JP7705306B2 - Pneumatic tires - Google Patents

Description

The present invention relates to a pneumatic tire.

A pneumatic tire is known that has a pattern on the sidewall surface formed by lining up multiple ridges that extend along the tire surface.

Many of the conventional patterns on the surface of the sidewall are made up of numerous linear ridges arranged at equal intervals. As disclosed in Patent Document 1, patterns with curved ridges arranged at equal intervals are also known. Either pattern enhances the design of the sidewall.

JP 2014-180947 A

Although various patterns have been proposed to date, there is a demand for groundbreaking patterns that will produce unprecedented visual effects.

Therefore, the objective of the present invention is to provide a pneumatic tire that creates a visual effect.

The pneumatic tire of this embodiment is characterized in that, in a pneumatic tire having a pattern on the surface of the sidewall, the pattern has a plurality of annular figures having the same length of a first axis and different lengths of a second axis perpendicular to the first axis, and the plurality of annular figures are arranged so that the second axes coincide with each other and the annular figures are arranged so that the annular figures become gradually larger from the smallest annular figure to one side of the second axis.

By incorporating the above features, the present invention can produce a distinctive, three-dimensional visual effect.

Axial half cross-section of a pneumatic tire FIG. 2 is a view of the pneumatic tire of FIG. 1 from the tire axial direction. Enlarge the pattern Cross-sectional view of a convex strip forming a ring shape Cross-sectional view of a convex strip forming a ring shape Cross-sectional view of a convex strip forming a ring shape Cross-sectional view of a convex strip forming a ring shape Cross-sectional view of a convex strip forming a ring shape Cross-sectional view of a convex strip forming a ring shape FIG. 1 is a diagram showing a modified pneumatic tire viewed from the tire axial direction. FIG. 1 is a diagram showing a modified pneumatic tire viewed from the tire axial direction. FIG. 1 is a diagram showing a modified pneumatic tire viewed from the tire axial direction. Enlarged image of the modified pneumatic tire pattern

One embodiment of the present invention will be described below with reference to the drawings.

The pneumatic tire 1 of the embodiment has a structure similar to that of a typical radial tire, except for the sidewall structure. 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.

In the pneumatic tire 1, beads 9 are provided on both sides of the tire in the axial direction. The beads 9 consist of a bead core made of a steel wire wound in a circle and a rubber bead filler provided on the radial outside of the bead core.

One or two carcass plies 2 are stretched across the beads 9 on both sides in the axial direction of the tire. 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 in the axial direction of the tire, and wraps the beads 9 by folding back and rolling up around the beads 9 from the inside to the outside in the axial direction of the tire. In addition, a rubber chafer 3 is provided at the axially outer location of the folded back portion 2a of the carcass ply 2.

In addition, 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. Tread rubber 6 is provided on the radially outer side of the belt reinforcing layer 5. The tread rubber 6 has many grooves to form a tread pattern.

In addition, sidewall rubber 7 is provided on both sides of the carcass ply 2 in the tire axial direction. The tread rubber 6 and the sidewall rubber 7 overlap at the buttresses, 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 tire axial direction.

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, other components such as underbelt pads and chafers are provided according to the functional needs of the tire.

As shown in Figures 1 and 2, a decorative area 11 and a band-shaped area 40 are provided on at least one of the sidewalls 10 on both sides in the tire axial direction.

The decorative area 11 is an annular area centered on the tire rotation axis. The decorative area 11 is an area 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 concavities, convexities, or steps on the tire surface, or may be imaginary lines that do not actually exist. The width HA of the decorative area 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).

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 in the tire axial direction to the surface of the other sidewall 10 in the tire axial direction is the longest.

The decorative area 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 the location of the end of a tire component, 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 tip of the folded-up portion 2a of the carcass ply 2 in the tire width direction.

As shown in FIG. 2, two opposing locations of the annular decorative area 11 are provided with mark areas 11a in which a mark 16 is formed. Also, two opposing locations of the annular decorative area 11 are provided with pattern areas 11b in which a pattern 30 is formed, sandwiched between the two mark areas 11a.

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

In the marking area 11a, one or more marks 16 are formed in a line in the tire circumferential direction CD. The marks 16 are made up of letters, numbers, symbols, figures, etc., and indicate various information such as the tire manufacturer, brand, variety, and size. These marks 16 that make up the marking area 11a are formed with a border of concave or convex lines.

In the pattern region 11b, a plurality of patterns 30 are formed in a line 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.

As shown in FIG. 3, the multiple annular figures 31 that make up the pattern 30 are annular figures with the same length of the first axis L1 and different lengths of the second axis L2 perpendicular to the first axis L1. The multiple annular figures 31 are arranged so that their second axes L2 coincide with each other and the annular figures 31 become gradually larger from the smallest annular figure 31a to one side L2a of the second axis L2.

As a result, a spaced portion 33 is formed on one side L2a of the second axis L2 of the pattern 30, in which multiple annular figures 31 are spaced apart. The multiple annular figures 31 may be arranged at equal intervals in the spaced portion 33, or may be arranged such that the spacing between the annular figures 31 gradually increases the closer they are to the one side L2a of the second axis L2 in the spaced portion 33.

The multiple annular figures 31 may be arranged such that the first axis L1 faces the tire radial direction RD and the second axis L2 faces the tire circumferential direction CD. The multiple annular figures 31 may be elliptical, with the first axis L1 being one of the major and minor axes of the ellipse and the second axis L2 being the other of the major and minor axes.

In the multiple annular figures 31, the ratio of the length of the second axis L2 to the length of the first axis L1 is preferably 0.5 or more and 2.0 or less. In other words, the length of the second axis L2 of the smallest annular figure 31a is preferably 0.5 times or more the length L1 of the first axis L1, and the length of the second axis L2 of the largest annular figure 31b is preferably 2.0 times or less the length of the first axis L1.

It is preferable that the length in the tire radial direction RD of the largest annular figure 31b among the multiple annular figures 31 (in this embodiment, the length of the first axis L1) is 50% or more and 95% or less of the width HA in the tire radial direction RD of the decorative area 11.

The multiple annular figures 31 may be arranged to form overlapping portions 32 on the other side L2b of the second axis L2 as shown in FIG. 3, or may be arranged to form adjacent portions 36 spaced apart on the other side L2b of the second axis L2 as shown in FIG. 13.

When forming the adjacent portion 36, the interval K1 in the second axis L2 direction of the annular figures 31 in the adjacent portion 36 is narrower than the interval K2 in the second axis L2 direction of the annular figures 31 in the separated portion 33. When forming the adjacent portion 36, the multiple annular figures 31 may be arranged so as to be equally spaced in the adjacent portion 36, or may be arranged so that the intervals in the adjacent portion 36 gradually increase toward one side L2a of the second axis L2. It is preferable that the interval K1 in the second axis L2 direction of the annular figures 31 in the adjacent portion 36 is 0.4 to 0.6 times the interval K2 in the second axis L2 direction of the annular figures 31 in the separated portion 33.

Each of the multiple ring-shaped figures 31 is formed by connecting a groove recessed into the surface of the sidewall or a ridge protruding from the surface of the sidewall in a ring shape. When the ring-shaped figure 31 is formed from the ridge 20, the cross-sectional shape in the direction perpendicular to the longitudinal direction of the ridge 20 can be a semicircle as shown in FIG. 4, a shape consisting of a semicircle and 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. Here, the triangle with rounded apexes as shown in FIG. 7 is a type of triangle. Although not shown, there may also be shapes that are slightly modified from these cross-sectional shapes, such as a sawtooth shape that is modified by tilting the triangle in FIG. 6. The line drawn as the ring-shaped figure 31 in FIG. 2 and FIG. 3 is the center line of the ridge 20 in the width direction (the line at the position indicated by T in FIG. 4 to FIG. 9).

In any of the cross-sectional shapes of the convex ribs 20 in Figures 4 to 9, the height H1 of the convex ribs 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 any of the cross-sectional shapes of the convex ribs 20, the width W1 of the convex ribs 20 is 0.1 mm or more and 1.0 mm or less. The convex ribs 20 can be formed by a mold used during vulcanization molding. The convex ribs 20 can be formed by various processes such as mechanical processing and laser processing. Small convex ribs 20 with 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 by a mold in which fine irregularities are formed by laser processing.

If the radius of the semicircle in Figures 4 and 5 is R, then the length H2 of the straight line of the convex rib 20 having a cross-sectional shape as shown in Figure 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 Figure 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).

In this embodiment, as shown in FIG. 2, multiple patterns 30 are provided in the decorative area 11 at intervals in the tire circumferential direction CD. It is preferable that the multiple patterns 30 are arranged so that other patterns 30 are located at positions opposite each other across the tire rotation axis.

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 of the tire circumferential direction CD. Therefore, the band-shaped region 40 is formed in a ring shape adjacent to the outside of the decorative region 11 and surrounding it over the entire circumference. The dimension HC (see FIG. 1) of the band-shaped region 40 in the tire radial direction RD is preferably 5 mm to 12 mm.

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 black band-like region 40 is formed by the light attenuation effect caused by providing the protruding stripes 41, making the decorative region 11 stand out.

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, locations where the end of the folded-back portion 2a of the carcass ply 2 overlaps in the tire width direction, locations where the end of the belt 4 overlaps in the tire width direction, and other tire component ends. 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 on the outer side of the tire radial direction of the band-like region 40.

In the pneumatic tire 1 of this embodiment, the pattern 30 on the sidewall 10 is configured by arranging a number of annular figures 31 so that the second axis L2 is aligned with each other and the annular figures 31 gradually become larger from the smallest annular figure 31a to one side L2a of the second axis L2. Therefore, the pattern 30 exerts a distinctive visual effect with a three-dimensional feel reminiscent of a curved bellows.

In addition, if an overlapping portion 32 is provided on the other side L2b of the second axis L2 of the pattern 30, in which multiple annular figures 31 are arranged so as to overlap each other, the three-dimensional effect of the pattern 30 can be emphasized.

In addition, when the pattern 30 has a proximal portion 36 on the other side L2b of the second axis L2 where multiple annular figures 31 are spaced apart, the multiple annular figures 31 are not too close to each other, and the proximal portion 36 can be easily molded into the desired uneven shape by vulcanization molding of the tire.

(Example of change)
The above-described embodiment is presented as an example and is not intended to limit the scope of the invention. This novel embodiment can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention.

For example, the shape of the multiple annular figures 31 is not limited to the approximately elliptical shape of the above embodiment.
Any ring-shaped figure 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 ring-shaped figures, a preferred shape is a shape called an oval. An oval is a closed ring-shaped shape that is mainly composed of curves (for example, more than half of the total length of the lines forming the outline of the ring-shaped figure 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 closed curves formed by the intersection of the surface of a cone with a plane that completely crosses the cone.

In addition, in the above embodiment, all of the patterns 30 are provided on the surface of the sidewall 10 so that the separation portions 33 are located on one side of the tire circumferential direction CD, but various arrangements of the separation portions 33 are possible.

For example, as shown in FIG. 10, the pattern 30 may be arranged so that the separated portion 33 faces one of the marking areas 11a (the marking area 11a on the left side in FIG. 10), or as shown in FIG. 11, the pattern 30 may be arranged so that the separated portion 33 faces the adjacent marking area 11a. Also, as shown in FIG. 12, the pattern 30 may be arranged so that the overlapping portion 32 faces away from the adjacent marking area 11a.

In addition, 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.

In addition, in the above embodiment, four patterns 30 are provided in one pattern area 11b, but any number of patterns 30 may be provided in one pattern area 11b.

The above dimensions in this specification are for a pneumatic tire mounted on a standard rim and inflated to the standard internal pressure under normal load. A standard rim is a "standard rim" in the JATMA standard, and a "Measuring Rim" in the TRA and ETRTO standards. A standard 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" in the TRA standard, or the "INFLATION PRESSURE" in the ETRTO standard. However, for passenger car tires, the standard is usually 180 kPa, but for tires labeled "Extra Load" or "Reinforced," the standard is 220 kPa.

The various numerical ranges described in the 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. In addition, a numerical range described as "X to Y" means greater than or equal to X and less than or equal to Y.

1...pneumatic tire, 4...belt, 6...tread rubber, 7...sidewall rubber, 9...bead, 10...sidewall, 11...decorative area, 11a...marking area, 11b...pattern area, 12...inner diameter side line, 13...outer diameter side line, 16...marking, 30...pattern, 31...ring shape, 32...overlapping portion, 33...separated portion, 36...adjacent portion, L1...first axis, L2...second axis

Claims (6)

In a pneumatic tire having a pattern on the surface of the sidewall,
The pattern has five or more annular figures having first axes each having the same length in a tire radial direction and second axes each having different lengths in a tire circumferential direction perpendicular to the first axis,
The multiple annular figures are figures formed by connecting in a ring shape recessed grooves that are recessed into the surface of the sidewall or protruding ridges that protrude from the surface of the sidewall, and are arranged in a row so that the second axis is coincident with each other and the lengths of the annular figures along the second axis gradually increase from the smallest annular figure to one side of the second axis . The pneumatic tire according to claim 1, wherein the multiple annular figures overlap on the other side of the second axis. 2. The pneumatic tire of claim 1, wherein a plurality of said annular figures are overlapping and spaced apart on the other side of said second axis. The pneumatic tire according to any one of claims 1 to 3, wherein the ratio of the length of the second axis of the annular figure to the length of the first axis is 0.5 or more and 2.0 or less. 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 4, wherein the cross-sectional shape of the plurality of annular figures is a triangle, a trapezoid, or a semicircle. The pneumatic tire according to any one of claims 1 to 5, wherein the sidewall is provided with an area in which a plurality of ridges extending in the tire radial direction are arranged at equal intervals in the tire circumferential direction, the area having a dimension in the tire radial direction of 5 mm to 12 mm, radially outward of the decorative area in which the annular figure is provided.

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