Tire

Abstract

The tire of the present application maintains high-load dry road grip performance, and further improves wet performance. The tire (1) includes a first land portion (3) including a first tread end (T1), and a second land portion (4) adjacent to the first land portion (3) in the tire axial direction. The width (Wa) of the first land portion (3) is greater than the width (Wb) of the second land portion (4). In the first land portion (3), a first inner side cross groove (11) extending from a first circumferential groove (7) to the outer side in the tire axial direction and having a first inner side interruption end (12) interrupted within the first land portion (3), and a first outer side cross groove (13) extending from the first tread end (T1) to the inner side in the tire axial direction and having a first outer side interruption end (14) interrupted within the first land portion (3) are provided.

Description

Technical Field

[0001] This disclosure relates to tires. Background Technology

[0002] Patent Document 1 describes a tire designed for high-load driving conditions, including on tracks and other challenging terrains, that provides excellent dry-road grip and wet-road performance. The tire's tread portion includes: first to third main grooves, an inner crown land portion divided by the first to third main grooves, an outer crown land portion, an inner shoulder land portion, and an outer shoulder land portion. Furthermore, closed grooves are provided within the outer crown land portion, the inner shoulder land portion, and the outer shoulder land portion.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2018-167717

[0004] When driving on wet surfaces, tires like those described above have the problem of insufficient water drainage near the land side of the inner tire shoulder. Summary of the Invention

[0005] This disclosure is made in view of the actual situation described above, and its main purpose is to provide a tire that can maintain dry road grip performance under high load driving and further improve wet performance.

[0006] The tire disclosed herein has a tread portion defined for installation in a vehicle. The tread portion includes: a first tread end located inside the vehicle during installation; a first land portion including the first tread end; a second land portion adjacent to the first land portion in the tire axial direction; and a first circumferential groove dividing the first land portion and the second land portion. The tire axial width of the first land portion is greater than the tire axial width of the second land portion. The first land portion is provided with: a first inner lateral groove extending outward from the first circumferential groove in the tire axial direction and having a first inner interrupted end within the first land portion; and a first outer lateral groove extending inward from the first tread end in the tire axial direction and having a first outer interrupted end within the first land portion.

[0007] The tire disclosed herein, by employing the above-described structure, is able to maintain dry road grip performance under high-load driving conditions and further improve wet road performance. Attached Figure Description

[0008] Figure 1 This is a top view of the tread section of one embodiment of the tire of this disclosure.

[0009] Figure 2 yes Figure 1 An enlarged view of the first landmass.

[0010] Figure 3 yes Figure 1 Enlarged views of the first and second landmasses.

[0011] Figure 4 This is a three-dimensional view of the acute-angled land section K1.

[0012] Figure 5 yes Figure 1 Enlarged views of the third and fourth landmasses.

[0013] Explanation of reference numerals in the attached drawings: 1...Tire; 3...First land section; 4...Second land section; 7...First circumferential groove; 11...First inner lateral groove; 12...First inner interruption; 13...First outer lateral groove; 14...First outer interruption; Wa...Width of the first land section; Wb...Width of the second land section; T1...First tread end. Detailed Implementation

[0014] The following description, based on the accompanying drawings, illustrates one embodiment of this disclosure.

[0015] Figure 1 This is a top view showing the unfolded tread section 2 of a tire 1 according to one embodiment of the present disclosure. The tire 1 of the present disclosure is, for example, a pneumatic tire for passenger cars, which can be driven under high loads on a racetrack in addition to normal driving on public roads. However, the tire 1 of the present disclosure can also be used, for example, as a pneumatic tire for heavy-duty vehicles, a pneumatic tire for motorcycles, or a non-air tire that is not filled with compressed air.

[0016] The tread portion 2 is specified to be installed in the direction of vehicle mounting. Thus, the tread portion 2 has a first tread end T1 located inside the vehicle when the tire 1 is mounted on the vehicle, and a second tread end T2 located outside the vehicle.

[0017] The first tread end T1 and the second tread end T2 are the outermost contact points along the tire's axial direction when the tire 1, in its normal condition, is subjected to a normal load and contacts the ground at a 0° camber angle, with the tire in the case of an inflated tire. The term "normal condition" refers to the state where the tire 1 is assembled onto a normal rim (not shown) and filled with normal internal pressure, and is unloaded. In this specification, unless otherwise specified, the dimensions of each part of the tire 1 are values ​​measured under the aforementioned normal condition. Furthermore, the axial distance between the first tread end T1 and the second tread end T2 is the tread width TW.

[0018] The aforementioned "standard rim" refers to a rim with a specified specification for each tire within a specification system that includes the specification on which tire 1 is based. For example, if it is JATMA, it is a "standard rim"; if it is TRA, it is a "Design Rim"; and if it is ETRTO, it is a "Measuring Rim".

[0019] The aforementioned "standard internal pressure" refers to the air pressure specified for each tire in the specification system, including the specification on which tire 1 is based. 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 LIMITSAT VARIOUS COLD INFLATION PRESSURES". If it is ETRTO, it is the INFLATION PRESSURE.

[0020] The aforementioned "regular load" refers to the load specified for each tire in the specification system, including the specification on which tire 1 is based. If it is JATMA, it is "maximum load capacity". If it is TRA, it is the maximum value recorded in the table "TIRE LOADLIMITS AT VARIOUS COLD INFLATION PRESSURES". If it is ETRTO, it is "LOADCAPACITY".

[0021] The tread portion 2 of this embodiment includes: a first land portion 3 including a first tread end T1, a second land portion 4 adjacent to the first land portion 3 in the tire axial direction, and a first circumferential groove 7 dividing the first land portion 3 and the second land portion 4.

[0022] The axial width Wa of the first land portion 3 is greater than the axial width Wb of the second land portion 4. This increases the axial rigidity of the first land portion 3, which experiences a relatively large lateral force, thus maintaining high grip performance on dry roads. While not particularly limited, the width Wa of the first land portion 3 is preferably at least 1.4 times the width Wb of the second land portion 4, more preferably at least 1.5 times, and even more preferably at least 1.9 times, and even more preferably at least 1.8 times. For example, the width Wa of the first land portion 3 is preferably at least 10% of the tread width TW, more preferably at least 15%, even more preferably at least 30%, and even more preferably at least 25%.

[0023] The first land portion 3 is provided with a first inner lateral groove 11 and a first outer lateral groove 13. The first inner lateral groove 11 extends outward from the first circumferential groove 7 in the tire axial direction and has a first inner interruption end 12 that is interrupted within the first land portion 3. The first outer lateral groove 13 extends inward from the first tread end T1 in the tire axial direction and has a first outer interruption end 14 that is interrupted within the first land portion 3. As described above, the first land portion 3 experiences a relatively larger lateral force than the second land portion 4. In particular, in tires 1 with a negative camber angle designed to improve the cornering performance of vehicles subjected to high loads, the first land portion 3 experiences a larger ground contact pressure. In such tires 1, it is necessary to improve the drainage performance of the first land portion 3 in order to improve wet performance. Therefore, as disclosed herein, a tire 1 with the first inner lateral groove 11 and the first outer lateral groove 13 provided in the first land portion 3 can smoothly drain water near the first land portion 3 to the first tread end T1 and the first circumferential groove 7, thereby significantly improving wet performance. In this specification, each interruption point is located on the center line of the width of the transverse groove where the interruption is located.

[0024] Figure 2 yes Figure 1 An enlarged view of the first land section 3. (See image below.) Figure 2 As shown, the first inner transverse groove 11 and the first outer transverse groove 13 of this embodiment include portions that are inclined in the same direction relative to the tire axial direction. Such first inner transverse grooves 11 and first outer transverse grooves 13 reduce the portion of the first land portion 3 that generates a rigidity difference, thereby maintaining a high level of grip performance on dry roads.

[0025] The first inner transverse groove 11 and the first outer transverse groove 13 include portions 11a and 13a whose angles θ1 and θ2 relative to each other with respect to the tire axial direction are equal or whose angle difference (θ1-θ2) is less than 5 degrees. The angle difference (θ1-θ2) is an absolute value in this specification. The portion 11a having the tire axial length L1 of the first inner transverse groove 11 is preferably 70% or more, more preferably 80% of the tire axial length L1a. The portion 13a having the tire axial length L2 of the first outer transverse groove 13 is preferably 70% or more, more preferably 80% of the tire axial length L2a. The angle θ1 of the first inner transverse groove 11 is the angle of the center line 11c of the groove width of the first inner transverse groove 11. And the angle θ2 of the first outer transverse groove 13 is the angle of the center line 13c of the groove width of the first outer transverse groove 13.

[0026] The angle θ1i at the first inner end 12 of the first inner transverse groove 11 relative to the tire axial direction is, for example, equal to or less than the angle θ2o at the first outer end 14 of the first outer transverse groove 13 relative to the tire axial direction. This effectively achieves the aforementioned function. Angles θ1i and θ2o are the angles of the groove width centerline 11c on the first inner end 12 and the groove width centerline 13c on the first outer end 14, respectively.

[0027] The angles θ1i and θ2o are preferably 5 degrees or more, more preferably 15 degrees or more, and even more preferably 60 degrees or less, and more preferably 45 degrees or less. Since the angles θ1i and θ2o are 5 degrees or more, water in each of the transverse grooves 11 and 13 can be smoothly discharged by utilizing the rotation of the tire 1. Since the angles θ1i and θ2o are 60 degrees or less, the decrease in the transverse rigidity of the first land portion 3 can be suppressed.

[0028] The angle θ2e at the first tread end T1 of the first outer lateral groove 13 relative to the tire axial direction is preferably 0 degrees ± 5 degrees. This minimizes the decrease in rigidity at the first tread end T1 of the first land portion 3. The angle θ2e is the angle of the groove width centerline 13c on the first tread end T1.

[0029] Figure 3 yes Figure 1 Enlarged views of the first landmass 3 and the second landmass 4. (See attached image.) Figure 3 As shown, in this embodiment, the first inner transverse groove 11 includes a first portion 15 having a first inner interrupted end 12. In this embodiment, when viewed from above, the first portion 15 is the portion where the groove width centerline 11c extends in a straight line. In this specification, the term "straight line" when viewed from above, in addition to the case where the groove width centerline extends in a straight line, also includes the case where the radius of curvature R1 extends in an arc of 200 mm or more.

[0030] The first outer transverse groove 13 includes a second portion 16 containing a first outer interrupted end 14, and a third portion 17 connecting the second portion 16 to the first tread end T1. In this embodiment, when viewed from above, the second portion 16 is a portion in which the groove width centerline 13c extends in a straight line. In this embodiment, when viewed from above, the third portion 17 is a portion in which the groove width centerline 13c extends in an arc shape. In this specification, "arc shape" refers to a shape in which the radius of curvature R1 of the groove width centerline extends with a radius of curvature less than 200 mm when viewed from above.

[0031] In this embodiment, the first inner interruption end 12 is located closer to the first tread end T1 than the first outer interruption end 14. Thus, an overlap portion Y is formed in the first land portion 3, where the first inner lateral groove 11 and the first outer lateral groove 13 overlap in the tire axial direction. This overlap portion Y increases the amount of water expelled near the first land portion 3, thereby improving wet performance. To balance the improvement of dry road grip and wet performance, the tire axial length La of the overlap portion Y is preferably 3% or more of the width Wa of the first land portion 3, more preferably 5% or more, and even more preferably 15% or less, and more preferably 10% or less.

[0032] A first sipe 19 is provided on the first land portion 3, connecting the first inner interrupted end 12 of the first inner transverse groove 11 to the first tread end T1. This first sipe 19 draws water from the first land portion 3 and discharges it towards the first inner transverse groove 11 and the first tread end T1, thus improving wet-weather performance. In this specification, the sipe is formed as a groove with a width of less than 1.5 mm. Therefore, the sipe is clearly distinguishable from circumferential grooves and transverse grooves with a width of 1.5 mm or more.

[0033] In this embodiment, the first cutting groove 19 extends in a straight line relative to the length direction. The first cutting groove 19 may also extend in a serrated or wavy shape, for example. The first cutting groove 19 may be inclined relative to the tire axial direction, for example.

[0034] The angle θ1i relative to the tire axis at the first inner end 12 of the first inner transverse groove 11 ( Figure 2 (As shown) Preferably, the angle θ3 between the first groove 19 and the tire axis is equal to or less than 5 degrees. This allows water in the first groove 19 to flow smoothly into the first inner transverse groove 11, thus further improving wetland performance. In this specification, the angle difference (θ1i-θ3) is an absolute value.

[0035] When viewed from above, the first inner lateral groove 11 is formed to completely encompass the imaginary extension line 19x, which is formed by extending the first sipe 19 along its length on the first land portion 3. Thus, the first inner lateral groove 11 and the first sipe 19 touch the ground at the same time, and both the groove 11 and the first sipe 19 deform in a larger opening manner, thereby increasing the apparent groove volume and sipe volume. This improves wet performance. In this specification, the term "imaginary extension line" refers to a line extending the center line of the groove width or the center line of the sipe. "Completely encompassing" in this specification means that the imaginary extension line continuously lies along the lateral groove from its inner end to its outer end in the tire's axial direction.

[0036] The width W5 of the first outer transverse groove 13 is, for example, larger than the width W4 of the first inner transverse groove 11. Furthermore, in this embodiment, the length L2 of the first outer transverse groove 13 is... Figure 2 The first outer transverse groove 13 (as shown) is formed to be longer than the length L1 of the first inner transverse groove 11. Therefore, compared to the first inner transverse groove 11, the first outer transverse groove 13 can collect more water near the first land portion 3 and discharge it to the outside of the first tread end T1, thus improving wetland performance. The width W5 of the first outer transverse groove 13 is preferably 1.1 times or more, more preferably 1.2 times or more, and even more preferably 1.4 times or less, and even more preferably 1.3 times or less. The width W5 of the first outer transverse groove 13 is preferably 10% or more, more preferably 15% or more, and even more preferably 30% or less, and even more preferably 25% or less, of the width Wa of the first land portion 3. The length L2 of the first outer transverse groove 13 is preferably 55% or more, more preferably 60% or more, and even more preferably 75% or less, and even more preferably 70% or less, of the width Wa of the first land portion 3.

[0037] When viewed from above, the first land portion 3 includes an acute-angled corner land portion K1 formed between the first inner transverse groove 11 and the first circumferential groove 7.

[0038] Figure 4 This is a three-dimensional diagram of the acute-angled land section K1. (Example) Figure 4 As shown, in this embodiment, the tread sidewall 3b of the acute-angled land portion K1 includes a chamfered portion 20 that slopes gently from the tread tread 3a side toward the groove width centerline 11c of the first inner transverse groove 11. The tread sidewall 3b also includes, for example, a first sidewall portion 21 and a second sidewall portion 22. In this embodiment, the first sidewall portion 21 extends radially inward from the tread tread 3a. In this embodiment, the second sidewall portion 22 extends radially outward from the groove bottom 11s of the first inner transverse groove 11. The first sidewall portion 21 and the second sidewall portion 22 are inclined, for example, at an angle smaller than that of the chamfered portion 20 relative to the normal n of the tread tread 3a. The chamfered portion 20 connects, for example, the first sidewall portion 21 and the second sidewall portion 22. Such an acute-angled land portion K1 suppresses a decrease in the rigidity of the first land portion 3.

[0039] The acute-angled corner land portion K1 includes the boundary between the tread wall surface 3b and the tread tread surface 3a, i.e., the land portion edge 24. When viewed from above, the radius of curvature R2 of the land portion edge 24 in this embodiment is formed in a single arc shape. The acute-angled corner land portion K1 forming such a land portion edge 24 further suppresses the decrease in rigidity of the first land portion 3. The radius of curvature R2 of the land portion edge 24 is preferably, for example, 5 mm or more, more preferably 6 mm or more, and also preferably 9 mm or less, more preferably 8 mm or less.

[0040] The first land portion 3 includes, for example, an obtuse-angled corner land portion K2 formed between the first inner transverse groove 11 and the first circumferential groove 7. In this embodiment, the obtuse-angled corner land portion K2 does not have a chamfered portion as described above.

[0041] like Figure 1 As shown, in this embodiment, the tread portion 2 further includes: a third land portion 5 adjacent to the second land portion 4 in the tire axial direction, and a fourth land portion 6 adjacent to the third land portion 5 in the tire axial direction and including the second tread end T2. Additionally, the tread portion 2 includes, for example, a second circumferential groove 8 dividing the second land portion 4 and the third land portion 5, and a third circumferential groove 9 dividing the third land portion 5 and the fourth land portion 6.

[0042] In this embodiment, the second circumferential groove 8 is adjacent to the first circumferential groove 7. In this embodiment, the second circumferential groove 8 is located on the side closer to the first tread end T1 than the tire equator C. In the second circumferential groove 8, for example, its groove width centerline 8c is located on the side closer to the first tread end T1 than the tire equator C.

[0043] In this embodiment, the third circumferential groove 9 is located on the side closer to the second tread end T2 than the second circumferential groove 8. For example, the third circumferential groove 9 is located on the side closer to the second tread end T2 than the tire equator C. The first circumferential groove 7, the second circumferential groove 8, and the third circumferential groove 9 extend continuously in a straight line in the tire circumferential direction. Alternatively, each circumferential groove 7-9 may extend in a serrated or wavy manner.

[0044] The width W2 of the second circumferential groove 8 is greater than the width W1 of the first circumferential groove 7. The width W3 of the third circumferential groove 9 is less than the width W1 of the first circumferential groove 7. The width W1 of the first circumferential groove 7 is preferably 3% or more of the tread width TW, more preferably 5% or more, and even more preferably 8% or less, more preferably 6% or less. The groove depth d1 of the first circumferential groove 7 ( Figure 4 (As shown) For example, it is 5.0 to 7.5 mm.

[0045] The tire axial width Wc of the third land portion 5 is less than the width Wa of the first land portion 3 and greater than the width Wb of the second land portion 4. The tire axial width Wd of the fourth land portion 6 is greater than the tire axial width Wa of the first land portion 3. The width Wc of the third land portion 5 is preferably 0.7 times or more than the width Wa of the first land portion 3, more preferably 0.75 times or more, and even more preferably 0.9 times or less, and even more preferably 0.85 times or less. The width Wd of the fourth land portion 6 is preferably 1.15 times or more than the width Wa of the first land portion 3, more preferably 1.2 times or more, and even more preferably 1.35 times or less, and even more preferably 1.3 times or less.

[0046] like Figure 3 As shown, in this embodiment, the second land portion 4 is provided with a second cutting groove 25 and a recess 26 formed by cutting off the edge 4e of the land portion 4 that extends along the tire circumference.

[0047] The recess 26 includes a first recess 26a connected to the first circumferential groove 7 and a second recess 26b connected to the second circumferential groove 8. Such a recess 26 helps to increase the groove volume of the appearance of each circumferential groove 7, 8.

[0048] The length of the recess 26 in the tire circumferential direction, Lb, decreases towards the center position 4c of the second land portion 4 in the tire axial direction. In this embodiment, the length of the recess 26 in the tire circumferential direction, Lb, continuously decreases towards the center position 4c of the second land portion 4. When viewed from above, the recess 26 is, for example, triangular in shape. Such a recess 26 suppresses a decrease in the rigidity of the land portion of the second land portion 4. The recess 26 is not limited to this shape.

[0049] The maximum value of the length Lb of the recess 26 is preferably 120% or more, more preferably 130% or more, and even more preferably 160% or less, and more preferably 150% or less, of the tire axial length Lc of the recess 26. Figure 1 The depth of the recess 26 (not shown) is preferably 10% or more, more preferably 15% or more, and even more preferably 30% or less, and even more preferably 25% or less. The depth of the recess 26 (not shown) is preferably 55% or more, more preferably 65% ​​or more, and even more preferably 100% or less of the groove depth d1 of the first circumferential groove 7.

[0050] In this embodiment, the second groove 25 extends across the second land portion 4. This second groove 25 improves wetland performance. In this embodiment, the second groove 25 extends in a manner that connects the first recess 26a and the second recess 26b. Therefore, the second groove 25 and the recess 26b are grounded at the same time, and thus both deform with a larger opening, increasing the apparent volume and thereby improving wetland performance.

[0051] In the second land section 4, apart from the second cutter groove 25, no transverse grooves or cutter grooves are provided that run through the second land section 4. This suppresses the decrease in rigidity of the land section 4, which experiences significant ground pressure during straight-line travel. Therefore, excellent road grip performance is achieved.

[0052] Figure 5 yes Figure 1Enlarged views of the third land section 5 and the fourth land section 6. In this embodiment, the third land section 5 is provided with a third transverse groove 28, a third transverse groove 29, and a third sipe 30. The third transverse groove 28 and the third transverse groove 29 are arranged alternately, for example, along the tire circumference.

[0053] In this embodiment, the third transverse groove 28 traverses the third land portion 5. In this embodiment, the third transverse groove 29 extends from the second circumferential groove 8 toward the second tread end T2 and has a third interrupted end 31 that is interrupted within the third land portion 5.

[0054] The third transverse groove 28 and the third transverse groove 29 are inclined in the same direction relative to the tire axis, for example. This reduces the rigidity difference generated in the third land portion 5. In this embodiment, the third transverse groove 28 and the third transverse groove 29 extend in parallel. The third transverse groove 28 and the third transverse groove 29 extend in a straight line, for example. This improves wet performance. The angle θ4 of the third transverse groove 28 relative to the tire axis and the angle θ5 of the third transverse groove 29 relative to the tire axis are preferably 10 degrees or more, more preferably 15 degrees or more, and even more preferably 30 degrees or less, and more preferably 25 degrees or less. The term "parallel" in this specification naturally includes cases where the absolute value of the difference between the angles is 0 degrees, and also includes cases where the difference is 5 degrees or less.

[0055] In this embodiment, when viewed from above, the third transverse groove 29 is formed to completely include the imaginary extension line 30x of the third sipe 30 extending along its length direction on the third land portion 5.

[0056] like Figure 1 As shown, when viewed from above, the third transverse groove 28 of the third land portion 5 is formed to completely include the imaginary extension line 25x of the second sipe 25 extending along its length on the third land portion 5. Thus, the third transverse groove 28 and the second sipe 25 deform in a larger opening manner, increasing the apparent groove volume and sipe volume, thereby further improving wet performance.

[0057] like Figure 5 As shown, the tire axial length L3 of the third transverse groove 29 is preferably the width Wc of the third land portion 5. Figure 1 The length L3 of the third transverse ditch 29 is 40% or more, more preferably 45% or more, and even more preferably 60% or less, and more preferably 55% or less. The length L3 of the third transverse ditch 29 is 40% or more of the width Wc of the third land portion 5, thus maintaining wetland performance. The length L3 of the third transverse ditch 29 is 60% or less of the width Wc of the third land portion 5, thus maintaining dry road grip performance.

[0058] The width W7 of the third transverse groove 29 is, for example, the same as the width W6 of the third transverse groove 28. This keeps the rigidity difference of the third land portion 5 relatively small. In this embodiment, the maximum value of the width W7 of the third transverse groove 29 is the same as the maximum value of the width W6 of the third transverse groove 28. The term "same" in this specification naturally includes the case where the difference in the width of each groove is 0 mm, and also includes the case where the absolute value of these differences is within 3 mm.

[0059] In this embodiment, the third cutting groove 30 connects the third circumferential groove 9 to the third transverse groove 29. The third cutting groove 30 is connected, for example, to the third interrupted end 31. In this embodiment, the third cutting groove 30 extends in a straight line.

[0060] The fourth land portion 6 of this embodiment includes: a fourth transverse groove 35 extending from the third circumferential groove 9 toward the second tread end T2 side, and a fourth small transverse groove 36 whose two ends are interrupted within the fourth land portion 6.

[0061] In this embodiment, the fourth transverse groove 35 includes a fourth portion 35A extending linearly from the third circumferential groove 9, and a fifth portion 35B connected to the fourth portion 35A and extending in an arc shape. The fifth portion 35B includes a fifth interruption end 37 where the fourth land portion 6 is interrupted.

[0062] The fourth small transverse groove 36 includes a sixth portion 36A extending in a straight line and a seventh portion 36B connected to the sixth portion 36A and extending in an arc shape. The sixth portion 36A and the seventh portion 36B respectively include a sixth interruption end 38 and a seventh interruption end 39 that are interrupted within the fourth land portion 6.

[0063] Although not specifically limited, the tire axial length L4 of the fourth lateral groove 35 is preferably the width Wd of the fourth land portion 6. Figure 1 The tire axial length L5 of the fourth small transverse groove 36 is preferably 65% ​​or more of the width Wd of the fourth land portion 6, more preferably 70% or more, more preferably 85% or less, and even more preferably 80% or less.

[0064] In this embodiment, the fourth portion 35A and the sixth portion 36A extend in parallel. The angle θ6 of the fourth portion 35A relative to the tire axial direction and the angle θ7 of the sixth portion 36A relative to the tire axial direction are preferably 10 degrees or more, more preferably 15 degrees or more, and even more preferably 30 degrees or less, and more preferably 25 degrees or less.

[0065] While not particularly limited, the tire axial length L4a of the fourth part 35A is preferably 75% or more, more preferably 80% or more, and further preferably 95% or less, and even more preferably 90% or less, of the tire axial length L4 of the fourth lateral groove 35. Furthermore, the tire axial length L5a of the sixth part 36A is preferably 70% or more, more preferably 75% or more, and further preferably 90% or less, and even more preferably 85% or less, of the tire axial length L5 of the fourth minor lateral groove 36.

[0066] When viewed from above, the fourth lateral groove 35 is formed as including an imaginary extension line 28x extending the third lateral groove 28 along its length direction on the fourth land portion 6. The fourth portion 35A of the fourth lateral groove 35 is, for example, formed to completely include the imaginary extension line 28x. Furthermore, the fourth lateral groove 35 is formed as including an imaginary extension line 25x extending the second sipe 25 towards the third land portion 5 and the fourth land portion 6. Figure 1 (As shown). Furthermore, the fourth small transverse groove 36 is formed to include an imaginary extension line 30y extending the third cutter groove 30 along its length direction on the fourth land portion 6. The sixth portion 36A of the fourth small transverse groove 36, for example, completely includes the imaginary extension line 30y.

[0067] like Figure 1 As shown, each lateral groove of the tread portion 2 in this embodiment is inclined in the same direction relative to the tire axial direction. For example, each of these lateral grooves is inclined in a first direction relative to the tire axial direction (in... Figure 1 The center (upper right) is tilted. Therefore, by utilizing the rotation of the tire 1, water in each groove is smoothly discharged towards the side of the tire's axial direction. Each sipe located on the tread portion 2 is also tilted in the same direction relative to the tire's axial direction. For example, each of these sipes is tilted in the first direction described above.

[0068] The first inner lateral groove 11, the first outer lateral groove 13, and the first sipe 19 formed on the first land portion 3 have a larger axial tilt relative to the tire compared to, for example, the second sipe 25, the third transverse groove 28, the third lateral groove 29, the third sipe 30, the fourth lateral groove 35, and the fourth small lateral groove 36 formed on the second land portions 4 to the fourth land portions 6. This tread pattern 2 improves drainage performance near the first land portion 3 and maintains high dry road grip performance on the second land portions 4 to the fourth land portions 6.

[0069] The above describes one embodiment of the present disclosure in detail, but the present disclosure is not limited to the specific embodiment described above, but can be implemented in various ways.

[0070] Example

[0071] Based on the specifications in Table 1, a prototype with... Figure 1The tires used had a basic tread pattern. Furthermore, the dry road grip and wet road grip performance of each test tire were tested. The common specifications and testing methods for all test tires are as follows.

[0072] <Dry road grip performance, wetland performance>

[0073] Each test tire was mounted on all wheels of the test vehicle described below. The test driver drove the vehicle at high speeds on a test route on a dry asphalt road surface and on a test route on an asphalt road surface with 5mm of standing water. The driver's sensory evaluation was used to assess the vehicle's stability, dry road grip, and wet road performance under these conditions. Results are expressed as a score of 100 (Comparative Example 1). Higher scores are better; tires with any score below 90 are considered unqualified.

[0074] Tire size: 245 / 40R18

[0075] Wheel rim: 18×8.5J

[0076] Internal pressure: 220 kPa (all wheels)

[0077] Vehicle: A four-wheel drive vehicle with a 2000cc engine.

[0078] Tread width (TW): 268mm

[0079] The test results are shown in Table 1 and Table 2.

[0080] “A” is the shape of the first inner transverse groove extending from the first tread end and interrupted at the first land portion.

[0081] “B” is the shape of the first outer transverse groove extending from the first circumferential groove and interrupted at the first land portion.

[0082] “C” is the shape that runs across the first landmass.

[0083] “D” is a shape that is interrupted at both ends on the first land surface.

[0084] “E” indicates the shape of the second circumferential groove located at the end of the second tread, closer to the tire equator.

[0085] Table 1

[0086]

[0087] Table 2

[0088]

[0089] The test results confirmed that the tires of the embodiment have excellent wet performance. Furthermore, it was confirmed that the tires of the embodiment maintain high dry road grip performance.

[0090] [Postscript]

[0091] This disclosure includes the following methods.

[0092] [This disclosure 1] A tire having a tread portion defined in a direction for installation onto a vehicle, wherein,

[0093] The tread portion includes: a first tread end located inside the vehicle during vehicle installation, a first land portion including the first tread end, a second land portion adjacent to the first land portion in the tire axial direction, and a first circumferential groove dividing the first land portion and the second land portion.

[0094] The axial width of the first land portion is greater than the axial width of the second land portion.

[0095] The first land portion is provided with: a first inner transverse groove that extends from the first circumferential groove toward the outer side of the tire axial direction and has a first inner interruption end that is interrupted within the first land portion; and a first outer transverse groove that extends from the first tread end toward the inner side of the tire axial direction and has a first outer interruption end that is interrupted within the first land portion.

[0096] [This Disclosure 2] The tire according to this Disclosure 1, wherein,

[0097] The first inner transverse groove and the first outer transverse groove include portions that are inclined in the same direction relative to the tire axial direction.

[0098] [This disclosure 3] The tire according to disclosure 1 or 2, wherein,

[0099] The first inner transverse groove and the first outer transverse groove include portions that are at an angle equal to or differ from each other by less than 5 degrees relative to the tire axial direction.

[0100] [This Disclosure 4] The tire according to any one of claims 1 to 3 of this disclosure, wherein,

[0101] The angle θ1i at the first inner end of the first inner transverse groove relative to the tire axis is equal to or the angle θ2o at the first outer end of the first outer transverse groove relative to the tire axis is less than 5 degrees.

[0102] [This disclosure 5] The tire according to this disclosure 4, wherein,

[0103] The angles θ1i and θ2o are 5 to 60 degrees.

[0104] [This Disclosure 6] The tire according to any one of claims 1 to 5 of this disclosure, wherein,

[0105] A first sipe is provided on the first land portion to connect the first inner interruption end of the first inner transverse groove to the first tread end.

[0106] [This disclosure 7] The tire according to this disclosure 6, wherein,

[0107] The angle of the first inner end of the first inner transverse groove relative to the tire axis is equal to or the angle of the first sipe relative to the tire axis is less than 5 degrees.

[0108] [This Disclosure 8] The tire according to any one of claims 1 to 7 of this disclosure, wherein,

[0109] The angle between the first tread end of the first outer transverse groove and the tire axis is 0 degrees ± 5 degrees.

[0110] [This Disclosure 9] The tire according to any one of claims 1 to 8 of this disclosure, wherein,

[0111] When viewed from above, the first land portion includes an acute-angled corner land portion formed between the first inner transverse groove and the first circumferential groove.

[0112] The tread wall of the acute-angled corner land portion includes a chamfered portion that slopes gently from the tread surface toward the center line of the groove width of the first inner transverse groove.

[0113] [This disclosure 10] The tire according to this disclosure 9, wherein,

[0114] The tread sidewall of the acute-angled corner land portion includes: a first sidewall extending radially inward from the tread tread side towards the inner side of the tire, and a second sidewall extending radially outward from the bottom of the first inner transverse groove towards the outer side of the tire.

[0115] The chamfered portion connects the first wall surface to the second wall surface.

[0116] [This disclosure 11] The tire according to disclosure 9 or 10, wherein,

[0117] The acute-angled corner land portion includes the boundary between the tread wall and the tread tread surface, i.e., the edge of the land portion.

[0118] When viewed from above, the radius of curvature of the edge of the land portion is a single circular arc.

[0119] [This Disclosure 12] The tire according to any one of claims 1 to 11 of this disclosure, wherein,

[0120] The tread portion includes: a second tread end located on the outer side of the vehicle during vehicle installation, a second circumferential groove adjacent to the first circumferential groove, and a third circumferential groove located on the side of the second tread end that is closer to the second circumferential groove than the second circumferential groove.

[0121] The first circumferential groove and the second circumferential groove are located at a position closer to the first tread end than the tire equator.

[0122] The third circumferential groove is located at the end of the second tread closer to the tire equator.

[0123] [This disclosure 13] The tire according to this disclosure 12, wherein,

[0124] The first circumferential groove, the second circumferential groove, and the third circumferential groove extend continuously in a straight line along the tire circumference.

Claims

1. A tire having a tread portion oriented in a direction specified for installation onto a vehicle, characterized in that, The tread portion includes: a first tread end located inside the vehicle during vehicle installation, a first land portion including the first tread end, a second land portion adjacent to the first land portion in the tire axial direction, and a first circumferential groove dividing the first land portion and the second land portion. The axial width of the first land portion is greater than the axial width of the second land portion. The first land portion is provided with: a first inner transverse groove extending from the first circumferential groove outward in the tire axial direction and having a first inner interrupted end within the first land portion; and a first outer transverse groove extending from the first tread end inward in the tire axial direction and having a first outer interrupted end within the first land portion. When viewed from above, the first land portion includes an acute-angled corner land portion formed between the first inner transverse groove and the first circumferential groove. The tread wall of the acute-angled corner land portion includes a chamfered portion that slopes gently from the tread tread side toward the centerline of the groove width of the first inner transverse groove. The tread sidewall of the acute-angled corner land portion includes: a first sidewall extending radially inward from the tread tread side towards the inner side of the tire, and a second sidewall extending radially outward from the bottom of the first inner transverse groove towards the outer side of the tire. The chamfered portion connects the first wall surface to the second wall surface.

2. The tire according to claim 1, characterized in that, The first inner transverse groove and the first outer transverse groove include portions that are inclined in the same direction relative to the tire axial direction.

3. The tire according to claim 1 or 2, characterized in that, The first inner transverse groove and the first outer transverse groove include portions that are at an angle equal to or differ from each other by less than 5 degrees relative to the tire axial direction.

4. The tire according to claim 1 or 2, characterized in that, The angle θ1i at the first inner end of the first inner transverse groove relative to the tire axis is equal to or the angle θ2o at the first outer end of the first outer transverse groove relative to the tire axis is less than 5 degrees.

5. The tire according to claim 4, characterized in that, The angles θ1i and θ2o are 5 to 60 degrees.

6. The tire according to claim 1 or 2, characterized in that, A first sipe is provided on the first land portion to connect the first inner interruption end of the first inner transverse groove to the first tread end.

7. The tire according to claim 6, characterized in that, The angle of the first inner end of the first inner transverse groove relative to the tire axis is equal to or the angle of the first sipe relative to the tire axis is less than 5 degrees.

8. The tire according to claim 1 or 2, characterized in that, The angle between the first tread end of the first outer transverse groove and the tire axis is 0 degrees ± 5 degrees.

9. The tire according to claim 1, characterized in that, The acute-angled corner land portion includes the boundary between the tread wall and the tread tread surface, i.e., the edge of the land portion. When viewed from above, the radius of curvature of the edge of the land portion is a single circular arc.

10. The tire according to claim 1 or 2, characterized in that, The tread portion includes: a second tread end located on the outer side of the vehicle during vehicle installation, a second circumferential groove adjacent to the first circumferential groove, and a third circumferential groove located on the side of the second tread end that is closer to the second circumferential groove than the second circumferential groove. The first circumferential groove and the second circumferential groove are located at a position closer to the first tread end than the tire equator. The third circumferential groove is located at the end of the second tread closer to the tire equator.

11. The tire according to claim 10, characterized in that, The first circumferential groove, the second circumferential groove, and the third circumferential groove extend continuously in a straight line along the tire circumference.

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