pneumatic tires

Abstract

To provide a pneumatic tire which can make inconspicious, irregularity generated on external surface of a side wall at tire molding.SOLUTION: A pneumatic tire is provided with a side wall which extends in a tire radial direction. The side wall is provided with a belt-like decorative region 3 which extends along a tire peripheral direction on outside surface. The decorative region 3 is provided with a plurality of first regions 31a, 31c, 31e which are surrounded by a polygonal line 310 comprising a plurality of line segments connected at angle of 80-110° and an outer edge of the decorative region 3. The first regions 31a, 31c, 31e are provided with a plurality of first ridges 41 which extend in a first direction, respectively and are also juxtaposed spaced apart from each other.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to pneumatic tires. [Background technology]

[0002] A pneumatic tire is formed by winding various strip-shaped tire components around the outer circumferential surface of a building drum, expanding the components to a toroidal shape to form a green tire, and then vulcanizing and molding the green tire. After vulcanization and molding, the outer surface of the tire sidewall is prone to appearing as localized irregularities at the joints between the winding start and end ends of the strip-shaped tire components, and these irregularities have been a cause of degrading the appearance quality of the tire.

[0003] It has been known to provide a decorative area on the outer surface of the sidewall to make such localized irregularities less noticeable. For example, Patent Document 1 below discloses a pneumatic tire in which a decorative area is formed by overlapping a first ridge group consisting of a plurality of ridges extending radially, a second ridge group consisting of ridges with the same specifications as the first ridge group, a third ridge group consisting of a plurality of ridges arranged concentrically with each other, and a fourth ridge group consisting of ridges with the same specifications as the third ridge group. However, although many proposals for decorative areas to be formed on the outer surface of the sidewall other than Patent Document 1 have been made, further improvements are desired. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-37387 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present disclosure is to provide a pneumatic tire that can make unevenness that occurs on the outer surface of the sidewall during tire molding less noticeable. [Means for solving the problem]

[0006] A pneumatic tire according to the present disclosure includes a sidewall extending in a tire radial direction, the sidewall has a strip-shaped decorative area extending along the tire circumferential direction on an outer surface thereof, The decorative area includes a plurality of first areas surrounded by a polygonal line consisting of a plurality of line segments connected at an angle of 80 to 110 degrees and an outer edge of the decorative area, The first region includes a plurality of first ridges that extend in a first direction and are arranged side by side at intervals from each other. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a cross-sectional view of a main part of a pneumatic tire according to an embodiment of the present invention taken along a tire meridian plane; [Figure 2] FIG. 1 is a front view of a pneumatic tire according to an embodiment of the present invention; [Figure 3] Enlarged view of area III in Figure 2 [Figure 4] Enlarged view of area III in Figure 2 [Figure 5] Enlarged view of the V region in Figure 3 [Figure 6] Cross section of the decorative area around the first ridge [Figure 7] An enlarged view of a main part of a pneumatic tire according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, one embodiment of a pneumatic tire will be described with reference to Figures 1 to 6. Note that in each figure (as well as Figure 7), the dimensional ratios in the drawing do not necessarily match the actual dimensional ratios, and the dimensional ratios between the drawings do not necessarily match either.

[0009] 1, a pneumatic tire 1 according to this embodiment includes a pair of beads 1b, 1b each having a bead core 1a, and a pair of sidewalls 2, 2 extending outward in the tire radial direction D2 from each bead 1b. The pneumatic tire 1 also includes a tread 1c connected to outer ends of the pair of sidewalls 2, 2 in the tire radial direction D2. Although not shown, various grooves, such as circumferential grooves and lug grooves, that form a tread pattern are provided on the outer peripheral surface of the tread 1c.

[0010] In each drawing, the tire width direction D1 is a direction parallel to the tire rotation axis 1d (see FIG. 2) which is the rotation center of the pneumatic tire 1, the tire radial direction D2 is a diameter direction of the pneumatic tire 1, and the tire circumferential direction D3 is a direction around the tire rotation axis 1d. The tire equatorial plane S1 is a plane perpendicular to the tire rotation axis 1d and located at the center of the pneumatic tire 1 in the tire width direction D1, and the tire meridian plane is a plane including the tire rotation axis 1d and perpendicular to the tire equatorial plane S1.

[0011] In the tire width direction D1, the inner side refers to the side closer to the tire equatorial plane S1, and the outer side refers to the side farther from the tire equatorial plane S1. In the tire radial direction D2, the inner side refers to the side closer to the tire rotational axis 1d, and the outer side refers to the side farther from the tire rotational axis 1d.

[0012] The pneumatic tire 1 includes a carcass 1e that spans between a pair of bead cores 1a, 1a, and an inner liner 1f that is disposed inside the carcass 1e and has an excellent function of preventing gas permeation in order to maintain air pressure. The carcass 1e and the inner liner 1f are disposed along the inner circumference of the tire, spanning the beads 1b, sidewalls 2, and tread 1c.

[0013] The sidewall 2 includes a sidewall rubber 2a disposed on the outer side of the carcass 1e in the tire width direction D1. As shown in Fig. 2, the sidewall rubber 2a includes a decorative region 3 disposed in a partial region of the outer surface 2b. The decorative region 3 is formed in a certain region of the outer surface 2b of the sidewall 2 in the tire radial direction D2, including the tire maximum width position 2c.

[0014] In this embodiment, the decorative area 3 has an arc shape extending along the tire circumferential direction D3. The decorative area 3 includes an inner circumferential edge 3a and an outer circumferential edge 3b extending in the tire circumferential direction D3, and a first side edge 3c and a second side edge 3d connecting the ends of the inner circumferential edge 3a and the outer circumferential edge 3b. Note that in this embodiment, the first side edge 3c and the second side edge 3d are polygonal, but the shapes of the first side edge 3c and the second side edge 3d are not particularly limited and may be linear, for example.

[0015] 2, the decorative region 3 may be formed only in a portion of the sidewall 2 in the tire circumferential direction D3, or may be formed over the entire circumference of the sidewall 2 in the tire circumferential direction D3. Furthermore, multiple decorative regions 3 may be formed along the tire circumferential direction D3 of the sidewall 2. When multiple decorative regions 3 are formed, the decorative regions 3 are preferably arranged at equal intervals in the tire circumferential direction D3.

[0016] 3 and 4, the decorative region 3 includes a plurality of first regions 31a to 31f and a second region 32 other than the plurality of first regions 31a to 31f. Note that first ridges 41 and second ridges 42, which will be described later, are not shown in FIG.

[0017] As shown in Fig. 4, the first regions 31a to 31f are regions surrounded by a folded line 310 consisting of multiple line segments 311 connected at an angle θ of 80 to 110° and the outer edge of the decorative region 3. The first regions 31a to 31f are regions on either side of the folded line 310 that bend at the angle θ. Here, the outer edge of the decorative region 3 refers to the inner peripheral edge 3a, the outer peripheral edge 3b, the first side edge 3c, and the second side edge 3d. Note that the folded line 310 shown in Fig. 4 is a virtual line used to define the first regions 31a to 31f and does not appear in an actual tire.

[0018] The first region 31a is an area surrounded by the fold line 310 consisting of two line segments 311 and the inner peripheral edge 3a. The first region 31b is an area surrounded by the fold line 310 consisting of three line segments 311 and the inner peripheral edge 3a. The first region 31c is an area surrounded by the fold line 310 consisting of two line segments 311 and the outer peripheral edge 3b. The first region 31d is an area surrounded by the fold line 310 consisting of three line segments 311 and the outer peripheral edge 3b. The first region 31e is an area surrounded by the fold line 310 consisting of two line segments 311, the fold line 310 consisting of two line segments 311, the inner peripheral edge 3a, and the outer peripheral edge 3b. The first region 31f is an area surrounded by the fold line 310 consisting of two line segments 311, the outer peripheral edge 3b, and the first side edge 3c or the second side edge 3d.

[0019] 5, the first regions 31a to 31f each include a plurality of first ridges 41 that extend in a first direction D41 and are arranged side by side at intervals. The second region 32 includes a plurality of second ridges 42 that extend in a second direction D42 different from the first direction D41 and are arranged side by side at intervals. The second direction D42 is inclined at an angle of 60 to 80 degrees from the first direction D41.

[0020] Fig. 6 is a cross-sectional view of the decorative area 3 around the first ridge 41, cut along a plane perpendicular to the first direction D41. In Fig. 6, the dashed line indicates a reference plane S2 (also referred to as a reference profile) of the outer surface 2b. In this embodiment, the reference plane S2 of the outer surface 2b is at the same position in the tire width direction D1 as the outer surface 2b of the sidewall 2 in a portion where the decorative area 3 is not formed.

[0021] The decorative region 3 has a recess 4 recessed from a reference plane S2 of the outer surface 2b. The recess 4 is formed over the entire decorative region 3. The depth of the recess 4 from the reference plane S2 is, for example, 0.3 to 1.5 mm.

[0022] The first ridge 41 is formed to protrude from the bottom of the recess 4. The position of the protruding end 41a of the first ridge 41 may be the same position or a different position relative to the reference plane S2 of the outer surface 2b. Figure 6 shows an example in which the position of the protruding end 41a of the first ridge 41 is recessed from the reference plane S2 of the outer surface 2b.

[0023] The first ridge 41 has a substantially triangular cross section. However, the first ridge 41 may have a cross section with rounded vertices of the triangle. The protruding height H1 of the first ridge 41 from the bottom of the recess 4 is, for example, 0.2 mm or more. The width W1 of the first ridge 41 is, for example, 0.1 mm or more. The spacing P1 between the parallel first ridges 41 is, for example, 0.6 to 1.0 mm.

[0024] The second ridge 42 has the same cross-sectional shape as the first ridge 41. Therefore, a detailed description of the second ridge 42 will be omitted.

[0025] 4, the plurality of line segments 311 are preferably configured only with line segments 311a parallel to the third direction D43 and line segments 311b parallel to a fourth direction different from the third direction D43. This configuration makes it easier to design the decorative area 3.

[0026] As described above, the pneumatic tire 1 of this embodiment has a sidewall 2 extending in the tire radial direction D2, and the sidewall 2 has a strip-shaped decorative region 3 extending along the tire circumferential direction D3 on its outer surface 2b, and the decorative region 3 has a plurality of first regions 31a to 31f surrounded by a broken line 310 consisting of a plurality of line segments 311 connected at an angle θ of 80 to 110° and the outer edges 3a to 3d of the decorative region 3, and the first regions 31a to 31f have a plurality of first ridges 41 each extending in a first direction D41 and arranged in parallel at intervals from each other.

[0027] According to this pneumatic tire 1, irregularities that occur on the outer surface 2b of the sidewall 2 during tire molding are less noticeable.

[0028] Furthermore, in the pneumatic tire 1 according to this embodiment, the decorative region 3 includes a second region 32 other than the first regions 31a to 31f, and the second region 32 includes a plurality of second ridges 42 that extend in a second direction D42 different from the first direction D41 and are arranged in parallel at intervals from each other.

[0029] According to this configuration, irregularities that occur on the outer surface 2b of the sidewall 2 during tire molding become even less noticeable, and the aesthetic appearance is also improved.

[0030] Furthermore, in the pneumatic tire 1 according to this embodiment, the second direction D42 is inclined at an angle of 60 to 80 degrees from the first direction D41.

[0031] According to this configuration, irregularities that occur on the outer surface 2b of the sidewall 2 during tire molding are even less noticeable.

[0032] Furthermore, in the pneumatic tire 1 according to this embodiment, the multiple line segments 311 are composed only of line segments 311a parallel to the third direction D43 and line segments 311b parallel to a fourth direction D44 different from the third direction D43.

[0033] According to this configuration, irregularities that occur on the outer surface 2b of the sidewall 2 during tire molding become even less noticeable, and the design of the decorative area 3 becomes easier.

[0034] The above-mentioned dimensional values, positional relationships, and magnitude relationships are measured when the pneumatic tire 1 is mounted on a standard rim, inflated to the standard internal pressure, and in a standard state with no load. For example, the tire maximum width position 2c is the position in the tire radial direction D2 of the position where the dimension in the tire width direction D1, excluding structures such as patterns and letters protruding from the outer surface 2b of the sidewall 2, is maximum when the pneumatic tire 1 is mounted on a standard rim, inflated to the standard internal pressure, and in a no-load state. A standard rim is a rim defined for each pneumatic tire 1 by a standard system including the standard on which the pneumatic tire 1 is based; for example, it is called a standard rim in the case of JATMA, and a "Measuring Rim" in the cases of TRA and ETRTO.

[0035] The normal internal pressure is the air pressure determined for each pneumatic tire 1 by the standards set forth in the standard system, including the standards on which the pneumatic tire 1 is based. For truck and bus tires and light truck tires, the normal internal pressure is the maximum air pressure for JATMA, the maximum value listed in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES" for TRA, and "INFLATION PRESSURE" for ETRTO. For passenger car tires, the normal internal pressure is usually 180 kPa, but for tires labeled "Extra Load" or "Reinforced," the normal internal pressure is 220 kPa.

[0036] The pneumatic tire 1 is not limited to the configurations of the above-described embodiments, nor is it limited to the above-described effects. It goes without saying that various modifications can be made to the pneumatic tire 1 without departing from the spirit of the present invention. For example, the configurations and methods of the above-described embodiments may be arbitrarily adopted and combined, and one or more of the configurations and methods of the various modified examples described below may be arbitrarily selected and adopted in the configurations and methods of the above-described embodiments.

[0037] (1) In the pneumatic tire 1 according to the above embodiment, the decorative region 3 includes a second region 32 other than the first regions 31a to 31f, and the second region 32 includes a plurality of second ridges 42 that extend in a second direction D42 different from the first direction D41 and are arranged in parallel at intervals. However, the pneumatic tire 1 is not limited to this configuration. Even if the second region 32 does not include a plurality of second ridges 42, it is possible to obtain to a certain extent the effect of making irregularities on the outer surface 2b of the sidewall 2 less noticeable by the plurality of first ridges 41 provided in the first regions 31a to 31f.

[0038] (2) In the pneumatic tire 1 according to the above embodiment, the second direction D42 is inclined at an angle of 60 to 80 degrees from the first direction D41. However, the pneumatic tire 1 is not limited to this configuration. For example, as shown in FIG. 7, the second direction D42 may be inclined at an angle of 90 degrees from the first direction D41. In the example shown in FIG. 7, the fourth direction D44 is inclined at an angle of 90 degrees from the third direction D43. Furthermore, the first direction D41 is inclined at an angle of 45 degrees from each of the third direction D43 and the fourth direction D44.

[0039] (3) In the pneumatic tire 1 according to the above embodiment, the multiple line segments 311 are configured only with line segments 311a parallel to the third direction D43 and line segments 311b parallel to a fourth direction D44 different from the third direction D43. However, the pneumatic tire 1 is not limited to this configuration. The multiple line segments 311 may include line segments other than the line segments 311a and 311b.

[0040] (4) In the pneumatic tire 1 according to the present embodiment, the first ridge 41 and the second ridge 42 may be configured so that their ends are connected to each other, as shown in Fig. 7. With this configuration, when the first ridge 41 and the second ridge 42 are formed on the outer surface 2b of the sidewall 2 by cutting using laser processing or the like, the first ridge 41 and the second ridge 42 can be formed continuously, improving work efficiency. [Explanation of symbols]

[0041] 1...pneumatic tire, 2...sidewall, 2a...sidewall rubber, 2b...outer surface, 2c...maximum tire width position, 3...decorative area, 3a...inner peripheral edge, 3b...outer peripheral edge, 3c...first side edge, 3d...second side edge, 4...recess, 31a to 31f...first area, 32...second area, 41...first ridge, 42...second ridge, 310...folded line, 311...line segment, 311a, 311b...line segment, D1...tire width direction, D2...tire radial direction, D3...tire circumferential direction, D41...first direction, D42...second direction, D43...third direction, D44...fourth direction, S2...reference plane of outer surface

Claims

1. The tire has a sidewall extending in a radial direction, the sidewall has a strip-shaped decorative area extending along the tire circumferential direction on an outer surface thereof, the decorative area includes a plurality of first areas surrounded by a polygonal line consisting of a plurality of line segments connected at an angle θ of 80 to 110 degrees and an outer edge of the decorative area; the first region includes a plurality of first ridges each extending in a first direction and arranged side by side at intervals from one another; The decorative area includes a second area other than the first area, the second region includes a plurality of second ridges that extend in a second direction different from the first direction and are arranged side by side at intervals from each other; the decorative region includes only the first region and the second region, the first region being a region on the side of the fold line that bends at an angle θ, and the second region being a region on the opposite side of the fold line that bends at an angle θ.

2. The pneumatic tire according to claim 1, wherein the second direction is inclined at an angle of 60 to 80 degrees from the first direction.

3. The pneumatic tire according to claim 1 or 2, wherein the first ridge and the second ridge are connected at their ends.

4. The pneumatic tire according to any one of claims 1 to 3, wherein the plurality of line segments are composed only of line segments parallel to a third direction and line segments parallel to a fourth direction different from the third direction.

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