JP2014181013A - Pneumatic tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tread pattern which improves the performance of draining from blocks and the circularity of a tire.SOLUTION: A pneumatic tire 10 includes a plurality of rib main grooves 12A to 12F formed on the tread surface 40 in the circumferential direction, two or more types of blocks 18A, 18B, 22A, 22B, 26A, and 26B which are divided by a plurality of lug grooves 16, 20, and 24 intersecting the rib main grooves obliquely and are different in circumferential length, sipings 28 which are arranged from one rib main groove to the other main groove of the blocks and in parallel with the lug grooves and divide one part of blocks of the same type with the same circumferential length at equal intervals in the circumferential direction, sipings which are arranged from one rib main groove to the other rib main groove and in parallel with the lug groove and divide the other part of blocks of the same type with the circumferential length at equal intervals in the circumferential direction, and fine grooves 30 and 36 connected to the sipings.

Description

  The present invention relates to a tread pattern of a pneumatic tire.

In the tread pattern of a pneumatic tire for the purpose of improving performance on snow, an ultra-thin groove called sipe is provided in the block, and the block is deformed at the time of ground contact and brought into contact with the road surface at a number of edges to improve steering stability. Technology has been developed. In addition, the sipe produces an effect of reducing the rigidity difference between adjacent blocks, increasing the roundness of the tire, and reducing vibration and noise during traveling.
For example, Patent Document 1 discloses a technique for providing sipes in a block.
In Patent Literature 1, a plurality of block rows in which a large number of blocks are arranged are formed in the circumferential direction on the tread surface of a winter pneumatic tire, and a plurality of sipes extending in the tire width direction are provided in each block. Describes a configuration in which a sipe is partitioned into a plurality of narrow blocks. Here, in the sipe, at least in the block section of the block row in the central region in the width direction of the tread surface, the narrow block width is made larger on the front and rear end sides in the tire circumferential direction than the intermediate position in the tire circumferential direction.

JP 2006-131097 A

However, in Patent Document 1, all blocks are partitioned by a sipe having the same groove width, and the amount of drainage is insufficient when a large amount of discharged water is required when discharging water on the road surface sucked up from the sipe. If the amount of drainage from the sipe on the icy and snowy road surface is insufficient, the steering stability will decrease. In addition, since the circumferential dimension of the narrow block defined by the sipe is different between the end portion and the center portion, the roundness of the tire is hindered, which causes generation of vibration and noise during traveling.
In view of the above facts, an object of the present invention is to provide a tread pattern that improves drainage performance by sipes and improves the roundness of a tire.

  The pneumatic tire according to the first aspect of the present invention is partitioned by a plurality of rib main grooves formed in the circumferential direction of the tread surface and a plurality of lug grooves that obliquely intersect the rib main grooves, A plurality of types of blocks having different lengths, and a part of the same type having the same circumferential length provided from one rib main groove to the other rib main groove of the plurality of types of blocks in parallel with the lug groove The sipe that divides the block at the same interval in the circumferential direction, and is provided in parallel with the lug groove from one rib main groove to the other rib main groove of the plurality of types of blocks. Are characterized by having other siblings of the same type having sipes that divide the same length in the circumferential direction and narrow grooves connected to the sipes.

According to the first aspect of the present invention, the tread surface of the pneumatic tire is provided with a plurality of rib main grooves formed in the circumferential direction and a plurality of lug grooves obliquely intersecting with the rib main grooves. A plurality of types of blocks having different sizes are partitioned. Some blocks of the same type are partitioned by sipe provided in parallel with the lug groove from one rib main groove to the other rib main groove, and other blocks of the same type are narrow grooves connected to the sipe and sipe It is divided by. Here, the narrow groove is a groove having a groove width wider than that of the sipe and equal to or smaller than the lug groove.
By partitioning the block with sipes and narrow grooves connecting to the sipes and the sipes, which have a wider groove width and larger drainage performance than the sipes, the drainage performance can be improved without reducing the rigidity of the block. Further, since the same type of blocks are partitioned in the circumferential direction at the same interval in accordance with the circumferential length of the block, the roundness of the tire can be improved, and noise and vibration during traveling can be suppressed.

According to a second aspect of the present invention, in the pneumatic tire according to the first aspect, the rib main groove has the tread surface, a central block row at a center portion in the width direction, and two end blocks at both end portions in the width direction. Partitioning into a row and two intermediate block rows between the central block row and the end block row, and the lug groove, the central block row, the end block row, the intermediate block row in the circumferential direction A large block and a small block having different lengths are partitioned, and the large block and the small block are alternately formed in the circumferential direction.
According to the invention described in claim 2, large blocks and small blocks are alternately formed in the central block row, the intermediate block row, and the end block row. Thereby, the rigidity of a block can be given periodicity, and the generation | occurrence | production of the sudden noise and vibration at the time of driving | running | working can be reduced.

According to a third aspect of the present invention, in the pneumatic tire according to the second aspect, the large block is partitioned by the two sipes or sipes and narrow grooves connected to the sipes, and the small blocks are 1 The sipe of the book, or the sipe and a narrow groove connected to the sipe are defined.
According to the invention described in claim 3, the large block is divided into three by two sipes or narrow grooves connected to the sipes and sipes, and the small block is narrow groove connected to one sipes or sipes and sipes. It is divided into two. Thereby, the difference in rigidity between the large block and the small block can be reduced, and the roundness of the tire can be improved.

According to a fourth aspect of the present invention, in the pneumatic tire according to the third aspect, the central block row includes the two large sipes in which the large block is formed with a narrow groove at one end of the sipes. The small block is defined by one sipe in which narrow grooves are formed at both ends of the sipe.
According to the fourth aspect of the present invention, the large block of the central block row is partitioned by two sipes in which a narrow groove is formed at one end of the sipes. Further, the small blocks in the central block row are partitioned by one sipe in which narrow grooves are formed at both ends of the sipe. As a result, the drainage performance of the central block row requiring high drainage performance can be enhanced.

The invention according to claim 5 is the pneumatic tire according to claim 4, wherein the two sipes that define the large block of the central block row are formed at one end of the sipes. One narrow groove is formed on each side of the rib main groove at both ends of the large block.
Thereby, it can be made to drain equally from a sipe and a narrow groove connected to a sipe to a rib main groove on both sides of a central block row from a sipe and a narrow groove, and drainage performance can be improved. This also improves steering stability.

  The invention according to claim 6 is the pneumatic tire according to any one of claims 3 to 5, wherein the intermediate block row has the large block, and a narrow groove is formed at one end of the sipe. Further, the small block is defined by one sipe in which a narrow groove is formed at one end of the sipe.

According to the sixth aspect of the present invention, the large block of the intermediate block row is partitioned by two sipes having narrow grooves formed at one end of the sipe, and the small block is one end of the sipe. It is divided by one sipe in which a narrow groove is formed.
As a result, the large block and the small block in the intermediate block row are partitioned at substantially equal intervals, the difference in rigidity between the large block and the small block block can be reduced, and the roundness of the tire can be increased. Moreover, the drainage performance of an intermediate | middle block row | line | column can be improved by arrange | positioning a narrow groove to one edge part of a sipe.

The invention according to claim 7 is the pneumatic tire according to claim 6, wherein the sipe and the narrow groove that connects the sipe that partitions the large block and the small block of the intermediate block row are The narrow grooves formed at one end are all formed on the central block row side.
Thereby, smooth drainage from the sipe to the narrow groove can be ensured, and the drainage performance of the intermediate block row can be enhanced by the sipe and the narrow groove.

The invention according to claim 8 is the pneumatic tire according to any one of claims 1 to 7, wherein the sipe or the sipe and the narrow groove connected to the sipe define the circumferential direction of the block. Is 8 to 12 mm.
As a result, the roundness of the tire can be increased while maintaining the block rigidity of the tire, and the performance on snow can be improved.

  Since the present invention is configured as described above, it is possible to provide a tread pattern that improves drainage performance by sipes and improves the roundness of the tire.

It is a front view of the tread surface which shows the tread pattern of the pneumatic tire concerning the embodiment of the present invention. (A) is a characteristic view showing the relationship between block width and block rigidity, and (B) is a side view comparing the basic configuration of a conventional pneumatic tire block and the pneumatic tire block of the present invention.

  As shown in the front view of the tread surface in FIG. 1, the tread pattern of the pneumatic tire 10 according to the embodiment of the present invention has six rib main grooves formed in the circumferential direction indicated by the arrow S of the tread surface 40. 12A to 12F are provided, and the central block row 14C at the center in the width direction indicated by the arrow H is continuously formed in the circumferential direction by the rib main groove 12C and the rib main groove 12D. The end block row 14A is continuously formed in the circumferential direction by the rib main groove 12A and the rib main groove 12B, and the end block row 14E is continuous in the circumferential direction by the rib main groove 12E and the rib main groove 12F. Is formed. The rib main groove 12B and the rib main groove 12C form the intermediate block row 14B continuously in the circumferential direction, and the rib main groove 12D and the rib main groove 12E form the intermediate block row 14D continuously in the circumferential direction. Has been.

The central block row 14C is partitioned into two types of blocks 18A and 18B having different circumferential lengths by a plurality of lug grooves 16 in a direction obliquely intersecting the rib main grooves 12C and 12D. The two types of blocks 18A and 18B are alternately arranged in the circumferential direction. The intermediate block row 14B is divided into two types of blocks 22A and 22B having different circumferential lengths by a plurality of lug grooves 20 in a direction obliquely intersecting the rib main grooves 12B and 12C. The rib main grooves 12D and 12E are partitioned into two types of blocks 22A and 22B having different circumferential lengths by a plurality of lug grooves 20 obliquely intersecting the rib main grooves 12D and 12E. The two types of blocks 22A and 22B are alternately arranged in the circumferential direction. Further, the end block row 14A is partitioned into two types of blocks 26A and 26B having different circumferential lengths by a plurality of lug grooves 24 obliquely intersecting the rib main grooves 12A and 12B. 14E is divided into two types of blocks 26A and 26B having different circumferential lengths by a plurality of lug grooves 24 in a direction obliquely intersecting the rib main grooves 12E and 12F. The two types of blocks 26A and 26B are alternately arranged in the circumferential direction.
Here, the pneumatic tire 10 is a rubber tire that is generally widely used, and the angle at which the rib main grooves 12A to 12F intersect the lug grooves 16, 20, and 24 obliquely intersect each other. It doesn't matter the angle. Further, the rib main grooves 12A to 12F and the lug grooves 16, 20, and 24 are not limited in width and depth.

The end block row 14A partitioned by the rib main grooves 12A and 12B and the end block row 14E partitioned by the rib main grooves 12E and 12F are partitioned by the lug grooves 24 into blocks 26A and 26B. The block 26A is longer in the circumferential direction than the block 26B. The block 26A includes two sipes 28 provided in parallel with the lug groove 24 from one rib main groove 12A to the other rib main groove 12B and from one rib main groove 12E to the other rib main groove 12F. It is divided by. Further, the block 26B is a single piece provided in parallel with the lug groove 24 from one rib main groove 12A to the other rib main groove 12B and from one rib main groove 12E to the other rib main groove 12F. It is partitioned by sipe 28.
That is, the larger blocks 26A are all divided by two sipes 28 with the same circumferential width, and the smaller blocks 26B are all divided by one sipe 28 with the same circumferential width. Thereby, the difference in rigidity between adjacent blocks can be reduced, and vibration and noise during traveling can be suppressed.

Here, when the sipe 28 is in contact with the road surface, the sipe 28 has such a narrow groove width that the side walls constituting the groove are in contact with each other. It is divided into two blocks of equal length. The ends of the sipe 28 are opened to the rib main grooves 12A and 12B or the rib main grooves 12E and 12F, and the water in the sipe 28 is drained to the rib main grooves 12A and 12B or the rib main grooves 12E and 12F. .
Further, when the sipe 28 divides the block 26A into three, the respective circumferential widths are within the range of 8 mm to 12 mm, and when the sipe 28 divides the block 26B into two, it is divided. The respective circumferential widths are also in the range of 8 mm to 12 mm. The groove width and depth of the sipe 28 are not limited.

The intermediate block row 14B partitioned by the rib main grooves 12B and 12C and the intermediate block row 14D partitioned by the rib main grooves 12D and 12E are partitioned by the lug groove 20 into blocks 22A and 22B. The block 22A is longer in the circumferential direction than the block 22B. The block 22A includes two sipe 30 provided in parallel with the lug groove 24 from one rib main groove 12B to the other rib main groove 12C and from one rib main groove 12D to the other rib main groove 12E. It is divided by. Further, the block 22B includes one rib main groove 12B to the other rib main groove 12C, and one rib main groove 12D to the other rib main groove 12E. It is partitioned by sipe 30.
That is, the larger blocks 22A are all partitioned by two sipes 30 with the same circumferential width, and the smaller blocks 22B are all partitioned by one sipe 30 with the same circumferential width. Thereby, the difference in rigidity between adjacent blocks can be reduced, and vibration and noise during traveling can be suppressed.

Here, the sipe 30 has a configuration in which a narrow groove 32 is provided at one end of the sipe 28 described above. The narrow grooves 32 are provided so as to be connected to the sipe 28, and are all arranged in contact with either one of the rib main grooves 12C and 12D toward the central block row 14C. The narrow groove 32 is a groove having a groove width wider than that of the sipe 28 and having the same groove width as that of the lug groove 16 or narrower than that of the lug groove 16. That is, the narrow groove 32 has a groove width that keeps the groove portion without deforming and coming into contact with the wall surface of the groove even when the surface contacts the road surface. The end of the sipe 28 is opened to the rib main groove 12B or the rib main groove 12E, and the end of the narrow groove 32 is opened to the rib main groove 12C or the rib main groove 12D. Thereby, the water in the sipe 30 is drained into the rib main grooves 12C and 12C or the rib main grooves 12D and 12E.
Further, when the sipe 30 divides the block 22A into three, the respective circumferential widths are within a range of 8 mm to 12 mm, and when the sipe 30 divides the block 22B into two, it is divided. The respective circumferential widths are also in the range of 8 mm to 12 mm. The groove width and depth of the sipe 28 and the narrow groove 32 are not limited.

The central block row 14C partitioned by the rib main grooves 12C and 12D is partitioned by the lug grooves 16 into blocks 18A and 18B. The block 18A is longer in the circumferential direction than the block 18B. The block 18A is partitioned by two sipes 30 provided in parallel with the lug groove 16 from one rib main groove 12C to the other rib main groove 12D. Further, the block 18B is partitioned by one sipe 36 provided in parallel with the lug groove 16 from one rib main groove 12C to the other rib main groove 12D.
That is, the larger blocks 18A are all divided by two sipes 30 with the same circumferential width, and the smaller blocks 18B are all divided by one sipe 36 with the same circumferential width. Thereby, the difference in rigidity between adjacent blocks can be reduced, and vibration and noise during traveling can be suppressed.

Here, the sipe 36 has a configuration in which the narrow grooves 32 are provided at both ends of the sipe 28 described above. The narrow groove 32 is provided so as to be connected to the sipe 28, and one of the rib main grooves 12C and 12D is in contact with one end thereof. The end of the narrow groove 32 is opened to the rib main groove 12C or the rib main groove 12D. Thereby, the water in the sipes 30 and 36 is drained into the rib main grooves 12C and 12D.
Further, when the sipe 30 divides the block 18A into three, the respective circumferential widths are within a range of 8 mm to 12 mm, and when the sipe 36 divides the block 18B into two, it is divided. The respective circumferential widths are also in the range of 8 mm to 12 mm. The groove width and depth of the sipe 28 and the narrow groove 32 are not limited.

FIG. 2A shows the rigidity characteristics of the blocks partitioned by sipes. The horizontal axis represents the block width (mm) partitioned by sipes, and the vertical axis represents the block rigidity ratio (stiffness ratio when 100 is not partitioned by sipes).
As shown by the characteristic G in FIG. 2A, the block rigidity rapidly decreases when the block width becomes smaller than about 8 mm. On the other hand, even if the minimum block width is larger than about 12 mm, it has a characteristic that hardly increases. That is, when the block width is smaller than about 8 mm, the block rigidity is too small and the running stability is lowered. Further, when the minimum block width is larger than about 12 mm, the difference in rigidity between the blocks is large, and noise and vibration during running increase. From these results, it can be seen that if the block width is set to an interval of 8 mm to 12 mm, the ground contact area of the tire can be increased without substantially reducing the block rigidity, and the running stability is improved.

  As shown in the conventional pneumatic tire 50 of FIG. 2 (B) and a partial side view of the pneumatic tire 10 of the present invention, the conventional tire 50 is not provided with sipes in the blocks 52A and 52B. For this reason, the rigidity difference between the blocks increases, and the roundness of the tire decreases. On the other hand, in the tire 10 of the present invention, the block 26A is divided into three by the sipe 30, and the block 26B is formed by the sipe 36. It is divided into two. For this reason, the roundness of the tire is increased, and vibration and noise during traveling can be reduced.

  Furthermore, in the central block 14C and the intermediate blocks 14B and 14D, the sipe 30 and the sipe 36 are provided with a narrow groove 30 at the end of the sipe 28 in the center part in the tire width direction. The drainage performance through the sipe 28 can be improved. Thereby, running stability increases. The rib main grooves 12C and 12D have intersections with the narrow grooves 32 in addition to the intersections with the lug grooves 16 and 20, and wide groove portions are concentrated at these intersections. ing. For this reason, when traveling on snow, a snow column is formed in a wide groove, and the snow column bites into the snow (snow column shearing force), thereby improving traveling performance.

  As described above, according to the present invention, the number of blocks divided by the sipe 28 is changed according to the size of the blocks 18A, 18B, 22A, 22B, 26A, and 26B constituting the tread pattern, and the divided blocks 18A, 18A, The width dimension in the circumferential direction of 18B, 22A, 22B, 26A, and 26B is in the range of 8 mm to 12 mm. As a result, the divided block width is in a substantially constant range regardless of the size of the blocks 18A, 18B, 22A, 22B, 26A, and 26B, and is substantially uniform in the circumferential direction. As a result, the roundness of the pneumatic tire 10 can be improved, and vibration and noise can be reduced. Further, by combining the sipe 28 and the narrow groove 32, the drainage performance of the sipe 28 can be improved, and the running stability can be increased.

  The tread pattern described with reference to FIGS. 1 and 2 has been described by taking two types of blocks 18A, 18B, 22A, 22B, 26A, and 26B having different sizes as an example. The structure which repeats 3 or more types of blocks from which it differs in the circumferential direction may be sufficient. In addition, the configuration in which two types of blocks having different sizes are repeated in the circumferential direction has been described as an example, but the present invention is not limited to this, and two types of blocks having different sizes, or three or more types of blocks in the circumferential direction. Alternatively, the configuration may be a random arrangement.

10 Pneumatic tire 12 Rib main groove 14A End block row 14B Intermediate block row 14C Central block row 14D Intermediate block row 14E End block row 16 Lug groove 18A block (large block)
18B block (small block)
20 lug groove 22A block (large block)
22B block (small block)
24 lug groove 26A block (large block)
26B block (small block)
28 sipe 30 sipe and narrow groove connected to sipe 32 narrow groove 34 sipe and narrow groove connected to sipe 36 sipe and narrow groove connected to sipe 40 tread surface S circumferential direction H width direction

Claims (8)

A plurality of types of blocks defined by a plurality of rib main grooves formed in the circumferential direction of the tread surface and a plurality of lug grooves that obliquely intersect the rib main grooves, and having different circumferential lengths;
A plurality of blocks of the same type that are provided in parallel with the lug groove from one rib main groove to the other rib main groove of the plurality of types of blocks, and have a circumferential length Sipes that are equally spaced,
Other blocks of the same type that are provided in parallel to the lug groove from one rib main groove to the other rib main groove of the plurality of types of blocks are the same in the circumferential length. A sipe that divides into spaces and a narrow groove connected to the sipe;
Pneumatic tire having The rib main groove has the tread surface, a central block row at the center in the width direction, two end block rows at both ends in the width direction, and two intermediate block rows between the center block row and the end block rows. And divided into
The lug groove divides the central block row, the end block row, and the intermediate block row into two types of large blocks and small blocks having different circumferential lengths, and the large block and the small block are: The pneumatic tire according to claim 1, wherein the pneumatic tire is alternately formed in a circumferential direction. The large block is defined by two sipes, or sipe and a narrow groove connected to the sipe, and the small block is defined by a single sipe, or sipe and a narrow groove connected to the sipe. Item 3. The pneumatic tire according to Item 2.   In the central block row, the large block is partitioned by the two sipes in which a narrow groove is formed at one end of the sipe, and the small block is formed by narrow grooves at both ends of the sipe. The pneumatic tire according to claim 3, wherein the pneumatic tire is partitioned by a single sipe.   The two sipes that divide the large block in the central block row have one narrow groove formed at one end of the sipes on the rib main groove side at both ends of the large block. The pneumatic tire according to claim 4 formed one by one.   In the intermediate block row, the large block is partitioned by the two sipes having a narrow groove formed at one end of the sipe, and the small block has a narrow groove formed at one end of the sipe. The pneumatic tire according to claim 3, wherein the pneumatic tire is partitioned by a single sipe.   The sipe and the narrow groove connecting to the sipe that define the large block and the small block in the intermediate block row are all the narrow grooves formed at one end of the sipe, on the central block row side. The pneumatic tire according to claim 6, wherein the pneumatic tire is formed.   The pneumatic tire according to any one of claims 1 to 7, wherein the sipe, or a sipe and a narrow groove connected to the sipe, have an interval that defines a circumferential direction of the block of 8 mm to 12 mm.

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