Pneumatic tire

Abstract

To provide a pneumatic tire improved in grip performance.SOLUTION: A plurality of first width-directional grooves 4 extending in a tire width direction, whose both ends terminate in a vehicle-mounted time outermost land part, and a plurality of second width-directional grooves 5 extending in a tire width direction are formed in the vehicle-mounted time outermost land part. The first width-directional grooves and the second width-directional grooves are arranged alternately in a tire circumferential direction while being separated from each other in the tire circumferential direction. One first width-directional groove and one second width-directional groove that is adjacent to one side in the tire circumferential direction with respect to the one first width-directional groove are paired. The paired one first width-directional groove has a first portion 41 extending to one side in the tire circumferential direction, from outside toward inside in a tire width direction. The paired one second width-directional groove extends to the other side in the tire circumferential direction, from outside toward inside in the tire width direction. An inner end in the tire width direction of the paired one second width-directional groove is positioned closer to outside in the tire width direction than an inner end in the tire width direction of the paired one first width-directional groove.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a pneumatic tire. [Background technology]

[0002] Conventionally, for pneumatic tires used at high speeds, such as at speeds exceeding 150 km / h, it has been proposed to provide widthwise grooves extending in the tire width direction in the outer shoulder land portion when mounted on the vehicle, thereby appropriately reducing the rigidity of the land portion and improving grip performance. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2021 / 054261 Brochure Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the technology of Patent Document 1, multiple widthwise grooves (71) that mainly extend in the same direction are arranged, and while the rigidity is high against input from the extension direction of the widthwise grooves, the rigidity is low against input, for example, from a direction perpendicular to the extension direction of the widthwise grooves, and the land portion is easily deformed. There is therefore room for improvement in grip performance.

[0005] An object of the present invention is to provide a pneumatic tire with improved grip performance. [Means for solving the problem]

[0006] The gist and configuration of the present invention are as follows. (1) A pneumatic tire having one or more circumferential main grooves extending in the tire circumferential direction on the tread surface, A plurality of land portions are defined between the circumferential main groove and a tread edge or between the circumferential main grooves, The tire has a plurality of first width direction grooves extending in the tire width direction and having both ends terminated within an outermost land portion when mounted on a vehicle, the outermost land portion when mounted on a vehicle being the outermost land portion in the tire width direction when mounted on a vehicle, and a plurality of second width direction grooves extending in the tire width direction, The first widthwise grooves and the second widthwise grooves are alternately arranged in the tire circumferential direction while being spaced apart from each other in the tire circumferential direction, One of the first widthwise grooves and one of the second widthwise grooves adjacent to the one of the first widthwise grooves on one side in the tire circumferential direction are paired, The first widthwise groove of the pair has a first portion extending from an outer side in the tire width direction toward an inner side in the tire circumferential direction, The second widthwise groove of the pair extends from the outer side toward the inner side in the tire width direction to the other side in the tire circumferential direction, A pneumatic tire, characterized in that an inner end in the tire width direction of the one second widthwise groove that constitutes the pair is located outward in the tire width direction than an inner end in the tire width direction of the one first widthwise groove that constitutes the pair.

[0007] Here, "tread surface" refers to the surface extending around the entire circumferential direction of the tire of the outer surface of the tread that comes into contact with the road surface when the pneumatic tire is mounted on an applicable rim, inflated to the specified internal pressure, and subjected to the maximum load. Moreover, the term "tread edge" refers to both outermost points of the tread surface in the tire width direction. Additionally, the term "circumferential main groove" refers to a groove that extends in the circumferential direction of the tire and has a groove width (opening width) of 2 mm or more in the standard state when the pneumatic tire is mounted on an applicable rim, inflated to a specified internal pressure, and no load is applied. In addition, a "first widthwise groove" refers to a groove extending in the tire width direction and having a groove width (opening width) of 2 mm or more over 80% or more of its extension length in the reference state, and a "second widthwise groove" refers to a groove extending in the tire width direction and having a groove width (opening width) of 2 mm or more over 80% or more of its extension length in the reference state.

[0008] In this specification, "applicable rim" refers to the standard rim (Measuring Rim in the ETRTO STANDARDS MANUAL, Design Rim in the TRA YEAR BOOK) for the applicable size which is an industrial standard valid in the region where the tire is produced and used, and which is described or will be described in the future in such industrial standards as those published in the JATMA YEAR BOOK of the Japan Automobile Tire Manufacturers Association (JATMA) in Japan, the STANDARDS MANUAL of the ETRTO (The European Tyre and Rim Technical Organisation) in Europe, and the YEAR BOOK of the TRA (The Tire and Rim Association, Inc.) in the United States (i.e., the above "rim" includes not only current sizes but also sizes which may be included in the above industrial standards in the future. An example of "sizes to be described in the future" is the size described as "FUTURE DEVELOPMENTS" in the 2013 edition of the ETRTO.), however, in the case of a size not described in the above industrial standards, it refers to a rim with a width which corresponds to the bead width of the tire. In addition, "prescribed internal pressure" refers to the air pressure (maximum air pressure) corresponding to the maximum load capacity of a single wheel in the applicable size and ply rating as stated in the above JATMA, etc., and in the case of a size not stated in the above industrial standards, "prescribed internal pressure" refers to the air pressure (maximum air pressure) corresponding to the maximum load capacity specified for each vehicle on which the tire is mounted. In addition, "maximum load" refers to the load corresponding to the above maximum load capacity.

[0009] (2) The pneumatic tire according to (1), wherein the second widthwise groove communicates with an outer tread end when mounted on a vehicle.

[0010] (3) The pneumatic tire according to (1) or (2), wherein the one of the first widthwise grooves constituting the pair and the one of the second widthwise grooves constituting the pair have overlapping portions when projected in the tire circumferential direction.

[0011] (4) The one first widthwise groove further has a second portion extending from an inner end in the tire width direction of the first portion to one side in the tire circumferential direction, The pneumatic tire according to any one of (1) to (3), wherein at least a part of the first portion or at least a part of the second portion has a chamfered portion at an opening to the tread surface.

[0012] (5) The pneumatic tire is mounted on an applicable rim, inflated to a specified internal pressure, and under no load, under a standard condition. The pneumatic tire according to (4), wherein an inclination angle of the tapered surface of the chamfered portion of the second portion with respect to the tire radial direction is larger than an inclination angle of the tapered surface of the chamfered portion of the first portion with respect to the tire radial direction.

[0013] (6) The pneumatic tire according to any one of (1) to (5), wherein an inner land portion that is on an inner side when mounted on a vehicle has only two of the circumferential main grooves.

[0014] (7) A pneumatic tire having one or more circumferential main grooves extending in the tire circumferential direction on the tread surface, A plurality of land portions are defined between the circumferential main groove and a tread edge or between the circumferential main grooves, The tire has a plurality of first width direction grooves extending in the tire width direction and having both ends terminated within an outermost land portion when mounted on a vehicle, the outermost land portion when mounted on a vehicle being the outermost land portion in the tire width direction when mounted on a vehicle, and a plurality of second width direction grooves extending in the tire width direction, The first widthwise grooves and the second widthwise grooves are alternately arranged in the tire circumferential direction while being spaced apart from each other in the tire circumferential direction, One of the first widthwise grooves and one of the second widthwise grooves adjacent to the one of the first widthwise grooves on one side in the tire circumferential direction are paired, The first widthwise groove of the pair has a first portion extending from the inner side in the tire width direction to the outer side toward one side in the tire circumferential direction, The second widthwise groove of the pair extends from the inner side toward the outer side in the tire width direction toward the other side in the tire circumferential direction, a tire width direction outer end of the one second width direction groove that constitutes the pair is located outward in the tire width direction than a tire width direction outer end of the one first width direction groove that constitutes the pair.

[0015] (8) The pneumatic tire according to (7), wherein the second widthwise groove communicates with an outer tread end when mounted on a vehicle.

[0016] (9) The pneumatic tire according to (7) or (8), wherein the one of the first widthwise grooves constituting the pair and the one of the second widthwise grooves constituting the pair have overlapping portions when projected in the tire circumferential direction.

[0017] (10) The one first widthwise groove further has a second portion extending from an inner end of the first portion in the tire width direction to one side in the tire circumferential direction, The pneumatic tire according to any one of (7) to (9), wherein at least a part of the first portion or at least a part of the second portion has a chamfered portion at an opening to the tread surface.

[0018] (11) The pneumatic tire is mounted on an applicable rim, inflated to a specified internal pressure, and under no load, under a standard condition. The pneumatic tire according to (10), wherein an inclination angle of the tapered surface of the chamfered portion of the second portion with respect to the tire radial direction is greater than an inclination angle of the tapered surface of the chamfered portion of the first portion with respect to the tire radial direction.

[0019] (12) The pneumatic tire according to any one of (7) to (11), wherein an inner land portion that is on an inner side when mounted on a vehicle has only two of the circumferential main grooves. Effect of the Invention

[0020] According to the present invention, a pneumatic tire with improved grip performance can be provided. [Brief description of the drawings]

[0021] [Figure 1] 1 is a diagram showing a tread pattern of a pneumatic tire according to one embodiment of the present invention. [Diagram 2] FIG. 1 is a diagram for explaining an example of an arrangement of communication devices. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0023] The internal structure of a pneumatic tire according to an embodiment of the present invention (hereinafter, simply referred to as a "tire") can be the same as that of a conventional tire, and therefore a detailed description thereof will be omitted. Meanwhile, as one example, the tire can include a pair of bead portions, a carcass toroidally straddling the pair of bead portions, and a belt disposed radially outward of the crown portion of the carcass.

[0024] 1 is a diagram showing a tread pattern of a pneumatic tire according to one embodiment of the present invention. In the following description, dimensions and the like refer to dimensions in the above-mentioned reference state unless otherwise specified.

[0025] As shown in FIG. 1, the tire has one or more (two in the illustrated example) circumferential main grooves 2 (2a, 2b) extending in the tire circumferential direction on a tread surface 1. The tire has a plurality of land portions 3 (3a, 3b (3b1, 3b2)) defined between the circumferential main groove 2 and the tread edge TE or between the circumferential main grooves 2 (2a, 2b). Specifically, on the outer side when mounted on a vehicle, which is bounded by the tire equatorial plane CL, an outermost land portion 3a when mounted on a vehicle is defined by the circumferential main groove 2a and the tread edge TE. On the inner side when mounted on a vehicle, which is bounded by the tire equatorial plane CL, an inner land portion 3b when mounted on a vehicle is defined between the circumferential main grooves 2a, 2b or by the circumferential main groove 2b and the tread edge TE. An inner land portion 3b2 of the inner land portion when mounted on a vehicle is defined between the circumferential main grooves 2a, 2b, and an outer land portion 3b1 of the inner land portion when mounted on a vehicle is defined by the circumferential main groove 2a and the tread edge TE.

[0026] This tire has a plurality of first widthwise grooves 4 extending in the tire width direction and terminating at both ends within the outermost land portion 3a when mounted on a vehicle, and a plurality of second widthwise grooves 5 extending in the tire width direction, in the outermost land portion 3a when mounted on a vehicle, which is the land portion that is outermost in the tire width direction when mounted on a vehicle.

[0027] As shown in the figure, the first widthwise grooves 4 and the second widthwise grooves 5 are alternately arranged in the tire circumferential direction while being spaced apart from each other in the tire circumferential direction. In other words, one first widthwise groove 4 and one second widthwise groove 5 adjacent to the one first widthwise groove 4 on one side in the tire circumferential direction form a pair, and a plurality of such pairs are provided at intervals in the tire circumferential direction. The pitch interval of the first widthwise grooves 4 in the tire circumferential direction is not particularly limited, but may be, for example, 40 to 140 mm. The pitch interval of the second widthwise grooves 5 in the tire circumferential direction is not particularly limited, but may be, for example, 40 to 140 mm. The shortest distance between the pair of the first widthwise grooves 4 and the second widthwise grooves 5 is not particularly limited, but may be, for example, 15 to 60 mm.

[0028] Each of the pair of first widthwise grooves 4 has a first portion 41 extending from the outer side in the tire width direction toward the inner side toward one side in the tire circumferential direction. The first widthwise groove 4 further has a second portion 42 extending from an inner end in the tire width direction of the first portion 41 toward one side in the tire circumferential direction. This second portion 42 can further ensure drainage.

[0029] The groove width (opening width) of the first widthwise groove 4 is not particularly limited, but may be, for example, 5 to 20 mm in consideration of the balance between drainage (compliance with regulations when used in racing tires; the same applies below) and the rigidity of the land portion. The groove depth (maximum depth) of the first widthwise groove 4 is not particularly limited, but may be, for example, 5 to 8 mm in consideration of the balance between drainage and the rigidity of the land portion. The inclination angle of the first portion 41 with respect to the tire width direction is not particularly limited, but may be, for example, 10 to 20°. By making it 20° or less, the rigidity against the input in the width direction (rigidity against shear deformation due to the input from the outside to the inside in the width direction during vehicle cornering) can be increased, and by making it 10° or more, the difference in the direction of inclination with the second widthwise groove 5 can be made clearer as described later, and both can improve grip performance. The inclination angle of the second portion 42 with respect to the tire circumferential direction is not particularly limited, but may be, for example, 10 to 15°.

[0030] As shown in the figure, one of the pair of second widthwise grooves 5 extends from the outer side toward the inner side in the tire width direction to the other side in the tire circumferential direction. That is, the first widthwise groove 4 and the second widthwise groove 5 are inclined in opposite directions to each other in the tire circumferential direction with respect to the tire width direction.

[0031] The groove width (opening width) of the second widthwise groove 5 is not particularly limited, but may be, for example, 5 to 20 mm in consideration of the balance between drainage (compliance with regulations when used in racing tires; the same applies below) and the rigidity of the land portion. The groove depth (maximum depth) of the second widthwise groove 5 is not particularly limited, but may be, for example, 5 to 8 mm in consideration of the balance between drainage and the rigidity of the land portion. In addition, the inclination angle of the second widthwise groove 5 with respect to the tire width direction is not particularly limited, but may be, for example, 5 to 15°. By making it 15° or less, the rigidity against the input in the width direction (rigidity against shear deformation due to the input from the outside to the inside in the width direction during vehicle cornering) can be increased, and by making it 5° or more, the difference in the direction of inclination with the first widthwise groove 4 can be made clearer as described later, and both can improve grip performance.

[0032] Here, the inner end in the tire width direction of one second width direction groove 5 constituting the pair is located outside in the tire width direction from the inner end in the tire width direction of one first width direction groove 4 constituting the pair (in this example, the inner end in the tire width direction of the second portion 42). Although not particularly limited, it is preferable that the inner end in the tire width direction of one second width direction groove 5 constituting the pair is located outside in the tire width direction from the inner end in the tire width direction of one first width direction groove 4 constituting the pair (in this example, the inner end in the tire width direction of the second portion 42) by a distance of 50 to 80% of the width in the tire width direction of the first width direction groove 4 (the width in the tire width direction when projected in the tire circumferential direction). In the illustrated example, the second width direction groove 5 (its outer end in the tire width direction) communicates with the tread edge TE on the outer side when mounted on the vehicle. In the illustrated example, the first width direction groove 4 constituting the pair and the second width direction groove 5 constituting the pair have overlapping portions when projected in the tire circumferential direction. This overlap width is not particularly limited, but can be, for example, 20 to 50% of the width in the tire width direction of the first widthwise groove 4 (the width in the tire width direction when projected in the tire circumferential direction).

[0033] At least a part of the first portion 41 or at least a part of the second portion 42 has a chamfered portion at the opening to the tread surface 1. This ensures high drainage when new (when used in a racing tire, it is easier to comply with regulations), while at the same time, grip performance can be ensured by suppressing the decrease in rigidity compared to when the groove bottom is the same as the opening width. A chamfered portion can be formed only on the first portion 41 (all around or part) (no chamfered portion is formed on the second portion 42). Alternatively, a chamfered portion can be formed only on the second portion 42 (all around or part) (no chamfered portion is formed on the first portion 41). Alternatively, a chamfered portion can be formed on both the first portion 41 (all around or part) and the second portion 42 (all around or part). In this example, a chamfered portion is formed on the entire circumference of the first portion 41 and the entire circumference of the second portion 42. Similarly, at least a part of the second widthwise grooves 5 (all around or part, all around in this example) has a chamfered portion at the opening to the tread surface 1. With respect to the first widthwise groove 4, in the reference state, the inclination angle of the tapered surface of the chamfered portion of the second portion 42 with respect to the tire radial direction is preferably larger than the inclination angle of the tapered surface of the chamfered portion of the first portion 41 with respect to the tire radial direction. This is because the second portion 42 can further suppress a decrease in rigidity when ensuring drainage performance in a new state.

[0034] In addition, this tire has only two circumferential main grooves 2a, 2b in the vehicle-mounted inner land portion 3b, which is on the inner side when mounted on a vehicle, thereby ensuring a good balance between drainage performance and rigidity of the land portion.

[0035] A plurality of third widthwise grooves 6 extending in the tire width direction are arranged in the outer land portion 3b1 of the inner land portion 3b when mounted on a vehicle. The third widthwise grooves 6 (their outer ends in the tire width direction) communicate with the tread edge TE. This can improve drainage. On the other hand, the third widthwise grooves 6 (their inner ends in the tire width direction) do not communicate with the circumferential main groove 2a. This can ensure the rigidity of the land portion.

[0036] The groove width (opening width) of the third widthwise groove 6 is not particularly limited, but may be, for example, 10 to 25 mm, in consideration of the balance between drainage (compliance with regulations when used in racing tires; the same applies below) and the rigidity of the land portion. The groove depth (maximum depth) of the third widthwise groove 6 is not particularly limited, but may be, for example, 5 to 8 mm, in consideration of the balance between drainage and the rigidity of the land portion. In addition, the inclination angle of the third widthwise groove 6 with respect to the tire width direction is not particularly limited, but may be, for example, 5 to 15°. By making it 15° or less, the rigidity against the input in the width direction (rigidity against shear deformation due to the input from the outside to the inside in the width direction during vehicle cornering) can be increased, and by making it 5° or more, the rigidity can be prevented from being locally reduced in the tire circumferential direction. It is preferable that the opening of the third widthwise groove 6 also has a chamfer formed on at least a part (all or a part) of the opening.

[0037] In addition, a plurality of cutouts 7 that communicate with the circumferential main groove 2a are provided on the inner side of the circumferential main groove 2a in the tire width direction. This allows the rigidity of the land portion in which the cutouts 7 are provided to be appropriately reduced, improving grip performance. In addition, since the cutouts 7 are provided within the inner land portion 3b when mounted on the vehicle, they are less susceptible to the effects of lateral forces during cornering.

[0038] It is preferable that the first widthwise groove 4 and the second widthwise groove 5 provided in the outermost land portion 3a when mounted on a vehicle and the third widthwise groove 6 provided in the inner land portion 3b when mounted on a vehicle do not overlap each other or only the chamfered portions overlap each other when projected in the tire width direction. This is because it is possible to balance the rigidity of the land portions in the tire circumferential direction. The effects of the pneumatic tire of the present embodiment will be described below.

[0039] The pneumatic tire of this embodiment first has a plurality of first widthwise grooves 4 extending in the tire width direction and both ends terminating within the outermost land portion 3a when mounted on a vehicle, and a plurality of second widthwise grooves 5 extending in the tire width direction, in the outermost land portion 3a when mounted on a vehicle, which is the land portion that is outermost in the tire width direction on the outside when mounted on a vehicle.This increases the rigidity against input in the width direction (rigidity against shear deformation due to input from the outside to the inside in the width direction during vehicle cornering), thereby improving grip performance. In the pneumatic tire of this embodiment, the first widthwise groove 4 of the pair has a first portion 41 extending from the outer side in the tire width direction toward the inner side toward one side in the tire circumferential direction, and the second widthwise groove 5 of the pair extends from the outer side in the tire width direction toward the inner side toward the other side in the tire circumferential direction. This means that there are always widthwise grooves with two types of extension directions (with inclination directions toward the tire circumferential direction with respect to the tire width direction being opposite to each other) for inputs from various directions, which solves the problem that the land portion is easily deformed in response to inputs from a specific direction, and improves grip performance. Furthermore, with this configuration, the first portion 41 and the second widthwise groove 5 are spaced apart from each other in the tire circumferential direction toward the outer side in the tire width direction, so that a large area of ​​the land portion on the outer side in the tire width direction can be secured, thereby improving grip performance. On the other hand, if only the direction of inclination is considered, the circumferential distance between the first portion 41 and the second widthwise groove 5 becomes smaller the further inward in the tire width direction. However, in the pneumatic tire of this embodiment, the tire widthwise inner end of one of the paired second widthwise grooves 5 is located outward in the tire width direction than the tire widthwise inner end of one of the paired first widthwise grooves 4. This avoids the creation of areas where the first widthwise groove 4 and the second widthwise groove 5 approach each other in the tire circumferential direction as much as possible, thereby ensuring a large land area even on the inner side in the tire width direction and improving grip performance. As described above, according to the pneumatic tire of the present embodiment, the grip performance can be improved.

[0040] Here, it is preferable that the second widthwise grooves 5 communicate with the outer tread edge when mounted on a vehicle, since this can further improve drainage performance.

[0041] In addition, it is preferable that one of the paired first widthwise grooves 4 and one of the paired second widthwise grooves 5 have an overlapping portion when projected in the tire circumferential direction, because this makes it easier to ensure a sufficient extension length of the widthwise grooves even when considering the arrangement relationship with other grooves (in the example of FIG. 1, the circumferential main groove 2a).

[0042] Each first widthwise groove 4 further has a second portion 42 extending from an inner end of the first portion 41 in the tire width direction to one side in the tire circumferential direction, and at least a part of the first portion 41 or at least a part of the second portion 42 preferably has a chamfered portion at an opening to the tread surface. This is because it is possible to further improve drainage performance when new while minimizing reduction in rigidity.

[0043] In the reference state, the inclination angle of the tapered surface of the chamfered portion of the second portion 42 relative to the tire radial direction is preferably larger than the inclination angle of the tapered surface of the chamfered portion of the first portion 41 relative to the tire radial direction. This is because it is possible to further improve the drainage performance when the tire is new, while minimizing deterioration in rigidity.

[0044] It is preferable that the inner land portion 3b, which is on the inner side when the tire is mounted on the vehicle, has only two circumferential main grooves 2a, 2b, which ensures a good balance between drainage performance and rigidity of the land portion.

[0045] Here, in another embodiment, both the direction of inclination of the first portion of the first widthwise groove in the tire circumferential direction relative to the tire width direction and the direction of inclination of the second widthwise groove in the tire circumferential direction relative to the tire width direction may be opposite to the above embodiment. That is, tires of other embodiments have a basic configuration similar to that of the above-described embodiments, and have one or more circumferential main grooves extending in the tire circumferential direction on the tread surface, and have a plurality of land portions partitioned between the circumferential main groove and the tread edge or between the circumferential main grooves, and have a plurality of first widthwise grooves extending in the tire width direction and both ends terminating within the outermost land portion when mounted on the vehicle, which is the land portion that is the outermost in the tire width direction when mounted on the vehicle, and a plurality of second widthwise grooves extending in the tire width direction, the first widthwise grooves and the second widthwise grooves being arranged alternately in the tire circumferential direction while being spaced apart from each other in the tire circumferential direction, and one first widthwise groove is paired with one second widthwise groove adjacent to one first widthwise groove on one circumferential side of the tire circumferential direction. On the other hand, unlike the above embodiment, in tires of other embodiments, a first widthwise groove of the pair has a first portion extending from the inner side in the tire width direction toward the outer side, toward one side in the tire circumferential direction, and a second widthwise groove of the pair extends from the inner side in the tire width direction toward the outer side, toward the other side in the tire circumferential direction, and the tire widthwise outer end of the second widthwise groove of the pair is located outward in the tire width direction than the tire widthwise outer end of the first widthwise groove of the pair.

[0046] Even in other embodiments of tires, first, the outermost land portion when mounted on a vehicle, which is the land portion that is the outermost in the tire width direction when mounted on a vehicle, has a plurality of first widthwise grooves that extend in the tire width direction and both ends terminating within the outermost land portion when mounted on a vehicle, and a plurality of second widthwise grooves that extend in the tire width direction. Therefore, it is possible to increase rigidity against widthwise input (rigidity against shear deformation due to input from the outside to the inside in the width direction during vehicle cornering) and improve grip performance. In another embodiment of the pneumatic tire, a first widthwise groove of the pair has a first portion extending from the inside to the outside in the tire width direction to one side in the tire circumferential direction, and a second widthwise groove of the pair extends from the inside to the outside in the tire width direction to the other side in the tire circumferential direction. This means that there are always widthwise grooves with two different extending directions (with inclination directions in the tire circumferential direction with respect to the tire width direction being opposite to each other) in response to inputs from various directions, which can solve the problem that the land portion is easily deformed in response to inputs from a specific direction, and can improve grip performance. Furthermore, with this configuration, the first portion and the second widthwise groove are spaced apart from each other in the tire circumferential direction toward the inner side in the tire width direction, so that a large area of ​​the land portion on the inner side in the tire width direction can be secured, thereby improving grip performance. On the other hand, if only the direction of inclination is considered, the circumferential distance between the first portion and the second widthwise groove becomes smaller the further outward in the tire width direction they are. However, in a pneumatic tire of another embodiment, the outer end of a second widthwise groove that constitutes a pair is located further outward in the tire width direction than the outer end of a first widthwise groove that constitutes the pair. This avoids areas where the first widthwise groove and the second widthwise groove approach each other in the tire circumferential direction as much as possible, thereby ensuring a large land area even on the outer side in the tire width direction and improving grip performance. As described above, the grip performance can be improved by the pneumatic tires of the other embodiments as well.

[0047] Here, in another embodiment, it is preferable that the second widthwise groove communicates with the outer tread edge when mounted on a vehicle, since this can further improve drainage performance.

[0048] In another embodiment, it is preferable that one of the first widthwise grooves constituting the pair and one of the second widthwise grooves constituting the pair have an overlapping portion when projected in the tire circumferential direction, because this makes it easier to ensure a sufficient extension length of the widthwise groove even when considering the arrangement relationship with other grooves.

[0049] In another embodiment, it is preferable that one of the first widthwise grooves further has a second portion extending from an inner end of the first portion in the tire width direction to one side in the tire circumferential direction, and at least a part of the first portion or at least a part of the second portion has a chamfered portion at an opening to the tread surface, because this can further improve drainage performance when new and can suppress deterioration in rigidity as much as possible.

[0050] In another embodiment, in the reference state, the inclination angle of the tapered surface of the chamfered portion of the second portion with respect to the tire radial direction is preferably larger than the inclination angle of the tapered surface of the chamfered portion of the first portion with respect to the tire radial direction, because this can further improve the drainage performance when new and minimize the decrease in rigidity.

[0051] In another embodiment, it is preferable that the inner land portion, which is on the inner side when installed on the vehicle, has only two circumferential main grooves, thereby ensuring a good balance between drainage performance and rigidity of the land portion.

[0052] In other embodiments, the dimensions and inclination angles of the first widthwise groove (first portion, second portion) and the second widthwise groove may be the same as those of the above embodiment, except for the direction of inclination in the tire circumferential direction with respect to the tire width direction. Similarly, the overlap width in the tire width direction of the first widthwise groove and the second widthwise groove, and the separation distance in the tire width direction between the outer ends may also be the same as those of the above embodiment.

[0053] Hereinafter, a case where a communication device is provided in a tire will be described. FIG. 2 is a diagram for explaining an example of the arrangement of the communication device. As shown in FIG. 2, the tire may be provided with an RF tag as a communication device 91. The RF tag includes an IC chip and an antenna. The RF tag may be arranged, for example, sandwiched between a plurality of members of the same or different types that constitute the tire. In this way, the RF tag can be easily attached during tire production, and the productivity of tires equipped with the RF tag can be improved. In this example, the RF tag may be arranged, for example, sandwiched between a bead filler and another member adjacent to the bead filler. The RF tag may be embedded in any of the members that constitute the tire. In this way, the load applied to the RF tag can be reduced compared to the case where the RF tag is arranged by being sandwiched between a plurality of members that constitute the tire. This can improve the durability of the RF tag. In this example, the RF tag may be embedded in a rubber member such as a tread rubber or a side rubber. It is preferable that the RF tag is not arranged at a position that is a boundary between members with different rigidities in the periphery length direction, which is a direction along the tire outer surface in a cross-sectional view in the tire width direction. In this way, the RF tag is not placed in a position where distortion is likely to concentrate due to a rigidity step. Therefore, the load applied to the RF tag can be reduced. This can improve the durability of the RF tag. In this example, it is preferable that the RF tag is not placed in a position that is a boundary between the end of the carcass and a member adjacent to the end of the carcass (e.g., a side rubber, etc.) in a cross-sectional view in the tire width direction. The number of RF tags is not particularly limited. A tire may include only one RF tag, or may include two or more RF tags. Here, an RF tag is illustrated as an example of a communication device, but a communication device different from the RF tag may be used.

[0054] The RF tag may be disposed, for example, in the tread portion of the tire. In this way, the RF tag is not damaged by a side cut of the tire. The RF tag may be disposed, for example, in the tread center portion in the tire width direction. The tread center portion is a position where deflection is unlikely to concentrate in the tread portion. In this way, the load applied to the RF tag can be reduced. This can improve the durability of the RF tag. In addition, it is possible to suppress the occurrence of a difference in communication with the RF tag from both outer sides of the tire in the tire width direction. In this example, the RF tag may be disposed, for example, within a range of 1 / 2 of the tread width with the tire equatorial plane as the center in the tire width direction. The RF tag may be disposed, for example, at the tread end in the tire width direction. When the position of the reader that communicates with the RF tag is predetermined, the RF tag may be disposed, for example, at the tread end on one side closer to the reader. In this example, the RF tag may be disposed, for example, within a range of 1 / 4 of the tread width with the tread end as the outer end in the tire width direction.

[0055] The RF tag may be disposed, for example, on the tire cavity side of a carcass including one or more carcass plies that spans between bead portions. In this way, the RF tag is less likely to be damaged by impacts applied from the outside of the tire, or damage such as side cuts and nail penetration. As an example, the RF tag may be disposed in close contact with the surface of the carcass on the tire cavity side. As another example, when there is another member on the tire cavity side of the carcass, the RF tag may be disposed, for example, between the carcass and another member located on the tire cavity side of the carcass. An example of another member located on the tire cavity side of the carcass is an inner liner that forms the tire inner surface. As another example, the RF tag may be attached to the tire inner surface facing the tire cavity. By configuring the RF tag to be attached to the tire inner surface, it is easy to attach the RF tag to the tire and to inspect and replace the RF tag. In other words, the attachability and maintainability of the RF tag can be improved. In addition, by attaching the RF tag to the inner surface of the tire, it is possible to prevent the RF tag from becoming the core of tire failure, compared to a configuration in which the RF tag is embedded in the tire. Furthermore, when the carcass has multiple carcass plies and there is a position where multiple carcass plies are overlapped, the RF tag may be disposed between the overlapped carcass plies.

[0056] The RF tag may be disposed, for example, in the tread portion of the tire, on the outer side in the tire radial direction of the belt including one or more belt plies. As an example, the RF tag may be disposed on the outer side in the tire radial direction of the belt and in close contact with the belt. In addition, as another example, in the case where a reinforcing belt layer is provided, the RF tag may be disposed on the outer side in the tire radial direction of the reinforcing belt layer and in close contact with the reinforcing belt layer. In addition, as another example, the RF tag may be embedded in the tread rubber on the outer side in the tire radial direction of the belt. By disposing the RF tag on the outer side in the tire radial direction of the belt in the tread portion of the tire, communication with the RF tag from the outside of the tire in the tire radial direction is unlikely to be hindered by the belt. Therefore, it is possible to improve the communication with the RF tag from the outside of the tire in the tire radial direction. In addition, the RF tag may be disposed, for example, in the tread portion of the tire, on the inner side in the tire radial direction of the belt. In this way, the outer side in the tire radial direction of the RF tag is covered by the belt, so that the RF tag is unlikely to be damaged by impact from the tread surface or nail penetration. As one example, the RF tag may be disposed in the tread portion of the tire between the belt and the carcass located radially inward of the belt. In addition, if the belt has a plurality of belt plies, the RF tag may be disposed in the tread portion of the tire between any two belt plies. In this manner, the outer side of the RF tag in the radial direction of the tire is covered by one or more belt plies, so that the RF tag is less susceptible to damage from impacts from the tread surface, nail penetration, and the like.

[0057] The RF tag may be disposed, for example, at a sidewall or bead of the tire. The RF tag may be disposed, for example, at one sidewall or one bead that is closer to a reader that can communicate with the RF tag. In this way, the communication between the RF tag and the reader can be improved. As an example, the RF tag may be disposed between the carcass and the side rubber, or between the tread rubber and the side rubber. The RF tag may be disposed, for example, between the position where the tire is at its maximum width and the position of the tread surface in the tire radial direction. In this way, the communication with the RF tag from the outside of the tire in the tire radial direction can be improved compared to a configuration in which the RF tag is disposed on the inner side in the tire radial direction from the position where the tire is at its maximum width. The RF tag may be disposed, for example, on the inner side in the tire radial direction from the position where the tire is at its maximum width. In this way, the RF tag is disposed near the bead portion that has high rigidity. Therefore, the load applied to the RF tag can be reduced. This can improve the durability of the RF tag. As an example, the RF tag may be disposed at a position adjacent to the bead core in the tire radial direction or the tire width direction. Distortion is less likely to concentrate near the bead core. Therefore, the load applied to the RF tag can be reduced. This improves the durability of the RF tag. In particular, it is preferable that the RF tag is disposed in a position radially inward of the maximum tire width position and radially outward of the bead core of the bead portion. In this manner, the durability of the RF tag can be improved, and communication between the RF tag and a reader is less likely to be hindered by the bead core, improving the communication performance of the RF tag. In addition, when the side rubber is composed of multiple rubber members of the same or different types adjacent to each other in the tire radial direction, the RF tag may be disposed by being sandwiched between the multiple rubber members constituting the side rubber.

[0058] The RF tag may be disposed by being sandwiched between the bead filler and a member adjacent to the bead filler. In this way, the RF tag can be disposed in a position where distortion is less likely to be concentrated due to the placement of the bead filler. This reduces the load applied to the RF tag. This improves the durability of the RF tag. The RF tag may be disposed, for example, sandwiched between the bead filler and the carcass. The portion of the carcass that sandwiches the RF tag together with the bead filler may be located on the outer side of the bead filler in the tire width direction, or may be located on the inner side of the tire width direction. When the portion of the carcass that sandwiches the RF tag together with the bead filler is located on the outer side of the bead filler in the tire width direction, the load applied to the RF tag due to impact or damage from the outside of the tire in the tire width direction can be further reduced. This can further improve the durability of the RF tag. Furthermore, the bead filler may have a portion disposed adjacent to the side rubber. In such a case, the RF tag may be disposed sandwiched between the bead filler and the side rubber. Furthermore, the bead filler may have a portion disposed adjacent to the rubber chafer. In such a case, the RF tag may be disposed sandwiched between the bead filler and the rubber chafer.

[0059] The RF tag may be disposed, for example, sandwiched between the rubber chafer and the side rubber. In this way, the RF tag can be disposed at a position where distortion is less likely to be concentrated due to the placement of the rubber chafer. Therefore, the load applied to the RF tag can be reduced. This allows the durability of the RF tag to be improved. The RF tag may be disposed, for example, sandwiched between the rubber chafer and the carcass. In this way, the load applied to the RF tag due to impact or damage from the rim can be reduced. This allows the durability of the RF tag to be improved.

[0060] The RF tag may be sandwiched between the wire chafer and another member adjacent to the wire chafer on the inner or outer side in the tire width direction. In this way, the position of the RF tag is less likely to fluctuate when the tire is deformed. Therefore, the load applied to the RF tag when the tire is deformed can be reduced. This can improve the durability of the RF tag. The other member adjacent to the wire chafer on the inner or outer side in the tire width direction may be, for example, a rubber member such as a rubber chafer. Also, the other member adjacent to the wire chafer on the inner or outer side in the tire width direction may be, for example, a carcass.

[0061] A belt reinforcing layer may be further provided on the radially outer side of the belt. For example, the belt reinforcing layer may be formed by winding a cord made of polyethylene terephthalate continuously in a spiral shape in the tire circumferential direction. Here, the cord may be 6.9×10 -2 The belt reinforcement layer may be formed by applying an adhesive treatment under a tension of 29.4 N / tex or more, and may have an elastic modulus of 2.5 mN / dtex·% or more when a load of 29.4 N is applied, as measured at 160°C. Furthermore, the belt reinforcement layer may be disposed so as to cover the entire belt, or may be disposed so as to cover only both ends of the belt. Furthermore, the winding density per unit width of the belt reinforcement layer may vary depending on the position in the width direction. In this way, road noise and flat spots can be reduced without reducing high-speed durability. [Explanation of symbols]

[0062] 1: Tread surface, 2, 2a, 2b: Circumferential main groove, 3: Rikube, 3a: Outermost land part when installed on vehicle, 3b: Inner land part when installed in vehicle, 3b1: Outer land part of inner land part when installed in vehicle, 3b2: The inner land part of the inner land part when installed in the vehicle, 4: first widthwise groove, 41: The first part, 42: The second part, 5: second widthwise groove, 6: third widthwise groove, 7: Cutout part, 91: Communication devices, CL: tire equatorial plane, TE: Tread end

Claims

1. A pneumatic tire having one or more circumferential main grooves extending in a tire circumferential direction on a tread surface, A plurality of land portions are defined between the circumferential main groove and a tread edge or between the circumferential main grooves, The tire has a plurality of first width direction grooves extending in the tire width direction and both ends terminating within an outermost land portion when mounted on a vehicle, the outermost land portion when mounted on a vehicle being the outermost land portion in the tire width direction when mounted on a vehicle, and a plurality of second width direction grooves extending in the tire width direction, The first widthwise grooves and the second widthwise grooves are alternately arranged in the tire circumferential direction while being spaced apart from each other in the tire circumferential direction, One of the first widthwise grooves and one of the second widthwise grooves adjacent to the one of the first widthwise grooves on one side in the tire circumferential direction are paired, The first widthwise groove of the pair has a first portion extending from an outer side in the tire width direction toward an inner side in the tire circumferential direction, The second widthwise groove of the pair extends from the outer side toward the inner side in the tire width direction to the other side in the tire circumferential direction, a tire width direction inner end of the one second width direction groove that constitutes the pair is located outward in the tire width direction than a tire width direction inner end of the one first width direction groove that constitutes the pair.

2. The pneumatic tire according to claim 1 , wherein the second widthwise groove communicates with an outer tread end when mounted on a vehicle.

3. 3. The pneumatic tire according to claim 1, wherein the one first widthwise groove of the pair and the one second widthwise groove of the pair have an overlapping portion when projected in the tire circumferential direction.

4. The first widthwise groove further has a second portion extending from an inner end of the first portion in the tire width direction to one side in the tire circumferential direction, The pneumatic tire according to claim 1 or 2, wherein at least a portion of the first portion or at least a portion of the second portion has a chamfer at an opening to the tread surface.

5. The pneumatic tire is mounted on an applicable rim, inflated to a specified internal pressure, and under no load, in a standard state. The pneumatic tire according to claim 4 , wherein an inclination angle of the tapered surface of the chamfered portion of the second portion with respect to the tire radial direction is larger than an inclination angle of the tapered surface of the chamfered portion of the first portion with respect to the tire radial direction.

6. The pneumatic tire according to claim 1 or 2, wherein an inner land portion that is on an inner side when mounted on a vehicle has only two of the circumferential main grooves.

7. A pneumatic tire having one or more circumferential main grooves extending in a tire circumferential direction on a tread surface, A plurality of land portions are defined between the circumferential main groove and a tread edge or between the circumferential main grooves, The tire has a plurality of first width direction grooves extending in the tire width direction and both ends terminating within an outermost land portion when mounted on a vehicle, the outermost land portion when mounted on a vehicle being the outermost land portion in the tire width direction when mounted on a vehicle, and a plurality of second width direction grooves extending in the tire width direction, The first widthwise grooves and the second widthwise grooves are alternately arranged in the tire circumferential direction while being spaced apart from each other in the tire circumferential direction, One of the first widthwise grooves and one of the second widthwise grooves adjacent to the one of the first widthwise grooves on one side in the tire circumferential direction are paired, The first widthwise groove of the pair has a first portion extending from an inner side in the tire width direction toward an outer side in the tire circumferential direction, The second widthwise groove of the pair extends from the inner side toward the outer side in the tire width direction toward the other side in the tire circumferential direction, a tire width direction outer end of the one second width direction groove that constitutes the pair is located outboard in the tire width direction of the one first width direction groove that constitutes the pair.

8. The pneumatic tire according to claim 7 , wherein the second widthwise groove communicates with an outer tread end when mounted on a vehicle.

9. The pneumatic tire according to claim 7 or 8, wherein the one first widthwise groove that constitutes the pair and the one second widthwise groove that constitutes the pair have an overlapping portion when projected in the tire circumferential direction.

10. The first widthwise groove further has a second portion extending from an inner end of the first portion in the tire width direction to one side in the tire circumferential direction, 9. The pneumatic tire according to claim 7 or 8, wherein at least a portion of the first portion or at least a portion of the second portion has a chamfer at an opening to the tread surface.

11. The pneumatic tire is mounted on an applicable rim, inflated to a specified internal pressure, and under no load, in a standard state. The pneumatic tire according to claim 10 , wherein an inclination angle of the tapered surface of the chamfered portion of the second portion with respect to the tire radial direction is larger than an inclination angle of the tapered surface of the chamfered portion of the first portion with respect to the tire radial direction.

12. The pneumatic tire according to claim 7 or 8, further comprising only two of the circumferential main grooves in an inner land portion that is located on an inner side when mounted on a vehicle.

Images