JP5659129B2 - tire - Google Patents

Description

  The present invention relates to a tire that includes a land portion that is partitioned by a circumferential groove extending in the tire circumferential direction and that extends in the tire circumferential direction, and a circumferential sipe extending in the tire circumferential direction is formed in the land portion.

  2. Description of the Related Art Conventionally, in a pneumatic tire (hereinafter referred to as a tire) mounted on a passenger car or the like, a tread pattern in which a circumferential sipe extending in the tire circumferential direction is formed on a land portion extending in the tire circumferential direction is used.

  For example, to ensure braking performance and anti-skid performance on wet road surfaces, a center land portion located in the center in the tread width direction and a land portion located outside the center land portion in the tread width direction (outside land portion) A tire having a circumferential sipe extending in the tire circumferential direction is known (for example, Patent Document 1). One end of the circumferential sipe terminates in the land portion, and the other end of the circumferential sipe communicates with an inclined groove that is inclined with respect to the tire circumferential direction. One end of the inclined groove terminates in the land portion, and the other end of the inclined groove communicates with a circumferential groove adjacent to the land portion.

JP 2006-224770 A (FIG. 1)

  However, with recent improvements in the performance of general passenger cars, there is an increasing demand for further improvements in various performances on wet road surfaces. In particular, there is a demand for a high level of compatibility between drainage and steering stability, which are normally in a trade-off relationship.

  Therefore, the present invention has been made in view of such a situation, and an object thereof is to provide a tire capable of achieving both high drainage performance and steering stability at a high level.

  A tire (pneumatic tire 1) according to a feature of the present invention is defined by a circumferential groove (circumferential groove 20 and circumferential groove 30) extending in the tire circumferential direction (tire circumferential direction Tc), and extends in the tire circumferential direction. A circumferential sipe that includes a portion (outer land portion 40) and extends in the tire circumferential direction is formed in the land portion. The land portion includes a first inclined groove (first inclined groove 110) extending from one side portion in the tread width direction (tread width direction Tw) of the land portion and inclined with respect to the tire circumferential direction, A second inclined groove (second inclined groove 120) extending from the other side portion in the tread width direction of the land portion and inclined with respect to the tire circumferential direction is formed, and the first inclined groove and the second inclined groove are formed. Are alternately formed in the tire circumferential direction, and the circumferential sipe (circumferential sipe 200) is an intermediate portion in the tread width direction of the second inclined groove from an end portion on the land portion side of the first inclined groove. The first circumferential sipe (first circumferential sipe 210) formed up to the second circumferential direction extending from the intermediate portion in the tread width direction of the second inclined groove along the extension line of the first circumferential sipe Sipe (second round) Include sipes 220) and said second circumferential sipes, and summarized in that terminates within the land portion.

  In the tire according to another aspect of the present invention, at least one of an inclination angle of the first inclined groove with respect to the tire circumferential direction or an inclination angle of the second inclined groove with respect to the tire circumferential direction is 20 degrees or more and 60 degrees or less. The gist is within the range.

  The tire according to another feature of the present invention further includes a center land portion (center land portion 50) formed on the inner side in the tread width direction than the land portion, and the center land portion is located at a position including the tire equator line. A width direction sipe (width direction sipe 300) extending in the tread width direction is formed in the center land portion, and the width direction sipe is on one side of the center land portion in the tread width direction. A first width direction sipe (first width direction sipe 310) that extends from the center land portion and extends from the other side portion in the tread width direction of the center land portion, and extends from the center land portion. And a second width direction sipe (second width direction sipe 320), the first width direction sipe and the second width direction sipe being a tire. And summarized in that terminates in the tread width direction outside than the road line.

  A tire according to another feature of the present invention is characterized in that the second width direction sipe extends along an extension line of the first width direction sipe.

  A tire according to another feature of the present invention is summarized in that the circumferential sipe is linear.

  According to the characteristics of the present invention, it is possible to provide a tire that can achieve both drainage performance and steering stability at a high level.

FIG. 1 is a partial plan development view of a tread of a pneumatic tire 1 according to an embodiment of the present invention. FIG. 2 is a partially enlarged plan view of the tread of the pneumatic tire 1 according to the embodiment of the present invention. FIG. 3 is a partially enlarged plan view of the tread of the pneumatic tire 1 according to the embodiment of the present invention.

  Next, an embodiment of a tire (pneumatic tire) according to 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 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) Schematic Configuration of Pneumatic Tire FIG. 1 is a partial plan development view of a tread of the pneumatic tire 1 according to this embodiment. As shown in FIG. 1, a circumferential groove 20 and a circumferential groove 30 are formed in the pneumatic tire 1. The circumferential groove 20 and the circumferential groove 30 extend along the tire circumferential direction Tc. The pneumatic tire 1 may be filled with an inert gas such as nitrogen gas instead of air. Moreover, in FIG. 1, the thin line part means the area | region which does not touch a road surface at the time of a regular internal pressure and a regular load. In other words, the inside of the tread width direction Tw is the tread grounding surface from the thin line portion.

  Here, in the present embodiment, both ends in the tread width direction Tw of the tread contact surface indicate both ends in the tread width direction Tw of the contact range in a state where the tire is in contact with the road surface. The state where the tire is in contact with the road surface indicates, for example, a state where the tire is mounted on a normal rim and a normal internal pressure and a normal load are applied. In addition, a regular rim refers to a standard rim in an applicable size defined in the 2008 Yearbook of JATMA (Japan Automobile Tire Association). The normal internal pressure is the air pressure corresponding to the maximum load capacity of JATMA's Year Book 2008 version, and the normal load is the load corresponding to the maximum load capacity when applying a single wheel of JATMA's Year Book 2008 version. . Outside Japan, the standards governing these are determined by industry standards that are valid in the region where the tire is produced or used. For example, in the United States, it is “The Year Book of The Tire and Rim Association Inc.”, and in Europe it is “The Standards Manual of the European Tire and Rim Technical Organization”.

  The pneumatic tire 1 includes an outer land portion 40 that extends in the tire circumferential direction Tc and a center land portion 50 that extends in the tire circumferential direction Tc by being partitioned into the circumferential groove 20 and the circumferential groove 30. In the present embodiment, two outer land portions 40 are formed on both sides of the tread width direction Tw with reference to the tire equator line CL. Further, the center land portion 50 is formed on the inner side in the tread width direction Tw than the outer land portion 40. The center land portion 50 is provided at a position including the tire equator line CL. That is, the center land portion 50 is provided on the tire equator line CL.

  In the present embodiment, the outer land portion 40 constitutes a “land portion” defined in the claims, and the center land portion 50 constitutes a “center land portion” defined in the claims.

  A plurality of inclined grooves 100 and a plurality of circumferential sipes 200 are formed in the outer land portion 40. The circumferential sipe 200 is a linear sipe extending in the tire circumferential direction Tc. In the present embodiment, the sipe has a groove width that can be closed when the land portion is grounded. Specifically, the sipe has a groove width of 1.5 mm or less. However, in a tire used for a large bus or truck such as a TBR tire, the groove width of the sipe may be 1.5 mm or more. The groove width of the circumferential sipe 200 is narrower than the groove width of the inclined groove 100.

  A width direction sipe 300 is periodically formed in the center land portion 50 with a predetermined interval in the tire circumferential direction Tc. The width direction sipe 300 extends in the tread width direction Tw. In the present embodiment, the width direction sipe 300 is a linear sipe extending so as to be inclined with respect to the tread width direction Tw.

(2) Shape of Outer Land Part FIG. 2 is a partially enlarged plan view of the tread of the pneumatic tire 1. As shown in FIG. 2, the outer land portion 40 includes a first inclined groove 110 extending from one side portion in the tread width direction Tw of the outer land portion 40 and inclined with respect to the tire circumferential direction Tc, and the outer land portion 40. A second inclined groove 120 extending from the other side portion of the portion 40 in the tread width direction Tw and inclined with respect to the tire circumferential direction Tc is formed as the inclined groove 100. The first inclined grooves 110 and the second inclined grooves 120 are alternately formed in the tire circumferential direction Tc.

  Further, at least one of the inclination angle θ1 of the first inclined groove 110 with respect to the tire circumferential direction Tc or the inclination angle θ2 of the second inclined groove 120 with respect to the tire circumferential direction Tc is within a range of 20 degrees to 60 degrees. Is preferred. In the present embodiment, a case where both the inclination angle θ1 and the inclination angle θ2 are in the range of 20 degrees or more and 60 degrees or less will be described as an example.

  Specifically, the inclination angle θ1 formed by the extending direction A1 of the first inclined groove 110 and a straight line parallel to the tire circumferential direction Tc is in the range of 20 degrees to 60 degrees. Here, the direction A1 in which the first inclined groove 110 extends refers to the center of the tire circumferential direction Tc on the side in the tread width direction Tw of the outer land portion 40 of the first inclined groove 110 and the first inclination in the tread surface view. It is indicated by a straight line connecting the end point located on the outermost land portion 40 side of the groove 110. In addition, when the edge part located in the outermost land part 40 side of the 1st inclination groove | channel 110 becomes a straight line along the tire circumferential direction Tc, this edge point is made into the center of the tire circumferential direction Tc of an edge part.

  On the other hand, the inclination angle θ2 formed by the direction A2 in which the second inclined groove 120 extends and the straight line parallel to the tire circumferential direction Tc is in the range of 20 degrees to 60 degrees. Here, the direction A2 in which the second inclined groove 120 extends refers to the center in the tire circumferential direction Tc of the side in the tread width direction Tw of the outer land portion 40 of the second inclined groove 120 and the second inclined in the tread surface view. It is indicated by a straight line connecting the end point located on the outermost land portion 40 side of the groove 120. In addition, when the edge part located in the outermost land part 40 side of the 2nd inclination groove | channel 120 becomes a straight line in the tire circumferential direction Tc, let this edge point be the center of the tire circumferential direction Tc of an edge part.

  Further, in the outer land portion 40, a first circumferential sipe 210 formed from an end portion of the first inclined groove 110 on the outer land portion 40 side to an intermediate portion in the tread width direction Tw of the second inclined groove 120, A second circumferential sipe 220 extending from an intermediate portion of the second inclined groove 120 in the tread width direction Tw along an extension line of the first circumferential sipe 210 is formed as a circumferential sipe 200. Further, the second circumferential sipe 220 terminates in the outer land portion 40. In the pneumatic tire 1, the outer land portion 40 has a first tread groove 110 that is inclined with respect to the tire circumferential direction Tc and a first circumferential sipe 210 that extends in the tire circumferential direction Tc. An acute angle portion is formed.

  Further, the first circumferential sipe 210 and the second circumferential sipe 220 extend substantially parallel to the tire circumferential direction Tc, but about 5 degrees to 10 degrees with respect to the tire circumferential direction Tc (tire equator line CL). It may be inclined. Further, the outer land portion 40 in which the first circumferential sipe 210 and the second circumferential sipe 220 are formed has a normal load on the pneumatic tire 1 set to a normal internal pressure defined by Japan Automobile Tire Association (JATMA) or the like. In a state where is added, it is preferably provided in a region of 60% of the tread width including the tire equator line CL.

(3) Shape of Center Land Part FIG. 3 is a partially enlarged plan view of the tread of the pneumatic tire 1. As shown in FIG. 3, the center land portion 50 includes a first width direction sipe 310 extending from one side portion in the tread width direction Tw of the center land portion 50 and terminating in the center land portion 50, A second width direction sipe 320 extending from the other side portion of the center land portion 50 in the tread width direction Tw and terminating in the center land portion 50 is formed as a width direction sipe 300.

  Specifically, in the first width direction sipe 310, one end portion 310a opens into the circumferential groove 30 adjacent to one of the center land portions 50, and the other end portion 310b terminates in the center land portion 50. Yes. In the second width direction sipe 320, one end portion 320 a opens into the circumferential groove 30 adjacent to the other of the center land portion 50, and the other end portion 320 b ends in the center land portion 50.

  Further, the second width direction sipe 320 preferably extends along an extension line of the first width direction sipe 310. In the present embodiment, the first width direction sipe 310 and the second width direction sipe 320 extend in substantially parallel directions, but may extend in different directions. The angle formed between the straight line along the tread width direction Tw and the direction in which the first width direction sipe 310 extends is preferably 0 degrees or more and less than 60 degrees with respect to the tread width direction Tw. Similarly, the angle formed between the straight line along the tread width direction Tw and the direction in which the second width direction sipe 320 extends is preferably 0 degrees or more and less than 60 degrees with respect to the tread width direction Tw.

  Further, the first width direction sipe 310 and the second width direction sipe 320 are terminated in the center land portion 50 outside the tire equator line CL in the tread width direction Tw. Specifically, the end portion 310b of the first width direction sipe 310 and the end portion 320b of the second width direction sipe 320 are located outside the tire equator line CL in the tread width direction Tw. That is, a separation portion where the first width direction sipe 310 and the second width direction sipe 320 are separated is formed on the tire equator line CL.

(4) Action / Effect According to the pneumatic tire 1 according to the present embodiment, the first inclined groove 110 and the second inclined groove 120 alternately formed in the tire circumferential direction Tc enter the outer land portion 40. Basic drainage of rainwater is secured. Further, since the linear first circumferential sipe 210 and the second circumferential sipe 220 are formed in communication with these inclined grooves 100 (the first inclined groove 110 and the second inclined groove 120), the outer land portion 40 is formed. The water removal (water absorption) effect in can also be enhanced. Moreover, since the outer land portion 40 is not divided in the tread width direction Tw, the rigidity of the outer land portion 40 can be secured.

  In the present embodiment, the inclination angle θ1 of the first inclined groove 110 with respect to the tire circumferential direction Tc and the inclination angle θ2 of the second inclined groove 120 with respect to the tire circumferential direction Tc are within a range of 20 degrees to 60 degrees. is there. According to such a pneumatic tire 1, since the corner portion formed in the outer land portion 40 by the first inclined groove 110 and the second inclined groove 120 is difficult to be turned during tire rolling, the ground contact property is improved. It becomes possible.

  In particular, in the outer land portion 40, the first inclined grooves 110 and the second inclined grooves 120 are alternately formed in the tire circumferential direction Tc, so that the inclination angles θ1 to θ2 are low angles (for example, 45 to 60). The rigidity of the outer land portion 40 can be secured not only in the case of degrees) but also in the case of a slightly high angle (for example, in the range of 30 to 45 degrees). Further, the outer land portion 40 is formed with a first circumferential sipe 210 communicating with the first inclined groove 110 and a second circumferential sipe 220 communicating with the second inclined groove, so that the inclination angles θ1 to θ1. Even when θ2 is a slightly high angle (for example, a range of 30 degrees or more and 45 degrees or less), a water removal (water absorption) effect on the surface of the outer land portion 40 can be secured. That is, the water removal effect can be secured while securing the rigidity of the outer land portion 40.

  Thus, according to the pneumatic tire 1 which concerns on this embodiment, drainage property and steering stability can be made compatible in a high dimension.

  In the present embodiment, a linear second circumferential sipe 220 that terminates in the outer land portion 40 is formed. The first circumferential sipe 210 and the second circumferential sipe 220 are formed at the same position in the tread width direction Tw. That is, the first circumferential sipe 210 and the second circumferential sipe 220 are formed to be linear in the tire circumferential direction Tc. For this reason, the water removal (water absorption) effect in the outer land portion 40 can be further enhanced.

  In the center land portion 50, the width direction sipe 300 is periodically formed in the tire circumferential direction Tc by the first width direction sipe 310 and the second width direction sipe 320. The second width direction sipe 320 extends along an extension line of the first width direction sipe 310. According to the pneumatic tire 1, it is possible to improve the drainage by removing the water that has entered the center land portion 50 from the ground contact surface. Furthermore, according to the pneumatic tire 1, it is possible to suppress the center wear by suppressing the rigidity of the center land portion 50 to an extent.

  Further, the first width direction sipe 310 and the second width direction sipe 320 are terminated in the center land portion 50 outside the tire equator line CL in the tread width direction Tw. That is, in the center land portion 50, a separation portion where the first width direction sipe 310 and the second width direction sipe 320 are separated is formed on the tire equator line CL. According to the pneumatic tire 1, it is possible to prevent the rigidity of the center land portion 50 from being excessively lowered, and thus it is possible to ensure steering stability.

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

  For example, the circumferential sipe 200 does not necessarily have to be linear, and for example, may have a shape meandering somewhat. The width direction sipe 300 does not necessarily have to be linear, for example, it may have a shape meandering somewhat.

  In the above-described embodiment, the second width direction sipe 320 is formed so as to extend on the extension line of the first width direction sipe 310, but the second width direction sipe 320 is the same as the first width direction sipe 310. It may be formed at a position shifted by a predetermined interval in the tire circumferential direction Tc from the extension line.

  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 20, 30 ... Circumferential groove, 40 ... Outer land part, 50 ... Center land part, 100 ... Inclined groove, 110 ... First inclined groove, 120 ... Second inclined groove, 200 ... Circumferential sipe , 210 ... 1st circumferential sipe, 220 ... 2nd circumferential sipe, 300 ... Width direction sipe, 310 ... 1st width direction sipe, 320 ... 2nd width direction sipe

Claims (5)

A tire that is partitioned by a circumferential groove extending in the tire circumferential direction, includes a land portion extending in the tire circumferential direction, and a circumferential sipe extending in the tire circumferential direction is formed in the land portion,
In the land,
A first inclined groove extending from one side portion in the tread width direction of the land portion and inclined with respect to the tire circumferential direction;
A second inclined groove extending from the other side portion in the tread width direction of the land portion and inclined with respect to the tire circumferential direction is formed.
The first inclined grooves and the second inclined grooves are alternately formed in the tire circumferential direction,
The circumferential sipe is
A first circumferential sipe formed from an end on the land portion side of the first inclined groove to an intermediate portion in the tread width direction of the second inclined groove;
A second circumferential sipe extending from an intermediate portion in the tread width direction of the second inclined groove along an extension line of the first circumferential sipe;
The tire according to claim 1, wherein the second circumferential sipe terminates in the land portion. The inclination angle of the first inclined groove with respect to the tire circumferential direction or the inclination angle of the second inclined groove with respect to the tire circumferential direction is within a range of 20 degrees or more and 60 degrees or less. The tire according to 1. Further comprising a center land portion formed on the inner side in the tread width direction than the land portion,
The center land portion is provided at a position including the tire equator line,
The center land portion is formed with a width sipe extending in the tread width direction,
The width sipe is
A first width direction sipe extending from one side in the tread width direction of the center land portion and terminating in the center land portion,
A second widthwise sipe extending from the other side portion in the tread width direction of the center land portion and terminating in the center land portion,
The tire according to claim 1 or 2, wherein the first width direction sipe and the second width direction sipe are terminated on the outer side in the tread width direction than the tire equator line. The tire according to claim 3, wherein the second width direction sipe extends along an extension line of the first width direction sipe. The tire according to any one of claims 1 to 4, wherein the circumferential sipe is linear.

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