Tire

Abstract

A tire according to the present invention has a sidewall section on which a decorative part having a plurality of recesses or protrusions is formed. The plurality of recesses or protrusions have a depth or height that varies continuously in the tire radial direction and the tire circumferential direction in the decorative part. At least portions of the plurality of recesses or protrusions in the decorative part are formed by curved surfaces.

Description

Tire

[0001] The present invention relates to a tire.

[0002] Conventionally, it has been proposed to form a decorative portion having a number of dimples on the sidewall portion of a tire (see, for example, Patent Document 1). According to Patent Document 1, it is said that good durability and quietness are achieved by this configuration.

[0003] On the other hand, such a configuration also gives a visual effect due to a number of dimples to the decorative portion of the sidewall portion.

[0004] Japanese Unexamined Patent Application Publication No. 2016 - 210284

[0005] An object of the present invention is to widen the range of expression of the visual effect of the decorative portion of the sidewall portion of a tire.

[0006] The gist configuration of the present invention is as follows. (1) A tire in which a decorative portion having a plurality of concave portions or convex portions is formed on a sidewall portion, wherein the plurality of concave portions or convex portions continuously change in depth or height in the tire radial direction and the tire circumferential direction within the decorative portion, and at least a part of the plurality of concave portions or convex portions within the decorative portion is formed of a curved surface.

[0007] According to the present invention, the range of expression of the visual effect of the decorative portion of the sidewall portion of a tire can be widened.

[0008] It is a side view of an example of a tire according to an embodiment of the present invention. It is a partial plan view showing an example of a decorative portion. It is a plan view showing an example in which the decorative portion parametrically changes. It is a partial cross - sectional view showing an example of a decorative portion.

[0009] Embodiments of the present invention will be described in detail below with reference to the drawings. Note that the internal structure of the tire can be the same as that of conventional tires, so a detailed explanation will be omitted. For example, a tire may comprise a pair of bead portions, a pair of sidewall portions connected to the pair of bead portions, and a tread portion connected between the pair of sidewall portions. Furthermore, a tire may comprise a carcass that spans the pair of bead portions in a toroidal manner. Additionally, a tire may comprise a belt positioned radially outward on the crown portion of the carcass.

[0010] Figure 1 is a side view of an example of a tire according to one embodiment of the present invention. As shown in Figure 1, this tire 1 has a decorative section on the sidewall portion with letters, patterns, trademarks, etc. This tire 1 has a decorative section 2 having a plurality of recesses or protrusions (two in the illustrated example). In the illustrated example, the decorative section located between the two plurality of recesses or protrusions of the decorative section 2 is exemplified by the letters "ABC", "DEF", "GHI", "JKLMN", the trademark "X", and the tire size, but in reality, it can display a distinctive trademark (product name, series name, company logo, etc.) or the actual tire size.

[0011] Figure 2 is a partial plan view showing an example of a decorative part. Figure 4 is a partial cross-sectional view showing an example of a decorative part. As shown in Figures 2 and 4, the decorative part 2 has a plurality of recesses 3 (or protrusions). The recesses 3 are recessed portions relative to the outer surface 4 of the sidewall portion of the tire 1. These recesses 3 define the protrusions that project from the base surface 5 of the sidewall portion. Therefore, the decorative part 2 has a plurality of recesses 3 and a plurality of protrusions at the same time.

[0012] As shown in Figures 2 and 4, the depth (or height) of the multiple recesses 3 (or protrusions) within the decorative part 2 changes continuously in the tire radial direction and tire circumferential direction. In other words, the portion of the decorative part 2 formed by the multiple recesses 3 (or protrusions) does not have any portion with a constant depth (or height).

[0013] Furthermore, in this embodiment, at least a portion of the multiple recesses 3 (or protrusions) within the decorative part 2 is formed as a curved surface. Preferably, 90% or more of the total surface area of ​​the multiple recesses 3 (or protrusions) within the decorative part 2 is formed as a curved surface, and more preferably, 100% of the total surface area is formed as a curved surface. The portion other than the curved surface can be formed as a flat surface. Also, as a whole, it is sufficient that at least a portion of the multiple recesses 3 (or protrusions) within the decorative part 2 is formed as a curved surface, and the decorative part 2 may include recesses 3 in which all portions are formed as flat surfaces.

[0014] Figure 3 is a plan view showing an example of a decorative part that changes parametrically. As shown in Figure 3, it is preferable that the decorative part 2 consists of a plurality of recesses 3 (or protrusions) that change parametrically in a predetermined direction. The "predetermined direction" can be, for example, the circumferential direction of the tire or the radial direction of the tire. Specifically, in the illustrated example, the recesses 3 gradually (continuously) approach a horizontally elongated shape from both ends toward the center.

[0015] Examples of parametric changes include changes in aspect ratio, changes in the number of sides of a polygon, changes in the curvature of a curved shape, changes in the roundness of corners (e.g., gradually approaching a circle from a rectangle), changes in symmetry (changing from a symmetrical figure to an asymmetrical figure, or vice versa), changes where a part of a circle is removed (approaching a crescent shape from a circle, or vice versa), changes in the height of vertices (e.g., the vertices of a square are extended in one direction, approaching a trapezoid or triangle), and changes in bulges or indentations (e.g., in the weight-shaped object shown in Figure 3, the width of the indentation gradually increases or decreases). Parametric changes may be stepwise (parametrically changing a certain region in a "predetermined direction" that is not parametrically changing, and arranging multiple such regions), or they may be continuous changes. The effects and advantages of the tire of this embodiment will be explained below with examples.

[0016] In this embodiment, the tire 1 has a decorative section 2 on the sidewall having a plurality of recesses 3 (or protrusions). The depth or height of the recesses 3 (or protrusions) changes continuously in the tire radial and circumferential directions within the decorative section 2, and at least a portion of the recesses 3 (or protrusions) within the decorative section 2 is formed as a curved surface. With this configuration, the recesses 3 are not separated by land portions of a certain height, but rather appear to be directly adjacent to each other. As a result, compared to the case where the recesses 3 are separated by land portions of a certain height, the impression of each individual recess 3 is weakened, and the overall impression of the decorative section 2 can be relatively enhanced. Furthermore, when the recesses 3 are separated by land portions of a certain height, it may give the impression that something has been gouged out, but with the configuration of this embodiment, such an impression can be mitigated. Furthermore, if the recesses 3 are separated by land portions having a certain height, the pattern of these land portions may stand out. For example, if the shape of the land portions is determined by an irregularity such as a Voronoi tessellation, such irregular land portions may stand out and create an unnatural appearance. However, in this embodiment, since land portions with width are not formed, such concerns can be eliminated. Also, if land portions are present, the visual effect of the land portions and the recesses 3 becomes mixed, but in this embodiment, the visual effect of the recesses 3 can be focused on (and as mentioned above, this is the visual effect of the entire decorative part 2, not each individual recess). In addition, if land portions are present, the land portions become discontinuous with respect to the recesses 3, making it difficult to adjust the contrast of the decorative part 2 during the design phase. However, in this embodiment, since land portions with width are not formed and the depth of the recesses 3 changes continuously, adjusting the contrast becomes easier. Furthermore, since at least a portion of the multiple recesses 3 (or protrusions) within the decorative part 2 are composed of curved surfaces, a smooth gradient effect can be given to the entire decorative part 2. Furthermore, by preventing the formation of prominent land areas and making each individual recess 3 less noticeable, the overall impression of the decorative part 2 can be moderately weakened, allowing attention to be drawn to other decorative parts that you want to stand out the most.As described above, the tire 1 of this embodiment provides a different visual effect from conventional tire 1, thereby broadening the range of visual effect expression for the decorative part 2 on the sidewall of the tire 1.

[0017] Preferably, 90% or more of the total surface area of ​​the multiple recesses 3 or protrusions within the decorative part 2 is formed as a curved surface, and more preferably, 100% of the total surface area is formed as a curved surface. This is because it allows for an even smoother gradient effect to be given to the decorative part 2 as a whole.

[0018] Preferably, the decorative part 2 has a plurality of recesses 3 (or protrusions) that change parametrically in a predetermined direction. This is because it provides a visual effect that is different from the conventional, thereby further expanding the range of expression of the visual effect of the decorative part 2 on the sidewall of the tire 1.

[0019] In the example shown in Figure 2, the recess 3 is weight-shaped in plan view (a shape in which the width of the central part is smaller than the width of the ends in the longitudinal direction, resulting in a recess), but it is not limited to this case and can be various planar shapes. Examples include circular, elliptical, polygonal, star-shaped, leaf-shaped, etc., in plan view. Furthermore, the weight-shaped example shown is a complementary shape in which the ends in the longitudinal direction of one recess 3 fit into the recess in the longitudinal center of an adjacent recess 3 (rotated by approximately 90°) in the longitudinal direction. Thus, it is also preferable for the planar shape of the recess 3 to be a complementary shape. The recesses 3 are arranged in multiple rows. Within the same row, in this example, adjacent weight shapes are arranged alternately, rotated by approximately 90°, so that they fit complementaryly. In adjacent rows to one row, the adjacent weight shapes are offset by one pitch (the width of one weight) from the row so that they fit complementaryly between rows.

[0020] The maximum diameter of the recess 3 in a plan view (the maximum distance between two points on the contour line of the recess 3) is not particularly limited, but can be, for example, 3.0 to 30.0 mm.

[0021] As shown in Figure 4, it is preferable that the maximum height h of the protrusion partitioned by the recess 3 from the base surface 5 is smaller than the height H of the sidewall portion from the base surface 5 to the outer surface 4. The ratio h / H can be, for example, 0.25 to 0.90, although it is not particularly limited. The minimum depth d (= H - h) of the recess 3 can be, for example, 0.01 to 0.40 mm, although it is not particularly limited.

[0022] The number density of recesses 3 in the decorative part 2 is not particularly limited, but for example, 0.5 to 8 recesses / cm². ２ This can be done. The recess 3 can be formed to consist of one or more arcs in cross-sectional view. In the case of one arc, or when multiple arcs are approximated into one arc by the least squares method, the radius of curvature of the recess 3 is not particularly limited, but can be, for example, 10 to 250 mm.

[0023] 1: Tire, 2: Decorative part, 3: Recess, 4: Outer surface, 5: Base surface

Claims

1. A tire having a decorative portion formed on the sidewall portion having a plurality of recesses or protrusions, wherein the depth or height of the plurality of recesses or protrusions changes continuously in the tire radial direction and tire circumferential direction within the decorative portion, and at least a portion of the plurality of recesses or protrusions within the decorative portion is formed as a curved surface.

2. The tire according to claim 1, wherein 90% or more of the total surface area of ​​the plurality of recesses or protrusions within the decorative part is formed as a curved surface.

3. The tire according to claim 2, wherein 100% of the total surface area of ​​the plurality of recesses or protrusions within the decorative portion is formed as a curved surface.

4. The tire according to any one of claims 1 to 3, wherein the decorative portion is formed by the plurality of recesses or protrusions changing parametrically in a predetermined direction.

5. The tire according to any one of claims 1 to 4, wherein the portion of the decorative part formed by the plurality of recesses or protrusions does not have a portion with a constant depth or height.

Images