JP5098427B2 - Pneumatic tire - Google Patents

Description

  The present invention relates to a pneumatic tire, and more particularly to a pneumatic tire suitable for application to a heavy duty pneumatic tire.

  Conventionally, for example, heavy duty pneumatic tires have a larger contact area, so wear resistance and handling stability are improved. Therefore, the tread shoulder end has an edge shape to effectively use the tread width as the contact area. A so-called square shoulder type is often used. In addition, in order to increase the contact area, the tread width tends to be widened. When the tread width is increased in this way, the wear resistance and steering stability are improved, while the ground contact pressure at the tread shoulder ends on both sides in the tire width direction becomes extremely high especially during turning, resulting in uneven wear. May occur.

  Therefore, for example, in the heavy-duty pneumatic radial tire described in Patent Document 1, a narrow groove is provided in the tire circumferential direction at the outermost end portion of the tread shoulder rib, and the outer side in the tire width direction is narrowed from the narrow groove. The tread shoulder rib is provided along the tire width direction from the narrow groove toward the inside in the tire width direction, and a plurality of sipes are provided at intervals in the circumferential direction. As a result, the rigidity of the shoulder rib end portions on both sides in the tire width direction is reduced, and by allowing deformation of the shoulder rib end portions, the contact pressure at the shoulder rib end portions is reduced, and uneven wear of the tread shoulder ribs is achieved. Is suppressed.

JP 2004-268783 A

  However, in the heavy-duty pneumatic radial tire described in Patent Document 1, for example, in order to suppress uneven wear of the tread shoulder rib, more sipes are provided in the circumferential direction to further reduce the rigidity, in other words, the tread shoulder rib To reduce the contact pressure, if the rigidity of the tread shoulder rib is lowered too much, for example, when excessive lateral force is applied to the tire during turning, when riding on a stationary road or when riding on a curb, etc. In the rib, there is a possibility that a so-called tear is generated, in which a crack is generated from the sipe and chipped in a block shape. On the other hand, if the number of the sipes (in other words, the density) is reduced, the desired uneven wear resistance performance cannot be obtained.

  Accordingly, an object of the present invention is to provide a pneumatic tire that can achieve both uneven wear resistance and tear resistance.

In order to achieve the above object, a pneumatic tire according to the invention according to claim 1 is partitioned by a groove continuous in the tire circumferential direction and is provided on a side portion in the tire width direction, and the tire in the shoulder rib. A rib end sipe provided along the tire width direction at the shoulder rib end portion on the outer side in the width direction and a plurality of rib end sipes provided in the tire circumferential direction, and the rib end extending along the tire width direction on the shoulder rib A plurality of widthwise sipes formed longer than the sipes, and extending from the center of the shoulder rib in the tire width direction toward the rib end sipe along the tire circumferential direction and shallower than the groove. and a circumferential shallow groove, the rib end sipe, set the range depth of the tire radial direction is not more than 0.9 times 0.5 times or more the depth of the groove It is, while one end is opened in the tire width direction outer side, and the other end portion is closed in the tire width direction inner side.

  The pneumatic tire according to a second aspect of the invention is characterized in that the widthwise sipe has a length in the tire width direction set to 50% or more of a length of the shoulder rib in the tire width direction. .

  The pneumatic tire according to a third aspect of the invention is characterized in that the widthwise sipe penetrates the shoulder rib along the tire width direction.

  The pneumatic tire according to a fourth aspect of the present invention is characterized in that the width direction sipe extends from the rib end sipe.

The pneumatic tire according to a fifth aspect of the invention is characterized in that the rib end sipes are set such that the interval between the rib end sipes adjacent to each other in the tire circumferential direction is 5.0 mm or greater and 10.0 mm or less. And

The pneumatic tire according to the invention of claim 6 is characterized in that the width direction sipe is set such that the depth in the tire radial direction is not less than 0.2 times and not more than 0.5 times the depth of the groove. And

In the pneumatic tire according to the invention according to claim 7 , in the width direction sipe, the interval between the width direction sipes adjacent in the tire circumferential direction is 3 of the interval between the rib end sipes adjacent in the tire circumferential direction. It is characterized by being set in a range of 0.0 times or more and 9.0 times or less.

The pneumatic tire according to the invention according to claim 8 is characterized in that the circumferential shallow groove has a length in the tire circumferential direction set to 50% or more of a length in the tire circumferential direction of the shoulder rib. To do.

The pneumatic tire according to the invention according to claim 9 is characterized in that the circumferential shallow groove penetrates the shoulder rib along the tire circumferential direction.

The pneumatic tire according to the invention according to claim 10 is characterized in that the circumferential shallow groove has a width in the tire width direction of 3.0 mm or less.

A pneumatic tire according to an eleventh aspect of the invention is characterized in that the circumferential shallow groove has a depth in the tire radial direction set in a range of 4.0 mm or less.

In a pneumatic tire according to a twelfth aspect of the present invention, the rib end sipe extends outward in the tire width direction through a narrow groove extending in the tire circumferential direction and formed narrower than the groove at the shoulder rib end. A thin rib provided on the side is provided.

In order to achieve the above object, a pneumatic tire according to the invention according to claim 13 is partitioned by a groove continuous in the tire circumferential direction and is provided on a side portion in the tire width direction, and the tire in the shoulder rib. A rib end sipe provided along the tire width direction at the shoulder rib end portion on the outer side in the width direction and a plurality of rib end sipes provided in the tire circumferential direction, and the rib end extending along the tire width direction on the shoulder rib A plurality of widthwise sipes formed longer than the sipes, and extending from the center of the shoulder rib in the tire width direction toward the rib end sipe along the tire circumferential direction and shallower than the groove. The rib end sipe has one end opened at the outer side in the tire width direction and the other end at the inner side in the tire width direction. In and said that they are closed.
In order to achieve the above object, a pneumatic tire according to a reference invention includes a shoulder rib that is partitioned by a groove continuous in the tire circumferential direction and provided on a side portion in the tire width direction, and the tire width direction of the shoulder rib. A plurality of rib end sipes provided along the tire width direction at the outer shoulder rib end, and the tire circumferential direction from the center of the shoulder rib in the tire width direction to the rib end sipe side And a circumferential shallow groove formed so as to be shallower than the groove.

According to the pneumatic tire of the inventions according to claim 1 and claim 13 , since the plurality of rib end sipes are provided in the tire circumferential direction at the shoulder rib end portion, the rigidity of the shoulder rib end portion is reduced. Further, uneven wear of the shoulder rib can be suppressed. Furthermore, since the rigidity of the shoulder rib in the tire circumferential direction is reduced by providing a width direction sipe along the tire width direction in the shoulder rib, the deformation of the shoulder rib as a whole in the tire circumferential direction is reduced when a load is applied. Is acceptable. As a result, the deformation of the entire shoulder rib in the tire circumferential direction reduces the stress on the end of the shoulder rib, further reducing the concentration of stress on the end of the shoulder rib, thereby reducing the rib on the end of the shoulder rib. It is possible to prevent cracks from being generated from the end sipes and chipping or flaking in blocks. As a result, both partial wear resistance and tear resistance can be achieved.

  According to the pneumatic tire of the invention according to claim 2, the width of the shoulder rib is such that [the length of the widthwise sipe in the tire width direction] ≧ [the length of the shoulder rib in the tire width direction × 0.5]. Since the direction sipe is provided, the rigidity of the shoulder rib in the tire circumferential direction can be sufficiently reduced.

  According to the pneumatic tire of the invention according to claim 3, since the width direction sipe is provided through the shoulder rib along the tire width direction, the closed end portion is not formed by this width direction sipe. It is possible to prevent cracks from occurring in the width direction sipe.

  According to the pneumatic tire of the invention according to claim 4, since the width direction sipe extends from the rib end sipe, an installation space for the width direction sipe is ensured between the rib end sipes adjacent in the tire circumferential direction. Since it is not necessary, the installation space of the width direction sipe can be made more efficient.

According to the pneumatic tire of the first aspect of the present invention, [groove depth × 0.5] ≦ [depth of rib end sipe in the tire radial direction] ≦ [groove depth × 0.9]. Since the rib end sipe is provided on the shoulder rib as described above, it is possible to prevent the rib end sipe from being too shallow or too deep to prevent the partial wear resistance at the shoulder rib end from being sufficiently secured. it can.

According to the pneumatic tire of the invention according to claim 5 , ribs are provided on the shoulder rib so that 5.0 [mm] ≦ [interval between rib end sipes adjacent in the tire circumferential direction] ≦ 10.0 [mm]. Since the end sipes are provided, it can be prevented that the rigidity of the shoulder rib end part becomes extremely low and the tear resistance is deteriorated, and the rigidity of the shoulder rib end part is too high to cause uneven wear. Can be prevented.

According to the pneumatic tire of the invention of claim 6 , [groove depth × 0.2] ≦ [depth in the tire radial direction of the width direction sipe] ≦ [groove depth × 0.5]. As described above, the shoulder ribs are provided with the sipe in the width direction, so that the tear resistance can be prevented from being lowered and so-called heel-and-toe wear can be prevented from occurring.

According to the pneumatic tire of the invention of claim 7 , [the interval between rib end sipes adjacent in the tire circumferential direction × 3.0] ≦ [the interval between width sipes adjacent in the tire circumferential direction] ≦ [tire Since the shoulder ribs are provided with a width direction sipe so that the interval between rib end sipes adjacent in the circumferential direction is 9.0], it is possible to prevent a decrease in tear resistance and a so-called heel and toe. Wear can be prevented from occurring.

According to the pneumatic tire of the invention according to claim 1 or claim 13 , the shoulder rib tire is further provided with the circumferential shallow groove extending in the tire circumferential direction at the shoulder rib end portion in the shoulder rib. Since the rigidity in the width direction is also reduced, deformation of the entire shoulder rib in the tire width direction is allowed when a load is applied. As a result, the deformation of the entire shoulder rib in the tire width direction reduces the stress on the shoulder rib end, further reducing the concentration of stress on the shoulder rib end, thereby reducing the rib on the shoulder rib end. It is possible to prevent cracks from being generated from the end sipes and chipping or flaking in blocks. As a result, the uneven wear resistance and tear resistance of the shoulder rib can be further improved.

According to the pneumatic tire of the invention according to claim 8 , the circumferential direction of the shoulder rib is such that [the circumferential length of the circumferential shallow groove] ≧ [the length of the shoulder rib tire circumferential direction × 0.5]. Since the shallow groove is provided, the rigidity of the shoulder rib in the tire width direction can be sufficiently reduced.

According to the pneumatic tire of the invention according to claim 9 , since the circumferential shallow groove is provided through the shoulder rib along the tire circumferential direction, the closed end portion is not formed in the circumferential shallow groove. Thus, it is possible to prevent cracks from occurring in the circumferential shallow groove.

According to the pneumatic tire of the invention according to claim 10 , since the circumferential shallow groove is provided in the shoulder rib so that [the width in the tire width direction of the circumferential shallow groove] ≦ 3.0 [mm], It is possible to prevent uneven wear from occurring due to excessive reduction in rigidity of the shoulder rib in the tire width direction.

According to the pneumatic tire of the invention according to claim 11 , the circumferential shallow groove is provided in the shoulder rib so that [the depth in the tire radial direction of the circumferential shallow groove] ≦ 4.0 [mm]. Further, it is possible to prevent uneven wear from occurring due to excessive reduction in rigidity in the tire width direction of the shoulder rib.

According to the pneumatic tire of the invention according to claim 12 , since the narrow groove and the thin rib that are continuous in the tire circumferential direction are provided on the outer side in the tire width direction of the shoulder rib, the stress concentration on the rib end sipe portion is concentrated. By being relaxed, uneven wear of the shoulder rib is suppressed. At this time, even when the thin ribs are more actively worn than the shoulder ribs, uneven wear at the shoulder rib ends of the shoulder ribs can be suppressed.

According to the pneumatic tire according to the reference invention, since the plurality of rib end sipes are provided in the circumferential direction of the shoulder rib at the end of the shoulder rib, the rigidity of the end of the shoulder rib is reduced, thereby causing uneven wear of the shoulder rib. Can be suppressed. Furthermore, the shoulder rib has a shallow circumferential groove extending in the tire circumferential direction at the end of the shoulder rib to reduce the rigidity of the shoulder rib in the tire width direction. Deformation in the entire tire width direction is allowed. As a result, the deformation of the entire shoulder rib in the tire width direction reduces the stress on the shoulder rib end, further reducing the concentration of stress on the shoulder rib end, thereby reducing the rib on the shoulder rib end. It is possible to prevent cracks from being generated from the end sipes and chipping or flaking in blocks. As a result, both partial wear resistance and tear resistance can be achieved.

Below, the reference form and embodiment of the pneumatic tire concerning the present invention are explained in detail based on a drawing. In addition, this invention is not limited by this reference form and embodiment . In addition, constituent elements in the following reference embodiments and embodiments include those that can be easily replaced by those skilled in the art, or those that are substantially the same.

( Reference form )
Figure 1 is a cutaway perspective view of a pneumatic tire according to the reference embodiment of the present invention, FIG. 2, meridional partial sectional view of a pneumatic tire according to the reference embodiment of the present invention, FIG. 3, according to a reference embodiment of the present invention It is meridional sectional drawing which shows the principal part of a pneumatic tire.

As shown in FIG. 3, the pneumatic tire 1 is suitable, for example, as a heavy duty pneumatic tire, and is configured to be substantially symmetrical about the equator plane 50. Here, the equatorial plane 50 is a plane that is orthogonal to the rotation axis and passes through the center of the width of the pneumatic tire 1. In this reference embodiment , the pneumatic tire 1 will be described as applied to a so-called square shoulder type heavy-duty pneumatic tire in which a shoulder rib end portion 21a described later is formed in an edge shape, but is not limited thereto. It can be applied to various pneumatic tires.

  In the following description, the tire width direction means a direction parallel to the rotation axis of the pneumatic tire, the tire radial direction means a direction perpendicular to the rotation axis, and the tire circumferential direction (see FIG. 1). The term “rotation direction” refers to a direction of rotation with the rotation axis serving as a rotation axis. Further, the inner side in the tire width direction refers to a direction toward the equator plane 50 in the tire width direction, and the outer side in the tire width direction refers to a direction away from the equator plane 50 in the tire width direction.

  As shown in FIG. 3, the pneumatic tire 1 includes a tread portion 6 having a tread surface 5, left and right shoulder portions 7 continuous on both sides thereof, sidewall portions 8, and bead portions 9. . The pneumatic tire 1 further includes a belt layer 10, a carcass 11, an inner liner 12, and a bead core 13.

  The carcass 11 is composed of a cord layer formed of organic fibers covered with rubber, and forms a tire skeleton. The carcass 11 extends from both sides of the tread portion 6 to the bead portion 9 via the left and right shoulder portions 7 and the sidewall portions 8 with the equator plane 50 as the center. The carcass 11 is a strength member that serves as a pressure vessel when the pneumatic tire 1 is filled with air. The carcass 11 has a structure that supports the load by its internal pressure and withstands a dynamic load during traveling. Yes.

  The belt layer 10 is a reinforcing layer attached in the tire circumferential direction. The belt layer 10 is provided between the tread surface 5 that is the surface of the tread portion 6 and the carcass 11. That is, the belt layer 10 is disposed on the inner side in the tire radial direction of the tread surface 5 and on the outer side in the tire radial direction of the carcass 11. The belt layer 10 includes a first belt 10a, a second belt 10b, a third belt 10c, and a fourth belt 10d in order from the inside in the tire radial direction. The belt layer 10 tightens the carcass 11 to increase the rigidity of the tread and relaxes the impact to prevent the carcass 11 from being damaged by the impact. The tread surface 5 of the tread portion 6 described above is formed on the outer circumferential side of the belt layer 10 in the tire radial direction.

  The bead core 13 supports the cord tension of the carcass 11 generated by the internal pressure of the pneumatic tire 1 at the bead portion 9. The pair of left and right bead cores 13 have a plurality of bead wires 14, and the bead wires 14 are made of steel wires as high-rigidity materials. The pair of bead cores 13 form a pair of bead cores 13 by continuously winding the bead wires 14 to form a ring shape. The bead core 13 serves to fix the pneumatic tire 1 to a wheel rim (not shown), and also functions as a strength member of the pneumatic tire 1 together with the carcass 11 and the belt layer 10.

  The carcass 11 described above is folded outward from the equatorial plane 50 side of the pneumatic tire 1 around the bead core 13, and the bead filler 15 is filled in the space between the carcass 11 and the bead core 13. Part 9 is configured. That is, the carcass 11 is spanned between a pair of bead cores 13 symmetrically with respect to the equator plane 50, extends from the tread portion 6 to the bead portion 9 via the sidewall portion 8, and further the bead core 13 is connected to the equator plane. It is wound up so as to wrap outward from the 50 side. The bead filler 15 is disposed on the outer circumference side of the bead core 13 in the tire radial direction, so that the carcass 11 is fixed to the bead core 13 and the shape of this portion is adjusted to increase the rigidity of the entire bead portion 9. An inner liner 12 is formed along the carcass 11 inside the carcass 11.

Tread surface 5 has a plurality of forming the tread pattern, this preferred embodiment the four main grooves 16 and a plurality of lug grooves (not shown) is provided. The main groove 16 is formed continuously in the tire circumferential direction. Further, the tread surface 5 has a plurality of land portions 17 that are adjacent to each other in the tire width direction through the main groove 16. In other words, each land portion 17 is partitioned by each main groove 16 on the tread surface 5. The land portion 17 has a central rib 18 located at the center in the tire width direction and shoulder ribs 19 located at both sides in the tire width direction. The tread surface 5 of the present embodiment is partitioned into five land portions 17 by four main grooves 16, that is, three central ribs 18 are provided in the center portion in the tire width direction, and a pair is provided on both side portions in the tire width direction. Shoulder ribs 19 are provided. The central rib 18 and the shoulder rib 19 are formed in a rib row base tone that is substantially continuous in the tire circumferential direction.

  In the following description, the pneumatic tire 1 is configured to be substantially symmetric with respect to the equator plane 50, and therefore, only one side with respect to the equator plane 50 will be described unless otherwise specified. The description on the other side is omitted as much as possible.

  As shown in FIGS. 1 and 2, each shoulder rib 19 is provided with a narrow groove 20 that continues in the tire circumferential direction. The narrow groove 20 is provided in the shoulder rib end portion 21a on the outer side in the tire width direction among the shoulder rib end portion 21a and the shoulder rib end portion 21b at both ends of the shoulder rib 19 in the tire width direction. Further, each shoulder rib 19 is provided with a plurality of multi-sipes 22 as a plurality of rib end sipes at the shoulder rib end portion 21a on the outer side in the tire width direction.

  The narrow groove 20 forms a thin rib 23 on the tread surface 5 outside the multi-sipe 22 in the tire width direction. That is, the thin rib 23 is provided on the outer side in the tire width direction of the multi-sipe 22 so as to be adjacent to the multi-sipe 22 through the narrow groove 20 extending in the tire circumferential direction. The thin ribs 23 are formed so as to be continuous in the tire circumferential direction, and the tread surface 5 is stepped down in the tire radial direction from the tread surface 5 of the main body portion of the shoulder rib 19. The thin ribs 23 function as so-called sacrificial ribs (discard ribs). Thereby, when the tire 1 is grounded, the rigidity of the shoulder rib end portion 21a is reduced by the narrow groove 20, so that the shoulder rib end portion 21a is allowed to be deformed when a load is applied. As a result, the shoulder rib end portion 21a. By reducing the concentration of stress on the shoulder rib, the ground pressure acting on the shoulder rib end 21a is reduced, and uneven wear of the shoulder rib 19 is suppressed. At this time, even when the thin ribs 23 are more actively worn than the shoulder ribs 19, uneven wear of the shoulder rib end portions 21 a of the shoulder ribs 19 is suppressed.

The plurality of multi-sipes 22 are formed along the width direction from the narrow grooves forming the thin ribs 23 toward the inside. Each multisipes 22 are formed at predetermined intervals P _S in the tire circumferential direction with is provided along the tire width direction. One end of the multi-sipe 22 opens and communicates with the narrow groove 20 at the main body end surface 24 of the shoulder rib end 21a, while the other end is closed on the inner side in the tire width direction. As a result, the rigidity of the shoulder rib end 21a is further reduced, thereby allowing further deformation of the shoulder rib end 21a when a load is applied. As a result, stress concentration on the shoulder rib end 21a is alleviated. As a result, the contact pressure acting on the shoulder rib end 21a is further reduced, and uneven wear of the shoulder rib 19 is suppressed.

  When the heavy-duty pneumatic tire 1 configured as described above is mounted on a vehicle such as a truck and travels, the pneumatic tire 1 rotates while the tread surface 5 is in contact with the road surface (not shown). At this time, in the heavy load pneumatic tire 1, a large load acts on the tread surface 5. For example, the large load tends to act near the shoulder portion 7 when the vehicle is cornered (turned). Although the ground pressure of the rib end portion 21a is likely to increase, the square shoulder type pneumatic tire 1 uses the tread surface 5 as a ground contact area effectively because the shoulder rib end portion 21a is formed in an edge shape. As a result, wear resistance, steering stability, and the like can be improved.

On the other hand, when the width of the tread surface 5 is increased as in the case of the pneumatic tire 1 described above, wear resistance and steering stability are improved. The ground pressure at the end 21a tends to be extremely high, and there is a risk that uneven wear occurs in this portion. However, the pneumatic tire 1 of the present embodiment is provided with the narrow grooves 20 and the thin ribs 23 that are continuous in the tire circumferential direction on the outer side in the tire width direction of the shoulder rib 19 and from the narrow grooves 20 to the inner side in the tire width direction. Since the plurality of multi-sipes 22 are provided toward the shoulder rib end portion 21a, the shoulder rib end portion 21a is easily deformed when a large load is applied to the shoulder rib end portion 21a. Therefore, the load can be dispersed over a wide range and received by the shoulder rib 19. Thereby, the partial wear which generate | occur | produces near the shoulder part 7 resulting from receiving a load in the narrow range of the shoulder part 7 vicinity can be suppressed more reliably.

  By the way, for example, in order to suppress uneven wear of the shoulder rib 19, more rigidity is reduced by providing more multi-sipes 22 in the tire circumferential direction at the shoulder rib end portion 21 a, in other words, a reduction in contact pressure of the shoulder rib 19. If the rigidity of the shoulder rib end portion 21a is too low, for example, when excessive lateral force is applied to the pneumatic tire 1 during turning, or when riding on a curb or on a curb, etc. The rib 19 may cause a so-called tear that cracks from the multi-sipe 22 and is chipped in a block shape. On the other hand, if the number of multi-sipes 22 (in other words, density) is reduced, the desired uneven wear resistance may not be obtained.

Accordingly, in the pneumatic tire 1 of the present embodiment , as shown in FIGS. 1 and 2, uneven wear resistance at the shoulder rib end portion 21a is provided by providing the shoulder rib 19 with a plurality of open sipes 25 as sipe in the width direction. Compatibility and tear resistance.

Here, in the pneumatic tire 1, in order to increase the number of multi-sipes 22 (in other words, density) and obtain a predetermined uneven wear resistance performance, a plurality of multi-sipes 22 are spaced apart from each other in the tire circumferential direction. P _S is preferably set in a range of 5.0 mm to 10.0 mm. That is, each multi-sipe 22 is provided on the shoulder rib 19 so that 5.0 [mm] ≦ P _S ≦ 10.0 [mm]. Thus, the multisipes 22 interval P _S of each other wider than 5.0 [mm], the rigidity of the shoulder rib end 21a and the interval P _S is too narrow is too extremely low, resistance to tear resistance is deteriorated Can be prevented. On the other hand, by multisipes 22 interval P _S between narrower than 10.0 [mm], prevents the interval P _S is the stiffness is too high the shoulder rib end 21a too wide, uneven wear occurs can do.

Further, this multi-sipe 22 has a depth H _S in the tire radial direction, preferably 0.5 times (50%) or more and 0.9 times (90%) or less of the depth GD of the main groove 16 in the tire radial direction. Is set in the range. That is, each multi-sipe 22 is provided on the shoulder rib 19 so that GD × 0.5 ≦ H _s ≦ GD × 0.9. This allows the depth H _S of the multisipes 22 and too deep or too shallow, to prevent the uneven wear resistance in the shoulder rib end 21a is not sufficiently secured.

The open sipes 25 are formed at a given interval P _OS in the tire circumferential direction with provided longer than multisipes 22 extend substantially parallel to the tire width direction to the shoulder rib 19. In the open sipe 25, the length W _{OS in} the tire width direction is set to 50% or more of the length W _sh of the shoulder rib 19 in the tire width direction. That is, each open sipe 25 is provided on the shoulder rib 19 so that W _OS ≧ W _sh × 0.5.

  Further, the open sipe 25 has one end opened to and communicates with the main groove 16 at the shoulder rib end 21 b, while the other end opens and communicates with one of the plurality of multi-sipes 22. That is, the open sipe 25 extends inward in the tire width direction from the multi-sipe 22 and penetrates the shoulder rib 19 along the tire width direction.

  Therefore, the pneumatic tire 1 has the shoulder rib 19 with the shoulder rib 19 extending in the tire width direction to reduce the rigidity of the shoulder rib 19 in the tire circumferential direction. Deformation in the entire tire circumferential direction is allowed. As a result, for example, even when an excessive lateral force or the like is applied to the pneumatic tire 1 when the vehicle turns, the stress on the shoulder rib end portion 21a is reduced by the deformation of the entire shoulder rib 19 in the tire circumferential direction. . As a result, the ground contact pressure acting on the shoulder rib end 21a is further reduced, the uneven wear of the shoulder rib 19 is suppressed, and the concentration of stress on the shoulder rib end 21a is alleviated. It is possible to prevent cracks from being generated from the multi-sipe 22 at the rib end portion 21a and chipping or flaking in a block shape. Therefore, the occurrence of tears at the shoulder rib end 21a is suppressed.

At this time, since each open sipe 25 is provided on the shoulder rib 19 so that W _OS ≧ W _sh × 0.5, the rigidity of the shoulder rib 19 in the tire circumferential direction is sufficiently reduced. Further, here, since each open sipe 25 penetrates the shoulder rib 19 along the tire width direction and no closed end portion is formed, for example, stress concentration occurs at the closed end portion. Generation of cracks can be prevented.

Further, each open sipe 25 has the other end opened to and communicates with the multi sipe 22 and is extended from the multi sipe 22 so that an installation space for the open sipe 25 is secured between the multi sipe 22 adjacent in the tire circumferential direction. Therefore, it is possible to improve the installation space of the open sipe 25. That is, the setting of the interval P _S of multisipes 22, installation of the open sipe 25 is not affected.

Here, in the open sipe 25, the depth H _OS in the tire radial direction is preferably 0.2 times (20%) or more and 0.5 times (50%) the depth GD of the main groove 16 in the tire radial direction. ) Set to the following range. That is, each open sipe 25 is provided on the shoulder rib 19 so that GD × 0.2 ≦ H _OS ≦ GD × 0.5. Accordingly, since the depth H _OS of the open sipe 25 is deeper than GD × 0.2, the depth H _OS is too shallow, and the effect of reducing the tire circumferential rigidity of the shoulder rib 19 cannot be sufficiently obtained. It is possible to prevent the deterioration of tear resistance. On the other hand, since the depth H _OS of the open sipe 25 is shallower than GD × 0.5, it is prevented that the depth H _OS is too deep and the rigidity in the tire circumferential direction of the shoulder rib 19 is excessively reduced. Occurrence of heel and toe wear can be prevented.

Furthermore, the open sipes 25, each open sipe 25 intervals P _OS between adjacent in the tire circumferential direction is preferably more than 3.0 times the distance P _S of the multisipes 22 adjacent to each other in the tire circumferential direction 9. The range is set to 0 times or less. That is, each open sipe 25 is provided on the shoulder rib 19 so that P _S × 3.0 ≦ P _OS ≦ P _S × 9.0. As a result, since the interval P _OS of the open sipes 25 is narrower than P _S × 9.0, it is possible to prevent the interval P _{OS from} being too wide and sufficiently reducing the tire circumferential rigidity of the shoulder rib 19. It is possible to prevent deterioration of tear resistance. On the other hand, since the interval P _OS of the open sipes 25 is wider than P _S × 3.0, it is prevented that the interval P _OS is too narrow and the tire rib rigidity in the tire circumferential direction is excessively reduced. -It is possible to prevent occurrence of AND-to-wear.

According to the pneumatic tire 1 according to the reference embodiment described above, the shoulder rib 19 that is partitioned by the main groove 16 that is continuous in the tire circumferential direction and that is provided on the side in the tire width direction, and the tire width direction of the shoulder rib 19 A plurality of multi-sipes 22 provided along the tire width direction at the outer shoulder rib end 21a and a plurality of tire ribs along the tire circumferential direction, and a shoulder rib 19 extending along the tire width direction and longer than the multi-sipe 22 are formed. And a plurality of open sipes 25.

Therefore, since having a plurality of multisipes 22 at predetermined intervals P _S in the tire circumferential direction in a shoulder rib end 21a, that rigidity of the shoulder rib end 21a is lowered, the shoulder rib end 21a Since deformation is allowed and the ground contact pressure acting on the shoulder rib end 21a is reduced, uneven wear of the shoulder rib 19 can be suppressed. Further, by providing an open sipe 25 along the tire width direction at the shoulder rib 19, the rigidity of the shoulder rib 19 in the tire circumferential direction is reduced, so that the tire of the entire shoulder rib 19 is loaded when a load is applied. Deformation in the circumferential direction is allowed. As a result, due to the deformation of the entire shoulder rib 19 in the tire circumferential direction, the stress on the shoulder rib end portion 21a is reduced, and the concentration of stress on the shoulder rib end portion 21a is further relaxed. It is prevented that a crack is generated from the multi-sipe 22 of the portion 21a and the chip is chipped or peeled off. As a result, both the uneven wear resistance and the tear resistance of the shoulder rib 19 can be achieved.

Further, according to the pneumatic tire 1 according to the reference embodiment described above, the open sipe 25 has a length W _{OS in} the tire width direction set to 50% or more of the length W _sh of the shoulder rib 19 in the tire width direction. Is done. Therefore, since the open sipe 25 is provided on the shoulder rib 19 so that W _OS ≧ W _sh × 0.5, the rigidity of the shoulder rib 19 in the tire circumferential direction can be sufficiently reduced.

Furthermore, according to the pneumatic tire 1 which concerns on the reference form demonstrated above, the open sipe 25 penetrates the shoulder rib 19 along a tire width direction. Accordingly, since the open sipe 25 is provided through the shoulder rib 19 along the tire width direction, a closed end portion is not formed in the open sipe 25, and thus cracks are prevented from occurring from the open sipe 25. can do. That is, an increase in crack generating elements can be prevented.

Furthermore, according to the pneumatic tire 1 according to the reference embodiment described above, the open sipe 25 is extended from the multi-sipe 22. Therefore, since the open sipe 25 is extended from the multi-sipe 22, it is not necessary to secure an installation space for the open sipe 25 between the multi-sipes 22 adjacent in the tire circumferential direction. Can be measured.

Furthermore, according to the pneumatic tire 1 according to the reference embodiment described above, the multi-sipe 22 has a tire radial depth H _S of 0.5 to 0.9 times the depth GD of the main groove 16. Set to range. Therefore, since the multi-sipe 22 is provided on the shoulder rib 19 so that GD × 0.5 ≦ H _S ≦ GD × 0.9, the depth H _S of the multi-sipe 22 is too shallow or too deep, and the shoulder It can be prevented that the partial wear resistance at the rib end 21a is not sufficiently ensured.

Furthermore, according to the pneumatic tire 1 according to the reference embodiment described above, it multisipes 22, the interval P _S of the multisipes 22 to each other is set to 10.0mm below the range of 5.0mm adjacent in the tire circumferential direction The Accordingly, since the multi-sipe 22 is provided on the shoulder rib 19 so that 5.0 [mm] ≦ P _S ≦ 10.0 [mm], the rigidity of the shoulder rib end portion 21a becomes extremely low and the tear resistance is reduced. It is possible to prevent the deterioration of the property and to prevent the shoulder rib end portion 21a from being too rigid and causing uneven wear.

Furthermore, according to the pneumatic tire 1 according to the reference embodiment described above, the open sipe 25 has a tire radial direction depth H _OS of 0.2 times to 0.5 times the depth GD of the main groove 16. Is set in the range. Therefore, since the open sipe 25 is provided on the shoulder rib 19 so that GD × 0.2 ≦ H _OS ≦ GD × 0.5, a decrease in tear resistance can be prevented and so-called heel and Toe wear can be prevented from occurring.

Furthermore, according to the pneumatic tire 1 according to the reference embodiment described above, the open sipes 25, the interval P _OS of the open sipe 25 adjacent to each other in the tire circumferential direction, between multisipes 22 adjacent in the tire circumferential direction The interval P _S is set in a range of 3.0 to 9.0 times. Therefore, since the open sipe 25 is provided on the shoulder rib 19 so that P _S × 3.0 ≦ P _OS ≦ P _S × 9.0, it is possible to prevent a decrease in tear resistance and a so-called heel- The occurrence of AND-to-wear can be prevented.

Furthermore, according to the pneumatic tire 1 according to the reference embodiment described above, the tire width of the multi-sipe 22 via the shoulder rib end portion 21a extending 20 in the tire circumferential direction and narrower than the main groove 16 is formed. A thin rib 23 provided outward in the direction is provided. Therefore, since the narrow groove 20 and the thin rib 23 that are continuous in the tire circumferential direction are provided outside the shoulder rib 19 in the tire width direction, the concentration of stress on the multi-sipe 22 portion is alleviated, so that the shoulder rib 19 Uneven wear is suppressed. At this time, uneven wear of the shoulder rib end portion 21 a of the shoulder rib 19 can also be suppressed by the fine rib 23 being more actively worn than the shoulder rib 19.

In addition, the pneumatic tire which concerns on the reference form of this invention mentioned above is not limited to the form mentioned above, A various change is possible. In the above description, the center rib and the shoulder rib are described as being formed in a rib row base tone that is substantially continuous in the tire circumferential direction. However, for example, the center rib may be in a block pattern base tone. Moreover, in the above description, although demonstrated as what provides the narrow groove and thin rib of this invention in the shoulder rib edge part, it is not necessarily required.

  In the above description, the width-direction sipe is described as being provided on the shoulder rib so as to extend substantially in parallel along the tire width direction. However, the width-direction sipe may be slightly inclined with respect to the tire width direction. Good. In addition, this width direction sipe has been described as extending inward in the tire width direction from the rib end sipe and passing through the shoulder rib along the tire width direction, but one end portion does not communicate with the main groove and is closed Alternatively, the other end may be directly open to communicate with the narrow groove. Moreover, the other end part may be a closed end. That is, the width sipe may be a closed sipe.

  Further, in the above description, the rib end sipe and the width direction sipe are described as being provided on the shoulder ribs on both sides of the tire width direction, but depending on the ground contact state of the tread surface when a pneumatic tire is mounted on the vehicle For example, it may be provided only on one side. In addition, it has been described that rib end sipes are provided only at the shoulder rib end portions on the outer side in the tire width direction among the shoulder rib end portions at both ends in the tire width direction of the shoulder ribs. An end sipe may be provided. Moreover, you may provide the sipe of the structure similar to a rib end sipe and the width direction sipe in center ribs other than a shoulder rib.

( Embodiment )
Figure 4 is a cutaway perspective view of a pneumatic tire according to an embodiment of the present invention, FIG 5 is a meridional partial sectional view of a pneumatic tire according to an embodiment of the present invention. The pneumatic tire according to the embodiment has substantially the same configuration as the pneumatic tire according to the reference embodiment , but further differs from the pneumatic tire according to the reference embodiment in that it includes a circumferential shallow groove. In addition, about the structure, effect | action, and effect which are common in the reference form mentioned above, while overlapping description is abbreviate | omitted as much as possible, the same code | symbol is attached | subjected.

As shown in FIGS. 4 and 5, the pneumatic tire 201 according to the embodiment includes a shoulder rib 19, a multi-sipe 22, and an open sipe 25, and further includes a shallow groove 226 as a circumferential shallow groove.

  The shallow groove 226 is provided on the multi-sipe 22 side from the center in the tire width direction of the shoulder rib 19, that is, provided close to the multi-sipe 22. The shallow groove 226 extends substantially parallel to the tire circumferential direction and is provided shallower than the main groove 16. The shallow groove 226 is set such that the length in the tire circumferential direction is 50% or more of the length of the shoulder rib 19 in the tire circumferential direction. That is, the shallow groove 226 is provided continuously or intermittently in the shoulder rib 19 so that the shallow groove tire circumferential length ≧ the shoulder rib tire circumferential length × 0.5. In the present embodiment, the shallow groove 226 penetrates the shoulder rib 19 along the tire circumferential direction, that is, is formed in an annular shape.

  Therefore, in the pneumatic tire 201, the shoulder rib 19 is provided with the shoulder rib 19 by the shallow groove 226 extending in the tire circumferential direction in addition to the rigidity in the tire circumferential direction of the shoulder rib 19 being reduced by the open sipes 25. By reducing the rigidity in the tire width direction of 19, deformation of the entire shoulder rib 19 in the tire width direction is allowed when a load is applied. As a result, for example, even when an excessive lateral force or the like is applied to the pneumatic tire 201 when the vehicle turns, the stress on the shoulder rib end portion 21a is reduced due to the deformation of the entire shoulder rib 19 in the tire width direction. . As a result, the ground contact pressure acting on the shoulder rib end 21a is further reduced, the uneven wear of the shoulder rib 19 is suppressed, and the concentration of stress on the shoulder rib end 21a is alleviated. It is more reliably prevented that a crack is generated from the multi-sipe 22 of the rib end portion 21a and is chipped or peeled in a block shape. Therefore, the occurrence of tears at the shoulder rib end 21a is suppressed.

  At this time, since the shallow groove 226 is provided in the shoulder rib 19 so that the length of the shallow groove tire circumferential direction ≧ the length of the shoulder rib tire circumferential direction × 0.5, the shoulder rib 19 sufficiently extends in the tire width direction. Stiffness is reduced. Further, here, since the shallow groove 226 penetrates the shoulder rib 19 along the tire width direction and the closed end portion is not formed, for example, stress concentration occurs in the closed end portion, and cracks are generated from the closed end portion. Can be prevented.

Wherein the shallow groove 226, the length W _a width direction of the tire is set in a range of 3.0 [mm] or less. Also, preferably, the shallow grooves 226, the length W _a width direction of the tire is set in a range of 2.0 [mm] or more. That is, the shallow groove 226 is provided in the shoulder rib 19 so that 2.0 [mm] ≦ W _a ≦ 3.0 [mm]. Thereby, since the length W _a of the shallow groove 226 in the tire width direction is shorter than 3.0 [mm], the length W _a is too long, and the rigidity of the shoulder rib 19 in the tire width direction is excessively reduced. Therefore, it is possible to prevent the occurrence of uneven wear. On the other hand, since the length W _{a of} the shallow groove 226 in the tire width direction is longer than 2.0 [mm], the length W _a is too short, and the effect of reducing the rigidity of the shoulder rib 19 in the tire width direction is sufficient. It is possible to prevent it from being obtained and to prevent a decrease in tear resistance.

Further, the shallow grooves 226, the depth H _a radial direction of the tire is set in a range of 4.0 [mm] or less. Also, preferably, the shallow groove 226 has a depth H _a radial direction of the tire is set in a range of 2.0 [mm] or more. That is, the shallow groove 226 is provided in the shoulder rib 19 so as to satisfy 2.0 [mm] ≦ H _a ≦ 4.0 [mm]. Thus, since the depth H _a shallow groove 226 is 4.0 [mm] shallower than the tire width direction stiffness of the depth H _a is too deep the shoulder rib 19 is prevented from excessively reduced, thus It is possible to prevent the occurrence of uneven wear. On the other hand, the depth H _a shallow groove 226, 2.0 since deeper than [mm], the effect of reducing the tire width direction rigidity of the shoulder rib 19 the depth H _a is too shallow can not be sufficiently obtained Can be prevented, and deterioration of tear resistance can be prevented.

  According to the pneumatic tire 201 according to the present embodiment described above, the shoulder rib 19 that is partitioned by the main groove 16 that is continuous in the tire circumferential direction and is provided on the side portion in the tire width direction, and the tire width in the shoulder rib 19. A multi-sipe 22 provided along the tire width direction at the shoulder rib end 21a on the outer side in the direction and provided in the tire circumferential direction, and a shoulder rib 19 extending along the tire width direction and longer than the multi-sipe 22 And a plurality of open sipes 25 to be formed. Therefore, the open sipe 25 can suppress uneven wear of the shoulder rib 19 and prevent a crack from being generated from the multi-sipe 22 of the shoulder rib end portion 21a and chipping or flaking in a block shape. As a result, both the uneven wear resistance and the tear resistance of the shoulder rib 19 can be achieved.

  Furthermore, according to the pneumatic tire 201 according to the present embodiment described above, the shoulder rib 19 is formed on the multi-sipe 22 side from the center in the tire width direction along the tire circumferential direction and is formed shallower than the main groove 16. The shallow groove 226 is provided. Therefore, since the shoulder rib 19 is further provided with a shallow groove 226 extending in the tire circumferential direction at the shoulder rib end portion 21a, the rigidity of the shoulder rib 19 in the tire width direction is also reduced. The entire shoulder rib 19 is allowed to be deformed in the tire width direction. As a result, due to the deformation of the entire shoulder rib 19 in the tire width direction, the stress on the shoulder rib end portion 21a is reduced, and the concentration of stress on the shoulder rib end portion 21a is further relaxed, so that the shoulder rib end portion is reduced. It is prevented that a crack is generated from the multi-sipe 22 of the portion 21a and the chip is chipped or peeled off. As a result, the uneven wear resistance and the tear resistance of the shoulder rib 19 can be further improved.

  Furthermore, according to the pneumatic tire 201 according to this embodiment described above, the shallow groove 226 is set such that the length in the tire circumferential direction is 50% or more of the length of the shoulder rib 19 in the tire circumferential direction. Therefore, since the shallow groove 226 is provided in the shoulder rib 19 so that the length in the circumferential direction of the shallow groove tire ≧ the length in the circumferential direction of the shoulder rib × 0.5, the rigidity of the shoulder rib 19 in the tire width direction is sufficiently increased. Can be reduced.

  Furthermore, according to the pneumatic tire 201 according to the present embodiment described above, the shallow groove 226 penetrates the shoulder rib 19 along the tire circumferential direction. Therefore, since the shallow groove 226 is provided through the shoulder rib 19 along the tire circumferential direction, a closed end portion is not formed in the shallow groove 226, so that the shallow groove 226 is prevented from generating a crack. can do. That is, an increase in crack generating elements can be prevented.

Further, according to the pneumatic tire 201 according to the present embodiment described above, the shallow groove 226, the length of the tire width direction (width) W _a is 2.0 [mm] or more 3.0 [mm] or less Is set in the range. Therefore, since the shallow groove 226 is provided in the shoulder rib 19 so that 2.0 [mm] ≦ W _a ≦ 3.0 [mm], it is possible to prevent uneven wear and to prevent tear resistance. The fall of property can be prevented.

Further, according to the pneumatic tire 201 according to the present embodiment described above, the shallow groove 226 has a depth H _a radial direction of the tire is 2.0 [mm] or more 4.0 [mm] in the following ranges Is set. Therefore, since the shallow groove 226 is provided in the shoulder rib 19 so that 2.0 [mm] ≦ H _a ≦ 4.0 [mm], uneven wear can be prevented and tear resistance can be prevented. The fall of property can be prevented. Even if the tread surface 5 is worn in accordance with the use of the pneumatic tire 201 and the shallow groove 226 is eventually lost, the initial wear of the tread surface 5 immediately after the use of the pneumatic tire 201 is started. Since the shallow groove 226 acts at the stage, it is possible to achieve an effect of achieving both partial wear resistance and tear resistance.

  FIG. 6 is a diagram showing the results of a performance test of a pneumatic tire according to an example of the present invention. An embodiment of the present invention will be described with reference to this figure. Pneumatic tires 1,201 according to the embodiment described above were prototyped, and performance evaluation tests of the pneumatic tires 1,201 and conventional pneumatic tires were performed. The performance evaluation test was performed on two items, uneven wear resistance and tear resistance. In this performance test, a pneumatic tire with a tire size of 295 / 80R22.5 with four grooves (four main grooves 16) rib pattern is mounted on a regular rim specified by JATMA, and the normal internal pressure and normal load are applied to the pneumatic tire. The pneumatic tire was mounted on the front of a 2-D4 test vehicle.

  The regular rim here refers to an “applied rim” defined in JATMA, a “Design Rim” defined in TRA, or a “Measuring Rim” defined in ETRTO. The normal internal pressure means “maximum air pressure” defined by JATMA, the maximum value of “TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES” defined by TRA, or “INFLATION PRESSURES” defined by ETRTO. The normal load means the “maximum load capacity” defined in JATMA, the maximum value of “TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES” defined in TRA, or “LOAD CAPACITY” defined in ETRTO.

  As for the evaluation method of each test item, the uneven wear resistance is generated in the shoulder rib 19 after traveling by running 60,000 km on the test course at a speed of 80 km / h on a test vehicle equipped with pneumatic tires. This was done by checking the uneven wear situation. The evaluation results are indicated by an index with the evaluation result of Conventional Example 1 described later as 100, and the larger the index, the better the uneven wear resistance.

  For tear resistance, check the number of tiers that occurred in the shoulder rib 19 after repeatedly entering and exiting the step provided in the test course at a fixed angle by a test vehicle equipped with pneumatic tires. Performed. The evaluation results are indicated by an index with the evaluation result of Conventional Example 1 described later as 100, and the larger the index, the better the tear resistance.

As shown in FIG. 6, two types as a conventional example, one type as a comparative example to be compared with the present invention, a reference example of the present invention, and six types as examples are tested by the above method. The pneumatic tires shown in “Reference Example 1”, “Reference Example 2”, “Example 1” to “Example 4 ” are provided with an open sipe 25 along with a multi-sipe 22 on a shoulder rib 19. Among these, the pneumatic tires shown in “Example 1 ” to “Example 4 ” further include a shallow groove 226 in the shoulder rib 19. On the other hand, the pneumatic tires shown in “Conventional Example 1” to “Conventional Example 2” include only the multi-sipe 22 on the shoulder rib 19, and the pneumatic tire shown in “Comparative Example” includes the multi-sipe 22, the open sipe 25, None of the shallow grooves 226 are provided.

As is apparent from FIG. 6, “Conventional Example 1” with P _S = 10.0 [mm] and H _S /GD=0.5 has improved uneven wear resistance as compared with “Comparative Example”. However, the tear resistance has decreased. On the other hand, “Conventional Example 2” with P _S = 5.0 [mm] and H _S /GD=0.9 has improved uneven wear resistance compared to “Conventional Example 1” and “Comparative Example”. However, the tear resistance is further reduced. That is, both “Conventional Example 1” and “Conventional Example 2” indicate that both uneven wear resistance and tear resistance cannot be achieved.

On the other hand, the pneumatic tires shown in “Reference Example 1”, “Reference Example 2”, “Example 1” to “Example 4 ”, in which the shoulder rib 19 is provided with the multi-sipe 22 and the open sipe 25, have uneven wear resistance. While maintaining or improving at least the performance of “Conventional Example 1”, the tear resistance is also improved. That is, it is shown that the uneven wear resistance and the tear resistance are compatible in all the examples.

Further, the pneumatic tires shown in “Example 1 ” to “Example 4 ” having the shallow groove 226 in the shoulder rib 19 can further improve the tear resistance as compared with “ Reference Example 1 ”. It shows that. The interval P _S of multisipes 22 provided in the shoulder rib 19, the depth H _S, spacing P _OS open sipes 25, depth H _OS, the length W _a shallow groove 226, the depth H _a like are optimized This shows that the uneven wear resistance and the tear resistance of the pneumatic tire can be maintained or improved.

  As described above, the pneumatic tire according to the present invention has both uneven wear resistance and tear resistance, and is useful when applied to various pneumatic tires in addition to heavy duty pneumatic tires. .

1 is a cutaway perspective view of a pneumatic tire according to a reference embodiment of the present invention. It is meridional fragmentary sectional view of the pneumatic tire which concerns on the reference form of this invention. It is meridional sectional drawing which shows the principal part of the pneumatic tire which concerns on the reference form of this invention. 1 is a cutaway perspective view of a pneumatic tire according to an embodiment of the present invention. It is meridional fragmentary sectional view of the pneumatic tire which concerns on embodiment of this invention. It is a figure which shows the result of the performance test of the pneumatic tire which concerns on the Example of this invention.

Explanation of symbols

1,201 Pneumatic tire 5 Tread surface 6 Tread portion 7 Shoulder portion 8 Side wall portion 9 Bead portion 11 Carcass 16 Main groove (groove)
19 Shoulder rib 20 Narrow groove 21a, 21b Shoulder rib end 22 Multi sipe (rib end sipe)
23 Thin rib 25 Open sipe (width direction sipe)
50 Equatorial plane 226 Shallow groove (circumferential shallow groove)

Claims (13)

A shoulder rib that is partitioned by a groove continuous in the tire circumferential direction and provided on the side in the tire width direction,
Rib end sipes provided along the tire width direction at the shoulder rib end on the outer side in the tire width direction of the shoulder rib and provided in a plurality in the tire circumferential direction;
A plurality of width direction sipes extending along the tire width direction on the shoulder rib and formed longer than the rib end sipes ;
A circumferentially shallow groove extending along the tire circumferential direction and shallower than the groove, on the rib end sipe side from the tire width direction center of the shoulder rib ,
The rib end sipes are set such that the depth in the tire radial direction is not less than 0.5 times and not more than 0.9 times the depth of the groove, and one end opens on the outer side in the tire width direction, while the other The end is closed on the inner side in the tire width direction ,
Pneumatic tire. The width direction sipe is characterized in that a length in the tire width direction is set to 50% or more of a length of the shoulder rib in the tire width direction.
The pneumatic tire according to claim 1. The width-direction sipe penetrates the shoulder rib along the tire width direction.
The pneumatic tire according to claim 1 or claim 2. The width direction sipe is extended from the rib end sipe,
The pneumatic tire according to any one of claims 1 to 3. The rib end sipes are characterized in that an interval between the rib end sipes adjacent in the tire circumferential direction is set in a range of 5.0 mm or more and 10.0 mm or less.
The pneumatic tire according to any one of claims 1 to 4 . The width direction sipe is characterized in that the depth in the tire radial direction is set in a range of 0.2 to 0.5 times the depth of the groove.
The pneumatic tire according to any one of claims 1 to 5 . In the width direction sipe, an interval between the width direction sipes adjacent in the tire circumferential direction is in a range of 3.0 times or more and 9.0 times or less of an interval between the rib end sipes adjacent in the tire circumferential direction. Characterized by being set,
The pneumatic tire according to any one of claims 1 to 6 . The circumferential shallow groove has a length in the tire circumferential direction set to 50% or more of a length in the tire circumferential direction of the shoulder rib,
The pneumatic tire according to any one of claims 1 to 7 . The circumferential shallow groove penetrates the shoulder rib along the tire circumferential direction,
The pneumatic tire according to any one of claims 1 to 8 . The circumferential shallow groove is characterized in that the width in the tire width direction is set in a range of 3.0 mm or less.
The pneumatic tire according to any one of claims 1 to 9. The circumferential shallow groove is characterized in that the depth in the tire radial direction is set in a range of 4.0 mm or less.
The pneumatic tire according to any one of claims 1 to 10. The shoulder rib end portion includes a thin rib provided on the outer side in the tire width direction of the rib end sipe through a narrow groove extending in the tire circumferential direction and formed narrower than the groove. To
The pneumatic tire according to any one of claims 1 to 11 . A shoulder rib that is partitioned by a groove continuous in the tire circumferential direction and provided on the side in the tire width direction,
  Rib end sipes provided along the tire width direction at the shoulder rib end on the outer side in the tire width direction of the shoulder rib and provided in a plurality in the tire circumferential direction;
  A plurality of width direction sipes extending along the tire width direction on the shoulder rib and formed longer than the rib end sipes;
  A circumferentially shallow groove extending along the tire circumferential direction and shallower than the groove, on the rib end sipe side from the tire width direction center of the shoulder rib,
  The rib end sipe is characterized in that one end portion is open on the outer side in the tire width direction and the other end portion is closed on the inner side in the tire width direction.
  Pneumatic tire.

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