JP2010132042A - Tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tire capable of eliminating any manufacturing trouble such as chipping of an uneven portion and damages of a die for vulcanized molding while obtaining sufficient cooling effect when a cooling uneven portion is provided in a buttress part. <P>SOLUTION: In the pneumatic tire, an uneven portion 30 is provided in a buttress part 10 from a tread end 6a to a maximum tire width portion 8. Grooves are arrayed in the tire radial direction TD, and the depth of a plurality of grooves is below 3 mm. When the shortest distance L from a belt end 14 to an outer surface of the tire closest to the belt end 14 is defined to be 1.0, the uneven portion 30 is provided between the outer end 16A and an inner end 16B. The outer end 16A locates on the outer side in the tire radial direction from the position of an outer surface 16 corresponding to the shortest distance L with the distance from the belt end 14 to the outer surface being 1.3, and the inner end 16B locates on the inner side in the tire radial direction from the position of the outer surface 16 corresponding to the shortest distance L with the distance from the belt end 14 to the outer surface 16 being 1.3. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a tire provided with an uneven portion formed by a plurality of grooves extending along a tire circumferential direction in a buttress portion which is a region from a widthwise end portion of a tread to a tire maximum width portion.

  Conventionally, when tires mounted on automobiles, particularly heavy-duty tires mounted on trucks and buses, roll on the road surface under a large load, tire side portions, specifically, the tread width direction The amount of heat generated from the buttress portion, which is the region from the end portion to the maximum width portion of the tire, increases. When the amount of heat generated in the buttress portion increases, there is a concern that separation of the belt layer starting from the end of the belt layer is likely to occur.

In order to suppress the occurrence of separation, various methods for suppressing heat generation in the buttress portion have been realized. For example, a method is known in which a plurality of grooves extending in the tire circumferential direction are formed in a buttress portion and fin-shaped uneven portions are provided (see Patent Document 1). Moreover, in the case of the uneven | corrugated | grooved part currently disclosed by the said patent document, in order to acquire the sufficient cooling effect of a buttress part, the depth of a groove | channel is set to 3 mm-10 mm.
JP 2004-66851 A (page 4-5, Fig. 2-3)

  However, in the conventional tire described above, since the depth of the groove forming the uneven portion is as deep as 3 mm to 10 mm, the uneven portion, specifically, the convex portion located between adjacent grooves is likely to be lost. There was a need for improvement.

  Also, the durability of the projections provided on the mold for vulcanization molding (split mold) to form the groove is low, or the projections of the mold are inserted into the tire side parts of the green tire (green tire) Therefore, there has been a demand for an improvement in that a manufacturing defect in which a tire constituent member (for example, a belt layer) is displaced easily occurs.

  Therefore, the present invention has been made in view of such a situation, and in the case where the buttress portion is provided with an uneven portion for cooling, the defect of the uneven portion or vulcanization molding is obtained while obtaining a sufficient cooling effect. An object of the present invention is to provide a tire that can eliminate manufacturing problems such as damage to a metal mold.

  In order to solve the above-described problems, the present invention has the following features. First, the first feature of the present invention is that a belt layer (belt layer 4) provided on the outer side in the tire radial direction from the carcass (carcass 2), and a tread end portion (tread) on the outer side in the tread width direction of the tread (tread 6). A plurality of grooves (grooves) extending in the tire circumferential direction (tire circumferential direction TR) in a buttress portion (buttress portion 10, buttress portion 12) that is an area from the end portion 6a) to the tire maximum width portion (tire maximum width portion 8). 20) is a tire (for example, the pneumatic tire 1) including the uneven portion (for example, the uneven portion 30, the uneven portion 32) formed by the tire radial direction (tire radial direction TD). ) And the depth of the plurality of grooves (groove depth 20D) is less than 3 mm, and the belt end (belt end 1) on the outer side in the tread width direction in the belt layer. When the shortest distance (shortest distance L), which is the distance from 4) to the outer surface (outer surface 16) of the tire closest to the belt end, is 1.0, It is located on the outer side in the tire radial direction from the position of the side surface, the outer end portion (outer end portion 16A) where the distance from the belt end to the outer surface is 1.3, and the position of the outer surface corresponding to the shortest distance The gist is that it is located between the inner end portion (inner end portion 16B) which is located on the inner side in the tire radial direction and whose distance from the belt end portion to the outer surface is 1.3.

  According to such a tire, since the depth of the plurality of grooves forming the concavo-convex portion is less than 3 mm, it is possible to suppress the loss of the convex portions located between the adjacent grooves.

  Moreover, since the depth of a some groove | channel is less than 3 mm, the metal mold | die for forming a some groove | channel can reduce the height of a convex part compared with the conventional metal mold | die. That is, it is possible to prevent the tire constituent member from being displaced by inserting the convex portion of the mold, and to improve the durability of the convex portion of the mold.

  The concavo-convex part has an outer end where the distance from the belt end to the outer surface is 1.3 when the shortest distance is 1.0, and an inner side where the distance from the belt end to the outer surface is 1.3 Since it is provided between the ends, the surface area of the tire increases in a region where the amount of heat generation is large and effective for the cooling effect.

  Therefore, when the unevenness for cooling is provided in the buttress part, the tire eliminates problems in manufacturing such as a defect in the uneven part and damage to the mold for vulcanization molding while obtaining a sufficient cooling effect. it can.

  In addition, when an uneven part is provided in the area | region where the distance from a belt edge part to an outer surface is wider than 1.3, the tire cannot fully obtain the cooling effect for the expanded area.

  The second feature of the present invention is related to the first feature of the present invention, and is summarized in that the uneven portion is provided in all regions from the outer end portion to the inner end portion in the tire radial direction.

  A third feature of the present invention is related to the first or second feature of the present invention, wherein the width along the tire radial direction of the plurality of grooves on the outer surface (groove width 20W) is 0.5 mm to 2.0 mm. It is a summary.

  A fourth feature of the present invention relates to any one of the first to third features of the present invention, and is provided on the outer side of a convex portion (convex portion 22) provided between a plurality of adjacent grooves among the concave and convex portions. The gist of the width along the tire radial direction on the side surface (convex portion width 22W) is 2 mm or less.

  A fifth feature of the present invention relates to any one of the first to fourth features of the present invention, wherein the plurality of grooves have an arc shape substantially parallel to the tire radial direction outer end in the tread width direction view. It is a summary.

  According to the feature of the present invention, in the case where the buttress portion is provided with an uneven portion for cooling, while obtaining a sufficient cooling effect, the manufacturing process such as the loss of the uneven portion or damage to the mold for vulcanization molding is performed. A tire that can solve the problem can be provided.

  Next, embodiments 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 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.

[Embodiment]
In this embodiment, (1) the configuration of the pneumatic tire, (2) the detailed configuration of the concavo-convex portion, (3) comparative evaluation, (4) action / effect, and (5) the modified example are shown in FIGS. Will be described. FIG. 1 is a perspective view including a cross section in the tread width direction of a pneumatic tire 1 in an embodiment of the present invention. FIG. 2 is a partial cross-sectional view of the pneumatic tire 1 in the tread width direction in the embodiment of the present invention.

(1) Configuration of Pneumatic Tire The pneumatic tire 1 according to the present embodiment is suitably used as a heavy load tire that is mounted on a truck, a bus, or the like. Each part which comprises the pneumatic tire 1 which concerns on this embodiment is demonstrated.

  Specifically, (1.1) carcass, (1.2) belt layer, (1.3) buttress part, and (1.4) uneven part will be described.

(1.1) Carcass The pneumatic tire 1 includes a carcass 2 made of a carcass cord and rubber and forming a skeleton of the pneumatic tire 1.

  Near the top of the carcass 2, a belt layer 4 formed in a belt shape along the tire circumferential direction TR is formed.

(1.2) Belt layer
The belt layer 4 is provided outside the carcass 2 in the tire radial direction and reinforces the carcass 2. The belt layer 4 includes a first belt layer 4a, a second belt layer 4b, a third belt layer 4c, and a fourth belt layer 4d that are coupled onto the carcass 2.

(1.3) Buttress Part The pneumatic tire 1 includes an uneven part in the buttress part. The buttress portion is a region from the tread end portion 6 a outside the tread width direction in the tread 6 to the tire maximum width portion 8.

  Here, the tread end portion 6a means that the pneumatic tire 1 is mounted on a standard rim prescribed in JATMA YEAR BOOK (2007 edition, Japan Automobile Tire Association Standard), and applicable size / prior rating in JATMA YEAR BOOK. Filled with 100% of the air pressure (maximum air pressure) corresponding to the maximum load capacity (internal pressure-load capacity correspondence table) as the internal pressure, and grounded at the outermost position in the tread width direction TW when the maximum load capacity is loaded Refers to the part. In addition, when TRA standard and ETRTO standard are applied in a use place or a manufacturing place, it follows each standard.

  The pneumatic tire 1 includes a pair of buttress portions 10 and a buttress portion 12 on both sides of the tread 6 in the tread width direction TW.

  Specifically, the buttress portion 10 is connected to the side end of the tread 6 on the vehicle outer side (OUT side) in the tread width direction TW.

  The buttress portion 12 is connected to the vehicle inner side (IN side) side end in the tread width direction TW in the tread 6.

(1.4) Concavity and convexity
The pneumatic tire 1 includes an uneven portion formed by a plurality of grooves 20 (details will be described later) extending in the tire circumferential direction TR in the buttress portion. Specifically, the pneumatic tire 1 includes a concavo-convex portion 30 and a concavo-convex portion 32 on the buttress portion 10 (buttress portion 12) on both sides of the tread 6 in the tread width direction TW.

(2) Detailed structure of uneven part The detailed structure of the uneven part 30 is demonstrated. Specifically, (2.1) the arrangement region of the concavo-convex portion and (2.2) the detailed configuration of the plurality of grooves will be described with reference to FIGS. FIG. 3 is a perspective view of the buttress portion of the pneumatic tire 1 according to the embodiment of the present invention. FIG. 4 is a side view of the buttress portion of the pneumatic tire 1 according to the embodiment of the present invention. FIG. 5 is a cross-sectional view (indicated by an arrow A in FIG. 4) along the tire radial direction of the uneven portion 30 of the pneumatic tire 1 according to the embodiment of the present invention.

  In addition, since the uneven | corrugated | grooved part 32 is equipped with the characteristic similar to the uneven | corrugated | grooved part 30, description of a detailed structure is abbreviate | omitted.

(2.1) Arrangement Area of Irregularities As shown in FIG. 2, the irregularities 30 are provided in the buttress 10 between the outer end 16A and the inner end 16B.

  The outer end portion 16A and the inner end portion 16B are closest to the belt end portion 14 (the central portion) from the central portion in the thickness direction (tire radial direction TD) of the belt end portion 14 in the belt layer 4 on the outer side in the tread width direction. When the shortest distance L, which is the distance to the outer surface 16 of the pneumatic tire 1, is 1.0, it is located in the following region.

  Specifically, the outer end portion 16A is located on the outer side in the tire radial direction from the position of the outer surface 16 corresponding to the shortest distance L, and the distance from the belt end portion 14 to the outer surface 16 is 1.3. Located in.

  The inner end portion 16B is positioned on the inner side in the tire radial direction from the position of the outer surface 16 corresponding to the shortest distance L, and is positioned in a region where the distance from the belt end portion 14 to the outer surface 16 is 1.3.

  The uneven portion 30 is provided in all regions from the outer end portion 16A to the inner end portion 16B in the tire radial direction TD. In the present embodiment, the uneven portion 30 is provided in all the above regions in the tire radial direction TD, and may not be provided over the entire tire circumference in the tire circumferential direction TR.

(2.2) A plurality of grooves The uneven portion 30 is formed by a plurality of grooves 20 extending in the tire circumferential direction TR.

  The groove 20 is formed side by side in the tire radial direction TD. Specifically, the groove 20 is formed in a substantially linear shape along the tire circumferential direction TR.

  The groove depth 20D which is the depth of the groove 20 is less than 3 mm. The groove depth 20D is more preferably 1 to 2.5 mm.

A groove width 20W that is a width along the tire radial direction TD of the plurality of grooves 20 on the outer side surface 16 is 0.5 mm to 2.0 mm. The plurality of grooves 20 have an arc shape substantially parallel to the outer end in the tire radial direction of the tread 6 when viewed in the tread width direction.

(2.3) Convex part In the uneven part 30, the convex part 22 is provided between the some groove | channels 20 adjacent to each other. A convex portion width 22W that is a width along the tire radial direction TD on the outer surface 16 of the convex portion 22 is 2 mm or less.

(3) Comparative Evaluation Next, in order to further clarify the effects of the present invention, comparative evaluation performed using pneumatic tires according to the following comparative examples and examples will be described. Specifically, (3.1) Evaluation method and (3.2) Evaluation result will be described. In addition, this invention is not limited at all by these examples.

(3.1) Evaluation method Using six types of pneumatic tires, (3.1.1) Cooling performance evaluation, (3.1.2) Concavity and convexity durability evaluation, (3.1.3) Heat generation durability Sex evaluation was performed. The pneumatic tires according to Comparative Examples 1 and 2 and Examples 1 to 4 used for comparative evaluation will be described with reference to Table 1. In addition, the data regarding a pneumatic tire were measured on the conditions shown below.

・ Tire size: 315 / 80R22.5
・ Rim size: Standard rim described in ETRTO ・ Internal pressure condition: Air pressure corresponding to the maximum load described in ETRTO ・ Load condition: Maximum load described in ETRTO (maximum load capacity)

  The configuration other than the uneven portion provided in each pneumatic tire is the same. The pneumatic tire according to Comparative Example 1 is not provided with an uneven portion. The pneumatic tire according to Comparative Example 2 and Examples 1 to 4 is provided with an uneven portion. In addition, about the structure of the uneven | corrugated | grooved part provided in the pneumatic tire which concerns on the comparative example 2 and Examples 1-4, it is as showing in Table 1.

(3.1.1) Evaluation of cooling performance Evaluation method: Immediately after the truck equipped with each pneumatic tire traveled at a speed of 90 km / h for 1 hour, a thermocouple was inserted from the tread to the belt end of the belt layer, and the belt The temperature at the belt end of the layer was measured. The temperature at the belt end of the belt layer in the pneumatic tire according to Comparative Example 1 was used as a reference temperature, and the temperature at the belt end of the belt layer in other pneumatic tires was compared.

(3.1.2) Evaluation of durability of irregularities Evaluation method: Immediately after a truck equipped with each pneumatic tire travels at a speed of 90 km / h for 1 hour, cracks occur in the irregularities provided in each pneumatic tire. It was visually evaluated whether it was done or not.

(3.1.3) Evaluation of heat generation durability Evaluation method: Travel distance until separation occurs between the pneumatic tire according to Comparative Example 1 and the pneumatic tire according to Examples 1-1 to 1-5 ( Failure distance). The failure distance of the pneumatic tire according to Comparative Example 1 was set to “100”, and the failure distances of other pneumatic tires were indexed. In addition, it shows that a separation is hard to generate | occur | produce, so that an index | exponent is large.

  In the pneumatic tire according to Examples 1-1 to 1-5, the arrangement region of the uneven portion provided in the pneumatic tire according to Example 1 (that is, the ratio of the distance from the belt end to the outer surface with respect to the shortest distance L) ) Is a modified tire. About the arrangement | positioning area | region of the uneven | corrugated | grooved part in the pneumatic tire which concerns on Examples 1.1-1.5, it shows in following Table 2. FIG.

(3.2) Evaluation Results Next, evaluation results using the pneumatic tires according to Comparative Examples 1 and 2 and Examples 1 to 4 described above will be described with reference to Tables 1 and 2. Specifically, (3.2.1) Cooling performance evaluation, (3.2.2) Concavity and convexity durability evaluation, and (3.2.3) Heat generation durability evaluation will be described.

(3.2.1) Cooling Performance Evaluation In the cooling performance evaluation, as shown in Table 1, the belt end portion of the belt layer in the pneumatic tire according to Examples 1 to 4 is the same as that in the pneumatic tire according to Comparative Example 1. It was found that the temperature was reduced compared to the belt end of the belt layer.

(3.2.2) Concavity and convexity portion durability evaluation In the concavity and convexity portion durability evaluation, as shown in Table 1, the concavity and convexity portions provided in the pneumatic tires according to Examples 1 to 4 should not crack. I understood.

(3.2.3) Heat generation durability evaluation

  In the heat generation durability evaluation, as shown in Table 2, it was found that the pneumatic tires according to Examples 1.1 to 1.5 are less likely to cause separation than the pneumatic tire according to Comparative Example 1. In particular, in the pneumatic tire according to Example 1.3, the ratio of the distance from the belt end to the outer surface with respect to the shortest distance L is 1.3 to the outer end from the belt end with respect to the shortest distance L. It was found that the uneven portion was provided in the region up to the inner end where the ratio of the distance to the side surface was 1.3, and the effect of the uneven portion was obtained efficiently and sufficiently.

(4) Actions / Effects As described above, according to the pneumatic tire 1 according to the present embodiment, the groove depths 20D of the plurality of grooves 20 forming the concavo-convex part 30 are less than 3 mm, and are adjacent to each other. It can suppress that the convex part 22 located between the groove | channels 20 to perform is missing.

  Further, since the groove depth 20D is less than 3 mm, the mold for forming the groove 20 can reduce the height of the convex portion as compared with the conventional mold. That is, it is possible to prevent the tire constituent member from being displaced by inserting the convex portion of the mold, and to improve the durability of the convex portion of the mold.

  The uneven portion 30 has an outer end portion 16A in which the distance from the belt end portion 14 to the outer side surface 16 is 1.3 and a distance from the belt end portion 14 to the outer side surface 16 when the shortest distance L is 1.0. Therefore, the surface area of the pneumatic tire 1 increases in a region where the amount of heat generation is large and effective for the cooling effect.

  Therefore, the pneumatic tire 1 is manufactured in the case where the cooling uneven portion 30 is provided in the buttress portion, while obtaining a sufficient cooling effect, such as a defect in the uneven portion 30 or damage to the vulcanization mold. The above problem can be solved.

  In addition, when the uneven | corrugated | grooved part 30 is provided in the area | region where the distance from the belt edge part 14 to the outer surface 16 is wider than 1.3, the pneumatic tire 1 can fully acquire the cooling effect for the expanded area. Can not.

  In the present embodiment, since the uneven portion 30 is provided in all regions from the outer end portion 16A to the inner end portion 16B in the tire radial direction TD, the pneumatic tire 1 is in a region effective for the cooling effect. The surface area of the pneumatic tire 1 can be further increased. Therefore, the pneumatic tire 1 can further obtain a cooling effect by the uneven portion 30.

  In this embodiment, since the groove width 20W of the plurality of grooves 20 is 0.5 mm to 2.0 mm, the pneumatic tire 1 can effectively increase the surface area of the pneumatic tire 1. Therefore, the pneumatic tire 1 can further obtain a cooling effect by the uneven portion 30.

  In this embodiment, since the convex part width 22W of the convex part 22 provided between the mutually adjacent grooves 20 among the concave and convex parts 30 is 2 mm or less, the surface area of the pneumatic tire 1 is effectively increased. it can. Therefore, the pneumatic tire 1 can further obtain a cooling effect by the uneven portion 30.

  In the present embodiment, the plurality of grooves 20 have an arc shape substantially parallel to the outer end in the tire radial direction of the tread 6 when viewed in the tread width direction, so that the concentration of stress on a part of the grooves 20 can be reduced. That is, the pneumatic tire 1 can further suppress the loss of the convex portion 22 (the concave / convex portion 30) located between the grooves 20 adjacent to each other.

  In the present embodiment, the groove depth 20D of the plurality of grooves 20 is 1 to 2.5 mm, so that the mold for forming the groove 20 can further reduce the height of the convex portion. That is, the pneumatic tire 1 can improve the rigidity of the convex portion of the mold while obtaining the cooling effect by the concave and convex portion 30, and can further eliminate manufacturing problems caused by the insertion of the convex portion of the mold.

(5) Modified Example The uneven portion 30 according to the above-described embodiment may be changed to a plurality of grooves 20 or less. In addition, the same code | symbol is attached | subjected to the same part as the pneumatic tire 1 which concerns on embodiment mentioned above, and a different part is mainly demonstrated.

(5.1) First Modification In the uneven portion 30 according to the above-described embodiment, the groove 20 is formed in a substantially linear shape along the tire circumferential direction TR. On the other hand, in the pneumatic tire according to the first modification, the shape of the uneven portion 30 is different. FIG. 6 is a perspective view of a buttress portion of a pneumatic tire according to a first modification of the present invention.

  As shown in FIG. 6, in the concavo-convex portion 30A, the groove 20A is formed in a wave shape along the tire circumferential direction TR.

  According to the first modified example, since the pneumatic tire includes the wavy uneven portion 30A, the uneven portion 30A causes the turbulent flow generated in the uneven portion 30A due to the rolling of the pneumatic tire to be linear unevenness. Can be made larger than the turbulent flow generated in the section. Therefore, the pneumatic tire can further obtain a cooling effect by the uneven portion 30A.

(5.2) Second Modification In the concavo-convex portion 30 according to the embodiment described above, convex portions 22 are provided between the plurality of adjacent grooves 20. On the other hand, in the pneumatic tire according to the second modified example, the shape of the uneven portion 30 is different. FIG. 7 is a cross-sectional view along the tire radial direction of the uneven portion 30B of the pneumatic tire according to the second modification of the present invention.

  As shown in FIG. 7, in the concavo-convex portion 30B, no convex portion is formed between the plurality of adjacent grooves 20B. That is, the convex part width | variety which concerns on a 2nd modification is 0 mm.

  According to the second modified example, the pneumatic tire can make the surface area of the tire along the tire circumferential direction TR larger than the surface area of the tire having the convex portion. A cooling effect can be further obtained.

(6) Other Embodiments As described above, the contents of the present invention have been disclosed through the embodiments of the present invention. However, it is understood that the description and drawings constituting a part of this disclosure limit the present invention. Should not. 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 described above, the concavo-convex portion 30 is provided in all regions from the outer end portion 16A to the inner end portion 16B in the tire radial direction TD, but is not limited thereto, and the concavo-convex portion 30 is provided in the tire radial direction TD. In this case, at least a part of the concavo-convex portion 30 may be provided between the outer end portion 16A and the inner end portion 16B. That is, it is only necessary that a part of the groove 20 forming the uneven portion 30 is formed between the outer end portion 16A and the inner end portion 16B.

  In the embodiment described above, the groove width 20W along the tire radial direction TD of the plurality of grooves 20 forming the uneven portion 30 is 0.5 mm to 2.0 mm, but is not limited to this, for example, the groove width 20W. May be 2.5 mm.

  In the embodiment described above, the convex portion width 22W is 2 mm or less, but is not limited thereto. For example, the convex portion width 22W may be 5.0 mm.

  In the above-described embodiment, the plurality of grooves 20 forming the concavo-convex portion 30 are linear along the tire circumferential direction TR. However, the present invention is not limited to this. For example, the plurality of grooves are along the tire circumferential direction TR. Thus, it may be formed in a so-called zigzag shape formed by an inclination toward the outer side in the tire radial direction and an inclination toward the inner side in the tire radial direction.

  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.

1 is a perspective view including a cross section in a tread width direction of a pneumatic tire 1 in an embodiment of the present invention. 1 is a partial cross-sectional view in the tread width direction of a pneumatic tire 1 in an embodiment of the present invention. 1 is a perspective view of a buttress portion of a pneumatic tire 1 according to an embodiment of the present invention. 1 is a side view of a buttress portion of a pneumatic tire 1 according to an embodiment of the present invention. It is sectional drawing (A arrow figure of FIG. 4) along the tire radial direction of the uneven | corrugated | grooved part 30 of the pneumatic tire 1 which concerns on embodiment of this invention. It is a perspective view of the buttress part of the pneumatic tire concerning the modification of the present invention. It is a partial cross section figure along the tire radial direction of the pneumatic tire concerning the example of a change of the present invention.

Explanation of symbols

TR: tire circumferential direction, L: shortest distance, TD ... tire radial direction, TW ... tread width direction 1 ... pneumatic tire, 2 ... carcass, 4 ... belt layer, 4a ... first belt layer,
4b ... 2nd belt layer, 6 ... Tread, 10, 12 ... Buttress part,
14 ... belt end, 16 ... outer surface, 16A ... outer end, 16B ... inner end,
20, 20A, 20B ... groove, 20W ... groove width, 22 ... projection, 22W ... projection width,
30, 30A, 30B, 32 ... uneven portions

Claims (5)

A belt layer provided on the outer side in the tire radial direction than the carcass;
A tire comprising a buttress portion that is a region from a tread end portion on the outer side in the tread width direction of the tread to a tire maximum width portion, and uneven portions formed by a plurality of grooves extending in the tire circumferential direction,
Each of the plurality of grooves is formed side by side in the tire radial direction, and the depth of the plurality of grooves is less than 3 mm,
When the shortest distance that is the distance from the belt end on the outer side in the tread width direction of the belt layer to the outer surface of the tire closest to the belt end is 1.0,
The uneven portion is
An outer end that is located on the outer side in the tire radial direction from the position of the outer surface corresponding to the shortest distance, and the distance from the belt end to the outer surface is 1.3;
A tire that is located between a position of the outer surface corresponding to the shortest distance and an inner end portion that is 1.3 mm in distance from the belt end portion to the outer surface.   The tire according to claim 1, wherein the uneven portion is provided in all regions from the outer end portion to the inner end portion in the tire radial direction.   The tire according to claim 1 or 2, wherein a width along the tire radial direction of the plurality of grooves on the outer surface is 0.5 mm to 2.0 mm.   The width | variety along the tire radial direction in the said outer surface of the convex part provided between these groove | channels adjacent to each other among the said uneven | corrugated | grooved parts is 2 mm or less. Tires.   The tire according to any one of claims 1 to 4, wherein the plurality of grooves have an arc shape substantially parallel to a tire radial direction outer end of the tread when viewed in the tread width direction.

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