JP7200486B2 - pneumatic tire - Google Patents

Description

TECHNICAL FIELD The present invention relates to a pneumatic tire, and more specifically to a pneumatic tire provided with a two-dimensional code stamped on the sidewall portion of the tire.

In recent years, it has been proposed to provide a two-dimensional code in which information is recorded on the sidewall portion of a pneumatic tire (hereinafter simply referred to as a tire). Since the two-dimensional code can contain more information than the one-dimensional code, various information can be contained in the two-dimensional code to manage tires. In particular, it has been proposed to provide a two-dimensional code composed of a pattern of dark and light elements on the tire side surface by imprinting a predetermined pattern of dot holes on the tire side surface (side wall portion) (Patent document 1).

The two-dimensional code, which is formed by imprinting a predetermined pattern of dot holes on the tire side surface, does not disappear unless the tire side surface is worn, so that the tire can be managed effectively.

WO2005/000714

In a pneumatic tire in which such a two-dimensional code is engraved and a plurality of dot holes are provided, the two-dimensional code can be read when new, but in some cases, the two-dimensional code cannot be read. . Reading of a two-dimensional code is reading of a two-dimensional code by a two-dimensional code reader, for example, a mobile terminal, and poor reading means that reading fails more often. In particular, the two-dimensional code may or may not be read depending on how the illumination light is applied or where the two-dimensional code is provided on the tire circumference. Such unstable two-dimensional code readability is not practically preferable for mass-produced pneumatic tires.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a pneumatic tire capable of suppressing unstable readability of a two-dimensional code stamped on a sidewall.

One aspect of the present invention is a pneumatic tire,
The sidewall of the pneumatic tire is provided with a rectangular two-dimensional code in which a dot pattern is formed by two types of dark and light elements that are formed to be mutually identifiable by surface unevenness,
When the pneumatic tire is filled with air having a specified internal pressure, the two-dimensional code is 5 degrees around the rotation center axis of the pneumatic tire with respect to the height distribution of the surface unevenness of the sidewall along the tire circumferential direction. Provided in a portion where the difference between the maximum value and the minimum value of the height of the surface unevenness is less than 0.5 mm in the angular range on the tire circumference,
In the portion, the change in the height of the surface unevenness accounts for more than half of the difference between the maximum value and the minimum value in the angular range of 2.5 degrees on the tire circumference around the rotation center axis, and it decreases continuously. or including increasing slope areas,
The two-dimensional code is provided on the smooth surface area of the sidewall surface.

In the two-dimensional code, the difference between the maximum value and the minimum value of the height of the surface unevenness is 0.3 mm with respect to the height distribution of the surface unevenness in the angular range of 10 degrees on the tire circumference around the rotation center axis. It is preferable that it is provided in a portion that is less than

It is preferable that the portion is separated from a carcass ply material overlapping portion where the carcass ply material of the pneumatic tire overlaps in two layers at a portion of the tire circumference.

In the pneumatic tire, a reinforcing material having reinforcing fibers coated with rubber is provided between the carcass ply material of the pneumatic tire and the surface of the sidewall. Having a reinforcing material overlapping part overlapping in two layers at a part of the upper part,
Preferably, said portion is remote from said stiffener overlap.

It is preferable that the portion has a difference between the maximum height and the minimum height of the surface unevenness .

In the portion where the two-dimensional cord is provided, the distance from the surface of the side rubber member forming the sidewall to the inner surface of the side rubber member on the carcass ply side of the pneumatic tire closest to the portion. is preferably 2.5 mm or more.

According to the pneumatic tire described above, unstable readability of the two-dimensional code stamped on the sidewall can be suppressed.

It is a figure showing an example of composition of a pneumatic tire of one embodiment. (a), (b) is a figure explaining the example of the two-dimensional code of one Embodiment. FIG. 4 is a diagram schematically showing an example of height distribution of surface unevenness of a sidewall; (a) is a diagram for explaining overlapping portions of carcass ply materials of a pneumatic tire, and (b) is a diagram for explaining irregularities on the sidewall surface that occur in the overlapping portions during internal pressure filling.

Hereinafter, the pneumatic tire of the embodiment will be described in detail.
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 the side away from the tire equator line CL (see FIG. 1) representing the tire equatorial plane in the tire width direction. Further, the inner side in the tire width direction is the side closer to the tire equator line CL in the tire width direction. The tire circumferential direction is the direction in which the pneumatic tire rotates about the rotation axis. The tire radial direction is a direction perpendicular to the rotation axis of the pneumatic tire. The outer side in the tire radial direction refers to the side away from the rotating shaft. Moreover, the inner side in the tire radial direction refers to the side closer to the rotating shaft.

In this specification, filling a pneumatic tire with air of a specified internal pressure means mounting the tire on a specified rim and filling the pneumatic tire with air of a specified internal pressure. Here, the specified rim means the "applicable rim" specified by JATMA, the "design rim" specified by TRA, or the "measuring rim" specified by ETRTO. In addition, the specified internal pressure means the maximum air pressure specified by JATMA, the maximum value of "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES" specified by TRA, or "INFLATION PRESSURES" specified by ETRTO.

In the embodiments described below, a two-dimensional code is engraved on the sidewall portion. The marking referred to in the present embodiment refers to a mode in which laser light is converged on the surface of the sidewall portion to concentrate energy to locally heat and incinerate the side rubber member to form a plurality of minute dot holes on the surface. It also includes forming a two-dimensional code by imprinting unevenness on the member by another means.

A two-dimensional code is a matrix display type code that has information in two directions, as opposed to a one-dimensional code (bar code) that has information only in the horizontal direction. As a two-dimensional code, for example, QR code (registered trademark), Data Matrix (registered trademark), Maxicode, PDF-417 (registered trademark), 16K code (registered trademark), 49 code (registered trademark), Aztec code (registered trademark) ), SP Code(R), VeriCode(R), and CP Code(R).

(pneumatic tire)
FIG. 1 is a diagram showing an example of the configuration of a pneumatic tire 10 (hereinafter simply referred to as tire 10) according to one embodiment. FIG. 1 shows a profile section on one side in the tire width direction with respect to the tire equator line CL.

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 sides provided on both sides of the tread portion 10T and connected to the pair of bead portions 10B and the tread portion 10T. and a wall portion 10S. The tread portion 10T is a portion that contacts the road surface. The sidewall portion 10S is a portion provided so as to sandwich the tread portion 10T from both sides in the tire width direction, and the surface thereof is the surface of the sidewall. The bead portion 10B is a portion connected to the sidewall portion 10S and positioned radially inward of the sidewall portion 10S.

The tire 10 has a carcass ply 12, a belt 14, and a bead core 16 as skeleton members, and a tread rubber member 18, a side rubber member 20, and a bead filler rubber member 22 around these skeleton members. , a rim cushion rubber member 24 and an inner liner rubber member 26 .

The carcass ply 12 is wound around a pair of annular bead cores 16 and provided between the pair of bead cores 16 to form a toroidal shape. The carcass ply 12 is composed of a carcass ply material in which organic fibers are coated with rubber. The carcass ply 12 is wound around the bead core 16 and extends outward in the tire radial direction. A belt 14 composed of two belt members 14a and 14b is provided on the tire equator line CL outside the carcass ply 12 in the tire radial direction. The belt 14 is composed of a member in which steel cords are arranged at a predetermined angle, for example, 20 to 30 degrees, with respect to the tire circumferential direction and covered with rubber. The width in the tire width direction is longer than that. The inclination directions of the steel cords of the two layers of belt materials 14a and 14b are opposite to each other. For this reason, the belt materials 14a and 14b are interlaced layers, which suppress the expansion of the carcass ply 12 due to the filled air pressure.

A tread rubber member 18 is provided outside the belt 14 in the tire radial direction, and side rubber members 20 are connected to both end portions of the tread rubber member 18 to form sidewall portions 10S. A rim cushion rubber member 24 is provided at the inner end in the tire radial direction of the side rubber member 20 and contacts the rim on which the tire 10 is mounted. On the outside of the bead core 16 in the tire radial direction, a bead is sandwiched between a portion of the carcass ply 12 before being wound around the bead core 16 and a portion of the carcass ply 12 after being wound around the bead core 16. A filler rubber member 22 is provided. An inner liner rubber member 26 is provided on the inner surface of the tire 10 facing the air-filled tire cavity area surrounded by the tire 10 and the rim.
In addition, between the belt material 14b and the tread rubber member 18, a three-layer belt cover 30 made of organic fibers coated with rubber is provided to cover the belt 14 from the outside in the tire radial direction. The belt cover 30 may be provided as required, and is not essential. The number of layers of the belt cover 30 is also not limited to three, and may be one or two.
A two-dimensional code 40 (indicated by a thick line in FIG. 1) is provided on the surface of the sidewall portion 10S of the tire 10 (surface of the sidewall).

(two-dimensional code)
FIGS. 2A and 2B are diagrams for explaining an example of the two-dimensional code 40 of one embodiment.
The two-dimensional code 40 is stamped on the surface (sidewall) of the side rubber member 20 of the sidewall portion 10S, as shown in FIG. According to one embodiment, the two-dimensional cords 40 are formed on the surfaces of the side rubber members 20 of both sidewall portions 10S on both sides in the tire width direction. According to another embodiment, it is formed on the surface of the side rubber member 20 of one of the sidewall portions 10S.
The two-dimensional code 40 is formed by forming a dot pattern with two kinds of dark and light elements formed so as to be mutually identifiable by unevenness of the surface. The two-dimensional code 40 converges laser light on the surface of the sidewall portion 10S to concentrate energy and locally heat and incinerate the side rubber member 20 to form minute dot holes 40a (see FIG. 2(b)) on the surface. It is a pattern formed by stamping multiple times. The dot hole 40a is, for example, a conical hole, and has a diameter on the tread surface of, for example, 0.1 to 1.0 mm, and a depth (b in FIG. 3(b)) of, for example, 0.3 to 1 mm. 0 mm.
As shown in FIG. 2(a), the two-dimensional code 40 is constructed by providing one dot hole 40a (concave portion) in the unit cell area of the dark area among the unit cells that divide the dark and light elements of the two-dimensional code 40. It is That is, the two-dimensional code 40 corresponds to a plurality of rectangular unit cell areas of the same size divided into a grid pattern, so that one dot hole 40a forms one unit cell area with a high density element. It has a configuration in which dot holes 40a are arranged. In FIG. 2(a), the dark area of the unit cell area is indicated by a black area.

The two-dimensional code 40 shown in FIG. 2(a) is a QR code (registered trademark) and includes a dot pattern area 42 in which a dot pattern is formed with two types of shading elements. A blank area 44 is provided around the dot pattern area 42 and is surrounded by light elements that are the same as the light elements among the light and dark elements. The blank area 44 is a quiet zone in the QR code (registered trademark), and is an area necessary for reading the QR code (registered trademark). The thickness of blank area 44 surrounding dot pattern area 42 is preferably, for example, 4 to 5 times the dimensional size of the unit cell area within dot pattern area 42 . For example, the thickness w of the blank area 44 is preferably 4 to 25% of the maximum dimension of the two dimensions of the rectangular shape of the dot pattern area 42 .
Since the two-dimensional code 40 shown in FIG. 2(a) is a QR code (registered trademark), the dot pattern area 42 includes a data cell area 42a displaying the data cells of the QR code (registered trademark) and a cutout symbol. and a clipped symbol area 42b.

Such a two-dimensional cord 40 is provided on the sidewall portion 10S so that the two-dimensional cord 40 shown in FIG. 2(a) extends along the tire circumferential direction or tire radial direction. In addition, the two-dimensional code 40 indicates the height distribution of the surface irregularities of the sidewall along the tire circumferential direction when the pneumatic tire 10 is filled with air having a specified internal pressure. It is provided in a portion where the difference between the maximum value and the minimum value of the height of surface irregularities is less than 0.5 mm in the range on the tire circumference where the angle is 5 degrees. That is, the two-dimensional cord 40 is provided on a portion of the tire circumference with less uneven surface. By providing the two-dimensional code 40 in such a portion, it is possible to solve the conventional problem of unstable readability of the two-dimensional code 40 . When the two-dimensional code 40 is provided in a place with large irregularities on the surface of the sidewall, depending on how the illumination light is applied, the direction of the reflected light on the surface of the sidewall changes, and the gradation element of the two-dimensional code 40 cannot be read correctly. may not be possible. That is, the two-dimensional code 40 may or may not be read depending on how the illumination light is applied, or the reading may be unstable. In order to solve this point, the two-dimensional cord 40 has a difference of less than 0.5 mm between the maximum value and the minimum value of the height of the surface unevenness in the range on the tire circumference where the viewing angle of the pneumatic tire 10 is 5 degrees. It is provided in the part where
The angle of view of 5 degrees roughly corresponds to a length of 15 to 32 mm, for example, in the case of a tire with a rim size of 12 to 22 inches. This length is equal to or greater than the length in the tire circumferential direction of the two-dimensional cord 40 practically provided on the sidewall, and corresponds to 200% or less, or 180% or less of the length.

FIG. 3 is a diagram schematically showing an example of the height distribution of the surface irregularities of the sidewall at the same position in the tire radial direction. As shown in FIG. 3, the difference between the maximum value (Max) and the minimum value (Min) in the range of the prospective angle θ (θ=5 degrees) is 0.5 mm.

The surface unevenness data along the tire circumferential direction of the stamped portion of the two-dimensional code 40 as shown in FIG. 3 cannot be directly measured from the stamped pneumatic tire 10. The surface unevenness on the tire circumference at the position in the tire radial direction of the blank area 44 located outside or inside the tire radial direction is measured using a laser shape measuring device, and this measurement data can be used as surface unevenness data. can. In this case, as the surface unevenness data, an average value of the surface unevenness data at each position in the tire radial direction of the blank regions 44 on the outside or inside of the two-dimensional code 40 in the tire radial direction can be used. Alternatively, it is also possible to use the data of the two surface unevenness data, which is selected from the larger variation with respect to the reference value. In addition, the data of the surface unevenness on the tire circumference at the position of the dot pattern area 42 of the two-dimensional code 40 in the tire radial direction is measured, and for the surface unevenness of the dot pattern area 42, the unevenness measurement data of the dot holes 40a is filtered. The data removed by the processing can also be used as surface unevenness data. It should be noted that since the change in surface unevenness on the circumference of the tire before and after providing the two-dimensional cord 40 is extremely small, the location of the sidewall where the two-dimensional cord 40 is not provided should be determined. , data on surface irregularities on the tire circumference.

According to one embodiment, in the portion where the two-dimensional code 40 is engraved, the change in the height of the uneven surface of the sidewall is between the maximum value and the minimum value when the angle of view θ is in the range of 2.5 degrees. It is preferred not to include a continuously decreasing or increasing slope region that accounts for more than half of the difference in . Since the angle of inclination is large in this inclined region, the incident illumination light does not sufficiently reach the reader of the two-dimensional code 40 due to specular reflection, and it is difficult to read the gradation elements accurately. From this point of view, the inclined region is excluded from the portion where the two-dimensional code 40 is printed.

Further, according to one embodiment, the two-dimensional code 40 can be used to determine the height distribution of the surface unevenness of the sidewall along the tire circumferential direction in a range on the tire circumference where the angle of view θ is 10 degrees. It is preferably provided in a portion where the difference between the maximum height and the minimum height is less than 0.3 mm. A flat portion with a smaller difference between the maximum value and the minimum value of surface unevenness in a wider range around the tire circumference provides more stable readability. The range on the tire circumference where the angle of view θ is 10 degrees is often wider than the actual size of the two-dimensional code 40 . However, even in such a case, since the flat portion is wide, the two-dimensional code 40 can be read without being affected by unnecessary reflected light from the surroundings of the two-dimensional code 40, thereby improving readability.

According to one embodiment, the portion where the two-dimensional code 40 is stamped is a carcass ply material overlap in which the carcass ply material constituting the carcass ply 12 of the pneumatic tire 10 overlaps in two layers at a part of the tire circumference. preferably away from the
If the two-dimensional code 40 is stamped before the pneumatic tire 10 is filled with air, it is not possible to obtain information about surface irregularities on the tire circumference of the sidewall when the tire is filled with air of a specified internal pressure. However, information on the position on the tire circumference of the carcass ply material overlapping portion where the carcass ply material overlaps in two layers on the tire circumference can be obtained in the tire manufacturing process. The overlapping part can be removed.

FIG. 4(a) is a diagram for explaining the carcass ply material overlapping portion 50 of the pneumatic tire 10, and FIG. 4(b) is for explaining unevenness of the sidewall surface generated in the carcass ply material overlapping portion 50 when the internal pressure is filled. It is a diagram.
The carcass ply 12 is a sheet-like carcass ply material composed of the carcass cords 11 and the coating rubber 13 covering the carcass cords 11. The carcass ply material is wound around the tire circumference in a toroidal shape, and the ends of the carcass ply material are joined together. It is a configuration that That is, in the carcass ply material overlapping portion (hereinafter referred to as the overlapping portion) 50, as shown in FIG. Therefore, the overlapping portion 50 has a smaller amount of elongation with respect to tension than the portion of the carcass ply 12 other than the overlapping portion 50 . Therefore, when the pneumatic tire 10 is attached to the rim and inflated with air, the amount of elongation of the carcass cords 11 in the overlapped portion 50 is smaller than that of the carcass cords 11 other than the overlapped portion 50. , a concave portion is likely to appear at a position corresponding to the overlapping portion 50 . In particular, the recesses are more noticeable when, for example, the thickness of the side rubber is reduced in order to reduce the weight of the tire, reduce the rolling resistance, and reduce the cost of the rubber material.
The overlapping portion 50 may be a portion formed by partially overlapping the end portions of the carcass ply material when the carcass ply material is wound on the tire forming drum, or may be a portion formed by overlapping the ends of the carcass ply material. It may be a portion formed by joining ends of a sheet-like carcass ply material of limited length to each other in order to produce the ply material.

As shown in FIG. 4(b), there are inclined regions 52a and 52b in such a concave portion, so that the two-dimensional code 40 is provided in this portion because the direction of the reflected light of the two-dimensional code 40 is It is preferable not to include the inclined regions 52a and 52b because it becomes difficult to read the unevenness and the gradation elements correctly. Further, in the sloped regions 52a and 52b, the amount of expansion of the sidewall due to air filling is different between the recessed portion and the portion adjacent to the recessed portion, so that a large strain is likely to occur. Therefore, the diameter of the dot holes 40a provided in the inclined regions 52a and 52b is also changed by the above-described strain, thereby deteriorating the readability.

In the pneumatic tire 10 shown in FIG. 1, the carcass ply 12 is composed of one carcass ply material, but may be composed of a plurality of carcass ply materials. In this case, it is preferable that the stamped portion of the two-dimensional code 40 be away from any position in the tire circumferential direction of the carcass ply material overlapping portion 50 formed by each of the carcass ply materials.

According to one embodiment, the portion where the two-dimensional code 40 is engraved is preferably provided in a ridge pattern region in which a plurality of linear ridges are formed, or a smooth surface region in which no ridges are provided. . In the ridge pattern region, the difference between the maximum value and the minimum value of the height of the surface unevenness is less than 0.5 mm in the range on the tire circumference where the expected angle θ of the pneumatic tire 10 is 5 degrees. , the height of the ridge is set. For example, the height of the peaks of the ridges from the valleys between the ridges may be less than 0.5 mm, preferably less than 0.4 mm.
Even if the two-dimensional code 40 is provided in the ridge pattern area, the degree of shading in the ridge pattern area is substantially constant, so the shading elements of the two-dimensional code 40 can be read accurately. In the vulcanization process of the pneumatic tire 10, the ridge pattern area allows the air existing between the tire mold and the unvulcanized tire being vulcanized to flow along the ridges and be discharged to the outside of the tire mold through the vent holes. Therefore, vulcanization failure due to insufficient vulcanization of the sidewall is unlikely to occur. Even in a place where the vulcanization failure is so minor that it cannot be confirmed, heat is applied to the place to locally alter the side rubber to form a dot hole 40a, thereby imprinting the two-dimensional code 40. As a result, the pneumatic tire 10 With long-term use, cracks or the like occur in the side rubber, and as a result, the surface unevenness of the two-dimensional code 40 changes greatly, and the shading factor also tends to change. From this point of view, it is preferable to provide the two-dimensional code 40 in the ridge pattern region where vulcanization failures are extremely rare, from the viewpoint of suppressing deterioration in readability of the two-dimensional code 40 after long-term use.
It is preferable that the entire two-dimensional code 40 is provided within the ridge pattern area or within the smooth surface area.

According to one embodiment, in the portion where the two-dimensional cord 40 is provided, the side rubber member 20 on the carcass ply side closest to the portion where the two-dimensional cord 40 is stamped from the side rubber member surface forming the sidewall. The distance to the inner surface is preferably 2.5 mm or more. That is, it is preferable that the thickness of the side rubber member 20 in the two-dimensional cord 40 is 2.5 mm or more. As a result, even if the pneumatic tire 10 is used for a long period of time, cracks are less likely to occur from the hole bottoms of the dot holes 40a, and even if cracks occur, they are less likely to reach the carcass ply material that is the skeleton material of the pneumatic tire 10. . That is, in terms of durability of the pneumatic tire 10, the thickness of the side rubber member 20 in the two-dimensional cord 40 is preferably 2.5 mm or more.

In some cases, the pneumatic tire 10 is provided with a reinforcing material in which reinforcing fibers are coated with rubber between the carcass ply material of the pneumatic tire 10 and the surface of the sidewall. In this case, the pneumatic tire 10 has a reinforcing material overlapping portion in which the reinforcing material overlaps in two layers at a part of the tire circumference. At this time, it is preferable that the portion of the surface of the sidewall where the two-dimensional cord 40 is provided is separated from the overlapping portion of the reinforcing material. As a result, the overlapped portion of the reinforcing material is a portion where surface irregularities of the sidewall are likely to be formed when the air of the regular internal pressure is filled. Therefore, for the same reason as the carcass ply material overlapping portion 50 described above, the portion where the two-dimensional cord 40 is provided is preferably separated from the reinforcing material overlapping portion.

(Example, Comparative Example)
In order to confirm the effect of the above embodiment, various pneumatic tires 10 (tire size: 195/65R15 91H) having different sidewall surface irregularities were prepared, and two-dimensional cords 40 were placed at different surface irregularities. has a QR code (registered trademark). The pneumatic tire 10 had the tire configuration shown in FIG. The surface unevenness of the sidewall was adjusted by changing the thickness of the side rubber member 20 . The pneumatic tire 10 was mounted on a "Measuring Rim" defined by ETRTO and filled with air having an internal pressure of "INFLATION PRESSURES" defined by ETRTO. Regarding the pneumatic tire 10, whether or not the two-dimensional code 40 can be read by the portable terminal was examined by variously changing the application of illumination light in each of the examples and the comparative examples.

Twenty-five pneumatic tires 10 were used in each example and comparative example, and the reading rate was defined as the ratio of the number of correct readings to the number of readings performed with various ways of applying illumination light. The reading rate was indexed to 100 based on Comparative Example 1, and the reading rates of the other Comparative Examples and Examples were indexed so that the higher the index, the better the reading rate.
Tables 1 and 2 below show information on the unevenness of the sidewall surface where the two-dimensional code 40 is engraved and the reading rate at that time.

In Tables 1 and 2, the "difference between the maximum and minimum values at a prospective angle of 5 degrees (mm)" and the "difference between the maximum and minimum values at a prospective angle of 10 degrees (mm)" are the tire circumference of the two-dimensional code 40. It means the difference between the maximum value and the minimum value within the range of angles 2.5 degrees and 5.0 degrees away from the central position in the tire circumferential direction. The “inclined region” means that, in the portion where the two-dimensional code 40 is provided, the change in the height of the uneven surface of the sidewall is the difference between the maximum value and the minimum value in the range of the angle of view of 2.5 degrees. A continuously decreasing or increasing region that occupies more than half of the When the “tilt region” is “present”, it means that the range in which the two-dimensional code 40 is provided includes the tilt region. means that it contains no regions.

From the comparison of Examples 1 to 3 and Comparative Examples 1 to 3 in Table 1, it can be seen that readability is improved when the difference between the maximum value and the minimum value at a prospective angle of 5 degrees is less than 0.5 mm.
In addition, from the comparison of Examples 1 and 2, it can be seen that it is preferable for the two-dimensional code 40 not to include an inclined region in terms of improving readability. Furthermore, from the comparison of Examples 3 and 4, it is found that the difference between the maximum value and the minimum value at a viewing angle of 10 degrees is preferably less than 0.3 mm in terms of improving readability.

Although the pneumatic tire of the present invention has been described in detail above, the present invention is not limited to the above embodiments and examples, and various improvements and modifications may be made without departing from the gist of the present invention. Of course.

10 pneumatic tire 10T tread portion 10S sidewall portion 10B bead portion 11 carcass cord 12 carcass ply 13 coating rubber 12a, 12b ply 12ae, 12be, 12e carcass ply end 14 belts 14a, 14b belt material 16 bead core 18 tread rubber member 20 side rubber Member 22 Bead filler rubber member 24 Rim cushion rubber member 26 Inner liner rubber member 30 Belt cover 40 Two-dimensional code 42 Dot pattern region 42a Data cell region 42b Cut-out symbol region 44 Blank region 50 Carcass ply material overlapping portions 52a, 52b Inclined region

Claims (6)

A pneumatic tire,
The sidewall of the pneumatic tire is provided with a rectangular two-dimensional code in which a dot pattern is formed by two types of dark and light elements that are formed to be mutually identifiable by surface unevenness,
When the pneumatic tire is filled with air having a specified internal pressure, the two-dimensional code is 5 degrees around the rotation center axis of the pneumatic tire with respect to the height distribution of the surface unevenness of the sidewall along the tire circumferential direction. Provided in a portion where the difference between the maximum value and the minimum value of the height of the surface unevenness is less than 0.5 mm in the angular range on the tire circumference,
In the portion, the change in the height of the surface unevenness accounts for more than half of the difference between the maximum value and the minimum value in the angular range of 2.5 degrees on the tire circumference around the rotation center axis, and it decreases continuously. or including increasing slope areas,
A pneumatic tire, wherein the two-dimensional code is provided on a smooth surface region of the surface of the sidewall. In the two-dimensional code, the difference between the maximum value and the minimum value of the height of the surface unevenness is 0.3 mm with respect to the height distribution of the surface unevenness in the angular range of 10 degrees on the tire circumference around the rotation center axis. 2. The pneumatic tire according to claim 1 , which is provided in a portion that is less than . The pneumatic tire according to claim 1 or 2 , wherein the portion is separated from a carcass ply overlapping portion where the carcass ply material of the pneumatic tire overlaps in two layers at a portion of the tire circumference . In the pneumatic tire, a reinforcing material having reinforcing fibers coated with rubber is provided between the carcass ply material of the pneumatic tire and the surface of the sidewall. Having a reinforcing material overlapping part overlapping in two layers at a part of the upper part,
A pneumatic tire according to any one of claims 1 to 3 , wherein said portion is remote from said reinforcement overlap . The pneumatic tire according to any one of claims 1 to 4 , wherein the portion has a difference between the maximum and minimum heights of the surface irregularities . In the portion where the two-dimensional cord is provided, the distance from the surface of the side rubber member forming the sidewall to the inner surface of the side rubber member on the carcass ply side of the pneumatic tire closest to the portion. is 2.5 mm or more, the pneumatic tire according to any one of claims 1 to 5 .

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