JP2010260480A - Tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tire capable of suppressing noise caused by the deformation of a block at the rolling of a tire while maintaining on-snow performance. <P>SOLUTION: The pneumatic tire 1 includes shoulder lands 15 divided by a circumferential groove 5 and a circumferential groove 7 at both sides in a tread width direction W. A lateral groove 17 extending in the tread width direction W and communicating with the circumferential groove 5 or the circumferential groove 7 is formed at the shoulder land 15, and the shoulder land 15 is divided to land blocks 25 arranged along a tire circumferential direction R. The lateral groove 17 is formed of: an inclination groove 21 having one end 21a opened to the circumferential groove 5 or the circumferential groove 7 and the other end 21b positioned at an outer side in the tread width direction than one end 21b and inclined and extended from one end 21a to the other end 21b to a tire rotation direction side; and an outer lateral groove 23 continued to the other end 21b of the inclination groove 21 and extended from the other end 21b to a ground-contact end of a tread positioned at an outer side in the tread width direction than the other end 21b along the tread width direction W. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention includes a shoulder land portion defined by circumferential grooves extending along the tire circumferential direction on both outer sides in the tread width direction, and a lateral groove extending in the tread width direction and communicating with the circumferential groove on the shoulder land portion. The tire is divided into a plurality of land blocks arranged in the tire circumferential direction.

  Conventionally, in tires suitable for running on icy and snowy roads, a method of improving the performance on snow by forming lug grooves and sipes on the tread surface has been widely used. Further, in the tire, uneven wear (heel) is achieved by arranging a plurality of sipes along the tire circumferential direction on the tread surface of the land block and changing the length along the tread width direction of each sipe of the shoulder land portion. A method for suppressing noise caused by & toe wear is known (for example, Patent Document 1).

JP-A-7-81328

  However, the tire described above has a shorter total length along the tread width direction of the sipe in the entire tread surface of the shoulder land portion than a tire in which the length of each sipe in the shoulder land portion is not changed. Therefore, the edge effect in the entire shoulder land portion is reduced, and it is difficult to ensure both on-snow performance and noise suppression.

  The objective of this invention is providing the tire which suppresses the noise resulting from uneven wear, ensuring the performance on snow.

  The first feature of the present invention is that circumferential grooves (circumferential groove 5, circumferential groove 7) extending along the tire circumferential direction (tire circumferential direction R) are provided on both sides in the tread width direction (tread width direction W). A shoulder land portion (shoulder land portion 15) is provided, and the shoulder land portion is formed in the shoulder land portion by forming a lateral groove (lateral groove 17) extending in the tread width direction and communicating with the circumferential groove. A tire (pneumatic tire 1) partitioned into a plurality of land blocks (land blocks 25) arranged along the circumferential direction, wherein the lateral groove has one end (one end 21a) that opens to the circumferential groove, and the one end An inclined groove (inclined groove 21) that extends from the one end to the other end and inclines toward the tire rotation direction, and the other end of the inclined groove. On the other end Made, from the other end, toward the ground end of the tread which is located outside the tread width direction than the other end, and summarized in that formed by the outer lateral grooves extending along the tread width direction (outside lateral groove 23).

  According to this feature, in the shoulder land portion, one of the lateral grooves communicates with the circumferential groove, and the other extends to the grounding end of the tread, so that an edge effect can be ensured.

  In addition, since the inclined groove in the lateral groove is formed so as to extend incline toward the tire rotation direction, the predetermined land block is partitioned by the circumferential groove and the inclination groove, and is a region opposite to the tire rotation direction. A kicking area is formed. Further, a stepping area which is an area closer to the tire rotation direction is formed in the land block adjacent to the kicking area via the inclined groove in the tire circumferential direction. Since these kicking area and stepping area overlap along the tread width direction, the stepping area overlaps along the tread width direction when the kicking area leaves the contact surface as the tire rolls. Is already in contact with the ground plane. That is, the stepping region can suppress slipping when the kicking region is separated from the ground contact surface, so that uneven wear (heel and toe wear) of the kicking region can be suppressed. Therefore, it is possible to provide a tire that suppresses noise caused by uneven wear while ensuring performance on snow.

  A second feature of the present invention relates to the first feature of the present invention, wherein the width of the inclined groove along the direction perpendicular to the extending direction of the inclined groove in the tread surface view of the tire is the outer lateral groove. The gist is that the width is narrower than the width along the direction substantially perpendicular to the extending direction.

  A third feature of the present invention relates to the first or second feature of the present invention, wherein the groove depth along the tire radial direction of the inclined groove is greater than the groove depth along the tire radial direction of the outer lateral groove. The summary is shallow.

  A fourth feature of the present invention relates to any one of the first to third features of the present invention, and is an angle formed by a straight line along the tire circumferential direction and the inclined groove in the tread surface view of the tire ( The gist of the angle θ) is 15 degrees or more and 50 degrees or less.

  A fifth feature of the present invention relates to any one of the first to fourth features of the present invention, and in the tread surface view of the tire, the width (width H) of the inclined groove along the tread width direction is: It is 10% or more and 40% or less of the width (width A) along the tread width direction from the one end of the inclined groove to the grounding end of the tread located outside the one end in the tread width direction. And

  According to the tire according to the present invention, it is possible to provide a tire that suppresses noise caused by uneven wear while ensuring on-snow performance.

1 is a tread pattern of a pneumatic tire according to a first embodiment of the present invention. It is an enlarged view which shows the tread pattern of the shoulder land part of the pneumatic tire which concerns on 2nd Embodiment of this invention. It is an enlarged view which shows the tread pattern of the shoulder land part of the pneumatic tire which concerns on 3rd Embodiment of this invention. It is a tread pattern of the pneumatic tire which concerns on the prior art example in an Example.

  Hereinafter, a first embodiment to a third embodiment, comparative evaluation, and other embodiments of a pneumatic tire according to an embodiment of the present invention will be described with reference to the drawings. 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 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.

[First embodiment]
A pneumatic tire according to a first embodiment of the present invention will be described. Specifically, (1) the configuration of the tread of the pneumatic tire, (2) the detailed configuration of the lateral groove, (3) the detailed configuration of the land block, and (4) the operation and effect will be described.

(1) Configuration of Tread of Pneumatic Tire FIG. 1 is a tread pattern of a pneumatic tire according to the first embodiment of the present invention. As shown in FIG. 1, a plurality of circumferential grooves are formed in the tread of the pneumatic tire 1 along the tire circumferential direction R, and a land portion is provided between the circumferential grooves. Specifically, the circumferential groove includes a circumferential groove 3 disposed in the vicinity of the tire center, a circumferential groove 5 extending along the tire circumferential direction R, and a circumferential groove 7 on both sides in the tread width direction W. , Is composed of. The circumferential groove 3 and the circumferential groove 5 are connected via a lug groove 9 extending in the tread width direction W. Similarly, the circumferential groove 3 and the circumferential groove 7 are connected via a lug groove 11. A central land portion 13 is provided between the pair of left and right circumferential grooves 5 and 7.

  In addition, the pneumatic tire 1 includes shoulder land portions 15 that are partitioned by a circumferential groove 5 and a circumferential groove 7 on both sides in the tread width direction W. The pneumatic tire 1 forms a lateral groove 17 and a lug groove 19 that extend in the tread width direction W and communicate with the circumferential groove 5 (or the circumferential groove 7) in the shoulder land portion 15. A plurality of lateral grooves 17 and lug grooves 19 are alternately arranged at predetermined intervals in the tire circumferential direction R.

(2) Detailed Configuration of Lateral Groove The lateral groove 17 is formed by the inclined groove 21 and the outer lateral groove 23. The inclined groove 21 has one end 21a that opens to the circumferential groove 5 (or the circumferential groove 7) and the other end 21b that is located on the outer side in the tread width direction than the one end 21a. The inclined groove 21 is inclined toward the tire rotation direction from one end 21a to the other end 21b and extends in the tread width direction W.

  In the tire tread surface view, the angle θ formed by the straight line along the tire circumferential direction R and the inclined groove 21 is preferably 15 degrees or more and 50 degrees or less. In the tire tread surface view, the width H of the inclined groove 21 along the tread width direction W is in the tread width direction W from one end 21a of the inclined groove 21 to the ground contact end located outside the one end 21a in the tread width direction. It is preferable that it is 10% or more and 40% or less of the width A along. The length L of the inclined groove 21 along the tire circumferential direction R is determined by the angle θ and the width H. The ground contact end indicated by a broken line indicates an end portion where the tread contacts the road surface when the pneumatic tire 1 set to the air pressure corresponding to the maximum load described in ETRTO is loaded with the maximum load described in ETRTO.

  The outer lateral groove 23 is connected to the other end 21b of the inclined groove 21, and extends along the tread width direction W from the other end 21b to the ground contact end of the tread located on the outer side in the tread width direction than the other end 21b. In the tread surface view of the tire, the width of the inclined groove 21 along the direction substantially perpendicular to the extending direction of the inclined groove 21 is narrower than the width along the direction substantially perpendicular to the extending direction of the outer lateral groove 23. . That is, the inclined groove 21 is a sipe (thin groove), and the outer lateral groove 23 is set wider than the inclined groove 21. Further, the groove depth along the tire radial direction of the inclined groove 21 is shallower than the groove depth along the tire radial direction of the outer lateral groove 23. A sipe 31 extending in the width direction is formed between the lateral groove 17 and the lug groove 19. Further, the lateral groove 17, the lug groove 19, and the sipe 31 are connected by a sipe 33 that extends along the tire circumferential direction R.

(3) Detailed configuration of land portion block The shoulder land portion 15 is divided into a plurality of land portion blocks 25 arranged along the tire circumferential direction R by the lateral grooves 17.

  Specifically, as shown in FIG. 1, each land portion block 25 is formed in a substantially rectangular shape in the tire tread surface view, and has an inclined groove 21 and a circumferential groove 5 (or circumferential direction). A substantially triangular kick-out area 25B is defined by the groove 7). The kicking area 25B is an area in the land block 25 that is closer to the opposite side of the tire rotation direction. The kick area 25B is disposed on the kick side with respect to the tire rotation direction. Further, a stepping area 25A is located on the other end side of the kicking area 25B in the land block 25. The depression area 25A is an area closer to the tire rotation direction. The stepping area 25A is disposed on the stepping side with respect to the tire rotation direction.

  That is, the kick region 25B that is a region near the tire rotation direction in the predetermined land block 25 and the stepping region 25A that is a region near the tire rotation direction in the land block 25 adjacent to the tire circumferential direction R are: It overlaps along the tread width direction W. In FIG. 1, the stepping area 25A and the kicking area 25B are hatched so that they can be clearly distinguished from other areas.

  In addition, since the shoulder part of the pneumatic tire 1 has a rounded and inclined shape, the outer side in the width direction of the shoulder land part 15 has a shape in which the kick region 25B of the land part block 25 is gradually separated without providing an inclination. Thus, uneven wear of the land block 25 is less likely to occur.

(4) Actions / Effects As described above, according to the pneumatic tire 1 according to the present embodiment, in the shoulder land portion 15, one of the lateral grooves 17 (one end 21 a) is the circumferential groove 5 (or circumferential direction). Since the other communicates with the groove 7) and extends to the contact end of the tread, the pneumatic tire 1 can ensure an edge effect.

  In addition, since the inclined groove 21 in the lateral groove 17 is formed so as to be inclined and extend toward the tire rotation direction, the predetermined land portion block 25 includes a circumferential groove 5 (circumferential groove 7) and an inclined groove 21. And a kick region 25B, which is a region opposite to the tire rotation direction, is formed. Further, a stepping area 25A, which is an area closer to the tire rotation direction, is formed in the land block 25 adjacent to the kicking area 25B in the tire circumferential direction R via the inclined groove 21. Since the kick region 25B and the stepping region 25A overlap along the tread width direction W, the kick region 25B moves along the tread width direction W when the kick region 25B moves away from the contact surface as the tire rolls. The overlapping stepping area 25A is already in contact with the ground plane. That is, since the slipping area 25B can be prevented from slipping when the kick area 25B is separated from the contact surface by the stepping area 25A, uneven wear (heel & toe wear) of the kick area 25B can be suppressed. Therefore, it is possible to provide the pneumatic tire 1 that suppresses noise caused by uneven wear while ensuring on-snow performance.

  According to this embodiment, the width of the inclined groove 21 along the direction substantially perpendicular to the extending direction of the inclined groove 21 in the tread surface view of the tire is substantially perpendicular to the extending direction of the outer lateral groove 23. Narrower than the width along. For this reason, at the time of tire rolling, the kicking area 25 </ b> B is easier to support the stepping area 25 </ b> A adjacent via the inclined groove 21 than the area of the land block 25 adjacent via the outer lateral groove 23. That is, the rigidity of the kicking area 25 </ b> B is higher than the rigidity of the other land block 25. Therefore, since the deformation amount of the kicking area 25B can be reduced and uneven wear can be suppressed, noise can be further suppressed.

  According to the present embodiment, the groove depth along the tire radial direction of the inclined groove 21 is shallower than the groove depth along the tire radial direction of the outer lateral groove 23. For this reason, at the time of tire rolling, the deformation amount of the kick region 25B is smaller than the deformation amount of the other land block 25. Therefore, the uneven wear of the kicking area 25B can be further suppressed.

  According to the present embodiment, in the tire tread surface view, the angle θ formed by the straight line along the tire circumferential direction R and the inclined groove 21 is not less than 15 degrees and not more than 50 degrees. For this reason, with the rolling of the tire, the kicking area 25B can reliably suppress slipping when leaving the contact surface by the stepping area 25A. Since the angle θ is 15 degrees or more, the shape of the kick region 25B can secure the width along the tread width direction W, and therefore the rigidity of the kick region 25B can be sufficiently secured. Since the angle θ is 50 degrees or less, the kicking area 25B sufficiently overlaps the stepping area 25A and the kicking area 25B as the tire rolls, so that slippage when leaving the contact surface is ensured. Can be suppressed.

  According to this embodiment, in the tire tread surface view, the width H of the inclined groove 21 along the tread width direction W is 10% of the width A along the tread width direction W from the one end 21a to the other end 21b. Above, it is 40% or less. For this reason, the pneumatic tire 1 can sufficiently suppress noise due to uneven wear while ensuring performance on snow. Generally, in the shoulder land portion 15, uneven wear is likely to occur at the inner end portion in the tread width direction. On the other hand, when the width H is 10% or more of the width A, a region in which uneven wear is likely to occur can be formed in the kick region 25B. Therefore, since uneven wear can be suppressed, noise can be sufficiently suppressed. Further, since the width H is 40% or less of the width A, the lateral groove 17 can sufficiently secure the edge effect.

[Second Embodiment]
Next, a pneumatic tire according to a second embodiment of the present invention will be described. However, the same components as those in the first embodiment described above are denoted by the same reference numerals and description thereof is omitted.

  FIG. 2 is an enlarged view showing a tread pattern of a shoulder land portion according to another embodiment of the present invention.

  As shown in FIG. 2, the shoulder land portion 40 is formed with a first lateral groove 41 and a second lateral groove 43. The first lateral groove 41 has a wide width along the tire circumferential direction R and extends along the tread width direction W. The second lateral groove 43 is formed with a narrower width along the tire circumferential direction R than the first lateral groove 41 and extends along the tread width direction W. The first lateral groove 41 is formed by an inclined groove 45 and an outer lateral groove 49. The second lateral groove 43 is formed by the inclined groove 47 and the outer lateral groove 51.

  The land block 53 is partitioned by the first lateral groove 41 and the second lateral groove 43. In addition, the groove depth along the tire radial direction of the first lateral groove 41 is preferably 6.5 mm, and the groove depth along the tire radial direction of the second lateral groove 43 is preferably 6.2 mm.

  Also in this embodiment, the performance on snow can be improved by forming the first lateral grooves 41 and the second lateral grooves 43.

[Third embodiment]
Next, a pneumatic tire according to a third embodiment of the present invention will be described. However, the same components as those in the first and second embodiments described above are denoted by the same reference numerals and description thereof is omitted.

  FIG. 3 is an enlarged view showing a tread pattern 55 of the shoulder land portion according to the third embodiment of the present invention.

  As shown in FIG. 3, the lateral grooves 57 arranged in the shoulder land portion along the circumferential direction may be set to have substantially the same shape and substantially the same width. The lateral groove 57 is formed by an inclined groove 59 and an outer lateral groove 61 disposed on the outer side in the width direction of the inclined groove 59. A land block 63 extending in the tread width direction is formed between the lateral grooves 57. A region near the tire rotation direction in the land block 63 is a stepping region 65. Further, the area from the opposite side of the tire rotation direction is a kicking area 67.

  Also in this embodiment, the performance on snow can be improved by forming the lateral groove 57.

  It should not be understood that the description and the drawings, which form part of the disclosure of the above-described embodiments, limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  For example, in the embodiment, the width direction inner portion of the wide lateral groove is inclined, but the width direction inner portion may be inclined to the narrow sipe.

[Comparison evaluation]
Next, the present invention will be described more specifically through comparative evaluation.

  First, put a pneumatic tire with a tire size of 225 / 45R17 on a European FR vehicle, drive 10,000 km on a smooth road at a speed of 0 to 80 km / h, and drive a noise feeling of in-vehicle noise due to worn tires. The sensitive evaluation was performed by a person with a five-step evaluation.

In the pneumatic tire 101 according to the comparative example, as shown in FIG. 4, the lateral grooves 117 extend in a substantially straight line along the width direction, and the depth D and width W of each groove are as shown in FIG. It is set to a numerical value. The pneumatic tire according to the example of the present invention has the tread pattern shown in FIG. Table 1 shows the structure of each pneumatic tire.

  As a result, the result of the noise feeling test in the case where the pneumatic tire according to the comparative example is mounted is evaluation 3 (market lower limit level), and the result of the noise feeling test of the pneumatic tire according to the present invention example is evaluation 4 (Satisfactory level).

[Other Embodiments]
Although the contents of the present invention have been disclosed through the embodiments of the present invention as described above, it should not be understood that the descriptions and drawings constituting a part of this disclosure limit the present invention. 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. The outer lateral groove 23 in the embodiment described above is formed along the tread width direction W, but is not limited thereto, and is inclined with respect to the tread width direction W within a range in which the edge effect of the lateral groove 17 is obtained. It may be.

  The width of the inclined groove 21 in the embodiment described above is narrower than the width of the outer lateral groove 23, but is not limited thereto, and may be wider than the width of the outer lateral groove 23. Similarly, the groove depth of the inclined groove 21 may be deeper than the groove depth of the outer lateral groove 23.

  The pneumatic tire 1 in the above-described embodiment is filled with a gas such as air or nitrogen so as to reach a predetermined pressure, but is not limited thereto, and may be formed of, for example, a solid tire.

A ... width, H ... width, R ... tire circumferential direction, W ... tread width direction, W ... width, 1 ... pneumatic tire, 3 ... circumferential groove, 5, 7 ... circumferential groove, 9, 11, 19 ... Lug groove, 13 ... central land portion, 15 ... shoulder land portion, 17 ... lateral groove, 21 ... inclined groove, 21a ... one end, 21b ... other end, 23 ... outer lateral groove, 25 ... land block, 25A ... stepping area, 25B ... kicking area 31, 33 ... sipe, 40 ... shoulder land, 41 ... first lateral groove, 43 ... second lateral groove, 45, 47 ... inclined groove, 49, 51 ... outer lateral groove, 53 ... land block, 55 ... Tread pattern, 57 ... Horizontal groove, 59 ... Inclined groove, 61 ... Outer lateral groove, 63 ... Land block, 65 ... Depression area, 67 ... Kicking area, 101 ... Pneumatic tire, 117 ... Horizontal groove

Claims (3)

A shoulder land portion defined by circumferential grooves extending along the tire circumferential direction is provided on both outer sides in the tread width direction, and a lateral groove extending in the tread width direction and communicating with the circumferential groove is formed on the shoulder land portion. By doing so, a tire that divides the shoulder land portion into a plurality of land portion blocks arranged along the tire circumferential direction,
The lateral groove is
An inclined groove that has one end that opens to the circumferential groove and the other end that is located on the outer side in the tread width direction than the one end, and that extends obliquely toward the tire rotation direction side from the one end to the other end;
A tire formed by an outer lateral groove that extends along the tread width direction from the other end to the ground contact end of the tread that is located on the outer side in the tread width direction than the other end. In the tread surface view of the tire,
The tire according to claim 1, wherein a width of the inclined groove along a direction substantially perpendicular to an extending direction of the inclined groove is narrower than a width along a direction substantially perpendicular to the extending direction of the outer lateral groove. .   The tire according to claim 1 or 2, wherein a groove depth along the tire radial direction of the inclined groove is shallower than a groove depth along the tire radial direction of the outer lateral groove.

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