Tire

Abstract

The invention provides a tire capable of maintaining steering stability and improving noise performance. A tire is provided with a tread portion (2). The first land portion (7) is provided with a plurality of first lateral grooves (11), and the second land portion (8) is provided with a plurality of second lateral grooves (12). The plurality of first lateral grooves (11) are arranged in a first layout throughout the circumference of the tire. In the first layout, the first lateral grooves (11) are arranged such that the first pitch (P1) of the first lateral grooves (11) becomes a type number a, and in the paired first lateral grooves (11), the first ends (11a) are provided at the same position in the tire circumferential direction as the second ends (11b). The plurality of second lateral grooves (12) are arranged in a second layout. In the second layout, the second lateral grooves (12) are arranged so that the second pitch (P2) of the second lateral grooves (12) becomes the number b of types, and the number b of types of the second pitch (P2) is greater than the number a of types of the first pitch (P1).

Description

Technical Field

[0001] The present invention relates to tires. Background Art

[0002] Patent Document 1 listed below proposes a tire in which uneven wear resistance and noise performance are improved by determining the number of pitches of lateral grooves.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2022-122121

[0004] As vehicles have become quieter in recent years, tires also need to further improve noise performance. As a method for this, there is a known method of increasing the number of types of intervals between lateral grooves provided in the tread portion. However, this method sometimes reduces the rigidity of the pattern blocks of the tread portion divided by the lateral grooves and impairs the handling stability. Summary of the invention

[0005] The present invention has been made in view of the above-mentioned actual situation, and a main object of the present invention is to provide a tire capable of maintaining steering stability and improving noise performance.

[0006] The tire of the present invention has a tread portion, wherein the tread portion includes: a plurality of circumferential grooves extending continuously along the circumferential direction of the tire, and a plurality of land portions divided by the plurality of circumferential grooves, the plurality of land portions including a first land portion and a second land portion adjacent to each other, a plurality of first lateral grooves completely crossing the tread of the first land portion along the axial direction of the tire are provided in the first land portion, a plurality of second lateral grooves completely crossing the tread of the second land portion along the axial direction of the tire are provided in the second land portion, the plurality of first lateral grooves respectively include: a first end on one side of the tire axial direction, and a second end on the other side of the tire axial direction, the plurality of first lateral grooves are arranged in a first layout throughout the tire, and in the first layout, the plurality of first lateral grooves are arranged in a first layout adjacent to each other in the circumferential direction of the tire. The first lateral grooves are arranged in a manner such that the interval in the tire circumferential direction, that is, the first pitch, is 1 or 2 or more types a throughout the tire, and in the pairs of the first lateral grooves adjacent in the tire circumferential direction, the first end of the first lateral groove on one side is set at the same position in the tire circumferential direction as the second end of the first lateral groove on the other side, and the multiple second lateral grooves are arranged in a second layout throughout the tire. In the second layout, the second lateral grooves are arranged in a manner such that the interval in the tire circumferential direction, that is, the second pitch, between the second lateral grooves adjacent in the tire circumferential direction, is 2 or more types b throughout the tire, and the number b of the second pitch is greater than the number a of the first pitch.

[0007] The tire of the present invention has the above-mentioned structure, thereby maintaining steering stability and improving noise performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a development view of the tread portion of the tire according to one embodiment of the present invention.

[0009] Figure 2 yes Figure 1 An angle view of the first land portion and the second land portion.

[0010] Figure 3 yes Figure 2 An enlarged view of the first land portion.

[0011] Figure 4 It is a development view of a tread portion of a tire according to another embodiment.

[0012] Figure 5 It is a development view of the tread portion of a tire of a comparative example.

[0013] Explanation of the reference numerals: 2...tread portion; 3...circumferential groove; 4...land portion; 7...first land portion; 8...second land portion; 11...first lateral groove; 12...second lateral groove; 11a...first end; 11b...second end; P1...first pitch; P2...second pitch; a...number of types of first pitch; ...b...number of types of second pitch. DETAILED DESCRIPTION

[0014] Hereinafter, several embodiments of the present invention will be described based on the accompanying drawings. Although the accompanying drawings include and record the features of the present invention, in order to help understand the present invention, sometimes exaggerated expressions and expressions with different dimensional ratios from the actual structure are included. In addition, the same reference numerals are marked on the same or common elements in each embodiment, and repeated descriptions are omitted.

[0015] Figure 1 FIG. 2 is a development diagram of the tread portion 2 of the tire 1 according to the present embodiment in a normal state. Figure 1 As shown, the tire 1 of this embodiment is implemented as a pneumatic tire for a passenger car, for example. The present invention can also be implemented as a tire for a motorcycle or a heavy load tire.

[0016] "Normal state" means: in the case of pneumatic tires with various specifications, the tire rim is assembled to the regular rim and filled with the regular internal pressure and is unloaded. In the case of tires with various specifications not specified or non-pneumatic tires, the above-mentioned normal state is a standard usage state corresponding to the purpose of use of the tire, which means an unloaded state. In this specification, unless otherwise specified, the dimensions of various parts of the tire are values ​​measured in the normal state. In addition, in this specification, unless otherwise specified, the method for measuring the above-mentioned dimensions can appropriately apply known methods.

[0017] A "regular rim" is a rim whose specifications are specified for each tire in a specification system that includes the specifications that the tire complies with, for example, a "standard rim" in JATMA, a "design rim" in TRA, and a "measuring rim" in ETRTO.

[0018] "Normal internal pressure" is the air pressure specified for each tire in the specification system that includes the specifications that the tire is based on. If it is JATMA, it is the "maximum air pressure". If it is TRA, it is the maximum value recorded in the table "TIRE LOAD LIMITS ATVARIOUS COLD INFLATION PRESSURES". If it is ETRTO, it is "INFLATION PRESSURE".

[0019] The tread portion 2 includes two tread ends Te and a tread surface therebetween. The tread end Te is the outermost contact position in the axial direction of the tire when 70% of the normal load is applied to the tire 1 in a normal state and the tire contacts the flat surface at a camber angle of 0°.

[0020] "Normal load" is the load specified for each tire in the specification system including the specifications to which the tire is based, in the case of pneumatic tires with various specifications specified. In the case of JATMA, it is the "maximum load capacity", in the case of TRA, it is the maximum value recorded in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES", and in the case of ETRTO, it is "LOAD CAPACITY". In the case of tires without various specifications specified, "Normal load" refers to the maximum load that can be applied based on the use of the tire in accordance with the above specifications.

[0021] The tread portion 2 includes: a plurality of circumferential grooves 3 extending continuously in the tire circumferential direction between two tread ends Te, and a plurality of land portions 4 divided by the plurality of circumferential grooves 3. The circumferential grooves 3 of this embodiment include two crown circumferential grooves 5 and two shoulder circumferential grooves 6. The two crown circumferential grooves 5 are provided in a manner of sandwiching the tire equator C. The shoulder circumferential grooves 6 are provided between the crown circumferential grooves 5 and the tread ends Te. Thus, the two shoulder circumferential grooves 6 are provided in a manner of sandwiching the tire equator C and the two crown circumferential grooves 5.

[0022] The groove width W1 of the circumferential groove 3 is 3.0 mm or more, for example, 3.0% to 6.0% of the tread width TW. The tread width TW corresponds to the tire axial distance from one tread end Te to the other tread end Te in the normal state. The depth of the circumferential groove 3 is preferably 5 to 10 mm, for example.

[0023] The plurality of land portions 4 include a first land portion 7 and a second land portion 8 adjacent to each other. The first land portion 7 of the present embodiment is defined between the crown circumferential groove 5 and the shoulder circumferential groove 6. The second land portion 8 is defined on the outer side of the shoulder circumferential groove 6 in the tire axial direction and includes the tread end Te. Thus, in the present embodiment, the paired first land portion 7 and second land portion 8 are provided on both sides of the tire axial direction. In addition, in the present embodiment, in addition to the above-mentioned land portions, a third land portion 9 is provided on the tire equator C. The third land portion 9 has substantially the same structure as the first land portion 7 described below.

[0024] exist Figure 2 FIG. 8 shows an enlarged view of the first land portion 7 and the second land portion 8. Figure 2 As shown, a plurality of first lateral grooves 11 are provided in the first land portion 7. The first lateral grooves 11 completely cross the tread 7s of the first land portion 7 in the tire axial direction. In addition, a plurality of second lateral grooves 12 are provided in the second land portion 8. The second lateral grooves 12 completely cross the tread 8s of the second land portion 8 in the tire axial direction.

[0025] exist Figure 3 FIG. 8 shows an enlarged view of the first land portion 7. Figure 3 As shown, each of the plurality of first lateral grooves 11 includes a first end 11 a on one side in the tire axial direction and a second end 11 b on the other side in the tire axial direction.

[0026] The plurality of first lateral grooves 11 are arranged around the tire in a first layout described below. In the first layout, the first lateral grooves 11 are arranged so that the circumferential interval between adjacent first lateral grooves 11 in the tire direction, i.e., the first pitch P1, becomes the number of types a of 1 or 2 or more around the tire.

[0027] Here, the pitch means the distance in the tire circumferential direction between the groove center lines of two adjacent lateral grooves in the tire circumferential direction. In addition, when the two adjacent lateral grooves are not parallel, the above distance means the average distance in the tire circumferential direction weighted by the length of the lateral grooves. That is, when observing two lateral grooves, the value of one pitch is determined according to their arrangement.

[0028] In the present invention, the first lateral grooves 11 are arranged in such a manner that the first pitch P1 is 1 or 2 or more types a throughout the tire. As a preferred embodiment, the number a is 1 in the present embodiment. That is, the first lateral grooves 11 are arranged at equal intervals along the tire circumferential direction. However, the present invention is not limited to such an embodiment.

[0029] In the first layout, in the pair of first lateral grooves 11 adjacent to each other in the tire circumferential direction, the first end 11a of one of the first lateral grooves 11 is arranged at the same position in the tire circumferential direction as the second end 11b of the other first lateral groove 11. In addition, this structure means that in more than 80% of the plurality of first lateral grooves 11 arranged in the first land portion 7, the first end 11a and the second end 11b are arranged at the same position in the tire circumferential direction. In a preferred embodiment, this is more than 90% of the first lateral grooves 11, and in a further preferred embodiment, in all the first lateral grooves 11, the first end 11a and the second end 11b are arranged in the above manner.

[0030] In addition, “the first end 11a and the second end 11b are at the same position in the tire circumferential direction” includes at least the following aspects: when the tread is viewed from above, the first end 11a of the first lateral groove 11 is aligned with the circumferential groove 3 (in the tire circumferential direction). Figure 3 The opening 13 of the shoulder circumferential groove 6) is extended in parallel with the tire axial direction in the region 14 (for ease of understanding, in Figure 3 The second end 11b of the first lateral groove 11 on the other side is connected to the circumferential groove 3 (at the middle application point) and Figure 3 In addition, from the viewpoint of allowing for the error contained in a rubber product such as a tire, even when the region 14 and the opening 15 do not overlap, when the distance in the tire circumferential direction is 5% or less of the first pitch P1 of the two corresponding first lateral grooves 11, it corresponds to the feature that "the first end 11a and the second end 11b are at the same position in the tire circumferential direction".

[0031] like Figure 2 As shown, the second lateral grooves 12 of the present invention are arranged in a second layout described below throughout the tire. In the second layout, the second lateral grooves 12 are arranged so that the interval between the second lateral grooves 12 adjacent in the tire circumferential direction, that is, the second pitch P2, becomes a number b of types greater than 2 throughout the tire. In addition, the number b of types of the second pitch P2 is greater than the number a of types of the first pitch P1.

[0032] The tire 1 of the present invention can improve noise performance while maintaining steering stability by having the above-mentioned structure. The reason for this is as follows.

[0033] In the past, pitch noise is known as the noise generated when the tire is running. One of the causes of the pitch noise is the impact force generated when the lateral groove contacts the road surface. Due to the impact force, the tread portion and the sidewall portion of the tire vibrate periodically, which can generate pitch noise. In contrast, in the present invention, in the paired first lateral grooves 11, the first end 11a of one of the first lateral grooves 11 is set at the same position as the second end 11b of the first lateral groove 11 on the other side in the tire circumferential direction. As a result, when the tire is running, the first lateral groove 11 can be continuously in contact with the ground without interruption, so that the change in the impact force of the first lateral groove 11 can be reduced. Therefore, the pitch noise of the first lateral groove 11 can be reduced, thereby improving the noise performance.

[0034] In addition, in the second layout of the present invention, the number b of the types of the second pitch P2 of the second lateral groove 12 is relatively large, so the pitch noise of the second lateral groove 12 can be whitened, and further improvement in noise performance can be expected. In addition, in the first layout, the number a of the types of the first pitch P1 is relatively small, so compared with the case where the number of types of pitches is increased in each land portion (hereinafter sometimes referred to as pitch variation), it is possible to suppress excessive reduction in pattern rigidity of the first land portion 7. Therefore, steering stability can be maintained.

[0035] The following describes a more detailed structure of the present embodiment. In addition, each structure described below represents a specific mode of the present embodiment. Therefore, it goes without saying that the present disclosure can exert the above-mentioned effects even if it does not have the structure described below. In addition, even if any one of the structures described below is applied alone in the tire 1 of the present invention having the above-mentioned characteristics, it is possible to expect an improvement in the performance corresponding to each structure. In addition, in the case of applying several of the structures described below in combination, it is possible to expect an improvement in the composite performance corresponding to each structure.

[0036] like Figure 1 As shown, the first land portion 7 is not disposed on the tire equator C and does not include the tread end Te. By maintaining the pattern rigidity of the first land portion 7 by the above-mentioned structure, the steering stability can be reliably maintained.

[0037] like Figure 3 As shown, the first lateral groove 11 of this embodiment extends linearly in the tire axial direction with a constant width. The maximum angle θ1 of the first lateral groove 11 with respect to the tire axial direction is, for example, 30° to 50°. However, the first lateral groove 11 is not limited to this form.

[0038] The number a of the types of the first pitch P1 is, for example, 1 to 3. In the present embodiment, the number a of the types of the first pitch P1 is 1, and the first lateral grooves 11 of the same shape are arranged at equal intervals along the tire circumferential direction. In other embodiments, when the number a of the types of the first pitch P1 is 2 or more, groups of first lateral grooves 11 of different angles and shapes may be periodically arranged along the tire circumferential direction. In this way, in addition to further improving the noise performance, it is also possible to expect an improvement in wet performance.

[0039] The first pitch P1 is, for example, 80% to 120% of the tire axial width W2 of the tread surface 7s of the first land portion 7. When the number a of types of the first pitch P1 is 2 or more, the maximum value of the first pitch P1 is preferably 80% to 95% of the width W2 of the first land portion 7. In addition, the maximum value of the first pitch P1 is preferably 105% to 120% of the width W2 of the first land portion 7.

[0040] like Figure 1 As shown, the second land portion 8 includes the tread end Te. Such a second land portion 8 easily transmits pitch noise to the outside, which has a great influence on noise performance. In this embodiment, since the pitch change of the land portion including the tread end Te is relatively increased, it is expected that the noise performance will be further improved.

[0041] like Figure 2 As shown, the second lateral groove 12 of the present embodiment extends linearly along the tire axial direction with a constant width. The maximum angle θ2 of the second lateral groove 12 relative to the tire axial direction is smaller than the maximum angle θ1 of the first lateral groove 11 relative to the tire axial direction. Specifically, the above-mentioned angle θ2 of the second lateral groove 12 is less than 10°, and is 0° in the present embodiment.

[0042] By setting the angle of the second lateral groove 12 in the above manner, in the second layout of the present embodiment, two second lateral grooves 12 adjacent in the tire circumferential direction do not overlap in the tire circumferential direction. That is, the imaginary area after the second lateral groove 12 of one of the two second lateral grooves 12 is extended parallel to the tire axial direction does not overlap with the other second lateral groove 12. In addition to improving the steering stability, it is also expected that the wear resistance of the second land portion 8 can be improved.

[0043] In this embodiment, the second lateral grooves 12 of the same shape are arranged along the tire circumferential direction at different intervals in the tire circumferential direction. However, the present invention is not limited to this embodiment, and groups of second lateral grooves 12 of different angles and shapes may be periodically arranged along the tire circumferential direction.

[0044] The number b of the types of the second pitch P2 is, for example, 3 to 5, and is 5 in the present embodiment. Figure 2In the embodiment, the second pitch P2 is marked with reference numerals P2a, P2b, P2c, P2d and P2e in order from the smallest length in the tire circumferential direction. The second pitch P2 of this embodiment includes the first pitch P1 ( Figure 3 As shown), there are the same pitch as the first pitch P1 (corresponding to P2c), a pitch smaller than the first pitch P1 (corresponding to P2a, P2b), and a pitch larger than the first pitch P1 (corresponding to P2d, P2e).

[0045] The minimum value of the second pitch P2 is preferably smaller than the minimum value of the first pitch P1. Specifically, the minimum value of the second pitch P2 is 70% to 90% of the minimum value of the first pitch P1. This can maintain steering stability and expand the frequency band of the pitch noise generated by the second lateral groove 12, thereby further improving noise performance.

[0046] The maximum value of the second pitch P2 is preferably greater than the maximum value of the first pitch P1. Specifically, the maximum value of the second pitch P2 is 105% to 120% of the maximum value of the first pitch P1. This can improve the steering stability and noise performance in a balanced manner.

[0047] From the same viewpoint, the total number N2 of the second lateral grooves 12 provided in the second land portion 8 is preferably greater than the total number N1 of the first lateral grooves 11 provided in the first land portion 7. Specifically, the total number N2 is preferably 105% to 120% of the total number N1.

[0048] exist Figure 4 2 shows a development view of a tread portion 2 of a tire 1 according to another embodiment of the present invention. In this embodiment, a first land portion 7 is formed between two shoulder circumferential grooves 6. In addition, a plurality of first lateral grooves 11 extending from one shoulder circumferential groove 6 to the other shoulder circumferential groove 6 are provided in the first land portion 7, and the plurality of first lateral grooves 11 are arranged in the first layout throughout the tire. In such an embodiment, the steering stability can be maintained and the noise performance can be improved by the above-mentioned mechanism.

[0049] In the first land portion 7 of this embodiment, one or more longitudinal grooves 20 are provided that cross the plurality of first lateral grooves 11 in the tire circumferential direction. The longitudinal grooves 20 may extend continuously in the tire circumferential direction or may be parallel to the longitudinal grooves 20. Figure 1 The crown circumferential groove 5 shown in the figure has substantially the same structure. In this embodiment, since the longitudinal groove 20 extends continuously in the tire circumferential direction, the first land portion 7 is divided into three pattern block rows 25. In this embodiment, the first lateral groove 11 and the longitudinal groove 20 are used to ensure wet performance and improve noise performance.

[0050] As mentioned above, several embodiments of the tire of the present invention have been described in detail, but the present invention is not limited to the above-mentioned specific embodiments, and can be implemented in various modified forms.

[0051] [Example]

[0052] As Examples 1 and 2, a Figure 1 or Figure 4 The pneumatic tire with a tread size of 195 / 65R15 (mounting rim 5×6.0, internal pressure 250 kPa) was produced as a comparative example. Figure 5 The tire has the tread portion shown. Figure 5 As shown, the first land portion a and the second land portion b of the tire of the comparative example are provided with lateral grooves c extending parallel to the tire axial direction in a manner of having the same pitch variation. The tire of the comparative example is substantially the same as the tire of the embodiment except for the above-mentioned matters. The handling stability and noise performance of these test tires were tested. The test method is as follows.

[0053] <Noise Performance>

[0054] The noise generated by each test tire when running on a drum tester under the conditions of a longitudinal load of 4.51 kN and a speed of 40 to 100 km / h was measured. The result is expressed as an index with the reciprocal of the sound pressure of the noise of the comparative example as 100. The larger the value, the smaller the noise and the better the noise performance.

[0055] <Handling stability>

[0056] The handling stability of a test vehicle (displacement 2000cc, front-wheel drive vehicle) mounted with the test tires and driven on a dry road was evaluated by the driver's senses. The results were scored with the comparative example as 100, and a larger value indicated better handling stability.

[0057] The test results are shown in Table 1.

[0058] [Table 1]

[0059] Comparative Example Example 1 Example 2 Diagram showing the pattern of the tread Figure 5 Figure 1 Figure 4 Noise performance (index) 100 130 115 Handling stability (rating) 100 100 120

[0060] As shown in Table 1, it was confirmed that the steering stability was maintained and the noise performance was improved.

[0061] [Note]

[0062] The present invention includes the following aspects.

[0063] [Present invention 1] A tire having a tread portion, wherein:

[0064] The tread portion includes: a plurality of circumferential grooves extending continuously in the tire circumferential direction, and a plurality of land portions divided by the plurality of circumferential grooves.

[0065] The plurality of land portions include a first land portion and a second land portion adjacent to each other,

[0066] The first land portion is provided with a plurality of first lateral grooves which completely cross the tread surface of the first land portion in the tire axial direction.

[0067] The second land portion is provided with a plurality of second lateral grooves which completely cross the tread surface of the second land portion in the tire axial direction.

[0068] The plurality of first lateral grooves respectively include: a first end on one side of the tire axial direction and a second end on the other side of the tire axial direction,

[0069] The plurality of first transverse grooves are arranged in a first layout throughout the tire.

[0070] In the first layout,

[0071] The first lateral grooves are arranged so that the interval between the first lateral grooves adjacent in the tire circumferential direction, that is, the first pitch, becomes 1 or 2 or more types a throughout the tire circumference, and

[0072] In the pair of the first lateral grooves adjacent to each other in the tire circumferential direction, the first end of one of the first lateral grooves is disposed at the same position in the tire circumferential direction as the second end of the other of the first lateral grooves.

[0073] The plurality of second transverse grooves are arranged in a second layout throughout the tire.

[0074] In the second layout,

[0075] The second lateral grooves are arranged so that a second pitch, which is a circumferential interval between adjacent second lateral grooves in the tire direction, becomes 2 or more types b throughout the tire circumference, and the second pitch type b is greater than the first pitch type a.

[0076] [Invention 2] The tire according to invention 1,

[0077] A minimum value of the second pitch is smaller than a minimum value of the first pitch.

[0078] [Invention 3] The tire according to invention 1 or 2,

[0079] The maximum value of the second pitch is greater than the maximum value of the first pitch.

[0080] [Invention 4] The tire according to any one of Inventions 1 to 3,

[0081] The number a of types of the first pitch is 1-3.

[0082] [Invention 5] The tire according to any one of Inventions 1 to 4,

[0083] The number b of types of the second pitch is 3-5.

[0084] [Invention 6] The tire according to any one of Inventions 1 to 5,

[0085] The total number of the second lateral grooves provided in the second land portion is greater than the total number of the first lateral grooves provided in the first land portion.

[0086] [Invention 7] The tire according to any one of Inventions 1 to 6,

[0087] In the second layout, two of the second lateral grooves adjacent to each other in the tire circumferential direction do not overlap in the tire circumferential direction.

[0088] [Invention 8] The tire according to any one of Inventions 1 to 7,

[0089] The maximum angle of the second lateral groove relative to the tire axial direction is smaller than the maximum angle of the first lateral groove relative to the tire axial direction.

[0090] [Invention 9] The tire according to any one of Inventions 1 to 8,

[0091] The first land portion is provided with one or more longitudinal grooves that cross the plurality of first lateral grooves in the tire circumferential direction.

Claims

1. A tire having a tread portion, characterized in that: The tread portion includes: a plurality of circumferential grooves extending continuously in the tire circumferential direction, and a plurality of land portions divided by the plurality of circumferential grooves. The plurality of land portions include a first land portion and a second land portion adjacent to each other, The first land portion is provided with a plurality of first lateral grooves which completely cross the tread surface of the first land portion in the tire axial direction. The second land portion is provided with a plurality of second lateral grooves which completely cross the tread surface of the second land portion in the tire axial direction. The plurality of first lateral grooves respectively include: a first end on one side of the tire axial direction and a second end on the other side of the tire axial direction, The plurality of first transverse grooves are arranged in a first layout throughout the tire. In the first layout, The first lateral grooves are arranged so that the interval between the first lateral grooves adjacent in the tire circumferential direction, that is, the first pitch, becomes 1 or 2 or more types a throughout the tire circumference, and In the pair of the first lateral grooves adjacent to each other in the tire circumferential direction, the first end of one of the first lateral grooves is disposed at the same position in the tire circumferential direction as the second end of the other of the first lateral grooves. The plurality of second transverse grooves are arranged in a second layout throughout the tire. In the second layout, The second lateral grooves are arranged so that a second pitch, which is a circumferential interval between adjacent second lateral grooves in the tire direction, becomes 2 or more types b throughout the tire circumference, and the second pitch type b is greater than the first pitch type a.

2. The tire according to claim 1, characterized in that A minimum value of the second pitch is smaller than a minimum value of the first pitch.

3. The tire according to claim 1 or 2, characterized in that: The maximum value of the second pitch is greater than the maximum value of the first pitch.

4. The tire according to claim 1 or 2, characterized in that: The number a of types of the first pitch is 1-3.

5. The tire according to claim 1 or 2, characterized in that: The number b of types of the second pitch is 3-5.

6. The tire according to claim 1 or 2, characterized in that: The total number of the second lateral grooves provided in the second land portion is greater than the total number of the first lateral grooves provided in the first land portion.

7. The tire according to claim 1 or 2, characterized in that: In the second layout, two of the second lateral grooves adjacent to each other in the tire circumferential direction do not overlap in the tire circumferential direction.

8. The tire according to claim 1 or 2, characterized in that: The maximum angle of the second lateral groove relative to the tire axial direction is smaller than the maximum angle of the first lateral groove relative to the tire axial direction.

9. The tire according to claim 1 or 2, characterized in that: The first land portion is provided with one or more longitudinal grooves that cross the plurality of first lateral grooves in the tire circumferential direction.

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