JP2010126076A - Tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tire having two different performances in higher level, the one being on snow-and-ice control performance and the other being on dry-road control performance, in the case of sipes being formed on the land part of blocks shapes. <P>SOLUTION: The tire 1 is equipped with: circumferential direction grooves 10 that extend along the tire peripheral direction R; horizontal grooves 20 that extend in the direction crossing the circumferential direction grooves 10; and a land part 30 of blocks defined by the circumferential direction grooves 10 and horizontal grooves 20, while a plurality of sipes are formed on the land part 30, whereas in a plane vision of the tread surface of the tire, the sipes found include first sipes 40 having an angle of plus side formed by a line extended from one end of the sipe to the direction in which the sipe is directed, and a line toward the width of the tread, and second sipes 50 having an angle of minus side formed by a line extended from one end of the sipe to the direction in which the sipe is directed, and a line toward the width of the tread, while the first sipes 40 and the second sipes 50 are so formed as to be adjacent to each other along the tire circumferential direction R. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a tire in which a plurality of sipes are formed in a land portion.

  Conventionally, in tires mounted on vehicles such as automobiles, in order to improve the performance on snow and ice, a large number of sipes extending in the tire width direction are formed on the block-shaped land portion provided on the tread, and A method of increasing the depth is widely used.

In such a tire, the snow column shearing force acting on the snow entering the sipe and the edge effect (digging frictional force) acting on the edge of the sipe or tread pattern cause the performance on snow and ice, specifically the braking force on icy and snowy roads. And traction are improved (for example, Patent Document 1).
Japanese Patent No. 3964693 (page 3-4, Fig. 1)

  However, the conventional sipe described above has the following problems. That is, if a large number of sipe extending in the tire width direction is formed on the block-shaped land portion or the depth of the sipe is increased, the performance on snow and ice against stress along the tire circumferential direction R is improved, There is a problem that the edge effect cannot be obtained with respect to a driving force or a lateral force such as a side slip, and the performance on snow and ice is lowered.

  Since the sipe extending in the tire width direction is formed on the land, the rigidity of the land (block stiffness) is reduced and the initial response to the lateral force such as front and rear driving force and side-sliding on dry road surfaces. There is a problem that the performance on the dry road such as performance and braking performance deteriorates.

  Therefore, an object of the present invention is to provide a tire in which the performance on snow and ice and the performance on a dry road are balanced at a higher level when a sipe is formed in a block-shaped land portion.

In order to solve the above-described problems, the present invention has the following features. First, the first feature of the present invention is that a circumferential groove (for example, circumferential groove 10) extending along the tire circumferential direction (tire circumferential direction R) and a lateral groove extending along a direction intersecting the circumferential groove ( For example, a tire including a lateral groove 20) and a block-shaped land portion (land portion 30) defined by the circumferential groove and the lateral groove, and a plurality of sipes (for example, the first sipes 40) formed in the land portion ( In the pneumatic tire 1), in the tire tread surface view, the sipe is a first sipe in which an angle (θ ₄₀ ) formed by a direction from the one end of the sipe toward the tread width direction is a plus side angle. , And a second sipe (second sipe 50) in which the angle formed by the direction of the sipe from one end of the sipe with respect to the tread width direction is a negative side angle opposite to the positive side. What is sipe Along the tire circumferential direction (the tire circumferential direction R), and subject matter to be formed adjacent.
According to such a tire, in the tread surface view, the angle formed by the direction of the sipe from one end of the sipe with respect to the tread width direction is opposite to the first sipe, which is a plus side angle, and the plus side angle. Since the second sipe with an angle on the minus side is alternately provided along the tire circumferential direction, it is applied to stress having a direction other than the tire circumferential direction, such as a lateral force along the tread width direction during a side slip. In the first sipe or the second sipe, an edge effect acting on the edge of the tread pattern can be obtained, and the performance on snow and ice can be ensured.

  Also on the dry road surface, the tread pattern is the same in the first sipe or the second sipe against stress having a direction other than the tire circumferential direction such as a lateral force along the tread width direction during a side slip. It can suppress falling in the direction, and can ensure the performance on the dry road.

  Therefore, the tire can achieve both higher performance on snow and ice and higher performance on the dry road.

  The second feature of the present invention relates to the first feature of the present invention, wherein the first sipe is formed at substantially the center of the groove bottom in the first longitudinal direction (longitudinal direction LD40) which is the longitudinal direction of the first sipe. The second sipe is formed at both ends of the groove bottom (groove bottom portion 56) in the second longitudinal direction (longitudinal direction LD50) which is the longitudinal direction of the second sipe. And a pair of second convex portions (the convex portion 52 and the convex portion 54).

  The third feature of the present invention relates to the first or second feature of the present invention, and is summarized in that at least a part of the sipe is linearly formed in the tread surface view.

  A fourth feature of the present invention relates to any one of the first to third features of the present invention, and is characterized in that a second sipe is formed at the end of the land portion along the tire circumferential direction. To do.

  A fifth feature of the present invention relates to any one of the first to fourth features of the present invention. When viewed from the tread surface, the sipe includes a plurality of first sipes and a plurality of second sipes. The first sipe is formed substantially parallel to each other, and the plurality of second sipes are formed substantially parallel to each other.

  A sixth feature of the present invention relates to any one of the first to fifth features of the present invention, in the first sipe, with respect to the tread width direction, the magnitude of the angle formed by the direction of the sipe from one end of the sipe, The gist of the second sipe is that the magnitude of the angle formed by the sipe from one end of the sipe with respect to the tread width direction is substantially the same.

  A seventh feature of the present invention is related to the second feature of the present invention, wherein the first convex portion is approximately 1 / of the length of the first sipe in the first longitudinal direction including the center of the first sipe. The gist is that it is formed in three regions.

  According to the characteristics of the present invention, when a sipe is formed in a block-shaped land portion, it is possible to provide a tire in which the performance on snow and ice and the performance on a dry road are balanced at a higher level.

  Next, embodiments according to the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic and ratios of dimensions are different from actual ones.

  Accordingly, specific dimensions and the like should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

[Embodiment]
In this embodiment, (1) tire configuration, (2) detailed configuration of sipe, (3) comparative evaluation, (4) action and effect, and (5) other embodiments will be described.

(1) Configuration of Tire FIG. 1 is a partially enlarged view of a development view of a tread constituting the pneumatic tire 1 in the embodiment of the present invention. The pneumatic tire 1 includes a circumferential groove, a lateral groove, a land portion, and a sipe.

  Each part formed in the tread in the pneumatic tire 1 will be described. Specifically, (1.1) circumferential groove, (1.2) lateral groove, (1.3) land portion, and (1.4) sipe will be described.

(1.1) Circumferential groove The pneumatic tire 1 includes a circumferential groove extending along the tire circumferential direction R. Specifically, the pneumatic tire 1 includes a circumferential groove 10 and a circumferential groove 12.

(1.2) Lateral groove The pneumatic tire 1 includes a lateral groove extending along a direction intersecting the circumferential groove. Specifically, the pneumatic tire 1 includes a lateral groove 20 and a lateral groove 22 that extend along a direction intersecting the circumferential groove 10 and the circumferential groove 12.

Transverse grooves 20 and transverse grooves 22, with respect to the tread width direction W _TR, along a straight line at a predetermined angle, extends. The lateral groove 20 and the lateral groove 22 are provided so as to be positioned in parallel to each other.

(1.3) Land portion The pneumatic tire 1 includes a block-shaped land portion 30 partitioned by a circumferential groove and a lateral groove. Specifically, the land portion 30 is partitioned by the circumferential groove 10, the circumferential groove 12, the lateral groove 20, and the lateral groove 22.

(1.4) Sipe
A plurality of sipes are formed in the land portion of the pneumatic tire 1. The sipe in the present embodiment is formed in a straight line in the tread surface view.

  Specifically, the sipe includes a plurality of first sipes 40 and a plurality of second sipes 50. The first sipe 40 and the second sipe 50 are formed adjacent to each other along the tire circumferential direction R. Further, the plurality of first sipes 40 are formed substantially in parallel along the tire circumferential direction R. The plurality of second sipes 50 are formed substantially in parallel along the tire circumferential direction R.

(2) Detailed configuration of sipe The detailed configuration of the sipe formed in the land portion 30 will be described. Specifically, detailed configurations of (2.1) the first sipe and (2.2) the second sipe will be described with reference to FIGS.

  FIG. 2 is a perspective view showing cross-sectional shapes of the land portion 30, the first sipe 40, and the second sipe 50 in the tread constituting the pneumatic tire 1. FIG. 3 is a cross-sectional view taken along line A-A ′ of the first sipe 40 shown in FIG. 1. FIG. 4 is a B-B ′ cross-sectional view of the second sipe 50 shown in FIG. 1.

(2.1) First sipe
As shown in FIG. 1, the first sipe 40, in a tread surface view of the pneumatic tire 1, with respect to the tread width direction W _TR, the angle formed from one end of the first sipe 40 of the direction in which the first sipes 40 toward the plus side It becomes the angle of. Angle Specifically, first sipes 40, which forms the tread surface view of the pneumatic tire 1, based on the straight line S1 along the tread width direction W _TR, the direction in which the first sipe 40 is directed, and the straight line S1 θ ₄₀ is not less than 15 ° and not more than 55 °. The first sipes 40 are positioned in parallel to the lateral grooves 20 and the lateral grooves 22. The first sipe 40 communicates with the circumferential groove 10 at one end and the circumferential groove 12 at the other end.

  Here, the direction from the one end of the first sipe 40 toward the first sipe 40 is from one end of the first sipe 40 communicating with the circumferential groove 10 to the other end of the first sipe 40 communicating with the circumferential groove 12. Indicates the direction to go. Accordingly, when the first sipe 40 is formed in a zigzag shape or a wave shape instead of a straight line, for example, the first sipe 40 extends from one end of the first sipe 40 toward the other end. The direction to go.

  As shown in FIGS. 2 and 3, the first sipe 40 has a convex portion 42 formed substantially at the center of the groove bottom in the longitudinal direction LD 40 that is the longitudinal direction of the first sipe 40, and a convex portion 42 in the longitudinal direction LD 40. A groove bottom portion 44 and a groove bottom portion 46 formed at both ends of the shape portion 42 and having a groove depth shallower than the circumferential groove 10 and the circumferential groove 12 are included.

  The groove depth D42 of the convex portion 42 is shallower than the groove depth D10 of the circumferential groove 10, the groove depth D44 of the groove bottom portion 44, and the groove depth D46 of the groove bottom portion 46. Specifically, the groove depth D42 of the convex portion 42 is 20% or more and 60% or less of the length of the groove depth D10 of the circumferential groove 10. The groove depth D42 of the convex portion 42 indicates the distance from the surface of the convex portion 42 to the road surface G.

  Further, the groove depth D 46 of the groove bottom 46 and the groove depth D 44 of the groove bottom 44 are shallower than the groove depth D 10 of the circumferential groove 10. Specifically, the groove depth D46 of the groove bottom 46 and the groove depth D44 of the groove bottom 44 are 45% or more and 85% or less of the length of the groove depth D10 of the circumferential groove 10.

  The convex portion 42 is formed in a region of approximately 1/3 including the center of the first sipe 40 in the length of the first sipe 40 in the longitudinal direction LD40.

  The width L42 of the convex portion 42 in the longitudinal direction LD40 is 15% or more and 40% or less of the length of the width L40 of the first sipe 40 in the longitudinal direction LD40.

(2.2) Second Sipe As shown in FIG. 1, the second sipe 50 has a second sipe 50 from one end of the second sipe 50 in the tread width direction W _TR in the tread surface view of the pneumatic tire 1. The angle formed by the heading direction is the negative side opposite to the positive side. Specifically, in the second sipe 50, the angle formed with the straight line S1 in the tread surface view of the pneumatic tire 1 is an angle on the minus side opposite to the plus side. The angle θ ₅₀ formed by the second sipe 50 and the straight line S1 is not less than 15 ° and not more than 55 °.

The opposite side of the plus side is the angle formed by the direction toward the second sipe 50 when the angle formed by the direction toward the first sipe 40 is defined as the plus side with respect to the tread width direction W _TR (straight line S1). Means on the opposite side with respect to the tread width direction W _TR (straight line S1).

In the first sipe 40, the angle θ ₄₀ formed by the direction from the one end of the first sipe 40 to the first sipe 40 with respect to the tread width direction (straight line S1), and in the tread width direction (straight line S1) in the second sipe 50. ) Is substantially equal to the angle θ ₅₀ formed by the direction from the one end of the second sipe 50 toward the second sipe 50. The second sipe 50 is positioned in parallel to the lateral groove 20 and the lateral groove 22. The second sipe 50 communicates with the circumferential groove 10 at one end and the circumferential groove 12 at the other end.

  As shown in FIGS. 2 and 4, the second sipe 50 includes a pair of second convex portions (convex portions 52) formed at both ends of the groove bottom portion 56 in the longitudinal direction LD 50 that is the longitudinal direction of the second sipe 50. And convex portion 54).

  A second sipe 50 is formed at the end of the land portion 30 along the tire circumferential direction R. Accordingly, the land portion 30 is formed such that the sum of the first sipes 40 and the second sipes 50 is an odd number.

  The groove depth D52 of the convex portion 52 and the groove depth D54 of the convex portion 54 are shallower than the groove depth D10 of the circumferential groove 10 and the groove depth D56 of the groove bottom portion 56. Specifically, the groove depth D52 of the convex portion 52 and the groove depth D54 of the convex portion 54 are 1 mm or more and 45% or less of the length of the groove depth D10 of the circumferential groove 10.

  Further, the groove depth D56 of the groove bottom 56 is not less than 45% and not more than 85% of the length of the groove depth D10 of the circumferential groove 10.

(Delete)
The convex portion 52 and the convex portion 54 are formed in approximately one third of the length of the second sipe 50 in the longitudinal direction LD50 including the center of the second sipe 50.

  The width L52 and the width L54 of the convex part 52 and the convex part 54 in the longitudinal direction LD50 are 1 mm or more, and 40% or less of the length of the width L50 of the longitudinal direction LD50 of the second sipe 50.

(Delete)
(3) Comparative Evaluation Next, in order to further clarify the effects of the present invention, comparative evaluation performed using pneumatic tires according to the following comparative examples and examples will be described. Specifically, (3.1) Evaluation method and (3.2) Evaluation result will be described. In addition, this invention is not limited at all by these examples.

(3.1) Evaluation method
Three types of pneumatic tires were used to evaluate block rigidity, dry road performance, and snow / ice performance.

・ Block stiffness: Finite Element Method (FEM) is used to evaluate land stiffness.

・ Performance on dry road: Feeling evaluation by driver for initial response performance and braking performance ・ Performance on snow and ice; Feeling evaluation by driver The block stiffness evaluation result is that of the pneumatic tire according to Comparative Example 1 which is a conventional pneumatic tire. The result is shown as a contrast index when the evaluation result is 100. The evaluation result of block rigidity shows that it has the outstanding performance, so that a large numerical value is shown.

  The evaluation results of the performance on the dry road and the performance on snow and ice were expressed as a contrast index when the driver's feeling full score was 10. The evaluation results of the performance on the dry road and the performance on snow and ice indicate that the larger the numerical value, the better the performance.

  The pneumatic tire of Comparative Example 1 includes a plurality of straight sipes. Specifically, the sipe of the pneumatic tire of Comparative Example 1 is formed along the tread width direction in the tread surface view. The pneumatic tire of Comparative Example 1 differs from the pneumatic tire of Example 1 only in the arrangement of sipes in the tread surface view. In addition, the shape, number, etc. of the circumferential grooves, land portions, and transverse grooves are the same.

The pneumatic tires of Examples 1 and 2 include the sipe shown in FIG. However, the pneumatic tire of Example 1 is formed only by the first sipe 40, and the first sipe 40 is also formed at the place where the second sipe 50 is provided in the tread surface view of FIG. It differs from the pneumatic tire of Example 2.

(3.2) Evaluation Results The evaluation results of each pneumatic tire will be described with reference to Table 1.

  It can be seen that the pneumatic tire according to Example 1 has superior snow and ice performance while ensuring block rigidity as compared with the pneumatic tire according to Comparative Example 1.

  It can be seen that the pneumatic tire according to Example 2 has improved block rigidity and performance on the dry road while ensuring equivalent snow and ice performance as compared with the pneumatic tire according to Example 1.

  As a result, as shown in FIG. 1, the pneumatic tires according to Examples 1 and 2 in which sipes along the direction where the positive and negative are different from the tread width direction are the pneumatic tires according to Comparative Example 1. It can be seen that the performance on snow and ice and the performance on dry road are balanced at a higher level.

(4) Action / Effect As described above, according to the pneumatic tire 1 according to the present embodiment, in the tread surface view, the angle formed by the sipe heading from one end of the sipe with respect to the tread width direction is the plus side. The first sipe 40 having a negative angle and the second sipe 50 having a negative angle opposite to the positive angle are alternately provided along the tire circumferential direction R. The edge effect acting on the edge of the tread pattern can be obtained with the first sipe 40 or the second sipe 50 with respect to stress having directionality other than the tire circumferential direction R such as lateral force along High performance can be secured.

  Also, on the dry road surface, the tread pattern in the first sipe 40 or the second sipe 50 is applied to stress having a direction other than the tire circumferential direction R such as a lateral force along the tread width direction during a side slip. However, it can suppress falling down to one direction, and can ensure the performance on a dry road.

  Therefore, the pneumatic tire 1 can achieve both higher performance on snow and ice and higher performance on the dry road.

  In the present embodiment, in the cross section along the longitudinal direction LD40, in the region where the convex portion 42 is formed, the distance from the surface of the convex portion 42 to the road surface G becomes short, so that deformation of the land portion 30 is suppressed. And it can further suppress that the rigidity of land part 30 falls.

  In the cross section along the longitudinal direction LD40, in the region where the groove bottom portion 44 and the groove bottom portion 46 are formed, the groove depth is shallower than the circumferential groove 10 and the circumferential groove 12, so that the performance on snow and ice is ensured. The deformation of the portion 30 can be suppressed, and the decrease in the rigidity of the land portion 30 can be further suppressed.

  In the cross section along the longitudinal direction LD50, in the region where the convex portion 52 and the convex portion 54 are formed, the distance from the surface of the convex portion 52 and the convex portion 54 to the road surface G becomes short. The deformation of 30 can be suppressed, and the decrease in rigidity of the land portion 30 can be further suppressed.

  In the cross section along the longitudinal direction LD50, in the region where the groove bottom portion 56 is formed, the groove depth is shallower than the circumferential groove 10 and the circumferential groove 12, so that the deformation of the land portion 30 is ensured while ensuring the performance on snow and ice. It is possible to further suppress the decrease in the rigidity of the land portion 30.

  Thereby, since the pneumatic tire 1 can suppress the deformation | transformation of the land part 30 and can distribute the area | region where the rigidity of the land part 30 falls to a different area | region, it is effective on snow-ice performance and dry road performance effectively. Can be further improved.

  In this embodiment, since the 2nd sipe 50 is formed in the edge part of the land part 30 along the tire circumferential direction R, the fall of the block rigidity of the land part 30 can be suppressed. Therefore, the pneumatic tire 1 can suppress a decrease in front and rear driving force.

  In the present embodiment, the plurality of first sipes 40 are formed substantially parallel to each other, and the plurality of second sipes 50 are formed substantially parallel to each other in the tread surface view. For this reason, the rigidity of each block of the land portion 30 partitioned into the first sipe 40 and the second sipe 50 can be made uniform, and the deformation of the land portion 30 can be further suppressed.

In the present embodiment, in the first sipe 40, with respect to the tread width direction, the magnitude of the angle θ ₄₀ formed by the direction from the one end of the first sipe 40 toward the first sipe 40, and the magnitude of the angle θ ₅₀ in the second sipe 50 Are substantially coincident with each other, so that an edge effect can be obtained in a balanced manner against stress having a direction other than the tire circumferential direction R such as a lateral force along a tread width direction during a side slip.

  In the present embodiment, the convex portion 42 is formed in a region of about 1/3 including the center of the first sipe 40 in the length of the first sipe 40 in the longitudinal direction LD40. Central rigidity can be improved. In the 1st sipe 40, since the center of the 1st sipe 40 is an area | region with low block rigidity, the pneumatic tire 1 can improve block rigidity effectively.

  In the present embodiment, since the convex portion 42, the groove bottom portion 44, and the groove bottom portion 46 are formed on a straight line along the longitudinal direction LD40 in the tread surface view, the convex portion 42, the groove bottom portion 44, and the groove are formed. It is possible to suppress the concentration of stress in each region of the bottom 46 and reduce the progress of cracks and the like.

  In the present embodiment, since the groove bottom portion 56 is formed in a straight line along the longitudinal direction LD50 in the tread surface view, the concentration of stress in each region of the groove bottom portion 56 is suppressed, and cracks and the like are suppressed. Progress can be reduced.

(5) Other Embodiments As described above, the contents of the present invention have been disclosed through the embodiments of the present invention. However, it is understood that the description and drawings constituting a part of this disclosure limit the present invention. Should not. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  For example, the embodiment of the present invention can be modified as follows.

  In the embodiment described above, the convex portion 42 is formed immediately above in the cross section along the longitudinal direction LD40, but may be formed in a convex curve.

  In the above-described embodiment, the convex portion 42, the groove bottom portion 44, and the groove bottom portion 46 are each formed immediately above in the cross section along the longitudinal direction LD 40.

  On the other hand, as shown in FIG. 5, the first sipe 40A may be formed in a convex curve with the convex portion 42A as the apex in the entire convex portion 42A, groove bottom portion 44A, and groove bottom portion 46A. Good. FIG. 5 is a cross-sectional view of the first sipe 40A. In this case, since the snow that has entered the sipe is likely to pass through both ends, the pneumatic tire 1 can improve the performance on snow and ice.

  In the above-described embodiment, the convex portion 52, the convex portion 54, and the groove bottom portion 56 are each formed immediately above in the cross section along the longitudinal direction LD50.

  On the other hand, as shown in FIG. 6, the second sipe 50A has a convex curve 52A, a convex curve part 54A and a groove bottom part 56A as a whole with a convex curve 52A and a convex curve 54A as a vertex. It may be formed. FIG. 6 is a cross-sectional view of the second sipe 50 shown in FIG. In this case, since the boundary between the convex portion 52A, the convex portion 54A, and the groove bottom portion 56A is not clear, the convex portion 52A, the convex portion 54A, compared to the convex portion 52, the convex portion 54, Stiffness can be improved.

  In the above-described embodiment, the sipe (the first sipe 40 and the second sipe 50) is linearly formed in the tread surface view, but is not limited thereto, and at least a part thereof is linearly formed. It is preferable.

  According to this, since at least a part is formed in a straight line in the tread surface view, stress having a directionality other than the tire circumferential direction R such as a lateral force along the tread width direction at the time of skidding or the like. On the other hand, it is possible to obtain an edge effect that acts on the edge of the tread pattern while maintaining rigidity in the linearly formed portion of the first sipe 40 or the second sipe 50. Therefore, the pneumatic tire can further improve the performance on snow and ice.

  Further, the sipe may be formed in a zigzag shape or a wave shape in the tread surface view. According to this, even in a sipe formed in a zigzag shape or a wave shape, the angle formed by the direction from the sipe toward one end of the sipe is the first sipe that is the plus side angle and the second sipe that is the minus side angle. By including sipes, the same effects as in the embodiment can be obtained.

  In the embodiment described above, the arrangement of the land portion 30 in the tread pattern of the pneumatic tire 1 is not particularly defined. For example, it is not necessary to form the land portion 30 on the entire tread pattern of the pneumatic tire 1.

  As described above, the present invention naturally includes various embodiments that are not described herein. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

It is an expanded view of the tread which constitutes pneumatic tire 1 concerning the embodiment of the present invention. It is a perspective view of land part 30 which constitutes pneumatic tire 1 concerning an embodiment of the present invention. It is a partial sectional view of the 1st sipe 40 which constitutes pneumatic tire 1 concerning an embodiment of the present invention. It is a partial sectional view of the 2nd sipe 50 which constitutes pneumatic tire 1 concerning an embodiment of the present invention. It is a partial sectional view of the 1st sipe 40A which constitutes a pneumatic tire concerning other embodiments of the present invention. It is a partial sectional view of the 2nd sipe 50A which constitutes the pneumatic tire concerning the embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Pneumatic tire 10, 12 ... Circumferential groove | channel, 20, 22 ... Lateral groove, 30 ... Land part,
40 ... 1st sipe, 42 ... Convex part, 44, 46 ... Bottom part, 50 ... 2nd sipe,
52, 54 ... convex part, 56 ... concave part, 58, 60 ... bottom part

Claims (7)

A circumferential groove extending along the tire circumferential direction;
A transverse groove extending along a direction intersecting the circumferential groove;
A block-shaped land portion defined by the circumferential groove and the lateral groove,
A tire in which a plurality of sipes are formed in the land portion,
In the tire tread surface view, the sipe is:
A first sipe in which an angle formed by a direction of the sipe from one end of the sipe with respect to a tread width direction is a plus angle;
A second sipe in which an angle formed by a direction in which the sipe is directed from the one end of the sipe with respect to a tread width direction is a negative side angle opposite to the positive side;
The first sipe and the second sipe are tires formed adjacent to each other along the tire circumferential direction. The first sipe is:
Including a first convex portion formed at substantially the center of the groove bottom in the first longitudinal direction which is the longitudinal direction of the first sipe;
The second sipe is:
The tire according to claim 1, comprising a pair of second convex portions formed at both ends of the groove bottom in the second longitudinal direction, which is the longitudinal direction of the second sipe.   The tire according to claim 1 or 2, wherein at least a part of the sipe is linearly formed in the tread surface view.   The tire according to any one of claims 1 to 3, wherein the second sipe is formed at an end of the land portion along the tire circumferential direction. In the tread surface view, the sipe is
A plurality of the first sipes and a plurality of the second sipes;
Each of the plurality of first sipes is formed substantially in parallel,
The tire according to any one of claims 1 to 4, wherein each of the plurality of second sipes is formed substantially in parallel. In the first sipe, with respect to the tread width direction, the size of the angle formed by the direction of the sipe from the one end of the sipe;
The tire according to any one of claims 1 to 5, wherein a magnitude of an angle formed by a direction in which the sipe is directed from the one end of the sipe with respect to a tread width direction in the second sipe substantially matches.   3. The tire according to claim 2, wherein the first convex portion is formed in an approximately 1/3 region including a center of the first sipe in a length of the first sipe in the first longitudinal direction.

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