Tire

Abstract

This tire has: a pattern region that is formed on the outer surface and that has a base part; a raised bottom part that is provided in the pattern region and that is raised from the base part; and minute protrusions that are formed on the base part and the raised bottom part. The width of the tips of the minute protrusions on the base part is equal to or less than the width of the tips of the minute protrusions on the raised bottom part.

Description

Tire ,

[0004]

[0001] The present disclosure relates to a tire having a pattern region formed on an outer surface.

[0002] Conventionally, fine protrusions have been formed on the side portion of a tire to form a pattern having contrast. For example, Japanese Patent Application Laid-Open No. 2024-82066 discloses a configuration in which a first surface portion and a second surface portion of a decorative region (pattern region) are arranged in a stepped manner via a first step. The protruding height h1 of the first minute protrusion of the first surface portion is equal to the sum of the height H1 of the first step and the protruding height h2 of the second minute protrusion of the second surface portion. That is, the protruding height of the first minute protrusion from the outer surface of the tire is equal to the protruding height of the second minute protrusion. And it is described that the blackness degree of the pattern region is increased by the minute protrusions.

[0003] However, it is considered that there is still room for improvement in the expression of the pattern region.

[0004] An object of the present disclosure is to enable richer expression of a pattern region on an outer surface of a tire.

[0005] A tire according to a first aspect has a pattern region formed on an outer surface of the tire, the pattern region having a base portion, a bottom-lifting portion provided in the pattern region and protruding from the base portion, and minute protrusions formed on the base portion and the bottom-lifting portion, respectively, wherein a width of a tip of the minute protrusion of the base portion is not more than a width of a tip of the minute protrusion of the bottom-lifting portion.

[0006] On the outer surface of this tire, a pattern region having a base portion is formed here. Here, the outer surface of the tire refers to a surface visible from the outside, such as a tire side portion, a tread portion, a groove bottom of the tread, a groove wall, and the like. Further, the tire of the present disclosure includes both a pneumatic tire and a non-pneumatic tire.

[0007] In this tire, these micro-protrusions are formed on the base and raised sections, which suppresses the reflection of light incident on the pattern area compared to the area outside the pattern area, while creating a difference in how light is reflected between the base and raised sections within the pattern area. If the width of the tip of the micro-protrusion on the raised section is greater than the width of the tip of the micro-protrusion on the base section, it is possible to further suppress the reflection of light on the base section while allowing the reflection of light on the raised section, thereby creating an even greater difference in how light is reflected.

[0008] In the second embodiment of the tire, the heights of the minute protrusions relative to the base portion are equal to those of the tire in the first embodiment.

[0009] In this tire, the heights of the micro-protrusions relative to the base are equal, so the depth from the tip of a micro-protrusion to the base is greater than the depth from the tip of a micro-protrusion to the raised base. Therefore, light reflection on the base side of the pattern region can be suppressed more than on the raised base side.

[0010] The third embodiment is a tire according to the first or second embodiment, wherein the width of the tip of the minute protrusion of the raised portion is greater than the width of the tip of the minute protrusion of the base portion.

[0011] In this tire, when the width of the tip of the micro-protrusion on the raised section is greater than the width of the tip of the micro-protrusion on the base section, reflection of light from the base section is further suppressed, while reflection of light from the raised section is permitted, thereby creating an even greater difference in how light is reflected.

[0012] The fourth embodiment is a tire according to any one of the first to third embodiments, wherein the height of the minute protrusions with respect to the base portion is 0.1 mm or more and 1.0 mm or less, and the distance between adjacent minute protrusions is 0.1 mm or more and 1.0 mm or less.

[0013] With this tire, by appropriately setting the height and spacing of the micro-protrusions, it is possible to create contrast through differences in light reflection.

[0014] A fifth aspect is a tire according to the fourth aspect, wherein the micro-protrusions include extensions that extend in multiple directions from a base point in a plan view, and the extension of one micro-protrusion is connected to the extension of another adjacent micro-protrusion by a connecting portion.

[0015] In this tire, the protruding portions of the micro-protrusions are connected by connecting parts, so the micro-protrusions support each other through the connecting parts, suppressing the collapse of the micro-protrusions. This improves durability.

[0016] According to this disclosure, it is possible to enable richer expression of the pattern area on the outer surface of the tire.

[0017] This is a front view showing a tire according to the first embodiment. This is an enlarged cross-sectional view showing minute protrusions in the pattern region. This is a further enlarged cross-sectional view of Figure 2. This is a perspective view showing a modified example of the minute protrusions. This is a front view showing a tire according to the second embodiment. This is an enlarged plan view showing the plan view shape of the first pattern region. (A) is an enlarged plan view showing a part of the first pattern region, and (B) is an enlarged plan view showing a part of the second pattern region. This is a cross-sectional view showing the first asterisk protrusion.

[0018] The embodiments for implementing this disclosure will be described below with reference to the drawings. Components indicated by the same reference numerals in each drawing are considered to be the same or similar components. In the embodiments described below, descriptions and reference numerals that are repeated may be omitted. Furthermore, the drawings used in the following description are all schematic, and the dimensional relationships and ratios of each element shown in the drawings do not necessarily correspond to reality. Also, the dimensional relationships and ratios of each element do not necessarily correspond between multiple drawings.

[0019] In the drawing, arrow C indicates the circumferential direction of the tire, and arrow R indicates the radial direction of the tire. The radial direction of the tire means the direction perpendicular to the tire rotation axis (not shown).

[0020] The outer surface of the tire 10, as described later, refers to the surface visible from the outside, such as the tire sidewall 12, the tread, the bottom of the tread grooves, and the groove walls. Furthermore, the tire 10 according to this embodiment includes both pneumatic and non-pneumatic tires.

[0021] [First Embodiment] In Figure 1, a decorative portion 14 is formed on the tire side portion 12 of the tire 10 according to this embodiment. The decorative portion 14 is in the shape of a strip-like arc and is formed at two symmetrical positions on either side of the tire central axis CE (see Figure 1). The decorative portion 14 has a pattern area 20 and a character area 16. The character area 16 is displayed with characters such as "ABCDEFGH" on a smooth surface. In the decorative portion 14A on the upper side of Figure 1, the pattern area 20 is a kind of decorative band in the part of the decorative portion 14A other than the character area 16, and is formed to surround the character area 16. On the other hand, in the decorative portion 14B on the lower side of Figure 1, the pattern area 20 is the same area as the character area 16 of the decorative portion 14B, and the part of the decorative portion 14B other than the character area 16 is the same as the outer surface of the tire side portion 12 other than the decorative portion 14. In this embodiment, the decorative portion 14A will be described. The decorative portion 14, including the pattern area 20, can be formed by laser processing to create corresponding irregularities within the tire mold. The pattern area 20 may also be positioned outside the tire radial radius R beyond the tire's maximum width (the maximum straight-line distance between the tire sidewalls).

[0022] In Figure 2, the tire 10 has a pattern region 20, a raised base portion 23, and minute protrusions 24 as unit patterns.

[0023] The pattern region 20 is formed on the outer surface of the tire 10 and has a base portion 22. The base portion 22 forms the bottom surface within the pattern region 20. The base portion 22 may be a recessed portion relative to the outer surface of the tire side portion 12.

[0024] The raised portion 23 is provided in the pattern area 20 and is a part that rises from the base portion 22. The height of the raised portion 23 relative to the base portion 22 may be constant or may vary depending on the location. The height may also vary within a single raised portion 23. In other words, the top surface of the raised portion 23 may be curved or inclined relative to the base portion 22. The proportion of the raised portion 23 in the pattern area 20 and the range of the raised portion 23 can be set arbitrarily.

[0025] The minute protrusions 24 are formed on the base portion 22 and the raised portion 23, respectively. Here, the minute protrusion on the base portion 22 is denoted as minute protrusion 24A, and the minute protrusion on the raised portion 23 is denoted as minute protrusion 24B. The width W1 of the tip of the minute protrusion 24A on the base portion 22 is less than or equal to the width W2 of the tip of the minute protrusion 24B on the raised portion 23. In other words, the width W1 of the tip of the minute protrusion 24A may be equal to the width W2 of the tip of the minute protrusion 24B, and the width W2 of the tip of the minute protrusion 24B may be greater than the width W1 of the tip of the minute protrusion 24A. As shown in Figure 4, the minute protrusion 24A may be conical, and the minute protrusion 24B may be frustoconical. Although not shown in the diagram, if both the minute projections 24A and 24B are frustums of a cone, the area of ​​the top surface of the minute projection 24B may be equal to the area of ​​the top surface of the minute projection 24A, and the area of ​​the top surface of the minute projection 24B may be larger than the area of ​​the top surface of the minute projection 24A.

[0026] In Figure 3, the heights Hb of the micro-protrusions 24A and 24B relative to the base portion 22 may be equal. Alternatively, the height Hb of the micro-protrusions 24 relative to the base portion 22 may be 0.1 mm or more and 1.0 mm or less, and the spacing P between adjacent micro-protrusions 24 may be 0.1 mm or more and 1.0 mm or less.

[0027] (Function) This embodiment is configured as described above, and its function will be explained below. In Figure 1, in the tire 10 according to this embodiment, minute protrusions 24 are formed on the base portion 22 and the raised portion 23. Specifically, minute protrusions 24A are formed on the base portion 22 and minute protrusions 24B are formed on the raised portion 23, so that the reflection of light incident on the pattern region 20 is suppressed compared to the outside of the pattern region 20, while a difference in the way light is reflected is made between the base portion 22 side and the raised portion 23 side within the pattern region 20. If the width W2 of the tip of the minute protrusion 24B on the raised portion 23 is greater than the width W1 of the tip of the minute protrusion 24A on the base portion 22, the reflection of light on the base portion 22 side is further suppressed, while the reflection of light on the raised portion 23 side is allowed, thereby further difference in the way light is reflected.

[0028] When the heights Hb of the micro-protrusions 24 are equal relative to the base portion 22, the depth from the tip of the micro-protrusion 24 to the base portion 22 is greater than the depth from the tip of the micro-protrusion 24 to the raised portion 23. Therefore, light reflection on the base portion 22 side of the pattern region 20 can be suppressed more than on the raised portion 23 side.

[0029] By appropriately setting the height Hb of the micro-protrusions 24 and the spacing P between the micro-protrusions 24, it is possible to produce contrast due to differences in light reflection.

[0030] Thus, according to this embodiment, it is possible to enable richer expression in the pattern area 20 on the outer surface of the tire 10.

[0031] [Second Embodiment] In Figures 5 to 8, in the tire 10 according to this embodiment, the decorative part 14 is arc-shaped when viewed from the axial direction of the tire 10 and is arranged at any position in the circumferential direction of the tire.

[0032] The tire sidewall portion 12, excluding the decorative portion 14, is smooth, just like a normal tire. The base portion 22 is the smoothed portion of the tire sidewall portion 12.

[0033] The decorative section 14 is composed of a plurality of first pattern areas 120 and second pattern areas 122 of different sizes and orientations. The first pattern areas 120 and the second pattern areas 122 are demarcated by the base section 22 over substantially the entire area of ​​the decorative section 14.

[0034] Since the first pattern region 120 and the second pattern region 122 have the same contour shape in plan view, differing only in orientation, the shape of the first pattern region 120 will be described as a representative example.

[0035] As shown in Figure 6, the first pattern region 120 has a shape comprising a pair of opposing arc recesses (convex inward) 124 and a pair of opposing arc protrusions 126 formed on both sides of the pair of arc recesses 124.

[0036] As shown in Figure 5, a first pattern region 120 and a second pattern region 122 of the same size are alternately arranged at intervals along a line TL in the circumferential direction of the tire, with their orientations rotated by 90° from each other. The line TL is inclined at an angle θ with respect to the radial direction of the tire (direction of arrow R).

[0037] Furthermore, the size of the first pattern region 120 and the second pattern region 122 increases as they are positioned on the clockwise side (arrow CW direction side), which is one side of the tire circumferential direction. In this embodiment, the first pattern region 120 and the second pattern region 122 positioned on the other line TL' positioned on the clockwise side are larger than the first pattern region 120 and the second pattern region 122 positioned on line TL.

[0038] In this embodiment, exceptionally, on the clockwise side of the decorative portion 14, some of the first pattern region 120 and the second pattern region 122 are in contact with each other without the base portion 22 in between.

[0039] The first pattern region 120 has a lower lightness (L*) compared to the base portion 22 and appears blacker than the base portion 22. The second pattern region 122 has a higher lightness than the first pattern region 120 and a lower lightness than the base portion 22. That is, the lightness decreases in the order of the base portion 22, the second pattern region 122, and the first pattern region 120. The second pattern region 122 appears blacker than the base portion 22, the first pattern region 120 appears blacker than the second pattern region 122, and the first pattern region 120 appears the blackest.

[0040] In the mold for molding the tire 10, by providing minute irregularities on the portions corresponding to the first pattern region 120 and the second pattern region 122, the first pattern region 120 and the second pattern region 122 can be formed on the surface of the tire side portion 12.

[0041] Minute protrusions protruding from the base portion 22 are formed in the first pattern region 120 and the second pattern region 122, whereby the surfaces of the first pattern region 120 and the second pattern region 122 are uneven. Although illustration is omitted, a bottom-raising portion is provided in the first pattern region 120 and the second pattern region 122.

[0042] As shown in FIG. 7, first asterisk protrusions 34 and second asterisk protrusions 36 as an example of minute protrusions are formed similar to each other in the first pattern region 120 and the second pattern region 122.

[0043] The shapes of the first asterisk protrusions 34 and the second asterisk protrusions 36 are similar in each region. Also, the interval P between the first asterisk protrusions 34 and the second asterisk protrusions 36 adjacent to each other varies according to the similarity ratio.

[0044] As described above, the shapes of the first asterisk protrusions 34 and the second asterisk protrusions 36 are similar in each region. Therefore, the shapes of the first asterisk protrusions 34 and the second asterisk protrusions 36 will be described below by taking the first pattern region 120 as an example.

[0045] (First Pattern Area 120) As shown in FIG. 7(A), the first pattern area 120 has a plurality of first asterisk protrusions 34 protruding from the base portion 22 and a plurality of second asterisk protrusions 36. The first asterisk protrusions 34 and the second asterisk protrusions 36 are alternately arranged in the tire circumferential direction and the tire radial direction.

[0046] (First Asterisk Protrusion 34) As shown in FIG. 7(A), the first asterisk protrusion 34 includes a plurality, six in this embodiment, of extending portions 34E extending in different directions from the center O₁ as a base point when viewed from a direction orthogonal to the base portion 22 (the rotation axis direction of the tire 10).

[0047] The six extending portions 34E form an angle of 60° with adjacent extending portions 34E respectively. In other words, the first asterisk protrusion 34 has a shape in which the six extending portions 34E extend radially from the center O₁. The extending portion 34E of the first asterisk protrusion 34 and the extending portion of the adjacent second asterisk protrusion 36 are connected by a connecting portion (linkage) 38.

[0048] As shown in FIG. 8, in the extending portion 34E of the first asterisk protrusion 34, the cross-section in a direction orthogonal to the extending direction has a substantially isosceles triangular shape having a flat top surface 34C. That is, the first asterisk protrusion 34 has a top surface 34C and a pair of side surfaces 34D. In this embodiment, the width (W1 in the figure) of the top surface 34C is 0.02 [mm], and the apex angle (D1 in the figure) of the first asterisk protrusion 34 is 26 [degrees]. Also, the height (H1 in the figure) of the first asterisk protrusion 34 is set to a predetermined value of 0.05 [mm] or more and 1.0 [mm] or less. When the height of the protrusion (projection height) is less than 0.05 [mm], it becomes difficult to form the protrusion, and there is a possibility that the incident light cannot be attenuated enough to make it look black. Further, by setting the height of the protrusion to 1.0 [mm] or less, the difference in rigidity between the protrusion part and the part around the protrusion is reduced, and local stress concentration is suppressed.

[0049] In this embodiment, dimensions such as the height of the protrusions and the spacing P (pitch) between the protrusions, as described later, can be measured, for example, using the VR-3000 series one-shot 3D shape measuring machine from Keyence Corporation.

[0050] (Second asterisk projection 36) As shown in Figure 7(A), the second asterisk projection 36 has the same shape as the first asterisk projection 34. Specifically, the second asterisk projection 36 is the first asterisk projection 34 rotated 90 degrees clockwise around the center O1 when viewed from a direction perpendicular to the base portion 22, and then the first asterisk projection 34 rotated 90 degrees around the center O1 is inverted vertically. That is, the second asterisk projection 36 has six extensions 36E extending in different directions from the center O2 which serves as the base point, and each extension 36E has a top surface 36C and a side surface 36D.

[0051] The first asterisk projection 34 and the second asterisk projection 36 are arranged alternately in the circumferential and radial directions of the tire, filling the entire area of ​​each region.

[0052] Furthermore, in the first asterisk projection 34 and the second asterisk projection 36 adjacent to each other in the tire radial and circumferential directions, the distance P between the centers O1 and O2 is set to a predetermined value of 0.1 mm or more and 1.0 mm or less. If the distance P is less than 0.1 mm, it becomes difficult to form the projection. Moreover, if the distance P is greater than 1.0 mm, there is a risk that the brightness cannot be reduced to the point where it appears black by attenuating the incident light.

[0053] (Second pattern region 122) Next, we will explain the second pattern region 122.

[0054] As shown in Figure 7(B), the second pattern region 122 has first asterisk protrusions 34 and second asterisk protrusions 36 that are similar in shape to those in the first pattern region 120, but the density of the protrusions is lower than that of the protrusions formed in the first pattern region 120. As a result, the second pattern region 122 appears relatively brighter than the first pattern region 120.

[0055] Furthermore, it is preferable that the first pattern region 120 and the second pattern region 122 be arranged in three or more locations in the circumferential direction of the tire, and more preferably in five or more locations.

[0056] (Effect) In other areas of the tire side portion 12 where no protrusions are formed, namely the base portion 22, the incident light is reflected outward by the smooth outer surface that constitutes the base portion 22.

[0057] In contrast, in the first pattern region 120 and the second pattern region 122, the light incident on the first asterisk projection 34 and the second asterisk projection 36 strikes the sides 34D and 36D shown in Figure 8. The incident light is then attenuated by repeatedly reflecting between the opposing sides 34D and 36D and is reflected outwards. Therefore, the first pattern region 120 and the second pattern region 122 appear darker compared to the base portion 22.

[0058] Furthermore, since the apex angles of each protrusion are similar, the area occupied per unit area by the base portion 22 of the second pattern region 122 is larger than the area occupied per unit area by the base portion 22 of the first pattern region 120.

[0059] As a result, the amount of light reflected outward in the second pattern region 122 is greater than the amount of light reflected outward in the first pattern region 120. In other words, the brightness of the second pattern region 122 is higher than that of the first pattern region 120. To put it another way, the second pattern region 122 appears relatively brighter than the first pattern region 120, and the first pattern region 120 appears relatively darker than the second pattern region 122.

[0060] As described above, the decorative section 14 of this embodiment is provided with a plurality of first pattern areas 120 and a plurality of second pattern areas 122 that are arranged adjacent to the first pattern areas 120 and have a higher brightness than the first pattern areas 120, and the areas of the first pattern areas 120 and the second pattern areas 122 increase in a clockwise direction. For this reason, compared to decorative sections that are not configured in this way, the decorative section 14 of this embodiment can greatly broaden the range of expression, and when viewing the decorative section 14, the viewer's gaze can be guided in a clockwise direction.

[0061] Furthermore, since the extensions of the first asterisk projection 34 and the second asterisk projection 36 are connected by the connecting portion 38, the first asterisk projection 34 and the second asterisk projection 36 support each other via the connecting portion 38, thereby suppressing the collapse of the first asterisk projection 34 and the second asterisk projection 36. This improves durability.

[0062] In the above embodiment, the decorative section 14 had two pattern areas with different brightness levels, but it may also have three or more pattern areas with different brightness levels.

[0063] [Other Embodiments] Although an example of an embodiment of the present disclosure has been described above, the embodiments of the present disclosure are not limited to those described above, and can of course be implemented in various modified forms without departing from the spirit of the disclosure.

[0064] Furthermore, the disclosure of Japanese Patent Application No. 2024-159439, filed on 13 September 2024, is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards described herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard were specifically and individually noted to be incorporated by reference.

Claims

1. A tire having a pattern region formed on the outer surface of the tire and having a base portion, a raised portion provided in the pattern region and rising from the base portion, and minute protrusions formed on the base portion and the raised portion, respectively, wherein the width of the tip of the minute protrusion on the base portion is less than or equal to the width of the tip of the minute protrusion on the raised portion.

2. The tire according to claim 1, wherein the heights of the minute protrusions are equal to each other with respect to the base portion.

3. The tire according to claim 1, wherein the width of the tip of the minute protrusion of the raised base portion is greater than the width of the tip of the minute protrusion of the base portion.

4. The tire according to claim 1, wherein the height of the minute protrusions relative to the base portion is 0.1 mm or more and 1.0 mm or less, and the distance between adjacent minute protrusions is 0.1 mm or more and 1.0 mm or less.

5. The tire according to claim 4, wherein the minute protrusions include extensions that extend in multiple directions from a base point in a plan view, and the extension of one minute protrusion is connected to the extension of another adjacent minute protrusion by a connecting portion.

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