Wheels for vehicles

Abstract

The present invention relates to a wheel for a vehicle. The wheel (10) for a vehicle includes a plurality of Helmholtz resonators, each of which includes an auxiliary air chamber (12) connected to a tire air chamber (R) through a communication hole (14). The Helmholtz resonator includes: one or more first Helmholtz resonators, the first Helmholtz resonators being set to have a sound-absorbing characteristic for the first-order resonance frequency of the air column resonance noise in the tire air chamber (R); and one or more second Helmholtz resonators, the second Helmholtz resonators being set to have a sound-absorbing characteristic for the second-order or higher-order resonance frequency of the air column resonance noise.

Description

Technical Field

[0001] The present invention relates to a wheel for a vehicle. Background Art

[0002] As is known, a wheel for a vehicle includes a Helmholtz resonator having an auxiliary air chamber communicating with a tire air chamber through a communication hole to reduce road noise generated when the vehicle is running (see, for example, WO 2015 / 137370). Summary of the Invention

[0003] The vehicle wheel described in WO 2015 / 137370 includes a Helmholtz resonator configured to provide a sound-damping characteristic at or near the first-order resonance frequency of the air column resonance noise in the tire air chamber. As a result, the air column resonance noise of the first-order resonance frequency generated in the tire air chamber while the vehicle is traveling is eliminated, thereby reducing road noise generated during vehicle travel.

[0004] However, the air column resonance noise in the tire air chamber actually includes not only the resonance noise of the first-order resonance frequency, but also the resonance noise of the second-order or higher-order resonance frequency. In the wheel for a vehicle described in WO2015 / 137370, the air column resonance noise of the first-order resonance frequency generated in the tire air chamber while the vehicle is running is eliminated, but the air column resonance noise of the second-order or higher-order resonance frequency generated in the tire air chamber cannot be eliminated. Therefore, the Helmholtz resonator does not have a sufficient silencing effect on the air column resonance noise in the tire air chamber. It is necessary to further improve the silencing effect of the Helmholtz resonator on the air column resonance noise in the tire air chamber.

[0005] The present invention provides a wheel for a vehicle including a Helmholtz resonator, which further improves its noise reduction effect on air column resonance noise in a tire air chamber.

[0006] A wheel for a vehicle according to one aspect of the present invention includes a plurality of Helmholtz resonators, each of which includes an auxiliary air chamber communicating with a tire air chamber through a communication hole.

[0007] In the above aspect, the Helmholtz resonator includes: one or more first Helmholtz resonators set to have a sound-absorbing characteristic for a first-order resonance frequency of air column resonance noise in the tire air chamber; and one or more second Helmholtz resonators set to have a sound-absorbing characteristic for a second-order or higher-order resonance frequency of the air column resonance noise.

[0008] Preferably, the Helmholtz resonators are arranged in the circumferential direction of the wheel (not overlapping each other in the circumferential direction of the wheel) at different positions in the circumferential direction of the wheel, but may also be arranged in the axial direction of the wheel and overlap each other in the circumferential direction of the wheel.

[0009] Thus, the one or more first Helmholtz resonators can remove air column resonance noise of a first-order resonant frequency generated in the tire air chamber, and the one or more second Helmholtz resonators can also remove air column resonance noise of a second-order resonant frequency or higher generated in the tire air chamber. Compared to the vehicle wheel described in WO 2015 / 137370, the Helmholtz resonators increase the muffling effect of the air column resonance noise in the tire air chamber by at least an amount corresponding to the removal of air column resonance noise of a second-order resonant frequency or higher.

[0010] In the above aspect, the number of Helmholtz resonators having a sound-absorbing characteristic for the a-order resonance frequency (a is a natural number) of the air column resonance noise is stipulated to be b (b is a natural number equal to or greater than 2), then one of the b communicating holes of the b Helmholtz resonators is a reference communicating hole, (b–1) natural numbers c equal to or greater than 2 and equal to or less than b are assigned to the (b–1) communicating holes other than the reference communicating hole in a one-to-one correspondence, n is an arbitrary natural number, and the angle z (in degrees) between the reference communicating hole and each of the (b–1) communicating holes other than the reference communicating hole from the reference communicating hole to one side in the circumferential direction of the vehicle can be a value represented by z=–180(c–1) / ab+180n / a.

[0011] According to the research conducted by the inventor, when the arrangement of the b connecting holes of the b Helmholtz resonators having the silencing characteristics for the a-order resonance frequency in the circumferential direction of the wheel is as specified above, the change in the silencing effect of the Helmholtz resonator on the air column resonance noise of the a-order resonance frequency can be minimized (details will be described later).

[0012] In the above aspect, the Helmholtz resonators can be arranged at different positions along the circumferential direction of the wheel. The length of the auxiliary air chamber of the second Helmholtz resonator in the circumferential direction of the wheel can be set to be smaller than the length of the auxiliary air chamber of the first Helmholtz resonator in the circumferential direction of the wheel. The multiple partition walls separating the Helmholtz resonators in the circumferential direction of the wheel can be arranged along the circumferential direction of the wheel so as to have linear symmetry with respect to a line segment passing through the rotational axis of the wheel and corresponding to the diameter. The valve hole for mounting a valve configured to supply air to the tire air chamber can be positioned on the line segment in the circumferential direction of the wheel.

[0013] Thus, the partition wall with mass is arranged with line symmetry about a line segment corresponding to the diameter, and the valve with mass installed in the valve hole is positioned on the line segment corresponding to the diameter in the circumferential direction of the wheel. Consequently, the weight balance of the area on one side of the line segment corresponding to the diameter in the circumferential direction of the wheel and the area on the other side of the line segment corresponding to the diameter in the circumferential direction of the wheel can be made uniform. Since the length of the auxiliary air chamber of the second Helmholtz resonator in the circumferential direction of the wheel is set to be smaller than the length of the auxiliary air chamber of the first Helmholtz resonator in the circumferential direction of the wheel, the weight of the vehicle wheel can be reduced compared to, for example, a case where the auxiliary air chambers of the first and second Helmholtz resonators have equal lengths in the circumferential direction of the wheel and the volume of the auxiliary air chamber of the second Helmholtz resonator is reduced.

[0014] In the above structure, the second Helmholtz resonator may include one or more second Helmholtz resonators that are set to have a muffler characteristic for a resonance frequency equal to the highest-order resonance frequency and are positioned to face the valve hole across the rotation axis in the circumferential direction of the wheel.

[0015] As the order of the resonant frequency of the air column resonance noise generated in the tire air chamber increases, the circumferential length of the Helmholtz resonator, which has a sound-absorbing characteristic for the resonant noise, decreases, and the circumferential distance between the two partition walls defining the Helmholtz resonator in the circumferential direction of the wheel decreases. When one or more second Helmholtz resonators, which have a sound-absorbing characteristic for the highest-order resonant frequency, are positioned facing the valve hole across the rotation axis, as in the above-described structure, the area facing the valve hole in the circumferential direction of the wheel includes more partition walls with mass than the area including the valve hole in the circumferential direction of the wheel. As a result, in this vehicle wheel, the area facing the valve hole in the circumferential direction of the wheel tends to be heavier than the area including the valve hole in the circumferential direction of the wheel. In this regard, according to the above-described structure, the valve having mass is arranged on the valve hole side (relatively light side) in the circumferential direction of the wheel, while being arranged in the valve hole (i.e., when the wheel is used for a vehicle). As a result, the weight balance between the area facing the valve hole in the circumferential direction of the wheel and the area including the valve hole in the circumferential direction of the wheel is close to uniform balance.

[0016] In the above aspect, a vehicle wheel may include: a plurality of hollow portions arranged at different positions along the circumferential direction of the wheel within a rim of the vehicle wheel; a plurality of partition walls provided on the rim of the vehicle wheel and separating adjacent hollow portions along the circumferential direction of the wheel; and a plurality of through-holes provided in the rim of the vehicle wheel and connecting the hollow portions to the tire air chamber. The hollow portions may function as auxiliary air chambers. The through-holes may function as communication holes. The hollow portions and the through-holes within the hollow portions may constitute Helmholtz resonators.

[0017] Thus, for example, the wheel for a vehicle according to the present invention can be realized without separately providing a plurality of resin Helmholtz resonators (auxiliary chamber members) on the wheel. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, wherein like reference numerals represent like elements, and wherein:

[0019] Figure 1 is a cross-sectional view schematically showing a wheel for a vehicle according to one embodiment of the present invention;

[0020] Figure 2 is a cross-sectional view schematically showing a wheel for a vehicle according to one modification; and

[0021] Figure 3 is a cross-sectional view schematically showing a wheel for a vehicle according to another modification. DETAILED DESCRIPTION

[0022] The following will refer to Figure 1 A vehicle wheel 10 according to one embodiment of the present invention will now be described. The vehicle wheel 10 is preferably made of an aluminum alloy, but may also be made of steel or resin. The wheel disc and rim that constitute the vehicle wheel 10 may be integrally formed or may be provided separately.

[0023] like Figure 1 As shown in FIG, a vehicle wheel 10 includes a plurality (specifically, six) of hollow portions 12 arranged within a rim 11 at different positions along the circumferential direction of the wheel (without overlapping each other in the wheel circumferential direction). The six hollow portions 12 are separated from each other in the circumferential direction by a plurality (specifically, six) of partition walls 13, thereby defining independent spaces. Each of the hollow portions 12 has a through-hole 14 that communicates with the tire air chamber R.

[0024] The hollow portion 12, the partition wall 13, and the through hole 14 are integrated into the rim 11. This structure can be achieved by, for example, the manufacturing method described in WO2012 / 114470. The partition wall 13 can be a member provided separately from the rim 11 (for example, a resin or rubber member).

[0025] The hollow portion 12 and the through-holes 14 in the hollow portion 12 constitute a plurality of (specifically, six) Helmholtz resonators H. That is, the hollow portion 12 serves as an auxiliary air chamber 12 of the Helmholtz resonator H, and the through-holes 14 serve as communication holes 14 of the Helmholtz resonator H. Thus, the wheel 10 for a vehicle includes six Helmholtz resonators H integrally incorporated in the rim 11.

[0026] For ease of explanation, Figure 1 As shown in the figure, the six partition walls 13 are referred to as "partition walls 13a, 13b, 13c, 13d, 13e and 13f" and the six Helmholtz resonators H are referred to as "Helmholtz resonators Ha, Hb, Hc, Hd, He and Hf".

[0027] The Helmholtz resonator Ha is defined by the adjacent partition walls 13a and 13b in the wheel circumferential direction. The Helmholtz resonator Hb is defined by the adjacent partition walls 13b and 13c in the wheel circumferential direction. The Helmholtz resonator Hc is defined by the adjacent partition walls 13c and 13d in the wheel circumferential direction. The Helmholtz resonator Hd is defined by the adjacent partition walls 13d and 13e in the wheel circumferential direction. The Helmholtz resonator He is defined by the adjacent partition walls 13e and 13f in the wheel circumferential direction. The Helmholtz resonator Hf is defined by the adjacent partition walls 13f and 13a in the wheel circumferential direction.

[0028] In a wheel 10 for a vehicle, each of the two Helmholtz resonators Hc and Hf is set to have a noise-damping characteristic for a first-order resonance frequency to remove the air column resonance noise of the first-order resonance frequency generated in the tire air chamber R. Each of the two Helmholtz resonators Ha and Hb is set to have a noise-damping characteristic for a second-order resonance frequency to remove the air column resonance noise of the second-order resonance frequency generated in the tire air chamber R. Each of the two Helmholtz resonators Hd and He is set to have a noise-damping characteristic for a third-order resonance frequency to remove the air column resonance noise of the third-order resonance frequency generated in the tire air chamber R. The first-order, second-order, and third-order resonance frequencies of the air column resonance noise in the tire air chamber R are determined, for example, by the length of the tire air chamber R in the wheel circumferential direction.

[0029] The two Helmholtz resonators Ha and Hb having a muffler characteristic for the second-order resonant frequency are adjacent to each other in the circumferential direction. The two Helmholtz resonators Hd and He having a muffler characteristic for the third-order resonant frequency are adjacent to each other in the circumferential direction. The two Helmholtz resonators Hc and Hf having a muffler characteristic for the first-order resonant frequency are not adjacent to each other in the circumferential direction (the two Helmholtz resonators Hd and He having a muffler characteristic for the third-order resonant frequency are interposed between the two Helmholtz resonators Hc and Hf).

[0030] The noise reduction characteristics of each Helmholtz resonator H are determined by, for example, the volume of the auxiliary air chamber 12, the opening diameter of the communication hole 14, and the length of the communication hole 14. Given the same opening diameter and length of the communication hole 14, the volume of the auxiliary air chamber 12 of the Helmholtz resonator H, which has a noise reduction characteristic for the resonant frequency of the air column resonance noise generated in the tire air chamber R, increases as the resonant frequency decreases.

[0031] pass Figure 1 It can be understood that the wheel circumferential length of the auxiliary air chamber 12 of each of the two Helmholtz resonators Hc and Hf having the sound-absorbing characteristics of the first-order resonant frequency is greater than the wheel circumferential length of the auxiliary air chamber 12 of each of the two Helmholtz resonators Ha and Hb having the sound-absorbing characteristics of the second-order resonant frequency, and the wheel circumferential length of the auxiliary air chamber 12 of each of the two Helmholtz resonators Ha and Hb having the sound-absorbing characteristics of the second-order resonant frequency is greater than the wheel circumferential length of the auxiliary air chamber 12 of each of the two Helmholtz resonators Hd and He having the sound-absorbing characteristics of the third-order resonant frequency.

[0032] In the wheel 10 for a vehicle, two Helmholtz resonators Hc and Hf remove air column resonance noise of a first-order resonance frequency generated in the tire air chamber R, two Helmholtz resonators Ha and Hb remove air column resonance noise of a second-order resonance frequency generated in the tire air chamber R, and two Helmholtz resonators Hd and He remove air column resonance noise of a third-order resonance frequency generated in the tire air chamber R. Compared to the wheel for a vehicle described in WO 2015 / 137370 , in which only the air column resonance noise of a first-order resonance frequency generated in the tire air chamber is removed, the silencing effect of the Helmholtz resonators Ha to Hf for the air column resonance noise generated in the tire air chamber R is increased by at least an amount corresponding to the removal of the air column resonance noise of the second- and third-order resonance frequencies.

[0033] In the vehicle wheel 10, the partition walls 13a to 13f are arranged in the circumferential direction of the wheel so as to have line symmetry with respect to a line segment L corresponding to the diameter and passing through the rotation axis O of the vehicle wheel 10. The valve hole 15 for installing a valve (not shown) for supplying air to the tire air chamber R is positioned on the line segment L in the circumferential direction of the wheel.

[0034] Therefore, the partition walls 13a to 13f having mass are arranged to have line symmetry with respect to the line segment L, and the valve having mass installed in the valve hole 15 is positioned on the line segment L in the circumferential direction of the wheel. Therefore, it is possible to make the area on one side of the line segment L in the circumferential direction of the wheel ( Figure 1 The area above the line segment L in the wheel) and the area on the other side of the line segment L in the circumferential direction of the wheel ( Figure 1 The weight balance between the two is uniform (the area below the line segment L in the figure).

[0035] In the wheel 10 for a vehicle, two Helmholtz resonators Hd and He having a muffler characteristic for the highest third-order resonance frequency are positioned to face the valve hole 15 across the rotation axis O in the circumferential direction of the wheel (at Figure 1 to the right of the rotation axis O in FIG).

[0036] As the order of the resonant frequency of the air column resonance noise generated in the tire air chamber increases, the circumferential length of the Helmholtz resonator H having the silencing characteristic for the resonant frequency of the air column resonance noise decreases, and the circumferential distance between the two partition walls 13 that define the Helmholtz resonator H in the circumferential direction of the wheel decreases. When the two Helmholtz resonators Hd and He having the silencing characteristic for the highest third-order resonant frequency are positioned to face the valve hole 15 across the rotation axis O, as described above, the area ( Figure 1 The area facing the valve hole in the circumferential direction of the wheel ( Figure 1 The area on the right side of the rotation axis O in the wheel 10 includes more partition walls 13 with mass. As a result, in the vehicle wheel 10, the area facing the valve hole 15 in the circumferential direction of the wheel tends to be heavier than the area including the valve hole 15 in the circumferential direction of the wheel. In this regard, according to the above-mentioned structure, the valve with mass is arranged on the valve hole side (relatively light side) in the circumferential direction of the wheel, while being arranged in the valve hole (i.e., when the vehicle wheel is in use). As a result, the weight balance between the area facing the valve hole 15 in the circumferential direction of the wheel and the area including the valve hole 15 in the circumferential direction of the wheel approaches a uniform balance.

[0037] In a wheel 10 for a vehicle, as Figure 1As shown, the angle in the wheel circumferential direction between the communication holes 14 of the two Helmholtz resonators Hc and Hf, which have a sound-absorbing characteristic for the first-order resonant frequency, is set to 90 degrees. The angle in the wheel circumferential direction between the communication holes 14 of the two Helmholtz resonators Ha and Hb, which have a sound-absorbing characteristic for the second-order resonant frequency, is set to 45 degrees. The angle in the wheel circumferential direction between the communication holes 14 of the two Helmholtz resonators Hd and He, which have a sound-absorbing characteristic for the third-order resonant frequency, is set to 30 degrees. The effects of this structure will be described below.

[0038] Generally speaking, the waveform of the air column resonance noise generated in the tire chamber of a vehicle wheel is a standing wave that does not move in the wheel's circumferential direction, with the antinodes and nodes alternating in the wheel's circumferential direction. Therefore, in a vehicle wheel including a Helmholtz resonator, the Helmholtz resonator's communication holes alternately pass through the antinodes and nodes of the air column resonance noise as the wheel rotates. As a result, periods of time in which the Helmholtz resonator's noise-absorbing effect increases and periods of time in which it decreases alternate, causing the Helmholtz resonator's noise-absorbing effect to vary. To suppress this variation in noise-absorbing effect, a method is known in which multiple Helmholtz resonators are arranged in the wheel's circumferential direction and the arrangement of the Helmholtz resonator's communication holes in the wheel's circumferential direction is adjusted.

[0039] Regarding the arrangement of the communicating holes of the Helmholtz resonators in the wheel circumferential direction, the inventors have discovered the following. Specifically, assuming that the number of Helmholtz resonators having silencing characteristics for the a-order resonant frequency (a is a natural number) of air column resonance noise is b (b is a natural number equal to or greater than 2), one of the b communicating holes of the b Helmholtz resonators is a reference communicating hole, (b–1) natural numbers c, which are equal to or greater than 2 and equal to or less than b, are assigned in a one-to-one correspondence to the (b–1) communicating holes other than the reference communicating hole, and n is an arbitrary natural number. Then, the angle z (in degrees) between the reference communicating hole and each of the (b–1) communicating holes other than the reference communicating hole, from the reference communicating hole toward one side in the wheel circumferential direction, is the value expressed by equation (1). In this case, it is possible to minimize variations in the silencing effect of the Helmholtz resonator on air column resonance noise at the a-order resonant frequency.

[0040] z=–180(c–1) / ab+180n / a...(1)

[0041] Regarding the Helmholtz resonator having a noise-cancelling characteristic for the first-order (a=1) resonant frequency, in equation (1), when a is 1, b is 2, c is 2, and n is 1, z is 90 degrees. Therefore, Figure 1In the illustrated vehicle wheel 10, two communicating holes 14 of Helmholtz resonators Hc and Hf having a noise-reducing characteristic for a first-order resonant frequency are provided. When the communicating hole 14 of the Helmholtz resonator Hc is defined as a reference communicating hole, the angle z (=90 degrees) between the reference communicating hole and the communicating hole 14 of the Helmholtz resonator Hf, measured counterclockwise from the reference communicating hole in the wheel circumferential direction, is the value expressed by equation (1). Thus, in the vehicle wheel 10, variations in the noise-reducing effect of the two Helmholtz resonators Hc and Hf for air column resonance noise at a first-order resonant frequency can be suppressed.

[0042] Regarding the Helmholtz resonator having a second-order (a=2) resonant frequency, in equation (1), when a is 2, b is 2, c is 2, and n is 1, z is 45 degrees. Figure 1 In the illustrated vehicle wheel 10, the two Helmholtz resonators Ha and Hb have communication holes 14 that have a noise-reducing characteristic for the second-order resonant frequency. When the communication hole 14 of the Helmholtz resonator Ha is defined as a reference communication hole, the angle z (=45 degrees) between the reference communication hole and the communication hole 14 of the Helmholtz resonator Hb, measured counterclockwise from the reference communication hole in the wheel circumferential direction, is the value expressed by equation (1). Thus, in the vehicle wheel 10, variations in the noise-reducing effect of the two Helmholtz resonators Ha and Hb for the air column resonance noise of the second-order resonant frequency can be suppressed.

[0043] Regarding the Helmholtz resonator having a noise-cancelling characteristic of the third-order (a=3) resonance frequency, in equation (1), when a is 3, b is 2, c is 2, and n is 1, z is 30 degrees. Therefore, Figure 1 In the illustrated vehicle wheel 10, two communicating holes 14 for Helmholtz resonators Hd and He having a noise reduction characteristic for the third-order resonant frequency are provided. When the communicating hole 14 for Helmholtz resonator Hd is defined as a reference communicating hole, the angle z (=30 degrees) between the reference communicating hole and the communicating hole 14 for Helmholtz resonator He in the counterclockwise direction from the reference communicating hole in the wheel circumferential direction is the value expressed by equation (1). Thus, in the vehicle wheel 10, variations in the noise reduction effect of the two Helmholtz resonators Hd and He for the air column resonance noise of the third-order resonant frequency can be suppressed.

[0044] As described above, in the wheel 10 for a vehicle, it is possible to minimize the variation in the silencing effect not only for the air column resonance noise of the first-order resonance frequency but also for the air column resonance noise of the second-order and third-order resonance frequencies.

[0045] Function and effect

[0046] In the vehicle wheel 10 according to an embodiment of the present invention, the two Helmholtz resonators Hc and Hf remove the air column resonance noise of the first-order resonant frequency generated in the tire air chamber R. Furthermore, the two Helmholtz resonators Ha and Hb can remove the air column resonance noise of the second-order resonant frequency generated in the tire air chamber R, and the two Helmholtz resonators Hd and He can remove the air column resonance noise of the third-order resonant frequency generated in the tire air chamber R. Compared to the vehicle wheel described in WO2015 / 137370, the Helmholtz resonators Ha to Hf increase the silencing effect of the air column resonance noise in the tire air chamber R by at least an amount corresponding to the removal of the air column resonance noise of the second- and third-order resonant frequencies.

[0047] The present invention is not limited to the above-described exemplary embodiments, and various applications and modifications are possible without departing from the object of the present invention. For example, the following embodiments can be implemented by applying the above-described embodiments.

[0048] In accordance with Figure 1 In the wheel 10 for a vehicle of the embodiment shown in , the two Helmholtz resonators Ha and Hb having the sound-absorbing characteristics of the second-order resonance frequency are adjacent to each other in the circumferential direction, and the two Helmholtz resonators Hd and He having the sound-absorbing characteristics of the third-order resonance frequency are adjacent to each other in the circumferential direction. The two Helmholtz resonators Hc and Hf having the sound-absorbing characteristics of the first-order resonance frequency are not adjacent to each other in the circumferential direction (the two Helmholtz resonators Hd and He having the sound-absorbing characteristics of the third-order resonance frequency are interposed between the two Helmholtz resonators Hc and Hf). Figure 2 A modified wheel 10A for a vehicle is shown in FIG. Figure 2 middle, Figure 1 Parts identical or equivalent to those shown in Figure 1 The same reference numerals as those shown in are denoted to omit description of those components.

[0049] Figure 2 The wheel 10A for a vehicle shown in the figure is different from the wheel 10 for a vehicle in that the two Helmholtz resonators Ha and Hb having the sound-absorbing characteristics of the first-order resonance frequency are adjacent to each other in the circumferential direction, the two Helmholtz resonators Hd and He having the sound-absorbing characteristics of the third-order resonance frequency are adjacent to each other in the circumferential direction, and the two Helmholtz resonators Hc and Hf having the sound-absorbing characteristics of the second-order resonance frequency are not adjacent to each other in the circumferential direction (the two Helmholtz resonators Hd and He having the sound-absorbing characteristics of the third-order resonance frequency are between the two Helmholtz resonators Hc and Hf).

[0050] Figure 2The vehicle wheel 10A shown in FIG. 1 is similar to the vehicle wheel 10 in that the partition walls 13 a to 13 f are arranged in the circumferential direction of the wheel so as to have line symmetry with respect to a line segment L corresponding to the diameter and passing through the rotation axis O of the vehicle wheel 10A, and the valve hole 15 for installing a valve (not shown) for supplying air to the tire air chamber R is positioned on the line segment L in the circumferential direction of the wheel. Therefore, in the vehicle wheel 10A, similar to the vehicle wheel 10, it is possible to make the area on one side of the line segment L in the circumferential direction of the wheel ( Figure 2 The area above the line segment L in the wheel) and the area on the other side of the line segment L in the circumferential direction of the wheel ( Figure 2 The weight balance of the area below the line segment L in the figure is uniform.

[0051] Figure 2 The wheel 10A for a vehicle shown in FIG is similar to the wheel 10 for a vehicle in that two Helmholtz resonators Hd and He having a muffling characteristic for the highest third-order resonance frequency are positioned facing the valve hole 15 ( Figure 2 (The valve is positioned to the right of the rotation axis O in FIG. ). Therefore, in vehicle wheel 10A, similar to vehicle wheel 10, the valve having mass is arranged on the valve hole side (relatively light side) in the circumferential direction of the wheel, while being arranged in the valve hole (i.e., when the vehicle wheel is in use). Thus, the weight balance between the area facing valve hole 15 in the circumferential direction of the wheel and the area including valve hole 15 in the circumferential direction of the wheel approaches a uniform balance.

[0052] exist Figure 2 In the vehicle wheel 10A shown in FIG, the angle between the communication holes 14 of the two Helmholtz resonators Ha and Hb having a first-order resonance frequency noise reduction characteristic is set to 90 degrees in the wheel circumferential direction. The angle between the communication holes 14 of the two Helmholtz resonators Hc and Hf having a second-order resonance frequency noise reduction characteristic is set to 135 degrees in the wheel circumferential direction. The angle between the communication holes 14 of the two Helmholtz resonators Hd and He having a third-order resonance frequency noise reduction characteristic is set to 30 degrees in the wheel circumferential direction.

[0053] Regarding the Helmholtz resonator having a muffler characteristic for the first-order (a=1) resonant frequency, in equation (1), when a is 1, b is 2, c is 2, and n is 1, z is 90 degrees. Figure 2In the illustrated vehicle wheel 10A, the communicating holes 14 of the two Helmholtz resonators Ha and Hb have a noise-reduction characteristic for the first-order resonant frequency. When the communicating hole 14 of the Helmholtz resonator Ha is defined as a reference communicating hole, the angle z (=90 degrees) between the reference communicating hole and the communicating hole 14 of the Helmholtz resonator Hb in the counterclockwise direction from the reference communicating hole in the wheel circumferential direction is the value expressed by equation (1). Thus, in the vehicle wheel 10A, it is possible to suppress variations in the noise-reduction effect of the two Helmholtz resonators Ha and Hb for the air column resonance noise of the first-order resonant frequency.

[0054] Regarding the Helmholtz resonator having a second-order (a=2) resonant frequency, in equation (1), when a is 2, b is 2, c is 2, and n is 2, z is 135 degrees. Therefore, Figure 2 In the illustrated vehicle wheel 10A, the two communicating holes 14 of the Helmholtz resonators Hc and Hf, which have a noise-reducing characteristic for the second-order resonant frequency, are provided. When the communicating hole 14 of the Helmholtz resonator Hc is defined as a reference communicating hole, the angle z (=135 degrees) between the reference communicating hole and the communicating hole 14 of the Helmholtz resonator Hf, measured counterclockwise from the reference communicating hole in the wheel circumferential direction, is the value expressed by equation (1). Thus, in the vehicle wheel 10A, variations in the noise-reducing effect of the two Helmholtz resonators Hc and Hf for the air column resonance noise of the second-order resonant frequency can be suppressed.

[0055] Regarding the Helmholtz resonator having a noise-cancelling characteristic of the third-order (a=3) resonance frequency, in equation (1), when a is 3, b is 2, c is 2, and n is 1, z is 30 degrees. Therefore, Figure 2 In the illustrated vehicle wheel 10A, two communicating holes 14 for Helmholtz resonators Hd and He having a noise-reduction characteristic for the third-order resonant frequency are provided. When the communicating hole 14 for Helmholtz resonator Hd is defined as a reference communicating hole, the angle z (=30 degrees) between the reference communicating hole and the communicating hole 14 for Helmholtz resonator He in the counterclockwise direction from the reference communicating hole in the wheel circumferential direction is the value expressed by equation (1). Thus, in the vehicle wheel 10A, variations in the noise-reduction effect of the two Helmholtz resonators Hd and He for the air column resonance noise of the third-order resonant frequency can be suppressed.

[0056] As described above, in the wheel 10A for a vehicle, similarly to the wheel 10 for a vehicle, variation in the silencing effect can be minimized not only for the air column resonance noise of the first-order resonance frequency but also for the air column resonance noise of the second and third-order resonance frequencies.

[0057] You can also use the Figure 3 A modified wheel 10B for a vehicle is shown in FIG. Figure 3In, with Figure 1 Parts identical or equivalent to those shown in Figure 1 The same reference numerals as those shown in are denoted to omit description of those components.

[0058] Figure 3 The wheel 10B for a vehicle shown in FIG is different from the wheel 10 for a vehicle in that two Helmholtz resonators Ha and Hb having a sound-absorbing characteristic of a first-order resonance frequency are adjacent to each other in the circumferential direction, two Helmholtz resonators He and Hf having a sound-absorbing characteristic of a second-order resonance frequency are adjacent to each other in the circumferential direction, and two Helmholtz resonators Hc and Hd having a sound-absorbing characteristic of a third-order resonance frequency are adjacent to each other in the circumferential direction.

[0059] exist Figure 3 In the vehicle wheel 10B shown in FIG, the angle between the communication holes 14 of the two Helmholtz resonators Ha and Hb having a first-order resonance frequency noise reduction characteristic is set to 90 degrees in the wheel circumferential direction. The angle between the communication holes 14 of the two Helmholtz resonators He and Hf having a second-order resonance frequency noise reduction characteristic is set to 45 degrees in the wheel circumferential direction. The angle between the communication holes 14 of the two Helmholtz resonators Hc and Hd having a third-order resonance frequency noise reduction characteristic is set to 30 degrees in the wheel circumferential direction.

[0060] Regarding the Helmholtz resonator having a muffler characteristic for the first-order (a=1) resonant frequency, in equation (1), when a is 1, b is 2, c is 2, and n is 1, z is 90 degrees. Figure 3 In the illustrated vehicle wheel 10B, the communicating holes 14 of the two Helmholtz resonators Ha and Hb have a noise-reduction characteristic for the first-order resonant frequency. When the communicating hole 14 of the Helmholtz resonator Ha is defined as a reference communicating hole, the angle z (=90 degrees) between the reference communicating hole and the communicating hole 14 of the Helmholtz resonator Hb in the counterclockwise direction from the reference communicating hole in the wheel circumferential direction is the value expressed by equation (1). Thus, in the vehicle wheel 10B, it is possible to suppress variations in the noise-reduction effect of the two Helmholtz resonators Ha and Hb for the air column resonance noise of the first-order resonant frequency.

[0061] Regarding the Helmholtz resonator having a second-order (a=2) resonant frequency, in equation (1), when a is 2, b is 2, c is 2, and n is 1, z is 45 degrees. Figure 3In the illustrated vehicle wheel 10B, the two Helmholtz resonators He and Hf have communication holes 14 that have a noise-reducing characteristic for the second-order resonant frequency. When the communication hole 14 of the Helmholtz resonator He is defined as a reference communication hole, the angle z (=45 degrees) between the reference communication hole and the communication hole 14 of the Helmholtz resonator Hf, measured counterclockwise from the reference communication hole in the wheel circumferential direction, is the value expressed by equation (1). Thus, in the vehicle wheel 10B, variations in the noise-reducing effect of the two Helmholtz resonators He and Hf for the air column resonance noise of the second-order resonant frequency can be suppressed.

[0062] Regarding the Helmholtz resonator having a noise-cancelling characteristic of the third-order (a=3) resonance frequency, in equation (1), when a is 3, b is 2, c is 2, and n is 1, z is 30 degrees. Therefore, Figure 3 In the illustrated vehicle wheel 10B, the two communicating holes 14 of the Helmholtz resonators Hc and Hd, which have a noise-reducing characteristic for the third-order resonant frequency, are provided. When the communicating hole 14 of the Helmholtz resonator Hc is defined as a reference communicating hole, the angle z (=30 degrees) between the reference communicating hole and the communicating hole 14 of the Helmholtz resonator Hd, in the counterclockwise direction from the reference communicating hole in the wheel circumferential direction, is the value expressed by equation (1). Thus, in the vehicle wheel 10A, variations in the noise-reducing effect of the two Helmholtz resonators Hc and Hd for the air column resonance noise of the third-order resonant frequency can be suppressed.

[0063] As described above, in the wheel 10B for a vehicle, similarly to the wheel 10 for a vehicle, variation in the silencing effect can be minimized not only for the air column resonance noise of the first-order resonance frequency but also for the air column resonance noise of the second and third-order resonance frequencies.

[0064] exist Figure 1 The embodiments shown in Figure 2 and Figure 3 In the modification shown in , two Helmholtz resonators H are provided as the Helmholtz resonators H set to have a silencing characteristic for the first-order resonance frequency of the air column resonance noise in the tire air chamber R. Three or more Helmholtz resonators H or a single Helmholtz resonator H set to have a silencing characteristic for the first-order resonance frequency of the air column resonance noise in the tire air chamber R may be provided.

[0065] exist Figure 1 The embodiments shown in Figure 2 and Figure 3In the modification shown in , two Helmholtz resonators H are provided as the Helmholtz resonators H set to have a sound-absorbing characteristic for the second-order resonance frequency of the air column resonance noise in the tire air chamber R. Three or more Helmholtz resonators H or a single Helmholtz resonator H set to have a sound-absorbing characteristic for the second-order resonance frequency of the air column resonance noise in the tire air chamber R may be provided. Furthermore, the Helmholtz resonator H set in this manner may be omitted.

[0066] exist Figure 1 The embodiments shown in Figure 2 and Figure 3 In the modification shown in , two Helmholtz resonators H are provided as the Helmholtz resonators H set to have a sound-absorbing characteristic for the third-order resonance frequency of the air column resonance noise in the tire air chamber R. Three or more Helmholtz resonators H or a single Helmholtz resonator H set to have a sound-absorbing characteristic for the third-order resonance frequency of the air column resonance noise in the tire air chamber R may be provided. Furthermore, the Helmholtz resonator H set in this manner may be omitted.

[0067] exist Figure 1 The embodiments shown in Figure 2 and Figure 3 In the modification shown in FIG, the Helmholtz resonators Ha to Hf are integrally incorporated in the rim 11. For example, a wheel for a vehicle according to the present invention can be implemented by fixing a plurality of resin Helmholtz resonators (auxiliary air chamber members) to the rim 11.

[0068] In this case, the resin Helmholtz resonators may be arranged in the wheel circumferential direction at different positions (not overlapping each other in the wheel circumferential direction) or may be arranged in the wheel axial direction and overlap each other in the wheel circumferential direction.

Claims

1. A wheel (10) for a vehicle, characterized in that The invention comprises a plurality of Helmholtz resonators, each of which comprises an auxiliary air chamber (12) connected to a tire air chamber (R) through a communication hole (14). Wherein, the Helmholtz resonator comprises: one or more first Helmholtz resonators, the first Helmholtz resonators being set to have a muffler characteristic for a first-order resonance frequency of air column resonance noise in the tire air chamber (R); and one or more second Helmholtz resonators, the second Helmholtz resonators being set to have a sound-absorbing characteristic for a second-order or higher-order resonance frequency of the air column resonance noise, Wherein, it is stipulated that the number of Helmholtz resonators having a sound-absorbing characteristic for the a-order resonance frequency of the air column resonance noise is b and a is a natural number and b is a natural number equal to or greater than 2, then one of the b communicating holes (14) of the b Helmholtz resonators is a reference communicating hole, (b-1) natural numbers c that are equal to or greater than 2 and equal to or less than b are assigned to the (b-1) communicating holes (14) other than the reference communicating hole in a one-to-one correspondence, and n is an arbitrary natural number, and an angle z between the reference communicating hole and each of the (b-1) communicating holes (14) other than the reference communicating hole, from the reference communicating hole to one side in the circumferential direction of the wheel (10), is a value represented by z=-180(c-1) / ab+180n / a, wherein the angle z is in degrees.

2. The wheel (10) according to claim 1, characterized in that: The Helmholtz resonators are arranged along the circumferential direction of the wheel (10) at different positions in the circumferential direction of the wheel (10); The length of the auxiliary air chamber (12) of the second Helmholtz resonator in the circumferential direction of the wheel (10) is set to be smaller than the length of the auxiliary air chamber (12) of the first Helmholtz resonator in the circumferential direction of the wheel (10); A plurality of partition walls (13) separating the Helmholtz resonators in the circumferential direction of the wheel (10) are arranged in the circumferential direction of the wheel (10) to have line symmetry with respect to a line segment passing through the rotation axis of the wheel (10) and corresponding to a diameter; and A valve hole (15) for mounting a valve is positioned on the line segment in the circumferential direction of the wheel (10), the valve being configured to supply air to the tire air chamber (R).

3. The wheel (10) according to claim 2, characterized in that The second Helmholtz resonator includes one or more second Helmholtz resonators that are set to have a muffler characteristic for a resonance frequency equal to a highest-order resonance frequency and are positioned to face the valve hole (15) across the rotation axis in the circumferential direction of the wheel (10).

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