Resonant sound absorber and method for installing the resonant sound absorber

Abstract

The resonance sound absorber is attached to the inner cavity surface of the tire and includes a resonance box having an opening that connects a hollow portion formed on the inside with an external space, and a box engagement portion that is provided on the resonance box and engages with a tire engagement portion that is provided on the inner cavity surface of the tire.

Description

[Technical field]

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

[0002] 2. Description of the Related Art Conventionally, a resonance sound absorber that reduces tire cavity resonance noise generated when a vehicle is traveling by using Helmholtz resonance has been known (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-067767 Summary of the Invention [Problem to be solved by the invention]

[0004] In such a resonance sound absorber, a resonance box that absorbs sound by Helmholtz resonance is attached to the inner cavity surface of the tire. When the tire tread surface deforms due to the influence of road surface unevenness, etc., the inner cavity surface of the tire also deforms, and stress is applied to the resonance box attached to the inner cavity surface. When the resonance box deforms, it may not be possible for the resonance sound absorber to absorb sound appropriately. Conventionally, the resonance box is attached to the inner cavity surface of the tire using an adhesive or double-sided adhesive tape, but in this case, the resonance box is easily subjected to stress due to tire deformation.

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

[0006] The resonant sound absorber of the present disclosure is a resonant sound absorber that is 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 engagement portion that is provided on the resonance box and engages with a tire engagement 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 in a state in which the resonance box is separated from the tire cavity surface or can be separated from it. Therefore, in this resonance sound absorber, even if the tire is deformed, stress from the tire is not directly applied to the resonance box. This suppresses deformation of the resonance box, and the resonance box can appropriately absorb sound. In this way, when the resonance sound absorber is attached to the tire cavity surface, it is possible to suppress the resonance box from being affected by stress from the tire.

[0008] The above-mentioned resonance sound absorber may include a flange portion extending outward from an outer surface of the resonance box, and the box engagement portion may be provided on the flange portion, thereby making it possible to further suppress the application of stress from the tire to the resonance box even when the tire is deformed.

[0009] In the above-mentioned 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 in a state separated or separable from the inner surface of the tire so as to be sandwiched between the first box engaging portion and the second box engaging portion. This allows the resonance sound absorber to more reliably attach the resonance box to the inner surface of the tire while suppressing the effect of stress on the resonance box from the tire.

[0010] In the above-mentioned resonance sound absorber, the Shore A hardness of the flange portion and the box engagement 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 engagement portion suppresses deformation of the flange portion and the box engagement portion. This makes it possible for the resonance sound absorber to suppress the box engagement portion from deforming and coming off the tire engagement portion (disengaging the engagement state).

[0011] In the above-mentioned resonance sound absorber, the box engagement portion may have 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. In this case, the resonance box is attached in a state separated or capable of being separated from the inner cavity surface of the tire by the first box engagement portion and the second box engagement portion. This allows the resonance sound absorber to more reliably attach the resonance box to the inner cavity surface of the tire while suppressing the effect of stress on the resonance box from the tire.

[0012] In the above-mentioned 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 the box engagement portion into the tire engagement portion. In addition, by making the box engagement portion convex, the weight of the resonance sound absorber can be reduced compared to when the box engagement portion is concave.

[0013] In the above-mentioned 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 portion 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 inner cavity surface of the tire.

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

[0015] In the above-mentioned resonance sound absorber, the resonance box may have a hollow neck portion that communicates between the opening and the hollow portion. In this resonance sound absorber, since the resonance box has a hollow neck portion that communicates between the opening and the hollow portion, the resonance frequency of the 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 range resonance sounds such as tire cavity resonance sounds.

[0016] In the above-mentioned 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-mentioned resonance sound absorber, the resonance box may include a bottom wall portion facing the inner cavity surface of the tire, a top wall portion forming a hollow portion between the bottom wall portion and the resonance box, and a support portion supporting the top wall portion against the bottom wall portion. In this resonance sound absorber, since the resonance box includes the support portion supporting the top wall portion against the bottom wall portion, deformation of the top wall portion due to centrifugal force when the tire rotates can be further suppressed.

[0018] The mounting method of the resonance sound absorber according to the present disclosure is a mounting method for mounting any of the above-mentioned resonance sound absorbers to the inner cavity surface of a tire, and includes a step of providing a tire engagement portion on the inner cavity surface of the tire, and a step of engaging the box engagement portion with the tire engagement portion to mount the resonance sound absorber to the inner cavity surface of the tire. Thus, this mounting method includes a step of providing a tire engagement portion on the inner cavity surface of the tire. As a result, in this mounting method, the box engagement portion of the resonance sound absorber can be engaged with the tire engagement portion provided on the inner cavity surface of the tire. Thus, in this mounting method, a resonance sound absorber that can suppress the effect of stress on the resonance box from being affected by the tire can be mounted on the inner cavity surface of the tire. Effect of the Invention

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

[0020] [Figure 1] FIG. 1 is a schematic cross-sectional view of a tire to which a sound absorber according to the first embodiment is attached. [Diagram 2] FIG. 2 is a schematic front view of the resonant sound absorber according to the first embodiment, as viewed from the opening side. [Diagram 3] FIG. 3 is a schematic top view of the resonant sound absorber according to the first embodiment as viewed from above. [Figure 4] FIG. 4 is a schematic cross-sectional view taken along line IV-IV shown in FIG. [Diagram 5] FIG. 5 is a schematic cross-sectional view taken along line VV shown in FIG. [Figure 6] FIG. 6 is a schematic plan view showing a tire engaging portion provided on the inner surface of a tire. [Figure 7] FIG. 7 is a schematic cross-sectional view showing a state in which a resonant sound absorber is attached to the inner cavity surface of a tire. [Figure 8] FIG. 8 is a diagram for explaining a method of calculating the resonant frequency of the Helmholtz resonance structure. [Figure 9]FIG. 9 is a schematic cross-sectional view of a resonance sound absorber according to the second embodiment. [Figure 10] FIG. 10 is a schematic cross-sectional view taken along the line XX shown in FIG. [Figure 11] FIG. 11 is a schematic cross-sectional view taken along line XI-XI shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, the embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are given the same reference numerals, and duplicated explanations will be omitted. In addition, a numerical range indicated using "~" indicates a range including the numerical values ​​before and after "~" as the minimum and maximum values, respectively.

[0022] (First implementation) FIG. 1 is a schematic cross-sectional view of a tire to which a resonant sound absorber according to a first embodiment is attached. In the tire T, cavity resonance may occur in which the air in the cavity S resonates due to vibrations caused when the vehicle passes over uneven road surfaces during travel. The frequency of the cavity resonance is about 200 Hz to 300 Hz, typically about 250 Hz. The resonant 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 shifted 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, as viewed from the opening side. Fig. 3 is a schematic top view of the resonance sound absorber according to the first embodiment, as viewed from above. Fig. 4 is a schematic cross-sectional view taken along line IV-IV shown in Fig. 2. Fig. 5 is a schematic cross-sectional view taken along line VV shown in Fig. 4.

[0025] 2 to 5, the resonance sound 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 in 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 and the hollow portion 12.

[0026] The outer wall 11 has a degree of self-supporting property that allows it to 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, for example, GS-709N TYPE A manufactured by Techlock Co., Ltd. If the allowable number of test pieces stacked in JIS K6253-3 (three or less) 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 resin such as a rubber-like material, and the like.

[0029] Examples of elastomer materials include thermoplastic elastomers such as styrene block copolymers (SBC), polyolefins (TPO), polyurethanes (TPU), polyesters (TPC), polyamides (TPA), dynamically crosslinked (TPV), soft polyvinyl chloride (PVC), and acrylics.

[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] An example of the rubber-like material is an acrylic rubber-like material having UV curing properties.

[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, an ellipse, etc., but in this embodiment, the opening 13 is a circular hole. That is, the cross-sectional shape of the opening 13 is circular. The inner diameter of the opening 13 is, for example, about 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 a rectangular plate shape that is long in a first direction D1 and short in a second direction D2 perpendicular to the first direction D1. A direction perpendicular to the first direction D1 and the second direction D2 is called 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 to the bottom wall portion 11a. The top wall portion 11b is curved in a convex shape. The top wall portion 11b being curved in a convex shape means that the top wall portion 11b is curved so as to be convex on the side opposite to the bottom wall portion 11a in the third direction D3, that the top wall portion 11b is curved so as to be convex in the direction away from the bottom wall portion 11a, or that the top wall portion 11b is curved so as to be convex on the side opposite to the hollow portion 12. To be more specific, the top wall portion 11b is formed in an arc shape (arch shape) in a cross section perpendicular to the first direction D1 (a cross section along the second direction D2 and the third direction D3). Then, 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 an arc-shaped curved plate shape so as to be 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 at 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 (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 first side wall portion 11c in the first direction D1 of the outer wall 11. 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 end 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 a flat plate shape extending in a direction perpendicular to the first direction D1 (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 of the neck portion 15 are open ends at which the 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 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 of the neck portion 15.

[0040] The neck portion 15 has non-air permeability similar to that of the resonance box 10. The neck portion 15 has a Shore A hardness similar to that of 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 equal to or larger than the cross section of the opening 13. The resonance frequency of the resonance box 10 can be lowered by increasing the extension length of the neck portion 15. That is, the resonance sound in the low frequency range can be reduced by increasing the extension length of the neck portion 15. 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 of the neck portion 15.

[0042] The neck portion 15 is disposed on the bottom wall portion 11a so as to extend along the bottom wall portion 11a. The neck portion 15 is, for example, integrally formed with the bottom wall portion 11a and connected to the bottom wall portion 11a. 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 this 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. In addition, as shown in Fig. 3, in this embodiment, the length of the first flange 21 and the second flange 22 in the first direction D1 is approximately the same as the length of the outer wall 11 in the first direction D1.

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

[0047] The first box engagement portion 31 is provided on the first flange 21. The first box engagement portion 31 is provided on an outer surface of the first flange 21 that faces the inner cavity surface Ta of the tire T (see FIG. 7). The first box engagement 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 engagement portion 31 is inserted into the concave first tire engagement portion 51 (tire engagement 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 tip portion 31b which is a part on the tip side of the convex shape, and a base portion 31a which is a part on the base side of the convex shape. The tip portion 31b is attached to the first flange 21 via the base portion 31a. The outer shape of the tip portion 31b is larger than that of the base portion 31a. In this embodiment, when viewed along the first direction D1, the outer shape of the tip portion 31b is larger than that of the base portion 31a. Note that the outer shape of the tip portion 31b is larger than that of the base portion 31a only needs to satisfy this relationship when the tip portion 31b and the base 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 engagement portion 32 is provided on the second flange 22. The second box engagement portion 32 is provided on an outer surface of the second flange 22 that faces the inner cavity surface Ta of the tire T (see FIG. 7). The second box engagement 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 engagement portion 32 is inserted into the concave second tire engagement portion 52 (tire engagement 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 tip portion 32b which is a part on the tip side of the convex shape, and a base portion 32a which is a part on the base side of the convex shape. The tip portion 32b is attached to the second flange 22 via the base portion 32a. The outer shape of the tip portion 32b is larger than that of the base portion 32a. In this embodiment, when viewed along the first direction D1, the outer shape of the tip portion 32b is larger than that of the base portion 32a. Note that the outer shape of the tip portion 32b is larger than that of the base portion 32a only needs to satisfy this relationship when the tip portion 32b and the base portion 32a are viewed from any direction perpendicular to the protruding direction (third direction D3) of the second box engagement portion 32.

[0053] The material of the flange 20 and the box engaging portion 30 can be the same as the material of 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, when 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, the flange 20, and the 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 side 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 inner cavity surface of the tire. Fig. 7 is a schematic cross-sectional view showing a state in which the resonance sound absorber is attached to the inner cavity surface of the tire. As shown in Figs. 6 and 7, a tire engagement portion 5 is provided on the inner 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 and holds the resonance sound absorber 1 on the inner 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 engagement portion 51 has a groove shape. The first tire engagement 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 edge portion of the groove 51a). The pair of retaining portions 51b are provided on one side of the opening edge of the groove 51a in the rotation direction of the tire T and on the other side of the rotation direction of the tire T, respectively. The pair of retaining portions 51b protrude inward from the opening edge of the groove 51a. That is, the pair of retaining portions 51b are aligned along the rotation direction of the tire T. In addition, a gap is provided between the pair of retaining portions 51b for inserting the first box engagement portion 31.

[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 of the first box engagement portion 31 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 is hooked onto 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 engagement portion 52 has a groove shape. The second tire engagement 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 edge portion of the groove 52a). The pair of retaining portions 52b are provided on one side of the opening edge of the groove 52a in the rotation direction of the tire T and on the other side of the rotation direction of the tire T, respectively. The pair of retaining portions 52b protrude inward from the opening edge of the groove 52a. That is, the pair of retaining portions 52b are aligned along the rotation direction of the tire T. In addition, a gap is provided between the pair of retaining portions 52b for inserting the second box engagement portion 32.

[0060] The second box engagement portion 32 is inserted into the groove 52a of the second tire engagement portion 52. The holding 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 of the second box engagement portion 32 does not slip out of the groove 52a. In this embodiment, the holding 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 holding portion 52b of the second tire engagement portion 52 is hooked onto 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] As shown in FIG. 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 of being 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 this embodiment, the opening edge portion of the groove 51a of the first tire engagement portion 51 protrudes upward (toward the inner diameter side) from the inner cavity surface Ta of the tire T. Without being limited to this configuration, the first tire engagement portion 51 may be provided in the inner liner layer Td so as not to protrude from the inner cavity surface Ta of the tire T, or may be provided in the inner liner layer Td so as to entirely protrude from the inner cavity surface Ta of the tire T. Similarly to the first tire engagement portion 51, the second tire engagement portion 52 is not limited to the configuration shown in FIG.

[0063] Next, a configuration for reducing the resonance sound in the cavity S of the tire T by the resonance box 10 of the resonance sound absorber 1 will be described. Here, as shown in FIG. 1, the frequency of the tire cavity resonance sound is F, the speed of light is c, the radius of the cavity surface Ta of the tire T is R, the radius of the rim Ha of the wheel H mounted on the tire T is r, and the circular constant is π. In this case, the frequency of the tire cavity resonance sound is calculated by F=c / ((R+r)×π). It is preferable that the resonance box 10 of the resonance sound absorber 1 has a Helmholtz resonance structure that generates a Helmholtz resonance with a resonance frequency within a range of ±100 Hz of the frequency of the tire cavity resonance sound 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 entering from an opening. In the resonance sound absorber 1, the Helmholtz resonance structure is configured by the resonance box 10. That is, in the resonance box 10, the non-air-permeable neck portion 15 communicates with the opening 13 and the hollow portion 12, so that the resonance frequency of the resonance box 10 that functions as a Helmholtz resonator changes 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 resonance frequency. Also, the smaller the inner diameter of the opening 13, the lower the resonance frequency. For this reason, it is preferable that the resonance box 10 has these conditions adjusted so that Helmholtz resonance occurs at a resonance 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 that 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 FIG. 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 set to 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, and 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, that is, the extension length of the neck portion 15 (hollow portion).

[0068] Next, a method for attaching the resonant sound absorber 1 to the cavity surface Ta of the tire T will be described. First, a tire engagement portion 5 is provided on the cavity surface Ta of the tire T (a step of providing a tire engagement portion). The tire engagement portion 5 may be formed on the cavity surface Ta during the manufacture of the tire T. Alternatively, the tire engagement portion 5 may be attached to the cavity 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 and the tire engagement portion 5 provided on the tire T are engaged, 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 engagement portion 30 provided on the resonance box 10 with the tire engagement 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 separated from the inner cavity surface Ta of the tire T or can be separated from the inner cavity surface Ta of the tire T. Therefore, in the resonance sound absorber 1, even if the tire T is deformed, the stress from the tire T is not directly applied to the resonance box 10. This suppresses the deformation of the resonance box 10, and the resonance box 10 can appropriately absorb sound. In this way, when the resonance sound absorber 1 is attached to the inner cavity surface Ta of the tire T, it is possible to suppress the resonance box 10 from being affected by the stress from the tire T.

[0071] The box engagement portion 30 is provided on a flange 20 extending 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 engagement portion 30 has a first box engagement portion 31 provided on the first flange 21, and a second box engagement portion 32 provided on the second flange 22. In this case, the resonance box 10 is attached to the tire T in a state separated from or capable of being separated from the inner cavity surface Ta of the tire T so as to be sandwiched between the first box engagement portion 31 and the second box engagement portion 32. 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 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 engagement 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 engagement portion 30 suppresses deformation of the flange 20 and the box engagement portion 30. This enables the resonance sound absorber 1 to suppress the box engagement portion 30 from deforming and coming off the tire engagement portion 5 (disengaging the engagement 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 each other by inserting them into the first tire engagement portion 51 and the second tire engagement portion 52, respectively. In addition, 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 a case in which 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 portion 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. Also, the resonance sound absorber 1 can ensure a long engagement portion 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 easily caught by the first tire engagement portion 51. Also, 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 easily caught by 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 communicates between the resonance box 10 and the hollow portion 12. Therefore, in the resonance sound absorber 1, the resonance frequency of the Helmholtz resonance can be adjusted by adjusting the length of the neck portion 15. By lengthening the neck portion 15, it is possible to generate Helmholtz resonance with a resonance frequency in the low frequency range. Therefore, in the resonance sound absorber 1, it is possible to 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. Therefore, in the resonance sound absorber 1, it is possible to suppress movement of the neck portion 15 due to centrifugal force when the tire T rotates.

[0079] The mounting method of the resonance sound absorber 1 includes a step of providing a tire engagement portion 5 on the cavity surface Ta of the tire T, and a step of 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 a step of providing the tire engagement portion 5 on the cavity surface Ta of the tire T. As a result, in this mounting method, it is 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, in this mounting method, it is possible to mount the resonance sound absorber 1, which can suppress the resonance box 10 from being affected by stress from the tire T, to the cavity surface Ta of the tire T.

[0080] Second Embodiment A resonant sound absorber 1A according to the 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 part. Therefore, only the differences from the first embodiment will be described below, and a description of the same points as in 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 XX 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 against 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 with a plate-shaped rib and extends in the third direction D3 from the neck portion 15 to the top wall portion 11b. That is, the support portion 17 supports the top wall portion 11b against the bottom wall portion 11a via the neck portion 15. The support portion 17 has a shape capable of maintaining the hollow portion 12 as one 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 part of the first direction D1, or may support the top wall portion 11b over the entire area of ​​the 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 the support portion 17 that supports the top wall portion 11b against the bottom wall portion 11a, so that deformation of the top wall portion 11b due to centrifugal force when the tire T rotates can be suppressed.

[0084] The present disclosure is not limited to the above-described embodiments, and can be modified 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 above-mentioned configuration. 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 to engage with each other. In addition, the engagement between the box engagement portion and the tire engagement portion may be such that the resonance 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.

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

[0087] In addition, 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 this disclosure is as follows [1] to

[12] . [1] A resonant sound absorber attached to the inner cavity surface of a tire, a resonance box having an opening communicating a hollow portion formed inside with an external space; A resonance sound absorber comprising: a box engaging portion provided on the resonance box and engaging with a tire engaging portion provided on an inner cavity surface of the tire. [2] A flange portion extending outward from the outer surface of the resonance box, The resonant sound absorber according to [2] above, wherein the box engagement 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, The resonant sound absorber described in [2] above, wherein 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 resonant 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 box engaging portion has a first box engaging portion and a second box engaging portion, The resonant sound absorber described in [1] above, wherein the first box engagement portion is provided at one end of the resonance box, and the second box engagement portion is provided at the other end of the resonance box. [6] The tire engagement portion has a concave shape, The resonant sound absorber according to any one of the above [1] to [5], wherein the box engagement portion has a convex shape that is inserted into the tire engagement portion. [7] The tire engagement portion has a groove shape, The resonant sound absorber described in [6] above, wherein the box engagement portion has a band shape extending along the groove of the tire engagement portion. [8] The resonant sound absorber described in [6] or [7] above, wherein the outer shape of the convex tip portion of the box engagement portion is larger than the outer shape of the convex base end portion of the box engagement portion. [9] The resonator sound absorber according to any one of the above [1] to [8], wherein the resonance box has a hollow neck portion that communicates with the opening and the hollow portion.

[10] The resonance box includes a bottom wall portion facing an inner cavity surface of the tire and a top wall portion forming the hollow portion between the bottom wall portion and a top wall portion, The resonant sound absorber described in [9] above, wherein the neck portion is disposed on the bottom wall portion so as to extend along the bottom wall portion.

[11] The resonance sound absorber described in any one of [1] to [9], wherein the resonance box includes a bottom wall portion facing an inner cavity surface of the tire, a top wall portion forming the hollow portion between the bottom wall portion and the top 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 the above [1] to

[11] to an inner surface of a tire, comprising: providing the tire engaging portion on an inner surface of the tire; and engaging the box engagement portion with the tire engagement portion to attach the resonant sound absorber to an inner cavity surface of the tire. [Explanation of symbols]

[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 resonant sound absorber attached to an inner cavity surface of a tire, a resonance box having an opening communicating a hollow portion formed inside with an external space; a box engagement portion provided on the resonance box and engaging with a tire engagement portion provided on an inner cavity surface of the tire; The tire engagement portion has a concave shape and a groove shape, A resonant sound absorber, wherein the box engagement portion has a convex shape that is inserted into the tire engagement portion and a band shape that extends along the groove of the tire engagement portion.

2. A flange portion extending outward from an outer surface of the resonance box is provided, The sound absorber according to claim 1 , wherein the box engagement portion is provided on the flange portion.

3. The flange portion has a first flange portion extending outward from one end of an 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, The resonant sound absorber according to claim 2 , wherein the box engaging portion comprises a first box engaging portion provided on the first flange and a second box engaging portion provided on the second flange.

4. The sound absorber according to claim 2 , 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 box engaging portion has a first box engaging portion and a second box engaging portion, The resonance absorber according to claim 1 , wherein 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.

6. The resonant sound absorber according to claim 1 , wherein an outer shape of a convex tip portion of said box engaging portion is larger than an outer shape of a convex base end portion of said box engaging portion.

7. The resonator sound absorber according to claim 1 , wherein the resonator box has a hollow neck portion communicating with the opening and the hollow portion.

8. The resonance box includes a bottom wall portion facing an inner cavity surface of the tire, and a top wall portion forming the hollow portion between the bottom wall portion and a top wall portion, 8. The resonant sound absorber of claim 7, wherein the neck portion is disposed on the bottom wall portion so as to extend along the bottom wall portion.

9. 2. The sound absorber according to claim 1, wherein the resonance box comprises a bottom wall portion facing an inner cavity surface of the tire, a top wall portion forming the hollow portion between the bottom wall portion and the top wall portion, and a support portion supporting the top wall portion against the bottom wall portion.

10. A resonant sound absorber attached to an inner cavity surface of a tire, a resonance box having an opening communicating a hollow portion formed inside with an external space; A box engagement portion provided on the resonance box and engaging with a tire engagement portion provided on an inner cavity surface of the tire; a flange portion extending outward from an outer surface of the resonance box, The box engaging portion is provided on the flange portion, A resonant sound absorber, 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.

11. The resonant sound absorber described in Claim 10, 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 the bottom wall portion and the top 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 claims 1 to 11 to an inner cavity surface of a tire, comprising the steps of: providing the tire engaging portion on an inner surface of the tire; and engaging the box engagement portion with the tire engagement portion to attach the resonant sound absorber to an inner cavity surface of the tire.

Images