Tire

Abstract

To improve noise performance.SOLUTION: Provided is a tire 1 having a tread part 2. The tread part 2 includes a plurality of circumferential grooves 3 and a plurality of land parts 4 divided by the circumferential grooves 3. A plurality of lateral groove-shaped elements 7 and 8 inclined with respect to a tire axial direction and a tire circumferential direction are formed on the plurality of land parts 4. The lateral groove-shaped elements 7 and 8, having a first end on a first side in the tire circumferential direction and a second end on a second side in the tire circumferential direction, extend linearly from the first end to the second end. The plurality of lateral groove-shaped elements 7 and 8 are arranged according to a first alignment over one circumference in the tire circumferential direction. In the first alignment, for each of all pairs of the adjacent lateral groove-shaped elements 7 and 8 in the tire circumferential direction, one first end of the one of the lateral groove-shaped elements 7 and 8 of the pair is formed at the same position in the tire circumferential direction as that of the other second end of the other of the lateral groove-shaped element 7 and 8 of the pair. At least one pair of the pairs is formed on the land part with the lateral groove-shaped elements 7 and 8 different from each other.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to tires. [Background technology]

[0002] Generally, sipes and lateral grooves extending in the tire axial direction are provided in the tread portion of a tire from the viewpoint of drainage performance, etc. (See, for example, Patent Document 1 below.) However, the sipes and lateral grooves generate noise during running. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2020-168946 Summary of the Invention [Problem to be solved by the invention]

[0004] As vehicles have become quieter in recent years, there is also a demand for further improvements in noise performance in tires, and there is a need to reduce driving noise caused by sipes and lateral grooves.

[0005] The present disclosure has been devised in view of the above circumstances, and has a main object to provide a tire that can improve noise performance. [Means for solving the problem]

[0006] The present disclosure relates to a tire having a tread portion, the tread portion including a plurality of circumferential grooves extending continuously in a tire circumferential direction and a plurality of land portions separated by the circumferential grooves, each of the plurality of land portions being formed with a plurality of lateral groove-like elements inclined with respect to the tire axial direction and the tire circumferential direction, each of the lateral groove-like elements having a first end on a first side in the tire circumferential direction and a second end on a second side in the tire circumferential direction, and extending linearly from the first end to the second end, the first end and the second end being each , an end of a centerline of the lateral groove element, the plurality of lateral groove elements are arranged in a first array around one circumference in the tire circumferential direction, in the first array, for each pair of lateral groove elements adjacent in the tire circumferential direction, the first end of one lateral groove element of the pair is formed at the same position in the tire circumferential direction as the second end of the other lateral groove element of the pair, and in at least one of the pairs, the lateral groove elements are formed in different land portions. Effect of the Invention

[0007] By adopting the above-described configuration, the tire of the present disclosure can improve noise performance. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is a development view of a tread portion of the tire of the present embodiment. [Diagram 2] 2 is an enlarged view of a first land portion and a second land portion of FIG. 1. [Diagram 3] 10 is an enlarged view of a first land portion and a second land portion showing another example. FIG. [Figure 4] 10 is an enlarged view of a first land portion and a second land portion showing another example. FIG. [Diagram 5] 10 is an enlarged view of a first land portion and a second land portion showing another example. FIG. [Figure 6] 10 is an enlarged view of a first land portion and a second land portion showing another example. FIG. [Figure 7] 10 is an enlarged view of a first land portion and a second land portion showing another example. FIG. [Figure 8]10 is an enlarged view of a first land portion and a second land portion showing another example. FIG. [Figure 9] 13 is an enlarged view of a first land portion, a second land portion, and a third land portion, showing another example. FIG. [Figure 10] 13 is an enlarged view of a first land portion, a second land portion, and a third land portion, showing another example. FIG. [Figure 11] 10 is an enlarged view of a first land portion and a second land portion showing another example. FIG. [Figure 12] 10 is an enlarged view of a first land portion and a second land portion showing another example. FIG. [Figure 13] FIG. 2 is a development view of the tread portion showing the contact surface. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Several embodiments of the present disclosure will now be described with reference to the drawings. In order to facilitate understanding of the present disclosure, the drawings may include exaggerated representations and representations different from the dimensional ratios of the actual structures. In addition, the same reference numerals are used to refer to the same or common elements throughout all the embodiments, and redundant explanations will be omitted.

[0010] Fig. 1 is a partial development view of a tread portion 2 of a tire 1 of this embodiment, and Fig. 2 is an enlarged view of a main part of Fig. 1. The tire of this embodiment is implemented as, for example, a pneumatic tire. As the pneumatic tire, for example, a passenger car tire is preferable, and in particular, a passenger car radial tire is preferable. The present disclosure may also be implemented as a motorcycle tire or a heavy load tire.

[0011] In Fig. 1, the tire 1 is in a normal state. In this specification, the normal state of the tire 1 means that the tire 1 is mounted on a normal rim with normal internal pressure and is in an unloaded state. Unless otherwise specified, the dimensions of each part of the tire 1 are values ​​measured in this normal state.

[0012] In this specification, a "genuine rim" refers to a rim that is defined for each tire by the standard system that includes the standard on which the tire is based, such as a "standard rim" in the case of JATMA, a "Design Rim" in the case of TRA, and a "Measuring Rim" in the case of ETRTO.

[0013] In this specification, the term "normal internal pressure" refers to the air pressure determined for each tire by each standard in the standard system including the standard on which the tire is based, and is the "maximum air pressure" in the case of JATMA, the maximum value listed in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES" in the case of TRA, and the "INFLATION PRESSURE" in the case of ETRTO.

[0014] As shown in Fig. 1, the tread portion 2 includes a first tread edge Te1, a second tread edge Te2, and a ground contact surface 2a between them. The ground contact surface 2a is intended to come into contact with the ground when the tire is running, and is formed of tread rubber. The first tread edge Te1 and the second tread edge Te2 are each the axially outermost edges of the ground contact surface under normal load.

[0015] In this specification, the "normal load condition" refers to a state in which the tire 1 in a normal state is loaded with a normal load and is in contact with a flat surface with a camber angle of zero. In addition, in this specification, the "normal load" refers to a load determined for each tire by each standard in a system of standards including the standards on which the tire is based, and is the "maximum load capacity" in the case of JATMA, the maximum value listed in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES" in the case of TRA, and the "LOAD CAPACITY" in the case of ETRTO.

[0016] The tread portion 2 is formed with, for example, a plurality of (for example, three) circumferential grooves 3 extending in the tire circumferential direction. The circumferential grooves 3 in this embodiment extend, for example, linearly in parallel to the tire circumferential direction. Although not particularly limited, in order to ensure sufficient drainage during wet driving, the groove width of the circumferential grooves 3 is, for example, greater than 2 mm, preferably 3 mm or more, and more preferably 4 mm or more. Similarly, the groove depth of the circumferential grooves 3 is, for example, 3 mm or more, preferably 4 mm or more, and more preferably 5 mm or more.

[0017] The tread portion 2 is divided into a plurality of land portions 4 by a plurality of circumferential grooves 3. In this embodiment, the plurality of land portions 4 are configured of four land portions. The four land portions include, for example, a pair of first land portions 101 and a pair of second land portions 102 arranged on both outer sides of the pair of first land portions 101 in the tire axial direction. In this embodiment, the first land portions 101 form a crown region of the tread portion 2, and the second land portions 102 form shoulder regions of the tread portion 2. In FIG. 1, the symbol C indicates the tire equator.

[0018] In this embodiment, a plurality of lateral groove-like elements are formed in the first land portion 101 and the second land portion 102 as the plurality of land portions 4. Hereinafter, the lateral groove-like elements formed in the first land portion 101 will be referred to as "first lateral groove-like elements 7," and the lateral groove-like elements formed in the second land portion 102 will be referred to as "second lateral groove-like elements 8," to be distinguished from each other. These first lateral groove-like elements 7 and second lateral groove-like elements 8 may be collectively referred to as "lateral groove-like elements" without any particular reference numeral.

[0019] The first lateral groove element 7 and the second lateral groove element 8 are inclined with respect to the tire axial direction and the tire circumferential direction, respectively. Therefore, the first lateral groove element 7 and the second lateral groove element 8 have a non-zero angle with respect to the tire axial direction and the tire circumferential direction, respectively.

[0020] 2, each of the first lateral groove elements 7 has a first end 7A on a first side S1 in the tire circumferential direction and a second end 7B on a second side S2 in the tire circumferential direction. Similarly, each of the second lateral groove elements 8 has a first end 8A on a first side S1 in the tire circumferential direction and a second end 8B on a second side S2 in the tire circumferential direction.

[0021] Both the first lateral grooved element 7 and the second lateral grooved element 8 are voids recessed from the ground contact surface of the land portion 4, and are a comprehensive concept including, for example, both sipes and grooves. In the example of Fig. 1 and Fig. 2, both the first lateral grooved element 7 and the second lateral grooved element 8 are formed by sipes. Alternatively, the first lateral grooved element 7 and the second lateral grooved element 8 may be grooves having a groove width larger than that of a sipe.

[0022] In this specification, a "sipe" is a slit-shaped gap having a width perpendicular to its longitudinal direction of 2 mm or less, preferably 1.5 mm or less. The sipe functions such that at least a portion of a pair of sipe walls contacts each other when the tire is in contact with the ground under a normal load. Therefore, the sipe minimizes the decrease in rigidity of the first land portion 101 and the second land portion 102, and thus helps to improve driving stability.

[0023] In this specification, a "groove" refers to a gap having a width in the longitudinal direction and a width perpendicular to the longitudinal direction, and a groove width of more than 2 mm. There is no particular upper limit on the groove width of the groove, but in the case of a passenger car tire, it may be, for example, 10 mm or less. Such a groove is useful for improving drainage.

[0024] In this embodiment, the first lateral groove-like elements 7 and the second lateral groove-like elements 8 are arranged in a first arrangement 10 over one circumference in the tire circumferential direction. The first arrangement 10 is a set of a plurality of first lateral groove-like elements 7 and a plurality of second lateral groove-like elements 8. In the example of FIG. 1 , one set of the first arrangement 10 is formed in two land portions, a first land portion 101 and a second land portion 102.

[0025] In the present disclosure, the first array 10 satisfies the following two conditions a and b: a) for each pair of lateral groove elements adjacent to each other in the tire circumferential direction, a first end in the tire circumferential direction of one lateral groove element of the pair is formed at the same position in the tire circumferential direction as a second end of the other lateral groove element of the pair; b) at least one pair of all said pairs has grooved elements formed on different land portions;

[0026] Conditions a and b will be described in more detail below. In the example of FIG. 2, for example, a pair of the uppermost first lateral groove-like element 7 and the uppermost second lateral groove-like element 8 is identified as "pair 1". In pair 1, the second end 7B of the first lateral groove-like element 7 is at the same position in the tire circumferential direction as the first end 8A of the second lateral groove-like element 8 (see the shorter imaginary line extending parallel to the tire axial direction). Therefore, pair 1 satisfies condition a. Furthermore, the first lateral groove-like element 7 and the second lateral groove-like element 8 of pair 1 are formed in different land portions. Therefore, pair 1 also satisfies condition b.

[0027] Next, for example, the pair of the first lateral groove-like element 7 located second from the top and the second lateral groove-like element 8 located at the topmost position is identified as "pair 2". In pair 2, the second end 8B of the second lateral groove-like element 8 is at the same position in the tire circumferential direction as the first end 7A of the first lateral groove-like element 7 (see the longer imaginary line extending parallel to the tire axial direction). Therefore, pair 2 satisfies condition a. Furthermore, the first lateral groove-like element 7 and the second lateral groove-like element 8 of pair 2 are formed in different land portions. Therefore, pair 2 also satisfies condition b.

[0028] In the example of Fig. 2, pairs 1 and pairs 2 are repeated alternately. Thus, in the first array 10 of the example of Fig. 2, the lateral groove elements 7 and 8 included in each pair are formed in different land portions.

[0029] Here, whether the first end and the second end of the two lateral groove-like elements are at the same position in the tire circumferential direction is determined using their center lines (in FIG. 2, the center line 7C of the first lateral groove-like element 7 and the center line 8C of the second lateral groove-like element 8). That is, the first end and the second end of the first lateral groove-like element 7 and the second lateral groove-like element 8 are identified by the ends of the center lines 7C and 8C, respectively. However, in consideration of the characteristics of a tire, which is a vulcanized rubber product, and in order to allow for manufacturing tolerances, the "same position" includes a state in which the two ends are shifted by a small distance in the tire circumferential direction. In this case, the distance is 5% or less of the sum (L1+L2) of the tire circumferential length L1 of the center line 7C of the first lateral groove-like element 7 and the tire circumferential length L2 of the center line 8C of the second lateral groove-like element 8, preferably 3% or less, and more preferably 1% or less. Most preferably, the two ends are not shifted in the tire circumferential direction.

[0030] Pitch noise is known as a type of noise that occurs when a tire is running. For example, an impact force occurs each time the land elements 11, 12, which are divided by the first lateral groove-like element 7 and the second lateral groove-like element 8, come into contact with the road surface. This impact force periodically vibrates the tread portion 2 and the sidewall portion (not shown), thereby generating pitch noise. However, in the above-mentioned first arrangement 10, the first lateral groove-like element 7 and the second lateral groove-like element 8 alternately and continuously come into contact with the ground during running of the tire, thereby reducing the fluctuation of the impact force. Therefore, the tire 1 of this embodiment can improve noise performance by reducing the pitch noise generated from the first land portion 101 and the second land portion 102.

[0031] Although not particularly limited, in order to further enhance the above-mentioned effect, it is desirable that only the first lateral groove elements 7 and the second lateral groove elements 8 constituting the first array 10 are formed in the first land portion 101 and the second land portion 102, as shown in Figure 1.

[0032] In the example of FIGS. 1 and 2, each pair (pair 1 and pair 2 above) is composed of a first lateral groove element 7 and a second lateral groove element 8 that are inclined in the same direction (for example, upward to the right) relative to the tire circumferential direction.

[0033] As shown in FIG. 3, each pair may be composed of a first lateral groove-like element 7 and a second lateral groove-like element 8 that are inclined in opposite directions relative to the tire circumferential direction.

[0034] Returning to FIG. 2, the angle θ1 of the first lateral groove element 7 relative to the tire circumferential direction and the angle θ2 of the second lateral groove element 8 relative to the tire circumferential direction are not particularly limited, but from the viewpoint of improving steering stability, they are, for example, 40 degrees or more, preferably 50 degrees or more, and more preferably 60 degrees or more. The upper limit of the angles θ1 and θ2 may be less than 90 degrees, but is preferably 85 degrees or less, and more preferably 80 degrees or less. In this embodiment, the angles θ1 and θ2 are equal to each other (θ1=θ2). In another example, θ1≠θ2 may be satisfied.

[0035] At least one of the multiple lateral groove elements desirably crosses the land portion completely in the tire axial direction. In the example of Fig. 2, the first lateral groove element 7 crosses the first land portion 101 completely in the tire axial direction. Similarly, the second lateral groove element 8 crosses the second land portion 102 completely in the tire axial direction. In such an embodiment, the first land portion 101 and the second land portion 102 provide excellent drainage.

[0036] In another example, at least one of the lateral groove elements may have at least one of the first end and the second end terminated within the land portion. For example, as shown in FIG. 4, at least one of the first end 7A and the second end 7B of each of the first lateral groove elements 7 may terminate within the first land portion 101. In the example of FIG. 4, in each of the first lateral groove elements 7, the first end 7A terminates within the first land portion 101, and the second end 7B is connected to the circumferential groove 3. Similarly, at least one of the first end 8A and the second end 8B of each of the second lateral groove elements 8 may terminate within the second land portion 102. In the example of FIG. 4, in each of the second lateral groove elements 8, the second end 8B terminates within the second land portion 102, and the first end 8A is connected to the circumferential groove 3. In such an embodiment, the reduction in rigidity of the first land portion 101 and the second land portion 102 is minimized, and the steering stability is improved.

[0037] FIG. 5 shows yet another example. FIG. 5 is different from FIG. 4 in that the inclination direction of the first lateral groove-like element 7 is reversed. Also, the second end 7B of the first lateral groove-like element 7 is connected to the circumferential groove 3 on the opposite side to the second land portion 102. In this example, a rib element 14 that is continuous in the tire circumferential direction can be formed on one side (left side in FIG. 5) of the first land portion 101 and the second land portion 102 in the tire axial direction. This embodiment is applied to a tire with a specified mounting direction on a vehicle, and it is desirable to configure the second land portion 102 side to be located on the outer side of the vehicle when mounted on the vehicle. This further improves the steering stability. In order to improve the steering stability, the width of the rib element 14 in the tire axial direction is 20% or more, preferably 25% to 50%, of the width of the first land portion 101 in the tire axial direction.

[0038] Yet another example is shown in Figure 6. Figure 6 differs from the above-mentioned examples in that the first lateral grooved elements 7 and / or the second lateral grooved elements 8 extend in a non-linear manner.

[0039] The first lateral groove element 7 has, for example, a first inclined portion 71 extending linearly and a second inclined portion 72 extending linearly connected to form a bent portion. In this embodiment, the first inclined portion 71 includes a second end 7B, and the second inclined portion 72 includes a first end 7A. The first end 7A terminates within the first land portion 101. As a result, the first land portion 101 can have a rib element 14 formed on the left side of the first end 7A, which extends continuously in the tire circumferential direction.

[0040] The angle θ11 of the first inclined portion 71 with respect to the tire circumferential direction is larger than the angle θ12 of the second inclined portion 72 with respect to the tire circumferential direction. The larger the angle of the lateral groove-like element with respect to the tire circumferential direction, the more advantageous it is for steering stability. In addition, when the vehicle is turning, the force acting near the edge of the land portion tends to be larger. In this embodiment, the angle θ11 of the first inclined portion 71 located at the edge of the first land portion 101 is larger than the angle θ12 of the second inclined portion 72, so that steering stability is further improved. In addition, uneven wear near the edge of the first land portion 101 where the first inclined portion 71 is open is suppressed. Furthermore, by bending the first lateral groove-like element 7 as described above, the adjacent land elements 11 can easily support each other when the tire is running. This helps to further improve steering stability. In addition, the second inclined portion 72 with a steep inclination helps to reduce the impact force when the tire touches the ground.

[0041] In order to further enhance the above-mentioned effect, the angle θ11 of the first inclined portion 71 with respect to the tire circumferential direction is, for example, 50 degrees or more, and preferably 60 degrees or more. The upper limit of the angle θ11 may be less than 90 degrees, but is preferably 85 degrees or less, and more preferably 80 degrees or less. Similarly, the angle θ12 of the second inclined portion 72 with respect to the tire circumferential direction is, for example, 20 degrees or more, and preferably 30 degrees or more, and is preferably 70 degrees or less, and more preferably 60 degrees or less.

[0042] The second lateral groove element 8 extends, for example, so as to completely cross the second land portion 102 in the tire axial direction. The second lateral groove element 8 of this embodiment includes a third inclined portion 83, a fourth inclined portion 84, and a fifth inclined portion 85, and each inclined portion extends linearly. The third inclined portion 83 is a portion including the first end 8A. The fifth inclined portion 85 is a portion including the second end 8B. The fourth inclined portion 84 is a portion between the third inclined portion 83 and the fifth inclined portion 85. In this embodiment, the third inclined portion 83, the fourth inclined portion 84, and the fifth inclined portion 85 are connected to form a bent portion. In a preferred embodiment, each bent portion may be formed by an arc portion having a radius of curvature R.

[0043] In this embodiment, the angle θ23 of the third inclined portion 83 relative to the tire circumferential direction and the angle θ25 of the fifth inclined portion 85 relative to the tire circumferential direction are smaller than the angle θ24 of the fourth inclined portion 84 relative to the tire circumferential direction. This allows the land elements 12 of the second land portion 102 to engage with each other and effectively support each other during cornering. Furthermore, the second lateral groove element 8 is provided with the fourth inclined portion 84 with a relatively large angle, which makes it possible to suppress deterioration of the lateral rigidity of the land elements 12. As described above, the second land portion 102 of this embodiment helps to provide excellent steering stability.

[0044] In order to further enhance the above-mentioned effect, the angle θ23 of the third inclined portion 83 with respect to the tire circumferential direction and the angle θ25 of the fifth inclined portion 85 with respect to the tire circumferential direction are, for example, 20 degrees or more, preferably 30 degrees or more, and preferably 80 degrees or less, more preferably 70 degrees or less. Similarly, the angle θ24 of the fourth inclined portion 84 with respect to the tire circumferential direction is, for example, 50 degrees or more, preferably 60 degrees or more, and preferably 85 degrees or less, more preferably 80 degrees or less. In a preferred embodiment, it is desirable that the angles of the adjacent inclined portions of these five inclined portions alternate between large and small, taking into account the order of contact with the ground. That is, it is desirable to satisfy the following. As a result, the noise frequency caused by the first lateral groove element 7 and the second lateral groove element 8 is dispersed over a wide frequency band, further improving the noise performance. θ12<θ11 θ11>θ23 θ23<θ24 θ24>θ25

[0045] In the example of Fig. 6, a bent groove is shown as a non-linear lateral groove-like element. In other examples, the lateral groove-like element may be a curved groove whose angle changes continuously, or may be a composite groove of such a curved groove and a linear groove.

[0046] FIG. 7 shows yet another example of the first arrangement 10. In the example of FIG. 7, the lateral groove elements include a first lateral groove element 7 and a second lateral groove element 8. The angle of one of the first lateral groove element 7 and the second lateral groove element 8 with respect to the tire circumferential direction is larger than the angle of the other of the first lateral groove element 7 and the second lateral groove element 8 with respect to the tire circumferential direction. In addition, the groove width (sipe width) of one of the first lateral groove element 7 and the second lateral groove element 8 is smaller than the groove width (sipe width) of the other of the first lateral groove element 7 and the second lateral groove element 8. In the example of FIG. 7, the angle θ2 of the second lateral groove element 8 is larger than the angle θ1 of the first lateral groove element 7, and the groove width (sipe width) W2 of the second lateral groove element 8 is smaller than the groove width (sipe width) W1 of the first lateral groove element 7. In this embodiment, in a cross section of the land portions 101, 102 in a plane perpendicular to the ground contact surface and parallel to the tire axial direction, the opening width of the first lateral groove-like element 7 and the opening width of the second lateral groove-like element 8 are similar to or equal to each other. This helps to further reduce the fluctuation in impact force during tire running, and further improve noise performance.

[0047] Fig. 8 shows yet another example of the first arrangement 10. In the example of Fig. 8, at least one pair of lateral groove-like elements adjacent in the tire circumferential direction is formed in the same land portion. For example, in the first land portion 101, as the first lateral groove-like elements 7, a first right lateral groove-like element 7R and a first left lateral groove-like element 7L are alternately arranged in the tire circumferential direction. In the second land portion 102, the second lateral groove-like elements 8 described in Fig. 4 are formed.

[0048] The first arrangement 10 of this example is composed of three types of pairs of lateral groove-like elements adjacent to each other in the tire circumferential direction, namely pair 1, pair 2 and pair 3.

[0049] Pair 1, for example, is composed of a first left lateral groove element 7L depicted at the top in the first land portion 101 and a first right lateral groove element 7R adjacent thereto on the second side S2 in the tire circumferential direction. In pair 1, the second end 7LB of the first left lateral groove element 7L and the first end 7RA of the first right lateral groove element 7R are at the same position in the tire circumferential direction. Therefore, the lateral groove elements constituting pair 1 are formed in the same land portion (first land portion 101).

[0050] Pair 2 continues to the second side S2 of pair 1. Pair 2 is composed of, for example, the first right lateral groove element 7R depicted at the top of the first right lateral groove elements 7R of the first land portion 101, and the second lateral groove element 8 adjacent thereto on the second side S2. In pair 2, the second end 7RB of the first right lateral groove element 7R and the first end 8A of the second lateral groove element 8 are at the same position in the tire circumferential direction. Therefore, pair 2 is a pair in which the lateral groove elements constituting pair 2 are formed in different land portions (the first land portion 101 and the second land portion 102).

[0051] Pair 3 continues to the second side S2 of pair 2. Pair 3 is composed of, for example, the second lateral groove element 8 of the second land portion 102 and the first left lateral groove element 7L adjacent thereto on the second side S2. In pair 3, the second end 8B of the second lateral groove element 8 and the first end 7LA of the first left lateral groove element 7L are at the same position in the tire circumferential direction. Therefore, pair 3 is a pair in which the lateral groove elements constituting pair 3 are formed in different land portions (the first land portion 101 and the second land portion 102).

[0052] In this way, at least one of the pairs in the first array 10 may have the lateral groove-like elements constituting the pair formed in the same land portion, and the above-mentioned effect can also be achieved in this example. In the example of Fig. 8, two types of lateral groove-like elements are provided in the first land portion 101, but instead of this, or in addition to this, two types of lateral groove-like elements may be provided in the second land portion 102. Also, three or more types of lateral groove-like elements may be provided in one land portion.

[0053] FIG. 9 shows yet another example of the first arrangement 10. In the example of FIG. 9, the lateral groove-like elements constituting the first arrangement 10 are formed in two land portions, but are different from the above example in that two or more circumferential grooves are arranged between the two land portions. That is, in the previous examples of the first arrangement 10, the first land portion 101 and the second land portion 102 are adjacent to each other via one circumferential groove 3. In contrast, in the example of FIG. 9, two or more circumferential grooves 3 may be arranged between the first land portion 101 and the second land portion 102. In addition, for example, a third land portion 103 is arranged between the first land portion 101 and the second land portion 102. The third land portion 103 is a rib that is continuous in the tire circumferential direction. The third land portion may be, for example, a plain rib without grooves or sipes.

[0054] FIG. 10 shows yet another example of the first arrangement 10. As in the example of FIG. 10, the lateral groove-like elements constituting the first arrangement 10 may be arranged in three or more land portions among the multiple land portions. In the example of FIG. 10, the first arrangement 10 is arranged in three land portions, namely, a first land portion 101, a second land portion 102, and a third land portion 103. In the third land portion 103, a plurality of third lateral groove-like elements 9 are formed in the tire circumferential direction as the lateral groove-like elements. This first arrangement 10 is composed of three types of pairs, namely, pair 1, pair 2, and pair 3. Pair 1 is composed of a first lateral groove-like element 7 and a second lateral groove-like element 8. Pair 2 is on the second side S2 of pair 1 and is composed of a second lateral groove-like element 8 and a third lateral groove-like element 9. Pair 3 is on the second side S2 of pair 2 and is composed of a third lateral groove-like element 9 and a first lateral groove-like element 7. In each of these pairs, the lateral groove elements constituting the pair are formed on different land portions. The first array 10 may be formed of four or more land portions.

[0055] 11 shows another embodiment of the present disclosure. In this embodiment, a plurality of sets of first arrays 10 are formed in the first land portion 101 and the second land portion 102. For example, the plurality of sets of first arrays 10 include an inner first array 10X and another outer first array 10Y. Even in such an embodiment, the pitch noise can be reduced to improve noise performance and steering stability performance.

[0056] In Fig. 11, the first inner array 10X is composed of first lateral groove elements 7X and second lateral groove elements 8X. The first lateral groove elements 7X are formed on the second land portion 102 side of the first land portion 101. The second lateral groove elements 8X are formed on the first land portion 101 side of the second land portion 102. In Fig. 11, the first lateral groove elements 7X and second lateral groove elements 8X constituting the first inner array 10X are painted black to facilitate understanding.

[0057] The outer first array 10Y is composed of first lateral groove elements 7Y and second lateral groove elements 8Y. The first lateral groove elements 7Y are formed on the side of the first land portion 101 opposite the second land portion 102. The second lateral groove elements 8Y are formed on the side of the second land portion 102 opposite the first land portion 101. In FIG. 11, the first lateral groove elements 7Y and second lateral groove elements 8Y constituting the outer first array 10Y are not filled in to easily distinguish them from the inner first array 10X.

[0058] In this way, even if multiple sets of the first arrays 10 are provided in a land area consisting of the first land portion 101 and the second land portion 102, it is possible to improve noise performance by reducing pitch noise, as in the previous embodiment.

[0059] FIG. 12 shows another example of the lateral grooved element. In this example, the lateral grooved element is a lateral groove (inclined groove). Specifically, the lateral groove elements of the first array 10 in this example include, for example, a first lateral groove element 7 and a second lateral groove element 8, which are formed by lateral grooves. In this manner, the lateral groove elements (the first lateral groove element 7 and the second lateral groove element 8) of the present disclosure are not limited to sipes.

[0060] Fig. 13 shows, with a virtual line, the contact patch GL of the tread portion 2 in Fig. 1 under normal load. The length D1 in the tire circumferential direction of an edge GL1 of the contact patch GL crossing the first land portion 101 is set to be 20% or less of the length L1 in the tire circumferential direction of one of the first lateral groove-like elements 7. Similarly, the length D2 in the tire circumferential direction of an edge GL2 of the contact patch GL crossing the second land portion 102 is set to be 20% or less of the length L2 in the tire circumferential direction of one of the second lateral groove-like elements 8.

[0061] In order to enhance the noise improvement effect, the inventors focused on the relationship between the tire circumferential lengths L1 and L2 of the first lateral groove-like element 7 and the second lateral groove-like element 8 and the tire circumferential lengths D1 and D2 of the edges GL1 and GL2 of the contact surface GL. In order to obtain the impact force fluctuation suppression effect expected from the first arrangement 10, it is most effective that the edges GL1 and GL2 of the contact surface GL crossing each land portion 101, 102 are parallel to the tire axial direction. However, in an actual tire, the edges GL1 and GL2 of the contact surface GL tend to be arc-shaped as shown in FIG. 13. Even in such a case, if the tire circumferential lengths D1 and D2 of the edges GL1 and GL2 of the contact surface GL are 20% or less of the tire circumferential length L1 of the first lateral groove-like element 7 and the tire circumferential length L2 of the second lateral groove-like element 8, respectively, the difference in the contact timing between the first edge e1 and the second edge e2 of the land portion 4 can be minimized. This helps to further reduce the above-mentioned fluctuation in impact force and further improve noise performance. In a particularly desirable embodiment, the length D1 is set to 10% or less, more preferably 5% or less, of the length L1 of one of the first lateral groove elements 7 in the tire circumferential direction, and the length D2 is set to 10% or less, more preferably 5% or less, of the length L2 of one of the second lateral groove elements 8 in the tire circumferential direction.

[0062] Although several embodiments of the present disclosure have been described above, the specific configurations shown in the embodiments and drawings are for understanding the contents of the present disclosure, and the present disclosure is not limited to the specific configurations shown in the drawings.

[0063] [Note] The present disclosure includes the following aspects.

[0064] [Disclosure 1] A tire having a tread portion, The tread portion includes a plurality of circumferential grooves extending continuously in a tire circumferential direction and a plurality of land portions separated by the circumferential grooves, A plurality of lateral groove-like elements inclined with respect to the tire axial direction and the tire circumferential direction are formed in each of the plurality of land portions, Each of the lateral groove elements has a first end on a first side in the tire circumferential direction and a second end on a second side in the tire circumferential direction, and extends linearly from the first end to the second end; the first end and the second end are each an end of a centerline of the grooved element; The plurality of lateral groove elements are arranged in a first arrangement around one circumference in the tire circumferential direction, In the first arrangement, for each pair of lateral groove elements adjacent to each other in the tire circumferential direction, the first end of one lateral groove element of the pair is formed at the same position in the tire circumferential direction as the second end of the other lateral groove element of the pair, At least one of the pairs has the lateral groove elements formed in different land portions. tire. [Disclosure 2] The tire of Disclosure 1, wherein the lateral grooved elements include sipes having a width of 2 mm or less. [Disclosure 3] 3. The tire of claim 1 or 2, wherein the lateral grooved elements include grooves having a width greater than 2 mm. [Disclosure 4] The tire according to any one of claims 1 to 3, wherein at least one of the pairs of lateral groove elements is made of lateral groove elements inclined in the same direction relative to the tire circumferential direction. [Disclosure 5] The tire according to any one of claims 1 to 4, wherein at least one of the pairs of lateral groove elements is composed of lateral groove elements inclined in directions different from each other with respect to the tire circumferential direction. [Disclosure 6] The tire according to any one of claims 1 to 5, wherein at least one of the plurality of lateral groove elements completely crosses the land portion in the tire axial direction. [Disclosure 7] The tire according to any one of the disclosures 1 to 6, wherein at least one of the first end and the second end of at least one of the lateral groove elements terminates within the land portion. [Disclosure 8] The lateral grooves include a first lateral groove and a second lateral groove; an angle of one of the first lateral groove element and the second lateral groove element with respect to the tire circumferential direction is larger than an angle of the other of the first lateral groove element and the second lateral groove element with respect to the tire circumferential direction, The tire according to any one of the first to seventh disclosures, wherein the groove width of one of the first lateral groove element and the second lateral groove element is smaller than the groove width of the other of the first lateral groove element and the second lateral groove element. [Disclosure 9] A tire as described in any one of claims 1 to 8 of the present disclosure, wherein in a contact patch under a normal load condition in which the tire is mounted to a normal rim at normal internal pressure and in contact with a flat surface with a normal load applied and a camber angle of zero, the circumferential length of the edge of the contact patch that crosses the land portion in which the lateral groove elements that constitute the first array are provided is 20% or less of the circumferential length of one of the lateral groove elements formed in the land portion. [Disclosure 10] The tire according to any one of claims 1 to 9, wherein the first arrangement is formed in a plurality of sets. [Disclosure 11] The tire according to any one of claims 1 to 10, wherein each of the pairs has two lateral groove elements formed in different land portions. [Disclosure 12] The tire according to any one of the disclosures 1 to 10, wherein in at least one of the pairs, the two lateral groove elements included in the pair are formed in the same land portion. [Disclosure 13] The tire according to any one of claims 1 to 12, wherein the lateral groove elements constituting the first arrangement are formed in two of the plurality of land portions. [Disclosure 14] The tire according to present disclosure 13, wherein the two land portions are adjacent to each other via one of the circumferential grooves. [Disclosure 15] The tire according to the present disclosure 13, wherein two or more of the circumferential grooves are disposed between the two land portions. [Disclosure 16] The tire according to any one of claims 1 to 12, wherein the lateral groove elements constituting the first arrangement are arranged in three or more land portions among the plurality of land portions. [Explanation of symbols]

[0065] 1 Tire 2 Tread section 4 Land 7 First grooved element 7A First End of First Grooved Element 7B Second end of first grooved element 8 Second grooved element 8A First end of second grooved element 8B: second end of second grooved element 10 First Array GLa Edge of ground plane S1 First Side S2 Second side

Claims

1. A tire having a tread portion, The tread portion includes a plurality of circumferential grooves extending continuously in a tire circumferential direction and a plurality of land portions separated by the circumferential grooves, A plurality of lateral groove-like elements inclined with respect to the tire axial direction and the tire circumferential direction are formed in each of the plurality of land portions, Each of the lateral groove elements has a first end on a first side in the tire circumferential direction and a second end on a second side in the tire circumferential direction, and extends linearly from the first end to the second end; the first end and the second end are each an end of a centerline of the grooved element; The plurality of lateral groove elements are arranged in a first arrangement around one circumference in the tire circumferential direction, In the first arrangement, for each pair of lateral groove elements adjacent to each other in the tire circumferential direction, the first end of one lateral groove element of the pair is formed at the same position in the tire circumferential direction as the second end of the other lateral groove element of the pair, At least one of the pairs has the lateral groove elements formed in different land portions. tire.

2. 2. The tire of claim 1, wherein the lateral grooved elements include sipes having a width of 2 mm or less.

3. 3. A tire according to claim 1 or 2, wherein the lateral grooved elements include grooves having a width greater than 2mm.

4. The tire according to claim 1 , wherein at least one of the pairs of lateral groove elements is made up of lateral groove elements inclined in the same direction relative to the tire circumferential direction.

5. The tire according to claim 1 , wherein at least one of the pairs of lateral groove elements is formed of lateral groove elements inclined in directions different from each other with respect to the tire circumferential direction.

6. The tire according to claim 1 , wherein at least one of the plurality of lateral groove elements completely crosses the land portion in the tire axial direction.

7. The tire according to claim 1 , wherein at least one of the first end and the second end of at least one of the lateral groove elements terminates within the land portion.

8. The lateral grooves include a first lateral groove and a second lateral groove, an angle of one of the first lateral groove element and the second lateral groove element with respect to the tire circumferential direction is larger than an angle of the other of the first lateral groove element and the second lateral groove element with respect to the tire circumferential direction, The tire according to claim 1 , wherein the groove width of one of the first lateral groove element and the second lateral groove element is smaller than the groove width of the other of the first lateral groove element and the second lateral groove element.

9. 9. The tire according to claim 1, wherein in a contact patch under a normal load condition in which the tire is mounted on a normal rim at normal internal pressure and in which the tire is in contact with a flat surface with a camber angle of zero under normal load, the circumferential length of an edge of the contact patch that crosses the land portion in which the lateral groove elements constituting the first arrangement are provided is 20% or less of the circumferential length of one of the lateral groove elements formed in the land portion.

10. The tire according to claim 1 , wherein the first arrangement is formed in a plurality of sets.

11. The tire according to claim 1 , wherein each of the pairs has two lateral groove elements formed in different land portions.

12. The tire according to claim 1 , wherein in at least one of the pairs, the two lateral groove elements included in the pair are formed in the same land portion.

13. The tire according to claim 1 , wherein the lateral groove elements constituting the first arrangement are formed in two of the plurality of land portions.

14. The tire according to claim 13 , wherein the two land portions are adjacent to each other via one of the circumferential grooves.

15. The tire according to claim 13 , wherein two or more of the circumferential grooves are disposed between the two land portions.

16. The tire according to claim 1 , wherein the lateral groove elements constituting the first arrangement are arranged in three or more of the plurality of land portions.

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