Tire

Abstract

To provide a tire which is enhanced in black color density to enhance contrast more than before.SOLUTION: A tire comprises, on a portion of an outer surface 3a of a side wall 3, a pattern region 7 formed visibly as a site different from the circumference of the portion, where a plurality of protrusions 20 are arranged in the pattern region 7. The protrusion 20 includes a bottom surface 21, a tip part 22 furthest away from the bottom surface 21, and a trunk part 30 joining the bottom surface 21 to the tip part 22. The trunk part 30 has: a bulging part 23, provided between the bottom surface 21 and the tip part 22, which has a cross section which is larger in equivalent circle diameter than the bottom surface 21 and is largest in equivalent circle diameter in the protrusion 20; a bottom surface-side trunk part 32, provided from the bulging part 23 to the bottom surface 21, of which an area of the cross section gradually become smaller as going from the bulging part 23 toward the bottom surface 21; and a tip part-side trunk part 31, provided from the bulging part 23 to the tip part 22, of which an area of the cross section gradually become smaller as going from the bulging part 23 toward the tip part 22.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a tire having a pattern area for displaying, for example, a logo, a pattern, etc. on a part of the outer surface of the sidewall.

Background Art

[0002] Conventionally, a tire having a pattern area in which a large number of fine protrusions are gathered on a part of the sidewall of a tire is known (for example, Patent Document 1, etc.). In such a pattern area, the incident light is repeatedly reflected between the protrusions, resulting in a light absorption effect. As a result, it is visually recognized as blacker than the outer surface of the surrounding sidewall, and the contrast is improved. By providing this type of pattern area, the tire can be improved in, for example, design effect and appearance.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The high contrast achieved by a large number of protrusions has the advantage that it is less likely to undergo aging changes than means such as painting, and its effect can be exerted over a long period of time. Therefore, there has been a demand for the formation of a pattern area by protrusions that can achieve a higher black density and a further improvement in contrast compared to the prior art, thereby further enhancing the design effect and appearance.

[0005] An object of the present invention is to provide a tire in which the black density is increased and a higher contrast is achieved compared to the prior art.

Means for Solving the Problems

[0006] The tire according to the present invention is a tire provided with a pattern area provided in a visible state as a part different from the periphery of a part of the outer surface of the sidewall, and a plurality of protrusions protruding from the surface of the pattern area are arranged in the pattern area. Each of the plurality of protrusions includes a bottom surface integrated with the surface of the pattern area, a tip portion farthest from the bottom surface, and a body portion connecting the bottom surface and the tip portion. The body portion is provided between the bottom surface and the tip portion, and has a bulging portion having a cross-sectional diameter larger than the equivalent circular diameter of the bottom surface and having the largest equivalent circular diameter among the protrusions, a bottom surface side body portion provided from the bulging portion to the bottom surface and having a gradually decreasing cross-sectional area from the bulging portion toward the bottom surface, and a tip portion side body portion provided from the bulging portion to the tip portion and having a gradually decreasing cross-sectional area from the bulging portion toward the tip portion.

Advantages of the Invention

[0007] According to the present invention, it is possible to provide a tire in which the black density is higher than before and a high contrast is achieved.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Mode for Carrying Out the Invention

[0009] Hereinafter, embodiments will be described with reference to the drawings. Note that "substantially" in this specification does not strictly specify the state, but means including a state approximated within a range capable of achieving those functions and effects.

[0010] FIG. 1 is a side view of a tire 1 according to an embodiment. The tire 1 is a so-called pneumatic tire filled with a predetermined air pressure in its inner cavity. The tire 1 of the embodiment is a pneumatic tire for passenger cars including light automobiles and SUVs. Note that the configuration of the tire 1 of the embodiment can also be applied to pneumatic tires for other vehicle types such as light trucks, trucks, and buses.

[0011] First, with reference to FIG. 1, an outline of the configuration mainly related to the side surface of the tire 1 will be described. FIG. 1 is a side view of the tire 1 viewed from the direction of the tire rotation axis X. Note that the tire axial direction, the tire circumferential direction, and the tire radial direction referred to in the following description are as follows. The tire axial direction is the direction in which the tire rotation axis X extends, and in FIG. 1, it refers to the front and back directions of the paper surface. Note that when viewed from the tire radial direction, since the tire axial direction becomes the left and right directions, the tire axial direction may be referred to as the left and right directions. The tire circumferential direction is an arc line centered on the tire rotation axis X and is the direction along the rotation direction of the tire 1, which is indicated by an arrow G in FIG. 1. The tire radial direction is the direction perpendicular to the tire rotation axis X, which is arbitrarily indicated by an arrow Y in FIG. 1.

[0012] As shown in Fig. 1, the tire 1 includes a bead 2, a sidewall 3 extending radially outward in the tire radial direction from the bead 2 away from the tire rotation axis X, and a tread 4. Each of the bead 2 and the sidewall 3 has a pair, i.e., a left and a right one, respectively, on the side of one side surface 1s of the tire 1 shown in Fig. 1 and on the side of the other side surface not shown in Fig. 1 that is axially separated from the tire. The tread 4 is disposed between the left and right sidewalls 3 on the outer side in the tire radial direction. The outer peripheral surface of the tread 4 includes a tread surface that contacts the road surface.

[0013] The tire 1 is mainly composed of a plurality of types of rubber that constitute the bead 2, the sidewall 3, and the tread 4 respectively. On the inner cavity side of the rubber constituting the entire tire 1, a carcass ply that constitutes the skeleton of the tire 1 is disposed, and further on the inner cavity side of the carcass ply, an inner liner for holding air pressure is disposed. Also, an annular reinforcing belt is embedded inside the rubber constituting the tread 4 (the carcass ply, the inner liner, and the reinforcing belt are not shown). In addition to these members, various members are provided as required for the function of the tire 1.

[0014] As shown in Fig. 1, the sidewall 3 has an annular decorative region 5 on its outer surface 3a over the entire circumference in the tire circumferential direction. The decorative region 5 is a region with a certain width sandwiched between an inner arc line 5a on the inner side in the tire radial direction close to the tire rotation axis X in the tire radial direction and an outer arc line 5b on the outer side in the tire radial direction than the inner arc line 5a. The inner arc line 5a and the outer arc line 5b may be lines formed by concave, convex, or steps on the outer surface 3a of the sidewall 3, or may be virtual lines that do not actually exist.

[0015] The tire radial position of the decorative region 5 on the outer surface 3a of the sidewall 3 may be on the outer side in the tire radial direction than the position of the maximum tire width, or may be at a position including the maximum tire width position. The maximum tire width position refers to the position where the axial length in the tire axial direction is the longest between the outer surfaces 3a of the left and right sidewalls 3.

[0016] The tire 1 includes a pattern area 7 provided in a visible state as a part different from the surrounding of a part of the outer surface 3a of the sidewall 3. The pattern area 7 is provided on the sidewall rubber which is a black rubber member constituting the outer surface 3a of the sidewall 3.

[0017] As shown in FIG. 1, emblem parts 6A are provided at two locations of the annular decorative area 5 facing each other across the tire rotation axis X. The emblem part 6A is formed by arranging a plurality of characters in the tire circumferential direction. At least one of emblems such as a manufacturer name, a product name, and a brand is displayed by these plurality of characters. Each character may be formed by being bordered by a concave or convex line, or the whole character may be formed by being concave or convex. For example, each character of the emblem part 6A is provided as the pattern area 7 of the embodiment.

[0018] As shown in FIG. 1, in the annular decorative area 5, pattern parts 6B are provided at two locations sandwiched between two emblem parts 6A in the circumferential direction. The pattern part 6B is provided with a pattern such that a parallelogram is curved following the annular decorative area 5. For example, each pattern of the pattern part 6B is also provided as the pattern area 7 of the embodiment.

[0019] Note that the shape of the pattern area 7 is not limited to these, and various shapes can be mentioned, such as an arbitrary shape, a shape depicting an emblem such as the manufacturer name, product name, brand, etc. described above, or a shape depicting other numbers, characters, etc.

[0020] Each of the above pattern areas 7 in the embodiment has a surface 7a along the profile of the sidewall 3. A plurality of protrusions 20 described later are formed on this surface 7a. The pattern area 7 is an area provided in a visible state as a part different from the surrounding of the pattern area 7 by forming a plurality of protrusions 20.

[0021] FIG. 2 shows an example of a tire molding die for vulcanizing and molding the tire 1 of the embodiment. FIG. 2 is a meridian cross-sectional view of such a tire molding die 10 along the axial direction of the tire 1 to be molded.

[0022] The tire molding die 10 shown in FIG. 2 includes a plurality of sectors 11 arranged circumferentially along the outer peripheral side of the tire 1, a pair of side plates 12 arranged on both axial sides of the annular body formed by the combination of the plurality of sectors 11, and a pair of bead rings (not shown). During vulcanization molding, as shown by the dashed line in FIG. 2, an unvulcanized tire 1a that will become the tire 1 is set inside the tire molding die 10. The combination of the sectors 11, the side plates 12, and the bead rings is a molding die for molding the tire 1, and the outer surface of the entire tire 1 is molded by the inner surfaces of the molding die, that is, the inner surface 11a of the sectors 11, the inner surface 12a of the side plates 12, and the inner surface of the bead rings. Also, during vulcanization molding, a bladder (not shown) that presses the unvulcanized tire 1a against the inner surface of the tire molding die 10 is arranged inside the unvulcanized tire 1a. The main tread 4 is formed by the plurality of sectors 11, and the main sidewall 3 is formed by the pair of side plates 12. The bead 2 is formed by the pair of bead rings, and the entire inner surface of the tire 1 is formed by the bladder.

[0023] The unvulcanized tire 1a is vulcanized by the tire molding die 10 to form the rubber shape of the entire tire 1, and a plurality of protrusions 20 described below are formed in the above-mentioned pattern region 7.

[0024] FIGS. 3 and 4 are views showing a plurality of protrusions 20 arranged in the pattern region 7, FIG. 3 is a perspective view, and FIG. 4 is a plan view and is a view taken along the arrow IV in FIG. 3. The plurality of protrusions 20 are arranged on the surface 7a of the pattern region 7 in a state of filling the entire area of the pattern region 7. In the following, the surface 7a of the pattern region 7 may sometimes be referred to as the pattern region surface 7a.

[0025] As shown in FIG. 4, the plurality of protrusions 20 are arranged vertically and horizontally on the surface 7a of the pattern region. In FIG. 4, the plurality of protrusions 20 are arranged in an aligned state in which they are linearly arranged at equal pitches in the horizontal direction, which is the left - right direction, and the vertical direction, which is the up - down direction. Note that the arrangement pattern of the plurality of protrusions 20 shown in FIG. 4 is an example and is not limited thereto. For example, as shown in FIG. 5, they may be arranged in a staggered pattern. That is, in FIG. 5, a plurality of protrusions 20 are arranged in a straight line at equal pitches in the left - right direction, and a plurality of such rows are arranged in the up - down direction. In a pair of adjacent rows in the up - down direction, the protrusions 20 on the other side are arranged between the protrusions 20 on one side.

[0026] The protrusion 20 of the embodiment is a minute protrusion protruding from the surface 7a of the pattern region. FIG. 6 is a perspective view showing a single protrusion 20, and FIG. 7 is a side view of a pair of adjacent protrusions 20 on the surface 7a of the pattern region. As shown in FIGS. 6 and 7, the protrusion 20 includes a bottom surface 21, a tip portion 22 that is farthest from the bottom surface 21, and a body portion 30 that connects the bottom surface 21 and the tip portion 22. The protrusion 20 of the embodiment generally presents an appearance of a chestnut shape depending on the shape of the body portion 30. The bottom surface 21 is a virtual surface that is integrally flush with the surface 7a of the pattern region.

[0027] The bottom surface 21 of the protrusion 20 of the embodiment is substantially circular. As shown in FIG. 7, the central axis 20c of the protrusion 20 connecting the center of the bottom surface 21 and the tip portion 22 is substantially perpendicular to the surface 7a of the pattern region and the bottom surface 21. Therefore, the protrusion 20 stands upright with respect to the surface 7a of the pattern region. As shown in FIG. 7, the distance of the central axis 20c from the bottom surface 21 to the tip portion 22 is the height H of the protrusion 20, and this height H is the shortest distance from the bottom surface 21 to the tip portion 22. The shape of the cross - section of the protrusion 20 from the bottom surface 21 to the tip portion 22 has a substantially circular shape over the entire length in the height direction. Note that the cross - section referred to in this specification is a plane substantially perpendicular to the central axis 20c, and the cross - section is substantially parallel to the surface 7a of the pattern region.

[0028] The body portion 30 of the protrusion 20 in the embodiment has a bulged portion 23 in the middle of its height direction. The bulged portion 23 has a cross-section that is larger than the equivalent diameter of the circle of the bottom surface 21 and is the portion where the equivalent diameter of the circle is the largest in the protrusion 20. In other words, the bulged portion 23 is the portion that bulges the most laterally in the body portion 30. Since the cross-section of the protrusion 20 in the embodiment is generally substantially circular, the equivalent diameter of the circle is, that is, the diameter. Note that in the present disclosure, the cross-sectional shape of the protrusion 20 is not limited to a perfect circle, and may be, for example, an elliptical shape, a triangular shape, a polygonal shape, etc. In the case of these cross-sections, the equivalent diameter of the circle is applied.

[0029] The body portion 30 of the protrusion 20 in the embodiment has a bottom surface side body portion 32 and a tip side body portion 31 with the bulged portion 23 as a boundary. The bottom surface side body portion 32 is the portion below the bulged portion 23, that is, the portion from the bulged portion 23 to the bottom surface 21 in FIGS. 6 and 7. The cross-sectional area of the bottom surface side body portion 32 gradually decreases as it goes from the bulged portion 23 to the bottom surface 21. The tip side body portion 31 is the portion above the bulged portion 23, that is, the portion from the bulged portion 23 to the tip portion 22 in FIGS. 6 and 7. The cross-sectional area of the tip side body portion 31 gradually decreases as it goes from the bulged portion 23 to the tip portion 22. That is, the bottom surface side body portion 32 has a shape that narrows toward the bottom surface 21 side, and the tip side body portion 31 has a shape that narrows toward the tip portion 22 side.

[0030] The tip side body portion 31 converges from the bulged portion 23 to the tip portion 22, and the tip portion 22 of the protrusion 20 is formed in a tapered and sharp shape. Note that the shape of the tip portion 22 is not limited to this, and for example, it may be formed in a hemispherical shape, or may have a shape with a flat portion where the tip is cut substantially parallel to the cross-section, for example.

[0031] As shown in FIG. 3, the plurality of protrusions 20 in the embodiment have substantially uniform shapes and dimensions. There are no particular limitations on the dimensions that specify the shape and the like of the protrusion 20 in the embodiment, but for example, the following preferred ranges can be mentioned.

[0032] The height of the protrusion 20 is preferably 2.0 times or more and 3.0 times or less the diameter of the bottom surface 21 (indicated by φB in FIGS. 6 and 7). Specifically, the height of the protrusion 20 is preferably 0.2 mm or more and 0.8 mm or less.

[0033] The diameter of the cross-section of the enlarged portion 23 of the protrusion 20 of the embodiment (indicated by φM in FIGS. 6 and 7) is preferably 120% or more and 150% or less the diameter of the bottom surface 21. Specifically, the diameter of the cross-section of the bottom surface 21 is preferably 0.1 mm or more and 0.4 mm or less, for example, and the diameter of the cross-section of the enlarged portion 23 is preferably 0.2 mm or more and 0.5 mm or less, for example.

[0034] As shown in FIG. 7, the height position of the enlarged portion 23 corresponding to the height H of the protrusion 20 of the embodiment is preferably arranged within the range indicated by H2 between the height position of 15% of the height of the protrusion 20 from the center H1 in the height direction of the protrusion 20 toward the bottom surface 21 side and the height position of 15% of the height of the protrusion 20 from the center H1 in the height direction of the protrusion 20 toward the tip portion 22 side.

[0035] Regarding the arrangement state of the plurality of protrusions 20 on the surface 7a of the pattern region, the plurality of protrusions 20 are preferably arranged at a density of two or more within 1 mm. 2 Also, as shown in FIG. 7, the closest distance P between the protrusions 20 is preferably 0.5 mm or less, for example.

[0036] The plurality of protrusions 20 of the embodiment arranged on the surface 7a of the pattern region can be formed, for example, by the above-described tire molding die 10. To form the plurality of protrusions 20 by the tire molding die 10, a plurality of recesses capable of forming the protrusions 20 are formed corresponding to the protrusions 20 on the inner surface 12a which is the tire molding surface of the side plate 12 forming the pattern region 7.

[0037] In that case, the method for forming the plurality of recesses is not limited, but laser processing in which the inner surface 12a of the side plate 12 is irradiated with laser light to partially remove the inner surface 12a is suitable as the forming method. As the laser processing, for example, removal processing using a pulsed fiber laser can be adopted, and as the conditions for the laser processing, laser processing at a center wavelength of 1080 nm, an average output of 100 W or more and 300 W or less, and a laser spot diameter of about 0.05 mm is suitable.

[0038] Particularly, when forming the recesses capable of forming the protrusions 20 of the embodiment in the tire molding die 10 by laser processing, for example, it can be formed by adjusting the output for each pulse or adjusting the irradiation angle of the laser light.

[0039] In addition, when forming the protrusions 20 by the tire molding die 10, there may be a concern that the protrusions 20 may not come out of the recesses forming the protrusions 20 when the tire is demolded because the protrusions 20 of the embodiment have a so-called undercut shape. In such a case, by setting the diameter of the bulging portion 23 to, for example, about 150% or less of the diameter of the bottom surface 21, it is possible to pull out the protrusions 20 without trouble by utilizing the elastic deformation of the rubber. Thereby, it is possible to avoid the trouble of dividing the tire molding die 10 in order to enable the demolding of the protrusions 20.

[0040] In the tire 1 of the embodiment in which the plurality of protrusions 20 are arranged in the pattern region 7 as described above, when light is incident on the pattern region 7, the light mainly enters the pattern region surface 7a and the body portion 30 of the protrusions 20 and is reflected by those surfaces. The reflected light is reflected again by the surrounding protrusions 20 and the pattern region surface 7a, and such reflections occur repeatedly between the plurality of protrusions 20 and between the protrusions 20 and the pattern region surface 7a. As a result, the light incident on the pattern region 7 is gradually attenuated and absorbed. When such a pattern region 7 is visually recognized, the pattern region 7 is visually recognized as darker than the outer surface 3a of the side wall 3 that reflects the light around the pattern region 7.

[0041] FIG. 8 schematically shows an example of the light absorption effect in the embodiment. When the light indicated by L in FIG. 8 is incident on the surface 7a of the pattern area, the light enters near the surface 7a of the pattern area while being reflected in a zigzag pattern between the bodies 30 of a pair of adjacent protrusions 20, and is reflected by the surface 7a of the pattern area. Then, the light reflected by the surface 7a of the pattern area reaches the bottom side body 32 of the body 30 of the protrusion 20. Here, since the bottom side body 32 tapers toward the bottom surface 21 side, the light reflected by the bottom side body 32 is likely to be directed toward the surface 7a of the pattern area. Therefore, the light reaching the surface 7a of the pattern area is confined within the pattern area 7 by being blocked in its path by the bottom side body 32 of the protrusion 20, and it is difficult to escape from the pattern area 7 to the outside, that is, it is difficult to be reflected to the outside. As a result, the light absorption effect of the light incident on the pattern area 7 is promoted, and high contrast is achieved with an improvement in black density.

[0042] According to the embodiment described above, the following effects can be obtained.

[0043] (1) The tire 1 according to the embodiment is a tire provided with a pattern area 7 provided in a visible state as a part different from the periphery of a part of the outer surface 3a of the sidewall 3, and in the pattern area 7, a plurality of protrusions 20 protruding from the surface 7a of the pattern area 7 are arranged. The plurality of protrusions 20 include a bottom surface 21 integral with the surface 7a of the pattern area 7, a tip portion 22 farthest from the bottom surface 21, and a body 30 connecting the bottom surface 21 and the tip portion 22. The body 30 is provided between the bottom surface 21 and the tip portion 22, and has a bulging portion 23 having a cross-sectional diameter larger than the equivalent diameter of the circle of the bottom surface 21 and having the largest equivalent diameter of the circle in the protrusion 20, a bottom side body 32 provided from the bulging portion 23 to the bottom surface 21 and having a cross-sectional area gradually decreasing from the bulging portion 23 toward the bottom surface 21, and a tip side body 31 provided from the bulging portion 23 to the tip portion 22 and having a cross-sectional area gradually decreasing from the bulging portion 23 toward the tip portion 22.

[0044] According to the tire 1 of the embodiment, when light is incident on the pattern area 7 where a plurality of protrusions 20 are arranged, the light mainly enters the surface 7a of the pattern area and the body part 30 of the protrusions 20, and is reflected on those surfaces. The reflected light is reflected again by the surrounding protrusions 20 and the surface 7a of the pattern area, and such reflections repeatedly occur between the plurality of protrusions 20 and between the protrusions 20 and the surface 7a of the pattern area. As a result, the light incident on the pattern area 7 gradually attenuates and is absorbed. When such a pattern area 7 is visually recognized, the pattern area 7 is visually recognized as blacker than the outer surface 3a of the sidewall 3 that reflects the light around the pattern area 7. Since the protrusion 20 of the embodiment has a bottom-side body part 32 that tapers from the bulging part 23 to the bottom surface 21 as it goes toward the bottom surface 21, the light that once enters the pattern area 7 is confined within the pattern area 7 by this bottom-side body part 32 and is difficult to exit to the outside and difficult to be reflected to the outside. For this reason, the absorption effect of the light incident on the pattern area 7 is promoted, and the pattern area 7 has a higher black density than before and a high contrast is achieved.

[0045] (2) In the tire 1 of the above (1) according to the embodiment, it is preferable that the equivalent circle diameter of the cross section of the bulging part 23 is 120% or more and 150% or less of the equivalent circle diameter of the bottom surface 21.

[0046] As a result, a bulging part 23 having a larger diameter than the bottom surface 21 is surely formed, and as a result, the light absorption effect by the bottom-side body part 32 is promoted. Further, when the protrusion 20 is formed by a recess formed in the tire molding die 10 as described above, the protrusion 20 can be demolded even if it has an undercut shape.

[0047] (3) In the tire 1 of the above (1) and (2) according to the embodiment, the protrusion 20 has a height that is the shortest distance from the bottom surface 21 to the tip 22, and the height position of the bulging part 23 corresponding to the height of the protrusion 20 is from the center in the height direction of the protrusion 20 to the bottom surface 21 side at a height position of 15% of the height of the protrusion 20 and from the center of the height of the protrusion 20 to the tip 22 side at a height position of 15% of the height of the protrusion 20, and it is preferably arranged between them.

[0048] As a result, the height position of the bulged portion 23 in the protrusion 20 is appropriately set, and the light absorption effect by the bottom surface side barrel portion 32 is promoted.

[0049] (4) In the tire 1 according to the above (1) to (3) of the embodiment, it is preferable that the plurality of protrusions 20 are arranged at a density of two or more within 1 mm in the pattern region 7. 2 Thereby, the light absorption effect generated between adjacent protrusions 20 is improved, and the pattern region 7 has a higher black density than before, achieving a high contrast.

[0050] Thereby, the light absorption effect generated between adjacent protrusions 20 is improved, and the pattern region 7 has a higher black density than before, achieving a high contrast.

[0051] (5) In the tire 1 according to the above (1) to (4) of the embodiment, it is preferable that the plurality of protrusions 20 are arranged linearly at equal intervals, and the pitch of the arrangement is 2.0 times or more and 3.0 times or less the equivalent diameter of the circle of the bottom surface 21.

[0052] Thereby, the light absorption effect generated between adjacent protrusions 20 is improved, and the pattern region 7 has a higher black density than before, achieving a high contrast.

[0053] (6) In the tire 1 according to the above (1) to (5) of the embodiment, it is preferable that the cross-sectional shape of the protrusion 20 is substantially circular.

[0054] As a result, the light reflected by the protrusion 20 is reflected radially around the protrusion 20, so the repeated light reflection between the protrusions 20 is likely to become complicated. Also, an effect of confining the light incident on the pattern region 7 within the pattern region 7 is likely to occur. From these facts, the light absorption effect is improved, and the pattern region 7 has a higher black density than before, achieving a high contrast.

[0055] (7) In the tire 1 according to the above (1) to (6) of the embodiment, it is preferable that the tip portion 22 has a tapered and sharp shape.

[0056] As a result, the light incident on the pattern area 7 is less likely to be reflected at the tip of the protrusion 20, and the amount of light reflected to the outside is reduced compared to the case where the shape is not sharp. As a result, the contrast of the pattern area 7 is increased.

[0057] As described above, the embodiments of the present invention have been described. However, the present invention is not limited to the above embodiments, and modifications, improvements, etc. may be made within the scope that can achieve the object of the present invention, and they are included in the scope of the present invention.

[0058] For example, the plurality of protrusions 20 arranged in the pattern area 7 may be randomly arranged irregularly instead of being arranged in an aligned manner as shown in FIGS. 4 and 5.

[0059] The protrusion 20 of the above embodiment is upright on the surface 7a of the pattern area, but the central axis 20c may be inclined with respect to the surface 7a of the pattern area and may be arranged in a tilted manner.

[0060] The shapes and dimensions of the plurality of protrusions 20 in the above embodiment are substantially uniform, but the shapes and dimensions of each of the plurality of protrusions 20 may be non-uniform. For example, the height of the protrusion 20, the diameter of the bottom surface 21, the diameter of the enlarged portion 23, the height position of the enlarged portion 23, etc. may be different from each other.

Explanation of Reference Numerals

[0061] 1 Tire 3 Sidewall 3a Outer surface of sidewall 7 Pattern area 7a Surface of pattern area 20 Protrusion 21 Bottom surface 22 Tip 23 Enlarged portion 30 Body 31 Body portion on the tip side 32 Body portion on the bottom surface side

Claims

1. A tire comprising a pattern region provided on a part of the outer surface of a sidewall in a visible state as a part different from the periphery of the part, A plurality of protrusions protruding from the surface of the pattern region are arranged in the pattern region, Each of the plurality of protrusions includes a bottom surface integral with the surface of the pattern region, a tip end portion farthest from the bottom surface, and a body portion connecting the bottom surface and the tip end portion, The body portion is provided between the bottom surface and the tip end portion, and has a bulging portion having a cross-sectional diameter larger than the equivalent circular diameter of the bottom surface and having the largest equivalent circular diameter in the protrusion, and is provided from the bulging portion to the bottom surface, and the cross-sectional area thereof gradually decreases from the bulging portion toward the bottom surface. A bottom surface side body portion, and a tip end side body portion provided from the bulging portion to the tip end portion, and the cross-sectional area thereof gradually decreases from the bulging portion toward the tip end portion.

2. The equivalent circular diameter of the cross section of the bulging portion is 120% or more and 150% or less of the equivalent circular diameter of the bottom surface. The tire according to claim 1.

3. The protrusion has a height which is the shortest distance from the bottom surface to the tip end portion, The height position of the bulging portion corresponding to the height of the protrusion is from the center in the height direction of the protrusion to the bottom surface side at a height position of 15% of the height of the protrusion, and from the center of the height of the protrusion to the tip end portion side. The tire according to claim 1 or 2, which is arranged between the height positions of 15% of the height of the protrusion.

4. The plurality of protrusions are arranged at a density of two or more within 1 mm ２ The tire according to claim 1 or 2.

5. The plurality of protrusions are linearly arranged at equal intervals, and the pitch of the arrangement is 2.0 times or more and 3.0 times or less of the equivalent circular diameter of the bottom surface. The tire according to claim 1 or 2.

6. The tire according to claim 1 or 2, wherein the cross-sectional shape of the protrusion is substantially circular.

7. The tire according to claim 1 or 2, wherein the tip portion has a tapered and sharp shape.

Images