JP5337566B2 - tire - Google Patents

Description

  The present invention relates to a tire in which a hole that is recessed inward in the tire radial direction from the surface of a tread is formed.

  Conventionally, in tires mounted on automobiles, the rigidity of the central portion and shoulder portion of the tread is different, so that the central portion and the shoulder portion do not wear uniformly, and either the central portion or the shoulder portion wears more. Wear may occur. Therefore, various methods are used to suppress such uneven wear.

  For example, by forming a narrow groove extending along the tire circumferential direction in the shoulder part that is wider in the tread width direction and higher in rigidity than the center part, the rigidity of the shoulder part is suppressed, and sudden deceleration during straight traveling, etc. Uneven wear due to input from the tire circumferential direction can be suppressed.

  In a tire in which such a narrow groove is formed, there is a concern that a so-called stone bite, in which pebbles or the like bite into the fine groove during running, may cause a crack in the tread due to the bited pebbles. Therefore, in order to suppress the occurrence of stone biting, a method of forming a narrow groove having a gradually increased width in the tread width direction from the inner side to the outer side in the tire radial direction in the vicinity of the surface of the tread is widely known (for example, Patent Document 1).

Japanese Patent Laid-Open No. 5-278414 (page 3-4, FIG. 2)

  However, the conventional tire described above has the following problems. In other words, although there is a certain effect on stone biting that occurs in the narrow groove along the tire circumferential direction, in order to increase the width along the tread width direction of the narrow groove, such as during turning, other than the tire circumferential direction It has been a further problem that uneven wear due to input along the direction occurs at the end of the tread that forms the narrow groove.

  Therefore, the present invention has been made in view of such a situation, and while suppressing the occurrence of uneven wear due to input from the tire circumferential direction and input from directions other than the tire circumferential direction, It aims at providing the tire which can suppress generation | occurrence | production of this further.

  In order to solve the above-described problems, the present invention has the following features. First, a first feature of the present invention is a tire (for example, a pneumatic tire 1) in which a hole (for example, a hole 10) that is recessed inward in the tire radial direction from the surface of the tread that contacts the road surface is formed. The hole extends along the tire radial direction (the tire radial direction D) from the surface of the tread (for example, the tread 40), and the tread width direction (tread width direction W) and the tire circumferential direction (tire circumferential direction R). An outer hole (for example, the outer hole 20) having a circular cross section along the outer hole, and an inner hole (for example, the inner hole) that is connected to the outer hole and is located on the inner side in the tire radial direction than the outer hole. The area (area S2) of the inner hole in the tread surface view is smaller than the area (area S1) of the outer hole.

  According to such a tire, the hole includes an outer hole having a circular cross section and an inner hole. Since conventional tires are formed with narrow grooves along the tire circumferential direction, uneven wear due to inputs along directions other than the tire circumferential direction occurs during turning. On the other hand, according to the present invention, stress is concentrated on a part of the tread that forms the hole even when a stress other than the tire circumferential direction is applied to the tire during turning. Can be suppressed. That is, it is possible to suppress the occurrence of uneven wear due to input along a direction other than the tire circumferential direction.

  Moreover, since a hole is comprised by the outer side hole part by which a cross section is formed circularly, and an inner side hole part, generation | occurrence | production of a stone biting can be suppressed compared with the narrow groove extended along a tire circumferential direction. Furthermore, the area of the inner hole in the tread surface view is smaller than the area of the outer hole. For this reason, even when pebbles enter the hole due to rolling of the tire, etc., the pebbles are less likely to enter the inner hole located on the inner side in the tire radial direction than the outer hole, and are easily discharged from the hole. .

  Therefore, according to the tire according to this embodiment, it is possible to provide a tire that can further suppress the occurrence of uneven wear while suppressing the occurrence of stone biting.

  The second feature of the present invention is related to the first feature of the present invention, wherein the inner hole includes a cylindrical surface portion (for example, a cylindrical surface portion 32) extending in the tire radial direction and a bottom surface portion (the cylindrical surface portion 32) serving as the bottom of the inner hole portion. For example, the bottom surface portion 34) and a wall portion (for example, the wall portion 36) that continues to a part of the cylindrical surface portion and protrudes toward the inside of the inner hole portion, the wall portion extends along the tire radial direction. The main point is that it extends to the bottom surface.

  The third feature of the present invention relates to the second feature of the present invention, wherein the wall portion is connected to the wall upper surface (wall upper surface 38A) substantially parallel to the surface of the tread and the wall upper surface, and the tire radial direction from the wall upper surface. And a side surface (side surface 39A) extending to the bottom surface portion (bottom surface portion 34A).

  A fourth feature of the present invention relates to any one of the features of the second or third feature of the present invention, and is a distance (distance) along the tire radial direction from the surface of the tread to the outer end of the wall portion in the tire radial direction. The gist of L1) is shorter than the diameter (diameter L2) of the outer hole portion on the surface of the tread and longer than the maximum distance (distance L3) from the side surface to the cylindrical surface portion.

  A fifth feature of the present invention relates to any one of the second to fourth features of the present invention, wherein the wall portion includes a first wall portion (wall portion 36B) and a second wall facing the first wall portion. The side surface (side surface 39B) of the first wall portion and the side surface (side surface 39C) of the second wall portion are positioned substantially parallel to each other in the tread surface view. To do.

  A sixth feature of the present invention relates to any one of the third to fifth features of the present invention, wherein a plurality of holes are formed in the tread along the tire circumferential direction. The gist is that each of the side surfaces to be formed faces in a different direction.

  A seventh feature of the present invention relates to any one of the first to sixth features of the present invention, and the outer hole portion (outer hole portion 20B) is a cone whose diameter increases toward the outer side in the tire radial direction. The gist is to form a trapezoid.

  According to the characteristics of the present invention, it is possible to provide a tire that can further suppress the occurrence of uneven wear while suppressing the occurrence of stone biting.

It is an expanded view of the tread of the pneumatic tire concerning a 1st embodiment of the present invention. It is a perspective view of the hole which concerns on 1st Embodiment of this invention. It is sectional drawing of the tire radial direction of the hole which concerns on 1st Embodiment of this invention. It is a figure for demonstrating the cross-sectional area of the hole which concerns on 1st Embodiment of this invention. It is an expanded view of the tread of the pneumatic tire concerning a 2nd embodiment of the present invention. It is a perspective view of the hole which concerns on 2nd Embodiment of this invention. It is sectional drawing of the tire radial direction of the hole which concerns on 2nd Embodiment of this invention. It is an expanded view of the tread of the pneumatic tire concerning a 3rd embodiment of the present invention. It is a perspective view of the hole which concerns on 3rd Embodiment of this invention. It is a tread surface view of the hole which concerns on 3rd Embodiment of this invention. It is sectional drawing of the tire radial direction of the hole which concerns on 3rd Embodiment of this invention. It is a perspective view of the hole which concerns on 4th Embodiment of this invention. It is sectional drawing of the tire radial direction of the hole which concerns on 4th Embodiment of this invention.

  Next, first to fourth embodiments, comparative evaluation, and other embodiments of the tire according to the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic and ratios of dimensions and the like are different from actual ones.

  Accordingly, specific dimensions and the like should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

[First Embodiment]
In the present embodiment, (1) the configuration of the tire, (2) the detailed configuration of the hole, and (3) the action / effect will be described.

(1) Configuration of Tire FIG. 1 is a development view of a tread constituting the pneumatic tire 1 according to the first embodiment of the present invention. The pneumatic tire 1 includes a plurality of ribs extending along the tire circumferential direction R. Specifically, the pneumatic tire 1 includes a central rib A1, a shoulder rib A2, and a shoulder rib A3. In the pneumatic tire 1, a circumferential groove 110, a circumferential groove 112, and a circumferential groove 114 extending along the tire circumferential direction R are formed between the plurality of ribs.

  A lateral groove 120 extending along the tread width direction W is formed in the central rib A1. The lateral groove 120 communicates with the circumferential groove and terminates in the central rib A1.

  A hole 10, a narrow groove 50, and a lateral groove 122 are formed in the shoulder rib A2 and the shoulder rib A3. A plurality of hole portions 10 are formed in the tread 40 along the tire circumferential direction R. The hole 10 is recessed inward in the tire radial direction from the surface of the tread 40 that contacts the road surface. The narrow groove 50 extends along the tire circumferential direction R.

(2) Detailed structure of hole The detailed structure of a hole is demonstrated. Specifically, (2.1) Detailed configuration of the outer hole and (2.2) Detailed configuration of the inner hole will be described with reference to FIGS. FIG. 2 is a perspective view of the hole according to the first embodiment of the present invention. FIG. 3 is a sectional view in the tire radial direction of the hole according to the first embodiment of the present invention. FIG. 4A is a cross-sectional view taken along line AA of the outer hole portion of the hole portion according to the first embodiment of the present invention shown in FIG. FIG. 4B is a cross-sectional view taken along line BB of the inner hole portion of the hole portion according to the first embodiment of the present invention shown in FIG. In FIG. 4, in order to clarify the cross-sectional areas of the outer hole portion and the inner hole portion, a part thereof is hatched.

(2.1) Detailed Configuration of Outer Hole As shown in FIGS. 2 and 3, the hole 10 extends along the tire radial direction D from the surface of the tread 40 and extends in the tread width direction W and the tire circumferential direction R. The outer hole 20 having a circular cross section is formed by the outer hole 20, and the inner hole 30 is connected to the outer hole 20 and is located on the inner side in the tire radial direction from the outer hole 20.

  (2.2) Detailed Configuration of Inner Hole As shown in FIGS. 2 and 3, the inner hole 30 is formed by a cylindrical surface portion 32, a bottom surface portion 34, and a wall portion 36. The cylindrical surface portion 32 continues to the side portion that forms the outer hole portion 20 and extends along the tire radial direction D. Specifically, the cylindrical surface portion 32 is formed in a cylindrical shape along the tire radial direction D. The diameter of the cylindrical surface portion 32 is formed to the same length as the diameter of the outer hole portion 20. The bottom surface portion 34 becomes the bottom of the inner hole portion 30. The bottom surface portion 34 is continuous with the cylindrical surface portion 32 on the inner side in the tire radial direction of the cylindrical surface portion 32. The bottom surface portion 34 is formed substantially parallel to the tread 40. The wall portion 36 continues to a part of the cylindrical surface portion 32 and protrudes toward the inside of the inner hole portion 30. The bottom surface portion 34 extends along the tire radial direction D and continues to the bottom surface portion 34.

  As shown in FIG. 3, in the cross section along the tire radial direction D, the wall portion 36 extends obliquely from the boundary between the outer hole portion 20 and the inner hole portion 30 to the inside of the inner hole portion 30. 38, and a side surface 39 that is continuous with the wall upper surface 38 and extends from the wall upper surface 38 along the tire radial direction D to the bottom surface portion 34.

  A distance L1 along the tire radial direction D from the surface of the tread 40 to the end of the wall portion 36 on the outer side in the tire radial direction is shorter than the diameter L2 of the outer hole 20 on the surface of the tread 40. The distance L1 is longer than the maximum length L3 from the side surface 39 to the cylindrical surface portion 32.

(2.3) Cross-sectional Area of Hole Part As shown in FIGS. 4A and 4B, the area S2 of the inner hole part 30 in the tread surface view is smaller than the area S1 of the outer hole part 20. Specifically, in the cross section along the tread width direction and the tire circumferential direction of the outer hole portion 20 and the inner hole portion 30, the outer hole portion 20 and the inner hole portion 30 are circular with the same diameter. Is smaller than the area S1 by the cross-sectional integral of the wall 36.

(3) Action / Effect As described above, according to the pneumatic tire 1 according to the present embodiment, the hole 10 is configured by the outer hole 20 and the inner hole 30 formed in a columnar shape. The For this reason, even if it is a case where stresses other than the tire circumferential direction R are applied to the tire, such as when turning, it is possible to suppress the stress from being concentrated on a part of the tread that forms the hole 10. That is, occurrence of uneven wear can be suppressed.

  According to the pneumatic tire 1 according to the present embodiment, the hole 10 is configured by the outer hole 20 and the inner hole 30 having a circular cross section. In conventional tires, since narrow grooves along the tire circumferential direction R are formed, uneven wear due to input along directions other than the tire circumferential direction R occurs during turning. On the other hand, according to the pneumatic tire 1 according to the present embodiment, the tread 40 that forms the hole 10 even when a stress other than the tire circumferential direction R is applied to the tire during turning or the like. It can suppress that stress concentrates on a part of. That is, it is possible to suppress the occurrence of uneven wear due to input along a direction other than the tire circumferential direction R.

  Moreover, since the hole part 10 is comprised by the outer side hole part 20 in which a cross section is formed circularly, and the inner side hole part 30, generation | occurrence | production of a stone bite is suppressed compared with the narrow groove extended along a tire circumferential direction. it can. Furthermore, the area S2 of the inner hole 30 in the tread surface view is smaller than the area S1 of the outer hole 20. For this reason, even when pebbles enter the hole 10 due to rolling of the tire, etc., the pebbles are less likely to enter the inner hole 30 positioned on the inner side in the tire radial direction than the outer hole 20, and the hole 10 It is easy to be discharged from.

  Therefore, according to the pneumatic tire 1 which concerns on this embodiment, the tire which can further suppress generation | occurrence | production of uneven wear can be provided, suppressing generation | occurrence | production of a stone bite.

  In the present embodiment, the inner hole portion 30 is connected to the cylindrical surface portion 32 extending in the tire radial direction D, the bottom surface portion 34 serving as the bottom of the inner hole portion 30, and a part of the cylindrical surface portion 32. And a wall portion 36 projecting toward the surface. For this reason, even when pebbles enter the hole portion 10 due to rolling of the tire, the inner hole portion 30 located on the inner side in the tire radial direction from the outer hole portion 20 continues to a part of the cylindrical surface portion 32, Since the pebble is formed by the wall portion 36 projecting inward of the inner hole portion 30, the wall portion 36 becomes an obstacle. Further, since the wall portion 36 extends along the tire radial direction D and continues to the bottom surface portion 34, the pebbles continuously extend along the tire radial direction D even when pebbles enter the hole 10. If 36 is not deformed, it cannot enter the inner hole 30. Accordingly, the pebbles are less likely to enter the inner hole 30.

  In the present embodiment, the distance L1 along the tire radial direction D from the surface of the tread 40 to the end of the wall portion 36 on the outer side in the tire radial direction is shorter than the diameter L2 of the outer hole 20 on the surface of the tread 40. For this reason, even when pebbles enter the outer hole 20 from the surface of the tread 40, the distance L1 along the tire radial direction D to the end of the wall 36 in the tire radial direction is equal to that of the outer hole 20. Since it is shorter than the diameter L2, the outer hole 20 is less likely to bite pebbles.

  In the present embodiment, the distance L1 is longer than the maximum distance L3 from the side surface 39 to the cylindrical surface portion 32. For this reason, even when the pebbles are pushed into the outer hole 20 as the tire rolls, the pebbles are more difficult to enter the inner hole 30.

[Second Embodiment]
In the first embodiment described above, the wall 36 includes the outer hole 20 and the wall upper surface 38 that extends from the boundary between the inner hole 30 and the inner hole 30 in an inclined manner.

  In the second embodiment, the configuration of the wall upper surface 38A formed substantially parallel to the tread 40 will be described with reference to FIGS. FIG. 5 is a partially enlarged view of a development view of a tire tread according to a second embodiment of the present invention. FIG. 6 is a perspective view of a hole according to the second embodiment of the present invention. FIG. 7 is a cross-sectional view in the tire radial direction of the hole according to the second embodiment of the present invention.

  In the following second to fourth embodiments, differences from the first embodiment will be mainly described, and overlapping descriptions will be omitted. In the present embodiment, (1) the structure of the hole and (2) the action and effect will be described.

(1) Configuration of Hole Part As shown in FIG. 5, a plurality of hole parts 10 </ b> A formed in the shoulder rib of the pneumatic tire 2 are formed in the tread 40 </ b> A along the tire circumferential direction R. In the tread surface view, each of the side surfaces 39A forming the hole 10A faces in a different direction. The different directions do not mean that the side surface 39A faces in a different direction in all the holes 10A, but means that the side surface 39A is not particularly determined and faces a random direction. Therefore, the side surface 39A facing the same direction may be included.

  As shown in FIGS. 6 and 7, the wall portion 36A is connected to the wall upper surface 38A substantially parallel to the surface of the tread 40 and the wall upper surface 38A, and extends from the wall upper surface 38A along the tire radial direction D to the bottom surface portion 34A. Side surface 39A. Specifically, the wall upper surface 38A is formed substantially parallel to the tread 40 in a cross section along the tire radial direction D.

(2) Action / Effect Each of the side surfaces 39A forming the hole 10A of the pneumatic tire 2 according to the present embodiment faces in a different direction. Further, the wall portion 36A formed by the side surface 39A can improve the rigidity of the block forming the hole portion 10A. In other words, the blocks forming the hole 10A are arranged in different directions because the side surfaces 39A face in different directions, so that the distribution of the highly rigid regions is also different. According to such a pneumatic tire 2, even if stress other than the tire circumferential direction R is applied to the tire, it is possible to suppress the stress from being concentrated on a part of the block that forms the hole 10A. Therefore, the occurrence of uneven wear can be further suppressed.

  According to the pneumatic tire 2 according to the present embodiment, the wall portion 36A is connected to the wall upper surface 38A substantially parallel to the surface of the tread 40, the wall upper surface 38A, and the bottom surface along the tire radial direction D from the wall upper surface 38A. And a side surface 39A extending to the portion 34A. For this reason, the wall portion 36 </ b> A is pushed into the pebbles entering the hole portion 10 </ b> A and hardly deforms. That is, pebbles are more difficult to enter the hole 10A, and the occurrence of stone biting can be further suppressed.

[Third Embodiment]
In the first embodiment described above, in the pneumatic tire 1, the hole 10 is configured by the columnar outer hole 20 and the inner hole 30 having the same inner diameter as the outer hole 20. Further, the inner hole portion 30 includes a cylindrical surface portion 32, a bottom surface portion 34, and a wall portion 36.

In the third embodiment, a configuration in which the outer hole portion 20B and the inner hole portion 30B are different in shape will be described with reference to FIGS. FIG. 8 is a partially enlarged view of a development view of a tire tread according to a third embodiment of the present invention. FIG. 9 is a perspective view of a hole according to the third embodiment of the present invention. FIG. 10 is a tread surface view of the hole according to the third embodiment of the present invention. FIG. 11 is a cross-sectional view in the tire radial direction of the hole according to the third embodiment of the present invention.
In the present embodiment, (1) the structure of the hole and (2) the action and effect will be described.

(1) Structure of hole part As shown in FIG. 8, the wall part which forms the hole part 10B formed in the shoulder rib of the pneumatic tire 3 includes a wall part 36B and a wall part 36C facing the wall part 36B. Consists of. Specifically, in the tread surface view, the side surface 39B of the wall portion 36B and the side surface 39C of the wall portion 36C are located substantially in parallel. Further, each of the side surfaces 39B (side surfaces 39C) forming the hole 10B of the pneumatic tire 3 faces in different directions.

  As shown in FIG. 9, in the pneumatic tire 3, the hole 10B includes a frustoconical outer hole 20B and an inner hole 30B. Specifically, the outer hole portion 20B is formed in a truncated cone shape having a boundary surface with the inner hole portion 30B as a bottom surface. That is, the outer hole portion 20B is formed in a truncated cone shape whose diameter increases as going outward in the tire radial direction.

  The inner hole portion 30B is formed by a cylindrical surface portion 32B, a bottom surface portion 34B, a wall portion 36B, and a wall portion 36C. That is, the inner hole 30B is formed in a plate shape including a surface formed by the wall 36B and the wall 36C.

  As shown in FIG. 10, the area S3 of the inner hole 30B in the tread surface view is defined by a cylindrical surface portion 32B, a side surface 39B, and a side surface 39C in a direction orthogonal to the tire radial direction D. In FIG. 10, only the area S3 is hatched in order to clarify the area S3.

  As shown in FIG. 11, the wall portion 36B includes a wall upper surface 38B substantially parallel to the surface of the tread 40B, and a side surface 39B. The wall portion 36C includes a wall upper surface 38C that is substantially parallel to the surface of the tread 40B, and a side surface 39C.

(2) Action / Effect According to the pneumatic tire 3 according to the present embodiment, the outer hole portion 20B is formed in a truncated cone shape that increases in diameter toward the outer side in the tire radial direction. For this reason, the outer hole 20B is further less likely to bite pebbles along the tire radial direction D than the cylindrical outer hole whose cross-sectional shape does not change.

  According to the pneumatic tire 3 according to the present embodiment, the wall portion of the inner hole portion 30B is configured by the wall portion 36B and the wall portion 36C facing the wall portion 36B. That is, since the inner hole 30B pushes back the pebbles back in the tire radial direction by the wall portion 36B, which is a pair of opposing wall portions, and the wall portion 36C, the wall portions are hardly pushed into the pebbles. Therefore, pebbles are less likely to enter the hole 10B, and the occurrence of stone biting can be further suppressed.

  According to the pneumatic tire 3 according to the present embodiment, the side surface 39B of the wall portion 36B and the side surface 39C of the wall portion 36C are positioned substantially parallel in the tread surface view. That is, when the shape of the inner hole 30B in the tread surface view is compared with the same area, the shape of the inner hole 30B is a vertically long shape with respect to the circular shape of the above-described embodiment, so that the occurrence of stone biting can be further suppressed.

[Fourth Embodiment]
In the first embodiment described above, in the pneumatic tire 1, the wall portion 36 that forms the inner hole portion 30 continues to a part of the cylindrical surface portion 32.

In the fourth embodiment, a configuration in which the shape of the inner hole portion 30C is different will be described with reference to FIGS. FIG. 12 is a perspective view of a hole according to the fourth embodiment of the present invention. FIG. 13 is a cross-sectional view in the tire radial direction of the hole according to the fourth embodiment of the present invention.
In the present embodiment, (1) the structure of the hole and (2) the action and effect will be described.

(1) Configuration of Hole Part As shown in FIG. 12, the hole part 10C includes an outer hole part 20 and an inner hole part 30C. The inner hole 30 </ b> C is formed in a columnar shape having a smaller diameter than the outer hole 20. Therefore, the area of the inner hole 30 </ b> C in the tread surface view is smaller than the area of the outer hole 20.

(2) Action / Effect The pneumatic tire 4 in which the hole 10C according to the present embodiment is formed includes the outer hole 20 and a cylindrical inner hole 30C having a diameter smaller than that of the outer hole 20. Therefore, manufacture is easy and generation | occurrence | production of a stone bite can be suppressed.

[Comparison evaluation]
Next, in order to further clarify the effects of the present invention, a comparative evaluation performed using pneumatic tires according to the following examples will be described. Specifically, (1) an evaluation method and (2) an evaluation result will be described. In addition, this invention is not limited at all by these examples.

(1) Evaluation method Using the pneumatic tires of Examples 1 and 2, (1.1) stone biting was evaluated. The pneumatic tire according to Examples 1 and 2 used for comparative evaluation will be specifically described. In addition, the data regarding a pneumatic tire were measured on the conditions shown below.

・ Tire size: 175 / 80R14 88S
・ Rim size: Standard rim described in ETRTO ・ Internal pressure condition: Standard internal pressure described in ETRTO ・ Load condition: Maximum load described in ETRTO (maximum load capacity)
-Test model: domestic car sedan-Number of holes per pneumatic tire: 740

  The configuration other than the holes provided in each pneumatic tire is the same.

  In the pneumatic tire according to the first embodiment, a hole configured by a frustoconical outer hole and an inner hole connected to the outer hole is formed. The area of the inner hole in the tread surface view is smaller than the area of the outer hole. The length along the tire radial direction of the hole is defined as D2.

  The pneumatic tire according to Example 2 has the same configuration as the pneumatic tire 3 according to this embodiment. Specifically, the pneumatic tire according to the embodiment includes a frustoconical outer hole 20B and an inner hole 30B configured by a cylindrical surface portion 32B, a bottom surface portion 34B, a wall portion 36B, and a wall portion 36C. A configured hole 10B is formed. As shown in FIG. 11, the length of the outer hole 20B along the tire radial direction is D1, and the length of the hole 10B along the tire radial direction is D2.

  (1.1) Evaluation of stone bite Evaluation method: Each pneumatic tire was mounted on a vehicle, traveled on a rough road containing pebbles for about 9000 km, and the number of stone bites per pneumatic tire was measured.

(2) Evaluation Results Evaluation results using the pneumatic tires according to Examples 1 and 2 described above will be described with reference to Table 1.

  Compared with the pneumatic tire according to Example 1, the pneumatic tire according to Example 2 was able to suppress the occurrence of stone biting.

[Other Embodiments]
Although the contents of the present invention have been disclosed through the embodiments of the present invention as described above, it should not be understood that the descriptions and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  For example, the embodiment of the present invention can be modified as follows.

  In the embodiment of the present invention described above, the pneumatic tire 1 has the hole 10 formed in the shoulder rib A2 and the shoulder rib A3, but the hole 10 forms the hole 10 only in one shoulder rib. Alternatively, the hole 10 may be formed in the central rib A1. For example, in a vehicle provided with a camber angle, the hole 10 can be formed only on the inner side or the outer side when the vehicle is mounted.

  In the embodiment of the present invention described above, the wall portion 36 continues to a part of the cylindrical surface portion 32 and is formed substantially parallel to the cylindrical surface portion 32, but is not limited to this, for example, gradually along the tire radial direction. The outer hole 20 may be formed so that the area S2 of the outer hole 20 is small.

  As described above, the present invention naturally includes various embodiments that are not described herein. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

L1, L3 ... distance, L2 ... diameter, L3 ... distance, A1 ... center rib, A2, A3 ... shoulder rib, D ... tire radial direction, L1 ... distance, L2 ... diameter, L3 ... maximum distance, R ... tire circumferential direction , S1, S2, S3 ... area, W ... tread width direction, 1, 2, 3, 4 ... tire, 10, 10A, 10B, 10C ... hole, 20, 20B ... outer hole, 30, 30B, 30C ... Inner hole part, 32, 32B ... Cylindrical part, 34, 34A, 34B ... Bottom part, 36,36A, 36B, 36C ... Wall part, 38,38A, 38B, 38C ... Wall top face, 39,39A, 39B, 39C ... Side surface, 40, 40A, 40B ... tread, 50 ... narrow groove, 110, 112, 114 ... circumferential groove, 120, 122 ... lateral groove

Claims (5)

A tire in which a hole that is recessed inward in the tire radial direction from the surface of the tread that contacts the road surface is formed,
The hole is
An outer hole that extends along the tire radial direction from the surface of the tread and has a circular cross section along the tread width direction and the tire circumferential direction;
Continuing from the outer hole part, it is configured by an inner hole part positioned on the inner side in the tire radial direction than the outer hole part,
The area of the inner hole in the tread surface view is
Rather smaller than the area of the outer hole portion,
The inner hole is
A cylindrical surface portion extending in the tire radial direction;
A bottom surface portion serving as a bottom of the inner hole portion;
A wall portion connected to a part of the cylindrical surface portion and projecting toward the inside of the inner hole portion;
Formed by
The wall is
While extending along the tire radial direction and continuing to the bottom surface,
It is composed of a first wall portion and a second wall portion facing the first wall portion,
In the tread surface view, the side surface of the first wall portion and the side surface of the second wall portion are substantially parallel to each other . The wall is
A wall upper surface substantially parallel to the surface of the tread;
2. The tire according to claim 1 , further comprising a side surface that is continuous with the wall upper surface and extends from the wall upper surface along the tire radial direction to the bottom surface portion. The distance along the tire radial direction from the surface of the tread to the outer end of the wall portion in the tire radial direction is:
3. The tire according to claim 1, wherein the tire is shorter than a diameter of the outer hole portion on a surface of the tread and longer than a distance from the side surface to the cylindrical surface portion. A plurality of the holes are formed in the tread along the tire circumferential direction,
The tire according to any one of claims 1 to 3 , wherein each of the side surfaces forming the hole faces in a different direction in a tread surface view. The tire according to any one of claims 1 to 4 , wherein the outer hole portion is formed in a truncated cone shape having a diameter that increases toward the outer side in the tire radial direction.