Pneumatic tires

Abstract

To provide a pneumatic tire having an excellent visual effect.SOLUTION: A pneumatic tire 1 has patterns 30 provided on a surface of a side wall 10. In the pneumatic tire 1, the pattern 30 has a plurality of annular diagrams 31 which are longer in a tire circumferential direction CD than a tire radial direction RD. The plurality of annular diagrams 31 are different in size from one another, and have a common center P, and large annular diagram 31 are located outside small annular diagrams 31 at intervals so that an interval Kr in the tire circumferential direction CD becomes larger than an interval Kr in the tire radial direction RD.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a pneumatic tire. [Background technology]

[0002] BACKGROUND ART Pneumatic tires are known that have a pattern formed by arranging a plurality of ridges extending along the tire surface on the surface of the sidewall.

[0003] Most of the conventional patterns on the surface of the sidewall consist of a large number of linear ridges arranged at equal intervals. Also known is a pattern with curved ridges arranged at equal intervals, as disclosed in Patent Document 1. Both patterns enhance the design of the sidewall. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-180947 Summary of the Invention [Problem to be solved by the invention]

[0005] Although various patterns have been proposed up to now, there is a demand for revolutionary patterns that will produce unprecedented visual effects.

[0006] Therefore, an object of the present invention is to provide a pneumatic tire that produces a visual effect. [Means for solving the problem]

[0007] The pneumatic tire of this embodiment is a pneumatic tire having a pattern on the surface of the sidewall, the pattern having a plurality of annular figures that are longer in the tire circumferential direction than in the tire radial direction, the plurality of annular figures having different sizes but a common center, and larger annular figures arranged at intervals outside smaller annular figures so that the spacing in the tire circumferential direction is greater than the spacing in the tire radial direction. [Effects of the Invention]

[0008] In the present invention, by providing the above-mentioned features, bleeding can be suppressed and a visual effect with a sense of depth can be produced. [Brief explanation of the drawings]

[0009] [Figure 1] Axial half cross-section of a pneumatic tire [Figure 2] Figure 1 shows the pneumatic tire as seen from the tire axial direction [Figure 3] Enlargement of the pattern. [Figure 4] Cross-sectional view of the ridges that make up the ring shape [Figure 5] Cross-sectional view of the ridges that make up the ring shape [Figure 6] Cross-sectional view of the ridges that make up the ring shape [Figure 7] Cross-sectional view of the ridges that make up the ring shape [Figure 8] Cross-sectional view of the ridges that make up the ring shape [Figure 9] Cross-sectional view of the ridges that make up the ring shape [Figure 10] FIG. 1 is a view of a decorative area of ​​a modified pneumatic tire from the tire axial direction. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0011] The pneumatic tire 1 of the embodiment has a structure similar to that of a general radial tire, except for the structure of the sidewall. Figure 1 shows the cross-sectional structure of the pneumatic tire 1 of the embodiment. Note that Figure 1 shows only half of the tire in the axial direction, and the actual pneumatic tire 1 is approximately symmetrical with respect to the center line C.

[0012] The pneumatic tire 1 has beads 9 on both sides in the tire axial direction. The bead 9 is made up of a bead core made of a steel wire wound in a circular shape, and a rubber bead filler provided radially outside the bead core.

[0013] One or two carcass plies 2 are laid across the beads 9 on both sides of the tire in the axial direction. The carcass ply 2 is a sheet-like member in which numerous ply cords arranged in a direction perpendicular to the tire circumferential direction are covered with rubber. The carcass ply 2 forms the skeleton shape of the pneumatic tire 1 between the beads 9 on both sides of the tire in the axial direction, and wraps around the beads 9 by being folded back from the axially inner side to the axially outer side. In addition, a rubber chafer 3 is provided at the axially outer side of the folded back portion 2a of the carcass ply 2.

[0014] Furthermore, one or more belts 4 are provided on the radially outer side of the carcass ply 2, and a belt reinforcing layer 5 is provided on the radially outer side of the belt 4. The belt 4 is a member made of many steel cords covered with rubber. The belt reinforcing layer 5 is a member made of many organic fiber cords covered with rubber. A tread rubber 6 is provided on the radially outer side of the belt reinforcing layer 5. The tread rubber 6 has many grooves formed therein to form a tread pattern.

[0015] Additionally, sidewall rubber 7 is provided on both axial sides of the carcass ply 2. The tread rubber 6 and the sidewall rubber 7 overlap at the buttress, but either the tread rubber 6 or the sidewall rubber 7 may overlap on the tire surface side. The radially inner portion of the sidewall rubber 7 extends close to the bead 9 and covers part of the rubber chafer 3. In this embodiment, the sidewall 10 refers to not only the portion of the sidewall rubber 7 that appears on the tire surface, but also the entire area that can be seen when the pneumatic tire 1 is viewed from the axial direction of the tire.

[0016] Additionally, a sheet-like inner liner 8 made of rubber with low air permeability is attached to the inside of the carcass ply 2. In addition to these components, components such as an underbelt pad and a chafer are provided as required for the tire's functionality.

[0017] As shown in FIGS. 1 and 2, a decorative region 11 and a band-like region 40 are provided on at least one of the sidewalls 10 on both axial sides of the tire.

[0018] The decorative region 11 is an annular region centered on the tire rotation axis. The decorative region 11 is a region of a constant width sandwiched between a small-diameter circular inner diameter side line 12 and a large-diameter circular outer diameter side line 13. The inner diameter side line 12 and the outer diameter side line 13 may be lines formed by recesses, protrusions, or steps on the tire surface, or may be imaginary lines that do not actually exist. The width HA of the decorative region 11 in the tire radial direction RD is 5% to 60% (preferably 10% to 35%) of the tire cross-sectional height H (the length in the tire radial direction RD from the inner diameter end of the bead core to the outer diameter surface of the pneumatic tire 1).

[0019] The location of the decorative area 11 in the tire radial direction RD is a location that includes the position of the maximum width of the pneumatic tire 1. Here, the position of the maximum width of the pneumatic tire 1 refers to the position where the length in the tire axial direction from the surface of one sidewall 10 on the tire axial side to the surface of the other sidewall 10 on the tire axial side is the longest.

[0020] The decorative region 11 may be provided on the sidewall 10 so as to include a location where a step is likely to appear on the surface of the sidewall 10. The location where a step is likely to appear on the surface of the sidewall 10 is typically a location at the end of a tire constituent member, such as a location where the interface between the tread rubber 6 and the sidewall rubber 7 appears on the tire surface or a location that overlaps with the end of the turned-up portion 2a of the carcass ply 2 in the tire width direction.

[0021] 2, two opposing marking areas 11a each having a mark 16 are provided in the annular decorative area 11. Two opposing patterning areas 11b each having a pattern 30 are provided in the annular decorative area 11 so as to be sandwiched between the two marking areas 11a.

[0022] To ensure sufficient spacing between the adjacent marking region 11a and pattern region 11b, the minimum value of the distance LB between the end of the marking region 11a and the end of the pattern region 11b (the length in the tire circumferential direction CD from the mark 16 provided in the marking region 11a to the end of the pattern 30 provided in the pattern region 11b) is set to 3 mm. Also, to ensure a sufficient area for the pattern 30 provided in the decorative region 11, the maximum value of the distance LB between the marking region 11a and the pattern region 11b is set to 60% of the length LA of the marking region 11a in the tire circumferential direction CD (the distance between the marks 16 provided at both ends of the marking region 11a in the tire circumferential direction).

[0023] In the marking area 11a, one or more marks 16 are formed and aligned in the tire circumferential direction CD. The marks 16 consist of letters, numbers, symbols, figures, etc., and indicate various information such as the tire manufacturer, brand, type, size, etc. These marks 16 that make up the marking area 11a are formed by being bordered by concave or convex lines.

[0024] In the pattern region 11b, a plurality of patterns 30 are formed side by side in the tire circumferential direction CD. As shown in Figures 2 and 3, the pattern 30 is formed by combining a plurality of annular figures 31 of different sizes. Preferably, the pattern 30 is formed by combining five or more annular figures 31.

[0025] Each of the plurality of annular figures 31 constituting the pattern 30 is an annular figure that is longer in the tire circumferential direction CD than in the tire radial direction RD. In this embodiment, the plurality of annular figures 31 are substantially elliptical.

[0026] The ratio of the length in the tire radial direction RD to the length in the tire circumferential direction CD of the plurality of annular figures 31 is preferably 0.5 or more and 0.8 or less. The length in the tire radial direction RD of the largest annular figure 31 among the plurality of annular figures 31 is preferably 50% or more and 95% or less of the width HA of the decorative area 11 in the tire radial direction RD.

[0027] The plurality of annular figures 31 constituting the pattern 30 have a common center P, and are arranged so that the plurality of annular figures 31 surround the smallest annular figure 31 in order at intervals without intersecting with each other.

[0028] Here, the center P of the annular figure 31 coincides with the center of gravity of the surface of the shape drawn by the annular figure 31. However, if the shape drawn by the annular figure 31 is a shape whose center is mathematically defined, the center P of the annular figure 31 will be determined according to that definition.

[0029] When the spacing Kr in the tire radial direction RD and the spacing Kc in the tire circumferential direction CD are compared between adjacent annular figures 31, the spacing Kc in the tire circumferential direction CR is larger than the spacing Kr in the tire radial direction RD.

[0030] Furthermore, when comparing the spacing Kro on the outer side of the center P in the tire radial direction RD with the spacing Kri on the inner side of the center P in the tire radial direction RD for the multiple annular figures 31, the spacing Kro and the spacing Kri may be equal to or different from each other. If the two spacings are different, it is preferable that the spacing Kro on the outer side in the tire radial direction RD is larger than the spacing Kri on the inner side in the tire radial direction RD.

[0031] Here, the interval Kc between adjacent annular figures 31 in the tire circumferential direction CD is the distance from the center P of each annular figure 31 to the farthest point in the tire circumferential direction CD, and if the annular figure 31 is elliptical, it is the distance between points on the major axis. Also, the interval Kr between adjacent annular figures 31 in the tire radial direction RD is the distance from the center P of each annular figure 31 to the farthest point in the tire radial direction RD, and if the annular figure 31 is elliptical, it is the distance between points on the minor axis.

[0032] The interval Kc between adjacent annular figures 31 in the tire circumferential direction CD is preferably 0.2 mm or more and 2.4 mm or less, and the interval Kr between adjacent annular figures 31 in the tire radial direction RD is preferably 0.5 to 0.8 times the interval Kc in the tire circumferential direction CD.

[0033] The intervals Kc between the plurality of annular figures 31 in the tire circumferential direction CD may be gradually increased from the inside to the outside as shown in Fig. 3, or may be equal intervals. The intervals Kr between the plurality of annular figures 31 in the tire radial direction RD may be gradually increased from the inside to the outside as shown in Fig. 3, or may be equal intervals.

[0034] The centers P of the multiple patterns 30 provided in the pattern region 11b are located on a single reference line 21. Here, the reference line 21 is a single line extending in the tire circumferential direction at a specific position in the tire radial direction in the decorative region 11. This reference line 21 is not actually drawn in the decorative region 11 but is a virtual line. The tire radial position of the reference line 21 is preferably the tire radial center position in the decorative region 11. Furthermore, the reference line 21 is preferably a line that describes a circle centered on the tire rotation axis and whose radius is 45% to 65% of the tire cross-sectional height H.

[0035] Each of the multiple annular figures 31 is formed by connecting a series of grooves recessed into the surface of the sidewall or ridges protruding from the surface of the sidewall. When the annular figure 31 is formed from the ridges 20, the cross-sectional shape of the ridges 20 in a direction perpendicular to the longitudinal direction may be a semicircle as shown in FIG. 4, a semicircle with a straight line below it as shown in FIG. 5, a triangle as shown in FIG. 6, a triangle with rounded apexes as shown in FIG. 7, a trapezoid as shown in FIG. 8, or a rectangle as shown in FIG. 9. The triangle with rounded apexes as shown in FIG. 7 is a type of triangle. Although not shown, these cross-sectional shapes may also be slightly modified, such as a sawtooth shape obtained by tilting the triangle in FIG. 6. The line depicted as the annular figure 31 in FIGS. 2 and 3 is the centerline of the ridges 20 in the width direction (the line indicated by T in FIGS. 4 to 9).

[0036] In the ridges 20 having any of the cross-sectional shapes shown in FIGS. 4 to 9, the height H1 of the ridges 20 is 0.1 mm or more and 0.8 mm or less (preferably 0.1 mm or more and 0.4 mm or less). In addition, in the ridges 20 having any of the cross-sectional shapes, the width W1 of the ridges 20 is 0.1 mm or more and 1.0 mm or less. The ridges 20 can be formed using a mold used during vulcanization molding. The ridges 20 can be formed by various processes such as mechanical processing and laser processing. Small ridges 20 having a height H1 of about 0.1 mm to 0.2 mm and a width W1 of about 0.1 mm to 0.2 mm can be formed using a mold in which fine irregularities are formed by laser processing.

[0037] 4 and 5, the length H2 of the straight line of the convex rib 20 having a cross-sectional shape as shown in Fig. 5, which is composed of a semicircle and a straight line, is (height H1 of the convex rib 20) - (radius R of the semicircle). In the convex rib 20 having a trapezoidal cross section as shown in Fig. 8, the length W2 of the upper base is 20% to 50% of the length of the lower base (i.e., width W1 of the convex rib 20).

[0038] In this embodiment, as shown in Fig. 2, a plurality of patterns 30 are provided in the decorative region 11 at intervals in the tire circumferential direction CD. The plurality of patterns 30 are preferably arranged such that one pattern 30 is positioned opposite another pattern 30 across the tire rotation axis.

[0039] The band-shaped region 40 is an annular region provided adjacent to the outer periphery of the decorative region 11. The band-shaped region 40 is provided with a plurality of ridges 41 protruding from the outer surface of the sidewall 10. In one embodiment, the plurality of ridges 41 are equally spaced apart in the tire circumferential direction CD at intervals of 0.3 to 1.0 mm. The band-shaped region 40 may be provided in a portion of the tire circumferential direction CD, but in this example, it is provided over the entire circumference in the tire circumferential direction CD. Therefore, the band-shaped region 40 is formed in an annular shape adjacent to the outside of the decorative region 11 and surrounding it over the entire circumference. The dimension HC of the band-shaped region 40 in the tire radial direction RD (see FIG. 1) is preferably 5 mm to 12 mm.

[0040] By providing such a band-like region 40, it is possible to suppress unevenness and bareness at the interface between the tread rubber 6 and the sidewall 10. In addition, the provision of the ridges 41 has a light attenuation effect, resulting in the formation of a black band-like region 40, which makes the decorative region 11 stand out.

[0041] Similar to the decorative region 11, such a band-like region 40 may be provided on the sidewall 10 so as to include locations where steps are likely to appear on the surface of the sidewall 10, such as locations where the interface between the tread rubber 6 and the sidewall rubber 7 appears on the tire surface, and locations of the ends of tire constituent members, such as locations overlapping in the tire width direction with the ends of the turned-up portion 2a of the carcass ply 2 and locations overlapping in the tire width direction with the ends of the belt 4. A parting line 42, which is a dividing line between the tread mold and the sidewall mold in the tire mold, may be formed at the boundary portion of the band-like region 40 on the outer side in the tire radial direction.

[0042] The pneumatic tire 1 of this embodiment has a pattern 30 on the sidewall 10, in which a plurality of annular figures 31 are arranged with a common center and spaced apart in the tire circumferential direction and the tire radial direction so that the spacing in the tire circumferential direction is greater than the spacing in the tire radial direction. Therefore, compared to when adjacent annular figures 31 are arranged at equal intervals in the tire radial direction RD and the tire circumferential direction CD, it is possible to create a visual effect with a sense of depth while suppressing blurring.

[0043] (Example of change) The above-described embodiments are presented as examples and are not intended to limit the scope of the invention. This novel embodiment can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention.

[0044] For example, the shape of the plurality of annular figures 31 is not limited to the approximately elliptical shape of the above embodiment. Any annular shape may be used as long as it is longer in the tire circumferential direction CD than in the tire radial direction RD when viewed from a direction perpendicular to the surface of the sidewall 10. Among such annular shapes, a shape called an oval is preferred. An oval is a closed annular shape consisting mainly of curves (for example, more than half of the total length of the lines forming the outline of the annular shape 31 are curves). In addition to the elliptical shape of the above embodiment, ovals also include ovals, perfect circles, egg shapes, etc. In addition, ovals also include a closed curve formed by the intersection of the surface of a cone with a plane that completely crosses the cone.

[0045] Furthermore, when a large number of annular figures 31 are provided in one pattern 30, some of the larger annular figures 31b may not fit within the decorative area 11 and may be cut off, as shown in Figure 14. In such a case, it is preferable to provide a large number of annular figures 31 in one pattern 30 so that five or more annular figures 31 fit within the decorative area 11.

[0046] Furthermore, in the above embodiment, two pattern regions 11b are provided for one sidewall 10, but one or three or more pattern regions 11b may be provided for one sidewall 10.

[0047] Furthermore, in the above embodiment, four patterns 30 are provided in one pattern region 11b, but any number of patterns 30 may be provided in one pattern region 11b.

[0048] The above dimensions in this specification are those in a normal, unloaded state with a pneumatic tire mounted on a normal rim and inflated to the normal internal pressure. A normal rim is a "standard rim" in the JATMA standard, and a "measuring rim" in the TRA and ETRTO standards. The normal internal pressure is the "maximum air pressure" in the JATMA standard, the "maximum value" listed in the "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES" section of the TRA standard, or the "INFLATION PRESSURE" in the ETRTO standard. However, for passenger car tires, the normal pressure is usually 180 kPa, but for tires labeled "Extra Load" or "Reinforced," the normal pressure is 220 kPa.

[0049] The various numerical ranges described in this specification can be arbitrarily combined with their upper and lower limits, and all such combinations are considered to be preferred numerical ranges described in this specification. Furthermore, a numerical range described as "X to Y" means from X to Y. [Explanation of symbols]

[0050] 1...pneumatic tire, 4...belt, 6...tread rubber, 7...sidewall rubber, 9...bead, 10...sidewall, 11...decorative area, 11a...mark area, 11b...pattern area, 12...inner diameter side line, 13...outer diameter side line, 16...mark, reference line...21, 30...pattern, 31...annular figure, P...center

Claims

1. In a pneumatic tire having a pattern on the surface of the sidewall, The pattern has a plurality of annular figures that are longer in the tire circumferential direction than in the tire radial direction, The pneumatic tire has a plurality of annular figures that are different in size, have a common center, and are arranged with a gap between smaller annular figures on the outside so that the gap between the larger annular figures is larger in the tire circumferential direction than in the tire radial direction.

2. 2. The pneumatic tire of claim 1, wherein said annular shape is an oval shape.

3. 3. The pneumatic tire according to claim 1, wherein a ratio of a length in a radial direction of the tire to a length in a circumferential direction of the annular figure is 0.5 or more and 0.8 or less.

4. The plurality of annular figures are formed of grooves recessed into a surface of the sidewall or ridges protruding from a surface of the sidewall, The pneumatic tire according to any one of claims 1 to 3, wherein the cross-sectional shape of the plurality of annular figures is a triangle, a trapezoid, or a semicircle.

5. The pneumatic tire according to any one of claims 1 to 4, wherein the interval between adjacent annular figures on the outer side in the tire radial direction is greater than the interval between adjacent annular figures on the inner side in the tire radial direction.

6. The pneumatic tire according to any one of claims 1 to 5, wherein a region is provided in the sidewall, radially outward of the decorative region in which the annular figure is provided, in which a plurality of ridges extending in the tire radial direction are arranged at equal intervals in the tire circumferential direction, the region having a dimension in the tire radial direction of 5 mm or more and 12 mm or less.

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