tire

Abstract

To provide a tire that can improve the visibility of the emblem while reducing the protrusion of the emblem. [Solution] A pneumatic tire 1 having a mark portion 40 on the tire side surface 31, which is the outer surface of the sidewall portion 30, wherein a ridge region 50 is arranged on the tire side surface 31 adjacent to the mark portion 40, and the distance S between adjacent ridges 51 in the ridge region 50 increases as the distance from the contour portion 41 of the mark portion 40 increases.

Description

Technical Field

[0002] , ,

[0001] The present invention relates to a tire.

Background Art

[0002] In tires mounted on vehicles, displays such as brands may be made by forming emblems consisting of characters, symbols, figures, etc. on the surface of the sidewall portion. Also, among tires that display characters, etc. on the sidewall portion, there are some that make the emblem stand out by decorating the emblem. For example, the tire described in Patent Document 1 has a marking protruding from the sidewall and a texture surrounding all or part of the marking, and the texture includes a plurality of substantially parallel plate-like bodies protruding from the sidewall, thereby enhancing the visibility of the marking.

[0003] Also, in the tire described in Patent Document 2, by attaching characters or numbers on the sidewall and forming a plurality of grooves formed in parallel at intervals approaching the characters or numbers, the discriminability of the characters or numbers on the sidewall is enhanced. Further, in the tire described in Patent Document 3, an ornamental region in which a plurality of minute protrusions are arranged is formed adjacent to a mark provided on the surface of the sidewall portion, and the ornamental region includes at least a part of a first region in which the height of the minute protrusions decreases as it moves away from the mark, thereby enhancing the visibility of the mark provided on the surface of the sidewall portion.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

[0005] In recent years, there has been a demand for side designs with raised lettering in all-season tires for SUVs (Sports Utility Vehicles), while at the same time, weight reduction is required to improve fuel efficiency. When using raised lettering for the markings on the surface of the sidewall, the visibility of the lettering can be improved by increasing the degree of raised lettering. However, increasing the degree of raised lettering increases the volume of rubber that forms the lettering. In this case, the mass of the rubber forming the lettering increases, which tends to increase the mass of the tire, potentially making it difficult to reduce the weight of the tire. Therefore, there was room for improvement in the markings on the surface of the tire sidewall in terms of improving the visibility of the markings without hindering tire weight reduction.

[0006] The present invention has been made in view of the above, and aims to provide a tire that can improve the visibility of the mark while suppressing the amount of protrusion of the mark. [Means for solving the problem]

[0007] To solve the above-mentioned problems and achieve the objective, the tire according to the present invention is a tire having a mark portion on the tire side surface, which is the outer surface of the sidewall portion, wherein a ridge region is arranged on the tire side surface adjacent to the mark portion, and the ridges of the ridge region are characterized in that the spacing between adjacent ridges increases as the distance from the contour portion of the mark portion increases.

[0008] Furthermore, in the above-mentioned tire, when the ridge region is positioned such that one side of the first direction, which is a predetermined direction along the tire side surface, is the upstream side and the other side is the downstream side, it is preferable that the ridge region is not positioned at a location on the upstream side in the first direction relative to the contour portion of the marking portion, but rather at a location on the downstream side in the first direction.

[0009] Furthermore, in the above-mentioned tire, the mark portion is a mark portion that represents characters, and the first direction is preferably determined relative to the mark portion in a direction from the upper left to the lower right of the characters, such that the upper left of the characters represented by the mark portion is the upstream side and the lower right of the characters is the downstream side.

[0010] Furthermore, in the above-mentioned tire, it is preferable that the ratio of the width W of the ridge region from the contour portion of the marking portion to the height h of the marking portion from the tire side surface is within the range of 1 ≤ W / h ≤ 10.

[0011] Furthermore, in the above-mentioned tire, it is preferable that the plurality of ridges in the ridge region have a pitch A between adjacent ridges A ≥ 0.03 mm, and that the pitch A increases as the distance from the contour portion of the mark increases, and that there is at least one portion where the pitch A is 0.55 mm or more.

[0012] Furthermore, in the above-mentioned tire, it is preferable that the pitch A between adjacent ridges in the ridge region is constant, and that the width of the ridges narrows as the distance from the contour portion of the mark increases.

[0013] Furthermore, in the above-mentioned tire, it is preferable that the ratio of the height H of the ridge to the height h of the marking portion from the tire side surface is within the range of 0.6 ≤ H / h ≤ 1.

[0014] Furthermore, in the above-mentioned tire, it is preferable that the height of the multiple ridges in the ridge region decreases as the distance from the contour portion of the mark portion increases.

[0015] Furthermore, in the above-mentioned tire, it is preferable that the angle of the wall surface constituting the contour portion of the marking portion with respect to the tire side surface is within the range of 90° to 150°. [Effects of the Invention]

[0016] The tire according to the present invention has an effect that the visibility of the logo part can be enhanced while suppressing the convex amount of the logo part.

Brief Description of the Drawings

[0017] [Figure 1] FIG. 1 is a meridian cross-sectional view showing a main part of a pneumatic tire according to an embodiment. [Figure 2] FIG. 2 is a plan view of the tire side surface shown in FIG. 1. [Figure 3] FIG. 3 is a detailed view of the logo part shown in FIG. 2. [Figure 4] FIG. 4 is a cross-sectional view taken along the line B-B of FIG. 3, and is a cross-sectional view of the ridge region as viewed in the extending direction of the ridge that the ridge region has. [Figure 5] FIG. 5 is a detailed view of the contour part that the logo part shown in FIG. 4 has. [Figure 6] FIG. 6 is a detailed view of the contour part that the logo part shown in FIG. 4 has. [Figure 7] FIG. 7 is a modified example of a pneumatic tire according to an embodiment, and is an explanatory view showing a form in which a concave part is formed around the logo part on the tire side surface. [Figure 8] FIG. 8 is a modified example of a pneumatic tire according to an embodiment, and is an explanatory view showing a form in which the width of the ridge changes. [Figure 9] FIG. 9 is a modified example of a pneumatic tire according to an embodiment, and is an explanatory view showing a form in which the height of the ridge changes. [Figure 10] FIG. 10 is a modified example of a pneumatic tire according to an embodiment, and is an explanatory view showing a modified example of the shape of the ridge. [Figure 11] FIG. 11 is a chart showing the results of a performance evaluation test of a pneumatic tire.

Modes for Carrying Out the Invention

[0018] Embodiments of the tire according to the present invention will be described in detail below with reference to the drawings. However, the present invention is not limited by these embodiments. Furthermore, the components in the following embodiments include those that are substituted and readily conceivable by those skilled in the art, or that are substantially identical.

[0019] [Embodiment] [Air-filled tires] In the following description, a pneumatic tire 1 will be used as an example of a tire according to the present invention. The pneumatic tire 1, which is an example of a tire, can be filled with air, an inert gas such as nitrogen, and other gases.

[0020] Furthermore, in the following explanation, the tire radial direction refers to the direction perpendicular to the tire rotation axis (not shown), which is the rotation axis of the pneumatic tire 1. The inner side of the tire radial direction refers to the side toward the tire rotation axis in the tire radial direction, and the outer side of the tire radial direction refers to the side away from the tire rotation axis in the tire radial direction. The tire circumferential direction refers to the direction around the tire rotation axis as the central axis. The tire width direction refers to the direction parallel to the tire rotation axis. The inner side of the tire width direction refers to the side toward the tire equatorial plane (tire equator line) CL in the tire width direction, and the outer side of the tire width direction refers to the side away from the tire equatorial plane CL in the tire width direction. The tire equatorial plane CL is a plane perpendicular to the tire rotation axis and passing through the center of the tire width of the pneumatic tire 1. The position of the tire equatorial plane CL in the tire width direction coincides with the center line in the tire width direction, which is the center position of the pneumatic tire 1 in the tire width direction. The tire width is the distance in the tire width direction between the outermost parts in that direction, that is, the distance between the parts furthest from the tire equatorial plane CL in that direction. The tire equatorial line is a line on the tire equatorial plane CL that runs along the circumferential direction of the pneumatic tire 1. In the following explanation, the tire meridional section refers to the cross-section obtained when the tire is cut by a plane containing the tire's axis of rotation.

[0021] Figure 1 is a meridional cross-sectional view showing the main part of a pneumatic tire 1 according to an embodiment. In the pneumatic tire 1 shown in Figure 1, the tread portion 2 is located at the outermost part in the tire radial direction when viewed in the tire meridional cross-section, and the surface of the tread portion 2, that is, the part that comes into contact with the road surface when a vehicle (not shown) equipped with the pneumatic tire 1 is running, is formed as a tread surface 3. Multiple circumferential main grooves 25 extending in the tire circumferential direction are formed on the tread surface 3 of the tread portion 2, and multiple land areas 20 are defined on the tread surface 3 by these circumferential main grooves 25. Grooves other than the circumferential main grooves 25 may be formed on the tread surface 3, and lug grooves (not shown) extending in the tire width direction or narrow grooves (not shown) different from the circumferential main grooves 25 may be formed.

[0022] Shoulder portions 8 are located at both ends of the tread portion 2 in the tire width direction, and sidewall portions 30 are positioned on the radially inner side of the shoulder portions 8. In other words, sidewall portions 30 are located at two locations on both sides of the pneumatic tire 1 in the tire width direction. The outer surface of the sidewall portions 30 is formed as a tire side surface 31, and the tire side surfaces 31 are located on both sides in the tire width direction. The two tire side surfaces 31 face opposite sides of each sidewall portion 30, in the tire width direction, to the side where the tire equatorial plane CL is located.

[0023] In this case, the tire side surface 31 refers to a surface that is uniformly continuous in the range from the contact end T of the tread portion 2 outward in the tire width direction and from the rim check line R outward in the tire radial direction. The contact end T refers to the outermost edges in the tire width direction in the region where the tread surface 3 of the tread portion 2 of the pneumatic tire 1 contacts the road surface when the pneumatic tire 1 is mounted on a regular rim, filled with the regular internal pressure, and subjected to 70% of the regular load, and is continuous in the tire circumferential direction. The rim check line R is a line used to check whether the tire has been mounted on the rim correctly, and is generally shown as an annular convex line that is continuous in the tire circumferential direction along the outer surface of the bead portion 10, outside the rim flange (not shown) in the tire radial direction and near the rim flange.

[0024] Furthermore, a "regular rim" refers to the "applicable rim" specified by JATMA, the "Design Rim" specified by TRA, or the "Measuring Rim" specified by ETRTO. Also, "regular internal pressure" refers to the "maximum air pressure" specified by JATMA, the maximum value of "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES" specified by TRA, or the "INFLATION PRESSURES" specified by ETRTO. Finally, "regular load" refers to the "maximum load capacity" specified by JATMA, the maximum value of "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES" specified by TRA, or the "LOAD CAPACITY" specified by ETRTO.

[0025] On the radially inner side of each sidewall portion 30 located on both sides in the tire width direction, there are bead portions 10. The bead portions 10 are arranged at two locations on both sides of the tire equatorial plane CL, similar to the sidewall portions 30. Each bead portion 10 is provided with a bead core 11, and a bead filler 12 is provided on the radially outer side of the bead core 11.

[0026] Furthermore, multiple belt layers 14 are provided on the inner side of the tread portion 2 in the tire radial direction. The belt layers 14 are formed by laminating multiple cross belts 141, 142 and a belt cover 143. Of these, the cross belts 141, 142 are constructed by covering multiple belt cords made of steel or organic fiber material with coated rubber and rolling them, and have a belt angle of 20° to 55° in absolute value. The multiple cross belts 141, 142 have different belt angles, defined as the inclination angle of the fiber direction of the belt cord with respect to the tire circumferential direction, and are constructed as a so-called cross-ply structure, where the fiber directions of the belt cords intersect with each other and are laminated. The belt cover 143 is constructed by rolling multiple cords made of steel or organic fiber material covered with coated rubber and has a belt angle of 0° to 10° in absolute value. This belt cover 143 is laminated and arranged on the outer side of the cross belts 141, 142 in the tire radial direction.

[0027] A carcass 13 containing the cords of the radial ply is continuously provided on the inner side of the belt layer 14 in the tire radial direction, and on the tire equatorial plane CL side of the sidewall portion 30. This carcass 13 has a single-layer structure consisting of one carcass ply, or a multi-layer structure consisting of multiple carcass ply stacked together, and is toroidally stretched between the bead cores 11 arranged on both sides in the tire width direction to form the tire's skeleton. More specifically, the carcass 13 is arranged from one bead portion 10 to the other bead portion 10, which are located on both sides in the tire width direction, and is wrapped back along the bead core 11 in the tire width direction outward at the bead portion 10 so as to enclose the bead core 11 and bead filler 12.

[0028] In the carcass 13, the portion of the bead core 11 that is wrapped back outward in the tire width direction forms a turn-up portion 18, which extends to the outer diameter of the bead filler 12. Therefore, the outer diameter of the turn-up portion 18 is located further outward than the bead filler 12, and is located near the portion of the sidewall 30 that has the maximum width in the tire width direction of the pneumatic tire 1. Furthermore, the carcass ply of the carcass 13 is constructed by coating multiple carcass cords made of steel or organic fiber materials such as aramid, nylon, polyester, or rayon with coating rubber and rolling it, and the carcass angle, which is the angle of inclination of the fiber direction of the carcass cord with respect to the tire circumferential direction, is formed to be between 80° and 95° in absolute value.

[0029] In the bead portion 10, rim cushion rubber 17 is arranged on the inner side in the tire radial direction and the outer side in the tire width direction of the bead core 11 and the reversal portion of the carcass 13, forming the contact surface of the bead portion 10 with the rim flange. In addition, an inner liner 15 is formed along the carcass 13 on the inside of the carcass 13, or on the inner side of the carcass 13 in the pneumatic tire 1.

[0030] Figure 2 is a plan view of the tire side surface 31 shown in Figure 1. The tire side surface 31, located at two locations on both sides in the tire width direction, has a marking section 40, which is arranged for the purpose of improving the appearance of the pneumatic tire 1 and displaying various information, and a peripheral area 60 arranged around the marking section 40.

[0031] The mark portion 40 includes a mark consisting of letters, figures, or symbols, or a combination thereof, and in particular includes a trademark that functions as an identifying mark indicating a tire manufacturer, tire brand, etc. The mark portion 40 is formed to protrude from the tire side surface 31. Furthermore, multiple mark portions 40 are arranged spaced apart in the circumferential direction of the tire. For example, in the configuration shown in Figure 2, the mark portion 40 has an element 40A of the string of characters "YOKOHAMA" indicating the tire manufacturer, and an element 40B of a logo that is a stylized version of the initial letter "Y," and elements 40A and 40B of the mark portion 40 are arranged on the tire side surface 31, respectively. Furthermore, a pair of mark portions 40 are arranged at two points on the annular tire side surface 31 that are point-symmetrical with respect to the rotation axis of the pneumatic tire 1.

[0032] The mark portion 40 has a height Da [mm] of each element 40A in the tire radial direction that is in the range of 0.05 ≤ Da / SH ≤ 0.80, preferably in the range of 0.10 ≤ Da / SH ≤ 0.70, relative to the tire cross-sectional height SH [mm] (see Figure 1). This improves the visibility of the mark portion 40. The height Da of element 40A in the tire radial direction is measured as the maximum value of the extended dimension of element 40A in the tire radial direction.

[0033] The tire section height SH is half the difference between the tire outer diameter and the rim diameter, and is measured under no-load conditions with a pneumatic tire 1 mounted on a specified rim and with the specified internal pressure applied.

[0034] The peripheral region 60 is the area surrounding the emblem portion 40 and is formed on the tire side surface 31. The peripheral region 60 may be a smooth surface with a smooth surface, or it may be an uneven surface with a surface treatment. In this embodiment, the peripheral region 60 is formed between a pair of thin ribs 65 and 66 that extend in the circumferential direction of the tire and are positioned at different locations in the radial direction of the tire. This enhances the design of the tire side surface 31 of the pneumatic tire 1. Furthermore, the peripheral region 60 has an annular structure that extends over the entire circumference of the tire side surface 31 in the circumferential direction of the tire, and thus includes both the emblem portions 40.

[0035] In the pneumatic tire 1 according to this embodiment, the marking portion 40 and the surrounding area 60 are positioned radially outward from the tire's maximum width position Ac. More specifically, the marking portion 40 and the surrounding area 60 are positioned in the region from the contact end T of the tread portion 2 (see Figure 1) to the tire's maximum width position Ac, with a pair of thin ribs 65 and 66 extending in the circumferential direction of the tire to demarcate the surrounding area 60, and the marking portion 40 is positioned between these thin ribs 65 and 66. This enhances the visibility of the marking portion 40 in the pneumatic tire 1. The configuration is not limited to this, and although not explicitly shown in the figure, the marking portion 40 and the surrounding area 60 may be positioned on the tire side surface 31 including the tire's maximum width position Ac, or they may be positioned radially inward from the tire's maximum width position Ac.

[0036] The maximum tire width position Ac is defined as the position of the maximum tire section width on the tire side surface 31. The tire section width is measured as the straight-line distance in the tire width direction between the tire side surface 31, excluding the marking portion 40, the surrounding area 60, and any irregularities such as patterns or letters like the thin ribs 65, 66, when the tire is mounted on a regular rim, subjected to regular internal pressure, and in an unloaded state.

[0037] Furthermore, the thin ribs 65 and 66 have a width of 0.4 mm to 0.8 mm and a height of 0.1 mm to 1.0 mm from the tire side surface 31, and function as a discharge path for residual air during tire vulcanization molding. As a result, the occurrence of vulcanization failures in the marking area 40 and surrounding area 60 of the pneumatic tire 1 is suppressed. In addition, in the pneumatic tire 1 of this embodiment, the thin rib 65 on the radially outer side of the tire is located at the split position of the mold of the tire molding die.

[0038] Furthermore, the height Da [mm] of element 40A in the tire radial direction of the emblem portion 40 is in the range of 0.30 ≤ Da / Db ≤ 0.80, preferably in the range of 0.40 ≤ Da / Db ≤ 0.70, relative to the arrangement spacing Db [mm] of the thin ribs 65, 66 in the tire radial direction. In addition, in the pneumatic tire 1 of the embodiment, it is preferable that the emblem portion 40 is positioned away from the pair of thin ribs 65, 66, as shown in Figure 2. These features enhance the visibility of the emblem portion 40 in the pneumatic tire 1.

[0039] Figure 3 is a detailed view of the mark portion 40 shown in Figure 2. Figure 3 is a detailed view of the mark portion 40 as seen from the front, and is a detailed view of some elements 40A of the mark portion 40 shown in Figure 2 as an example of the mark portion 40. A ridge region 50 is located on the tire side surface 31 adjacent to the mark portion 40. The ridge region 50 has a plurality of ridges 51 that protrude from the tire side surface 31 and extend parallel to the contour portion 41 of the mark portion 40. When a predetermined direction along the tire side surface 31 is considered the first direction, and one side of the first direction is considered the upstream side and the other side is considered the downstream side, the ridge region 50 is not located at a position on the upstream side in the first direction relative to the contour portion 41 of the mark portion 40, but is located at a position on the downstream side in the first direction.

[0040] In other words, if the contour portion 41 of the mark portion 40 that faces upstream in the first direction is designated as the upstream contour portion 41a, and the contour portion 41 that faces downstream in the first direction is designated as the downstream contour portion 41b, then the ridge region 50 is not located at the position of the upstream contour portion 41a, but is located adjacent to the downstream contour portion 41b.

[0041] The first direction referred to here is, for example, the direction of irradiation of light directed onto the mark portion 40, and the upstream and downstream sides of the first direction are the directions of the upstream and downstream sides in the direction of light irradiation. In other words, the first direction is the direction of irradiation of light directed from the upstream side to the downstream side, the upstream side in the first direction is the direction of the upstream side in the direction of light irradiation, and the downstream side in the first direction is the direction of the downstream side in the direction of light irradiation.

[0042] For example, if the trademark portion 40 is a trademark portion 40 representing characters, as shown in element 40A in Figure 3, the first direction is defined relative to the trademark portion 40 as a direction from the upper left to the lower right of the characters, with the upper left of the characters represented by the trademark portion 40 being the upstream side of the first direction and the lower right of the characters being the downstream side of the first direction. In other words, in this embodiment, the first direction is the direction assumed to be the direction of light irradiated from the upper left to the lower right of element 40A, which is the trademark portion 40 representing characters. For this reason, in the example shown in Figure 3, among the contour portions 41 of the trademark portion 40, the contour portion 41 facing the upper left becomes the upstream contour portion 41a, and the contour portion 41 facing the upper left becomes the downstream contour portion 41b. The ridge region 50 is not positioned at the location of the upstream contour portion 41a defined in this way, but is positioned adjacent to the downstream contour portion 41b.

[0043] The ridge region 50 has multiple ridges 51 that extend parallel to the adjacent downstream contour portion 41b, and the multiple ridges 51 extend parallel to the downstream contour portion 41b while being spaced apart from each other.

[0044] Furthermore, the multiple ridges 51 in the ridge region 50 are arranged such that the ends 51a of each ridge 51 that do not abut the mark portion 40 in the direction of extension of the ridge 51 are aligned with adjacent ridges 51 in a direction along the first direction. In addition, the ends 51a of each ridge 51 that do not abut the mark portion 40 in the direction of extension of the ridge 51 are also aligned with the ends of the downstream contour portion 41b in the direction of extension in a direction along the first direction.

[0045] Figure 4 is a cross-sectional view of the BB of Figure 3, and is a cross-sectional view of the ridge region 50 as seen in the direction of extension of the ridge 51 of the ridge region 50. The marking portion 40, which protrudes from the tire side surface 31 and is positioned on the tire side surface 31, protrudes from the profile reference plane P. The profile reference plane P is the contour line that smoothly connects the shoulder portion 8 and the bead portion 10 in the tire meridional section shown in Figure 1. The profile reference plane P is composed of one or more arcs. The profile reference plane P is defined by excluding partial irregularities such as the marking portion 40 and the thin ribs 65, 66 (see Figure 2).

[0046] Furthermore, in this embodiment, the ridge 51 of the ridge region 50 also protrudes from the profile reference plane P. In this embodiment, the ridge 51 is formed in the shape of an isosceles triangle, where the width of the ridge 51 narrows from the base to the tip when viewed in the direction of its extension.

[0047] The width W of the ridge region 50 from the contour portion 41 of the mark portion 40 is such that the ratio of the width W of the ridge region 40 to the height h of the mark portion 40 from the tire side surface 31 is within the range of 1 ≤ W / h ≤ 10. In this case, the height h of the mark portion 40 is, in other words, the height from the profile reference surface P. It is preferable that the ratio of the width W of the ridge region 50 to the height h of the mark portion 40 is within the range of 2 ≤ W / h ≤ 5.

[0048] The multiple ridges 51 of the ridge region 50 have a width G in the range of 0.5 mm to 2 mm and a height H in the range of 0.5 mm to 1.5 mm. The ratio of the height H of the ridge 51 to the height h of the mark portion 40 is in the range of 0.6 ≤ H / h ≤ 1.

[0049] The multiple ridges 51 in the ridge region 50 have a spacing S between adjacent ridges 51 that increases as the distance from the contour portion 41 of the mark portion 40 increases. The spacing S between adjacent ridges 51 here is the distance between adjacent ridges 51 at the position where the distance between them is smallest.

[0050] In this embodiment, the multiple ridges 51 in the ridge region 50 have substantially the same width G, and the pitch A between adjacent ridges 51 increases as the distance from the contour portion 41 of the mark portion 40 increases. As a result, the spacing S between adjacent ridges 51 in the multiple ridges 51 in the ridge region 50 increases as the distance from the contour portion 41 of the mark portion 40 increases.

[0051] Furthermore, in this embodiment, the multiple ridges 51 in the ridge region 50 satisfy the condition that the pitch A between adjacent ridges 51 is A ≥ 0.03 mm, and includes at least one location where the pitch A is 0.55 mm or more. Therefore, among the multiple ridges 51 in the ridge region 50, the pitch A between at least the ridge 51 located furthest from the contour portion 41 of the mark portion 40 and the ridge 51 adjacent to that ridge 51 is 0.55 mm or more.

[0052] Figures 5 and 6 are detailed views of the contour portion 41 of the mark portion 40 shown in Figure 4. The wall surface 42 constituting the contour portion 41 of the mark portion 40 is formed at an angle of 90° with respect to the profile reference plane P of the tire side surface 31, as shown in Figure 5. The wall surface 42 constituting the contour portion 41 of the mark portion 40 may be formed to be inclined away from the ridge 51 of the ridge region 50 as it moves away from the profile reference plane P, as shown in Figure 6. Preferably, the angle θ of the wall surface 42 constituting the contour portion 41 of the mark portion 40 with respect to the profile reference plane P of the tire side surface 31 is formed within the range of 90° to 150°.

[0053] [Mechanism of Action and Effects] Next, the operation and effects of the pneumatic tire 1 according to the embodiment will be described. In the pneumatic tire 1 according to the embodiment, a marking portion 40 is arranged on the tire side surface 31. This allows for improved appearance and the display of various information through the marking portion 40. In addition, a ridge region 50 is arranged adjacent to the marking portion 40 on the tire side surface 31, and the ridge region 50 has a plurality of ridges 51 that extend parallel to the contour portion 41 of the marking portion 40. This makes the marking portion 40 more conspicuous due to the plurality of ridges 51 of the ridge region 50, thereby improving the visibility of the marking portion 40.

[0054] Furthermore, the multiple ridges 51 in the ridge region 50 have a spacing S between adjacent ridges 51 that increases as the distance from the contour portion 41 of the mark portion 40 increases. As a result, the ridge region 50 can make the mark portion 40 appear to protrude significantly from the tire side surface 31 due to the multiple ridges 51 whose spacing S increases as the distance from the contour portion 41 of the mark portion 40 increases.

[0055] In other words, the ridge region 50 is made up of multiple ridges 51, the spacing S of which increases as the distance from the outline 41 of the mark portion 40 increases. This creates the illusion that the ridge region 50 is the shadow of the mark portion 40, which becomes lighter as it moves away from the mark portion 40. More specifically, in areas where the spacing S of the ridges 51 is narrow, the light reflected by the ridges 51 is more easily diffusely scattered, so these areas appear relatively dark. In areas where the spacing S of the ridges 51 is wide, the diffuse scattering of light reflected by the ridges 51 is reduced, so these areas appear relatively brighter. For this reason, the ridge region 50 can be made to appear as the shadow of the mark portion 40, which is darker when close to the mark portion 40 and becomes lighter as it moves away from the mark portion 40.

[0056] As a result, the ridge region 50 creates an optical illusion that makes the emblem portion 40 appear to protrude significantly from the tire side surface 31, to the point where it casts a wide shadow, thus making the emblem portion 40 stand out. Therefore, the ridge region 50 having multiple ridges 51 can make the emblem portion 40 appear to protrude significantly without increasing the height h of the emblem portion 40 from the tire side surface 31, thereby improving the visibility of the emblem portion 40 without increasing the amount of protrusion of the emblem portion 40. As a result, the visibility of the emblem portion 40 can be improved while suppressing the amount of protrusion of the emblem portion 40.

[0057] Furthermore, the ridge region 50 is not positioned upstream of the outline 41 of the mark portion 40 in the first direction, but rather downstream in the first direction. This creates an optical illusion that makes the ridge region 50 appear as the shadow of the mark portion 40. This makes it possible to create the illusion that the mark portion 40 protrudes significantly from the tire side surface 31 without increasing the protrusion of the mark portion 40, thereby improving the visibility of the mark portion 40. As a result, the visibility of the mark portion 40 can be improved while suppressing the protrusion of the mark portion 40.

[0058] Furthermore, when the mark portion 40 represents a character, the first direction is determined relative to the mark portion 40 such that the upper left of the character represented by the mark portion 40 is the upstream side and the lower right of the character is the downstream side. As a result, the ridge region 50 adjacent to the mark portion 40 can create the illusion that the character represented by the mark portion 40 protrudes significantly from the tire side surface 31. This makes it possible to improve the visibility of the mark portion 40 while suppressing the amount of protrusion of the mark portion 40.

[0059] Furthermore, the width W of the ridge region 50 from the contour portion 41 of the mark portion 40 is within the range of 1 ≤ W / h ≤ 10 in ratio to the height h of the mark portion 40. This prevents the width W of the ridge region 50 from becoming too wide while still allowing the optical illusion effect of the ridge region 50 to be achieved. In other words, if the width W of the ridge region 50 is W / h < 1 relative to the height h of the mark portion 40, the width W of the ridge region 50 is too narrow, which may make it difficult to achieve the optical illusion effect of making the ridge region 50 appear as a shadow of the mark portion 40. Also, if the width W of the ridge region 50 is W / h > 10 relative to the height h of the mark portion 40, the width W of the ridge region 50 is too wide, which may cause the ridge region 50 to stand out too much relative to the mark portion 40, potentially reducing the visibility of the mark portion 40.

[0060] In contrast, if the width W of the ridge region 50 is within the range of 1 ≤ W / h ≤ 10 relative to the height h of the mark portion 40, it is possible to create an optical illusion that makes the ridge region 50 appear as a shadow of the mark portion 40 while preventing the width W of the ridge region 50 from becoming too wide. As a result, the visibility of the mark portion 40 can be more reliably improved.

[0061] Furthermore, the multiple ridges 51 in the ridge region 50 have a pitch A between adjacent ridges 51, so that changes in the spacing S between ridges 51 can be recognized more reliably. In other words, if the pitch A between adjacent ridges 51 is A < 0.03 mm, the pitch A between the ridges 51 is too narrow, which may make it difficult to recognize changes in the spacing S between ridges 51. However, because the pitch A between ridges 51 is A ≥ 0.03 mm, changes in the spacing S between ridges 51 can be recognized more reliably.

[0062] Furthermore, since the multiple ridges 51 of the ridge region 50 include at least one section where the pitch A is 0.55 mm or more, the perceived shade of the shadow can be more reliably created by changing the spacing S between the ridges 51. In other words, if there is no section where the pitch A between adjacent ridges 51 is 0.55 mm or more, there will be no section that makes the shadow appear faint, and it may be difficult to obtain the effect of creating shades in the perceived shadow. On the other hand, if there is at least one section where the pitch A between adjacent ridges 51 is 0.55 mm or more, the effect of creating shades in the perceived shadow can be obtained more reliably. As a result, the optical illusion effect of making the ridge region 50 appear as the shadow of the mark 40 can be obtained more reliably, and the visibility of the mark 40 can be more reliably improved.

[0063] Furthermore, since the ratio of the height H of the ridge 51 to the height h of the mark portion 40 is within the range of 0.6 ≤ H / h ≤ 1, the ridge 51 can exert its optical illusion effect while preventing the height H of the ridge 51 from becoming too high. In other words, if the ratio of the height H of the ridge 51 to the height h of the mark portion 40 is H / h < 0.6, the height H of the ridge 51 is too low relative to the height h of the mark portion 40, which may make the ridge 51 difficult to see. In this case, even if the ridge 51 is placed near the mark portion 40, it may be difficult to exert the optical illusion effect of making the ridge region 50 appear as a shadow of the mark portion 40. Also, if the ratio of the height H of the ridge 51 to the height h of the mark portion 40 is H / h > 1, the height H of the ridge 51 is too high relative to the height h of the mark portion 40, which may make the ridge 51 stand out too much relative to the mark portion 40, potentially reducing the visibility of the mark portion 40.

[0064] In contrast, if the height H of the ridge 51 relative to the height h of the mark portion 40 is within the range of 0.6 ≤ H / h ≤ 1, it is possible to create an optical illusion that makes the ridge region 50 appear as a shadow of the mark portion 40 while preventing the height H of the ridge 51 from becoming too high. As a result, the visibility of the mark portion 40 can be more reliably improved.

[0065] Furthermore, since the angle θ of the wall surface 42 constituting the contour portion 41 of the mark portion 40 with respect to the tire side surface 31 is within the range of 90° to 150°, the illusion effect that the ridge region 50 adjacent to the contour portion 41 of the mark portion 40 is the shadow of the mark portion 40 can be obtained more reliably. In other words, if the angle θ of the wall surface 42 of the mark portion 40 exceeds 150°, the angle θ of the wall surface 42 is too large, and there is a risk that the ridge region 50 adjacent to the contour portion 41 of the mark portion 40 will not be recognized as the shadow of the mark portion 40.

[0066] In contrast, if the angle θ of the wall surface 42 of the mark portion 40 is within the range of 90° to 150°, the illusion effect that the ridge region 50 adjacent to the contour portion 41 of the mark portion 40 is the shadow of the mark portion 40 can be obtained more reliably. As a result, the visibility of the mark portion 40 can be more reliably improved while suppressing the amount of protrusion of the mark portion 40.

[0067] [Differentiation] In the above-described embodiment, the ridge 51 of the ridge region 50 was formed protruding from the profile reference surface P, but the ridge 51 of the ridge region 50 does not have to protrude from the profile reference surface P.

[0068] Figure 7 is an explanatory diagram showing a modified example of the pneumatic tire 1 according to the embodiment, in which a recess 32 is formed around the mark portion 40 on the tire side surface 31. On the tire side surface 31, a recess 32 may be formed near the mark portion 40 on the tire side surface 31, for example, as shown in Figure 7, so that the mark portion 40 appears to protrude more.

[0069] In this case, the recess 32 is formed indented from the profile reference plane P at a position adjacent to the mark portion 40 on the tire side surface 31. As a result, the height of the mark portion 40 from the bottom surface of the recess 32 is increased, so the effective amount of protrusion relative to the bottom surface of the recess 32 can be increased without increasing the height h from the profile reference plane P. Therefore, the visibility of the mark portion 40 can be improved.

[0070] Furthermore, if a recess 32 is formed around the mark portion 40 in this manner, the ridge region 50 may be located in the recess 32. When the ridge region 50 is located in the recess 32, the ridges 51 of the ridge region 50 are located on the bottom surface of the recess 32. That is, when a recess 32 is formed around the mark portion 40, the ridges 51 of the ridge region 50 are located on the bottom surface of the recess 32, which is recessed from the profile reference surface P, rather than protruding from the profile reference surface P.

[0071] By positioning a ridge region 50 having multiple ridges 51 in a recess 32 formed around the mark portion 40, the mark portion 40 appears to protrude more significantly due to the optical illusion effect of the multiple ridges 51 on the ridge region 50, in addition to the substantial amount of protrusion relative to the bottom surface of the recess 32. As a result, the visibility of the mark portion 40 can be more reliably improved while suppressing the amount of protrusion of the mark portion 40.

[0072] Furthermore, in the embodiment described above, the distance S between the ridges 51 in the ridge region 50 changes as the pitch A between adjacent ridges 51 changes. However, the distance S between adjacent ridges 51 may be changed by means other than changing the pitch A.

[0073] Figure 8 is an explanatory diagram showing a modified example of the pneumatic tire 1 according to the embodiment, in which the width G of the ridge 51 changes. The multiple ridges 51 in the ridge region 50 may be formed such that, for example as shown in Figure 8, the pitch A between adjacent ridges 51 is constant, and the width G of the ridges 51 narrows as the distance from the contour portion 41 of the mark portion 40 increases. By forming the multiple ridges 51 in the ridge region 50 with a narrowing width G of the ridges 51 as the distance from the contour portion 41 of the mark portion 40 increases, the spacing S between adjacent ridges 51 can be increased as the distance from the contour portion 41 of the mark portion 40 increases.

[0074] In this way, by narrowing the width G of the ridge 51 as the distance from the contour 41 of the emblem portion 40 increases, the ridge 51 becomes less visible as the distance from the contour 41 of the emblem portion 40 increases. Therefore, the ridge region 50 can more reliably create the illusion of shadowing the emblem portion 40 by the multiple ridges 51, with the shadow intensity decreasing as it moves away from the emblem portion 40. As a result, the ridge region 50 having multiple ridges 51 can make the emblem portion 40 appear to protrude significantly without increasing the height h of the emblem portion 40 from the tire side surface 31. As a result, the visibility of the emblem portion 40 can be improved while suppressing the amount of protrusion of the emblem portion 40.

[0075] Furthermore, in the embodiment described above, the height H of the multiple ridges 51 in the ridge region 50 is constant, but the height H of the ridges 51 does not have to be constant.

[0076] Figure 9 is an explanatory diagram showing a modified example of the pneumatic tire 1 according to the embodiment, in which the height H of the ridge 51 changes. The multiple ridges 51 in the ridge region 50 may be formed such that, for example, as shown in Figure 9, the height H of the ridge 51 decreases as the distance from the contour portion 41 of the mark portion 40 increases. By lowering the height H of the ridge 51 as the distance from the contour portion 41 of the mark portion 40 increases, the volume of the ridge 51 decreases as the distance from the contour portion 41 of the mark portion 40 increases, making it difficult to see.

[0077] Therefore, the ridge region 50 can more reliably create the illusion of shadowing the emblem portion 40 by the multiple ridges 51, with the shadow intensity decreasing as it moves away from the emblem portion 40. As a result, the ridge region 50 with multiple ridges 51 can make the emblem portion 40 appear to protrude significantly without increasing the height h of the emblem portion 40 from the tire side surface 31. Consequently, the visibility of the emblem portion 40 can be improved while suppressing the amount of protrusion of the emblem portion 40.

[0078] Furthermore, in the above-described embodiment, the ridge 51 of the ridge region 50 is formed in the shape of an isosceles triangle when viewed in the direction of extension of the ridge 51, but the ridge 51 of the ridge region 50 may be formed in a shape other than this.

[0079] Figure 10 is a modified example of the pneumatic tire 1 according to the embodiment, and is an explanatory diagram showing modified shapes of the ridge 51. The ridge 51 of the ridge region 50 may be, for example, trapezoidal in shape as shown in Figure 10(a), or be a chamfered rectangular shape as shown in Figure 10(b), or a shape that combines a triangle and a rectangle as shown in Figure 10(c). Furthermore, the ridge 51 of the ridge region 50 may be formed with a curved surface, or be a rectangular shape with an arc-shaped chamfer as shown in Figure 10(d), or be a shape that combines a semicircle and a rectangle as shown in Figure 10(e).

[0080] Furthermore, the ridges 51 of the ridge region 50 may be formed in a shape that is asymmetrical when viewed in the direction of extension of the ridge 51. For example, as shown in Figure 10(f), the ridges 51 may be formed in the shape of a right triangle with an asymmetrical shape when viewed in the direction of extension of the ridge 51. The shape of the individual ridges 51 of the ridge region 50 does not matter as long as the spacing S between adjacent ridges 51 increases as the distance from the contour portion 41 of the mark portion 40 increases.

[0081] Furthermore, in the embodiment described above, the first direction is defined as the direction in which light is assumed to be irradiated from the upper left to the lower right of the mark portion 40, but the first direction may be defined as a direction other than this with respect to the mark portion 40. Regardless of the orientation of the first direction, the ridge region 50 is not to be placed at a position adjacent to the contour portion 41 of the mark portion 40 that faces upstream in the first direction, but rather the ridge region 50 is to be placed at a position adjacent to the contour portion 41 that faces downstream in the first direction.

[0082] Furthermore, in the embodiments described above, a ridge region 50 adjacent to an element 40A representing characters was described as an example of a trademark portion 40. However, the trademark portion 40 adjacent to the ridge region 50 may not be a trademark portion 40 representing characters, and may be a trademark portion 40 representing any logo, such as element 40B shown in Figure 2. Regardless of the type of trademark portion 40, as the distance from the contour portion 41 of the trademark portion 40 increases, the spacing S between adjacent ridges 51 increases, thereby increasing the visibility of the trademark portion 40 while suppressing the amount of protrusion of the trademark portion 40.

[0083] Furthermore, the embodiments and modifications described above may be combined as appropriate. In addition, although the embodiments described above used pneumatic tire 1 as an example of a tire according to the present invention, the tire according to the present invention may be other than pneumatic tire 1. The tire according to the present invention may be, for example, a so-called airless tire that can be used without filling with gas.

[0084] [Examples] Figure 11 is a chart showing the results of the performance evaluation test of the pneumatic tire. Below, the performance evaluation tests conducted on the above-mentioned pneumatic tire 1, a conventional pneumatic tire, the pneumatic tire 1 according to the present invention, and a comparative example pneumatic tire to be compared with the pneumatic tire 1 according to the present invention will be described. The performance evaluation test focused on the visibility of the mark.

[0085] The performance evaluation test was conducted using pneumatic tires of size 235 / 60R18 107V as defined by JATMA, mounted on JATMA standard rim wheels, and with the air pressure adjusted to the JATMA-specified standard internal pressure.

[0086] The visibility evaluation method for the test item involved the evaluator visually assessing how three-dimensional the markings on the tire sidewall of each pneumatic tire being tested appeared. The visibility evaluation result was calculated using an index where the height of the markings estimated by the evaluator's visual inspection was set to 100, based on the height of the markings estimated by visually inspecting a conventional pneumatic tire, as described later. The higher the index value, the more three-dimensional the markings appear, and the greater the optical illusion effect where the ridge area appears as the shadow of the markings, indicating superior visibility performance of the markings.

[0087] Performance evaluation tests were conducted on 12 types of pneumatic tires, including a conventional pneumatic tire (an example of a conventional pneumatic tire), Examples 1 to 10 (pneumatic tires 1 according to the present invention), and comparative examples (pneumatic tires compared to pneumatic tire 1 according to the present invention). All of these pneumatic tires, including the conventional example, comparative examples, and Examples 1 to 10, have a marking portion on the tire side surface, and the height of the marking portion, i.e., the amount of protrusion of the marking portion, is the same for all of them. Of these conventional example, comparative examples, and Examples 1 to 10, the conventional pneumatic tire does not have a ridge region adjacent to the marking portion. The comparative example pneumatic tire has a ridge region adjacent to the marking portion, but the spacing between the ridges in the ridge region does not increase as it moves away from the marking portion.

[0088] In contrast, all of the pneumatic tire 1 examples according to the present invention, from Embodiment 1 to 10, are equipped with a ridge region 50 adjacent to the mark portion 40, and the spacing S between the ridges 51 in the ridge region 50 increases as it moves away from the mark portion 40. Furthermore, the pneumatic tire 1 according to Embodiments 1 to 10 differs in the following ways: whether the ridge region 50 is positioned upstream or downstream of the contour portion 41 of the mark portion 40 in the first direction; the ratio W / h of the width W of the ridge region 50 to the height h of the mark portion 40; whether A ≥ 0.03 mm between adjacent ridges 51; whether there is a portion where the pitch A between ridges 51 is 0.55 mm or more; the ratio H / h of the height H of the ridge 51 to the height h of the mark portion 40; whether the height of the ridge 51 decreases as the distance from the mark portion 40 increases; and the angle θ of the wall surface 42 of the mark portion 40.

[0089] As a result of evaluation tests conducted using these pneumatic tires 1, as shown in Figure 11, it was found that the pneumatic tires 1 according to Examples 1 to 10, despite having the same amount of protrusion as the conventional example and comparative example, made the mark appear more three-dimensional, thus improving the visibility of the mark. In other words, the pneumatic tires 1 according to Examples 1 to 10 can improve the visibility of the mark 40 while suppressing the amount of protrusion of the mark 40.

[0090] This disclosure encompasses the following inventions: Invention [1] A tire having a marking portion on the tire side surface, which is the outer surface of the sidewall portion, On the tire side surface, a ridge region is provided having a plurality of ridges that extend parallel to the contour of the mark portion, adjacent to the mark portion. A tire characterized in that the plurality of ridges in the ridge region have a spacing between adjacent ridges that increases as the distance from the contour portion of the mark portion increases. invention[2] The tire according to invention [1], wherein the ridge region is not positioned at a location on the upstream side in the first direction relative to the contour portion of the mark, but is positioned at a location on the downstream side in the first direction, when one direction in the first direction, which is a predetermined direction along the tire side surface, is considered the upstream side and the other direction is considered the downstream side. Invention [3] The aforementioned mark portion is a mark portion that represents characters, The tire according to invention [2], wherein the first direction is defined relative to the mark portion in a direction from the upper left to the lower right of the character, such that the upper left of the character represented in the mark portion is the upstream side and the lower right of the character is the downstream side. invention [4] The tire according to any one of inventions [1] to [3], wherein the width W of the ridge region from the contour portion of the mark portion is in the range of 1 ≤ W / h ≤ 10, and the ratio of the width W of the ridge region from the tire side surface to the height h of the mark portion is within the range of 1 ≤ W / h ≤ 10. invention [5] A tire according to any one of inventions [1] to [4], wherein the plurality of ridges in the ridge region have a pitch A between adjacent ridges A ≥ 0.03 mm, and the pitch A increases as the distance from the contour portion of the mark portion increases, and there is at least one portion where the pitch A is 0.55 mm or more. invention [6] A tire according to any one of the inventions [1] to [5], wherein the plurality of ridges in the ridge region have a constant pitch A between adjacent ridges, and the width of the ridges narrows as the distance from the contour portion of the mark portion increases. invention [7] The tire according to any one of inventions [1] to [6], wherein the ridge is such that the ratio of the height H of the ridge to the height h of the marking portion from the tire side surface is in the range of 0.6 ≤ H / h ≤ 1. invention [8] A tire according to any one of the inventions [1] to [7], wherein the height of the ridges in the ridge region decreases as the distance from the contour portion of the mark portion increases. invention[9] The tire according to any one of inventions [1] to [8], wherein the mark portion is such that the angle of the wall surface constituting the contour portion of the mark portion with respect to the tire side surface is within the range of 90° to 150°. [Explanation of Symbols]

[0091] 1. Pneumatic tire 2 Tread section 3. Tread surface 8 Shoulder section 10 Bead section 11 Bead core 12 Bead Fillers 13 Carcass 14 Belt Layer 15 Inner liner 17 Rim cushion rubber 18 Turn-up section 20 Land 25 Circumferential main groove 30 Sidewall section 31 Tire side surface 32 recesses 40 Emblem Section 40A, 40B elements 41 Contour 41a Upstream contour 41b Downstream contour 42 Wall surface 50 Ridge Regions 51 Ridge 51a End 60 Peripheral area 65, 66 Fine Rib

Claims

1. A tire having a marking portion on the tire side surface, which is the outer surface of the sidewall portion, On the tire side surface, a ridge region is provided having a plurality of ridges that extend parallel to the contour of the mark portion, adjacent to the mark portion. A tire characterized in that the distance between adjacent ridges in the ridge region increases as the distance from the contour portion of the mark portion increases.

2. The tire according to claim 1, wherein the ridge region is not positioned at a location on the upstream side in the first direction relative to the contour portion of the mark, but is positioned at a location on the downstream side in the first direction, when one direction in the first direction, which is a predetermined direction along the tire side surface, is considered the upstream side and the other direction is considered the downstream side.

3. The aforementioned mark portion is a mark portion that represents characters, The tire according to claim 2, wherein the first direction is defined relative to the mark portion in a direction from the upper left to the lower right of the character, such that the upper left of the character represented by the mark portion is the upstream side and the lower right of the character is the downstream side.

4. The tire according to claim 1, wherein the width W of the ridge region from the contour portion of the marking portion is in the range of 1 ≤ W / h ≤ 10, and the ratio of the width W of the ridge region from the tire side surface to the height h of the marking portion is within the range of 1 ≤ W / h ≤ 10.

5. The tire according to claim 1, wherein the plurality of ridges in the ridge region have a pitch A between adjacent ridges A ≥ 0.03 mm, and the pitch A increases as the distance from the contour portion of the mark increases, and the tire includes at least one portion where the pitch A is 0.55 mm or more.

6. The tire according to claim 1, wherein the plurality of ridges in the ridge region have a constant pitch A between adjacent ridges, and the width of the ridges narrows as the distance from the contour portion of the mark increases.

7. The tire according to claim 1, wherein the ratio of the height H of the ridge to the height h of the marking portion from the tire side surface is in the range of 0.6 ≤ H / h ≤ 1.

8. The tire according to claim 1, wherein the height of the ridges in the ridge region decreases as the distance from the contour portion of the mark portion increases.

9. The tire according to claim 1, wherein the angle of the wall surface constituting the contour of the mark portion with respect to the tire side surface is within the range of 90° to 150°.

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