阅读说明：本技术 轮胎 (Tyre for vehicle wheels ) 是由 石原畅之 松永翠 于 2018-05-01 设计创作，主要内容包括：抑制在轮胎产生偏磨损,并且确保轮胎的冰雪上性能,兼顾耐偏磨损性能和冰雪上性能。分离花纹块(51)位于一对划分刀槽花纹(24)的轮胎周向(S)的两侧,在轮胎周向(S)上分离开地形成。台阶花纹块(52)被划分在一对划分刀槽花纹(24)之间,利用位于比分离花纹块(51)的接地面(53)靠轮胎半径方向的内侧的位置的接地面(54)相对于分离花纹块(51)形成台阶。相邻花纹块(61)在轮胎宽度方向(H)上与分离花纹块(51)和台阶花纹块(52)隔着周向槽(12)相邻,在接地时,不与台阶花纹块(52)接触而与分离花纹块(51)接触。(The separated blocks (51) are located at on both sides of the pair of divided sipes (24) in the tire circumferential direction (S) and are formed separately in the tire circumferential direction (S). The step blocks (52) are divided between the pair of divided sipes (24) in the pair, and form steps with respect to the separated blocks (51) by means of the contact surfaces (54) located on the inner side in the tire radial direction than the contact surfaces (53) of the separated blocks (51). The adjacent blocks (61) are adjacent to the separated blocks (51) and the step blocks (52) in the tire width direction (H) with the circumferential groove (12) therebetween, and when the blocks are in contact with the ground, the adjacent blocks are not in contact with the step blocks (52) but in contact with the separated blocks (51).)

1, tire, wherein the tire comprises:

pairs of dividing sipes extending in the tire width direction;

separate blocks located at both sides of pairs in the tire circumferential direction that divide the sipe, formed separately in the tire circumferential direction;

a step block divided between the pairs of divided sipes and having a step formed with respect to the divided block by a ground contact surface located inward in the tire radial direction with respect to the ground contact surface of the divided block, and

and adjacent blocks which are adjacent to the separated blocks and the step blocks in the tire width direction with the circumferential groove therebetween, and which do not contact the step blocks but contact the separated blocks when in ground contact.

2. The tire according to claim 1, wherein,

the side wall of the adjacent block on the circumferential groove side has a concave portion opposed to the side wall of the step block.

3. The tire according to claim 2, wherein,

the circumferential groove is closed between the portion of the adjacent block other than the recessed portion and the split block when the adjacent block is in contact with the ground.

4. Tire according to any of claims 1-3, wherein,

the tire is provided with sipes formed on the separated pattern blocks and the adjacent pattern blocks respectively,

all of the sipes separating the blocks and adjacent blocks are closed sipes.

5. The tire according to claim 4,

the closed sipes of adjacent blocks extend in the tire circumferential direction.

6. Tire according to any of claims 1-5, wherein,

the tire is provided with a plurality of main grooves extending in the tire circumferential direction,

the separation block, the step block, and the adjacent block are formed on the outer side in the tire width direction of the main groove located on the outermost side in the tire width direction among the plurality of main grooves.

Technical Field

The present invention relates to tires each having blocks defined by a sipe extending in the tire width direction.

Background

In a tire used on an icy or snowy road surface, a tread pattern is set according to the performance of the tire on an icy or snowy road surface (performance on ice or snow), and various blocks are formed in a tread portion, and in addition, kinds of tires have been known in the past, in which a plurality of sipes extending in the tire width direction are used to increase an edge component, thereby ensuring performance on ice or snow (see patent document 1).

However, in the conventional tire described in patent document 1, it is difficult to improve the edge effect by the sipe by , and there is room for improvement from the viewpoint of securing the performance on ice and snow by steps.

Disclosure of Invention

Problems to be solved by the invention

The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to provide a tire that can suppress uneven wear of the tire and ensure performance on ice and snow of the tire, thereby achieving both uneven wear resistance and performance on ice and snow.

Means for solving the problems

The tire of the present invention includes pairs of divisional sipes extending in a tire width direction, separated blocks located on both sides of pairs of divisional sipes in the tire circumferential direction and formed separately in the tire circumferential direction, step blocks divided between pairs of divisional sipes and forming a step with respect to the separated blocks with a ground contact surface located on an inner side in a tire radial direction than the ground contact surface of the separated blocks, and adjacent blocks adjacent to the separated blocks and the step blocks across a circumferential groove in the tire width direction and contacting the separated blocks without contacting the step blocks when in ground contact.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, uneven wear of the tire can be suppressed, and the performance on ice and snow of the tire can be ensured, and both the uneven wear resistance performance and the performance on ice and snow can be achieved.

Drawings

Fig. 1 is a plan view showing a tread pattern of a tire according to the present embodiment.

Fig. 2 is a plan view showing the 3 rd land portion and the 4 th land portion of the present embodiment.

Fig. 3 is a side view showing a part of the 3 rd land portion of the present embodiment.

Fig. 4 is a side view showing a state where the split block and the step block of the present embodiment are in contact with the ground.

Detailed Description

An embodiment of the tire of the present invention is 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, a bus, a heavy-duty tire, a passenger car tire), and is formed of a known structure by a usual tire member, that is, the tire includes pairs of bead portions, pairs of side wall portions located on the outer side in the tire radial direction of pairs of bead portions, a tread portion in contact with a road surface, and pairs of shoulder portions located between the tread portion and pairs of side wall portions, and the tire further includes pairs of bead cores, a carcass disposed between pairs of bead cores, a belt disposed 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 a tire 1 according to the present embodiment, and schematically shows a part of a tread portion 2 in a tire circumferential direction S.

As shown in the figure, the tire 1 includes a plurality of main grooves 10, 11 formed in a tread portion 2, a plurality of circumferential grooves 12, a plurality of widthwise grooves 13 to 15, a plurality of sipes 20 to 26, and a plurality of land portions 30, 40, 50, 60. When the vehicle is running, the tire 1 contacts the road surface at the plurality of land portions 30, 40, 50, 60 and rolls on the road surface. At this time, the ground surfaces of the plurality of ground contact portions 30, 40, 50, 60 contact the road surface. The contact surface is a surface on the outer side in the tire radial direction of the land portions 30, 40, 50, 60.

The plurality of main grooves 10, 11 are circumferential main grooves extending in the tire circumferential direction S, and are arranged at intervals in the tire width direction H. Here, the tire 1 includes 4 main grooves (two 1 st main grooves 10 and two 2 nd main grooves 11) formed continuously along the tire circumferential direction S. The 1 st main groove 10 is an inner main groove located on the innermost side (the tire equatorial plane 3 side) in the tire width direction H among the plurality of main grooves 10, 11, and is formed on the inner side in the tire width direction H of the 2 nd main groove 11. The tire equatorial plane 3 is located at the center portion of the tread portion 2 in the tire width direction H.

The 1 st main groove 10 is a center-side main groove located on both sides of the tire equatorial plane 3 in the tire width direction H, and is formed between the tire equatorial plane 3 and the 2 nd main groove 11 on both sides of the tire equatorial plane 3. The 2 nd main groove 11 is an outer main groove located on the outermost side (shoulder portion 4 side) in the tire width direction H among the plurality of main grooves 10 and 11, and is formed on the outer side in the tire width direction H of the 1 st main groove 10. The shoulder portion 4 is located on the outer side of the tread portion 2 in the tire width direction H. On both sides of the tire equatorial plane 3, the 2 nd main groove 11 is formed between the 1 st main groove 10 and the shoulder portion 4 on the inner side of the shoulder portion 4 in the tire width direction H.

The plurality of circumferential grooves 12 are circumferential narrow grooves (sub-grooves) that are narrower than the main grooves 10, 11 and extend in the tire circumferential direction S. Here, the tire 1 includes two circumferential grooves 12 formed continuously along the tire circumferential direction S. On both sides of the tire equatorial plane 3, the circumferential grooves 12 are located on the outer side in the tire width direction H of the 2 nd main groove 11 (on the inner side in the tire width direction H of the shoulder portion 4) and formed between the 2 nd main groove 11 and the shoulder portion 4.

The plurality of widthwise grooves 13 to 15 are lateral grooves (lug grooves) extending in the tire widthwise direction H, and are formed in the land portions 30, 40, and 60, respectively, and portions of the groove bottoms of the widthwise grooves 13 to 15 are raised portions (tie bar: reinforcing plate) raised outward in the tire radial direction and are formed shallower than the main grooves 10 and 11 and the circumferential groove 12, and the plurality of sipes 20 to 26 are slits formed in the land portions 30, 40, 50, and 60, respectively, and are formed from the contact surfaces of the land portions 30, 40, 50, and 60 toward the inside of the land portions 30, 40, 50, and 60.

The tread portion 2 of the tire 1 is divided in the tire width direction H by the plurality of main grooves 10, 11 and the circumferential groove 12, and a plurality of land portions 30, 40, 50, 60 are formed in the tread portion 2. The land portions 30, 40, 50, and 60 are convex portions protruding outward in the tire radial direction, and extend in the tire circumferential direction S along the grooves 10, 11, and 12. The land portions 30, 40, 50, 60 are arranged at intervals in the tire width direction H.

The land portions 30, 40, 50, 60 are rib-shaped land portions formed in a rib shape or block rows (intermittent land portions) having a plurality of blocks arranged in the tire circumferential direction S. Here, the tire 1 includes 7 land portions (1 of the 1 st land portion 30, two of the 2 nd land portions 40, two of the 3 rd land portions 50, and two of the 4 th land portions 60). The 1 st land portion 30, the 2 nd land portion 40, and the 4 th land portion 60 are block rows, and the 3 rd land portion 50 is a rib-shaped land portion.

The 1 st land portion 30 is a central land portion divided by the two 1 st main grooves 10, and is formed in a central region of the tread portion 2 including the tire equatorial plane 3. The tire equatorial plane 3 is located at the center portion in the tire width direction H of the 1 st land portion 30. Further, the width of the 1 st land portion 30 in the tire width direction H is wider than the widths of the other land portions 40, 50, 60 in the tire width direction H, and the 1 st land portion 30 is the widest land portion having the widest width among the plurality of land portions 30, 40, 50, 60. The 1 st land portion 30 is formed between the two 1 st main grooves 10 and is positioned inside the two 2 nd land portions 40 in the tire width direction H.

The 1 st land portion 30 has a plurality of widthwise grooves 13, a plurality of sipes 20 to 22 (divided sipes 20, 21, closed sipes 22), and a plurality of blocks 31, the plurality of widthwise grooves 13 are arranged at intervals in the tire circumferential direction S on both sides of the tire equatorial plane 3, an end of the widthwise groove 13 is opened to the 1 st main groove 10, and the other end of the widthwise groove 13 is closed in the 1 st land portion 30, the widthwise groove 13 on the side of the tire equatorial plane 3 and the widthwise groove 13 on the other side of the tire equatorial plane 3 are formed so as to be shifted in the tire circumferential direction S, the divided sipes 20, 21 are circumferential sipes extending in the tire circumferential direction S, are formed between the widthwise grooves 13 at a center portion in the tire widthwise direction H of the 1 st land portion 30, both end portions of the divided sipes 20, 21 are opened to the widthwise groove 13, and the 1 st land portion 30 is divided in the tire widthwise direction H by the plurality of divided sipes 20, 21.

The block 31 of the 1 st land portion 30 is a center block located in the center region of the tread portion 2. the two 1 st main grooves 10, the plurality of widthwise grooves 13, and the plurality of divided sipes 20 and 21 are used to divide the plurality of blocks 31 between the two 1 st main grooves 10 and form them on the 1 st land portion 30. on both sides of the tire equatorial plane 3, the plurality of blocks 31 are arranged in order in the tire circumferential direction S, the widthwise grooves 13 are formed between the blocks 31, the block 31 on the side of the tire equatorial plane 3 is formed offset from the block 31 on the other side of the tire equatorial plane 3 in the tire circumferential direction S.

The closed sipe 22 is a sipe closed in the block 31, and extends in the tire width direction H. Here, the block 31 has 1 or more closed sipes 22 as curved sipes. The closed sipe 22 is bent a plurality of times and extends in a zigzag shape in the tire width direction H. The closed sipe 22 has both ends located in the block 31 and is closed in the block 31. Both wall surfaces of the closed sipe 22 are formed in a curved shape and face each other in the block 31. In each block 31, a plurality of (4 in this case) closed sipes 22 are arranged at intervals in the tire circumferential direction S.

The 2 nd land portion 40 is an intermediate land portion divided by the 1 st main groove 10 and the 2 nd main groove 11, and is formed in an intermediate region of the tread portion 2 between the tire equatorial plane 3 and the shoulder portion 4, the 2 nd land portion 40 is formed between the 1 st main groove 10 and the 2 nd main groove 11 and between the 1 st land portion 30 and the 3 rd land portion 50 on both sides of the tire equatorial plane 3, the 2 nd land portion 40 has a plurality of widthwise grooves 14, a plurality of sipes (closed sipes) 23, and a plurality of blocks 41, the plurality of widthwise grooves 14 are formed between the 1 st main groove 10 and the 2 nd main groove 11, and are arranged at intervals in the tire circumferential direction S, an end portion and another end portion of the widthwise grooves 14 open to the 1 st main groove 10 and the 2 nd main groove 11, respectively, the plurality of widthwise grooves 14 cross the 2 nd land portion 40 in the tire widthwise direction H, and cut the 2 nd land portion 40 in the tire circumferential direction S.

The block 41 of the 2 nd land portion 40 is a middle block located in a middle region of the tread portion 2. The 1 st main groove 10, the 2 nd main groove 11, and the plurality of widthwise grooves 14 define a plurality of blocks 41 between the 1 st main groove 10 and the 2 nd main groove 11, and are formed in the 2 nd land portion 40. On both sides of the tire equatorial plane 3, a plurality of blocks 41 are arranged in order in the tire circumferential direction S, and the widthwise grooves 14 are formed between the blocks 41.

The closed sipe 23 is a sipe closed in the block 41, and extends in the tire width direction H. Here, the block 41 has 1 or more closed sipes 23 as curved sipes. The closed sipe 23 is bent a plurality of times and extends in a zigzag shape in the tire width direction H. The closed sipe 23 has both ends located in the block 41 and is closed in the block 41. Both wall surfaces of the closed sipe 23 are formed in a curved shape and face each other in the block 41. In each block 41, a plurality of (4 in this case) closed sipes 23 are arranged at intervals in the tire circumferential direction S.

The 3 rd land portion 50 is an outer land portion defined by the 2 nd main groove 11 and the circumferential groove 12, and is formed in an outer region (a region on the shoulder portion 4 side) of the tread portion 2 in the tire width direction H. On both sides of the tire equatorial plane 3, the 3 rd land portion 50 is formed between the 2 nd main groove 11 and the circumferential groove 12, between the 2 nd land portion 40 and the 4 th land portion 60. In addition, the 3 rd land portion 50 has a plurality of sipes 24, 25 (divided sipe 24, closed sipe 25) and a plurality of blocks 51, 52.

The divisional sipes 24 are width-direction sipes extending in the tire width direction H and formed between the 2 nd main groove 11 and the circumferential groove 12, the end portion and the other end portion of the divisional sipe 24 open to the 2 nd main groove 11 and the circumferential groove 12, respectively, the plurality of divisional sipes 24 are crossing sipes crossing the 3 rd land portion 50 in the tire width direction H and arranged at intervals in the tire circumferential direction S, and the 3 rd land portion 50 is divided in the tire circumferential direction S by the plurality of divisional sipes 24.

The blocks 51, 52 of the land portion 3 are outer blocks located in an outer region of the tread portion 2. the blocks 51, 52 are divided between the main groove 11 and the circumferential groove 12 by the main groove 11, the circumferential groove 12, and the divided sipes 24 to be formed in the land portion 3, the blocks 52 are sequentially arranged in the tire circumferential direction S on both sides of the tire equatorial plane 3, the divided sipes 24 are formed between the block 51 and the other block 52, and the block 51 and the other block 52 are formed in different shapes from each other.

The closed sipe 25 is a sipe which is closed in an block 51 and extends in the tire width direction H, here, the block 51 has 1 or more closed sipes 25 which are curved sipes, the closed sipe 25 is bent a plurality of times and extends in a zigzag shape in the tire width direction H, both end portions of the closed sipe 25 are located in the block 51 and are closed in the block 51, both wall surfaces of the closed sipe 25 are formed in a curved shape and are opposed in the block 51, and in each block 51, a plurality of (here, 4) closed sipes 25 are arranged at intervals in the tire circumferential direction S.

The 4 th land portion 60 is an outer land portion divided by the circumferential groove 12, and is formed in an outer region in the tire width direction H of the tread portion 2 from the 3 rd land portion 50 , the 4 th land portion 60 is an outermost land portion (shoulder portion 4 side land portion) located on an outermost side (shoulder portion 4 side) in the tire width direction H among the plurality of land portions 30, 40, 50, 60, the 4 th land portion 60 is formed on both sides of the tire equatorial plane 3, the 4 th land portion 60 is formed on an outer side in the tire width direction H of the circumferential groove 12, and is located on an outer side in the tire width direction H of the 3 rd land portion 50, the circumferential groove 12 is formed between the 3 rd land portion 50 and the 4 th land portion 60, and the 3 rd land portion 50 and the 4 th land portion 60 are adjacent to each other with the circumferential groove 12 therebetween in the tire width direction H.

The 4 th land portion 60 has a plurality of width direction grooves 15, a plurality of sipes (closed sipes) 26, and a plurality of blocks 61, the plurality of width direction grooves 15 are formed outside the circumferential groove 12 in the tire width direction H and arranged at intervals in the tire circumferential direction S, an end portion and another end portion of the width direction grooves 15 open to the circumferential groove 12 and the outside portion of the tread portion 2, respectively, the plurality of width direction grooves 15 cross the 4 th land portion 60 in the tire width direction H to cut the 4 th land portion 60 in the tire circumferential direction S.

The blocks 61 of the 4 th land portion 60 are outer blocks located in the outer region of the tread portion 2. The block 61 is an outermost block (shoulder portion 4 side block) located on the outermost side (shoulder portion 4 side) in the tire width direction H among the plurality of blocks 31, 41, 51, 52, 61. The circumferential groove 12 and the plurality of widthwise grooves 15 define a plurality of blocks 61 outside the circumferential groove 12 in the tire widthwise direction H, and these blocks are formed in the 4 th land portion 60. On both sides of the tire equatorial plane 3, a plurality of blocks 61 are arranged in order in the tire circumferential direction S, and the widthwise grooves 15 are formed between the blocks 61.

The closed sipe 26 is a sipe closed in the block 61, and extends in the tire circumferential direction S. Here, the block 61 has 1 or more closed sipes 26 as curved sipes. The closed sipe 26 is bent a plurality of times and extends in a zigzag shape in the tire circumferential direction S. Both ends of the closed sipe 26 are located in the block 61, and are closed in the block 61. Both wall surfaces of the closed sipe 26 are formed in a curved shape and face each other in the block 61. In each block 61, 1 closed sipe 26 is formed in the center portion of the block 61 in the tire width direction H.

Fig. 2 is a plan view showing the 3 rd land portion 50 and the 4 th land portion 60 of the present embodiment, and shows a part of fig. 1 in an enlarged manner, and fig. 3 is a side view showing a part of the 3 rd land portion 50 of the present embodiment, and schematically shows a case where the 3 rd land portion 50 is viewed from the side (inside or outside) in the tire width direction H.

As shown in the figure, 2 types of blocks 51 and 52 (split block 51 and step block 52) are formed in the 3 rd land portion 50, and 1 type of block (adjacent block) 61 is formed in the 4 th land portion 60.

The tire 1 includes pairs of divisional sipes 24 formed in the 3 rd land portion 50, separated blocks 51 separated from each other in the tire circumferential direction S, a step block 52 forming a step with respect to the separated block 51, an adjacent block 61 adjacent to the separated block 51 and the step block 52, and sipes 25, 26 formed respectively in the separated block 51 and the adjacent block 61, the divisional sipe 24 being a straight-blade groove extending straight and formed between the separated block 51 and the step block 52, both wall surfaces of the divisional sipe 24 being formed in a planar shape opposing in the tire circumferential direction S.

The separation block 51, the step block 52, and the adjacent block 61 are formed outside the tire width direction H of the main groove (2 nd main groove 11) located on the outermost side in the tire width direction H among the plurality of main grooves 10, 11. In addition, the adjacent block 61 is formed on the outer side in the tire width direction H of the separation block 51 and the step block 52. The separation block 51 and the adjacent block 61 are formed offset in the tire circumferential direction S. The circumferential groove 12 is formed between the separation block 51 and the adjacent block 61 and between the step block 52 and the adjacent block 61. As the intra-block sipe, only the closed sipes 25, 26 are formed in the separated block 51 and the adjacent block 61.

The pair of divisional sipes 24 are a combination of sipe pairs (double sipes) formed at a plurality of locations in the tire circumferential direction S of the 3 rd land portion 50 at intervals in the tire circumferential direction S, the pair of divisional sipes 24 are formed in parallel between two ( pairs) of split blocks 51 at each formation location, being adjacent in the tire circumferential direction S, the two split blocks 51 are located on both sides of the pair of divisional sipes 24 (double sipes) in the tire circumferential direction S, being formed separately from each other in the tire circumferential direction S, and the step block 52 is divided between pairs of divisional sipes 24, being formed between the two split blocks 51 located on both sides of the tire circumferential direction S.

The dimension (length) of the separation block 51 in the tire circumferential direction S is larger than the dimension (width) of the separation block 51 in the tire width direction H. Thus, the separation blocks 51 are circumferential blocks that are longer in the tire circumferential direction S than in the tire width direction H. In contrast, the dimension (length) of the step blocks 52 in the tire width direction H is larger than the dimension (width) of the step blocks 52 in the tire circumferential direction S. Thus, the step blocks 52 are width direction blocks that are longer in the tire width direction H than in the tire circumferential direction S. In addition, the dimension (width) of the step block 52 in the tire circumferential direction S is smaller than the dimension (length) of the separated block 51 in the tire circumferential direction S and the dimension (width) of the separated block 51 in the tire width direction H. The step blocks 52 are formed thinner than the separation blocks 51 when viewed in the tire circumferential direction S. As described above, the step block 52 is a small block smaller than the split block 51, and is a plate-shaped block formed in a plate shape.

The two separation blocks 51 and the 1 step block 52 form 1 block group, in the 3 rd land portion 50 (refer to fig. 1), the separation blocks 51 and the step blocks 52 are alternately arranged along the tire circumferential direction S, therefore, the separation blocks 51 form block groups with the step block 52 and the separation block 51 located on the side in the tire circumferential direction S, respectively, and form block groups with the step block 52 and the separation block 51 located on the other side in the tire circumferential direction S, the plurality of block groups are arranged in order along the tire circumferential direction S in a state where the separation blocks 51 are overlapped.

In the 3 rd land portion 50, the step block 52 is divided by pairs of the divisional sipes 24, and is formed in a block shape between pairs of the divisional sipes 24, the separation block 51 is divided by the divisional sipes 24 on both sides in the tire circumferential direction S, and is formed in a block shape between the divisional sipes 24 on both sides in the tire circumferential direction S, further, the separation block 51 is formed between two step blocks 52 (the step blocks 52 on both sides in the tire circumferential direction S), in each block group, pairs of the divisional sipes 24 and the step blocks 52 are formed between two separation blocks 51 (the separation blocks 51 on both sides in the tire circumferential direction S), the separation block 51 and the step block 52 are formed in a state of being separated from each other by the divisional sipes 24, opposing each other with the divisional sipes 24 therebetween.

The split block 51, the step block 52, and the adjacent block 61 (see fig. 2) have respective ground contact surfaces 53, 54, 62 that contact the road surface when the tire 1 rolls (when the vehicle travels), the split block 51 and the adjacent block 61 are formed so that the heights of the ground contact surfaces 53, 62 are equal to each other, the height of the ground contact surface 54 of the step block 52 is lower than the height of the ground contact surface 53 of the split block 51 and the height of the ground contact surface 62 of the adjacent block 61, the step block 52 is formed so as to be lower than the split block 51 and the adjacent block 61 (see fig. 3), the plurality of split blocks 51 of the 3 rd land portion 50 and the plurality of adjacent blocks 61 of the 4 th land portion 60 are arranged with being shifted from each other by half pitch in the tire circumferential direction S, and the center portions of the step block 52 and the adjacent blocks 61 in the tire circumferential direction S are adjacent in the tire width direction H.

When comparing the heights in the tire radial direction K (see fig. 3), the separation block 51 is a high block higher than the step block 52, and the step block 52 is a low block lower than the separation block 51. The contact surface 54 of the step block 52 is located inward in the tire radial direction K from the contact surfaces 53 of the block 51 on both sides in the tire circumferential direction S. The step block 52 forms a step 55 with the split blocks 51 on both sides of the ground contact surface 54 with respect to the tire circumferential direction S. The step 55 is a stepped portion formed between the ground surface 53 of the separation block 51 and the ground surface 54 of the step block 52. The step 55 is formed to be lower from the contact surface 53 of the block 51 toward the contact surface 54 of the block 52 and to be inward in the tire radial direction K. The step 55 forms a portion of the step block 52 between the two split blocks 51 in a concave shape on the ground contact surfaces 53 and 54.

The adjacent block 61 (see fig. 2) is adjacent to two separated blocks 51 and 1 step block 52 across the circumferential groove 12 in the tire width direction H, a side wall 63 on the circumferential groove 12 side of the adjacent block 61 is opposed to the side walls 56 on the circumferential groove 12 side of the two separated blocks 51 and the side wall 57 on the circumferential groove 12 side of the step block 52, the side walls 56, 57, 63 protrude from the groove bottom of the circumferential groove 12 to the outside in the tire radial direction K and are located inside the circumferential groove 12, the adjacent block 61 has a concave portion 64 formed in the side wall 63, and the concave portion 64 of the adjacent block 61 is formed in a position where the side wall 63 is opposed to an end portion (opening portion) on the circumferential groove 12 side of the partitioning pattern 24 from the side walls 57 and of the step block 52.

The concave portion 64 of the adjacent block 61 is formed along the side walls 57 and of the step block 52 to partition the end of the sipe 24, opposite the side walls 57 and of the step block 52 to partition the end of the sipe 24. here, the concave portion 64 of the adjacent block 61 is formed along the tire radial direction K, opposite the entirety of the side walls 57 of the step block 52 and the entirety of the to partition the end of the sipe 24. the concave portion 64 of the adjacent block 61 is formed to a position opposite the side walls 56 of the two split blocks 51 beyond the position of to partition the end of the sipe 24. further, the concave portion 64 of the adjacent block 61 is formed at a position where the side walls 63 cover the ends of the side walls 57 and of the step block 52 to partition the sipe 24, and is adjacent to the ends of the side walls 57 and of the step block 52 to partition the sipe 24 in the tire width direction H (here, outside the tire width direction H).

The groove width of the circumferential groove 12 at the recessed portion 64 is larger than the groove width of the circumferential groove 12 at other portions, and the circumferential groove 12 is locally widened at the recessed portion 64. When the adjacent block 61 is in contact with the ground, the circumferential groove 12 is closed between the portion of the adjacent block 61 other than the recessed portion 64 and the split block 51, and is not closed between the adjacent block 61 and the step block 52 due to the recessed portion 64.

Specifically, when the adjacent block 61, the separated block 51, and the step block 52 are in contact with the ground, the side wall 63 of the adjacent block 61 is in contact with the side wall 56 of the separated block 51 except for the position of the concave portion 64, and the circumferential groove 12 is closed at the contact portion of the side walls 63, 56, at the position of the concave portion 64, the side wall 63 of the adjacent block 61 is not in contact with the side wall 57 of the step block 52, and a void is formed between the adjacent block 61 and the step block 52 by the concave portion 64, the void extending in the tire radial direction K is formed in the range of the entirety of the side wall 57 of the step block 52 and the entirety of the pair of side walls that partition the end portion of the.

The adjacent block 61 is not in contact with the step block 52 but in contact with the separation block 51 when contacting the ground (when contacting the road surface). Therefore, the adjacent block 61 and the separated block 51 support each other when contacting the ground. The adjacent blocks 61 support the split blocks 51, and deformation of the split blocks 51 is suppressed. This increases the rigidity of the block 51, and suppresses uneven wear (for example, zigzag wear) from occurring in the block 51 and the land portion 3. At the same time, the adjacent blocks 61 are supported by the split blocks 51, suppressing deformation of the adjacent blocks 61. This increases the rigidity of the adjacent block 61, and suppresses uneven wear from occurring in the adjacent block 61 and the 4 th land portion 60. In addition, the step block 52 is deformed between the two separation blocks 51, improving the edge effect of the separation blocks 51.

Fig. 4 is a side view showing a state where the split block 51 and the step block 52 of the present embodiment are in contact with the ground, and schematically shows a case where two split blocks 51 and 1 step block 52 are viewed from the side (inner side or outer side) in the tire width direction H.

As shown in the drawing, when the vehicle travels, the tire 1 rotates in the tire rotation direction R, and the separation block 51 and the step block 52 come into contact with the road surface G. Thereby, the contact surface 53 of the separation block 51 and the contact surface 54 of the step block 52 are pressed against the road surface G, and the separation block 51 and the step block 52 are deformed, respectively.

The separation blocks 51 are deformed at both sides of the step block 52 in the tire circumferential direction S so as to protrude toward the step block 52. The step block 52 is sandwiched between the two split blocks 51, and is deformed so as to extend outward in the tire radial direction K. At this time, due to the step 55 between the separation block 51 and the step block 52, the step block 52 is pressed against the road surface G in an expanded state, compressed toward the inner side in the tire radial direction K. Thereby, the step block 52 is deformed in a buckling manner between the two separation blocks 51. In addition, the adjacent block 61 does not contact the step block 52, and therefore the step block 52 is not restrained by the adjacent block 61 and is smoothly deformed.

As the step block 52 is deformed, the step block 52 comes into contact with the separation block 51, and the separation block 51 is pressed by the step block 52 (see arrow P). The step block 52 presses the separation block 51A located on the rear side in the tire rotation direction R (the front side in the traveling direction of the vehicle) diagonally upward, and applies a force (moment) in the direction of pressing the separation block 51A against the road surface G (see arrow M). Thereby, the peripheral portion of the edge 58 of the block 51A is pressed against the road surface G, and the edge pressure of the edge 58 is increased. The edge 58 is an edge of the block 51A located on the front side in the tire rotation direction R (the rear side in the vehicle traveling direction), and is a leading end of the contact surface 53 of the block 51A. By increasing the edge pressure, the edge effect of the separation block 51A is improved, and the performance on ice and snow of the tire 1 is improved.

As described above, in the tire 1 of the present embodiment, uneven wear of the tire 1 can be suppressed, and the performance on ice and snow of the tire 1 can be ensured, and both of the uneven wear resistance performance and the performance on ice and snow can be achieved at the same time, and further, the contact between the adjacent block 61 and the step block 52 can be reliably prevented by the concave portion 64 of the adjacent block 61, and the step block 52 can be more smoothly deformed, and when the tire 1 rolls on an ice and snow road surface, snow in the concave portion 64 exhibits a snow column shear force, and the performance on ice and snow of the tire 1 is further improved .

The circumferential groove 12 is closed between the adjacent block 61 and the separated block 51, thereby firmly supporting the adjacent block 61 and the separated block 51 to each other, and as a result, the rigidity of the adjacent block 61 and the rigidity of the separated block 51 can be further increased all the sipes of the separated block 51 and the adjacent block 61 are closed sipes 25, 26, and therefore, the rigidity of the separated block 51 and the rigidity of the adjacent block 61 can be maintained, and the edge component and the on-ice and snow performance of the tire 1 can be ensured.

The closed sipes 26 of the adjacent blocks 61 extend in the tire circumferential direction S. Therefore, the edge component of the adjacent blocks 61 in the tire circumferential direction S can be increased, and the anti-spin performance of the tire 1 can be improved. When a force in the tire width direction H is applied to the adjacent blocks 61, the edge in the tire circumferential direction S contacts the road surface G, thereby ensuring the on-ice and snow performance of the tire 1.

Partial wear is more likely to occur in the portion of the tread portion 2 on the shoulder portion 4 side than in other portions. Since the split blocks 51, the step blocks 52, and the adjacent blocks 61 are formed on the outer side in the tire width direction H of the 2 nd main groove 11 located on the outermost side in the tire width direction H, the rigidity of the outer portion in the tire width direction H of the tread portion 2 can be improved. This can suppress the occurrence of uneven wear in the shoulder portion 4 side portion of the tread portion 2.

The closed sipe 25 of the separating block 51 and the closed sipe 26 of the adjacent block 61 are curved sipes. Therefore, when the separated block 51 and the adjacent block 61 contact the ground, both wall surfaces of the closed sipes 25, 26 are firmly supported by each other. This can suppress deformation of the split block 51 and the adjacent block 61, and can maintain the rigidity of the split block 51 and the rigidity of the adjacent block 61. An edge (circumferential edge) extending in the tire circumferential direction S is formed in the adjacent block 61 by the closed sipe 26 extending in the tire circumferential direction S. When a lateral force (lateral force) acts on the tire 1, since the circumferential edges of the adjacent blocks 61 extend in a direction perpendicular to the orientation of the lateral force, an edge effect with respect to the lateral force can be effectively obtained. Therefore, the rigidity of the adjacent blocks 61 can be improved while ensuring the on-ice/snow performance of the tire 1, and the uneven wear resistance and the on-ice/snow performance can be more reliably achieved at the same time.

In addition, 1 closed sipe 25 may be formed in the separation block 51, or a plurality of closed sipes 25 may be formed in the separation block 51. In addition, 1 closed sipe 26 may be formed in the adjacent block 61, or a plurality of closed sipes 26 may be formed in the adjacent block 61. The closed sipes 25 and 26 may be straight sipes that extend straight in the blocks 51 and 61.

The split block 51 and the step block 52 may be formed in the 4 th land portion 60 and the adjacent block 61 may be formed in the 3 rd land portion 50, the split block 51, the step block 52, and the adjacent block 61 may be formed in a land portion other than the 3 rd land portion 50 and the 4 th land portion 60, the split block 51, the step block 52, and the adjacent block 61 may be formed in a land portion adjacent in the tire width direction H with the circumferential groove 12 interposed therebetween, the adjacent block 61 may be adjacent to the split block 51 and the step block 52 on the side (for example, the inner side or the outer side) in the tire width direction H, or the adjacent block 61 may be adjacent to the split block 51 and the step block 52 on both sides in the tire width direction H.

The land portions forming the separation blocks 51 and the step blocks 52 may be rib-shaped land portions or block rows. The block row has a plurality of blocks (array blocks) arranged at intervals in the tire circumferential direction S. When the land portion is a block row, the separation block 51 and the step block 52 are formed as an array block of the block row. In this case, the separation block 51 and the step block 52 are sub blocks constituting part of the array blocks, and a block group is formed in the array blocks. The 1 block group is formed as 1 array block, or a plurality of block groups are formed as 1 array block. The plurality of arranged blocks of the block array respectively have more than 1 block group.

Description of the reference numerals

1 … tire, 2 … tread portion, 3 … tire equatorial plane, 4 … shoulder portion, 10 … 1 st main groove, 11 … 2 nd main groove, 12 … circumferential groove, 13 … widthwise groove, 14 … widthwise groove, 15 … widthwise groove, 20 … divided sipe, 21 … divided sipe, 22 … closed sipe, 23 … closed sipe, 24 … divided sipe, 25 … closed sipe, 26 … closed sipe, 30 … 1 st land portion, 31 … block, 40 … 2 nd land portion, 41 … block, 50 … 3 rd land portion, 51 … divided block, 52 … step 3653, 53 … ground contact surface, 54 …, 55 … step, 56 … side wall, 57 … side wall, 58 … edge, 60 … th land portion, 61 … adjacent block, 62 … ground contact surface, … side wall, 3664, … G …, … H road surface width of tire, k … tire radial direction, R … tire rotational direction, S … tire circumferential direction.