tire

Abstract

We provide tires that can improve both ice performance and dry performance. [Solution] The tire 1 has a tread section 2 comprising three circumferential grooves 3 and four land sections 4. The land sections 4 include an outer crown land section 4B adjacent to the outer shoulder land section 4A. The tire equator C is located on the contact surface of the outer crown land section 4B. The outer crown land section 4B has the largest axial width W2 of the tire, and its width W2 is 25% or more of the tread width TW. Each of the four land section blocks 4 has a block edge that defines the contour of the contact surface. The sum of the outer crown block edges ΣA is 35% to 50% of the sum of the pattern block edges ΣB.

Description

[Technical Field]

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

[0002] The following Patent Document 1 describes a pneumatic tire provided with a plurality of blocks. The plurality of blocks are provided with a plurality of sipes. This type of tire is expected to have excellent cornering performance on ice. [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2021-195048 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] In general, such a tire with improved cornering performance on ice causes a reduction in the rigidity of the land portion, and has the problem that the steering stability performance on dry road surfaces (hereinafter referred to as "dry performance") tends to deteriorate.

[0005] The present invention has been devised in view of the above actual circumstances, and a main object thereof is to provide a tire capable of improving both performance on ice and dry performance. [Means for Solving the Problem]

[0006] The present invention relates to a tire having a tread portion whose orientation for mounting on a vehicle is specified, wherein the tread portion includes an inner tread end located on the inside of the vehicle when mounted on the vehicle, an outer tread end located on the outside of the vehicle when mounted on the vehicle, and a tread width which is the tire axial distance from the inner tread end to the outer tread end, the tread portion comprises three circumferential grooves extending continuously in the tire circumferential direction with a groove width of 3.0 mm or more, and four land portions divided by the three circumferential grooves, each of the four land portions comprises a plurality of blocks divided by a plurality of transverse grooves that completely cross each of the land portions in the tire axial direction with a groove width of 1.0 mm or more, and the land portions are adjacent to the outer shoulder land portion including the outer tread end. A tire comprising an outer crown land portion in contact with the ground, wherein the tire equator is located on the contact surface of the outer crown land portion, the outer crown land portion has the largest axial width among the four land portions, the width of the outer crown land portion is 25% or more of the tread width, each of the plurality of blocks has a block edge that defines the contour of the contact surface and has a plurality of sipes having a width of less than 1.0 mm, and the outer crown block edge summation ΣA, which is the sum of the lengths of all the block edges included in the outer crown land portion, is 35% to 50% of the pattern block edge summation ΣB, which is the sum of the lengths of all the block edges included in the four land portions. [Effects of the Invention]

[0007] By adopting the above-described configuration, the tire of the present invention can improve both ice performance and dry performance. [Brief explanation of the drawing]

[0008] [Figure 1] This is a developed view of the tread portion showing one embodiment of the tire of the present invention. [Figure 2] This is a diagram showing the tread section. [Figure 3] (A) is a plan view of the block to illustrate the "length" of the block edge, and (B) is a plan view of the sipe to illustrate the "length" of the sipe. [Figure 4] This is an enlarged view of Figure 1. [Figure 5] This is an enlarged view of Figure 1. [Figure 6] This is an enlarged view of Figure 1. [Figure 7] (A) is an enlarged view of Figure 1, and (B) is a cross-sectional view of (A) along line AA. [Figure 8] This is an enlarged view of Figure 1. [Figure 9] Figure 8 is a cross-sectional view along line BB. [Figure 10] This is a diagram showing the tread section. [Figure 11] Figure 10 is a cross-sectional view along the CC line. [Modes for carrying out the invention]

[0009] Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings. The drawings contain exaggerations and representations that differ from the actual structural dimensional ratios in order to aid in understanding the content of the present invention. Furthermore, the same or common elements are denoted by the same reference numerals throughout each embodiment, and redundant explanations may be omitted. Moreover, the specific configurations shown in the embodiments and drawings are for the purpose of understanding the content of the present invention. For this reason, the present invention is not limited to the specific configurations shown in the drawings.

[0010] Figure 1 is an exploded view of the tread portion 2 of the tire 1 of this embodiment. As shown in Figure 1, the tire 1 of this embodiment is used, for example, as a pneumatic tire for passenger cars intended for use in winter. However, the present invention is not limited to this embodiment and may also be applied to pneumatic tires for heavy loads such as trucks and buses, or to non-pneumatic tires that do not contain compressed air.

[0011] As shown in Figure 1, the tread portion 2 of the present embodiment has a specified mounting orientation on a vehicle. Accordingly, the tread portion 2 includes an inner tread edge Ti positioned on the inner side of the vehicle when the tire is mounted on the vehicle, an outer tread edge To positioned on the outer side of the vehicle when the tire is mounted on the vehicle, and a tread width TW which is the distance from the inner tread edge Ti to the outer tread edge To in the tire axial direction. The inner tread edge Ti and the outer tread edge To are the outermost ground contact positions in the tire axial direction when the tire 1 in a normal state is loaded with 75% of the normal load and brought into contact with a flat surface at a camber angle of 0°, which is referred to as the normal load loaded state.

[0012] The "normal state" refers to a no-load state in which, for a tire defined by various standards, the tire is mounted on a normal rim (not shown) and filled with normal internal pressure. For a tire not defined by any standards or a non-pneumatic tire, the normal state means a standard no-load use state corresponding to the intended purpose of the tire. In the present specification, unless otherwise specified, dimensions and the like of respective portions are values measured in the normal state. It should be noted that each configuration described in the present specification allows for ordinary errors included in rubber molded products.

[0013] A "normal rim" is a rim specified for each tire by the relevant standard in the standard system that includes the standard on which the tire is based. For example, it is a "standard rim" for JATMA, "Design Rim" for TRA, and "Measuring Rim" for ETRTO.

[0014] A "normal internal pressure" is an air pressure specified for each tire by the relevant standard in the standard system that includes the standard on which the tire is based. It is the "maximum air pressure" for JATMA, the maximum value described in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES" for TRA, and "INFLATION PRESSURE" for ETRTO.

[0015] Said "normal load" refers, for tires defined by various standards, to the load specified for each tire by the respective standard in the standard system including the standard on which the tire is based. For JATMA, it is the "maximum load capacity"; for TRA, it is the maximum value described in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES"; for ETRTO, it is "LOAD CAPACITY". In addition, for tires for which various standards are not specified, or non-pneumatic tires, "normal load" refers to the load acting on one tire when the tire is in a standard mounted state. Said "standard mounted state" refers to a state where the tire is mounted on a standard vehicle corresponding to the intended use of the tire, and the vehicle is stationary on a flat road surface in a drivable condition.

[0016] In addition, the tread portion 2 includes three circumferential grooves 3 that continuously extend in the tire circumferential direction with a groove width w1 of 3.0 mm or more, and four land portions 4 divided by the three circumferential grooves 3. Such a tire 1 secures the edge component provided by the edges 4E along the circumferential grooves 3 of the land portions 4 and the rigidity of the land portions 4, thereby exhibiting basic on-ice performance and dry performance.

[0017] The land portions 4 include an outer shoulder land portion 4A including an outer tread end To, and an outer crown land portion 4B adjacent to the outer shoulder land portion 4A. The tire equator C is located on the contact patch 4a of the outer crown land portion 4B. Such an outer crown land portion 4B receives large ground contact pressure during straight running and large lateral force during cornering. In the present specification, said "contact patch" refers to the surface of the tread portion 2 in contact with a flat surface under the normal load condition, and is referred to as the contact patch of the tread portion 2, the contact patch of the land portion 4, the contact patch of a block described later, and the like.

[0018] Further, the outer crown land portion 4B has the largest width W2 in the tire axial direction among the four land portions 4. In addition, the width W2 of the outer crown land portion 4B is 25% or more of the tread width TW. Since such an outer crown land portion 4B has high lateral rigidity, it improves dry performance.

[0019] Figure 2 is an unfolded view of the tread section 2. As shown in Figure 2, each of the four land sections 4 comprises multiple blocks 13. Each block 13 is separated by multiple lateral grooves 14 that completely traverse each land section 4 in the tire axial direction. The lateral grooves 14 have a groove width wa of 1.0 mm or more.

[0020] Each of the blocks 13 has a block edge 15 that defines the contour of the contact surface 13a of each block 13. In addition, each of the blocks 13 has multiple sipes 17 with a width wb of less than 1.0 mm. Such a tire 1 has a large edge component due to the block edges 15 of the multiple blocks 13 and the multiple sipes 17, and ensures the lateral rigidity of the blocks 13 of each land area 4, thus exhibiting basic ice performance and dry performance. The block edge 15 is defined, for example, by circumferential grooves 3, lateral grooves 14, and secondary grooves 19, which will be described later. Each block edge 15 exhibits more basic ice performance. In this specification, the "groove width," "(sipe) width," and "(land area) width" refer to the length (width) on the contact surface, but if a notch (not shown) consisting of a gentle slope or the like is formed at the intersection of the contact surface and the groove wall or sipe wall, the notch is specified as not existing.

[0021] The sum of the lengths of all the block edges 15 included in the outer crown land area 4B is defined as the outer crown block edge sum ΣA. The sum of the lengths of all the block edges 15 included in the four land areas 4 is defined as the pattern block edge sum ΣB. In this case, the outer crown block edge sum ΣA is set to be 35% to 50% of the pattern block edge sum ΣB. Since the outer crown block edge sum ΣA is 35% or more of the pattern block edge sum ΣB, the sum of the block edges 15 in the outer crown land area 4B is relatively larger than the sum of the block edges 15 in each of the other land areas 4. As a result, a large edge effect is exerted in the outer crown land area 4B, where large ground pressure and large lateral forces act, thus improving ice performance.

[0022] To further enhance this effect, the sum of outer crown block edges ΣA is preferably 38% or more of the sum of pattern block edges ΣB, and more preferably 40% or more. Also, since the sum of outer crown block edges ΣA is 50% or less of the sum of pattern block edges ΣB, the sum of the lengths of the block edges 15 of the outer crown land area 4B is prevented from becoming excessively large, and the ground pressure and lateral force acting on each land area 4 become appropriate. This improves both dry performance and ice performance. To further enhance this effect, the sum of outer crown block edges ΣA is preferably 49% or less of the sum of pattern block edges ΣB, and more preferably 48% or less, in combination with any of the lower limits mentioned above. For example, the sum of outer crown block edges ΣA is preferably 38% to 49% of the sum of pattern block edges ΣB, and more preferably 40% to 48%.

[0023] Figure 3(A) is a plan view of block 13 to illustrate the "length" of the block edge 15. Figure 3(A) shows the "length" of the block edge 15 in one block 13. In this specification, the "length" of the block edge 15 for calculating the sum of each block edge, the sum of the pattern block edges, and the sum of the pattern edges is defined as follows. The "length" is distinguished into a tire axial component xi and a tire circumferential component yi of each block edge 15 adjacent to any of the circumferential grooves 3, each transverse groove 14, or sub-grooves 19 (shown in Figure 2). The length of the block edge 15 of block 13 shown in Figure 3(A) is distinguished into a tire axial component xi (x1, x2, ..., x8) and a tire circumferential component yi (y1, y2, ..., y8). In this case, the maximum value of i is 8. For example, the sum of the lengths of all block edges 15 included in the outer crown land portion 4B (ΣA) is equal to the square of the sum of the axial components of all block edges 15 included in the outer crown land portion 4B (Σxi). 2 ) and the square of the sum of the circumferential components of all outer crown blocks 5 Σyi ((Σyi) 2 The square root of the sum of (√(Σxi)) 2 +(Σyi) 2The sum of the lengths of the block edges 15 used to calculate the sum of each other block edge, the sum of the pattern block edges, and the sum of the pattern edges is calculated in the same way.

[0024] The configuration of this embodiment will be described in more detail below. Note that each configuration described below represents a specific aspect of this embodiment. Therefore, it goes without saying that the present invention can achieve the above-described effects even without the configurations described below. Furthermore, even if any one of the configurations described below is applied individually to a tire of the present invention having the above-described features, an improvement in performance corresponding to each configuration can be expected. Moreover, if several of the configurations described below are applied in combination, a combined improvement in performance corresponding to each configuration can be expected.

[0025] As shown in Figure 1, in this embodiment, each of the three circumferential grooves 3 extends in a straight line. However, the circumferential grooves 3 may also extend in a zigzag or wavy pattern, for example.

[0026] The circumferential groove 3 includes a first circumferential groove 3A adjacent to the outer tread edge To, a second circumferential groove 3B adjacent to the inner tread edge Ti, and a third circumferential groove 3C located between the first circumferential groove 3A and the second circumferential groove 3B. The third circumferential groove 3C is the closest of the circumferential grooves 3 to the tire equator C. For this reason, the third circumferential groove 3C has the largest groove width w1c among the three circumferential grooves 3. Such a third circumferential groove 3C helps to smoothly discharge ice and melted ice (hereinafter referred to as "ice, etc.") that adheres to the contact surface 4a near the tire equator C when driving on icy roads.

[0027] The groove width w1c of the third circumferential groove 3C is preferably 3% or more of the tread width TW, more preferably 4% or more, preferably 7% or less, and even more preferably 6% or less. The groove width w1a of the first circumferential groove 3A is preferably 65% ​​or more of the groove width w1c of the third circumferential groove 3C, more preferably 70% or more, preferably 85% or less, and even more preferably 80% or less. In this embodiment, the groove width w1b of the second circumferential groove 3B is smaller than the groove width w1a of the first circumferential groove 3A. The groove width w1b of the second circumferential groove 3B is preferably 80% or more of the groove width w1a of the first circumferential groove 3A, more preferably 85% or more, preferably 95% or less, and even more preferably 90% or less. The groove depth of the circumferential groove 3 (not shown) is preferably, for example, 7 to 12 mm.

[0028] The four land sections 4 further include an inner shoulder land section 4C, which includes the inner tread edge Ti, and an inner crown land section 4D adjacent to the inner shoulder land section 4C. The entirety of the inner shoulder land section 4C and the inner crown land section 4D is located on the inner tread edge Ti side of the tire equator C.

[0029] If the width W2 of the outer crown land portion 4B is excessively large, the lateral rigidity of at least one of the other land portions 4 may become excessively small. For this reason, the width W2 of the outer crown land portion 4B is preferably 28% or more of the tread width TW, more preferably 30% or more, preferably 45% or less, and more preferably 40% or less.

[0030] The inner crown land area 4D is a land area 4 in which both lateral force during turning and ground pressure during straight-line driving are relatively small. For this reason, in this embodiment, the inner crown land area 4D has the smallest tire axial width W4 among the four land areas 4. The width W4 of the inner crown land area 4D is preferably 40% or more, more preferably 45% or more, more preferably 60% or less, and more preferably 55% or less of the width W2 of the outer crown land area 4B.

[0031] While not particularly limited, the width W1 in the tire axial direction of the outer shoulder land portion 4A is preferably 10% or more of the tread width TW, more preferably 15% or more, 30% or less, and even more preferably 25% or less. Similarly, the width W3 in the tire axial direction of the inner shoulder land portion 4C is preferably 90% or more of the width W1 of the outer shoulder land portion 4A, more preferably 95% or more, 110% or less, and even more preferably 105% or less. For example, the width W3 of the inner shoulder land portion 4C is considered to be the same as the width W1 of the outer shoulder land portion 4A.

[0032] The sum of the lengths of all block edges 15 and all the sipes 17 included in the four land sections 4 is defined as the total pattern edge length ΣC. In this case, the total outer crown block edge length ΣA is preferably 10% or more of the total pattern edge length ΣC, more preferably 13% or more, more preferably 20% or less, and more preferably 18% or less. Since the total outer crown block edge length ΣA is 10% or more and 20% or less of the total pattern edge length ΣC, an appropriate edge effect is achieved in the outer crown land section 4B, while suppressing a decrease in the rigidity of the outer crown land section 4B. As a result, both dry performance and ice performance are improved in a balanced manner.

[0033] Figure 3(B) is a plan view of a sipe 17 to illustrate its "length". Figure 3(B) shows the "length" of one sipe 17. In this specification, the "length" of a sipe 17 for calculating the sum of the pattern edges and the sum of each sipe described later is defined as follows. The "length" is distinguished into the tire axial component ui and the tire circumferential component vi of the sipe width centerline 17c of the sipe 17. The length of the sipe 17 shown in Figure 3(B) is distinguished into the tire axial component ui (u1, u2, ..., u6) and the tire circumferential component vi (v1, v2..., v6). In this case, the maximum value of i is 6. For example, the sum of the lengths of all sipes 17 included in the outer crown land area 4B (ΣG) is the sum of the tire axial components Σui of all sipes 17 included in the outer crown land area 4B ((Σui) 2) and the sum of the circumferential components of all sipes 17, Σyi, squared ((Σvi) 2 The square root of the sum of (√{(Σui) 2 +(Σvi) 2 The sum of the lengths of the sipes 17 is calculated in the same way as the sum of the pattern edges and the sum of each of the other sipes described later.

[0034] As shown in Figure 2, the sum of the lengths of all block edges 15 included in the outer shoulder land area 4A is defined as the outer shoulder block edge summation ΣD. The sum of the lengths of all block edges 15 included in the inner crown land area 4D is defined as the inner crown block edge summation ΣE. The sum of the lengths of all block edges 15 included in the inner shoulder land area 4C is defined as the inner shoulder block edge summation ΣF. Therefore, it is desirable that the sum of the outer crown block edge summation ΣA and the outer shoulder block edge summation ΣD (ΣA + ΣD) is greater than the sum of the inner crown block edge summation ΣE and the inner shoulder block edge summation ΣF (ΣE + ΣF). The outer crown land area 4B and the outer shoulder land area 4A are land areas 4 that experience relatively greater lateral forces during turning than the inner crown land area 4D and the inner shoulder land area 4C. Therefore, by making the sum of the sums (ΣA+ΣD) larger than the sum of the sums (ΣE+ΣF), an effective edge effect can be achieved during turning, thereby further improving ice performance.

[0035] If the sum (ΣA+ΣD) is excessively larger than the sum (ΣE+ΣF), the length of the block edge 15 of the inner crown land portion 4D or the inner shoulder land portion 4C becomes too small, which may result in unstable driving during turns where the inner tread edge Ti side is on the outside of the turn. For this reason, the sum (ΣA+ΣD) is preferably 1.35 times or more of the sum (ΣE+ΣF), more preferably 1.40 times or more, preferably 1.60 times or less, and more preferably 1.55 times or less.

[0036] The sum of the lengths of all sipes 17 included in the outer crown land section 4B is defined as the outer crown sipe sum ΣG. Similarly, the sum of the lengths of all sipes 17 included in the outer shoulder land section 4A is defined as the outer shoulder sipe sum ΣH. Furthermore, the sum of the lengths of all sipes 17 included in the inner crown land section 4D is defined as the inner crown sipe sum ΣI. Similarly, the sum of the lengths of all sipes 17 included in the inner shoulder land section 4C is defined as the inner shoulder sipe sum ΣJ. Moreover, the ratio of the outer crown block edge sum ΣA to the outer crown sipe sum ΣG is defined as the ratio (ΣA / ΣG). Similarly, the ratio of the outer shoulder block edge sum ΣD to the outer shoulder sipe sum ΣH is defined as the ratio (ΣD / ΣH). Furthermore, the ratio of the inner crown block edge sum ΣE to the inner crown sipe sum ΣI is defined as the ratio (ΣE / ΣI). Furthermore, the ratio of the sum of the inner shoulder block edges ΣF to the sum of the inner shoulder sipes ΣJ is given as the ratio (ΣF / ΣJ). Generally, the edge effect of the block edges 15 is greater than the edge effect of the sipes 17. Therefore, by relatively increasing the ratio of the sum of the lengths of the block edges 15 to the sum of the lengths of the sipes 17 in the outer crown land area 4B, it is possible to maintain high rigidity in the outer crown land area 4B while exhibiting a large edge effect. Consequently, both ice performance and dry performance can be improved. From this perspective, it is desirable that the ratio (ΣA / ΣG) is greater than any of the ratios (ΣD / ΣH), (ΣE / ΣI), and (ΣF / ΣJ).

[0037] The outer crown land portion 4B experiences relatively large ground pressure during straight-line driving and lateral forces during cornering. To improve ice performance and dry performance in a balanced way, the ratio (ΣA / ΣG) should preferably be 0.55 or higher, more preferably 0.60 or higher, more preferably 0.70 or lower, and more preferably 0.68 or lower.

[0038] The outer shoulder land portion 4A experiences less ground pressure during straight-line driving than the outer crown land portion 4B. Therefore, the difference between the ratio (ΣA / ΣG) and the ratio (ΣD / ΣH) {(ΣA / ΣG)-(ΣD / ΣH)} is preferably 0.15 or greater, more preferably 0.17 or greater, preferably 0.30 or less, and more preferably 0.27 or less. Also, the difference between the ratio (ΣA / ΣG) and the ratio (ΣE / ΣI) {(ΣA / ΣG)-(ΣE / ΣI)} is preferably 0.05 or greater, more preferably 0.07 or greater, preferably 0.15 or less, and more preferably 0.12 or less. Similarly, the difference between the ratio (ΣA / ΣG) and the ratio (ΣF / ΣJ) {(ΣA / ΣG)-(ΣF / ΣJ)} should preferably be 0.15 or greater, more preferably 0.17 or greater, more preferably 0.30 or less, and more preferably 0.27 or less. This further improves both ice performance and dry performance.

[0039] Figure 4 is an enlarged view of Figure 1. Figure 4 shows the outer crown land area 4B. As shown in Figure 4, the outer crown land area 4B has pattern constituent units M arranged repeatedly in the circumferential direction of the tire. The outer crown land area 4B also includes a first outer crown lateral groove 6A that completely crosses the pattern constituent units M in the axial direction of the tire. Such a first outer crown lateral groove 6A divides the pattern constituent units M into two outer crown blocks 5. Because the pattern constituent units M are divided into two outer crown blocks 5, the pattern noise caused by the impact when the outer crown land area 4B makes contact with the ground is reduced.

[0040] Furthermore, the outer crown land portion 4B includes a first outer crown lateral groove 6A and a second outer crown lateral groove 6B, which has a different groove contour shape in plan view from the first outer crown lateral groove 6A. In this embodiment, the first outer crown lateral groove 6A and the second outer crown lateral groove 6B are arranged alternately in the circumferential direction of the tire. The second outer crown lateral groove 6B is formed to completely cross the outer crown land portion 4B in the axial direction of the tire. In this specification, the first outer crown lateral groove 6A or the second outer crown lateral groove 6B is referred to as the outer crown lateral groove 6. The outer crown lateral groove 6 has a groove width w2 of 1.0 mm or more. The groove width w2 of each outer crown lateral groove 6 is preferably 1.5 mm or more, more preferably 2.0 mm or more, preferably 4.0 mm or less, and more preferably 3.5 mm or less.

[0041] Each outer crown lateral groove 6 includes at least one main bend 10. As a result, the outer crown block 5 has a V-shape with a convex apex 11 toward the first side f1 in the tire circumferential direction. As a result, the block edge e1 of the outer crown block 5 along the outer crown lateral groove 6 has an edge component in the tire circumferential direction and an edge component in the tire axial direction, thus achieving both turning performance and braking performance on ice and improving ice performance. In this embodiment, the rotation direction R is specified so that contact begins from the apex 11 of the outer crown block 5. In this embodiment, the leading side of the rotation direction R is in the same direction as the first side f1 in the tire circumferential direction.

[0042] In this specification, the "top portion" is the portion of the outer crown block 5 that protrudes most convexly to the first side f1 in the circumferential direction of the tire. Also, in this specification, the "main bend portion" is the portion of the outer crown lateral groove 6 that protrudes most strongly to the first side f1 in the circumferential direction of the tire.

[0043] Figure 5 is an enlarged view of Figure 1. Figure 5 shows the outer crown land portion 4B. As shown in Figure 5, it is desirable that the groove width w21 at the inner end 6i in the tire axial direction of the first outer crown lateral groove 6A is different from the groove width w22 at the inner end 6f in the tire axial direction of the second outer crown lateral groove 6B. And / or, it is desirable that the groove width w23 at the outer end 6e in the tire axial direction of the first outer crown lateral groove 6A is different from the groove width w24 at the outer end 6j in the tire axial direction of the second outer crown lateral groove 6B. This makes it easier for ice and other debris from the icy road surface that has entered the outer crown lateral groove 6 to be discharged at least one of the inner end 4i side or outer end 4e side of the outer crown land portion 4B in the tire axial direction, while maintaining the rigidity of the outer crown land portion 4B. As a result, it is possible to maintain a better balance between ice performance and dry performance.

[0044] In order to exert the above-described effects near the inner end 4i and outer end 4e of the outer crown land portion 4B in the tire axial direction, it is desirable that the groove width w21 at the inner end 6i of the first outer crown lateral groove 6A is different from the groove width w22 at the inner end 6f of the second outer crown lateral groove 6B. In addition, it is even more desirable that the groove width w23 at the outer end 6e of the first outer crown lateral groove 6A is different from the groove width w24 at the outer end 6j of the second outer crown lateral groove 6B.

[0045] In this embodiment, the groove width w21 at the inner end 6i of the first outer crown groove 6A is greater than the groove width w22 at the inner end 6f of the second outer crown groove 6B. Also, the groove width w23 at the outer end 6e of the first outer crown groove 6A is greater than the groove width w24 at the outer end 6j of the second outer crown groove 6B. On the other hand, if the groove width w21 at the inner end 6i of the first outer crown groove 6A and the groove width w22 at the inner end 6f of the second outer crown groove 6B differ excessively, the difference in circumferential rigidity of the outer crown block 5 on the inner end 5i side in the tire axial direction may become large. This may reduce dry performance. Therefore, the groove width w21 at the inner end 6i of the first outer crown groove 6A is preferably 1.5 times or more, more preferably 1.6 times or more, preferably 2.1 times or less, and even more preferably 1.9 times or less, of the groove width w22 at the inner end 6f of the second outer crown groove 6B. Similarly, the groove width w23 at the outer end 6e of the first outer crown groove 6A is preferably 1.5 times or more, more preferably 1.6 times or more, preferably 2.1 times or less, and even more preferably 1.9 times or less, of the groove width w24 at the outer end 6j of the second outer crown groove 6B. This keeps the difference in circumferential rigidity of the outer crown block 5 on the outer end 5e side in the tire axial direction small. Note that the groove width w21 at the inner end 6i of the first outer crown groove 6A may be smaller than the groove width w22 at the inner end 6f of the second outer crown groove 6B. Furthermore, the groove width w23 at the outer end 6e of the first outer crown lateral groove 6A may be smaller than the groove width w24 at the outer end 6j of the second outer crown lateral groove 6B.

[0046] The first outer crown lateral groove 6A includes a central portion 20, a first inner portion 21, and an outer portion 22. The central portion 20 extends in a V-shape with equal groove width w2a, including a main bend portion 10. The first inner portion 21 connects the central portion 20 to the inner end 6i. The first inner portion 21 includes a first sub-bend portion 23 that is convex toward the first side F1 in the circumferential direction of the tire, and a first equal-width portion 24 that connects to the first sub-bend portion 23 and extends to the inner end 6i with equal width w21. The outer portion 22 connects the central portion 20 to the outer end 6e and extends with equal groove width w23. The groove width w2a of the central portion is smaller than the groove width w21 of the first equal-width portion 24 and the groove width w23 of the outer portion 22. In this specification, "equal groove width" includes embodiments in which the difference between the maximum and minimum values ​​of the groove width is 1 mm or less.

[0047] While not particularly limited, the groove width w2a of the central section 20 is preferably 45% or more, more preferably 50% or more, 65% or less, and even more preferably 60% or less of the groove width w21 of the first equal-width section 24. The groove width w21 of the first equal-width section 24 is preferably 90% or more, more preferably 95% or more, 110% or less, and even more preferably 105% or less of the groove width w23 of the outer section 22. In addition, the axial length L1 of the first equal-width section 24 is preferably 20% or more, more preferably 25% or more, 40% or less, and even more preferably 35% or less of the axial length Ls between the main bend 10 and the inner end 6i of the first outer crown lateral groove 6A. Similarly, the axial length L2 of the outer portion 22 is preferably 40% or more, more preferably 45% or more, more preferably 60% or less, and more preferably 55% or less of the axial length Li between the main bend portion 10 and the outer end 6e of the first outer crown lateral groove 6A.

[0048] Furthermore, the maximum groove width w2m of the first outer crown lateral groove 6A is preferably 1.5 times or more, more preferably 1.7 times or more, preferably 2.5 times or less, and more preferably 2.3 times or less than the minimum groove width w2n of the second outer crown lateral groove 6B. The maximum groove width w2m of the first outer crown lateral groove 6A is, for example, the groove width w21 of the first equal-width section 24 or the groove width w23 of the outer section 22. The minimum groove width w2n of the second outer crown lateral groove 6B is, for example, the groove width w22 of the second equal-width section 28 described later, or the groove width w2b of the main section 25 described later.

[0049] The second outer crown lateral groove 6B includes a main portion 25 that extends in a V-shape with an equal groove width w2b, including the main bend portion 10, and a second inner portion 26 that connects the main portion 25 to the inner end 6f. The main portion 25 extends to the outer end 6j of the second outer crown lateral groove 6B. The second inner portion 26 includes a second sub-bend portion 27 that is convex toward the first side F1 in the circumferential direction of the tire, and a second equal-width portion 28 that connects to the second sub-bend portion 27 and extends to the inner end 6f with an equal width w22. The groove width w2b of the main portion 25 is preferably 90% or more, more preferably 95% or more, preferably 110% or less, and more preferably 105% or less of the groove width w22 of the second equal-width portion 28. In this embodiment, the groove width w2b of the main portion 25 and the groove width w22 of the second equal-width portion 28 are the same.

[0050] The groove width w2a of the central section 20 and the groove width w2b of the main section 25 are preferably 3% or more, more preferably 4% or more, 8% or less, and even more preferably 7% or less of the width W2 of the outer crown land section 4B (shown in Figure 1). The groove depth d2 of the outer crown transverse groove 6 (shown in Figure 9) is preferably 60% or more, more preferably 65% ​​or more, 80% or less, and even more preferably 75% or less of the groove depth of the circumferential groove 3 (not shown). In addition, the groove depth d2 of each outer crown transverse groove 6 is preferably 3.0 mm or more, more preferably 3.5 mm or more, 12 mm or less, and 11 mm or less. The first outer crown transverse groove 6A has the same groove depth as the second outer crown transverse groove 6B.

[0051] Figure 6 is an enlarged view of Figure 1. Figure 6 shows the outer crown land portion 4B. As shown in Figure 6, each outer crown block 5 includes, for example, at least one first crown block 5A. The outer crown block 5 also includes, for example, at least one second crown block 5B. In this embodiment, each outer crown block 5 includes a plurality of first crown blocks 5A and a plurality of second crown blocks 5B. In this embodiment, the first crown blocks 5A and the second crown blocks 5B are arranged alternately in the circumferential direction of the tire. The second crown blocks 5B have a different contour shape in plan view from the first crown blocks 5A.

[0052] The outer crown block 5 includes an outer inclined portion 30 and an inner inclined portion 31. The outer inclined portion 30 extends, for example, from the top 11 to the end 5x on the outer tread end To side of the outer crown block 5. In this embodiment, the outer inclined portion 30 is inclined from the top 11 toward the end 5x in the opposite direction to the first side f1 in the tire circumferential direction. The inner inclined portion 31 extends, for example, from the top 11 to the end 5y on the inner tread end Ti side of the outer crown block 5. In this embodiment, the inner inclined portion 31 is inclined from the top 11 toward the end 5y in the opposite direction to the first side f1 in the tire circumferential direction. The outer inclined portion 30 and the inner inclined portion 31 are inclined in opposite directions with respect to the tire circumferential direction.

[0053] Furthermore, when the length of the outer inclined portion 30 in the tire axial direction is B1 and the length of the inner inclined portion 31 in the tire axial direction is B2, it is desirable that the following equation (1) is satisfied. 50% ≤ B2 / (B1 + B2) ≤ 75% …(1) In other words, the top portion 11 is located between the center 5c of the outer crown block 5 in the tire axial direction and a distance in the tire axial direction that is 25% of the sum of lengths B1 and B2 (B1+B2) from the center 5c toward the outer tread edge To. A greater lateral force acts on the outer tread edge To side from the center 5c of the outer crown block 5 during cornering than on the inner tread edge Ti side from the center 5c. Also, at positions beyond 25% of the sum (B1+B2) from the center 5c toward the outer tread edge To, the longitudinal rigidity of the outer crown block 5 tends to be relatively smaller. Therefore, an outer crown block 5 with the top portion 11 positioned as described above can effectively utilize the edge effect of the opposite inclination of the outer inclined portion 30 and the inner inclined portion 31 connected to the top portion 11 during cornering, thereby improving dry performance and ice performance. Note that, as shown in Figure 6, the top portion 11 of the first crown block 5A and the top portion 11 of the second crown block 5B are misaligned in the tire axial direction. Therefore, in this embodiment, the length B1 of the outer inclined portion 30 of the first crown block 5A is different from the length B1 of the outer inclined portion 30 of the second crown block 5B. Also, the sum (B1 + B2) is the width W2 of the outer crown base 4B (shown in Figure 1).

[0054] The block edge 15 of the outer crown block 5 includes a pair of longitudinal block edges 15v and a pair of transverse block edges 15h. The pair of longitudinal block edges 15v are located on both sides of the outer crown block 5 in the axial direction of the tire. The pair of longitudinal block edges 15v are defined by the circumferential groove 3. The pair of transverse block edges 15h connect the circumferential ends of the pair of longitudinal block edges 15v. Each transverse block edge 15h is defined by the outer crown transverse groove 6.

[0055] Each lateral block edge 15h is divided into a first block edge 33 located on the first side f1 in the circumferential direction of the tire, and a second block edge 34 located on the opposite side in the circumferential direction from the first block edge 33. The first block edge 33 includes an outer first edge 35 defined by an outer inclined portion 30 and an inner first edge 36 defined by an inner inclined portion 31. The second block edge 34 includes an outer second edge 37 defined by an outer inclined portion 30 and an inner second edge 38 defined by an inner inclined portion 31.

[0056] Figure 7(A) is an enlarged view of Figure 1. Figure 7(A) shows the outer crown land portion 4B. As shown in Figure 7(A), in the outer crown block 5, the inner first edge 36 has a first bend 40 at a first position P1 in the tire axial direction. The inner second edge 38 has a second bend 41 at a second position P2 in the tire axial direction, which is different from the first position P1. As a result, a multi-directional edge effect is exerted at different turning angles, improving ice performance. In this embodiment, in the first crown block 5A, the first position P1a of the first bend 40a of the inner first edge 36a is different in the tire axial direction from the second position P2a of the second bend 41a of the inner second edge 38a. Also in this embodiment, in the second crown block 5B, the first position P1b of the first bend 40b of the inner first edge 36b is different in the tire axial direction from the second position P2b of the second bend 41b of the inner second edge 38b.

[0057] In the first crown block 5A, the axial separation distance L3 between the first position P1a and the second position P2a is preferably 13% or more of the width W2 of the outer crown land portion 4B, more preferably 15% or more, preferably 28% or less, and even more preferably 25% or less. In the second crown block 5B, the axial separation distance L4 between the first position P1b and the second position P2b is preferably 13% or more of the width W2 of the outer crown land portion 4B, more preferably 15% or more, preferably 28% or less, and even more preferably 25% or less. This allows the edge effect to be effectively exerted while suppressing a decrease in the block rigidity of the outer crown block 5.

[0058] Each of the first crown block 5A and the second crown block 5B has a V-shape with a top portion 11, an outer inclined portion 30, and an inner inclined portion 31. Furthermore, the maximum length LM of the outer crown block 5 in the tire circumferential direction is preferably 45% or more of the width W2 of the outer crown land portion 4B, more preferably 50% or more, preferably 65% ​​or less, and more preferably 60% or less.

[0059] Figure 7(B) is a cross-sectional view taken along line AA in Figure 7(A). As shown in Figures 7(A) and (B), the first crown block 5A is provided with, for example, a sub-groove 19 in the inner inclined portion 31 that extends in the tire circumferential direction so as to divide the inner inclined portion 31. The sub-groove 19 has, for example, a groove width w4 of 1.0 mm or more and a groove depth d3 that is smaller than the outer crown lateral groove 6. Such a sub-groove 19 increases the edge component in the tire circumferential direction without excessively reducing the rigidity of the inner inclined portion 31. This enables more stable cornering on ice. For convenience, in this specification, the sub-groove 19 provided in the first crown block 5A is referred to as the first sub-groove 43. Note that the outer inclined portion 30 of the first crown block 5A is not provided with a sub-groove.

[0060] The first sub-groove 43 is located, for example, on the inner tread edge Ti side from the top 11, closer to the top 11 than the center 31c of the inner inclined portion 31 in the tire axial direction. This minimizes the reduction in the rigidity of the inner inclined portion 31. To effectively achieve this effect, the axial separation distance L5 between the top 11 and the first sub-groove 43 is preferably 20% or more of the length B2 of the inner inclined portion 31 (shown in Figure 6), more preferably 25% or more, more preferably 40% or less, and more preferably 35% or less.

[0061] The first sub-groove 43 extends, for example, parallel to the circumferential direction of the tire. In this embodiment, the first sub-groove 43 is connected to the central portion 20 and the second inner portion 26. The first sub-groove 43 is connected to, for example, the second sub-bend portion 27. This suppresses the reduction in rigidity near the second bend portion 41a, where relatively large ground pressure is likely to act, thereby improving dry performance.

[0062] While not particularly limited, the groove width w4a of the first sub-groove 43 is preferably 20% or more, more preferably 25% or more, 40% or less, and even more preferably 35% or less of the groove width w1a of the first circumferential groove 3A (shown in Figure 1). The groove depth d3 of the first sub-groove 43 is preferably 60% or more, more preferably 65% ​​or more, 80% or less, and even more preferably 75% or less of the groove depth d2 of the outer crown transverse groove 6 (shown in Figure 9).

[0063] Furthermore, the inner inclined portion 31 of the second crown block 5B does not have grooves with a groove width of 1.0 mm or more. Such a second crown block 5B maintains high rigidity of the inner inclined portion 31 of the second crown block 5B, thereby improving dry performance. Thus, in this embodiment, the outer crown land portion 4B has alternating first crown blocks 5A with first sub-grooves 43 and second crown blocks 5B without grooves in the circumferential direction of the tire, so that dry performance and ice performance can be improved in a well-balanced manner. The outer inclined portion 30 of the second crown block 5B in this embodiment also does not have grooves with a groove width of 1.0 mm or more.

[0064] Figure 8 is an enlarged view of Figure 1. Figure 8 shows the outer crown land portion 4B. As shown in Figure 8, the length in the tire circumferential direction at the outer end 5e1 in the tire axial direction of the first crown block 5A is defined as length B. The length in the tire circumferential direction at the outer end 5e2 in the tire axial direction of the second crown block 5B is defined as length C. In this case, for each pattern configuration unit M, the sum of the length B of the first crown block 5A and the length C of the second crown block 5B (B+C) is preferably 60% or more, more preferably 64% or more, more preferably 80% or less, and more preferably 78% or less of the tire circumferential length La of the pattern configuration unit M. Since the sum (B+C) is 60% or more of the length La of the pattern configuration unit M, the tire circumferential lengths B and C of the first crown block 5A and the second crown block 5B are secured, and the tire circumferential rigidity of each outer crown block 5 is maintained at a high level. Since the sum (B+C) is 80% or less of the length La of the pattern-forming unit M, the groove width w2 of the outer crown lateral groove 6 is secured, allowing ice and other debris in the outer crown lateral groove 6 to be smoothly discharged, thus improving ice performance.

[0065] Furthermore, the length in the tire circumferential direction at the inner end 5i1 in the tire axial direction of the first crown block 5A is defined as length D. The length in the tire circumferential direction at the inner end 5i2 in the tire axial direction of the second crown block 5B is defined as length E. In this case, in each pattern configuration unit M, the sum of the length D of the first crown block 5A and the length E of the second crown block 5B (D+E) is preferably 60% or more, more preferably 64% or more, more preferably 80% or less, and more preferably 78% or less of the length La of the pattern configuration unit M. This allows the above-mentioned effects to be effectively exerted.

[0066] Lengths B, C, D, and E are preferably 5% or more of the width W2 of the outer crown land portion 4B, more preferably 10% or more, preferably 25% or less, and more preferably 20% or less. Since each of lengths B, C, D, and E is 5% or more of the width W2 of the outer crown land portion 4B, the circumferential rigidity of the tire at the outer end 5e1 and inner end 5i1 of the first crown block 5A, and the outer end 5e2 and inner end 5i2 of the second crown block is maintained at a high level, thereby improving dry performance. Since each of lengths B, C, D, and E is 20% or less of the width W2 of the outer crown land portion 4B, the groove width w2 of the outer crown lateral groove 6 is secured, allowing ice and other debris in the outer crown lateral groove 6 to be smoothly discharged.

[0067] The apex angle θ1 of the top 11 of the outer crown block 5 is preferably 90 degrees or more, more preferably 100 degrees or more, even more preferably 110 degrees or more, preferably 140 degrees or less, even more preferably 130 degrees or less, and even more preferably 120 degrees or less. Since the apex angle θ1 is 90 degrees or more, the rigidity of the top 11 can be maintained at a high level. Since the apex angle θ1 is 140 degrees or less, the edge effect can be exerted in multiple directions (two directions). In order to effectively exert such an effect, the angle θ2 between the outer inclined portion 30 and the tire circumferential line Y1, and the angle θ3 between the inner inclined portion 31 and the tire circumferential line Y1 are preferably 45 degrees or more, more preferably 50 degrees or more, preferably 70 degrees or less, and even more preferably 65 degrees or less. The apex angle θ1 is determined by the first block edge 33 including the top 11 of each outer crown block 5. The angle θ2 is determined by the outer first edge 35 and the tire circumferential line Y1. The angle θ3 is determined by the inner first edge 36 and the tire circumferential line Y1.

[0068] Furthermore, each outer crown block 5 has multiple sipes 7 with a width w3 of less than 1.0 mm. The sipes 7 are included in the sipes 17. The sipes 7, together with the outer crown lateral grooves 6, moderately increase the edge component of the outer crown land portion 4B, thereby further improving ice performance.

[0069] Multiple sipes 7 include a first sipe 7A extending in a first extending direction and a second sipe 7B extending in a second extending direction different from the first extending direction. Such first sipes 7A and second sipes 7B exert an edge effect in multiple directions, thereby improving ice performance.

[0070] The first sipe 7A of this embodiment is provided on the outer inclined portion 30. The second sipe 7B of this embodiment is provided on the inner inclined portion 31. At least one of the first sipes 7A is connected to, for example, at least one of the first block edge 33 or the second block edge 34. The second sipe 7B is connected to, for example, at least one of the first block edge 33 or the second block edge 34. Such first sipes 7A and second sipes 7B provide a large edge effect.

[0071] The first sipe 7A and the second sipe 7B are inclined in opposite directions with respect to the tire circumferential direction. The first sipe 7A is inclined toward the first side f1 in the tire circumferential direction from the inner tread end Ti side toward the outer tread end To side. For example, the first sipe 7A is inclined toward the opposite direction with respect to the tire circumferential direction to the outer inclined portion 30. The second sipe 7B is inclined toward the first side f1 in the tire circumferential direction from the outer tread end To side toward the inner tread end Ti side. For example, the second sipe 7B is inclined toward the opposite direction with respect to the tire circumferential direction to the inner inclined portion 31.

[0072] In this embodiment, at least one of the sipes 7 is connected to the outer crown lateral groove 6 at an intersection angle θ5 of 35 to 65 degrees. Since the intersection angle θ5 is 35 degrees or more and 65 degrees or less, the rigidity of the outer crown block 5 between the sipe 7 and the outer crown lateral groove 6 is maintained at a high level, and the edge component by the sipe 7, the first block edge 33 and the second block edge 34 becomes multi-directional. This improves both dry performance and ice performance. To effectively exert these effects, an intersection angle θ5 of 40 degrees or more is more desirable, and 60 degrees or less is more desirable. In this embodiment, at least one of both the first sipe 7A and the second sipe 7B is connected to the outer crown lateral groove 6 at an intersection angle θ5 of 35 to 65 degrees.

[0073] Figure 9 is a cross-sectional view along line BB in Figure 8. Figure 9 shows a cross-section of a sipe 7 arranged on the outer crown block 5. As shown in Figures 8 and 9, at least one of the multiple sipes 7 is a three-dimensional sipe that extends in a zigzag pattern from the contact surface 5a of the outer crown block 5 in the radial direction of the tire, and also extends in a zigzag pattern on the contact surface 5a. Such a three-dimensional sipe allows the walls of opposing sipes 7 to firmly support each other when in contact with the ground, thereby increasing the rigidity of the outer crown block 5 when in contact with the ground and improving dry performance and ice performance.

[0074] Furthermore, at least one of the multiple sipes 7 includes a shallow bottom portion 45 in which the sipe bottom 7s is raised in the center in the direction of extension. The shallow bottom portion 45 suppresses the reduction in rigidity of the outer crown block 5 and improves dry performance. Note that the multiple sipes 7 may not include the shallow bottom portion 45. In the outer crown land portion 4B of this embodiment, the total number of sipes 7 including the shallow bottom portion 45 is preferably 50% or more of the total number of all sipes 7, more preferably 55% or more, preferably 70% or less, and more preferably 65% ​​or less.

[0075] Figure 10 is an unfolded view of the tread section 2. As shown in Figure 10, from the viewpoint of enhancing ice performance by maximizing the edge effect of the outer crown land section 4B, it is desirable that the land ratio of the outer crown land section 4B be smaller than that of the tread section 2. If the land ratio of the outer crown land section 4B is excessively smaller than that of the tread section 2, the rigidity of the outer crown land section 4B, which is subjected to relatively large ground pressure, will decrease, potentially worsening dry performance. For this reason, the land ratio of the outer crown land section 4B is preferably 85% or more of the land ratio of the tread section 2, more preferably 88% or more, 97% or less, and even more preferably 94% or less. Furthermore, the land ratio of the outer crown land section 4B is preferably 55% or more, more preferably 60% or more, 70% or less, and even more preferably 65% ​​or less. In this specification, the "land ratio of each tread section 2" is the ratio of the area of ​​the contact surface to the area of ​​the virtual contact surface obtained by filling each groove and each sipe. Furthermore, the "land ratio of the outer crown land section 4B" is the ratio of the area of ​​the contact surface between the groove width centerlines c1 and c2 of the circumferential grooves 3A and 3C adjacent to the outer crown land section 4B to the area of ​​the virtual contact surface SA obtained by filling each groove and each sipe between the groove width centerlines c1 and c2. The virtual contact surface SA is shown in Figure 10.

[0076] The outer shoulder land portion 4A is provided with outer shoulder lateral grooves 14A arranged in the circumferential direction of the tire, and outer shoulder blocks 13A separated by the outer shoulder lateral grooves 14A. The outer shoulder blocks 13A are provided with a plurality of outer shoulder sipes 17A and a second sub-groove 19A extending in the circumferential direction of the tire so as to divide the outer shoulder blocks 13A. In this embodiment, the second sub-groove 19A is provided with a third bend portion 46 in the center in the circumferential direction of the tire. The outer shoulder land portion 4A has outer shoulder lateral grooves 14A and outer shoulder lateral grooves 14A arranged alternately in the circumferential direction of the tire.

[0077] In this embodiment, the inner shoulder land portion 4C is provided with inner shoulder lateral grooves 14C arranged in the circumferential direction of the tire, and inner shoulder blocks 13C separated by the inner shoulder lateral grooves 14C. The inner shoulder blocks 13C are provided with a plurality of sipes 17C and a third sub-groove 19C that extends in the circumferential direction of the tire so as to divide the inner shoulder blocks 13C. In this embodiment, the third sub-groove 19C is provided with a fourth bend portion 47 in the center in the circumferential direction of the tire. The inner shoulder land portion 4C is arranged with the inner shoulder lateral grooves 14C and inner shoulder blocks 13C alternating in the circumferential direction of the tire.

[0078] The inner crown land portion 4D of this embodiment is provided with inner crown lateral grooves 14D arranged in the circumferential direction of the tire, and inner crown blocks 13D separated by the inner crown lateral grooves 14D. The inner crown lateral grooves 14D extend inclined with respect to the tire axis, for example. The inner crown lateral grooves 14D include, for example, a first inner crown lateral groove 49A that extends in a straight line and a second inner crown lateral groove 49B that extends in a zigzag pattern. The first inner crown lateral groove 49A and the second inner crown lateral groove 49B are arranged alternately in the circumferential direction of the tire. The groove width w5a of the first inner crown lateral groove 49A is formed to be larger than the groove width w5b of the second inner crown lateral groove 49B. The first inner crown lateral groove 49A can smoothly discharge ice and the like. The second inner crown lateral groove 49B can exert an edge effect in multiple directions and can suppress an excessive reduction in the rigidity of the inner crown land portion 4D. While not particularly limited, the groove width w5a of the first inner crown lateral groove 49A is preferably 3.5 times or more, more preferably 3.5 times or more, preferably 5.0 times or less, and more preferably 4.5 times or less than the groove width w5b of the second inner crown lateral groove 49B. The groove width w5b of the second inner crown lateral groove 49B is preferably less than 1.5 mm, and preferably 1.4 mm or less.

[0079] Figure 11 is a cross-sectional view along the CC line of Figure 10. As shown in Figure 10, the groove depth d5b of the second inner crown transverse groove 49B is preferably 22% or more, more preferably 27% or more, preferably 42% or less, and even more preferably 37% or less of the groove depth d5a of the first inner crown transverse groove 49A. For example, the groove depth d5b of the second inner crown transverse groove 49B is preferably 1.5 mm or more, more preferably 2.0 mm or more, preferably less than 3.0 mm, and even more preferably 2.8 mm or less.

[0080] The inner crown block 13D is formed from a first inner crown block 50A and a second inner crown block 50B, which has a different contour shape in plan view from the first inner crown block 50A. The first inner crown block 50A and the second inner crown block 50B are arranged alternately in the circumferential direction of the tire.

[0081] Although particularly preferred embodiments of the present invention have been described in detail above, the present invention is not limited to the embodiments described above and can be implemented in various modified forms.

[0082] [Note] The present invention includes the following embodiments.

[0083] [Invention 1] A tire having a tread portion in which the orientation of mounting on the vehicle is specified, The aforementioned tread portion is The tread includes an inner tread end located on the inside of the vehicle when mounted on the vehicle, an outer tread end located on the outside of the vehicle when mounted on the vehicle, and a tread width which is the axial distance of the tire from the inner tread end to the outer tread end. The tread portion comprises three circumferential grooves extending continuously in the circumferential direction of the tire with a groove width of 3.0 mm or more, and four land portions separated by the three circumferential grooves. Each of the four land areas is comprised of multiple blocks separated by multiple transverse grooves with a groove width of 1.0 mm or more that completely cross each land area in the tire axis direction. The said land portion includes an outer crown land portion adjacent to the outer shoulder land portion including the outer tread end, The tire equator is located on the contact surface of the outer crown land portion, The outer crown land portion has the largest tire axial width among the four land portions. The width of the outer crown land portion is 25% or more of the tread width. Each of the aforementioned blocks has a block edge that defines the contour of the contact surface, and has a plurality of sipes having a width of less than 1.0 mm. The total outer crown block edge length ΣA, which is the sum of the lengths of all the block edges included in the outer crown land area, is 35% to 50% of the total pattern block edge length ΣB, which is the sum of the lengths of all the block edges included in the four land areas. tire. [2nd Invention] The tire according to Invention 1, wherein the sum of the outer crown block edges ΣA is 40% to 48% of the sum of the pattern block edges ΣB. [Invention 3] The tire according to invention 1 or 2, wherein the sum of the outer crown block edges ΣA is 10% to 20% of the sum of the pattern edges, which is the sum of the lengths of all the block edges included in the four land portions and the lengths of all the plurality of sipes. [4th Invention] The four land portions include an inner crown land portion adjacent to the inner shoulder land portion, which includes the inner tread end. The tire according to any one of inventions 1 to 3, wherein the sum of the outer crown block edge sum ΣA and the outer shoulder block edge sum ΣD, which is the sum of the lengths of all the block edges included in the outer shoulder land portion (ΣA + ΣD) is greater than the sum of the inner crown block edge sum ΣE, which is the sum of the lengths of all the block edges included in the inner crown land portion, and the inner shoulder block edge sum ΣF, which is the sum of the lengths of all the block edges included in the inner shoulder land portion (ΣE + ΣF). [5th ​​Invention] The tire according to Invention 4, wherein the sum (ΣA + ΣD) is 1.35 to 1.60 times the sum (ΣE + ΣF). [Invention 6] The four land portions include an inner crown land portion adjacent to the inner shoulder land portion, which includes the inner tread end. The tire according to any one of invention 1 to 5, wherein the ratio (ΣA / ΣG) of the total outer crown block edge length ΣA to the total outer crown sipe length ΣG, which is the sum of the lengths of all the sipes included in the outer crown land portion, is greater than any of the ratios (ΣD / ΣH) of the total outer shoulder block edge length ΣD, which is the sum of the lengths of all the block edges included in the outer shoulder land portion, to the total outer shoulder sipe length ΣH, which is the sum of the lengths of all the sipes included in the outer shoulder land portion; the ratio (ΣE / ΣI) of the total inner crown block edge length ΣE, which is the sum of the lengths of all the block edges included in the inner crown land portion, to the total inner crown sipe length ΣI, which is the sum of the lengths of all the sipes included in the inner crown land portion; and the ratio (ΣF / ΣJ) of the total inner shoulder block edge length ΣF, which is the sum of the lengths of all the block edges included in the inner shoulder land portion, to the total inner shoulder sipe length ΣJ, which is the sum of the lengths of all the sipes included in the inner shoulder land portion. [7th Invention] The tire according to claim 6 of the present invention, wherein the ratio (ΣA / ΣG) is 0.55 to 0.70. [8th Invention] The tire according to invention 6 or 7, wherein the difference between the ratio (ΣA / ΣG) and the ratio (ΣD / ΣH) {(ΣA / ΣG)-(ΣD / ΣH)} is 0.15 to 0.30. [Invention 9] The tire according to any one of inventions 1 to 8, wherein the land ratio of the outer crown land portion is smaller than the land ratio of the tread portion. [Invention 10] The tire according to claim 9 of the present invention, wherein the land ratio of the outer crown land portion is 85% to 97% of the land ratio of the tread portion. [Explanation of Symbols]

[0084] 1 tire 2 Tread section 3 Circumferential groove 4 Land 4A Outer shoulder land area 4B Outer Crown Land Section 4a Ground plane 13 blocks 13a Ground plane 15 Block Edge C Tire Equator TW Tread width

Claims

1. A tire having a tread portion in which the orientation of mounting on the vehicle is specified, The aforementioned tread portion is The tread includes an inner tread end located on the inside of the vehicle when mounted on the vehicle, an outer tread end located on the outside of the vehicle when mounted on the vehicle, and a tread width which is the axial distance of the tire from the inner tread end to the outer tread end. The tread portion comprises three circumferential grooves extending continuously in the circumferential direction of the tire with a groove width of 3.0 mm or more, and four land portions separated by the three circumferential grooves. Each of the four land sections is comprised of multiple blocks separated by multiple transverse grooves with a groove width of 1.0 mm or more that completely cross each land section in the tire axis direction. The said land portion includes an outer crown land portion adjacent to the outer shoulder land portion including the outer tread end, The tire equator is located on the contact surface of the outer crown land portion, The outer crown land portion has the largest tire axial width among the four land portions. The width of the outer crown land portion is 25% or more of the tread width. Each of the aforementioned blocks has a block edge that defines the contour of the contact surface, and has a plurality of sipes having a width of less than 1.0 mm. The total outer crown block edge length ΣA, which is the sum of the lengths of all the block edges included in the outer crown land area, is 35% to 50% of the total pattern block edge length ΣB, which is the sum of the lengths of all the block edges included in the four land areas. tire.

2. The tire according to claim 1, wherein the sum of the outer crown block edges ΣA is 40% to 48% of the sum of the pattern block edges ΣB.

3. The tire according to claim 1, wherein the sum of the outer crown block edges ΣA is 10% to 20% of the total pattern edge length, which is the sum of the lengths of all the block edges included in the four land portions and the lengths of all the plurality of sipes.

4. The four land portions include an inner crown land portion adjacent to the inner shoulder land portion, which includes the inner tread end. The tire according to claim 1, wherein the sum of the outer crown block edge sum ΣA and the outer shoulder block edge sum ΣD, which is the sum of the lengths of all the block edges included in the outer shoulder land portion (ΣA + ΣD) is greater than the sum of the inner crown block edge sum ΣE, which is the sum of the lengths of all the block edges included in the inner crown land portion (ΣE + ΣF), which is the sum of the inner shoulder block edge sum ΣF, which is the sum of the lengths of all the block edges included in the inner shoulder land portion.

5. The tire according to claim 4, wherein the sum (ΣA + ΣD) is 1.35 to 1.60 times the sum (ΣE + ΣF).

6. The four land portions include an inner crown land portion adjacent to the inner shoulder land portion, which includes the inner tread end. The tire according to claim 1, wherein the ratio (ΣA / ΣG) of the total outer crown block edge length ΣA to the total outer crown sipe length ΣG, which is the sum of the lengths of all the sipes included in the outer crown land portion, is greater than any of the ratios (ΣD / ΣH) of the total outer shoulder block edge length ΣD, which is the sum of the lengths of all the block edges included in the outer shoulder land portion, to the total outer shoulder sipe length ΣH, which is the sum of the lengths of all the sipes included in the outer shoulder land portion; the ratio (ΣE / ΣI) of the total inner crown block edge length ΣE, which is the sum of the lengths of all the block edges included in the inner crown land portion, to the total inner crown sipe length ΣI, which is the sum of the lengths of all the sipes included in the inner crown land portion; and the ratio (ΣF / ΣJ) of the total inner shoulder block edge length ΣF, which is the sum of the lengths of all the block edges included in the inner shoulder land portion, to the total inner shoulder sipe length ΣJ, which is the sum of the lengths of all the sipes included in the inner shoulder land portion.

7. The tire according to claim 6, wherein the ratio (ΣA / ΣG) is 0.55 to 0.

70.

8. The tire according to claim 6, wherein the difference between the ratio (ΣA / ΣG) and the ratio (ΣD / ΣH) {(ΣA / ΣG) - (ΣD / ΣH)} is 0.15 to 0.

30.

9. The tire according to any one of claims 1 to 8, wherein the land ratio of the outer crown land portion is smaller than the land ratio of the tread portion.

10. The tire according to claim 9, wherein the land ratio of the outer crown land portion is 85% to 97% of the land ratio of the tread portion.

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