Resonance absorber and method for mounting resonance absorber

Abstract

This resonance absorber is mounted on the inner-cavity surface of a tire. The resonance absorber comprises: a resonance box having an opening that connects a hollow portion formed on the inside with an outside space; and a box engagement portion provided on the resonance box to engage with a tire engagement portion provided on the inner-cavity surface of the tire.

Description

Resonant sound absorber and installation method for the resonant sound absorber

[0001] The present disclosure relates to a resonance sound absorber and a method for attaching the resonance sound absorber.

[0002] BACKGROUND ART Conventionally, a resonance sound absorber that reduces tire cavity resonance noise generated when a vehicle is running by Helmholtz resonance has been known (see, for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2021-067767

[0004] In such a resonance sound absorber, a resonance box that absorbs sound through Helmholtz resonance is attached to the tire's inner cavity surface. When the tire's tread surface deforms due to road irregularities or other factors, the tire's inner cavity surface also deforms, and stress is applied to the resonance box attached to the inner cavity surface. When the resonance box deforms, the resonance sound absorber may not be able to properly absorb sound. Conventionally, the resonance box has been attached to the tire's inner cavity surface using adhesive or double-sided adhesive tape, but in this case, the resonance box is susceptible to stress due to tire deformation.

[0005] Therefore, this disclosure describes a resonance sound absorber that can suppress the effect of stress from the tire on the resonance box, and a method for attaching the resonance sound absorber.

[0006] The resonant sound absorber according to the present disclosure is a resonant sound absorber attached to the inner cavity surface of a tire, and includes a resonance box having an opening that connects a hollow portion formed on the inside with the external space, and a box engaging portion that is provided on the resonance box and engages with a tire engaging portion that is provided on the inner cavity surface of the tire.

[0007] This resonance sound absorber is attached to the tire cavity surface by engaging the box engagement portion provided on the resonance box with the tire engagement portion. In other words, this resonance sound absorber is attached to the tire cavity surface so that the resonance box is spaced or can be spaced from the tire cavity surface. Therefore, with this resonance sound absorber, even if the tire deforms, stress from the tire is not directly applied to the resonance box. This suppresses deformation of the resonance box, allowing the resonance box to adequately absorb sound. In this way, when attached to the tire cavity surface, the resonance sound absorber can suppress the resonance box from being affected by stress from the tire.

[0008] The resonance sound absorber may include a flange portion extending outward from the outer surface of the resonance box, and the box engaging portion may be provided on the flange portion, thereby further reducing the stress applied to the resonance box from the tire even when the tire is deformed.

[0009] In the above-described resonance sound absorber, the flange portion may have a first flange portion extending outward from one end of the outer surface of the resonance box and a second flange portion extending outward from the other end of the outer surface of the resonance box, and the box engaging portion may have a first box engaging portion provided on the first flange and a second box engaging portion provided on the second flange. In this case, the resonance box is attached to the tire so as to be sandwiched between the first box engaging portion and the second box engaging portion and spaced or removably from the tire cavity surface. This allows the resonance sound absorber to more reliably attach the resonance box to the tire cavity surface while suppressing the influence of stress on the resonance box from the tire.

[0010] In the above-described resonance sound absorber, the Shore A hardness of the flange portion and the box engaging portion may be higher than the Shore A hardness of the resonance box. In this case, the high hardness of the flange portion and the box engaging portion suppresses deformation of the flange portion and the box engaging portion. This prevents the resonance sound absorber from deforming the box engaging portion and disengaging from the tire engaging portion (disengaging).

[0011] In the above-described resonance sound absorber, the box engaging portion may have a first box engaging portion and a second box engaging portion, the first box engaging portion being provided at one end of the resonance box, and the second box engaging portion being provided at the other end of the resonance box. In this case, the resonance box is attached by the first box engaging portion and the second box engaging portion in a state where it is spaced apart from or can be spaced apart from the tire cavity surface. This allows the resonance sound absorber to more reliably attach the resonance box to the tire cavity surface while suppressing the influence of stress from the tire on the resonance box.

[0012] In the above-described resonance sound absorber, the tire engagement portion may be concave, and the box engagement portion may be convex so as to be inserted into the tire engagement portion. In this case, the tire engagement portion and the box engagement portion of the resonance sound absorber can be easily engaged by inserting them into each other. Furthermore, by making the box engagement portion convex, the resonance sound absorber can be made lighter than when the box engagement portion is concave.

[0013] In the above-described resonance sound absorber, the tire engagement portion may be groove-shaped, and the box engagement portion may be strip-shaped extending along the groove of the tire engagement portion. In this case, the resonance sound absorber can ensure a long engagement area between the box engagement portion and the tire engagement portion by engaging the strip-shaped box engagement portion with the groove-shaped tire engagement portion. This allows the resonance sound absorber to more reliably attach the resonance box to the tire inner surface.

[0014] In the above-described resonance sound absorber, the outer shape of the convex tip portion of the box engaging portion may be larger than the outer shape of the convex base portion of the box engaging portion. In this case, when the box engaging portion is inserted into the tire engaging portion, the tip portion of the box engaging portion is more likely to be caught in the tire engaging portion. This allows the resonance sound absorber to more reliably attach the resonance box to the tire inner surface.

[0015] In the above-described resonance sound absorber, the resonance box may have a hollow neck portion that connects the opening and the hollow portion. In this resonance sound absorber, the resonance box has a hollow neck portion that connects the opening and the hollow portion, so the resonance frequency of Helmholtz resonance can be adjusted by adjusting the length of the neck portion. Furthermore, by lengthening the neck portion, Helmholtz resonance with a resonance frequency in the low-frequency range can be generated. Therefore, the resonance sound absorber can reduce low-frequency resonance sounds such as tire cavity resonance sounds.

[0016] In the above-described resonance sound absorber, the resonance box may include a bottom wall portion facing the inner cavity surface of the tire and a top wall portion forming a hollow portion between the bottom wall portion and the resonance box, and the neck portion may be disposed on the bottom wall portion so as to extend along the bottom wall portion. In this resonance sound absorber, since the neck portion is disposed on the bottom wall portion so as to extend along the bottom wall portion, movement of the neck portion due to centrifugal force when the tire rotates can be suppressed.

[0017] In the above-described resonance sound absorber, the resonance box may include a bottom wall facing the inner cavity surface of the tire, a top wall forming a hollow between the bottom wall and the resonance box, and a support portion supporting the top wall against the bottom wall. In this resonance sound absorber, the resonance box includes the support portion supporting the top wall against the bottom wall, which can further suppress deformation of the top wall due to centrifugal force when the tire rotates.

[0018] A method for attaching a resonance sound absorber according to the present disclosure is a method for attaching any of the above-described resonance sound absorbers to the tire cavity surface, and includes the steps of providing a tire engagement portion on the tire cavity surface and engaging the box engagement portion with the tire engagement portion to attach the resonance sound absorber to the tire cavity surface. Thus, this attachment method includes the step of providing the tire engagement portion on the tire cavity surface. This allows the box engagement portion of the resonance sound absorber to engage with the tire engagement portion provided on the tire cavity surface. Thus, this attachment method allows a resonance sound absorber that can suppress the effect of stress on the resonance box from the tire to be attached to the tire cavity surface.

[0019] According to various aspects of the present disclosure, the resonance box can be prevented from being affected by stress from the tire.

[0020] FIG. 1 is a schematic cross-sectional view of a tire to which a resonance sound absorber according to a first embodiment is attached. FIG. 2 is a schematic front view of the resonance sound absorber according to the first embodiment, viewed from the opening side. FIG. 3 is a schematic top view of the resonance sound absorber according to the first embodiment, viewed from above. FIG. 4 is a schematic cross-sectional view taken along line IV-IV in FIG. 2. FIG. 5 is a schematic cross-sectional view taken along line V-V in FIG. 4. FIG. 6 is a schematic plan view showing a tire engagement portion provided on the inner surface of a tire. FIG. 7 is a schematic cross-sectional view showing a state in which a resonance sound absorber is attached to the inner surface of a tire. FIG. 8 is a diagram for explaining a method for calculating the resonant frequency of a Helmholtz resonance structure. FIG. 9 is a schematic cross-sectional view of a resonance sound absorber according to a second embodiment. FIG. 10 is a schematic cross-sectional view taken along line X-X in FIG. 9. FIG. 11 is a schematic cross-sectional view taken along line XI-XI in FIG. 9.

[0021] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, identical or corresponding parts are designated by the same reference numerals, and duplicate explanations will be omitted. Numerical ranges indicated using "to" indicate ranges that include the numerical values ​​before and after "to" as the minimum and maximum values, respectively.

[0022] (First embodiment) Fig. 1 is a schematic cross-sectional view of a tire equipped with a resonance sound absorber according to a first embodiment. In the tire T, cavity resonance can occur, in which the air in the cavity S resonates due to vibrations caused by passing over uneven road surfaces while the vehicle is traveling. The frequency of the cavity resonance is approximately 200 Hz to 300 Hz, typically approximately 250 Hz. The resonance sound absorber 1 according to this embodiment is attached to the cavity surface Ta of the tire T in order to efficiently absorb cavity resonance in the low frequency band. The cavity surface Ta is the inner circumferential surface of the tread Tb of the tire T.

[0023] In this embodiment, two resonance sound absorbers 1 are provided in the cavity S of the tire T. In this embodiment, the two resonance sound absorbers 1 are attached to the cavity surface Ta at positions offset by 180° in the rotational direction of the tire T. However, the number and attachment positions of the resonance sound absorbers 1 are not limited to the configuration shown in FIG.

[0024] The resonance sound absorber 1 according to the first embodiment will be described with reference to Fig. 2 to Fig. 5. Fig. 2 is a schematic front view of the resonance sound absorber according to the first embodiment, seen from the opening side. Fig. 3 is a schematic top view of the resonance sound absorber according to the first embodiment, seen from above. Fig. 4 is a schematic cross-sectional view taken along line IV-IV in Fig. 2. Fig. 5 is a schematic cross-sectional view taken along line V-V in Fig. 4.

[0025] 2 to 5, the resonance absorber 1 according to this embodiment includes a resonance box 10, a flange 20, and a box engaging portion 30. The resonance box 10 has a Helmholtz resonance structure. The resonance box 10 includes an outer wall 11, a hollow portion 12 formed within the outer wall 11, an opening 13 that opens the hollow portion 12 to the outside of the outer wall 11 (the external space of the resonance box 10), and a hollow neck portion 15 that connects the opening 13 to the hollow portion 12.

[0026] The outer wall 11 has a self-supporting property to the extent that it can maintain its shape in a stationary state. The outer wall 11 is non-breathable. The outer wall 11 has a Shore A hardness of 40 or more and 100 or less. In this case, the Shore A hardness of the outer wall 11 may be 50 or more and 80 or less, or 60 or more and 70 or less.

[0027] The Shore A hardness of the exterior wall 11 can be measured using a durometer in accordance with JIS K6253-3, and for example, a GS-709N TYPE A manufactured by Teclock Corporation can be used. If the allowable number of stacked test pieces (three or less) specified in JIS K6253-3 does not satisfy the specified measurement thickness (6 mm or more), more than three pieces can be stacked and the measurement can be performed at the specified thickness.

[0028] The material of the outer wall 11 includes, for example, an elastomer such as a thermoplastic elastomer, a plastic, a rubber, a rubber-like material, or other resin.

[0029] Examples of elastomer materials include thermoplastic elastomers such as styrene block copolymer (SBC), polyolefin (TPO), polyurethane (TPU), polyester (TPC), polyamide (TPA), dynamically crosslinked (TPV), soft polyvinyl chloride (PVC), and acrylic.

[0030] Examples of plastic materials include polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), polyvinyl chloride (PVC), polystyrene (PS), acrylonitrile butadiene styrene (ABS), polyphenylene sulfide (PPS), polyurethane (PU), epoxy resin, phenolic resin, and melamine resin.

[0031] Examples of rubber materials include natural rubber (NR), styrene butadiene rubber (SBR), acrylonitrile butadiene rubber (NBR), chloroprene rubber (CR), ethylene propylene rubber (EPM), ethylene propylene diene rubber (EPDM), silicone rubber, and urethane rubber.

[0032] Examples of rubber-like materials include UV-curable acrylic rubber-like materials.

[0033] The opening 13 is formed in the outer wall 11 and penetrates the outer wall 11. The opening 13 serves as an entrance for tire cavity resonance sound in the resonance box 10. The shape (cross-sectional shape) of the opening 13 is not particularly limited and may be various shapes such as a circle, a triangle, a rectangle, a polygon, or an ellipse. In this embodiment, the opening 13 is a circular hole. In other words, the cross-sectional shape of the opening 13 is circular. The inner diameter of the opening 13 is, for example, approximately 1 mm to 5 mm.

[0034] The outer wall 11 includes a bottom wall portion 11a, a top wall portion 11b, a first side wall portion 11c, and a second side wall portion 11d. The thickness of the outer wall 11 is, for example, about 0.1 mm to 2 mm. That is, the thickness of each of the bottom wall portion 11a, the top wall portion 11b, the first side wall portion 11c, and the second side wall portion 11d is, for example, about 0.1 mm to 2 mm.

[0035] The bottom wall portion 11a is a portion facing the inner cavity surface Ta of the tire T. The bottom wall portion 11a is formed in the shape of a rectangular plate that is long in a first direction D1 and short in a second direction D2 perpendicular to the first direction D1. The direction perpendicular to the first direction D1 and the second direction D2 is referred to as a third direction D3. The third direction D3 is also the thickness direction or height direction of the resonance box 10.

[0036] The top wall portion 11b is a portion that forms the hollow portion 12 between itself and the bottom wall portion 11a. The top wall portion 11b covers the hollow portion 12 from the side opposite the bottom wall portion 11a. The top wall portion 11b is convexly curved. The top wall portion 11b being convexly curved means that the top wall portion 11b is curved so as to be convex on the side opposite the bottom wall portion 11a in the third direction D3, so as to be convex in the direction away from the bottom wall portion 11a, or so as to be convex on the side opposite the hollow portion 12. Specifically, the top wall portion 11b is formed in an arc shape (arch-like) in a cross section perpendicular to the first direction D1 (a cross section along the second direction D2 and the third direction D3). Both ends of the top wall portion 11b in the second direction D2 are connected to both ends of the bottom wall portion 11a in the second direction D2. In other words, the top wall portion 11b is formed in the shape of an arc-shaped curved plate so that it is convex on the opposite side to the bottom wall portion 11a in the third direction D3, and is connected to one end of the bottom wall portion 11a in the second direction D2 and the other end of the bottom wall portion 11a in the second direction D2.

[0037] The first side wall portion 11c is a portion located at one end of the outer wall 11 in the first direction D1. The first side wall portion 11c is located on one side of the hollow portion 12 in the first direction D1 and covers the hollow portion 12 from one side in the first direction D1. An opening 13 is formed in the first side wall portion 11c. That is, the opening 13 penetrates the first side wall portion 11c and communicates with the hollow portion 12. The first side wall portion 11c is formed in a flat plate shape extending in a direction intersecting the first direction D1 and is connected to one end of the bottom wall portion 11a and the top wall portion 11b in the first direction D1. In this embodiment, the first side wall portion 11c is formed in a flat plate shape extending in a direction perpendicular to the first direction D1 (a direction along the second direction D2 and the third direction D3).

[0038] The second side wall portion 11d is a portion located at the other end of the outer wall 11 in the first direction D1. The other side of the outer wall 11 in the first direction D1 is also the opposite side of the outer wall 11 from the first side wall portion 11c in the first direction D1. The second side wall portion 11d is located on the other side of the hollow portion 12 in the first direction D1 and covers the hollow portion 12 from the other side in the first direction D1. The second side wall portion 11d is formed in a flat plate shape extending in a direction intersecting the first direction D1 and is connected to the other ends of the bottom wall portion 11a and the top wall portion 11b in the first direction D1. The second side wall portion 11d is formed in, for example, a flat plate shape extending in a direction perpendicular to the first direction D1 (a direction along the second direction D2 and the third direction D3).

[0039] At least a portion of the neck portion 15 is disposed within the outer wall 11. In this embodiment, the entire neck portion 15 is disposed within the outer wall 11. The base end and the tip end of the neck portion 15 are open ends at which a hollow portion 15a of the neck portion 15 is exposed. The base end of the neck portion 15 is connected to the opening 13. The hollow portion 15a of the neck portion 15 opens from the opening 13 to the outside of the outer wall 11 (outside the resonance box 10) at the base end of the neck portion 15. The tip end of the neck portion 15 is located within the hollow portion 12. The hollow portion 15a of the neck portion 15 opens to the hollow portion 12 at the tip end of the neck portion 15.

[0040] The neck portion 15 is non-air permeable, similar to the resonance box 10. The neck portion 15 has the same Shore A hardness as the resonance box 10. The material of the neck portion 15 can be the same as the material of the resonance box 10.

[0041] The hollow portion 15a of the neck portion 15 has, for example, a cross section that is equal to or larger than the cross section of the opening 13. By increasing the extension length of the neck portion 15, the resonance frequency of the resonance box 10 can be lowered. In other words, by increasing the extension length of the neck portion 15, resonance sounds in the low frequency range can be reduced. The extension length of the neck portion 15 is the length of the extension axis of the neck portion 15 from the base end of the neck portion 15 to the tip end of the neck portion 15.

[0042] The neck portion 15 is disposed on the bottom wall portion 11 a so as to extend along the bottom wall portion 11 a. The neck portion 15 is, for example, integrally formed with the bottom wall portion 11 a and connected to the bottom wall portion 11 a. The neck portion 15 extends in the first direction D1, but the extending direction, extending shape, etc. of the neck portion 15 are not particularly limited.

[0043] The flange 20 extends outward from the outer surface of the outer wall 11 of the resonance box 10. The flange 20 has a first flange 21 and a second flange 22. The first flange 21 extends outward from one end of the outer surface of the outer wall 11 of the resonance box 10. The second flange 22 extends outward from the other end of the outer surface of the outer wall 11 of the resonance box 10. In other words, the first flange 21 and the second flange 22 extend in opposite directions from the outer surface of the resonance box 10.

[0044] In this embodiment, the first flange 21 and the second flange 22 extend outward from the outer surface of the top wall portion 11b of the outer wall 11 of the resonance box 10. The first flange 21 extends from the outer surface of one side of the top wall portion 11b in the second direction D2 toward one side in the second direction D2. The second flange 22 extends from the outer surface of the other side of the top wall portion 11b in the second direction D2 toward the other side in the second direction D2.

[0045] In the present embodiment, the first flange 21 and the second flange 22 are provided, for example, on the outer surface of the top wall portion 11b at a position spaced a predetermined height from the bottom wall portion 11a in the third direction D3. However, the first flange 21 and the second flange 22 may extend outward from the bottom wall portion 11a (the end surface of the bottom wall portion 11a) on the outer surface of the resonance box 10. Also, as shown in Fig. 3, in the present embodiment, the length of the first flange 21 and the second flange 22 in the first direction D1 is substantially the same as the length of the outer wall 11 in the first direction D1.

[0046] The box engaging portion 30 is provided on the resonance box 10 and engages with the tire engaging portion 5 (see FIG. 7 ) provided on the inner cavity surface Ta of the tire T. In this embodiment, the box engaging portion 30 is provided on the flange 20. The box engaging portion 30 is provided on the resonance box 10 via the flange 20. The box engaging portion 30 has a first box engaging portion 31 and a second box engaging portion 32.

[0047] The first box engaging portion 31 is provided on the first flange 21. The first box engaging portion 31 is provided on the outer surface of the first flange 21, on a surface facing the inner cavity surface Ta of the tire T (see FIG. 7 ). The first box engaging portion 31 has a convex shape that protrudes in the third direction D3 from the outer surface of the first flange 21. The convex first box engaging portion 31 is inserted into the concave first tire engaging portion 51 (tire engaging portion 5).

[0048] The first tire engagement portion 51 has a groove 51a (see FIG. 6 ). The first box engagement portion 31 has a strip shape extending along the groove 51a of the first tire engagement portion 51. In this embodiment, the length of the first box engagement portion 31 in the first direction D1 is approximately the same as the length of the first flange 21 in the first direction D1.

[0049] The first box engagement portion 31 has a distal end portion 31b, which is a distal end portion of the convex shape, and a proximal end portion 31a, which is a proximal end portion of the convex shape. The distal end portion 31b is attached to the first flange 21 via the proximal end portion 31a. The distal end portion 31b has a larger outer shape than the proximal end portion 31a. In this embodiment, the distal end portion 31b has a larger outer shape than the proximal end portion 31a when viewed along the first direction D1. Note that the distal end portion 31b having a larger outer shape than the proximal end portion 31a only needs to satisfy this relationship when the distal end portion 31b and the proximal end portion 31a are viewed from any direction perpendicular to the protruding direction (third direction D3) of the first box engagement portion 31.

[0050] The second box engaging portion 32 is provided on the second flange 22. The second box engaging portion 32 is provided on the outer surface of the second flange 22, on a surface facing the lumen surface Ta of the tire T (see FIG. 7 ). The second box engaging portion 32 has a convex shape that protrudes in the third direction D3 from the outer surface of the second flange 22. The convex second box engaging portion 32 is inserted into the concave second tire engaging portion 52 (tire engaging portion 5).

[0051] The second tire engagement portion 52 has a groove 52a similar to the first tire engagement portion 51 (see FIG. 6 ). The second box engagement portion 32 has a strip shape extending along the groove 52a of the second tire engagement portion 52. In this embodiment, the length of the second box engagement portion 32 in the first direction D1 is approximately the same as the length of the second flange 22 in the first direction D1.

[0052] The second box engagement portion 32 has a distal end portion 32b, which is a portion of the distal end of the convex shape, and a proximal end portion 32a, which is a portion of the proximal end of the convex shape. The distal end portion 32b is attached to the second flange 22 via the proximal end portion 32a. The distal end portion 32b has a larger outer shape than the proximal end portion 32a. In this embodiment, the distal end portion 32b has a larger outer shape than the proximal end portion 32a when viewed along the first direction D1. Note that the distal end portion 32b having a larger outer shape than the proximal end portion 32a only needs to satisfy this relationship when the distal end portion 32b and the proximal end portion 32a are viewed from any direction perpendicular to the protruding direction (third direction D3) of the second box engagement portion 32.

[0053] The flange 20 and the box engaging portion 30 may be made of the same material as the resonance box 10. The Shore A hardness of the flange 20 and the box engaging portion 30 is higher than the Shore A hardness of the resonance box 10. For example, if the Shore A hardness of the resonance box 10 is 60 or more and 70 or less, the Shore A hardness of the flange 20 and the box engaging portion 30 may be 90 or more. The Shore A hardness of the flange 20 and the Shore A hardness of the box engaging portion 30 may be the same as or different from each other.

[0054] The resonance box 10, flange 20, and box engaging portion 30 configured in this manner can be manufactured by, for example, injection molding, extrusion molding, modeling using a 3D printer, salt coagulation method, or the like.

[0055] Next, the configuration of the tire T to which the resonance sound absorber 1 is attached will be described. Fig. 6 is a schematic plan view showing a tire engagement portion provided on the tire cavity surface. Fig. 7 is a schematic cross-sectional view showing the state in which the resonance sound absorber is attached to the tire cavity surface. As shown in Figs. 6 and 7 , a tire engagement portion 5 is provided on the cavity surface Ta of the tire T. The tire engagement portion 5 engages with the box engagement portion 30 of the resonance sound absorber 1 to hold the resonance sound absorber 1 on the cavity surface Ta.

[0056] In this embodiment, the tire engagement portion 5 has a first tire engagement portion 51 and a second tire engagement portion 52. The first tire engagement portion 51 engages with the first box engagement portion 31 of the resonance sound absorber 1. The second tire engagement portion 52 engages with the second box engagement portion 32 of the resonance sound absorber 1.

[0057] The first tire engaging portion 51 has a groove shape. The first tire engaging portion 51 has a groove 51a extending in the width direction of the tire T. A pair of retaining portions 51b is provided on the opening edge of the groove 51a (the bottom portion of the groove 51a). The pair of retaining portions 51b is provided on one side of the opening edge of the groove 51a in the rotational direction of the tire T and on the other side of the opening edge of the groove 51a in the rotational direction of the tire T, respectively. The pair of retaining portions 51b protrude inward from the opening edge of the groove 51a. In other words, the pair of retaining portions 51b are lined up along the rotational direction of the tire T. In addition, a gap is provided between the pair of retaining portions 51b to allow the first box engaging portion 31 to be inserted.

[0058] The first box engagement portion 31 is inserted into the groove 51a of the first tire engagement portion 51. The retaining portion 51b of the first tire engagement portion 51 holds the tip portion 31b of the first box engagement portion 31 so that the tip portion 31b does not slip out of the groove 51a. In this embodiment, the retaining portion 51b of the first tire engagement portion 51 holds the tip portion 31b of the first box engagement portion 31 so that the first box engagement portion 31 does not slip out of the groove 51a of the first tire engagement portion 51, thereby engaging the first box engagement portion 31 with the first tire engagement portion 51. In other words, the retaining portion 51b of the first tire engagement portion 51 gets caught on the tip portion 31b of the first box engagement portion 31, thereby engaging the first box engagement portion 31 with the first tire engagement portion 51.

[0059] The second tire engaging portion 52 has a groove shape. The second tire engaging portion 52 has a groove 52a extending in the width direction of the tire T. A pair of retaining portions 52b is provided on the opening edge of the groove 52a (the bottom portion of the groove 52a). The pair of retaining portions 52b is provided on one side of the opening edge of the groove 52a in the rotational direction of the tire T and on the other side of the opening edge of the groove 52a in the rotational direction of the tire T, respectively. The pair of retaining portions 52b protrude inward from the opening edge of the groove 52a. In other words, the pair of retaining portions 52b are aligned along the rotational direction of the tire T. In addition, a gap is provided between the pair of retaining portions 52b to allow the second box engaging portion 32 to be inserted.

[0060] The second box engagement portion 32 is inserted into the groove 52a of the second tire engagement portion 52. The retaining portion 52b of the second tire engagement portion 52 holds the tip portion 32b of the second box engagement portion 32 so that the tip portion 32b does not slip out of the groove 52a. In this embodiment, the retaining portion 52b of the second tire engagement portion 52 holds the tip portion 32b of the second box engagement portion 32 so that the second box engagement portion 32 does not slip out of the groove 52a of the second tire engagement portion 52, thereby engaging the second box engagement portion 32 with the second tire engagement portion 52. In other words, the retaining portion 52b of the second tire engagement portion 52 gets caught on the tip portion 32b of the second box engagement portion 32, thereby engaging the second box engagement portion 32 with the second tire engagement portion 52.

[0061] 7 , in this embodiment, the first tire engaging portion 51 and the second tire engaging portion 52 are configured by an inner liner layer Td provided on the carcass layer Tc of the tire T (on the inner circumferential surface of the carcass layer Tc). That is, the first tire engaging portion 51 and the second tire engaging portion 52 are configured integrally with the inner liner layer Td. In this case, the first tire engaging portion 51 and the second tire engaging portion 52 may be formed on the carcass layer Tc when manufacturing the tire T. However, the first tire engaging portion 51 and the second tire engaging portion 52 may be separate from the inner liner layer Td. In the case where they are separate, the first tire engaging portion 51 and the second tire engaging portion 52 may be attached to the inner cavity surface Ta (inner liner layer Td) of the tire T using an adhesive or double-sided adhesive tape.

[0062] 7 , in the present embodiment, the opening edge portion of the groove 51 a of the first tire engaging portion 51 protrudes upward (toward the inner diameter side) above the cavity surface Ta of the tire T. Without being limited to this configuration, the first tire engaging portion 51 may be provided in the inner liner layer Td so as not to protrude from the cavity surface Ta of the tire T, or may be provided in the inner liner layer Td so as to entirely protrude from the cavity surface Ta of the tire T. Like the first tire engaging portion 51, the second tire engaging portion 52 is not limited to the configuration shown in FIG.

[0063] Next, a configuration for reducing resonance noise within the tire cavity S of the tire T using the resonance box 10 of the resonance sound absorber 1 will be described. Here, as shown in FIG. 1 , F is the frequency of tire cavity resonance noise, c is the speed of light, R is the radius of the cavity surface Ta of the tire T, r is the radius of the rim Ha of the wheel H mounted on the tire T, and π is the circular constant. In this case, the frequency of tire cavity resonance noise is calculated by F = c / ((R + r) × π). The resonance box 10 of the resonance sound absorber 1 preferably has a Helmholtz resonance structure that generates Helmholtz resonance with a resonance frequency within a range of ±100 Hz of the frequency of tire cavity resonance noise calculated from F = c / ((R + r) × π).

[0064] The Helmholtz resonance structure is a structure that includes components of a Helmholtz resonator that resonates with sound incident through an opening. In the resonance sound absorber 1, the Helmholtz resonance structure is formed by the resonance box 10. That is, in the resonance box 10, the non-air-permeable neck portion 15 connects the opening 13 and the hollow portion 12, and therefore the resonant frequency of the resonance box 10, which functions as a Helmholtz resonator, varies depending on the extension length of the neck portion 15, the inner diameter of the opening 13, and the like. For example, the longer the extension length of the neck portion 15, the lower the resonant frequency. Furthermore, the smaller the inner diameter of the opening 13, the lower the resonant frequency. For this reason, it is preferable that these conditions of the resonance box 10 be adjusted so that Helmholtz resonance occurs at a resonant frequency within a range of ±100 Hz of the frequency of tire cavity resonance sound calculated from F = c / ((R + r) × π).

[0065] In this way, by providing a Helmholtz resonance structure that generates Helmholtz resonance at a resonance frequency within a range of ±100 Hz of the frequency of tire cavity resonance noise, tire cavity resonance noise can be reduced.

[0066] 8 is a diagram for explaining a method for calculating the resonant frequency of the Helmholtz resonance structure. The resonant frequency of the Helmholtz resonance structure, which resonates with the sound incident from the opening 13, can be adjusted from various dimensions of the hollow portion 12 according to this calculation method.

[0067] In Figure 8, V is the volume of the hollow portion 12. If a neck portion 15 extends into the hollow portion 12, the volume obtained by subtracting the volume of the neck portion 15 is taken as V. α is the area of ​​the opening 13 when viewed from the thickness direction of the outer wall 11. δ is an opening end correction; for example, if the shape of the opening 13 is circular, δ can be calculated as 0.8 times the diameter of the opening 13. If the shape of the opening 13 is not circular, δ can be calculated as 0.8 times the diameter of a perfect circle having the same area as the area of ​​the opening 13. L is the depth of the opening 13, i.e., the extension length of the neck portion 15 (hollow portion).

[0068] Next, a method for attaching the resonance sound absorber 1 to the lumen surface Ta of the tire T will be described. First, a tire engagement portion 5 is provided on the lumen surface Ta of the tire T (a step of providing a tire engagement portion). The tire engagement portion 5 may be formed on the lumen surface Ta during the manufacture of the tire T. Alternatively, the tire engagement portion 5 may be attached to the lumen surface Ta after the tire T is completed.

[0069] Next, the box engagement portion 30 of the resonance sound absorber 1 is engaged with the tire engagement portion 5, and the resonance sound absorber 1 is attached to the inner cavity surface Ta of the tire T (step of attaching the resonance sound absorber). At this time, in this embodiment, the first box engagement portion 31 of the resonance sound absorber 1 is inserted into the first tire engagement portion 51, and the second box engagement portion 32 of the resonance sound absorber 1 is inserted into the second tire engagement portion 52. As a result, the box engagement portion 30 of the resonance sound absorber 1 engages with the tire engagement portion 5 provided on the tire T, and the resonance sound absorber 1 is attached to the inner cavity surface Ta of the tire T.

[0070] As described above, the resonance sound absorber 1 is attached to the inner cavity surface Ta of the tire T by engaging the box engaging portion 30 provided on the resonance box 10 with the tire engaging portion 5. In other words, the resonance sound absorber 1 is attached to the inner cavity surface Ta of the tire T such that the resonance box 10 is spaced or can be spaced from the inner cavity surface Ta of the tire T. Therefore, with this resonance sound absorber 1, even if the tire T deforms, stress from the tire T is not directly applied to the resonance box 10. This suppresses deformation of the resonance box 10, allowing the resonance box 10 to appropriately absorb sound. In this way, when attached to the inner cavity surface Ta of the tire T, the resonance sound absorber 1 can suppress the resonance box 10 from being affected by stress from the tire T.

[0071] The box engaging portion 30 is provided on a flange 20 that extends outward from the outer surface of the resonance box 10. This allows the resonance sound absorber 1 to further suppress the application of stress from the tire T to the resonance box 10 even when the tire T is deformed.

[0072] The flange 20 has a first flange 21 extending outward from one end of the outer surface of the resonance box 10, and a second flange 22 extending outward from the other end of the outer surface of the resonance box 10. The box engaging portion 30 has a first box engaging portion 31 provided on the first flange 21 and a second box engaging portion 32 provided on the second flange 22. In this case, the resonance box 10 is sandwiched between the first box engaging portion 31 and the second box engaging portion 32, and is attached to the tire T in a state separated from or releasable from the inner surface Ta of the tire T. This allows the resonance sound absorber 1 to more reliably attach the resonance box 10 to the inner surface Ta of the tire T while suppressing the resonance box 10 from being affected by stress from the tire T.

[0073] The Shore A hardness of the flange 20 and the box engaging portion 30 is higher than the Shore A hardness of the resonance box 10. In this case, the high hardness of the flange 20 and the box engaging portion 30 suppresses deformation of the flange 20 and the box engaging portion 30. This enables the resonance sound absorber 1 to suppress the box engaging portion 30 from deforming and coming off the tire engaging portion 5 (disengaging from the engaged state).

[0074] The first tire engagement portion 51 and the second tire engagement portion 52 are concave. The first box engagement portion 31 and the second box engagement portion 32 of the resonance sound absorber 1 are convex so as to be inserted into the first tire engagement portion 51 and the second tire engagement portion 52, respectively. In this case, in the resonance sound absorber 1, the first box engagement portion 31 and the second box engagement portion 32 can be easily engaged with the first tire engagement portion 51 and the second tire engagement portion 52 by inserting them into them, respectively. Furthermore, by making the first box engagement portion 31 and the second box engagement portion 32 convex, the weight of the resonance sound absorber 1 can be reduced compared to when the first box engagement portion 31 and the second box engagement portion 32 are concave.

[0075] The first tire engagement portion 51 and the second tire engagement portion 52 are each groove-shaped. The first box engagement portion 31 and the second box engagement portion 32 are strip-shaped. In this case, the resonance sound absorber 1 can ensure a long engagement area between the first box engagement portion 31 and the first tire engagement portion 51 by engaging the strip-shaped first box engagement portion 31 with the groove-shaped first tire engagement portion 51. Furthermore, the resonance sound absorber 1 can ensure a long engagement area between the second box engagement portion 32 and the second tire engagement portion 52 by engaging the strip-shaped second box engagement portion 32 with the groove-shaped second tire engagement portion 52. This allows the resonance sound absorber 1 to more reliably attach the resonance box 10 to the inner cavity surface Ta of the tire T.

[0076] The outer shape of the tip portion 31b of the first box engagement portion 31 is larger than the outer shape of the base end portion 31a. The outer shape of the tip portion 32b of the second box engagement portion 32 is larger than the outer shape of the base end portion 32a. In this case, when the first box engagement portion 31 is inserted into the first tire engagement portion 51, the tip portion 31b of the first box engagement portion 31 is more likely to catch on the first tire engagement portion 51. Furthermore, when the second box engagement portion 32 is inserted into the second tire engagement portion 52, the tip portion 32b of the second box engagement portion 32 is more likely to catch on the second tire engagement portion 52. This allows the resonance sound absorber 1 to more reliably attach the resonance box 10 to the inner cavity surface Ta of the tire T.

[0077] The resonance sound absorber 1 has a hollow neck portion 15 that connects the resonance box 10 and the hollow portion 12. Therefore, with the resonance sound absorber 1, the resonant frequency of Helmholtz resonance can be adjusted by adjusting the length of the neck portion 15. Furthermore, by lengthening the neck portion 15, Helmholtz resonance with a resonant frequency in the low-frequency range can be generated. Therefore, the resonance sound absorber 1 can reduce low-frequency resonance sounds such as tire cavity resonance sounds.

[0078] In the resonance sound absorber 1, the neck portion 15 is disposed on the bottom wall portion 11a so as to extend along the bottom wall portion 11a, so that the resonance sound absorber 1 can suppress movement of the neck portion 15 due to centrifugal force when the tire T rotates.

[0079] The mounting method for the resonance sound absorber 1 includes the steps of providing a tire engagement portion 5 on the cavity surface Ta of the tire T, and engaging the box engagement portion 30 of the resonance sound absorber 1 with the tire engagement portion 5 to mount the resonance sound absorber 1 to the cavity surface Ta of the tire T. In this manner, this mounting method includes the step of providing the tire engagement portion 5 on the cavity surface Ta of the tire T. As a result, this mounting method makes it possible to engage the box engagement portion 30 of the resonance sound absorber 1 with the tire engagement portion 5 provided on the cavity surface Ta of the tire T. In this manner, this mounting method makes it possible to mount the resonance sound absorber 1, which can suppress the effect of stress from the tire T on the resonance box 10, on the cavity surface Ta of the tire T.

[0080] Second Embodiment A resonant sound absorber 1A according to a second embodiment will be described with reference to Figures 9 to 11. The second embodiment is basically the same as the first embodiment (Figures 2 to 5), and differs from the first embodiment only in that it includes a support portion. Therefore, only the differences from the first embodiment will be described below, and a description of the same aspects as the first embodiment will be omitted.

[0081] Fig. 9 is a schematic cross-sectional view of a resonance sound absorber according to the second embodiment. Fig. 10 is a schematic cross-sectional view taken along line X-X in Fig. 9. Fig. 11 is a schematic cross-sectional view taken along line XI-XI in Fig. 9. As shown in Figs. 9 to 11, a resonance box 10A of a resonance sound absorber 1A according to the second embodiment includes an outer wall 11, a hollow portion 12, an opening 13, a neck portion 15, and a support portion 17.

[0082] The support portion 17 is a portion for supporting the top wall portion 11b relative to the bottom wall portion 11a. The support portion 17 extends from the bottom wall portion 11a side to the top wall portion 11b side in the hollow portion 12. Specifically, the support portion 17 is configured as a plate-shaped rib and extends in the third direction D3 from the neck portion 15 to the top wall portion 11b. In other words, the support portion 17 supports the top wall portion 11b relative to the bottom wall portion 11a via the neck portion 15. The support portion 17 has a shape that allows the hollow portion 12 to maintain a single space. For example, the support portion 17 has a shape in which a portion between the neck portion 15 and the second side wall portion 11d is cut out. The support portion 17 may support the top wall portion 11b only in a portion of the first direction D1, or may support the top wall portion 11b over the entire first direction D1. For example, the support portion 17 may be connected to the top wall portion 11b over the entire area in the first direction D1 so as to support the top wall portion 11b over the entire area in the first direction D1.

[0083] As described above, in the resonant sound absorber 1A of the second embodiment, the resonance box 10A is provided with a support portion 17 that supports the top wall portion 11b against the bottom wall portion 11a, thereby suppressing deformation of the top wall portion 11b due to centrifugal force when the tire T rotates.

[0084] The present disclosure is not limited to the above-described embodiments, and modifications can be made as appropriate without departing from the spirit of the present disclosure.

[0085] For example, the manner of engagement between the box engagement portion 30 and the tire engagement portion 5 is not limited to the configuration described above. In the above, the convex box engagement portion 30 is inserted into the concave tire engagement portion 5, but the convex tire engagement portion may be inserted into the concave box engagement portion and engaged with each other. Furthermore, the engagement between the box engagement portion and the tire engagement portion only needs to be such that the resonant sound absorber does not fall off from the inner cavity surface of the tire. For example, the engagement between the box engagement portion and the tire engagement portion may be such that the box engagement portion and the tire engagement portion are fitted together, the convex box engagement portion is press-fitted into the concave tire engagement portion, or the convex tire engagement portion is press-fitted into the concave box engagement portion, etc.

[0086] For example, the resonance sound absorber may not have a flange. In this case, the box engaging portion may be attached directly to the resonance box. Even in this case, by providing the box engaging portion in the resonance sound absorber, the resonance box can be more reliably attached to the tire inner surface while suppressing the effect of stress on the resonance box from the tire.

[0087] Furthermore, for example, the shape of the outer wall of the resonance box, the position of the opening, the position of the neck, the shape of the support, etc. are not particularly limited and can be modified in various ways. For example, the above-mentioned resonance sound absorber may be configured to include multiple resonance boxes.

[0088] The gist of the present disclosure is as follows: [1] to

[12] . [1] A resonance sound absorber to be attached to the inner cavity surface of a tire, comprising: a resonance box having an opening that connects a hollow portion formed on the inside with an external space; and a box engaging portion that is provided on the resonance box and engages with a tire engaging portion that is provided on the inner cavity surface of the tire. [2] The resonance sound absorber according to [2] above, comprising a flange portion that extends outward from an outer surface of the resonance box, the box engaging portion being provided on the flange portion. [3] The resonance sound absorber according to [2] above, wherein the flange portion has a first flange portion that extends outward from one end of the outer surface of the resonance box and a second flange portion that extends outward from the other end of the outer surface of the resonance box, and the box engaging portion has a first box engaging portion provided on the first flange and a second box engaging portion provided on the second flange. [4] The resonance sound absorber according to [2] or [3] above, wherein the Shore A hardness of the flange portion and the box engagement portion is higher than the Shore A hardness of the resonance box. [5] The resonance sound absorber according to [1] above, wherein the box engagement portion has a first box engagement portion and a second box engagement portion, the first box engagement portion being provided at one end of the resonance box, and the second box engagement portion being provided at the other end of the resonance box. [6] The resonance sound absorber according to any one of [1] to [5] above, wherein the tire engagement portion has a concave shape, and the box engagement portion has a convex shape that is inserted into the tire engagement portion. [7] The resonance sound absorber according to [6] above, wherein the tire engagement portion has a groove shape, and the box engagement portion has a strip shape that extends along the groove of the tire engagement portion. [8] The sound-resonating body according to [6] or [7] above, wherein the outer shape of the convex tip portion of the box engaging portion is larger than the outer shape of the convex base end portion of the box engaging portion. [9] The sound-resonating body according to any one of [1] to [8] above, wherein the resonance box has a hollow neck portion that communicates with the opening and the hollow portion.

[10] The sound-resonating body according to [9] above, wherein the resonance box has a bottom wall portion that faces the inner cavity surface of the tire and a top wall portion that forms the hollow portion between itself and the bottom wall portion, and the neck portion is disposed on the bottom wall portion so as to extend along the bottom wall portion.

[11] The resonance sound absorber according to any one of [1] to [9], wherein the resonance box comprises a bottom wall portion facing the inner cavity surface of the tire, a top wall portion forming the hollow portion between itself and the bottom wall portion, and a support portion supporting the top wall portion against the bottom wall portion.

[12] A method for attaching the resonance sound absorber according to any one of [1] to

[11] above to the inner cavity surface of the tire, the method comprising the steps of: providing the tire engaging portion on the inner cavity surface of the tire; and attaching the resonance sound absorber to the inner cavity surface of the tire by engaging the box engaging portion with the tire engaging portion.

[0089] 1, 1A...resonance sound absorber, 5...tire engagement portion, 10, 10A...resonance box, 11...outer wall, 11a...bottom wall portion, 11b...top wall portion, 12...hollow portion, 13...opening, 15...neck portion, 17...support portion, 20...flange, 21...first flange, 22...second flange, 30...box engagement portion, 31...first box engagement portion, 31a...base end portion, 31b...tip portion, 32...second box engagement portion, 32a...base end portion, 32b...tip portion, 51...first tire engagement portion, 52...second tire engagement portion, T...tire, Ta...inner cavity surface.

Claims

1. A resonance sound absorber attached to the inner cavity surface of a tire, comprising a resonance box having an opening that communicates a hollow portion formed inside with an external space, and a box engaging portion provided on the resonance box and engaging with a tire engaging portion provided on the inner cavity surface of the tire.

2. The resonance sound absorber according to claim 1, further comprising a flange portion extending outward from the outer surface of the resonance box, wherein the box engaging portion is provided on the flange portion.

3. The flange portion has a first flange portion extending outward from one end of the outer surface of the resonance box and a second flange portion extending outward from the other end of the outer surface of the resonance box, and the box engaging portion has a first box engaging portion provided on the first flange and a second box engaging portion provided on the second flange. The resonance sound absorber according to claim 2.

4. The resonance sound absorber according to claim 2, wherein the Shore A hardness of the flange portion and the box engaging portion is higher than the Shore A hardness of the resonance box.

5. The box engaging portion has a first box engaging portion and a second box engaging portion. The first box engaging portion is provided at one end of the resonance box, and the second box engaging portion is provided at the other end of the resonance box. The resonance sound absorber according to claim 1.

6. The tire engaging portion has a concave shape, and the box engaging portion has a convex shape to be inserted into the tire engaging portion. The resonance sound absorber according to claim 1.

7. The tire engaging portion has a groove shape, and the box engaging portion has a strip shape extending along the groove of the tire engaging portion. The resonance sound absorber according to claim 6.

8. The outer shape of the tip portion of the convex shape in the box engaging portion is larger than the outer shape of the base end portion of the convex shape in the box engaging portion. The resonance sound absorber according to claim 6.

9. The resonance box includes a hollow neck portion that communicates the opening with the hollow portion. The resonance sound absorber according to claim 1.

10. The resonance box includes a bottom wall portion facing the inner cavity surface of the tire and a top wall portion that forms the hollow portion between the bottom wall portion. The neck portion is disposed on the bottom wall portion so as to extend along the bottom wall portion. The resonance sound absorber according to claim 9.

11. The resonance box includes a bottom wall portion facing the inner cavity surface of the tire, a top wall portion forming the hollow portion between the bottom wall portion, and a support portion supporting the top wall portion with respect to the bottom wall portion. The resonance sound absorber according to claim 1.

12. A method of attaching a resonance sound absorber according to any one of claims 1 to 11 to the inner cavity surface of a tire, the method including: providing the tire engaging portion on the inner cavity surface of the tire; and engaging the box engaging portion with the tire engaging portion to attach the resonance sound absorber to the inner cavity surface of the tire. A method of attaching a resonance sound absorber.

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