Tire

Abstract

A pneumatic tire 1 comprises: a ridge region 50 in which a plurality of ridges 55 are disposed, the ridge region 50 being formed on a tire side part 31 which is the surface of a side wall part 30; and a plurality of projection patterns 60 which are disposed in the ridge region 50 at a height higher than the ridges 55 in the height direction of the ridges 55, and extend in a direction crossing the extension direction of the ridges 55. The plurality of projection patterns 60 includes a projection pattern 60 in contact with a contour part 51 on the outside of the ridge region 50 in the tire radius direction, and a projection pattern 60 spaced apart from the contour part 51 of the ridge region 50, and thus suppress the extension of cracks to continuously maintain an attractive appearance while suppressing a decrease in mold processability.

Description

tire

[0001] The present invention relates to a tire.

[0002] Some recent tires have decorative protruding patterns on the surface of the sidewall portion to improve their appearance. For example, the pneumatic tires described in Patent Documents 1 to 5 have decorative portions with ridges on the surface of the sidewall portion.

[0003] Japanese Patent No. 5325129 Japanese Patent Laid-Open No. 2006-347202 Japanese Patent No. 3614973 Japanese Patent No. 6047016 Japanese Patent No. 4640517

[0004] However, applying a complex pattern to the sidewall portion leads to deterioration in processability when processing the mold used to mold the tire. For this reason, it is preferable that the decorative pattern applied to the sidewall portion be a pattern that can be formed with as few mold processing steps as possible, but if the decorative pattern is simple, it may be difficult to improve the appearance even if the sidewall portion is decorated.

[0005] It is also important that tires maintain their appearance not only when new, but also during use when exposed to outdoor environments for long periods of time. Specifically, cracks can occur on the surface of the sidewall during tire use due to the load acting on the sidewall and aging. When cracks occur on the surface of the sidewall, the appearance deteriorates, making it difficult to maintain the appearance. For these reasons, it has been difficult to maintain the appearance while suppressing deterioration in mold processability when decorating the sidewall.

[0006] The present invention has been made in view of the above, and aims to provide a tire that can continuously maintain its appearance by suppressing the extension of cracks while suppressing deterioration of mold processability.

[0007] In order to solve the above-mentioned problems and achieve the object, the tire of the present invention comprises a ridge region formed in the tire side portion, which is the surface of the sidewall portion, and in which a plurality of ridges are arranged, and a plurality of protrusion patterns arranged in the ridge region at a height in the height direction of the ridge that is higher than the height of the ridge, and extending in a direction intersecting the extension direction of the ridge, wherein the plurality of protrusion patterns include protrusion patterns that are in contact with a contour portion on the tire radial outer side of the ridge region and protrusion patterns that are spaced apart from the contour portion of the ridge region.

[0008] Furthermore, in the above tire, a smooth surface region is formed in the tire side portion, which is a planar region whose height in the height direction of the ridge is higher than the height of the ridge, and it is preferable that the height of the protrusion pattern in the height direction of the ridge is within a range of ±0.80 mm of the height of the smooth surface region.

[0009] In the tire, it is preferable that adjacent protrusion patterns are arranged parallel to each other.

[0010] In addition, in the above tire, it is preferable that the pitch P of the multiple ridges arranged in the ridge region is within the range of 0.55 mm≦P≦1.50 mm, and the ratio H / B of the height H of the ridge to the width B of the ridge is within the range of 0.60≦H / B≦1.40.

[0011] In addition, in the above tire, it is preferable that the protrusion pattern is formed so that wide portions and narrow portions whose width in a direction intersecting the extension direction of the protrusion pattern is narrower than the width of the wide portions are alternately formed in the extension direction of the protrusion pattern.

[0012] In the tire, the protrusion pattern preferably has a ratio d / D of a width D of the wide portion to a width d of the narrow portion in a range of 0.10≦d / D≦0.50.

[0013] In the tire, the plurality of protrusion patterns preferably have a pitch X within a range of 1.00 mm≦X≦5.00 mm.

[0014] In the tire, it is preferable that adjacent protrusion patterns are arranged parallel to each other, and that the ratio D / X of the width D of the wide portion to the pitch X of the plurality of protrusion patterns is within a range of 0.20≦D / X≦5.00.

[0015] In the tire, it is preferable that the length L1 of the wide portion and the length L2 of the narrow portion in the extending direction of the protrusion pattern satisfy the relationship 0.30≦L1 / (L1+L2)≦0.70.

[0016] In addition, in the above tire, it is preferable that the multiple protrusion patterns have a portion where the wide portion of one of the protrusion patterns and the narrow portion of the other of the adjacent protrusion patterns are at the same position in the tire radial direction.

[0017] The tire according to the present invention has the effect of suppressing deterioration of mold processability, while suppressing crack propagation, thereby enabling the tire to continuously maintain a good appearance.

[0018] FIG. 1 is a meridian cross-sectional view showing a main portion of a pneumatic tire according to an embodiment. FIG. 2 is a view taken along the arrow A-A in FIG. 1. FIG. 3 is a view taken along the arrow A-A in FIG. 1, and is an explanatory diagram showing a state in which the ridges in the ridge region are not shown. FIG. 4 is a detailed view of portion B in FIG. 2. FIG. 5 is a cross-sectional view of the ridges viewed along the extension direction of the ridges. FIG. 6 is a detailed view of portion B in FIG. 2, and is an explanatory diagram showing a state in which the ridges in the ridge region are not shown. FIG. 7 is a cross-sectional view schematically showing a tire molding mold that is part of a pneumatic tire manufacturing system. FIG. 8 is an explanatory diagram showing a modified example of a pneumatic tire according to an embodiment, in which the protrusion pattern arranged in the ridge region is formed with a constant width. FIG. 9 is a table showing the results of a performance evaluation test of a pneumatic tire.

[0019] Hereinafter, embodiments of a tire according to the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to these embodiments. Furthermore, the components in the following embodiments include those that are replaceable and easily conceivable by a person skilled in the art, or those that are substantially the same.

[0020] [Embodiment] [Pneumatic Tire] 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, or other gases.

[0021] In the following description, 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 tire radially inner side refers to the side toward the tire rotation axis in the tire radial direction, and the tire radially outer side 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 tire widthwise inner side refers to the side toward the tire equatorial plane (tire equator line) CL in the tire width direction, and the tire widthwise outer side refers to the side away from the tire equatorial plane CL in the tire width direction. The tire equatorial plane CL is a plane that is perpendicular to the tire rotation axis and passes through the center of the tire width of the pneumatic tire 1. The tire equatorial plane CL coincides in position in the tire width direction with the tire widthwise centerline, which is the center position of the pneumatic tire 1 in the tire width direction. The tire width is the width in the tire width direction between the portions located outermost in the tire width direction, that is, the distance in the tire width direction between the portions farthest from the tire equatorial plane CL. The tire equator line refers to a line that is on the tire equatorial plane CL and extends along the tire circumferential direction of the pneumatic tire 1. In the following description, the tire meridian cross section refers to a cross section obtained by cutting the tire along a plane that includes the tire rotation axis.

[0022] FIG. 1 is a meridian cross-sectional view showing a main portion of a pneumatic tire according to an embodiment. When viewed in meridian cross-section, the pneumatic tire 1 shown in FIG. 1 has a tread portion 2 disposed at the radially outermost portion of the tire. The surface of the tread portion 2, i.e., the portion that comes into contact with the road surface when a vehicle (not shown) equipped with the pneumatic tire 1 is traveling, is formed as a tread surface 3. The tread surface 3 of the tread portion 2 has a plurality of circumferential main grooves 25 formed therein that extend in the tire circumferential direction, and these circumferential main grooves 25 define a plurality of land portions 20 on the tread surface 3. Grooves formed on the tread surface 3 may include grooves other than the circumferential main grooves 25, such as lug grooves (not shown) that extend in the tire width direction or narrow grooves (not shown) that are different from the circumferential main grooves 25.

[0023] Shoulder portions 8 are located at both ends of the tread portion 2 in the tire width direction, and sidewall portions 30 are arranged on the radially inward side of the shoulder portions 8. That is, the sidewall portions 30 are arranged at two locations on both sides of the pneumatic tire 1 in the tire width direction. The outer surfaces of the sidewall portions 30 are formed as tire side portions 31, and the tire side portions 31 are located on both sides in the tire width direction. The two tire side portions 31 face the opposite side of each sidewall portion 30 from the side on which the tire equatorial plane 5 is located in the tire width direction.

[0024] In this case, the tire side portion 31 refers to a surface that is uniformly continuous from the ground contact edge 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 ground contact edges T refer to both outermost ends in the tire width direction in the region where the tread surface 3 of the tread portion 2 of the pneumatic tire 1 comes into contact with the road surface when the pneumatic tire 1 is mounted on a normal rim, inflated to a normal internal pressure, and subjected to 70% of a normal load, and are continuous in the tire circumferential direction. The rim check line R is a line used to check whether the tire is properly mounted on the rim, and is generally shown as a circular convex line that is continuous in the tire circumferential direction on the front side of the bead portion 10, radially outward of the rim flange (not shown) and along a portion near the rim flange.

[0025] Note that "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 the "tire load limits at various cold inflation pressures" specified by TRA, or the "inflation pressures" specified by ETRTO. Also, "regular load" refers to the "maximum load capacity" specified by JATMA, the maximum value of the "tire load limits at various cold inflation pressures" specified by TRA, or the "load capacity" specified by ETRTO.

[0026] Bead portions 10 are located on the tire radially inward side of each sidewall portion 30 located on both sides in the tire width direction. Similar to the sidewall portions 30, the bead portions 10 are arranged in two locations on both sides of the tire equatorial plane 5. Each bead portion 10 is provided with a bead core 11, and a bead filler 12 is provided on the tire radially outward side of the bead core 11.

[0027] Additionally, multiple belt layers 14 are provided on the tire radially inner side of the tread portion 2. The belt layer 14 is provided by laminating multiple cross belts 141, 142 and a belt cover 143. Of these, the cross belts 141, 142 are formed by coating multiple belt cords made of steel or organic fiber material with coating rubber and rolling them, and are configured to have a belt angle of 20° to 55° in absolute value. Furthermore, 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 configured as a so-called cross-ply structure in which the belt cords are laminated with their fiber directions crossing each other. Furthermore, the belt cover 143 is formed by rolling multiple cords made of steel or organic fiber material coated with coating rubber, and has a belt angle of 0° to 10° in absolute value. The belt cover 143 is arranged by laminating on the tire radially outer side of the cross belts 141, 142.

[0028] A carcass 13 containing radial ply cords is continuously provided on the tire radially inward side of the belt layer 14 and on the tire equatorial plane 5 side of the sidewall portion 30. The carcass 13 has a single-layer structure consisting of one carcass ply or a multi-layer structure consisting of a laminate of multiple carcass plies, and is toroidally spanned between the bead cores 11 arranged on both sides in the tire width direction to form the tire skeleton. More specifically, the carcass 13 is disposed from one of the bead portions 10 located on both sides in the tire width direction to the other bead portion 10, and is wound back along the bead cores 11 at the bead portions 10 toward the tire width direction outside to enclose the bead cores 11 and the bead fillers 12. The portion of the carcass 13 that is wound back toward the tire width direction outside the bead cores 11 forms a turnup portion 18, which extends to the tire radially outside of the bead fillers 12. For this reason, the radially outer end 18a of the turnup portion 18 is located radially outward of the bead filler 12, and is located near the portion of the sidewall portion 30 that is the widest in the tire width direction of the pneumatic tire 1. The carcass ply of the carcass 13 is formed by coating a plurality of carcass cords made of steel or organic fiber material such as aramid, nylon, polyester, or rayon with coating rubber and rolling the coated cords, and is formed so that the carcass angle, which is the inclination angle of the fiber direction of the carcass cords with respect to the tire circumferential direction, is between 80° and 95° in absolute value.

[0029] Rim cushion rubber 17 that forms the contact surface of the bead portion 10 with the rim flange is disposed on the radially inner side and the widthwise outer side of the bead core 11 and the turned-up portion of the carcass 13 in the bead portion 10. An inner liner 15 is formed along the carcass 13 on the inner side of the carcass 13 or on the inner side of the carcass 13 in the pneumatic tire 1.

[0030] Fig. 2 is a view taken along the arrows A-A in Fig. 1. A smooth surface region 40 and a ridge region 50 are formed in each of the tire side portions 31 located on two opposite sides in the tire width direction, for the purpose of improving the appearance of the pneumatic tire 1 and displaying various information. The smooth surface region 40 and the ridge region 50 are provided in the same configuration on the tire side portions 31 on both sides in the tire width direction. Of these, the smooth surface region 40 is an area where the base surface is flat, and various information such as a brand name, logo, or product name is displayed in the smooth surface region 40 to identify the pneumatic tire 1 or to indicate to the user.

[0031] The ridge region 50 is a decorative portion that improves the appearance of the pneumatic tire 1, and multiple ridges 55 (see FIG. 4 ) are arranged in the ridge region 50. The multiple ridges 55 are arranged throughout the entire range of the ridge region 50 in the tire circumferential direction. The ridge region 50 has a constant width in the tire radial direction and is arranged in a position in the tire circumferential direction that is different from the position where the smooth surface region 40 is provided. Note that information is marked not only in the smooth surface region 40 but also in the ridge region 50 as appropriate, as necessary.

[0032] In this embodiment, the smooth surface regions 40 are arranged at two locations in the tire circumferential direction of one tire side portion 31, and the ridge regions 50 are arranged at two locations between the two smooth surface regions 40 in the tire circumferential direction. In other words, the two smooth surface regions 40 are each arranged in a region between the two ridge regions 50 in the tire side portion 31. The lengths in the tire circumferential direction of the ranges in which the two ridge regions 50 are arranged are approximately the same, and the lengths in the tire circumferential direction of the ranges in which the two smooth surface regions 40 are arranged are also approximately the same. Therefore, the ranges in the tire side portion 31 in which the two smooth surface regions 40 and the two ridge regions 50 are arranged are point-symmetrical with respect to the rotational axis of the pneumatic tire 1.

[0033] In this embodiment, the boundary between the smooth surface region 40 and the ridge region 50 extends in the tire radial direction and is inclined in the tire circumferential direction. Therefore, at the boundary between the smooth surface region 40 and the ridge region 50, the smooth surface region 40 and the ridge region 50 are formed to overlap in the tire radial direction.

[0034] 3 is a view taken along the line A-A in FIG. 1 , and is an explanatory diagram showing a state in which the ridges 55 of the ridge region 50 are not shown. In FIG. 3, the ridges 55 are not shown in order to make it easier to recognize the protrusion patterns 60 arranged in the ridge region 50. In addition to the ridges 55 (see FIG. 4 ), a plurality of protrusion patterns 60 are arranged in the ridge region 50. Similar to the ridges 55, the plurality of protrusion patterns 60 arranged in the ridge region 50 are arranged across the entire range of the ridge region 50 in the tire circumferential direction.

[0035] 4 is a detailed view of portion B in FIG. 2 . The ridge region 50 is provided with a plurality of ridges 55 that are mountain-like convex portions extending along the tire side portion 31 and are arranged side by side in the tire circumferential direction. The ridges 55 protrude from the tire side portion 31 outward in the tire width direction or toward the tire outer side, which is the direction opposite to the tire cavity side, and are provided on the tire side portion 31 integrally with the tire side portion 31. The inclination angle of the ridges 55 relative to the tire radial direction or the tire circumferential direction is within a predetermined range. In the ridge region 50, adjacent ridges 55 are arranged at an angle close to parallel to each other, so that adjacent ridges 55 are substantially parallel to each other, and the plurality of ridges 55 are arranged at approximately equal intervals in the tire circumferential direction, so that a pattern is formed by the plurality of ridges 55.

[0036] Since the ridge region 50 is arranged along the tire circumferential direction, the multiple ridges 55 arranged in the ridge region 50 are arranged approximately radially, but if the relative angle between adjacent ridges 55 is approximately the same as the relative angle between the positions of the ridges 55 in the tire circumferential direction, the adjacent ridges 55 are considered to be substantially parallel to each other.

[0037] The inclination angle θ1 of the ridges 55 arranged in the ridge region 50 in the tire circumferential direction with respect to the tire radial direction is in the range of 10° to 70°. The inclination angle θ1 of the ridges 55 in the tire circumferential direction with respect to the tire radial direction is preferably in the range of 20° to 70°.

[0038] The protrusion patterns 60 arranged in the ridge region 50 protrude outward in the tire width direction from the tire side portion 31 or toward the outside of the tire, similar to the ridge 55, and are provided integrally with the tire side portion 31 on the tire side portion 31. Furthermore, the height of the protrusion patterns 60 in the height direction of the ridge 55 relative to the tire side portion 31 is formed to be higher than the height of the ridge 55. Therefore, the protrusion patterns 60 are formed to protrude outward from the tire side portion 31 further than the ridge 55. In this way, the protrusion patterns 60 formed to protrude from the tire side portion 31 further than the ridge 55 extend along the tire side portion 31, and multiple protrusion patterns 60 are arranged side by side in the tire circumferential direction.

[0039] The protrusion patterns 60 extending along the tire side portion 31 in the ridge region 50 extend in a direction intersecting the extension direction of the ridges 55. In this embodiment, the direction of inclination of the protrusion patterns 60 in the tire circumferential direction with respect to the tire radial direction is opposite to the direction of inclination of the ridges 55 in the tire circumferential direction with respect to the tire radial direction. The multiple protrusion patterns 60 whose direction of inclination in the tire circumferential direction with respect to the tire radial direction is opposite to the inclination direction of the ridges 55 have an inclination angle θ2 in the tire circumferential direction with respect to the tire radial direction that is in the range of 10° or more and 80° or less. The inclination angle θ2 of the protrusion patterns 60 in the tire circumferential direction with respect to the tire radial direction is preferably in the range of 20° or more and 70° or less.

[0040] The multiple protrusion patterns 60 arranged in the ridge region 50 extend in a direction intersecting the ridges 55, and adjacent protrusion patterns 60 are arranged at an angle close to parallel to each other, so that adjacent protrusion patterns 60 are arranged substantially parallel to each other, and the multiple protrusion patterns 60 are arranged at approximately equal intervals in the tire circumferential direction. As a result, in the ridge region 50, a pattern is formed not only by the multiple ridges 55 but also by the multiple protrusion patterns 60. In other words, in the ridge region 50, the multiple ridges 55 and the multiple protrusion patterns 60 combine to form a pattern.

[0041] Since the ridge region 50 is arranged along the tire circumferential direction, the multiple protrusion patterns 60 arranged in the ridge region 50 are arranged approximately radially, similar to the ridge 55, but if the relative angle between adjacent protrusion patterns 60 is approximately the same as the relative angle between the arrangement positions of the protrusion patterns 60 in the tire circumferential direction, the adjacent protrusion patterns 60 are considered to be substantially parallel to each other.

[0042] Furthermore, the multiple protrusion patterns 60 arranged in the ridge region 50 include protrusion patterns 60 that are in contact with the contour portion 51 on the tire radial outer side of the ridge region 50 and protrusion patterns 60 that are spaced apart from the contour portion 51 of the ridge region 50. That is, the multiple protrusion patterns 60 include contacting protrusion patterns 60a that are in contact with the contour portion 51 on the tire radial outer side of the ridge region 50 and non-contacting protrusion patterns 60b that are spaced apart from the contour portion 51 of the ridge region 50. These contacting protrusion patterns 60a and non-contacting protrusion patterns 60b are arranged alternately in the tire circumferential direction. Furthermore, the multiple non-contacting protrusion patterns 60b have the same distance in the tire circumferential direction from the contour portion 51 on the tire radial outer side of the ridge region 50.

[0043] Furthermore, all of the multiple protrusion patterns 60 arranged in the ridge region 50 are spaced apart from the contour portion 52 on the tire radially inner side of the ridge region 50. That is, both the multiple contacting protrusion patterns 60a and the multiple non-contacting protrusion patterns 60b are spaced apart from the contour portion 52 on the tire radially inner side of the ridge region 50. Furthermore, the distances in the tire circumferential direction of the protrusion patterns 60 from the contour portion 52 on the tire radially inner side of the ridge region 50 are different between the protrusion patterns 60 adjacent to each other in the tire circumferential direction.

[0044] In this case, the contour portion 51 on the outer side in the tire radial direction of the ridge region 50 is indicated by an imaginary line connecting the outer ends in the tire radial direction of each of the multiple ridges 55 arranged in the ridge region 50. Similarly, the contour portion 52 on the inner side in the tire radial direction of the ridge region 50 is indicated by an imaginary line connecting the inner ends in the tire radial direction of each of the multiple ridges 55 arranged in the ridge region 50.

[0045] 5 is a cross-sectional view of the ridge 55 viewed along the extension direction of the ridge 55. The smooth surface region 40 formed in the tire side portion 31 is a planar region in which the height S of the smooth surface region 40 in the height direction of the ridge 55 is higher than the height H of the ridge 55. In this case, the height H of the ridge 55 and the height S of the smooth surface region 40 are the heights measured in the direction from the base surface 53 of the ridge region 50 toward the outside of the tire.

[0046] The base surface 53 of the ridge region 50 is the surface at the base of the ridge 55 in the ridge region 50, and is a surface recessed from a profile line (not shown) toward the tire cavity. The profile line is a contour line that smoothly connects the shoulder portion 8 and the bead portion 10 in the tire meridian cross section shown in FIG. 1. The profile line is composed of a single or multiple arcs. The profile line is defined excluding partial irregularities. The height H of the ridge 55 from the base surface 53 is preferably within a range of 0.50 mm to 1.00 mm, and the height S of the smooth surface region 40 from the base surface 53 is preferably within a range of 0.70 mm to 1.20 mm.

[0047] The height Y of the protrusion pattern 60 arranged in the ridge region 50 in the height direction of the ridge 55 is within a range of ±0.80 mm with respect to the height S of the smooth surface region 40. In other words, the height Y of the protrusion pattern 60 arranged in the ridge region 50 is substantially the same as the height S of the smooth surface region 40. In this case, the height Y of the protrusion pattern 60 is the height in the direction from the base surface 53 of the ridge region 50 toward the outside of the tire. It is preferable that the height Y of the protrusion pattern 60 arranged in the ridge region 50 in the height direction of the ridge 55 is within a range of ±0.50 mm with respect to the height S of the smooth surface region 40.

[0048] Furthermore, the plurality of ridges 55 arranged in the ridge region 50 have a pitch P, which is the period of arrangement of the ridges 55 in the direction in which the ridges 55 are arranged, that is, within the range of 0.55 mm≦P≦1.50 mm. Furthermore, the ratio H / B of the height H of the ridge 55 to the width B of the ridge 55 is within the range of 0.60≦H / B≦1.40. Note that, because the plurality of ridges 55 are arranged in a substantially radial pattern, the angles between adjacent ridges 55 are, strictly speaking, different from each other, and the pitch P varies depending on the position in the extension direction of the ridges 55, but the pitch P of the ridges 55 is within the range of 0.55 mm≦P≦1.50 mm at any position in the extension direction of the ridges 55.

[0049] FIG. 6 is a detailed view of portion B in FIG. 2 , and is an explanatory diagram showing a state in which the ridges 55 of the ridge region 50 are omitted. In FIG. 6 , as in FIG. 3 , the ridges 55 are omitted in order to make it easier to recognize the protrusion patterns 60 arranged in the ridge region 50. The protrusion patterns 60 arranged in the ridge region 50 have wide portions 61 and narrow portions 62 that have different widths in a direction intersecting the extension direction of the protrusion patterns 60. The narrow portions 62 have a width narrower than that of the wide portions 61 in a direction intersecting the extension direction of the protrusion patterns 60. The multiple protrusion patterns 60 arranged in the ridge region 50 each have a plurality of wide portions 61 and narrow portions 62, and the wide portions 61 and narrow portions 62 are alternately formed in the extension direction of the protrusion patterns 60. That is, the multiple protrusion patterns 60 arranged in the ridge region 50, both the contact protrusion pattern 60a and the non-contact protrusion pattern 60b, have multiple wide portions 61 and narrow portions 62, and the wide portions 61 and narrow portions 62 are formed alternately in the extension direction of the contact protrusion pattern 60a and the non-contact protrusion pattern 60b.

[0050] In this embodiment, the wide portions 61 of the plurality of contact protrusion patterns 60 a arranged in the ridge region 50 are in contact with the contour portion 51 of the ridge region 50 on the outer side in the tire radial direction.

[0051] The protrusion pattern 60 has a wide portion 61 and a narrow portion 62, and the ratio d / D of the width D of the wide portion 61 to the width d of the narrow portion 62 is within the range of 0.10≦d / D≦0.50. The protrusion pattern 60 is formed such that the length L1 of the wide portion 61 in the extension direction of the protrusion pattern 60 and the length L2 of the narrow portion 62 in the extension direction of the protrusion pattern 60 satisfy the relationship 0.30≦L1 / (L1+L2)≦0.70.

[0052] The relationship between the length L1 of the wide portion 61 of the protrusion pattern 60 and the length L2 of the narrow portion 62 thereof is preferably within the range of 0.35≦L1 / (L1+L2)≦0.65. In this embodiment, the length L1 of the wide portion 61 of the protrusion pattern 60 and the length L2 of the narrow portion 62 thereof are approximately the same.

[0053] Furthermore, the multiple protrusion patterns 60 have portions where the wide portion 61 of one protrusion pattern 60 and the narrow portion 62 of the other protrusion pattern 60 of adjacent protrusion patterns 60 are located at the same position in the tire radial direction. In this embodiment, the position of the wide portion 61 of one protrusion pattern 60 in the tire radial direction and the position of the narrow portion 62 of the other protrusion pattern 60 of adjacent protrusion patterns 60 are located at the same position in the tire radial direction. In other words, between adjacent protrusion patterns 60, the wide portion 61 of one protrusion pattern 60 and the narrow portion 62 of the other protrusion pattern 60 are located adjacent in the tire circumferential direction, and the narrow portion 62 of one protrusion pattern 60 and the wide portion 61 of the other protrusion pattern 60 are located adjacent in the tire circumferential direction.

[0054] Furthermore, the plurality of protrusion patterns 60 arranged in the ridge region 50 in the tire circumferential direction have a pitch X, which is the period of the arrangement of the protrusion patterns 60 in the direction in which the protrusion patterns 60 are arranged, in the range of 1.00 mm≦X≦5.00 mm. Furthermore, the plurality of protrusion patterns 60 have a ratio D / X, where D is the width D of the wide portion 61 and the pitch X of the plurality of protrusion patterns 60, in the range of 0.20≦D / X≦5.00. Note that because the plurality of protrusion patterns 60 are arranged in a substantially radial pattern, the angles between adjacent protrusion patterns 60 are, strictly speaking, different from each other, and the pitch X varies depending on the position in the extension direction of the protrusion patterns 60, but the pitch X of the protrusion patterns 60 is within the range of 1.00 mm≦X≦5.00 mm at any position in the extension direction of the protrusion patterns 60.

[0055] [Tire Manufacturing Method] Next, an example of a manufacturing method for a pneumatic tire 1 according to the embodiment will be described. Fig. 7 is a cross-sectional view that schematically shows a tire molding mold 500 that is part of a manufacturing system for the pneumatic tire 1. The pneumatic tire 1 is manufactured by vulcanizing a green tire, which is a raw tire, using the vulcanization molding mold 500. The green tire is placed inside the mold 500 and is vulcanized while supported by the mold 500. The mold 500 is arranged in the tire circumferential direction, and includes a plurality of sector molds 501 for molding the tread portion 2 of the pneumatic tire 1, and a side mold 502 for molding the sidewall portion 30 of the pneumatic tire 1.

[0056] The sector mold 501 is a component obtained by dividing an annular mold in the tire circumferential direction. A plurality of sector molds 501 are arranged in the tire circumferential direction. Each of the plurality of sector molds 501 is movable in the tire radial direction. The sector mold 501 comes into contact with the tread portion 2 of the pneumatic tire 1 by moving inward in the tire radial direction. The sector mold 501 moves away from the tread portion 2 of the pneumatic tire 1 by moving outward in the tire radial direction. The plurality of sector molds 501 are integrated by moving inward in the tire radial direction to form an annular mold. The plurality of sector molds 501 are divided by moving outward in the tire radial direction.

[0057] The tread portion 2 is molded by a sector mold 501. The sector mold 501 has a protrusion that protrudes radially inward from the inner surface of the sector mold 501 facing the tread portion 2. A tread pattern design including circumferential main grooves 25 is formed in the tread portion 2 by the protrusion of the sector mold 501.

[0058] The side mold 502 includes an upper side mold 502A and a lower side mold 502B. The pneumatic tire 1 is disposed between the upper side mold 502A and the lower side mold 502B. The upper side mold 502A moves upward to separate from the sidewall portion 30 of the pneumatic tire 1. The upper side mold 502A moves downward to come into contact with the sidewall portion 30 of the pneumatic tire 1. The lower side mold 502B moves downward to separate from the sidewall portion 30 of the pneumatic tire 1. The lower side mold 502B moves upward to come into contact with the sidewall portion 30 of the pneumatic tire 1.

[0059] The sidewall portion 30 is formed by a side mold 502. The side mold 502 has an uneven portion provided on the inner surface of the side mold 502 facing the sidewall portion 30. The uneven portion of the side mold 502 forms the smooth surface region 40 and the ridge region 50 in the sidewall portion 30.

[0060] [Actions and Effects] Next, the actions and effects of the pneumatic tire 1 according to the embodiment will be described. The pneumatic tire 1 according to the embodiment has a ridge region 50 formed in the tire side portion 31, which can improve the appearance. In particular, the ridge region 50 of the pneumatic tire 1 according to the present embodiment has a plurality of ridges 55 and a plurality of protrusion patterns 60 intersecting each other, which can enhance the aesthetic appearance of the ridge region 50 and more reliably improve the overall appearance.

[0061] Here, when the pneumatic tire 1 is in use, the sidewall portion 30 is repeatedly deformed by the load acting on the pneumatic tire 1. Furthermore, the rubber composition constituting the pneumatic tire 1 may deteriorate over time as the pneumatic tire 1 is used for a long period of time. Cracks may occur in the ridge regions 50 formed in the tire side portions 31 due to repeated deformation and deterioration over time of the sidewall portions 30. The ridge regions 50 are provided primarily for the purpose of improving the external appearance of the pneumatic tire 1, but if cracks occur in the ridge regions 50, the appearance is likely to deteriorate.

[0062] In contrast, in the pneumatic tire 1 according to the present embodiment, in addition to the ridges 55, a plurality of protrusion patterns 60 are arranged in the ridge region 50, the protrusion patterns 60 extending in a direction intersecting the extension direction of the ridges 55 at a height higher than the height of the ridges 55. Therefore, for example, even if a crack occurs between adjacent ridges 55 and the crack propagates along the extension direction of the ridges 55, the crack will stop propagating when it reaches the position of the protrusion patterns 60. This makes it possible to prevent long cracks from occurring in the ridge region 50 and to prevent deterioration of the appearance, thereby enabling the appearance to be continuously maintained.

[0063] On the other hand, in order to form the protrusion pattern 60 in the ridge region 50, it is necessary to form a portion for molding the protrusion pattern 60 in the mold used to mold the ridge region 50 during the manufacture of the pneumatic tire 1. The portion of the mold used to mold the ridge region 50 is formed in a shape that can mold the multiple ridges 55, but forming a portion for molding the protrusion pattern 60 also increases the number of steps required for mold processing during mold manufacturing, which may easily deteriorate the processability during mold processing.

[0064] In contrast, in the pneumatic tire 1 according to this embodiment, the multiple protrusion patterns 60 formed in the ridge region 50 have contacting protrusion patterns 60a that contact the contour portion 51 on the tire radial outer side of the ridge region 50, and non-contacting protrusion patterns 60b that are spaced apart from the contour portion 51, thereby preventing deterioration in mold processability due to the arrangement of the multiple protrusion patterns 60 in the ridge region 50.

[0065] In other words, because the protrusion pattern 60 has contact protrusion patterns 60a and non-contact protrusion patterns 60b, the multiple protrusion patterns 60 are formed so that the positions of the ends of the contact protrusion patterns 60a and the non-contact protrusion patterns 60b in the tire radial direction are different. The protrusion patterns 60 formed in this manner are formed in a shape that protrudes outward from the tire, so the portions of the mold 500 where the protrusion patterns 60 are molded are formed in a groove-like shape. At this time, because the positions of the ends of the contact protrusion patterns 60a and the non-contact protrusion patterns 60b in the tire radial direction are different, the positions of the ends of the contact protrusion patterns 60a and the non-contact protrusion patterns 60b in the mold 500 in the tire radial direction are also different. This improves the workability of mold processing when forming the portions of the mold 500 where the protrusion patterns 60 are molded.

[0066] Specifically, when forming grooves in the portions of the mold 500 where the protrusion patterns 60 are to be formed, a drill for machining the mold 500 is used. However, since the end positions of the portions of the mold 500 where the contact protrusion patterns 60a are to be formed and the portions of the mold 500 where the non-contact protrusion patterns 60b are to be formed are different, when the drill is moved between the two ends, the drill can be moved in a natural motion, while continuing the flow of groove machining by moving the drill along the extension direction of the protrusion patterns 60. This improves workability when forming the portions of the mold 500 where the protrusion patterns 60 are to be formed, and suppresses deterioration of mold processability caused by arranging multiple protrusion patterns 60 in the ridge region 50. As a result, it is possible to suppress deterioration of mold processability while suppressing crack propagation, thereby continuously maintaining a good appearance.

[0067] Furthermore, since the height Y of the protrusion pattern 60 is within a range of ±0.80 mm with respect to the height S of the smooth surface region 40, when a crack occurs in the ridge region 50, the height of the protrusion pattern 60 can suppress the propagation of the crack. As a result, the propagation of the crack can be more reliably suppressed, and the appearance of the external appearance can be continuously maintained.

[0068] Furthermore, because adjacent protrusion patterns 60 are arranged parallel to each other, the appearance of the ridge region 50 can be more reliably improved by the plurality of protrusion patterns 60, not just the plurality of ridges 55. Furthermore, because adjacent protrusion patterns 60 are arranged parallel to each other, when forming grooves in the mold 500 for molding the protrusion patterns 60 in the tire side portion 31 with a drill, the grooves can be formed by moving the drill in the same direction. This improves workability when forming portions of the mold 500 for molding the protrusion patterns 60, and suppresses deterioration in mold processability caused by arranging multiple protrusion patterns 60 in the ridge region 50. As a result, the appearance of the exterior can be improved while suppressing deterioration in mold processability.

[0069] Furthermore, because the pitch P of the multiple ridges 55 arranged in the ridge region 50 is within the range of 0.55 mm≦P≦1.50 mm, tire wax can be appropriately applied to the tire side portion 31, for example, as a protective layer. That is, tire wax is sometimes applied to the tire side portion 31 to protect and polish the tire side portion 31, but if the pitch P of the multiple ridges 55 is less than 0.55 mm, the pitch P is too small, which may make it difficult to apply the tire wax to the ridge region 50. If the pitch P of the multiple ridges 55 is greater than 1.50 mm, the pitch P is too large, which may make it difficult to apply the tire wax to the ridge region 50.

[0070] In contrast, when the pitch P of the multiple ridges 55 is within the range of 0.55 mm≦P≦1.50 mm, tire wax can be applied appropriately to the ridge region 50 and the applied tire wax is less likely to peel off. This allows the tire wax to polish the ridge region 50 and protect the ridge region 50, thereby preventing cracks from occurring in the ridge region 50. As a result, the appearance can be improved and maintained.

[0071] Furthermore, the ratio H / B of the height H of the ridge 55 to the width B of the ridge 55 of the multiple ridges 55 arranged in the ridge region 50 is within the range of 0.60≦H / B≦1.40, so that when tire wax is applied to the ridge region 50, the effects of the applied tire wax can be maintained for a long period of time. In other words, if the ratio H / B of the height H of the ridge 55 to the width B of the ridge 55 is less than 0.60, the height H is too low relative to the width B of the ridge 55, and therefore the tire wax cannot be protected from external impact when applied to the ridge region 50, and there is a risk that the tire wax will be easily peeled off. Furthermore, if the ratio H / B of the height H of the ridge 55 to the width B of the ridge 55 is greater than 1.40, the height H is too high relative to the width B of the ridge 55, and therefore penetration of the tire wax into the spaces between the ridges 55 is slow when tire wax is applied to the ridge region 50, and there is a risk that it will be difficult to efficiently apply tire wax to the ridge region 50.

[0072] In contrast, when the ratio H / B of the height H to the width B of the ridge 55 is within the range of 0.60≦H / B≦1.40, tire wax can be applied efficiently to the ridge region 50, and the effects of the applied tire wax can be maintained for a long period of time. As a result, the tire wax applied to the ridge region 50 can improve the appearance and continuously maintain that appearance.

[0073] Furthermore, since the protrusion pattern 60 has wide portions 61 and narrow portions 62 alternately formed in the extension direction of the protrusion pattern 60, when a crack that has occurred in the ridge region 50 propagates along the protrusion pattern 60, the direction of the crack propagation can be changed in a stepped manner. This makes it possible to prevent a crack that has occurred in the ridge region 50 from propagating in a short period of time and to prevent the appearance from deteriorating. As a result, the propagation of the crack can be suppressed, and the appearance of the external appearance can be continuously maintained.

[0074] Furthermore, since the ratio d / D of the width D of the wide portion 61 to the width d of the narrow portion 62 of the protrusion pattern 60 is within the range of 0.10≦d / D≦0.50, the appearance of the external appearance can be effectively improved while suppressing the occurrence of vulcanization defects. In other words, if the ratio d / D of the width D of the wide portion 61 to the width d of the narrow portion 62 of the protrusion pattern 60 is d / D<0.10, the width d of the narrow portion 62 is too narrow, making the narrow portion 62 of the protrusion pattern 60 difficult to see, and there is a risk that it will be difficult to effectively improve the appearance of the external appearance. Furthermore, if the ratio d / D of the width D of the wide portion 61 to the width d of the narrow portion 62 of the protrusion pattern 60 is d / D>0.50, the width d of the narrow portion 62 is too wide, making the overall volume of the protrusion pattern 60 too large, and there is a risk that vulcanization defects will be more likely to occur around the protrusion pattern 60 during vulcanization molding of the pneumatic tire 1.

[0075] In contrast, when the ratio d / D of the width D of the wide portion 61 of the protrusion pattern 60 to the width d of the narrow portion 62 is within the range of 0.10≦d / D≦0.50, the width d of the narrow portion 62 can be set to an appropriate size, and therefore the protrusion pattern 60 can effectively improve the appearance of the tire while suppressing the occurrence of vulcanization defects during vulcanization molding of the pneumatic tire 1. As a result, the appearance of the tire can be more reliably improved while suppressing vulcanization defects during manufacturing of the pneumatic tire 1.

[0076] Furthermore, since the pitch X of the multiple protrusion patterns 60 arranged in the ridge region 50 is within the range of 1.00 mm≦X≦5.00 mm, an increase in the incidence of vulcanization failures can be suppressed, and the extension of cracks can be effectively suppressed by the protrusion patterns 60. In other words, if the pitch X of the protrusion patterns 60 is less than 1.00 mm, the pitch X is too small, and the distance between adjacent protrusion patterns 60 is too close, which may increase the incidence of vulcanization failures during the manufacture of the pneumatic tire 1. Furthermore, if the pitch X of the protrusion patterns 60 is greater than 5.00 mm, the pitch X is too large, and the distance between adjacent protrusion patterns 60 is too far, which may make it difficult for the protrusion patterns 60 to effectively suppress the extension of cracks that have occurred in the ridge region 50.

[0077] In contrast, when the pitch X of the multiple protrusion patterns 60 is within the range of 1.00 mm≦X≦5.00 mm, it is possible to prevent an increase in the incidence of vulcanization failures resulting from arranging the protrusion patterns 60 in the ridge region 50, and the protrusion patterns 60 can effectively suppress the propagation of cracks that have occurred in the ridge region 50. As a result, it is possible to suppress the occurrence of vulcanization failures during the manufacture of the pneumatic tire 1, and also to suppress the propagation of cracks, thereby continuously maintaining the appearance of the tire.

[0078] Furthermore, the ratio D / X of the width D of the wide portions 61 of the protrusion patterns 60 to the pitch X of the protrusion patterns 60 is within the range of 0.20≦D / X≦5.00, so that an increase in the incidence of vulcanization failures can be suppressed, and the extension of cracks can be effectively suppressed by the protrusion patterns 60. In other words, when the ratio D / X of the width D of the wide portions 61 of the protrusion patterns 60 to the pitch X of the protrusion patterns 60 is D / X<0.20, the pitch X of the protrusion patterns 60 is too large, and the distance between adjacent protrusion patterns 60 becomes too great, which may make it difficult for the protrusion patterns 60 to effectively suppress the extension of cracks that have occurred in the ridge region 50. Furthermore, when the ratio D / X of the width D of the wide portion 61 of the protrusion pattern 60 to the pitch X of the protrusion pattern 60 is D / X > 5.00, the pitch X of the protrusion pattern 60 is too small, and the distance between adjacent protrusion patterns 60 is too close, which may increase the incidence of vulcanization failures during the manufacture of the pneumatic tire 1.

[0079] In contrast, when the ratio D / X of the width D of the wide portion 61 of the protrusion pattern 60 to the pitch X of the protrusion pattern 60 is within the range of 0.20≦D / X≦5.00, it is possible to prevent an increase in the incidence of vulcanization failures resulting from the placement of the protrusion pattern 60 in the ridge region 50, and the protrusion pattern 60 can effectively suppress the propagation of cracks that have occurred in the ridge region 50. As a result, it is possible to suppress the occurrence of vulcanization failures during the manufacture of the pneumatic tire 1, and also to suppress the propagation of cracks, thereby continuously maintaining the appearance of the tire.

[0080] Furthermore, since the length L1 of the wide portion 61 and the length L2 of the narrow portion 62 of the protrusion pattern 60 satisfy the relationship 0.30≦L1 / (L1+L2)≦0.70, it is possible to prevent the difference in area between the portion of the ridge region 50 where the ridge 55 is disposed adjacent to the wide portion 61 of the protrusion pattern 60 and the portion where the ridge 55 is disposed adjacent to the narrow portion 62 from becoming too large. This makes it possible to prevent large localized stresses from occurring in the ridge region 50 when the sidewall portion 30 elastically deforms, making it less likely for cracks to occur in the ridge region 50. As a result, the appearance can be continuously maintained.

[0081] Furthermore, the protrusion patterns 60 have a portion where the wide portion 61 of one protrusion pattern 60 and the narrow portion 62 of the other protrusion pattern 60 between adjacent protrusion patterns 60 are located at the same position in the tire radial direction, which prevents the difference in area between the portion located between the wide portion 61 of one protrusion pattern 60 and the narrow portion 62 of the other protrusion pattern 60 and the portion located between the narrow portion 62 of one protrusion pattern 60 and the wide portion 61 of the other protrusion pattern 60 from becoming too large. This prevents localized large stress from occurring in the ridge region 50 when the sidewall portion 30 elastically deforms, making it less likely for cracks to occur in the ridge region 50. As a result, the tire's external appearance can be continuously maintained.

[0082] [Modifications] In the above-described embodiment, the protrusion pattern 60 has a wide portion 61 and a narrow portion 62, but the protrusion pattern 60 does not have to have a wide portion 61 and a narrow portion 62. FIG. 8 is an explanatory diagram showing a modification of the pneumatic tire 1 according to the embodiment, in which the protrusion pattern 60 arranged in the ridge region 50 is formed with a constant width. The protrusion pattern 60 arranged in the ridge region 50 may be formed with a constant width, for example, as shown in FIG. 8. The multiple protrusion patterns 60 arranged in the ridge region 50 may extend in a direction intersecting the extension direction of the ridge 55, and may have contacting protrusion patterns 60a that contact the contour portion 51 of the ridge region 50 on the outer side in the tire radial direction, and non-contacting protrusion patterns 60b that are spaced apart from the contour portion 51 of the ridge region 50.

[0083] The multiple protrusion patterns 60 arranged in the ridge region 50 extend in a direction intersecting the extension direction of the ridge 55, and by having contacting protrusion patterns 60a and non-contacting protrusion patterns 60b, it is possible to suppress the extension of cracks and also to suppress the deterioration of mold processability caused by arranging the protrusion patterns 60 in the ridge region 50. As a result, it is possible to suppress the deterioration of mold processability while suppressing the extension of cracks, thereby continuously maintaining the appearance of the external appearance.

[0084] Furthermore, in the pneumatic tire 1 according to the above-described embodiment, the ridge regions 50 provided in two locations in one tire side portion 31 have the same configuration, but the ridge regions 50 provided in one tire side portion 31 may have different configurations. In other words, the ridge regions 50 may differ from one another in the angle and spacing of the ridges 55 arranged in the ridge region 50, the angle, spacing, and length of the protrusion patterns 60, the sizes of the wide portions 61 and narrow portions 62 of the protrusion patterns 60, the arrangement order of the contacting protrusion patterns 60a and the non-contacting protrusion patterns 60b, the size of the ridge regions 50, etc.

[0085] Furthermore, in the pneumatic tire 1 according to the above-described embodiment, the ridge regions 50 are provided in two locations in one tire side portion 31, but the ridge regions 50 may be provided in a number other than two locations in one tire side portion 31. For example, the ridge regions 50 may be provided in three or more locations in one tire side portion 31, or one ridge region 50 may be provided in one tire side portion 31. When one ridge region 50 is provided in one tire side portion 31, the ridge region 50 may be provided in a partial region in the tire circumferential direction of the tire side portion 31, or the ridge region 50 may be provided over the entire circumference in the tire circumferential direction. When the ridge region 50 is provided over the entire circumference in the tire circumferential direction and a smooth surface region 40 is also provided, the smooth surface region 40 may be provided at a position in the tire radial direction different from the ridge region 50, or may be provided within the ridge region 50.

[0086] Furthermore, in the pneumatic tire 1 according to the embodiment described above, the smooth surface region 40 and the ridge region 50 have the same configuration in the two tire side portions 31 on both sides in the tire width direction, but the smooth surface region 40 and the ridge region 50 may be provided in different configurations in the two tire side portions 31 on both sides in the tire width direction. By making the smooth surface region 40 and the ridge region 50 different for each tire side portion 31, it is possible to improve the design, and in a pneumatic tire 1 with a specified vehicle mounting direction, it is possible to further suppress the propagation of cracks in the ridge region 50 of the tire side portion 31 on the side where cracks are likely to occur.

[0087] The above-described embodiments and modified examples may be combined as appropriate. In the above-described embodiments, the pneumatic tire 1 has been used as an example of a tire according to the present invention, but the tire according to the present invention may be a tire other than the pneumatic tire 1. The tire according to the present invention may be, for example, a so-called airless tire that can be used without being filled with gas.

[0088] [Example] Figure 9 is a table showing the results of performance evaluation tests of pneumatic tires. Below, performance evaluation tests conducted on the conventional pneumatic tire and the pneumatic tire 1 according to the present invention will be described for the above-mentioned pneumatic tire 1. The performance evaluation tests were conducted on mold processability, crack extension suppression ability, and appearance at the end of the product's life.

[0089] The performance evaluation test was carried out by mounting a pneumatic tire 1 having a tire nominal size of 235 / 50R18 as specified by JATMA on a JATMA standard rim wheel having a rim size of 18×7.5J.

[0090] As for the evaluation method for each test item, for mold processability, the cost incurred in manufacturing the portion of the mold that forms the ridge region 50 was calculated. The mold processability was evaluated by indexing the reciprocal of the calculated cost, with the conventional example described below being set at 100. The larger the index evaluation value for mold processability, the lower the cost incurred in manufacturing the portion of the mold that forms the ridge region 50, indicating superior mold processability. Note that if the index is 98 or higher, the mold processability is maintained at a similar level to the conventional example, and deterioration of mold processability is suppressed.

[0091] In addition, the evaluation test for crack extension suppression was performed using an indoor drum test on a test tire using a drum testing machine with a drum diameter of 600 mm. The test tire was deteriorated by rotating the test tire in the drum testing machine while injecting ozone, and then the test tire was rotated at high speed while applying a load to the test tire in the drum testing machine. The length of cracks generated in the ridge region 50 of the tire side portion 31 was then measured, the number of cracks was counted, and the total crack length was calculated. The crack extension suppression was evaluated using an index value calculated by calculating the reciprocal of the total crack length, with the conventional example described below being set at 100. The larger the index value for crack extension suppression, the less crack extension in the ridge region, indicating better crack extension suppression.

[0092] Furthermore, for the appearance at the end of the product life, a road test was conducted using a vehicle fitted with a test tire with water-based tire wax applied to the tire side portion 31, and the test tire was collected after 4,000 km of travel and the appearance of the external appearance was visually evaluated by an evaluator. The evaluation of the appearance at the end of the product life was carried out by visual evaluation by the evaluator using an index rating, with the conventional example described below being set at 100. The larger the index rating value for the appearance at the end of the product life, the fewer cracks there were in the ridge region 50, indicating a better appearance at the end of the product life.

[0093] The performance evaluation test was conducted on 14 types of pneumatic tires, including a conventional pneumatic tire, which is an example of a conventional pneumatic tire, and Examples 1 to 13, which are pneumatic tires 1 according to the present invention. Of these, the conventional pneumatic tire has a ridge region in the tire side portion, but no protrusion pattern is arranged in the ridge region.

[0094] In contrast, all of Examples 1 to 13, which are examples of the pneumatic tire 1 according to the present invention, have a protrusion pattern 60 having contacting protrusion patterns 60a and non-contacting protrusion patterns 60b arranged in the ridge region 50. Furthermore, the pneumatic tires 1 according to Examples 1 to 13 are different in the difference between the height Y of the protrusion pattern 60 and the height S of the smooth surface region 40, the pitch P of the ridges 55, the ratio H / B of the height H of the ridges 55 to the width B of the ridges 55, the presence or absence of wide portions 61 and narrow portions 62 of the protrusion pattern 60, the ratio d / D of the width D of the wide portions 61 and the width d of the narrow portions 62 of the protrusion pattern 60, the pitch X of the protrusion pattern 60, and the relationship L1 / (L1+L2) between the length L1 of the wide portions 61 and the length L2 of the narrow portions 62 of the protrusion pattern 60.

[0095] 9, it was found that the pneumatic tires 1 according to Examples 1 to 13 were able to minimize deterioration in mold processability when providing the protrusion pattern 60 in the ridge region 50 compared to the conventional example, and were able to improve crack extension suppression in the ridge region 50 and the appearance at the end of the product's life compared to the conventional example. In other words, the pneumatic tires 1 according to Examples 1 to 13 were able to suppress deterioration in mold processability while suppressing crack extension and continuously maintaining an appearance that is attractive.

[0096] The present disclosure includes the following inventions. Invention [1] A tire comprising: a ridge region formed in a tire side portion, which is the surface of a sidewall portion, and in which a plurality of ridges are arranged; and a plurality of protrusion patterns arranged in the ridge region at a height in the height direction of the ridge that is higher than the height of the ridge, and extending in a direction intersecting the extension direction of the ridge, wherein the plurality of protrusion patterns include a protrusion pattern that is in contact with a contour portion of the ridge region on the tire radial outer side, and a protrusion pattern that is spaced apart from the contour portion of the ridge region. Invention [2] The tire according to Invention [1], in which a smooth surface region that is a planar region whose height in the height direction of the ridge is higher than the height of the ridge, and in which the height of the protrusion pattern in the height direction of the ridge is within a range of ±0.80 mm of the height of the smooth surface region, is formed in the tire side portion. Invention [3] The tire according to Invention [1] or Invention [2], in which adjacent protrusion patterns are arranged parallel to each other. Invention [4] A tire according to any one of Inventions [1] to [3], wherein the plurality of ridges arranged in the ridge region have a pitch P within a range of 0.55 mm≦P≦1.50 mm, and a ratio H / B of the ridge height H to the ridge width B within a range of 0.60≦H / B≦1.40. Invention [5] A tire according to any one of Inventions [1] to [4], wherein the protrusion pattern alternates between wide portions and narrow portions whose width in a direction intersecting the extension direction of the protrusion pattern is narrower than the width of the wide portions in the extension direction of the protrusion pattern. Invention [6] A tire according to Invention [5], wherein the protrusion pattern has a ratio d / D of the width D of the wide portions to the width d of the narrow portions within a range of 0.10≦d / D≦0.50. Invention [7] A tire according to Invention [3], wherein the plurality of protrusion patterns have a pitch X within a range of 1.00 mm≦X≦5.00 mm. Invention [8] The tire according to Invention [5] or Invention [6], wherein adjacent protrusion patterns are arranged parallel to each other, and the ratio D / X of the width D of the wide portion to the pitch X of the plurality of protrusion patterns is within the range of 0.20≦D / X≦5.00.Invention [9] The tire according to any one of Inventions [5], [6], and [8], wherein the protrusion pattern has a length L1 of the wide portion and a length L2 of the narrow portion in the extension direction of the protrusion pattern satisfying the relationship 0.30≦L1 / (L1+L2)≦0.70. Invention

[10] The tire according to any one of Inventions [5], [6], [8], and [9], wherein the plurality of protrusion patterns have portions where the wide portion of one of the protrusion patterns and the narrow portion of the other of the protrusion patterns are in the same position in the tire radial direction.

[0097] REFERENCE SIGNS LIST 1 pneumatic tire 2 tread portion 3 tread surface 5 tire equatorial plane 8 shoulder portion 10 bead portion 11 bead core 12 bead filler 13 carcass 14 belt layer 15 inner liner 17 rim cushion rubber 18 turn-up portion 20 land portion 25 circumferential main groove 30 sidewall portion 31 tire side portion 40 smooth surface region 50 ridge region 51 contour portion 52 contour portion 53 base surface 55 ridge 60 protrusion pattern 60a contact protrusion pattern 60b non-contact protrusion pattern 61 wide portion 62 narrow portion 500 mold 501 sector mold 502 side mold

Claims

1. A tire comprising: a ridge region formed on a tire side portion, which is the surface of a sidewall portion, and in which a plurality of ridges are arranged; and a plurality of protrusion patterns arranged in the ridge region at a height in the height direction of the ridge that is higher than the height of the ridge, and extending in a direction intersecting the extension direction of the ridge, wherein the plurality of protrusion patterns include a protrusion pattern that contacts a contour portion on the tire radial outer side of the ridge region and a protrusion pattern that is spaced apart from the contour portion of the ridge region.

2. A tire as described in claim 1, wherein a smooth surface area is formed in the tire side portion, which is a planar area whose height in the height direction of the ridge is greater than the height of the ridge, and the height of the protrusion pattern in the height direction of the ridge is within a range of ±0.80 mm of the height of the smooth surface area.

3. A tire as set forth in claim 1 or 2, wherein adjacent protrusion patterns are arranged parallel to each other.

4. A tire as claimed in claim 1 or 2, wherein the plurality of ridges arranged in the ridge region have a pitch P within the range of 0.55 mm≦P≦1.50 mm, and a ratio H / B of the height H of the ridge to the width B of the ridge is within the range of 0.60≦H / B≦1.

40.

5. A tire as described in claim 1, wherein the protrusion pattern is formed such that wide portions and narrow portions whose width in a direction intersecting the extension direction of the protrusion pattern is narrower than the width of the wide portions are alternately formed in the extension direction of the protrusion pattern.

6. The tire according to claim 5, wherein the ratio d / D of the width D of the wide portion to the width d of the narrow portion of the protrusion pattern is within the range of 0.10≦d / D≦0.

50.

7. The tire according to claim 3, wherein the plurality of protrusion patterns have a pitch X within the range of 1.00 mm≦X≦5.00 mm.

8. A tire as claimed in claim 5 or 6, wherein adjacent protrusion patterns are arranged parallel to each other, and the ratio D / X of the width D of the wide portion to the pitch X of the plurality of protrusion patterns is within the range of 0.20≦D / X≦5.

00.

9. A tire as set forth in claim 5 or 6, wherein the protrusion pattern has a length L1 of the wide portion and a length L2 of the narrow portion in an extending direction of the protrusion pattern that satisfy the relationship: 0.30≦L1 / (L1+L2)≦0.

70.

10. A tire as described in claim 5 or 6, wherein the plurality of protrusion patterns have a portion where the wide portion of one of the protrusion patterns and the narrow portion of the other of the adjacent protrusion patterns are in the same position in the tire radial direction.

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