tire

Abstract

To have excellent dry performance.SOLUTION: A tire 1 has a tread part 2 provided with a first land part 3 that is defined by a shoulder circumferential-direction groove 5A and a tread end Te. The first land part 3 is provided with a first sipe 7 that is extended in a circumferential direction of the tire, a plurality of lateral sipes 8, and a first lug groove 9 that is extended from the tread end Te. The first sipe 7 does not communicate with the first lug groove 9. An inner end 8i of the lateral sipe 8 is connected to the shoulder circumferential-direction groove 5A. An outer end 8e of the lateral sipe 8 is connected to the first sipe 7.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a tire. [Background technology]

[0002] The following Patent Document 1 describes a pneumatic tire having an outer region that is on the outer side of the vehicle relative to the tire equator when mounted on the vehicle. The outer region is provided with a middle land portion and a shoulder land portion. The middle land portion is provided with an outer middle lateral groove that crosses the middle land portion, and the shoulder land portion is provided with an outer shoulder lateral groove that crosses the shoulder land portion. The following Patent Document 1 claims to improve dry performance, wet performance, and wear resistance by defining the inclination direction and inclination angle of the outer middle lateral groove and the outer shoulder lateral groove. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-196286 A Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, there has been a demand for further improvement in dry performance. To improve dry performance, for example, it is required to increase the equivalent cornering power (equivalent CP) of the tire.

[0005] Equivalent CP is cornering power (CP) divided by self-aligning torque power (SATP). CP generally increases by increasing the rigidity of the tread. SATP is the self-aligning torque (SAT) when a slip angle of 1 degree is applied to a tire while it is moving. SAT is expressed as the sum of the braking force and driving force on the circumferential line of the tread contact surface. For this reason, an increase in the rigidity of the tread in the circumferential direction of the tire leads to an increase in SATP, making it impossible to increase the equivalent CP.

[0006] Therefore, in order to improve the dry performance, it is effective to keep the SATP small while suppressing the decrease in CP, that is, to suppress the increase in the circumferential stiffness of the tread portion. In particular, it is desirable to suppress the increase in the circumferential stiffness on the tread end where the SAT is maximum.

[0007] The present invention has been devised in view of the above circumstances, and has as its main object to provide a tire with further improved dry performance. [Means for solving the problem]

[0008] The present invention is a tire having a tread portion, the tread portion being provided with a shoulder circumferential groove extending circumferentially of the tire closest to the tread end, and a first land portion defined by the shoulder circumferential groove and the tread end, the first land portion being provided with a plurality of first sipes extending circumferentially of the tire, a plurality of lateral sipes, and a plurality of first lug grooves extending axially inward from the tread end, the first sipes not communicating with the first lug grooves, the axial inner ends of each of the lateral sipes being connected to the shoulder circumferential groove, and the axial outer ends of each of the lateral sipes being connected to any of the first sipes.

[0009] In the tire according to the present invention, it is preferable that a plurality of the lateral sipes are connected to at least one of the plurality of first sipes.

[0010] In the tire according to the present invention, it is preferable that a plurality of second sipes are provided in the first land portion, and each of the second sipes is connected to an axially inner end of any one of the plurality of first lug grooves.

[0011] In the tire according to the present invention, it is preferable that the plurality of second sipes extend in the tire circumferential direction.

[0012] In the tire according to the present invention, it is preferable that the second sipes are connected only to the first lug grooves.

[0013] In the tire according to the present invention, it is preferable that the length of the first lug groove in the tire axial direction is 75% to 85% of the width of the first land portion in the tire axial direction.

[0014] In the tire according to the present invention, the angle of the first lug groove with respect to the tire axial direction is preferably 20 to 45 degrees.

[0015] In the tire according to the present invention, it is preferable that the tread portion is provided with a second land portion adjacent to the shoulder circumferential groove on the axially inner side of the tire, and the second land portion is provided with a second lug groove extending in the axial direction of the tire.

[0016] In the tire according to the present invention, it is preferable that the length of the second lug groove in the tire axial direction is 50% to 85% of the width of the second land portion in the tire axial direction.

[0017] In the tire according to the present invention, it is preferable that the tread portion is provided with a crown circumferential groove that defines the second land portion on the inner side in the tire axial direction, and the second lug groove is connected to the crown circumferential groove.

[0018] In the tire according to the present invention, it is preferable that an angle between the second lug groove and the crown circumferential groove is 30 to 60 degrees.

[0019] In the tire according to the present invention, it is preferable that the second land portion is provided with a lug sipe that extends from the crown circumferential groove outward in the tire axial direction and terminates within the second land portion.

[0020] In the tire according to the present invention, it is preferable that the second land portion is provided with a transverse sipe that crosses the second land portion. Effect of the Invention

[0021] The tire of the present invention, by adopting the above-mentioned configuration, can exhibit excellent dry performance. [Brief description of the drawings]

[0022] [Figure 1] 1 is a plan view of a first land portion of a tread portion showing one embodiment of a tire of the present invention. [Diagram 2] 1A is an enlarged view of a first sipe, and FIG. 1B is an enlarged view of a second sipe. [Diagram 3] FIG. [Figure 4] FIG. [Diagram 5] FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1 is an enlarged plan view of a tread portion 2 of a tire 1 according to the present embodiment. The tire 1 according to the present embodiment is suitable for use as a pneumatic tire for passenger cars, for example. However, the present invention can also be used as a pneumatic tire for heavy loads or light trucks, or as a non-pneumatic tire that is not filled with compressed air.

[0024] As shown in Fig. 1, the tread portion 2 of this embodiment is provided with circumferential grooves 5 that extend continuously in the tire circumferential direction. In this embodiment, the circumferential grooves 5 include a shoulder circumferential groove 5A that is disposed closest to the tread end Te. The tread portion 2 is provided with a first land portion 3 that is defined by, for example, the shoulder circumferential groove 5A and the tread end Te.

[0025] The tread end Te is the axially outermost contact point when the tire 1 is mounted on a normal rim (not shown), inflated to a normal internal pressure, and unloaded, and is placed on a flat surface with a normal load and a camber angle of 0°. Unless otherwise specified, the dimensions of each part of the tire are values ​​measured in the normal state. The axial distance between the tread ends Te on both sides of the tire is the tread width TW (shown in FIG. 3).

[0026] The "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, "standard rim" in the case of JATMA, "Design Rim" in the case of TRA, and "Measuring Rim" in the case of ETRTO.

[0027] The "normal internal pressure" is the air pressure determined for each tire by each standard in the standard system including the standard on which the tire is based. In the case of JATMA, it is the "maximum air pressure." In the case of TRA, it is the maximum value listed in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES." In the case of ETRTO, it is the "INFLATION PRESSURE."

[0028] The "normal load" is the load determined for each tire by each standard in the standard system including the standard 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.

[0029] The first land portion 3 is provided with a plurality of first sipes 7 extending in the tire circumferential direction, a plurality of lateral sipes 8, and a first lug groove 9 extending from the tread end Te toward the inside in the tire axial direction. The first lug groove 9 extending from the tread end Te reduces the tire circumferential rigidity on the tread end Te of the first land portion 3, lowering the SATP and increasing the equivalent CP. This improves dry performance. In addition, the first lug groove 9 smoothly discharges the water film on the tread surface 3a of the first land portion 3 from the tread end Te, thereby improving wet performance. In this specification, the "sipe" means a cut-like body with a width of less than 1.5 mm. In addition, in this specification, the "groove" including the lug groove and the circumferential groove means a groove-like body with a groove width of 1.5 mm or more.

[0030] The first sipes 7 do not communicate with the first lug grooves 9. Such first sipes 7 suppress localized reduction in rigidity of the first land portion 3, thereby maintaining high dry performance. In addition, such first sipes 7 improve uneven wear resistance. In this embodiment, the first sipes 7 do not communicate with all grooves arranged in the first land portion 3 and the shoulder circumferential grooves 5A.

[0031] An inner end 8i in the tire axial direction of the lateral sipe 8 is connected to the shoulder circumferential groove 5A. An outer end 8e in the tire axial direction of the lateral sipe 8 is connected to any one of the first sipes 7. This reduces the SATP at the connection portion between the lateral sipe 8 and the first sipe 7 and at the connection portion between the lateral sipe 8 and the shoulder circumferential groove 5A, improving the contact with the road surface, thereby further improving the dry performance.

[0032] Fig. 3 is a plan view of the tread portion 2. As shown in Fig. 3, the circumferential groove 5 of this embodiment includes a pair of shoulder circumferential grooves 5A, 5A and a crown circumferential groove 5B arranged between the shoulder circumferential grooves 5A, 5A. In this embodiment, the crown circumferential groove 5B is arranged on the tire equator C. In this embodiment, the tread portion 2 has a point-symmetric pattern with respect to an arbitrary point on the tire equator C as the center.

[0033] Further, the tread portion 2 is provided with a second land portion 4 adjacent to the shoulder circumferential groove 5A on the inner side in the tire axial direction. In this embodiment, the second land portion 4 is defined by the shoulder circumferential groove 5A and the crown circumferential groove 5B. The second land portion 4 in this embodiment is disposed on both sides of the tire equator C.

[0034] In this embodiment, the shoulder circumferential grooves 5A and the crown circumferential grooves 5B extend linearly along the tire circumferential direction. The shoulder circumferential grooves 5A and the crown circumferential grooves 5B may extend in a wavy or zigzag shape, for example.

[0035] The groove width Wb of the crown circumferential groove 5B is preferably larger than the groove width Wa of the shoulder circumferential groove 5A. This allows the water film on the tread surface 4a of the second land portion 4, which is difficult to drain, to be effectively discharged, improving wet performance. From the viewpoint of achieving both dry performance and wet performance, the groove width Wb of the crown circumferential groove 5B is preferably about 110% to 140% of the groove width Wa of the shoulder circumferential groove 5A. The groove width Wa of the shoulder circumferential groove 5A is preferably, for example, about 3% to 10% of the tread width TW. In addition, the groove depth (not shown) of the shoulder circumferential groove 5A is preferably, for example, 8.5 to 11.5 mm. Furthermore, the groove depth (not shown) of the crown circumferential groove 5B is preferably 85% to 115% of the groove depth of the shoulder circumferential groove 5A.

[0036] In this way, the first land portion 3 includes the tread end Te and is disposed at the outermost position in the tire axial direction, so that the first land portion 3 is subjected to a large lateral force during cornering. The first sipes 7 are provided in the first land portion 3, which improves the dry and wet performances during cornering in particular.

[0037] As shown in Fig. 1, each of the first sipes 7 extends in an arc shape. Such first sipes 7 are relatively longer than straight sipes (not shown). This enhances the effect of discharging the water film between the road surface and the tread surface 3a of the first land portion 3 by the scratching force of the first sipes 7, improving wet performance. The term "arc shape" includes not only a mode in which the angle of the sipe with respect to the tire axial direction changes continuously, but also a mode in which there are at least two bends where the angle changes by 5 degrees or less with respect to any point on the sipe as a boundary.

[0038] Fig. 2(a) is an enlarged view of the first sipe 7. As shown in Fig. 2(a), in the first sipe 7 in a plan view of the tread, a virtual sipe reference line n1 connecting both ends 7e, 7e of the first sipe 7 with a straight line has an angle α1 of 10 degrees or less with respect to the tire circumferential direction. Such a first sipe 7 enhances the contact with the road surface while suppressing an excessive decrease in the rigidity of the first land portion 3 in the tire circumferential direction, thereby improving dry performance and wet performance.

[0039] As shown in FIG. 1, in the plan view of the tread, the radius of curvature R1 of the first sipe 7 (shown in FIG. 2(a)) is preferably 100% or more of the width Ws of the first land portion 3 in the tire axial direction, more preferably 150% or more, more preferably 250% or less, and even more preferably 200% or less. Since the radius of curvature R1 of the first sipe 7 is 100% or more of the width Ws of the first land portion 3, excessive reduction in the rigidity of the first land portion 3 is suppressed. Since it is 250% or less of the width Ws of the first land portion 3, the length of the first sipe 7 can be secured. The radius of curvature R1 of the first sipe 7 is preferably larger than the width Ws of the first land portion 3 in the tire axial direction. In this specification, the radius of curvature is the radius of a single arc passing through three points, namely, both ends of the sipe and its center.

[0040] The circumferential length L1 of the first sipes 7 is, for example, desirably 40% or more of the pitch P1 of the circumferentially adjacent first sipes 7, more desirably 45% or more, desirably 70% or less, and even more desirably 65% ​​or less. This makes it possible to maintain the improvement of wet performance due to the cutting force of the first sipes 7 while suppressing an excessive decrease in rigidity of the first land portion 3.

[0041] The depth of the first sipes 7 (not shown) is, for example, preferably 50% or more, more preferably 75% or more, more preferably 100% or less, and more preferably 85% or less of the groove depth of the shoulder circumferential groove 5A. The depth of the first sipes 7 is preferably smaller than the groove depth of the shoulder circumferential groove 5A.

[0042] For example, a plurality of lateral sipes 8 are connected to one first sipe 7. In this embodiment, two lateral sipes 8 are connected to one first sipe 7. This improves ground contact at the connection portion K. In addition, such lateral sipes 8 appropriately reduce the circumferential rigidity of the first land portion 3, thereby reducing the SATP. The circumferential pitch P2 of the lateral sipes 8 connected to one first sipe 7 is, for example, desirably 40% or more of the circumferential length L1 of the first sipe 7, more desirably 45% or more, more desirably 60% or less, and even more desirably 55% or less.

[0043] The lateral sipes 8 are, for example, continuously inclined toward one side in the tire axial direction (downward to the left in the figure). The lateral sipes 8 are also formed in a convex arc shape toward one side in the tire circumferential direction (the lower side in the figure). Such lateral sipes 8 have a relatively longer length than straight sipes, improving wet performance. The lateral sipes 8 are not limited to this embodiment, and various shapes may be adopted.

[0044] Although not particularly limited, the length W1 of the lateral sipe 8 in the tire axial direction is desirably 25% or more, more desirably 30% or more, desirably 55% or less, and more desirably 50% or less of the width Ws of the first land portion 3. In addition, the depth of the lateral sipe 8 (not shown) is desirably 80% or more, more desirably 90% or more, desirably 120% or less, and more desirably 110% or less of the depth of the first sipe 7.

[0045] The first lug grooves 9 are arranged, for example, between the first sipes 7 adjacent in the tire circumferential direction. For example, one first lug groove 9 is arranged between the first sipes 7. This prevents the first land portion 3 from excessively decreasing in rigidity, achieving both wet performance and dry performance.

[0046] The first lug grooves 9 are, for example, continuously inclined toward one side in the tire axial direction (downward to the left in the figure). In this way, the first lug grooves 9 are inclined in the same direction as the lateral sipes 8. The first lug grooves 9 are also formed in a convex arc shape toward one side in the tire circumferential direction (the lower side in the figure). In this way, the first lug grooves 9 are formed in a convex arc shape toward the same direction as the lateral sipes 8. This ensures the length in the tire circumferential direction between the first lug grooves 9 and the lateral sipes 8, thereby suppressing localized reduction in rigidity of the first land portion 3 and maintaining high uneven wear performance.

[0047] The first lug grooves 9 overlap, for example, with the lateral sipes 8 in the tire axial direction. In other words, an overlap region J in which the first lug grooves 9 and the lateral sipes 8 overlap in the tire axial direction is formed in the first land portion 3 so as to extend in the tire circumferential direction. Such an overlap region J appropriately reduces the rigidity of the first land portion 3 in the tire circumferential direction, thereby enabling further reduction in the SATP.

[0048] Although not particularly limited, the width Wj of the overlap region J in the tire axial direction is desirably 5% or more of the width Wj of the first land portion 3, more desirably 10% or more, desirably 35% or less, and even more desirably 30% or less.

[0049] FIG. 4 is a plan view of the first land portion 3. As shown in FIG. 4, the angle θ2 of the first lug groove 9 relative to the tire axial direction is preferably smaller than the angle θ1 of the lateral sipe 8 relative to the tire axial direction. This maintains high rigidity in the tire axial direction on the tread end Te side of the first land portion 3 where a large lateral force acts, improving uneven wear resistance. In this specification, the angle θ2 of the first lug groove 9 is the inclination of a virtual straight line m2 connecting both ends 9d, 9d of the center line 9c of the first lug groove 9. The angle θ1 of the lateral sipe 8 is the inclination of a virtual straight line m1 connecting both ends.

[0050] Although not particularly limited, in order to improve dry performance and uneven wear resistance, the difference (θ1-θ2) between the angle θ1 of the lateral sipes 8 and the angle θ2 of the first lug groove 9 is preferably 5 degrees or more, more preferably 7 degrees or more, more preferably 15 degrees or less, and more preferably 13 degrees or less. Moreover, the angle θ2 of the first lug groove 9 is preferably 20 degrees or more, more preferably 25 degrees or more, more preferably 40 degrees or less, and more preferably 35 degrees or less.

[0051] The length L2 of the first lug groove 9 in the tire axial direction is preferably 75% or more, more preferably 77% or more, more preferably 85% or less, and even more preferably 83% or less of the width Ws of the first land portion 3. Since the length L2 of the first lug groove 9 is 75% or more of the width Ws of the first land portion 3, wet performance is improved. Since the length L2 of the first lug groove 9 is 85% or less of the width Ws of the first land portion 3, excessive decrease in rigidity is suppressed and uneven wear resistance is improved.

[0052] Although not particularly limited, the groove width W1 of the first lug groove 9 is preferably 65% ​​or more of the groove width Wa of the shoulder circumferential groove 5A, more preferably 70% or more, more preferably 85% or less, and more preferably 80% or less. Also, the groove depth (not shown) of the first lug groove 9 is preferably 60% or more of the groove depth of the shoulder circumferential groove 5A, more preferably 70% or more, more preferably 100% or less, and more preferably 90% or less.

[0053] In the present embodiment, the first land portion 3 is provided with a second sipe 10 that is connected to an axially inner end 9i of the first lug groove 9. Such a second sipe 10 serves to appropriately reduce the axial stiffness of the tire near the inner end 9i of the first lug groove 9, thereby reducing the SATP.

[0054] The second sipes 10 extend, for example, in the circumferential direction of the tire. This improves the ground contact of the tread surface 3a of the first land portion 3, thereby improving the dry performance and the wet performance.

[0055] Fig. 2(b) is an enlarged view of the second sipe 10. As shown in Fig. 2(b), in the second sipe 10 in the tread plan view, a virtual sipe reference line n2 connecting both ends 10e of the second sipe 10 with a straight line has an angle α2 of 10 degrees or less with respect to the tire circumferential direction. This allows the above-mentioned action to be effectively exerted.

[0056] As shown in FIG. 4, in the plan view of the tread, the second sipes 10 are arc-shaped convex toward the inside in the tire axial direction. Thus, the second sipes 10 of this embodiment are arc-shaped convex toward the opposite direction to the first sipes 7. In other words, in the plan view of the tread, the first sipes 7 are arc-shaped convex toward the outside in the tire axial direction. Thus, in the first land portion 3 of this embodiment, the first sipes 7 convex toward the outside in the tire axial direction and the second sipes 10 convex toward the inside in the tire axial direction are alternately provided in the tire circumferential direction. As a result, the local decrease in rigidity of the first land portion 3 due to the first sipes 7 and the second sipes 10 is mitigated, so that the uneven wear resistance is maintained at a high level.

[0057] The second sipes 10 are arranged on the inner side of the first sipes 7 in the tire axial direction. As a result, in the first land portion 3 of this embodiment, the concave side portion 10a of the second sipe 10 and the concave side portion 7a of the first sipe 7 are formed to face each other. Such an arrangement of the first sipes 7 and the second sipes 10 improves the handleability (transient characteristics) during cornering. In addition, the end of the first sipe 7 on one side in the tire circumferential direction and the end of the second sipe 10 on the other side in the tire circumferential direction are arranged close to each other. As a result, the water film that cannot be sucked up by one sipe 8 or 10 can be easily sucked up by the other sipe 8 or 10, thereby improving wet performance. In addition, such an arrangement of the first sipes 7 and the second sipes 10 is shaped like a single wavy sipe, so that the flow of water in each sipe 7, 10 is smoothed and wet performance is improved.

[0058] The second sipe 10 is formed, for example, of a first portion 10A continuing to a first end 9a of the first lug groove 9 in the tire circumferential direction, a second portion 10B continuing to a second end 9b on the opposite side to the first end 9a, and a third portion 10C joining the first portion 10A and the second portion 10B. The third portion 10C extends, for example, to form the first lug groove 9. The depth (not shown) of the first portion 10A is, for example, the same as the depth (not shown) of the second portion 10B.

[0059] The depth of the first portion 10A and the second portion 10B is preferably equal to or less than the groove depth of the first lug groove 9. Also, the depth of the third portion 10C (not shown) is preferably equal to or greater than the depth of the first portion 10A. Furthermore, the depth of the third portion 10C (not shown) is preferably equal to or greater than the groove depth of the first lug groove 9.

[0060] The second sipes 10 are connected only to the first lug grooves 9. In other words, in this embodiment, the second sipes 10 are not connected to the first sipes 7 and the lateral sipes 8. This prevents the rigidity of the first land portion 3 from being excessively reduced.

[0061] FIG. 5 is a plan view of the second land portion 4. As shown in FIG. 5, the second land portion 4 of this embodiment is provided with a second lug groove 15 extending in the tire axial direction. The second lug groove 15 of this embodiment is connected to the crown circumferential groove 5B. Such a second lug groove 15 extending in the tire axial direction also helps to reduce the SATP. In addition, the second lug groove 15 discharges water in the groove to the crown circumferential groove 5B, which has a relatively large groove width, thereby improving wet performance.

[0062] The second lug groove 15 includes a first groove portion 15A extending from the crown circumferential groove 5B and a second groove portion 15B continuing to the first groove portion 15A and inclined at an angle θ4 with respect to the tire axial direction that is larger than that of the first groove portion 15A. The first groove portion 15A is inclined with respect to the tire axial direction, for example.

[0063] The axial length L3 of the second lug groove 15 is preferably 50% or more of the axial width Wc of the second land portion 4, more preferably 55% or more, and more preferably 85% or less, and even more preferably 80% or less.

[0064] The angle α3 between the second lug groove 15 and the crown circumferential groove 5B is preferably 30 to 60 degrees. Since the angle α3 is 30 degrees or more, the flow of water between the second lug groove 15 and the crown circumferential groove 5B becomes smooth, and high wet performance is exhibited. Since the angle α3 is 60 degrees or less, the decrease in rigidity at the intersection between the second lug groove 15 and the crown circumferential groove 5B is suppressed, and the occurrence of uneven wear is suppressed. For this reason, the angle α is more preferably 35 degrees or more, and more preferably 55 degrees or less. In this specification, the angle α3 is the angle between one groove edge 15i of the second lug groove 15 and the groove edge 5i of the crown circumferential groove 5B connected to the one groove edge 15i.

[0065] The second land portion 4 is provided with, for example, lug sipes 16 that extend from the crown circumferential groove 5B to the outside in the tire axial direction and terminate within the second land portion 4. The lug sipes 16 include a first sipe portion 16A extending from the crown circumferential groove 5B and a second sipe portion 16B that is continuous with the first sipe portion 16A and inclined at an angle θ6 with respect to the tire axial direction that is larger than that of the first sipe portion 16A. The first sipe portion 16A in this embodiment is inclined with respect to the tire axial direction.

[0066] The second land portion 4 is provided with, for example, a transverse sipe 17 that transverses the second land portion 4. The transverse sipe 17 of this embodiment includes a third sipe portion 17A extending from the crown circumferential groove 5B and a fourth sipe portion 17B that is continuous with the third sipe portion 17A and inclined at an angle θ8 with respect to the tire axial direction that is larger than that of the third sipe portion 17A. The third sipe portion 17A of this embodiment is inclined with respect to the tire axial direction.

[0067] The first bending point 19 connecting the first groove portion 15A and the second groove portion 15B, the second bending point 20 connecting the first sipe portion 16A and the second sipe portion 16B, and the third bending point 21 connecting the third sipe portion 17A and the fourth sipe portion 17B are arranged at the same position in the tire axial direction. This reduces the tire circumferential rigidity of the second land portion 4 on the tire circumferential line where the first bending point 19 is provided, and the SATP can be reduced. In this specification, the same position means that the maximum separation distance L4 between each of the bending points 19 to 21 in the tire axial direction is within 10% of the width Wc of the second land portion 4. In addition, it is preferable that the tire axial distance L5 between the first bending point 19 and the inner end 4i of the second land portion 4 in the tire axial direction is arranged at a position of 45% to 55% of the width Wc of the second land portion 4. As a result, an excessive decrease in the rigidity of the second land portion 4 is suppressed.

[0068] It is desirable that the angle θ3 of the first groove portion 15A relative to the tire axial direction, the angle θ5 of the first sipe portion 16A relative to the tire axial direction, and the angle θ7 of the third sipe portion 17A relative to the tire axial direction are the same. This prevents excessive reduction in the rigidity of the second land portion 4, which is subjected to a large ground pressure during straight driving. In this specification, the angle is "the same" means that the absolute value of the difference between the angle θ3 of the first groove portion 15A and the angles θ5 and θ7 of each sipe portion 16A and 17A is 5 degrees or less. The angle θ3 of the first groove portion 15A is, for example, desirably 30 degrees or more, more desirably 35 degrees or more, desirably 60 degrees or less, and more desirably 55 degrees or less.

[0069] From the same viewpoint, it is desirable that the angle θ4 of the second groove portion 15B, the angle θ6 of the second sipe portion 16B, and the angle θ8 of the fourth sipe portion 17B are the same. The angle θ4 of the second groove portion 15B is, for example, desirably 35 degrees or more, more desirably 40 degrees or more, desirably 55 degrees or less, and more desirably 50 degrees or less.

[0070] It is desirable that the axial length L6 of the second groove portion 15B is the same as the axial length L7 of the second sipe portion 16B. In this specification, the term "same length" means that the absolute value of the difference between the length L6 of the second groove portion 15B and the length L7 of the second sipe portion 16B is 10% or less of the width Wc of the second land portion 4.

[0071] The depth (not shown) of the second lug grooves 15 is desirably greater than the depth (not shown) of the lug sipes 16. This provides the effect of improving drainage while suppressing a decrease in block rigidity.

[0072] From the same viewpoint, it is preferable that the groove depth (not shown) of the second lug groove 15 is greater than the depth of the transverse sipe 17 (not shown).

[0073] Although not particularly limited, the groove depth of the second lug groove 15 is desirably 30% or more of the groove depth of the crown circumferential groove 5B, more desirably 40% or more, and desirably 100% or less, more desirably 90% or less.

[0074] Although the tire according to one embodiment of the present invention has been described in detail above, the present invention is not limited to the above specific embodiment and can be modified and carried out in various aspects. EXAMPLES

[0075] Tires were prototyped with the basic pattern shown in Fig. 3. The dry performance, wet performance, and uneven wear resistance of each sample tire were then tested. The common specifications and test methods for each sample tire are as follows:

[0076] <Dry performance, wet performance and uneven wear resistance> Each sample tire was mounted on the following test vehicle. A test driver ran the test vehicle on a test course with a dry asphalt road surface and a wet asphalt road surface and evaluated the dry performance and the wet performance based on the stability and operability of each test vehicle by sensory evaluation. The test driver also visually evaluated the uneven wear resistance based on the uneven wear caused by running on the test course. The results are shown in a score with Comparative Example 1 being 100. The higher the value, the better the result. Tire size: 205 / 65R16 Rim: 16×6.5J Internal pressure (kPa): 390 (front wheel) / 420 (rear wheel) Vehicle: 2000cc passenger car The test results are shown in Table 1.

[0077] [Table 1]

[0078] [Table 2]

[0079] As a result of the test, it was confirmed that the tires of the examples have excellent dry performance. In addition, the tires of the examples have excellent wet performance and uneven wear resistance. [Explanation of symbols]

[0080] 1 Tire 2 Tread section 3 1st Land Department 7 First sipe 8 Horizontal sipes 8i Inner end of horizontal sipe 8e Outer end of horizontal sipe 9 First lug groove Te tread edge

Claims

1. A tire including a tread portion, A tire having a tread portion, The tread portion is provided with a shoulder circumferential groove extending in the tire circumferential direction on a side closest to a tread end, and a first land portion defined by the shoulder circumferential groove and the tread end, The first land portion is provided with a plurality of first sipes extending in a tire circumferential direction, a plurality of lateral sipes, and a plurality of first lug grooves extending from the tread end toward an axially inner side of the tire, The first sipe does not communicate with the first lug groove, An axially inner end of each of the lateral sipes is connected to the shoulder circumferential groove, An axially outer end of each of the lateral sipes is connected to any one of the first sipes, A plurality of second sipes are provided in the first land portion, Each of the second sipes is connected to an axially inner end of any one of the first lug grooves, The plurality of second sipes extend in the tire circumferential direction. tire.

2. The tire according to claim 1 , wherein a plurality of the lateral sipes are connected to at least one of the plurality of first sipes.

3. A tire as described in claim 1 or 2, wherein the plurality of second sipes are connected only to the plurality of first lug grooves.

4. A tire as described in any one of claims 1 to 3, wherein the axial length of the first lug groove is 75% to 85% of the axial width of the first land portion.

5. A tire as described in any one of claims 1 to 4, wherein the angle of the first lug groove with respect to the tire axial direction is 20 to 45 degrees.

6. The tread portion is provided with a second land portion adjacent to the shoulder circumferential groove on the inner side in the tire axial direction, The tire according to claim 1 , wherein the second land portion is provided with a second lug groove extending in an axial direction of the tire.

7. A tire as described in claim 6, wherein the axial length of the second lug groove is 50% to 85% of the axial width of the second land portion.

8. The tread portion is provided with a crown circumferential groove that defines the second land portion on the inner side in the tire axial direction, The tire according to claim 6 or 7, wherein the second lug groove is connected to the crown circumferential groove.

9. The tire as described in claim 8, wherein an angle between the second lug groove and the crown circumferential groove is 30 to 60 degrees.

10. A tire as described in claim 8 or 9, wherein the second land portion is provided with a lug sipe extending from the crown circumferential groove axially outwardly and terminating within the second land portion.

11. A tire as described in any one of claims 6 to 10, wherein the second land portion is provided with a transverse sipe that crosses the second land portion.

Images