JP2011031840A - Tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tire reduced in road noise, while suppressing a rise of manufacturing cost. <P>SOLUTION: This pneumatic tire 1 includes rib-shaped land parts extending in a tire peripheral direction TC and is formed with peripheral direction grooves extending in the tire peripheral direction TC to be adjacent to the land parts. In the land parts, peripheral direction shallow grooves 70 having shallower groove depths than those of the peripheral direction grooves and continuously extending along the tire peripheral direction TC are formed. In the peripheral direction shallow grooves 70, a plurality of sipes recessed to the tire radial direction TR inside more than the peripheral direction shallow grooves 70 are formed. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a tire including a rib-like land portion extending in the tire circumferential direction, and having a circumferential groove adjacent to the land portion and extending in the tire circumferential direction.

  Conventionally, in a tire mounted on a passenger car or the like, in order to reduce road noise caused by road surface unevenness, it has been widely adopted to define a reinforcing layer provided inside the tire. For example, a tire is known in which a reinforcing layer is provided on the outer side in the tire radial direction of the belt layer, in which a cord that is coated with rubber is wound spirally at a predetermined interval (for example, 2 to 10 mm) in the tread width direction. (For example, Patent Document 1).

  According to such a tire, the rigidity of the tire itself is lower than a reinforcing layer in which cord dead cords are spirally wound so as not to leave a predetermined interval in the tread width direction. For this reason, the tire is easily deformed with respect to the unevenness of the road surface, and road noise is reduced.

JP 2004-66922 A (page 4, FIG. 1)

  However, the conventional tire described above has the following problems. That is, there is a problem that a process of winding the cord dead cord in a spiral shape with a predetermined interval in the tread width direction is necessary and the manufacturing process of the tire increases because the process is complicated.

  Therefore, an object of the present invention is to provide a tire with reduced road noise while suppressing an increase in manufacturing cost.

  In order to solve the above-described problems, the present invention has the following features. First, a first feature of the present invention includes a rib-like land portion (land portion) extending in a tire circumferential direction (tire circumferential direction TC), a circumferential groove (adjacent to the land portion) and extending in the tire circumferential direction ( A circumferential tire) (for example, a pneumatic tire 1), in which the land portion has a groove depth shallower than the circumferential groove and continuously extends along the tire circumferential direction. A shallow shallow groove (circumferential shallow groove 70) is formed, and a plurality of sipes (sipe 81 and sipe 82) are formed in the circumferential shallow groove that are recessed inward in the tire radial direction from the circumferential shallow groove. Is the gist.

  According to such a feature, in addition to the circumferential groove, the circumferential shallow groove is formed in the land portion, so that a part of the tread surface on which the circumferential shallow groove is formed does not easily contact the road surface. For this reason, the input from the unevenness | corrugation of a road surface reduces, and the road noise resulting from the unevenness | corrugation of the said road surface can be reduced.

  Moreover, the circumferential shallow groove extends continuously along the tire circumferential direction. For this reason, compared with the case where the circumferential shallow groove is divided at predetermined intervals in the tire circumferential direction, it is possible to reduce noise (pattern noise) caused by the edge formed on the land portion being in contact with the road surface.

  Further, by providing a plurality of sipes, the rigidity (compression rigidity) of the land portion can be adjusted (that is, can be lowered). For this reason, road noise caused by road surface unevenness can be further reduced, and road noise after wear can also be reduced.

  As described above, road noise and pattern noise can be reduced only by forming a circumferential shallow groove and a plurality of sipes in the land portion as described above. The process of placing and winding in a spiral shape is not necessary, and the manufacturing of the tire is simplified, so that an increase in the manufacturing cost of the tire can be suppressed.

  A second feature of the present invention relates to the first feature of the present invention, and is summarized in that the circumferential shallow groove is formed in a land portion located at a shoulder portion of the tire in contact with a road surface.

  A third feature of the present invention relates to the second feature of the present invention, and is summarized in that a plurality of the circumferential shallow grooves are formed adjacent to each other in the tread width direction.

  A fourth feature of the present invention relates to the first to third features of the present invention, wherein the position of the sipe formed in one circumferential shallow groove is the one formed in the other circumferential shallow groove adjacent thereto. The gist is that they are provided at different positions with respect to the sipe and the tire circumferential direction.

A fifth feature of the present invention relates to the first to fourth features of the present invention, wherein the depth of the sipe (D ₈₀ ) is deeper than the depth of the circumferential shallow groove (D ₇₀ ). And

  A sixth feature of the present invention relates to the first to fifth features of the present invention, and is summarized in that the sipe has a vertically long shape along a tire circumferential direction.

  According to the characteristics of the present invention, it is possible to provide a tire with reduced road noise while suppressing an increase in manufacturing cost.

FIG. 1 is a development view showing a part of the tread surface 10 of the pneumatic tire 1 according to the present embodiment. FIG. 2 is a perspective view showing a part of the tread surface 10 of the pneumatic tire 1 according to the present embodiment. Fig.3 (a) is a tread width direction sectional drawing (AA sectional drawing of FIG. 1) which shows a part of tread surface 10 of the pneumatic tire 1 which concerns on this embodiment. FIG. 3B is an enlarged schematic view showing the circumferential shallow groove 70 of FIG. FIG. 4 is a development view illustrating a part of the tread surface 10A of the pneumatic tire 1A according to the first modification. FIG. 5 is a perspective view showing a part of the tread surface 10A of the pneumatic tire 1A according to the first modification. Fig.6 (a) is a tread width direction sectional drawing (AA sectional drawing of FIG. 4) which shows a part of tread surface 10A of the pneumatic tire 1 which concerns on this embodiment. FIG. 6B is an enlarged schematic diagram showing only the circumferential groove 31 in FIG. FIG. 7 is an enlarged schematic view showing the shallow groove portion 40 and the deep groove portion 50.

  Next, an embodiment of a pneumatic tire according to the present invention will be described with reference to the drawings. Specifically, (1) Overall configuration of pneumatic tire, (2) Detailed configuration of circumferential shallow groove, (3) Modified example, (4) Comparative evaluation, (5) Action / effect, (6) 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) Whole structure of pneumatic tire First, the whole structure of the pneumatic tire 1 which concerns on this embodiment is demonstrated, referring drawings. FIG. 1 is a development view showing a part of the tread surface 10 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 FIG. 1, the pneumatic tire 1 includes a rib-like land portion extending in the tire circumferential direction TC. On the tread surface 10 of the land portion, a rectangular circumferential groove is formed adjacent to the land portion and extending in the tire circumferential direction TC.

  The land portion includes a land portion 21, a land portion 22, a land portion 23, a land portion 24, and a land portion 25 from the left side to the right side of FIG. The circumferential groove includes a circumferential groove 31, a circumferential groove 32, a circumferential groove 33, and a circumferential groove 34 from the left side to the right side in FIG.

  A plurality of auxiliary lateral grooves are provided in the land portion. Specifically, the land portion 21 is formed with a circumferential shallow groove 70 having a groove depth shallower than that of the circumferential groove and extending along the tire circumferential direction TC. That is, the circumferential shallow groove 70 is formed in the land portion 21 located at the shoulder portion of the pneumatic tire 1 in contact with the road surface. The configuration of the circumferential shallow groove 70 will be described later.

  Each of the land portion 21, the land portion 23, the land portion 24, and the land portion 25 includes a plurality of auxiliary lateral grooves 61, a plurality of auxiliary lateral grooves 63, and a plurality of auxiliary lateral grooves at predetermined intervals in the tire circumferential direction TC. 64 and a plurality of auxiliary lateral grooves 65 are formed. Note that no auxiliary lateral groove is formed in the land portion 22.

  Each of the auxiliary horizontal groove 61, the auxiliary horizontal groove 63, the auxiliary horizontal groove 64, and the auxiliary horizontal groove 65 is curved along the tread width direction TW in the tread tread view, and opens to the circumferential groove. The auxiliary horizontal groove 63 and the auxiliary horizontal groove 64 are provided on an extension line along the auxiliary horizontal groove 65. Each of the auxiliary horizontal grooves 61, the auxiliary horizontal grooves 63, the auxiliary horizontal grooves 64, and the auxiliary horizontal grooves 65 has a width that is narrower than the respective widths along the tread width direction TW of the circumferential grooves.

(2) Detailed Configuration of Circumferential Shallow Groove Next, a detailed configuration of the circumferential shallow groove 70 described above will be described with reference to the drawings. FIG. 2 is a perspective view showing a part of the tread surface 10 of the pneumatic tire 1 according to the present embodiment. Fig.3 (a) is a tread width direction sectional drawing (AA sectional drawing of FIG. 1) which shows a part of tread surface 10 of the pneumatic tire 1 which concerns on this embodiment. FIG. 3B is an enlarged schematic view showing the circumferential shallow groove 70 of FIG. The tread width direction sectional view shows a sectional view along the tread width direction TW and the tire radial direction TR.

  As shown in FIGS. 1 to 3, a plurality of circumferential shallow grooves 70 are formed adjacent to the tread width direction TW. In the present embodiment, the circumferential shallow groove 70 includes an inner shallow groove 71 and an outer shallow groove 72.

  The inner shallow groove 71 is located on the tire equator line CL side. The inner shallow groove 71 is curved in the tread width direction sectional view. The boundary (R1 in FIG. 3B) between the inner shallow groove 71 and the tread surface 10 of the land portion 21 is continuous in a curved shape in the cross section in the tread width direction. In the inner shallow groove 71, a plurality of sipes 81 that are recessed inward in the tire radial direction TR from the circumferential shallow groove 70 are formed.

The sipes 81 are arranged at predetermined intervals in the tire circumferential direction TC. The sipe 81 has a vertically long shape (so-called blade sipe) along the tire circumferential direction TC. The depth (D ₈₀ ) of the sipe 81 is deeper than the depth (D ₇₀ ) of the circumferential shallow groove 70. Note that the boundary (R2 in FIG. 3B) between the sipe 81 and the inner shallow groove 71 may be continuous in a curved shape in the cross section in the tread width direction.

  The outer shallow groove 72 is located outside the inner shallow groove 71 on the outer side in the tread width direction TW. The outer shallow groove 72 is curved in the tread width direction sectional view. The boundary (R1 in FIG. 3A) between the outer shallow groove 72 and the tread surface 10 of the land portion 21 is continuous in a curved shape in the cross section in the tread width direction. The outer shallow groove 72 is formed with a plurality of sipes 82 that are recessed more inwardly in the tire radial direction TR than in the circumferential shallow groove 70.

The sipes 82 are arranged at predetermined intervals in the tire circumferential direction TC. The sipe 82 has a vertically long shape (so-called blade sipe) along the tire circumferential direction TC. The depth of the sipe 82 _{(D 80)} is the same as the depth of the sipe 81 _{(D 80),} deeper than the depth of the circumferential shallow groove _{70 (D} 70). Note that the boundary (R2 in FIG. 3B) between the sipe 82 and the outer shallow groove 72 may be continuous in a curved shape in the cross section in the tread width direction.

  Here, the sipe 81 formed in the inner shallow groove 71 is provided at a position different from the sipe 82 formed in the outer shallow groove 72 adjacent to the tread width direction TW and the tire circumferential direction TC.

(3) Modification Example Next, a modification example of the tread surface 10 of the pneumatic tire 1 according to the embodiment described above will be described with reference to the drawings. FIG. 4 is a development view illustrating a part of the tread surface 10A of the pneumatic tire 1A according to the first modification. FIG. 5 is a perspective view showing a part of the tread surface 10A of the pneumatic tire 1A according to the first modification.

  Fig.6 (a) is sectional drawing which shows a part of 10 A of tread surface of the pneumatic tire 1 which concerns on this embodiment. That is, FIG. 6A shows a cross-sectional view taken along line AA in FIG. 1 along the tire radial direction TR as viewed from the direction B in FIG. FIG. 6B is an enlarged schematic view showing the circumferential groove 31 of FIG. FIG. 7 is an enlarged schematic view showing the shallow groove portion 40 and the deep groove portion 50.

  In the embodiment described above, the circumferential groove has a rectangular shape. On the other hand, in the first modification, as shown in FIGS. 4 to 7, the circumferential groove 31 and the circumferential groove 33 among the circumferential grooves include a shallow groove portion 40 and a deep groove portion 50. In addition, the same code | symbol is attached | subjected to the same part as the tread surface 10 of the pneumatic tire 1 which concerns on embodiment mentioned above, and a different part is mainly demonstrated.

  In the first modification, the circumferential groove includes the circumferential groove 31, the circumferential groove 32, and the circumferential groove 33. The land portion is composed of the land portion 21, the land portion 22, the land portion 23, and the land portion 24. No auxiliary lateral groove is formed in the land.

  The shallow groove portion 40 is formed between the land portion 21 and the land portion 22 adjacent to each other. The shape of the side wall 40a of the shallow groove portion 40 is a half-moon shape recessed in the tire radial direction TR in the cross section in the tread width direction (see FIGS. 5 and 6).

  As shown in FIG. 6B, at least the side wall 40a of the shallow groove portion 40 of the shallow groove portion 40 and the deep groove portion 50 passes through the circumferential groove side end of the land portion in the cross section in the tread width direction, and the tire equator line. The distance CP to the straight line PL parallel to CL is inclined so as to become longer toward the deepest portion 40 b of the shallow groove portion 40. The shallow groove portion 40 includes an inner shallow groove 41 and an outer shallow groove 42 (see FIGS. 4 to 6).

  The inner shallow groove 41 is located on the tire equator line CL side with respect to the groove center line DCL passing through the tread width direction TW of the circumferential groove 31 and the circumferential groove 33. The outer shallow groove 42 is continuous with the inner shallow groove 41 and is located outside the in-groove center line DCL in the tread width direction TW.

  The inner shallow groove 41 and the outer shallow groove 42 are curved so as to be opposite to the tire circumferential direction TC. Specifically, as shown in FIG. 7, the outer convex portion 41a that protrudes when the inner shallow groove 41 is curved and the outer convex portion 42a that protrudes when the outer shallow groove 42 curves are Located on the line DCL side. That is, the inner shallow groove 41 and the outer shallow groove 42 are provided point-symmetrically with respect to the center point P1 of the shallow groove portion 40 located on the in-groove center line DCL. Further, the end portion 41p on the land portion 22 side in the inner shallow groove 41 and the end portion 42p of the land portion 21 in the outer shallow groove 42 are arranged so as to be shifted in the tire circumferential direction TC.

  The deep groove portion 50 is adjacent to the shallow groove portion 40 in the tire circumferential direction TC and extends in the tread width direction TW. Specifically, the deep groove portion 50 extends so as to be curved along the tread width direction TW in the tread tread view. The deep groove portion 50 has a groove bottom 40c of the shallow groove portion 40 as an upper end and is recessed more inward in the tire radial direction TR than the shallow groove portion 40.

  The deep groove portion 50 is more rectangular than the shallow groove portion 40 in the cross section in the tread width direction. Specifically, the shape of the side wall 50a of the deep groove portion 50 is a straight shape along the tire radial direction TR in the cross section in the tread width direction. The shape of the groove bottom 50b of the deep groove portion 50 is a straight line shape along the tread width direction TW in the cross section in the tread width direction. The boundary between the side wall 50a and the groove bottom 50b is continuous in a curved shape in the cross section in the tread width direction. The deep groove part 50 is comprised by the inner side deep groove 51 and the outer side deep groove 52 (refer FIGS. 4-7).

  The inner deep groove 51 is located closer to the tire equator line CL than the in-groove center line DCL. The outer deep groove 52 is continuous with the inner deep groove 51 and is located outside the center line DCL in the tread width direction TW.

  The inner deep groove 51 and the outer deep groove 52 are curved so as to be opposite to the tire circumferential direction TC. Specifically, as shown in FIG. 7, the outer convex portion 51 a that protrudes when the inner deep groove 51 curves and the outer convex portion 52 a that protrudes when the outer deep groove 52 curves are each in-groove center line DCL. Located on the side. That is, the inner deep groove 51 and the outer deep groove 52 are provided point-symmetrically with respect to the center point P2 of the deep groove portion 50 located on the in-groove center line DCL. Further, the end portion 51p on the land portion 22 side in the inner deep groove 51 and the end portion 52p of the land portion 21 in the outer deep groove 52 are arranged so as to be shifted in the tire circumferential direction TC.

  Note that the number of circumferential grooves is not limited to that described in the embodiment or the modification, and can be appropriately selected according to the purpose. That is, the shallow groove part 40 and the deep groove part 50 may be provided in all the circumferential grooves, and are preferably provided in at least one circumferential groove.

  Further, auxiliary lateral grooves may be formed in the land portion. In this case, the tread tread surface 10A in the land portion preferably forms a smooth surface without a gap in a state where a normal load is applied to the pneumatic tire 1 and in a state where the pneumatic tire 1 is in contact with the road surface.

  Further, the end portion 41p on the land portion 22 side in the inner shallow groove 41 and the end portion 42p of the land portion 21 in the outer shallow groove 42 may be arranged at the same position with respect to the tire circumferential direction TC. That is, the inner shallow groove 41 and the outer shallow groove 42 may be provided symmetrically with respect to the tire equator line CL. Similarly, the end portion 51p on the land portion 22 side in the inner deep groove 51 and the end portion 52p of the land portion 21 in the outer deep groove 52 may be disposed at the same position with respect to the tire circumferential direction TC. That is, the inner deep groove 51 and the outer deep groove 52 may be provided symmetrically with respect to the tire equator line CL.

  Moreover, although the shallow groove part 40 and the deep groove part 50 were demonstrated as what extends so that it might curve along the tread width direction TW in tread tread surface view, it is not limited to this, For example, it has extended linearly. Also good. In addition, the shape of the shallow groove portion 40 and the shape of the deep groove portion 50 are not necessarily limited to those described in the modification example, and can be appropriately set according to the purpose.

(4) 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, (4-1) Configuration of each pneumatic tire and (4-2) Evaluation result will be described. In addition, this invention is not limited at all by these examples.

(4-1) Configuration of Each Pneumatic Tire First, a pneumatic tire according to a comparative example and an example will be briefly described. In addition, the data regarding a pneumatic tire were measured on the conditions shown below.
・ Tire size: 225 / 45R17
・ Rim size: 8J-17
・ Vehicle conditions: Domestic FF car (displacement 2000cc)
・ Internal pressure condition: Regular internal pressure ・ Load condition: Driver load + 600N

  In the pneumatic tire according to the comparative example, the circumferential shallow groove is not formed in the land portion. On the other hand, in the pneumatic tire according to the example, circumferential shallow grooves 70 (inner shallow grooves 71 and outer shallow grooves 72) are formed in the land portion.

  In addition, the pneumatic tire which concerns on a comparative example and an example shall be a tread pattern shown to embodiment (FIGS. 1-3) mentioned above. The pneumatic tires according to the comparative example and the example are the same except for the configuration of the circumferential shallow groove (sipe).

(4-2) Evaluation Results Next, the evaluation results of the road noise performance of the vehicle equipped with each tire will be described with reference to Table 1.

  For road noise performance, road noise of a vehicle equipped with the pneumatic tire according to the comparative example was set to '100', and road noise of the vehicle equipped with the pneumatic tire of the example was indexed. In addition, road noise is so small that an index | exponent is small.

  As a result, as shown in Table 1, it was found that the vehicle equipped with the pneumatic tire according to the example can reduce road noise compared to the vehicle equipped with the pneumatic tire according to the comparative example.

(5) Action / Effect In the embodiment described above, the land portion is formed with the circumferential shallow groove 70 in addition to the circumferential groove, so that the tread tread 10 having the circumferential shallow groove 70 formed therein is formed. Part of the road becomes difficult to touch. For this reason, the input from the unevenness | corrugation of a road surface is reduced, and the road noise resulting from the unevenness | corrugation of the said road surface can be reduced. Note that the circumferential shallow groove 70 has a shallower groove depth than the circumferential groove, thereby suppressing a decrease in rigidity of the land portion and maintaining steering stability and drivability.

  In addition, the circumferential shallow groove 70 extends continuously along the tire circumferential direction TC. For this reason, compared with the case where the circumferential shallow groove 70 is divided at predetermined intervals in the tire circumferential direction TC, noise (pattern noise) caused by a plurality of edges formed in the land contacting the road surface is reduced. Can also be reduced.

  Further, by providing a plurality of sipes (sipe 81 or sipe 82), the rigidity (compression rigidity) of the land portion 21 can be adjusted (that is, can be lowered). For this reason, road noise caused by road surface unevenness can be further reduced, and road noise after wear can also be reduced.

  As described above, road noise and pattern noise can be reduced only by forming the circumferential shallow groove 70 and a plurality of sipes in the land portion as described above. Therefore, the code dead code is predetermined in the tread width direction TW as in the past. The process of winding in a spiral at intervals is not necessary, and the production of the pneumatic tire 1 is simplified, so that an increase in the production cost of the pneumatic tire 1 can be suppressed.

  In general, road noise generated at the shoulder portion of the pneumatic tire 1 near the wheel rim is easily transmitted to the interior of the vehicle. For this reason, in the embodiment, the circumferential shallow groove 70 is formed in the land portion 21 located in the shoulder portion of the pneumatic tire 1, so that road noise generated in the land portion 21 can be further reduced.

  In the embodiment, a plurality of circumferential shallow grooves 70 are formed adjacent to the tread width direction TW. For this reason, the input from the unevenness | corrugation of a road surface is further reduced, and the road noise which generate | occur | produces in the land part 21 can further be reduced.

  In the embodiment, the position of the sipe 81 formed in the inner shallow groove 71 is provided at a position different from the sipe 82 formed in the outer shallow groove 72 adjacent to the tread width direction TW and the tire circumferential direction TC. For this reason, noise (road noise and pattern noise) generated in the land portion 21 is easily dispersed. Therefore, the generation of road noise and pattern noise can be more reliably reduced.

In the embodiment, the depth D ₈₀ of the sipe 81 and the sipe 82 is deeper than the depth (D ₇₀ ) of the circumferential shallow groove 70. Incidentally, the shallower than the depth of the depth _{D 52} of the depth _{D 51} and sipes 82 of the sipe 81 in the circumferential direction shallow grooves 70 _{(D 40),} difficult to adjust the rigidity of the land portion 21 (compression stiffness) (i.e. , Hard to lower). For this reason, the effect of reducing road noise caused by road surface unevenness may not be sufficiently obtained.

  In the embodiment, the sipe 81 has a vertically long shape (so-called blade sipe) along the tire circumferential direction TC. For this reason, the sipe 81 can be largely formed in the circumferential shallow groove 70, and the rigidity (compression rigidity) of the land portion 21 can be easily adjusted. Therefore, road noise caused by road surface unevenness can be efficiently reduced.

  In the modified example, the circumferential groove 31 and the circumferential groove 33 include a shallow groove portion 40 and a deep groove portion 50. According to this, since the shallow groove portion 40 and the deep groove portion 50 are not grounded in the initial stage of wear, pattern noise does not occur. On the other hand, the shallow groove portion 40 and the deep groove portion 50 appear on the tread surface 10 after a certain amount of wear from the early wear stage (late wear stage). For this reason, the edge component in the tread surface 10 by the shallow groove part 40 and the deep groove part 50 increases in the late stage of wear, and the braking performance can be improved. That is, both pattern noise and braking performance can be achieved after a certain amount of wear from the beginning of wear.

  In this way, in the modified example, the braking performance can be improved after a certain amount of wear from the beginning of wear, so it is not necessary to form an auxiliary lateral groove in the land portion, and the edge formed in the land portion by the auxiliary lateral groove contacts the road surface. The pattern noise resulting from the above can be surely reduced.

(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, in the embodiment, the tire has been described as the pneumatic tire 1 filled with air, nitrogen gas, or the like, but is not limited thereto, and is not filled with air, nitrogen gas, or the like. It may be a solid tire.

  In the embodiment, the tread pattern of the pneumatic tire 1 is not limited to the one described in the embodiment, and can be appropriately set according to the purpose. That is, the configuration (shape and number) of the land portion, the circumferential groove, the auxiliary lateral groove, and the circumferential shallow groove 70 can be appropriately set according to the purpose.

  For example, the circumferential shallow groove 70 has been described as being formed in the land portion 21 located in the shoulder portion of the pneumatic tire 1 in contact with the road surface, but is not limited thereto, and is located in the other shoulder portion. The land portion 25 may be formed.

  Moreover, although the circumferential direction shallow groove 70 was demonstrated as what was comprised by the inner side shallow groove 71 and the outer side shallow groove 72, it is not limited to this, One may be sufficient and three You may be comprised by the above shallow groove.

  In the embodiment, the sipe 81 and the sipe 82 have been described as having a vertically long shape along the tire circumferential direction TC. However, the present invention is not limited to this, and for example, in a tread tread view, It may have a triangular shape, a rectangular shape, or the like (so-called pin sipe).

  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.

DESCRIPTION OF SYMBOLS 1,1A ... Pneumatic tire, 10, 10A ... Tread tread, 21-25 ... Land part, 31-34 ... Circumferential groove | channel, 40 ... Shallow groove part, 40a ... Side wall, 40b ... Deepest part, 40c ... Groove bottom, 41 ... inner shallow groove, 41a ... outer convex part, 41p ... end part, 42 ... outer shallow groove, 42a ... outer convex part, 42p ... end part, 50 ... deep groove part, 50a ... side wall, 50b ... groove bottom, 51 ... inner part Deep groove, 51a ... outer convex part, 51p ... end, 52 ... outer deep groove, 52a ... outer convex part, 52p ... end, 61-65 ... auxiliary lateral groove, 70 ... circumferential shallow groove, 71 ... inner shallow groove, 72 ... Outer shallow groove, 81,82 ... Sipe

Claims (6)

With a rib-like land extending in the tire circumferential direction,
A tire formed with a circumferential groove adjacent to the land portion and extending in the tire circumferential direction,
The land portion has a shallower groove than the circumferential groove, and a circumferential shallow groove extending continuously along the tire circumferential direction is formed.
The tire in which the circumferential shallow groove is formed with a plurality of sipes that are recessed inward in the tire radial direction than the circumferential shallow groove.   The tire according to claim 1, wherein the circumferential shallow groove is formed in a land portion located at a shoulder portion of the tire in contact with a road surface.   The tire according to claim 1, wherein a plurality of the circumferential shallow grooves are formed adjacent to each other in the tread width direction.   The position of the sipe formed in one circumferential shallow groove is provided at a position different from the sipe formed in the other circumferential shallow groove adjacent to the tire circumferential direction. The tire according to one item.   The tire according to any one of claims 1 to 4, wherein a depth of the sipe is deeper than a depth of the circumferential shallow groove.   The tire according to any one of claims 1 to 5, wherein the sipe has a vertically long shape along a tire circumferential direction.

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