tire

Abstract

The present invention aims to broaden the range of visual effects that can be expressed in decorative parts on the sidewall of a tire. [Solution] The tire of the present invention has a decorative portion formed on the sidewall portion, wherein a plurality of minute protrusions are arranged thereon, the decorative portion has a bottom surface whose height from the base surface of the sidewall portion gradually increases or decreases, the minute protrusions are formed on at least the bottom surface, the height of the minute protrusions is lower than the maximum height of the bottom surface, the plurality of minute protrusions are of the same height, and the height of the maximum height portion of the minute protrusions is lower than the height of the outer surface of the sidewall portion.

Description

Technical Field

[0001] The present invention relates to a tire.

Background Art

[0002] Conventionally, it has been proposed to form fine protrusions on the decorative part of the sidewall part of a tire to form a pattern area having a contrast (see, for example, Patent Document 1). According to this configuration, it is said that a contrast can be exhibited over the entire pattern area.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present invention is to widen the range of expression of the visual effect of the decorative part of the sidewall part of a tire.

Means for Solving the Problems

[0005] The gist configuration of the present invention is as follows. (1) A tire having a decorative part in which a plurality of minute protrusions are arranged on a sidewall part, the decorative part has a bottom surface whose height from the base surface of the sidewall part gradually increases or decreases, the minute protrusions are formed at least on the bottom surface, the height of the minute protrusions is lower than the maximum height of the bottom surface, the plurality of minute protrusions have the same height, a tire, characterized in that the height of the maximum height portion of the minute protrusions is lower than the height of the outer surface of the sidewall part.

[0006] (2) The tire according to (1), wherein the height of the minute protrusions is 50% or less of the maximum height of the bottom surface.

[0007] (3) The tire according to (1) or (2) above, wherein at least a portion of the bottom surface is curved. [Effects of the Invention]

[0008] According to the present invention, the range of visual effects that can be expressed in the decorative parts of the tire sidewall can be broadened. [Brief explanation of the drawing]

[0009] [Figure 1] This is a side view of an example of a tire according to one embodiment of the present invention. [Figure 2] This is a partial plan view showing an example of a decorative section. [Figure 3] This is a partial cross-sectional view showing an example of a decorative part. [Figure 4] This is a plan view showing the area where minute protrusions are formed. [Figure 5] This is a diagram illustrating the dimensions of the minute protrusions. [Figure 6] This is a schematic cross-sectional view in the tire width direction showing an example of the arrangement of communication equipment. [Figure 7] This is a schematic cross-sectional view in the tire width direction showing an example of the arrangement of communication equipment. [Modes for carrying out the invention]

[0010] 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.

[0011] FIG. 1 is a side view of an example of a tire according to an embodiment of the present invention. As shown in FIG. 1, this tire 1 forms a decorative portion with characters, patterns, trademarks, etc. on the sidewall portion. This tire 1 has a decorative portion 2 having a plurality of concave portions or convex portions (two locations in the illustrated example). In the decorative portion located between the decorative portions 2 composed of the plurality of concave portions or convex portions at two locations, in the illustrated example, characters "ABC", "DEF", "GHI", "JKLMN", trademark "X", and tire size are exemplified. However, in actuality, a distinguishable trademark (product name, series name, company logo, etc.) or an actual tire size can be displayed.

[0012] FIG. 2 is a partial plan view showing an example of the decorative portion. FIG. 3 is a partial cross-sectional view showing an example of the decorative portion. As shown in FIGS. 2 and 3, the decorative portion 2 has a plurality of concave portions 3 (or convex portions). The concave portion 3 is a portion recessed with respect to the outer surface 4 of the sidewall portion of the tire 1. By this concave portion 3, a convex portion protruding with respect to the base surface 5 of the sidewall portion is defined. Therefore, the decorative portion 2 has a plurality of concave portions 3 and at the same time has a plurality of convex portions.

[0013] As shown in FIGS. 2 and 3, the depths (or heights) of the plurality of concave portions 3 (or convex portions) continuously change in the tire radial direction and the tire circumferential direction within the decorative portion 2. In other words, in the decorative portion 2, the portion formed by the plurality of concave portions 3 (or convex portions) does not have a portion with a constant depth (or height).

[0014] As shown in FIG. 3, the decorative portion 2 has a bottom surface (the surface of the convex portion defined by the concave portion 3) whose height from the base surface 5 of the sidewall portion gradually increases or gradually decreases. In the illustrated example, the height of the bottom surface from the base surface 5 gradually increases and gradually decreases alternately from one side to the other side in the illustrated left-right direction.

[0015] As shown in FIG. 3, this tire 1 is formed with a decorative portion 2 having a plurality of minute projections 6 disposed on the sidewall portion, and the minute projections 6 are formed at least on the bottom surface. In the illustrated example, the minute projections 6 are disposed only on a part of the bottom surface (the surfaces of some convex portions).

[0016] FIG. 5 is a view for explaining the dimensions of the minute projections. In FIG. 5, for the sake of simplicity, it is shown that a plurality of minute projections 6 project from a base surface having the same height, but actually, the bottom surface has a gradually increasing or decreasing height from the base surface. As shown in FIGS. 3 and 5, the height h1 of the minute projection 6 is lower than the maximum height h of the bottom surface. Also, the plurality of minute projections 6 have the same height h1. Further, the height (h + h1) of the maximum height portion of the minute projection 6 (from the base surface 5) is lower than the height H of the outer surface 4 of the sidewall portion (from the base surface 5). Hereinafter, the operation and effect of the tire of this embodiment will be described.

[0017] The tire 1 of this embodiment is formed with a decorative portion 2 having a plurality of minute projections 6 disposed on the sidewall portion, and the minute projections 6 are formed at least on the bottom surface. The height h1 of the minute projection 6 is lower than the maximum height h of the bottom surface. Also, the plurality of minute projections 6 have the same height h1. Further, the height (h + h1) of the maximum height portion of the minute projection 6 (from the base surface 5) is lower than the height H of the outer surface 4 of the sidewall portion (from the base surface 5). The light incident on the decorative portion 2 is attenuated while being repeatedly reflected between the side surfaces of adjacent minute projections 6 and is reflected to the outside of the tire 1. Therefore, the minute projections 6 exhibit a contrast effect in which the portion where the minute projections 6 are formed appears dark. According to the configuration of this embodiment, since the minute projections 6 having such a low height are provided, this contrast effect can be moderately reduced. As a result, the impression of the decorative portion 2 where the minute projections 6 are formed can be moderately weakened, and attention can be directed to other decorative portions that are most prominent. 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.

[0018] The height h1 of the minute protrusion 6 is preferably 50% or less of the maximum height h of the base. This is because it allows for a moderate reduction in the contrast effect, drawing more attention to other decorative parts that you want to stand out the most.

[0019] It is preferable that at least a portion of the bottom surface be curved, as this allows for a contrast effect. Preferably, more than 90% of the total surface area of ​​the base is formed as a curved surface, and more preferably, 100% of the total surface area is formed as a curved surface. Furthermore, parts other than curved surfaces can be formed using flat surfaces. A curved surface can be formed such that, in cross-sectional view, it consists of one or more circular arcs. In the case of a single circular arc, or when multiple circular arcs are approximated into a single circular arc by the least squares method, the radius of curvature of the curved surface is not particularly limited, but can be, for example, 10 to 250 mm.

[0020] 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 both ends in the longitudinal direction, resulting in a recess), but it is not limited to this case and can be any planar shape. Examples include circular, elliptical, polygonal, star-shaped, leaf-shaped, etc., in plan view. Furthermore, the weight shape in the illustrated example is a complementary shape, configured such that both longitudinal ends of one recess 3 fit into the recess in the longitudinal center of an adjacent recess 3 (rotated approximately 90°). 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 rotated approximately 90° alternately so that they fit together complementaryly. In adjacent rows to one row, the weight shapes are offset by one pitch (the width of one weight) from the row in question, so that adjacent weight shapes fit together complementaryly even between rows.

[0021] 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.

[0022] As shown in Figure 3, 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 this is not particularly limited. The minimum depth d (=Hh) of the recess 3 can be, for example, 0.01 to 0.40 mm, although this is not particularly limited.

[0023] The number density of recesses 3 in the decorative part 2 is not particularly limited, but for example, 0.5 to 8 recesses / cm 2 It can be done this way.

[0024] Figure 4 is a plan view showing the portion where the micro-protrusions are formed. As shown in Figure 4, the micro-protrusions 6 are preferably asterisk-shaped in plan view. That is, the micro-protrusions 6 are preferably shaped having multiple extending portions radiating from the center in plan view. The number, width, and length of the extending portions are not particularly limited and can be set as appropriate. The spacing between the centers of the multiple asterisk shapes is also not particularly limited and can be set as appropriate. Furthermore, as shown in the figure, some of the extending portions between the multiple asterisk shapes may be connected. The planar shape of the micro-protrusions 6 can be various, and the above asterisk shape is an example.

[0025] The height h1 of the microprojection 6 is not particularly limited, but can be, for example, 0.05 to 0.5 mm. Also, the apex angle θ of the microprojection 6 (see Figure 5) is not particularly limited, but can be, for example, 20 to 90°.

[0026] The number density of the microprojections 6 is not particularly limited, but for example, 10 to 40 per cm². 2 This can be done. Furthermore, in the case of an asterisk shape in plan view, the density of the number of intersection points of the asterisk shape is not particularly limited, but for example, 10 to 40 points / cm². 2 It can be done this way.

[0027] The following describes examples of communication device placement. Figure 6 is a schematic cross-sectional view in the tire width direction showing an example of communication device placement for passenger car tires. Figure 7 is a schematic cross-sectional view in the tire width direction showing an example of communication device placement for truck and bus tires.

[0028] The tire may be equipped with RF tags as communication devices 100, 200. The RF tag comprises an IC chip and an antenna. The RF tag may be positioned, for example, sandwiched between multiple identical or different components that make up the tire. This makes it easier to attach the RF tag during tire production and improves the productivity of tires equipped with RF tags. In this example, the RF tag may be positioned, for example, sandwiched between a bead filler and other components adjacent to the bead filler. The RF tag may be embedded within one of the components that make up the tire. This reduces the load on the RF tag compared to when it is sandwiched between multiple components that make up the tire. This improves the durability of the RF tag. In this example, the RF tag may be embedded within a rubber component such as the tread rubber or side rubber. It is preferable that RF tags are not placed at locations that are boundaries between members with different rigidities in the peripheral length direction, which is the direction along the outer surface of the tire in a cross-sectional view in the tire width direction. By doing so, RF tags are not placed at locations where strain is likely to concentrate due to rigidity differences. Therefore, the load applied to RF tags can be reduced. This improves the durability of RF tags. In this example, it is preferable that RF tags are not placed at locations that are boundaries between, for example, the end of the carcass and a member adjacent to the end of this carcass (e.g., side rubber) in a cross-sectional view in the tire width direction. The number of RF tags is not particularly limited. A tire may have only one RF tag, or it may have two or more RF tags. Here, RF tags are used as an example of a communication device, but other communication devices may be used.

[0029] The RF tag may be placed, for example, on the tire tread. In this way, the RF tag will not be damaged by a tire side cut. The RF tag may be positioned, for example, in the center of the tread in the tire width direction. The center of the tread is a position where flexing is less likely to concentrate in the tread. This reduces the load on the RF tag, thereby improving its durability. It also suppresses differences in communication with the RF tag from both outer sides of the tire in the tire width direction. In this example, the RF tag may be positioned, for example, within a range of half the tread width centered on the tire equator in the tire width direction. The RF tag may be placed, for example, at the tread edge in the tire width direction. If the position of the reader that communicates with the RF tag is predetermined, the RF tag may be placed, for example, at one tread edge closest to this reader. In this example, the RF tag may be placed, for example, within a quarter of the tread width in the tire width direction, with the tread edge as the outer edge.

[0030] The RF tag may be positioned on the inner side of the tire cavity, for example, beyond the carcass, which includes one or more carcass plies that span between the bead portions. This makes the RF tag less susceptible to damage from impacts applied from outside the tire, such as side cuts or nail punctures. As an example, the RF tag may be positioned in close contact with the inner surface of the carcass facing the inner cavity. As another example, if there is another component on the inner side of the tire cavity beyond the carcass, the RF tag may be positioned, for example, between the carcass and the other component located on the inner side of the carcass facing the inner cavity. An example of another component located on the inner side of the tire cavity beyond the carcass is the inner liner that forms the inner surface of the tire. As yet another example, the RF tag may be attached to the inner surface of the tire facing the inner cavity. By configuring the RF tag to be attached to the inner surface of the tire, it becomes easier to attach the RF tag to the tire and to inspect and replace the RF tag. In other words, the ease of attachment and maintenance of the RF tag can be improved. Furthermore, by attaching the RF tag to the inner surface of the tire, it is possible to prevent the RF tag from becoming the core of tire failure, compared to a configuration where the RF tag is embedded inside the tire. Furthermore, if the carcass has multiple carcass plies and there are positions where multiple carcass plies overlap, the RF tag may be placed between the overlapping carcass plies.

[0031] The RF tag may be positioned, for example, on the tire tread, outside the belt, which includes one or more belt plies, in the radial direction of the tire. For example, the RF tag may be positioned outside the belt in the radial direction of the tire, in close contact with the belt. Another example is when a reinforcing belt layer is provided, the RF tag may be positioned outside the reinforcing belt layer in the radial direction of the tire, in close contact with the reinforcing belt layer. Yet another example is when the RF tag is embedded in the tread rubber, outside the belt in the radial direction of the tire. By positioning the RF tag outside the belt in the tire tread, communication with the RF tag from the outside of the tire in the radial direction is less likely to be hindered by the belt. Therefore, communication with the RF tag from the outside of the tire in the radial direction of the tire can be improved. Furthermore, the RF tag may be positioned, for example, in the tire tread area, radially inward from the belt. In this way, the outer side of the RF tag in the radial direction of the tire is covered by the belt, making the RF tag less susceptible to damage from impacts from the tread surface or nail punctures. As an example, the RF tag may be positioned in the tire tread area between the belt and the carcass located radially inward from the belt. Furthermore, if the belt has multiple belt plies, the RF tag may be positioned between any two belt plies on the tire tread. In this way, the outer side of the RF tag in the radial direction of the tire is covered by one or more belt plies, making the RF tag less susceptible to damage from impacts from the tread surface or nail punctures.

[0032] The RF tag may be positioned, for example, sandwiched between the cushioning rubber and the tread rubber, or between the cushioning rubber and the side rubber. In this way, the impact on the RF tag can be mitigated by the cushioning rubber. Therefore, the durability of the RF tag can be improved. Furthermore, the RF tag may be embedded, for example, within the cushion rubber. The cushion rubber may also be composed of multiple adjacent rubber members of the same or different types. In this case, the RF tag may be positioned sandwiched between the multiple rubber members constituting the cushion rubber.

[0033] The RF tag may be placed, for example, in the sidewall or bead area of ​​the tire. The RF tag may be placed, for example, in the sidewall or bead area on one side that is closer to the reader that can communicate with the RF tag. This improves the communication between the RF tag and the reader. As an example, the RF tag may be placed between the carcass and the side rubber, or between the tread rubber and the side rubber. The RF tag may be positioned, for example, between the position of the tire's maximum width and the position of the tread surface in the tire's radial direction. This configuration improves communication with the RF tag from the outside of the tire in the tire's radial direction compared to a configuration where the RF tag is positioned inside the position of the tire's maximum width in the tire's radial direction. The RF tag may be positioned, for example, radially inward from the point of maximum tire width. This positioning places the RF tag near the highly rigid bead, thus reducing the load on the RF tag and improving its durability. As another example, the RF tag may be positioned adjacent to the bead core in either the radial or widthwise direction. Strain is less likely to concentrate near the bead core, further reducing the load on the RF tag and improving its durability. In particular, it is preferable that the RF tag be positioned radially inward from the point of maximum tire width, and radially outward from the bead core of the bead portion. This improves the durability of the RF tag, and also makes communication between the RF tag and the reader less likely to be hindered by the bead core, thereby improving the communication performance of the RF tag. Furthermore, if the side rubber is composed of multiple identical or different rubber members adjacent to each other in the radial direction of the tire, the RF tag may be positioned sandwiched between the multiple rubber members that make up the side rubber.

[0034] The RF tag may be positioned sandwiched between the bead filler and a component adjacent to the bead filler. This allows the RF tag to be placed in a location where strain is less likely to concentrate due to the placement of the bead filler. Therefore, the load on the RF tag can be reduced, thereby improving the durability of the RF tag. The RF tag may be positioned, for example, sandwiched between the bead filler and the carcass. The portion of the carcass that sandwiches the RF tag together with the bead filler may be located either on the outside or inside of the tire width direction relative to the bead filler. If the portion of the carcass that sandwiches the RF tag together with the bead filler is located on the outside of the tire width direction relative to the bead filler, the load on the RF tag from impacts and damage from the outside of the tire in the tire width direction can be further reduced. This can further improve the durability of the RF tag. Furthermore, the bead filler may include a portion positioned adjacent to the side rubber. In such a case, the RF tag may be positioned sandwiched between the bead filler and the side rubber. Furthermore, the bead filler may include a portion positioned adjacent to the rubber chafer. In such a case, the RF tag may be positioned sandwiched between the bead filler and the rubber chafer.

[0035] The RF tag may be positioned sandwiched between a stiffener and a member adjacent to the stiffener. This allows the RF tag to be placed in a location where strain is less likely to concentrate due to the stiffener's placement. Therefore, the load on the RF tag can be reduced, thereby improving the durability of the RF tag. The RF tag may also be positioned, for example, sandwiched between a stiffener and a side rubber. Furthermore, the RF tag may be positioned, for example, sandwiched between the stiffener and the carcass. The portion of the carcass that sandwiches the RF tag together with the stiffener may be located either on the outside or inside of the tire width direction relative to the stiffener. If the portion of the carcass that sandwiches the RF tag together with the stiffener is located on the outside of the tire width direction relative to the stiffener, the load on the RF tag due to impacts or damage from the outside of the tire in the tire width direction can be further reduced. This can further improve the durability of the RF tag. The stiffener may include a portion positioned adjacent to the rubber chafer. In such a case, the RF tag may be positioned sandwiched between the stiffener and the rubber chafer. The stiffener may have a portion adjacent to the hat rubber on the outside in the tire width direction. In such a case, the RF tag may be positioned sandwiched between the stiffener and the hat rubber. The stiffener may be composed of multiple rubber members with different hardnesses. In such a case, the RF tag may be positioned sandwiched between the multiple rubber members that make up the stiffener. The RF tag may be positioned sandwiched between a hat elastic and a component adjacent to the hat elastic. For example, the RF tag may be positioned sandwiched between a hat elastic and a carcass ply. In this way, the impact on the RF tag can be mitigated by the hat elastic. Therefore, the durability of the RF tag can be improved.

[0036] The RF tag may be positioned, for example, sandwiched between a rubber chafer and a side rubber. This allows the RF tag to be placed in a location where strain is less likely to concentrate due to the placement of the rubber chafer. Therefore, the load on the RF tag can be reduced, thereby improving the durability of the RF tag. The RF tag may be positioned, for example, sandwiched between a rubber chafer and a carcass. This reduces the load on the RF tag from impacts and damage from the rim, thereby improving the durability of the RF tag.

[0037] The RF tag may be positioned sandwiched between a nylon chafer and another adjacent member on the outer or inner side of the nylon chafer in the tire width direction. This arrangement makes it less likely for the RF tag's position to shift during tire deformation. Therefore, the load on the RF tag during tire deformation can be reduced, thereby improving the durability of the RF tag. The nylon chafer may, for example, have a portion adjacent to the rubber chafer on the outer side in the tire width direction. In this case, the RF tag may be positioned sandwiched between the nylon chafer and the rubber chafer. The nylon chafer may, for example, have a portion adjacent to the side rubber on the outer side in the tire width direction. In this case, the RF tag may be positioned sandwiched between the nylon chafer and the side rubber. The nylon chafer may, for example, have a portion adjacent to the stiffener on the inner side in the tire width direction. In this case, the RF tag may be positioned sandwiched between the nylon chafer and the stiffener. The nylon chafer may also have a portion adjacent to the hat rubber on the inner side in the tire width direction. In this case, the RF tag may be positioned sandwiched between the nylon chafer and the hat rubber. Furthermore, the nylon chafer may, for example, have a portion adjacent to the carcass on the inner side in the tire width direction. In this case, the RF tag may be positioned sandwiched between the nylon chafer and the carcass. Furthermore, the nylon chafer may, for example, have a portion adjacent to the wire chafer on the inner side in the tire width direction. In this case, the RF tag may be positioned sandwiched between the nylon chafer and the wire chafer. Thus, the RF tag may be positioned sandwiched between a nylon chafer and another adjacent member on the outer or inner side of the nylon chafer in the tire width direction. In particular, by covering the outer side of the RF tag in the tire width direction with the nylon chafer, the load applied to the RF tag due to impacts and damage from the outside of the tire in the tire width direction can be further reduced. Therefore, the durability of the RF tag can be further improved.

[0038] The RF tag may be positioned sandwiched between the wire chafer and another component adjacent to the wire chafer on the inner or outer side in the tire width direction. This arrangement makes it less likely for the RF tag's position to change during tire deformation. Therefore, the load on the RF tag during tire deformation can be reduced, thereby improving the durability of the RF tag. The other component adjacent to the wire chafer on the inner or outer side in the tire width direction may be, for example, a rubber component such as a rubber chafer. Alternatively, the other component adjacent to the wire chafer on the inner or outer side in the tire width direction may be, for example, a carcass.

[0039] A belt reinforcing layer may be further provided on the radially outer side of the belt. For example, the belt reinforcing layer may consist of a cord made of polyethylene terephthalate wound continuously in a spiral shape in the circumferential direction of the tire. Here the cord is 6.9 × 10 -2 The belt is treated with adhesive under a tension of N / tex or higher, and its modulus of elasticity at a load of 29.4N measured at 160°C may be 2.5mN / dtex·% or higher. Furthermore, the belt reinforcement layer may be arranged to cover the entire belt or to cover only the ends of the belt. In addition, the winding density per unit width of the belt reinforcement layer may differ at different positions in the width direction. By doing so, road noise and flat spots can be reduced without reducing high-speed durability. [Explanation of Symbols]

[0040] 1: Tires, 2: Decorative part, 3: recessed, 4: Outer surface, 5: Base surface, 6: Microprotrusions, 100, 200: Communication equipment

Claims

1. A tire having a decorative section formed on the sidewall with multiple minute protrusions, The decorative portion has a bottom surface whose height from the base surface of the sidewall portion gradually increases or decreases. The aforementioned minute protrusions are formed at least on the bottom surface, The height of the aforementioned minute protrusions is lower than the maximum height of the bottom surface. The aforementioned multiple minute protrusions are of the same height, A tire characterized in that the height of the maximum height portion of the aforementioned minute protrusion is lower than the height of the outer surface portion of the sidewall.

2. The tire according to claim 1, wherein the height of the minute protrusions is 50% or less of the maximum height of the bottom surface.

3. The tire according to claim 1 or 2, wherein at least a portion of the bottom surface is curved.

Images