JP7182515B2 - tire - Google Patents

Description

TECHNICAL FIELD The present invention relates to a tire having a tread portion with a plurality of circumferential main grooves and a plurality of land portions.

For tires used on icy and snowy roads, tread patterns are set according to tire performance on icy roads (ice performance) and tire performance on snowy roads (snow performance). formed in the part. Further, conventionally, a pneumatic tire is known in which a block is divided into two small blocks in a center land portion and two second land portions to improve performance on ice and snow (see Patent Document 1).

In the conventional pneumatic tire described in Patent Document 1, a plurality of lug grooves are formed in the center land portion and the second land portion, and two sipes are formed in the small block. The water removal effect of the sipes removes water between the small blocks and the road surface, and the edge component (edge effect) of the sipes and lug grooves improves the grip of the tire. However, in the center land portion and the second land portion, only one end of the lug groove is open to the main groove, and the other end of the lug groove is closed inside the land portion. Therefore, on a snowy road surface, there is a possibility that the snow will be difficult to come out of the lug groove. There is concern that snow clogging the lug grooves will affect the performance of small blocks on snow. Therefore, there is room for further improvement from the viewpoint of achieving both performance on ice and performance on snow of the tire.

JP-A-2008-149768

SUMMARY OF THE INVENTION The present invention has been made in view of the conventional problems, and an object of the present invention is to achieve both ice performance and snow performance of a tire.

The present invention provides two first circumferential main grooves formed on both sides of the tire equatorial plane in the tire width direction, and two second circumferential main grooves formed on the outside of each of the first circumferential main grooves in the tire width direction. A directional main groove, a first land portion defined by two first circumferential main grooves and positioned on the tire equatorial plane, and a second land portion defined by the first circumferential main groove and the second circumferential main groove. and a tire with The first land portion has a circumferential narrow groove that divides the first land portion in the tire width direction, and is formed on both sides of the circumferential narrow groove in the tire width direction and opens to the first circumferential main groove and the circumferential narrow groove. and a plurality of blocks partitioned on both sides of the circumferential fine groove in the tire width direction by the plurality of width direction grooves. The second land portion has a plurality of width direction grooves opening to the first circumferential direction main groove and the second circumferential direction main groove, and a plurality of blocks partitioned by the plurality of width direction grooves. In the first land portion, the width direction grooves on one side in the tire width direction and the width direction grooves on the other side of the circumferential narrow grooves are alternately arranged in the tire circumferential direction. Each of the block of the first land portion and the block of the second land portion has a plurality of width direction sipes formed adjacent to each other in the central portion in the tire circumferential direction, and the tire is provided from both end walls in the tire circumferential direction. It is formed in a shape that gradually widens on both sides in the tire width direction toward the central portion in the circumferential direction.

ADVANTAGE OF THE INVENTION According to this invention, the performance on ice of a tire and the performance on snow can be made compatible.

It is a top view showing the tread pattern of the tire of this embodiment. It is a top view which shows the block of this embodiment. FIG. 4 is a plan view showing another example of the tread pattern of the tire of this embodiment;

One embodiment of the tire of the present invention will be described with reference to the drawings.
The tire of this embodiment is a pneumatic tire for vehicles (for example, a tire for trucks and buses, a tire for heavy loads, and a tire for passenger cars), and is formed into a well-known structure using general tire constituent members. That is, the tire includes a pair of bead portions, a pair of sidewall portions located outside the pair of bead portions in the tire radial direction, and a tread portion that contacts the road surface. A tire includes a pair of bead cores, a carcass arranged between the pair of bead cores, a belt arranged on the outer peripheral side of the carcass, and a tread rubber having a predetermined tread pattern.

FIG. 1 is a plan view showing the tread pattern of the tire 1 of this embodiment, and schematically shows a portion of the tread portion 2 in the tire circumferential direction S. As shown in FIG.
As shown, the tire 1 has a tread portion 2 with a plurality (at least four) of circumferential main grooves 10, 11, one circumferential narrow groove 12, a plurality of width direction grooves 13, 14, 15, a plurality of It has width direction sipes 20, 21, a plurality of land portions 30, 40, 50, and a plurality of blocks 31, 41, 51. When the vehicle is running, the tire 1 contacts the road surface and rolls on the plurality of land portions 30 , 40 , 50 and the blocks 31 , 41 , 51 . The outer surfaces of the land portions 30, 40, 50 and the blocks 31, 41, 51 in the tire radial direction are tread surfaces that come into contact with the road surface.

The plurality of circumferential main grooves 10 and 11 extend along the tire circumferential direction S and are arranged in parallel in the tire width direction H at intervals. Here, the tire 1 includes four circumferential main grooves (two first circumferential main grooves 10 and two second circumferential main grooves 11) continuously formed in the tire circumferential direction S. The first circumferential main groove 10 is the innermost inner circumferential main groove in the tire width direction H among the plurality of circumferential main grooves 10 and 11, and is the innermost circumferential main groove of the two second circumferential main grooves 11. is formed inside in the tire width direction H (on the tire equatorial plane 3 side). The tire equatorial plane 3 is located at the central portion of the tread portion 2 in the tire width direction H.

The first circumferential main grooves 10 are center-side circumferential main grooves formed on both sides of the tire equatorial plane 3 in the tire width direction H. It is located between the main grooves 11 . The second circumferential main groove 11 is an outer circumferential main groove located on the outermost side in the tire width direction H among the plurality of circumferential main grooves 10 and 11, and is the outermost circumferential main groove of the two first circumferential main grooves 10. is formed outside in the tire width direction H (on the side of the shoulder portion 4). The shoulder portions 4 are positioned on both outer sides of the tread portion 2 in the tire width direction H, and the second circumferential main grooves 11 are formed on both outer sides of the two first circumferential main grooves 10 in the tire width direction H. It is On both sides of the tire equatorial plane 3, the second circumferential main grooves 11 are formed inside the shoulder portion 4 in the tire width direction H, and are positioned between the first circumferential main groove 10 and the shoulder portion 4. there is

The circumferential narrow groove 12 is a circumferential minor groove narrower than the circumferential main grooves 10 and 11 , and the width of the circumferential narrow groove 12 is narrower than the width of the circumferential main grooves 10 and 11 . The circumferential narrow groove 12 is located on the tire equatorial plane 3 and formed between the two first circumferential main grooves 10 . Moreover, the circumferential narrow groove 12 is, for example, a circumferential sipe and extends along the tire circumferential direction S and the tire equatorial plane 3 . The plurality of widthwise grooves 13 , 14 , 15 are lug grooves extending along the tire width direction H and formed in the land portions 30 , 40 , 50 . The widthwise grooves 13 , 14 , 15 are formed in a direction crossing the circumferential main grooves 10 , 11 and connected to the circumferential main grooves 10 , 11 . The plurality of width direction sipes 20, 21 are cuts formed in the blocks 31, 41, are formed from the tread surfaces of the blocks 31, 41 toward the inside of the blocks 31, 41, and extend along the tire width direction H. .

The tread portion 2 is partitioned in the tire width direction H by the plurality of circumferential main grooves 10 , 11 , and the plurality of land portions 30 , 40 , 50 are formed in the tread portion 2 . The plurality of land portions 30 , 40 , 50 are protrusions separated from each other in the tire width direction H by the circumferential main grooves 10 , 11 and extend in the tire circumferential direction S along the circumferential main grooves 10 , 11 . The land portions 30, 40, and 50 are block-shaped land portions and are arranged side by side in the tire width direction H at intervals. A plurality of blocks 31, 41, 51 are formed in the land portions 30, 40, 50 and arranged in the tire circumferential direction S. As shown in FIG.

The tire 1 includes five land portions (one first land portion 30, two second land portions 40, two third land portions 50). The first land portion 30 is a central land portion formed between the two first circumferential main grooves 10 and formed in the central region of the tread portion 2 including the tire equatorial plane 3 . The tire equatorial plane 3 is located at the center of the first land portion 30 in the tire width direction H, and the first land portion 30 is located between the two second land portions 40 . The second land portion 40 is an intermediate land portion formed between the first circumferential main groove 10 and the second circumferential main groove 11, and is located in the middle of the tread portion 2 between the tire equatorial plane 3 and the shoulder portion 4. formed in the area. The third land portion 50 is an outer land portion (shoulder land portion) formed outside the second circumferential main groove 11 in the tire width direction H, and is an outer region (shoulder portion) of the tread portion 2 in the tire width direction H. 4 side region).

The first land portion 30 is defined by two first circumferential main grooves 10 and located on the tire equatorial plane 3 . Also, the first land portion 30 has one circumferential narrow groove 12 , a plurality of widthwise grooves 13 , a plurality of blocks 31 , and a plurality of widthwise sipes 20 formed in the blocks 31 . The circumferential narrow groove 12 is a dividing groove that divides the first land portion 30 in the tire width direction H, and is located in the center portion of the first land portion 30 in the tire width direction H. The first land portion 30 is divided into two in the tire width direction H by the circumferential narrow groove 12 , and block rows are formed on both sides of the circumferential narrow groove 12 in the tire width direction H.

The plurality of width direction grooves 13 are formed on both sides of the circumferential narrow groove 12 in the tire width direction H and open to the first circumferential main groove 10 and the circumferential narrow groove 12 . On both sides of the circumferential narrow groove 12 in the tire width direction H, a plurality of width direction grooves 13 are formed between the first circumferential main groove 10 and the circumferential narrow groove 12, and are spaced apart in the tire circumferential direction S. parallel. On one side of the circumferential narrow groove 12 in the tire width direction H, the width direction groove 13 is formed from the circumferential narrow groove 12 to the first circumferential main groove 10 on one side of the circumferential narrow groove 12 in the tire width direction H. and is opened to the first circumferential main groove 10 on one side. On the other side of the circumferential narrow groove 12 in the tire width direction H, the width direction groove 13 is formed from the circumferential narrow groove 12 to the first circumferential main groove 10 on the other side of the circumferential narrow groove 12 in the tire width direction H. and open to the first circumferential main groove 10 on the other side.

The block 31 of the first land portion 30 is the first block (central block) located in the central region of the tread portion 2, and includes two first circumferential main grooves 10, one circumferential narrow groove 12, and a plurality of It is formed between the first circumferential main groove 10 and the circumferential narrow groove 12 by the width direction groove 13 of . The plurality of width direction grooves 13 divide the first land portion 30 in the tire circumferential direction S on both sides in the tire width direction H of the circumferential narrow grooves 12 . The plurality of blocks 31 are partitioned on both sides in the tire width direction H of the circumferential narrow groove 12 by the plurality of width direction grooves 13 and are separated from each other in the tire circumferential direction S. As shown in FIG. The width direction grooves 13 are formed between the blocks 31 on both sides of the circumferential narrow grooves 12 in the tire width direction H, and the blocks 31 are arranged in the tire circumferential direction S at intervals.

The circumferential narrow groove 12 is positioned between the block 31 on one side in the tire width direction H and the block 31 on the other side. The block 31 of the first land portion 30 has a plurality of widthwise sipes 20 formed between the first circumferential main groove 10 and the circumferential narrow grooves 12 . The plurality of width direction sipes 20 are formed adjacent to each other in the central portion of the block 31 in the tire circumferential direction S, and are arranged side by side in the tire circumferential direction S at intervals. The widthwise sipe 20 traverses the block 31 in the tire width direction H from the first circumferential main groove 10 to the circumferential narrow groove 12 and opens into the first circumferential main groove 10 and the circumferential narrow groove 12 . there is

In the first land portion 30, the plurality of width direction grooves 13 on one side of the circumferential narrow grooves 12 and the plurality of width direction grooves 13 on the other side of the tire width direction H are alternately arranged in the tire circumferential direction S. , are shifted in the tire circumferential direction S. The width direction grooves 13 on one side and the width direction grooves 13 on the other side are alternately formed in the tire circumferential direction S and open to the circumferential narrow grooves 12 alternately. A plurality of blocks 31 on one side of the circumferential narrow groove 12 in the tire width direction H and a plurality of blocks 31 on the other side of the circumferential narrow groove 12 are shifted in the tire circumferential direction S in correspondence with the positions of the width direction grooves 13 . . On both sides of the circumferential narrow groove 12 in the tire width direction H, the ends (openings) of the width direction grooves 13 on the side of the circumferential narrow groove 12 are formed at positions facing the central portion of the block 31 in the tire circumferential direction S. It is

The two second land portions 40 are separated by the first circumferential main groove 10 and the second circumferential main groove 11, respectively, and are located on both sides of the first land portion 30 in the tire width direction H. The second land portion 40 is positioned between the first land portion 30 and the third land portion 50 on both sides of the tire equatorial plane 3 in the tire width direction H. In addition, the second land portion 40 has a plurality of widthwise grooves 14 spaced apart in parallel in the tire circumferential direction S, a plurality of blocks 41, and a plurality of widthwise sipes 21 formed in the blocks 41. there is The plurality of widthwise grooves 14 are formed between the first circumferential main groove 10 and the second circumferential main groove 11 and open to the first circumferential main groove 10 and the second circumferential main groove 11. . The width direction groove 14 crosses the second land portion 40 in the tire width direction H from the first circumferential direction main groove 10 to the second circumferential direction main groove 11 .

The block 41 of the second land portion 40 is a second block (intermediate block) located in the intermediate region of the tread portion 2, and includes the first circumferential main groove 10, the second circumferential main groove 11, and a plurality of width A directional groove 14 is formed between the first circumferential main groove 10 and the second circumferential main groove 11 . The plurality of width direction grooves 14 divide the second land portion 40 in the tire circumferential direction S. The plurality of blocks 41 are separated from each other in the tire circumferential direction S by being partitioned by the plurality of width direction grooves 14 . The widthwise grooves 14 are formed between the blocks 41 , and the blocks 41 are spaced apart in the tire circumferential direction S.

The block 41 of the second land portion 40 has a plurality of widthwise sipes 21 formed between the first circumferential main groove 10 and the second circumferential main groove 11 . The plurality of width direction sipes 21 are formed adjacent to each other in the central portion of the block 41 in the tire circumferential direction S, and are arranged side by side in the tire circumferential direction S at intervals. The widthwise sipe 21 traverses the block 41 in the tire width direction H from the first circumferential main groove 10 to the second circumferential main groove 11 to form the first circumferential main groove 10 and the second circumferential main groove 11 . is open to

The two third land portions 50 are separated by the second circumferential main grooves 11 and positioned outside the second land portion 40 in the tire width direction H. As shown in FIG. The third land portion 50 is located between the second land portion 40 and the shoulder portion 4 on both sides of the tire equatorial plane 3 in the tire width direction H. Also, the third land portion 50 has a plurality of widthwise grooves 15 and a plurality of blocks 51 . The plurality of width direction grooves 15 are formed between the second circumferential direction main groove 11 and the shoulder portion 4 and arranged side by side in the tire circumferential direction S at intervals. The widthwise groove 15 opens into the second circumferential main groove 11 and crosses the third land portion 50 in the tire width direction H.

The block 51 of the third land portion 50 is a third block (outer block) located in the outer region of the tread portion 2 , and the second circumferential main groove 11 and the plurality of width direction grooves 15 form the second circumferential main groove 11 and the plurality of width direction grooves 15 . It is formed outside the groove 11 in the tire width direction H. The plurality of width direction grooves 15 divide the third land portion 50 in the tire circumferential direction S. The plurality of blocks 51 are separated from each other in the tire circumferential direction S by being partitioned by the plurality of width direction grooves 15 . The widthwise grooves 15 are formed between the blocks 51 , and the blocks 51 are spaced apart in the tire circumferential direction S. In addition, the block 51 has widthwise narrow grooves 52 narrower than the widthwise grooves 15 and a plurality of sipes 53 . The widthwise narrow grooves 52 and the sipes 53 are formed along the tire width direction H.

FIG. 2 is a plan view showing the blocks 31 and 41 of this embodiment, showing the blocks 31 and 41 viewed from the outside in the tire radial direction. 2A shows one block 31 of the first land portion 30, and FIG. 2B shows one block 41 of the second land portion 40. FIG.
As shown, each of the blocks 31 of the first land portion 30 and the blocks 41 of the second land portion 40 has two or three widthwise sipes 20,21. Here, the block 31 of the first land portion 30 has two widthwise sipes 20 and the block 41 of the second land portion 40 has two widthwise sipes 21 .

In the first land portion 30 (see FIG. 2A ), the block 31 is divided in the tire circumferential direction S by the width direction sipes 20 to form inter-sipe blocks 32 and divided blocks 33 within the block 31 . The inter-sipe block 32 and the divided block 33 are small blocks that constitute the block 31 , and the block 31 has one inter-sipe block 32 and two divided blocks 33 . The inter-sipe block 32 is formed between two width direction sipes 20 adjacent to each other in the tire circumferential direction S and positioned at the central portion of the block 31 in the tire circumferential direction S. As shown in FIG. The dividing blocks 33 are formed between the widthwise sipes 20 and the widthwise grooves 13 adjacent to each other in the tire circumferential direction S, and are positioned on both sides of the inter-sipe blocks 32 in the tire circumferential direction S. As shown in FIG.

The width direction sipe 20 of the block 31 is formed apart from the end wall 34 of the block 31 in the tire circumferential direction S. The end walls 34 of the block 31 are the end faces of the block 31 positioned within the width direction groove 13 (groove walls of the width direction groove 13), and are formed at both end portions of the block 31 in the tire circumferential direction S. The distance in the tire circumferential direction S between the widthwise sipe 20 adjacent in the tire circumferential direction S and the end wall 34 is longer than the distance in the tire circumferential direction S between the two widthwise sipes 20 adjacent in the tire circumferential direction S. Therefore, the width of the inter-sipe block 32 in the tire circumferential direction S is narrower than the width of the divided block 33 in the tire circumferential direction S.

In the second land portion 40 (see FIG. 2B ), the block 41 is divided in the tire circumferential direction S by the width direction sipes 21 to form inter-sipe blocks 42 and divided blocks 43 within the block 41 . The inter-sipe block 42 and the divided block 43 are small blocks that constitute the block 41 , and the block 41 has one inter-sipe block 42 and two divided blocks 43 . The inter-sipe block 42 is formed between two width direction sipes 21 adjacent to each other in the tire circumferential direction S and positioned at the central portion of the block 41 in the tire circumferential direction S. As shown in FIG. The dividing blocks 43 are formed between the widthwise sipes 21 and the widthwise grooves 14 adjacent to each other in the tire circumferential direction S, and are positioned on both sides of the inter-sipe blocks 42 in the tire circumferential direction S. As shown in FIG.

The width direction sipe 21 of the block 41 is formed apart from the end wall 44 of the block 41 in the tire circumferential direction S. The end walls 44 of the block 41 are the end faces of the block 41 positioned within the width direction groove 14 (groove walls of the width direction groove 14), and are formed at both end portions of the block 41 in the tire circumferential direction S. The distance in the tire circumferential direction S between the width direction sipe 21 adjacent in the tire circumferential direction S and the end wall 44 is longer than the distance in the tire circumferential direction S between two width direction sipes 21 adjacent in the tire circumferential direction S. Therefore, the width of the inter-sipe block 42 in the tire circumferential direction S is narrower than the width of the divided block 43 in the tire circumferential direction S.

The blocks 31 of the first land portion 30 and the blocks 41 of the second land portion 40 extend from the end walls 34, 44 on both sides in the tire circumferential direction S to the central portion in the tire circumferential direction S when viewed from the outside in the tire radial direction. It is formed in a shape that gradually widens on both sides in the tire width direction H. The blocks 31, 41 are formed in a hexagonal shape when viewed from the outside in the tire radial direction, and protrude toward both sides in the tire width direction H between the end walls 34, 44 on both sides. The width of the blocks 31 and 41 in the tire width direction H gradually widens from the end walls 34 and 44 toward the central portion in the tire circumferential direction S.

The block 41 of the second land portion 40 is a wide block that is wider in the tire width direction H than the block 31 of the first land portion 30, and the maximum width of the block 41 in the tire width direction H is equal to the tire width greater than the maximum width in direction H; Also, the area of the tread of the block 41 is larger than the area of the tread of the block 31 , and the volume of the block 41 is larger than the volume of the block 31 . The widthwise sipes 20 formed in the blocks 31 of the first land portions 30 are deeper in the tire radial direction than the widthwise sipes 21 formed in the blocks 41 of the second land portions 40 . is greater than the depth of the width direction sipe 21 in the tire radial direction.

When the vehicle is running, the blocks 31, 41, 51 of the land portions 30, 40, 50 come into contact with the road surface and the tire 1 rotates. At this time, since the first land portion 30 is positioned on the tire equatorial plane 3 , the ground pressure of the first land portion 30 is higher than the ground pressure of the other land portions 40 and 50 . In the first land portion 30 , blocks 31 and widthwise grooves 13 are formed on both sides of the circumferential narrow grooves 12 in the tire width direction H, and a plurality of widthwise sipes 20 are formed in the blocks 31 . Therefore, the edge component of the block 31 increases and is dispersed in the tire circumferential direction S in the first land portion 30 where the contact pressure is high. Thereby, the on-ice performance of the tire 1 is improved.

In the second land portion 40 , the width direction grooves 14 are open to the first circumferential main groove 10 and the second circumferential direction main groove 11 , so that snow can easily flow out of the width direction grooves 14 . As a result, the snow removal performance of the width direction grooves 14 is improved, and clogging of the width direction grooves 14 with snow is suppressed. The on-snow performance of the tire 1 is ensured by the blocks 41 having the plurality of widthwise sipes 21 and the widthwise grooves 14 .

Each of the blocks 31 and 41 gradually widens on both sides in the tire width direction H from the end walls 34 and 44 on both sides in the tire circumferential direction S toward the central portion in the tire circumferential direction S. As shown in FIG. Therefore, even if forces are applied to the blocks 31 and 41 in various directions (for example, the tire circumferential direction S, the tire width direction H, and oblique directions), deformation of the blocks 31 and 41 is suppressed. As a result, the blocks 31 and 41 are prevented from being worn (e.g., unevenly worn). In addition, since the blocks 31 and 41 have high grounding performance, the performance on ice and snow of the blocks 31 and 41 is improved. Edge components of the blocks 31 and 41 are also increased by lengthening the width direction sipes 20 and 21 of the blocks 31 and 41 .

Therefore, with the tire 1 of the present embodiment, both performance on ice and performance on snow can be achieved. Since the block 41 of the second land portion 40 is wider in the tire width direction H than the block 31 of the first land portion 30, the on-snow performance of the second land portion 40 can be reliably ensured. Also, the widthwise sipes 20 formed in the blocks 31 of the first land portions 30 are deeper than the widthwise sipes 21 formed in the blocks 41 of the second land portions 40 . As a result, the performance on ice by the first land portion 30 can be ensured for a long period of time.

When one widthwise sipe 20, 21 is formed in the blocks 31, 41, the edge components of the blocks 31, 41 are reduced, which may affect performance on ice and snow. On the other hand, when four or more width direction sipes 20, 21 are formed in the blocks 31, 41, the width of the inter-sipe blocks 32, 42 or the divided blocks 33, 43 in the blocks 31, 41 in the tire circumferential direction S is The narrowing may affect the chipping resistance performance of the blocks 31 and 41 . Therefore, it is preferable to form two or three width direction sipes 20, 21 in the blocks 31, 41. FIG. As a result, the performance on ice and the performance on snow can be ensured more reliably, and damage to the blocks 31 and 41 can be suppressed.

FIG. 3 is a plan view showing another example of the tread pattern of the tire 1 of this embodiment, and schematically shows a part of the tread portion 2 in the tire circumferential direction S. As shown in FIG.
As illustrated, here, the number of widthwise sipes 20 formed in one block 31 of the first land portion 30 is equal to the number of widthwise sipes 21 formed in one block 41 of the second land portion 40. more than The block 31 of the first land portion 30 has three widthwise sipes 20 and the block 41 of the second land portion 40 has two widthwise sipes 21 . By making the width direction sipes 20 of the block 31 larger than the width direction sipes 21 of the block 41, the edge component of the block 31 can be increased in the first land portion 30 where the ground pressure is high. Therefore, the on-ice performance of the tire 1 can be further improved.

Regarding the depth in the tire radial direction of the plurality of widthwise sipes 20, 21 within one block 31, 41, the plurality of widthwise sipes 20, 21 may be formed to have the same depth. Directional sipes 20, 21 may be formed at different depths. Also, three width direction sipes 21 may be formed in the block 41 of the second land portion 40 . The configuration of the tire 1 of this embodiment can be applied to various tires having land portions.

DESCRIPTION OF SYMBOLS 1... Tire, 2... Tread part, 3... Tire equatorial surface, 4... Shoulder part, 10... First circumferential main groove, 11... Second circumferential main groove, 12 Circumferential narrow groove 13 Width direction groove 14 Width direction groove 15 Width direction groove 20 Width direction sipe 21 Width direction sipe 30 ... first land portion, 31 ... block, 32 ... block between sipes, 33 ... division block, 34 ... end wall, 40 ... second land section, 41 ... block , 42... Inter-sipe block, 43... Divided block, 44... End wall, 50... Third land portion, 51... Block, 52... Width direction narrow groove, 53...・Sipe, H: tire width direction, S: tire circumferential direction.

Claims (5)

Two first circumferential main grooves formed on both sides in the tire width direction of the tire equatorial plane, and two second circumferential main grooves formed outside the first circumferential main grooves in the tire width direction. , a first land portion defined by two first circumferential main grooves and positioned on the tire equatorial plane, and a second land portion defined by the first circumferential main groove and the second circumferential main groove. a tire that
The first land portion has a circumferential narrow groove that divides the first land portion in the tire width direction, and is formed on both sides of the circumferential narrow groove in the tire width direction and opens to the first circumferential main groove and the circumferential narrow groove. and a plurality of blocks partitioned on both sides in the tire width direction of the circumferential fine groove by the plurality of width direction grooves,
The second land portion has a plurality of width direction grooves opening to the first circumferential main groove and the second circumferential direction main groove, and a plurality of blocks partitioned by the plurality of width direction grooves,
In the first land portion, the width direction grooves on one side in the tire width direction and the width direction grooves on the other side of the circumferential narrow grooves are alternately arranged in the tire circumferential direction,
Each of the block of the first land portion and the block of the second land portion has a plurality of width direction sipes formed adjacent to each other in the central portion in the tire circumferential direction, and the tire is provided from both end walls in the tire circumferential direction. A tire formed in a shape that gradually widens on both sides in the tire width direction toward the center in the circumferential direction. In the tire according to claim 1,
Each of the block of the first land portion and the block of the second land portion has two or three transverse sipes. In the tire according to claim 1 or 2,
The block of the second land portion is wider in the tire width direction than the block of the first land portion. In the tire according to any one of claims 1 to 3,
A tire in which the number of width direction sipes formed in the block of the first land portion is greater than the number of width direction sipes formed in the block of the second land portion. In the tire according to any one of claims 1 to 4,
A tire in which widthwise sipes formed in blocks of first land portions are deeper in the tire radial direction than widthwise sipes formed in blocks of second land portions.

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