JP2016222207A - Pneumatic tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pneumatic tire that is improved in abrasion resistance and quietness while further enhancing traction performance.SOLUTION: The pneumatic tire has one or more land part sandwiched between a plurality of continuous circumferential main grooves 21 and 22 provided at a tread surface 1. In the at least one of the land parts, a plurality of blocks are formed of sub grooves in a width direction at least including inclining grooves 8. The plurality of blocks comprise: a first block 71 having a recessed part 62 inclining in a width direction formed; a second block 72 arranged at a position opposing to the recessed part of the first block; and a third block 73 arranged at a position opposing to a first side wall part 71c adjacent to the recessed part in one block part 71a of two block parts forming the recessed part of the first block. A side wall part adjacent to the recessed part in the other block part 71b, of the two block parts, is positioned in an extending direction of the inclining groove which inclines at 55°-90° relative to the width direction.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a pneumatic tire.

  Conventionally, a pattern having a circumferential main groove and a width direction groove is known as a tread pattern that achieves both tire drainage performance and traction performance (see, for example, Patent Document 1). According to such a tread pattern, the traction performance is ensured by the edge effect obtained by dividing the land portion into blocks by the width direction groove while enhancing the drainage by the circumferential main groove and the width direction groove having a large groove width. can do. In tires having a tread pattern as described in Patent Document 1, in order to ensure traction performance on rough roads such as muddy grounds, gravel roads, and snowy roads, the inclination angle of the width direction grooves with respect to the tire circumferential direction is set. There is a larger tire.

JP 2008-44441 A

  As in Patent Document 1, in a tire in which the inclination angle of the width direction groove with respect to the tire circumferential direction is increased, the noise outside the vehicle tends to increase. In recent years, there has been an increasing demand for lowering the passing noise when driving vehicles in urban areas, etc., and even in tires with high traction performance on bad roads such as muddy areas, gravel roads, snowy roads, etc., the block rigidity is increased and the wear resistance is increased. There is a demand for a technique that can improve the noise and improve the quietness.

  The present invention is intended to solve the above-mentioned problem, and while improving the traction performance, it can ensure sufficient block rigidity, improve wear resistance, and can improve quietness. The object is to provide a tire.

The gist configuration of the present invention is as follows.
The pneumatic tire of the present invention has one or more land portions sandwiched by a plurality of circumferential main grooves extending continuously in the tire circumferential direction on the tread surface, and at least one of the land portions is in the tire width direction. A plurality of blocks are formed by being partitioned by sub-grooves that include at least an inclined groove extending with respect to the tread surface, and the plurality of blocks are inclined with respect to the tire width direction when viewed from the tread surface. A first block having a recess formed therein, a second block disposed at a position facing the recess of the first block, and two block portions forming the recess of the first block A third block disposed at a position facing the first side wall portion adjacent to the recess in one block portion, and the other block of the two block portions. Side wall portion adjacent to the recess in the click portion is located in the extending direction of the inclined groove which is inclined in the range of 55 ° to 90 ° with respect to the tire width direction, it is characterized in.
According to the pneumatic tire of the present invention, the block rigidity can be sufficiently secured to improve the wear resistance and the quietness can be improved while further improving the traction performance.

  Here, the `` tread surface '' means that when a tire that is assembled to the applicable rim and filled with the specified internal pressure is rolled with a load corresponding to the maximum load capacity applied, the tire will come into contact with the road surface. It means the outer peripheral surface over the entire circumference of the tire. Here, the “applicable rim” is a standard rim defined in the following standard according to the tire size (“Design Rim” in YEAR BOOK of TRA below. “Measuring Rim” in STANDARDDS MANUAL of ETRTO below). The "specified internal pressure" means the air pressure specified in accordance with the maximum load capacity in the following standards, and the "maximum load capacity" is allowed to be applied to the tire according to the following standards. The maximum mass. The standard is determined by an industrial standard that is effective in the region where the tire is produced or used. For example, in the United States, “YEAR BOOK” of “The Tire and Rim Association, Inc. (TRA)” is used. “In Europe,“ The European Tire and Rim Technical Organization (ETRTO) ”is“ STANDARDS MANUAL ”. In Japan,“ Japan Auto Tire Association (JATMA) ”is“ JATMA YEAR BOOK ”.

Further, the phrase “the circumferential main groove extends continuously in the tread circumferential direction” means that the circumferential main groove extends continuously in the tread circumferential direction, and the zigzag extends continuously in the tread circumferential direction. The case where it extends continuously while curving toward the tread circumferential direction is also included.
Further, “arranged at opposing positions” means that at least some of the elements are arranged at positions opposing each other.

In the pneumatic tire of the present invention, it is preferable that the second block has a size in the tire circumferential direction that is larger toward the outer side in the tire width direction than the central portion in the tire width direction.
Here, “the tire circumferential dimension increases from the center in the tire width direction toward the outer side in the tire width direction” means that the dimension in the tire circumferential direction becomes constant toward the outer side in the tire width direction. This includes the case where the rate of increase in the tire circumferential dimension increases or decreases, but does not include the case where the tire circumferential dimension decreases.
According to this configuration, steering stability can be improved.

In the pneumatic tire according to the present invention, the side wall facing the first side wall portion of the third block has a dimension in the extending direction of the auxiliary groove that divides the first block and the third block. It is preferable that the dimension of the first side wall portion is larger than the dimension in the extending direction of the sub-groove, and the first side wall portion is chamfered on the tread tread surface side.
According to this configuration, the rigidity of the block can be further increased to further increase the wear resistance, and the traction performance can be further improved.
Here, “the tread tread surface side is chamfered” includes that the entire tread tread surface is chamfered.

In the pneumatic tire of the present invention, the inclined groove is sandwiched between another first block adjacent to the first block and the second block, and the inclination of the second block It is preferable that a stepped portion that is convex toward the inclined groove is formed on the side wall defined by the groove.
According to this configuration, the traction performance can be further improved.

In the pneumatic tire according to the present invention, the second block is formed with a stepped recess having one end opened in the circumferential main groove and a step that protrudes in the tire radial direction is formed at the bottom. It is preferable.
According to this configuration, the steering stability can be improved, and the traction performance and the block rigidity can be improved to further improve the wear resistance.

In the pneumatic tire according to the present invention, the tread tread surface side of the side wall forming the concave portion of the first block of one block portion and the other block portion of the first block forming the concave portion of the first block is provided. In the unfolded view of the tread surface, the concave portion of the first block is connected to a side wall that forms the concave portion of the first block of the one block portion and the other block portion. It preferably has a curved surface shape.
According to this configuration, it is possible to further improve the wear resistance by further securing the block rigidity while further improving the traction performance.

  ADVANTAGE OF THE INVENTION According to this invention, the pneumatic tire which can improve both traction performance and silence can be provided, raising block rigidity and raising abrasion resistance further.

It is an expanded view which shows the tread pattern of the pneumatic tire concerning one Embodiment of this invention. FIG. 2 is a partially enlarged view of a central land portion of the pneumatic tire of FIG. 1.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a development view showing a tread pattern of a pneumatic tire (hereinafter also simply referred to as a tire) according to an embodiment of the present invention. The tire is mounted on an applied rim, filled with a specified internal pressure, FIG. 2 is a partially enlarged view of the central land portion of FIG. 1 to be described later. Hereinafter, unless otherwise specified, the shape and dimensions of the tread pattern are those when the tread tread is viewed unfolded.

As shown in FIG. 1, in a tire according to an embodiment of the present invention, a circumferential main groove that extends continuously in the tread circumferential direction is formed on a tread tread surface 1. In the example of FIG. 1, the tread surface 1 has two circumferential main grooves 21 and 22 that extend linearly along the tread circumferential direction. In the present embodiment, the two circumferential main grooves 21 and 22 have the same shape, and the circumferential drainage of the tire can be ensured by the circumferential main grooves 21 and 22.
In the example shown in FIG. 1, the two circumferential main grooves 21 and 22 are provided symmetrically with respect to the tire equatorial plane CL.

Further, as shown in FIG. 1, a plurality of land portions are defined by two circumferential main grooves 21 and 22 and tread ends TE1 and TE2. Specifically, an outer land portion 31 on one side in the tread width direction is defined by the circumferential main groove 21 on one side in the tread width direction and the tread end TE1 on one side, and the circumferential main groove 21 and the tread are formed. The central land portion 32 is defined by the circumferential main groove 22 on the other side in the width direction, and the outer land portion 33 on the other side in the tread width direction is defined by the circumferential main groove 22 and the tread end TE2 on the other side. Is formed.
In the example of illustration, it forms so that the dimension of the tread width direction of the outer land part 31 and the outer land part 33 may become equal.
Here, the “tread end” refers to the outermost position of the tread surface in the tread width direction.

In the outer land portion 31 of the present embodiment, one end opens at the tread end TE1, the other end opens at the circumferential main groove 21, and one end opens at the tread end TE1, and the other end at the outer land. A lug groove 42 that terminates in the portion 31 is formed. The outer land portion 31 of the present embodiment is further formed with a widthwise concave portion 61 that is recessed outward in the tire width direction on the side wall defined by the circumferential main groove 21. In the outer land portion 31 of this embodiment, one end is opened in the circumferential main groove 21 and the other end is terminated in the outer land portion 31, and one end is opened in the lug groove 42 and the other end is wide. A sipe 52 that opens to the directional recess 61 is formed.
Here, “sipe” refers to a thin notch cut into the inside from the outer surface of the block, which can be closed when grounded.

  In the outer land portion 33 on the other side of the present embodiment, lug grooves 41 and 42, a recess 61, a sipe 51, and a sipe 52 are formed in the same manner as the outer land portion 31 on one side.

In the present embodiment, the central land portion 32 sandwiched between the circumferential main grooves 21 and 22 is partitioned by the sub-groove 25 including at least the inclined groove 8 extending inclined with respect to the tire width direction, and a plurality of blocks. Is formed. Specifically, the central land portion 32 is defined by the sub-groove 25 including at least the inclined groove 8, is disposed on the center of the central land portion 32 in the tire width direction, and is recessed so as to be inclined with respect to the tire width direction. The first block 71 in which the first block 71 is formed, the second block 72 disposed at a position facing the concave portion 62 of the first block 71, and the first block forming the concave portion 62 of the first block 71. Among the two block portions 71a and 71b of 71, there is provided a third block 73 disposed at a position facing one side wall portion 71c adjacent to the recess 62 in one block portion 71a.
Here, “arranged at an opposing position” means that at least a part of the elements is arranged at an opposing position.
In the present embodiment, the first block 71 is disposed on the center of the central land portion 32 in the tire width direction. Further, in the present embodiment, the center position in the tire width direction of the central land portion 32 coincides with the position of the tire equatorial plane CL.
In the present embodiment, of the two block portions 71a and 71b, the second side wall portion 71d adjacent to the recess 62 in the other block portion 71b is 55 ° to the tire width direction in the sub-groove 25. It is located in the extending direction of the inclined groove 8 that is inclined in the range of 90 °. The inclined groove 8 is preferably inclined in the range of 60 ° to 90 ° with respect to the tire width direction.
In the present embodiment, all the secondary grooves 25 extending to the central land portion 32 are inclined in the range of 45 ° to 90 ° with respect to the tire width direction.
In the present embodiment, the first block 71, the second block 72, and the third block 73 are partitioned so as to be point-symmetric about the point on the tire equatorial plane CL.
In the present embodiment, the first block 71, the second block 72, and the third block 73 are repeatedly arranged in the tire circumferential direction.

  In the embodiment shown in FIGS. 1 and 2, one block portion 71 a and the other block portion 71 b of the first block 71 that form the recess 62 of the first block 71 are the same as those of the first block 71. The tread tread surface side of the side walls 71e and 71f forming the recess 62 is chamfered. Further, the concave portion 62 of the first block 71 has a curved shape in the connecting portion 62a between the side wall 71e forming the concave portion 62 of one block portion 71a and the side wall 71f forming the concave portion 62 of the other block portion 71b. ing. Therefore, mud, gravel, snow and the like that have entered the recess 62 can be easily discharged out of the recess 62 from the side walls 71e and 71f and the connection portion 62a, so that the traction performance can be improved. Moreover, since the connection part 62a has a curved surface shape, it is possible to alleviate the concentration of distortion, improve the block rigidity, and improve the wear resistance. In particular, in the present embodiment, the side walls 71 e and 71 f forming the recess 62 and the entire connection portion 62 a are configured to be inclined with respect to the bottom of the recess 62.

  In the embodiment shown in FIGS. 1 and 2, the concave portion 62 of the first block 71 is formed in a triangular shape when the tread surface is viewed in a developed manner. Therefore, mud, gravel, snow and the like can be compressed at the connection portion 62a at the apex of the triangle, and the traction performance can be improved by improving the shearing force against the compressed mud, gravel and snow.

  In the embodiment shown in FIGS. 1 and 2, the first side wall portion 71 c is chamfered on the tread surface side. The second side wall portion 71d is chamfered on the tread tread surface side. In the present embodiment, the entire first side wall portion 71 c and second side wall portion 71 d are chamfered so as to be inclined with respect to the groove bottom of the sub-groove 25.

  In the embodiment shown in FIGS. 1 and 2, a plurality of sipes 53 are formed in the first block 71. Specifically, a sipe 53 a is formed with one end opening in the connecting portion 62 a of the recess 62 of the first block 71 and the other end opening in the sub-groove 25. Therefore, the rigidity of the first block 71 is made uniform, and the wear resistance is improved. In particular, in the embodiment shown in FIG. 1, the sipe 53 a is formed to have one bent portion F. Therefore, the first block 71 of this embodiment can support each other when the portion divided into two by the sipe 53a is deformed so as to fall down due to the addition of a force such as a side force. The movement of the groove 25 and the sipe 53a is interlocked with each other, so that large stress is prevented from concentrating on one portion divided by the sipe 53a, thereby improving the wear resistance. In the embodiment shown in FIG. 1, the sipe 53b adjacent to the sipe 53a is formed to have two bent portions F, and the wear resistance of the first block 71 is also improved by the sipe 53b. ing.

  In the present embodiment, as shown in FIGS. 1 and 2, the second block 72 has an end 72 a that extends toward the recess 62 of the first block 71. With such a configuration, mud, gravel, snow and the like are guided by the side wall of the end portion 72a and easily enter the recess 62, so that the traction performance can be improved.

  In the present embodiment, as shown in FIGS. 1 and 2, the end portion 72 a of the second block is chamfered on the tread tread surface side of the side wall 72 b facing the concave portion 62 of the first block 71. With such a configuration, mud, gravel, snow, and the like are easily guided to the inside of the recess 62 by the chamfered side wall 72b, so that the traction performance can be further improved. In the present embodiment, the entire side wall 72 b is chamfered so as to be inclined with respect to the groove bottom of the sub-groove 25.

  In the embodiment shown in FIGS. 1 and 2, the second block 72 has a shape in which the dimension in the tire circumferential direction increases from the center in the tire width direction toward the outer side in the tire width direction. This configuration increases the rigidity of the outer side in the tire width direction of the second block 72 receiving a large side force in a state in which the load on the wheel on the outside of the turn increases during cornering and the contact pressure is increased. Can increase the sex.

  Further, in the embodiment shown in FIGS. 1 and 2, the end portion 72 a of the second block 72 enters the recess 62 of the first block 71. With such a configuration, it is possible to prevent the grooves from concentrating in the vicinity of the recess 62 and forming a large space in the vicinity of the recess 62. Therefore, silence can be improved. Further, it can be avoided that mud, gravel, snow or the like concentrates in the recess 62 and a large stress is applied to the first block 71, and the wear resistance of the first block 71 can be improved.

  In this case, the end portion 72a of the second block 72 is equal to or more than 1/3 of the distance between the opening position of the concave portion 62 of the first block 71 and the wall portion of the concave portion 62 farthest from the opening position. It is preferable to extend from the opening position of the recess 62 of the block 71 to the inside of the recess 62 of the first block 71. According to this structure, it is suppressed that a groove | channel concentrates on the recessed part 62 and the recessed part 62 becomes large space. Therefore, silence can be improved. Further, it can be avoided that mud, gravel, snow or the like concentrates in the recess 62 and a large stress is applied to the first block 71, and the rigidity of the first block 71 is increased to further improve the wear resistance. it can.

  In the embodiment shown in FIGS. 1 and 2, the second block 72 has a step portion in which one end is opened in the circumferential main groove 21 or 22 and a step portion 9 that protrudes in the tire radial direction is formed in the bottom portion. A recessed portion 63 is formed. Since the stepped recess 63 captures mud, gravel, snow, etc. during turning, the steering stability during turning can be improved. Moreover, since the bottom part of the recessed part 63 with a step part becomes step shape, since the edge of the step part 9 functions as an edge, an edge component can be increased and traction performance can further be improved. Moreover, by making the bottom part into a step shape, the block rigidity of the 2nd block 72 can be improved and abrasion resistance can further be improved.

  Further, in the embodiment shown in FIGS. 1 and 2, a plurality of sipes 54 including sipes 54 a having two bent portions F are formed in the second block 72.

  In the embodiment shown in FIG. 1 and FIG. 2, the side wall 73 a of the third block 73 facing the first side wall portion 71 c of the first block 71 partitions the first block 71 and the third block 73. The dimension in the extending direction of the auxiliary groove 25 is larger than the dimension of the first side wall portion 71c. In addition, an inclined wall is formed in a portion of the side wall 73 a of the third block 73 on the circumferential main groove 21 or 22 side. When the first block 71 is deformed so as to fall toward the third block 73, the entire first side wall portion 71c is supported by the side wall 73a, so that the rigidity of the first block 71 is increased. Thus, the wear resistance can be further improved, and the edge component can be increased by chamfering the first side wall portion 71c of the first block 71, and the traction performance can be further improved.

  In the embodiment shown in FIGS. 1 and 2, a plurality of sipes 55 are formed in the third block 73.

  In the embodiment shown in FIGS. 1 and 2, the inclined block 8 in which the second side wall portion 71d of the other block portion 71b of the first block 71 is located in the extending direction is adjacent to the first block 71. It is sandwiched between another first block 71 and a second block 72. Further, a stepped portion 72 d that protrudes toward the inclined groove 8 is formed on the side wall 72 c of the second block 72 that is partitioned by the inclined groove 8. According to this configuration, since the edge component is increased by the stepped portion 72d that is convex toward the inclined groove 8, the traction performance is further improved.

  Hereinafter, the function and effect of the tire of this embodiment will be described.

According to the tire of one embodiment of the present invention, first, since the recess 62 is formed in the first block 71 so as to incline with respect to the tire width direction, mud, gravel, snow, etc. are formed in the recess 62. Because it can catch and remove mud, gravel, snow, etc., traction performance can be improved. Moreover, since the 2nd block 72 is arrange | positioned in the position facing the recessed part 62 of the 1st block 71, it suppresses that excessive mud, gravel snow, etc. enter into the recessed part 62 of the 1st block 71. The amount of mud, gravel, snow, etc. entering the recess 62 can be optimized. Furthermore, since it is possible to suppress the concentration of grooves in the vicinity of the recess 62, it is possible to suppress a large stress from being applied to the side wall of the first block 71 in the vicinity of the recess 62, and to increase the rigidity of the first block 71. Abrasion resistance can be further increased. In addition, of the two block portions 71a and 71b forming the concave portion 62 of the first block 71, the third block portion 71a is positioned at a position facing the first side wall portion 71c adjacent to the concave portion 62. Since the block 73 is disposed, mud, gravel, snow and the like are guided to the recess 62 by the side wall of the third block 73, so that the traction performance can be improved. Further, when the first block 71 is deformed so as to fall down toward the third block 73, the third block 73 can support the first block 71, so that the block rigidity is increased and the wear resistance is increased. Can be further enhanced. In addition, of the two block portions 71a and 71b, the second side wall portion 71d adjacent to the concave portion 62 in the other block portion 71b is inclined in a range of 55 ° to 90 ° with respect to the tire width direction. Since it is located in the extending direction of 8, the timing at which the groove wall of the inclined groove 8 that guides mud, gravel, snow and the like most to the recess 62 can be dispersed, and the quietness can be improved.
Therefore, while further improving the traction performance, the block rigidity can be sufficiently secured to improve the wear resistance, and the quietness can be improved.

  In particular, in the embodiment of FIG. 1, the traction performance is further enhanced by arranging the first block 71 on the tire equator plane CL that has the longest tire ground contact length during traveling and greatly affects the traction performance.

  Here, in the present invention, as shown in one embodiment of FIG. 1, the second block 72 has a tire circumferential dimension that is larger toward the outer side in the tire width direction than in the center part in the tire width direction. It is preferable that With such a configuration, it is possible to increase the rigidity in the outer side in the tire width direction of the second block 72 that receives a large side force in a state where the load on the wheel on the outer side of the turn increases during cornering and the contact pressure is increased. , Can improve steering stability.

  Furthermore, in the present invention, as shown in the embodiment of FIG. 1, the side wall of the third block 73 that faces the first side wall portion 71 c defines the first block 71 and the third block 73. It is preferable that the dimension in the extending direction of the sub-groove 25 is larger than the dimension of the first side wall portion 71c, and the first side wall portion 71c is chamfered on the tread tread surface side. According to this configuration, when the first block 71 is deformed so as to fall toward the third block 73, the entire first side wall portion 71c is supported by the side wall 73a. The rigidity of the block 71 can be further increased, and the edge component can be increased by the chamfering of the one block portion 71a to further improve the traction performance.

  In the present invention, as shown in one embodiment of FIG. 1, the inclined groove 8 is sandwiched between a first block 71 adjacent to a first block 71 and a second block 72. It is preferable that a stepped portion 72 d that protrudes toward the inclined groove 8 is formed on the side wall 72 c of the second block 72 defined by the inclined groove 8. According to this configuration, the edge component is increased by the stepped portion 72d that protrudes toward the inclined groove 8, so that the traction performance can be further improved.

  In addition, in the present invention, as shown in the embodiment of FIG. 1, the second block 72 has a step 9 having one end opened in the circumferential main groove 21 or 22 and convex in the tire radial direction. It is preferable that the recessed part 63 with the step part formed in the bottom part is formed. According to this configuration, the stepped concave portion 63 captures mud, gravel, snow and the like during turning, so that the steering stability during turning can be improved. Further, since the bottom of the stepped recess 63 has a stepped shape, the end of the step 9 functions as an edge, so that the edge component can be increased to further enhance the traction performance. Moreover, the block rigidity of the 2nd block 72 can be improved by making bottom part into step shape.

  In addition, in the present invention, as shown in one embodiment of FIG. 1, the first block portion 71 a and the other block portion 71 b of the first block 71, which form the recess 62 of the first block 71, The tread tread surface side of the side walls 71e and 71f forming the concave portion 62 of the block 71 is chamfered, and the concave portion 62 of the first block 71 has one block portion 71a and the other block portion 71b in a developed view of the tread tread surface. It is preferable that the connection part 62a which connects the side walls 71e and 71f which form the recessed part 62 of the first block 71 has a curved surface shape. According to this configuration, mud, gravel and the like that have entered the recess 62 can be easily discharged out of the recess 62 from the side walls 71e and 71f and the connection portion 62a, so that the traction performance can be improved. Further, since the connecting portion 62a is a curved surface, the concentration of distortion can be alleviated and the block rigidity can be improved.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to said embodiment at all. For example, three or more circumferential main grooves may be formed on the tread surface. Various other modifications and changes are possible.

In order to confirm the effect of the present invention, a tire according to Examples 1 to 6 and a tire according to Comparative Examples 1 to 2 were made as trials, and a test for evaluating the performance of the tire was performed. The specifications of each tire are shown in Table 1 below. The test was carried out by assembling the above tires of tire size 215 / 55R17 on the applicable rim and mounting them on the vehicle with an internal pressure of 230 kPa.
In addition, as shown in FIG. 1, each tire is a tire which has the two circumferential main grooves 21 and 22 extended on the tread tread surface 1 continuously in the tread circumferential direction.

<Quietness test>
About each said tire, the tire side sound at the time of making it drive | work on an indoor drum test machine at the speed of 80 km / h was measured on the conditions defined by JASO C606 standard, and air column resonance sound was evaluated. The evaluation result of the tire according to Comparative Example 1 is evaluated as a relative value when the tire is set to 100, and a larger numerical value indicates better silence.

<Traction test>
About each said tire, it carried out by measuring the traction force when drive | working a farm field (muddy ground) at the speed of 5 km / h. The evaluation result of the tire according to Comparative Example 1 is evaluated with a relative value when the value is 100, and a larger numerical value indicates better traction.

<Steering stability test>
About each said tire, the driving | running | working performance at the time of drive | working on the dry road surface was evaluated by the sensory sense by a driver. The evaluation result of the tire according to Comparative Example 1 is evaluated as a relative value when the value is 100, and a larger numerical value indicates better steering stability.

<Abrasion test>
About each said tire, it carried out by measuring the rubber volume of the lug which lose | disappeared by the heel and toe wear after running 20000 km on the concrete road surface at the speed of 40 km / h. The evaluation result of the tire according to Comparative Example 1 is evaluated as a relative value when the value is 100, and a larger numerical value indicates better wear resistance.

  As shown in Table 1, the tires according to Examples 1 to 6 all have higher traction performance than the tires according to Comparative Examples 1 and 2, while ensuring sufficient block rigidity and wear resistance. It can be seen that it is possible to improve the quietness and quietness.

  ADVANTAGE OF THE INVENTION According to this invention, while improving traction performance, the pneumatic tire which can ensure block rigidity fully, can improve abrasion resistance, and can also improve quietness can be provided.

1: tread tread, 21: circumferential main groove, 22: circumferential main groove, 31: outer land portion, 32: central land portion, 33: outer land portion, 41, 42: lug groove, 51, 52: sipe, 53: Sipe, 53a: Sipe, 53b: Sipe, 54: Sipe, 54a Sipe, 61: Recess in the width direction, 62: Recess, 62a: Connection portion, 63: Recess with stepped portion, 71: First block, 71a: One block portion, 71b: the other block portion, 71c: a first side wall portion, 71d: a second side wall portion, 71e, 71f: a side wall forming a recess, 72: a second block, 72a: an end portion, 72b: side wall 72c: side wall 72d: stepped portion 73: third block 73a: side wall 8: inclined groove 9: stepped portion CL: tire equatorial plane F: bent portion TE1 E2: tread end

Claims (6)

The tread has one or more land portions sandwiched by a plurality of circumferential main grooves extending continuously in the tire circumferential direction,
At least one of the land portions is partitioned by a sub-groove including at least an inclined groove extending inclined with respect to the tire width direction, and a plurality of blocks are formed.
In the development view of the tread surface, the plurality of blocks are:
A first block having a recess formed so as to be inclined with respect to the tire width direction;
A second block disposed at a position facing the recess of the first block;
A third block disposed at a position facing the first side wall portion adjacent to the concave portion in one of the two block portions forming the concave portion of the first block;
Of the two block parts, the side wall part adjacent to the recess in the other block part is located in the extending direction of the inclined groove that is inclined in the range of 55 ° to 90 ° with respect to the tire width direction. A pneumatic tire characterized by that.   2. The pneumatic tire according to claim 1, wherein the second block has a size in a tire circumferential direction that is larger toward a tire width direction outer side than a tire width direction central portion. The side wall of the third block that faces the first side wall portion has a dimension in the extending direction of the sub-groove that defines the first block and the third block. Bigger than
The pneumatic tire according to claim 1 or 2, wherein the first side wall portion is chamfered on a tread surface side. The inclined groove is sandwiched between another first block adjacent to the first block and the second block,
The pneumatic section according to any one of claims 1 to 3, wherein a stepped portion that is convex toward the inclined groove is formed on a side wall of the second block that is partitioned by the inclined groove. tire.   The second block is formed with a stepped recess having one end opened in the circumferential main groove and a step that protrudes in the tire radial direction is formed at the bottom. A pneumatic tire given in any 1 paragraph. The tread tread surface side of the side wall forming the concave portion of the first block of the one block portion and the other block portion of the first block forming the concave portion of the first block is chamfered,
In a developed view of the tread surface, the concave portion of the first block has a curved connection portion that connects the side walls forming the concave portion of the first block of the one block portion and the other block portion. The pneumatic tire according to any one of claims 1 to 5.

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