JP5357662B2 - tire - Google Patents

Description

  The present invention relates to a tire in which a widthwise groove extending along a tread width direction is formed in a rib-like land portion formed by a plurality of circumferential grooves extending along a tire circumferential direction.

  Conventionally, in a tread surface of a pneumatic tire for an icy / snowy road surface (snowy road surface or icy road surface), the rib-like land portion formed by a plurality of circumferential grooves extending along the tire circumferential direction extends along the tread width direction. A plurality of lug grooves (width direction grooves) are formed at predetermined intervals in the tire circumferential direction.

  In particular, in pneumatic tires where the width of the rib-like land portion along the tread width direction is specified, the effect of scratching ice and snow etc. by shortening the interval in the tire circumferential direction and providing many lug grooves in the tire circumferential direction (So-called edge effect) increases, and steering stability, braking performance, driving performance and the like on an icy and snowy road surface are improved (for example, see Patent Document 1).

JP-A-9-66710 (page 2-3, FIG. 1)

  However, the conventional pneumatic tire described above has the following problems. That is, as the edge effect increases, the rigidity of the rib-like land portion decreases, so that the small land portion formed by the circumferential groove and the lug groove is likely to fall backward in the tire rotation direction. For this reason, there is a problem that steering stability, braking performance, and driving performance on a dry road surface are deteriorated.

  Therefore, the present invention has an object to provide a tire that can achieve a high level of handling stability, braking performance, and driving performance on icy and snowy road surfaces and dry road surfaces when a plurality of lug grooves are formed in the rib-like land portion. To do.

  In order to solve the above-described problems, the present invention has the following features. First, the first feature of the present invention is that a first rib-shaped land portion (central land portion 20C) and a first groove are formed by circumferential grooves (circumferential grooves 11 to 14) extending along the tire circumferential direction (tire circumferential direction TC). 2 rib-shaped land portions (intermediate land portions 20M) are formed, and the first rib-shaped land portions are formed with first width direction grooves (central lug grooves 50) extending along the tread width direction. The two-rib land portion is a tire (pneumatic tire 1) in which a second width direction groove (intermediate lug groove 60) extending along the tread width direction is formed, and the first width direction groove is A first dividing groove (dividing groove 51) that divides the first rib-shaped land portion in the tire circumferential direction is provided substantially in parallel with the first dividing groove, and one end is provided with the first rib-shaped land portion and the second An opening is made in the circumferential groove located between the rib-shaped land portion and the other end ends in the first rib-shaped land portion. And the second width direction groove includes a second dividing groove (dividing groove 61) that divides the second rib-shaped land portion in the tire circumferential direction, and the second width direction groove. A second terminal groove (inner terminal groove 62A) provided at one end of the circumferential groove and having one end opened in the circumferential groove and the other end terminated in the second rib-shaped land portion; One end of one terminal groove is opposed to one end of the second dividing groove through the circumferential groove, and one end of the second terminal groove is opposed to one end of the first dividing groove through the circumferential groove. The gist is to do.

  Here, “substantially parallel” refers to a target groove (for example, a first termination groove or a second termination groove) with respect to a reference line along the extending direction of a reference groove (for example, a first division groove or a second division groove), The target line along the extending direction of the (third terminal groove) indicates a range of ± 5 degrees.

  According to this feature, the first width direction groove includes a first dividing groove and a first termination groove, and the second width direction groove includes a second division groove and a second termination groove. According to this, between the 1st parting groove and the 2nd parting groove which adjoin the tire peripheral direction, the portion which follows in the tire peripheral direction is formed by the 1st end slot and the 2nd end slot. Therefore, the rigidity of the first rib-shaped land portion and the second rib-shaped land portion is not lowered excessively, and the small land portion formed by the circumferential groove and the first dividing groove and the second dividing groove is difficult to fall down. . For this reason, it is possible to ensure steering stability, braking performance, and driving performance on a dry road surface.

  The gist of the invention is that one end of the first terminal groove is opposed to the second dividing groove via the circumferential groove, and one end of the second terminal groove is opposed to the first dividing groove via the circumferential groove. . That is, one end of the terminal groove is always opposed to the dividing groove. According to this, drainage can be improved compared with the case where terminal grooves face each other. Further, on the icy and snowy road surface, a snow column continuous to the first terminal groove and the second dividing groove is formed, and a snow column continuous to the second terminal groove and the first dividing groove is formed. For this reason, steering stability, braking performance, and driving performance on an icy and snowy road surface can be ensured by a shearing force caused by a continuous snow column.

  Thus, in the case where a plurality of lug grooves are formed in the rib-like land portion, it is possible to achieve a high level of handling stability, braking performance, and driving performance on icy and snowy road surfaces and dry road surfaces.

  A second feature of the present invention relates to the first feature of the present invention, wherein a plurality of the circumferential grooves are provided, and a third rib-shaped land portion adjacent to the second rib-shaped land portion by the circumferential groove. (End land portion 20S) is formed, the second width direction groove is provided substantially in parallel with the second dividing groove, and one end is formed between the second rib-shaped land portion and the third rib-shaped land portion. It further includes a third termination groove (outer termination groove 62B) having an opening in the circumferential groove positioned therebetween and the other end terminating in the second rib-shaped land portion, wherein the third termination groove is the second termination groove. The gist is to be located on a virtual line (virtual line L) along the extending direction of the terminal groove.

  A third feature of the present invention relates to the second feature of the present invention, wherein a third widthwise groove (end lug groove 70) extending along the tread width direction is formed in the third rib-shaped land portion. The third width direction groove has one end opened to the circumferential groove located between the second rib-shaped land portion and the third rib-shaped land portion, and the other end is the third rib-shaped groove. The present invention includes a fourth termination groove (termination groove 71) that terminates in the land portion, and one end of the fourth termination groove is opposed to one end of the third termination groove via the circumferential groove.

  A fourth feature of the present invention is related to the third feature of the present invention, and is summarized in that the fourth terminal groove is located on an imaginary line along the extending direction of the second terminal groove.

  A fifth feature of the present invention relates to the first to fourth features of the present invention, wherein the first dividing groove and the second dividing groove are inclined with respect to a tire equator line (tire equator line CL). And

  A sixth feature of the present invention relates to the feature of the fifth feature of the present invention, wherein the slope of the first widthwise groove and the slope of the second widthwise groove are the first rib-like land portion and the second rib-like land. The gist of the present invention is that it is symmetrical with respect to a center line in the groove (center line DL in the groove) that passes through the center of the circumferential groove located between the two portions and extends in parallel with the tire equator line.

  According to the feature of the present invention, when a plurality of lug grooves are formed in a rib-like land portion, a tire capable of achieving a high level of handling stability, braking performance, and driving performance on ice and snow road surfaces and dry road surfaces is provided. be able to.

FIG. 1 is a development view showing a part of a tread pattern of a pneumatic tire 1 according to the present embodiment. FIG. 2 is a perspective view showing a part of the tread pattern of the pneumatic tire 1 according to the present embodiment. It is an expanded view which shows a part of tread pattern of the pneumatic tire which concerns on Example 2 of comparative evaluation.

  Next, an embodiment of a tire according to the present invention will be described with reference to the drawings. Specifically, (1) Configuration of pneumatic tire, (2) Configuration of lug groove, (3) Comparative evaluation, (4) Action and effect, (5) Other embodiments will be described.

  In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic and ratios of dimensions and the like are different from actual ones.

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

(1) Configuration of Pneumatic Tire First, the configuration of the pneumatic tire 1 according to the present embodiment will be described with reference to the drawings. FIG. 1 is a development view showing a part of a tread pattern of a pneumatic tire 1 according to the present embodiment. The pneumatic tire 1 is a general radial tire (studless tire) including a bead portion, a carcass layer, a belt layer, and a tread portion (not shown). The pneumatic tire 1 may be filled with an inert gas such as nitrogen gas instead of air.

  As shown in FIG. 1, a plurality of circumferential grooves extending along the tire circumferential direction TC are formed in the pneumatic tire 1. In the rib-shaped land portion formed by the circumferential groove, a plurality of lug grooves extending along the tread width direction TW are formed at predetermined intervals in the tire circumferential direction TC.

  Specifically, the circumferential groove includes a circumferential groove 11, a circumferential groove 12, a circumferential groove 13, and a circumferential groove 14 from the left side to the right side in FIG. On the other hand, the rib-shaped land portion includes a central land portion 20C (first rib-shaped land portion), an intermediate land portion 20M (second rib-shaped land portion), and an end land portion 20S (third rib-shaped land portion). Consists of.

  The central land portion 20C is located on the tire equator line CL. The central land portion 20 </ b> C is formed by the circumferential groove 12 and the circumferential groove 13.

The intermediate land portion 20M is adjacent to the tread width direction TW outside of the central land portion 20C, specifically, in the tread width direction TW of the central land portion 20C. Intermediate land portion 20M is circumferential groove 11 and the first intermediate land portion 20M ₁ formed by the circumferential groove 12, the circumferential groove 13 and the second formed by the circumferential groove 14 intermediate land portion 20M ₂ It is comprised by.

The end land portion 20S is adjacent to the tread width direction TW of the intermediate land portion 20M. End land portion 20S has a first end land portion 20S ₁ positioned in the tread width direction TW outer than the circumferential groove 11, a second end land located in the tread width direction TW outer than the circumferential groove 14 It constituted by a part 20S _2.

  A plurality of lug grooves and a plurality of sipes are formed in the central land portion 20C, the intermediate land portion 20M, and the end land portion 20S. Details of the lug groove will be described later.

  In each land portion, the plurality of sipes are configured by a circumferential sipe 41 that extends along the tire circumferential direction TC and a width-direction sipe 42 that extends along the tread width direction TW. The circumferential sipe 41 and the width sipe 42 have a narrower width than the circumferential groove and the lug groove.

(2) Structure of lug groove Next, the structure of the lug groove which concerns on this embodiment is demonstrated, referring FIG.1 and FIG.2. FIG. 2 is a perspective view showing a part of the tread pattern of the pneumatic tire 1 according to this embodiment.

  As shown in FIGS. 1 and 2, the lug groove includes a central lug groove 50 (first width direction groove) formed in the central land portion 20C and an intermediate lug groove 60 (second groove) formed in the intermediate land portion 20M. A width direction groove) and an end lug groove 70 (third width direction groove) formed in the end land portion 20S.

  Specifically, the central lug groove 50 includes a dividing groove 51 (first dividing groove) and a terminal groove 52 (first terminal groove). The dividing groove 51 divides the central land portion 20C in the tire circumferential direction TC. The dividing groove 51 is inclined with respect to the tire equator line CL. On the other hand, the terminal groove 52 is provided substantially in parallel with the dividing groove 51. One end of the termination groove 52 opens into the circumferential groove 12 or the circumferential groove 13 located between the central land portion 20C and the intermediate land portion 20M, and the other end terminates in the central land portion 20C. One end of the termination groove 52 is opposed to one end of a dividing groove 61 formed in the intermediate land portion 20 </ b> M, which will be described later, via the circumferential groove 12 or the circumferential groove 13.

  The intermediate lug groove 60 includes a dividing groove 61 (second dividing groove) and a terminal groove 62. The dividing groove 61 divides the intermediate land portion 20M in the tire circumferential direction TC. The dividing groove 61 is inclined with respect to the tire equator line CL. On the other hand, the terminal groove 62 is provided substantially parallel to the dividing groove 61. The termination groove 62 includes an inner termination groove 62A (second termination groove) and an outer termination groove 62B (third termination groove).

  One end of the inner end groove 62A opens into the circumferential groove 12 or the circumferential groove 13 located between the central land portion 20C and the intermediate land portion 20M, and the other end terminates in the intermediate land portion 20M. One end of the inner terminal groove 62A faces the dividing groove 51 formed in the central land portion 20C via the circumferential groove 12 or the circumferential groove 13.

  One end of the outer terminal groove 62B opens into the circumferential groove 11 or the circumferential groove 14 located between the intermediate land portion 20M and the end land portion 20S, and the other end terminates in the intermediate land portion 20M. One end of the outer end groove 62B faces one end of the end groove 71 formed in the end land portion 20S described later via the circumferential groove 11 or the circumferential groove 14. Further, the outer end groove 62B is located on an imaginary line L along the extending direction of the inner end groove 62A.

  The end lug groove 70 includes a termination groove 71 (fourth termination groove). One end of the termination groove 71 opens into the circumferential groove 11 or the circumferential groove 14 located between the intermediate land portion 20M and the end land portion 20S, and the other end terminates in the end land portion 20S. The termination groove 71 is opposed to the dividing groove 61 or the outer termination groove 62B formed in the intermediate land portion 20M via the circumferential groove 11 or the circumferential groove 14. Further, the termination groove 71 is located on a virtual line L along the extending direction of the inner termination groove 62A.

  In addition to the end groove 71, the end land portion 20S includes a circumferential narrow groove 72 extending along the tire circumferential direction TC, and a widthwise narrow groove extending from the circumferential narrow groove 72 toward the tread width direction TW. 73 and the like are formed.

  Here, the inclination of the central lug groove 50 (the dividing groove 51 and the terminating groove 52) and the inclination of the intermediate lug groove 60 (the dividing groove 61 and the terminating groove 62) are located between the central land portion 20C and the intermediate land portion 20M. It is symmetrical with respect to a center line DL in the groove that passes through the center of the circumferential groove 12 or the circumferential groove 13 and extends in parallel with the tire equator line CL. That is, the central lug groove 50 and the intermediate lug groove 60 are provided point-symmetrically at predetermined locations on the tire equator line CL.

(3) Comparative Evaluation Next, in order to further clarify the effects of the present invention, comparative evaluation performed using pneumatic tires according to the following comparative examples and examples will be described. Specifically, (3-1) Configuration of each pneumatic tire and (3-2) evaluation results will be described. In addition, this invention is not limited at all by these examples.

(3-1) Configuration of Each Pneumatic Tire First, the pneumatic tires according to Comparative Examples 1 and 2 and Examples 1 and 2 will be briefly described. In addition, the data regarding a pneumatic tire were measured on the conditions shown below.

・ Tire size: PC225 / 65R17
・ Rim size: 17 × 61 / 2JJ
・ Vehicle conditions: FF vehicle (displacement 2000cc)
・ Internal pressure conditions: Vehicle specified internal pressure (front 210 kPa, rear 210 kPa)
-Load conditions: Regular load + 1 driver In the pneumatic tire according to Comparative Example 1, in the tire described in the above-described embodiment, all the lug grooves formed in the rib-like land portion are tired from the rib-like land portion. It is divided in the circumferential direction TC. In the pneumatic tire according to Comparative Example 2, in the tire described in the above-described embodiment, all lug grooves formed in the rib-shaped land portion terminate in the rib-shaped land portion without dividing the rib-shaped land portion. doing.

  The pneumatic tire according to Example 1 is the tire described in the above-described embodiment. In the pneumatic tire according to Example 2, in the tire described in the above-described embodiment, the outer end groove 62B is not formed in the intermediate land portion 20M, and the end groove 71 is not formed in the end land portion 20S ( (See FIG. 3). In addition, the pneumatic tire according to the second embodiment is the same as the pneumatic tire according to the first embodiment.

(3-2) Evaluation results Next, the stability of steering on dry road surfaces, riding comfort, braking performance, braking performance on wet road surfaces, and steering stability on ice and snow road surfaces of vehicles equipped with pneumatic tires. The evaluation results will be described with reference to Table 1.

(3-2A) Steering stability on dry road surface Steering stability evaluation is performed on a dry road surface test course by running a vehicle equipped with each pneumatic tire and steering stability of the vehicle equipped with each pneumatic tire. The feeling was evaluated by a professional driver (10 points maximum). In addition, the larger the index, the better the steering stability on the dry road surface.

  As a result, as shown in Table 1, since the vehicle equipped with all the pneumatic tires 1 has the driving stability on the dry road surface within an allowable range (6 points or more), the driving stability on the dry road surface. It was found that

(3-2B) Riding comfort on dry road surface Riding comfort evaluation is carried out by driving a vehicle equipped with each pneumatic tire on a dry road surface test course, and riding comfort of the vehicle equipped with each pneumatic tire. The feeling was evaluated by a professional driver (10 points maximum). In addition, the larger the index, the better the steering stability on the dry road surface.

  As a result, as shown in Table 1, a vehicle equipped with all the pneumatic tires 1 has a ride comfort on a dry road surface within an allowable range (6 points or more), and therefore a ride comfort on a dry road surface. It was found that

(3-2C) Brake performance on dry roads Brake performance evaluation is based on the distance from a vehicle equipped with pneumatic tires at a speed of 100 km / h until the vehicle stops and loses full brakes. did. Note that the shorter the distance, the better the braking performance.

  As a result, as shown in Table 1, the vehicle on which the pneumatic tire 1 according to Examples 1 and 2 is mounted is more braking on a dry road than the vehicle on which the pneumatic tire according to Comparative Example 1 is mounted. It was found to be excellent.

(3-2D) Braking performance on wet road surface The braking performance evaluation is based on the distance from a vehicle equipped with pneumatic tires to a speed of 100km / h until the vehicle stops with a full brake. did. Note that the shorter the distance, the better the braking performance.

  As a result, as shown in Table 1, the vehicle on which the pneumatic tire 1 according to Examples 1 and 2 is mounted is more braking on the wet road than the vehicle on which the pneumatic tire according to Comparative Example 2 is mounted. It was found to be excellent.

(3-2E) Steering stability on icy and snowy roads Steering stability evaluation is performed on a test course on icy and snowy roads by running a vehicle equipped with each pneumatic tire and steering stability of the vehicle equipped with each pneumatic tire. The feeling was evaluated by a professional driver (10 points maximum). In addition, the larger the index, the better the steering stability on the icy and snowy road surface.

  As a result, as shown in Table 1, the vehicle equipped with the pneumatic tire 1 according to Examples 1 and 2 is more stable in handling on an icy and snowy road surface than the vehicle equipped with the pneumatic tire according to Comparative Example 2. It was found to be excellent in properties.

(4) Action / Effect In the embodiment described above, the central lug groove 50 includes the dividing groove 51 and the terminal groove 52, and the intermediate lug groove 60 includes the dividing groove 61 and the inner terminal groove 62A. According to this, between the dividing groove 51 and the dividing groove 61 adjacent to each other in the tire circumferential direction, a portion continuous in the tire circumferential direction is formed by the terminal groove 52 and the inner terminal groove 62A. For this reason, the small land portion formed by the circumferential groove and the dividing groove 51 and the dividing groove 61 is not easily collapsed without excessively reducing the rigidity of the central land portion 20C and the intermediate land portion 20M. For this reason, it is possible to ensure steering stability, braking performance, and driving performance on a dry road surface.

  One end of the end groove 52 is opposed to the dividing groove 61 via the circumferential groove 11 or the circumferential groove 13, and one end of the inner end groove 62 </ b> A is divided via the circumferential groove 11 or the circumferential groove 13. The gist is to face 51. That is, one end of the terminal groove is always opposed to the dividing groove. According to this, drainage can be improved compared with the case where terminal grooves face each other. On the icy and snowy road surface, a continuous snow column is formed in the terminal groove 52 and the dividing groove 61, and a continuous snow column is formed in the inner terminal groove 62A and the dividing groove 51. For this reason, steering stability, braking performance, and driving performance on an icy and snowy road surface can be ensured by a shearing force caused by a continuous snow column.

  Thus, in the case where a plurality of lug grooves are formed in the rib-like land portion, it is possible to achieve a high level of handling stability, braking performance, and driving performance on icy and snowy road surfaces and dry road surfaces.

  In the embodiment, the intermediate lug groove 60 further includes an outer terminal groove 62B, and the outer terminal groove 62B is located on a virtual line (virtual line L) along the extending direction of the inner terminal groove 62A. According to this, while maintaining the rigidity of the intermediate land portion 20M on the dry road surface, a snow column continuous to the inner terminal groove 62A and the outer terminal groove 62B is formed on the icy and snowy road surface. For this reason, handling stability, braking performance, and driving performance on icy and snowy road surfaces and dry road surfaces can be achieved at a higher level.

  In the embodiment, the end lug groove 70 includes a termination groove 71, and one end of the termination groove 71 faces one end of the outer termination groove 62 </ b> B via the circumferential groove 11 or the circumferential groove 14. In particular, the termination groove 71 is located on an imaginary line L along the extending direction of the inner termination groove 62A. According to this, a snow column that is continuous with the outer end groove 62B and the end groove 71 is formed on the icy and snowy road surface while ensuring the rigidity of the end land portion 20S on the dry road surface. For this reason, steering stability, braking performance, and driving performance on icy and snowy road surfaces and dry road surfaces can be achieved at a higher level.

  In the embodiment, the dividing groove 51 and the dividing groove 61 are inclined with respect to the tire equator line CL. According to this, as compared with the case where the dividing groove 51 and the dividing groove 61 are orthogonal to the tire equator line CL, the drainage can be improved reliably, and the edge effect can be obtained even when the vehicle is not traveling straight (such as when turning). It becomes easy to demonstrate. For this reason, it is possible to reliably ensure steering stability, braking performance, and driving performance on icy and snowy road surfaces.

  In the embodiment, the inclination of the central lug groove 50 (the dividing groove 51 and the terminating groove 52) and the inclination of the intermediate lug groove 60 (the dividing groove 61 and the terminating groove 62) are axisymmetric with respect to the in-groove center line DL. That is, the central lug groove 50 and the intermediate lug groove 60 are provided point-symmetrically at predetermined locations on the tire equator line CL. According to this, the inclination directions of the central lug groove 50 and the intermediate lug groove 60 are reversed in the adjacent central land portion 20C and intermediate land portion 20M, and the bias of the edge effect during cornering (so-called curve) can be suppressed. For this reason, the steering stability on the snowy and snowy road surface can be ensured more reliably.

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

  For example, the embodiment of the present invention can be modified as follows. Specifically, in the embodiment, the pneumatic tire 1 has been described as a general radial tire (studless tire) including a bead portion, a carcass layer, a belt layer, and a tread portion (not shown). It is not limited to these, and other tires having different configurations may be used.

  Further, the tire has been described as the pneumatic tire 1 filled with air, nitrogen gas, or the like, but is not limited to this, and may be a solid tire that is not filled with air, nitrogen gas, or the like. .

  Further, the tread pattern of the pneumatic tire 1 has been described as being provided with a plurality of sipes. However, the present invention is not limited to this, and a plurality of sipes may not be provided, and may be appropriately changed according to the purpose. Of course you can.

  Further, it is assumed that the dividing groove 51 and the terminating groove 52 formed in the central land portion 20C and the dividing groove 61 and the terminating groove 62 formed in the intermediate land portion 20M are inclined with respect to the tire equator line CL. However, it is not limited to this, and may be provided so as to be orthogonal to the tire equator line CL.

  Although it has been described that the first dividing groove is constituted by the dividing groove 51 and the second dividing groove is constituted by the dividing groove 61, the present invention is not limited to this, and the first dividing groove is constituted by the dividing groove 61. The second dividing groove may be constituted by the dividing groove 51. In this case, the first termination groove is constituted by the termination groove 62, and the second termination groove is constituted by the termination groove 52.

  Further, the inclination of the central lug groove 50 (the dividing groove 51 and the terminating groove 52) and the inclination of the intermediate lug groove 60 (the dividing groove 61 and the terminating groove 62) are provided symmetrically with respect to the center line DL in the groove. Although described as a thing, it is not limited to this, Each may be point-symmetrical on the basis of the centerline DL in a groove | channel. That is, the central lug groove 50 and the intermediate lug groove 60 are provided symmetrically with respect to the tire equator line CL.

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

1 ... pneumatic tire, 11 to 14 ... circumferential groove, 20C ... central land portion (first rib-like land portion), 20M (20M _1, 20M ₂₎ ... intermediate land portion (second rib-like land portion), 20S (20S ₁ , 20S ₂ ) ... end land part (third rib-shaped land part), 41 ... circumferential sipe, 42 ... width direction sipe, 50 ... central lug groove (first width direction groove), 51 ... dividing groove 52 ... Terminal groove, 60 ... Intermediate lug groove (second width direction groove), 61 ... Division groove, 62 ... Termination groove, 62A ... Inner termination groove, 62B ... Outer termination groove, 70 ... End lug groove (third) (Width direction groove), 71 ... termination groove, 72 ... circumferential direction narrow groove, 73 ... width direction narrow groove

Claims (4)

A first rib-like land portion and a second rib-like land portion are formed by a circumferential groove extending along the tire circumferential direction,
The first rib-shaped land portion is formed with a first width direction groove extending along the tread width direction,
The second rib-shaped land portion is a tire in which a second width direction groove extending along the tread width direction is formed,
The first width direction groove is
A first dividing groove for dividing the first rib-like land portion in the tire circumferential direction;
Provided substantially parallel to the first dividing groove, one end opens into the circumferential groove located between the first rib-like land portion and the second rib-like land portion, and the other end is the first. Including a first termination groove that terminates in the rib-like land portion,
The second width direction groove is
A second dividing groove for dividing the second rib-shaped land portion in the tire circumferential direction;
Provided substantially parallel to the second dividing groove, one end opens into the circumferential groove located between the first rib-like land portion and the second rib-like land portion, and the other end is the second. A second terminal groove that terminates in the rib-like land portion,
One end of the first terminal groove is opposed to the second dividing groove through the circumferential groove,
One end of the second terminal groove is opposed to the first dividing groove through the circumferential groove ,
The first dividing groove and the second dividing groove are inclined with respect to the tire equator line,
The inclination of the first width direction groove and the inclination of the second width direction groove pass through the center of the circumferential groove located between the first rib-like land portion and the second rib-like land portion and the tire. Tires provided symmetrically with respect to the center line in the groove extending parallel to the equator line . A plurality of the circumferential grooves are provided,
A third rib-shaped land portion adjacent to the second rib-shaped land portion is formed by the circumferential groove,
The second width direction groove is
Provided substantially parallel to the second dividing groove, one end opens into the circumferential groove located between the second rib-shaped land portion and the third rib-shaped land portion, and the other end is the second A third termination groove that terminates in the rib-like land portion;
The tire according to claim 1, wherein the third terminal groove is located on an imaginary line along an extending direction of the second terminal groove. The third rib-shaped land portion is formed with a third width direction groove extending along the tread width direction,
The third width direction groove has one end opening in the circumferential groove located between the second rib-shaped land portion and the third rib-shaped land portion, and the other end in the third rib-shaped land portion. Including a fourth termination groove terminating at
The tire according to claim 2, wherein one end of the fourth terminal groove is opposed to one end of the second dividing groove or the third terminal groove via the circumferential groove.   The tire according to claim 3, wherein the fourth terminal groove is located on an imaginary line along an extending direction of the second terminal groove.

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