, are positioned in the annular area divided by the pair of thin stripe patterns 5A, 5B. This improves the design flexibility of the tire sidewall. However, it is not limited to this; the unit U, consisting of the marking 2, the surface-processed area 3, and the smooth area 4, can also be positioned further radially inward than the tire's maximum width position Ac (illustration omitted).

[0081] The maximum width position Ac of the tire is defined as the maximum width position of the tire profile width DW (see Figure 1).

[0082] It should be noted that the aforementioned pair of fine stripe patterns 5A and 5B 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. They serve as a path for residual air to escape during tire vulcanization, thereby particularly suppressing vulcanization failures in the smooth area 4 surrounding the marking 2.

[0083] [Identifier]

[0084] Figure 3 is an enlarged view of the marking 2 on the sidewall of the tire shown in Figure 2. This figure shows a portion of marking 2. Figure 4 is a cross-sectional view from view A of the marking 2 shown in Figure 3.

[0085] In Figure 2, the identifier 2 specifies the vertical direction. In the configuration of Figure 2, the vertical direction is specified by making the identifier 2 a combination of the "Y" symbol and the string "YOKOHAMA".

[0086] Furthermore, as shown in Figure 2, the mark 2 is arranged with its lower part facing the radially outward side of the tire. For example, in the configuration of Figure 2, by bending the mark 2 as a whole along the curvature of the tire, the elements 21A to 21E (see Figure 3) constituting the mark 2 are arranged so that their vertical direction is parallel to the radial direction of the tire. In addition, a plurality of marks 2, 2 arranged at predetermined intervals in the circumferential direction of the tire are arranged with their upper part facing the radially inward side of the tire and their lower part facing the radially outward side of the tire.

[0087] In this configuration, when the tire 1 is mounted in a wheel well and a cover 20 (see Figure 2, the so-called "wheel arch" or "side skirt") covering the wheel sidewall is provided, the visual recognizability of the marking 2 on the tire 1 is improved. Specifically, in the vehicle equipped with the aforementioned cover 20, the area above the vertical direction of the tire sidewall is covered by the cover 20, with only a portion of the road surface (not shown, lower part of the figure) exposed. In this case, by arranging the marking 2 with its lower part facing radially outward from the tire, the marking 2 is displayed without being reversed, thereby improving the visual recognizability of the marking 2 from outside the vehicle. Furthermore, by arranging multiple markings 2, 2 along the tire circumference, the exposure opportunity of the marking 2 is increased, further improving the visual recognizability of the marking 2.

[0088] Furthermore, as shown in Figure 3, the marking 2 is arranged intersectingly at the tire's maximum width position Ac. In this configuration, marking 2 is located on the outermost side in the tire's width direction, thus improving its visual visibility. However, it is not limited to this; marking 2 can also be positioned further radially outward from the tire's maximum width position Ac (see Figure 1) (illustration omitted). Thus, even when the lower end of the aforementioned cover 20 is relatively long, marking 2 will still be appropriately exposed near the road surface, thereby improving its visual visibility.

[0089] It should be noted that, in addition to the above methods, the mark 2 can also be positioned further radially inside the tire than the tire's maximum width position Ac, or the mark 2 can be positioned intersectingly at the tire's maximum width position Ac (illustration omitted).

[0090] Furthermore, in the configuration of Figure 2, as described above, the mark 2 is entirely positioned within the smooth region 4. Therefore, the mark 2 is surrounded by the smooth region 4 and does not overlap with the surface-finished region 3. For example, in the configuration of Figure 2, a pair of marks 2, 2 surrounded by the smooth region 4 and a pair of surface-finished regions are arranged alternately in the tire circumferential direction. Furthermore, a pair of units U, U formed by the mark 2, the surface-finished region 3, and the smooth region 4 are positioned within an annular region divided by a pair of fine stripe patterns 5A, 5B. This improves the design flexibility of the tire sidewall.

[0091] Furthermore, in Figure 2, the extension range φ2[deg] of the marking 2 in the tire circumferential direction is within the range of 25≤φ2≤85, preferably within the range of 35≤φ2≤75. This ensures the visual recognizability of the marking 2.

[0092] Furthermore, as shown in Figure 3, the multiple elements 21A to 21E constituting mark 2 are arranged separately from each other. In this case, the minimum distance I [mm] between adjacent elements 21A, 21B; 21B, 21C; 21C, 21D; 21D, 21E is within the range of 0.001 ≤ I / OD ≤ 0.015 relative to the tire outer diameter OD [mm], preferably within the range of 0.003 ≤ I / OD ≤ 0.013. This improves the visual recognizability of mark 2.

[0093] Furthermore, in Figure 3, the radial height H2 [mm] of elements 21A to 21E constituting mark 2 is within the range of 0.010 ≤ H2 / OD ≤ 0.070 relative to the tire outer diameter OD [mm], preferably within the range of 0.020 ≤ H2 / OD ≤ 0.060. Furthermore, the circumferential width W2 [mm] of elements 21A to 21E constituting mark 2 is within the range of 0.010 ≤ W2 / OD ≤ 0.100 relative to the tire outer diameter OD [mm], preferably within the range of 0.020 ≤ W2 / OD ≤ 0.090. Furthermore, the thickness T2 [mm] of the text constituting mark 2, i.e., elements 21B to 21E, is within the range of 0.001 ≤ T2 / OD ≤ 0.040 relative to the tire outer diameter OD [mm], preferably within the range of 0.005 ≤ T2 / OD ≤ 0.030. This improves the visual recognizability of mark 2.

[0094] Regarding the radial height H2 of elements 21A to 21E, the measurement is the maximum value of the extension length of elements 21A to 21E in the radial direction of the tire. Similarly, regarding the circumferential width W2 of elements 21A to 21E, the measurement is the maximum value of the extension length of elements 21A to 21E in the circumferential direction of the tire. Furthermore, regarding the thickness T2 of the text, i.e., elements 21B to 21E, the measurement is the maximum value of the thickness of the line displaying the text.

[0095] Furthermore, as shown in Figure 2, the mark 2 is positioned between a pair of thin stripe patterns 5A and 5B extending circumferentially along the tire. This reduces residual air in the area surrounding the mark 2, particularly in the smooth area 4, during tire vulcanization, thus reducing the occurrence of vulcanization defects in the tire 1. Furthermore, in Figure 3, the radial height H2 [mm] of the elements 21A to 21E constituting the mark 2, relative to the arrangement interval H4 [mm] of the thin stripe patterns 5A and 5B in the tire's radial direction, is within the range of 0.30 ≤ H2 / H4 ≤ 0.70, preferably within the range of 0.40 ≤ H2 / H4 ≤ 0.80. Moreover, in the configuration of Figure 3, the mark 2 is separated from the pair of thin stripe patterns 5A and 5B. This improves the visual recognizability of the mark 2.

[0096] Furthermore, in the configuration of Figure 2, as shown in Figures 3 and 4, a portion of the elements constituting the identifier 2 (specifically, the text, i.e., elements 21B to 21E) has a surface-processed portion formed by arranging multiple concave and convex portions 211 and 212. Examples of such surface-processed portions include, for instance, a serrated portion formed by arranging multiple grooves or stripes side by side, and a concave-convex portion formed by arranging multiple concave or convex portions.

[0097] For example, in the configurations of Figures 3 and 4, elements 21B to 21E of identifier 2 are engravings formed in the smooth area, having a structure that is entirely recessed relative to the plane of the smooth area 4. Furthermore, elements 21B to 21E have multiple parallel grooves 211 and fine stripe patterns 212 on their bottom surface. Thus, elements 21B to 21E are formed with a striped surface finish.

[0098] Furthermore, in Figure 4, the sidewall angle θ21 [deg] of the uneven portions 211 and 212 in the surface-processed parts of elements 21B to 21E (identified by label 2) is in the range of 10 ≤ θ21 ≤ 20°, and preferably in the range of 12 ≤ θ21 ≤ 18°. Furthermore, the pitch length P21 [mm] of the uneven portions 211 and 212 is in the range of 0.5 ≤ P21 ≤ 1.5°, and preferably in the range of 0.7 ≤ P21 ≤ 1.3°. Furthermore, the height difference H21 [mm] of the uneven portions 211 and 212 is in the range of 0.3 ≤ H21 ≤ 1.0°, and preferably in the range of 0.4 ≤ H21 ≤ 0.8°. Furthermore, the step difference H21' [mm] of the contour lines forming elements 21B to 21E, relative to the height difference H21 [mm] of the concave and convex portions 211 and 212, is within the range of 1.20 ≤ H21' / H21 ≤ 2.50, and preferably within the range of 1.50 ≤ H21' / H21 ≤ 2.30. This improves the visual recognizability of the mark 2.

[0099] Regarding the sidewall angle θ21[deg] of the concave and convex portions 211 and 212, it is measured as the angle formed by the virtual straight line connecting the top edge and the bottom raised portion of the concave and convex portions 211 and 212 in a cross-sectional view perpendicular to the length direction of the concave and convex portions 211 and 212 (see Figure 4), and the direction perpendicular to the tire sidewall profile (illustration omitted. The surface of smooth region 4 is shown in Figure 4).

[0100] Regarding the height difference H21 between the concave and convex parts 211 and 212, the measured value is the height difference between the maximum depth position and the maximum height position of the concave and convex parts 211 and 212 (in Figure 4, it is the height difference between the maximum depth position of the groove 211 and the maximum height position of the strip pattern 212).

[0101] Regarding the step difference H21' of the concave and convex portions 211 and 212, the maximum value of the step difference between the maximum depth position of the concave and convex portion (groove 211 in Figure 4) that forms the contour lines of the elements 21B to 21E of the mark 2 and the surface of the region surrounding the elements 21B to 21E of the mark 2 (surface of smooth region 4 in Figure 4) is measured.

[0102] It should be noted that, in the configurations of Figures 3 and 4, as described above, elements 21B to 21E of the mark 2 have a structure that is entirely recessed relative to the plane of the smooth region 4. However, this is not a limitation; elements 21B to 21E of the mark 2 may also have a structure that is entirely protruding relative to the plane of the smooth region 4 (illustration omitted). In this case, the amount of protrusion of elements 21B to 21E relative to the plane of the smooth region 4 is preferably 0.3 mm or more and 1.0 mm or less. This ensures the visual recognizability of the mark 2 and reduces the aerodynamic impact of the mark 2.

[0103] [Surface Finished Area]

[0104] Figure 5 is an enlarged view of the surface-finished area 3 of the tire sidewall shown in Figure 2. This figure shows a portion of the surface-finished area 3. Figure 6 is a cross-sectional view from view B of the surface-finished area 3 shown in Figure 5.

[0105] In Figure 6, the surface-processed area 3 is a region formed by a plurality of protrusions and recesses 311, 312 arranged together, and its boundary is defined by a virtual line (not shown) surrounding a densely arranged set of protrusions and recesses 311, 312. Examples of surface-processed areas 3 include, for instance, a serrated area formed by arranging a plurality of fine grooves or stripes side by side, and a textured area formed by arranging a plurality of recesses or protrusions. This surface-processed area 3 improves the design flexibility of the tire sidewall.

[0106] For example, in the configuration of FIG2, as shown in FIG5 and FIG6, the surface-processed region 3 has a planar recessed structure relative to the smooth region 4 (refer to FIG2). Furthermore, the surface-processed region 3 has a plurality of grooves 311 and fine stripe patterns 312 arranged side-by-side. Thus, a surface-processed region 3 with a stripe-like surface finish is formed. It should be noted that the boundary of the surface-processed region formed by the plurality of grooves 311 and fine stripe patterns 312 is defined by a virtual line (not shown) connecting the ends of adjacent grooves 311 and fine stripe patterns 312.

[0107] Furthermore, in the configuration of Figure 2, as described above, a pair of markings 2, 2 and a pair of surface-finished areas are arranged alternately in the tire circumferential direction. Additionally, markings 2 and surface-finished areas 3 are positioned within an annular area defined by a pair of fine stripe patterns 5A, 5B. Therefore, surface-finished areas 3 are located at the same position in the tire's radial direction relative to markings 2, i.e., at a position overlapping markings 2 when viewed from the tire's circumferential direction. This forms an annular design composed of markings 2 and surface-finished areas 3.

[0108] Furthermore, in Figure 2, the extension range φ3 [deg] of the surface-processed area 3 in the tire circumferential direction is within 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, preferably within the range of 1.50 ≤ φ3 / φ2 ≤ 3.50. Thus, the extension range φ3 [deg] of the surface-processed area 3 and the extension range φ2 [deg] of the mark 2 are balanced, improving the design flexibility of the tire sidewall.

[0109] Furthermore, in the configuration of Figure 2, the surface-processed area 3 has a wavy shape with amplitude in the radial direction of the tire, and a continuous surface-processed area 3 is arranged between adjacent markings 2, 2. This improves the visual recognizability of marking 2. However, it is not limited to this; the surface-processed area 3 may also have a strip shape without amplitude, or multiple discontinuous surface-processed areas 3 may be arranged between adjacent markings 2, 2 (illustration omitted).

[0110] Furthermore, as shown in Figure 5, the pitch length P3 [deg] of the wavy shape of the surface-processed area 3 is in the range of 5 ≤ P3 ≤ 30, preferably in the range of 10 ≤ P3 ≤ 20. Furthermore, the radial height H3 [mm] of the surface-processed area 3 relative to the tire outer diameter OD [mm] is in the range of 0.010 ≤ H3 / OD ≤ 0.070, preferably in the range of 0.02 ≤ H3 / OD ≤ 0.06. Furthermore, the width W3 [mm] of the surface-processed area 3 with the wavy shape relative to the tire outer diameter OD [mm] is in the range of 0.010 ≤ W3 / OD ≤ 0.030, preferably in the range of 0.015 ≤ W3 / OD ≤ 0.025.

[0111] Regarding the radial height H3 of the surface-processed area 3, the maximum value of the extension length of the surface-processed area 3 in the radial direction of the tire was measured. Furthermore, regarding the width W3 of the surface-processed area 3 with a wavy shape, the maximum value of the width of the lines constituting the wavy shape was measured.

[0112] Furthermore, as shown in Figure 2, the surface-finished area 3 is positioned between a pair of thin stripe patterns 5A and 5B extending along the tire circumference. In Figure 5, the radial height H3 [mm] of the surface-finished area 3, relative to the arrangement interval H4 [mm] of the thin stripe patterns 5A and 5B in the tire's radial direction, is within the range of 0.45 ≤ H3 / H4 ≤ 0.95, preferably within the range of 0.50 ≤ H3 / H4 ≤ 0.90. Moreover, in the configuration of Figure 5, the surface-finished area 3 is separated from the pair of thin stripe patterns 5A and 5B. This improves the visual visibility of the surface-finished area 3.

[0113] Furthermore, in the configuration of Figure 5, polygonal smooth portions 6A and 6B are formed in the area between the surface-processed area 3 and the pair of striped patterns 5A and 5B. No grooves or unevenness are formed in these smooth portions 6A and 6B. For example, in the configuration of Figure 5, the surface-processed area 3 has a stepped, wavy shape. In the area between the surface-processed area 3 and the pair of striped patterns 5A and 5B, multiple hexagonal smooth portions 6A with a wider width and quadrilateral smooth portions 6B with a narrower width are alternately arranged along the tire circumference. By filling the gap between the surface-processed area 3 and the pair of striped patterns 5A and 5B with these smooth portions 6A and 6B, the visual visibility of the surface-processed area 3 is improved. Furthermore, in the corners of the hexagonal smooth portions 6A, the angle D6 [deg] (dimension markings omitted in the figure) of the corners where two sides meet the surface-processed area 3 is within the range of 0.1 ≤ D6 / OD ≤ 0.3 relative to the tire outer diameter OD [mm].

[0114] Furthermore, in Figure 6, the sidewall angle θ31[deg] of the uneven portions 311, 312 constituting the surface-finished area 3 has a relationship of 0 < θ31 - θ21 relative to the sidewall angle θ21[deg] of the multiple uneven portions 211, 212 (see Figure 4) in the surface-finished portions of elements 21B to 21E of the mark 2 (see Figure 3), and preferably has a relationship of 5 ≤ θ31 - θ21 ≤ 25. Therefore, the visual recognizability of elements 21B to 21E of the mark 2 is relatively improved compared to the surface-finished area 3. Furthermore, the sidewall angle θ31[deg] of the uneven portions 311, 312 constituting the surface-finished area 3 is in the range of 25 ≤ θ31 ≤ 35, and preferably in the range of 27 ≤ θ31 ≤ 33.

[0115] Regarding the sidewall angle θ31 [deg] of the concave and convex portions 311 and 312, it is measured as the angle formed by the virtual straight line connecting the top edge and the bottom raised portion of the concave and convex portions 311 and 312 in a cross-sectional view perpendicular to the length direction of the concave and convex portions 311 and 312 (see Figure 6), and the direction perpendicular to the tire sidewall profile (illustration omitted. The surface of the smooth portion 6A is shown in Figure 6).

[0116] Furthermore, in Figure 6, the pitch length P31 [mm] of the uneven portions 311, 312 constituting the surface-finished area 3 is in the range of 0.70 ≤ P31 / P21 ≤ 1.30 relative to the pitch length P21 of the plurality of uneven portions 211, 212 (see Figure 4) in the surface-finished portions of elements 21B to 21E of the mark 2 (see Figure 3), and preferably in the range of 0.80 ≤ P31 / P21 ≤ 1.20. Therefore, the visual recognizability of elements 21B to 21E of the mark 2 is relatively improved compared to the surface-finished area 3. Furthermore, the pitch length P31 [mm] of the uneven portions 311, 312 constituting the surface-finished area 3 is in the range of 0.5 ≤ P31 ≤ 1.5, and preferably in the range of 0.7 ≤ P31 ≤ 1.3.

[0117] Furthermore, in Figure 6, the height difference H31 [mm] of the uneven portions 311, 312 constituting the surface-processed area 3, relative to the height difference H21 [mm] of the multiple uneven portions 211, 212 (see Figure 4) in the surface-processed portions of elements 21B to 21E of the mark 2 (see Figure 3), is within the range of 0.10 ≤ H31 / H21 ≤ 1.00, and preferably within the range of 0.30 ≤ H31 / H21 ≤ 0.90. Therefore, the visual recognizability of elements 21B to 21E of the mark 2 is relatively improved compared to the surface-processed area 3. Furthermore, the height difference H31 [mm] of the uneven portions 311, 312 constituting the surface-processed area 3 is within the range of 0.1 ≤ H31 ≤ 0.8, and preferably within the range of 0.2 ≤ H31 ≤ 0.6.

[0118] Regarding the height difference H31 between the concave and convex parts 311 and 312, the measured value is the height difference between the maximum depth position and the maximum height position of the concave and convex parts 311 and 312 (in Figure 6, it is the height difference between the maximum depth position of the groove 311 and the maximum height position of the fine strip pattern 312).

[0119] Furthermore, in the configuration of Figure 6, the step difference H31' [mm] of the boundary line forming the surface-processed area 3 is approximately equal to the height difference H31 [mm] of the uneven parts 311 and 312. In contrast, as described above, the step difference H21' [mm] of the contour lines forming the elements 21B to 21E of the mark 2 is set to be greater than the height difference H21 [mm] of the uneven parts 211 and 212 of the elements 21B to 21E. As a result, the visual recognizability of the elements 21B to 21E of the mark 2 is relatively improved compared to the surface-processed area 3.

[0120] Regarding the step difference H31' of the concave and convex portions 311 and 312, the maximum value of the step difference between the maximum depth position of the concave and convex portion (groove 311 in Figure 6) forming the boundary line of the surface processed area 3 and the surface of the area surrounding the surface processed area 3 (surface of smooth portion 6A in Figure 6) is measured.

[0121] [Effect]

[0122] As described above, [1] the tire 1 has a marking 2 on the sidewall that defines the vertical direction (see Figure 2). Furthermore, the marking 2 is arranged so that the lower part faces the radial outer side of the tire.

[0123] In this configuration, when the tire 1 is mounted in a wheel well and a cover 20 covering the sidewall of the wheel is provided (see Figure 2), the visual recognizability of the marking 2 on the tire 1 is improved. Specifically, in the vehicle provided with the cover 20, the area above the vertical direction of the tire sidewall is covered by the cover 20, and only a portion of the area on the road surface (not shown in the figure, lower part) is exposed. In this case, by arranging the marking 2 with its lower part facing radially outward from the tire, the marking 2 is displayed without being reversed, thereby improving the visual recognizability of the marking 2 from outside the vehicle.

[0124] Furthermore, [2] in the tire 1 described in [1] above, the marking 2 of the tire 1 is arranged intersectingly at the position Ac where the tire is at its maximum width. In this configuration, the marking 2 is located on the outermost side in the tire width direction, thus having the advantage of improving the visual recognizability of the marking 2.

[0125] Furthermore, [3] in the tire 1 described in [1] or [2] above, the marking 2 in the tire 1 is positioned further radially outward than the tire's maximum width position Ac (see Figures 1 and 2). Thus, even when the lower end of the vehicle's outer cover 20 is relatively long, the marking 2 will be appropriately exposed near the road surface, thereby improving the visual visibility of the marking 2.

[0126] Furthermore, [4] in any one of the tires [1] to [3] described above, the mark 2 in the tire 1 is positioned further radially inward than the tire's maximum width position Ac (illustration omitted). With this configuration, when the tire 1 is mounted on the vehicle, the mark 2 can be seen from outside the vehicle at a gentle angle, thus improving the visual visibility of the mark 2.

[0127] Furthermore, [5] in any one of the tires [1] to [4] above, the marking 2 in the tire 1 is composed of a plurality of elements 21A to 21E arranged separately from each other (see Figures 2 and 3). Furthermore, the minimum distance I [mm] between adjacent elements 21A, 21B; 21B, 21C; 21C, 21D; 21D, 21E is within the range of 0.001 ≤ I / OD ≤ 0.015 relative to the tire outer diameter OD [mm]. This provides the advantage of improved visual recognizability of the marking 2.

[0128] Furthermore, [6] in any one of [1] to [5] above, the tire 1 has a plurality of markings 2, 2 arranged separately in the tire circumferential direction (see FIG2). In addition, the plurality of markings 2, 2 are arranged downward toward the radially outward side of the tire. As a result, when the tire 1 is mounted on a vehicle equipped with the above-described cover 20, the visibility of the markings 2 is increased, thereby improving the visual recognizability of the markings 2.

[0129] Furthermore, [7] in any one of [1] to [6] above, the tire 1 has a pair of thin stripe patterns 5A, 5B extending along the tire circumference on the sidewall (see Figure 2). In addition, the marking 2 is disposed between the pair of thin stripe patterns 5A, 5B. As a result, during tire vulcanization molding, the residual air in the area surrounding the marking 2, especially the smooth area 4, is reduced, thereby having the advantage of reducing vulcanization failure of the tire 1.

[0130] Furthermore, [8] in any one of [1] to [7] above, the tire 1 has a surface-processed area 3 formed by arranging a plurality of protrusions and recesses (grooves 211 and stripe patterns 212 shown in FIG. 4 in FIG. 2) and a smooth area 4 having a smooth surface (see FIG. 2). In addition, the mark 2 is disposed entirely in the smooth area 4. As a result, the outline of the mark 2 becomes clear, thereby having the advantage of improving the visual recognition of the mark 2.

[0131] Furthermore, [9] in any one of [1] to [8] above, the extension range φ3[deg] of the surface-processed area 3 in the tire circumferential direction of the tire 1 is within 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 (see Figure 2). Thus, the extension range φ3[deg] of the surface-processed area 3 and the extension range φ2[deg] of the marking 2 are balanced, which has the advantage of improving the design of the tire sidewall.

[0132] Furthermore,

[10] in any one of [1] to [9] above, the tire 1 has a surface-processed area 3 (see FIG2) on the sidewall portion formed by a plurality of protrusions and recesses (grooves 311 and stripe patterns 312 shown in FIG6 in FIG2). Furthermore, the elements 21B to 21E constituting the mark 2 have a surface-processed portion (see FIG3 and FIG4) formed by a plurality of protrusions and recesses (grooves 211 and stripe patterns 212 shown in FIG4 in FIG2). Furthermore, the sidewall angle θ31 [deg] (see FIG6) of the plurality of protrusions and recesses in the surface-processed area 3 has a relationship of 0 < θ31 - θ21 with respect to the sidewall angle θ21 [deg] (see FIG4) of the plurality of protrusions and recesses in the surface-processed portion of elements 21B to 21E. As a result, the visual recognizability of elements 21B to 21E having the mark 2 is relatively improved compared to the surface-processed area 3.

[0133] Furthermore,

[11] in any of the tires [1] to

[10] described above, the height difference H31 [mm] of the uneven portions 311, 312 constituting the surface-processed area 3 relative to the height difference H21 [mm] of the plurality of uneven portions 211, 212 (see Figure 4) in the surface-processed portions of the elements 21B to 21E of the marking 2 (see Figure 3) is within the range of 0.10 ≤ H31 / H21 ≤ 1.00. Therefore, the visual recognizability of the elements 21B to 21E of the marking 2 is relatively improved compared to the surface-processed area 3.

[0134] Furthermore,

[12] in any one of [1] to

[11] above, the tire 1 includes a pair of bead cores 11, 11, a carcass layer 13 mounted on the pair of bead cores 11, 11, and a belt layer 14 disposed radially outside the carcass layer 13 (see FIG1). Furthermore, the tire outer diameter OD [mm] is in the range of 200 ≤ OD ≤ 660, and the tire total width SW [mm] is in the range of 100 ≤ SW ≤ 400 (see FIG1). This small-diameter tire, by including the aforementioned marking 2, has the advantage of effectively improving the visual recognizability of the marking 2.

[0135] Furthermore,

[13] in the tire 1 described in

[12] above, the strength Tcs [N / 50mm] of each 50mm width of the carcass ply constituting the carcass layer 13 is within 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, thus providing the advantage of suppressing sidewall deformation under applied load and improving the visual visibility of the marking 2.

[0136] Example

[0137] Figures 7 and 8 are graphs showing the performance test results of tires according to embodiments of the present invention.

[0138] In this performance test, visual confirmability evaluations of various test tires were conducted.

[0139] (1) In the evaluation of visual confirmability of the markings, a test tire with a tire size of 145 / 80R12 was mounted on a rim with a rim size of 12×4.00B, and an internal pressure of 80% of the JATMA specified internal pressure and a load of 88% of the JATMA specified load were applied to the test tire. In addition, the test tire was mounted on all wheels of a low-floor vehicle equipped with an outer cover 20 covering the tire sidewall (see Figure 2). Then, the evaluator visually observed the markings 2 on the tire sidewall from a distance of 8m from the vehicle and evaluated their visual confirmability. This evaluation was carried out by an index evaluation based on a comparative example (100), with a higher value being more preferred.

[0140] The test tires of the comparative examples and embodiments have the configuration shown in Figures 1 and 2, and have a pair of units U, U on the sidewall consisting of a marking 2, a surface-processed area 3, and a smooth area 4. Furthermore, the tire outer diameter OD is 531 mm, and the total tire width SW is 143 mm. Additionally, the radial height H2 of elements 21A to 21E constituting the marking 2 is 18 mm, and the radial height H3 of the surface-processed area 3 is 25.5 mm.

[0141] As the test results show, the test tires of the embodiment can improve the visual recognition of the markings.

[0142] Explanation of reference numerals in the attached figures

[0143] 1: Tire; 2: Markings; 21A, 21B: Elements; 211: Groove; 212: Striped pattern; 3: Surface finished area; 311: Groove; 312: Striped pattern; 4: Smooth area; 5A, 5B: Striped pattern; 6A, 6B: Smooth section; 10: Rim; 11: Bead core; 12: Sidewall core; 13: Carcass layer; 14: Belt layer; 141, 142: Cross belts; 143: Belt cover layer; 144: Belt edge cover layer; 15: Tread rubber; 151: Crown tread; 152: Base tread; 16: Sidewall rubber; 17: Rim cushion rubber; 18: Inner liner; 20: Outer cover.

Claims

1. A tire having markings indicating the vertical direction on its sidewall, characterized in that, The markings are configured such that they face radially outward from the tire.

2. The tire according to claim 1, wherein, The markings are arranged in a crisscross pattern at the position of maximum tire width.

3. The tire according to claim 1 or 2, wherein, The marking is positioned further radially outward from the tire's maximum width position.

4. The tire according to any one of claims 1 to 3, wherein, The marking is positioned further radially inside the tire than at the tire's maximum width position.

5. The tire according to any one of claims 1 to 4, wherein, The identifier consists of multiple elements arranged separately from each other, and the minimum distance I [mm] between adjacent elements is in the range of 0.001≤I / OD≤0.015 relative to the tire outer diameter OD [mm].

6. The tire according to any one of claims 1 to 5, comprising a plurality of said markings disposed separately in the tire circumferential direction, and said plurality of markings being disposed downward toward the radially outward side of the tire.

7. The tire according to any one of claims 1 to 6, wherein the tire sidewall has a pair of fine stripe patterns extending in the tire circumferential direction, and the marking is disposed between the pair of fine stripe patterns.

8. The tire according to any one of claims 1 to 7, wherein the tire sidewall has a surface-processed area formed by a plurality of protrusions and recesses, and a smooth area having a smooth surface, and the marking is integrally disposed in the smooth area.

9. The tire according to any one of claims 1 to 8, wherein, The extension range φ3 [deg] of the surface-processed area in the tire circumferential direction is within the range of 1.00 ≤ φ3 / φ2 ≤ 4.00 relative to the extension range φ2 [deg] of the mark in the tire circumferential direction.

10. The tire according to any one of claims 1 to 9, wherein a surface-processed area consisting of a plurality of protrusions and recesses is provided on the sidewall portion, the element constituting the identifier has a surface-processed portion consisting of a plurality of protrusions and recesses, and the sidewall angle θ31[deg] of the plurality of protrusions and recesses in the surface-processed area has a relationship of 0 < θ31 - θ21 with respect to the sidewall angle θ21[deg] of the plurality of protrusions and recesses in the surface-processed portion of the element.

11. The tire according to any one of claims 1 to 10, wherein a surface-processed area consisting of a plurality of protrusions and depressions is provided on the sidewall, the element constituting the identifier has a surface-processed portion consisting of a plurality of protrusions and depressions, and the height difference H31 [mm] of the plurality of protrusions and depressions in the surface-processed area is in the relationship of 0.10 ≤ H31 / H21 ≤ 1.00 with respect to the height difference H21 [mm] of the plurality of protrusions and depressions in the surface-processed portion of the element.

12. The tire according to any one of claims 1 to 11, comprising a pair of bead cores, a carcass layer mounted on the pair of bead cores, and a belt layer disposed radially outward of the carcass layer, wherein the tire outer diameter OD [mm] is in the range of 200≤OD≤660, and the tire total width SW [mm] is in the range of 100≤SW≤400.

13. The tire according to claim 12, wherein, The strength Tcs [N / 50mm] of each 50mm width of the carcass ply constituting the carcass layer is in the range of 17≤Tcs / OD≤120 relative to the tire outer diameter OD [mm].

Images