tire

Abstract

To provide a tire that can achieve fuel economy performance and wet performance in a balanced manner regardless of a progress status of abrasion.SOLUTION: A plurality of lateral grooves 3 extending in a tire axial direction is formed in a tread part 2. The lateral groove 3 includes narrow groove part 4 and widened parts 5. The narrow groove part 4 has a groove width in which the part is blocked in a normal load application state of the tire. The widened parts 5 are communicated with inner ends in a tire radial direction of the narrow grooves 5. The widened parts 5 are larger in a groove width than the narrow groove parts 4 and have a groove width in which the parts are not blocked in the normal load application state. Distances D in the tire radial direction from a tread surface 21 of the tread part 2 to a position 45 at which the narrow groove parts 4 are communicated with the widened parts 5 are not constant in a longitudinal direction of the lateral grooves 3.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a tire having a tread portion. [Background technology]

[0002] BACKGROUND ART Tires having underwater lateral grooves in the tread portion have been disclosed (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2012-501914 Summary of the Invention [Problem to be solved by the invention]

[0004] The tire disclosed in Patent Document 1 does not provide sufficient wet performance in the early stages of wear when the submerged lateral grooves are hidden. On the other hand, as the wear of the tread progresses, the submerged lateral grooves become visible, causing greater deformation of the tread and resulting in reduced fuel economy.

[0005] The present disclosure has been devised in view of the above circumstances, and has as its main object to provide a tire that can achieve balanced fuel economy and wet performance regardless of the state of wear. [Means for solving the problem]

[0006] The present disclosure provides a tire having a tread portion, A plurality of axially extending lateral grooves are formed in the tread portion, The lateral groove includes a narrow groove portion and a widened portion, the narrow groove portion has a groove width that closes when the tire is under normal load, the widened portion communicates with an inner end of the narrow groove portion in the tire radial direction, the widened portion has a groove width that is larger than the groove width of the narrow groove portion and does not close under the normal load condition, The lateral grooves are a first lateral groove, the narrow groove portion and the widened portion communicating with each other at a first distance from the tread surface of the tread portion; a second lateral groove, the communication position of which is located at a second distance from the tread surface that is greater than the first distance; It's a tire. [Effects of the Invention]

[0007] In the tire of the present disclosure, in the early stage of wear of the tread portion, the narrow groove portions are closed by the load of the normal load, thereby suppressing deformation of the tread portion and reducing rolling resistance. Meanwhile, as wear of the tread portion progresses, the widened portions that are not closed by the load of the normal load appear, thereby improving drainage performance. Furthermore, the lateral grooves include the first lateral groove and the second lateral groove, which have different connection positions between the narrow groove portions and the widened portions. As wear progresses, it is possible to stagger the timing at which the widened portions appear in the first lateral groove and the second lateral groove. Therefore, balanced fuel economy and wet performance can be achieved regardless of the progress of wear. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a perspective view of a tread portion showing one embodiment of a tire of the present disclosure. [Figure 2] FIG. 2 is a cross-sectional view showing a tread portion under normal load conditions. [Figure 3] FIG. 2 is a perspective view of a tread portion in which a plurality of lateral grooves having different distances D are formed. [Figure 4] FIG. 4 is a cross-sectional view showing the tread portion of FIG. 3 under a normal load. [Figure 5] FIG. 4 is a development view of a modified example of the transverse groove of FIG. 3. [Figure 6] FIG. 4 is a perspective view of a modification of the tread portion of FIG. 3. [Figure 7] FIG. 7 is a development view of the tread portion of FIG. 6. [Figure 8]FIG. 7 is a perspective view of a modification of the tread portion of FIG. 6. [Figure 9] FIG. 9 is a development view of a tread portion including the configuration of FIG. 8. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. FIG. 1 is a perspective view of a tire according to the present embodiment, with a part of the tread portion 2 cut away.

[0010] A plurality of lateral grooves 3 extending in the tire axial direction (a direction intersecting the tire equator) are formed in the tread portion 2. The lateral grooves 3 may be not only parallel to the tire axial direction, but also inclined relative to the tire axial direction.

[0011] The lateral groove 3 includes a narrow groove portion 4 and a widened portion 5 .

[0012] The narrow groove portion 4 is open at the tread surface 21 of the tread portion 2. The narrow groove portion 4 has a groove width that closes when the tire is in a normal load state.

[0013] The "normal load condition" refers to a condition in which a normal load is applied to a tire in a normal state and the tire is in contact with a flat surface with a camber angle of 0°.

[0014] "Normal condition" means, in the case of a pneumatic tire, a condition in which the tire is mounted on a normal rim (not shown), inflated to the normal internal pressure, and no load is applied. In the case of an airless tire, it means a condition in which the tire is mounted on a normal rim. Unless otherwise specified below, the dimensions of each part of the tire are values ​​measured in this normal condition.

[0015] A "genuine rim" is a rim that is defined for each tire by the standard system that includes the standard on which the tire is based. For example, in the case of JATMA, it is called a "standard rim," in the case of TRA, it is called a "design rim," and in the case of ETRTO, it is called a "measuring rim."

[0016] "Normal internal pressure" refers to the air pressure specified for each tire in the standard system, including the standard on which the tire is based. For JATMA, this is the "maximum air pressure," for TRA, this is the maximum value listed in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES," and for ETRTO, this is the "INFLATION PRESSURE." If the tire is for a passenger car, the normal internal pressure is, for example, 180 kPa.

[0017] "Normal load" refers to the load specified for each tire in the standard system, including the standard on which the tire is based. For JATMA, it is "maximum load capacity." For TRA, it is the maximum value listed in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES." For ETRTO, it is "LOAD CAPACITY." If the tire is for a passenger car, the normal load is, for example, a load equivalent to 88% of the load.

[0018] The widened portion 5 is connected to the radially inner end of the narrow groove portion 4. The widened portion 5 has a groove width that is larger than the groove width of the narrow groove portion 4 and does not close under normal load conditions. The groove width of the narrow groove portion 4 is, for example, less than 1.5 mm, and the groove width of the widened portion 5 is, for example, 1.5 mm or more.

[0019] Figure 2 shows a portion of the tread portion 2 under normal load. When a normal load is applied, the narrow grooves 4 are closed, increasing the circumferential rigidity of the tread portion 2. This suppresses deformation of the tread portion 2 and reduces rolling resistance.

[0020] In the tire of this embodiment, in the early stage of wear of the tread portion 2, the narrow groove portions 4 are closed by the application of a normal load, thereby suppressing deformation of the tread portion 2 and reducing rolling resistance. On the other hand, as the wear of the tread portion 2 progresses, widened portions 5 that do not close even under the application of a normal load appear, thereby improving drainage performance.

[0021] In the tire of this embodiment, the distance D in the tire radial direction from the tread surface 21 of the tread portion 2 to the connecting position 45 between the narrow groove portion 4 and the widened portion 5 is not constant in the longitudinal direction of the lateral groove 3. In such a lateral groove 3, the narrow groove portion 4 and the widened portion 5 coexist as the wear of the tread portion 2 progresses. This allows for balanced fuel economy and wet performance to be achieved regardless of the progress of wear.

[0022] The distance D being "non-constant in the longitudinal direction" means that the distance D is not a constant value in the longitudinal direction of the lateral groove 3 (in other words, in the axial direction of the tire). Therefore, the distance D may be a form that changes continuously in the longitudinal direction of the lateral groove 3, or a form that changes in stages. Furthermore, as shown in FIG. 1 , the distance D is not limited to a form in which it changes in one lateral groove 3, and multiple lateral grooves 3 with different distances D may be formed in the tread portion 2.

[0023] 3 partially shows a tread portion 2 in which a plurality of lateral grooves 3 are formed with different distances D. That is, the lateral grooves 3 include a first lateral groove 31 and a second lateral groove 32.

[0024] The first lateral groove 31 is a lateral groove 3 having a communication position 45 at a first distance D1 from the tread 21. The second lateral groove 32 is a lateral groove 3 having a communication position 45 at a second distance D2 from the tread 21. The first distance D1 and the second distance D2 themselves may be constant or may not be constant.

[0025] In Figure 3, the second distance D2 is greater than the first distance D1. Therefore, as wear progresses, the widened portions 5 of the first lateral grooves 31 appear first on the tread surface 21 of the tread portion 2, improving wet performance. At this time, the narrow groove portions 4 of the second lateral grooves 32 open to the tread surface 21. The narrow groove portions 4 of the second lateral grooves 32 close under normal load, suppressing deformation of the tread portion 2. This provides a balanced combination of fuel economy and wet performance regardless of the degree of wear.

[0026] Fig. 4 shows a portion of the tread portion 2 of Fig. 3 under normal load conditions. When a normal load is applied, the narrow groove portions 4 of the first lateral grooves 31 and the second lateral grooves 32 are closed, increasing the circumferential rigidity of the tread portion 2. This suppresses deformation of the tread portion 2 and reduces rolling resistance.

[0027] In the tire of this embodiment, in the early stage of wear of the tread portion 2, the narrow groove portions 4 of the first lateral grooves 31 and the second lateral grooves 32 are closed by the application of a normal load, thereby suppressing deformation of the tread portion 2 and reducing rolling resistance. On the other hand, as the wear of the tread portion 2 progresses, widened portions 5 that do not close even under the application of a normal load appear, thereby improving drainage performance.

[0028] 3 and 4, the lateral groove 3 includes the first lateral groove 31 and the second lateral groove 32, which have different connection positions 45 between the narrow groove portion 4 and the widened portion 5. As a result, it is possible to shift the timing at which the widened portion 5 appears in the first lateral groove 31 and the second lateral groove 32 as wear progresses. Therefore, balanced fuel economy and wet performance can be obtained regardless of the progress of wear.

[0029] The first distance D1 is preferably 80% or less of the second distance D2. By making the first distance D1 80% or less of the second distance D2, it becomes possible to stagger the timing at which the widened portions 5 appear in the first lateral grooves 31 and the second lateral grooves 32, thereby achieving a better balance between fuel economy and wet performance.

[0030] It is desirable that the first lateral grooves 31 and the second lateral grooves 32 are arranged alternately in the tire circumferential direction, so that the first lateral grooves 31 and the second lateral grooves 32 alternately come into contact with the ground in the rolling tread portion 2, thereby achieving a better balance between fuel economy and wet performance.

[0031] FIG. 5 shows a modified example of the lateral groove 3 in FIG. 1. As shown in FIG. 5, the lateral groove 3 may extend in a zigzag pattern. The lateral grooves 3 in FIG. 3, i.e., the first lateral grooves 31 and the second lateral grooves 32, may also extend in a zigzag pattern. In such a lateral groove 3, the narrow groove portions 4 are closed under normal load, thereby increasing the circumferential and axial rigidity of the tread portion 2 and further improving fuel economy. Note that in the lateral grooves 3, the narrow groove portions 4 may extend in a zigzag pattern and the widened portions 5 may extend linearly.

[0032] Fig. 6 shows a modification of the tread portion 2 of Fig. 1. As shown in Fig. 6, it is desirable that the tread portion 2 is formed with circumferential grooves 6 extending in the circumferential direction of the tire.

[0033] The circumferential groove 6 includes a narrow groove portion 7 and a widened portion 8 .

[0034] The narrow groove portion 7 is open at the tread surface 21 of the tread portion 2. The narrow groove portion 7 has a groove width that closes when the tire is in a normal load state.

[0035] The widened portion 8 communicates with the radially inner end of the narrow groove portion 7. The widened portion 8 has a groove width that is larger than the groove width of the narrow groove portion 7 and does not close under normal load conditions.

[0036] The wet performance of the tire is improved by forming circumferential grooves 6 in the tread portion 2. In the early stage of wear of the tread portion 2, the narrow groove portions 7 are closed by the application of a normal load, which suppresses deformation of the tread portion 2 and reduces rolling resistance. On the other hand, as the wear of the tread portion 2 progresses, widened portions 8 that do not close even under the application of a normal load appear, improving drainage performance.

[0037] It is desirable that the lateral grooves 3 communicate with the circumferential grooves 6. This allows water to flow between the lateral grooves 3 and the circumferential grooves 6, thereby improving the drainage performance of the tread portion 2.

[0038] The lateral grooves 3 may be connected to circumferential grooves (not shown) that do not include the narrow groove portions 7. In this configuration, regardless of whether the narrow groove portions 4 are blocked, water that has flowed into the circumferential grooves flows into the widened portions 5 of the lateral grooves 3, thereby improving the drainage performance of the tread portion 2.

[0039] The circumferential grooves 6 may extend in a zigzag pattern. In the circumferential grooves 6 having such a configuration, the narrow groove portions 7 are closed when a normal load is applied, thereby increasing the rigidity of the tread portion 2 in the tire axial direction and the tire circumferential direction, and further improving fuel economy.

[0040] Fig. 7 shows the tread surface 21 of the tread portion 2 of Fig. 6. In Fig. 6 and Fig. 7, the first lateral grooves 31 and the second lateral grooves 32 are arranged on one side of the circumferential groove 6 in the tire axial direction.

[0041] The narrow groove portions 4 of the first lateral grooves 31 preferably communicate with the narrow groove portions 7 of the circumferential grooves 6 at an angle θ1 of 60° to 120°, thereby improving the traction performance of the tread portion 2. Similarly, the narrow groove portions 4 of the second lateral grooves 32 preferably communicate with the narrow groove portions 7 of the circumferential grooves 6 at an angle θ2 of 60° to 120°.

[0042] Fig. 8 is another diagram showing a modification of the tread portion 2 of Fig. 6. As shown in Fig. 8, the depth D13 of the widened portion 8 of the circumferential groove 6 is preferably larger than the width W of the widened portion 8 of the circumferential groove 6. This prevents the wet performance from changing suddenly as wear progresses. Also, it becomes possible to easily ensure the wet performance at the final stage of wear.

[0043] The first distance D1 and the second distance D2 are preferably 100 to 150% of the third distance D3 from the tread to the connecting position 78 between the narrow groove portion 7 and the widened portion 8 of the circumferential groove 6.

[0044] By making the first distance D1 and the second distance D2 100% or more of the third distance D3, the widened portions 5 of the first lateral grooves 31 and the second lateral grooves 32 communicate with the widened portions 8 of the circumferential grooves 6, improving wet performance. Also, rolling resistance is reduced in the early stages of wear. By making the first distance D1 and the second distance D2 150% or less of the third distance D3, the circumferential rigidity of the tread portion 2 is maintained, reducing rolling resistance, while good wet performance can be easily obtained in the final stages of wear due to the widened portions 8 of the circumferential grooves 6.

[0045] The depth D11 of the widened portions 5 of the first lateral grooves 31 is preferably smaller than the depth D13 of the widened portions 8 of the circumferential grooves 6. The depth D12 of the widened portions 5 of the second lateral grooves 32 is preferably smaller than the depth D13 of the widened portions 8 of the circumferential grooves 6. This maintains the circumferential rigidity of the tread portion 2 and reduces rolling resistance, while allowing the widened portions 8 of the circumferential grooves 6 to easily provide good wet performance in the final stage of wear.

[0046] The depths D11 and D12 of the widened portions 5 of the lateral grooves 3 are preferably 30 to 50% of the depth D13 of the widened portions 8 of the circumferential grooves 6.

[0047] When the depths D11 and D12 are 30% or more of the depth D13, wet traction performance at the end of wear is improved. When the depths D11 and D12 are 50% or less of the depth D13, a decrease in the rigidity of the tread portion 2 in the tire circumferential direction is suppressed, and rolling resistance can be reduced.

[0048] FIG. 9 shows a tread portion 2A including the configuration of the tread portion 2 described above.

[0049] The tread portion 2A is formed with a pair of circumferential grooves 106 extending in the tire circumferential direction and a plurality of lateral grooves 103 extending in the tire axial direction.

[0050] The circumferential grooves 106 are arranged on both sides of the tire equator C. The circumferential grooves 106 extend in a zigzag pattern.

[0051] Each lateral groove 103 is disposed axially outward of the circumferential groove 106. The lateral grooves 103 communicate with the circumferential grooves 106.

[0052] The circumferential groove 106 includes a narrow groove portion 7 and a widened portion 8 shown in Fig. 6. The lateral groove 103 includes a first lateral groove 31 and a second lateral groove 32 shown in Fig. 6. The first lateral groove 31 and the second lateral groove 32 include a narrow groove portion 4 and a widened portion 5 shown in Fig. 6.

[0053] The tread portion 2A having the above configuration exhibits the same effects as the tread portion 2.

[0054] A pair of wide circumferential grooves 107 are formed axially outward of the lateral grooves 103, each having a groove width that does not close under normal load conditions. The wide circumferential grooves 107 are formed in a zigzag pattern. The lateral grooves 103 communicate with the wide circumferential grooves 107. This facilitates good wet performance in the vicinity of the shoulders from the initial to final stages of wear.

[0055] A plurality of wide lateral grooves 104 having a groove width that does not close under normal load conditions are formed between adjacent lateral grooves 3 in the tire circumferential direction. The wide lateral grooves 104 communicate with the circumferential grooves 106 and the wide circumferential grooves 107. This makes it easy to obtain good wet traction performance from the initial to final stages of wear.

[0056] Although the tire of the present disclosure has been described in detail above, the present disclosure is not limited to the above-described specific embodiments and may be modified in various ways. [Example]

[0057] Pneumatic tires with a size of 315 / 70R22.5 and the basic pattern shown in Figure 9 were prototyped based on the specifications in Table 1, and their fuel economy performance and wet performance at new and end-of-wear stages were evaluated. The wet performance at end-of-wear stages was tested using tires from which the rubber in the tread had been removed by buffing until the remaining circumferential groove depth was 3 mm (the same applies hereinafter). All specifications of the test tires that are not listed in Table 1 are common to all tires. For example, the first distance D1 is 8.5 mm, the second distance D2 is 11.0 mm (the same applies to Tables 2 to 8). The third distance D3 is 8.0 mm (the same applies to Tables 2 to 5 and 7 to 8). The test method was as follows.

[0058] <Fuel efficiency> Each test tire was mounted on a 22.5x9.00 rim with an internal pressure of 900kPa, and the rolling resistance was measured using a rolling resistance tester at a load of 31.25kN and a speed of 80km / h. The results are expressed as an index, with Comparative Example 1 being set at 100, and the larger the index, the smaller the rolling resistance and the better the fuel economy performance.

[0059] <Wet performance> The wet performance of each test tire was tested using a method conforming to the UN-ECE R117 certification test. That is, each test tire was run on a wet road surface with 0.5 mm of water depth at a speed of 65±2 km / h under a load of 75% of the load index, and the braking distance was measured. The results were expressed as an index, with Comparative Example 1 being set at 100, and a larger index indicates a shorter braking distance and better wet performance.

[0060] [Table 1]

[0061] As is clear from Table 1, it was confirmed that the tires of the examples have significantly improved wet performance at the end of wear, while maintaining the same fuel economy performance and wet performance as new tires, compared to the comparative examples.

[0062] Pneumatic tires of the above sizes having the basic pattern shown in Figure 9 were prototyped based on the specifications in Table 2, and similarly to the above, fuel economy performance and wet performance at new and end of wear were evaluated. Specifications of each test tire that are not listed in Table 2 are common to all tires. The test method is as follows.

[0063] <Fuel efficiency> The rolling resistance of each test tire was measured in the same manner as above. The results were expressed as an index, with Example 2 being set at 100, and a larger index value indicates lower rolling resistance and better fuel economy performance.

[0064] <Wet performance> The braking distance of each test tire was measured in the same manner as above. The results are expressed as an index, with Example 2 being 100, and a larger index value indicates a shorter braking distance and better wet performance.

[0065] [Table 2]

[0066] Pneumatic tires of the above sizes having the basic pattern shown in Figure 9 were prototyped based on the specifications in Table 3, and similarly to the above, fuel economy performance and wet performance at new and end of wear were evaluated. Specifications of each test tire that are not listed in Table 3 are common to all tires. The test method is as follows.

[0067] <Fuel efficiency> The rolling resistance of each test tire was measured in the same manner as above. The results were expressed as an index, with Example 4 being 100, and a larger index value indicates lower rolling resistance and better fuel economy performance.

[0068] <Wet performance> The braking distance of each test tire was measured in the same manner as above. The results are expressed as an index, with Example 4 being 100, and a larger index indicates a shorter braking distance and better wet performance.

[0069] [Table 3]

[0070] Pneumatic tires of the above sizes having the basic pattern shown in Figure 9 were prototyped based on the specifications in Table 4, and similarly to the above, fuel economy performance and wet performance at new and end of wear were evaluated. Specifications of each test tire that are not listed in Table 4 are common to all tires. The test method is as follows.

[0071] <Fuel efficiency> The rolling resistance of each test tire was measured in the same manner as above. The results were expressed as an index, with Example 9 being set at 100, and a larger index value indicates lower rolling resistance and better fuel economy performance.

[0072] <Wet performance> The braking distance of each test tire was measured in the same manner as above. The results are expressed as an index, with Example 9 being 100, and a larger index value indicates a shorter braking distance and better wet performance.

[0073] [Table 4]

[0074] Pneumatic tires of the above sizes having the basic pattern shown in Figure 9 were prototyped based on the specifications in Table 5, and similarly to the above, fuel economy performance and wet performance at new and end of wear were evaluated. Specifications of each test tire that are not listed in Table 5 are common to all tires. The test method is as follows.

[0075] <Fuel efficiency> The rolling resistance of each test tire was measured in the same manner as above. The results were expressed as an index, with Example 14 being set at 100, and a larger index value indicates lower rolling resistance and better fuel economy performance.

[0076] <Wet performance> The braking distance of each test tire was measured in the same manner as above. The results are expressed as an index, with Example 14 being 100, and a larger index indicates a shorter braking distance and better wet performance.

[0077] [Table 5]

[0078] Pneumatic tires of the above sizes having the basic pattern shown in Figure 9 were prototyped based on the specifications in Table 6, and similarly to the above, fuel economy performance and wet performance at new and end of wear were evaluated. Specifications of each test tire that are not listed in Table 6 are common to all tires. The test method is as follows.

[0079] <Fuel efficiency> The rolling resistance of each test tire was measured in the same manner as above. The results were expressed as an index, with Example 19 being set at 100, and a larger index value indicates lower rolling resistance and better fuel economy.

[0080] <Fuel efficiency> The braking distance of each test tire was measured in the same manner as above. The results are expressed as an index, with Example 19 being 100, and a larger index indicates a shorter braking distance and better wet performance.

[0081] [Table 6]

[0082] Pneumatic tires of the above sizes having the basic pattern shown in Figure 9 were prototyped based on the specifications in Table 7, and similarly to the above, fuel economy performance and wet performance at new and end of wear were evaluated. Specifications of each test tire that are not listed in Table 7 are common to all tires. The test method is as follows.

[0083] <Fuel efficiency> The rolling resistance of each test tire was measured in the same manner as above. The results were expressed as an index, with Example 24 being set at 100, and a larger index value indicates lower rolling resistance and better fuel economy performance.

[0084] <Fuel efficiency> The braking distance of each test tire was measured in the same manner as above. The results are expressed as an index, with Example 24 being 100, and a larger index indicates a shorter braking distance and better wet performance.

[0085] [Table 7]

[0086] Pneumatic tires of the above sizes having the basic pattern shown in Figure 9 were prototyped based on the specifications in Table 8, and similarly to the above, fuel economy performance and wet performance at new and end of wear were evaluated. Specifications of each test tire that are not listed in Table 8 are common to all tires. The test method is as follows.

[0087] <Fuel efficiency> The rolling resistance of each test tire was measured in the same manner as above. The results were expressed as an index, with Example 29 being set at 100, and a larger index value indicates lower rolling resistance and better fuel economy performance.

[0088] <Wet performance> The braking distance of each test tire was measured in the same manner as above. The results are expressed as an index, with Example 29 being 100, and a larger index value indicates a shorter braking distance and better wet performance.

[0089] [Table 8]

[0090] [Note] The present disclosure includes the following aspects.

[0091] [Disclosure 1] A tire having a tread portion, A plurality of axially extending lateral grooves are formed in the tread portion, The lateral groove includes a narrow groove portion and a widened portion, the narrow groove portion has a groove width that closes when the tire is under normal load, the widened portion communicates with an inner end of the narrow groove portion in the tire radial direction, the widened portion has a groove width that is larger than the groove width of the narrow groove portion and does not close under the normal load condition, The lateral grooves are a first lateral groove, the narrow groove portion and the widened portion communicating with each other at a first distance from the tread surface of the tread portion; a second lateral groove, the communication position of which is located at a second distance from the tread surface that is greater than the first distance; tire. [Disclosure 2] The tire of Disclosure 1, wherein the first distance is 80% or less of the second distance. [Disclosure 3] The tire according to Disclosure 1 or 2, wherein the first lateral grooves and the second lateral grooves are arranged alternately in the tire circumferential direction. [Disclosure 4] The tire according to any one of Disclosures 1 to 3, wherein the narrow groove portions of the lateral grooves extend in a zigzag pattern. [Disclosure 5] The tread portion has a circumferential groove extending in the tire circumferential direction, The circumferential groove includes a narrow groove portion and a widened portion, the narrow groove portion has a groove width that closes when the tire is under normal load, the widened portion communicates with an inner end of the narrow groove portion in the tire radial direction, The tire according to any one of Disclosures 1 to 4, wherein the widened portion has a groove width that is larger than the groove width of the narrow groove portion and does not close under the normal load condition. [Disclosure 6] The tire according to the present disclosure 5, wherein the lateral grooves are in communication with the circumferential grooves. [Disclosure 7] The tire according to Disclosure 6, wherein the narrow groove portions of the lateral grooves communicate with the narrow groove portions of the circumferential grooves at an angle of 60° to 120°. [Disclosure 8] The tire according to any one of the present disclosures 5 to 7, wherein the depth of the widened portion of the circumferential groove is greater than the width of the widened portion of the circumferential groove. [Disclosure 9] The tire according to any one of Disclosures 5 to 8, wherein the first distance and the second distance are 100 to 150% of a third distance from the tread surface to a connecting position between the narrow groove portion and the widened portion of the circumferential groove. [Disclosure 10] The tire according to any one of the present disclosures 5 to 9, wherein the depth of the widened portion of the lateral groove is smaller than the depth of the widened portion of the circumferential groove. [Disclosure 11] The tire according to Disclosure 10, wherein the depth of the widened portion of the lateral groove is 30 to 50% of the depth of the widened portion of the circumferential groove. [Disclosure 12] The tire according to any one of claims 6 to 11, wherein the circumferential groove extends in a zigzag pattern. [Disclosure 13] The tire according to any one of claims 6 to 12, wherein the lateral grooves are arranged axially outward of the circumferential grooves. [Disclosure 14] A wide circumferential groove having a groove width that does not close under the normal load condition is formed on the tire axially outer side of the lateral groove, The tire of this disclosure 13, wherein the lateral grooves are in communication with the wide circumferential grooves. [Disclosure 15] The tire described in this disclosure 14, wherein wide lateral grooves having a groove width that does not close under the normal load condition are formed between the lateral grooves adjacent to each other in the tire circumferential direction. [Disclosure 16] The tire of the present disclosure 15, wherein the wide lateral groove is in communication with the circumferential groove and the wide circumferential groove. [Explanation of symbols]

[0092] 2 Tread section 3 Yokomizo 4 Narrow groove 5 Widening section 6 Circumferential groove 7 Narrow groove 8 Widening section 21 tread 23 Tread section 31 First Yokomizo 32 Second Yokomizo 45 Communication position 78 Communication position D distance D1 First distance D2 2nd distance D3 Third distance

Claims

1. A tire having a tread portion, A plurality of axially extending lateral grooves are formed in the tread portion, The lateral groove includes a lateral narrow groove portion and a lateral widened portion, the lateral narrow groove portion has a groove width that closes when the tire is under normal load, the lateral widened portion communicates with an inner end of the lateral narrow groove portion in the tire radial direction, the lateral widened portion has a groove width that is larger than the groove width of the lateral narrow groove portion and does not close under the normal load condition, The lateral grooves are a first lateral groove, the lateral narrow groove portion and the lateral widened portion communicating with each other at a first distance from the tread surface of the tread portion; a second lateral groove, the communication position of which is located at a second distance from the tread surface that is greater than the first distance; The tread portion has a circumferential groove extending in the tire circumferential direction, The circumferential groove includes a circumferential narrow groove portion and a circumferential widened portion, the circumferential narrow groove portion has a groove width that closes when the tire is in the normal load state, the circumferential widened portion is in communication with an inner end of the circumferential narrow groove portion in the tire radial direction, the circumferential widened portion has a groove width that is larger than the groove width of the circumferential narrow groove portion and does not close under the normal load condition, The length of the circumferential widening portion in the tire radial direction is greater than the width of the circumferential widening portion. tire.

2. A tire having a tread portion, A plurality of axially extending lateral grooves are formed in the tread portion, The lateral groove includes a lateral narrow groove portion and a lateral widened portion, the lateral narrow groove portion has a groove width that closes when the tire is under normal load, the lateral widened portion communicates with an inner end of the lateral narrow groove portion in the tire radial direction, the lateral widened portion has a groove width that is larger than the groove width of the lateral narrow groove portion and does not close under the normal load condition, The lateral grooves are a first lateral groove, the lateral narrow groove portion and the lateral widened portion communicating with each other at a first distance from the tread surface of the tread portion; a second lateral groove, the communication position of which is located at a second distance from the tread surface that is greater than the first distance; The tread portion has a circumferential groove extending in the tire circumferential direction, The circumferential groove includes a circumferential narrow groove portion and a circumferential widened portion, the circumferential narrow groove portion has a groove width that closes when the tire is in the normal load state, the circumferential widened portion is in communication with an inner end of the circumferential narrow groove portion in the tire radial direction, the circumferential widened portion has a groove width that is larger than the groove width of the circumferential narrow groove portion and does not close under the normal load condition, The length of the lateral widening portion in the tire radial direction is smaller than the length of the circumferential widening portion in the tire radial direction. tire.

3. A tire as described in claim 1 or 2, wherein the first distance is 80% or less of the second distance.

4. The tire according to claim 1 , wherein the first lateral grooves and the second lateral grooves are arranged alternately in the tire circumferential direction.

5. A tire described in any one of claims 1 to 4, wherein the lateral narrow groove portion extends in a zigzag pattern in the tire axial direction.

6. A tire described in any one of claims 1 to 5, wherein the lateral grooves are connected to the circumferential grooves.

7. A tire as described in any one of claims 1 to 6, wherein the lateral narrow groove portion communicates with the circumferential narrow groove portion at an angle of 60° to 120°.

8. A tire described in any one of claims 1 to 7, wherein the first distance and the second distance are 100 to 150% of a third distance from the tread surface to a connecting position between the circumferential narrow groove portion and the circumferential widened portion.

9. A tire described in any one of claims 1 to 8, wherein the radial length of the lateral widening portion is 30 to 50% of the radial length of the circumferential widening portion.

10. A tire as described in any one of claims 6 to 9, wherein the circumferential grooves extend in a zigzag pattern around the tire.

11. A tire described in any one of claims 6 to 10, wherein the lateral grooves are arranged axially outside the circumferential grooves.

12. A wide circumferential groove having a groove width that does not close under the normal load condition is formed on the axially outer side of the lateral groove, The tire of claim 11 , wherein the lateral grooves communicate with the wide circumferential grooves.

13. A tire as described in claim 12, wherein wide lateral grooves having a groove width that does not close under the normal load condition are formed between adjacent lateral grooves in the tire circumferential direction.

14. A tire as described in claim 13, wherein the wide lateral groove is connected to the circumferential groove and the wide circumferential groove.

Images