Tire

Abstract

A tire according to the present invention comprises a circumferential groove extending along the tire circumferential direction in the tread surface and a tread ridge section demarcated on one side in the tire width direction by the circumferential groove. A resonator is arranged in the tread ridge section. The resonator opens at the surface of the tread ridge section and comprises an air chamber groove terminating within the tread ridge section and a neck groove that is narrower than the air chamber groove and whereby the air chamber groove and the circumferential groove communicate. The opening angle formed in a developed view of the tread surface by a first wall of the air chamber groove having one side wall of the neck groove connected thereto and a second wall of the air chamber groove having the other side wall of the neck groove connected thereto is 170º-200º. The air chamber groove is inclined with respect to the tire width direction and the tire circumferential direction. The length of extension of the air chamber groove in the tire circumferential direction is longer than the length of extension of the air chamber groove in the tire width direction.

Description

tire

[0001] The present invention relates to a tire.

[0002] Tire-induced noise has long been known as a type of noise generated by automobiles while they are running. Tire-induced noise includes, for example, air column resonance noise. In tires, air column resonance noise is known to be generated by resonance of air within a tube formed by the road surface and circumferential grooves extending in the tire circumferential direction on the tread surface.

[0003] The frequency of this air column resonance noise is often around 1000 Hz in ordinary passenger cars. Generally, human hearing is particularly sensitive in the frequency band around 1000 Hz, so reducing air column resonance noise is also effective in improving the quietness of automobiles while they are running.

[0004] Patent Document 1 discloses a tire equipped with a Helmholtz resonator that reduces air column resonance noise. The tire disclosed in Patent Document 1 has a tread land portion provided with a Helmholtz resonator having an air chamber that opens to the surface and a narrowed neck that connects the air chamber to a circumferential groove.

[0005] International Publication No. 2014 / 174813

[0006] In a Helmholtz resonator, the volume of the air chamber, the length of the constricted neck, and other factors are set according to the frequency of the air column resonance noise to be reduced. In this case, if the frequency of the air column resonance noise to be reduced is set low, the volume of the air chamber needs to be increased. Increasing the volume of the air chamber reduces the rigidity of the tread land portion, which may deteriorate the tire's driving performance.

[0007] An object of the present invention is to provide a tire that can achieve both quietness and driving performance.

[0008] A first aspect of the present invention is a tire comprising a tread surface having circumferential grooves extending circumferentially along the tire circumferential direction, and a tread land portion defined on one side in the tire width direction by the circumferential groove, wherein a resonator is disposed in the tread land portion, and the resonator comprises an air chamber groove that opens to the surface of the tread land portion and terminates within the tread land portion, and a neck groove that connects the air chamber groove and the circumferential groove and is narrower than the air chamber groove, wherein an opening angle formed by a first wall of the air chamber groove that is continuous with one side wall of the neck groove and a second wall of the air chamber groove that is continuous with the other side wall of the neck groove in a developed view of the tread surface is 170 to 200 degrees, the air chamber groove extends at an angle with respect to the tire width direction and the tire circumferential direction, and the extension length of the air chamber groove in the tire circumferential direction is longer than the extension length of the air chamber groove in the tire width direction.

[0009] According to the present invention, it is possible to provide a tire that can achieve both quietness and driving performance.

[0010] Fig. 3 is a cross-sectional view in the tire width direction of a tire as one embodiment of the present invention. Fig. 4 is a development view of a portion of the tread surface of the tire shown in Fig. 1. Fig. 5 is an enlarged view of a first resonator shown in Fig. 2. Fig. 6 is a diagram schematically showing a Helmholtz resonator having one narrowed neck. Fig. 7 is a cross-sectional view showing a cross section perpendicular to the extension direction of the communicating groove shown in Fig. 2. Fig. 8 is a development view of a portion of the tread surface of a tire as a modified example of the tire shown in Fig. 1.

[0011] Hereinafter, embodiments of a tire according to the present invention will be described by way of example with reference to the drawings. The same reference numerals are used to designate common components in each drawing. In this specification, the tire width direction refers to the direction parallel to the tire's rotation axis. The tire radial direction refers to the radial direction of a circle around the tire's rotation axis. The tire circumferential direction refers to the direction in which the tire rotates around the tire's rotation axis.

[0012] In this specification, "tread surface" refers to the outer peripheral surface of the tire that comes into contact with the road surface when the tire, mounted on a rim and inflated to a specified internal pressure, rolls under a maximum load (hereinafter also referred to as "maximum load condition"). Also, "tread edge" refers to the outer edge of the tread surface in the tire width direction. Furthermore, in this specification, "ground contact length" refers to the maximum length in the tire circumferential direction of the contact area where the tread surface comes into contact with the road surface.

[0013] In this specification, "rim" refers to the standard rim (Measuring Rim in the ETRTO Standards Manual, Design Rim in the TRA Year Book) for the applicable size that is described or will be described in the future in the industry standards valid in the region where the tire is produced and used, such as the JATMA Year Book of the Japan Automobile Tire Manufacturers Association (JATMA) in Japan, the Standards Manual of the European Tyre and Rim Technical Organization (ETRTO) in Europe, and the Year Book of the Tire and Rim Association, Inc. (TRA) in the United States. For sizes not described in the above industry standards, this refers to a rim with a width corresponding to the tire bead width. "Rim" includes not only current sizes but also sizes that may be included in the above industry standards in the future. Examples of "sizes that will be described in the future" include sizes described as "FUTURE DEVELOPMENTS" in the 2013 edition of the ETRTO Standards Manual.

[0014] In this specification, "specified internal pressure" refers to the air pressure (maximum air pressure) corresponding to the maximum load capacity of a single wheel for the applicable size and ply rating as specified in the above-mentioned industrial standards, such as the JATMA Yearbook, and in the case of a size not specified in the above-mentioned industrial standards, refers to the air pressure (maximum air pressure) corresponding to the maximum load capacity specified for each vehicle on which the tire is to be mounted. Also, in this specification, "maximum applied load" refers to the load corresponding to the maximum load capacity of a tire for the applicable size as specified in the above-mentioned industrial standards, and in the case of a size not specified in the above-mentioned industrial standards, refers to the load corresponding to the maximum load capacity specified for each vehicle on which the tire is to be mounted.

[0015] Hereinafter, a pneumatic tire 1 (hereinafter simply referred to as "tire 1") as one embodiment of a tire according to the present invention will be described with reference to the drawings. In this embodiment, a radial tire for a passenger vehicle will be described as an example of the tire 1, but other types of tires may also be used.

[0016] Fig. 1 is a cross-sectional view in the tire width direction of a tire 1. As shown in Fig. 1, the tire 1 includes a pair of bead portions 11, a pair of sidewall portions 12, and a tread portion 13. The sidewall portions 12 are continuous with the outer sides of the bead portions 11 in the tire radial direction A. The tread portion 13 is continuous with the pair of sidewall portions 12. Both ends of the tread portion 13 in the tire width direction B are continuous with each sidewall portion 12.

[0017] Each bead portion 11 includes a bead core 11a and a bead filler 11b disposed on the outer side of the bead core 11a in the tire radial direction A. The tire 1 includes a carcass 14 spanning between the pair of bead cores 11a. The carcass 14 includes a carcass ply in which carcass cords, such as organic fiber cords or steel cords, are arranged. The tire 1 further includes a belt 15 disposed on the outer side of a crown portion of the carcass 14 in the tire radial direction A. The belt 15 includes a belt ply in which belt cords, such as organic fiber cords or steel cords, are arranged. The belt ply of the belt 15 may include an inclined belt layer in which the belt cords are inclined at an angle of 10° or more with respect to the tire circumferential direction C. The belt ply of the belt 15 may also include a circumferential belt layer in which the belt cords extend along the tire circumferential direction C. "The belt cords extend along the tire circumferential direction" means that the inclination angle of the belt cords with respect to the tire circumferential direction C is 0° or more and less than 10°. Furthermore, the belt 15 may include a plurality of belt plies stacked in the tire radial direction A, each of which includes at least one of the above-mentioned inclined belt layer and circumferential belt layer.

[0018] The tire 1 also includes a tread rubber 17 disposed on the outer side of the belt 15 in the tire radial direction A, and a side rubber 18 disposed on the outer side of the side portion of the carcass 14 in the tire width direction B. A plurality of circumferential grooves 2 and a tread land portion 3 are formed on the tread surface T, which will be described in detail later (see FIG. 2 ). The tire 1 also includes an inner liner 16 laminated on the inner surface of the carcass 14.

[0019] Although the tire 1 of the present embodiment has the above-described internal structure, the internal structure is not particularly limited, and the tire may have another internal structure. Also, the tire 1 of the present embodiment has a tread pattern formed on the tread surface T having an asymmetric pattern that is asymmetric with respect to the tire equatorial plane CL, but is not limited to this structure, and may have a symmetric structure with respect to the tire equatorial plane CL.

[0020] 2 is a developed view showing a portion of a tread surface T of a tread portion 13 of a tire 1. The tire 1 includes, on the tread surface T, a circumferential groove 2 extending along the tire circumferential direction C, and a tread land portion 3, one side of which in the tire width direction B is defined by the circumferential groove 2. The circumferential groove 2 in this embodiment is an annular groove extending endlessly in the tire circumferential direction C. In a developed view of the tread surface T (see FIG. 2), the circumferential groove 2 in this embodiment extends linearly in the tire circumferential direction C, but is not limited to this configuration. In a developed view of the tread surface T (see FIG. 2), the circumferential groove 2 may extend in a zigzag or wavy pattern.

[0021] Specifically, the tire 1 of this embodiment has four circumferential grooves 2 on the tread surface T. Five tread land portions 3 are defined between the four circumferential grooves 2 and between the circumferential groove 2 located outermost in the tire width direction B and the tread edge.

[0022] More specifically, in this embodiment, two inner circumferential grooves 2a and two outer circumferential grooves 2b are formed on the tread surface T. The two inner circumferential grooves 2a define a rib-shaped central land portion 3a as the tread land portion 3 between them in the tire width direction B. The central land portion 3a intersects with the tire equatorial plane CL. The two outer circumferential grooves 2b are located outward of the two inner circumferential grooves 2a in the tire width direction B. The inner circumferential groove 2a and the outer circumferential groove 2b define a rib-shaped intermediate land portion 3b as the tread land portion 3 between them in the tire width direction B. Furthermore, the outer circumferential groove 2b and the tread edge TE define a shoulder land portion 3c as the tread land portion 3 between them in the tire width direction B. The intermediate land portion 3b is located between the central land portion 3a and the shoulder land portion 3c in the tire width direction B.

[0023] In this embodiment, the circumferential grooves 2 include the two inner circumferential grooves 2 a and the two outer circumferential grooves 2 b described above, but there are no particular limitations on the number of circumferential grooves 2 and their positions in the tire width direction B. Therefore, for example, three or less or five or more circumferential grooves 2 may be formed on the tread surface T.

[0024] As shown in FIG. 2 , in the central land portion 3a of this embodiment, sipes 4 are formed, one end of which communicates with the inner circumferential groove 2a located on one side in the tire width direction B and the other end of which terminates within the central land portion 3a. The sipes 4 are narrow grooves with a maximum width of 1 mm or less. The maximum width of the sipes 4 is narrower than the minimum width of the circumferential grooves 2. The sipes 4 of this embodiment extend at an angle with respect to the tire width direction B and the tire circumferential direction C, but may also extend along the tire width direction B, for example. The sipes 4 are arranged at regular intervals in the tire circumferential direction C over the entire area of ​​the tire circumferential direction C. When the sipes 4 come into contact with the road surface, both side walls abut and close.

[0025] 2, a resonator 5 is disposed in the intermediate land portion 3b of this embodiment. The resonator 5 is a Helmholtz resonator including an air chamber 6 and a narrowed neck 7.

[0026] The resonator 5 as a Helmholtz resonator can be modeled as a shape as shown in FIG. 4, and its resonant frequency f ０ is the extension length of the constricted neck 7, ０ When the cross-sectional area is S, the volume of the air chamber 6 is V, and the sound speed is c, it can be expressed by the following equation (1).

[0027]

[0028] However, the length of the constricted neck 7 is l ０ is preferably not an actually measured value but an effective value corrected for the opening end, taking into consideration that in addition to the air inside the resonator 5, the air around the opening also vibrates.

[0029] Therefore, the resonant frequency f ０ is the cross-sectional area S of the constricted neck 7, and the length l of the constricted neck 7. ０ , and the volume V of the air chamber 6. In addition, when there are multiple constriction necks 7 connected to one air chamber 6, it has been found that there is no practical problem in performing calculations by regarding the multiple constriction necks 7 as equivalent to a single constriction neck 7 having a cross-sectional area equal to the sum of the cross-sectional areas of the multiple constriction necks 7 and an extension length equal to the average length of the multiple constriction necks 7.

[0030] In this embodiment, a first resonator 5a serving as a resonator 5 is disposed in one intermediate land portion 3b1 of the two intermediate land portions 3b. In this embodiment, a second resonator 5b serving as a resonator 5 is disposed in the other intermediate land portion 3b2 of the two intermediate land portions 3b. Hereinafter, for convenience of explanation, the intermediate land portion 3b1 on which the first resonator 5a is disposed will be referred to as the "first intermediate land portion 3b1," and the other intermediate land portion 3b2 on which the second resonator 5b is disposed will be referred to as the "second intermediate land portion 3b2."

[0031] FIG. 3 is an enlarged view of the first resonator 5a in FIG. 2 . As shown in FIGS. 2 and 3 , the first resonator 5a of the first intermediate land portion 3b1 includes an air chamber groove 6a serving as an air chamber 6 and a neck groove 7a serving as a narrowed neck 7. The air chamber groove 6a opens onto the surface of the first intermediate land portion 3b1 serving as the tread land portion 3 and terminates within the first intermediate land portion 3b1. More specifically, both ends of the air chamber groove 6a terminate within the first intermediate land portion 3b1. The neck groove 7a communicates between the air chamber groove 6a and the inner circumferential groove 2a serving as the circumferential groove 2. More specifically, one end of the neck groove 7a communicates with the inner circumferential groove 2a. The other end of the neck groove 7a communicates with the air chamber groove 6a.

[0032] Furthermore, in this embodiment, the air chamber groove 6a and the neck groove 7a extend at an incline with respect to the tire width direction B and the tire circumferential direction C. Furthermore, the air chamber groove 6a and the neck groove 7a in this embodiment are inclined to the same side with respect to the tire circumferential direction C. However, as shown in FIG. 3 , the inclination angle θ1 of the air chamber groove 6a with respect to the tire circumferential direction C is smaller than the inclination angle θ2 of the neck groove 7a with respect to the tire circumferential direction C. Note that the inclination angle θ1 of the air chamber groove 6a with respect to the tire circumferential direction C is the inclination angle with respect to the tire circumferential direction C of a straight line L1 (see FIG. 3 ) that passes through both ends of the air chamber groove 6a in the tire circumferential direction C in the developed view of the tread surface T (see FIGS. 2 and 3 ). If the end of the air chamber groove 6a in the tire circumferential direction C is not determined to be a single point, the end of the air chamber groove 6a in the tire circumferential direction C means the midpoint in the tire width direction B. The inclination angle θ2 of the neck groove 7a with respect to the tire circumferential direction C is the inclination angle of a straight line L2 (see FIG. 3) passing through both ends of the neck groove 7a in the tire circumferential direction C with respect to the tire circumferential direction C in a developed view of the tread surface T (see FIGS. 2 and 3). When the end of the neck groove 7a in the tire circumferential direction C is not determined to be a single point, the end of the neck groove 7a in the tire circumferential direction C means the midpoint in the tire width direction B.

[0033] By having the air chamber grooves 6a extend at an angle relative to the tire width direction B and the tire circumferential direction C, it is easier to ensure the extension length of the air chamber grooves 6a within the range of the ground contact length, compared to a configuration in which the air chamber grooves 6a extend along the tire width direction B or the tire circumferential direction C. This makes it easier to ensure the volume of the air chamber grooves 6a, and it is easy to deal with cases in which the frequency of the air column resonance noise to be reduced is low (see formula (1) above).

[0034] 3, the extension length D1 of the air chamber groove 6a in the tire circumferential direction C is longer than the extension length D2 of the air chamber groove 6a in the tire width direction B. This makes it easier to ensure the extension length of the air chamber groove 6a within the range of the ground contact length, compared to a configuration in which the air chamber groove 6a extends along the tire width direction B or the tire circumferential direction C. This makes it easier to ensure the volume of the air chamber groove 6a, and makes it easier to deal with cases in which the frequency of the air column resonance noise to be reduced is low (see formula (1) above).

[0035] Furthermore, by having the air chamber grooves 6a extend at an angle with respect to the tire width direction B and the tire circumferential direction C, localized reduction in rigidity in the tire width direction B of the first intermediate land portion 3b1 as the tread land portion 3 is less likely to occur in the range of the tire circumferential direction C where the air chamber grooves 6a are provided, compared to a configuration in which the air chamber grooves 6a extend along the tire circumferential direction C. Furthermore, by having the air chamber grooves 6a extend at an angle with respect to the tire width direction B and the tire circumferential direction C, localized reduction in rigidity at the position where the air chamber grooves 6a are provided in the tire circumferential direction C can be suppressed, compared to a configuration in which the air chamber grooves 6a extend along the tire width direction B. In this way, by having the air chamber grooves 6a extend at an angle with respect to the tire width direction B and the tire circumferential direction C, localized reduction in rigidity at the position of the air chamber grooves 6a can be suppressed.

[0036] In other words, by configuring the air chamber groove 6a to extend at an angle relative to the tire width direction B and the tire circumferential direction C, and the extension length D1 of the air chamber groove 6a in the tire circumferential direction C to be longer than the extension length D2 in the tire width direction B, it becomes easier to achieve both quietness and driving performance in the tire 1.

[0037] In this embodiment, as described above, the neck groove 7a is also inclined with respect to the tire width direction B and the tire circumferential direction C, but is not limited to this configuration. The neck groove 7a may extend, for example, along the tire width direction B. However, as in this embodiment, it is preferable that the neck groove 7a extend at an incline with respect to the tire width direction B and the tire circumferential direction C. By doing so, it is easy to ensure the extension length of the neck groove 7a within the range of the contact length, and it is easy to deal with cases where the frequency of the air column resonance noise to be reduced is low (see formula (1) above).

[0038] The inclination angle θ2 of the neck groove 7a with respect to the tire circumferential direction C is preferably 30 to 70°, and more preferably 40 to 55°. By setting the inclination angle θ2 to 30° or more, it is easy to suppress a local decrease in rigidity in the tire width direction B of the first intermediate land portion 3b1 as the tread land portion 3 within the range of the tire circumferential direction C in which the neck groove 7a is provided. Furthermore, by setting the inclination angle θ2 to 70° or less, it is easy to ensure that the neck groove 7a has a desired extension length.

[0039] As described above, the neck grooves 7a in this embodiment are inclined to the same side as the air chamber grooves 6a with respect to the tire circumferential direction C, but they may be inclined to the opposite side with respect to the tire circumferential direction C. However, as in this embodiment, it is preferable that the neck grooves 7a are inclined to the same side as the air chamber grooves 6a with respect to the tire circumferential direction C. By doing so, it is possible to prevent the air chamber grooves 6a and the neck grooves 7a from being concentrated in a part of the tire width direction B or the tire circumferential direction C in the first intermediate land portion 3b1 as the tread land portion 3.

[0040] As shown in Fig. 2, the neck groove 7a of this embodiment extends so as to overlap an extension line of the sipe 4 of the central land portion 3a in the extending direction. This can improve the design.

[0041] 3, in this embodiment, the extension length D3 of the neck groove 7a in the tire circumferential direction C is shorter than the extension length D4 of the neck groove 7a in the tire width direction B. However, the extension length D3 of the neck groove 7a in the tire circumferential direction C may be longer than or equal to the extension length D4 of the neck groove 7a in the tire width direction B.

[0042] Furthermore, the first resonator 5 a of the present embodiment has only one neck groove 7 a. This makes it possible to suppress a decrease in rigidity due to the first resonator 5 a in the first intermediate land portion 3 b 1 of the tread land portion 3, compared to when there are multiple neck grooves 7 a.

[0043] In the first resonator 5a, the neck groove 7a is narrower than the air chamber groove 6a. Here, "the neck groove 7a is narrower than the air chamber groove 6a" means that the maximum width W2max of the neck groove 7a is narrower than the maximum width W1max of the air chamber groove 6a. The width W2 of the neck groove 7a means the length in a direction perpendicular to the above-mentioned straight line L2 in a developed view of the tread surface T (see FIGS. 2 and 3). Therefore, the maximum width W2max of the neck groove 7a is the maximum value of the width W2 of the neck groove 7a. Furthermore, the width W1 of the air chamber groove 6a means the length in a direction perpendicular to the above-mentioned straight line L1 in a developed view of the tread surface T (see FIGS. 2 and 3). Therefore, the maximum width W1max of the air chamber groove 6a is the maximum value of the width W1 of the air chamber groove 6a.

[0044] The minimum width of the neck groove 7a is wider than the maximum width of any of the above-mentioned sipe 4, as well as the first sipe 8, second sipe 9, narrow portion 51a of the connecting groove 51, circumferential sipe 52, and widthwise sipes 53a, 53b (hereinafter sometimes referred to as "sipe 4, etc.").

[0045] The neck groove 7a of the present embodiment may also have a widened portion in which the width W2 is widened on the groove bottom side, which is on the inner side in the tire radial direction A from the tread surface T side.

[0046] 3, the opening angle θ3 at the position where the neck groove 7a connects to the air chamber groove 6a is 170 to 200°. The opening angle θ3 is the angle formed by the first wall 21 of the air chamber groove 6a and the second wall 22 of the air chamber groove 6a in a developed view of the tread surface T. The first wall 21 of the air chamber groove 6a is the wall of the air chamber groove 6a to which one side wall 23 of the neck groove 7a connects. The second wall 22 of the air chamber groove 6a is the wall of the air chamber groove 6a to which the other side wall 24 of the neck groove 7a connects. When the first wall 21 and the second wall 22 of the air chamber groove 6a are curved in a developed view of the tread surface T, the opening angle θ3 means the angle formed by the tangent at the position where the first wall 21 connects to one side wall 23 of the neck groove 7a and the tangent at the position where the second wall 22 connects to the other side wall 24 of the neck groove 7a.

[0047] As shown in Figure 3, the first wall 21 and the second wall 22 of the air chamber groove 6a in this embodiment are one of the inclined side walls 6a1 of the air chamber groove 6a, which extend at an angle relative to the tire width direction B and the tire circumferential direction C. In other words, the neck groove 7a in this embodiment is connected to the air chamber groove 6a at a middle portion of the inclined side wall 6a1 of the air chamber groove 6a, excluding the ends. By making the wall of the air chamber groove 6a to which the neck groove 7a is connected the inclined side wall 6a1 in this way, it becomes easier to ensure the opening angle θ3 of 170 to 200° described above.

[0048] More specifically, the air chamber groove 6a of this embodiment has one inclined side wall 6a1 to which the neck groove 7a is connected, and the other inclined side wall 6a2 that faces the one inclined side wall 6a1 and is inclined to the same side as the one inclined side wall 6a1 with respect to the tire circumferential direction C.

[0049] The air chamber groove 6a of this embodiment includes a gradually increasing portion 31, a maximum width portion 32, and a gradually decreasing portion 33 extending in one direction in the tire circumferential direction C (upward in FIGS. 2 and 3). The maximum width portion 32 is a portion where the width W1 between one inclined sidewall 6a1 and the other inclined sidewall 6a2 is a maximum width W1max. Here, the width W1 between one inclined sidewall 6a1 and the other inclined sidewall 6a2 has the same meaning as the width W1 of the air chamber groove 6a described above. The gradually increasing portion 31 is a portion where the width W1 gradually increases to the maximum width portion 32 extending in one direction in the tire circumferential direction C (upward in FIGS. 2 and 3). The gradually decreasing portion 33 extends from the maximum width portion 32 in one direction in the tire circumferential direction C (upward in FIGS. 2 and 3) and where the width W1 gradually decreases.

[0050] 3, in this embodiment, the length D1a of the gradually increasing portion 31 in the tire circumferential direction C is longer than the length D1b of the gradually decreasing portion 33 in the tire circumferential direction C. Furthermore, the neck groove 7a is continuous with one of the inclined side walls 6a1 at the gradually increasing portion 31 of the air chamber groove 6a.

[0051] The first resonators 5 a are arranged at regular intervals in the tire circumferential direction C, all over the tire circumferential direction C. The arrangement intervals of the first resonators 5 a in the tire circumferential direction C are wider than the arrangement intervals of the sipes 4 in the central land portion 3 a in the tire circumferential direction C.

[0052] As shown in FIG. 2 , the first intermediate land portion 3b1 of this embodiment is formed with first sipes 8, one end of which is continuous with the outer circumferential groove 2b located on the outside in the tire width direction B and the other end of which terminates within the first intermediate land portion 3b1. Like the sipes 4 described above, the first sipes 8 are narrow grooves with a maximum width of 1 mm or less. The maximum width of the first sipes 8 is narrower than the minimum width of the circumferential groove 2. The first sipes 8 of this embodiment extend at an incline with respect to the tire width direction B and the tire circumferential direction C. The first sipes 8 of this embodiment are inclined toward the same side with respect to the tire circumferential direction C as the sipes 4 of the central land portion 3a described above. Furthermore, the first sipes 8 of this embodiment are inclined toward the same side with respect to the tire circumferential direction C as the air chamber groove 6a and neck groove 7a described above. The first sipes 8 are arranged at regular intervals in the tire circumferential direction C throughout the tire circumferential direction C. The spacing between the first sipes 8 in the tire circumferential direction C is wider than the spacing between the sipes 4 in the central land portion 3a described above in the tire circumferential direction C. Furthermore, the spacing between the first sipes 8 in the tire circumferential direction C is substantially equal to the spacing between the first resonators 5a described above in the tire circumferential direction C. In this embodiment, the first sipes 8 and the first resonators 5a are arranged so that an end of one side (the lower side in FIG. 2 ) of the first sipe 8 in the tire circumferential direction C and an end of one side (the lower side in FIG. 2 ) of the first resonator 5a in the tire circumferential direction C (one end of the air chamber groove 6a in this embodiment) are positioned at the same position in the tire circumferential direction C. When the first sipe 8 comes into contact with the road surface, both side walls abut and close.

[0053] As shown in FIG. 2 , the first intermediate land portion 3b1 of this embodiment is formed with a second sipe 9, one end of which is connected to the inner circumferential groove 2a located on the inner side in the tire width direction B and the other end of which terminates within the first intermediate land portion 3b1. Like the sipes 4 and first sipes 8 described above, the second sipe 9 is a narrow groove with a maximum width of 1 mm or less. The maximum width of the second sipe 9 is narrower than the minimum width of the circumferential groove 2. The second sipe 9 of this embodiment includes a base end 9a extending at an angle with respect to the tire width direction B and the tire circumferential direction C, a tip end 9b having a smaller angle of inclination with respect to the tire circumferential direction C than the base end 9a, and a curved portion 9c connecting the base end 9a and the tip end 9b. One end of the base end 9a is connected to the inner circumferential groove 2a. The other end of the base end 9a is connected to the curved portion 9c. One end of the tip end 9b terminates within the first intermediate land portion 3b1. The other end of the tip portion 9b is connected to a curved portion 9c.

[0054] As shown in FIG. 2, the base end portion 9a of the second sipe 9 extends so as to overlap an extension line of the sipe 4 of the central land portion 3a in the extending direction.

[0055] As shown in FIG. 2, the tip end 9b of the second sipe 9 extends so as to overlap an extension line of the air chamber groove 6a of the first resonator 5a in the extending direction.

[0056] The second sipes 9 are arranged at regular intervals in the tire circumferential direction C over the entire area in the tire circumferential direction C. The arrangement interval of the second sipes 9 in the tire circumferential direction C is wider than the arrangement interval of the sipes 4 in the central land portion 3a in the tire circumferential direction C described above. The arrangement interval of the second sipes 9 in the tire circumferential direction C is also approximately equal to the arrangement interval of the first sipes 8 and the first resonators 5a in the tire circumferential direction C described above. However, the first sipes 8 and the second sipes 9 are arranged at different positions in the tire circumferential direction C. When the second sipes 9 come into contact with the road surface, both side walls abut and close.

[0057] As shown in FIG. 2 , the second resonator 5b of the second intermediate land portion 3b2 includes an air chamber groove 6b as an air chamber 6 and a neck groove 7b as a narrowed neck 7. The air chamber groove 6b opens to the surface of the second intermediate land portion 3b2 as the tread land portion 3 and terminates within the second intermediate land portion 3b2. More specifically, both ends of the air chamber groove 6b terminate within the second intermediate land portion 3b2. The neck groove 7b communicates between the air chamber groove 6b and the inner circumferential groove 2a as the circumferential groove 2. More specifically, one end of the neck groove 7b communicates with the inner circumferential groove 2a. The other end of the neck groove 7b communicates with the air chamber groove 6b.

[0058] Furthermore, in this embodiment, the air chamber groove 6b and the neck groove 7b extend at an incline with respect to the tire width direction B and the tire circumferential direction C. Furthermore, the air chamber groove 6b and the neck groove 7b in this embodiment are inclined to the same side with respect to the tire circumferential direction C. However, as shown in FIG. 2 , the inclination angle θ4 of the air chamber groove 6b with respect to the tire circumferential direction C is smaller than the inclination angle θ5 of the neck groove 7b with respect to the tire circumferential direction C. Note that the inclination angle θ4 of the air chamber groove 6b with respect to the tire circumferential direction C is the inclination angle with respect to the tire circumferential direction C of a straight line L3 (see FIG. 2 ) that passes through both ends of the air chamber groove 6b in the tire circumferential direction C in a developed view of the tread surface T (see FIG. 2 ). When the end of the air chamber groove 6b in the tire circumferential direction C is not determined to be a single point, the end of the air chamber groove 6b in the tire circumferential direction C means the midpoint in the tire width direction B. The inclination angle θ5 of the neck groove 7b with respect to the tire circumferential direction C is the inclination angle of a straight line L4 (see FIG. 2) passing through both ends of the neck groove 7b in the tire circumferential direction C with respect to the tire circumferential direction C in a developed view of the tread surface T (see FIG. 2). When the end of the neck groove 7b in the tire circumferential direction C is not determined to be a single point, the end of the neck groove 7b in the tire circumferential direction C means the midpoint in the tire width direction B.

[0059] Here, the air chamber groove 6b and neck groove 7b of the second resonator 5b of this embodiment are inclined toward the same side with respect to the tire circumferential direction C as the air chamber groove 6a and neck groove 7a of the first resonator 5a described above.

[0060] 2, the extension length D5 of the air chamber groove 6b in the tire circumferential direction C is longer than the extension length D6 of the air chamber groove 6b in the tire width direction B. However, the extension length D5 of the air chamber groove 6b in the tire circumferential direction C is shorter than the extension length D1 of the first resonator 5a in the tire circumferential direction C.

[0061] As described above, the neck groove 7b in this embodiment is inclined with respect to the tire width direction B and the tire circumferential direction C, but is not limited to this configuration. The neck groove 7b may extend along the tire width direction B, for example.

[0062] As described above, the neck grooves 7b in this embodiment are inclined to the same side as the air chamber grooves 6b with respect to the tire circumferential direction C, but they may be inclined to the opposite side with respect to the tire circumferential direction C. However, as in this embodiment, it is preferable that the neck grooves 7b are inclined to the same side as the air chamber grooves 6b with respect to the tire circumferential direction C. By doing so, it is possible to prevent the air chamber grooves 6b and the neck grooves 7b from being concentrated in a part of the tire width direction B or the tire circumferential direction C in the second intermediate land portion 3b2 as the tread land portion 3.

[0063] As shown in Fig. 2, the neck groove 7b of this embodiment extends so as to overlap an extension line of the sipe 4 of the central land portion 3a in the extending direction. This can improve the design.

[0064] Furthermore, the second resonator 5b of this embodiment has only one neck groove 7b, but may have a plurality of neck grooves.

[0065] In the second resonator 5b, the neck groove 7b is narrower than the air chamber groove 6b. Here, "the neck groove 7b is narrower than the air chamber groove 6b" means that the maximum width W4max of the neck groove 7b is narrower than the maximum width W3max of the air chamber groove 6b. The width W4 of the neck groove 7b means the length in a direction perpendicular to the above-mentioned straight line L4 in a developed view of the tread surface T (see FIG. 2). Therefore, the maximum width W4max of the neck groove 7b is the maximum value of the width W4 of the neck groove 7b. Furthermore, the width W3 of the air chamber groove 6b means the length in a direction perpendicular to the above-mentioned straight line L3 in a developed view of the tread surface T (see FIG. 2). Therefore, the maximum width W3max of the air chamber groove 6b is the maximum value of the width W3 of the air chamber groove 6b.

[0066] The neck groove 7b of the present embodiment may also have a widened portion in which the width W4 is widened on the groove bottom side, which is on the inner side in the tire radial direction A from the tread surface T side.

[0067] 2, the opening angle θ6 at the position where the neck groove 7b connects to the air chamber groove 6b is 1 to 45°. The opening angle θ6 is the angle formed by the first wall 41 of the air chamber groove 6b and the second wall 42 of the air chamber groove 6b in a developed view of the tread surface T. The first wall 41 of the air chamber groove 6b is the wall of the air chamber groove 6b to which one side wall 43 of the neck groove 7b connects. The second wall 42 of the air chamber groove 6b is the wall of the air chamber groove 6b to which the other side wall 44 of the neck groove 7b connects. When the first wall 41 and the second wall 42 of the air chamber groove 6b are curved in a developed view of the tread surface T, the opening angle θ6 refers to the angle formed by the tangent line at the position where the first wall 41 connects to one side wall 43 of the neck groove 7b and the tangent line at the position where the second wall 42 connects to the other side wall 44 of the neck groove 7b.

[0068] As shown in FIG. 2, the neck groove 7b of this embodiment communicates with the air chamber groove 6b at the end of the air chamber groove 6b in the tire circumferential direction C.

[0069] The second resonators 5b are arranged at regular intervals in the tire circumferential direction C, over the entire area in the tire circumferential direction C. The arrangement intervals of the second resonators 5b in the tire circumferential direction C are narrower than the arrangement intervals of the above-described first resonators 5a in the tire circumferential direction C.

[0070] The second resonator 5b of this embodiment includes an air chamber groove 6b as the air chamber 6, but is not limited to this configuration and may be, for example, a recessed portion that is not a groove.

[0071] The tire 1 has two shoulder land portions 3c on the tread surface T. Hereinafter, for convenience of explanation, of the two shoulder land portions 3c, the shoulder land portion 3c1 located on the outer side in the tire width direction B of the first intermediate land portion 3b1 where the first resonator 5a is arranged will be referred to as the "first shoulder land portion 3c1." Also, of the two shoulder land portions 3c, the shoulder land portion 3c2 located on the outer side in the tire width direction B of the second intermediate land portion 3b2 where the second resonator 5b is arranged will be referred to as the "second shoulder land portion 3c2." Hereinafter, when there is no need to particularly distinguish between the first shoulder land portion 3c1 and the second shoulder land portion 3c2, they will simply be referred to as the "shoulder land portion 3c."

[0072] As shown in Fig. 2, a communicating groove 51 is formed in the shoulder land portion 3c as the tread land portion 3. The communicating groove 51 traverses the shoulder land portion 3c in the tire width direction B. One end of the communicating groove 51 is connected to the outer circumferential groove 2b as the circumferential groove 2. The other end of the communicating groove 51 is located outward in the tire width direction B from the tread edge TE. In other words, the communicating groove 51 extends from the inner side to the outer side in the tire width direction B with respect to the tread edge TE.

[0073] Fig. 5 is a cross-sectional view perpendicular to the extension direction of the communicating groove 51. As shown in Fig. 5, the communicating groove 51 has a widened portion 51b on the groove bottom side where the groove width is widened. More specifically, the communicating groove 51 of this embodiment has a narrowed portion 51a extending inward in the tire radial direction A from the tread surface T, and a widened portion 51b that is wider than the narrowed portion 51a and continues to the inside of the narrowed portion 51a in the tire radial direction A.

[0074] The narrow width portion 51a in this embodiment is a thin groove with a maximum width of 1 mm or less. The maximum width of the narrow width portion 51a in this embodiment is narrower than the minimum width of the circumferential groove 2. When the shoulder land portion 3c comes into contact with the road surface, the narrow width portion 51a is closed by the side walls on both sides coming into contact with each other, but the wide width portion 51b is not closed. Therefore, even when the shoulder land portion 3c comes into contact with the road surface, the wide width portion 51b communicates with the outer circumferential groove 2b and a position on the outer surface of the tire 1 that is outward of the tread edge TE in the tire width direction B.

[0075] By providing such a communicating groove 51 in the shoulder land portion 3c, the air column resonance noise of the outer circumferential groove 2b, where the first resonator 5a and the second resonator 5b are not connected, can be reduced by the widened portion 51b of the communicating groove 51.

[0076] 2, the communication grooves 51 of the present embodiment are inclined with respect to the tire width direction B and the tire circumferential direction C, but are not limited to this configuration. The communication grooves 51 may also extend along the tire width direction B.

[0077] The communicating grooves 51 of this embodiment are arranged at regular intervals in the tire circumferential direction C, over the entire area in the tire circumferential direction C. The arrangement interval of the communicating grooves 51 in the tire circumferential direction C is approximately equal to the arrangement interval of the sipes 4 in the central land portion 3 a in the tire circumferential direction C. Furthermore, the arrangement interval of the communicating grooves 51 in the tire circumferential direction C is narrower than the arrangement interval of the first resonators 5 a in the tire circumferential direction C.

[0078] 2, the first sipe 8 of the first intermediate land portion 3b1 described above extends so as to overlap with an extension line of the communicating groove 51 of the first shoulder land portion 3c1 in the extending direction. This can improve the design.

[0079] Additionally, circumferential sipes 52 extending along the tire circumferential direction C are formed in the shoulder land portion 3c. The circumferential sipes 52 are annular sipes extending over the entire tire circumferential direction C so as to intersect with the above-mentioned communicating grooves 51. The circumferential sipes 52 are narrow grooves with a maximum width of 1 mm or less. In this embodiment, the maximum width of the circumferential sipes 52 is narrower than the minimum width of the circumferential grooves 2. When the shoulder land portion 3c comes into contact with the road surface, the circumferential sipes 52 are closed by abutting on both side walls.

[0080] The first shoulder land portion 3c1 is formed with widthwise sipes 53a located between two adjacent communicating grooves 51 in the tire circumferential direction C. The widthwise sipes 53a communicate with the circumferential sipes 52 on the inner side in the tire width direction B. The widthwise sipes 53a extend from the tread edge TE to the outer side in the tire width direction B. The widthwise sipes 53a are narrow grooves with a maximum width of 1 mm or less. In this embodiment, the maximum width of the widthwise sipes 53a is narrower than the minimum width of the circumferential groove 2. When the first shoulder land portion 3c1 comes into contact with the road surface, the side walls of the widthwise sipes 53a abut and close.

[0081] The second shoulder land portion 3c2 is formed with widthwise sipes 53b located between two adjacent communicating grooves 51 in the tire circumferential direction C. The widthwise sipes 53b are not connected to the circumferential sipes 52 on the inner side in the tire width direction B. The widthwise sipes 53b extend from the tread edge TE to the outer side in the tire width direction B. The widthwise sipes 53b are narrow grooves with a maximum width of 1 mm or less. In this embodiment, the maximum width of the widthwise sipes 53b is narrower than the minimum width of the circumferential groove 2. When the first shoulder land portion 3c1 comes into contact with the road surface, the sidewalls on both sides of the widthwise sipes 53b come into contact with each other and are closed.

[0082] As shown in FIG. 2, the outer ends in the tire width direction B of the communicating grooves 51 and width-direction sipes 53a of the first shoulder land portion 3c1 and the communicating grooves 51 and width-direction sipes 53b of the second shoulder land portion 3c2 may be connected to, for example, recesses 1a formed on the outer surface of the tire 1.

[0083] As described above, the tire 1 of this embodiment includes, on the tread surface T, the tread land portion 3, which includes the central land portion 3a, the first intermediate land portion 3b1, the second intermediate land portion 3b2, the first shoulder land portion 3c1, and the second shoulder land portion 3c2. In the tire 1 of this embodiment, the first resonator 5a is disposed in the first intermediate land portion 3a1. However, the tread land portion 3 in which the first resonator 5a is disposed is not limited to the first intermediate land portion 3b1. The first resonator 5a may be disposed in the central land portion 3a. Furthermore, the first resonator 5a may be disposed in the first shoulder land portion 3c1 or the second shoulder land portion 3c2.

[0084] However, as in the present embodiment, it is preferable that the first resonator 5a be arranged in the intermediate land portion 3b adjacent to the shoulder land portion 3c across the circumferential groove 2. In other words, when the tread land portion 3 in which the first resonator 5a is arranged is defined as the "first tread land portion" (first intermediate land portion 3b1 in the present embodiment), and the circumferential groove 2 adjacent to the first tread land portion on one side in the tire width direction B and communicating with the neck groove 7a of the first resonator 5a is defined as the "first circumferential groove" (inner circumferential groove 2a in the present embodiment), it is preferable that the tire 1 include, on the tread surface T, a second circumferential groove (outer circumferential groove 2b in the present embodiment) that defines the other side in the tire width direction B of the first tread land portion. Furthermore, it is preferable that the tire 1 include, on the tread surface T, a second tread land portion (first shoulder land portion 3c1 in the present embodiment) defined between the second circumferential groove and the tread edge TE. It is preferable to provide the above-mentioned communicating groove 51 in the second tread land portion.

[0085] In this manner, the first resonator 5a can reduce air column resonance noise of the first circumferential groove (inner circumferential groove 2a in this embodiment) located on one side in the tire width direction B of the first tread land portion (first intermediate land portion 3b1 in this embodiment). Also, the widened portion 51b of the communicating groove 51 can reduce air column resonance noise of the second circumferential groove (outer circumferential groove 2b in this embodiment) located on the other side in the tire width direction B of the first tread land portion (first intermediate land portion 3b1 in this embodiment). In other words, even in a configuration in which the first resonator 5a of the first tread land portion (first intermediate land portion 3b1 in this embodiment) is connected only to the first circumferential groove (inner circumferential groove 2a in this embodiment), the communicating groove 51 of the second tread land portion (first shoulder land portion 3c1 in this embodiment) can also be used to reduce air column resonance noise of the second circumferential groove (outer circumferential groove 2b in this embodiment).

[0086] Furthermore, as shown in FIG. 2 , the tread pattern formed on the tread surface T of this embodiment is not a symmetric pattern that is point-symmetric with respect to a point on the tire equatorial plane CL. In other words, the tread pattern formed on the tread surface T of this embodiment is an asymmetric pattern. In such a case, the first resonator 5a is preferably disposed at a position that is on the vehicle inner side with respect to the tire equatorial plane CL when mounted on a vehicle. As described above, the first resonator 5a of this embodiment can suppress localized reduction in rigidity at the position of the air chamber groove 6a. Therefore, even on the vehicle inner side, where the impact of reduced rigidity is greater than on the vehicle outer side when mounted on a vehicle, it is easy to dispose the first resonator 5a, thereby achieving both quietness and driving performance.

[0087] The tire according to the present invention is not limited to the specific configurations shown in the above-described embodiments, and various modifications, changes, and combinations are possible without departing from the scope of the claims.

[0088] In the above-described embodiment, the relationship between the widths of the central land portion 3a, the intermediate land portion 3b, and the shoulder land portion 3c in the tire width direction B is not particularly limited, but as shown in Fig. 6, the width of the central land portion 3a is preferably larger than the width of the shoulder land portion 3c. This increases the rigidity of the central land portion 3a and improves steering stability. Furthermore, as shown in Figs. 2 and 6, the width of the central land portion 3a is preferably smaller than the width of the intermediate land portion 3b.

[0089] As described above, the neck groove 7a of the first resonator 5a and the neck groove 7b of the second resonator 5b may have a widened portion whose width increases from the tread surface T toward the groove bottom, which is on the inner side in the tire radial direction A. However, when a widened portion is provided in at least one of the neck grooves 7a of the first resonator 5a and the neck grooves 7b of the second resonator 5b, it is particularly preferable to provide a widened portion only in the neck groove 7b of the second resonator 5b that is on the outer side of the vehicle relative to the tire equatorial plane CL when mounted on the vehicle, and not to provide a widened portion in the neck groove 7a of the first resonator 5a that is on the inner side of the vehicle relative to the tire equatorial plane CL when mounted on the vehicle. As described above, the first intermediate land portion 3b1 that is on the inner side of the vehicle when mounted on the vehicle is more susceptible to a decrease in rigidity than the second intermediate land portion 3b2 that is on the outer side of the vehicle when mounted on the vehicle. Therefore, even if an expanded portion is provided in the neck groove 7 b of the second resonator 5 b of the second intermediate land portion 3 b 2 that faces the vehicle outer side when mounted on the vehicle, the impact of reduced rigidity due to the provision of the expanded portion can be reduced compared to a configuration in which an expanded portion is provided in the neck groove 7 a of the first resonator 5 a of the first intermediate land portion 3 b 1 that faces the vehicle inner side when mounted on the vehicle. In this way, by providing an expanded portion only in the neck groove 7 b of the second resonator 5 b that faces the vehicle outer side with respect to the tire equatorial plane CL when mounted on the vehicle, the impact of reduced rigidity due to the expanded portion can be reduced, and by adjusting the cross-sectional area of ​​the neck groove 7 b using the expanded portion, it is possible to adjust the sound deadening performance of the entire tire 1.

[0090] Furthermore, if the amount of sipes formed in the second intermediate land portion 3b2 is smaller than the amount of sipes formed in the first intermediate land portion 3b1, the effect of reducing rigidity due to the provision of the widened portion can be further reduced. The amount of sipes is the total length of the sipes. In the above-described embodiment, an example in which no sipes are formed in the second intermediate land portion 3b2 is shown (see FIG. 2).

[0091] Furthermore, as described above, if the width of the intermediate land portion 3b (in the above-mentioned embodiment, the first intermediate land portion 3b1 and the second intermediate land portion 3b2) is configured to be larger than that of the central land portion 3a and the shoulder land portion 3c, the effect of reduced rigidity due to the provision of an expanded portion in the second intermediate land portion 3b2 can be further reduced.

[0092] The present invention relates to a tire.

[0093] 1: tire, 1a: recess, 2: circumferential groove, 2a: inner circumferential groove (an example of a first circumferential groove), 2b: outer circumferential groove (an example of a second circumferential groove), 3: tread land portion, 3a: central land portion, 3b: intermediate land portion, 3b1: first intermediate land portion (an example of a first tread land portion), 3b2: second intermediate land portion, 3c: shoulder land portion, 3c1: first shoulder land portion (an example of a second tread land portion), 3c2: second shoulder land portion, 4: sipe, 5: resonator, 5a: first resonator, 5b: second resonator, 6: air chamber, 6a: air chamber groove of first resonator, 6a1: one inclined side wall, 6a2: the other inclined side wall, 6b: air chamber groove of second resonator, 7: narrowed neck, 7a: neck groove of first resonator, 7b: neck groove of second resonator, 8: first sipe, 9: second sipe, 9a: base end portion, 9b: tip portion, 9c: curved portion, 11: bead portion, 11a: bead core, 11b: bead filler, 12: sidewall portion, 13: tread portion, 14: carcass, 15: belt, 16: inner liner, 17: tread rubber, 18: side rubber, 21: first wall of air chamber groove of first resonator, 22: second wall of air chamber groove of first resonator, 23: one side wall of neck groove of first resonator, 24: other side wall of neck groove of first resonator, 31: gradually increasing portion, 32: maximum width portion, 33: gradually decreasing portion, 41: first wall of air chamber groove of second resonator, 42: second wall of air chamber groove of second resonator, 43: one side wall of neck groove of second resonator, 44: other side wall of neck groove of second resonator, 51: communicating groove, 51a: narrow width portion, 51b: wide width portion, 52: circumferential sipe, 53a: widthwise sipe of first shoulder land portion, 53b: widthwise sipe of second shoulder land portion, A: tire radial direction, B: tire width direction, C: tire circumferential direction, CL: tire equatorial plane, D1: extension length of air chamber groove of first resonator in the tire circumferential direction, D1a: extension length of gradually increasing portion of air chamber groove of first resonator in the tire circumferential direction, D1b: extension length of gradually decreasing portion of air chamber groove of first resonator in the tire circumferential direction, D2: extension length of air chamber groove of first resonator in the tire width direction, D3: extension length of the neck groove of the first resonator in the tire circumferential direction, D4: extension length of the neck groove of the first resonator in the tire width direction, D5: extension length of the air chamber groove of the second resonator in the tire circumferential direction, D6: extension length of the air chamber groove of the second resonator in the tire width direction,L1: a straight line passing through both ends of the air chamber groove of the first resonator in the tire circumferential direction, L2: a straight line passing through both ends of the neck groove of the first resonator in the tire circumferential direction, L3: a straight line passing through both ends of the air chamber groove of the second resonator in the tire circumferential direction, L4: a straight line passing through both ends of the neck groove of the second resonator in the tire circumferential direction, T: tread surface, TE: tread edge, W1: width of the air chamber groove of the first resonator, W2: width of the neck groove of the first resonator, W3: width of the air chamber groove of the second resonator, W4: width of the neck groove of the second resonator, θ1: inclination angle of the air chamber groove of the first resonator, θ2: inclination angle of the neck groove of the first resonator, θ3: opening angle of the first resonator, θ4: inclination angle of the air chamber groove of the second resonator, θ5: inclination angle of the neck groove of the second resonator, θ6: opening angle of the second resonator,

Claims

1. A tire having, on a tread surface, a circumferential groove extending along the tire circumferential direction, and a tread land portion defined on one side in the tire width direction by the circumferential groove, A resonator is disposed in the tread land portion, The resonator comprises: an air chamber groove that opens to a surface of the tread land portion and terminates within the tread land portion; a neck groove that is narrower than the air chamber groove and that connects the air chamber groove and the circumferential groove, an opening angle formed by a first wall of the air chamber groove, which is continuous with one side wall of the neck groove, and a second wall of the air chamber groove, which is continuous with the other side wall of the neck groove, is 170 to 200° in a developed view of the tread surface, The air chamber groove extends at an angle with respect to the tire width direction and the tire circumferential direction, A tire in which the extension length of the air chamber groove in the tire circumferential direction is longer than the extension length of the air chamber groove in the tire width direction.

2. The tire according to claim 1 , wherein the neck groove extends at an angle relative to the tire width direction and the tire circumferential direction.

3. The tire according to claim 2 , wherein the air chamber groove and the neck groove are inclined toward the same side with respect to the tire circumferential direction.

4. The tire according to claim 1 , wherein the resonator has only one neck groove.

5. The tire according to claim 1 , wherein the first wall and the second wall of the air chamber groove are one inclined side walls of the air chamber groove that extend at an angle with respect to the tire width direction and the tire circumferential direction.

6. The air chamber groove is the one inclined side wall; a second inclined sidewall that faces the first inclined sidewall and is inclined toward the same side as the first inclined sidewall with respect to the tire circumferential direction, The air chamber groove is formed in one direction in the tire circumferential direction as follows: a gradually increasing portion in which the width gradually increases to a maximum width portion in which the width between the one inclined side wall and the other inclined side wall is the maximum width; a tapered portion extending from the maximum width portion and in which the width gradually decreases, a circumferential length of the gradually increasing portion is longer than a circumferential length of the gradually decreasing portion, The tire according to claim 5 , wherein the neck groove is continuous with the one of the inclined side walls at the gradually increasing portion of the chamber groove.

7. When the circumferential groove is a first circumferential groove and the tread land portion is a first tread land portion, The tread surface further includes a second circumferential groove defining the other side of the first tread land portion in the tire width direction, and a second tread land portion defined between the second circumferential groove and a tread edge, a communicating groove extending across the second tread land portion in the tire width direction, one end of which is connected to the second circumferential groove and the other end of which is located outward of the tread edge in the tire width direction; The tire according to claim 1 , wherein the communicating groove has a widened portion at a groove bottom side where the groove width is widened.

8. The tread pattern formed on the tread surface is an asymmetric pattern, The tire according to claim 1 , wherein the resonator is disposed at a position on an inner side of the vehicle relative to the tire equatorial plane when the tire is mounted on the vehicle.