JP6591206B2 - Pneumatic tire - Google Patents

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 rough 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 problem, and an object thereof is to provide a pneumatic tire that can improve quietness and further improve wear resistance while further improving traction performance. .

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 divided by sub-grooves including at least an inclined groove extending in an inclined manner with respect to the tread surface, and the plurality of blocks are disposed on the tire equatorial plane. And a first block having a recess formed so as to be inclined with respect to the tire width direction, and a second block disposed at a position facing the recess of the first block. To do.
According to the pneumatic tire of the present invention, it is possible to improve quietness and further improve wear resistance while further improving 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 ”, and in Japan,“ Japan Auto Tire Association (JATMA) ”“ 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.

The pneumatic tire of the present invention is arranged at a position facing a first side wall portion adjacent to the concave portion in one of the two block portions forming the concave portion of the first block. Preferably, it further comprises three blocks.
According to this configuration, wear resistance and traction performance can be further improved.

In the pneumatic tire of the present invention, of the two block portions forming the concave portion of the first block, the length of the other block portion is longer than the length of the tire circumferential direction of the side wall forming the concave portion of the one block portion. It is preferable that the tire circumferential direction length of the side wall forming the recess is longer.
According to this configuration, the traction performance can be further improved.

In the pneumatic tire of the present invention, of the two block portions, the side wall portion adjacent to the concave portion in the other block portion is located in the extending direction of the inclined groove inclined with respect to the tire width direction. Is preferable.
According to this configuration, the traction performance can be further improved while ensuring drainage.

In the pneumatic tire of the present invention, it is preferable that the inclined groove is inclined in a range of 55 ° to 90 ° with respect to the tire width direction.
According to this configuration, silence can be further improved.

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 of the present invention, it is preferable that the size of the second block in the tire circumferential direction is larger toward the outer side in the tire width direction than the center portion in the tire width direction.
Here, “the dimension in the tire circumferential direction of the second block is larger toward the outer side in the tire width direction than the central part in the tire width direction” means that the second block is moved outward in the tire width direction. This includes the case where the tire circumferential dimension is constant and the case where the tire circumferential dimension increase rate 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 first block is formed with a hollow portion in which a side wall opposite to the side wall where the concave portion is formed is recessed inward, and the hollow portion is formed by the first block. It is preferable that the block is formed so as to be opposed to the convex portion of the side wall in which the hollow portion of the other adjacent first block is formed.
According to this configuration, the traction performance can be further improved.

In the pneumatic tire according to the aspect of the invention, it is preferable that the second block has an end extending to the inside of the recess along a side surface of the recess of the first block.
According to this configuration, the traction performance can be further improved.

In the pneumatic tire of the present invention, it is preferable that the end portion of the second block is chamfered on the tread tread surface side of the side wall facing the concave portion of the first block.
According to this configuration, the traction performance can be further improved.

It is preferable that the second block is formed with a stepped recess having one end opened in the circumferential main groove and a step protruding in the tire radial direction is formed at the bottom.
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.

  According to the present invention, it is possible to provide a pneumatic tire that can improve quietness while further improving traction performance.

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 extending 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.

The outer land portion 31 of the present embodiment is formed with a lug groove 41 having one end opened to the tread end TE1 and the other end opened to the circumferential main groove 21. 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. The outer land portion 31 of the present embodiment is also formed with a sipe 51 having one end opening in the circumferential main groove 21 and the other end terminating in the outer land portion 31.
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, a lug groove 41, a width direction concave portion 61, and a sipe 51 are formed in the same manner as the outer land portion 31 on the 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 recesses 62 of the first block 71. The tread tread surface side of the side walls 71e and 71f forming the chamfer 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 tire circumferential direction length of the side wall 71f forming the concave portion 62 of the other block portion 71b is larger than the tire circumferential direction length of the side wall 71e forming the concave portion 62 of the one block portion 71a. That is longer. Therefore, mud, gravel, snow or the like guided by the side wall of the second block 72 can be easily guided into the recess 62 along the second side wall portion 71d, so that the traction performance can be improved.

  In the embodiment shown in FIGS. 1 and 2, the second side wall portion 71 d is chamfered on the tread tread surface side. In the present embodiment, the entire second side wall portion 71 d 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, a plurality of sipes 52 are formed in the first block 71. Specifically, a sipe 52a is formed in which one end opens to the connection portion 62a of the recess 62 and the other end opens to 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 52 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 52a 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 52a is interlocked with each other, so that a large stress is prevented from concentrating on one portion divided by the sipe 52a, thereby improving the wear resistance. In the embodiment shown in FIG. 1, the sipe 52b adjacent to the sipe 52a is formed to have two bent portions F, and the sipe 52b also increases the wear resistance of the first block 71. ing.

  In the embodiment shown in FIGS. 1 and 2, the first block 71 is formed with a recessed portion 71 g in which a side wall opposite to the side wall where the recessed portion 62 is formed is recessed inward. The depression 71g is formed so as to face the convex portion 71h on the side wall in which the depression 71g of the other adjacent first block 71 is formed. In particular, in the present embodiment, the recess portion 71g is formed so that the position 71i of the recess portion 71g farthest from the wall portion where the recess portion 71g opens is opposed to the convex portion 71h. Providing such a depression 71g increases the edge component, so that the traction performance can be further improved.

  In the embodiment shown in FIGS. 1 and 2, the size of the second block 72 in the tire circumferential direction is larger toward the outer side in the tire width direction than the center portion in the tire width direction. When cornering, the load on the wheel on the outside of the turn increases and the contact pressure increases, so that the rigidity of the second block 72 receiving the large side force in the tire width direction outside can be increased, so that the steering stability is improved. Can do.

  In the embodiment shown in FIGS. 1 and 2, the second block 72 has an end 72 a that extends to the inside of the recess 62 along the side surface of 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 addition, since the end portion 72 a enters the recess 62 of the first block 71, it is possible to prevent the grooves from concentrating near the recess 62 and forming a large space near 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 particular, in the embodiment 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 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, the block rigidity of the 2nd block 72 can be improved by making bottom part into step shape.

  In the embodiment shown in FIGS. 1 and 2, a plurality of sipes 53 including sipe 53 a having two bent portions F are formed in the second block 72. Further, a sipe 54 having two bent portions is 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. In particular, in the present invention, the first block 71 having the concave portion 62 formed on the tire equatorial plane CL that has the longest tire ground contact length during traveling and greatly affects the traction performance is arranged, so that the traction performance is further improved. Yes. 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 can suppress that a groove | channel concentrates on the vicinity of the recessed part 62, it can suppress that the recessed part 62 causes a noise. Furthermore, 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 concave portion 62, thereby increasing the rigidity of the first block 71 and further improving the wear resistance.
Therefore, in the pneumatic tire of the present embodiment, quietness can be improved while further improving the traction performance.

  Here, in the present invention, as shown in one embodiment of FIG. 1, of the two block portions 71a and 71b forming the concave portion 62 of the first block 71, the concave portion 62 in one block portion 71a. It is preferable to further include a third block 73 disposed at a position facing the first side wall portion 71c adjacent to the first side wall portion 71c. With such a configuration, 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 further enhanced. 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.

  Furthermore, in this invention, as shown in one Embodiment of FIG. 1, the recessed part 62 of the other block part 71b is formed rather than the tire circumferential direction length of the side wall 71e which forms the recessed part 62 of one block part 71a. It is preferable that the length of the side wall 71f in the tire circumferential direction is longer. With such a configuration, it becomes easier to guide mud, gravel, snow, etc., guided by the side wall of the second block 72 into the recess 62 along the second side wall portion 71d, thereby further improving the traction performance. Can be made.

  Furthermore, in the present invention, as shown in one embodiment of FIG. 1, the second side wall portion 71d adjacent to the recess 62 in the other block portion 71b of the two block portions 71a and 71b has a tire width. It is preferable to be located in the extending direction of the inclined groove 8 inclined with respect to the direction. With such a configuration, the mud, gravel, snow and the like guided along the inclined groove 8 are captured by the second side wall portion 71d, and the flow in the tire circumferential direction such as mud, gravel and snow is branched in two directions. While mud, gravel, snow, etc. are guided to the recess 62, mud, gravel, snow, etc. can flow in the circumferential direction of the tire, further improving traction performance while ensuring drainage. Can be improved.

  Furthermore, in this invention, as shown in one Embodiment of FIG. 1, it is preferable that the inclination groove | channel 8 inclines in the range of 55 degrees-90 degrees with respect to a tire width direction. If comprised in this way, the timing which the groove wall of the inclined groove | channel 8 which guides mud, gravel, snow, etc. most to the recessed part 62 grounds can be disperse | distributed, and silence can be improved further.

  In the present invention, as shown in one embodiment of FIG. 1, the inclined groove 8 is sandwiched between another first block 71 adjacent to the first block 71 and the second block 72. The side wall 72c defined by the inclined groove 8 of the second block 72 is preferably provided with a stepped portion 72d that protrudes toward 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.

  Here, in the present invention, as shown in one embodiment of FIG. 1, the size of the second block 72 in the tire circumferential direction is larger from the center in the tire width direction toward the outside in the tire width direction. Is preferable. With such a configuration, it is possible to increase the rigidity of the outer side in the tire width direction of the second block 72 that receives 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 ground pressure increases. , Can improve steering stability.

  In addition, in the present invention, as shown in one embodiment of FIG. 1, the first block 71 is formed with a recessed portion 71g in which a side wall opposite to the side wall where the recessed portion 62 is formed is recessed inward. The recess 71g is preferably formed so as to face the convex portion 71h on the side wall where the recess 71g of the other first block 71 adjacent to the first block is formed. With such a configuration, the edge component is increased by the depression 71g, 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 an end 72 a that extends to the inside of the recess 62 along the side surface of the recess 62 of the first block 71. It is preferable. 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 further improved.

  In addition, in the present invention, as shown in the embodiment of FIG. 1, the end portion 72 a of the second block 72 is chamfered on the tread tread surface side of the side wall 72 b facing the concave portion 62 of the first block 71. It is preferable. Since the chamfered side wall 72b makes it easy to guide mud, gravel, snow and the like to the inside of the recess 62, 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. 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, 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, 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 is made into a curved surface, the concentration of distortion can be alleviated, the block rigidity can be secured, and the wear resistance can be further 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 Invention Examples 1 to 12 and a tire according to Comparative Examples 1 and 2 were prototyped, 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 performed by assembling the above tires of tire size 265 / 65R17 to an applicable rim and mounting the tire on a 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 with a relative value when the value is 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 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 Inventive Examples 1 to 12 all improve the quietness and further improve the wear resistance while further improving the traction performance as compared with the tires according to Comparative Examples 1 and 2. It can be seen that it can be increased.

  According to the present invention, it is possible to provide a pneumatic tire that can improve quietness and further improve wear resistance while further improving traction performance.

1: tread surface 21: circumferential main groove 22: circumferential main groove 25: minor groove 31: outer land portion 32: central land portion 33: outer land portion 41: lug groove 51, 52 : Sipe, 52a: Sipe, 52b: Sipe, 53: Sipe, 53a Sipe, 61: Concave part in the width direction, 62: Concave part, 62a: Connection part, 63: Concave part with stepped part, 71: First block, 71a: One side 71b: the other block part, 71c: the first side wall part, 71d: the second side wall part, 71e, 71f: the side wall forming the recess, 71g: the recessed part, 71i: the position, 71h: the end part 72: Second block 72a: 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 equator surface, F: Bending part, TE1, TE2: Tread edge

Claims (11)

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 formed on a tire equatorial plane and formed with a recess having a side wall extending in a direction inclined with respect to the tire width direction;
Having an end portion extending toward said recess of said first block, saw including a second block,
The first block is formed with a recessed portion inwardly recessed on the side wall opposite to the side wall on which the recessed portion is formed,
The pneumatic tire according to claim 1, wherein the hollow portion is formed so as to face a convex portion of a side wall in which the hollow portion of the other first block adjacent to the first block is formed . 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 formed on a tire equatorial plane and formed with a recess having a side wall extending in a direction inclined with respect to the tire width direction;
Having an end portion extending toward said recess of said first block, saw including a second block,
The second block is formed with a stepped recess having one end opened in the circumferential main groove and a step protruding in the tire radial direction is formed at the bottom. tire. The two-block part which forms the said recessed part of the said 1st block further includes the 3rd block arrange | positioned in the position facing the 1st side wall part adjacent to the said recessed part in one block part. Item 3. The pneumatic tire according to Item 1 or 2 . Of the two block portions forming the concave portion of the first block, the tire of the side wall forming the concave portion of the other block portion rather than the tire circumferential direction length of the side wall forming the concave portion of one block portion. The pneumatic tire according to claim 3 , wherein a circumferential length is longer. Of the two block portions, the sidewall portion adjacent to the recess in the other block portion is located in the extending direction of the inclined grooves inclined with respect to the tire width direction, according to claim 3 or 4 Pneumatic tires. The pneumatic tire according to claim 5 , wherein the inclined groove is inclined in a range of 55 ° to 90 ° with respect to the tire width direction. The inclined groove is sandwiched between another first block adjacent to the first block and the second block,
The pneumatic tire according to claim 5 or 6 , 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. The pneumatic tire according to any one of claims 1 to 7 , wherein a dimension of the second block in a tire circumferential direction is larger toward a tire width direction outer side than a tire width direction central portion. An end portion of the second block, the Ru extends to the inside of the recess along the side face of the recess of the first block, the pneumatic tire according to any one of claims 1-8.   The pneumatic tire according to claim 9, wherein an end portion of the second block is chamfered on a tread tread surface side of a side wall facing the concave portion of the first block. 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 10 .

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