Tire

Abstract

To provide a tire having a higher black density and a higher contrast than a conventional tire.SOLUTION: A tire 1 includes, in a part of an external surface 3a of a sidewall 3, a pattern region 7 visibly provided as a portion different from a periphery of the part. In the pattern region 7, a plurality of band-shaped protrusions 20 protruding from the external surface 7a of the pattern region 7 are disposed. A ridge-shaped top portion 30 of the band-shaped protrusion 20 has: a ridge line 40 continuously extending along an extending direction of the top portion 30; and a recessed portion 50 formed such that a height of the band-shaped protrusion 20 is locally reduced from the ridge line 40.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a tire having a pattern area for displaying, for example, a logo or a pattern on a part of the outer surface of a 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 being 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] Increasing the contrast by a large number of protrusions has an advantage that it is less likely to undergo aging changes compared to means such as painting, and its effect is 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, and thus a further improvement in design effect and appearance, compared to the prior art.

[0005] An object of the present invention is to provide a tire in which the black density is increased and the contrast is improved 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 strip-shaped convex portions protruding from the surface of the pattern area are arranged in the pattern area. The ridgeline-shaped top of the strip-shaped convex portion has a ridgeline continuously extending along the extending direction of the top, and a recess formed so that the height of the strip-shaped convex portion is locally reduced from the ridgeline.

Effects of the Invention

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

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Mode for Carrying Out the Invention

[0009] Hereinafter, embodiments will be described with reference to the drawings. 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 a passenger car including a light automobile, an SUV, etc. 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.

[0010] 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.

[0011] As shown in FIG. 1, the tire 1 includes a bead 2, a sidewall 3 extending from the bead 2 to the outside in the tire radial direction away from the tire rotation axis X in the tire radial direction, and a tread 4. Each of the bead 2 and the sidewall 3 includes one on each 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 separated in the tire axial direction, that is, a pair on the left and right. The tread 4 is disposed between the left and right sidewalls 3 on the outside in the tire radial direction. The outer peripheral surface of the tread 4 includes a tread surface that contacts the road surface.

[0012] 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 that constitutes the entire tire 1, a carcass ply that constitutes the skeleton of the tire 1 is arranged, and on the inner cavity side of the carcass ply, an inner liner that holds air pressure is arranged. Further, an annular reinforcing belt is embedded inside the rubber that constitutes the tread 4 (the carcass ply, the inner liner, and the reinforcing belt are not shown in the figure). In addition to these members, various members are provided as necessary for the function of the tire 1.

[0013] As shown in FIG. 1, the sidewall 3 has an annular decorative region 5 on its outer surface 3a that extends 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 that is closer 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 that is more outside 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 on the outer surface 3a of the sidewall 3 by concave, convex, or steps, or may be virtual lines that do not actually exist.

[0014] The position of the decorative region 5 in the tire radial direction 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 tire axial length is the longest between the outer surfaces 3a of the left and right sidewalls 3.

[0015] The tire 1 includes a pattern region 7 provided in a visible state as a part different from the periphery on a part of the outer surface 3a of the sidewall 3.

[0016] As shown in FIG. 1, at two locations on the annular decorative region 5 that face each other across the tire rotation axis X, there are provided logo portions 6A. The logo portions 6A are formed by arranging a plurality of characters in the tire circumferential direction. By these plurality of characters, at least one of logos such as a manufacturer name, a product name, a brand, etc. is displayed. Each character may be formed by being bordered by a concave or convex line, or the entire character may be formed in a concave or convex shape. For example, each character of the logo portion 6A is provided as the pattern region 7 of the embodiment.

[0017] As shown in FIG. 1, in the annular decorative region 5, at two locations sandwiched between two logo portions 6A in the circumferential direction, there are provided pattern portions 6B. The pattern portions 6B are provided with a pattern such that a parallelogram is curved following the annular decorative region 5. For example, each pattern of the pattern portion 6B is also provided as the pattern region 7 of the embodiment.

[0018] Note that the shape of the pattern region 7 is not limited to these, and various shapes can be mentioned, such as any shape, or a shape depicting a logo such as the manufacturer name, product name, brand, etc. described above, or a shape depicting other numbers, characters, etc.

[0019] Each of the above pattern regions 7 in the embodiment has a surface 7a along the profile of the sidewall 3. A plurality of strip-shaped convex portions 20 described later are formed on this surface 7a. The pattern region 7 is a region provided in a visible state as a part different from the periphery of the pattern region 7 by forming a plurality of strip-shaped convex portions 20. The pattern region 7 is provided on the sidewall rubber, which is a black rubber member constituting the outer surface 3a of the sidewall 3.

[0020] 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.

[0021] 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 plurality of sectors 11 mainly form the tread 4, and the pair of side plates 12 mainly form the sidewall 3. The pair of bead rings form the bead 2, and the bladder forms the entire inner surface of the tire 1.

[0022] 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 strip-shaped convex portions 20 described below are formed in the above-mentioned pattern region 7.

[0023] Figs. 3 and 4 are views showing a part of the plurality of strip-shaped convex portions 20 arranged in the pattern region 7. Fig. 3 is a perspective view, Fig. 4 is a plan view, and is a view taken along the arrow IV in Fig. 3. The plurality of strip-shaped convex portions 20 shown in Figs. 3 and 4 are arranged on the surface 7a of the pattern region 7 in a state of filling the entire region of the pattern region 7. Hereinafter, the surface 7a of the pattern region 7 may be referred to as the pattern region surface 7a. Some of the plurality of strip-shaped convex portions 20 shown in Figs. 3 and 4 have a recessed portion 50 described later, but Figs. 3 and 4 omit the illustration of the recessed portion 50. That is, some of the strip-shaped convex portions 20 have a recessed portion 50 and some do not. Fig. 5 is a perspective view showing a strip-shaped convex portion 20 having a recessed portion 50 alone.

[0024] As shown in FIG. 4, the strip-shaped convex portion 20 of the embodiment has a point-symmetrical shape in which "S" is horizontally reversed in a plan view. The plurality of strip-shaped convex portions 20 are arranged in the vertical direction and the horizontal direction in a state where "the horizontally reversed S" is written vertically in FIG. 4. Each strip-shaped convex portion 20 has an upper first arc portion 21 and a lower second arc portion 22 in FIG. 4. Each of the arc portions 21 and 22 has a shape that is reverse C-shaped in a plan view and is curved so as to extend in opposite directions.

[0025] Among the plurality of strip-shaped convex portions 20 arranged vertically and horizontally, in the plurality of strip-shaped convex portions 20 on the vertical column side, the first arc portion 21 of the lower strip-shaped convex portion 20 enters the inside of the second arc portion 22 of the upper strip-shaped convex portion 20 in FIG. 4. Therefore, in the plurality of strip-shaped convex portions 20 on the vertical column side, the first arc portion 21 and the second arc portion 22 overlap when viewed from the horizontal direction. On the other hand, although the plurality of strip-shaped convex portions 20 on the horizontal row side are close to each other, they do not overlap when viewed from the vertical direction. In the arrangement pattern of the plurality of strip-shaped convex portions 20 shown in FIG. 4, the second arc portion 22 of a certain strip-shaped convex portion 20 and the first arc portion 21 of the strip-shaped convex portion 20 arranged at the lower left in FIG. 4 of that strip-shaped convex portion 20 are close to each other. This close portion is the portion where the strip-shaped convex portions 20 are closest to each other.

[0026] FIG. 5 is a perspective view showing the strip-shaped convex portion 20 having the recessed portion 50 described above, but other strip-shaped convex portions 20 without the recessed portion 50 have the same basic configuration. As shown in FIG. 5, the strip-shaped convex portion 20 of the embodiment includes one end portion 20a and the other end portion 20b as both ends in its extending direction, and further includes a vertex 20c between these one end portion 20a and the other end portion 20b. The strip-shaped convex portion 20 has a ridge-shaped top portion 30 extending from the one end portion 20a through the vertex 20c to the other end portion 20b. The top portion 30 extends in the extending direction of the strip-shaped convex portion 20 and has a generally mountain-shaped shape as a whole when viewed from the side of the pattern region surface 7a. Here, the height refers to the height from the pattern region surface 7a. The width of the strip-shaped convex portion 20 is substantially constant from the one end portion 20a to the other end portion 20b.

[0027] The side from the vertex 20c to one end 20a constitutes the first arc portion 21, and the side from the vertex 20c to the other end 20b constitutes the second arc portion 22. Since the plan view of the strip-shaped convex portion 20 is a point-symmetrical shape, the first arc portion 21 and the second arc portion 22 extend in different directions in the plan view. Both the first arc portion 21 and the second arc portion 22 have side surfaces 20e that reach from the top 30 to the surface 7a of the pattern region respectively. The side surface 20e is curved along the extending direction of the strip-shaped convex portion 20.

[0028] The top 30 includes a first top 31 on the side of the first arc portion 21 extending from the vertex 20c to one end 20a, and a second top 32 on the side of the second arc portion 22 extending from the vertex 20c to the other end 20b. Since the first arc portion 21 and the second arc portion 22 extend in different directions from each other, the first top 31 and the second top 32 extend in different directions from each other. The height of the first top 31 gradually decreases as it goes from the vertex 20c to one end 20a. Similarly, the height of the second top 32 gradually decreases as it goes from the vertex 20c to the other end 20b.

[0029] The vertex 20c is the portion where the height of the top 30 is the largest and is the highest portion in the strip-shaped convex portion 20. The vertex 20c of the embodiment is not sharp but extends in a ridgeline shape and has a certain length.

[0030] The top 30 of the strip-shaped convex portion 20 has a ridge line 40 and a recessed portion 50. The ridge line 40 is a linear portion that continuously extends along the extending direction of the top 30 and corresponds to the outer contour line that depicts the top 30 extending from one end 20a through the vertex 20c to the other end 20b. For example, the ridge line 40 is a line connecting the portions with the highest height at the top 30 and is a continuous line connecting the highest points of the top 30 extending from one end 20a to the other end 20b. The ridgeline-shaped top 30 has no restriction on its cross-sectional shape and is formed, for example, in a semi-circular shape, a semi-elliptical shape, a triangular shape, a flat shape, an inclined surface shape, etc. The ridge line 40 is represented by a point in the cross-sectional view of such a top 30. The ridge line 40 of the embodiment includes a first ridge line 41 on the side of the first top 31 and a second ridge line 42 on the side of the second top 32.

[0031] The recessed portion 50 is a portion formed such that the height of the strip-shaped convex portion 20 is locally reduced from the ridge line 40. The recessed portion 50 is formed in both the first top portion 31 and the second top portion 32. As described above, the height of the first top portion 31 and the second top portion 32 gradually decreases from the vertex 20c toward one end portion 20a and the other end portion 20b, respectively. Specifically, the height is locally lower at the recessed portion 50.

[0032] As shown in FIG. 5, the recessed portion 50 is provided in a set such that each of the first top portion 31 and the second top portion 32 has a point-symmetrical shape with the vertex 20c as the center of symmetry. The recessed portion 50 includes a stepped portion 51a and a plurality of valley portions 51b extending in a direction intersecting the extending direction of each of the arc portions 21 and 22. A mountain portion 52 is formed by the adjacent stepped portion 51a and valley portion 51b. The stepped portion 51a is open to the outer peripheral side edge of the arc portions 21 and 22. Each valley portion 51b is open at both ends in the width direction of the arc portions 21 and 22. The region where the recessed portion 50 is formed includes a jagged shape formed by the valley portions 51b and the mountain portion 52 in a cross section along the extending direction of the arc portions 21 and 22. Note that the recessed portion 50 is not limited to being regularly arranged so as to be point-symmetrical, for example, and may be arranged at any position of the top portion 30, such as being arranged irregularly and scattered.

[0033] Regarding the dimensions of the strip-shaped convex portion 20, although they are designed to functionally satisfy and are not limited, for example, the following dimensions can be cited as preferred examples.

[0034] The width of the top 30 of the strip-shaped convex portion 20 is preferably 50 μm or more and 150 μm or less. The width at the center in the height direction of the strip-shaped convex portion 20 is preferably 50 μm or more and 150 μm or less. The maximum height of the strip-shaped convex portion 20, that is, the height of the apex 20c is preferably 150 μm or more and 300 μm or less. When the height of the strip-shaped convex portion 20 is H and the width is W, the ratio H / W is preferably 1 or more and 5 or less, and more preferably 2 or more and 3 or less. The maximum depth of the recessed portion 50 is preferably 50% or less of the height of the strip-shaped convex portion 20, and more preferably 10% or more and 20% or less. The length of the recessed portion 50 along the extending direction of the strip-shaped convex portion 20 is preferably larger than the maximum depth of the recessed portion 50.

[0035] The plurality of strip-shaped convex portions 20 having the recessed portions 50 of the above-described embodiment arranged on the surface 7a of the pattern region can be formed, for example, by the tire molding die 10 described above. To form the plurality of strip-shaped convex portions 20 by the tire molding die 10, a plurality of strip-shaped concave portions capable of forming those strip-shaped convex portions 20 are formed corresponding to the strip-shaped convex portions 20 having the recessed portions 50 on the inner surface 12a which is the tire molding surface of the side plate 12 forming the pattern region 7.

[0036] In that case, the method for forming the plurality of strip-shaped concave portions is not limited, but laser processing for irradiating the inner surface 12a of the side plate 12 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 employed, 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.

[0037] Further, as a specific example of a method for forming a strip-shaped concave portion including a recessed portion 50 on the inner surface of the side plate 12, the following methods can be mentioned. A strip-shaped concave portion that does not include a convex portion in which the recessed portion 50 can be formed is formed by, for example, laser processing as described above. Then, an organic substance such as resin or an inorganic substance such as metal is partially filled into the strip-shaped concave portion by means such as spraying. Next, a part of the filling is partially removed by means such as sandblasting in which metal powder such as alumina or glass beads is projected by high-pressure air. Thereby, the filling is formed into a desired shape and dimensions according to the recessed portion 50. After that, when the tire 1 is vulcanized and molded using the tire molding die 10, the strip-shaped concave portion is formed into the strip-shaped convex portion 20, and the filling serves as a core and the recessed portion 50 is formed. According to this processing method, it is possible to easily obtain the strip-shaped convex portion 20 having a desired shape or a recessed portion 50 having a complicated shape without taking the trouble of generating complicated processing data and processing based on it. Further, from the viewpoint of enhancing the mold release property from the rubber, the filling is preferably formed with 10% or more and 50% or less of the surface area of the strip-shaped convex portion.

[0038] When light is incident on the pattern region 7 in which a plurality of strip-shaped convex portions 20 having the recessed portion 50 are arranged as described above, the light is incident on the recessed portion 50 in addition to the surface 7a of the pattern region, the side surface 20e and the top portion 30 of the strip-shaped convex portion 20, and is reflected by those surfaces. The reflected light is reflected again by the surrounding strip-shaped convex portions 20, and such reflection occurs between the plurality of strip-shaped convex portions 20, so that 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.

[0039] Among the strip-shaped convex portions 20 formed in the pattern region 7 of the embodiment, those having the recessed portion 50 and those not having the recessed portion 50 are mixed. In the strip-shaped convex portion 20 having the recessed portion 50, light is reflected even in the recessed portion 50, so that the number of times of light reflection increases and the light reflection becomes more complicated. Thereby, the absorption action of the light incident on the pattern region 7 is promoted, and high contrast is achieved with an improvement in black density.

[0040] The mode of the recessed portion 50 that promotes the light absorption action is not limited to the above embodiment. FIGS. 6 to 8 show other examples of the recessed portion 50 formed in each of the first arc portion 21 and the second arc portion 22 of the strip-shaped convex portion 20 of the above embodiment.

[0041] The recessed portion 50 shown in FIG. 6 includes a plurality of arc-shaped notches 53 formed so as to generally follow the arcs of the arc portions 21 and 22. The recessed portion 50 is disposed in a portion close to one end portion 20a and the other end portion 20b of each of the arc portions 21 and 22. These notches 53 provided in the arc portions 21 and 22 have a point-symmetrical shape with respect to each other with the vertex 20c as the center of symmetry. Between the adjacent notches 53, an arc-shaped ridge portion 54 having a shape along the notch 53 is formed. The region where the recessed portion 50 is formed by the plurality of notches 53 and the ridge portions 54 includes a jagged shape. Thereby, the light reflection is complicated and the absorption action of the light incident on the pattern region 7 is promoted, and high contrast is achieved with an improvement in black density.

[0042] The recessed portion 50 shown in FIG. 7 includes notches 55 that reduce the heights of the respective tops 31 and 32 of portions close to one end portion 20a and the other end portion 20b of the strip-shaped convex portion 20. Due to this notch 55, wall surfaces 56 along the height direction of the strip-shaped convex portion 20 are formed at both ends of the notch 55. The recessed portion 50 provided in each of the arc portions 21 and 22 has a point-symmetrical shape with respect to each other with the vertex 20c as the center of symmetry. According to this recessed portion 50, light is reflected by the bottom surface 55a and the wall surface 56 of the notch 55, so that the absorption action of the light incident on the pattern region 7 is promoted, and high contrast is achieved with an improvement in black density.

[0043] As shown in Fig. 8, the strip-shaped convex portion 20 has a plurality of recessed portions 50 scattered on its top portion 30. In this case, the recessed portion 50 is a hole that opens to the top portion 30. The cross-sectional shape of the hole is, for example, circular, but is not limited thereto, and may be a cross-sectional shape such as triangular, rectangular, polygonal, etc. In the case of such a recessed portion 50 having a hole shape, the recessed portion 50 may also open to the side surface 20e. According to this recessed portion 50, the light that enters the recessed portion 50 is reflected by the inner wall surface and the bottom surface of the recessed portion 50, thereby promoting the absorption action of the light incident on the pattern region 7 and achieving a high contrast with an improvement in the black density.

[0044] The planar view shape of the strip-shaped convex portion 20 is not limited to the above-described embodiment, and any shape may be used as long as it is a shape extending in a strip shape. Figs. 9 and 10 are views showing a state in which a plurality of strip-shaped convex portions 20 having a shape different from that of the strip-shaped convex portion 20 of the above-described embodiment are arranged on the pattern region surface 7a. Fig. 9 is a perspective view, and Fig. 10 is a plan view and is a view seen in the direction of arrow X in Fig. 9. Some of the plurality of strip-shaped convex portions 20 shown in Figs. 9 and 10 have a recessed portion 50 to be described later, but Figs. 9 and 10 omit the illustration of the recessed portion 50. Fig. 11 is a perspective view showing a single strip-shaped convex portion 20 having the recessed portion 50. In Figs. 9 to 11, the same reference numerals are given to the same components as those of the strip-shaped convex portion 20 shown in Figs. 3 to 5.

[0045] As shown in Fig. 10, the strip-shaped convex portion 20 of this embodiment has a point-symmetric shape that is Z-shaped in a planar view. Each strip-shaped convex portion 20 has an upper first bent portion 25 and a lower second bent portion 26 in Fig. 4. Each of the bent portions 25 and 26 has a shape that is substantially V-shaped in a planar view. The plurality of strip-shaped convex portions 20 are arranged in the vertical direction and the horizontal direction in a state where "Z" is written vertically in Fig. 10. The plurality of strip-shaped convex portions 20 on the vertical column side are arranged obliquely so as to shift to the right as they go downward. The strip-shaped convex portions 20 on the horizontal row side are arranged in the left-right direction in Fig. 10.

[0046] Each strip-shaped convex portion 20 has an upper first bending portion 25 and a lower second bending portion 26 in FIG. 10. Each of the bending portions 25 and 26 has a V-shaped shape in plan view. Among the plurality of strip-shaped convex portions 20 arranged vertically and horizontally, in the plurality of strip-shaped convex portions 20 on the vertical row side, the first bending portion 25 of the lower strip-shaped convex portion 20 enters the inside of the second bending portion 26 of the upper strip-shaped convex portion 20 in FIG. 10. Therefore, in the plurality of strip-shaped convex portions 20 on the vertical row side, the first bending portion 25 and the second bending portion 26 overlap when viewed from the lateral direction. On the other hand, the plurality of strip-shaped convex portions 20 on the horizontal row side are arranged while sandwiching the first bending portion 25 or the second bending portion 26 of the strip-shaped convex portion 20 therebetween, and do not overlap when viewed from the vertical direction.

[0047] As shown in FIG. 10, the strip-shaped convex portion 20 includes one end portion 20a and the other end portion 20b as both end portions in its extending direction, and further includes a vertex 20c between the one end portion 20a and the other end portion 20b. The strip-shaped convex portion 20 has a ridge-shaped top portion 30 extending from the one end portion 20a through the vertex 20c to the other end portion 20b. The top portion 30 extends in the extending direction of the strip-shaped convex portion 20 and has a generally mountain-shaped shape as a whole when viewed in the plane direction of the pattern region surface 7a. The height is the largest at the vertex 20c. Here, the height refers to the height from the pattern region surface 7a.

[0048] The side from the vertex 20c to the one end portion 20a constitutes the first bending portion 25, and the side from the vertex 20c to the other end portion 20b constitutes the second bending portion 26. Each of the first bending portion 25 and the second bending portion 26 has a corner portion 27 that is a vertex forming a V shape. The first bending portion 25 and the second bending portion 26 each have a side surface 20e extending from the top portion 30 to the pattern region surface 7a. The side surface 20e is bent along the extending direction of the strip-shaped convex portion 20.

[0049] The top portion 30 includes a first top portion 31 on the side of the first bending portion 25 extending from the vertex 20c to one end portion 20a, and a second top portion 32 on the side of the second bending portion 26 extending from the vertex 20c to the other end portion 20b. Further, both the first top portion 31 and the second top portion 32 include a central side top portion 33c extending from the vertex 20c to the corner portion 27, and an end side top portion 33e extending from the corner portion 27 to each of the end portions 20a, 20b. In plan view, the central side top portions 33c of the first top portion 31 and the second top portion 32 extend continuously in a straight line, and the end side top portions 33e of the first top portion 31 and the second top portion 32 are parallel to each other and extend in opposite directions to each other. The first bending portion 25 and the second bending portion 26 extend in different directions from each other, and thus the first top portion 31 and the second top portion 32 extend in different directions from each other. The central side top portions 33c of the first top portion 31 and the second top portion 32 gradually decrease in height from the vertex 20c toward the corner portion 27.

[0050] The vertex 20c is the portion where the height of the top portion 30 is the largest and is the highest portion in the strip-shaped convex portion 20.

[0051] The top portion 30 of the strip-shaped convex portion 20 has a ridge line 40 and a recessed portion 50. In this case, the ridge line 40 includes a first ridge line 41 on the side of the first top portion 31 and a second ridge line 42 on the side of the second top portion 32.

[0052] The recessed portion 50 is a portion formed such that the height of the strip-shaped convex portion 20 is locally reduced from the ridge line 40, and is provided at the end side top portions 33e of the first top portion 31 and the second top portion 32. The recessed portion 50 has the same configuration as the recessed portion 50 shown in FIG. 5 and includes a stepped portion 57a and a plurality of valley portions 57b. A plurality of peak portions 58 are formed by the stepped portion 57a and the valley portions 57b. The region where the recessed portion 50 is formed includes a jagged shape due to the stepped portion 57a, the valley portions 57b, and the peak portions 57 in a cross section along the extending direction of the arc portions 21, 22.

[0053] Even in the pattern region 7 where a plurality of strip-shaped convex portions 20 shown in FIGS. 9 to 11 are arranged, due to the light absorption action by the plurality of strip-shaped convex portions 20, it is visually recognized as blacker than the outer surface 3a of the side wall 3 that reflects the light around the pattern region 7. Furthermore, the light absorption action is promoted by the recessed portion 50, and high contrast is achieved with the improvement of the black density.

[0054] As the strip-shaped convex portion 20, the vertex 20c having the largest height is arranged not at the midpoint of the ridge line 40 but on one or both of the one end portion 20a side and the other end portion 20b side, and a portion where the height of the top portion 30 is the smallest may be arranged in the middle of the one end portion 20a and the other end portion 20b.

[0055] FIG. 12 shows an example of such a strip-shaped convex portion 20. This strip-shaped convex portion 20 has an inverted S shape in which the S shape in plan view is reversed left and right, but has vertices 20c of substantially the same height on both the vicinity of the one end portion 20a and the vicinity of the other end portion 20b, and a bottom point 20d where the height of the top portion 30 is the smallest in the middle of the one end portion 20a and the other end portion 20b. The S-shaped top portion 30 extends from the one end portion 20a to the other end portion 20b and has a continuous ridge line 40. In this case, the top portion 30 is formed on a flat inclined surface that inclines to one side in the width direction. A recessed portion 50 in a mode where the vertex 20c is flatly cut is formed at each vertex 20c. Also with such a strip-shaped convex portion 20, since the overall shape becomes complicated, the light absorption action generated by reflection between the strip-shaped convex portions 20 is promoted, and high contrast is achieved with the improvement of the black density.

[0056] According to the embodiment described above, the following effects can be obtained.

[0057] (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 strip-shaped convex portions 20 protruding from the surface 7a of the pattern area 7 are arranged. The ridge-shaped top 30 of the strip-shaped convex portion 20 has a ridge line 40 continuously extending along the extending direction of the top 30, and a recessed portion 50 formed so that the height of the strip-shaped convex portion 20 is locally reduced from the ridge line 40.

[0058] The light incident on the pattern area 7 of the tire 1 is incident on the recessed portion 50 in addition to the surface 7a of the pattern area, the side surfaces 20e of the plurality of strip-shaped convex portions 20, and the top 30, and is reflected by those surfaces. The reflected light is reflected again by the surrounding strip-shaped convex portions 20, and such reflection occurs between the plurality of strip-shaped convex portions 20, so that the light incident on the pattern area 7 is gradually attenuated and absorbed. When such a pattern area 7 is visually recognized, the pattern area 7 is visually recognized as darker than the outer surface 3a of the sidewall 3 that reflects the light around the pattern area 7. By arranging the plurality of strip-shaped convex portions 20, the reflection of light occurs complicatedly, whereby the pattern area 7 has a higher black density and a higher contrast than before. The strip-shaped convex portion 20 formed in the pattern area 7 of the embodiment has a recessed portion 50, and light is also reflected by the recessed portion 50, so that the number of times of light reflection increases and the light reflection becomes more complicated. Thereby, the absorption action of the light incident on the pattern area 7 is promoted, and a higher contrast is achieved with an improvement in black density.

[0059] (2) In the tire 1 of (1) according to the embodiment, the strip-shaped convex portion 20 includes one end portion 20a and the other end portion 20b, and includes a vertex 20c having the largest height of the top 30 between the one end portion 20a and the other end portion 20b. The top 30 includes a first top 31 extending from the vertex 20c to the one end portion 20a and a second top 32 extending from the vertex 20c to the other end portion 20b. The first top 31 and the second top 32 extend in different directions from each other, and a form in which the recessed portion 50 is arranged on at least one of the first top 31 and the second top 32 is included.

[0060] Since the first top portion 31 and the second top portion 32 extend in different directions from each other in this way, the strip-shaped convex portion 20 is likely to have a complex shape as a whole. As the shape of the strip-shaped convex portion 20 becomes complex, the absorption effect of light generated by reflection between the strip-shaped convex portions 20 is promoted, and high contrast associated with an improvement in black density is achieved.

[0061] (3) In the tire 1 according to the above (2) of the embodiment, the first top portion 31 includes a form in which the height gradually decreases from the apex 20c toward one end portion 20a, and the second top portion 32 includes a form in which the height gradually decreases from the apex 20c toward the other end portion 20b.

[0062] When the heights of the respective top portions 31 and 32 gradually decrease in this way, the lengths of the top portions 31 and 32 can be made larger than the length in the extending direction of the strip-shaped convex portion 20. As a result, the recessed portion 50 is likely to be formed, or the length of the recessed portion 50 can be increased. As a result, the absorption effect of light by the recessed portion 50 is promoted, and high contrast associated with an improvement in black density is achieved.

[0063] (4) In the tire 1 according to the above (1) of the embodiment, the strip-shaped convex portion 20 includes one end portion 20a and the other end portion 20b, and a top portion 30 is formed from the one end portion 20a to the other end portion 20b. At least one of the one end portion 20a side and the other end portion 20b side includes an apex 20c where the height of the top portion 30 is the largest, and between the one end portion 20a and the other end portion 20b, a bottom point 20d where the height of the top portion 30 is the smallest is included.

[0064] Thereby, since the strip-shaped convex portion 20 has a complex shape as a whole, the absorption effect of light generated by reflection between the strip-shaped convex portions 20 is promoted, and high contrast associated with an improvement in black density is achieved.

[0065] 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. can be made within the scope in which the object of the present invention can be achieved, and they are included in the scope of the present invention.

[0066] For example, the plurality of strip-shaped convex portions 20 disposed on the surface 7a of the pattern region may be randomly arranged instead of being arranged in an aligned arrangement such as a vertical and horizontal arrangement.

[0067] The top portion 30 of the strip-shaped convex portion 20 of the above embodiment has a vertex 20c at the center, and is generally mountain-shaped with the height gradually decreasing from the vertex 20c toward the end portion. However, the height of the top portion 30 may be constant, or the top portion 30 may be inclined from one end portion 20a to the other end portion 20b. Further, the top portion 30 may be in a mode in which the height changes in a wave shape. Also, in the arrangement mode in which, in two adjacent strip-shaped convex portions 20, the other end portion 20b of one strip-shaped convex portion 20 is disposed near one end portion 20a of the other strip-shaped convex portion 20, a difference in height may be given by making the height of the one end portion 20a larger than the height of the other end portion 20b. In this case, compared with the case where the heights of the adjacent one end portion 20a and the other end portion 20b are the same, the reflection of light is complicated and the light absorption effect is more promoted, and high contrast accompanying an improvement in black density is achieved.

[0068] The recessed portion 50 is in a mode of being recessed in a side view, and the recessed shape thereof may be an arc shape, a rectangular shape, a triangular shape, a polygonal shape, or an irregular shape. And the shapes of the recessed portions 50 formed in the strip-shaped convex portion 20 may be the same or different from each other. Also, a plurality of small recesses may be disposed in one recessed portion 50. The recessed portion 50 of the above embodiment is disposed on both the first top portion 31 and the second top portion 32, but may be disposed on either one of the top portions. Further, the recessed portion 50 may be formed at at least a part of the vertex 20c.

[0069] The width of the strip-shaped convex portion 20 may be substantially constant from one end portion 20a to the other end portion 20b, or may be in a mode in which the width is partially reduced or conversely increased.

Explanation of Reference Numerals

[0070] 1 Tire 3 Sidewall 3a Outer surface of sidewall 7 Pattern region Surface of the 7a pattern region 20 Strip-shaped convex part 20a One end of the strip-shaped convex part 20b The other end of the strip-shaped convex part 20c Vertex 20d Bottom point 30 Top part 31 First top part 32 Second top part 40 Ridge line 50 Depressed part

Claims

1. A tire comprising a pattern area 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, wherein a plurality of strip-shaped convex portions protruding from the surface of the pattern area are arranged in the pattern area, and the ridge-shaped top of the strip-shaped convex portion has a ridge line continuously extending along the extending direction of the top and a recess formed such that the height of the strip-shaped convex portion is locally reduced from the ridge line. The tire.

2. The strip-shaped convex portion includes one end portion and the other end portion, and includes a vertex having the largest height of the top between the one end portion and the other end portion, the top includes a first top extending from the vertex to the one end portion and a second top extending from the vertex to the other end portion, the first top and the second top extend in different directions from each other, and the tire according to claim 1, wherein the recess is arranged on at least one of the first top and the second top.

3. The first top gradually decreases in height from the vertex toward the one end portion, and the second top gradually decreases in height from the vertex toward the other end portion. The tire according to claim 2.

4. The strip-shaped convex portion includes one end portion and the other end portion, and the top is formed from the one end portion to the other end portion, and at least one of the one end portion side and the other end portion side includes a vertex having the largest height of the top, and between the one end portion and the other end portion, The tire according to claim 1, including a bottom point having the smallest height of the top.

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