Tire and tire forming mold

Abstract

Provided is a tire in which the black density is further improved compared to conventional tires, thereby achieving a higher contrast ratio. A tire (1) is provided with a pattern region (7) in a portion of an outer surface (3a) of a sidewall (3), the pattern region (7) being provided in a state of being visible as a different portion from the periphery of the portion, and in a UV deployment reference surface (7b) when a reference surface (7a) of the pattern region (7) is UV-deployed, each of a plurality of oblique cones (20) is disposed in a state in which the apex (22) thereof is farthest from the UV deployment reference surface (7b). The plurality of tapered cones (20) have a central axis (20c) connecting the apex of the tapered cones (20) and the center of the bottom surface (23), and the plurality of tapered cones (20) include three or more types in which the angles of the central axis (20c) with respect to the UV deployment reference surface (7b) are different.

Description

Technical Field

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

[0002] Conventionally, a tire having a pattern area formed by a plurality of fine protrusions provided on a part of the sidewall of the tire has been known (for example, Patent Document 1, etc.). In such a pattern area, the incident light is repeatedly reflected between the protrusions to generate 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 such a pattern area, the tire can achieve, for example, an improvement in design effect and appearance.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2017-1440 Summary of the Invention

[0006] Problems to be Solved by the Invention

[0007] The high contrast achieved by a plurality of protrusions is less likely to change over time compared to the method achieved by painting or the like, and has the advantage of maintaining its effect for a long time. Therefore, compared with the prior art, the black density is further increased to promote high contrast, and the formation of a pattern area based on protrusions is sought to further improve the design effect and appearance.

[0008] An object of the present invention is to provide a tire having a further increased black density and achieving high contrast compared to the prior art, and a tire molding die capable of manufacturing such a tire.

[0009] Means for Solving the Problems

[0010] The tire of the present invention has a pattern area on a part of the outer surface of the sidewall, and the pattern area is provided in a state where it can be visually recognized as a part different from the surrounding of the part. Among them, on the UV development reference plane when the reference plane of the pattern area is UV-developed, a plurality of oblique cones are respectively arranged in a state where their tops are farthest from the UV development reference plane.

[0011] The tire molding die of the present invention is for molding the tire of the present invention, and the tire molding die has an oblique cone forming portion including a plurality of concave portions corresponding to the plurality of oblique cones.

[0012] Advantages of the Invention

[0013] According to the present invention, it is possible to provide a tire with a further increased black density and a higher contrast compared to the prior art, and a tire molding die capable of manufacturing such a tire. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a side view of the tire of the embodiment.

[0015] Figure 2 It is a cross-sectional view showing an example of a molding die for vulcanizing and molding the tire of the embodiment.

[0016] Figure 3 It is a perspective view showing a plurality of oblique cones provided in the pattern area of the tire of the embodiment.

[0017] Figure 4 It is Figure 3 View IV of.

[0018] Figure 5 It is Figure 3 View V of.

[0019] Figure 6 It is Figure 3 View VI of.

[0020] Figure 7 It is a side view showing a plurality of oblique cones extracted from the embodiment.

[0021] Figure 8 It is a top view showing a pair of oblique cones having an overlapping portion.

[0022] Figure 9 It is a top view showing another pair of oblique cones having an overlapping portion.

[0023] Figure 10 It is a top view showing yet another pair of oblique cones having an overlapping portion.

[0024] Figure 11 It is a perspective view showing another arrangement of the oblique cones of the embodiment.

[0025] Figure 12 It is Figure 11 View XII of.

[0026] Figure 13 It is shown to form Figures 3 to 6 A cross-sectional view of the oblique cone forming portion of the tire molding die showing the plurality of oblique cones shown.

[0027] Figure 14 It is shown to form Figure 11 , Figure 12 A cross-sectional view of the oblique cone forming portion of the tire molding die showing the plurality of oblique cones shown.

[0028] Description of the reference numerals:

[0029] 1 Tire

[0030] 3 Sidewall

[0031] 3a Outer surface of the sidewall

[0032] 7 Pattern area

[0033] 7b UV unfolding reference plane

[0034] 10 Tire forming die

[0035] 16, 18 Oblique cone forming part

[0036] 20 Oblique cone

[0037] 20c Central axis

[0038] 23 Bottom surface of the oblique cone

[0039] 24 Slope foot part

[0040] 25A, 25B, 25C Overlapping part

[0041] 26 Non - overlapping part

[0042] 27 Acute angle part

[0043] h Height of the oblique cone

[0044] θ1 Angle of the central axis relative to the UV unfolding reference plane

[0045] θ2 Apex angle of the oblique cone. Detailed implementation mode

[0046] Hereinafter, the implementation mode will be described with reference to the drawings. Figure 1 is a side view of the tire 1 of the implementation mode. The tire 1 is a so - called pneumatic tire in which a prescribed air pressure is filled in its inner cavity. The tire 1 of the implementation mode is a pneumatic tire for passenger cars including light vehicles, SUVs, etc. It should be noted that the structure of the tire 1 of the implementation mode can also be applied to pneumatic tires for other vehicle types such as light trucks, trucks, buses, etc.

[0047] First, with reference to Figure 1 a summary of the main side - related structure of the tire 1 will be described. Figure 1 is a side view of the tire 1 observed from the direction of the tire rotation axis X. It should be noted that the tire axial direction, the tire circumferential direction, and the tire radial direction are as follows. The tire axial direction is the extending direction of the tire rotation axis X, and in Figure 1"In" refers to the front and back directions of the paper surface. It should be noted that when observing from the radial direction of the tire, the axial direction of the tire is the left-right direction, so sometimes the axial direction of the tire is referred to as the left-right direction. The circumferential direction of the tire refers to the circular arc line centered on the tire rotation axis X and is the direction along the rotation direction of the tire 1. In Figure 1 it is indicated by the arrow G. The radial direction of the tire refers to the direction perpendicular to the tire rotation axis X and is arbitrarily indicated by the arrow Y in Figure 1 .

[0048] As Figure 1 shown, the tire 1 includes a bead 2, a sidewall 3 extending radially outward from the bead 2 away from the tire rotation axis X in the radial direction of the tire, and a tread 4. The bead 2 and the sidewall 3 are respectively provided with one, that is, a pair of left and right, on this side of one side 1s of the tire 1 shown in Figure 1 and on the side of the other side not shown separated in the axial direction of the tire. The tread 4 is disposed between the outer sides in the 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. Figure 1

[0049] The tire 1 is configured with various rubbers that respectively form the bead 2, the sidewall 3, and the tread 4 as the main body. A carcass ply that forms the skeleton of the tire 1 is disposed on the inner cavity side of the rubber that forms the entire tire 1, and further, an airtight layer that maintains the air pressure is disposed on the inner cavity side of the carcass ply. In addition, an annular reinforcing belt layer (the carcass ply, the airtight layer, and the reinforcing belt layer are omitted from the illustration) is embedded inside the rubber that forms the tread 4. It should be noted that in addition to these components, various components are also provided as needed in terms of the functions of the tire 1.

[0050] As Figure 1 shown, the sidewall 3 has an annular decorative area 5 on its outer surface 3a that extends throughout the entire circumferential direction of the tire. The decorative area 5 is a region with a constant width sandwiched between an inner arc line 5a closer to the tire rotation axis X in the radial direction of the tire and an outer arc line 5b farther from the tire rotation axis X in the radial direction than the inner arc line 5a. The inner arc line 5a and the outer arc line 5b can be lines formed by concave, convex, or steps on the outer surface 3a of the sidewall 3, or can be imaginary lines that do not actually exist.

[0051] The radial position of the decorative area 5 on the outer surface 3a of the sidewall 3 can be located at a position farther from the tire rotation axis X in the radial direction than the position of the maximum width of the tire, or can be located at a position including the position of the maximum width of the tire. It should be noted that the position of the maximum width of the tire refers to the position where the axial length is the longest between the outer surfaces 3a of the left and right sidewalls 3.

[0052] The tire 1 has a pattern area 7 on a part of the outer surface 3a of the sidewall 3, and the pattern area 7 is set to be visually recognizable as a part different from the surroundings of this part. The pattern area 7 is provided on the sidewall rubber, which is a black rubber member constituting the outer surface 3a of the sidewall 3.

[0053] As Figure 1 shown, badge portions 6A are provided at two positions of the annular decorative area 5 that are opposed to each other across the tire rotation axis X. The badge portion 6A is formed by arranging a plurality of characters along the tire circumferential direction. At least one of the badges such as the manufacturer name, product name, brand, etc. is displayed by these plurality of characters. Each character can be formed by being bordered by concave or convex lines, or the whole character is formed by being concave or convex. For example, each character of the badge portion 6A is set as the pattern area 7 of the embodiment.

[0054] As Figure 1 shown, in the annular decorative area 5, tread portions 6B are provided at two positions that are sandwiched by the two badge portions 6A in the circumferential direction. A pattern in which a parallelogram is bent following the annular decorative area 5 is provided in the tread portion 6B. For example, each pattern of the tread portion 6B is also set as the pattern area 7 of the embodiment.

[0055] It should be noted that the shape of the pattern area 7 is not limited to this, and various shapes can be cited, such as any shape, or the shape of the above-mentioned badges such as the manufacturer name, product name, brand, etc., or the shape of other numbers, characters, etc.

[0056] Each of the above-mentioned pattern areas 7 in the embodiment has a reference plane 7a along the contour of the sidewall 3. A plurality of oblique cones 20 described later are formed on the reference plane 7a. The pattern area 7 is an area that is set to be visually recognizable as a part different from the surroundings of the pattern area 7 by forming a plurality of oblique cones 20.

[0057] Figure 2 An example of a tire forming die for vulcanizing and forming the tire 1 of the embodiment is shown. Figure 2 It is a meridian sectional view along the axial direction of the formed tire 1 of such a tire forming die 10.

[0058] Figure 2 The shown tire forming die 10 includes a plurality of sector dies 11 arranged in a circular shape 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 sector dies 11, and a pair of bead rings (not shown). At the time of vulcanizing and forming, as Figure 2As shown by the middle dotted line, an unvulcanized tire 1a, which will become the tire 1, is provided inside the tire forming mold 10. The combination of the sector mold 11, the side plate 12 and the bead ring is a forming mold for forming the tire 1, and the outer surface of the entire tire 1 is formed by the inner surface of the forming mold, that is, the inner surface 11a of the sector mold 11, the inner surface 12a of the side plate 12 and the inner surface of the bead ring. In addition, during vulcanization forming, an air bag (not shown) is arranged inside the unvulcanized tire 1a to press the unvulcanized tire 1a against the inner surface of the tire forming mold 10. The tread 4 is mainly formed by the plurality of sector molds 11, and the sidewall 3 is mainly formed by the pair of side plates 12. The bead 2 is formed by the pair of bead rings, and the inner surface of the tire 1 is formed by the air bag.

[0059] The unvulcanized tire 1 a is vulcanized by the tire forming mold 10 to form the rubber shape of the entire tire 1 , and a plurality of oblique cones 20 described below are formed in the pattern region 7 .

[0060] Figures 3 to 6 2 is a diagram showing a plurality of oblique cones 20 arranged in a portion of the pattern region 7. Figure 3 It is a stereogram. Figure 4 is a top view and is Figure 3 IV view, Figure 5 is a side view and is Figure 3 V-view, Figure 6 is a side view and is Figure 3 VI view of the VI. Figure 7 It is a side view which extracts multiple types (four types in this case) of oblique cones 20 having different inclination angles.

[0061] The plurality of oblique cones 20 are arranged in the pattern area 7 so as to fill the entire area of ​​the pattern area 7. The plurality of oblique cones 20 are protrusions protruding from the reference surface 7a of the pattern area 7, but Figures 3 to 6 The figure shows a state where a plurality of oblique cones 20 protrude from a UV development reference plane 7b when the reference plane 7a of the pattern area 7 is UV developed. The UV development reference plane 7b is a plane obtained by two-dimensionally developing the outer surface 3a of the three-dimensional sidewall 3. The plurality of oblique cones 20 are arranged in an irregular, i.e., disordered state on the UV development reference plane 7b without adopting a specific arrangement.

[0062] like Figure 7 As shown, the oblique cone 20 has a conical shape, and its central axis 20c is inclined relative to the UV development reference plane 7b. Figure 7 This is a schematic diagram of making the inclination direction of the oblique cone 20 consistent with either the left or right direction. Figure 7 The central axes 20c shown are along Figure 7 The oblique cones 20 each have a slope foot portion 24 that is continuous with the UV unfolding reference plane 7b.

[0063] As shown Figures 3 to 6 in the figure, a plurality of oblique cones 20 are conical protrusions protruding from the UV unfolding reference plane 7b. As shown Figure 7 in the figure, each oblique cone 20 has a conical side surface 21 and a top 22 formed by being flatly cut. Each oblique cone 20 is arranged on the UV unfolding reference plane 7b in a state where its top 22 is farthest from the UV unfolding reference plane 7b. Each oblique cone 20 has an imaginary bottom surface 23 that is integral with the UV unfolding reference plane 7b and is on the same plane as the UV unfolding reference plane 7b. The oblique cone 20 has a conical shape in which the cross-sectional area parallel to the UV unfolding reference plane 7b gradually decreases from the bottom surface 23 toward the top 22, and the degree of decrease does not change. The central axis 20c of the oblique cone 20 is a line connecting the imaginary vertex on the top 22 and the center of the bottom surface 23.

[0064] It should be noted that the bottom surface 23 of each oblique cone 20 in the embodiment is in a circular shape, but it can also be in an elliptical shape. In addition, the flat surface of the top 22 in the embodiment is a circular shape that is substantially parallel to the bottom surface 23, but it can also not be parallel to the bottom surface 23. Furthermore, the top 22 can be not flatly cut but in a sharp form, or can be formed into a spherical shape.

[0065] As shown Figure 7 in the figure, a plurality of oblique cones 20 include more than three types with different angles θ1 of the central axis 20c with respect to the UV unfolding reference plane 7b. It should be noted that the angles θ1 here are all acute angles. A plurality of oblique cones 20 with different angles θ1 of the central axis 20c are arranged irregularly on the UV unfolding reference plane 7b. In addition, the inclination direction of the plurality of oblique cones 20, that is, the inclination direction of the central axis 20c, is not a constant direction but is inclined in an irregular direction. It should be noted that the acute angle of the central axis 20c with respect to the UV unfolding reference plane 7b is preferably, for example, 30° or more and 80° or less.

[0066] As shown Figure 7 in the figure, a plurality of oblique cones 20 include more than three types with different heights h from the UV unfolding reference plane 7b. Here, the height h is the shortest distance from the UV unfolding reference plane 7b to the top 22. In addition, a plurality of oblique cones 20 include more than three types with different areas of their bottom surfaces 23. In addition, a plurality of oblique cones 20 include more than three types with different apex angles θ2. The apex angle θ2 in this case refers to the angle at the imaginary vertex on the top 22. It should be noted that the height h of the oblique cone 20 is preferably, for example, 0.05 mm or more and 0.5 mm or less. In addition, the area of the bottom surface 23 of the oblique cone 20 is preferably, for example, 0.01 mm 2 or more and 0.3 mm 2 or less.

[0067] As Figure 7 shown, a part of the plurality of frustum cones 20 has an undercut shape including an acute angle portion 27 where the side surface 21 contacts the UV development reference plane 7b at an acute angle. These acute angle portions 27 sometimes also contact the reference plane 7a of the pattern region 7 at an acute angle. The undercut shape refers to the shape of the portion that contacts the tire forming die 10 when the tire 1 is vulcanized and formed using the above-described tire forming die 10. If it is an undercut shape of the size of the frustum cone 20 in the embodiment, the mold can be opened by elastic deformation generated by the rubber.

[0068] Figure 8 Shown are Figure 3 and Figure 4 two specific frustum cones 20A and frustum cone 20B as shown. Figure 9 Shown are Figure 3 and Figure 4 two specific frustum cones 20C and frustum cone 20D as shown. Figure 10 Shown are Figure 3 and Figure 4 two specific frustum cones 20E and frustum cone 20F as shown.

[0069] As Figure 8 shown, the frustum cone 20A has a slope foot portion 24a continuous with the UV development reference plane 7b, and the frustum cone 20B has a slope foot portion 24b continuous with the UV development reference plane 7b. Moreover, these slope foot portions 24a and 24b partially overlap each other. That is, the frustum cones 20A and 20B have a common overlapping portion 25A where the slope foot portions 24a and 24b overlap each other. In Figure 8 this, the overlapping portion 25A is indicated by diagonal lines.

[0070] As Figure 9 shown, the frustum cone 20C has a slope foot portion 24c continuous with the UV development reference plane 7b, and the frustum cone 20D has a slope foot portion 24d continuous with the UV development reference plane 7b. Moreover, these slope foot portions 24c and 24d partially overlap each other. That is, the frustum cones 20C and 20D have a common overlapping portion 25B where the slope foot portions 24c and 24d overlap each other. In Figure 9 this, the overlapping portion 25B is indicated by diagonal lines.

[0071] As Figure 10 shown, the frustum cone 20E has a slope foot portion 24e continuous with the UV development reference plane 7b, and the frustum cone 20F has a slope foot portion 24f continuous with the UV development reference plane 7b. Moreover, these slope foot portions 24e and 24f partially overlap each other. That is, the frustum cones 20E and 20F have a common overlapping portion 25C where the slope foot portions 24e and 24f overlap each other. InFigure 10 In [the figure], the overlapping portion 25C is indicated by diagonal lines.

[0072] As described above, the plurality of frustum cones 20 have a plurality of overlapping portions 25A, 25B, 25C where the slope foot portions 24 of an adjacent pair of frustum cones 20 overlap each other. The overlapping amounts of the respective overlapping portions 25A, 25B, 25C are different from each other. That is, the plurality of frustum cones 20 include three or more overlapping portions with different overlapping amounts.

[0073] On the other hand, as Figure 3 , Figure 4 and Figure 7 show, the UV development reference plane 7b has a plurality of non-overlapping portions 26 where the slope foot portions 24 of an adjacent pair of frustum cones 20 do not overlap.

[0074] As Figures 3 to 6 shows, the plurality of frustum cones 20 are arranged irregularly on the UV development reference plane 7b without adopting a specific arrangement method, and the inclination direction and inclination angle along the central axis 20c are also irregular. However, the plurality of frustum cones 20 can also be arranged on the UV development reference plane 7b in a certain arrangement method.

[0075] Figure 11 and Figure 12 show an example of such a specific arrangement method. In this case, the plurality of frustum cones 20 are arranged linearly along one direction, and the inclination directions are the same toward one direction. The flat tops 22 of the plurality of frustum cones 20 are flat surfaces orthogonal to the central axis. The areas and apex angles of the tops 22 of the plurality of frustum cones 20 are the same as each other. That is, except for the difference in the inclination angles, the basic shapes such as the conical shapes and dimensions of these frustum cones 20 are the same. The plurality of frustum cones 20 change in such a way that the inclination angles of their respective central axes 20c gradually become steeper, that is, gradually become smaller, in the order of their arrangement (in Figure 11 and Figure 12 from left to right). In such a case where the inclination angles gradually decrease, the inclination angles of three or more frustum cones 20 can also gradually decrease, and the inclination angles of four or more frustum cones 20 can also gradually decrease.

[0076] In Figure 11 and Figure 12 the plurality of frustum cones 20 shown, the central axis 20c of the leftmost frustum cone 20 is perpendicular to the UV development reference plane 7b. That is, this frustum cone 20 can be said to be a straight cone. And as it goes toward the right, the frustum cone 20 topples to the right, and the degree of toppling becomes larger as it goes toward the right. In the embodiment, at least one straight cone can also be included in such a plurality of frustum cones 20.

[0077] Figures 3 to 6The plurality of frustum cones 20 shown, Figure 11 and Figure 12 the plurality of frustum cones 20 shown can be formed by the side plates 12 of the above-described tire forming die 10, respectively. As shown in Figure 13 and Figure 14 shown, the side plate 12 may include frustum cone forming portions 16, 18 in which these plurality of frustum cones 20 are formed.

[0078] Figure 13 The state in which a plurality of recesses 15 are formed in the UV expansion reference plane 12b when the inner surface 12a of the side plate 12 is UV-expanded is shown. The plurality of recesses 15 are respectively conical depressions formed in the pattern area 7 after vulcanization and corresponding to the Figures 3 to 6 shape and size of the plurality of frustum cones 20 shown, and are arranged at positions corresponding to the arrangement of these frustum cones 20. The frustum cone forming portion 16 includes these plurality of recesses 15.

[0079] Figure 14 The state in which a plurality of recesses 17 are formed in the UV expansion reference plane 12b when the inner surface 12a of the side plate 12 is UV-expanded is shown. The plurality of recesses 17 are respectively conical depressions formed in the pattern area 7 after vulcanization and corresponding to the Figure 11 and Figure 12 shape and size of the plurality of frustum cones 20 shown, and are arranged at positions corresponding to the arrangement of these frustum cones 20. The frustum cone forming portion 18 includes the plurality of recesses 17 that form these plurality of frustum cones 20.

[0080] The method of forming the recesses 15 and the recesses 17 is not limited, but laser processing in which the inner surface 12a is locally removed by irradiating the inner surface 12a of the side plate 12 with a laser is preferred as the forming method. As the laser processing, for example, removal processing using pulsed fiber laser can be employed. As the conditions for this laser processing, laser processing with 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 preferred.

[0081] According to the embodiment described above, the following effects are achieved.

[0082] (1) The tire 1 of the embodiment has a pattern area 7 on a part of the outer surface 3a of the tire side 3, and the pattern area 7 is set to be visually recognizable as a part different from the periphery of this part. Among them, when the reference plane 7a of the tire pattern area 7 is UV-expanded, the plurality of frustum cones 20 are respectively arranged in a state where their tops 22 are farthest from the UV expansion reference plane 7b.

[0083] The light incident on the pattern area 7 of the tire 1 is reflected by the side surface 21 of the oblique cone 20, and the reflected light is mainly reflected by the side surfaces 21 of a plurality of other oblique cones 20 around the oblique cone 20. By generating such reflection of light between the plurality of oblique cones 20, the light incident on the pattern area 7 is gradually attenuated and absorbed. When visually recognizing such a pattern area 7, the pattern area 7 is visually recognized as darker than the outer surface 3a of the tire sidewall 3 of the reflected light around the pattern area 7. The oblique cone 20 complexly causes reflection of light by arranging a plurality of oblique cones 20 having a conical shape, whereby the black density of the pattern area 7 is increased compared to the prior art, and high contrast is achieved.

[0084] (2) Based on the tire 1 in the above (1) of the embodiment, preferably, the plurality of oblique cones 20 have a central axis 20c connecting the vertex of the oblique cone 20 and the center of the bottom surface 23, and the plurality of oblique cones 20 include three or more types having different angles of the central axis 20c with respect to the UV development reference plane 7b.

[0085] The central axis 20c of the plurality of oblique cones 20 in the embodiment is inclined and not orthogonal to the UV development reference plane 7b. However, by including three or more types having different angles of the central axis 20c, at least three or more oblique cones 20 having different degrees of inclination are arranged in the pattern area 7. Thus, by arranging three or more oblique cones 20 having different degrees of inclination in the pattern area 7, the light incident on the pattern area 7 is further developed in the light absorption effect due to the increase in the number of reflections of light between the oblique cones 20 or the diversification of the reflection angles. As a result, high contrast accompanied by an increase in black density can be further achieved.

[0086] (3) Based on the tire 1 in the above (2) of the embodiment, preferably, the plurality of oblique cones 20 having different angles of the central axis 20c with respect to the UV development reference plane 7b are arranged irregularly on the UV development reference plane 7b.

[0087] Thus, the light incident on the pattern area 7 is further developed in the light absorption effect due to the increase in the number of reflections of light between the oblique cones 20 or the diversification of the reflection angles. As a result, high contrast accompanied by an increase in black density can be further achieved.

[0088] (4) Based on the tire 1 in the above (2) or (3) of the embodiment, it may also be that the plurality of oblique cones 20 are arranged along one direction, and in the order of this arrangement, the central axes 20c of the plurality of oblique cones 20 are inclined, and their inclination angles gradually change.

[0089] By gradually changing the inclination angles of the plurality of frustum cones 20 arranged in one direction in this way, the reflection angles of the light reflected between the adjacent frustum cones 20 become non-constant and complicated, and the number of reflections of the light with respect to the reference plane 7a of the pattern area 7 also increases. As a result, the light absorption effect further develops, and as a result, it is possible to further achieve a high contrast accompanied by an increase in the black density. It should be noted that in the case where the inclination angles of the frustum cones 20 gradually decrease, the inclination angles of three or more frustum cones 20 may gradually decrease, and the inclination angles of four or more frustum cones 20 may also gradually decrease.

[0090] (5)On the basis of the tire 1 of the above (1) to (4) in the embodiment, preferably, the plurality of frustum cones 20 include three or more having different heights h from the UV development reference plane 7b.

[0091] As a result, the reflection of the light incident on the pattern area 7 between the frustum cones 20 can be complicated, and as a result, it is possible to further achieve a high contrast accompanied by an increase in the black density.

[0092] (6)On the basis of the tire 1 of the above (1) to (5) in the embodiment, preferably, the plurality of frustum cones 20 include three or more having different areas of their bottom surfaces 23.

[0093] As a result, the reflection of the light incident on the pattern area 7 between the frustum cones 20 can be complicated, and as a result, it is possible to further achieve a high contrast accompanied by an increase in the black density.

[0094] (7)On the basis of the tire 1 of the above (1) to (6) in the embodiment, preferably, the plurality of frustum cones 20 include three or more having different apex angles.

[0095] As a result, the reflection of the light incident on the pattern area 7 between the frustum cones 20 can be complicated, and as a result, it is possible to further achieve a high contrast accompanied by an increase in the black density.

[0096] (8)On the basis of the tire 1 of the above (1) to (7) in the embodiment, preferably, the plurality of frustum cones have slope foot portions 24 continuous with the UV development reference plane 7b, and there are overlapping portions where the slope foot portions 24 of at least a pair of adjacent frustum cones 20 overlap each other.

[0097] By having overlapping portions where the slope foot portions 24 of the plurality of frustum cones 20 overlap each other, the density of the plurality of frustum cones 20 arranged in the pattern area 7 increases and the number increases. As a result, the light absorption effect of the light incident on the pattern area 7 further develops, and as a result, it is possible to further achieve a high contrast accompanied by an increase in the black density.

[0098] (9) Based on the tire 1 in the above (8) of the embodiment, preferably, the plurality of overlapping portions include three or more with different overlapping amounts.

[0099] Thus, the reflection effect of light by the plurality of frustum cones 20 arranged in the pattern region 7 is complicated, so the absorption effect of the light incident on the pattern region 7 is further developed. As a result, a higher contrast accompanied by an increase in black density can be further achieved.

[0100] (10) Based on the tire 1 in the above (8) and (9) of the embodiment, the UV development reference plane 7b has a non-overlapping portion where the slope foot portions 24 of a pair of adjacent frustum cones 20 do not overlap.

[0101] Thus, a non-overlapping portion where the slope foot portions 24 of the frustum cones 20 do not overlap is also provided in the reference plane 7a of the pattern region 7. Therefore, the light incident on the pattern region 7 is reflected not only between the plurality of frustum cones 20 but also at the non-overlapping portion. Therefore, in addition to between the frustum cones 20, light reflection also occurs between the frustum cones 20 and the non-overlapping portion, and the light absorption effect is further developed. As a result, a higher contrast accompanied by an increase in black density can be further achieved.

[0102] (11) Based on the tire 1 in the above (1) to (10) of the embodiment, the plurality of frustum cones 20 have an undercut shape including an acute angle portion 27 where the surface including their sides contacts the reference plane 7a of the pattern region 7 at an acute angle.

[0103] Thus, the reflection between the frustum cones 20 of the light incident on the pattern region 7 can be complicated, and as a result, a higher contrast accompanied by an increase in black density can be further achieved.

[0104] (12) The tire forming die 10 of the embodiment is used to form the tire 1 in the above (1) to (11). The tire forming die includes a frustum cone forming portion 16 including a plurality of concave portions 15 corresponding to the plurality of frustum cones 20 and a frustum cone forming portion 18 including a plurality of concave portions 17.

[0105] Using the plurality of concave portions 15 and the concave portions 17 respectively included in the frustum cone forming portion 16 and the frustum cone forming portion 18 of the tire forming die 10, a plurality of frustum cones 20 that achieve a higher contrast accompanied by an increase in black density are formed in the pattern region 7. Thus, the tire 1 formed using the tire forming die 10 can improve the design effect and appearance.

[0106] The above describes the embodiments of the present invention, but the present invention is not limited to the above embodiments. Even if there are deformations, improvements, etc. within the range that can achieve the purpose of the present invention, they are included in the scope of the present invention.

[0107] For example, the frustum 20 of the above-described embodiment has a conical shape, but it may also have a pyramidal shape. Additionally, the frustum 20 of the above-described embodiment has a conical shape in which the cross-sectional area parallel to the UV unfolding reference plane 7b gradually decreases from the bottom surface 23 toward the top 22 and the degree of decrease does not change, but it may also have a secondary shape in which the degree of decrease changes, or a multi-stage shape of three or more stages.

Claims

1. A tire comprising a pattern region on a portion of an outer surface of a sidewall, wherein the pattern region is provided in a state where it can be visually recognized as a portion different from the surroundings of the portion, wherein: When UV development is performed on the reference plane of the pattern region, the plurality of oblique cones are arranged in a state where their tops are farthest from the UV development reference plane.

2. The tire according to claim 1, wherein: The plurality of oblique cones have a central axis connecting the apex of the oblique cone and the center of the bottom surface. The plurality of oblique cones include three or more types of cones in which the central axis has different angles with respect to the UV development reference plane.

3. The tire according to claim 2, wherein: The plurality of oblique cones whose central axes have different angles with respect to the UV unfolding reference plane are randomly arranged on the UV unfolding reference plane.

4. The tire according to claim 2 or 3, wherein: The plurality of oblique cones are arranged along one direction, and, in the order of the arrangement, the central axis of each of the plurality of oblique cones is inclined, and the inclination angle thereof changes gradually.

5. The tire according to claim 1 or 2, wherein: The plurality of oblique cones include three or more types having different heights from the UV development reference plane.

6. The tire according to claim 1 or 2, wherein: The plurality of oblique cones include three or more types having different bottom surface areas.

7. The tire according to claim 1 or 2, wherein: The plurality of oblique cones include three or more types having different apex angles.

8. The tire according to claim 1 or 2, wherein: The plurality of oblique cones have foot portions continuous with the UV development reference plane, and have a plurality of overlapping portions where the foot portions of at least a pair of adjacent oblique cones overlap each other.

9. The tire according to claim 8, wherein: The plurality of overlapping portions include three or more portions having different overlapping amounts.

10. The tire according to claim 8, wherein: The UV unfolding reference plane has a non-overlapping portion where the foot portions of a pair of adjacent oblique cones do not overlap.

11. The tire according to claim 1 or 2, wherein: The plurality of oblique cones have an undercut shape including an acute angle portion in which side surfaces thereof contact the reference surface of the pattern area at an acute angle.

12. A tire forming mold for forming the tire according to claim 1 or 2, wherein: The tire forming mold includes an oblique taper forming portion including a plurality of recessed portions corresponding to the plurality of oblique tapers.

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