阅读说明：本技术 充气轮胎 (Pneumatic tire ) 是由 新泽达朗 石黑和也 于 2018-12-14 设计创作，主要内容包括：充气轮胎的侧壁部的表面具备：凸脊花纹区域,在一个方向连续延伸的多个凸脊隔开间隔而设置；非凸脊花纹区域,不设有所述凸脊,由平滑面构成；以及二维码,由通过表面的凹凸形成为能相互识别的两种浓淡要素形成点图案。二维码以所述二维码的整个与所述凸脊花纹区域重合的方式刻印,或者,以所述二维码与所述凸脊花纹区域和所述非凸脊花纹区域重合的方式刻印。(The surface of the sidewall of the pneumatic tire is provided with: a raised ridge pattern region in which a plurality of raised ridges continuously extending in one direction are provided at intervals; the non-convex ridge pattern area is not provided with the convex ridge and consists of a smooth surface; and a two-dimensional code in which dot patterns are formed by two types of shading elements that can be recognized from each other by the surface irregularities. The two-dimensional code is engraved in a manner that the whole two-dimensional code coincides with the raised ridge pattern area, or in a manner that the two-dimensional code coincides with the raised ridge pattern area and the non-raised ridge pattern area.)

1. A pneumatic tire, characterized by comprising:

a pair of side wall portions provided so as to sandwich a tread portion extending annularly in a tire circumferential direction from both sides in a tire width direction,

at least one surface of the side wall portion includes: a raised ridge pattern region in which a plurality of raised ridges continuously extending in one direction are provided at intervals; the non-convex ridge pattern area is not provided with the convex ridge and consists of a smooth surface; and a two-dimensional code in which dot patterns are formed by two types of shading elements that can be recognized from each other by the surface irregularities,

the two-dimensional code is engraved in a way that the whole area of the two-dimensional code coincides with the raised ridge pattern area, or in a way that the area of the two-dimensional code coincides with the raised ridge pattern area and the non-raised ridge pattern area.

2. The pneumatic tire of claim 1,

the two-dimensional code includes dot-shaped holes constituting the dot pattern, and the bottom of each dot-shaped hole is located on a side recessed from the surface of the side wall portion with respect to the bottom of the valley between the ridges.

3. The pneumatic tire of claim 2,

the hole bottom has a hole depth d deeper than a valley depth ds of the valley bottom, and the hole depth d-the valley depth ds is 0.3mm or more.

4. The pneumatic tire according to any one of claims 1 to 3,

the length p of one side of the unit cell region in the dot pattern of the two-dimensional code is shorter than the interval Ps between the adjacent ridges in the ridge pattern region.

5. The pneumatic tire according to any one of claims 1 to 4,

in a portion where the two-dimensional code region overlaps the raised ridge pattern region, the interval between the adjacent raised ridges of the raised ridge pattern region is fixed.

6. The pneumatic tire according to any one of claims 1 to 5,

in a portion where the two-dimensional code region overlaps the ridge pattern region, the valley depth of the valley between adjacent ridges of the ridge pattern region is fixed.

7. The pneumatic tire according to any one of claims 1 to 6,

in a part where the area of the two-dimensional code coincides with the raised ridge pattern area, the extending direction of the raised ridge is the same at any position.

8. The pneumatic tire according to any one of claims 1 to 7,

the valley depth of valleys between adjacent ridges of the ridge pattern region in a portion where the two-dimensional code region overlaps the ridge pattern region is shallower than the valley depth of valleys between adjacent ridges in a portion of the ridge pattern region that surrounds the two-dimensional code region and is in contact with the two-dimensional code region.

9. The pneumatic tire according to any one of claims 1 to 8,

the two-dimensional code includes a dot pattern region of a rectangular shape in which a dot pattern is formed by the two kinds of gradation elements, a blank region is provided around the dot pattern region, the blank region is surrounded by an element lighter than the gradation element among the gradation elements, a thickness of the blank region surrounding the dot pattern region is 10% to 25% of a maximum size among sizes in two orthogonal directions in the rectangular shape of the dot pattern region,

at least a portion of the void region is configured to coincide with the raised ridge land region.

10. The pneumatic tire according to any one of claims 1 to 8,

the two-dimensional code includes a dot pattern region of a rectangular shape in which a dot pattern is formed by the two kinds of gradation elements, a blank region is provided around the dot pattern region, the blank region is surrounded by an element lighter than the gradation element among the gradation elements, a thickness of the blank region surrounding the dot pattern region is 10% to 25% of a maximum size among sizes in two orthogonal directions in the rectangular shape of the dot pattern region,

the blank area is a smooth surface without the ridges.

11. The pneumatic tire according to any one of claims 1 to 10,

the two-dimensional code is provided on the sidewall portions on both sides of the pneumatic tire in the tire width direction.

Technical Field

The present invention relates to a pneumatic tire, and more particularly, to a pneumatic tire provided with a two-dimensional code imprinted on a sidewall of the tire.

Background

In recent years, it has been proposed to provide a two-dimensional code as an identification code of recorded information on a sidewall portion of a tire. The two-dimensional code can contain more information than the one-dimensional code, so that various kinds of information can be contained in the two-dimensional code to manage the tire. In particular, it has been proposed to provide a two-dimensional code on a sidewall of a tire by imprinting a predetermined dot pattern on the sidewall of the tire (patent document 1).

The two-dimensional code formed by engraving a predetermined dot-shaped hole pattern in the sidewall of the tire does not disappear unless the tire sidewall is worn, and therefore, the tire management can be performed efficiently.

Disclosure of Invention

Problems to be solved by the invention

In the pneumatic tire having a plurality of dot-shaped holes formed by imprinting the two-dimensional code, the two-dimensional code can be sufficiently read when the tire is new, but the two-dimensional code may be read when the tire is rotated while being loaded with a load in an outdoor environment. The reading of the two-dimensional code means reading of the two-dimensional code by a two-dimensional code reader such as a portable terminal, and the reduction of the reading means that the reading fails in many cases. Since the two-dimensional code provided on the pneumatic tire reads and effectively utilizes information recorded on the two-dimensional code during use of the pneumatic tire, it is not preferable that the two-dimensional code has a reduced readability because unevenness is generated on the surface of the two-dimensional code due to generation and spread of cracks in the dot-shaped holes during long-term use of the tire, and it is difficult to distinguish between shade elements. Therefore, it is preferable to suppress a decrease in the readability of the two-dimensional code when the tire is used for a long period of time.

Further, since the dot-shaped hole has a shape recessed substantially perpendicularly from the surface of the sidewall portion, the dot-shaped hole is cracked with use of the tire, and the crack progresses further along the surface of the sidewall portion in the depth direction of the sidewall rubber, which is not preferable from the viewpoint of the durability of the sidewall rubber, and further, the durability of the pneumatic tire.

Accordingly, an object of the present invention is to provide a pneumatic tire engraved with a two-dimensional code, which can suppress a reduction in the readability of the two-dimensional code even when the pneumatic tire is used for a long period of time.

Technical scheme

One aspect of the present invention is a pneumatic tire including:

a pair of side wall portions provided so as to sandwich a tread portion extending annularly in a tire circumferential direction from both sides in a tire width direction,

at least one surface of the side wall portion includes:

a raised ridge pattern region in which a plurality of raised ridges continuously extending in one direction are provided at intervals; the non-convex ridge pattern area is not provided with the convex ridge and consists of a smooth surface; and a two-dimensional code in which dot patterns are formed by two types of shading elements that can be recognized from each other by the surface irregularities.

The two-dimensional code is engraved in a manner that all areas of the two-dimensional code coincide with the raised ridge pattern areas, or in a manner that the areas of the two-dimensional code coincide with the raised ridge pattern areas and the non-raised ridge pattern areas.

Preferably, the two-dimensional code includes dot-shaped holes constituting the dot pattern, and a bottom of each of the dot-shaped holes is located on a side recessed from a surface of the side wall portion with respect to a bottom of a valley portion between the ridges.

Preferably, the hole bottom has a hole depth d deeper than a valley depth ds of the valley bottom, and the hole depth d-valley depth ds is 0.3mm or more.

Preferably, a length p of one side of a unit cell region in the dot pattern of the two-dimensional code is shorter than a distance Ps between adjacent ridges in the raised ridge pattern region.

Preferably, in a portion where the two-dimensional code region overlaps the raised ridge pattern region, the interval between adjacent raised ridges of the raised ridge pattern region is fixed.

Preferably, in a portion where the two-dimensional code region overlaps the ridge pattern region, a valley depth of a valley between adjacent ridges of the ridge pattern region is fixed.

Preferably, in a portion where the two-dimensional code region overlaps the raised ridge pattern region, the extending direction of the raised ridge is the same at any position.

In the region of the two-dimensional code that overlaps the ridge pattern region, the valley depth of the valleys between adjacent ridges of the ridge pattern region is preferably shallower than the valley depth of the valleys between adjacent ridges of the ridge pattern region that surrounds the two-dimensional code and is in contact with the two-dimensional code region.

Preferably, the two-dimensional code includes a rectangular dot pattern region in which dot patterns are formed by the two kinds of gradation elements, a blank region is provided around the dot pattern region, the blank region is surrounded by a lighter-than-dense element of the gradation elements, a thickness of the blank region surrounding the dot pattern region is 10% to 25% of a maximum size among sizes in two orthogonal directions in the rectangular shape of the dot pattern region,

at least a portion of the void region is configured to coincide with the raised ridge land region.

It is also preferable that the two-dimensional code includes a dot pattern region of a rectangular shape in which a dot pattern is formed by the two kinds of gradation elements, a blank region is provided around the dot pattern region, the blank region is surrounded by an element lighter than the gradation elements, the thickness of the blank region surrounding the dot pattern region is 10% to 25% of the largest size among the sizes in two orthogonal directions in the rectangular shape of the dot pattern region,

the blank area is a smooth surface without the raised ridge.

Preferably, the two-dimensional codes are provided on side wall portions on both sides of the pneumatic tire in the tire width direction.

Effects of the invention

According to the pneumatic tire, the deterioration of the readability of the two-dimensional code can be suppressed even if the pneumatic tire is used for a long period of time.

Drawings

Fig. 1 is a diagram showing an example of a configuration of a pneumatic tire according to an embodiment.

Fig. 2 is a diagram showing an example of a sidewall pattern provided in a sidewall portion of a tire according to an embodiment.

Fig. 3 is an enlarged view of a portion of the sidewall pattern shown in fig. 2.

Fig. 4 is a photograph showing an example of a QR code (registered trademark) imprinted on the raised ridge pattern region according to the embodiment.

Fig. 5(a) and 5(b) are schematic diagrams illustrating the surface irregularities of the ridge pattern region and the surface irregularities of the two-dimensional code.

Detailed Description

The pneumatic tire of the present embodiment will be described in detail below.

In this specification, the tire width direction is a direction parallel to the rotation axis of the pneumatic tire, the tire width direction outer side is a side distant from a tire equator line C L (see fig. 1) indicating a tire equator plane in the tire width direction, the tire width direction inner side is a side close to the tire equator line C L in the tire width direction, the tire circumferential direction is a direction rotating with the rotation axis of the pneumatic tire as the center of rotation, the tire radial direction is a direction orthogonal to the rotation axis of the pneumatic tire, the tire radial direction outer side is a side distant from the rotation axis, and the tire radial direction inner side is a side close to the rotation axis.

In the embodiments described below, the side wall portion is imprinted with a two-dimensional code. The imprint referred to in the present embodiment is a method of forming a two-dimensional code by providing unevenness on a sidewall rubber member by another method, in addition to a method of forming a plurality of fine dot-shaped holes on the surface by locally heat-ablating the sidewall rubber member by concentrating the energy of laser light on the surface of the sidewall.

The two-dimensional code referred to in the present embodiment is a code of a matrix display system having information only in the horizontal direction (barcode, information in both directions), and examples of the two-dimensional code include a QR code (registered trademark), a data matrix (registered trademark), a Maxi code, PDF-417 (registered trademark), a 16K code (registered trademark), a 49 code (registered trademark), an Aztec code (registered trademark), an SP code (registered trademark), a veri code (registered trademark), and a CP code (registered trademark).

(pneumatic tires)

Fig. 1 is a diagram showing an example of the configuration of a pneumatic tire 10 (hereinafter, simply referred to as a tire 10) according to the present embodiment, and fig. 1 shows a profile cross section on one side in the tire width direction with respect to a tire equator line C L.

The tire 10 includes: a tread portion 10T having a tread pattern, a pair of bead portions 10B on both sides in the tire width direction, and a pair of sidewall portions 10S provided on both sides of the tread portion 10T and connected to the pair of bead portions 10B and the tread portion 10T. The tread portion 10T is a portion that contacts the road surface. The side wall portion 10S is a portion provided to sandwich the tread portion 10T from both sides in the tire width direction. The bead portion 10B is a portion connected to the sidewall portion 10S and located on the inner side in the tire radial direction with respect to the sidewall portion 10S.

The tire 10 has cords 12, belts 14, and bead cores 16 as frame members, and mainly includes, around these frame members: a tread rubber member 18, a sidewall rubber member 20, a bead filler rubber member 22, a rim cushion rubber member 24, and an inner liner rubber member 26.

The carcass layer 12 is made of a carcass material wound between a pair of annular bead cores 16 to form a toroidal shape and coated with rubber and organic fibers. The ply 12 is wound around the bead core 16 and extends radially outward of the tire. A belt 14 composed of two belt materials 14a, 14b is provided on the tire radial direction outer side of the ply 12. The belt 14 is formed by covering a steel cord disposed at a predetermined angle, for example, 20 to 30 degrees, with rubber, and the width of the belt material 14a in the lower layer in the tire width direction is longer than the width of the belt material 14b in the upper layer in the tire width direction. The inclination directions of the steel cords of the two belt materials 14a, 14b are opposite to each other. Therefore, the belt materials 14a and 14b become alternate layers, and the expansion of the ply layer 12 due to the filled air pressure is suppressed.

A tread rubber member 18 is provided on the outer side of the belt 14 in the tire radial direction, and sidewall rubber members 20 are connected to both ends of the tread rubber member 18 to form a sidewall 10S. A rim cushion rubber member 24 is provided at the tire radial direction inner end of the side wall rubber member 20, and contacts the rim to which the tire 10 is attached. On the outer side of the bead core 16 in the tire radial direction, a bead filler member 22 is provided so as to be sandwiched between the portion of the ply 12 before being wound around the bead core 16 and the portion of the ply 12 after being wound around the bead core 16. An inner liner rubber member 26 is provided on the inner surface of the tire 10 facing the air-filled tire cavity region surrounded by the tire 10 and the rim.

In addition, a three-layer belt cover layer 30 that covers the belt 14 from the tire radial direction outer side of the belt 14 and is coated with rubber and organic fibers is provided between the belt material 14b and the tread rubber member 18. The belt cover 30 may be provided as needed, and is not essential. The number of the belt cover layers 30 is not limited to three, and may be one or two.

The two-dimensional code 40 is provided on the surface of the sidewall 10S of the tire 10.

(sidewall pattern)

Fig. 2 is a diagram showing an example of a sidewall pattern provided in the sidewall portion 10S of the tire 10 according to the embodiment. Fig. 3 is an enlarged view of a portion of the sidewall pattern shown in fig. 2.

As shown in fig. 2, a sidewall pattern is formed on the surface of the sidewall portion 10S. The sidewall pattern includes primarily raised ridge pattern areas and non-raised ridge pattern areas. In fig. 2, a two-dimensional code engraved on the surface of the side wall portion 10S, which will be described later, is not shown.

The raised ridge pattern region includes: a background ridge area 52, a first band-shaped ridge area 53, a second band-shaped ridge area 54 and a stamp display area 57. The non-raised land areas include smooth surface areas (non-raised land areas) 56.

The background ridge region 52 is a region in which a plurality of ridges continuously extending in one direction are provided at predetermined intervals, and functions as a background for making the first band-shaped ridge region 53 and the second band-shaped ridge region 54 conspicuous.

The first band-shaped ridge region 53 and the second band-shaped ridge region 54 are band-shaped regions in which a plurality of ridges continuously extending in one direction are provided at prescribed intervals, and these regions are displaced in the tire radial direction when moving in the tire circumferential direction. Thereby, the belt exhibits a pattern that fluctuates like a wave on the side wall portion 10S.

The types of ridges of the background ridge region 52, the first band-shaped ridge region 53 and the second band-shaped ridge region 54 are different so as to be visually distinguishable from each other. The difference in the kind of the ridges means that at least one of the valley depth from the ridge to the valley bottom between the adjacent ridges, the distance between the adjacent ridges, and the extending direction of the ridge is different.

The second band-shaped ridge region 54 is configured to split into two, or to merge, as shown in fig. 3. In fig. 3, the ridges are represented by lines, and in the example shown in fig. 3, the distance between the ridges of the first band-shaped ridge region 53 is the largest in the order of the background ridge region 52, the second band-shaped ridge region 54, and the first band-shaped ridge region 53 in the order of the distance between the adjacent ridges from small to large. The direction of extension of the ridges also differs from each other in the background ridge area 52, the first band-shaped ridge area 53 and the second band-shaped ridge area 54.

The stamp display area 57 is provided to be surrounded by the smooth surface area 56, and displays a stamp as shown in fig. 2. A ridge extending in one direction is provided inside the stamp display area 57 so as to be recognizable with the smooth surface area 56.

The smooth surface area 56 has no ridges, forming a smooth surface.

The two-dimensional code 40 is provided on such a sidewall pattern.

(two-dimensional code)

As shown in fig. 3, the two-dimensional code 40 is imprinted on the background land area 52. Such a two-dimensional code 40 is formed on the surface of the sidewall rubber member 20 of both the sidewall portions 10S located on both sides in the tire width direction. According to another embodiment, the sidewall rubber member 20 is formed on the surface of either one of the sidewall portions 10S.

The two-dimensional code 40 is formed in a dot pattern of two types of shading elements formed so as to be distinguishable from each other by the unevenness of the surface. The two-dimensional code 40 of the present embodiment is a pattern formed by converging laser light on the surface of the sidewall portion 10S to concentrate energy, locally heat-ablating the sidewall rubber member 20, and imprinting a plurality of fine dot-shaped holes 40a (see fig. 5(b)) on the surface. The dot-like holes 40a are, for example, conical holes, and have a diameter of, for example, 0.1mm to 1.0mm and a depth of, for example, 0.3mm to 1.0mm on the tread surface.

The two-dimensional code 40 is configured such that one dot-shaped hole 40a (concave portion) is provided in a unit cell region of a dark region in unit cells that divide the dark and light elements of the two-dimensional code. That is, the two-dimensional code 40 has a configuration in which dot-shaped holes 40a are arranged so that one dot-shaped hole 40a forms one unit cell region with a dense or dense element in correspondence with a plurality of unit cell regions of rectangular shapes of the same size divided into a lattice shape. In fig. 3, the dark regions of the unit cell region are indicated by the black regions.

The two-dimensional code 40 shown in fig. 3 is a QR code (registered trademark) and includes a dot pattern region 42 in which dot patterns are formed by two kinds of gradation elements. A blank region 44 is provided around the dot pattern region, and is surrounded by a lighter element of the light and dark elements, preferably a lighter element of the light and dark elements. The blank area 44 is an area of the QR code (registered trademark) that is a blank area (quick zone), and is an area necessary for reading the QR code (registered trademark). The thickness of the blank region 44 surrounding the dot pattern region is preferably 4 to 5 times the size of the unit cell region in the dot pattern region 42, for example. For example, the thickness w of the blank region 44 is preferably 10% to 25% of the maximum size among the sizes in two orthogonal directions in the rectangular shape of the dot pattern region 42.

The two-dimensional code 40 shown in fig. 3 is a QR code (registered trademark), and thus the dot pattern area 42 includes a data cell area displaying data cells of the QR code (registered trademark) and an end symbol area displaying an end symbol.

As described above, since the two-dimensional code 40 is engraved on the background ridge area 52, the dot-shaped holes 40a are formed in the ridges or the valleys between the ridges. Therefore, ridges or valleys are formed also in the portions where the light elements of the dot-shaped holes 40a are not formed.

Fig. 4 is a photograph showing an example of a QR code (registered trademark) printed on a raised ridge pattern region in a manner different from that of fig. 3. As shown in fig. 4, even if the QR code (registered trademark) is engraved in the raised ridge pattern region, the QR code (registered trademark) can be visually confirmed and read by a two-dimensional code reader.

Since the ridges of such a ridge pattern region are shaped by the projections and depressions formed on the side wall forming surface of the tire mold, a plurality of rib-shaped minute grooves corresponding to the ridges extend on the side wall forming surface of the tire mold. Therefore, when the green tire is expanded and pressed against the side wall forming surface of the tire mold during tire vulcanization, the plurality of rib-shaped minute grooves of the side wall forming surface function as passages through which gas existing between the tire mold and the green tire escapes, and therefore, vulcanization failure does not occur. The vulcanization failure is a portion where the gas between the tire mold and the green tire is not sufficiently discharged during vulcanization of the tire, the gas is trapped in the gap between the tire mold and the green tire, and the gas blocks contact between the sidewall forming surface controlled at a high temperature and the green tire, and vulcanization of the green tire is insufficient. Such a vulcanization failure has an influence on tire performance, and therefore it is preferable that the vulcanization failure is not easily generated. In particular, in recent years, the thickness of the side rubber member 20 has been reduced in order to reduce rolling resistance and weight, but when such a tire is produced using a tire mold, the gap between the side wall forming surface and the green tire is wider than in the conventional art, and the amount of gas to be discharged from the tire mold increases. Therefore, partial gas cannot be sufficiently discharged due to minute shape irregularities of the green tire, uneven expansion of the green tire in the tire mold, or the like, and vulcanization failure is likely to occur.

The imprinting of the two-dimensional code 40 is often performed on a tire before appearance inspection after vulcanization of the tire. In this case, when the two-dimensional code 40 is engraved in a vulcanization-failure portion, the degree of vulcanization failure, that is, the degree of defect is deteriorated due to heat generated by the engraving, and further, the size of the dot-shaped hole 40a (see fig. 5(b)) engraved in the vulcanization-failure portion is not uniform, and further, cracks are likely to occur with long-term use of the tire. Even in a portion with a mild vulcanization failure that can be repaired or a very mild vulcanization failure that cannot be detected, the size of the dot-shaped hole 40a in the portion with a vulcanization failure is not uniform, and further, cracks are likely to be generated and developed with long-term use of the tire. When the crack is generated and progresses, the surface unevenness of the two-dimensional code 40 changes, and the visibility of the shade element is lowered, and the readability is lowered. That is, even if there is a slight vulcanization failure or an extremely slight vulcanization failure, it is not preferable to emboss the two-dimensional code 40 on the portion in consideration of the durability of the side wall portion 10S and the readability of the tire that changes with the long-term use. From such a viewpoint, it is preferable that the imprint position of the two-dimensional code 40 is provided in a region free from a vulcanization failure. Therefore, it is effective to imprint the two-dimensional code 40 in a ridge pattern region that does not cause a vulcanization failure, such as the background ridge region 52. By imprinting the two-dimensional code 40 on the raised ridge pattern region, it is possible to suppress the size inconsistency of the dot-shaped holes 40a due to imprinting on the vulcanization failure portion, without imprinting the two-dimensional code 40 on the vulcanization failure portion (including light and extremely light vulcanization failures). Further, since the mark is not engraved in a portion where the vulcanization failure is mild or extremely mild, the generation and development of cracks accompanying the use of the tire can be suppressed, and the deterioration of the durability accompanying the side wall portion 10S and the readability accompanying the use of the tire can be suppressed.

When the two-dimensional code 40 is engraved in the raised ridge pattern region and the tire is used for a long period of time, it is likely that the identification of the shade elements of the two-dimensional code 40 with respect to the shade elements of the raised ridge pattern becomes difficult, and the readability of the two-dimensional code 40 may be reduced. However, in the case of using the tire for a long period of time, the decrease in the readability of the two-dimensional code 40 due to the imprinting in the raised pattern region is smaller than the decrease in the readability due to the cracks generated and developed by the imprinting of the two-dimensional code 40 in the above-described vulcanization failure (including a light vulcanization failure and an extremely light vulcanization failure). That is, by imprinting the two-dimensional code 40 on the raised ridge pattern region, the decrease in the readability of the two-dimensional code 40 is smaller in the case where the tire is used for a long period of time than in the case where the two-dimensional code 40 is imprinted on the non-raised ridge pattern region. In this manner, from the viewpoint of the readability when reading the two-dimensional code 40 after a long-term use of the tire, it is preferable to imprint the two-dimensional code 40 in the raised ridge pattern region where no vulcanization failure occurs.

In the present embodiment, the case where the two-dimensional code 40 is engraved on the raised ridge pattern region is shown, but even in the smooth surface region which is a non-raised ridge pattern region around the raised ridge pattern region, the number of vulcanization failures (including light and extremely light vulcanization failures) is extremely small in the region near the boundary with the raised ridge pattern region. Therefore, the two-dimensional code 40 may be engraved in the area near the boundary of the smooth surface area and the ridge pattern area. For example, the two-dimensional code 40 may be engraved in the area X shown in fig. 2. That is, the two-dimensional code 40 may be engraved such that the entire two-dimensional code 40 overlaps the raised ridge pattern region, or the two-dimensional code 40 may be engraved such that the raised ridge pattern region and the smooth surface region (non-raised ridge pattern region) overlap each other. In other words, the two-dimensional code 40 may be engraved such that at least a part thereof overlaps the raised ridge pattern region. Since such a two-dimensional code 40 is engraved in an area near the boundary with the raised pattern area, it is possible to suppress deterioration in the durability of the side wall portion 10S and the readability of the tire over a long period of use.

In such a two-dimensional code 40, it is preferable that the dot-shaped holes 40a constituting the dot pattern have hole bottoms on the side of depressions with respect to the surface of the side wall portion 10S, rather than valley bottoms of valleys between ridges. Therefore, when the surface of the side wall portion 10S is viewed from one side of the dot-like holes 40a, as shown in fig. 4, the dense (dark) area can be visually confirmed, and the dot pattern can be easily recognized from the raised ridge pattern area.

Fig. 5(a) and 5(b) are schematic diagrams illustrating the surface irregularities of the raised pattern region and the surface irregularities of the two-dimensional code 40. From the viewpoint of easily recognizing the dot pattern from the raised ridge pattern region, it is preferable that the difference between the hole depth d (see fig. 5(b)) of the hole bottom of the dot hole 40a and the valley depth ds (see fig. 5 (a)) of the valley bottom between the adjacent ridges is 0.3mm or more. That is, the depth of the bottom of the dot-like hole 40a is preferably greater than the depth of the valley bottom of the valley between the ridges. If the difference is too large, the hole depth d of the dot-shaped hole 40a becomes too deep, which is not preferable from the viewpoint of durability of the side wall portion 10S. Therefore, the difference is preferably 1mm or less. As shown in fig. 4, dot holes are formed in the ridges of the ridge pattern region for a part of the dot holes 40. In addition, a dot-like hole is formed in the valley portion. When the dot-shaped holes are formed on the ridges of the ridge pattern region, the hole depth d is the depth from the top of the ridge to the bottom of the hole; when a dot-like hole is formed in the valley portion, the hole depth d is a depth from the valley portion to the bottom of the hole.

Further, according to one embodiment, the length p (see fig. 5(b)) of one side of the unit cell region in the dot pattern of the two-dimensional code 40 is preferably shorter than the interval ps (see fig. 5 (a)) between the adjacent ridges in the ridge pattern region. When the length p is equal to or longer than the interval ps, a plurality of ridges are present in the unit cell region of the dot pattern, and the difference in the dot pattern shading between the unit cell region where the dot hole 40a is present and the unit cell region where the dot hole 40a is absent is reduced, thereby degrading the readability.

Further, according to one embodiment, it is preferable that the interval ps between the adjacent ridges is fixed in a portion where the region of the two-dimensional code 40 overlaps the ridge pattern region. When the interval ps between ridges changes in a portion where the area of the two-dimensional code 40 overlaps the embossed pattern area, the difference in shade between the portion where the interval ps between ridges changes and the dark or light elements of the dot pattern is different from the difference in shade between the portion where the interval ps between ridges does not change and the dark or light elements of the dot pattern, and thus readability is likely to decrease. In this respect, it is preferable that the interval ps between adjacent ridges be constant in a portion where the region of the two-dimensional code 40 overlaps the ridge pattern region.

According to one embodiment, it is preferable that the valley depth ds of the valleys between adjacent ridges is fixed in the portion where the region of the two-dimensional code 40 overlaps the ridge pattern region. When the valley depth ds varies in a portion where the area of the two-dimensional code 40 overlaps the raised ridge pattern area, the difference in shade between the portion where the valley depth ds varies and the dark or light elements of the dot pattern is different from the difference in shade between the portion where the valley depth ds does not vary and the dark or light elements of the dot pattern, and thus readability is likely to be reduced. In this regard, it is preferable that the valley depth ds between adjacent ridges be constant in a portion where the region of the two-dimensional code 40 overlaps the ridge pattern region.

Preferably, in a portion where the region of the two-dimensional code 40 overlaps the ridge pattern region, the extending direction of the ridges is the same at any position. Since the ridges look thick or thin depending on the direction of light irradiation, the change in the extending direction of the ridges at the overlapping portion is not preferable because the readability of the two-dimensional code 40 is reduced.

Further, according to one embodiment, it is preferable that the valley depth ds of the valleys between the adjacent ridges in the portion where the region of the two-dimensional code 40 overlaps the ridge pattern region be shallower than the valley depth ds of the valleys between the adjacent ridges in the portion of the ridge pattern region that contacts the region of the two-dimensional code 40 surrounding the region of the two-dimensional code 40. When the valley depth ds in the portion where the area of the two-dimensional code 40 overlaps the ridge pattern area is as deep as the valley depth ds in the ridge pattern area adjacent to the two-dimensional code, the ridge pattern area is likely to be thickened, and it is difficult to distinguish the thickened elements from the thickened elements of the two-dimensional code 40, thereby degrading the readability of the two-dimensional code 40.

According to one embodiment, as described above, at least a part of the blank region 44 is preferably arranged so as to overlap the ridge pattern region together with the dot pattern region 42. The blank area 44 also needs to be read as a light element of the light and dark elements when the dot pattern is read, and preferably, the blank area 44 is also specified as an element lighter than the area of the light and dark elements in the dot pattern area 42, and preferably specified as an element lighter than the light element of the light and dark elements. From this point of view, it is preferable that at least a part of the blank region 44 is disposed so as to overlap with the land pattern region free from the vulcanization failure.

In addition, according to one embodiment, the blank region 44 may be a smooth surface without ridges. The smooth surface is preferable from the viewpoint of readability because it can reliably function as a light element among the light and dark elements as compared with the raised ridge pattern region.

(example, conventional example)

In order to confirm the effect of the tire 10, the two-dimensional code 40, specifically, the QR code (registered trademark) is engraved on the sidewall portion 10S shown in fig. 2, and after the tire 10 is run, the two-dimensional code 40 is read.

The tire 10 (tire size 195/65R 1591H) provided with the two-dimensional code 40 was attached to a rim 15 × 6 j. after ozone irradiation was performed on the tire 10 under the condition of ozone concentration 100pphm, indoor drum running (speed 120 km/hour) by a low pressure test (X L: air pressure 160kPa, load 100% L I) according to FMVSS139 was performed, and ozone irradiation of the above-mentioned concentration was performed at prescribed time intervals to run for 1.5 hours.

Ten tires each having the two-dimensional code 40 were prepared for the example and the conventional example, and the above-described test was performed.

The two-dimensional code 40 is read by a two-dimensional code reader, the two-dimensional code 40 is irradiated with a predetermined illumination light from a predetermined direction, ten can be read without any problem as an evaluation a, ten can be read, but the case where the illumination light irradiation method is changed for 1 to 2 tires is read as an evaluation B, the case where the illumination light irradiation method is changed for 3 to 4 tires is read as an evaluation C, the case where the illumination light irradiation method is changed for 5 to 6 tires is read as an evaluation D, the case where the illumination light irradiation method is changed for 7 to 10 tires is read as an evaluation E, and the case where the illumination light irradiation method is changed for at least one of the 10 tires is not read as an evaluation F. The evaluation A to E were passed, and the evaluation F was failed.

The specifications and the evaluation results are shown in tables 1 and 2 below.

In tables 1 and 2 below, a QR code (registered trademark) is engraved such that the hole depth d of the two-dimensional code 40 is 1.5mm and the length p is 0.6 mm. The two-dimensional code 40 is engraved in the vicinity of the background ridge area 52, or the area X shown in fig. 2, changing the ratio (15%, 80%) of the overlapped portion with respect to the area of the two-dimensional code 40.

In examples 1 to 9, the valley depth ds was set to 1.0mm, 1.2mm, or 1.3mm, and the interval ps was set to 0.8mm or 0.6 mm. In embodiment 9, the two-dimensional code 40 is engraved with the orientation of the ridges changed.

[ Table 1]

[ Table 2]

As is apparent from the conventional examples and examples 1 to 3 in Table 1: the two-dimensional code 40 is excellent in readability because at least a part thereof is engraved in the embossed pattern region. As described above, the readability of the two-dimensional code 40 is preferably an area engraved on a smooth surface rather than an area engraved with a raised pattern, in view of the readability in the early stage of use of the tire. However, since a vulcanization failure (including a slight or extremely slight vulcanization failure) is likely to occur in a portion of the smooth surface separated from the raised pattern region, when the two-dimensional code is engraved in this portion, the deterioration of the readability due to the occurrence of a crack after a long-term use of the tire and the subsequent progress is large as compared with the case where the two-dimensional code is engraved in the raised pattern region or its vicinity. From this point of view, it is excellent in terms of readability that at least a part of the two-dimensional code 40 is engraved in the raised ridge pattern region.

Furthermore, from a comparison of examples 3 to 5 in tables 1 and 2, it can be seen that: from the viewpoint of improving the readability, it is preferable that the hole depth d is deeper than the valley depth ds, and the hole depth d [ mm ] to the valley depth ds [ mm ] is 0.3mm or more.

From a comparison of examples 3 and 6 in tables 1 and 2, it can be seen that: from the viewpoint of readability, it is preferable that the length p of one side of the unit cell region in the dot pattern of the two-dimensional code 40 is shorter than the interval ps in the ridge pattern region.

From the comparison between example 3 and examples 7 to 9 in tables 1 and 2, it can be seen that: the valley depth ds, the interval ps, and the extending orientation of the ridges of the ridge pattern region that coincides with the region of the two-dimensional code 40 may vary, but from the viewpoint of readability, it is preferable that the valley depth ds, the interval ps, and the extending orientation of the ridges do not vary.

The pneumatic tire of the present invention has been described in detail, but the present invention is not limited to the above embodiment, and various improvements and modifications can be made without departing from the scope of the present invention.

Description of the reference numerals

10 pneumatic tire

10T tread portion

10S side wall part

10B bead part

12 ply

14 belts

14a, 14b belt material

16 bead core

18 tread rubber component

20 side wall rubber component

22 bead core rubber component

24 rim cushion rubber member

26 lining rubber component

30 Belt overlay

40 two-dimensional code

40a point-shaped hole

44 blank area

52 background raised ridge pattern area

53 first band ridge region

54 second raised land area

56 smooth surface area

57 seal display area