Tire and tire molding die

Abstract

To provide a tire which is enhanced in black color density to enhance contrast more than before.SOLUTION: A tire 1 comprises, on a portion of an outer surface 3a of a side wall 3, a patter region 7 formed visibly as a site that is different from a circumference of the portion, where a plurality of protruding-part aggregates 20 protruding from a surface 7a of the pattern region 7 are arranged in the patter region 7. The protruding-part aggregates 20 include main cones 30 as first protruding parts having first skirt portions 37 leading to the surface 7a of the pattern region 7 and sub conical bodies 40 as a plurality of second protruding parts arranged around the main conical bodies 30 and arranged so that portions thereof overlap with the first skirt portions 37.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 or a pattern on a part of the outer surface of a sidewall, and a tire molding die for molding such a tire.

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 has been known (for example, Patent Document 1, etc.). In such a pattern area, incident light is repeatedly reflected between the protrusions, resulting in a light absorption effect, whereby it is visually recognized as darker 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] High contrast by a large number of protrusions has an advantage that it is less likely to undergo aging changes than 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 in which the black density is further increased and the contrast is further improved compared to the conventional case, so as to further improve 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 higher contrast is achieved compared to the conventional case, and a tire molding die capable of manufacturing such a tire.

Means for Solving the Problems

[0006] The tire according to the present invention is a tire provided with a pattern area provided on a part of the outer surface of the sidewall in a visible state as a part different from the periphery of the part, and a plurality of convex portion aggregates protruding from the surface of the pattern area are arranged in the pattern area. The convex portion aggregate includes a main cone as a first convex portion having a first skirt portion continuous with the surface of the pattern area, and a plurality of second convex portions arranged around the main cone and at least a part of which is arranged so as to overlap the first skirt portion of the main cone.

[0007] The tire molding die according to the present invention is a die for molding the tire of the present invention, and includes a convex portion aggregate forming portion including a plurality of concave portions corresponding to the plurality of convex portion aggregates.

Effects of the Invention

[0008] According to the present invention, it is possible to provide a tire in which the black density is increased and high contrast is achieved more than in the prior art, and a tire molding die capable of manufacturing such a tire.

Brief Description of the Drawings

[0009]

Figure 1

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Figure 14

MODE FOR CARRYING OUT THE INVENTION

[0010] 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 in which a predetermined air pressure is filled 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, referring to FIG. 1, an overview of the structure mainly related to the side surface of the tire 1 will be described. FIG. 1 is a side view of the tire 1 as seen from the direction of the tire rotation axis X. In the following description, the tire axial direction, the tire circumferential direction, and the tire radial direction 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. When viewed from the tire radial direction, since the tire axial direction becomes the left - right direction, the tire axial direction may be referred to as the left - right direction. 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 and 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 from the bead 2 in the tire radial direction away from the tire rotation axis X, and a tread 4. Each of the bead 2 and the sidewall 3 has a pair, that is, a left - right pair, 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 separated in the tire axial direction. The tread 4 is disposed between the outer sides in the tire radial direction of the left and right sidewalls 3. 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 rubbers 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 the figure). In addition to these members, various members are provided as required for the functions of the tire 1.

[0014] As shown in FIG. 1, the sidewall 3 has, on its outer surface 3a, an annular decorative region 5 extending over the entire circumference in the tire circumferential direction. The decorative region 5 is a region having a constant width sandwiched between an inner arc line 5a 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 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 stepped portions 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 tire axial length is the longest between the outer surfaces 3a of the left and right sidewalls 3.

[0016] 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. 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.

[0017] As shown in FIG. 1, at two locations of the annular decorative region 5 facing each other across the tire rotation axis X, a logo portion 6A is provided. The logo portion 6A is formed by arranging a plurality of characters in the tire circumferential direction. At least one of logos such as a manufacturer name, a product name, and a brand is displayed by these plurality of characters. Each character may be formed with an edge defined by a concave or convex line, or the entire character may be formed concave or convex. For example, each character of the logo portion 6A is provided as the pattern region 7 of the embodiment.

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

[0019] 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 emblems 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 regions 7 in the embodiment has a surface 7a along the profile of the sidewall 3. A plurality of convex portion aggregates 20, which will be described later, are formed on this surface 7a. The pattern region 7 is a region provided in a visually recognizable state as a part different from the periphery of the pattern region 7 by forming a plurality of convex portion aggregates 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 disposed 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 disposed 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.

[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 convex portion aggregates 20 described below are formed in the above-described pattern region 7.

[0024] Figs. 3 and 4 are views showing a plurality of convex portion aggregates 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 convex portion aggregates 20 shown in Figs. 3 and 4 are arranged in the pattern region 7 according to the first arrangement pattern 21. The plurality of convex portion aggregates 20 are disposed on the surface 7a of the pattern region 7 in a state of filling the entire area of the pattern region 7. Hereinafter, the surface 7a of the pattern region 7 may be referred to as the pattern region surface 7a.

[0025] The convex portion assembly 20 of the embodiment includes a main cone 30 as a first convex portion and a plurality of sub-cones 40 as second convex portions. There is one main cone 30, and a plurality of sub-cones 40 are arranged around the one main cone 30 disposed at the center of the convex portion assembly 20 so as to surround the main cone 30.

[0026] FIG. 5 shows each of the main cone 30 and the sub-cones 40 individually in order to clarify their respective shapes. The left side of FIG. 5 is a side view of the main cone 30, and the right side of FIG. 5 is a side view of the sub-cone 40.

[0027] As shown in FIG. 5, the main cone 30 is a conical protrusion protruding from the surface 7a of the pattern region. The main cone 30 has a conical side surface 31 and a top 32 formed by being flatly cut. The top 32 of the main cone 30 is disposed on the surface 7a in a state where it is farthest from the pattern region surface 7a. The main cone 30 is integral with the pattern region surface 7a and has a virtual bottom surface 33 that is flush with the surface 7a. The bottom surface 33 is a perfect circle. The main cone 30 has a central axis 30c that connects the center of the bottom surface 33 and a virtual vertex on the top 32. The central axis 30c extends perpendicular to the pattern region surface 7a. Therefore, the main cone 30 is a straight cone that protrudes vertically from the pattern region surface 7a.

[0028] The main cone 30 of the embodiment includes a conical base 35 continuous with the surface 7a of the pattern region 7 and a conical tip 36 extending in a direction away from the pattern region surface 7a from the base 35. The tip 36 is concentric with the base 35. The side surface 31 of the main cone 30 includes a base side surface 35a that is the side surface of the base 35 and a tip side surface 36a that is the side surface of the tip 36.

[0029] As shown in Fig. 5, the inclination angle θ1 of the base side surface 35a in the main cone 30 is larger than the inclination angle θ2 of the tip side surface 36a. In this case, the inclination angle is, in side view, the angle of each of the side surfaces 35a and 36a with respect to the line perpendicular to the pattern region surface 7a. The base 35 includes a first skirt portion 37 continuous with the pattern region surface 7a. The main cone 30 has a circular cross-sectional shape parallel to the pattern region surface 7a from the bottom surface to the top surface. The area of the cross-sectional shape of the main cone 30 parallel to the pattern region surface 7a generally decreases gradually from the bottom surface 33 toward the top surface 32, but the degree of decrease changes at the boundary between the base 35 and the tip 36. That is, the degree of decrease in the area of the cross-sectional shape is larger for the base 35 with the larger inclination angle than for the tip 36.

[0030] Note that the bottom surface 33 of the main cone 30 in the embodiment is circular, but it may be elliptical. Also, the flat surface of the top 32 in the embodiment is circular and substantially parallel to the bottom surface 33, but it does not have to be parallel to the bottom surface 33. Furthermore, the top 32 may not be cut flat but may be in a sharp mode, or may be formed in a spherical shape.

[0031] As shown in Fig. 5, the sub-cone 40 is a conical protrusion protruding from the pattern region surface 7a. The sub-cone 40 has the same shape as the main cone 30 and is a conical protrusion with a reduced scale. That is, the sub-cone 40, like the main cone 30, has a conical side surface 41, a top 42 formed by being cut flat, and a circular bottom surface 43. The top 42 of the sub-cone 40 is arranged on the surface 7a in a state where it is farthest from the pattern region surface 7a. The sub-cone 40 has a central axis 40c connecting the center of the bottom surface 43 and a virtual vertex on the top 42. The sub-cone 40 is also a straight cone in which the central axis 40c extends perpendicular to the pattern region surface 7a, like the main cone 30.

[0032] The sub-conical body 40 of the embodiment includes a conical base portion 45 continuous with the surface 7a of the pattern region 7, and a conical tip portion 46 extending from the base portion 45 in a direction away from the pattern region surface 7a. The tip portion 46 is concentric with the base portion 45. The side surface 41 of the sub-conical body 40 includes a base side surface 45a that is the side surface of the base portion 45 and a tip side surface 46a that is the side surface of the tip portion 46.

[0033] As shown in FIG. 5, when the sub-conical body 40 is viewed from the side, the inclination angle with respect to the line perpendicular to the pattern region surface 7a is such that the inclination angle θ3 of the base side surface 45a is larger than the inclination angle θ4 of the tip side surface 46a. The base portion 45 includes a second skirt portion 47 continuous with the pattern region surface 7a. The sub-conical body 40 has a circular cross-sectional shape parallel to the pattern region surface 7a from the bottom surface to the top surface. The area of the cross-sectional shape of the sub-conical body 40 parallel to the pattern region surface 7a generally decreases gradually from the bottom surface 43 toward the top surface 42, but the degree of decrease changes at the boundary between the base portion 45 and the tip portion 46. That is, the degree of decrease in the area of the cross-sectional shape is larger for the base portion 45 with the larger inclination angle than for the tip portion 46.

[0034] Note that the bottom surface 43 of the sub-conical body 40 of the embodiment is circular, but it may be elliptical. Also, the flat surface of the top portion 42 of the embodiment is circular and substantially parallel to the bottom surface 43, but it does not have to be parallel to the bottom surface 43. Furthermore, the top portion 42 may not be cut flat and may be in a sharp mode, or may be formed in a spherical shape.

[0035] As shown in FIG. 5, the height h2 of the sub-conical body 40 is smaller than the height h1 of the main conical body 30. The height h1 of the main conical body 30 and the height h2 of the sub-conical body 40 are both the lengths of the central axes 30c and 40c from the pattern region surface 7a to the respective top portions 32 and 42.

[0036] In one convex portion assembly 20, a plurality of sub-conical bodies 40 are arranged concentrically around one main conical body 30 and surround the main conical body 30. The number of sub-conical bodies 40 arranged around the main conical body 30 is preferably 3 or more, and may be 4 or more, or a larger number.

[0037] FIG. 6 is an enlarged plan view showing a pair of convex portion assemblies 20 arranged in the first array pattern 21. As shown in FIG. 6, a plurality of sub-cones 40 surrounding the main cone 30 are arranged at equal pitches in the circumferential direction. The plurality of sub-cones 40 constituting the convex portion assembly 20 have second skirt portions 47 partially overlapping each other. That is, a pair of adjacent sub-cones 40 in the circumferential direction have a common second overlap portion 52 where the second skirt portions 47 overlap each other.

[0038] Also, each of the second skirt portions 47 of the plurality of sub-cones 40 surrounding the main cone 30 partially overlaps the first skirt portion 37 of the main cone 30. That is, the second skirt portion 47 of the sub-cone 40 and the first skirt portion 37 of the main cone 30 have a common third overlap portion 53 that overlaps each other.

[0039] As shown in FIGS. 3 and 4, in the first array pattern 21, a linear array portion 21A in which a plurality of convex portion assemblies 20 are linearly arranged at equal pitches in the first direction F1 is arranged in a plurality of rows in a second direction F2 orthogonal to the first direction F1. In a pair of adjacent linear array portions 21A in the second direction F2, the convex portion assemblies 20 of the other linear array portion 21A are arranged in a staggered pattern between the convex portion assemblies 20 of one side linear array portion 21A.

[0040] In the linear array portion 21A in which a plurality of convex portion assemblies 20 are arranged in the first direction, as shown in FIG. 6, the sub-cones 40 are adjacent to each other, and a pair of adjacent sub-cones 40 have a second overlap portion 52 where the second skirt portions 47 overlap each other. On the other hand, as shown in FIG. 4, there is a gap between the linear array portions 21A adjacent in the second direction F2, and the second skirt portions 47 of the adjacent sub-cones 40 do not overlap. That is, the pattern region surface 7a has a non-overlap portion 55 where the second skirt portions 47 of the sub-cones 40 do not overlap between the linear array portions 21A adjacent in the second direction F2.

[0041] The first array pattern 21 including a plurality of convex portion aggregates 20 shown in FIGS. 3 and 4 can be formed by the side plate 12 of the tire molding die 10 described above. As shown in FIG. 7, the side plate 12 can include a convex portion aggregate forming portion 100 in which the plurality of convex portion aggregates 20 are formed.

[0042] FIG. 7 is a cross-sectional view showing a state in which a plurality of convex portion aggregate forming recesses 110 are formed on the inner surface 12a of the side plate 12. As shown in FIG. 7, each of the plurality of convex portion aggregate forming recesses 110 is a recess corresponding to the convex portion aggregate 20 formed in the pattern region 7 after vulcanization, and includes one main recess 130 and a plurality of sub-recesses 140.

[0043] The main recess 130 is a conical recess corresponding to the shape and size of the main cone 30. The sub-recess 140 is a conical recess corresponding to the shape and size of the sub-cone 40. The plurality of sub-recesses 140 are arranged around one main recess 130 so as to surround the main recess 130. The plurality of convex portion aggregate forming recesses 110 are arranged in a pattern corresponding to the first array pattern 21 on the inner surface 12a of the side plate 12. The convex portion aggregate forming portion 100 includes these plurality of convex portion aggregate forming recesses 110. The main recess 130 and the sub-recess 140 are examples of the plurality of recesses of the present disclosure included in the convex portion aggregate forming portion 100.

[0044] The method for forming the main recess 130 and the sub-recess 140 is not limited, but laser processing in which the inner surface 12a is partially removed by irradiating the inner surface 12a of the side plate 12 with laser light 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.

[0045] When vulcanizing and molding the tire 1 with the tire molding die 10, unvulcanized rubber is filled into a plurality of convex portion aggregate forming recesses 110 of the convex portion aggregate forming portion 100, and when the rubber is vulcanized, a plurality of convex portion aggregates 20 are formed. That is, the rubber filled in the main recess 130 is formed into the main cone 30, and the rubber filled in the sub-recess 140 is formed into the sub-cone 40. As a result, as shown in FIGS. 3 and 4, a plurality of convex portion aggregates 20 arranged in the first arrangement pattern 21 are formed in the pattern region 7 of the sidewall 3.

[0046] When light is incident on the pattern region 7 in which a plurality of convex portion aggregates 20 are arranged as described above, the light is reflected by the side surface 31 of the main cone 30 and the side surface 41 of the sub-cone 40 of the convex portion aggregate 20. The light reflected in this way is reflected again by the side surfaces 31 and 41 of the surrounding main cones 30 and sub-cones 40, and such reflections occur between the main cones 30, between the sub-cones 40, and between the main cone 30 and the sub-cone 40. As a result, the light incident on the pattern region 7 gradually attenuates and is 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 sidewall 3 that reflects the light around the pattern region 7.

[0047] In the plurality of sub-cones 40 in the above embodiment, by increasing the number of circumferential arrangements and arranging them densely, they can become one annular convex portion.

[0048] FIGS. 8 and 9 are diagrams schematically showing the convex portion aggregate 20 provided with the annular convex portion 60 formed in this way, FIG. 8 is a perspective view, and FIG. 9 is a view taken along arrow IX of FIG. 8. This annular convex portion 60 is arranged concentrically with the main cone 30 so as to surround the main cone 30 on the pattern region surface 7a. The annular convex portion 60 constitutes the second convex portion of the present disclosure, similar to the sub-cone 40.

[0049] Figures 10 and 11 are diagrams showing in detail an example of a convex portion aggregate 20 in which an annular convex portion 60 formed by a number of sub-cones 40 is arranged around a main cone 30 as the second convex portion of the present disclosure. Figure 10 is a perspective view, and Figure 11 is a view taken along arrow XI in Figure 10. As shown in Figures 10 and 11, this annular convex portion 60 is formed by arranging a number of sub-cones 40 closely adjacent to each other in the circumferential direction around the main cone 30. For a pair of adjacent sub-cones 40 in the circumferential direction, the base 35 and the tip 36 overlap each other, and the tops 42 are close to each other. The annular top 61 of the annular convex portion 60 has an uneven shape in which the unevenness is continuously annular due to a plurality of adjacent tops 42 arranged in the circumferential direction. By having such an uneven shape, the reflection of light occurring at the top 61 of the annular convex portion 60 becomes complicated. Thereby, the absorption effect of the light incident on the pattern region 7 is promoted.

[0050] As shown in Figure 5, since the height h2 of each sub-cone 40 of the embodiment from the pattern region surface 7a is smaller than the height h1 of the main cone 30 from the pattern region surface 7a, the height of the annular convex portion 60 from the pattern region surface 7a is also smaller than the height of the main cone 30 from the pattern region surface 7a.

[0051] The first array pattern 21 is an example of an array pattern of a plurality of convex portion aggregates 20. Figures 12 and 13 show a state in which a plurality of convex portion aggregates 20 are arranged on the pattern region surface 7a according to a second array pattern 22 different from the first array pattern 21. Figure 12 is a perspective view, and Figure 13 is a plan view and is a view taken along arrow XIII in Figure 12. Figure 14 is an enlarged plan view of a plurality of convex portion aggregates arranged in the second array pattern.

[0052] As shown in FIGS. 12 and 13, in the second array pattern 22, a plurality of convex portion aggregates 20 similar to the convex portion aggregate 20 shown in FIGS. 3 and 4 are linearly arranged at equal pitches in the first direction F1. As shown in FIG. 14, in a pair of convex portion aggregates 20 adjacent in the first direction F1, the main cones 30 are close to each other, and their first skirt portions 37 partially overlap each other. That is, the pattern region 7 has a first overlap portion 51 where the first skirt portions 37 of the plurality of main cones 30 overlap each other. In this second array pattern 22, the plurality of main cones 30 are linearly arranged while partially overlapping in the first direction F1, and a plurality of sub-cones 40 are arranged around the plurality of main cones 30 so as to surround the plurality of main cones 30. In the plurality of sub-cones 40, the adjacent second skirt portions 47 partially overlap each other.

[0053] According to the embodiment described above, the following effects can be obtained.

[0054] (1) The tire 1 according to the embodiment is a tire including 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. In the pattern region 7, a plurality of convex portion aggregates 20 protruding from the surface 7a of the pattern region 7 are arranged. The convex portion aggregate 20 includes a main cone 30 as a first convex portion having a first skirt portion 37 continuous with the surface 7a of the pattern region 7, and a plurality of second convex portions arranged around the main cone 30 and arranged so that at least a part thereof overlaps the first skirt portion 37 of the main cone 30. In the embodiment, the second convex portion is the sub-cone 40.

[0055] The light incident on the pattern area 7 of the tire 1 is reflected by the side surface 31 of the main cone 30 and the side surface 41 of the sub-cone 40 of the convex portion aggregate 20, and the reflected light is reflected again by the side surfaces 31 and 41 of the surrounding main cones 30 and sub-cones 40. Such light reflection occurs between the main cones 30, between the sub-cones 40, and between the main cone 30 and the sub-cone 40, 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 a plurality of convex portion aggregates 20, light reflection occurs in a complicated manner, whereby the pattern area 7 has a higher black density than before and a high contrast is achieved. By arranging the sub-cones 40 so as to overlap with the first skirt portion 37 of the main cone 30, in the convex portion aggregate 20, since the main cone 30 and the sub-cones 40 are close to each other and the density increases, the absorption action of the light incident on the pattern area 7 is promoted, and a high contrast is achieved with an improvement in the black density.

[0056] (2) In the tire 1 according to the above (1) of the embodiment, the plurality of sub-cones 40 that are the second convex portions may be arranged so as to surround the main cone 30.

[0057] As a result, the light radially reflected from the main cone 30 to the surroundings reaches each sub-cone 40, and the probability of being reflected by these sub-cones 40 increases. Therefore, as the number of repetitions of light reflection increases, the light reflection becomes complicated. For this reason, the absorption action of the light incident on the pattern area 7 is promoted, and a high contrast is achieved with an improvement in the black density.

[0058] (3) In the tire 1 according to the above (1) and (2) of the embodiment, the second convex portion is a sub-cone 40, and it is preferable that three or more of the sub-cones 40 are arranged around the main cone 30.

[0059] The second convex portion is composed of a sub-cone 40 that is a cone together with the main cone 30, so that the reflection of light can be made more complex. Therefore, the absorption of light incident on the pattern area 7 is promoted, and high contrast with an increase in black density can be achieved.

[0060] (4) In the tire 1 according to the above (3) of the embodiment, it is preferable that the height from the surface 7a of the pattern area 7 is smaller for the sub-cone 40 than for the main cone 30.

[0061] When the height of the sub-cone 40 is smaller than the height of the main cone 30 rather than when the heights of the main cone 30 and the sub-cone 40 are equal, the uneven shape of the surface shape of the convex portion aggregate 20 becomes more complex. As a result, the reflection of light can be made more complex, so that the absorption of light incident on the pattern area 7 is promoted, and high contrast with an increase in black density can be achieved.

[0062] (5) In the tire 1 according to the above (3) and (4) of the embodiment, each of the plurality of sub-cones 40 has a second skirt portion 47, and it is preferable that adjacent sub-cones 40 have a second overlap portion 52 where the second skirt portions 47 overlap each other.

[0063] As a result, the density of the plurality of sub-cones 40 constituting the convex portion aggregate 20 increases and the number increases, so that the absorption of light incident on the pattern area 7 is further promoted. As a result, high contrast with an increase in black density can be achieved even more.

[0064] (6) In the tire 1 according to the above (1) to (5) of the embodiment, the second convex portion may be an annular convex portion 60 arranged so as to surround the main cone 30.

[0065] As a result, the light radiated radially from the main cone 30 to the surroundings reaches the annular convex portion 60 and the probability of reflection by the annular convex portion 60 increases. Therefore, the number of repetitions of light reflection increases, the light reflection becomes complex, and the light absorption action is promoted. As a result, high contrast with an increase in black density can be achieved even more.

[0066] (7) In the tire 1 according to the above (6) of the embodiment, it is preferable that the height from the surface 7a of the pattern region 7 is smaller for the annular convex portion 60 than for the main cone 30.

[0067] When the height of the annular convex portion 60 is smaller than the height of the main cone 30 rather than when the heights of the main cone 30 and the annular convex portion 60 are equal, the uneven shape of the surface shape of the convex portion aggregate 20 becomes more complicated. As a result, the reflection of light can be made more complicated, so that the absorption effect of the light incident on the pattern region 7 is promoted, and high contrast accompanying an improvement in black density can be achieved.

[0068] (8) In the tire 1 according to the above (6) or (7) of the embodiment, it is preferable that the top 61 of the annular convex portion 60 has an uneven shape in which the unevenness is continuously annular.

[0069] As a result, the reflection of light generated at the top 61 of the annular convex portion 60 can be made complicated, so that the absorption effect of the light incident on the pattern region 7 is promoted, and high contrast accompanying an improvement in black density can be achieved.

[0070] (9) In the tire 1 according to the above (1) to (8) of the embodiment, the pattern region 7 may be in a mode having a first overlap portion 51 where the first skirt portions 37 of the plurality of main cones 30 overlap each other.

[0071] As a result, since the main cones 30 of the plurality of convex portion aggregates 20 are close to each other and the density increases, the absorption effect of light by the plurality of main cones 30 is promoted, and high contrast accompanying an improvement in black density can be achieved.

[0072] (10) The tire molding die 10 according to the embodiment is a tire molding die for molding the tire 1 according to the above (1) to (9), and includes a convex portion aggregate forming portion 100 including a plurality of main concave portions 130 and sub-concave portions 140 corresponding to the plurality of convex portion aggregates 20.

[0073] A plurality of convex portion aggregates 20, which are configured by a plurality of main concave portions 130 and sub-concave portions 140 included in the convex portion aggregate forming portion 100 of the tire molding die 10, are formed in the pattern region 7 so as to achieve high contrast with the improvement of the black density. As a result, the tire 1 molded by this tire molding die 10 can improve the design effect and appearance.

[0074] As described above, the embodiments of the present invention have been described. However, the present invention is not limited to the above embodiments, and even if modifications, improvements, etc. are made within the range that can achieve the object of the present invention, they are included in the scope of the present invention.

[0075] For example, the plurality of convex portion aggregates 20 may be arranged randomly without being arranged in a specific arrangement pattern such as the first arrangement pattern 21 and the second arrangement pattern 22.

[0076] The main cone 30 and the sub-cone 40 that constitute the convex portion aggregate 20 are conical shapes, but either one or both of them may be polygonal pyramid shapes. Further, the main cone 30 and the sub-cone 40 are two-stage conical shapes in which the inclination angle of the side surface changes, but either one or both of them may be multi-stage conical shapes of three or more stages, or conversely, a simple conical shape in which the inclination angle of the side surface does not change may be used.

[0077] The main cone 30 and the sub-cone 40 of the embodiment are straight cones whose central axis is perpendicular to the pattern region surface 7a, but either one or both of them may be oblique cones whose central axis is inclined with respect to the pattern region surface 7a. Among a plurality of sub-cones 40 in one convex portion aggregate 20, both a straight cone and an oblique cone may be included. Among a plurality of convex portion aggregates 20, the main cone 30 may be a straight cone or an oblique cone. Further, the main cone 30 and the sub-cone 40 may be oblique cones including an undercut shape including a portion where a part of the side surface is inclined at an acute angle with respect to the pattern region surface 7a.

[0078] Among the plurality of convex part aggregates 20, the height h1, the bottom surface 33, and the apex angle (indicated by θ in FIG. 5) of the main cone 30 may each be uniform or non-uniform. Among one convex part aggregate 20, the height h1, the bottom surface 33, and the apex angle (indicated by θ in FIG. 5) of the plurality of sub-cones 40 may each be uniform or non-uniform.

[0079] The height h1 of the main cone 30 and the height h2 of the sub-cone 40 may be the same, or conversely, the height h1 of the main cone 30 may be smaller than the height h2 of the sub-cone 40. The area of the bottom surface 33 of the main cone 30 and the area of the bottom surface 43 of the sub-cone 40 may be the same, or conversely, the area of the bottom surface 33 of the main cone 30 may be smaller than the area of the bottom surface 43 of the sub-cone 40. The apex angle of the main cone 30 and the apex angle of the sub-cone 40 may be the same or different.

[0080] The overlapping amounts of the plurality of overlapping parts 51 where the first skirt parts 37 of the main cone 30 overlap may be uniform or non-uniform. The overlapping amounts of the plurality of overlapping parts 52 where the second skirt parts 47 of the sub-cones 40 overlap may be uniform or non-uniform. The overlapping amounts of the plurality of third overlapping parts 53 where the first skirt part 37 of the main cone 30 and the second skirt part 47 of the sub-cone 40 overlap may be uniform or non-uniform.

[0081] In the first arrangement pattern 21, there is a non-overlapping part 55 where the second skirt part 47 of the sub-cone 40 does not overlap between the linear arrangement parts 21A adjacent in the second direction F2. However, it may not have this non-overlapping part 55, and the second skirt parts 47 of the plurality of sub-cones 40 may overlap even in the second direction F2. When there is no non-overlapping part 55, almost all light reflection occurs on the surface of the convex part aggregate 20, so the light reflection is more likely to be complicated than when there is a non-overlapping part 55, which is preferable.

Explanation of Reference Numerals

[0082] 1... Tire, 3... Sidewall, 3a... Outer surface of the sidewall, 7... Pattern area, 7a... Surface of the pattern area, 10... Tire molding die, 20... Convex portion aggregate, 30... Main cone (first convex portion), 37... First skirt portion, 40... Sub-cone (second convex portion), 47... Second skirt portion, 51... First overlap portion, 52... Second overlap portion, 60... Annular convex portion (second convex portion), 61... Top of the annular convex portion, 100... Convex portion aggregate forming portion, 130... Main concave portion (concave portion), 140... Sub-concave portion (concave portion), h1... Height of the main cone, h2... Height of the sub-cone.

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 convex portion aggregates protruding from the surface of the pattern region are arranged in the pattern region, The convex portion aggregate includes a main cone as a first convex portion having a first skirt portion continuous with the surface of the pattern region, and a plurality of second convex portions arranged around the main cone and at least a part of which is arranged so as to overlap the first skirt portion of the main cone.

2. The tire according to claim 1, wherein the plurality of second convex portions are arranged so as to surround the main cone.

3. The tire according to claim 1 or 2, wherein the second convex portion is a sub-cone, and three or more of the sub-cones are arranged around the main cone.

4. The tire according to claim 3, wherein the height from the surface of the pattern region is smaller for the sub-cone than for the main cone.

5. The tire according to claim 3, wherein each of the plurality of sub-cones has a second skirt portion, and adjacent sub-cones have a second overlap portion where the second skirt portions overlap each other.

6. The tire according to claim 1 or 2, wherein the second convex portion is an annular convex portion arranged so as to surround the main cone.

7. The tire according to claim 6, wherein the height from the surface of the pattern region is smaller for the annular convex portion than for the main cone.

8. The tire according to claim 6, wherein the top of the annular convex portion has an uneven shape in which the unevenness is continuously annular.

9. The tire according to claim 1 or 2, wherein the pattern region has a first overlap portion where the first skirt portions of the plurality of main cones overlap each other.

10. A tire molding die for molding the tire according to claim 1 or 2, comprising a convex portion aggregate forming portion including a plurality of concave portions corresponding to the plurality of convex portion aggregates.

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