Tire and tire molding mold

Abstract

To provide a tire and a tire molding mold capable of achieving higher black density and higher contrast than conventional tires.SOLUTION: A tire 1 includes a pattern region 7 provided in a visible state as a portion different from the periphery on a portion of an outer surface 3a of a sidewall 3, where the pattern region 7 is provided with a plurality of projections 20 projecting from a reference surface 7a of the pattern region 7, and the projections 20 have a plurality of projecting lines 30 on outer surfaces thereof. The protrusion 20 has a conical shape in which a cross-sectional outer shape intersecting a protruding direction is reduced as the protrusion heads toward the protruding direction from the reference surface 7a.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a tire having a pattern area for displaying, for example, a mark or a design on a portion of the outer surface of the sidewall, and to a tire molding mold for molding such a tire. [Background technology]

[0002] Conventionally, tires have been known that have a pattern area in which a large number of minute protrusions are arranged in a portion of the tire sidewall (for example, Patent Document 1, etc.). Such pattern areas absorb light as incident light is repeatedly reflected between the protrusions, which makes the area appear darker than the surrounding outer surface of the sidewall, improving contrast. By providing this type of pattern area, the tire can be improved in terms of design effect and appearance, for example. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-131904 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a tire and a tire molding die that can achieve higher black density and higher contrast than conventional tires. [Means for solving the problem]

[0005] The tire of the present invention is a tire having a pattern area provided on a portion of the outer surface of the sidewall in a state that is visibly different from the surrounding area of ​​the portion, and the pattern area has a plurality of protrusions that protrude from a reference plane of the pattern area, and the protrusions have a plurality of ridges on their outer surface.

[0006] A tire molding mold according to the present invention is a mold for molding the tire of the present invention, and includes a pattern area forming section for forming the pattern area. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a tire and a tire molding die that can achieve higher black density and higher contrast than conventional tires. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a side view of a tire according to an embodiment. [Figure 2] FIG. 1 is a cross-sectional view showing an example of a tire molding mold for vulcanizing and molding a tire according to an embodiment. [Figure 3] FIG. 2 is a perspective view showing a plurality of protrusions arranged in a pattern region of the tire according to the embodiment. [Figure 4] 4 is a plan view showing a plurality of protrusions arranged in a pattern region of the tire according to the embodiment, taken along the arrow T in FIG. 3. FIG. [Figure 5] FIG. 2 is a perspective view of a protrusion according to an embodiment. [Figure 6] FIG. 2 is a side view of a protrusion according to an embodiment. [Figure 7] FIG. 10 is a side view of a protrusion according to a first modification based on the embodiment. [Figure 8] FIG. 10 is a side view of a protrusion according to a second modification based on the embodiment. [Figure 9] FIG. 11 is a side view of a protrusion according to a third modification based on the embodiment. [Figure 10] 7 is a cross-sectional view of a protrusion according to a fourth modified example based on the embodiment, which is a cross-sectional view corresponding to the cross section XX in FIG. 6. FIG. [Figure 11] 7 is a cross-sectional view of a protrusion according to a fifth modified example based on the embodiment, which is a cross-sectional view corresponding to cross section XX in FIG. 6. FIG. [Figure 12] FIG. 13 is a perspective view of a protrusion according to a sixth modified example based on the embodiment. [Figure 13]FIG. 13 is a perspective view of a protrusion according to a seventh modification based on the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments will be described with reference to the drawings. Note that the term "approximately" used in this specification does not strictly specify the state, but rather means to include a state that is approximate to the extent that the functions and effects can be achieved.

[0010] FIG. 1 is a side view of a tire 1 according to an embodiment. The tire 1 is a so-called pneumatic tire whose inner cavity is filled with air at a predetermined pressure. The tire 1 according to the embodiment is a pneumatic tire for passenger vehicles, including light cars and SUVs. Note that the configuration of the tire 1 according to 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 configuration of the tire 1, mainly related to its side surface, will be described. FIG. 1 is a side view of the tire 1 as viewed from the direction of the tire rotational axis X. In the following description, the tire axial direction, tire circumferential direction, and tire radial direction are as follows: The tire axial direction is the direction in which the tire rotational axis X extends, and in FIG. 1 refers to the front-to-back direction of the page. When viewed from the tire radial direction, the tire axial direction is the left-to-right direction, and therefore may also be referred to as the left-to-right direction. The tire circumferential direction is an arc line centered on the tire rotational axis X and is the direction along the rotational direction of the tire 1, and is indicated by arrow G in FIG. 1. The tire radial direction is the direction perpendicular to the tire rotational axis X, and is arbitrarily indicated by 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 away from the tire rotational axis X in the tire radial direction, and a tread 4. Each of the bead 2 and the sidewall 3 is provided on one side of the tire 1 shown in Fig. 1 on one side of the tire 1, and on the other side of the tire 1 not shown in Fig. 1 away from the tire axial direction, i.e., a pair of left and right bead 2 and sidewall 3. The tread 4 is disposed between the left and right sidewalls 3 on the outer sides in the tire radial direction. The outer peripheral surface of the tread 4 includes a tread surface that comes into contact with the road surface.

[0013] The tire 1 is mainly composed of multiple types of rubber that form the beads 2, sidewalls 3, and tread 4. A carcass ply that forms the framework of the tire 1 is disposed on the inner cavity side of the rubber that forms the entire tire 1, and an inner liner that maintains air pressure is disposed on the inner cavity side of the carcass ply. An annular reinforcing belt is embedded inside the rubber that forms the tread 4 (the carcass ply, inner liner, and reinforcing belt are not shown). In addition to these components, various other components may be provided as necessary for the function of the tire 1.

[0014] As shown in Fig. 1, the sidewall 3 has an annular decorative area 5 on its outer surface 3a, spanning the entire circumference in the tire circumferential direction. The decorative area 5 is an area of ​​a constant width sandwiched between an inner arc line 5a on the inner side in the tire radial direction and close to the tire rotation axis X, 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 concavities, convexities, or steps on the outer surface 3a of the sidewall 3, or may be imaginary lines that do not actually exist.

[0015] The decorative area 5 on the outer surface 3a of the sidewall 3 may be located radially outward of the maximum tire width position or may be located at a position that includes the maximum tire width position. The maximum tire width position refers to the position between the outer surfaces 3a of the left and right sidewalls 3 that has the longest axial length.

[0016] The tire 1 has a pattern area 7 provided in a part of the outer surface 3a of the sidewall 3 in a state where it is visibly different from the surrounding area of ​​the part. The pattern area 7 is provided in the sidewall rubber, which is a black rubber member that forms the outer surface 3a of the sidewall 3.

[0017] As shown in FIG. 1 , the annular decorative region 5 is provided with marking portions 6A at two opposing locations across the tire rotation axis X. The marking portions 6A are formed by a plurality of characters arranged in the tire circumferential direction. These characters indicate at least one mark such as the manufacturer's name, product name, or brand. Each character may be formed with a concave or convex border, or the entire character may be formed in a concave or convex shape. For example, each character in the marking portion 6A is provided as a pattern region 7 of the embodiment.

[0018] 1, pattern portions 6B are provided in two locations in the annular decorative area 5, sandwiched between two emblem portions 6A in the circumferential direction. The pattern portions 6B are provided with a pattern that resembles a parallelogram curved to imitate the annular decorative area 5. For example, each pattern in the pattern portions 6B is also provided as a pattern area 7 of the embodiment.

[0019] The shape of the pattern area 7 is not limited to these, and various shapes can be used, such as any shape, or a shape depicting marks such as the manufacturer name, product name, brand, etc. mentioned above, or a shape depicting other numbers, letters, etc.

[0020] Each of the pattern regions 7 in the embodiment has a reference surface 7a that follows the profile of the sidewall 3. A plurality of protrusions 20, which will be described later, are formed on this reference surface 7a. The pattern region 7 is an area that is provided in a state where it can be visually recognized as a part that is different from the surrounding area of ​​the pattern region 7 by forming a plurality of protrusions 20. Note that the reference surface 7a may protrude axially outward from the profile of the sidewall 3, may be recessed axially inward from the profile of the sidewall 3, or may be a surface that is in the same position as the profile of the sidewall 3 in the tire axial direction.

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

[0022] The tire mold 10 shown in Fig. 2 includes a plurality of sectors 11 arranged circumferentially along the outer periphery of the tire 1, a pair of side plates 12 arranged on both axial sides of an annular body formed by combining the plurality of sectors 11, and a pair of bead rings 13. During vulcanization molding, an unvulcanized tire 1a that will become the tire 1 is set inside the tire mold 10, as indicated by the dashed line in Fig. 2. The combination of the sectors 11, the side plates 12, and the pair of bead rings 13 forms a mold for molding the tire 1, and the outer surface of the entire tire 1 is formed by the inner surfaces of the mold, i.e., the inner surfaces 11a of the sectors 11, the inner surfaces 12a of the side plates 12, and the inner surfaces 13a of the bead rings 13. During vulcanization molding, a bladder 14 is arranged inside the unvulcanized tire 1a to press the unvulcanized tire 1a against the inner surface of the tire mold 10. The plurality of sectors 11 mainly form the tread 4, the pair of side plates 12 mainly form the sidewall 3, and the pair of bead rings 13 mainly form the bead 2. The entire inner surface of the tire 1 is then formed by the bladder 14.

[0023] The unvulcanized tire 1a is vulcanized in the tire mold 10 to form the rubber shape of the entire tire 1, and a plurality of protrusions 20, which will be described next, are formed in the pattern region 7 described above.

[0024] FIG. 3 is a perspective view showing a plurality of protrusions 20 arranged in the pattern region 7. FIG. 4 is a plan view showing the arrangement of the plurality of protrusions 20 in the pattern region 7, as viewed from the arrow T in FIG. 3. The plurality of protrusions 20 are provided protruding from a reference surface 7a of the pattern region 7. FIGS. 3 and 4 show a state in which the plurality of protrusions 20 are provided protruding from a UV development reference surface 7b when the reference surface 7a of the pattern region 7 is UV developed. The UV development reference surface 7b is a surface obtained by two-dimensionally developing the outer surface 3a of the three-dimensional sidewall 3. The plurality of protrusions 20 are arranged on the reference surface 7a of the pattern region 7 so as to fill the entire area of ​​the pattern region 7. In this embodiment, the shape and dimensions of the plurality of protrusions 20 are substantially uniform.

[0025] A plurality of protrusions 20 are arranged so as to protrude from the reference surface 7a substantially axially outward of the tire. In this embodiment, the protrusions 20 are arranged regularly in a plurality of rows as shown in Fig. 4. Specifically, in one linear row, the protrusions 20 are arranged closely together at equal intervals (equal pitch), and adjacent rows are shifted by half a pitch relative to each other in a close-packed arrangement. As shown in Fig. 4, the plurality of protrusions 20 are arranged linearly in the D direction, E direction, and F direction, which are adjacent to each other in the close-packed arrangement.

[0026] The arrangement of the plurality of protrusions 20 is not limited to a close-packed arrangement, but may be, for example, a matrix arrangement in which each row is linear and the pitch between adjacent rows is uniform. Also, adjacent protrusions 20 may be arranged at a predetermined interval without being closely adjacent, or may be arranged randomly within a range that maintains a predetermined arrangement density.

[0027] FIG. 5 is a perspective view of one protrusion 20. FIG. 6 is a side view of the protrusion 20. As shown in FIGS. 5 and 6, the protrusion 20 of this embodiment has a conical shape in which the cross-sectional outline perpendicular to the protrusion direction decreases as the protrusion extends from the reference plane 7a. The cross-sectional outline is a nearly perfect circle. Therefore, the protrusion 20 is a right cone whose central axis is nearly perpendicular to the reference plane 7a. The protrusion 20 has a conical body 21, a tip 23 including a circular tip surface 22 formed by cutting flat, and a virtual, nearly perfect circular bottom surface 24 that is integral with the reference plane 7a and is flush with the reference plane 7a. The body 21 is a conical surface inclined at a predetermined angle with respect to the reference plane 7a.

[0028] As shown in FIG. 5 , a hole 26 having a cone-shaped inner surface 25 is formed in the tip 23 of the protrusion 20. The hole 26 is formed concentrically with the protrusion 20. The opening diameter and depth of the hole 26 at the tip surface 22 are not limited. However, for example, it is preferable that the depth of the hole 26 be approximately half or deeper than half the height of the protrusion 20 in terms of the light absorption effect described below. The height of the protrusion 20 refers to the shortest distance from the reference plane 7a to the tip surface 22. The direction in which the protrusion 20 protrudes from the reference plane 7a is synonymous with the height direction of the protrusion 20. The depth of the hole 26 refers to the distance corresponding to the height direction from the tip surface 22 to the deepest part of the hole 26. The height direction of the protrusion 20 corresponds to the rubber thickness direction in the sidewall 3 and the pattern region 7.

[0029] As specific examples of the dimensions of the protrusion 20, the height of the protrusion 20 is preferably, for example, 0.3 mm or more and 2.0 mm or less. The diameter of the bottom surface 24 of the protrusion 20 is preferably, for example, 0.7 mm or more and 2.0 mm or less. The outer diameter of the tip surface 22 of the protrusion 20 is preferably, for example, 0.4 times or more and less than 0.95 times the diameter of the bottom surface 24 of the protrusion. The inner diameter of the tip surface 22 of the protrusion 20, i.e., the opening diameter of the hole 26, is preferably smaller than the outer diameter of the tip surface 22 by, for example, 0.2 mm or more and 0.6 mm or less. The depth of the hole 26 is preferably, for example, 0.5 times or more and 1.3 times or less the height of the protrusion 20. Note that the depth of the hole 26 may exceed the height of the protrusion 20. In this case, the bottom of the hole 26 is formed by a convex portion protruding from the surface forming the reference surface 7a of the mold.

[0030] 5 and 6, the projection 20 has a body portion 21 as its outer surface, which has a plurality of ridges 30. The body portion 21 of the projection 20 has grooves 35 between the ridges 30 adjacent to each other in the circumferential direction.

[0031] In this embodiment, the cross section of the ridge 30 has a rectangular shape, such as a trapezoidal shape, but is not limited to a rectangular shape. The multiple ridges 30 all extend along the inclination direction of the body 21 and the protrusion direction of the protrusion 20, and are arranged in parallel with the body 21 at equal intervals (equal pitch) in the circumferential direction. The inclination direction of the body 21 here refers to the direction of the generatrix of a cone when the protrusion 20 has a truncated cone shape (frustum of a cone) with the top removed. The base end 20a of the ridge 30, which is the end on the reference plane 7a side, is continuous with the reference plane 7a and is integral with the reference plane 7a. Meanwhile, the tip 20b of the ridge 30, which is on the side away from the reference plane 7a, is slightly spaced from the tip surface 22 of the protrusion 20 toward the base end 20a. The multiple ridges 30 in this embodiment have approximately the same length from the base end 20a to the tip 20b, and the tip 20b is aligned in the height direction of the protrusion 20.

[0032] The above-mentioned protrusion 30 being aligned along the protrusion direction of the protrusion 20 means that the protrusion 30 extends from the base end 20a to the tip end 20b within a radial cross section passing through the central axis of the protrusion 20.

[0033] The formation region of the multiple ridges 30 may be anywhere between the reference surface 7a and the tip surface 22. That is, as in the present embodiment, the ridges may be formed in a range starting from the reference surface 7a but not reaching the tip surface 22, or may be formed between the reference surface 7a and the tip surface in a range that does not include both the reference surface 7a and the tip surface, or may be formed in a range starting from the tip surface 22 but not reaching the reference surface 7a. Furthermore, the region in the height direction of the protrusion 20 where the multiple ridges 30 are formed is preferably, for example, 30% or more in the height direction. The ridges 30 may extend over the entire height direction region from the reference surface 7a to the tip surface 22, i.e., 100%.

[0034] 5, in the protrusion 20 of this embodiment, a plurality of ridges, i.e., a plurality of inner surface ridges 40, are also formed on the inner surface 25 of the hole 26. The inner surface 25 of the protrusion 20 has an inner surface groove portion 45 that includes the inner surface 25 between the inner surface ridges 40 that are adjacent in the circumferential direction.

[0035] The cross section of the inner surface ridge 40 has a rectangular shape such as a trapezoid, but is not limited to a rectangular shape. The multiple inner surface ridges 40 all extend along the inclination direction of the inner surface 25 and the protrusion direction of the protrusion 20, and are arranged in parallel with the inner surface 25 at equal intervals (equal pitch) in the circumferential direction. The inclination direction of the inner surface 25 here refers to the direction of the generatrix of the cone, assuming that the hole 26 is conical. The tip 40b of the inner surface ridge 40, which is the end closest to the tip surface 22, is slightly separated from the tip surface 22 of the protrusion 20. The end of the inner surface ridge 40 (not shown) on the bottom side of the hole 26 may be located at the bottom, or may not reach the bottom. The tip 40b side of the inner surface ridge 40 may extend until it coincides with the tip surface 22. The multiple inner surface ridges 40 in this embodiment have approximately the same length, and the tips 40b are aligned in the height direction of the protrusion 20. The lengths of the multiple inner surface ridges 40 do not have to be the same.

[0036] In this embodiment, the tip surface 22 of the protrusion 20 is formed in an uneven shape. Specifically, the tip surface 22 of the protrusion 20 has an uneven portion 27 formed by alternatingly arranging a plurality of recesses 27a and protrusions 27b. In this embodiment, the shapes of the recesses 27a and protrusions 27b are substantially rectangular in a side view of the protrusion 20, but the shapes are not limited thereto and may be, for example, arc shapes or V shapes. The shapes of the recesses 27a and protrusions 27b may be the same or different. Furthermore, the shapes of the plurality of recesses 27a may all be the same or different. The shapes of the plurality of protrusions 27b may all be the same or different.

[0037] The multiple protrusions 20 of the embodiment arranged on the reference surface 7a can be formed, for example, by the tire molding mold 10 described above. To form the multiple protrusions 20 by the tire molding mold 10, multiple recesses that correspond to the multiple protrusions 20 and that can form the protrusions 20 are formed on the inner surface 12a, which is the tire molding surface of the side plate 12 that forms the pattern region 7. In other words, the inner surface 12a of the side plate 12 includes a pattern region forming portion where the multiple protrusions 20 are formed.

[0038] In this case, the method for forming the multiple recesses on the tire molding die 10 is not limited, but a suitable method is laser processing, in which laser light is applied to the inner surface 12a of the side plate 12 to partially remove the inner surface 12a. For example, a removal process using a pulse fiber laser can be used as the laser processing, and suitable conditions for the laser processing are, for example, 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 approximately 0.05 mm.

[0039] Similarly to the protrusions 20, the multiple ridges 30 and grooves 35 on the barrel portion 21 side of the protrusions 20, and the inner surface ridges 40 and inner surface grooves 45 on the hole 26 side can also be formed by laser processing the inner surface 12a of the side plate 12 of the molding die 10. That is, by forming recesses and protrusions corresponding to the ridges 30 and grooves 35, and the inner surface ridges 40 and inner surface grooves 45, respectively, in the portions of the inner surface 12a of the side plate 12 where the protrusions 20 are to be formed, and then vulcanizing and molding the tire 1, the ridges 30 and grooves 35, the inner surface ridges 40 and inner surface grooves 45 can be formed along with the protrusions 20.

[0040] In particular, when forming multiple recesses in the tire molding mold 10 by laser processing that can form the protrusions 20, ridges 30, inner surface ridges 45, etc. of the embodiment, they can be formed by, for example, adjusting the output of each pulse or adjusting the irradiation angle of the laser light.

[0041] By forming a plurality of recesses on the inner surface 12a of the side plate 12 by laser processing, in which a plurality of protrusions 20 can be formed, the side plate 12 is hardened, thereby improving durability.

[0042] 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 is mainly incident on the reference surface 7a and the body portions 21 of the protrusions 20 and is reflected by these surfaces. The reflected light is then reflected again by the surrounding protrusions 20 and the reference surface 7a, and such reflection occurs repeatedly between the plurality of protrusions 20 and between the protrusions 20 and the reference 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 observed, the pattern region 7 appears darker than the outer surface 3a of the sidewall 3, which reflects the light around the pattern region 7.

[0043] Here, in the tire 1 of the embodiment, a plurality of ridges 30 are formed particularly on the body portion 21 of the protrusion 20. As a result, light incident on the body portion 21 is reflected on the surface of the ridges 30 in accordance with the cross-sectional shape of the ridges 30. This increases the degree of light reflection and makes the light reflection more complex. This promotes light absorption, further increasing the black density and increasing the contrast of the pattern region 7.

[0044] In the tire 1 of the embodiment, a hole 26 having a cone-shaped inner surface 25 is formed at the tip 23 of the protrusion 20, and multiple inner surface ridges 40 are formed on the inner surface 25 of the hole 26. A portion of light incident on the pattern region 7 enters the hole 26 and is reflected by the inclined inner surface 25. The reflected light is further reflected inside the hole 26. As this repeated reflection of light occurs inside the hole 26, the light that reaches the hole 26 is gradually attenuated and absorbed. Furthermore, in the tire 1 of the embodiment, multiple inner surface ridges 40 are formed on the inner surface 25 of the hole 26, and therefore complex light reflection according to the cross-sectional shape of the inner surface ridges 40 is further generated. This promotes light absorption, further increasing the black density and enhancing the contrast of the pattern region 7. Because the protrusion 20 has the hole 26 at the tip 23, when stress is applied to the protrusion 20, the stress is dispersed, making the protrusion 20 less likely to deform or be damaged.

[0045] In the tire 1 of the embodiment, the tip surface 22 of the protrusion 20 has an uneven portion 27 consisting of multiple recesses 27a and protrusions 27b. A portion of light incident on the pattern region 7 is incident on the recesses 27a and protrusions 27b on the tip surface 22 of the protrusion 20. A portion of the light incident on the recesses 27a is repeatedly reflected within the recesses 27a. A portion of the light incident on the protrusions 27b is reflected from the protrusions 27b, for example, onto the inner surface 25 of the hole 26. In this way, the light reflection is complicated by the uneven portion 27, and the light is gradually attenuated and absorbed. This promotes light absorption, further increasing the black density and increasing the contrast of the pattern region 7. By having the uneven portion 27 on the tip portion 23 of the protrusion 20, when stress is applied to the tip portion 23 of the protrusion 20, the stress is dispersed, making the protrusion 20 less likely to deform or be damaged.

[0046] According to the embodiment described above, the following effects are achieved.

[0047] (1) The tire 1 according to the embodiment is a tire having a pattern area 7 provided on a portion of the outer surface 3a of the sidewall 3 in a state that makes it visible as a part that is different from the surrounding area of ​​the portion, and the pattern area 7 has a plurality of protrusions 20 that protrude from the reference surface 7a of the pattern area 7, and the protrusions 20 have a plurality of ridges 30 on their outer surface.

[0048] According to the tire 1 of the embodiment, the plurality of protrusions 20 absorbs light, increasing the black density of the pattern region 7 and providing high contrast. Furthermore, the plurality of ridges 30 provided on the protrusions 20 promotes light absorption, further increasing the black density and providing even higher contrast in the pattern region 7. This allows the tire 1 to have improved design effects and appearance.

[0049] (2) In the tire 1 according to the embodiment (1), the protrusions 20 preferably have a cone shape in which the cross-sectional outline intersecting the protruding direction decreases as the protrusions 20 protrude from the reference plane 7a.

[0050] This makes it easier for light to be reflected repeatedly between the protrusions 20 to become more complex, improving the light absorption effect and increasing the black density of the pattern region 7, thereby achieving high contrast.

[0051] (3) In the tire 1 according to the above embodiments (1) and (2), the ridge 30 may extend in a direction in which the projection 20 protrudes from the reference plane 7a.

[0052] This makes it easier for light to be reflected between the ridges 30, which in turn makes the light reflection more complex, improving the light absorption effect and increasing the black density of the pattern area 7, thereby achieving high contrast.

[0053] (4) In the tire 1 according to the above embodiments (1) to (3), a hole 26 having a mortar-shaped inner surface 25 is formed at the tip of the protrusion 20, and it is preferable that a plurality of inner surface ridges 40 are formed on the inner surface 25 of the hole 26.

[0054] By forming the holes 26 and the plurality of inner surface ridges 40 on the inner surface 25 of the holes 26, the light absorption effect is improved, and the black density of the pattern region 7 is increased, thereby achieving high contrast.

[0055] (5) The tire molding mold 10 according to the embodiment is a mold for molding the tire 1 according to the embodiment, and has an inner surface 12a of a side plate 12 as a pattern area forming portion that forms the pattern area 7 of the tire 1.

[0056] According to the tire molding mold 10 of the embodiment, the pattern region 7 having the plurality of protrusions 20 of the embodiment is provided by the inner surface 12a of the side plate 12. This makes it possible to mold a tire 1 with a high contrast due to a high black density in the pattern region 7.

[0057] The above-mentioned ridges 30 and inner ridges 40 according to the embodiment have the same length, width, pitch, etc., and are arranged in a line. That is, they are arranged in a regular pattern. However, the ridges and inner ridges according to the present invention are not limited to being arranged in a regular pattern, and may be arranged in a random pattern, for example. Below, modified examples (modifications 1 to 7) of the protrusion 20 in which the ridges 30 and inner ridges 40 are arranged in such a random pattern will be described. Note that these modified examples have a configuration based on the above-mentioned embodiment, and therefore in the drawings referred to in the description, the same components as those in the above-mentioned embodiment and components having the same functions will be assigned the same reference numerals, and their description will be omitted.

[0058] Fig. 7 is a side view of a protrusion 20 having ridges 30 according to Modification 1. Fig. 8 is a side view of a protrusion 20 having ridges 30 according to Modification 2. The multiple ridges 30 in the protrusions 20 shown in Figs. 7 and 8 all have a rectangular cross section and are generally the same in length and width, similar to the above embodiment. Also, the base ends 20a are continuous with the reference surface 7a, and the tips 20b are aligned and slightly spaced from the tip surface 22.

[0059] 7, like the above embodiment, the multiple ridges 30 extend along the inclination direction of the body 21 and the protrusion direction of the projections 20, but are not arranged at equal intervals in the circumferential direction of the body 21, but are arranged at irregular intervals, i.e., at unequal pitches. Note that two or more of the circumferential pitches may be the same, or all of the pitches may be different.

[0060] The multiple ridges 30 in Modification 2 of Fig. 8 are arranged at uneven pitches in the circumferential direction, as in Modification 1, and some of the extending directions are not aligned with the protruding direction of the projections 20 and are not aligned with the inclination direction of the body 21. Note that the extending directions of two or more ridges 30 may be the same, or all of the ridges 30 may extend in different directions.

[0061] FIG. 9 is a side view of a protrusion 20 having ridges 30 according to Modification 3. The multiple ridges 30 in the protrusion 20 shown in FIG. 9 extend along the inclination direction of the body 21 and the protrusion direction of the protrusion 20, but are uneven in length and width. The base ends 20a of the multiple ridges 30 are all continuous with the reference plane 7a, but because they have different lengths, the tips 20b are uneven in the height direction. Note that two or more ridges 30 may have the same length, or all of the ridges 30 may have different lengths. Note that two or more ridges 30 may have the same width, or all of the ridges 30 may have different widths.

[0062] Fig. 10 is a cross-sectional view of a protrusion 20 having ridges 30 and inner ridges 40 according to Modification 4, and this cross-section corresponds to cross-section XX in Fig. 6. In the protrusion 20 shown in Fig. 10, the heights of the multiple ridges 30 and the multiple inner ridges 40 are different. In this case, the cross-sectional shapes of the ridges 30 and the inner ridges 40 are rectangular, as in the above embodiment. In this case, the heights of two or more of the ridges 30 and the inner ridges 40 may be the same, or all of them may be different.

[0063] FIG. 11 is a cross-sectional view of a protrusion 20 having ridges 30 and inner ridges 40 according to Modification 5, and this cross-section corresponds to cross-section XX in FIG. 6. In the protrusion 20 shown in FIG. 11, the multiple ridges 30 and the multiple inner ridges 40 have different cross-sectional shapes. In this case, the ridges 30 and the inner ridges 40 have cross-sectional shapes that include triangular ridges 30a and inner ridges 40a, rectangular ridges 30c and inner ridges 40c, and arc ridges 30d and inner ridges 40d. Note that the cross-sectional shapes of the ridges 30 and inner ridges 40 may be various shapes other than these.

[0064] 12 is a perspective view of a protrusion 20 having ridges 30 according to Modification 6. The extension direction of the multiple ridges 30 in the protrusion 20 of Modification 6 is inclined relative to the inclination direction of the body 21 described above, and the extension directions are opposite to each other, forming a mesh-like configuration in which the ridges 30 intersect at multiple locations. The circumferential intervals of the multiple ridges 30 inclined in the same direction may be the same (equal pitch) or may be different (unequal pitch). The length and width of each ridge 30 may also be the same or different.

[0065] FIG. 13 is a perspective view of a protrusion 20 having ridges 30 according to Modification 7. The ridges 30 of the protrusion 20 of Modification 7 have a wave-like shape. In this case, the amplitude of the waves in each ridge 30 may be constant or may vary. The circumferential spacing of the ridges 30 may be the same (equal pitch) or may be different (unequal pitch). The length and width of each ridge 30 may also be the same or different.

[0066] In the projections 20 according to the above-described first to seventh modifications, the plurality of ridges 30 may be provided in a random pattern.

[0067] (6) That is, in the tire 1 according to the embodiment described above in (1) to (4), the plurality of ridges 30 may be provided in a random pattern.

[0068] This makes the manner in which light is reflected and the light absorption effect of the ridges 30 more diverse and complex, and effectively makes it possible to increase the contrast of the pattern region 7.

[0069] (7) In the tire 1 according to the embodiment (6), the plurality of ridges 30 may have different random elements, such as at least one of their length, width, height, and extending direction.

[0070] This makes the manner in which light is reflected and the light absorption effect of the ridges 30 more diverse and complex, and effectively makes it possible to increase the contrast of the pattern region 7.

[0071] (8) In the tire 1 according to the embodiment (7), the plurality of ridges 30 may extend in different directions as a random element, and at least two ridges may intersect with each other.

[0072] This makes the manner in which light is reflected and the light absorption effect of the ridges 30 more diverse and complex, and effectively makes it possible to increase the contrast of the pattern region 7.

[0073] (9) In the tire 1 according to the embodiment (6) above, the plurality of ridges 30 are arranged in parallel, and the pitch between adjacent ridges 30 may be different as a random element.

[0074] This makes the manner in which light is reflected and the light absorption effect of the ridges 30 more diverse and complex, and effectively makes it possible to increase the contrast of the pattern region 7.

[0075] The above describes the embodiments of the present invention and modifications based on the embodiments, but the present invention is not limited to these embodiments and modifications, and even if modifications and improvements are made within the scope of the present invention, they will still be included in the scope of the present invention.

[0076] For example, the protrusion 20 is not limited to a conical shape, but may be a pyramidal shape such as a triangular pyramid or a polygonal pyramid. Furthermore, the protrusion 20 is not limited to a conical shape, but may be a polygonal prism shape including a cylindrical shape and a rectangular parallelepiped shape. Furthermore, protrusions having these shapes may have a central axis that is inclined relative to the reference plane 7a.

[0077] In the above embodiment, the shapes and dimensions of the multiple protrusions 20 are approximately uniform, but the shapes and dimensions of each of the multiple protrusions 20 may be non-uniform; for example, the heights, diameters, etc. of the protrusions 20 may be different, and the protrusions themselves may be random. [Explanation of symbols]

[0078] 1 tire 3 Sidewall 3a Outer surface of sidewall 7 Pattern Area 7a Reference surface of pattern area 10 Tire molding mold 12a Inner surface of side plate (pattern area forming portion) 20 protrusions 23 Tip 25 Inner 26 holes 30 Convex strips 40 Inner ridges

Claims

1. A tire having a pattern area provided on a portion of the outer surface of a sidewall in a state where the pattern area is visibly different from the surrounding area of ​​the portion, the pattern area is provided with a plurality of protrusions protruding from a reference surface of the pattern area; The protrusion has a plurality of ridges on its outer surface.

2. The tire according to claim 1 , wherein the protrusion has a cone shape in which a cross-sectional outline intersecting the protruding direction decreases in a direction in which the protrusion protrudes from the reference plane.

3. The tire according to claim 1 or 2, wherein the ridge extends in a direction in which the projection protrudes from the reference surface.

4. The tire according to claim 1 or 2, wherein the plurality of ridges are arranged in a random pattern.

5. The tire according to claim 4 , wherein the plurality of ridges are different in at least one of length, width, height, and extending direction as the random element.

6. The tire according to claim 5 , wherein the plurality of ridges have different extending directions as the random elements, and at least two of the ridges intersect with each other.

7. The tire according to claim 4 , wherein the plurality of ridges are arranged in parallel, and the pitch between adjacent ridges is different as the random element.

8. A hole having a mortar-shaped inner surface is formed at the tip of the protrusion, The tire of claim 2 , wherein the inner surface of the hole has a plurality of inner surface ridges formed thereon.

9. 3. A mold for molding the tire according to claim 1, comprising a pattern area forming portion for forming the pattern area.

Images