JP7293889B2 - pneumatic tire - Google Patents

Description

TECHNICAL FIELD The present invention relates to a pneumatic tire with well-balanced improvement in tire noise performance, wet braking performance, and steering stability performance.

Various techniques have been proposed for improving tire noise performance.

For example, the tread width TW, which is the tire axial distance between the ground contact edges of the tread portion, is set to 0.65 to 0.90 times the tire maximum width SW, and 50% of the tread width TW centered on the tire equator. The profile of the outer surface of the tread center region, which is the region, is made into an arc shape that is convex and curved outward in the tire radial direction, and the angle of the band cord of the band ply with respect to the tire circumferential direction is gradually decreased from the ground contact side toward the tire equator side. Furthermore, a technology has been proposed in which tire noise performance is improved by giving characteristics to the relationship between the curvature radii of the profile when the internal pressure is 10 kPa, 230 kPa, and 300 kPa (Patent Document 1).

Japanese Patent No. 5952587

However, for example, when tire noise performance is improved by reducing the area of the grooves formed in the tread portion, there is concern that wet braking performance may deteriorate due to the decrease in groove area. Further, when the tire noise performance is improved by reducing the rigidity of the tread portion by lowering the rigidity of the belt, etc., there is concern that the reduced rigidity of the tread portion may deteriorate steering stability performance.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to provide a pneumatic tire that achieves well-balanced improvements in tire noise performance, wet braking performance, and steering stability performance.

In a pneumatic tire according to the present invention, at least two circumferential main grooves extending in the tire circumferential direction are formed in the tread portion,
In a state where it is incorporated in a specified rim and filled with specified internal pressure,
If SW is the total width of the tire, CW100 is the contact width when the load is 100% of the maximum load capacity, and CW70 is the contact width when the load is 70% of the maximum load capacity,
1.04≤CW100/CW70≤1.15, and 0.75≤CW100/SW≤0.90
The filling,
When the groove area ratio when a load of 70% of the maximum load capacity is applied is GR70,
15%≤GR70≤27%
The filling,
GRA is the groove area ratio excluding the circumferential main groove when a load of 70% of the maximum load capacity is applied, and the area that touches the ground when a load of 70% of the maximum load capacity is applied and 100% of the maximum load capacity. When GRB is the groove area ratio in the difference area between the ground contact area and the difference area when the load is applied,
Groove area ratio GRA<Groove area ratio GRB
meet.

In the pneumatic tire according to the present invention, the ratio of the contact width under braking load to the contact width under normal load, the ratio of the contact width to the total tire width under braking load, and the groove area under normal load and the relationship between the groove area ratio when a normal load is applied and the groove area ratio when a braking load is applied. As a result, according to the pneumatic tire of the present invention, tire noise performance, wet braking performance, and steering stability performance can be improved in a well-balanced manner.

FIG. 1 is a tire meridional cross-sectional view showing a pneumatic tire according to an embodiment of the present invention. 2 is a plan view of the pneumatic tire shown in FIG. 1. FIG. FIG. 3 is a tire meridional cross-sectional view showing only one side in the tire width direction from the tire equatorial plane CL from the sidewall portion to the tread portion of the pneumatic tire of the present embodiment shown in FIG. FIG. 4 is a plan view showing a modification of the pneumatic tire of this embodiment shown in FIG.

EMBODIMENT OF THE INVENTION Below, embodiment of the pneumatic tire which concerns on this invention (a basic form and additional forms 1-6 shown below) is described in detail based on drawing. It should be noted that these embodiments do not limit the present invention. In addition, the constituent elements of the embodiments include those that can be easily replaced by those skilled in the art, or those that are substantially the same. Furthermore, various forms included in the embodiment can be arbitrarily combined within the scope obvious to those skilled in the art.

[Basic form]
The basic configuration of the pneumatic tire according to the present invention will be described below. In the following description, the tire radial direction refers to the direction perpendicular to the rotation axis of the pneumatic tire, the tire radial direction inner side refers to the side facing the rotation axis in the tire radial direction, and the tire radial direction outer side refers to the tire radial direction. The side away from the rotation axis. In addition, the tire circumferential direction refers to a circumferential direction around the rotation axis. Furthermore, the tire width direction refers to a direction parallel to the rotation axis, the tire width direction inner side refers to the side facing the tire equatorial plane (tire equator line) in the tire width direction, and the tire width direction outer side refers to the direction in the tire width direction. The side away from the tire equatorial plane. The tire equatorial plane is a plane perpendicular to the rotation axis of the pneumatic tire and passing through the center of the tire width of the pneumatic tire.

FIG. 1 is a tire meridional cross-sectional view showing a pneumatic tire (at no load) according to the present embodiment. A pneumatic tire 10 shown in FIG. 1 includes a pair of left and right bead portions 12, sidewall portions 14, 14 extending radially outwardly of the bead portions 12, and a tread portion 16 extending between the sidewall portions 14, 14. .

In addition, the pneumatic tire 10 shown in FIG. A belt 24 including at least one (three layers in the figure) belt layers 24a, 24b, and 24c containing cords arranged outside the tire radial direction of the belt 24, and a belt 24 arranged outside the tire width direction of the belt 24, and a tread portion 16 and a tread rubber 26 forming part of the tread rubber 26 .

FIG. 2 is a plan view of the pneumatic tire (at no load) shown in FIG. As shown in FIGS. 1 and 2, the pneumatic tire 10 of the present embodiment has at least two (four in these drawings) circumferential main grooves 28 extending in the tire circumferential direction in the tread portion 16. (28a, 28b, 28c, 28d) are formed.

In the pneumatic tire 10 of the present embodiment, as shown in FIG. 2, a plurality of grooves inclined with respect to the tire width direction are provided outside the tire width direction outermost circumferential main grooves 28a and 28d in the tire width direction, respectively. lug grooves 30 are formed at regular intervals in the tire circumferential direction. Further, in the example shown in FIG. 2, narrow grooves 32 extending inward in the tire width direction from each of the two circumferential main grooves 28b and 28c on the inner side in the tire width direction and terminating in the land portion are constant in the tire circumferential direction. formed at intervals. Furthermore, in the example shown in FIG. 2, narrow grooves 34 extending inward in the tire width direction from each of the two circumferential main grooves 28a and 28d on the outer side in the tire width direction and terminating in land portions are fixed in the tire circumferential direction. formed at intervals.

The circumferential main grooves 28a to 28d shown above have a groove width of 6 mm to 12 mm and a groove depth of 6 mm to 9 mm. The lug groove 30 has a groove width of 1.5 mm to 4 mm and a groove depth of 4.4 mm to 7.4 mm. The narrow grooves 32 and 34 have a groove width of 0.6 mm to 1.5 mm and a groove depth of 4.4 mm to 7.4 mm. Here, the groove width is the maximum dimension in the direction perpendicular to the extending direction of the groove, and the groove depth is the maximum dimension in the tire radial direction from the tire profile line to the groove bottom when there is no groove. be.

Under the premise as described above, the pneumatic tire 10 of the present embodiment is installed in a specified rim and filled with a specified internal pressure.
Let SW be the total width of the tire (Fig. 1), CW100 be the contact width when a load of 100% of the maximum load capacity is applied, and CW70 be the contact width when a load of 70% of the maximum load capacity is applied.
1.04≤CW100/CW70≤1.15, and 0.75≤CW100/SW≤0.90
meet. The load of 100% of the maximum load capacity is assumed to be the load when the front wheels are under braking load (hereinafter referred to as braking), and the load of 70% of the maximum load capacity is the normal load of the front wheels. Time (meaning the time of use other than when starting and braking. Hereinafter referred to as normal use) is assumed.

Here, the specified rim means the "applicable rim" specified by JATMA, the "design rim" specified by TRA, or the "measuring rim" specified by ETRTO. In addition, the specified internal pressure refers to the "maximum air pressure" specified by JATMA, the maximum value of "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES" specified by TRA, or "INFLATION PRESSURES" specified by ETRTO. Furthermore, the maximum load capacity means the "maximum load capacity" specified by JATMA, the maximum value of "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES" specified by TRA, or the "LOAD CAPACITY" specified by ETRTO. .

Further, when the pneumatic tire 10 of the present embodiment has a groove area ratio of GR70 in normal use,
15%≤GR70≤27%
meet.

Furthermore, in the pneumatic tire 10 of the present embodiment, the groove area ratio excluding the circumferential main groove during normal use is set to GRA, and the groove in the difference area between the ground contact area during normal use and the ground contact area during braking. When the area ratio is GRB,
Groove area ratio GRA<Groove area ratio GRB
meet.

(action, etc.)
By setting the ratio CW100/CW70 to 1.04 or more, it is possible to secure a sufficient contact width during braking, increase the contact area and contact pressure during braking, and improve wet braking performance ( Action and effect 1).

On the other hand, by setting the ratio CW100/CW70 to 1.15 or less, it is possible to secure a sufficient contact width during normal use, to increase the contact area and grip force, and in turn to improve steering stability performance ( Function and effect 2).

In addition, by setting the ratio CW100/SW to 0.75 or more, a sufficient contact width during braking can be secured, the contact area and contact pressure during braking can be increased, and wet braking performance can be enhanced. (Effect 3).

On the other hand, by setting the ratio CW100/SW to 0.90 or less, the contact width during braking does not become excessively large, and the contact pressure can be maintained within a range that does not impede drainage (effect 4).

In addition, by setting the groove area ratio GR70 to 15% or more, a sufficient groove area ratio is secured during normal use to improve drainage, and by adjusting the pattern rigidity to an appropriate range, steering stability performance is achieved. can be increased (effect 5).

On the other hand, by setting the GR70 to 27% or less, it is possible to suppress an increase in the source of road noise without excessively increasing the groove area ratio during normal use, thereby improving the tire noise performance (Effect 6). ).

In addition, road noise during regular use, which causes tire noise, is generated from the target area of the groove area ratio GRA (the area with relatively low dot density (low dot area) in FIG. 2), and is generated from the target area of the groove area ratio GRB. It hardly occurs from the area (area with relatively high dot density (high dot area) in FIG. 2). ), the number of sources of road noise can be reduced, and the tire noise performance can be improved (Effect 7). In addition, by increasing the groove area ratio GRB of the area (high dot area) that is in contact with the road surface only during braking, water remaining on the road surface during braking can escape. It is possible to sufficiently secure the road and improve the wet braking performance (effect 9).

As described above, in the pneumatic tire of the present embodiment, the ratio of the contact width under braking load to the contact width under normal load, the ratio of the contact width to the total tire width under braking load, and the normal use By improving the groove area ratio under load, the relationship between the groove area ratio under normal load and the groove area ratio under braking load, the above effects 1 to 9 are combined to improve tire noise performance, Wet braking performance and steering stability performance can be improved in a well-balanced manner.

In addition, the pneumatic tire of the present embodiment shown above includes the usual manufacturing processes, that is, the tire material mixing process, the tire material processing process, the green tire molding process, the vulcanization process, and the inspection process after vulcanization. etc. When manufacturing the pneumatic tire of the present embodiment, the inner wall of the vulcanization mold is formed with protrusions and recesses corresponding to the grooves and protrusions formed in the tread portion shown in FIG. Vulcanization is performed using this mold.

[Additional forms]
Next, additional forms 1 to 6, which can optionally be implemented with respect to the basic form of the pneumatic tire according to the present invention, will be described.

(Additional form 1)
FIG. 3 is a tire meridional cross-sectional view showing only one side in the tire width direction from the tire equatorial plane CL from the sidewall portion 14 to the tread portion 16 of the pneumatic tire of the present embodiment shown in FIG. More specifically, FIG. 3 is a meridional cross-sectional view of a tire assembled on a specified rim and filled with a specified internal pressure at no load.

In the basic configuration, as shown in FIG. 3, the point on the tire surface in the tire equatorial plane CL is P0, the point in the tire width direction corresponding to the ground contact edge during braking is P1, and the ground contact edge during normal use is P1. The corresponding point in the tire width direction is P2, the point in the tire width direction position corresponding to the ground contact edge when a load of 50% of the maximum load capacity is applied is P3, and each line connecting the point P0 and the points P1 to P3. θ100, θ70, and θ50, respectively, when the angles formed by the minute with respect to the tire width direction are θ100, θ70, and θ50,
4.5°≦θ100≦7.5°,
1.15≤θ100/θ70≤1.35 and 1.60≤θ100/θ50≤2.10
The filling,
Further, the effective belt width BW and the contact width CW100 are
0.87≤BW/CW100≤0.97
(additional form 1) is preferred.

Note that the load of 50% of the maximum load capacity assumes that the rear wheels are normally loaded. Further, the effective belt width BW refers to the dimension in the tire width direction of the belt layer that is the longest in the tire width direction among the belt layers that make up the belt.

By setting θ100 to 4.5° or more, the load dependency of the contact width can be increased, the contact area during braking can be further increased, and wet braking performance can be further improved.

On the other hand, by setting θ100 to 7.5° or less, the load dependence of the ground contact width is not excessively increased, and the ground contact width is not excessively different between normal use and braking. Stability performance can be further enhanced.

Further, by setting θ100/θ70 to be 1.15 or more, it is possible to further enhance the load dependence of the contact width of the front wheels. As a result, the ground contact area during braking can be further increased, and wet braking performance can be further increased.

On the other hand, by setting θ100/θ70 to 1.35 or less, it is possible to further avoid excessively increasing the load dependence of the contact width of the front wheels. As a result, the steering stability performance in particular can be further enhanced without excessively changing the ground contact width between normal use and braking.

Furthermore, by setting θ100/θ50 to be 1.60 or more, it is possible to further improve the load dependency of the contact width of the rear wheels. As a result, the ground contact area during braking can be further increased, and wet braking performance can be further increased.

On the other hand, by setting θ100/θ50 to 2.10 or less, it is possible to further avoid excessively increasing the load dependence of the contact width of the rear wheels. As a result, the steering stability performance in particular can be further enhanced without excessively changing the ground contact width between normal use and braking.

In addition, by setting BW/CW100 to 0.87 or more, it is possible to further increase the rigidity by arranging the belt layer in most of the area that touches the ground during braking, which in turn can further increase the wet braking performance. .

On the other hand, by setting BW/CW100 to 0.97 or less, regions where no belt layer is arranged exist on both outer sides in the tire width direction of the region that contacts the ground during braking, and the rigidity of these portions is reduced. Deformation of the tread portion can be made easier. As a result, it is possible to further increase the ground contact pressure during braking, thereby further enhancing the wet braking performance.

(Additional form 2)
In the basic mode or the mode obtained by adding the additional mode 1 to the basic mode, the difference between the groove area ratio GRA and the groove area ratio GRB satisfies 10% ≤ (GRB - GRA) ≤ 20% (additional mode 2 ) is preferred.

In additional form 2, the difference (GRB-GRA) is set to 10% or more, that is, the high dot area (area that touches the ground only during braking) and the low dot area (area that touches the ground only during normal use and braking) in FIG. The difference in groove area ratio from the groove area) is set to 10% or more. Therefore, it is possible to further increase the amount of increase in the groove area in the contact surface when shifting from normal use to braking, thereby further enhancing wet braking performance.

On the other hand, in additional mode 2, the difference (GRB-GRA) is set to 20% or less, that is, the difference in groove area ratio between the high dot area and the low dot area in FIG. 2 is set to 20% or less. For this reason, the amount of increase in the groove area in the ground contact surface when shifting from normal use to braking should not be excessively increased, and in particular, the groove area of the lug grooves 30 included in the ground contact surface during braking in FIG. 2 should be suppressed. can be done. As a result, it is possible to suppress an increase in road noise during the transition from normal use to braking, thereby further improving tire noise performance.

(Additional form 3)
In the basic mode or in the mode obtained by adding at least one of the additional modes 1 and 2 to the basic mode, it is preferable that the total tire width SW shown in FIG. 1 is equal to or less than the standard median value (additional mode 3). Here, the standard means JATMA, TRA, or ETRTO mentioned above. In addition, the median value of the standard refers to the value located in the center when a plurality of total tire widths SW listed in JATMA and the like are arranged in ascending order.

By making the total tire width SW equal to or less than the standard median value, in other words, by reducing the total tire width SW to some extent, the ground contact width SW can be reduced from the time of normal use to the time of braking. As a result, the groove area in the contact patch can be kept low from normal use to braking, road noise can be reduced, and tire noise performance can be further enhanced.

(Additional form 4)
In the basic mode or in the mode obtained by adding at least one of the additional modes 1 to 3 to the basic mode, it is preferable that the tire outer diameter is equal to or larger than the standard median value (additional mode 4). Here, the standard means JATMA, TRA, or ETRTO mentioned above. In addition, the standard median value refers to the value located in the center when multiple tire outer diameters listed in JATMA, etc., are arranged in ascending order.

By making the tire outer diameter larger than the median value of the standard, in other words, by increasing the tire outer diameter to some extent, the tread surface will be in contact with the road surface in the area where the grooves are formed, both during normal use and during braking. The contact area can be made even smaller. As a result, from normal use to braking, the groove area within the contact surface can be kept low, road noise can be reduced, and tire noise performance can be further enhanced.

By setting the tire outer diameter to a value smaller than the standard maximum by 3 mm or more, the above effect can be exhibited at a higher level.

(Additional form 5)
In the basic configuration or a configuration in which at least one of the additional configurations 1 to 4 is added to the basic configuration, the outermost two circumferential main grooves 28a to 28d shown in FIG. The ratio (GEW/CW70) is 0.85, where GEW is the dimension in the tire width direction between the main grooves 28a and 28d (more specifically, between the outer positions of the grooves 28a and 28d in the tire width direction). It is preferable that it is 0.92 or less (additional mode 5).

By setting the ratio (GEW/CW70) to 0.85 or more, the circumferential main grooves 28a and 28d are formed up to the regions close to both end portions of the CW70 in the tire width direction for the front wheels, and as a result, the circumferential main grooves 28a are formed. , 28d can be formed in regions close to both end portions of the CW 100 in the tire width direction. As a result, drainage performance during braking can be further improved, and wet braking performance can be further enhanced.

On the other hand, by setting the ratio (GEW/CW70) to 0.92 or less, in FIG. It is possible to sufficiently secure the rigidity of the land portion on the inner side of the groove 30 in the tire width direction (that is, the portion where the contact pressure with the road surface is high both during regular use and during braking). As a result, steering stability performance and wet braking performance can be further enhanced.

While FIG. 2 shows an example in which there are four circumferential main grooves (where two grooves 28b and 28c constitute an air column), FIG. 4 is a modification of FIG. Specifically, it is an example showing a case where there are five circumferential main grooves (28a, 28b, 28c, 28d and 28e) (when three grooves 28f, 28g and 28h form an air column). In both cases of FIGS. 2 and 4, by setting the ratio (GEW/CW70) within the above range, the above effects can be obtained.

(Additional form 6)
In the basic configuration or a configuration obtained by adding at least one of additional configurations 1 to 5 to the basic configuration, a belt cover 36 (36a, 36b) is provided outside the belt 24 shown in FIG. 3, the tire radial dimension MG of the carcass 14, the belt 24, and the belt cover 36 is preferably 2.0 mm or more and 5.5 mm or less (additional mode 6).

By setting the tire radial dimension MG to 2.0 mm or more, excellent durability performance can be achieved. On the other hand, by setting the tire radial dimension MG to 5.5 mm or less, the rigidity of the tread as a whole is not excessively increased. As a result, the tread portion can be sufficiently deformed during running, and a sufficient contact area can be ensured, so that steering stability and wet braking performance can be further enhanced.

The tire radial dimension MG is more preferably 3.5 mm or more and 5.0 mm or less, and extremely preferably 3.7 mm or more and 4.8 mm or less.

Pneumatic tires of invention examples 1 to 7 and a conventional pneumatic tire having a tire size of 205/60R16 92V and having the tire meridional cross-sectional shape shown in FIGS. 1 and 2 (FIG. 4 in some cases) were produced. The detailed conditions of these pneumatic tires are as shown in Tables 1 and 2 below. In Tables 1 and 2, SW is the total width of the tire, CW100 is the ground width when a load of 100% of the maximum load capacity is applied, CW70 is the ground width when a load of 70% of the maximum load capacity is applied, and GR70. is the groove area ratio at a load of 70% of the maximum load capacity, GRA is the groove area ratio excluding the circumferential main groove at a load of 70% of the maximum load capacity, GRB is 70% of the maximum load capacity .theta.100, .theta.70, and .theta.50 are points P0 and points P1 to P3 shown in FIG. 3, respectively. BW is the effective belt width, and GEW is the outermost in the tire width direction of the circumferential main groove when a load of 70% of the maximum load capacity is applied. MG indicates the tire width direction dimension between two circumferential main grooves, and MG indicates the tire radial dimension of the carcass, belt, and belt cover on the tire equatorial plane. All of these codes and the like conform to the description of the present specification described above.

The pneumatic tires of Invention Examples 1 to 7 and the test tires of Conventional Example thus prepared were assembled on a specified rim (16 x 6J), and a load (441 kg) of 70% of the maximum load capacity was applied to the front wheel. In addition to loading the rear wheels, load 50% of the maximum load capacity (315 kg) and install it on a front-wheel drive vehicle (test vehicle) with a displacement of 2000 cc. Braking performance and steering stability performance were evaluated.

(Tire noise performance)
The sound pressure level (dB) of passing sound was measured when the transmission was put into neutral at a speed of 50 km/h and the engine was stopped. Then, index evaluation was performed with the sound pressure level of the conventional example set to 100 (reference value). A higher index value means higher tire noise performance. The results are also shown in Table 1.

(Wet braking performance)
On a wet road surface with a water film of 1 mm, the distance from an initial speed of 100 km/h to braking and stopping was measured. Then, using the reciprocal of this measured value, index evaluation was performed with the value of the conventional example set to 100 (reference value). A higher index value means higher wet braking performance. The results are also shown in Table 1.

(Steering stability performance)
The test vehicle was run on a test course with dry road surfaces, and a sensory evaluation was conducted by a skilled test driver regarding linearity (vehicle tracking performance during steering wheel operation) during lane changes and cornering. In this sensory evaluation, index evaluation was performed with the value of the conventional example set to 100 (reference value). A higher index value means higher steering stability performance. The results are also shown in Table 1.

According to Tables 1 and 2, it belongs to the technical scope of the present invention (that is, the ratio of the contact width under braking load to the contact width under normal load, the contact width under braking load and the total tire width ratio, the groove area ratio under normal load, and the relationship between the groove area ratio under normal load and the groove area ratio under braking load. , all of which are improved in a well-balanced manner in tire noise performance, wet braking performance, and steering stability performance, compared to the pneumatic tire of the conventional example, which does not belong to the technical scope of the present invention.

10 pneumatic tire 12 bead portion 14 sidewall portion 16 tread portion 22 carcass 24 belt 26 tread rubber 28 main direction main groove 30 lug grooves 32, 34 narrow groove 36 belt cover GEW between two circumferential direction main grooves 28a, 28d , Tire width direction dimension CL Tire equatorial plane CW70 Ground width when load is 70% of maximum load capacity CW100 Ground width when load is 100% of maximum load capacity SW Total tire width

Claims (7)

A pneumatic tire in which at least two circumferential main grooves extending in the tire circumferential direction are formed in a tread portion,
In a state where it is incorporated in a specified rim and filled with specified internal pressure,
If SW is the total width of the tire, CW100 is the contact width when the load is 100% of the maximum load capacity, and CW70 is the contact width when the load is 70% of the maximum load capacity,
1.04≤CW100/CW70≤1.15, and 0.75≤CW100/SW≤0.90
The filling,
When the groove area ratio when a load of 70% of the maximum load capacity is applied is GR70,
15%≤GR70≤27%
The filling,
GRA is the groove area ratio excluding the circumferential main groove when a load of 70% of the maximum load capacity is applied, and the area that is grounded when a load of 70% of the maximum load capacity is applied and 100% of the maximum load capacity. When GRB is the groove area ratio in the difference area between the ground contact area and the difference area when the load is applied,
Groove area ratio GRA<Groove area ratio GRB
A pneumatic tire characterized by satisfying In a meridional cross-sectional view of a tire assembled on a specified rim and filled with a specified internal pressure, the point on the tire surface on the tire equatorial plane is P0, and corresponds to the ground contact edge when a load of 100% of the maximum load capacity is applied. The point in the tire width direction is P1, the point in the tire width direction corresponding to the ground contact edge when a load of 70% of the maximum load capacity is applied is P2, and the tire width direction position is equivalent to the ground contact edge when a load of 50% of the maximum load capacity is applied. Let P3 be the point in the tire width direction, and let θ100, θ70, and θ50 be the angles formed by the line segments connecting the point P0 and the points P1 to P3 with respect to the tire width direction.
4.5°≦θ100≦7.5°,
1.15≤θ100/θ70≤1.35, and
1.60≤θ100 /θ50≤2.10
The filling,
Furthermore, the effective belt width BW and the contact width CW100 are
0.87≤BW/CW100≤0.97
The pneumatic tire of claim 1, which satisfies: Regarding the difference between the groove area ratio GRA and the groove area ratio GRB,
10% ≤ (GRB-GRA) ≤ 20%
The pneumatic tire according to claim 1 or 2, which satisfies The pneumatic tire according to any one of claims 1 to 3, wherein the total tire width SW is equal to or less than the standard median value. The pneumatic tire according to any one of claims 1 to 4, wherein the tire outer diameter is equal to or larger than the standard median value. When there is no load, GEW is the dimension in the tire width direction between the two outermost circumferential main grooves in the tire width direction of the circumferential main grooves,
0.85≤GEW/CW70≤0.92
The pneumatic tire according to any one of claims 1 to 5, satisfying: A carcass, a belt on the outer side of the carcass in the tire radial direction, and a belt cover on the outer side of the belt in the tire radial direction, and the sum of the carcass, the belt, and the belt cover in the tire radial direction on the tire equatorial plane When the dimension is MG,
2.0mm≦MG≦5.5mm
The pneumatic tire according to any one of claims 1 to 6, which satisfies

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