JP5636758B2 - Pneumatic tire - Google Patents

Description

  The present invention relates to a pneumatic tire provided with a tread pattern.

Conventionally, a pneumatic tire having a tread pattern has been provided with a pitch variation in which the pattern pitch length is dispersed in the tire circumferential direction in order to reduce pattern noise.
Pitch variation refers to distributing the pattern noise frequency by dispersing the pitch length on the tire circumference so that the level of pattern noise at a specific frequency does not increase when the tire rolls on the ground.
Since the pitch variation has a very large degree of freedom in how to distribute the pitch length, more and more pitch variations and pneumatic tires to which the pitch variations are applied have been proposed.

  For example, a tread pattern of a tire tread is formed by a pattern constituent unit row in which three or more types of pattern constituent units having different pitches P, which are circumferential lengths, are arranged in the tire peripheral direction. It comprises a pattern constituent unit row arranged to include the pattern constituent units arranged at intervals of one or more adjacent pitches, and has a test subject pattern constituent unit row obtained by performing a predetermined test. Pitch variation pneumatic tires are known (Patent Document 1).

There is also known a pneumatic tire for making it possible to achieve both improvement in steering stability on a dry road surface and reduction in pattern noise (Patent Document 2).
That is, in the pneumatic tire in which the tire front and back mounting directions with respect to the vehicle are designated, a plurality of tires arranged in the tire circumferential direction in the vehicle inner side (IN) and the vehicle outer side (OUT) with the tire equator E of the tread therebetween. The block elements on the inner side of the vehicle have a pitch number of 60 to 80, the number of types of block elements on the inner side of the vehicle is four or more, and the pitch number of block elements on the outer side of the vehicle is 50 to 70. The number of pitch types of the block elements outside the vehicle is four or more. Further, the pitch number of the block elements inside the vehicle is made larger than the pitch number of the block elements outside the vehicle, and the ratio of the average pitch length of the block elements outside the vehicle to the average pitch length of the block elements inside the vehicle is 1.05. The range is ˜1.20.

JP 2001-130226 A JP 2009-262874 A

In the pneumatic tire described in the above-mentioned Patent Document 1, since it is arranged including the pattern constituent units arranged by skipping one or more adjacent pitches in the order of the length, the shortest pitch having the shortest length is aligned, It is possible to prevent the block rigidity of the tread from becoming small. Therefore, it is possible to suppress a decrease in responsiveness due to a decrease in block rigidity in steering stability.
However, since it is arranged to include one or more pattern constituent units that are arranged adjacent to each other in the order of the length, there is a portion where the change in the adjacent pitch length is large in the tire circumferential direction. May cause wear. The heel & toe wear refers to a form in which the wear difference between adjacent land portions in the tire circumferential direction is greatly different and a wear step is generated in a sawtooth shape in the tire circumferential direction. When rolling tires, there are many cases where noise occurs when the heel and toe wear parts touch the ground.

  In the pneumatic tire described in Patent Document 2, it is possible to achieve both improvement in handling stability including turning performance on a dry road surface and improvement in vibration riding comfort including pattern noise. Nothing is said about suppression of toe wear.

  Accordingly, an object of the present invention is to provide a pneumatic tire capable of improving vibration riding comfort and / or steering stability while maintaining heel & toe wear in a mode different from the above pitch variation. .

One embodiment of the present invention is a pneumatic tire provided with a tread pattern.
The pneumatic tire has a circumferential groove in a tread portion.
The tread portion includes a pattern region on the shoulder side to be grounded, formed by distributing a plurality of pitch types having different pitch lengths in the tire circumferential direction by the first pitch arrangement with the circumferential groove as a boundary, and the pitch A pattern area on the center side for grounding, which is formed by dispersing and arranging a plurality of pitch types having different lengths in the tire circumferential direction by the second pitch arrangement.
For each of the first pitch arrangement and the second pitch arrangement, when arranging the plurality of pitch types in the order of the pitch length, when adjacent pitch types are referred to as adjacent pitch types,
The first pitch arrangement is an arrangement in which the same pitch type or the adjacent pitch type is arranged in a pitch adjacent to the tire circumferential direction,
The second pitch arrangement includes a portion other than the adjacent pitch type in a pitch adjacent to the tire circumferential direction , and a portion in which different pitch types are arranged, and the pitch type having the shortest pitch length is adjacent to each other. Is a sequence of 3 or less.
The number of pitches in the first pitch arrangement is larger than the number of pitches in the second pitch arrangement.

The number of pitches in the first pitch arrangement is preferably 50 or more and 140 or less in the pattern region on at least one shoulder side, and the number of pitches in the second pitch arrangement is preferably 10 or more and 80 or less.
Further, the second pitch array is preferably an array in which the number of adjacent pitch types included in a range where the pitch length is 10% longer than the shortest pitch length is 3 or less. .

The circumferential groove and the pattern region on the shoulder side are provided on each of the half tread portions on both sides of the center line of the tread portion,
When the pneumatic tire is mounted on a normal rim and the width in the tire direction of the contact shape measured under the conditions of normal air pressure and 80% of the normal load is determined as the contact width in the tread portion, The directional groove is preferably located within a range of 30 to 98% of the ground contact width of the tread portion with the center line as the center.

The pattern area on the shoulder side in the half tread portion of the pneumatic tire is designated to be mounted on the inside or outside of the vehicle,
N _CE <N _IN , where N _IN is the number of pitch types in the first pitch arrangement in the pattern area on the shoulder side mounted on the inside of the wheel, and N _CE is the number of pitch types in the second pitch arrangement. It is preferable that
At this time, when the number of pitch species of the first pitch sequence in the shoulder side of the pattern area to be mounted on the outside of the wheel and the N _OUT, a N _CE ≦ N _OUT, it is preferable. More preferably, N _CE ≦ N _OUT <N _IN .
The N _CE is, for example, 10 to 80, the N _OUT is, for example, 20 to 100, and the N _IN is, for example, 50 to 140.

  According to the pneumatic tire, it is possible to achieve both vibration riding comfort and / or steering stability while maintaining heel and toe wear.

It is an expanded view of the tread pattern of the pneumatic tire for passenger cars of this embodiment. (A), (b) is a figure explaining the pitch variation in the tread pattern shown in FIG. It is an expanded view of the tread pattern of the pneumatic tire for passenger cars of other embodiments of the present invention.

  Hereinafter, the pneumatic tire of the present invention will be described in detail.

(First embodiment)
FIG. 1 is a development view of a tread pattern 10 provided on a tread of a passenger car pneumatic tire (hereinafter referred to as a tire) according to a first embodiment. The tread pattern 10 is a point-symmetric pattern around the tire center line CL.
The passenger car tire according to the present embodiment refers to a tire defined in Chapter A of JATMA YEAR BOOK 2008 (Japan Automobile Tire Association Standard), for example. In addition, the pneumatic tire of the present invention can be applied to a small truck tire defined in Chapter B or a truck and bus tire defined in Chapter C.

The tread pattern 10 includes circumferential ribs 12 and 14, a block 16, and a shoulder block 18 in order from the tire center line CL.
The tread pattern 10 is divided into a pattern region R _CE on the center side and a pattern region R _S on both shoulder sides by a circumferential groove 20 provided between the block 16 and the shoulder block 18.
The circumferential rib 12 is defined by two circumferential grooves 22, and the circumferential rib 12 is provided with an inclined lug groove 24 whose one end is closed.
The circumferential rib 14 is defined between the circumferential groove 22 and the circumferential narrow groove 26.
The block 16 is defined by a circumferential narrow groove 26, a circumferential groove 20, and an inclined lug groove 28 that connects the circumferential narrow groove 26 and the circumferential groove 20.
The shoulder block 18 is provided with a shoulder closing lug groove 30 that extends from the shoulder end and closes in the middle. Therefore, the shoulder block 18 forms a rib that is continuously connected in the tire circumferential direction.

For the circumferential grooves 20 and 22, for example, the groove width is 6 to 9 mm, and the groove depth is 7 to 9 mm. For the circumferential narrow groove 26, for example, the groove width is 1 to 3 mm, and the groove depth is 4 to 5 mm. For the inclined lug groove 24, for example, the groove width is 2 to 6 mm, and the groove depth is 3 to 7 mm.
Moreover, about the inclination lug groove | channel 28, for example, a groove width is 2-7 mm and a groove depth is 3-7 mm.
For the shoulder closing lug groove 30 in the pattern region on the shoulder side, for example, the groove width is 2 to 4 mm, and the groove depth is 3 to 6 mm.

The circumferential groove 20 of the tread pattern 10 is preferably located within a range of 30 to 98% of the ground contact width of the tread portion around the center line CL, and more preferably within a range of 50 to 70%. The contact width of the tread portion refers to the width in the tire direction of the contact shape measured when the tire is mounted on a normal rim and is measured under the conditions of normal internal pressure and 80% of the normal load.
Here, the regular rim means “standard rim” defined in JATMA, “Design Rim” defined in TRA, or “Measuring Rim” defined in ETRTO. The normal internal pressure means “maximum air pressure” defined by JATMA, the maximum value of “TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES” defined by TRA, or “INFLATION PRESSURES” defined by ETRTO. The normal load means the “maximum load capacity” defined in JATMA, the maximum value of “TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES” defined in TRA, or “LOAD CAPACITY” defined in ETRTO.

  As described above, the circumferential groove 20 is provided within the range of 30 to 98% of the ground contact width of the tread portion with the center line CL as the center. In the tread portion of the rear wheel, in the pattern area on the center side between the circumferential grooves 20 on both sides, the block rigidity of the tread in the area that contacts the ground when the rear wheel is loaded is prevented from being reduced in a part on the tire circumference. This is to suppress a decrease in responsiveness to steering, and to suppress heel and toe wear in the pattern areas outside the circumferential grooves 20 on both sides (the pattern areas on the shoulder side).

Such a tread pattern 10 has the following pitch variations.
Here, the pitch of the tread pattern 10 is a minimum unit in which the same pattern is repeated. For example, FIG. 1 shows the pitch length P ₁ of the pattern region R _S on the shoulder side and the pitch length P ₂ of the pattern region R _CE on the center side.

Specifically, a plurality of pitch types having different pitch lengths are distributed in the tire circumferential direction in the shoulder-side pattern region R _S and the center-side pattern region R _CE with the circumferential groove 20 in the tread portion as a boundary. The arrangement form is different. Here, when a plurality of pitch types are arranged in the order of the pitch length, when adjacent pitch types are referred to as adjacent pitch types, the pitch arrangement of the shoulder-side pattern region is adjacent in the tire circumferential direction at any pitch. This is an arrangement in which the same pitch type or adjacent pitch type is arranged in the pitch. The pitch arrangement of the pattern area on the center side includes a portion in which a pitch type other than the adjacent pitch type is arranged on a pitch adjacent in the tire circumferential direction, and the number of adjacent pitch types having the shortest pitch length is 3 or less. Is an array.

FIG. 2A is a diagram for explaining an example of the pitch arrangement of the pattern area on the center side. Here, A to E are pitch types having different pitch lengths, and “E2” and “D2” in FIG. 2A mean that two pitch types E are continuous, and the pitch type D is It means that two are arranged in succession. Therefore, in the case of FIG. 2A, in order from the left, there is one pitch type C, two pitch types E, two pitch types D, one pitch type B, and one pitch type C. One pitch type D, ... represents that the tires are sequentially arranged in the tire circumferential direction.
The pitch arrangement shown in FIG. 2A includes a portion in which a pitch type other than the adjacent pitch type is arranged on a pitch adjacent in the tire circumferential direction, and the number of adjacent pitch types having the shortest pitch length is 3 An array that is: For example, a pitch type E that is not an adjacent pitch type is arranged for the first “C1” from the left in FIG. Further, the shortest pitch type E is 1 or 2 or less continuously provided.
In the present embodiment, the number of adjacent pitch types having the shortest pitch length is two or less, but the number may be three or less.
Further, in the pitch arrangement shown in FIG. 2 (a), the number of adjacent pitch types included in a range where the pitch length is 10% longer than the shortest pitch length is 3 or less. It is preferable at the point which improves.

On the other hand, FIG. 2B is a diagram for explaining an example of the pitch arrangement of the pattern region R _S on the shoulder side. Here, A to E are pitch types having different pitch lengths, and may be the same as or different from the pitch types A to E in FIG. Note that “A3” and “B3” in the drawing mean that three pitch types A are continuous, and three pitch types B are continuous, as in the above description.
The pitch arrangement shown in FIG. 2 (b) is an arrangement in which the same pitch type or adjacent pitch type is arranged in the pitches adjacent in the tire circumferential direction. That is, when the pitch type changes, the adjacent pitch type is always arranged. For example, when the pitch type B changes, the pitch type A or the pitch type C is always arranged at the adjacent pitch.
Here, number of pitches of the pitch arrangement which is provided on the center side of the pattern area R _CE (pitch arrangement shown in FIG. 2 (a)) is 45, the pitch sequence (FIG. 2 provided on the shoulder side of the pattern area R _S ( The pitch number of the pitch arrangement shown in b) is 66 pitches. That is, the number of pitches in the pitch array provided in the shoulder-side pattern region R _S is larger than the number of pitches in the pitch array provided in the center-side pattern region R _CE . This is because by increasing the number of pitches on the shoulder side, one pitch length of the pattern region R _S on the shoulder side can be shortened, and the frequency dispersion of pattern noise can be improved. Since the shoulder-side pattern region R _S contributes less to the steering stability than the center-side pattern region R _CE , even if the pitch length in the shoulder-side pattern region R _S is shortened to reduce the block rigidity, Does not reduce steering stability.

For example, when the center circumferential length in the pattern area R _CE on the center side of the tire 10 is 1985 mm, the pitch length of each pitch type in the pattern area R _CE on the center side is, for example, as follows. Pitch type A = 52.75 mm, Pitch type B = 47.43 mm, Pitch type C = 44.21 mm, Pitch type D = 41.94 mm, Pitch type E = 35.30 mm.
On the other hand, when the circumferential length in the shoulder-side pattern region R _S is 1985 mm, the pitch length of each pitch type in the shoulder-side pattern region R _S is, for example, as follows. Pitch type A = 40.78 mm, Pitch type B = 36.39 mm, Pitch type C = 30.18 mm, Pitch type D = 24.57 mm, Pitch type E = 21.14 mm.

The number of pitches in the pitch arrangement of the shoulder-side pattern region R _S is 50 or more and 140 or less in at least one shoulder-side pattern region, and the number of pitches in the pitch arrangement of the center-side pattern region R _CE is It is preferably 10 or more and 80 or less from the viewpoint of improving vibration ride comfort (particularly, pattern noise), steering stability (particularly turning performance), and heel & toe wear.
Further, the pitch arrangement of the pattern area R _CE on the center side is such that the pitch length is included in a range 10% longer than the shortest pitch length (in the example shown in FIG. 2A, the pitch length of the pattern type E). Is an arrangement in which the number of adjacent consecutive numbers is 3 or less, which is compatible with vibration ride comfort (especially pattern noise), steering stability (especially turning performance) and heel & toe wear. From the point, it is more preferable.

  About the tire 10 provided with such a pitch arrangement | sequence, pattern noise and / or steering stability can be improved, maintaining heel & toe wear so that the Example mentioned later may show.

(Second Embodiment)
FIG. 3 is a development view of the tread pattern 100 provided on the tread of the tire according to the second embodiment. The tread pattern 100 is an asymmetric pattern with respect to the tire center line CL. Specifically, it is specified that the shoulder-side pattern region R _S in the half tread portion of the tire is mounted on the inside or the outside of the vehicle. In the tread pattern 100 shown in FIG. 3, the pattern region on the right shoulder side in the drawing is a region R _IN located on the vehicle inner side, and the pattern region on the left shoulder side in the drawing is a region R _OUT located on the vehicle outer side. .

Specifically, like the tread pattern 10, the tread pattern 100 includes circumferential ribs 112, 114, a block 116, and a shoulder block 118 in order from the tire center line CL.
The tread pattern 100 is divided into a center-side pattern region R _CE and both shoulder-side pattern regions R _S (R _IN , R _OUT ) by a circumferential groove 120 provided between the block 116 and the shoulder block 118.
Since the circumferential ribs 112 and 114 and the block 116 have the same configuration as the circumferential ribs 12 and 14 and the block 16 of the tread pattern 10, description thereof is omitted.

Unlike the shoulder block 18 of the tread pattern 10, the shoulder block 118 extends from the ground end toward the circumferential groove 120 in a region _RIN , and a shoulder lug groove 130 that connects the ground end and the circumferential groove 120. And a shoulder closing lug groove 132 that is closed at the same time. The shoulder lug groove 130 and the shoulder closing lug groove 132 are provided adjacent to each other in the tire circumferential direction. Thus, region R _IN is different from the tread pattern 10 does not form a rib land portion connected continuously in the tire circumferential direction.
On the other hand, in the region R _OUT , a shoulder closing lug groove 132 that extends from the ground contact end toward the circumferential groove 120 but is blocked in the middle, and a closed sipe 134 that extends from the ground contact end side toward the circumferential groove 120 are provided. Yes. Therefore, similarly to the toledo pattern 10, the region R _OUT forms ribs that are continuously connected to the land portion in the tire circumferential direction.

The pitch arrangement in the region R _CE of the tread pattern 100 is provided with a pitch variation as shown in FIG. 2A, similarly to the pattern region on the center side in the tread pattern 10. Specifically, the arrangement includes a portion in which a pitch type other than the adjacent pitch type is arranged in the pitch adjacent to the tire circumferential direction, and the number of adjacent pitch types having the shortest pitch length is 3 or less. .
On the other hand, the pitch sequence in the region R _IN of the tread pattern 100, similar to the shoulder side of the pattern region in the tread pattern 10, a pitch variation as shown in FIG. 2 (b) has been subjected. Specifically, the pitch arrangement is an arrangement in which the same pitch seeds or adjacent pitch seeds are arranged in adjacent pitches in the tire circumferential direction.
The pitch arrangement in the region R _OUT of the tread pattern 100 is also an arrangement in which the same pitch type or the adjacent pitch type is arranged in the pitch adjacent in the tire circumferential direction, like the pitch arrangement in the region R _IN .

Here, the number of pitches in the pitch sequence of the region R _CE and N _CE, the number of pitches in the pitch sequence of the region R _OUT and N _OUT, the number of pitches in the pitch sequence of the region R _IN and N _IN. At this time, N _CE <N _IN . Furthermore, it is preferable that N _CE ≦ N _OUT . More preferably, N _CE ≦ N _OUT <N _IN .
By limiting the number of pitches in this manner, it is possible to more preferably achieve both improvement in pattern noise and steering stability while maintaining heel & toe wear.

Specific value of the pitch number, for example, N _CE is 10 to 80, N _OUT is 20 to 100, N _IN is 50 to 140. Preferably, N _CE is 20-50, N _OUT is 30-60, and N _IN is 60-90. Or, N _CE is 0,2 to 0.8 times N _IN and N _CE is 0,5 to 1.0 times N _OUT , so that vibration riding comfort including steering stability and pattern noise It is preferable in terms of achieving compatibility.
If N _CE is less than 10, although improved steering stability by increasing the block rigidity, the block rigidity difference between the block 118 of a region R _IN is increased, wear resistance is lowered. Further, although the block rigidity increases in the pattern area on the center side, the difference from the block rigidity in the pattern area on the shoulder side becomes large, the balance of the block rigidity of the tire is deteriorated, and the vibration riding comfort is lowered.
When _NCE exceeds 80, the frequency dispersibility of the pattern noise is improved, but the block rigidity is lowered and the steering stability is lowered.

On the other hand, when N _OUT is less than 20, steering stability, particularly turning performance, is improved, but since the frequency dispersion of pattern noise is not sufficient, vibration ride quality, particularly pattern noise, is reduced. If N _OUT exceeds 100, the frequency dispersion of the pattern noise is sufficiently performed, so that the vibration ride comfort, especially the pattern noise, is improved, but the pitch length is shortened and the block rigidity is reduced, so that the steering stability, In particular, the turning performance is reduced.

Further, when N _IN is less than 50, the steering stability, particularly the turning performance is improved, but the pattern noise is lowered because the frequency dispersion of the pattern noise is not sufficient. When N _IN exceeds 140, the difference in block rigidity between the region R _IN and the region R _CE becomes too large, and the balance of the block stiffness is deteriorated, so that the steering stability performance, particularly turning performance is deteriorated.

In the tire having the tread pattern 100, it is specified that the pattern region R _S (region R _IN , R _OUT ) on the shoulder side is mounted on the inside or the outside of the vehicle. Region R _CE affects steering stability, especially straightness, and region R _OUT affects heel & toe wear, vibration ride comfort (especially pattern noise), and steering stability (especially turning). The region R _IN affects heel & toe wear and vibration ride comfort (particularly pattern noise). Thus, for the tread pattern 10, increasing the number of pitches N _IN of the region R _IN, by reducing the number of pitches N _OUT of the region R _OUT, steering stability (particularly turning performance), including size of the pattern vibration Riding comfort (particularly pattern noise) can be more preferably achieved. Of course, since the pitch arrangement of the region R _IN and the region R _{OUT has} a pitch arrangement as shown in FIG. 2B, the occurrence of heel and toe wear can be suppressed. The pitch number N _OUT of the region R _OUT, as seen from the examples to be described later in the same as the number of pitches N _CE region R _CE, can be driving stability (cornering performance) to both pattern noise .

(Example)
The tire of this embodiment, the conventional tire, and the like were manufactured and evaluated for steering stability, pattern noise, and heel & toe wear. The tire size of the tire to be evaluated is 205 / 55R16.
The tire was assembled on a regular rim, filled with regular internal pressure, mounted on four wheels of a 1.5-liter class front wheel drive vehicle, and evaluated by applying a load of 80% of the regular load. The normal rim, normal internal pressure, and normal load mentioned here are defined in the above-mentioned JATMA, ETRTO, and TRA.

Evaluation of steering stability is a sensory evaluation of the driver when driving on a dry road surface at 100 km / hour. Steering stability is divided into the initial steering response (initial response) when steering is started from the straight running state and the ease of turning (turning) when turning at a constant radius of curvature. evaluated.
Regarding the pattern noise, sensory evaluation was performed for the pattern noise sound during straight traveling at 100 km / hour.
On the other hand, heel & toe wear was evaluated by measuring the wear state of the tread pattern after running the front wheel drive vehicle for 10,000 km with a caliper and evaluating the heel & toe wear. Specifically, the level difference between the adjacent pitches of the tread pattern was measured to determine the level difference.
The sensory evaluation results and the level difference results were indexed based on Conventional Example 1. The larger the value of the index, the better the evaluation.

In Conventional Example 1, both the center-side pattern region R _CE and the shoulder-side pattern region R _S have a pitch arrangement as shown in FIG.
In Conventional Example 2, both the center side pattern region R _CE and the shoulder side pattern region R _S have a pitch arrangement as shown in FIG.
Example 1 was in the form of the tread pattern 10 shown in FIG. 1, and Examples 2 to 5 were in the form of the tread pattern 100 shown in FIG. In the comparative example, the pattern area R _CE on the center side has a pitch arrangement as shown in FIG. 2A, and the pattern area R _S on the shoulder side has a pitch arrangement as shown in FIG. For numbers, N _CE = N _IN = N _OUT .
Table 1 below shows the specifications and evaluation results.

  As can be seen from Table 1 above, in Example 1, the initial responsiveness is improved while maintaining the heel & toe wear, pattern noise, and turning performance. In Example 2, initial responsiveness and turning performance are improved while maintaining heel & toe wear and pattern noise. In Examples 3 and 4, pattern noise, initial response, and turning performance are improved while maintaining heel and toe wear. In Example 5, the turning performance is 98, but this index 98 is substantially the same as that of Conventional Example 1 in turning performance. Therefore, also in Example 5, pattern noise and initial responsiveness are improved while maintaining heel & toe wear and turning performance.

  As mentioned above, although the pneumatic tire of this invention was demonstrated in detail, this invention is not limited to the said embodiment, Of course, in the range which does not deviate from the main point of this invention, you may make a various improvement and change. is there.

10,100 tread pattern 12, 14, 112, 114 circumferential rib 16, 116 block 18, 118 shoulder block 20, 22, 120, 122 circumferential groove 24, 28, 124 inclined lug groove 26, 126 circumferential narrow groove 30 , 132 Shoulder closure lug groove 130 Shoulder lug groove 134 Closed sipe

Claims (8)

A pneumatic tire provided with a tread pattern,
The pneumatic tire has a circumferential groove in a tread portion,
The tread portion includes a pattern region on the shoulder side to be grounded, formed by distributing a plurality of pitch types having different pitch lengths in the tire circumferential direction by the first pitch arrangement with the circumferential groove as a boundary, and the pitch A pattern area on the center side to be grounded, formed by dispersing and arranging a plurality of pitch types having different lengths in the tire circumferential direction by the second pitch arrangement,
For each of the first pitch arrangement and the second pitch arrangement, when arranging the plurality of pitch types in the order of the pitch length, when adjacent pitch types are referred to as adjacent pitch types,
The first pitch arrangement is an arrangement in which the same pitch type or the adjacent pitch type is arranged in a pitch adjacent to the tire circumferential direction,
The second pitch arrangement includes a portion other than the adjacent pitch type in a pitch adjacent to the tire circumferential direction , and a portion in which different pitch types are arranged, and the pitch type having the shortest pitch length is adjacent to each other. Is a sequence of 3 or less,
The pneumatic tire according to claim 1, wherein the number of pitches in the first pitch arrangement is greater than the number of pitches in the second pitch arrangement.   2. The air according to claim 1, wherein the number of pitches in the first pitch arrangement is 50 or more and 140 or less in the pattern region on at least one shoulder side, and the number of pitches in the second pitch arrangement is 10 or more and 80 or less. Enter tire.   The second pitch arrangement is an arrangement in which the number of adjacent pitch types included in a range where the pitch length is 10% longer than the shortest pitch length is three or less. Pneumatic tire described in 2. The circumferential groove and the pattern region on the shoulder side are provided on each of the half tread portions on both sides of the center line of the tread portion,
When the pneumatic tire is mounted on a normal rim and the width in the tire direction of the contact shape measured under the conditions of normal air pressure and 80% of the normal load is determined as the contact width in the tread portion, The pneumatic tire according to any one of claims 1 to 3, wherein the directional groove is located within a range of 30 to 98% of a contact width of the tread portion with a center line as a center. The pattern area on the shoulder side in the half tread portion of the pneumatic tire is designated to be mounted on the inside or outside of the vehicle,
N _CE <N _IN , where N _IN is the number of pitch types in the first pitch arrangement in the pattern area on the shoulder side mounted on the inside of the wheel, and N _CE is the number of pitch types in the second pitch arrangement. The pneumatic tire according to claim 4, wherein The pneumatic tire according to claim 5, wherein N _CE ≦ N _OUT, where N _OUT is the number of pitch types of the first pitch arrangement in the shoulder side pattern region mounted on the outside of the wheel. The pneumatic tire according to claim 6, wherein N _CE ≦ N _OUT <N _IN . The N _CE is 10 to 80, wherein N _OUT is 20 to 100, wherein N _IN is 50 to 140, pneumatic tire according to claim 7.