JP7700566B2 - tire - Google Patents

Description

This disclosure relates to tires.

The following Patent Document 1 describes a pneumatic tire in which a pair of sipings are provided on a block. Each of the sipes has a constant width portion that extends radially inward of the tire, and a widening portion that extends radially inward of the constant width portion and gradually increases in sipe width. Sipings with such widening portions are said to reduce stress concentration at the bottom of the sipes and suppress cracks.

JP 2013-95196 A

However, the above-mentioned tires left room for further improvement in terms of performance on snow and ice. Also, increasing the number of sipes per block in order to improve performance on ice leads to a significant decrease in the rigidity of the block, which can cause chipping of the bottom of the sipes or make it difficult to remove the tire from the vulcanization mold.

This disclosure was devised in consideration of the above problems, and its main objective is to provide a tire that improves performance on snow and ice while maintaining high chipping resistance and mold removal performance.

The present disclosure relates to a tire having a tread portion, the tread portion being provided with a plurality of blocks, at least one of the plurality of blocks being provided with a plurality of sipes, the plurality of sipes having two or more sipe pairs formed such that the spacing between adjacent sipes is smaller than the spacing between other adjacent sipes, and in at least one of the sipe pairs, each of the sipes includes a main body portion and a widened portion that is disposed radially inward of the main body portion and has a width greater than that of the main body portion, and each of the widened portions widens only in a direction away from each other.

By adopting the above configuration, the tire disclosed herein can improve performance on snow and ice while maintaining high resistance to chipping and mold removal.

FIG. 2 is an enlarged plan view conceptually illustrating a tread portion of one embodiment of the present disclosure. 2 is a cross-sectional view taken along line AA in FIG. 1. FIG. 2 is a plan view of one embodiment of a tread portion. 4 is a cross-sectional view taken along line BB in FIG. 3. FIG. 4 is a plan view of the first middle block of FIG. 3 . 6 is a cross-sectional view taken along line CC of FIG. 5.

Hereinafter, one embodiment of the present disclosure will be described with reference to the drawings.
1 is an enlarged plan view conceptually illustrating a portion of a tread portion 2 of a tire 1 according to the present disclosure. The present disclosure is applied to, for example, a pneumatic tire for heavy loads that can be driven even in winter. However, the present disclosure may also be applied to, for example, a tire 1 for passenger cars or light trucks.

In this embodiment, the tread portion 2 is provided with a plurality of blocks 3. In this embodiment, the plurality of blocks 3 are arranged in the tire circumferential direction and the tire circumferential direction.

At least one of the blocks 3 is provided with a number of sipes 4. The sipes 4 provide a gripping force against snowy and icy road surfaces, improving performance on snow and ice. The sipes 4 also have two or more sipe pairs 5 each consisting of adjacent sipes 4, 4. This improves performance on snow and ice. Such sipes 4 are formed, for example, by a thin knife blade provided in a vulcanization mold of known construction (not shown).

2 is a cross-sectional view taken along line A-A in FIG. 1. As shown in FIG. 2, in at least one of the sipe pairs 5, each of the sipes 4 includes a main body portion 6 and a widened portion 7 that is disposed radially inward of the main body portion 6 and has a width greater than that of the main body portion 6. The widened portion 7 suppresses stress concentration at the bottom side of the sipe 4 and prevents the occurrence of chips or cracks (hereinafter referred to as "chips, etc."). In this embodiment, each of the sipes 4 of the two sipe pairs 5 is formed to include a main body portion 6 and a widened portion 7.

Each of the widened portions 7 of the sipe pair 5 is widened only in the direction away from each other. As a result, in the portion of the sipe pair 5 between each sipe 4, which has a relatively small block rigidity, the shear force caused by the removal of the vulcanization mold is small, so chipping resistance and mold removal performance are maintained at a high level.

The sipes 4 of the sipe pair 5 are formed so that the spacing La between adjacent sipes 4 is smaller than the spacing Lb between other adjacent sipes 4. This makes the block rigidity relatively large between the sipes 4 of the sipe pair 5 and the other sipes 4. Therefore, high chipping resistance and mold removal performance are maintained between the sipes 4 of the sipe pair 5 and the other sipes 4. Although not particularly limited, the spacing La between adjacent sipes 4 of the sipe pair 5 is preferably 3.5 mm or more, more preferably 4 mm or more, more preferably 7 mm or less, and even more preferably 6 mm or less.

In this specification, a sipe refers to a cut-like recess with a width of less than 2.5 mm, and is clearly distinguished from grooves, including main grooves and lateral grooves, which are 2.5 mm or more in width.

Figure 3 is an overall plan view of the tread portion 2 of this embodiment. As shown in Figure 3, in this embodiment, the tread portion 2 includes a pair of crown main grooves 21, 21 arranged on either side of the tire equator C, and a pair of shoulder main grooves 22, 22 arranged on the outer side of the pair of crown main grooves 21, 21 in the tire axial direction. As a result, in this embodiment, the tread portion 2 is divided into a crown land portion 25, a pair of middle land portions 26, 26, and a pair of shoulder land portions 27, 27. In this embodiment, the crown land portion 25 is arranged between the pair of crown main grooves 21, 21. In this embodiment, the middle land portion 26 is arranged between the crown main groove 21 and the shoulder main groove 22. In this embodiment, the shoulder land portion 27 is arranged between the shoulder main groove 22 and the tread edge Te.

"Tread edge Te" is the axially outermost contact point when tire 1 is in a normal condition, mounted on a normal rim, inflated to normal internal pressure, and unloaded, and placed on a flat surface with a normal load and a camber angle of 0 degrees. Unless otherwise specified, the dimensions of each part of the tire are values measured in a normal condition.

"Genuine rim" refers to a rim that is determined for each tire by the standard system that includes the standard on which the tire is based. For example, JATMA calls it a "standard rim," TRA calls it a "design rim," and ETRTO calls it a "measuring rim."

"Normal internal pressure" is the air pressure set for each tire by each standard in the standard system on which the tire is based. For JATMA, it is the "maximum air pressure." For TRA, it is the maximum value listed in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES." For ETRTO, it is the "INFLATION PRESSURE."

"Normal load" is the load that each standard specifies for each tire in the system of standards on which the tire is based. For JATMA, it is "maximum load capacity." For TRA, it is the maximum value listed in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES." For ETRTO, it is "LOAD CAPACITY."

The crown land portion 25 of this embodiment includes crown longitudinal sipes 30 extending in the tire circumferential direction and crown lateral grooves 31 aligned in the tire circumferential direction. The crown longitudinal sipes 30 are arranged at the axially intermediate position of the crown land portion 25. The crown lateral grooves 31 extend from the crown main grooves 21 to the crown longitudinal sipes 30. As a result, the crown land portion 25 is formed with a plurality of crown blocks 33 defined by the crown main grooves 21, the crown longitudinal sipes 30, and the crown lateral grooves 31 adjacent in the tire circumferential direction. The crown blocks 33 are aligned, for example, in the tire circumferential direction as well as in the tire axial direction.

The middle land portion 26 of this embodiment includes a middle longitudinal sipe 35 extending in the tire circumferential direction, a first middle lateral groove 36 arranged in the tire circumferential direction, and a second middle lateral groove 37 arranged in the tire circumferential direction. The middle longitudinal sipe 35 is arranged, for example, at the middle position in the tire axial direction of the middle land portion 26. The first middle lateral groove 36 extends, for example, from the crown main groove 21 to the middle longitudinal sipe 35. The second middle lateral groove 37 extends, for example, from the shoulder main groove 22 to the middle longitudinal sipe 35. As a result, the middle land portion 26 is formed with a plurality of first middle blocks 40 and a plurality of second middle blocks 41. The first middle block 40 of this embodiment is defined by the crown main groove 21, the middle longitudinal sipe 35, and the first middle lateral groove 36 adjacent in the tire circumferential direction, and is arranged in the tire circumferential direction. In this embodiment, the second middle block 41 is defined by the shoulder main groove 22, the middle longitudinal sipe 35, and the second middle lateral groove 37 adjacent in the tire circumferential direction, and is aligned in the tire circumferential direction.

In this embodiment, the shoulder land portion 27 includes a shoulder longitudinal sipe 44 extending in the tire circumferential direction, a first shoulder lateral groove 45 arranged in the tire circumferential direction, and a second shoulder lateral groove 46 arranged in the tire circumferential direction. The shoulder longitudinal sipe 44 is arranged, for example, at the middle position in the tire axial direction of the shoulder land portion 27. The first shoulder lateral groove 45 extends, for example, from the shoulder main groove 22 to the shoulder longitudinal sipe 44. The second shoulder lateral groove 46 extends, for example, from the tread edge Te to the shoulder longitudinal sipe 44. As a result, the shoulder land portion 27 is formed with a plurality of first shoulder blocks 48 and a plurality of second shoulder blocks 49. The first shoulder blocks 48 are defined, for example, by the shoulder main groove 22, the shoulder longitudinal sipe 44, and the first shoulder lateral groove 45 adjacent in the tire circumferential direction, and are arranged in the tire circumferential direction. The second shoulder blocks 49 are defined by, for example, the tread edge Te, the shoulder longitudinal sipes 44, and the second shoulder lateral grooves 46 adjacent in the tire circumferential direction, and are arranged in the tire circumferential direction. Note that the shape of the tread portion 2 is not limited to this embodiment, and various shapes can be adopted.

In this embodiment, the crown block 33, the first middle block 40, and the second middle block 41 each have three sipe pairs 5. The first shoulder block 48 in this embodiment has two sipe pairs 5 and one sipe 4 on each side of the two sipe pairs 5 in the tire circumferential direction. The second shoulder block 49 in this embodiment has two sipe pairs 5 and one sipe 4 sandwiched between the two sipe pairs 5.

The sipe pairs 5 arranged in the first middle block 40 will be described in detail below. In addition, the sipe pairs 5 arranged in blocks 3 other than the first middle block 40 will be described in terms of the differences from the sipe pairs 5 arranged in the first middle block 40.

Figure 4 is a cross-sectional view taken along line B-B in Figure 3, showing a longitudinal section of the sipe 4 in the sipe width direction. As shown in Figure 4, each sipe 4 of the sipe pair 5 has a pair of wall surfaces 8, 8 that extend radially inward from the tread surface 40t of the first middle block 40.

The pair of wall surfaces 8, 8 includes a first wall surface 8A on the side where the sipes 4 of the sipe pair 5 are adjacent to each other, and a second wall surface 8B on the opposite side to the first wall surface 8A. The first wall surface 8A and the second wall surface 8B are connected by a bottom portion 9. In this embodiment, the bottom portion 9 is the innermost end 4i of the sipe 4 in the tire radial direction. The bottom portion 9 may be a plane extending in the sipe width direction on the innermost side of the sipe 4 in the tire radial direction (not shown).

In this embodiment, the first wall surface 8A includes a first arc portion 10 that extends from the bottom portion 9 in an arc shape outward in the tire radial direction. The first wall surface 8A includes, for example, a first arc portion 10 and a first linear portion 12 that is connected to the first arc portion 10 and extends in a straight line. The first arc portion 10 in this embodiment is formed to be convex toward the outside of the sipe 4. Such a first arc portion 10 effectively relieves stress concentration. The first arc portion 10 is formed, for example, by a single arc having the same radius of curvature. The first arc portion 10 may be formed by a plurality of arcs having different radii of curvature. For example, the first arc portion 10 is formed without extending further toward the sipe 4 side of the adjacent sipe pair 5 than the first linear portion 12. The first linear portion 12 is, for example, smoothly connected to the first arc portion 10 and extends to the tread surface 40t.

The second wall surface 8B includes a second arc portion 11 that extends from the bottom portion 9 in an arc shape outward in the tire radial direction. In this embodiment, the second arc portion 11 is formed to be convex toward the outside of the sipe 4. Such a second arc portion 11 more effectively relieves stress concentration. The second wall surface 8B includes, for example, the second arc portion 11, the inward arc portion 13, the second linear portion 14, and the bulge portion 15. The inward arc portion 13 is, for example, connected to the second arc portion 11 and has a concave arc shape toward the inside of the sipe 4. The second linear portion 14 is, for example, connected to the inward arc portion 13 and extends linearly outward in the tire radial direction. The bulge portion 15 extends, for example, connecting the second linear portion 14 and the tread surface 40t, in a direction that widens the sipe width, in this embodiment, in the same direction as the widening portion 7.

The radius of curvature r1 of the first arc portion 10 is preferably 0.3 to 0.5 mm. The radius of curvature r2 of the second arc portion 11 is preferably 0.5 to 0.8 mm. This improves chipping resistance and mold removal performance. When the first arc portion 10 or the second arc portion 11 is formed with multiple radii of curvature, the radii of curvature r1 and r2 are determined as the average of the minimum and maximum radii of curvature, respectively.

The widened portion 7 has a maximum half-width Wa from the width center 6c of the main body portion 6. In order to improve the mold release performance while suppressing chipping on the bottom side, the maximum half-width Wa is preferably 1.5 times or more the half-width Wb of the main body portion 6, more preferably 2.0 times or more, more preferably 4.0 times or less, and even more preferably 3.5 times or less. Although not particularly limited, the half-width Wb is preferably 0.1 mm or more, more preferably 0.2 mm or more, more preferably 0.5 mm or less, and even more preferably 0.4 mm or less.

The bulge 15 is formed so that the half-width Wc from the width center 6c of the main body 6 is larger than the maximum half-width Wa of the widened portion 7. Such a bulge 15 particularly improves on-snow performance. The half-width Wc of the bulge 15 is preferably 1.2 times or more of the maximum half-width Wa, more preferably 1.3 times or more, even more preferably 1.4 times or more, preferably 2.0 times or less, even more preferably 1.9 times or less, and even more preferably 1.8 times or less.

5 is a plan view of the first middle block 40 of FIG. 3. As shown in FIG. 5, in this embodiment, the first middle block 40 includes a pair of first block edges 40a, 40a and a pair of second block edges 40b, 40b that connect both ends of the pair of first block edges 40a, 40a. Each of the first block edges 40a is spaced apart from the sipe 4 of the sipe pair 5 in the sipe width direction. Each of the second block edges 40b is spaced apart from the sipe 4 in the longitudinal direction. One of the pair of second block edges 40b is in contact with, for example, the middle longitudinal sipe 35. The other of the pair of second block edges 40b is in contact with, for example, the crown main groove 21.

The spacing La between adjacent sipes 4, 4 in a sipe pair 5 is preferably 0.3 times or more the spacing Lb between the other sipes 4, more preferably 0.4 times or more, more preferably 0.8 times or less, and even more preferably 0.7 times or less. Since the spacing La between the sipes 4, 4 is 0.3 times or more the spacing Lb between the other sipes 4, a decrease in block rigidity between the sipes 4, 4 can be suppressed. Since the spacing La between the sipes 4, 4 is 0.8 times or less the spacing Lb between the other sipes 4, the block rigidity on the side where the widening portion 7 widens can be maintained high, large openings between the sipes 4 are suppressed, and chipping resistance is improved.

From the same viewpoint, the spacing La between the sipes 4, 4 of the sipe pair 5 is preferably 0.3 times or more, more preferably 0.4 times or more, more preferably 0.8 times or less, and even more preferably 0.7 times or less, of the spacing Lc between the sipe 4 closest to the first block edge 40a and the first block edge 40a. In this specification, the spacing Lb and the spacing Lc are the maximum lengths of the sipes 4 in the longitudinal direction.

The sipes 4 of the sipe pair 5 each extend at an angle α of 40 degrees or less relative to the tire axial direction. Such sipes 4 increase the tire's circumferential cutting force and improve performance on snow and ice. In this specification, the angle α is specified by the imaginary straight line 4n that connects both ends 4e, 4e of the sipe 4.

Figure 6 is a cross-sectional view of line CC in Figure 5. As shown in Figure 6, the depth d1 of the sipes 4 in the first middle block 40 is equal to or less than the depth d2 of the middle longitudinal sipes 35. This maintains high circumferential rigidity of the first middle block 40, improving performance on ice. Note that the depth d1 of the sipes 4 in this embodiment is the same as the depth d2 of the middle longitudinal sipes 35. Also, it is desirable that the depth of each sipe 4 (not shown) in the second middle block 41 is equal to or less than the depth d2 of the middle longitudinal sipes 35. In this embodiment, the depth of each sipe 4 in the second middle block 41 is the same as the depth d2 of the middle longitudinal sipes 35.

Furthermore, it is desirable that the depth of each sipe 4 (not shown) in the crown block 33 is equal to or less than the depth of the crown longitudinal sipe 30. In this embodiment, the depth of each sipe 4 in the crown block 33 is the same as the depth of the crown longitudinal sipe 30. In addition, it is desirable that the depth of each sipe 4 in the shoulder land portion 27 is equal to or less than the depth of the shoulder longitudinal sipe 44. In this embodiment, the depth of each sipe 4 in the first shoulder block 48 is the same as the depth of the shoulder longitudinal sipe 44. In this embodiment, the depth of each sipe 4 in the second shoulder block 49 is formed smaller than the depth of the shoulder longitudinal sipe 44.

Although a tire according to one embodiment of the present disclosure has been described in detail above, the present disclosure is not limited to the specific embodiment described above and can be modified and implemented in various ways.

Heavy-duty pneumatic tires of size 11R22.5 with the basic pattern shown in Figure 3 were prototyped based on the specifications in Table 1. Each test tire was then tested for performance on snow, performance on ice, chipping resistance, and mold removal performance. The common specifications and test methods for each test tire are as follows.

<Performance on snow and ice>
The time required for the test vehicle described below to travel 200 m on a test course on snow and ice, each of which had a series of curves with a radius of curvature of 30 m, was measured. The results are expressed as an index, with the reciprocal of the travel time in Example 1 taken as 100. The larger the value, the better the performance on snow and on ice.
Rim: 7.50 x 22.5
Tire pressure: 800kPa
Test vehicle: 10 ton truck (2-D vehicle) with 5 ton load Tire mounting position: All wheels "A" in Table 1 indicates a mode in which the widened portions of the sipe pairs are widened only in the direction away from each other.
The "B" is a mode in which the widening portions are widened only in the direction facing each other,
The shape "C" is one in which the widened portions are widened both in the direction facing each other and in the direction separating from each other.

<Chipping resistance>
When the blocks had worn down 40% on the test vehicle, the number of chips originating from the sipes was visually counted and rated on a four-point scale as shown below. The higher the value, the better the chip resistance.
100: No chipping or the like occurred.
95: There are 1 to 5 chips or chips.
90: There are 6 to 10 chips or chips.
85: There are 11 or more chips or chips.

<Mold removal performance>
The condition between the knife blades of the vulcanization mold after each test tire was vulcanized and molded was confirmed. The results were evaluated by visual inspection by an examiner and shown as a score with Example 1 being 100. A larger value indicates less rubber remaining between the knife blades and better performance.
The test results are shown in Table 1. It should be noted that in each test, a sample with a score of less than 95 in any one item is a failure, and a sample with a score of 95 or more in all items is a pass.

As a result of the test, it was confirmed that the tires of the embodiment exhibited excellent performance on ice and snow. It was also confirmed that the tires of the embodiment were less prone to chipping and had excellent mold removal performance.

[Additional Notes]
The present disclosure includes the following aspects.

[Disclosure 1]
A tire having a tread portion,
The tread portion is provided with a plurality of blocks,
At least one of the blocks is provided with a plurality of sipes,
The plurality of sipes include two or more sipe pairs formed such that a distance between adjacent sipes is smaller than a distance between other adjacent sipes,
In at least one of the sipe pairs, each of the sipes includes a main body portion and a widened portion that is disposed radially inward of the main body portion and has a width larger than that of the main body portion,
The widening portions are widened only in directions away from each other.
tire.
[Disclosure 2]
Each sipe has a pair of wall surfaces extending inward in the tire radial direction from the tread surface of the block,
The pair of wall surfaces includes a first wall surface on a side where the sipes of the sipe pair are adjacent to each other, and a second wall surface on an opposite side to the first wall surface,
The first wall surface and the second wall surface are continuous at a bottom portion,
In a vertical cross section in the sipe width direction, the first wall surface includes a first arc portion extending in an arc shape from the bottom portion to an outer side in the tire radial direction,
The tire described in Disclosure 1, wherein the radius of curvature of the first arc portion is 0.3 to 0.5 mm.
[Disclosure 3]
In a vertical cross section in the sipe width direction, the second wall surface includes a second arc portion extending in an arc shape from the bottom portion to an outer side in the tire radial direction,
The tire according to Disclosure 2, wherein the second arcuate portion has a radius of curvature of 0.5 to 0.8 mm.
[Disclosure 4]
The tire according to any one of claims 1 to 3, wherein each of the sipes extends at an angle of 40 degrees or less with respect to the tire axial direction.
[Disclosure 5]
The widened portion has a maximum half width from a width center of the main body portion,
The tire according to any one of claims 1 to 4, wherein the maximum half-width is 1.5 to 4.0 times the half-width of the main body portion.
[Disclosure 6]
The tire of Disclosure 5, wherein the maximum half-width is 2.0 to 3.5 times the half-width of the main body portion.
[Disclosure 7]
The tire according to any one of disclosures 1 to 6, wherein the spacing between adjacent sipes of the sipe pair is 0.3 to 0.8 times the spacing between other adjacent sipes.
[Disclosure 8]
The block includes a block edge spaced apart from the sipe of the sipe pair in a sipe width direction,
The tire according to any one of disclosures 1 to 7, wherein the interval between the adjacent sipes of the sipe pair is 0.3 to 0.8 times the interval between the sipe most adjacent to the block edge and the block edge.
[Disclosure 9]
The blocks are defined by interconnected sipes in which each sipe in each sipe pair is interconnected,
The tire according to any one of disclosures 1 to 8, wherein a depth of each of the sipes is equal to or less than a depth of the interconnecting sipes.
[Disclosure 10]
The tire according to any one of disclosures 1 to 9, wherein three or more sipe pairs are provided in each block.

Reference Signs List 1 Tire 4 Sipe 6 Body portion 7 Widened portion

Claims (10)

A tire having a tread portion,
The tread portion is provided with a plurality of blocks,
At least one of the blocks is provided with a plurality of sipes,
The plurality of sipes include two or more sipe pairs formed such that a distance between adjacent sipes is smaller than a distance between other adjacent sipes,
In at least one of the sipe pairs, each of the sipes includes a main body portion and a widened portion that is disposed radially inward of the main body portion and has a width larger than that of the main body portion,
The widening portions are widened only in directions away from each other ,
The widened portion has a maximum half width from a width center of the main body portion,
Each sipe constituting the sipe pair has a pair of wall surfaces extending inward in the tire radial direction from the tread surface of the block,
The pair of wall surfaces includes a first wall surface on a side where the sipes of the sipe pair are adjacent to each other, and a second wall surface on an opposite side to the first wall surface,
The first wall surface and the second wall surface are continuous at a bottom portion which is an innermost end of the sipe in the tire radial direction,
In a vertical cross section in the sipe width direction, the first wall surface includes a first arc portion extending continuously from the bottom portion outward in a radial direction of the tire in an arc shape, and a first linear portion extending linearly and connected to the first arc portion,
the first linear portion is disposed at a position furthest from a width center of the main body portion on a side of the other sipe of the sipe pair from the bottom portion,
the second wall surface includes a second arc portion extending continuously in an arc shape from the bottom portion outward in the tire radial direction to a position where the maximum half-width is reached,
The bottom is located at the width center of the main body.
tire. 2. The tire according to claim 1, wherein the first arcuate portion has a radius of curvature of 0.3 to 0.5 mm. 3. The tire according to claim 2, wherein the second arcuate portion has a radius of curvature of 0.5 to 0.8 mm. The tire according to any one of claims 1 to 3, wherein each of the sipes extends at an angle of 40 degrees or less relative to the tire axial direction. The widened portion has a maximum half width from a width center of the main body portion,
5. The tire according to claim 1, wherein the maximum half width is 1.5 to 4.0 times the half width of the main body portion. The tire according to claim 5, wherein the maximum half width is 2.0 to 3.5 times the half width of the main body portion. The tire according to any one of claims 1 to 6, wherein the spacing between adjacent sipes in the sipe pair is 0.3 to 0.8 times the spacing between other adjacent sipes. The block includes a block edge spaced apart from the sipe of the sipe pair in a sipe width direction,
8. The tire according to claim 1, wherein the interval between the adjacent sipes of the sipe pair is 0.3 to 0.8 times the interval between the sipe most adjacent to the block edge and the block edge. The blocks are defined by interconnected sipes in which each sipe in each sipe pair is interconnected,
The tire according to claim 1 , wherein a depth of each of the sipes is equal to or less than a depth of the interconnecting sipes. The second wall surface further includes a bulge portion connected to the tread surface,
The bulge portion includes a half width from a width center of the main body portion,
10. The tire according to claim 1 , wherein the half width of the bulge is 1.2 to 1.9 times the maximum half width .

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