Vehicle wheel

Abstract

To provide a vehicle wheel having a new structure which enables reduction in vibration of a predetermined frequency band.SOLUTION: In a vehicle wheel 10, holes 16 and dynamic dampers 20 each including a mass member 22 which is provided separated from an inner surface 25 of the hole 16 at the inner side of the hole 16 and a rubber member 23 for connecting the inner surface 25 to the mass member 22 are provided on a disk 13. The dynamic dampers 20 are provided at positions offset from a rotation axis 14 of the vehicle wheel 10.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] In order to reduce vibrations of a vehicle while it is running, a dynamic damper may be provided on a vehicle wheel. As a structure for mounting a dynamic damper on a vehicle wheel, a structure in which one dynamic damper is fitted on the inner diameter surface of the rim of the vehicle wheel, as described in Patent Document 1, is known.

[0003] Dynamic dampers are designed to reduce vibrations in a specific frequency band, but the direction in which they can reduce vibrations in that frequency band is fixed. For example, the dynamic damper in Patent Document 1 includes a ring-shaped member, a weight disposed inside the ring-shaped member, and a spring element disposed between the ring-shaped member and the weight. In this type of dynamic damper, when the arrangement of the spring element and the weight meets a specific condition, for example, when the spring element is above the weight, vibrations in the specific frequency band can be reduced.

[0004] If such a dynamic damper is fixed to the inner diameter surface of the rim of a vehicle wheel, the dynamic damper will rotate when the vehicle wheel rotates, and the dynamic damper will not be able to reduce vibrations in a specified frequency band in most situations while the vehicle wheel is rotating.

[0005] As a countermeasure, Patent Document 1 proposes a structure designed to prevent the dynamic damper from rotating even when the vehicle wheel rotates. However, in order to prevent the dynamic damper from rotating even when the vehicle wheel rotates, the attachment structure of the dynamic damper to the vehicle wheel must be made complex. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2018-17356 A Summary of the Invention [Problem to be solved by the invention]

[0007] In light of the above circumstances, the emergence of a vehicle wheel with a new structure was desired.

[0008] Therefore, an object of the present invention is to provide a vehicle wheel having a new structure that makes it easy to reduce vibrations in a specified frequency band. [Means for solving the problem]

[0009] The present invention includes the embodiments set forth below.

[0010] [1] A vehicle wheel having a dynamic damper provided on a disk, the dynamic damper comprising a hole, a mass member provided inside the hole and spaced apart from the inner surface of the hole, and an elastic body connecting the inner surface and the mass member, characterized in that a plurality of the dynamic dampers are provided at locations offset from the rotation axis of the vehicle wheel.

[0011] [2] The vehicle wheel described in [1], wherein a plurality of the elastic bodies are arranged around the mass member in a direction around a central axis that passes through the center of gravity of the mass member and is parallel to the rotation axis, and an outer elastic body, which is one of the plurality of elastic bodies, is provided at a location that is radially outward of the vehicle wheel relative to the center of gravity of the mass member.

[0012] [3] The vehicle wheel according to [2], wherein the outer elastic body has a greater elastic force than the other elastic bodies provided in the same dynamic damper.

[0013] [4] A vehicle wheel as described in [1] or [2], wherein a plurality of the dynamic dampers are arranged at equal intervals in the circumferential direction of the vehicle wheel. Effect of the Invention

[0014] Since the vehicle wheel of the present embodiment has the above-described new structure, it is easy to reduce vibrations in a predetermined frequency band. [Brief description of the drawings]

[0015] [Figure 1] 1 is a diagram showing a vehicle wheel according to an embodiment of the present invention as viewed from the wheel axial direction. [Diagram 2] Cross-sectional view taken along line AA in Figure 1. [Diagram 3] A rotating vehicle wheel viewed from the wheel axial direction. (a) is the dynamic damper directly above. (b) is the vehicle wheel rotated 60°. (c) is the vehicle wheel rotated 120°. (d) is the vehicle wheel rotated 180°. (e) is the vehicle wheel rotated 240°. (f) is the vehicle wheel rotated 300°. [Figure 4] FIG. 11 is a cross-sectional view taken along the central axis of the mass member of the dynamic damper of Modification Example 3. [Diagram 5] 14A and 14B are diagrams showing the dynamic damper of the fourth modification example as viewed from the wheel axial direction. (a) shows the outer cylinder and mass member are triangular. (b) shows the outer cylinder and mass member are square. (c) shows the outer cylinder is triangular and the mass member is circular. [Figure 6] FIG. 13 is a view of a vehicle wheel according to a fifth modified example, viewed from the wheel axial direction. [Figure 7] FIG. 13 is a view of a vehicle wheel according to a sixth modified example, viewed from the wheel axial direction. [Figure 8] A diagram of a vehicle wheel with two dynamic dampers, viewed from the wheel axial direction. (a) shows the dynamic damper located directly to the side of the vehicle wheel's axis of rotation. (b) shows the vehicle wheel rotated 180°. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] The embodiments will be described with reference to the drawings. Note that the embodiments described below are merely examples, and any appropriate modifications that do not depart from the gist of the present invention are included in the scope of the present invention.

[0017] The vehicle wheel 10 of this embodiment has a tire T mounted on its outer circumferential surface, and is mounted on a vehicle such as a passenger car or truck for use.

[0018] As shown in FIGS. 1 and 2, a vehicle wheel 10 of this embodiment includes a wheel body 11 and a plurality of dynamic dampers 20 provided on the wheel body 11.

[0019] The wheel body 11 comprises a cylindrical rim 12 which holds the tire T, and a circular disk 13 which is provided on the inner diameter side of the rim 12. The rim 12 and disk 13 are made of metal such as aluminum alloy, magnesium alloy, steel, etc., and are molded as a single unit. A mounting part 15 which is attached to a hub is formed in the center of the circular disk 13.

[0020] In the following description, the extension direction of the rotation shaft 14 of the vehicle wheel 10 is referred to as the wheel axial direction (the direction of the arrow X in Fig. 2), the radial direction of the vehicle wheel 10 which is also perpendicular to the rotation shaft 14 is referred to as the wheel radial direction (the direction of the arrow Y in Figs. 1 and 2), and the circumferential direction of the vehicle wheel 10 is referred to as the wheel circumferential direction (the direction of the arrow Z in Fig. 1). Additionally, the wheel radially inward direction refers to the direction approaching the rotation shaft 14 in the wheel radial direction, and the wheel radially outward direction refers to the direction away from the rotation shaft 14 in the wheel radial direction.

[0021] The disk 13 is provided with a plurality of dynamic dampers 20 (three in FIG. 1). These dynamic dampers 20 are intended to reduce vibration of the vehicle wheel 10. In this embodiment, the term "vibration" refers to vertical vibration unless otherwise specified. Furthermore, the term "frequency" refers to the frequency of vertical vibration unless otherwise specified.

[0022] These dynamic dampers 20 provided on the disk 13 are arranged at equal intervals in the wheel circumferential direction around the rotation axis 14 of the vehicle wheel 10. The distance in the wheel radial direction from the rotation axis 14 of the vehicle wheel 10 to each dynamic damper 20 is the same. It is preferable that each dynamic damper 20 is located as far inward as possible in the wheel radial direction.

[0023] The dynamic damper 20 includes an outer cylinder 21 having a hole 24, a mass member 22 provided inside the hole 24 and spaced apart from the outer cylinder 21, and a plurality of rubber members 23 connecting the outer cylinder 21 and the mass member 22.

[0024] The outer cylinder 21 is cylindrical, and the inner surface 25 of the hole 24 opened at the center thereof is also a cylindrical curved surface. The mass member 22 is cylindrical with no hole (the hole is filled). The outer cylinder 21 and the mass member 22 are circular when viewed from the wheel axial direction. A line passing through the center of gravity of the mass member 22 and extending parallel to the rotation axis 14 of the vehicle wheel 10 is defined as the central axis 26 of the mass member 22. Multiple rubber members 23 (three in FIG. 1) are arranged at equal intervals between the outer cylinder 21 and the mass member 22 in the direction around the central axis 26 of the mass member 22.

[0025] The outer cylinder 21 and the mass member 22 are made of, for example, metal. The rubber member 23 is connected to the outer cylinder 21 and the mass member 22 by vulcanization adhesion. Since the rubber member 23 is an elastic body, the mass member 22 can vibrate relative to the outer cylinder 21.

[0026] The outer elastic body 23a, which is one of the multiple rubber members 23, is provided at a location that is radially outward of the center of gravity of the mass member 22. That is, as shown in Fig. 1, the outer elastic body 23a is provided on a straight line (a dashed line in Fig. 1) that passes through the rotation axis 14 of the vehicle wheel 10 and the central axis 26 of the mass member 22, and on a location on the opposite side of the rotation axis 14 with respect to the mass member 22 as the center, when viewed from the wheel axial direction.

[0027] The rubber member 23 as the outer elastic body 23a has a larger elastic force than the other rubber members 23 included in the same dynamic damper 20. Therefore, the rubber member 23 as the outer elastic body 23a has a larger cross-sectional area than the other rubber members 23 included in the same dynamic damper 20. Here, the cross-sectional area refers to the area in a plane perpendicular to the direction in which the rubber member 23 extends from the outer cylinder 21 toward the mass member 22. The cross-sectional area of ​​the outer elastic body 23a is preferably 1.5 times larger than the cross-sectional area of ​​the other rubber members 23.

[0028] The outer elastic body 23a in this embodiment is thick on the outer cylinder 21 side and thin on the mass member 22 side, and is generally trapezoidal when viewed from the wheel axial direction in Fig. 1. Due to this shape, the cross-sectional area of ​​the outer elastic body 23a gradually decreases as it approaches the mass member 22. When the cross-sectional area of ​​the rubber member 23 changes from the outer cylinder 21 toward the mass member 22 in this manner, the cross-sectional areas of the rubber members 23 are compared based on the average value from the portion in contact with the outer cylinder 21 to the portion in contact with the mass member 22. The rubber members 23 other than the outer elastic body 23a are also generally trapezoidal when viewed from the wheel axial direction.

[0029] A plurality of holes 16 are formed in the disk 13 of the wheel body 11, and the dynamic dampers 20 are press-fitted into some of these holes 16. By being press-fitted, a stress is applied to the outer cylinder 21 of the dynamic damper 20 in the direction toward the central axis 26 of the mass member 22, compressing the rubber member 23.

[0030] All of the dynamic dampers 20 provided on the vehicle wheel 10 have the same structure. Moreover, all of the dynamic dampers 20 are provided with the outer elastic body 23a oriented so as to be located on the outer side in the wheel radial direction with respect to the center of gravity of the mass member 22.

[0031] When a tire T mounted on the vehicle wheel 10 configured as described above rolls over a protrusion while rolling and the vehicle wheel 10 vibrates, the mass members 22 of each dynamic damper 20 vibrate in the direction opposite to the vibration direction of the vehicle wheel 10. This suppresses the vibration of the vehicle wheel 10, and ultimately suppresses the vibration of the vehicle on which the vehicle wheel 10 is mounted.

[0032] Here, since multiple dynamic dampers 20 are provided on the vehicle wheel 10, vibrations in a predetermined frequency band are reduced by the dynamic dampers 20 multiple times during one rotation of the vehicle wheel 10. This will be described using as an example a case in which three dynamic dampers 20 are arranged at equal intervals in the wheel circumferential direction as shown in Figure 1, and the distribution of the dynamic dampers 20 on the vehicle wheel 10 has three-fold rotational symmetry.

[0033] The vehicle wheel 10 is designed to reduce vibrations in a predetermined frequency band when the dynamic damper 20 is directly above the rotation shaft 14 of the vehicle wheel 10 and when the dynamic damper 20 is directly below the rotation shaft 14 of the vehicle wheel 10. Then, during one rotation of the vehicle wheel 10, starting from when the dynamic damper 20 is directly above the rotation shaft 14 as shown in FIG. 3(a) (the dynamic damper 20 directly above at this time is indicated by an arrow in the figure), the vehicle wheel 10 assumes a posture capable of reducing vibrations in a predetermined frequency band six times: when the dynamic damper 20 rotates 60° as shown in FIG. 3(b), when the dynamic damper 20 rotates 120° as shown in FIG. 3(c), when the dynamic damper 20 rotates 180° as shown in FIG. 3(d), when the dynamic damper 20 rotates 240° as shown in FIG. 3(e), and when the dynamic damper 20 rotates 300° as shown in FIG. 3(f). As a result, vibrations in a predetermined frequency band are suppressed while the vehicle is running and the vehicle wheel 10 continues to rotate.

[0034] Next, the effects of this embodiment will be described. As described above, the vehicle wheel 10 of this embodiment is provided with a plurality of dynamic dampers 20 at locations that are off the rotation axis 14. This allows the dynamic dampers 20 to be arranged in a way that can reduce vibrations in a predetermined frequency band multiple times during one rotation of the vehicle wheel 10. For example, if the dynamic dampers 20 can reduce vibrations in a predetermined frequency band when they are directly above and below the rotation axis 14 of the vehicle wheel 10, then the dynamic dampers 20 can be arranged in a way that can reduce vibrations in a predetermined frequency band multiple times during one rotation of the vehicle wheel 10. Therefore, the vehicle wheel 10 of this embodiment makes it easy to reduce vibrations in a predetermined frequency band.

[0035] However, the manner in which the frequency of vibration that the vehicle wheel 10 can reduce during one rotation of the vehicle wheel 10 changes depends on the distribution of the dynamic dampers 20 on the vehicle wheel 10. Therefore, the number of times that the vehicle wheel 10 can reduce vibration in a predetermined frequency band during one rotation of the vehicle wheel 10 depends on the distribution of the dynamic dampers 20 on the vehicle wheel 10.

[0036] In this embodiment, since multiple dynamic dampers 20 are arranged at equal intervals in the wheel circumferential direction, the same arrangement of the dynamic dampers 20 for reducing vibrations in a predetermined frequency band is periodically realized multiple times during one rotation of the vehicle wheel 10. Therefore, vibrations in a predetermined frequency band can be easily reduced during the rotation of the vehicle wheel 10. Furthermore, the rotation balance of the vehicle wheel 10 is not disturbed.

[0037] In addition, since vibrations in a predetermined frequency band can be reduced even if the dynamic damper 20 rotates together with the wheel body 11, it is not necessary to prevent the dynamic damper 20 from rotating relative to the wheel body 11. Therefore, the structure of the vehicle wheel 10 does not become complicated.

[0038] In addition, since there are structures for mounting the vehicle wheel 10 to the vehicle near the rotation axis 14 of the vehicle wheel 10, it is difficult to mount the dynamic damper 20. If a dynamic damper were to be mounted in this location, design constraints would be imposed on the dynamic damper, such as the need to make the dynamic damper extremely small, which would reduce the effect of the dynamic damper. In contrast, in this embodiment, the dynamic damper 20 is mounted in a location away from the rotation axis 14, so that the dynamic damper 20 can be designed to provide a sufficient effect.

[0039] In addition, the dynamic damper 20 of this embodiment has a plurality of rubber members 23 provided around the mass member 22, and an outer elastic body 23a, which is one of the mass members 22, is provided at a location that is on the wheel radial outer side with respect to the center of gravity of the mass member 22. Due to the presence of this outer elastic body 23a, the mass member 22 is less likely to become eccentric when the vehicle wheel 10 rotates and centrifugal force acts on the mass member 22. Since the mass member 22 is less likely to become eccentric in this way, the mass member 22 can move sufficiently near the center of the outer cylinder 21 without hitting the outer cylinder 21, and the vibration of the vehicle wheel 10 is absorbed firmly. Furthermore, since the mass member 22 is less likely to become eccentric, hitting noise caused by the mass member 22 hitting the outer cylinder 21 is less likely to occur, and the dynamic damper 20 is less likely to break down.

[0040] In particular, since the outer elastic body 23a has a greater elastic force than the other rubber members 23 provided in the same dynamic damper 20, the mass member 22 is less likely to become eccentric when centrifugal force acts on the mass member 22.

[0041] As described above, the outer elastic body 23a is thick on the outer cylinder 21 side and thin on the mass member 22 side, in other words, the outer elastic body 23a becomes thicker toward the outside in the wheel radial direction. Therefore, the force of the outer elastic body 23a to restrict the displacement of the mass member 22 increases as the amount of displacement of the mass member 22 toward the outside in the wheel radial direction increases. This makes the mass member 22 less likely to become eccentric.

[0042] Furthermore, the further inward the dynamic damper 20 is located in the radial direction of the wheel, the smaller the centrifugal force acting on the mass member 22 becomes, making the mass member 22 less likely to become eccentric.

[0043] In addition, the dynamic damper 20 is press-fitted into the hole 16 of the disk 13, and the rubber member 23 is compressed, thereby extending the life of the rubber member 23.

[0044] Various modifications can be made to the above embodiment. Any one of the modifications described below may be applied to the above embodiment, or any two or more of them may be combined and applied to the above embodiment. The combination may be arbitrary.

[0045] <Change Example 1> In the dynamic damper, instead of each rubber member 23, other elastic bodies such as springs may be provided.

[0046] Further, instead of providing a plurality of rubber members 23, one ring-shaped rubber member may fill the space between the outer cylinder 21 and the mass member 22.

[0047] <Change Example 2> When the rubber member serving as the outer elastic body is thick on the outer cylinder side and thin on the mass member side, the shape does not have to be trapezoidal when viewed in the wheel axial direction as in the above embodiment.

[0048] Furthermore, the rubber member serving as the outer elastic body may have a constant cross-sectional area from the outer cylinder 21 side to the mass member 22 side, and may be rectangular when viewed from the wheel axial direction, for example.

[0049] Furthermore, the rubber member as the outer elastic body may have the same elastic force as other rubber members included in the same dynamic damper, and therefore, for example, the rubber member as the outer elastic body may have the same cross-sectional area as other rubber members included in the same dynamic damper.

[0050] <Change Example 3> In addition to being aligned in the direction around the central axis 26 of the mass member 22 as in Fig. 1, the multiple rubber members 123 may also be aligned at intervals in the wheel axial direction as shown in Fig. 4. In this case, the mass member 22 is more likely to move than when there are no such intervals.

[0051] <Change Example 4> The shapes of the outer cylinder and the mass member when the dynamic damper is viewed from the wheel axial direction are not limited to a circle. The shapes of the outer cylinder and the mass member when viewed from the wheel axial direction may be polygonal, such as a regular polygon. As a specific example, the outer cylinder 121a and the mass member 122a may be equilateral triangles as shown in FIG. 5(a), and the outer cylinder 121b and the mass member 122b may be squares as shown in FIG. 5(b). Also, as shown in FIG. 5(c), the shapes of the outer cylinder 121c and the mass member 122c when viewed from the wheel axial direction may be different. In either case, the outer cylinder and the mass member are connected by an elastic body such as the rubber member 23.

[0052] <Change Example 5> The dynamic damper does not need to have an outer cylinder. Specifically, as shown in Fig. 6, a mass member 22 may be provided inside a hole 16 formed in the wheel body 11, separated from an inner surface 17 of the hole 16. The inner surface 17 of the hole 16 and the mass member 22 are connected by a plurality of rubber members 23. In this case, the inner surface 17 of the hole 16, the mass member 22, and the plurality of rubber members 23 can be said to constitute a dynamic damper 120.

[0053] <Change Example 6> 7, in each dynamic damper 220, a buffer member 227 fixed to the outer cylinder 21 and separated from the mass member 22 may be provided between adjacent rubber members 23. The buffer member 227 is preferably provided at the midpoint between the adjacent rubber members 23 in all locations where two rubber members 23 are adjacent to each other.

[0054] Each of the buffer members 227 preferably has a tapered shape toward the mass member 22, or in other words, is preferably thick on the outer tube 21 side and thin on the mass member 22 side. Also, the buffer members 227 are preferably made of a material with buffer properties, and more preferably made of an elastic material such as rubber.

[0055] By providing such a buffer member 227, even if the mass member 22 moves significantly, it is possible to prevent the mass member 22 from hitting the outer cylinder 21. Therefore, it is possible to prevent the mass member 22 from hitting the outer cylinder 21, which would cause a hitting sound or damage to the dynamic damper 220.

[0056] <Change Example 7> When multiple dynamic dampers are arranged at equal intervals around the wheel circumference, the number of dynamic dampers may be more than one and is not limited to three as shown in Fig. 1. However, it is preferable that the number of dynamic dampers is an odd number.

[0057] If the number of dynamic dampers is an odd number, vibrations in a predetermined frequency band can be reduced twice the number of dynamic dampers during one rotation of the vehicle wheel. For example, as described in FIG. 3, if the number of dynamic dampers 20 is three, vibrations in a predetermined frequency band can be reduced six times during one rotation of the vehicle wheel 10. As a result, vibrations in a predetermined frequency band are suppressed while the vehicle is running and the vehicle wheel 10 continues to rotate.

[0058] On the other hand, when the number of dynamic dampers is an even number, vibrations in a predetermined frequency band can be reduced the same number of times as the number of dynamic dampers during one rotation of the vehicle wheel. For example, in the case where the number of dynamic dampers 20 is two as shown in FIG. 8, the dynamic dampers 20 are designed to reduce vibrations in a predetermined frequency band when they are located directly beside the rotating shaft 14 of the vehicle wheel 10. Then, vibrations in a predetermined frequency band can be reduced twice during one rotation of the vehicle wheel 10, at the time shown in FIG. 8(a) (the dynamic damper 20 located to the left of the rotating shaft 14 at this time is indicated by an arrow in the figure) and at the time shown in FIG. 8(b) when the vehicle wheel 10 rotates 180° from that time. [Explanation of symbols]

[0059] 10...vehicle wheel, 11...wheel body, 12...rim, 13...disk, 14...rotating shaft, 15...mounting portion, 16...hole, 17...inner surface, 20...dynamic damper, 21...outer cylinder, 22...mass member, 23...rubber member, 23a...outer elastic body, 24...hole, 25...inner surface, 26...central shaft, 120...dynamic damper, 123...rubber member, 121a...outer cylinder, 121b...outer cylinder, 121c...outer cylinder, 122a...mass member, 122b...mass member, 122c...mass member, 220...dynamic damper, 227...buffer member

Claims

1. A vehicle wheel in which a dynamic damper is provided on a disk, the dynamic damper including a hole, a mass member provided inside the hole and spaced apart from an inner surface of the hole, and an elastic body connecting the inner surface and the mass member, A vehicle wheel, characterized in that a plurality of said dynamic dampers are provided at locations offset from an axis of rotation of said vehicle wheel.

2. a plurality of the elastic bodies are arranged around the mass member in a direction around a central axis that passes through a center of gravity of the mass member and is parallel to the rotation axis, 2. The vehicle wheel according to claim 1, wherein an outer elastic body which is one of the plurality of elastic bodies is provided at a location which is radially outward of the center of gravity of the mass member.

3. 3. The vehicle wheel according to claim 2, wherein the outer elastic body has a greater elastic force than the other elastic bodies provided on the same dynamic damper.

4. 3. The vehicle wheel according to claim 1, wherein a plurality of the dynamic dampers are arranged at equal intervals in the circumferential direction of the vehicle wheel.

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