JP2024018104A - pneumatic tires - Google Patents

Abstract

An object of the present invention is to provide a pneumatic tire that can streamline puncture repair using a puncture repair material. SOLUTION: A pneumatic tire 1 having a tread portion 2. In the pneumatic tire 1, a sponge-like sound absorber 9 is provided on the inner surface 2b of the tread portion 2. The sound absorber 9 has an outer circumferential surface 9a facing outward in the tire radial direction. The adhesion area between the outer circumferential surface 9a of the sound absorber 9 and the inner surface 2b of the tread portion 2 is 52% to 88% of the projected area of the sound absorber 9 projected onto the inner surface 2b. [Selection diagram] Figure 1

Description

The present invention relates to a pneumatic tire having a tread portion.

BACKGROUND ART Conventionally, pneumatic tires are known in which a sound absorbing device is provided on the inner surface of a tread portion in order to reduce road noise. For example, Patent Document 1 below proposes a pneumatic tire that further reduces road noise by forming convex portions and concave portions on the inward surface of a sound absorbing device in the tire radial direction.

JP 2019-108034 Publication

However, when the pneumatic tire of Patent Document 1 is punctured at the part to which the sound absorber is fixed, when the puncture repair material is used to repair the tire, the puncture repair material is supplied through the sound absorber. Sometimes the time required to do so was extended.

The present invention was devised in view of the above-mentioned circumstances, and provides a pneumatic tire that can streamline puncture repair using a puncture repair material, based on the provision of a sponge-like sound absorber on the inner surface of the tread portion. The main purpose is to.

The present invention provides a pneumatic tire having a tread portion, wherein a sponge-like sound absorber is fixed to the inner surface of the tread portion, and the sound absorber has an outer circumferential surface facing outward in the tire radial direction. The pneumatic tire is such that the fixed area between the outer peripheral surface and the inner surface is 52% to 88% of the projected area of the sound absorber projected onto the inner surface.

The pneumatic tire of the present invention has the above-described configuration, thereby making it possible to efficiently repair a puncture using a puncture repair material.

1 is a sectional view showing an embodiment of a pneumatic tire of the present invention. It is a partial perspective view of a sound absorber. FIG. 3 is an enlarged cross-sectional view perpendicular to the longitudinal direction of the groove. FIG. 3 is an enlarged cross-sectional view perpendicular to the longitudinal direction of a groove in which a chamfered portion is formed. FIG. 2 is a developed view of the sound absorber of the present embodiment viewed from the outer circumferential surface side. FIG. 1 is a partial cross-sectional view of a pneumatic tire. It is a schematic diagram showing the material of a sound absorber. It is an explanatory view at the time of manufacturing a sound absorber. FIG. 7 is a developed view of a sound absorber according to another embodiment as viewed from the outer circumferential surface side.

Hereinafter, one embodiment of the present invention will be described in detail based on the drawings.
FIG. 1 is a tire meridian cross-sectional view including a rotating shaft in a normal state, showing a pneumatic tire 1 of this embodiment. Here, the "regular state" is an unloaded state in which the pneumatic tire 1 is mounted on a regular rim, and the internal pressure is adjusted to a regular value. Hereinafter, unless otherwise mentioned, the dimensions of each part of the pneumatic tire 1 are values measured in this normal state.

If there is a standard system that includes the standard on which the pneumatic tire 1 is based, the "regular rim" is a rim specified for each tire by the standard, for example, "standard rim" for JATMA, "Design rim" for TRA, etc. Rim", and for ETRTO it is "Measuring Rim". If there is no standard system including the standard on which the pneumatic tire 1 is based, the "regular rim" is the one with the smallest rim diameter among the rims that can be assembled and does not cause air leakage. It has a narrow rim.

"Regular internal pressure" is the air pressure specified for each tire by each standard when there is a standard system including the standard on which the pneumatic tire 1 is based, and for JATMA it is the "maximum air pressure", and for TRA it is the air pressure specified in the table "TIRE". LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURE", and for ETRTO it is "INFLATION PRESSURE". "Regular internal pressure" is an air pressure determined for each tire by a manufacturer, etc., if there is no standard system including the standard on which the pneumatic tire 1 is based.

As shown in FIG. 1, the pneumatic tire 1 of the present embodiment includes a tread portion 2 extending annularly, a pair of sidewall portions 3 on both sides of the tread portion 2 in the tire axial direction, and each sidewall portion 3. It has a bead portion 4 on the inner side in the tire radial direction.

In the tread portion 2 of this embodiment, the outer surface 2a constitutes a ground contact surface that contacts the road surface during running. It is desirable that the sidewall portions 3 extend inward in the tire radial direction from both sides of the tread portion 2 in the tire axial direction. For example, a buttress portion is provided between the tread portion 2 and the sidewall portion 3. The bead portion 4 includes, for example, a portion that comes into contact with the rim when the rim is assembled. The bead portion 4 of this embodiment has a bead core 5 that extends annularly. The bead core 5 is made of steel wire, for example.

The pneumatic tire 1 of this embodiment includes a carcass 6 extending from a tread portion 2 through a pair of sidewall portions 3 to a pair of bead portions 4, and a belt disposed outside the carcass 6 in the tire radial direction in the tread portion 2. It has a layer 7. The pneumatic tire 1 may include, for example, a band layer (not shown) disposed outside the belt layer 7 in the tire radial direction.

It is desirable that the carcass 6 extends in a toroidal manner between the bead cores 5 of the pair of bead portions 4 via the tread portion 2 and the pair of sidewall portions 3. The carcass 6 includes at least one, for example, one carcass ply 6A. The carcass ply 6A of this embodiment extends between the pair of bead portions 4 via the tread portion 2 and the pair of sidewall portions 3.

The carcass ply 6A includes, for example, a main body part 6a that extends from the tread part 2 through the sidewall part 3 to the bead core 5 of the bead part 4, and is continuous with the main body part 6a, and extends around the bead core 5 from the inside to the outside in the tire axial direction. It includes a folded part 6b which is folded back. Such a carcass 6 improves the rigidity of the bead portion 4 and is useful for improving the durability performance of the pneumatic tire 1.

The belt layer 7 includes at least one, for example two, belt plies 7A and 7B. The two belt plies 7A and 7B include, for example, a first belt ply 7A located on the inside in the tire radial direction, and a second belt ply 7B located on the outside of the first belt ply 7A. Such a belt layer 7 can increase the rigidity of the tread portion 2 and improve the durability performance of the pneumatic tire 1.

In the pneumatic tire 1, for example, a bead apex 8 extending outward in the tire radial direction is arranged in the bead portion 4. The bead apex 8 extends outward in the tire radial direction from the bead core 5, for example, between the main body portion 6a and the folded portion 6b of the carcass 6. Such a bead apex 8 improves the rigidity of the bead portion 4 and is useful for improving the durability performance of the pneumatic tire 1.

In the pneumatic tire 1 of this embodiment, a spongy sound absorbing body 9 is provided on the inner surface 2b of the tread portion 2 in the tire radial direction. It is desirable that the sound absorber 9 has an outer circumferential surface 9a facing outward in the tire radial direction and an inner circumferential surface 9b facing inward in the tire radial direction. In the sound absorber 9 of this embodiment, the outer peripheral surface 9a is fixed to the inner surface 2b of the tread portion 2.

Such a sound absorber 9 can reduce road noise of the pneumatic tire 1. Here, fixing of the sound absorber 9 includes not only adhering to the inner surface 2b with an adhesive, adhesive, double-sided tape, etc., but also fixing via a sealant applied to the inner surface 2b.

The fixed area between the outer circumferential surface 9a and the inner surface 2b is preferably 52% to 88% of the projected area of the sound absorber 9 projected onto the inner surface 2b. Since the fixed area is 52% or more of the projected area, peeling of the sound absorber 9 can be suppressed even when the tread portion 2 is largely deformed during high-speed driving, and the high-speed durability performance of the pneumatic tire 1 is improved. Very useful.

When the fixed area is 88% or less of the projected area, a gap can be formed between the sound absorber 9 and the inner surface 2b, and the puncture repair material can be supplied to the puncture site through the gap. Therefore, the pneumatic tire 1 of the present embodiment can improve the efficiency of puncture repair using the puncture repair material.

FIG. 2 is a partial perspective view of the sound absorber 9. As shown in FIGS. 1 and 2, in a more preferred embodiment, a plurality of grooves 10 and a plurality of land portions 11 separated by the plurality of grooves 10 are formed on the outer peripheral surface 9a of the sound absorber 9. There is. In this embodiment, the plurality of land portions 11 are each continuously fixed to the inner surface 2b of the tread portion 2 along the longitudinal direction of the groove 10.

Even when the pneumatic tire 1 is punctured, such a sound absorber 9 can supply the puncture repair material to the puncture location via the groove 10, and can efficiently repair the puncture. Furthermore, since a gap is formed between the sound absorber 9 and the tread portion 2 by the grooves 10, heat storage by the sound absorber 9 can be suppressed even when the tread portion 2 generates heat during high-speed running. . Therefore, the pneumatic tire 1 of this embodiment can achieve both efficiency in puncture repair and improvement in high-speed durability performance.

FIG. 3 is an enlarged sectional view of the groove 10 perpendicular to the longitudinal direction. As shown in FIGS. 2 and 3, each of the plurality of grooves 10 has an opening width w1 at the outer peripheral surface 9a that is smaller than a groove bottom width w2 of the groove 10 in a cross section perpendicular to the longitudinal direction of the groove 10. is desirable. Such a sound absorber 9 can increase the cross-sectional area of the groove 10 while increasing the adhesion area to the inner surface 2b, and is effective in achieving both efficiency in puncture repair and improvement in high-speed durability performance. It is.

Each of the plurality of grooves 10 has, for example, a trapezoidal cross-sectional shape in a cross section perpendicular to the longitudinal direction of the groove 10. Such a groove 10 is effective in achieving both an increase in the area of adhesion to the inner surface 2b and an increase in the cross-sectional area of the groove 10.

The plurality of grooves 10 of this embodiment have the same opening width w1 in a cross section perpendicular to the longitudinal direction of the groove 10. Further, the plurality of grooves 10 of this embodiment have the same groove bottom width w2 in a cross section perpendicular to the longitudinal direction of the groove 10. Such a sound absorber 9 can suppress imbalance in the direction perpendicular to the longitudinal direction and improve the noise performance of the pneumatic tire 1 in a well-balanced manner.

In the cross section orthogonal to the longitudinal direction of the groove 10, the plurality of land portions 11 of this embodiment have the same width w3 at the outer circumferential surface 9a. It is desirable that the width w3 of the land portion 11 be equal to the groove bottom width w2 of the groove 10. The plurality of land portions 11 of this embodiment have the same narrowest width w4 in a cross section perpendicular to the longitudinal direction of the groove 10. It is desirable that the narrowest width w4 of the land portion 11 be equal to the opening width w1 of the groove 10.

That is, it is desirable that the cross-sectional shape of the land portion 11 be equal to the cross-sectional shape of the groove 10. When manufacturing such a sound absorber 9 by cutting one material M (shown in FIG. 7) along the outer circumferential surface 9a, both of the cut pieces can be used as the sound absorber 9, reducing manufacturing loss. can be reduced.

Each of the plurality of grooves 10 preferably has an opening width w1 of 3.0 to 11.0 mm. Since the opening width w1 is 3.0 mm or more, a gap is reliably formed between the inner surface 2b and the inner surface 2b, so that the efficiency of puncture repair and the effect of suppressing heat accumulation by the sound absorber 9 can be reliably achieved. By setting the opening width w1 to 10 mm or less, the force acting on one land portion 11 during traveling can be reduced, and separation of the sound absorber 9 can be suppressed.

Each of the plurality of grooves 10 preferably has a groove bottom width w2 of 3.7 to 23.0 mm. By setting the groove bottom width w2 to 3.7 mm or more, the cross-sectional area of the groove 10 can be increased, and the supply of puncture repair material can be made more efficient. By setting the groove bottom width w2 to 23.0 mm or less, the strength of the land portion 11 can be prevented from being excessively reduced, and the high-speed durability performance of the pneumatic tire 1 can be improved.

Each of the plurality of grooves 10 preferably has a groove depth d of 1 to 10 mm from the outer peripheral surface 9a. Since the groove depth d is 1 mm or more, a gap is reliably formed between the inner surface 2b and the inner surface 2b, so that the effect of suppressing heat accumulation and the efficiency of puncture repair can be achieved. From this point of view, when the means for fixing the sound absorber 9 is an adhesive or double-sided tape, the groove depth d is preferably 2 mm or more, and when the sound absorber 9 is fixed via a sealant, The groove depth d is preferably 3 mm or more. When the groove depth d is 10 mm or less, a decrease in the strength of the land portion 11 due to the formation of the groove 10 can be suppressed, and peeling of the sound absorber 9 can be suppressed.

As shown in FIG. 3, each of the plurality of grooves 10 preferably has a pair of groove walls 10a. Each of the pair of groove walls 10a of this embodiment has a wall surface 10b that is inclined with respect to the outer peripheral surface 9a. The inclination angle θ1 between the wall surface 10b and the outer circumferential surface 9a is preferably 45 to 85 degrees. Such a groove 10 can increase both the fixing area and the cross-sectional area of the groove 10.

It is desirable that each of the plurality of grooves 10 has a bottom surface 10c that connects a pair of wall surfaces 10b. The inclination angle θ2 between the wall surface 10b and the bottom surface 10c in this embodiment is equal to the inclination angle θ1 between the wall surface 10b and the outer peripheral surface 9a. Such a sound absorber 9 can be formed with an outer circumferential surface 9a and a bottom surface 10c parallel to each other, and when manufactured by cutting one material M (shown in FIG. 7) along the outer circumferential surface 9a. It is useful to use both of them as the sound absorber 9.

FIG. 4 is an enlarged cross-sectional view orthogonal to the longitudinal direction of the groove 10 in which the chamfered portion 10d is formed. As shown in FIG. 4, for example, a chamfered portion 10d may be formed at each corner between the wall surface 10b and the bottom surface 10c. The chamfered portion 10d is formed, for example, in an arc shape in a cross section perpendicular to the longitudinal direction of the groove 10. Such a groove 10 is useful for suppressing a decrease in the strength of the land portion 11 and suppressing separation of the sound absorber 9.

In this case, a chamfered portion 12 is formed at each corner between the wall surface 10b and the outer circumferential surface 9a. It is desirable that the chamfer 10d on the bottom surface 10c side and the chamfer 12 on the outer peripheral surface 9a side have the same radius of curvature r. Such a land portion 11 maintains good strength and is useful for suppressing separation of the sound absorber 9.

It is desirable that the opening width w1 of the groove 10 in which the chamfered portions 12 are formed is defined as the minimum distance between the chamfered portions 12. Further, the groove bottom width w2 of the groove 10 in which the chamfered portions 10d are formed is defined as, for example, the length of the straight portion between the chamfered portions 10d. Similarly, the width w3 of the land portion 11 on which the chamfered portion 12 is formed is defined as the length of the straight line between the chamfered portions 12, and the narrowest width w4 of the land portion 11 on which the chamfered portion 10d is formed. is preferably defined as the minimum distance between the chamfered portions 10d.

The radius of curvature r of the chamfered portion 10d on the bottom surface 10c side and the chamfered portion 12 on the outer peripheral surface 9a side is preferably 0.5 to 2 mm, respectively. When the radius of curvature r is 0.5 mm or more, the strength of the land portion 11 is maintained, and separation of the sound absorber 9 due to deformation of the tread portion 2 during running can be suppressed. By setting the radius of curvature r to 2 mm or less, it is possible to suppress the adhesion area of the sound absorber 9 from becoming small and to suppress peeling of the sound absorber 9.

FIG. 5 is a developed view of the sound absorber 9 of this embodiment viewed from the outer circumferential surface 9a side. As shown in FIG. 5, each of the plurality of grooves 10 of this embodiment extends parallel to the tire circumferential direction. The sound absorber 9 has, for example, a pair of end surfaces 9c in the tire circumferential direction. It is desirable that each of the plurality of grooves 10 opens at a pair of end surfaces 9c. Such a sound absorber 9 has both a fixed area and strength, and can improve the efficiency of puncture repair of the sound absorber 9 while suppressing separation of the sound absorber 9.

FIG. 6 is a partial cross-sectional view of the pneumatic tire 1 at the tire equator C. Here, as shown in FIG. 1, the tire equator C is the center position of the tread contact edges Te on both sides in the tire axial direction. The tread contact edge Te is the outermost ground contact position in the tire axial direction when the pneumatic tire 1 in a normal state is loaded with a normal load and contacts the ground on a flat surface at a camber angle of 0°. That is, the tread contact width TW between the tread contact edges Te is the maximum width of the contact patch when a normal load is applied to the pneumatic tire 1 in a normal state.

Here, the "regular load" is the load specified for each tire by each standard when there is a standard system including the standard on which the pneumatic tire 1 is based, and in the case of JATMA, it is the "maximum load capacity", and in the case of TRA If it is ETRTO, it is the maximum value listed in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES", and if it is ETRTO, it is "LOAD CAPACITY". The "regular load" is a load determined for each tire by a manufacturer, etc., if there is no standard system including the standard on which the pneumatic tire 1 is based.

As shown in FIG. 6, a gap L is formed between the pair of end surfaces 9c of the sound absorbers 9 fixed to the inner surface 2b of the pneumatic tire 1 of this embodiment. Such a sound absorber 9 can supply puncture repair material from the end surface 9c of the groove 10, and can perform puncture repair more efficiently.

The gap L between the end faces 9c is preferably 3 to 60 mm. By setting the gap L to 3 mm or more, the puncture repair material can be reliably supplied from the end surface 9c of the groove 10. Having a gap L of 60 mm or less helps to suppress imbalance in the tire circumferential direction, and suppresses occurrence of vibrations, noise, etc. during high-speed running.

At least one of the pair of end surfaces 9c, both in this embodiment, have a tapered surface 9d whose height in the tire radial direction gradually decreases. The tapered surface 9d of this embodiment is formed into a planar shape. The tapered surface 9d may be formed, for example, in an arc shape. Such a sound absorber 9 can suppress peeling from the end face 9c where stress is concentrated during running, and can improve the high-speed durability of the pneumatic tire 1.

The tapered surface 9d of this embodiment is formed in a part of the end surface 9c. The height H of the portion of the end surface 9c where the tapered surface 9d is not formed is preferably 3 to 10 mm. Such a sound absorber 9 can suppress damage to the acute angle portion of the end surface 9c, and can improve the efficiency of the work of fixing the sound absorber 9 to the inner surface 2b of the tread portion 2. Note that the tapered surface 9d may be formed on the entire end surface 9c, for example.

The tapered surface 9d is preferably inclined at an angle θ3 of 30 to 80° with respect to the inner circumferential surface 9b. Since the angle θ3 with respect to the inner circumferential surface 9b is 30° or more, a good sound absorption effect by the sound absorber 9 can be maintained. Since the angle θ3 with respect to the inner circumferential surface 9b is 80° or less, the effect of suppressing peeling from the end surface 9c can be reliably achieved.

In the pneumatic tire 1 of the present embodiment, the pair of end surfaces 9c of one sound absorber 9 are fixed with a gap L in the tire circumferential direction, but the pneumatic tire 1 is not limited to such a mode. The inner tire 1 may have a plurality of sound absorbers 9 fixed to each other with gaps L in the tire circumferential direction. In this case, a gap L is formed between the end surfaces 9c of the sound absorbers 9 adjacent to each other. In such a pneumatic tire 1, the amount, shape, etc. of the sound absorber 9 can be selected depending on the purpose.

As shown in FIG. 1, the width W1 of the sound absorber 9 in the tire axial direction is preferably smaller than the width Wa of the belt layer 7 in the tire axial direction. Such a sound absorber 9 suppresses the weight of the pneumatic tire 1 from becoming excessively large, and is useful for improving the steering stability performance of the pneumatic tire 1.

FIG. 7 is a schematic diagram showing the material M of the sound absorber 9, and FIG. 8 is an explanatory diagram when the sound absorber 9 is manufactured. As shown in FIGS. 7 and 8, the sound absorber 9 of this embodiment is manufactured by cutting a single material M along the outer peripheral surface 9a. For example, the sound absorber 9 is cut along the grooves 10 and the land portions 11, and then slid in the longitudinal direction of the grooves 10 to be separated into two sound absorbers 9.

The sound absorber 9 of this embodiment is asymmetrical in the width direction in a cross section perpendicular to the longitudinal direction of the groove 10. Therefore, in the sound absorbing body 9 of this embodiment, two separated sound absorbing bodies 9 can be used as sound absorbing bodies 9 having the same shape, and manufacturing loss can be further reduced.

FIG. 9 is a developed view of the sound absorber 19 of another embodiment viewed from the outer circumferential surface 19a side. As shown in FIG. 9, the outer circumferential surface 19a of the sound absorber 19 of this embodiment includes a plurality of grooves 10 and a plurality of land portions 11 separated by the plurality of grooves 10, similar to the sound absorber 9 described above. is formed. Also in this embodiment, a plurality of land portions 11 are each continuously fixed to the inner surface 2b (shown in FIG. 1) of the tread portion 2 along the longitudinal direction of the groove 10.

Each of the plurality of grooves 10 in this embodiment extends at an angle θ4 of 1 to 90° with respect to the tire circumferential direction. The angle θ4 of the groove 10, for example, is effective for high-speed durability when it is about 15 to 45 degrees, and effective for supplying puncture repair material when it is close to 90 degrees. For these reasons, the angle θ4 of the groove 10 is preferably 45 to 60°. Such a sound absorbing body 19 is useful for achieving both high-speed durability and efficiency in puncture repair.

Although particularly preferred embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and can be implemented in various forms.

[Additional notes]
The present invention is as follows.

[Invention 1]
A pneumatic tire having a tread portion,
A sponge-like sound absorber is fixed to the inner surface of the tread portion,
The sound absorber has an outer peripheral surface facing outward in the tire radial direction,
A fixed area between the outer circumferential surface and the inner surface is 52% to 88% of a projected area of the sound absorber projected onto the inner surface,
pneumatic tires.

[Invention 2]
A plurality of grooves and a plurality of land portions separated by the plurality of grooves are formed on the outer peripheral surface,
The pneumatic tire according to the present invention, wherein each of the plurality of grooves has an opening width on the outer circumferential surface smaller than a groove bottom width of the groove in a cross section perpendicular to the longitudinal direction of the groove.

[Invention 3]
The pneumatic tire according to the second aspect of the present invention, wherein each of the plurality of grooves has a trapezoidal cross-sectional shape in the cross section.

[Invention 4]
The plurality of grooves have the same groove bottom width in the cross section,
In the cross section, each of the plurality of land portions has the same width on the outer peripheral surface,
The pneumatic tire according to Invention 2 or 3, wherein the width is equal to the groove bottom width.

[Present invention 5]
Each of the plurality of grooves has a pair of groove walls,
Each of the pair of groove walls has a wall surface inclined with respect to the outer peripheral surface,
The pneumatic tire according to any one of inventions 2 to 4, wherein the inclination angle between the wall surface and the outer circumferential surface is 45 to 85 degrees.

[Invention 6]
The pneumatic tire according to the present invention, wherein a chamfer is formed at each corner between the wall surface and the outer circumferential surface.

[Present invention 7]
Each of the plurality of grooves has an opening width of 3.0 to 11.0 mm, and a groove bottom width of 3.7 to 23.0 mm, the air inlet according to any one of Inventions 2 to 6. tire.

[Invention 8]
The pneumatic tire according to any one of the present inventions 2 to 7, wherein each of the plurality of grooves extends at an angle of 1 to 90° with respect to the tire circumferential direction.

[Present invention 9]
The pneumatic tire according to any one of inventions 2 to 7, wherein each of the plurality of grooves extends parallel to the tire circumferential direction.

[Invention 10]
The sound absorber has a pair of end surfaces in the tire circumferential direction,
The pneumatic tire according to any one of Inventions 1 to 9, wherein a gap is formed between the pair of end surfaces.

1 Pneumatic tire 2 Tread portion 2b Inner surface 9 Sound absorber 9a Outer peripheral surface

Claims (10)

A pneumatic tire having a tread portion,
A sponge-like sound absorber is fixed to the inner surface of the tread portion,
The sound absorber has an outer peripheral surface facing outward in the tire radial direction,
A fixed area between the outer circumferential surface and the inner surface is 52% to 88% of a projected area of the sound absorber projected onto the inner surface,
pneumatic tires. A plurality of grooves and a plurality of land portions separated by the plurality of grooves are formed on the outer peripheral surface,
The pneumatic tire according to claim 1, wherein each of the plurality of grooves has an opening width on the outer circumferential surface smaller than a groove bottom width of the groove in a cross section perpendicular to the longitudinal direction of the groove. The pneumatic tire according to claim 2, wherein each of the plurality of grooves has a trapezoidal cross-sectional shape in the cross section. The plurality of grooves have the same groove bottom width in the cross section,
In the cross section, each of the plurality of land portions has the same width on the outer peripheral surface,
The pneumatic tire according to claim 2 or 3, wherein the width is equal to the groove bottom width. Each of the plurality of grooves has a pair of groove walls,
Each of the pair of groove walls has a wall surface inclined with respect to the outer peripheral surface,
The pneumatic tire according to claim 2 or 3, wherein the inclination angle between the wall surface and the outer circumferential surface is 45 to 85 degrees. The pneumatic tire according to claim 5, wherein a chamfer is formed at each corner between the wall surface and the outer peripheral surface. The pneumatic tire according to claim 2 or 3, wherein each of the plurality of grooves has an opening width of 3.0 to 11.0 mm and a groove bottom width of 3.7 to 23.0 mm. The pneumatic tire according to claim 2 or 3, wherein each of the plurality of grooves extends at an angle of 1 to 90° with respect to the tire circumferential direction. The pneumatic tire according to claim 2 or 3, wherein each of the plurality of grooves extends parallel to the tire circumferential direction. The sound absorber has a pair of end surfaces in the tire circumferential direction,
The pneumatic tire according to claim 9, wherein a gap is formed between the pair of end surfaces.

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