JP2020199789A - tire - Google Patents

Abstract

To achieve both on-ice performance and on-snow performance of a tire.SOLUTION: A tire 1 includes a first land part 30 partitioned by two first circumferential direction main grooves 10 and a second land part 40 partitioned by the first circumferential direction main groove 10 and a second circumferential direction main groove 11. The first land part 30 has a plurality of width direction grooves 13 and a plurality of blocks 31 on both sides in a tire width direction H of a circumferential direction narrow groove 12. The width direction groove 13 on one side and the width direction groove 13 on the other side in the tire width direction H of the circumferential direction narrow groove 12 are alternately arranged in a tire circumferential direction S. The second land part 40 has a plurality of width direction grooves 14 and a plurality of blocks 41. The blocks 31 and 41 have a plurality of width direction sipes 20 and 21, and are formed to have such a shape as to gradually extend toward a central part in the tire circumferential direction S from end walls on both sides in the tire circumferential direction S to both sides in the tire width direction H.SELECTED DRAWING: Figure 1

Description

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

For tires used on icy and snowy roads, tread patterns are set according to the tire performance on icy roads (performance on ice) and the performance of tires on snowy roads (performance on snow), and various blocks are treaded. It is 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 sipe removes water between the small block and the road surface, and the edge component (edge effect) of the sipe and lug groove improves the grip of the tire. However, in the center land portion and the second land portion, only one end of the lug groove opens to the main groove, and the other end of the lug groove is closed in the land portion. Therefore, on a snowy road surface, it may be difficult for snow to come out of the rug groove. It is feared that the clogging of the lug groove with snow will affect the performance of small blocks on snow. Therefore, there is room for further improvement from the viewpoint of achieving both the performance on ice and the performance on snow of the tire.

Japanese Unexamined Patent Publication No. 2008-149768

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

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

According to the present invention, it is possible to achieve both the performance on ice and the performance on snow of a tire.

It is a top view which shows the tread pattern of the tire of this embodiment. It is a top view which shows the block of this embodiment. It is a top view which shows another example of the tread pattern of the tire of this embodiment.

An embodiment of the tire of the present invention will be described with reference to the drawings.
The tire of the present embodiment is a pneumatic tire for a vehicle (for example, a tire for a truck / bus, a tire for a heavy load, a tire for a passenger car), and is formed in a well-known structure by general tire components. 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 comes into contact with the road surface. Further, the 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 a tread pattern of the tire 1 of the present embodiment, and schematically shows a part of the tire circumferential direction S of the tread portion 2.
As shown in the figure, the tire 1 has a plurality of (at least four) circumferential main grooves 10, 11, one circumferential narrow groove 12, a plurality of widthwise grooves 13, 14, 15, and a plurality of circumferential grooves 12 in the tread portion 2. It includes widthwise sipes 20, 21, a plurality of treads 30, 40, 50, and a plurality of blocks 31, 41, 51. When the vehicle is running, the tire 1 rolls in contact with the road surface at the plurality of land portions 30, 40, 50 and 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 treads in contact with the road surface.

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

The first circumferential main groove 10 is a central circumferential main groove formed on both sides of the tire equatorial plane 3 in the tire width direction H, and is a tire equatorial plane 3 and a second circumferential direction on both sides of the tire equatorial plane 3. 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 of the tire width direction H among the plurality of circumferential main grooves 10, 11, and each of the two first circumferential main grooves 10 It is formed on the outside (shoulder portion 4 side) of the tire width direction H. The shoulder portion 4 is located on both outer sides of the tread portion 2 in the tire width direction H, and the second circumferential main groove 11 is formed on both outer sides of the two first circumferential main grooves 10 in the tire width direction H. Has been done. Further, on both sides of the tire equatorial plane 3, the second circumferential main groove 11 is formed inside the tire width direction H of the shoulder portion 4, and is located between the first circumferential main groove 10 and the shoulder portion 4. There is.

The circumferential narrow groove 12 is a circumferential sub-groove narrower than the circumferential main grooves 10 and 11, and the width of the circumferential fine groove 12 is narrower than the width of the circumferential main grooves 10 and 11. The circumferential narrow groove 12 is located on the equatorial plane 3 of the tire and is formed between the two first circumferential main grooves 10. Further, the circumferential 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, and 15 are lug grooves extending along the tire width direction H, and are formed on the land portions 30, 40 and 50. The widthwise grooves 13, 14 and 15 are formed in a direction intersecting the circumferential main grooves 10 and 11 and are connected to the circumferential main grooves 10 and 11. The plurality of width direction sipes 20 and 21 are cuts formed in the blocks 31 and 41, are formed from the treads of the blocks 31 and 41 toward the inside of the blocks 31 and 41, and extend along the tire width direction H. ..

The tread portion 2 is divided in the tire width direction H by the plurality of circumferential main grooves 10 and 11, and the plurality of land portions 30, 40 and 50 are formed in the tread portion 2. The plurality of land portions 30, 40, 50 are convex portions separated from each other in the tire width direction H by the circumferential main grooves 10 and 11, and extend in the tire circumferential direction S along the circumferential main grooves 10 and 11. Further, the land portions 30, 40, and 50 are block-shaped land portions, and are arranged in parallel at intervals in the tire width direction H. The plurality of blocks 31, 41, 51 are formed on the land portions 30, 40, 50 and are arranged in the tire circumferential direction S.

Tire 1 includes five land parts (one first land part 30, two second land parts 40, and two third land parts 50). The first land portion 30 is a central land portion formed between two main grooves 10 in the first circumferential direction, and is 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 main groove 10 in the first circumferential direction and the main groove 11 in the second circumferential direction, and is intermediate between the tread portion 2 between the tire equatorial plane 3 and the shoulder portion 4. It is formed in the area. The third land portion 50 is an outer land portion (shoulder land portion) formed outside the tire width direction H of the second circumferential main groove 11, and is an outer region (shoulder portion) of the tread portion 2 in the tire width direction H. It is formed in the four-sided region).

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

The plurality of widthwise grooves 13 are formed on both sides of the circumferential narrow groove 12 in the tire width direction H, and are open to the first circumferential main groove 10 and the circumferential narrow groove 12. A plurality of widthwise grooves 13 are formed between 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, and are spaced apart from each other in the tire circumferential direction S. In parallel. On one side of the tire width direction H of the circumferential narrow groove 12, 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 tire width direction H of the circumferential narrow groove 12. Then, it opens in the main groove 10 in the first circumferential direction 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 tire width direction H of the circumferential narrow groove 12. Then, it opens in the main groove 10 in the first circumferential direction on the other side.

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

The circumferential groove 12 is located between the block 31 on one side and the block 31 on the other side in the tire width direction H. 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 groove 12. The plurality of width direction sipes 20 are formed adjacent to each other in the central portion of the tire circumferential direction S of the block 31, and are arranged in parallel with each other at intervals in the tire circumferential direction S. The width direction sipe 20 crosses the block 31 from the first circumferential direction main groove 10 to the circumferential direction narrow groove 12 in the tire width direction H, and opens into the first circumferential direction main groove 10 and the circumferential direction fine groove 12. There is.

In the first land portion 30, the plurality of widthwise grooves 13 on one side of the tire width direction H and the plurality of widthwise grooves 13 on the other side of the circumferential narrow groove 12 are alternately arranged in the tire circumferential direction S. , The tire is formed so as to be displaced in the circumferential direction S. The widthwise groove 13 on one side and the widthwise groove 13 on the other side are alternately formed in the tire circumferential direction S, and alternately open in the circumferential narrow groove 12. The plurality of blocks 31 on one side and the plurality of blocks 31 on the other side of the tire width direction H of the circumferential narrow groove 12 are formed so as to be offset in the tire circumferential direction S, corresponding to the position of the width direction groove 13. .. On both sides of the circumferential groove 12 in the tire width direction H, the ends (openings) of the width groove 13 on the circumferential direction 12 side are formed at positions facing the central portion of the block 31 in the tire circumferential direction S. Has been done.

The two second land portions 40 are partitioned by the first circumferential direction main groove 10 and the second circumferential direction 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 located 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. Further, the second land portion 40 has a plurality of widthwise grooves 14 arranged in parallel at intervals 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 direction main groove 10 and the second circumferential direction main groove 11, and are open to the first circumferential direction main groove 10 and the second circumferential direction 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 has a first circumferential direction main groove 10, a second circumferential direction main groove 11, and a plurality of widths. The 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 partitioned by a plurality of widthwise grooves 14 and are separated from each other in the tire circumferential direction S. Width direction grooves 14 are formed between the blocks 41, and the blocks 41 are arranged at intervals 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 tire circumferential direction S of the block 41, and are arranged in parallel with each other at intervals in the tire circumferential direction S. The width direction sipe 21 crosses the block 41 from the first circumferential direction main groove 10 to the second circumferential direction main groove 11 in the tire width direction H, and the first circumferential direction main groove 10 and the second circumferential direction main groove 11 It is open to.

The two third land portions 50 are each partitioned by the main groove 11 in the second circumferential direction, and are located outside the tire width direction H of the second land portion 40. 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. Further, 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 are arranged in parallel at intervals in the tire circumferential direction S. The width direction groove 15 opens in the second circumferential direction 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 is mainly formed in the second circumferential direction by the second circumferential main groove 11 and the plurality of widthwise grooves 15. It is formed on the outside of 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 partitioned by a plurality of widthwise grooves 15 and are separated from each other in the tire circumferential direction S. Width direction grooves 15 are formed between the blocks 51, and the blocks 51 are arranged at intervals in the tire circumferential direction S. Further, the block 51 has a narrow groove 52 in the width direction narrower than the groove 15 in the width direction, and a plurality of sipes 53. The widthwise groove 52 and the sipe 53 are formed along the tire width direction H.

FIG. 2 is a plan view showing blocks 31 and 41 of the present embodiment, and shows blocks 31 and 41 viewed from the outside in the radial direction of the tire. FIG. 2A shows one block 31 of the first land portion 30, and FIG. 2B shows one block 41 of the second land portion 40.
As shown in the figure, each of the block 31 of the first land portion 30 and the block 41 of the second land portion 40 has two or three widthwise sipes 20 and 21. Here, the block 31 of the first land portion 30 has two width direction sipes 20, and the block 41 of the second land portion 40 has two width direction 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 sipe 20, and the inter-sipe block 32 and the division block 33 are formed in the block 31. The inter-sipe block 32 and the division block 33 are small blocks constituting the block 31, and the block 31 has one inter-sipe block 32 and two division blocks 33. The inter-sipe block 32 is formed between two widthwise sipes 20 adjacent to the tire circumferential direction S, and is located at the center of the tire circumferential direction S of the block 31. The split blocks 33 are formed between the width direction sipes 20 and the width direction grooves 13 adjacent to the tire circumferential direction S, and are located on both sides of the tire circumferential direction S of the inter-sipe blocks 32.

The width direction sipes 20 of the block 31 are formed so as to be separated from the end wall 34 of the block 31 in the tire circumferential direction S. The end wall 34 of the block 31 is an end surface of the block 31 (groove wall of the width direction groove 13) located in the width direction groove 13, and is formed at both end portions of the block 31 in the tire circumferential direction S. The distance between the width direction sipe 20 adjacent to the tire circumferential direction S and the tire circumferential direction S of the end wall 34 is longer than the distance between the tire circumferential directions S of the two width direction sipes 20 adjacent to 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 split 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 sipe 21, and the inter-sipe block 42 and the divided block 43 are formed in the block 41. The inter-sipe block 42 and the division block 43 are small blocks constituting the block 41, and the block 41 has one inter-sipe block 42 and two division blocks 43. The inter-sipe block 42 is formed between two widthwise sipes 21 adjacent to the tire circumferential direction S, and is located at the center of the block 41 in the tire circumferential direction S. The dividing block 43 is formed between the width direction sipe 21 and the width direction groove 14 adjacent to the tire circumferential direction S, and is located on both sides of the tire circumferential direction S of the inter-sipe block 42.

The width direction sipes 21 of the block 41 are formed so as to be separated from the end wall 44 of the block 41 in the tire circumferential direction S. The end wall 44 of the block 41 is an end surface of the block 41 (groove wall of the width direction groove 14) located in the width direction groove 14, and is formed at both end portions of the block 41 in the tire circumferential direction S. The distance between the width direction sipe 21 adjacent to the tire circumferential direction S and the tire circumferential direction S of the end wall 44 is longer than the distance between the tire circumferential directions S of the two width direction sipes 21 adjacent to 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 split block 43 in the tire circumferential direction S.

The block 31 of the first land portion 30 and the block 41 of the second land portion 40 are the central portions of the tire circumferential direction S from the end walls 34 and 44 on both sides of the tire circumferential direction S when viewed from the outside in the tire radial direction, respectively. It is formed in a shape that gradually spreads on both sides in the tire width direction H toward. The blocks 31 and 41 are formed in a hexagonal shape when viewed from the outside in the tire radial direction, and project toward both sides in the tire width direction H between the end walls 34 and 44 on both sides. The width of the blocks 31 and 41 in the tire width direction H gradually increases 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 wider in the tire width direction H than the block 31 of the first land portion 30, and the maximum value of the width of the block 41 in the tire width direction H is the tire width of the block 31. It is larger than the maximum value of the width of the direction H. Further, the area of the tread surface of the block 41 is larger than the area of the tread surface of the block 31, and the volume of the block 41 is larger than the volume of the block 31. The width direction sipe 20 formed in the block 31 of the first land portion 30 is deeper in the tire radial direction than the width direction sipe 21 formed in the block 41 of the second land portion 40, and is in the tire radial direction of the width direction sipe 20. The depth of the sipe 21 in the width direction is larger than the depth in the radial direction of the tire.

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

In the second land portion 40, the width direction groove 14 is opened in the first circumferential direction main groove 10 and the second circumferential direction main groove 11, and snow easily comes out from the width direction groove 14. Therefore, the snow removal performance of the width direction groove 14 is improved, and the snow is suppressed from being clogged in the width direction groove 14. The block 41 having a plurality of width direction sipes 21 and the width direction groove 14 ensure the performance of the tire 1 on snow.

Each of the blocks 31 and 41 gradually spreads from the end walls 34 and 44 on both sides of the tire circumferential direction S toward the central portion of the tire circumferential direction S on both sides of the tire width direction H. Therefore, even if forces in various directions (for example, tire circumferential direction S, tire width direction H, and oblique direction) are applied to the blocks 31 and 41, the deformation of the blocks 31 and 41 is suppressed. As a result, wear (for example, uneven wear) of the blocks 31 and 41 is suppressed. Further, by increasing the ground contact performance of the blocks 31 and 41, the performance on ice and snow of the blocks 31 and 41 is improved. As the widthwise sipes 20 and 21 of the blocks 31 and 41 become longer, the edge components of the blocks 31 and 41 also increase.

Therefore, in the tire 1 of the present embodiment, it is possible to achieve both the performance on ice and the performance on snow of the tire 1. 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 performance on snow by the second land portion 40 can be reliably ensured. Further, the width direction sipe 20 formed in the block 31 of the first land portion 30 is deeper than the width direction sipe 21 formed in the block 41 of the second land portion 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 sipes 20 and 21 are formed in the blocks 31 and 41, the edge components of the blocks 31 and 41 are reduced, which may affect the performance on ice and the performance on snow. On the other hand, when four or more width direction sipes 20 and 21 are formed in the blocks 31 and 41, the width of the tire circumferential direction S of the inter-sipe blocks 32 and 42 in the blocks 31 and 41 or the divided blocks 33 and 43 is increased. The narrowing may affect the fracture resistance performance of the blocks 31 and 41. Therefore, it is preferable to form two or three widthwise sipes 20 and 21 in the blocks 31 and 41. As a result, the performance on ice and the performance on snow can be more reliably secured, and the defects of 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 the present embodiment, and schematically shows a part of the tire circumferential direction S of the tread portion 2.
As shown in the figure, here, the number of widthwise sipes 20 formed in one block 31 of the first land portion 30 is 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 increasing the width direction sipes 20 of the block 31 more 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 performance of the tire 1 on ice can be further improved.

Regarding the depths of the plurality of widthwise sipes 20 and 21 in one block 31 and 41 in the tire radial direction, the plurality of widthwise sipes 20 and 21 may be formed at the same depth, and the plurality of widths may be formed. Directional sipes 20 and 21 may be formed at different depths. Further, three widthwise sipes 21 may be formed in the block 41 of the second land portion 40. The configuration of the tire 1 of the present embodiment can be applied to various tires having a land portion.

1 ... Tire, 2 ... Tread part, 3 ... Tire equatorial surface, 4 ... Shoulder part, 10 ... Main groove in the first circumferential direction, 11 ... Main groove in the second circumferential direction, 12 ... Circumferential groove, 13 ... Width groove, 14 ... Width groove, 15 ... Width groove, 20 ... Width sipe, 21 ... Width sipe, 30 ... 1st land part, 31 ... block, 32 ... inter-sipe block, 33 ... split block, 34 ... end wall, 40 ... 2nd land part, 41 ... block , 42 ... Inter-sipe block, 43 ... Divided block, 44 ... End wall, 50 ... Third land, 51 ... Block, 52 ... Width narrow groove, 53 ...・ Sipe, H: tire width direction, S: tire circumference direction.

Claims (5)

Two main grooves in the first circumferential direction formed on both sides of the equatorial plane of the tire in the tire width direction, and two main grooves in the second circumferential direction formed outside each of the main grooves in the first circumferential direction in the tire width direction. It is provided with a first land portion located on the equatorial plane of the tire, which is partitioned by two first circumferential main grooves, and a second land portion, which is partitioned by a first circumferential main groove and a second circumferential main groove. It ’s a tire
The first land portion is formed in 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 in the first circumferential main groove and the circumferential narrow groove. It has a plurality of widthwise grooves and a plurality of blocks partitioned on both sides of the circumferential narrow groove in the tire width direction by a plurality of widthwise grooves.
The second land portion has a plurality of widthwise grooves opened in the first circumferential direction main groove and the second circumferential direction main groove, and a plurality of blocks partitioned by the plurality of widthwise grooves.
In the first land portion, the width direction groove on one side in the tire width direction and the width direction groove on the other side of the circumferential narrow groove are arranged alternately in the tire circumferential direction.
Each of the first land block and the second land block has a plurality of widthwise sipes formed adjacent to each other in the central portion in the tire circumferential direction, and the tire is formed from the end walls on both sides in the tire circumferential direction. A tire formed in a shape that gradually spreads on both sides in the tire width direction toward the center in the circumferential direction. In the tire according to claim 1,
A tire having two or three widthwise sipes in each of the first land block and the second land block. In the tire according to claim 1 or 2.
The block of the second land part is a tire wider in the tire width direction than the block of the first land part. In the tire according to any one of claims 1 to 3.
A tire in which the number of widthwise sipes formed in the first land block is larger than the number of widthwise sipes formed in the second land block. In the tire according to any one of claims 1 to 4.
The width direction sipe formed in the first land block is a tire deeper in the tire radial direction than the width direction sipe formed in the second land block.

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