JP5478211B2 - tire - Google Patents

Description

  The present invention relates to a tire in which a land portion is formed by a circumferential groove extending along the tire circumferential direction.

  2. Description of the Related Art Conventionally, in a pneumatic tire (hereinafter abbreviated as a tire as appropriate) mounted on a vehicle such as an automobile, a depression is formed in a tread width direction on a side wall surface of a land portion formed by a circumferential groove extending along the tire circumferential direction. In addition, a tread pattern in which a plurality of recesses opening on the tread surface is formed is used (see, for example, Patent Document 1).

  In the tire disclosed in Patent Document 1, the hysteresis loss of rubber constituting the land portion is increased by the recess. As a result, the coefficient of friction increases and braking performance improves. It is known that grooves (concave portions) formed in the tread surface that intersect the tire circumferential direction contribute to the effect of the tire scratching the road surface (so-called edge effect). Since the tire disclosed in Patent Document 1 has an increased groove (concave) component that intersects in the tire circumferential direction, an improvement in braking performance and driving performance due to an increased edge effect can be considered.

Japanese Unexamined Patent Publication No. 2007-112337 (2nd page, FIGS. 1 to 2)

  However, the conventional tire described above has the following problems. That is, since the concave portion is formed on the side wall surface of the land portion, the shear rigidity of the land portion is lower than that of a tire having no concave portion. For this reason, there is a drawback that steering stability when a lateral force (cornering force) is generated in the tire during turning is inferior to that of a tire without a recess.

  Therefore, an object of the present invention is to provide a tire that can more reliably improve braking performance and driving performance without deteriorating steering stability during turning.

  In order to solve the above-described problems, the present invention has the following features. First, a first feature of the present invention is that a land portion (for example, outer end land portion row 20S) is formed by a circumferential groove (for example, end side main groove 10S) extending along the tire circumferential direction (tire circumferential direction TC). The land portion includes a land portion end (land portion end 21a) along the tire circumferential direction of the land portion on a tread surface where the tire contacts a road surface. To a tire radial direction (tire radial direction TR) from a pair of cut lines (cut line L51) heading inward of the land portion along a crossing direction (for example, tread width direction TW) crossing the tire circumferential direction And a connecting line (connecting line L53) that connects the inner side edge (inner side 51a) of the cutting line located inside the land portion on the tread surface. , Groove bottom surface of the circumferential groove (groove bottom surface 11 And summarized in that a cut bottom (inclined surface 52) communicating with is formed.

  According to this feature, the cut side surface is formed in the land portion. According to this, since the hysteresis loss of the rubber constituting the land portion is increased, the friction coefficient is increased and the braking performance is improved. Further, since the edge effect due to the cut side surface is increased, the driving performance is improved in addition to the braking performance.

  Further, the cut bottom surface continues from the connecting line to the groove bottom surface of the circumferential groove. That is, the reinforcing portion is formed on the inner side in the tire radial direction of the cut bottom surface by the cut side surface and the cut bottom surface. According to this, it is possible to reliably prevent the land portion from falling between the cut side surfaces (within the cut portion) from the time when the tire is new (early wear) to the late wear phase. For this reason, the shear rigidity of a land part becomes high compared with the tire without a reinforcement part. Therefore, even when a lateral force (cornering force) is generated in the tire during a turn or the like, it is possible to reliably suppress a decrease in steering stability without causing excessive deformation of the land portion.

  A second feature of the present invention relates to the first feature of the present invention, and is summarized in that the cut bottom surface is inclined with respect to the tread surface.

  A third feature of the present invention relates to the first or second feature of the present invention, wherein the land portion has a side wall surface (side wall surface 21) continuous from the land portion end to the groove bottom surface, and the notch The gist is that the intersection line (11) between the bottom surface and the groove bottom surface is located outside the land portion with respect to the intersection line (intersection line (l2)) between the side wall surface and the groove bottom surface.

  A fourth feature of the present invention relates to the first or second feature of the present invention, wherein the land portion has a side wall surface continuous from the land portion end to the groove bottom surface, and the side wall surface, the groove bottom surface, The intersection line (l2) is located on the outer side of the land portion with respect to the intersection line (l1) between the cut bottom surface and the groove bottom surface.

  A fifth feature of the present invention relates to the first to fourth features of the present invention, wherein the land portion has a side wall surface continuous from the land portion end to the groove bottom surface, and the side wall surface is inclined. The intersection line (12) between the side wall surface and the groove bottom surface is located on the circumferential groove side with respect to the land portion end.

  A sixth feature of the present invention relates to the fifth feature of the present invention, wherein an inclination angle (inclination angle θ1) formed by a straight line (straight line LR) along the tire radial direction and the cut bottom surface is the straight line. And the side wall surface is larger than the inclination angle (inclination angle θ2).

  A seventh feature of the present invention relates to the first to sixth features of the present invention, and is summarized in that the cut side surface is continuous with the cut bottom surface.

  An eighth feature of the present invention relates to the first to sixth features of the present invention, wherein the cut side surface and the cut bottom surface are narrow grooves (gap) that open into the circumferential groove and terminate in the land portion. The gist is that it is divided by the portion 70 or the narrow groove 80).

  A ninth feature of the present invention is related to the first to eighth features of the present invention, and is summarized in that a distance between the pair of cut lines in the tire circumferential direction (interval (S1)) is substantially equal.

  A tenth feature of the present invention is related to the first to eighth features of the present invention, wherein a distance between the pair of cut lines in the tire circumferential direction (interval (S2)) is narrower toward the inside of the land portion. Is the gist.

  An eleventh feature of the present invention relates to the first to tenth features of the present invention, and is summarized in that the cut line and the connecting line are straight lines.

  A twelfth feature of the present invention relates to the first to eleventh features of the present invention, wherein the cut side surface and the cut bottom surface are the land portions (outer end land portion row 20S) located on the outermost side in the tread width direction. ).

  A thirteenth feature of the present invention relates to the first to twelfth features of the present invention, wherein the land portion on which the cut side surface and the cut bottom surface are formed has a rib shape extending continuously in the tire circumferential direction. The gist is that it is formed.

  According to the features of the present invention, it is possible to provide a tire that can more reliably improve braking performance and driving performance without reducing steering stability during turning.

FIG. 1 is a partial perspective view showing a tread of a pneumatic tire 1 according to the present embodiment. FIG. 2 is a development view showing a tread pattern of the pneumatic tire 1 according to the present embodiment. FIG. 3A is an enlarged perspective view showing a part of the outer end land portion row 20S according to the present embodiment. FIG. 3B is a plan view showing a part of the outer end land portion row 20S according to the present embodiment. FIG. 4A is an enlarged perspective view showing a part of the outer end land portion row 20S-A according to the first modification. FIG. 4B is a plan view illustrating a part of the outer end land portion row 20S-A according to the first modification. FIG. 5A is an enlarged perspective view showing a part of the outer end land portion row 20S-B according to the second modification. FIG. 5B is a plan view illustrating a part of the outer end land portion row 20S-B according to the second modification. FIG. 6A is an enlarged perspective view showing a part of the outer end land portion row 20S-C according to the third modification. FIG. 6B is a plan view illustrating a part of the outer end land portion row 20S-C according to the third modification. FIG. 7A is an enlarged perspective view showing a part of the outer end land portion row 20S-D according to the fourth modification. FIG. 7B is a plan view illustrating a part of the outer end land portion row 20S-D according to the fourth modification. FIG. 8 is an enlarged perspective view showing a part of each outer end land portion row 20S in the comparative evaluation. FIG. 9 is a plan view showing a part of the outer end land portion row 20S according to another embodiment. FIG. 10 is an enlarged perspective view showing a part of the outer end land portion row 20S according to another embodiment.

  Next, an embodiment of a pneumatic tire according to the present invention will be described with reference to the drawings. Specifically, (1) Configuration of pneumatic tire, (2) Configuration of cut section, (3) Action / effect, (4) Modification example, (5) Comparative evaluation, (6) Other embodiments explain.

  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, the part from which the relationship and ratio of a mutual dimension differ also in between drawings may be contained.

(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 partial perspective view showing a tread of a pneumatic tire 1 according to the present embodiment. FIG. 2 is a development view showing a tread pattern of the pneumatic tire 1 according to the present embodiment. The pneumatic tire 1 may be filled with an inert gas such as nitrogen gas instead of air.

  As shown in FIGS. 1 and 2, in the pneumatic tire 1, a plurality of land portion rows along the tire circumferential direction TC are formed by circumferential grooves extending along the tire circumferential direction TC.

  Specifically, the circumferential groove is configured by a pair of central-side main grooves 10C and a pair of end-side main grooves 10S. The center side main groove 10C is formed closer to the tire equator line CL than the end side main groove 10S. The end-side main groove 10S is formed outside the center-side main groove 10C in the tread width direction TW.

  On the other hand, the land portion row includes a central land portion row 20C, a pair of intermediate land portion rows 20M, and a pair of outer end land portion rows 20S.

  The central land portion row 20C is located on the tire equator line CL and is provided between the pair of central-side main grooves 10C. The central land portion row 20C is configured by providing a plurality of central blocks 40C along the tire circumferential direction TC. The central block 40C is formed by a pair of central main grooves 10C and a plurality of central lateral grooves 30C extending in the tread width direction TW.

  The intermediate land portion row 20M is adjacent to the outer side of the central land portion row 20C in the tread width direction TW, and is provided between the center side main groove 10C and the end side main groove 10S. The intermediate land portion row 20M is configured by providing a plurality of intermediate blocks 40M along the tire circumferential direction TC. The intermediate block 40M is formed by the center side main groove 10C and the end side main groove 10S, and a plurality of intermediate lateral grooves 30M extending in the tread width direction TW.

  The outer end land portion row 20S is adjacent to the tread width direction TW outside of the intermediate land portion row 20M, and is provided outside the end portion main groove 10S in the tread width direction TW. The outer end land portion row 20S is formed in a rib shape extending continuously in the tire circumferential direction TC.

  The outer end land portion row 20S is a side of the tread surface on which the pneumatic tire 1 is in contact with the road surface, the side extending from the land portion end 21a along the tire circumferential direction TC of the outer end land portion row 20S so as to be substantially orthogonal to the groove bottom surface 11. A wall surface 21 is provided. A plurality of cut portions 50 are formed in the outer end land portion row 20S.

(2) Configuration of Cutting Section Next, the configuration of the cutting section 50 according to the present embodiment will be described with reference to FIGS. FIG. 3A is an enlarged perspective view showing a part of the outer end land portion row 20S according to the present embodiment. FIG. 3B is a plan view showing a part of the outer end land portion row 20S according to the present embodiment.

  As shown in FIGS. 1 to 3, the notches 50 are provided at predetermined intervals in the tire circumferential direction TC. The notch 50 is formed on the tread surface along the crossing direction (in the present embodiment, the tread width direction TW) intersecting the tire circumferential direction TC from the land portion end 21a of the outer end land portion row 20S. It is cut toward the inside.

  In the present embodiment, the cut portion 50 is formed in a rectangular shape on the tread surface. Specifically, the cut portion 50 has a cut side surface 51 and an inclined surface 52 (cut bottom surface).

  The cut side surface 51 extends in the tire radial direction TR from the pair of cut lines L51. The cut line L51 indicates a pair of straight lines extending from the land portion end 21a toward the inside of the outer end land portion row 20S along the tread width direction TW on the tread surface.

  The cut side surfaces 51 are provided along the tread width direction TW and face each other in parallel. That is, the interval (S1) in the tire circumferential direction TC between the pair of cut lines L51 is substantially equal.

  The inclined surface 52 is inclined with respect to the tread surface. The inclined surface 52 is connected to the groove bottom surface 11 of the end-side main groove 10S from a linear connecting line L53 that connects the inner ends 51a of the cut lines L51 located inside the outer-end land portion row 20S. Further, the inclined surface 52 is continuous with the cut side surface 51. For example, the inclination angle θ1 formed by the straight line LR along the tire radial direction TR and the inclined surface 52 is preferably 15 to 45 °.

  The intersection line (11) between the inclined surface 52 and the groove bottom surface 11 is located closer to the central lateral groove 30C than the inner end 51a of the cut line L51. Specifically, the intersection line (l1) is located outside the outer end land portion row 20S with respect to the intersection line (l2) between the side wall surface 21 and the groove bottom surface 11 of the outer end land portion row 20S. That is, the intersection line (l1) is located in the end portion side main groove 10S.

  A reinforcing portion 60 that reinforces the outer end land portion row 20 </ b> S is formed by the cut side surface 51 and the inclined surface 52. The reinforcing portion 60 is formed with the inclined surface 52 as an upper surface. The reinforcing portion 60 is provided with a side surface 61. The side surface 61 continues to the groove bottom surface 11 with the inclined surface 52 located in the end-side main groove 10S as the upper end. That is, the side surface 61 is located in the end portion side main groove 10S. The side surface 61 is substantially orthogonal to the side wall surface 21 and the groove bottom surface 11.

(3) Action / Effect In the embodiment described above, a cut side surface 51 constituting the cut portion 50 is formed in the outer end land portion row 20S. According to this, since the hysteresis loss of the rubber constituting the outer end land portion row 20S is increased, the friction coefficient is increased and the braking performance is improved. In addition, since the edge effect by the cut side surface 51 is increased, the driving performance is improved in addition to the braking performance.

  Further, the inclined surface 52 is continuous from the connecting line L53 to the groove bottom surface 11 of the end-side main groove 10S. That is, the reinforcing portion 60 is formed inside the tire radial direction TR of the inclined surface 52 by the cut side surface 51 and the inclined surface 52. According to this, the outer end land portion row 20S is reliably prevented from falling into the cut portion 50 (between the cut side surfaces 51) by the reinforcing portion 60 from the so-called new tire (early wear) to late wear. it can. For this reason, compared with the tire without the reinforcement part 60, the shear rigidity of the outer end land part row | line | column 20S becomes high. Therefore, even when a lateral force (cornering force) is generated in the pneumatic tire 1 at the time of turning or the like, the outer end land portion row 20S is not deformed excessively, and a decrease in steering stability can be reliably suppressed.

  In particular, the inclination angle θ1 formed by the straight line LR along the tire radial direction TR and the inclined surface 52 is preferably 15 to 45 °. In addition, if the inclination angle θ1 is smaller than 15 °, the outer end land portion row 20S is likely to be deformed, and a decrease in steering stability may not be suppressed. On the other hand, when the inclination angle θ1 is larger than 45 °, the reinforcing portion 60 protrudes too much into the end-side main groove 10S, and the drainage performance may deteriorate.

  In the embodiment, the inclined surface 52 is inclined with respect to the tread surface. According to this, as the wear progresses, the edge along the connecting line L53 gradually approaches the end-side main groove 10S. For this reason, the edge effect by the cut side surface 51 and the side surface 61 can be exhibited stably, ensuring the drive performance at the time of turning.

  In the embodiment, the intersecting line (11) between the inclined surface 52 and the groove bottom surface 11 is more than the intersecting line (12) between the side wall surface 21 and the groove bottom surface 11 connected to the groove bottom surface 11 from the land end 21a. Located outside the row 20S. According to this, even if the edge effect by the cut side surface 51 is reduced due to wear, the edge effect can be exhibited by the side surface 61 of the reinforcing portion 60. For this reason, it is possible to improve the braking performance and the driving performance more reliably while preventing the deformation of the end-side main groove 10S even in the later stage of wear.

  In the embodiment, the cut side surface 51 continues to the inclined surface 52. That is, the reinforcing portion 60 is formed integrally with the cut side surface 51. According to this, it can prevent more reliably that the outer end land part row | line | column 20S falls into the notch part 50 by the reinforcement part 60. FIG. For this reason, the shear rigidity of the outer end land portion row 20S is increased, and it is possible to more reliably suppress a decrease in steering stability during turning.

  In the embodiment, the distance (S1) between the pair of cut lines L51 in the tire circumferential direction TC is substantially equal. According to this, since the edge effect by the cut side surface 51 can be exhibited stably during straight traveling, the braking performance and the driving performance can be improved more reliably.

  In the embodiment, the cut line L51 and the connecting line L53 are straight lines. According to this, compared with the case where the cut line L51 and the connecting line L53 are wavy lines or zigzag shapes, it is possible to prevent the mold used for tire manufacture from becoming complicated. For this reason, it is possible to more reliably improve the braking performance and the driving performance without lowering the steering stability during turning while reducing the manufacturing cost of the pneumatic tire 1.

  In the embodiment, the cut side surface 51 and the inclined surface 52 (cut portion 50) are formed in the rib-shaped outer end land portion row 20S. According to this, since the shear rigidity of the outer end land portion row 20S is higher than when the cut portion 50 is formed in the block-like outer end land portion row 20S, the steering stability at the time of turning is improved. The decrease can be suppressed more reliably.

(4) Modification Example Next, a modification example of the outer end land portion row 20S according to the above-described embodiment will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the same part as the outer end land part row | line | column 20S which concerns on embodiment mentioned above, and a different part is mainly demonstrated.

(4-1) Modification 1
First, the configuration of the outer end land portion row 20S-A according to the first modification will be described with reference to the drawings. FIG. 4A is an enlarged perspective view showing a part of the outer end land portion row 20S-A according to the first modification. FIG. 4B is a plan view illustrating a part of the outer end land portion row 20S-A according to the first modification.

  In the embodiment described above, the side wall surface 21 is continuous from the land portion end 21 a so as to be substantially orthogonal to the groove bottom surface 11. On the other hand, in the first modification, as shown in FIG. 4, the side wall surface 21 is inclined.

  Specifically, the line of intersection (l2) between the side wall surface 21 and the groove bottom surface 11 is located closer to the end side main groove 10S than the land end 21a. The inclination angle θ1 formed by the straight line LR and the inclined surface 52 along the tire radial direction TR is larger than the inclination angle θ2 formed by the straight line LR and the side wall surface 21. For example, the tilt angle θ1 is 30 °, and the tilt angle θ2 is 7 °. For this reason, the shear rigidity of the outer end land portion row 20S tends to be high.

  In the modified example 1 described above, the side wall surface 21 is inclined, and the intersection line (12) is positioned closer to the end portion side main groove 10S than the land portion end 21a, whereby the outer end land portion row 20S is sheared. The rigidity is further increased. For this reason, even when a lateral force (cornering force) is generated in the pneumatic tire 1 at the time of turning or the like, the outer end land portion row 20S is hardly deformed, and it is possible to more reliably suppress a decrease in steering stability.

(4-2) Modification 2
Next, the configuration of the outer end land portion row 20S-B according to the modification example 2 will be described with reference to the drawings. FIG. 5A is an enlarged perspective view showing a part of the outer end land portion row 20S-B according to the second modification. FIG. 5B is a plan view illustrating a part of the outer end land portion row 20S-B according to the second modification.

  In the embodiment described above, the cut portion 50 is formed in a rectangular shape on the tread surface. That is, the interval (S1) in the tire circumferential direction TC between the pair of cut lines L51 is substantially equal. On the other hand, in the modified example 2, as shown in FIG. 5, the cut portion 50 is formed in a trapezoidal shape on the tread surface.

  Specifically, the cut side surfaces 51 are inclined in different directions with respect to the tire circumferential direction TC. In the modified example 2, the interval (S2) in the tire circumferential direction TC of the cut line L51 is narrower toward the inner side of the outer end land portion row 20S-B.

  The cut side surface 51 is not continuous with the inclined surface 52. That is, the cut side surface 51 and the inclined surface 52 are divided by the gap 70 (thin groove) that opens into the end-side main groove 10S and terminates in the outer end land portion row 20S-B.

  In the modified example 2 described above, even when the cut portion 50 is formed in a trapezoidal shape on the tread surface, as in the embodiment, the braking performance and Drive performance can be improved more reliably.

  In the second modification, the above-described interval (S2) is described as being narrower toward the inner side of the outer end land portion row 20S-B, but is not limited to this, and the outer end land portion row 20S-B is not limited thereto. It may be configured to become wider toward the inside.

(4-3) Modification 3
Next, the configuration of the outer end land portion row 20S-C according to the modification example 3 will be described with reference to the drawings. FIG. 6A is an enlarged perspective view showing a part of the outer end land portion row 20S-C according to the third modification. FIG. 6B is a plan view illustrating a part of the outer end land portion row 20S-C according to the third modification.

  In the embodiment described above, the cut portion 50 is formed in a rectangular shape on the tread surface. That is, the cut side surfaces 51 are provided along the tread width direction TW, and are opposed to each other in parallel. On the other hand, in the modified example 3, as shown in FIG. 6, the notch 50 is formed in a trapezoidal shape on the tread surface.

  Specifically, each of the cut side surfaces 51 is provided so as to expand toward the tread surface. In the third modification, the interval (S3) in the tire circumferential direction TC of the cut line L51 is narrower toward the inner side of the outer end land portion row 20S-C.

  The cut side surface 51 is continuous with the inclined surface 52. That is, the cut side surface 51 and the inclined surface 52 are not divided by the gap 70 as in the third modification.

  In the modified example 3 described above, even when the cut portion 50 is formed in a trapezoidal shape on the tread surface and the cut side surface 51 is continuous with the inclined surface 52, the rigidity of the cut portion 50 is increased. The shear rigidity of the endland portion row 20S is further increased. For this reason, even when a lateral force is generated in the pneumatic tire 1 during a turn or the like, the outer end land portion row 20S is not easily deformed, and it is possible to more reliably suppress a decrease in steering stability.

  In the third modification, the above-described interval (S3) is described as being narrower toward the inner side of the outer end land portion row 20S-B, but is not limited to this, and the outer end land portion row 20S-B is not limited thereto. It may be configured to become wider toward the inside.

(4-4) Modification 4
Next, the configuration of the outer edge land portion row 20S-D according to the modification example 4 will be described with reference to the drawings. FIG. 7A is an enlarged perspective view showing a part of the outer end land portion row 20S-D according to the fourth modification. FIG. 7B is a plan view illustrating a part of the outer end land portion row 20S-D according to the fourth modification.

  In the embodiment described above, the intersection line (l1) is located outside the outer end land portion row 20S with respect to the intersection line (l2). That is, the intersection line (l1) is located in the end portion side main groove 10S. On the other hand, in the modified example 4, as shown in FIG. 7, the intersection line (l2) is located outside the outer end land portion row 20S with respect to the intersection line (l1). That is, the intersection line (l2) is located in the end portion side main groove 10S. That is, the inclined surface 52 is continuous with the groove bottom surface 11.

  In the modified example 4 described above, even when the intersection line (l2) is located outside the outer end land portion row 20S with respect to the intersection line (l1), the maneuvering during turning is performed as in the embodiment. The braking performance and driving performance can be improved more reliably without reducing the stability.

(5) Comparative Evaluation Next, in order to further clarify the effect of the present invention, comparative evaluation performed using pneumatic tires according to the following comparative examples and examples will be described. Specifically, (5-1) Configuration of each pneumatic tire and (5-2) Evaluation result will be described. In addition, this invention is not limited at all by these examples.

(5-1) Configuration of Each Pneumatic Tire First, the pneumatic tires according to Comparative Examples 1 to 4 and Examples 1 to 5 will be briefly described. In addition, the data regarding each pneumatic tire were measured on the conditions shown below.

・ Tire size: 295 / 75R22.5
・ Internal pressure condition: 650kPa
As shown in FIG. 8, the pneumatic tire according to Comparative Examples 1 to 4 is not provided with the reinforcing portion 60 described in the embodiment. Specifically, in the pneumatic tire according to Comparative Example 1, a recess 100A similar to the shape of the cut portion 50 described in the embodiment is provided (see FIG. 8A). The pneumatic tire according to Comparative Example 2 is provided with a recess 100B similar to the shape of the notch 50 described in Modification 1 (see FIG. 8B).

  The pneumatic tire according to Comparative Example 3 is provided with a recess 100C similar to the shape of the cut portion 50 described in Modification 2 (see FIG. 8C). In the pneumatic tire according to Comparative Example 4, the concave portion 100D similar to the shape of the cut portion 50 described in Modification Example 2 is provided, and the side wall surface 21 of the land portion is inclined (see FIG. 8D). .

  The pneumatic tire according to Example 1 has been described in the embodiment. The pneumatic tire according to the second embodiment is the same as that described in the first modification. The pneumatic tire according to the third embodiment is the same as that described in the second modification. The pneumatic tire according to the fourth embodiment is the same as that described in the third modification. The pneumatic tire according to the fifth embodiment is the same as that described in the fourth modification. In addition, inclination angle (theta) 1 in each reinforcement part 60 shall be 30 degrees, and let the dimension of the notch part 50 be the same as the dimension of each recessed part which concerns on Comparative Examples 1-4.

(5-2) Evaluation Results Evaluation results (driving performance and steering stability) using the pneumatic tires according to Comparative Examples 1 to 4 and Examples 1 to 5 described above will be described with reference to Table 1.

(5-2A) Drive performance The drive performance evaluation was performed on a dry road surface test course when the accelerator was fully opened from the stop state of the vehicle equipped with the pneumatic tire according to Comparative Example 1 and the vehicle traveled 50 m. The time required (so-called driving time) was set to '100', and the driving time of a vehicle equipped with other pneumatic tires was evaluated by a professional driver. The larger the index, the better the driving performance.

  As a result, as shown in Table 1, the vehicle equipped with the pneumatic tires according to Examples 1, 2, 4, and 5 has better driving performance than the vehicle equipped with the pneumatic tire according to Comparative Example 1. It turned out to be excellent.

(5-2B) Steering Stability Steering stability evaluation is based on a dry road surface test course where the steering stability of a vehicle equipped with the pneumatic tire according to Comparative Example 1 is set to '100', and other pneumatic tires are The driving stability of the mounted vehicle was evaluated by a professional driver. The larger the index, the better the steering stability.

  As a result, as shown in Table 1, the vehicle equipped with the pneumatic tires according to Examples 1 to 5 is superior in handling stability compared to the vehicle equipped with the pneumatic tire according to Comparative Examples 1 to 4. I found out.

(6) 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, the tire has been described as the pneumatic tire 1 filled with air, nitrogen gas, or the like, but is not limited thereto, and may be a solid tire (no puncture tire).

  Moreover, about the tread pattern of the pneumatic tire 1, it is not limited to what was demonstrated by embodiment, Of course, it can set suitably according to the objective. For example, although the center side main groove 10C and the end side main groove 10S have been described as extending along the tire circumferential direction TC, the present invention is not limited thereto, and is inclined with respect to the tire equator line CL. It may extend. Similarly, the central lateral groove 30C and the intermediate lateral groove 30M have been described as extending along the tread width direction TW. However, the present invention is not limited to this, and is inclined with respect to a line orthogonal to the tire equator line CL. It may extend.

  Further, the inclined surface 52 and the cut side surface 51 have been described as being continuous. However, the present invention is not limited to this. For example, as shown in FIG. It may be divided by a narrow groove 80 (sipe) that terminates in the partial row 20S.

  Moreover, although the inclined surface 52 of the cutting part 50 was demonstrated as what is inclined, it is not limited to this. For example, as shown in FIG. 10, the cut bottom surface 55 of the cut portion 50 </ b> A may be curved or not illustrated, but may be stepped.

  Moreover, although the cut line L51 and the connecting line L53 have been described as being straight lines, the present invention is not limited thereto, and may be, for example, a wavy line shape or a zigzag shape.

  Further, the outer end land portion row 20S has been described as being formed in a rib shape extending continuously in the tire circumferential direction TC, but is not limited thereto, and a plurality of blocks divided in the tire circumferential direction TC. It may be a shape.

  Moreover, although the notch part 50 was demonstrated as what is formed in the outer end land part row | line | column 20S, it is not limited to this, For example, the central land part row | line | column 20C (central block 40C) and the intermediate land part row | line | column It may be formed in 20M (intermediate block 40M).

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

DESCRIPTION OF SYMBOLS 1 ... Pneumatic tire, 10C ... Central side main groove, 10S ... End side main groove, 11 ... Groove bottom face, 20C ... Central land part row | line | column, 20M ... Middle land part row | line | column, 20S (20S-A-20S-D) ... outer end land portion row, 21 ... side wall surface, 21a ... land portion end, 30C ... central transverse groove, 30M ... intermediate transverse groove, 40C ... central block, 40M ... intermediate block, 50, 50A ... notch, 51 ... notch Side surface, 51a ... inner end, 52 ... inclined surface (cut bottom surface), 55 ... cut bottom surface, 60 ... reinforcing portion, 61 ... side surface, 70 ... gap portion, 80 ... narrow groove

Claims (12)

A tire in which a land portion is formed by a circumferential groove extending along a tire circumferential direction,
In the land,
From a pair of score lines that go to the inside of the land portion along the intersecting direction intersecting the tire circumferential direction from the land portion end along the tire circumferential direction of the land portion on the tread surface where the tire is in contact with the road surface, A cut side surface extending in the tire radial direction;
From the connecting line that connects the inner ends of the cutting lines located inside the land portion on the tread tread, a cutting bottom surface connected to the groove bottom surface of the circumferential groove is formed ,
The circumferential groove has an end side main groove located on the inner side in the tire width direction of the land portion located on the outermost side in the tread width direction,
The said cut side surface and the said cut bottom face are tires which are formed in the said land part most located in the tread width direction outer side, and are provided only in the one side in the tire width direction of the said edge part side main groove.   The tire according to claim 1, wherein the cut bottom surface is inclined with respect to the tread surface. The land portion has a side wall surface continuous from the land portion end to the groove bottom surface,
The tire according to claim 1 or 2, wherein an intersection line (l1) between the cut bottom surface and the groove bottom surface is located outside the land portion with respect to an intersection line (l2) between the side wall surface and the groove bottom surface. . The land portion has a side wall surface continuous from the land portion end to the groove bottom surface,
The tire according to claim 1 or 2, wherein an intersection line (l2) between the side wall surface and the groove bottom surface is located outside the land portion with respect to an intersection line (l1) between the cut bottom surface and the groove bottom surface. . The land portion has a side wall surface continuous from the land portion end to the groove bottom surface,
The side wall surface is inclined,
The tire according to any one of claims 1 to 4, wherein an intersection line (l2) between the side wall surface and the groove bottom surface is located closer to the circumferential groove than the land end.   The tire according to claim 5, wherein an inclination angle formed by a straight line along the tire radial direction and the cut bottom surface is larger than an inclination angle formed by the straight line and the side wall surface.   The tire according to any one of claims 1 to 6, wherein the cut side surface is continuous with the cut bottom surface.   The tire according to any one of claims 1 to 6, wherein the cut side surface and the cut bottom surface are divided by a narrow groove that opens in the circumferential groove and terminates in the land portion.   The tire according to any one of claims 1 to 8, wherein a distance between the pair of cut lines in the tire circumferential direction is substantially equal.   The tire according to any one of claims 1 to 8, wherein a distance between the pair of cut lines in the tire circumferential direction is narrower toward an inner side of the land portion.   The tire according to any one of claims 1 to 10, wherein the cut line and the connecting line are straight lines. The tire according to any one of claims 1 to 11 , wherein the land portion where the cut side surface and the cut bottom surface are formed is formed in a rib shape extending continuously in a tire circumferential direction.

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