Tire

Abstract

Provided is a tire (T01) in which a tread surface (8) is provided with: a plurality of main grooves (3) each extending in a tire circumferential direction; a pair of shoulder land sections (5) defined between a pair of main grooves located on the outermost side in the tire width direction among the plurality of main grooves and a pair of ground contact ends; one or more central lands (6) defined between the plurality of main grooves. In a print (FP) measured under a reference measurement condition, an end portion of the first side in the tire circumferential direction of each center land portion is located on the first side in the tire circumferential direction with respect to an end portion of the first side in the tire circumferential direction of each shoulder land portion.

Description

Technical Field

[0001] The present disclosure relates to a tire.

[0002] This application claims the priority of Japanese Patent Application No. 2022-201606 filed in Japan on December 16, 2022, the entire content of which is incorporated herein by reference. Background Art

[0003] There already exist tires including main grooves on the tread surface (for example, see Patent Document 1).

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2008-126931 Summary of the Invention

[0007] Problems to be Solved by the Invention

[0008] In recent years, in order to reduce the weight and rolling resistance of tires, some studies have been made on reducing the thickness of the tread rubber of tires. When the thickness of the tread rubber of a tire is made thinner, the groove depth of the main groove tends to become shallower, which may cause a reduction in the hydroplaning performance on wet roads.

[0009] An object of the present disclosure is to provide a tire that can obtain good hydroplaning performance on wet roads even when the thickness of the tread rubber is made thinner.

[0010] Solutions to the Problems

[0011] [1] A tire, wherein

[0012] the tread is provided with:

[0013] a plurality of main grooves each extending in the circumferential direction of the tire;

[0014] a pair of shoulder lands defined between a pair of the outermost main grooves in the tire width direction among the plurality of main grooves and a pair of grounding ends; and

[0015] one or more central lands defined between the plurality of main grooves, wherein

[0016] in the footprint measured under reference measurement conditions, the end on the first circumferential side of each central land is located on the first circumferential side of the tire with respect to the end on the first circumferential side of each shoulder land.

[0017] Effects of the Invention

[0018] According to the present disclosure, a tire can be provided that can obtain good wet road hydroplaning performance even when the thickness of the tread rubber is made thin. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In the drawings:

[0020] Figure 1 is a schematic view illustrating the footprint and the ground contact surface of a tire according to an embodiment of the present disclosure under reference measurement conditions;

[0021] Figure 2 is a view illustrating when unfolded on a flat surface Figure 1 the unfolded view of the tread surface 8 of the tire in

[0022] Figure 3 is a view illustrating an example of the internal structure of a tire that can be applied to a tire according to any embodiment of the present disclosure, and is a tire width direction cross-sectional view schematically illustrating the tire width direction cross-section of a tire half;

[0023] Figure 4 is a view illustrating the behavior of the tire in Figure 1 when rolling on a road surface wetted with water;

[0024] Figure 5 is a schematic view illustrating the footprint and the ground contact surface of a tire according to a reference example; and

[0025] Figure 6 is a view illustrating the behavior of the tire in Figure 5 when rolling on a road surface wetted with water. DETAILED DESCRIPTION

[0026] The tire according to the present disclosure can be used for any type of four-wheel vehicle tire and is particularly suitable for passenger car tires. In addition, the tire of the present disclosure can be used for pneumatic tires.

[0027] Hereinafter, embodiments of the tire according to the present disclosure will be described by way of example with reference to the drawings.

[0028] The same components and parts are denoted by the same reference numerals in each drawing.

[0029] Figure 1 is a schematic view illustrating the footprint FP and the ground contact surface CS of a tire T01 according to an embodiment of the present disclosure under reference measurement conditions. For convenience, the footprint FP and the ground contact surface CS of the tire T01 are illustrated in Figure 1 the same figure in. The reference measurement conditions will be described later. Figure 2 is a view illustrating when unfolded on a flat surface Figure 1 the unfolded view of the tread surface 8 of the tire T01 inFigure 3 FIG. 1 is a view showing an example of the internal structure of a tire T01 that can be applied to any embodiment according to the present disclosure, and is a cross-sectional view in the tire width direction of a tire half portion 2 (one side of the tire T01 with respect to the tire equatorial plane CL) of the tire T01, schematically showing the cross-section in the tire width direction.

[0030] The tire T01 of the present embodiment is configured as a pneumatic tire for a passenger car. However, the tire T01 of each embodiment of the present disclosure can be configured as a tire for any type of four-wheel vehicle, and in particular can be configured as a tire for a passenger car. In addition, the tire T01 of each embodiment of the present disclosure can be appropriately configured as a pneumatic tire.

[0031] As Figure 3 shown, the tire T01 of each embodiment of the present disclosure includes a tread portion T01t, a pair of sidewall portions T01w extending radially inward in the tire width direction from both ends in the tire width direction of the tread portion T01t, and a pair of bead portions T01b provided at the radially inner ends of each sidewall portion T01w. The bead portion T01b is configured such that when the tire T01 is mounted on a specified rim, the bead portion T01b will contact the specified rim on the radially inner side and the outer side in the tire width direction.

[0032] In the tread portion T01t, the tread rubber T07 is located radially outside the belt portion T06. The tread rubber T07 constitutes the tread surface 8, which is the surface on the radially outer side of the tread portion T01t. As Figure 2 shown, tread patterns are formed on the tread surface 8.

[0033] In this specification, the "footprint (FP)" ( Figure 1 ) should be measured under reference measurement conditions. The "reference measurement conditions" refer to a state where the tire is mounted on a specified rim and filled with a specified internal pressure, the tire camber angle is set to 0°, and the tire is loaded with 70% of the maximum load. The footprint (FP) is a representation of the shape of the ground contact surface (CS) of the tire under the reference measurement conditions.

[0034] In this specification, the "tread contact surface (8)" ( Figure 2 ) refers to the entire outer circumference of the tire that contacts the road surface when the tire, which has been assembled on a specified rim and filled with a specified internal pressure, rolls under the application of the maximum load.

[0035] In this specification, the "ground contact end (E)" refers to the end in the tire width direction of the tread surface (8).

[0036] In this specification, the "ground contact width" refers to the distance in the tire width direction between a pair of ground contact ends of the tread surface (8).

[0037] As used herein, "prescribed rim" means a standard prescribed rim of applicable dimensions (measuring rim in the ETRTO Standard Manual and design rim in the TRA Yearbook) as described or that may be described in industry standards effective in the region where the tire is produced and used, such industry standards being, for example, the JATMA Yearbook of the Japan Automobile Tire Manufacturers Association (JATMA) in Japan, the Standard Manual of the European Tyre and Rim Technical Organization (ETRTO) in Europe, and the Yearbook of the Tire and Rim Association, Inc. (TRA) in the United States (that is to say, the above "prescribed rim" includes current dimensions and future dimensions that will be listed in the above industry standards. An example of "future dimensions that will be listed" may be the dimensions listed as "FUTURE DEVELOPMENTS" in the ETRTO 2013 Edition). For dimensions not listed in these industry standards, the term "prescribed rim" means a rim whose width corresponds to the bead width of the inflated tire).

[0038] As used herein, "prescribed internal pressure" means the air pressure (maximum air pressure) corresponding to the maximum load capacity of a single wheel for applicable dimensions and ply ratings as described in the above JATMA Yearbook and other industry standards. In the case where dimensions are not listed in the above industry standards, "prescribed internal pressure" means the air pressure (maximum air pressure) corresponding to the maximum load capacity prescribed for each vehicle on which the tire is mounted).

[0039] As used herein, "maximum load" means the load corresponding to the maximum load capacity).

[0040] It should be noted that the air used herein may also be replaced by an inert gas such as nitrogen).

[0041] Unless otherwise specified, the dimensions of each element such as grooves and lands shall be measured when the tire is mounted on a prescribed rim, filled with prescribed internal pressure and unloaded. Herein, the dimensions of each element such as grooves and lands of the tread shall be measured in a developed view of the tread surface. In this specification, "developed view of the tread surface" means a plan view of the tread surface when the tread surface is developed on a flat surface).

[0042] For clarity, in some of the drawings, the circumferential direction of the tire is indicated by an arrow CD, the first side of the tire circumferential direction (one side of the tire circumferential direction) is indicated by an arrow CD1, and the second side of the tire circumferential direction (the other side of the tire circumferential direction) is indicated by an arrow CD2).

[0043] As Figure 2As shown, the tread surface 8 is provided with: a plurality of main grooves 3 extending in the circumferential direction of the tire; a pair of land portions 5 (hereinafter also referred to as "shoulder land portions 5"), which are defined between a pair of main grooves 3 located at the outermost positions in the tire width direction among the plurality of main grooves 3 (hereinafter also referred to as "shoulder main grooves 31") and a pair of grounding ends E; and one or more land portions 6 (hereinafter also referred to as "central land portions 6"), which are defined between the plurality of main grooves 3. In this specification, among the plurality of main grooves 3, each main groove 3 located on the inner side in the tire width direction with respect to the pair of shoulder main grooves 31 is referred to as a "central main groove 32". The pair of shoulder main grooves 31 are located on both sides of the tire equatorial plane CL.

[0044] In Figure 1 and Figure 2 the illustrated example, three main grooves (one of which is the central main groove 32) and two central land portions 6 are provided. However, the number of main grooves 3 can be two, four or more. In addition, it is not necessary to provide the central main groove 32, or two or more central main grooves 32 can be provided. Further, the number of central land portions 6 can be one, three or more.

[0045] In Figure 1 and Figure 2 the example, each main groove 3 extends in a straight line. However, the main groove 3 can also extend in a zigzag shape.

[0046] In Figure 2 the example, each shoulder land portion 5 is provided with a plurality of lateral grooves 71 extending substantially in the tire width direction, and these plurality of lateral grooves 71 are arranged at intervals in the tire circumferential direction. In addition, each central land portion 6 and one shoulder land portion 5 are provided with a plurality of sipes 72, and these plurality of sipes 72 are arranged at intervals in the tire circumferential direction.

[0047] However, each land portion 5 and 6 can be provided with any grooves and / or sipes.

[0048] As Figure 2 in the example, each land portion 5 and 6 is preferably formed as a rib (a land portion continuous in the tire circumferential direction, that is, a land portion not divided by a groove intersecting the land portion in the tire width direction in the tire circumferential direction). However, each land portion 5 and 6 can be formed as a block row (a land portion composed of a plurality of blocks, the plurality of blocks being divided by a plurality of grooves intersecting the land portion in the tire width direction in the tire circumferential direction). Further, among the land portions 5 and 6, some (one or more) land portions can be formed as ribs, while other land portions can be formed as block rows.

[0049] In this embodiment, the tread rubber T07 of the tire T01 has a thickness L thinner than that of a general tire ( Figure 3) This makes it possible to reduce the weight and rolling resistance of the tire T01.

[0050] From the perspective of reducing the weight and rolling resistance of the tire T01, the thickness L of the tread rubber T07 is preferably 7.8 mm or less. Further, the thickness L of the tread rubber T07 is preferably 6.5 mm or more.

[0051] It should be noted that the thickness L of the tread rubber T07, as the thickness from the radially outermost end of the belt portion T06 to the tread surface 8 in the central land portion 6 in the cross-section in the tire width direction, should be measured in a direction perpendicular to the belt portion T06 ( Figure 3 ).

[0052] In this embodiment, when the tread rubber T07 has a relatively thin thickness L, the depth of each main groove 3 is shallower than that of a general tire. It is desirable to ensure that the thickness of the tread rubber T07 from the radially outermost end of the belt portion T06 to the bottom of the main groove 3 is approximately 2 mm (for example, 1.5 to 2.5 mm). From this perspective, the groove depth of each main groove 3 is preferably 5.8 mm or less. Further, the groove depth of each main groove 3 is preferably 5.0 mm or more.

[0053] As Figure 1 shown, in the footprint FP of the tire T01 of this embodiment, the end 6t1 of the first tire circumferential side CD1 of each central land portion 6 is located on the first tire circumferential side CD1 with respect to the end 5t1 of the first tire circumferential side CD1 of each shoulder land portion 5. Therefore, in the footprint FP, each central land portion 6 protrudes more toward the first tire circumferential side CD1 than each shoulder land portion 5, and it can be said that the outer periphery FPe1 of the first tire circumferential side CD1 of the footprint FP (i.e., the ground contact surface CS) has a curved shape that schematically protrudes toward the first tire circumferential side CD1 (with the vertex near the tire equatorial plane CL).

[0054] Figure 4Schematically illustrated is the contact surface CS of the tire T01 of this embodiment when the tire rolls on a road surface wetted with water toward the second circumferential side CD2 of the tire. In this embodiment, as described above, in the footprint FP, the end 6t1 of the first circumferential side CD1 of each central land portion 6 is located on the first circumferential side CD1 of the tire with respect to the end 5t1 of the first circumferential side CD1 of each shoulder land portion 5. Therefore, during rotation of the tire T01, the outer periphery FPe1 of the first circumferential side CD1 of the contact surface CS has a curved shape that schematically protrudes toward the first circumferential side CD1 of the tire (the vertex is near the tire equatorial plane CL). This effectively prevents water from entering the contact surface CS and, in turn, prevents the formation of the hydroplaning region HPR on the wet road surface, thereby improving the hydroplaning performance on the wet road. In the hydroplaning region HPR on the wet road surface, a water film is interposed between the contact surface CS and the road surface, causing the tire T01 to float above the road surface.

[0055] Figure 5 is a schematic view showing the footprint FP and the contact surface CS of the tire T01 according to the reference example, and Figure 6 is an illustration of the behavior of the tire T01 in Figure 5 when it rolls on a road surface wetted with water toward the second circumferential side CD2 of the tire. In Figure 5 and Figure 6 the illustration of grooves and sipes other than the main groove 3 is omitted. As Figure 5 shown, in the reference example tire T01, in the footprint FP, the end 6t1 of the first circumferential side CD1 of each central land portion 6 is located at the same position in the tire circumference as compared with the end 5t1 of the first circumferential side CD1 of each shoulder land portion 5. Therefore, the outer periphery FPe1 of the first circumferential side CD1 of the footprint FP (i.e., the contact surface CS) can be said to have a roughly straight shape parallel to the tire width direction. In this case, as Figure 6 shown, during rolling of the tire T01, water is likely to enter the contact surface CS, and this, in turn, makes it easier to form the hydroplaning region HPR. Therefore, there is a risk that the hydroplaning performance on the wet road will not be very good. Although the illustration is omitted, in the footprint FP, when the end 6t1 of the first circumferential side CD1 of each central land portion 6 is located on the second circumferential side CD2 of the tire with respect to the end 5t1 of the first circumferential side CD1 of each shoulder land portion 5, that is, when the outer periphery FPe1 of the first circumferential side CD1 of the footprint FP (i.e., the contact surface CS) is roughly recessed toward the second circumferential side CD2 of the tire and has a curved shape with the vertex near the tire equatorial plane CL, water can easily enter the contact surface CS, and there is a risk that the hydroplaning performance on the wet road will not be very good.

[0056] In the tire T01 of this embodiment ( Figures 1 to 4) In the case of Figure 3 ), the thickness L of the tread rubber T07 is made thinner than that of a general tire, and accordingly, the depth of each main groove 3 is made shallower. Generally, when the depth of the main groove 3 becomes shallower, there is a tendency for the wet road hydroplaning performance to deteriorate. To prevent the wet road hydroplaning performance from deteriorating, it can be conceived to increase the groove volume by, for example, increasing the groove width of the main groove 3, thereby improving drainage. However, when the thickness L of the tread rubber T07 is made thinner, it will first be difficult to significantly increase the groove volume, and it will also be difficult to sufficiently prevent the deterioration of the wet road hydroplaning performance by increasing the groove volume. On the other hand, in this embodiment, by adjusting the shape of the contact patch FP (and thus the contact surface CS) as described above, good wet road hydroplaning performance can be obtained while keeping the thickness L of the tread rubber T07 thin and effectively preventing the decrease in the wet road hydroplaning performance.

[0057] It should be noted that the shape of the above-mentioned contact patch FP (and thus the contact surface CS) not only helps to improve the wet road hydroplaning performance of a tire (such as the tire T01 having a thin thickness L of the tread rubber T07), but also helps to improve the wet road hydroplaning performance of a tire having the same thickness L of the tread rubber T07 as that of a general tire.

[0058] As described above, even when the thickness of the tread rubber is made thinner, good wet road hydroplaning performance can be obtained by means of the shape of the above-mentioned contact patch FP (and thus the contact surface CS).

[0059] From the same perspective, it is also preferable that the contact patch FP has the same configuration on the second tire circumferential side CD2 as described above. In other words, as Figure 1 shown, it is preferable that in the contact patch FP, the end 6t2 of the second tire circumferential side CD2 of each central land portion 6 of the tire T01 is located on the second tire circumferential side CD2 with respect to the end 5t2 of the second tire circumferential side CD2 of each shoulder land portion 5. This improves the wet road hydroplaning performance when the tire T01 rolls toward the first tire circumferential side CD1.

[0060] In this specification, the ends 5t1 and 6t1 of the land portions 5 and 6 on the first tire circumferential side CD1 in the contact patch FP refer to the outermost points on the first tire circumferential side CD1 of the outer peripheries 5e1 of the land portion 5 and the outer peripheries 6e1 of the land portion 6.

[0061] Similarly, in this specification, the ends 5t2 and 6t2 of the land portions 5 and 6 on the second tire circumferential side CD2 in the contact patch FP refer to the outermost points on the second tire circumferential side CD2 of the outer peripheries 5e2 of the land portion 5 and the outer peripheries 6e2 of the land portion 6.

[0062] As Figure 1As shown, preferably, in the footprint FP, the outer periphery FPe1 of the first tire circumferential side CD1 extends in such a way that when the portion of the outer periphery FPe1 that spans all (one or more, two in this embodiment) of the central land portions 6 is regarded as a single unit, as this portion moves towards the inner side in the tire width direction, this portion extends in the direction towards the first tire circumferential side CD1. Thus, it can be said that the outer periphery FPe1 of the first tire circumferential side CD1 of the footprint FP (and thus the contact surface CS) roughly protrudes towards the first tire circumferential side CD1 and has a curved shape with a vertex near the tire equatorial plane CL. As Figure 4 shown, this allows for more effectively preventing water from entering the contact surface CS when the tire T01 rolls towards the second tire circumferential side CD2 on a water-wetted road surface, thereby improving the wet-road hydroplaning performance.

[0063] From the same perspective, it is also preferable for the footprint FP to have the same configuration on the second tire circumferential side CD2. That is, it is preferable for the tire T01 that the outer periphery FPe2 of the second tire circumferential side CD2 extends in such a way that when the portion of the outer periphery FPe2 that spans all (one or more, two in this embodiment) of the central land portions 6 is regarded as a single unit, as this portion moves towards the inner side in the tire width direction, this portion extends in the direction towards the second tire circumferential side CD2. This improves the wet-road hydroplaning performance when the tire T01 rolls towards the first tire circumferential side CD1.

[0064] In this specification, the outer periphery FPc1 of the first tire circumferential side CD1 of the footprint FP refers to the portion of the outer periphery of the footprint FP on the first tire circumferential side CD1, and specifically, refers to the portion of the outer periphery of the footprint FP that extends from the end on the first tire circumferential side CD1 of one grounding end E to the end on the first tire circumferential side CD1 of the other grounding end E.

[0065] In the footprint FP, the outer periphery 5e1 of the first tire circumferential side CD1 of the shoulder land portion 5 refers to the portion of the outer periphery of the shoulder land portion 5 that extends from the end on the first tire circumferential side CD1 of the shoulder main groove 31 to the end on the first tire circumferential side CD1 of the grounding end E. In the footprint FP, the outer periphery 6e1 of the first tire circumferential side CD1 of the central land portion 6 refers to the portion of the outer periphery of the central land portion 6 that extends from the end on the first tire circumferential side CD1 of one main groove adjacent to the central land portion 6 to the end on the first tire circumferential side CD1 of the other main groove adjacent to the central land portion 6.

[0066] In addition, in this specification, the outer periphery FPe2 of the second tire circumferential side CD2 of the footprint FP refers to the portion of the outer periphery of the footprint FP on the second tire circumferential side CD2, and specifically, refers to the portion of the outer periphery of the footprint FP extending from the end of the second tire circumferential side CD2 of one ground contact end E to the end of the second tire circumferential side CD2 of the other ground contact end E.

[0067] In the footprint FP, the outer periphery 5e2 of the second tire circumferential side CD2 of the shoulder land portion 5 refers to the portion of the outer periphery of the shoulder land portion 5 extending from the end of the second tire circumferential side CD2 of the shoulder main groove 31 to the end of the second tire circumferential side CD2 of the ground contact end E. In the footprint FP, the outer periphery 6e2 of the second tire circumferential side CD2 of the central land portion 6 refers to the portion of the outer periphery of the central land portion 6 extending from the end of the second tire circumferential side of one main groove adjacent to the central land portion 6 to the end of the second tire circumferential side CD2 of the other main groove adjacent to the central land portion 6.

[0068] In this specification, when referring to the shape or dimensions of the outer periphery of the footprint FP or the lands 5 and 6, the presence of the grooves should be ignored, that is, the shape and dimensions of the imaginary outer periphery that smoothly connects the outer peripheries divided by the grooves (main grooves 3, lateral grooves 71, etc.) should be referred to.

[0069] As Figure 1 shown, preferably, as going toward the inner side in the tire width direction, the outer periphery FPe1 of the first tire circumferential side CD1 of the footprint FP extends throughout its entire length toward the first tire circumferential side CD1. Therefore, it can be said that the outer periphery FPe1 of the first tire circumferential side CD1 of the footprint FP (and thus the ground contact surface CS) roughly protrudes toward the first tire circumferential side CD1 while having a curved shape with a vertex near the tire equatorial plane CL. As Figure 4 shown, this allows for more effectively preventing water from entering the ground contact surface CS when the tire T01 rolls toward the second tire circumferential side CD2 on a water-wetted road surface, thereby improving the wet road hydroplaning performance.

[0070] From the same perspective, it is also preferable for the footprint FP to have the same structure on the second tire circumferential side CD2. That is, preferably, as going toward the inner side in the tire width direction, the outer periphery FPe2 of the second tire circumferential side CD2 of the footprint FP extends throughout its entire length toward the second tire circumferential side CD2. This improves the wet road hydroplaning performance when the tire T01 rolls toward the first tire circumferential side CD1.

[0071] As Figure 1As shown, preferably, as going toward the inner side in the tire width direction, the outer periphery 5e1 of the first tire circumferential side CD1 of the contact patch FP at each shoulder land portion 5 extends toward the first tire circumferential side CD1 and has a curved shape that bulges and bends toward the first tire circumferential side CD1. Thus, as Figure 4 shown, when the tire T01 rolls on a road surface wetted with water, the water attempting to enter the contact surface CS can be effectively discharged to the outer side in the tire width direction on the shoulder side (outer side in the tire width direction). This makes it possible to more effectively prevent water from entering the contact surface CS and improves the wet road hydroplaning performance.

[0072] From the same perspective, it is also preferable for the contact patch FP to have the same configuration as described above on the second tire circumferential side CD2. That is, as Figure 1 shown, preferably, as going toward the inner side in the tire width direction, the outer periphery 5e2 of the second tire circumferential side CD2 of the contact patch FP at each shoulder land portion 5 extends toward the second tire circumferential side CD2 and has a curved shape that bulges and bends toward the second tire circumferential side CD2. This improves the wet road hydroplaning performance when the tire T01 rolls toward the first tire circumferential side CD1.

[0073] As Figure 1 shown, preferably, in the contact patch FP, the ends 5t1 and 6t1 of each land portion 5 and 6 on the first tire circumferential side CD1 that are more inner in the width direction are located closer to the first tire circumferential side CD1. Thus, it can be said that the outer periphery FPe1 of the first tire circumferential side CD1 of the contact patch FP (and thus the contact surface CS) roughly protrudes toward the first tire circumferential side CD1 while having a curved shape with the vertex near the tire equatorial plane CL. As Figure 4 shown, this allows for more effectively preventing water from entering the contact surface CS when the tire T01 rolls on a road surface wetted with water toward the second tire circumferential side CD2, thereby improving the wet road hydroplaning performance.

[0074] From the same perspective, it is also preferable for the contact patch FP to have the same configuration as described above on the second tire circumferential side CD2. That is, as Figure 1 shown, for the tire T01, preferably, in the contact patch FP, the ends 5t1 and 6t1 of each land portion 5 and 6 on the second tire circumferential side CD2 that are more inner in the tire width direction are located closer to the second tire circumferential side CD2. This improves the wet road hydroplaning performance when the tire T01 rolls toward the first tire circumferential side CD1.

[0075] Although illustrations are omitted, when three or more central lands 6 are provided on the tread surface 8, preferably, in the footprint FP, the end 6t1 of each central land 6 on the first tire circumferential side CD1 closer to the inner side in the tire width direction is located closer to the first tire circumferential side CD1, or is located at the same position in the tire circumferential direction as the other ends 6t1. Accordingly, it can be said that the outer periphery FPe1 of the first tire circumferential side CD1 of the footprint FP (and thus the ground contact surface CS) roughly protrudes toward the first tire circumferential side CD1, while having a curved shape with a vertex near the tire equatorial plane CL. This allows more effective prevention of water from entering the ground contact surface CS when the tire T01 rolls on a water-wetted road surface toward the second tire circumferential side CD2, thereby improving the wet road hydroplaning performance.

[0076] From the same perspective, it is also preferable for the footprint FP to have the same configuration on the second tire circumferential side CD2. That is, although illustrations are omitted, when three or more central lands 6 are provided on the tread surface 8, preferably, in the footprint FP, the end 6t2 of each central land 6 on the second tire circumferential side CD2 closer to the inner side in the tire width direction is located closer to the second tire circumferential side CD2, or is located at the same position in the tire circumferential direction as the other ends 6t2. This improves the wet road hydroplaning performance when the tire T01 rolls toward the first tire circumferential side CD1.

[0077] In Figure 1 the example of, in the footprint FP, the end 6t1 of each central land 6 on the first tire circumferential side CD1 is located at the inner end in the tire width direction of the outer periphery 6e1 of each central land 6 on the first tire circumferential side CD1. However, in the footprint FP, the end 6t1 of each central land 6 on the first tire circumferential side CD1 can be located at any position of the outer periphery 6e1 of each central land 6 on the first tire circumferential side CD1.

[0078] The same applies to the second tire circumferential side CD2 in the footprint FP. That is, in Figure 1 the example of, in the footprint FP, the end 6t2 of each central land 6 on the second tire circumferential side CD2 is located at the inner end in the tire width direction of the outer periphery 6e2 of each central land 6 on the second tire circumferential side CD2. However, in the footprint FP, the end 6t2 of each central land 6 on the second tire circumferential side CD2 can be located at any position of the outer periphery 6e2 of each central land 6 on the second tire circumferential side CD2.

[0079] The shape of the footprint FP of the tire T01 can be adjusted using various methods.

[0080] For example, the shape of the footprint FP of the tire T01 can be adjusted by adjusting the shape of the forming surface of the mold for vulcanizing the tire T01, thereby adjusting the bending shape (R shape) of the crown portion in the cross section of the tire T01 in the tire width direction, or the amount of fall or the fall rate of the tread surface T01t.

[0081] Furthermore, the shape of the footprint FP of the tire T01 can be adjusted by adjusting the shape of the forming surface of the mold for vulcanizing the tire T01, thereby adjusting the bending shape (R shape) of each land portion 5 and 6 in the cross section of the tire T01 in the tire width direction.

[0082] Furthermore, the shape of the footprint FP of the tire T01 can be adjusted by adjusting the reinforcement provided by the belt portion T06.

[0083] The ground contact shape ratio of the footprint FP is preferably 80% to 90%.

[0084] Here, the ground contact shape ratio of the footprint FP refers to the ratio of the ground contact length (the circumferential length of the footprint FP in the tire circumferential direction) at a position 80% of the half ground contact width away from the tire equatorial plane CL in the tire width direction (i.e., 40% of the ground contact width) to the ground contact length (the circumferential length of the footprint FP in the tire circumferential direction) on the tire equatorial plane CL.

[0085] In each example described in this specification, the tire T01 can have any internal structure. Referring to Figure 3 , the following is a description of an example of the internal structure of the tire T01. Figure 3 The internal structure of the example in

[0086] In Figure 3 the example shown, the tire T01 includes a pair of bead cores T02, a pair of bead fillers T03, a carcass T05, a belt portion T06, a tread rubber T07, a sidewall rubber T08, and a liner T09.

[0087] Each bead core T02 is buried in the corresponding bead portion T01b. The bead core T02 includes a plurality of bead wires covered with rubber. The bead wires can be made of metal (such as steel) or organic fibers (such as polyester, nylon, rayon, or aramid). For example, the bead wires can be made of monofilaments or stranded wires.

[0088] Each bead filler T03 is located radially outside the corresponding bead core T02 in the tire. The bead filler T03 extends in a tapered shape toward the outside in the tire radial direction. The bead filler T03 is made of rubber.

[0089] Generally, the bead filler is sometimes referred to as a "reinforcement".

[0090] The carcass T05 spans a pair of bead cores T02 in an annular shape. The carcass T05 is composed of one or more (one in the example of Figure 2 ) carcass plies T05p. Each carcass ply T05p includes one or more carcass cords and a coating rubber covering the carcass cords. The carcass cords can be formed of monofilaments or stranded wires.

[0091] The carcass cords can be made of metal (such as steel) or organic fibers (such as polyester, nylon, rayon, or aramid).

[0092] The carcass T05 preferably has a radial structure, but can also have a bias structure.

[0093] The belt T06 is disposed radially outside the crown portion of the carcass T05 with respect to the tire. The belt T06 includes one or more (two in the example of Figure 2 ) belt plies T06p. Each belt ply T06p includes one or more belt cords and a coating rubber covering the belt cords. The belt cords can be formed of monofilaments or stranded wires. The belt cords can be made of metal (such as steel) or organic fibers (such as polyester, nylon, rayon, or aramid).

[0094] The tread rubber T07 is disposed radially outside the belt T06 in the tread portion T01t. The tread rubber T07 forms the tread surface 8, which is the surface on the radially outer side of the tread portion T01t of the tire. Tread patterns are formed on the tread surface 8.

[0095] The sidewall rubber T08 is located in the sidewall portion T01w. The sidewall rubber T08 forms the outer surface on the outer side in the tire width direction of the sidewall portion T01w. The sidewall rubber T08 is located outside the carcass T05 in the tire width direction. The sidewall rubber T08 is located outside the bead filler T03 in the tire width direction. The sidewall rubber T08 is molded integrally with the tread rubber T07.

[0096] The inner liner T09 is disposed on the inner side of the tire of the carcass T05 and can be laminated, for example, on the inner side of the tire of the carcass T05. The inner liner T09 is made of, for example, a butyl-based rubber having low air permeability. The butyl-based rubber includes, for example, butyl rubber and its derivatives, halogenated butyl rubber. The inner liner T09 can be made not only of a butyl-based rubber but also of other rubber compositions, resins, or elastomers.

[0097] The illustration is omitted, but the tire T01 can include a buffer rubber between the carcass T05 and the tread rubber T07 in the tire radial direction. The buffer rubber can be located near the end in the tire width direction of the belt T06.

[0098] As Figure 3As shown, the tire T01 may include a rubber chafer T11 in a portion of each bead portion T01b configured to contact a specified rim.

[0099] As Figure 3 shown, the tire T01 may include one or more (one in the Figure 3 example) wire chafe T14 around each bead core T02. The wire chafe T14 may be disposed on the opposite side of the bead core T02 relative to the carcass T05, as in the Figure 3 example. The wire chafe T14 is made of metal (e.g., steel).

[0100] Although not shown, the tire T01 may have one or more nylon chafers around each bead core T02. The nylon chafers may be positioned on the opposite side of the bead core T02 relative to the carcass T05, as in the Figure 2 example. The nylon chafers are made of nylon.

[0101] Although not shown, the tire T01 may have a cap rubber between the bead filler T03 and the sidewall rubber T08 in the tire width direction in each tire half.

[0102] As Figure 3 shown, the tire T01 may include an RF tag 10 as a communication device 100. The RF tag 10 includes an IC chip and an antenna. For example, the RF tag 10 may be disposed, for example, by being sandwiched between a plurality of members of the same type or different types that make up the tire T01. This makes it easier to attach the RF tag 10 during the manufacture of the tire T01 and improves the productivity of the tire T01 including the RF tag 10. In Figure 3In the illustrated example, the RF tag 10 can be arranged by being sandwiched between the bead filler T03 and other components adjacent to the bead filler T03. The RF tag 10 can be embedded in any component constituting the tire T01. In this way, compared with the case where the RF tag 10 is arranged by being sandwiched between a plurality of components constituting the tire T01, the load applied to the RF tag 10 can be reduced. This improves the durability of the RF tag 10. In the present example, the RF tag 10 can be embedded in rubber components such as the tread rubber T07 and the sidewall rubber T08. Preferably, in the cross-sectional view in the tire width direction, the RF tag 10 is not arranged at a position that is the boundary between components having different stiffness levels in the circumferential length direction, which is the direction along the outer surface of the tire. In this way, the RF tag 10 is not arranged at a position where strain is likely to concentrate due to the difference in rigidity. As a result, the load applied to the RF tag 10 can be reduced. This improves the durability of the RF tag 10. In the present example, preferably, in the cross-sectional view in the tire width direction, the RF tag 10 is not arranged at the boundary between the end of the carcass T05 and a component (e.g., the sidewall rubber T08, etc.) adjacent to this end of the carcass T05. The number of RF tags 10 is not particularly limited. The tire T01 can include only one RF tag 10, or can include two or more RF tags 10. Here, the RF tag 10 is described as an example of a communication device, but a communication device other than the RF tag 10 can also be used.

[0103] For example, the RF tag 10 can be arranged in the tread portion T01t of the tire T01. In this way, the RF tag 10 will not be damaged by the side cut on the tire T01. For example, the RF tag 10 can be arranged at the center of the tread in the tire width direction. The center of the tread is a position where deflection does not concentrate in the tread portion T01t. In this way, the load applied to the RF tag 10 can be reduced. This improves the durability of the RF tag 10. In addition, this also prevents a difference in communication performance of the tire from the two outer sides in the tire width direction of the tire T01 having the RF tag 10. In the present example, in the case where the tire equatorial plane is the center CL, the RF tag 10 can be arranged, for example, within a range of 1 / 2 of the tread width in the tire width direction. For example, the RF tag 10 can be arranged at the tread end in the tire width direction. If the position of the reader that communicates with the RF tag 10 is predetermined, the RF tag 10 can be arranged, for example, at the tread end on the side closer to the reader. In the present example, in the case where the tread end is the outer end, the RF tag can be arranged, for example, within a range of 1 / 4 of the tread width in the tire width direction.

[0104] The RF tag 10 can be arranged to be closer to the tire cavity than, for example, the carcass T05 including one or more carcass plies T05p that straddle the bead portion T01b. In this way, the RF tag 10 becomes less vulnerable to damage caused by external impacts on the tire T01 (such as side cuts and nail punctures). As an example, the RF tag 10 can be arranged to be in close contact with the surface of the carcass T05 on the tire cavity side (refer to point P31 in Figure 3 ). As another example, when there is another component closer to the tire cavity than the carcass T05, the RF tag 10 can be arranged, for example, between the carcass T05 and this other component closer to the tire cavity than the carcass T05. An example of another component located closer to the tire cavity than the carcass T05 is the liner T09 that forms the inner surface of the tire. As another example, the RF tag 10 can be attached to the inner surface of the tire facing the tire cavity (refer to point P32 in Figure 3 ). By having a configuration in which the RF tag 10 is attached to the inner surface of the tire, it is easy to attach the RF tag 10 to the tire T01, and it is easy to inspect and replace the RF tag 10. In other words, the ease of attachment and maintenance of the RF tag 10 can be improved. In addition, by attaching the RF tag 10 to the inner surface of the tire, compared with a configuration in which the RF tag 10 is buried inside the tire T01, the RF tag 10 can be prevented from becoming the core of a tire failure.

[0105] In addition, when the carcass T05 has a plurality of carcass plies T05t and there is a position where the plurality of carcass plies T05t overlap each other, the RF tag 10 can be arranged between the overlapping carcass plies T05t.

[0106] For example, in the tread portion T01t of the tire T01, the RF tag 10 can be arranged on the tire radial outer side of the belt portion T06 including one or more belt plies T06p. As an example, the RF tag 10 can be arranged on the tire radial outer side of the belt portion T06 and in close contact with the belt portion (refer to point P44 in Figure 3 ). As another example, when the belt reinforcement layer T04 is provided, the RF tag 10 can be arranged on the tire radial outer side of the belt reinforcement layer T04 and in close contact with the belt reinforcement layer (refer to point P45 in Figure 3 ). As yet another example, the RF tag 10 can be buried in the tread rubber T07 on the tire radial outer side of the belt portion T06 (refer to point P41 in Figure 3 ). By arranging the RF tag 10 on the tire radial outer side of the belt portion T06 in the tread portion T01t of the tire T01, communication with the RF tag 10 from the tire radial outer side of the tire T01 is less likely to be interfered with by the belt portion 6. This improves the communication performance with the RF tag 10 from the tire radial outer side of the tire T01.

[0107] In addition, in the tread surface T01t of the tire T01, the RF tag 10 can be disposed radially inward of the belt T06 in the tire. In this way, the radially outer side of the RF tag 10 is covered by the belt T06, so the RF tag 10 is less likely to be damaged by an impact from the tread surface or a nail stuck into the tread surface. As an example, the RF tag 10 can be disposed between the belt T06 and the carcass T05 located radially inward of the belt T06 (refer to Figure 3 point P42 in

[0108] In addition, when the belt T06 includes a plurality of belt plies T06p, the RF tag 10 can be disposed between any two belt plies T06p in the tread surface T01t of the tire T01. In this way, the radially outer side of the RF tag 10 is covered by one or more belt plies T06p, so the RF tag 10 becomes less likely to be damaged by an impact from the tread surface or a nail stuck into the tread surface.

[0109] The RF tag can be disposed, for example, between the buffer rubber and the tread rubber T07, or between the buffer rubber and the sidewall rubber T08. In this way, the impact on the RF tag 10 can be mitigated by the buffer rubber. This improves the durability of the RF tag.

[0110] In addition, for example, the RF tag can be embedded in the buffer rubber. In addition, the buffer rubber can be composed of a plurality of rubber members of the same or different types adjacent to each other. In this case, the RF tag 10 can be disposed by being sandwiched between the plurality of rubber parts constituting the buffer rubber.

[0111] This configuration is particularly suitable when the tire T01 is a heavy-duty pneumatic tire (for example, a pneumatic tire for trucks and buses, a pneumatic tire for off-road (construction vehicle) use, etc.).

[0112] The RF tag 10 can be disposed at a position, for example, in the sidewall portion T01w or the bead portion T01b of the tire T01. For example, the RF tag 10 can be disposed on the sidewall portion T01w or the bead portion T01b on the side closer to the reader that can communicate with the RF tag 10 (refer to Figure 3 points P6, P62 in Figure 3 ). In this way, the communication performance between the RF tag 10 and the reader can be improved. As an example, the RF tag 10 can be disposed between the carcass T05 and the sidewall rubber T08, or between the tread rubber T07 and the sidewall rubber T08 (refer to

[0113] For example, the RF tag 10 can be arranged between the position where the tire T01 has the maximum width and the position of the tread surface in the tire radial direction. In this way, compared with the configuration in which the RF tag 10 is arranged on the inner side in the tire radial direction at the maximum width position of the tire, the communication performance with the RF tag 10 from the outer side in the tire radial direction of the tire T01 can be improved.

[0114] For example, the RF tag 10 can be arranged on the inner side in the tire radial direction at the maximum width position of the tire. In this way, the RF tag 10 is arranged near the bead part T01b with higher rigidity. Therefore, the load applied to the RF tag 10 is reduced, which in turn improves the durability of the RF tag 10. As an example, the RF tag 10 can be arranged at a position adjacent to the bead core T02 in the radial direction or the tire width direction. The area around the bead core T02 is not easily subjected to strain. Therefore, the load applied to the RF tag 10 is reduced, which in turn improves the durability of the RF tag 10.

[0115] In particular, it is preferable that the RF tag 10 is arranged on the inner side in the tire radial direction at the maximum width position of the tire and on the outer side in the tire radial direction of the bead core T02 in the bead part T01b. In this way, the durability of the RF tag 10 can be improved, while the communication between the RF tag 10 and the reader is less likely to be interfered by the bead core T02, and the communication performance of the RF tag 10 can be improved.

[0116] In addition, when the sidewall rubber T08 is composed of a plurality of rubber members of the same or different types adjacent to each other in the tire radial direction, the RF tag 10 can be arranged by being sandwiched between the plurality of rubber members constituting the sidewall rubber T08.

[0117] The RF tag 10 can be arranged by being sandwiched between the bead filler T03 and the member adjacent to the bead filler T03. In this way, the RF tag 10 can be arranged at a position where strain is less likely to concentrate due to the configuration of the bead filler T03. Therefore, the load applied to the RF tag 10 is reduced, which in turn improves the durability of the RF tag 10.

[0118] The RF tag 10 can be arranged, for example, by being sandwiched between the bead filler T03 and the carcass T05. The part of the carcass T05 that sandwiches the RF tag 10 together with the bead filler T03 can be located outside the tire width direction with respect to the bead filler T03, or can be located inside the tire width direction with respect to the bead filler T03. When the part of the carcass T05 that sandwiches the RF tag 10 together with the bead filler T03 is located outside the tire width direction of the bead filler T03, the load applied to the RF tag 10 caused by an impact or damage to the tire from the outer side in the tire width direction of the tire T01 can be further reduced. This makes it possible to further improve the durability of the RF tag 10.

[0119] In addition, the bead filler T03 may have a portion disposed adjacent to the sidewall rubber T08. In this case, the RF tag 10 may be arranged by being sandwiched between the bead filler T03 and the sidewall rubber T08.

[0120] In addition, the bead filler T03 may also have a portion disposed adjacent to the rubber chafer T11. In this case, the RF tag 10 may be arranged by being sandwiched between the bead filler T03 and the rubber chafer T11.

[0121] This construction is particularly suitable when the tire T01 is a pneumatic passenger tire.

[0122] The RF tag may be arranged between the reinforcement T03 and a component adjacent to the reinforcement T03. In this way, the RF tag 10 can be arranged at a position where concentrated deformation is less likely to occur due to the placement of the reinforcement T03. Therefore, the load applied to the RF tag 10 is reduced, which in turn improves the durability of the RF tag 10. For example, the RF tag 10 may be arranged by being sandwiched between the reinforcement T03 and the sidewall rubber T08.

[0123] Alternatively, the RF tag 10 may be arranged by being sandwiched between the reinforcement T03 and the carcass T05. The portion of the carcass T05 that sandwiches the RF tag 10 together with the reinforcement T03 may be located outside the tire width direction with respect to the reinforcement T03, or may be located inside the tire width direction with respect to the reinforcement T03. When the portion of the carcass T05 that sandwiches the RF tag 10 together with the reinforcement T03 is located outside the tire width direction with respect to the reinforcement T03, the load applied to the RF tag 10 caused by an impact or damage to the tire T01 from the outside in the tire width direction of the tire T01 can be reduced even more. This makes it possible to further improve the durability of the RF tag 10.

[0124] The reinforcement T03 may also include a portion disposed adjacent to the rubber chafer T11. In this case, the RF tag 10 may be arranged by being sandwiched between the reinforcement T03 and the rubber chafer T11.

[0125] The reinforcement T03 may include a portion adjacent to the cap rubber on the outside in the tire width direction. In this case, the RF tag 10 may be arranged by being sandwiched between the reinforcement T03 and the cap rubber.

[0126] The reinforcement T03 may be composed of a plurality of rubber components with different hardnesses. In this case, the RF tag 10 may be arranged by being sandwiched between the plurality of rubber components that make up the reinforcement T03.

[0127] The RF tag 10 can be arranged by being sandwiched between the cap-shaped rubber and a component adjacent to the cap-shaped rubber. For example, the RF tag 10 can be arranged by being sandwiched between the cap-shaped rubber and the carcass ply T05p. In this way, the impact on the RF tag 10 can be mitigated by the cap-shaped rubber, and this improves the durability of the RF tag 10.

[0128] This configuration is particularly suitable when the tire T01 is a heavy-duty pneumatic tire (e.g., a pneumatic tire for trucks and buses, a pneumatic tire for off-road (construction vehicle) use, etc.).

[0129] The RF tag 10 can be arranged, for example, between the rubber chafer T11 and the sidewall rubber T08 (refer to point P82 in Figure 3 . In this way, the RF tag 10 can be arranged at a position where deformation is less likely to concentrate due to the arrangement of the rubber chafer T11. This reduces the load applied to the RF tag 10 and improves the durability of the RF tag 10.

[0130] The RF tag 10 can be arranged, for example, by being sandwiched between the rubber chafer T11 and the carcass T05 (refer to point P81 in Figure 3 . In this way, the load applied to the RF tag 10 due to impact or damage from the rim can be reduced. This improves the durability of the RF tag 10.

[0131] The RF tag 10 can be arranged by being sandwiched between the nylon chafer and another component on the outer or inner side in the tire width direction adjacent to the nylon chafer. In this way, when the tire deforms, the position of the RF tag 10 is less likely to change. This reduces the load applied to the RF tag 10 when the tire deforms, and this improves the durability of the RF tag 10.

[0132] For example, the nylon chafer may include a portion adjacent to the rubber chafer T11 on the outer side in the tire width direction. In this case, the RF tag 10 can be arranged by being sandwiched between the nylon chafer and the rubber chafer T11. For example, the nylon chafer may include a portion adjacent to the sidewall rubber T08 on the outer side in the tire width direction. In this case, the RF tag 10 can be arranged by being sandwiched between the nylon chafer and the sidewall rubber T08.

[0133] For example, the nylon bead filler may have a portion adjacent to the reinforcing member T03 on the inner side in the tire width direction. In this case, the RF tag 10 can be arranged by being sandwiched between the nylon bead filler and the reinforcing member T03. In addition, the nylon bead filler may include, for example, a portion adjacent to the cap rubber T12 on the inner side in the tire width direction. In this case, the RF tag 10 can be arranged by being sandwiched between the nylon bead filler and the cap rubber T12. In addition, the nylon bead filler may include a portion adjacent to the carcass T05 on the inner side in the tire width direction. In this case, the RF tag 10 can be arranged by being sandwiched between the nylon bead filler and the carcass T05. In addition, the nylon bead filler may include a portion adjacent to the wire bead filler T14 on the inner side in the tire width direction. In this case, the RF tag 10 can be arranged by being sandwiched between the nylon bead filler and the wire bead filler T14.

[0134] In this way, the RF tag 10 can be arranged by being sandwiched between the nylon bead filler and another component adjacent to the nylon bead filler on the outer or inner side in the tire width direction. In particular, when the outer side in the tire width direction of the RF tag 10 is covered with the nylon bead filler, the load applied to the RF tag 10 due to impact or damage from the outer side in the tire width direction of the tire can be further reduced. This makes it possible to further improve the durability of the RF tag 10.

[0135] This configuration is particularly suitable when the tire T01 is a heavy-duty pneumatic tire (for example, a pneumatic tire for trucks and buses, a pneumatic tire for off-road (construction vehicle) use, etc.).

[0136] The RF tag 10 can be arranged by being sandwiched between the wire bead filler T14 and another component adjacent to the wire bead filler T14 on the inner or outer side in the tire width direction. In this way, when the tire deforms, the position of the RF tag 10 is less likely to change. This reduces the load applied to the RF tag 10 when the tire deforms. This improves the durability of the RF tag 10. Another component adjacent to the wire bead filler T14 on the inner or outer side in the tire width direction can be a rubber member, such as the rubber bead filler T14 (refer to Figure 3 point P102). Another component adjacent to the wire bead filler T14 on the inner or outer side in the tire width direction can be the carcass T05 (refer to Figure 3 point P101).

[0137] The belt reinforcing layer T04 can be provided on the radially outer side of the belt T06 of the tire. For example, the belt reinforcing layer T04 can be formed of cords made of polyethylene terephthalate continuously spirally wound circumferentially of the tire. The cords of the belt reinforcing layer T04 are made by applying an adhesive treatment under a tension of 6.9×10-2 N / tex or more, and the elastic modulus under a load of 29.4 N measured at 160 °C can be 2.5 mN / dtex·% or more. In addition, the belt reinforcing layer T04 can be arranged to cover the entire belt T06, or can be arranged to cover only both ends of the belt T06. Further, the winding density per unit width of the belt reinforcing layer T04 can vary according to the width direction position. In this way, road noise and flat spots can be reduced without degrading high-speed durability.

[0138] This configuration is particularly suitable when the tire T01 is a pneumatic tire for a passenger car.

[0139] Examples

[0140] Tires T01 according to the examples and comparative examples were prepared and evaluated, and will be described below.

[0141] The shape of the footprint FP of the tire in Example 1 is as Figure 1 shown.

[0142] The shape of the footprint FP of the tire in Comparative Example 1 is as Figure 5 shown.

[0143] Each exemplary tire has three main grooves 3 and four (ribbed) land portions 5 and 6 on the tread surface 8.

[0144] Each exemplary tire has the same tire size.

[0145] Details of each exemplary tire are provided in Table 1.

[0146] The wet road hydroplaning performance of each exemplary tire was evaluated. When evaluating the wet road hydroplaning performance, turning wet road hydroplaning was evaluated. Specifically, when evaluating each tire, four tires of the example were mounted on a vehicle, and then the vehicle was driven at a constant speed while turning on a wet road surface, and the maximum lateral G-force (turning force) acting on the vehicle at this time was measured. Next, the speed was slightly increased and the maximum lateral G-force was measured in the same manner, and then this was repeated while increasing the speed. When wet road hydroplaning occurs, the vehicle slides laterally and the maximum lateral G-force decreases. Finally, the maximum lateral G-forces at each speed were added together (integrated) and evaluated using an exponent. The results are provided in Table 1. In Table 1, the wet road hydroplaning performance of Example 1 is expressed as an exponent value when the wet road hydroplaning performance of Comparative Example 1 is set to 100. The higher the exponent value of the wet road hydroplaning performance provided in Table 1, the better the wet road hydroplaning performance.

[0147] [Table 1]

[0148]

[0149] As can be seen from Table 1, the tire of Example 1 has the same thickness L of the tread rubber T07 and the same groove depth of each main groove 3 as the tire of Comparative Example 1. However, it can improve the wet road hydroplaning performance.

[0150] Industrial Applicability

[0151] The tire according to the present disclosure can be used for any type of four-wheel vehicle tire and is particularly suitable for passenger vehicle tires. In addition, the tire of the present disclosure can be used for pneumatic tires.

[0152] List of Reference Numerals

[0153] T01 Tire

[0154] 3 Main groove (groove)

[0155] 31 Shoulder main groove

[0156] 32 Center main groove

[0157] 5 Shoulder land (land)

[0158] 5e1 Outer periphery of the first circumferential side of the tire

[0159] 5t1 End of the first circumferential side of the tire

[0160] 5e2 Outer periphery of the second circumferential side of the tire

[0161] 5t2 End of the second circumferential side of the tire

[0162] 6 Center land (land)

[0163] 6e1 Outer periphery of the first circumferential side of the tire

[0164] 6t1 End of the first circumferential side of the tire

[0165] 6e2 Outer periphery of the second circumferential side of the tire

[0166] 6t2 End of the second circumferential side of the tire

[0167] 71 Transverse tread groove (groove)

[0168] 72 Sipes

[0169] 8 Tread surface

[0170] E Ground contact end

[0171] FP Footprint

[0172] Outer circumference of the first circumferential side of the FPe1 tire

[0173] Outer circumference of the second circumferential side of the FPe2 tire

[0174] CS Contact surface

[0175] CD Tire circumference

[0176] CD1 First circumferential side of the tire

[0177] CD2 Second circumferential side of the tire

[0178] HPR Hydroplaning area on wet road

[0179] T01t Tread surface

[0180] T01w Sidewall part

[0181] T01b Bead part

[0182] T02 Bead core

[0183] T03 Bead filler

[0184] T04 Belt reinforcement layer

[0185] T05 Carcass

[0186] T05P Carcass ply

[0187] T06 Belt

[0188] T06P Belt ply

[0189] T07 Tread rubber

[0190] T08 Sidewall rubber

[0191] T09 Inner liner

[0192] T11 Rubber bead filler

[0193] T14 Wire bead filler

[0194] CL Tire equatorial plane

[0195] 10 RF tag

Claims

1. A tire, wherein, the tread is provided with: a plurality of main grooves, each main groove extending along the circumferential direction of the tire; a pair of shoulder lands, which are defined between a pair of main grooves located on the outermost sides in the tire width direction among the plurality of main grooves and a pair of grounding ends; and one or more central lands, which are defined between the plurality of main grooves, wherein, in the footprint measured under the reference measurement conditions, the end portion on the first circumferential side of the tire of each of the central lands is located on the first circumferential side of the tire with respect to the end portion on the first circumferential side of the tire of each of the shoulder lands.

2. The tire according to claim 1, wherein, The outer circumference on the first circumferential side of the footprint extends toward the first circumferential side of the tire in a portion crossing the one or more central lands as it goes toward the inner side in the tire width direction.

3. The tire according to claim 1, wherein, The outer circumference on the first circumferential side of the footprint extends toward the first circumferential side of the tire over its entire length as it goes toward the inner side in the tire width direction.

4. The tire according to claim 1, wherein, The outer circumference on the first circumferential side of the footprint at each of the shoulder lands extends toward the first circumferential side of the tire as it goes toward the inner side in the tire width direction, and has a curved shape that bulges and curves toward the first circumferential side of the tire.

5. The tire according to claim 1, wherein, the thickness of the tread rubber is 7.8 mm or less, and the depth of each of the main grooves is 5.8 mm or less.

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