JP5851274B2 - Pneumatic tire - Google Patents

Description

  The present invention relates to a pneumatic tire.

  2. Description of the Related Art Conventionally, there has been known a pneumatic tire that is attached to a rim and has a tire lumen formed between the rim and the rim as shown in Patent Document 1, for example.

JP 2010-95150 A

  However, in the conventional pneumatic tire, since it is difficult to dissipate the heat generated in the tire during running from the inner surface side of the tire that defines the tire lumen, the temperature of the tire is likely to rise and the durability There was room for improvement in ensuring.

  This invention is made | formed in view of the situation mentioned above, Comprising: The objective is to provide the pneumatic tire which can make durability easy to ensure.

In order to solve the above problems, the present invention proposes the following means.
A pneumatic tire according to the present invention is a pneumatic tire that is attached to a rim and has a tire lumen formed between the rim and the inner surface of the pneumatic tire that defines the tire lumen. A large number of minute projections are arranged with gaps between adjacent ones, and the minute projections are formed in a plate shape extending in one direction along the inner surface, and are formed on the inner surface. A pitch between adjacent minute projections is 0.1 μm or more and less than 1000 μm, and is disposed along the other direction perpendicular to the one direction . The width of the minute convex portion may be 0.1 μm or more and less than 100 μm.
A pneumatic tire according to a reference example of the present invention is a pneumatic tire that is mounted on a rim and has a tire lumen formed between the rim and the pneumatic tire that defines the tire lumen. A large number of minute recesses are disposed on the inner surface with a gap between adjacent ones, and a pitch between the adjacent minute recesses is 0.1 μm or more and less than 1000 μm.

According to the present invention, since the pitch between adjacent minute convex portions or the pitch between adjacent minute concave portions is 0.1 μm or more and less than 1000 μm, when the pneumatic tire rotates, the tire lumen It is possible to suppress the air on the inner surface of the tire from moving following the inner surface of the tire, and to generate air turbulence on the inner surface of the tire that is opposite to the rotation direction of the tire. As a result, it is possible to easily dissipate heat generated in the tire during traveling from the inner surface side of the tire, and it is possible to suppress the temperature rise of the tire and to ensure durability.
In addition, when the pitch between the adjacent minute convex portions or the pitch between the adjacent minute concave portions is less than 0.1 μm, the tire is difficult to release from the mold after vulcanization in the manufacturing process of the pneumatic tire. Since the convex portion or the minute concave portion is easily damaged and it is difficult to form the minute convex portion or the minute concave portion into an intended shape, it may be difficult to dissipate heat generated in the tire from the inner surface side of the tire. In addition, when the pitch between adjacent minute convex portions or the pitch between adjacent minute concave portions is 1000 μm or more, the pitch is too large and it is difficult to generate turbulent air flow in the reverse direction of the tire. It may be difficult to dissipate the heat generated in the tire from the inner surface side of the tire.

  Further, the height of the minute convex portion or the depth of the minute concave portion may be 0.1 μm or more and less than 1000 μm.

In this case, since the height of the minute convex portion or the depth of the minute concave portion is 0.1 μm or more and less than 1000 μm, the heat generated in the tire during traveling can be further radiated from the inner surface side of the tire. it can.
That is, if the height of the minute convex portion or the depth of the minute concave portion is less than 0.1 μm, the tire is difficult to release from the mold after the vulcanization, and the minute convex portion or the minute concave portion is easily damaged, Since it becomes difficult to form the minute convex portion or the minute concave portion into an intended shape, it may be difficult to dissipate heat generated in the tire from the inner surface side of the tire. In addition, when the height of the minute convex portion or the depth of the minute concave portion is 1000 μm or more, the minute convex portion is too high or the minute concave portion is too deep, and air turbulence reverses in the tire rotation direction. Since it becomes difficult to generate a flow, it may be difficult to dissipate heat generated in the tire from the inner surface side of the tire.

  According to the pneumatic tire of the present invention, durability can be easily ensured.

1 is a longitudinal sectional view showing a pneumatic tire according to a first embodiment of the present invention. It is a top view of the tread tread part of the pneumatic tire shown in FIG. FIG. 2 is an enlarged perspective view including a partial cross section of a top surface of a land portion of the pneumatic tire shown in FIG. 1. It is an expansion perspective view which shows the principal part in the modification of the pneumatic tire which concerns on 1st Embodiment of this invention. It is an expansion perspective view which shows the principal part in the modification of the pneumatic tire which concerns on 1st Embodiment of this invention. It is an expansion perspective view which shows the principal part in the modification of the pneumatic tire which concerns on 1st Embodiment of this invention. It is an expansion perspective view which shows the principal part of the pneumatic tire which concerns on 2nd Embodiment of this invention. It is an expansion perspective view which shows the principal part of the pneumatic tire which concerns on 2nd Embodiment of this invention. It is an expansion perspective view which shows the principal part in the modification of the pneumatic tire which concerns on 2nd Embodiment of this invention. It is an expansion perspective view which shows the principal part in the modification of the pneumatic tire which concerns on 2nd Embodiment of this invention.

(First embodiment)
Hereinafter, a pneumatic tire according to a first embodiment of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the pneumatic tire 10 has a belt layer 13 and a tread portion 14 in this order on the outer side in the tire radial direction R of a crown portion 12a of a carcass 12 extending in a toroidal shape between a pair of left and right beads 11. Is provided. Further, the pneumatic tire 10 includes a pair of left and right bead portions 15 in which beads 11 are embedded, and a pair of left and right sidewall portions 16 that connect both ends of the tread portion 14 in the tire width direction W and the bead portions 15. And are provided. The pneumatic tire 10 is mounted on a rim (not shown) and forms a tire lumen A between the pneumatic tire 10 and the rim. Note that, on the outer surface of the pneumatic tire 10, a mark (not shown) that clearly indicates the mounting direction to the vehicle is disposed.

  A land portion 18 is disposed on the tread surface portion 17 of the pneumatic tire 10. The tread tread portion 17 means that the pneumatic tire 10 is mounted on a standard rim defined in “JATMA Year Book”, and the tire 10 has a maximum applicable size / ply rating in the “JATMA Year Book”. The tread portion 14 in a state where the maximum load capacity is loaded by filling an internal pressure (hereinafter referred to as a specified internal pressure) of 100% of the air pressure (maximum air pressure) corresponding to the load capacity (internal pressure-load capacity correspondence table in bold). This is the ground plane. In addition, when the area where the pneumatic tire 10 is produced or used is an area other than Japan, the tread tread part 17 is an industrial standard applied to the area (for example, “TRA Year Book” of the United States of America, Europe (ETRTO Standard Manual), etc.)).

  As shown in FIG. 2, the land portion 18 is partitioned by a circumferential groove 19 and a lateral groove 20 disposed in the tread tread surface portion 17. A plurality of circumferential grooves 19 extend in the tire circumferential direction C and are formed at intervals in the tire width direction W. In the illustrated example, the plurality of circumferential grooves 19 are provided on the tread tread surface portion 17 at a position avoiding a central portion (hereinafter referred to as a tire equator portion CL) in the tire width direction W of the pneumatic tire 10. It is arranged symmetrically with respect to. The lateral groove 20 extends in the tire width direction W, and both end portions of the lateral groove 20 in the tire width direction W are individually opened in a pair of circumferential grooves 19 that sandwich the lateral groove 20 in the tire width direction W.

A sipe 21 extending in the tire width direction W is formed on the land portion 18. The sipe 21 is a groove that closes in the contact surface when the pneumatic tire 10 is mounted on the standard rim and the tire 10 is filled with the specified internal pressure and loaded with the maximum load capacity as described above. A narrow groove with a width. In addition, when the region where the pneumatic tire 10 is produced or used is a region other than Japan, the sipe 21 has a groove width that is blocked in the ground plane in a state that conforms to an industrial standard applied to the region. This means the narrow groove.
The sipe 21 has a linear shape in a tire plan view when the tread tread portion 17 is viewed from the outside in the tire radial direction R. Further, the sipe 21 crosses the land portion 18 in the tire width direction W, and both ends of the sipe 21 in the tire width direction W are respectively provided in a pair of circumferential grooves 19 that partition the land portion 18 in the tire width direction W. It is open separately. Further, the sipe 21 is not open in the lateral groove 20.

Here, as shown in FIG. 1 and FIG. 3, on the inner surface 22 of the pneumatic tire 10 that defines the tire lumen A, a large number of minute convex portions 23 leave gaps between adjacent ones. It is arranged. In the present embodiment, the minute convex portion 23 is disposed in a portion of the inner surface 22 that is located on the inner side in the tire radial direction R with respect to the tread portion 14, and as illustrated in FIG. 3, the inner surface 22. Projecting inward in the tire radial direction R, and a large number of minute convex portions 23 are formed in the same shape and size. Further, the minute convex portion 23 is formed in a columnar shape, and in the illustrated example, the end surface of the minute convex portion 23 extends along the inner surface 22 of the pneumatic tire 10. Further, the minute convex portion 23 is provided so as to project along the tire radial direction R, and the center line O1 of the minute convex portion 23 extends along the tire radial direction R.
In addition, the length from the base end of the micro convex part 23 which is the height H of the micro convex part 23 to a protrusion is 0.1 micrometer or more and less than 1000 micrometers. Further, the outer diameter L1 of the minute convex portion 23 may be, for example, 0.1 μm or more and less than 100 μm, preferably 0.5 μm or more and less than 100 μm.

The large number of minute protrusions 23 are regularly arranged so that the pitch P between the adjacent minute protrusions 23, that is, the distance between the center lines O1 of the adjacent minute protrusions 23 is equal to each other. In the example shown in the drawing, a plurality of minute convex portions 23 are arranged with an equivalent gap in one direction D1 along the inner surface 22 of the pneumatic tire 10, and form a convex portion row 24 extending in the one direction D1. The convex row 24 is arranged along the inner surface 22 with an equivalent gap in the other direction D2 orthogonal to the one direction D1. And the pitch P between the micro convex parts 23 adjacent to the said one direction D1 and the said other direction D2 is mutually equal.
The one direction D1 may be along the tire circumferential direction C or the tire width direction W, or may be inclined in both directions. Further, the other direction D2 may be along the tire circumferential direction C or the tire width direction W, or may be inclined in both directions.

In the present embodiment, the pitch P between the adjacent minute convex portions 23 is 0.1 μm or more and less than 1000 μm, preferably 0.3 μm or more and less than 100 μm. In addition, the pitch P between the adjacent minute convex parts 23 may not be equal to each other, and may vary within a range of 0.1 μm or more and less than 1000 μm or within a range of 0.3 μm or more and less than 100 μm, for example.
Here, the minute projections 23 can be formed by, for example, forming minute grooves on the inner surface of a mold (not shown) for forming the pneumatic tire 10 by cutting, electric discharge machining, or etching.

As described above, according to the pneumatic tire 10 according to the present embodiment, the pitch P between the adjacent minute convex portions 23 is 0.1 μm or more and less than 1000 μm, so the pneumatic tire 10 rotates. The air on the inner surface 22 of the tire 10 in the tire lumen A is prevented from moving following the inner surface 22 of the tire 10, and on the inner surface 22 of the tire 10 in the rotational direction of the tire 10. A reverse air turbulence can be generated. Thereby, it is possible to easily dissipate heat generated in the tire 10 during traveling from the inner surface 22 side of the tire 10, and it is possible to suppress the temperature increase of the tire 10 and to ensure durability.
In addition, when the pitch P between the adjacent minute convex portions 23 is less than 0.1 μm, the tire 10 is difficult to release from the mold after vulcanization in the manufacturing process of the pneumatic tire 10, and the minute convex portions 23 are damaged. This makes it difficult to form the minute projections 23 in the intended shape, and it may be difficult to dissipate heat generated in the tire 10 from the inner surface 22 side of the tire 10. Further, when the pitch P between the adjacent minute convex portions 23 is 1000 μm or more, the pitch P is too large and it is difficult to generate turbulent air flow in the direction opposite to the rotation direction of the tire 10. In addition, it may be difficult to dissipate heat from the inner surface 22 side of the tire 10.

Further, since the height H of the minute convex portion 23 is 0.1 μm or more and less than 1000 μm, the heat generated in the tire 10 during traveling can be further radiated from the inner surface 22 side of the tire 10.
That is, when the height H of the minute projections 23 is less than 0.1 μm, the tire 10 is difficult to release from the mold after the vulcanization, and the minute projections 23 are easily damaged, and the minute projections 23 are intended. Therefore, it may be difficult to dissipate heat generated in the tire 10 from the inner surface 22 side of the tire 10. In addition, when the height H of the minute protrusions 23 is 1000 μm or more, the minute protrusions 23 are too high and it is difficult to generate turbulent air flow in the direction opposite to the rotation direction of the tire 10. In addition, it may be difficult to dissipate heat from the inner surface 22 side of the tire 10.

  In the present embodiment, the minute convex portion 23 is projected along the tire radial direction R. However, the present invention is not limited to this, for example, as in the pneumatic tire 30 shown in FIG. The minute projections 23 may be projected so that the center line O1 of the minute projections 23 is inclined with respect to a virtual line O2 extending along the tire radial direction R.

Moreover, in this embodiment, although the micro convex part 23 shall be formed in the column shape, it is not restricted to this, For example, like the pneumatic tire 40 shown in FIG. Further, it may be formed in a hexagonal column shape. In the illustrated example, the minute protrusions 23 have a regular hexagonal shape in the tire plan view, and the minute protrusions 23 adjacent in the one direction D1 are such that the corners of the minute protrusions 23 face each other. The minute projections 23 adjacent to each other in the other direction D2 are arranged such that the side surfaces of the minute projections 23 face each other. In addition, the diagonal diameter which is the outer diameter L1 of the micro convex part 23 may be 0.1 micrometer or more and less than 100 micrometers as mentioned above.
Furthermore, the minute convex portion 23 is not limited to a hexagonal column shape, and may be a polygonal column shape different from the hexagonal column shape.

  Moreover, in this embodiment, although the micro convex part 23 shall be formed in the column shape, it is not restricted to this, For example, you may form in the shape of a cone or a polygonal cone. In this case, the outer diameter L1 of the base end of the minute protrusion 23 may be, for example, 0.1 μm or more and less than 100 μm as described above.

  Moreover, the micro convex part 23 may be formed in the flat form which the front and back extends along the said one direction D1, for example like the pneumatic tire 50 shown in FIG. In the illustrated example, the minute protrusions 23 are arranged with an equivalent gap in the other direction D2, and the pitches P between the minute protrusions 23 adjacent in the other direction D2 are equal to each other. . Note that the width L2 of the minute projection 23, which is the length along the other direction D2 of the minute projection 23, is, for example, 0.1 μm or more and less than 100 μm, similarly to the outer diameter L1 of the minute projection 23 in the embodiment. It may be.

(Second Embodiment)
Next, a pneumatic tire according to a second embodiment of the present invention will be described.
In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, description thereof is omitted, and only different points will be described.

As shown in FIGS. 7 and 8, in the pneumatic tire 60 according to the present embodiment, the inner surface 22 of the pneumatic tire 10 has a large number of minute concave portions 61 instead of the large number of minute convex portions 23. It arrange | positions with the clearance gap between adjacent things. The minute recesses 61 are recessed from the inner surface 22 toward the inside in the tire radial direction R, and the numerous minute recesses 61 are formed in the same shape and size. In addition, the minute recess 61 is recessed in a columnar shape, and in the illustrated example, the bottom of the minute recess 61 extends along the inner surface 22 of the pneumatic tire 10. Further, the minute recess 61 is recessed along the tire radial direction R, and the center line O3 of the minute recess 61 extends along the tire radial direction R.
In addition, the length from the opening surface of the micro recessed part 61 which is the depth D of the micro recessed part 61 to a bottom part is 0.1 micrometer or more and less than 1000 micrometers. In addition, the inner diameter L3 of the minute recess 61 may be, for example, 0.1 μm or more and less than 100 μm, preferably 0.5 μm or more and less than 100 μm, similarly to the outer diameter L1 of the minute protrusion 23 in the above embodiment.

  The large number of minute recesses 61 are regularly arranged so that the pitch P between the adjacent minute recesses 61, that is, the distance between the center lines O3 of the adjacent minute recesses 61 becomes equal to each other. In the illustrated example, a plurality of minute recesses 61 are arranged with an equivalent gap in the one direction D1 to form a recess row 62 extending in the one direction D1, and the recess row 62 is in the other direction. It is arranged with a gap equivalent to D2 and shifted in the one direction D1. And the pitch P between the micro recessed parts 61 adjacent to the said one direction D1 and the said other direction D2 is mutually equal.

In this embodiment, the pitch P between adjacent minute recesses 61 is not less than 0.1 μm and less than 1000 μm.
The minute recess 61 can be formed, for example, by forming minute protrusions on the inner surface of a mold (not shown) for forming the pneumatic tire 60 by cutting, electric discharge machining, or etching.

As described above, according to the pneumatic tire 60 according to the present embodiment, the pitch P between the adjacent minute recesses 61 is 0.1 μm or more and less than 1000 μm, so the pneumatic tire 60 rotates. Sometimes, the air on the inner surface 22 of the tire 60 in the tire lumen A is prevented from moving following the inner surface 22 of the tire 60, and reverses the rotation direction of the tire 60 on the inner surface 22 of the tire 60. Turbulent air flow can be generated. Thereby, it is possible to easily dissipate heat generated in the tire 60 during traveling from the inner surface 22 side of the tire 60, and it is possible to suppress the temperature increase of the tire 60 and to ensure durability.
When the pitch P between adjacent minute recesses 61 is less than 0.1 μm, the tire 60 is difficult to release from the mold after vulcanization in the manufacturing process of the pneumatic tire 60, and the minute recesses 61 are easily damaged. Since it becomes difficult to form the minute recess 61 in the intended shape, it may be difficult to dissipate heat generated in the tire 60 from the inner surface 22 side of the tire 60. Further, when the pitch P between the adjacent minute recesses 61 is 1000 μm or more, the pitch P is too large and it is difficult to generate turbulent air flow in the direction opposite to the rotation direction of the tire 60. It may be difficult to dissipate heat from the inner surface 22 side of the tire 60.

Further, since the depth D of the minute recess 61 is 0.1 μm or more and less than 1000 μm, the heat generated in the tire 60 during traveling can be further radiated from the inner surface 22 side of the tire 60.
That is, when the depth D of the minute recess 61 is less than 0.1 μm, the tire 60 is difficult to release from the mold after the vulcanization, and the minute recess 61 is easily damaged, and the minute recess 61 has a shape intended. Since it becomes difficult to form, it may be difficult to radiate the heat generated in the tire 60 from the inner surface 22 side of the tire 60. In addition, when the depth D of the minute recess 61 is 1000 μm or more, the minute recess 61 is too deep and it is difficult to generate turbulent air flow in the direction opposite to the rotation direction of the tire 60. It may be difficult to dissipate heat from the inner surface 22 side of 60.

In the present embodiment, the minute recess 61 is recessed in a columnar shape, but is not limited thereto.
For example, like the pneumatic tire 70 shown in FIG. 9, the minute recess 61 may be recessed in a hemispherical shape.
Further, for example, like the pneumatic tire 80 shown in FIG. 10, the minute recess 61 may be recessed in a hexagonal column shape. In the illustrated example, the micro concave portion 61 has a regular hexagonal shape in the tire plan view, and the micro concave portion 61 adjacent to the one direction D1 and the micro concave portion 61 adjacent to the other direction D2 are both It arrange | positions so that the side parts of the said micro recessed part 61 may be arranged in parallel. In addition, the diagonal diameter which is the internal diameter L3 of the micro recessed part 61 may be 0.1 micrometer or more and less than 100 micrometers as mentioned above.

The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, in the above-described embodiment, the height H of the minute convex portion 23 or the depth D of the minute concave portion 61 is 0.1 μm or more and less than 1000 μm, but is not limited thereto. For example, the height H of the minute convex portion or the depth D of the minute concave portion 61 may be 500 μm or more and less than 7000 μm.

  Moreover, in the said embodiment, the micro convex part 23 or the micro recessed part 61 is tire radial direction R with respect to the tread part 14 among the inner surfaces 22 of the said pneumatic tire 10, 30, 40, 50, 60, 70, 80. However, the present invention is not limited to this. For example, the inner surface 22 may be disposed in a portion of the sidewall portion 16 located inside the tire width direction W.

  Further, the sipe 21 is not limited to the one shown in the above embodiment, and for example, both end portions of the sipe 21 in the tire width direction W may not be opened individually in the pair of circumferential grooves 19. Further, for example, the sipe 21 may be curved or bent in the tire plan view. Furthermore, the sipe 21 may not be provided.

  The land portion 18 is not limited to that shown in the above embodiment. For example, the land portion is partitioned by a circumferential groove so as to continuously extend over the entire length in the tire circumferential direction, and there is no lateral groove. Good.

  In addition, it is possible to appropriately replace the constituent elements in the embodiment with known constituent elements without departing from the spirit of the present invention, and the above-described modified examples may be appropriately combined.

  Next, first to fourth verification tests on the above-described operational effects were performed.

In the first verification test, the pitch between adjacent minute convex portions was verified. In the first verification test, five pneumatic tires of Examples 1 to 3 and Comparative Examples 1 and 2 were prepared.
Each of the pneumatic tires of Examples 1 to 3 commonly adopts the same configuration as the pneumatic tire shown in the first embodiment, and the pitch between adjacent minute convex portions is in a range of 0.1 μm or more and less than 1000 μm. In Table 1, it was made different from each other as shown in Table 1 below. In the pneumatic tires of Comparative Examples 1 and 2, the pitch between adjacent minute convex portions was different from each other as shown in Table 1 below, outside the range of 0.1 μm or more and less than 1000 μm.

  And durability was evaluated about each pneumatic tire of Examples 1 to 3 and Comparative Examples 1 and 2.

In evaluating durability, first, each pneumatic tire mounted on a regular rim and having an internal pressure of 210 kPa was attached to a drum testing machine having a steel plate surface with a diameter of 1.7 m and subjected to a regular load at a temperature of 38 ° C. On the other hand, the vehicle was run at 80 km / h with a load of 150%, and the running distance until failure was measured. “Regular rim” refers to the standard rim in the applicable size specified in “JATMA Year Book” (2011 version), and “Regular load” refers to the application specified in “JATMA Year Book” (2011 version) The maximum load in size and ply rating.
Then, the evaluation index based on the travel distance of the pneumatic tire of Comparative Example 1 was set to 100, and the durability of each pneumatic tire was evaluated by a relative index.

  The results are shown in Table 1 below.

  From the above, it was confirmed that the pneumatic tires of Examples 1 to 3 were superior in durability compared to Comparative Examples 1 and 2.

Next, in the second verification test, the height of the minute convex portion was verified. In the second verification test, five pneumatic tires of Examples 4 to 6 and Comparative Examples 3 and 4 were prepared.
The pneumatic tires of Examples 4 to 6 commonly adopt the same configuration as the pneumatic tire shown in the first embodiment, and the height of the minute protrusions is within a range of 0.1 μm or more and less than 1000 μm. These were made different from each other as shown in Table 2 below. In each of the pneumatic tires of Comparative Examples 3 and 4, the height of the minute protrusions was different from each other as shown in Table 2 below, outside the range of 0.1 μm or more and less than 1000 μm.

  The durability of each pneumatic tire of Examples 4 to 6 and Comparative Examples 3 and 4 was evaluated. The durability was evaluated in the same manner as in the first verification test.

  The results are shown in Table 2 below.

  From the above, it was confirmed that the pneumatic tires of Examples 4 to 6 were superior in durability compared to Comparative Examples 3 and 4.

Next, in the third verification test, the pitch between adjacent minute recesses was verified. In the third verification test, five pneumatic tires of Examples 7 to 9 and Comparative Examples 5 and 6 were prepared.
The pneumatic tires of Examples 7 to 9 commonly adopt the same configuration as the pneumatic tire shown in the second embodiment, and the pitch between adjacent minute recesses is in the range of 0.1 μm or more and less than 1000 μm. Thus, they were different from each other as shown in Table 3 below. In the pneumatic tires of Comparative Examples 5 and 6, the pitch between adjacent minute recesses was different from each other as shown in Table 3 below, outside the range of 0.1 μm or more and less than 1000 μm.

  The durability of each of the pneumatic tires of Examples 7 to 9 and Comparative Examples 5 and 6 was evaluated. The durability was evaluated in the same manner as in the first verification test.

  The results are shown in Table 3 below.

  From the above, it was confirmed that the pneumatic tires of Examples 7 to 9 were superior in durability compared to Comparative Examples 5 and 6.

Next, in the fourth verification test, the depth of the minute recess was verified. In the fourth verification test, five pneumatic tires of Examples 10 to 12 and Comparative Examples 7 and 8 were prepared.
Each pneumatic tire of Examples 10 to 12 adopts the same configuration as the pneumatic tire shown in the second embodiment in common, and the depth of the minute recesses is in the range of 0.1 μm or more and less than 1000 μm, Different from each other as shown in Table 4 below. In each of the pneumatic tires of Comparative Examples 7 and 8, the depth of the minute recesses was different from each other as shown in Table 4 below, outside the range of 0.1 μm or more and less than 1000 μm.

  The durability of each pneumatic tire of Examples 10 to 12 and Comparative Examples 7 and 8 was evaluated. The durability was evaluated in the same manner as in the first verification test.

  The results are shown in Table 4 below.

  From the above, it was confirmed that each of the pneumatic tires of Examples 10 to 12 was superior in durability as compared with Comparative Examples 7 and 8.

10, 30, 40, 50, 60, 70, 80 Pneumatic tire 22 Inner surface 23 Minute convex portion 61 Minute concave portion A Tire lumen D Depth H Height P Pitch

Claims (3)

A pneumatic tire mounted on a rim and forming a tire lumen with the rim,
On the inner surface of the pneumatic tire that defines the tire lumen, a large number of minute convex portions are disposed with gaps between adjacent ones,
The micro-projections are formed in a plate shape extending in one direction along the inner surface, and are disposed with a gap in the other direction along the inner surface and perpendicular to the one direction.
A pneumatic tire characterized in that a pitch between adjacent minute convex portions is 0.1 μm or more and less than 1000 μm. The pneumatic tire according to claim 1,
The pneumatic tire according to claim 1 , wherein a height of the minute convex portion is 0.1 μm or more and less than 1000 μm.   The pneumatic tire according to claim 1 or 2,
  The pneumatic tire according to claim 1, wherein a width of the minute convex portion is 0.1 μm or more and less than 100 μm.

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