JP5396203B2 - tire - Google Patents

Description

  The present invention relates to a tire provided with a resonator that is recessed inward in the tire radial direction, forms a predetermined space when a rib-like land portion comes in contact with a road surface, and communicates with a circumferential groove.

  Conventionally, in a tire mounted on a passenger car or the like, various methods of reducing air column resonance noise caused by a space formed by a circumferential groove extending along the tire circumferential direction and a road surface have been realized. For example, the tread forms a certain space by contacting with the road surface, and includes a longitudinal groove extending along the tire circumferential direction, and a lateral groove that communicates with the longitudinal groove and the circumferential groove and extends along the tread width direction. A tire in which a branch type resonator is provided in a rib-like land portion extending along the tire circumferential direction is known (for example, Patent Document 1).

JP 2008-302898 A (page 3-4, FIG. 1)

  By the way, in recent years, in passenger cars and the like, there has been an increasing demand for reducing tire noise due to further progress in reducing vehicle noise (wind noise, mechanical noise, etc.) and further consideration for the environment. It is growing.

  Of the tire noise, passing noise caused by air column resonance noise generally has a volume level peak around 1 kHz. When the side branch type resonator is used to reduce the passing noise having such characteristics, there are the following problems.

  That is, the volume of the side branch type resonator needs to be changed according to the resonance frequency band. However, if the resonance frequency band is set to around 1 kHz, the volume of the side branch type resonator increases, and the rib-shaped land portion The number of side branch type resonators that can be provided along the tire circumferential direction is limited. For this reason, it is difficult to sufficiently reduce the passing noise, and further reduction of the passing noise has been demanded.

  Therefore, an object of the present invention is to provide a tire that further reduces tire noise, particularly passing noise, using a resonator that forms a certain space by contacting with a road surface.

  In order to solve the above-described problems, the present invention has the following features. First, the first feature of the present invention is that a plurality of rib-shaped land portions (for example, rib-shaped land portions 110) partitioned by a plurality of circumferential grooves (for example, the circumferential grooves 11) extending along the tire circumferential direction. And a resonator (for example, resonator R1, resonator R1, which forms a predetermined space when the rib-shaped land portion is in contact with the road surface (road surface RS) and is recessed toward the inside in the tire radial direction. The tire (pneumatic tire 10) provided with a resonator R2), and a plurality of the resonators provided along the tire circumferential direction (resonator R1) and the first resonator And a plurality of second resonators (for example, resonators R2) provided along the tire circumferential direction, and the first resonators extend along the tire circumferential direction. And in the longitudinal groove (vertical groove 154) and the circumferential groove A side branch type resonator having a lateral groove extending along the tread width direction (e.g., lateral groove 152), and the second resonator is an air chamber portion (e.g. Chamber 220) and a Helmholtz resonator having a narrowed groove (for example, narrowed groove 230) communicating with the air chamber and the circumferential groove, and the volume of the first resonator is the second resonance. The gist is that it is larger than the volume of the vessel.

  According to such a tire, the first resonator is located outside the second resonator when the vehicle is mounted. For this reason, it is possible to effectively reduce outside noise such as passing noise that is easily transmitted outward from a vehicle equipped with tires.

  Further, since the first resonator is a side branch type resonator, the volume of the side branch type resonator becomes large when the resonance frequency band is set to around 1 kHz. Since the volume of the first resonator is larger than the volume of the second resonator, it is possible to effectively reduce passing noise having a volume level peak around 1 kHz.

  Further, since the second resonator is a Helmholtz resonator having an air chamber portion and a constricted groove portion, the volume of the Helmholtz resonator is reduced when the resonance frequency band is set to around 1 kHz. Since the volume of the second resonator is smaller than the volume of the first resonator, it is possible to effectively reduce passing noise having a volume level peak around 1 kHz. Furthermore, since the volume of the second resonator is smaller than the volume of the first resonator, it is possible to reduce the outside noise of a wide frequency range as a whole. Thereby, the noise felt by human ears can be effectively reduced.

  That is, according to such a pneumatic tire 10, tire noise, particularly passing noise can be further reduced by the first resonator and the second resonator.

  The second feature of the present invention relates to the first feature of the present invention, and is summarized in that the number of the second resonators is larger than the number of the first resonators.

  A third feature of the present invention relates to the first or second feature of the present invention, wherein the length of the first resonator along the tire circumferential direction is the length of the second resonator along the tire circumferential direction. The gist is that it is longer than this.

  A fourth feature of the present invention relates to any one of the first to third features of the present invention, wherein the first resonator is located on the outer side when the vehicle is mounted with reference to a tire equator line passing through the center in the tread width direction. The second resonator is provided on the first rib-shaped land portion (rib-shaped land portion 110) located on the inside of the vehicle when mounted on the vehicle with respect to the tire equator line (for example, The gist is provided in the rib-like land portion 210).

  A fifth feature of the present invention relates to any one of the first to fourth features of the present invention, wherein the number of the second resonators located on the ground contact surface in a state where a normal load is applied to the tire. Is summarized as being larger than the number of the first resonators located on the ground plane.

  According to the characteristics of the present invention, it is possible to provide a tire that further reduces tire noise, particularly passing noise, using a resonator that forms a certain space by contacting with a road surface.

It is a partial development view of the tread pattern of the tire concerning the embodiment of the present invention. It is a partial perspective view of the rib-shaped land part 110 which concerns on embodiment of this invention. It is a figure which shows the rib-shaped land part 210 and the rib-shaped land part 240 which concern on embodiment of this invention. It is a figure which shows the shape of resonator R1 in the tread width direction view which concerns on embodiment of this invention. It is a partial front view of the tire which concerns on the modification of embodiment of this invention. It is a graph which shows the result of the test concerning the comparative evaluation of the present invention.

  Next, an embodiment of a tire according to the present invention will be described with reference to the drawings. Specifically, (1) overall schematic configuration of tire, (2) shape of rib-like land, (3) modification, (4) comparative evaluation, (5) action / effect, and (6) other implementations A form is demonstrated.

  In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic and ratios of dimensions and the like are different from actual ones.

  Accordingly, specific dimensions and the like should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

(1) Overall Schematic Configuration of Tire FIG. 1 is a partial front view of a pneumatic tire 10 according to an embodiment of the present invention. The pneumatic tire 10 is a tire that is designed to reduce tire noise such as air columnar resonance and is mounted on a passenger car or the like that requires high silence. The pneumatic tire 10 may be filled with an inert gas such as nitrogen gas instead of air.

  A plurality of circumferential grooves are formed in the pneumatic tire 10. Specifically, circumferential grooves 11, 12, 21 and 22 are formed in the pneumatic tire 10. The circumferential grooves 11, 12, 21, and 22 extend along the tire circumferential direction (direction D1 in FIG. 1). Further, the pneumatic tire 10 is provided with a plurality of rib-like land portions 110, 210, and 240 partitioned by the circumferential grooves 11, 12, 21, and 22.

  Specifically, the rib-like land portion 110 is provided adjacent to the circumferential groove 11 and the circumferential groove 12 between the circumferential groove 11 and the circumferential groove 12. The rib-shaped land portion 110 extends along the tire circumferential direction. The rib-like land portion 110 is provided on the outer side (hereinafter referred to as the vehicle mounting outer side) when the pneumatic tire 10 is mounted on the vehicle with the tire equator line CL as a reference.

  The rib-like land portion 210 is provided adjacent to the circumferential groove 12 and the circumferential groove 21 between the circumferential groove 12 and the circumferential groove 21. The rib-like land portion 240 is provided adjacent to the circumferential groove 21 and the circumferential groove 22 between the circumferential groove 21 and the circumferential groove 22. The rib-like land portion 210 and the rib-like land portion 240 extend along the tire circumferential direction. The rib-shaped land portion 210 and the rib-shaped land portion 240 are provided on the inner side (hereinafter referred to as the vehicle mounting inner side) when the pneumatic tire 10 is mounted on the vehicle with reference to the tire equator line CL. The rib-like land portion 210 is not necessarily provided on the inner side when the vehicle is mounted than the tire equator line CL, and may be provided on the inner side when the vehicle is mounted than the rib-like land portion 110.

  The pneumatic tire 10 is provided with a resonator that is recessed toward the inside in the tire radial direction and that forms a predetermined space when the rib-like land portion contacts the road surface. Specifically, the rib-shaped land portion 110 is provided with a resonator R1. The rib-like land portion 210 is provided with a resonator R2. The rib-shaped land portion 240 is provided with a resonator R3.

(2) Shape of rib-like land portion Next, the shape of the rib-like land portion will be described. Specifically, the shape of the rib-like land portion 110 and the rib-like land portions 210 and 240 will be described.

(2.1) Rib-shaped land portion 110
FIG. 2 is a partial perspective view of the rib-like land portion 110 according to the embodiment of the present invention. As shown in FIG. 2, the rib-shaped land portion 110 is provided with a resonator R1 that is recessed toward the inner side in the tire radial direction and forms a predetermined space when the rib-shaped land portion 110 contacts the road surface. The resonator R1 constitutes a first resonator. A plurality of resonators R1 are located outside the resonators R2 and R3 when the vehicle is mounted, and a plurality of resonators R1 are provided along the tire circumferential direction.

  The resonator R <b> 1 is a side branch type resonator having a lateral groove 152, a longitudinal groove 154, and a lateral groove 156. The longitudinal groove 154 extends along the tire circumferential direction. The lateral groove 152 communicates with one end of the longitudinal groove 154 and the circumferential groove 12, and extends along the tread width direction (direction D2 in FIG. 1). The lateral groove 156 does not communicate with the other end which is the end opposite to the one end of the longitudinal groove 154 and the circumferential groove 12 and extends along the tread width direction. The groove widths of the horizontal groove 152, the vertical groove 154, and the horizontal groove 156 are substantially the same and are narrower than the groove width of the circumferential groove 12. The groove depths from the ground surface G to the bottom surfaces of the horizontal grooves 152, the vertical grooves 154, and the horizontal grooves 156 are shallower than the circumferential groove depths from the ground surface G to the bottom surfaces of the circumferential grooves 12.

(2.2) Rib-shaped land portions 210 and 240
FIG. 3 is a diagram showing the rib-like land portion 210 and the rib-like land portion 240 according to the embodiment of the present invention. Specifically, FIG. 3A is a partial perspective view of the rib-like land portions 210 and 240 according to the embodiment of the present invention. FIG.3 (b) is sectional drawing of the air chamber part 220 along the F10-F10 line | wire shown to Fig.3 (a) based on embodiment of this invention. Specifically, FIG. 3B is a cross-sectional view along the tread width direction and the tire radial direction of the air chamber portion 220 of the rib-like land portion 210 according to the embodiment of the present invention. FIG. 4 shows the shape of the resonator R2 formed by the pneumatic tire 10 and the road surface RS. Specifically, FIG. 4 is a diagram illustrating the shape of the resonator R2 when viewed in the tread width direction. Further, the region surrounded by the alternate long and short dash line in FIG. 3 shows the shape of the resonator R2 when viewed in the tread width direction.

  As shown in FIG. 3, the rib-shaped land portion 210 has a land portion 211. The rib-shaped land portion 240 has a land portion 241. The land portion 211 of the rib-like land portion 210 is provided with a resonator R2 that is recessed toward the inner side in the tire radial direction and forms a predetermined space when the rib-like land portion 210 contacts the road surface. Similarly, a resonator R <b> 3 is provided in the land portion 241 of the rib-like land portion 240. The resonator R2 and the resonator R3 constitute a second resonator. A plurality of resonators R2 and R3 are located on the inner side when the vehicle is mounted than the resonator R1, and a plurality of resonators R2 and R3 are provided along the tire circumferential direction. A plurality of resonators R2 and resonators R3 are Helmholtz resonators that are provided along the tire circumferential direction and include an air chamber portion and a narrowed groove portion. Since the resonator R3 has the same configuration as the resonator R2, the resonator R2 will be mainly described below.

  The resonator R2 includes an air chamber 220 and a constricted groove 230. The air chamber 220 is an air chamber communicating with the narrowed groove 230 and includes a concave portion 221 that is recessed toward the inside in the tire radial direction. The resonator R <b> 3 includes an air chamber part 250 and a narrowed groove part 260.

  As shown in FIG. 3B, the depth DP1 of the concave portion 221 with respect to the ground contact surface on which the land portion 211 contacts the road surface changes along the tire circumferential direction. Specifically, the depth DP1 is deepest at the end 220b that is one end of the air chamber 220 in the tire circumferential direction, and is shallowest at the end 220a that is the other end of the air chamber 220.

  The bottom surface 222 of the concave portion 221 has a curved portion 223 that is curved in a cross-sectional view along the tire circumferential direction. A center CT2 of the arc along the curved portion 223 is located on the inner side in the tire radial direction than the bottom surface 222. The curved portion 223 may be configured by a plurality of arcs. In this case, the center CT2 is the center of one arc approximated to a curve formed by the plurality of arcs.

  Further, the bottom surface 222 has a linear portion 224 that is linear in a cross-sectional view along the tire circumferential direction. The straight portion 224 is formed on the end 220 b side of the air chamber 220. An end portion 224a that is one end of the linear portion 224 is continuous with the end portion 223b of the curved portion 223, and an end portion 224b that is the other end of the linear portion 224 is continuous with a ground plane on which the land portion 211 contacts the road surface. .

  The narrowed groove portion 230 communicates with the air chamber portion 220. Specifically, one end of the narrowed groove portion 230 communicates with the end portion 220a of the air chamber portion 220 in the tire circumferential direction. That is, the narrowed groove portion 230 communicates with a closed space formed by the air chamber portion 220 and the road surface RS. Further, the other end of the narrowed groove portion 230 communicates with at least one of the plurality of circumferential grooves, specifically, the circumferential groove 21. The volume of the space formed by the narrowed groove portion 230 and the road surface is smaller than the volume of the space formed by the concave portion 221 and the road surface.

  The narrowed groove portion 230 includes an outer groove portion 231 and an inner groove portion 232. The outer groove portion 231 communicates with the circumferential groove 21 and extends to the end portion 220 a of the air chamber portion 220. The inner groove portion 232 communicates with the outer groove portion 231 and extends to the end portion 220 b of the air chamber portion 220, specifically, to the side of the linear portion 224. In the present embodiment, the inner groove portion 232 constitutes an extended portion. The inner groove portion 232 is formed between the concave portion 221 and the ground surface on which the land portion 211 contacts the road surface.

  As shown in FIG. 3B, the depth DP2 of the narrowed groove portion 230, specifically, the inner groove portion 232 is deeper than the depth DP1 of the concave portion 221 from the ground contact surface where the land portion 211 contacts the road surface. . Further, the cross-sectional area S along the tread width direction (direction D2) and the tire radial direction (direction D3) of the concave portion 221 is an end portion that is the other end from the end portion 223a that is one end in the tire circumferential direction of the curved portion 223. It is substantially the same up to 223b.

(2.3) Comparison between the rib-like land portion 110 and the rib-like land portions 210 and 240 The resonator R1, which is the first resonator formed in the above-described rib-like land portion 110, and the rib-like land portion 210 (ribs) Comparing each of the resonators R2 and R3, which are the second resonators formed in the land portion 240), the volume of the first resonator is larger than the volume of the second resonator. Specifically, the total volume of the horizontal groove 152, the vertical groove 154, and the horizontal groove 156 of the resonator R1 is larger than the total volume of the air chamber portion 220 and the narrowed groove portion 230 of the resonator R2. Further, the total volume of the lateral groove 152, the longitudinal groove 154, and the lateral groove 156 of the resonator R1 is larger than the total volume of the air chamber portion 250 and the narrowed groove portion 260 of the resonator R3.

  Further, the total volume of the plurality of first resonators located in the ground plane G that contacts the road surface RS is larger than the total volume of the plurality of second resonators located in the ground plane G. That is, each volume of the plurality of resonators R1 located in the ground plane G is larger than each volume of the plurality of resonators R2 located in the ground plane G and the plurality of resonators R3. Each volume of the resonator R1 is a total volume of the horizontal groove 152, the vertical groove 154, and the horizontal groove 156, and each volume of the resonator R2 is a total volume of the air chamber portion 220 and the constricted groove portion 230. Each volume of the vessel R3 is a total volume of the air chamber portion 250 and the narrowed groove portion 260.

  Further, the number of second resonators is larger than the number of first resonators. That is, the number of the plurality of resonators R2 is larger than the number of the plurality of resonators R1. Further, the number of the plurality of resonators R3 is larger than the number of the plurality of resonators R1.

  Further, in a state where a normal load is applied to the pneumatic tire 10, the number of second resonators located in the ground contact surface G that contacts the road surface RS is the first number located in the ground contact surface G that contacts the road surface RS. More than the number of resonators.

  The length of the resonator R1 along the tire circumferential direction is longer than the length of the resonator R2 and the resonator R3 along the tire circumferential direction.

(3) Modification In the embodiment described above, the rib-like land portion 110 outside the vehicle is provided with the resonator R1 that is a side branch type resonator. Similarly, a resonator R2 and a resonator R3, which are Helmholtz resonators, are provided on the rib-shaped land portion 210 and the rib-shaped land portion 240 on the inner side of the vehicle. In the modification, a rib-like land portion 110 provided with a resonator that is a side branch type resonator will be described. Note that, in the following modifications, differences from the embodiment will be mainly described, and redundant description will be omitted. And (3.1) Modification 1
FIG. 5 is a partial front view of a tire according to a modification of the embodiment of the present invention. Specifically, FIG. 5 is a front view of the rib-like land portion 110 of the ground plane G according to a modification of the embodiment of the present invention. In the embodiment of the present invention, in the tread surface view, the longitudinal groove 154 of the resonator R1 extends along the tire circumferential direction, and the lateral groove 152 and the lateral groove 156 extend along the tread width direction. For example, as shown in FIG. 5A, the side branch type resonator includes a lateral groove 152 </ b> A extending obliquely along the tread width direction and a tire circumferential direction. It may have a longitudinal groove and 154A extending partly, and a part thereof may be curved.

  Further, as shown in FIG. 5B, a side branch type resonator may be formed by a lateral groove 152B extending obliquely along the tread width direction and a vertical groove 154B extending along the tire circumferential direction.

  Further, as shown in FIG. 5C, the side branch type resonator includes a lateral groove 152C extending obliquely along the tread width direction, a vertical groove 154C extending along the tire circumferential direction, and an end portion of the vertical groove 154C. You may have a lateral groove 156C in the position.

(4) Comparative Evaluation Next, a test method for comparative evaluation between the pneumatic tire according to the example having the pattern similar to the pneumatic tire 10 described above and the pneumatic tire according to the comparative example and the result thereof will be described.

(4.1) Test method The noise level of the pneumatic tire according to the example and the comparative example was measured using a test vehicle. The test conditions for the comparative evaluation are as follows.

・ Test vehicle: Sedan type passenger car (Japanese car)
・ Used tire size: 215 / 55R17
・ Rim size used: 7J × 17
・ Set internal pressure: 210kPa
・ Set load: 4.41kN
・ Running speed: 80km / h
· Measuring method:
・ 1. 1. Install a microphone in the car and measure noise. Measurement of passing noise by installing a microphone outside the vehicle (4.2) Test results FIG. 6 shows the results of the tests related to the comparative evaluation described above. A comparative example is a pneumatic tire provided with no resonator. Example 1 is a pneumatic tire in which a pneumatic resonator 10 is provided with an outer first resonator on the entire tread when the vehicle is mounted. Example 2 is a pneumatic tire in which the pneumatic resonator 10 is provided with the second resonator on the entire tread when the vehicle is mounted. That is, Example 2 is a pneumatic tire in which the volume of the air chamber portion is smaller than that of Example 1 and the number of air chamber portions is set larger than that of Example 1.

  As shown in FIG. 6, the noise level is lowered by providing a resonator. In particular, in the pneumatic tire according to Example 1, the peak of outside noise having a volume level peak around 1 kHz can be significantly suppressed as compared with the comparative example. Specifically, the outside noise of the comparative example was 71 dB (A), whereas the outside noise of the example 1 was 69 dB (A), and the outside noise of the example 2 was 70 dB (A). Further, in the pneumatic tire according to the second embodiment, it is possible to suppress the vehicle exterior noise having a wide frequency as a whole as compared with the comparative example. Further, it has been found that it is more effective for the noise felt by the human ear to suppress the vehicle exterior noise of a wide frequency as a whole like the pneumatic tire according to the second embodiment.

(5) Action / Effect According to the pneumatic tire 10 described above, the resonator R1 constituting the first resonator is located on the outer side when the vehicle is mounted than the resonator R2 and the resonator R3 constituting the second resonator. To do. For this reason, it is possible to effectively reduce outside noise such as passing noise that is easily transmitted outward from a vehicle equipped with tires.

  Since the resonator R1 is a side branch type resonator, when the resonance frequency band is set to around 1 kHz, the volume of the side branch type resonator is larger than the volume of the Helmholtz type resonator. Since the volume of the resonator R1 is larger than the volumes of the resonator R2 and the resonator R3, it is possible to effectively reduce passing noise having a volume level peak around 1 kHz.

  Further, the resonator R2 (resonator R3) is a Helmholtz resonator having the air chamber portion 220 (air chamber portion 250) and the constricted groove portion 230 (constricted groove portion 260), so that the resonance frequency band is set to about 1 kHz. When set, the volume of the Helmholtz resonator is smaller than the volume of the side branch resonator. Since the volume of each of the resonator R2 and the resonator R3 is smaller than the volume of the resonator R1, it is possible to effectively reduce passing noise having a volume level peak around 1 kHz. Furthermore, since the volume of each of the resonator R2 and the resonator R3 is smaller than the volume of the resonator R1, as shown in the second embodiment of the comparative evaluation, it is possible to reduce the outside noise with a wide frequency as a whole. it can. Thereby, the noise felt by human ears can be effectively reduced.

  That is, according to such a pneumatic tire 10, tire noise, particularly passing noise can be further reduced by the first resonator and the second resonator.

  According to this embodiment, the number of resonators R2 and resonators R3 constituting the second resonator is larger than the number of resonators R1 constituting the first resonator. Therefore, the rib-like land portion 210 (rib-like land portion 240) where the resonator R2 (resonator R3) is provided has more concave portions 221 than the rib-like land portion 110 where the resonator R1 is provided. The As a result, the block rigidity of the rib-shaped land portion 210 (rib-shaped land portion 240) is lower than the block rigidity of the rib-shaped land portion 110, and the road noise transmitted to the interior by transmitting the suspension, the body, and the like is reduced. it can. In particular, road noise is likely to be transmitted from the inner portion of the pneumatic tire 10 close to the suspension or axle when the vehicle is mounted. Therefore, when a large number of resonators R2 and R3 are provided on the inner side of the vehicle, road noise generated from the portion. Can be effectively suppressed.

  According to this embodiment, the length of the resonator R1 along the tire circumferential direction is longer than the length of the resonator R2 and the resonator R3 along the tire circumferential direction. In addition, since the volume of the resonator R1 is larger than the volume of each of the resonator R2 and the resonator R3, the peak of the passing noise can be further effectively reduced as shown in the first comparative example. it can.

  According to this embodiment, the groove widths of the vertical groove 154, the horizontal groove 152, and the horizontal groove 156 are substantially the same. For this reason, the resonator R1 having the lateral groove 152, the longitudinal groove 154, and the lateral groove 156 functions more effectively as a side branch type resonator, and can reduce the passing noise more effectively.

  According to the present embodiment, the resonator R1 is provided on the rib-like land portion 110 located on the outer side when the vehicle is mounted with the tire equator line CL as a reference, and therefore, the outside of the vehicle such as passing noise that is easily transmitted outward from the vehicle. Noise can be effectively suppressed. Further, since the resonator R2 (resonator R3) is provided on the rib-like land portion 210 (rib-like land portion 240) located on the inner side when the vehicle is mounted with respect to the tire equator line CL, air close to the suspension or the axle. Road noise that is easily transmitted from the inner portion of the entering tire 10 when the vehicle is mounted can be effectively suppressed.

  According to the present embodiment, in a state where a normal load is applied to the tire, the number of resonators R2 and resonators R3 located on the ground contact surface G is larger than the number of resonators R1. Specifically, the total number of resonators R2 and R3 located on the ground plane G is larger than the total number of resonators R1. For this reason, in the rib-like land portion 210 (rib-like land portion 240) where the resonator R2 and the resonator R3 are provided, more concave portions are formed than the rib-like land portion 110 where the resonator R1 is provided. As a result, the block rigidity of the rib-shaped land portion 210 (rib-shaped land portion 240) is lower than the block rigidity of the rib-shaped land portion 110, and road noise transmitted to the interior of the vehicle by transmitting the suspension and the body is further increased. It can be effectively suppressed.

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

  For example, the shape of the Helmholtz resonator is not necessarily limited to the resonator R2 and the resonator R3 described above, and may be different shapes or shapes other than the resonator R2 and the resonator R3. .

  Further, the shape of the side branch type resonator is not necessarily limited to the above-described resonator R1, and a side branch type resonator having a different volume may be provided according to a required resonance frequency band. The shape may also be

  In the above-described embodiment, the resonator R1 is provided along the tire circumferential direction as the resonator constituting the first resonator. However, the present invention is not limited to this, and for example, a plurality of resonators are arranged around the tire circumference. It may be provided along the direction. Similarly, two resonators R2 and R3 are provided along the tire circumferential direction as resonators constituting the second resonator. However, the present invention is not limited to this, and, for example, the resonator is constituted only by the resonator R2. It may be constituted by three resonators.

  In the above-described embodiment, the circumferential grooves 11, 12, 21, and 22 extend linearly along the tire circumferential direction. However, if the circumferential groove extends along the tire circumferential direction, The shape is not limited to a straight line, and may be a zigzag shape or a wave shape.

  As described above, the present invention naturally includes various embodiments that are not described herein. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

CL: tire equator line, D1 ... direction, D2 ... direction, D3 ... direction, G ... ground plane, R1, R2, R3 ... resonator, RS ... road surface, S ... cross-sectional area, 10 ... pneumatic tire, 11, 12 , 21, 22 ... circumferential grooves, 110, 210, 240 ... rib-like land portions, 152, 152A, 152B, 152C, 156, 156C ... lateral grooves, 154, 154C ... longitudinal grooves, 210, 240 ... rib-like land portions , 211 ... land part, 220 ... air chamber part, 220a, 220b ... end part, 221 ... concave part, 222 ... bottom face, 223 ... curved part, 223a, 223b ... end part, 224 ... linear part, 224a, 224b ... End part, 230 ... narrowed groove part, 231 ... outer groove part, 232 ... inner groove part, 240 ... rib-like land part, 241 ... land part, 250 ... air chamber part, 260 ... narrowed groove part

Claims (4)

A plurality of rib-like land portions defined by a plurality of circumferential grooves extending along the tire circumferential direction;
A tire provided with a resonator that is recessed toward the inside in the tire radial direction, forming a predetermined space by the rib-shaped land portion contacting the road surface, and communicating with the circumferential groove,
The resonator is
A plurality of first resonators provided along the tire circumferential direction;
A plurality of second resonators that are located on the inner side of the first resonator than the first resonator and are provided along the tire circumferential direction,
The first resonator is a side branch type resonator having a longitudinal groove extending along a tire circumferential direction, a lateral groove communicating with the longitudinal groove and the circumferential groove, and extending along a tread width direction.
The second resonator is a Helmholtz resonator having an air chamber portion recessed toward the inside in the tire radial direction, and a narrowed groove portion communicating with the air chamber portion and the circumferential groove,
The volume of the first resonator is much larger than the volume of the second resonator,
The number of the second resonators is larger than the number of the first resonators,
The first resonator is provided in a first rib-shaped land portion located on the outer side when the vehicle is mounted with reference to a tire equator line passing through the center in the tread width direction,
The second resonator is a tire provided in a second rib-shaped land portion located on the inner side when the vehicle is mounted with respect to the tire equator line . The length along the tire circumferential direction of the first resonator, the tire according to a long claim 1 than the length along the tire circumferential direction of the second resonator. The number of the second resonators located on the ground contact surface that contacts the road surface in a state where a normal load is applied to the tire is greater than the number of the first resonators located on the ground contact surface. Or the tire of 2 .   The bottom surface of the second resonator has a curved portion that is curved in a sectional view along the tire circumferential direction,
  4. The tire according to claim 1, wherein the center of the arc along the curved portion is located on the inner side in the tire radial direction from the bottom surface of the second resonator. 5.

Images