JP7779122B2 - Vibration-damping structures, interior parts and automobiles - Google Patents

Description

The present invention relates to vibration-damping structures, interior parts, and automobiles.

Damping structures for suppressing vibrations are used, for example, in automobiles. Various configurations have been proposed for damping structures; for example, Non-Patent Document 1 describes a damping structure that uses an acoustic black hole structure.

T. Zhou, L. Cheng, A resonant beam damper tailored with Acoustic Black Hole features for broadband vibration reduction, Journal of sound and vibration 430 (2018) 174-184

It is desirable for such vibration-damping structures to achieve a greater amount of vibration damping. Therefore, the present invention aims to provide a vibration-damping structure, interior part, and automobile that can achieve a greater amount of vibration damping.

The vibration-damping structure of the present invention comprises an elastic member including a shaft-shaped member having one end and the other end, a central portion connected between the one end and the other end of the shaft-shaped member, and a wedge-shaped portion provided on the outer periphery of the central portion and satisfying the following formula (1), and a vibration-damping member joined to the periphery of the wedge-shaped portion.

According to the present invention, an elastic member having an acoustic black hole structure is provided between one end and the other end of the shaft-shaped member. This allows vibrations transmitted from one end of the shaft-shaped member to the other end to be effectively damped by the elastic member. This makes it possible to achieve a greater amount of vibration damping.

1 is a perspective view showing a configuration of a vibration damping structure according to an embodiment of the present invention, together with a member to be damped and a vibration source. FIG. 2 is a diagram showing a cross-sectional configuration taken along line II-II shown in FIG. FIG. 2 is a perspective view showing a configuration of an elastic member shown in FIG. 1 . 1 is a cross-sectional view showing a configuration of a vibration damping structure according to a comparative example, together with a member to be damped and a vibration source. FIG. 10 is a side view showing the configuration of a vibration damping structure according to Modification 1, together with a member to be damped and a vibration source. FIG. 10 is a cross-sectional view showing the configuration of a main part of a vibration damping structure according to Modification 2. FIG. 11 is a cross-sectional view showing the configuration of a main part of a vibration damping structure according to Modification 3. 10A and 10B are plan views showing the configuration of the main part of a vibration damping structure according to a fourth modified example. 10A, 10B, and 10C are plan views showing the configuration of the main part of a vibration damping structure according to a fifth modified example. FIG. 1 is a block diagram showing the configuration of a measurement system for measuring inertance. FIG. 1 is a diagram showing the inertance measured in Example 1 and Comparative Example 1. FIG. 10 is a diagram showing the inertance measured in Example 2 and Comparative Example 2. 1A is a diagram showing the inertance measured in Examples 1 and 3 to 5, and FIG. 1B is an enlarged view of a portion of FIG. 1A. FIG. 10 is a diagram showing the inertance obtained in Examples 6 to 9 and Comparative Example 3.

Embodiments of the present invention will be described below with reference to the drawings, but the technical scope of the present invention is not limited to the following embodiments. Note that the dimensional proportions in the drawings have been exaggerated for the sake of explanation and may differ from the actual proportions. In this specification, the range "a-b" means "a or more and b or less." Furthermore, unless otherwise specified, operations and measurements of physical properties, etc., are performed at room temperature (20-25°C) and a relative humidity of 40-50%.

<Embodiment>
[Configuration of vibration control structure]
1 and 2 show the configuration of a vibration damping structure 10 according to one embodiment of the present invention, together with a damped member 20 and a vibration source 30. FIG. 2 is a cross-sectional view taken along line II-II in FIG. 1. The vibration damping structure 10 includes an elastic member 11, a damping member 12, and a shaft-shaped member 13. The vibration source 30 is provided on one end of the shaft-shaped member 13, and the damped member 20 is provided on the other end thereof, and the vibration damping structure 10 attenuates vibrations transmitted from the vibration source 30 to the damped member 20. In the following description, the extension direction of the shaft-shaped member 13 may be referred to as the Z direction, and the directions intersecting therewith may be referred to as the X direction and the Y direction.

(Elastic member)
3 shows an example of the configuration of the elastic member 11. The elastic member 11 is made of, for example, a plate-like member having a circular planar shape (shape in the XY plane). For example, the main surface (XY plane) of this elastic member 11 is provided approximately perpendicular to the extension direction of the shaft-shaped member 13. The elastic member 11 may be made of any elastic material, but from the standpoint of ease of handling, it is preferable that the elastic member 11 be made of a metal material such as iron or steel.

This elastic member 11 includes a central portion 11C connected between one end and the other end of the shaft-shaped member 13, and a wedge-shaped portion 11W provided on the outer periphery of the central portion 11C (Figures 2 and 3). The central portion 11C has, for example, a circular planar shape and is provided in the center of the elastic member 11. The wedge-shaped portion 11W has a ring shape that surrounds the central portion 11C.

The central portion 11C has a predetermined thickness hc (Figure 2). The thickness hc is the size of the central portion 11C in the z direction, and is preferably 0.5 mm to 10 mm, and more preferably 5 mm or less. The diameter of the central portion 11C is, for example, 1 mm to 500 mm, and preferably 5 mm to 100 mm.

The central portion 11C has a through-hole 11H for connecting the elastic member 11 to the shaft-shaped member 13. The through-hole 11H is a hole that penetrates the elastic member 11 in the thickness direction and has, for example, a circular planar shape. The through-hole 11H is disposed, for example, at the center of the central portion 11C, i.e., the center of the elastic member 11. The through-hole 11H has, for example, approximately the same size as the shaft diameter of the shaft-shaped member 13. By passing the shaft-shaped member 13 through this through-hole 11H, the central portion 11C is connected between one end and the other end of the shaft-shaped member 13. Providing such a through-hole 11H in the elastic member 11 facilitates attachment to the shaft-shaped member 13, improving applicability.

Wedge-shaped portion 11W is located adjacent to central portion 11C, for example. This wedge-shaped portion 11W has a predetermined length (length L) from a position adjacent to central portion 11C to periphery e1 (Figure 2). Periphery e1 of wedge-shaped portion 11W corresponds to the periphery of elastic member 11, for example. Vibration-damping member 12 is joined to periphery e1 of wedge-shaped portion 11W. Periphery e1 of wedge-shaped portion 11W may be located at a position different from the periphery of elastic member 11.

The thickness h of the wedge-shaped portion 11W gradually decreases from the position adjacent to the central portion 11C toward the peripheral edge e1. That is, the thickness h of the wedge-shaped portion 11W is greatest at the position adjacent to the central portion 11C and smallest at the peripheral edge e1. For example, one main surface of the wedge-shaped portion 11W (the main surface facing the member to be damped 20) is flat, and the other main surface (the main surface facing the vibration source 30) is curved. The thickness h of this wedge-shaped portion 11W satisfies the following formula (1):

The arbitrary position on the periphery e1 side, which is the measurement starting point for distance x in the above equation (1), is an arbitrary position closer to periphery e1 than central portion 11C, for example, a predetermined position on periphery e1. Distance x is measured, for example, along a straight line from the measurement starting point (periphery e1) toward the center of elastic member 11, i.e., along the direction of length L. Note that, as described below, when a notch (for example, notch 11n in Figures 8(A) and (B) described below) is provided in elastic member 11, the direction of length L is the direction along this notch. Furthermore, y corresponds to the thickness of elastic member 11 at the measurement starting point for distance x (for example, a predetermined position on periphery e1), and is, for example, 0.01 to 1 mm. To suppress reflection of vibration waves, it is desirable for y to be 0.5 mm or less.

By providing this wedge-shaped portion 11W on the outer periphery of the central portion 11C, a so-called acoustic black hole structure is realized. This suppresses the reflection of vibration waves at the periphery e1, effectively damping vibrations. During vibration damping, for example, the periphery e1 of the wedge-shaped portion 11W vibrates.

The frequency threshold f _cut-on at which vibration can be attenuated by the wedge-shaped portion 11W can be calculated using, for example, the following equation (2).

The wedge-shaped portion 11W can attenuate vibrations at frequencies equal to or greater than the threshold value f _cut-on in the above formula (2). That is, by increasing the length L (FIG. 2) of the wedge-shaped portion 11W, the vibration damping structure 10 can effectively attenuate vibrations at lower frequencies. The length L of the wedge-shaped portion 11W is, for example, 1 mm to 1000 mm, and is preferably 10 mm or greater.

In this embodiment, the elastic member 11 having such an acoustic black hole structure is connected between one end and the other end of the shaft-shaped member 13. As will be described in detail later, this effectively attenuates vibrations transmitted from the vibration source 30 to the damped member 20 via the shaft-shaped member 13.

(Vibration damping member)
The vibration-damping member 12, which is bonded to the periphery e1 of the wedge-shaped portion 11W, serves to convert the vibration energy collected at the periphery e1 by the acoustic black hole structure into thermal energy and thereby attenuate the vibration. The vibration-damping member 12 is bonded, for example, to one main surface of the elastic member 11. The vibration-damping member 12 has, for example, a ring shape with a periphery that follows the periphery e1 of the wedge-shaped portion 11W, and is positioned so as to overlap the wedge-shaped portion 11W. In other words, the periphery of the vibration-damping member 12 and the periphery e1 of the wedge-shaped portion 11W are positioned so as to overlap in a planar (XY) view. This allows the vibration energy collected at the periphery e1 to be more effectively attenuated.

The vibration-damping member 12 is made of, for example, a plate-shaped viscoelastic material. The thickness of this plate-shaped vibration-damping member 12 is preferably greater than the thickness of the peripheral edge e1 of the wedge-shaped portion 11W. The viscoelastic material that makes up the vibration-damping member 12 is preferably a polymer material such as rubber. The specific gravity of the vibration-damping member 12 is preferably the same as or greater than the specific gravity of the elastic member 11. Such a vibration-damping member 12 can efficiently attenuate the vibration energy collected at the peripheral edge e1.

(Shaft-shaped member)
The shaft-shaped member 13 is capable of transmitting vibrations in its extending direction. For example, a vibration source 30 is connected to one end of the shaft-shaped member 13, and a vibration-to-be-damped member 20 is connected to the other end, and vibrations generated by the vibration source 30 can be transmitted to the vibration-to-be-damped member 20 via the shaft-shaped member 13. The shaft-shaped member 13 is, for example, a bolt. The shaft-shaped member 13 may also be an automobile part such as a suspension or shaft. The shaft-shaped member 13 is made of, for example, a metal such as iron. The shaft-shaped member 13 may also be made of stainless steel.

[Configuration of the vibration-damped member]
The damped member 20 connected to the other end of the shaft-shaped member 13 is made of, for example, a thin metal plate. For example, this plate-shaped damped member 20 is arranged approximately parallel to the elastic member 11. By using the damping structure 10 described above for a damped member 20 with a smaller vibration damping effect (damping coefficient), vibration of the damped member 20 can be more effectively suppressed. The damped member 20 is preferably arranged at a predetermined distance from the elastic member 11 in the Z direction. By preventing the damped member 20 from contacting (interfering with) the wedge-shaped portion 11W during vibration damping, transmission of vibration to the damped member 20 can be effectively suppressed. The damped member 20 may be arranged between the elastic member 11 and the other end of the shaft-shaped member 13. The damped member 20 may be, for example, an automobile body.

[Configuration of vibration source]
The vibration source 30 connected to one end of the shaft-shaped member 13 generates vibrations. The vibration source 30 may be in temporary contact with the shaft-shaped member 13, or may be provided at a distance from the shaft-shaped member 13. The vibration source 30 is preferably disposed at a predetermined distance in the Z direction from the elastic member 11. By preventing the vibration source 30 from coming into contact with the wedge-shaped portion 11W during vibration damping, transmission of vibrations to the damped member 20 can be effectively suppressed. The vibration source 30 is, for example, an engine, a motor, a tire, or the like. The vibration source 30 may also be a sound source. The vibration source 30 may also be, for example, a hammer or the like that temporarily generates vibrations.

[Action and effect of vibration control structure]
In the vibration damping structure 10 according to this embodiment, an elastic member 11 having an acoustic black hole structure is provided between one end and the other end of the shaft-shaped member 13. As a result, vibrations transmitted from one end to the other end of the shaft-shaped member 13 are effectively damped by the elastic member 11. This makes it possible to obtain a greater amount of vibration damping. This effect will be described in detail below.

Figure 4 shows the configuration of a vibration damping structure 1000 according to a comparative example. The elastic member 11 of this vibration damping structure 1000 is attached to the damped member 20. In other words, the elastic member 11 is not provided in the vibration transmission path from the vibration source 30 to the damped member 20 via the shaft-shaped member 13. When vibration is transmitted to the damped member 20, which is an oscillation system, bending waves are generated throughout the entire damped member 20. For this reason, it is difficult for the elastic member 11 attached to only a part of the damped member 20 to sufficiently damp the vibration.

In contrast, in the vibration control structure 10, an elastic member 11 is attached to the shaft member 13 that connects the vibration source 30 and the member to be damped 20, i.e., the shaft member 13 is the vibration transmission system, so vibrations are effectively damped upstream of the member to be damped 20, which is the oscillation system. Therefore, it is possible to achieve a greater amount of vibration damping compared to the vibration control structure 1000.

Below, we will explain modified examples of the vibration-damping structure 10 described in the above embodiment. Note that, to avoid duplication, detailed explanations of components similar to those of the vibration-damping structure 10 described in the above embodiment will be omitted.

<Modification 1>
5 shows the configuration of a vibration damping structure 10 according to Modification 1. This vibration damping structure 10 includes a fixing member 14 and a washer 15 in addition to an elastic member 11, a vibration damping member 12, and a shaft-shaped member 13. Except for this point, this vibration damping structure 10 has the same configuration as the vibration damping structure 10 described in the above embodiment.

The fixing member 14 is used to fix the elastic member 11 to a predetermined position on the shaft-shaped member 13, and is made of, for example, a fastening material. For example, when the shaft-shaped member 13 is made of a bolt, a nut can be used as the fixing member 14. By using the fixing member 14, the elastic member 11 can be easily attached to the shaft-shaped member 13.

The washer 15 is provided between the fixed member 14 and the elastic member 11. By providing the washer 15, it is possible to prevent damage to the elastic member 11 caused by the fixed member 14.

The central portion 11C of the elastic member 11 is preferably wider than the fixed member 14, and further preferably wider than the damped member 20 and the vibration source 30. In other words, when viewed in a plan view (XY plane), the fixed member 14, damped member 20, and vibration source 30 are preferably located inside the central portion 11C. In such an elastic member 11, the wedge-shaped portion 11W is positioned away from the fixed member 14, damped member 20, and vibration source 30 in the XY plane, preventing the wedge-shaped portion 11W from coming into contact with other members (specifically, the fixed member 14, damped member 20, and vibration source 30) during damping. This effectively suppresses the transmission of vibrations to the damped member 20.

Like the vibration-damping structure 10 described in the above embodiment, the vibration-damping structure 10 according to this first modification also has an elastic member 11 with an acoustic black hole structure between one end and the other end of the shaft-shaped member 13. This makes it possible to obtain a large amount of vibration damping. Furthermore, since it has a fixing member 14, the elastic member 11 can be easily attached to a predetermined position on the shaft-shaped member 13.

<Modification 2>
Figure 6 shows the configuration of the main parts of the vibration damping structure 10 according to Modification 2. The shaft-shaped member 13 is not shown in Figure 6. The elastic member 11 of this vibration damping structure 10 has a first wedge-shaped portion 11WA and a second wedge-shaped portion 11WB that face each other in the Z direction. Except for this point, this vibration damping structure 10 has the same configuration as the vibration damping structure 10 described in the above embodiment.

The wedge-shaped portion 11W of the elastic member 11 includes a first wedge-shaped portion 11WA and a second wedge-shaped portion 11WB that face each other in the Z direction. The thicknesses ha and hb of the first wedge-shaped portion 11WA and the second wedge-shaped portion 11WB satisfy the above formula (1). In the wedge-shaped portion 11W that includes the first wedge-shaped portion 11WA and the second wedge-shaped portion 11WB, both main surfaces are curved. In other words, the distance in the Z direction from the damped member 20 side and the vibration source 30 side to the wedge-shaped portion 11W increases as it approaches the periphery e1. This makes it easier to prevent the wedge-shaped portion 11W from coming into contact with other members (e.g., the damped member 20 and the vibration source 30) during vibration damping.

The constants (ε, n, and y) in equation (1) representing the thicknesses ha and hb of the first wedge-shaped portion 11WA and the second wedge-shaped portion 11WB are preferably the same, and the thicknesses ha and hb are preferably the same at a given position on the XY plane. This improves the symmetry of the elastic member 11, making it possible to efficiently suppress vibrations in the vibration-damped member 20.

Similar to the vibration-damping structure 10 described in the above embodiment, the vibration-damping structure 10 according to this second modification also has an elastic member 11 with an acoustic black hole structure between one end and the other end of the shaft-shaped member 13. This makes it possible to obtain a large amount of vibration damping. Furthermore, because the wedge-shaped portion 11W has a first wedge-shaped portion 11WA and a second wedge-shaped portion 11WB, it is easier to prevent the wedge-shaped portion 11W from coming into contact with other members during vibration damping.

<Modification 3>
Fig. 7 shows the configuration of the main parts of the vibration damping structure 10 according to Modification 3. The shaft-shaped member 13 is not shown in Fig. 7. This vibration damping structure 10 has a raising member 16 at a position overlapping the central portion 11C of the elastic member 11. Except for this point, this vibration damping structure 10 has the same configuration as the vibration damping structure 10 described in the above embodiment.

The raising member 16 is positioned so as to overlap the central portion 11C when viewed in a plan view (XY plane). This raising member 16 is, for example, provided in contact with the central portion 11C. The raising member 16 is, for example, a plate-shaped member having a predetermined thickness. The raising member 16 is, for example, formed of a washer or the like. When the vibration control structure 10 includes such a raising member 16, the distance in the Z direction from the damped member 20 side or the vibration source 30 side to the elastic member 11 increases. This makes it easier to prevent the wedge-shaped portion 11W from coming into contact with other members (for example, the damped member 20 or the vibration source 30) during vibration control.

The raising member 16 is preferably provided in the central portion 11 on the flat surface side (the lower side of the paper in Figure 7) of the wedge-shaped portion 11W. The flat surface side of the wedge-shaped portion 11W is more likely to come into contact with other components (nearby in the vertical direction of the paper in Figure 7) than the curved surface side (the upper side of the paper in Figure 7). Therefore, by providing the raising member 16 in the central portion 11 on the flat surface side of the wedge-shaped portion 11W, it is possible to more effectively prevent contact between the wedge-shaped portion 11W and other components.

Like the vibration-damping structure 10 described in the above embodiment, the vibration-damping structure 10 according to Variation 3 also has an elastic member 11 with an acoustic black hole structure between one end and the other end of the shaft-shaped member 13. This makes it possible to obtain a large amount of vibration damping. Furthermore, a raising member 16 is provided at a position overlapping the central portion 11C of the elastic member 11, which makes it easier to prevent the wedge-shaped portion 11W from coming into contact with other members during vibration damping.

<Modification 4>
8(A) and (B) show the configuration of the main parts of the vibration damping structure 10 according to Modification 4. In Figures 8(A) and (B), the vibration damping members 12 and the shaft-shaped members 13 are not shown. In this vibration damping structure 10, a notch 11n is provided in the wedge-shaped portion 11W of the elastic member 11, extending from the peripheral edge e1 toward the central portion 11C. Except for this point, this vibration damping structure 10 has the same configuration as the vibration damping structure 10 described in the above embodiment.

The wedge-shaped portion 11W has, for example, multiple notches 11n. These notches 11n are arranged radially in a planar (XY) view. While each notch 11n may be arranged linearly from the periphery e1 toward the central portion 11C (FIG. 8A), it is preferable that the notches 11n are arranged nonlinearly. For example, the notches 11n are arranged curvedly, preferably in an arc shape (FIG. 8B). By arranging the notches 11n nonlinearly, the length L (FIG. 2) of the wedge-shaped portion 11W becomes greater than the length L when the notches 11n are not provided. This allows the threshold value f _cut-on calculated from the above formula (2) to be lowered. This allows for more efficient damping of low-frequency vibrations.

Like the vibration-damping structure 10 described in the above embodiment, the vibration-damping structure 10 according to this fourth modification also has an elastic member 11 with an acoustic black hole structure between one end and the other end of the shaft-shaped member 13. This makes it possible to obtain a large amount of vibration damping. Furthermore, a notch 11n is provided in the wedge-shaped portion 11W of the elastic member 11, making it possible to efficiently damp low-frequency vibrations.

<Modification 5>
9A to 9C show the configuration of a vibration damping structure 10 according to Modification 5. In FIGS. 9A to 9C, the vibration damping members 12 and shaft-shaped members 13 are omitted from the illustration. In this vibration damping structure 10, the elastic members 11 have a planar shape other than a circle. Except for this point, this vibration damping structure 10 has the same configuration as the vibration damping structure 10 described in the above embodiment.

The elastic member 11 has a polygonal planar shape, such as a rectangle (Figure 9(A)) or a hexagon (Figure 9(B)). The elastic member 11 may also have a triangular planar shape, or a polygon with seven or more sides. Alternatively, the elastic member 11 may have an elliptical planar shape (Figure 9(C)). It is preferable that the elastic member 11 have a highly symmetrical planar shape, such as a circle or a regular polygon. This makes it possible to attenuate vibrations transmitted via the shaft-shaped member 13 while improving manufacturability and mountability (attachability).

Similar to the vibration-damping structure 10 described in the above embodiment, the vibration-damping structure 10 according to this modification 5 also has an elastic member 11 with an acoustic black hole structure between one end and the other end of the shaft-shaped member 13. This makes it possible to obtain a large amount of vibration damping.

<Application example>
The vibration-damping structure 10 described in the above embodiment can be suitably used for damping various vibrations. In particular, the vibration-damping structure 10 is preferably mounted on a vehicle for use. Examples of applicable parts include dash insulators, dash panels, floor carpets, spacers, door trims, sound-absorbing structures in door trims, sound-absorbing structures in compartments, instrument panels, instrument center boxes, instrument upper boxes, air conditioner housings, roof trims, sound-absorbing structures in roof trims, sun visors, rear seat air conditioning ducts, cooling ducts for battery cooling systems in battery-powered vehicles, cooling fans, center console trims, sound-absorbing structures in consoles, parcel trims, parcel panels, seat headrests, front seat backs, and rear seat backs. Furthermore, in the trunk, the vibration-damping structure 10 can be applied to trunk floor trims, trunk boards, trunk side trims, sound-absorbing structures in trims, and drafter covers. It can also be applied to the vehicle frame or between panels, such as pillar trims and fenders. Among these, it is preferable to use it for automobile interior parts because it has excellent vibration damping properties in the low frequency range and is relatively lightweight.

The present invention will be described in more detail below using examples. However, the technical scope of the present invention is not limited to the following examples.

<<Inertance Measurement>>
The inertance of each vibration control structure was measured using a measurement system 300 shown in Fig. 10. The measurement system 300 includes an impulse hammer 310 (PCB Piezotronics, Inc., Model 086C03, hard chip), an acceleration sensor 320 (PCB Piezotronics, Inc., Model 356A01), a data conversion module 330 (The Modal Shop, Inc., Model 485B39), and a PC (Personal Computer) 340. The impulse hammer 310 and the acceleration sensor 320 are connected to the data conversion module 330, which is communicatively connected to the PC 340. The data conversion module 330 is a device that supplies a constant current to the impulse hammer 310 and the acceleration sensor 320 and converts a USB signal into a digital output signal. A vibration-damping structure and an acceleration sensor 320 were attached to the member to be damped, and one end of the shaft-shaped member was struck with an impulse hammer 310. The force (input) of the impulse hammer 310 and the acceleration (response) of the acceleration sensor 320 at this time were input to a PC 340 using a data conversion module 330, and a Fourier transform was performed to obtain the inertance. The member to be damped was placed on a sponge. The member to be damped was supported in a free position.

[Example 1]
Elastic members having the following conditions were prepared:
Material: Stainless steel Volume: 2843mm ³
Thickness of the center part: 2 mm
Minimum thickness of wedge: 0.2 mm
Planar shape: 64 mm diameter circle Center size: 32 mm diameter
Through-hole size: diameter 17 mm
In formula (1), n=2, ε=(2-0.2)/(16) ² , y=0.2.

The vibration damping members were prepared under the following conditions:
Material: Rubber Dimensions: Outer diameter 64mm, inner diameter 44mm.

A shaft-shaped member having the following conditions was prepared:
Material: Stainless steel Shape: M8 bolt Length: 100mm.

The vibration-damping structure of Example 1 was obtained by inserting and attaching the shaft-shaped member into the through-hole of the elastic member, the periphery of which was bonded the vibration-damping member. The elastic member was attached to the shaft-shaped member using a nut (fixing member) and a washer.

The other end of the shaft-shaped member of the vibration-damping structure obtained above was connected to a member to be damped under the following conditions, and then one end of the shaft-shaped member was struck with an impulse hammer 310 to measure the inertance:
Material: Hot-rolled steel plate (SS400)
Dimensions: length 400mm, width 300mm, thickness 4.5mm.

[Comparative Example 1]
The inertance was measured in the same manner as in Example 1, except that the elastic member having the vibration-damping member bonded to its periphery was bonded to the member to be damped using double-sided tape (see Figure 4).

The results of the inertance measurements in Example 1 and Comparative Example 1 are shown in Figure 11. The horizontal axis of Figure 11 represents frequency (Hz), and the vertical axis represents inertance (dB). As indicated by the arrows in Figure 11, frequencies at which the peak gain was lower in Example 1 compared to Comparative Example 1 were confirmed. On the other hand, almost no frequencies at which the peak gain was higher in Example 1 compared to Comparative Example 1 were confirmed. This shows that the vibration damping structure of Example 1 has a greater amount of vibration damping than the vibration damping structure of Comparative Example 1.

[Example 2]
Elastic members having the following conditions were prepared:
Material: Stainless steel Volume: 2843mm ³
Thickness of the center part: 2 mm
Minimum thickness of the first and second wedge-shaped portions: 0.2 mm
Planar shape: 64 mm diameter circle Center size: 32 mm diameter
Through-hole size: diameter 17 mm
In formula (1), n=2, ε=(2-0.2)/(16) ² , y=0.2.

The vibration damping members were prepared under the following conditions:
Material: Rubber Dimensions: Outer diameter 64mm, inner diameter 44mm.

A shaft-shaped member having the following conditions was prepared:
Material: Stainless steel Shape: M16 bolt Length: 25mm.

The vibration-damping structure of Example 2 was obtained by inserting and attaching the shaft-shaped member into the through-hole of the elastic member, the periphery of which was bonded the vibration-damping member. The elastic member was attached to the shaft-shaped member using a nut (fixing member).

The other end of the shaft-shaped member of the vibration-damping structure obtained above was connected to a member to be damped under the following conditions, and then the inertance was measured by striking one end of the shaft-shaped member with an impulse hammer 310. The inertance measurement was performed by replacing the data conversion module 330 of the measurement system 300 with a FET analyzer (SCADAS III manufactured by Siemens KK):
Material: Cold-rolled steel plate (SPCC)
Dimensions: length 300mm, width 300mm, thickness 1.6mm.

[Comparative Example 2]
The inertance was measured in the same manner as in Example 2 above, except that an elastic member having a constant thickness, i.e., an elastic member not having an acoustic black hole structure, was used.

The results of the inertance measurements in Example 2 and Comparative Example 2 are shown in Figure 12. The horizontal axis of Figure 12 represents frequency (Hz), and the vertical axis represents inertance (dB). It was confirmed that in Example 2, most peak gains above 4000 Hz were lower than the peak gains in Comparative Example 2. This demonstrates that the vibration damping structure of Example 2, which has first and second wedge-shaped portions, has a greater amount of vibration damping than Comparative Example 2.

[Example 3]
Inertance was measured in the same manner as in Example 2, except that eight linear notches were made in the wedge-shaped portion of the elastic member used in Example 1. The eight notches were arranged radially.

[Example 4]
The inertance was measured in the same manner as in Example 3, except that the shape of the notch was changed to an arc shape.

[Example 5]
The inertance was measured in the same manner as in Example 4 above, except that a longer cut was made.

Figures 13(A) and (B) show the inertance results measured in Examples 3 to 5 above, along with the results of Example 1. Figure 13(B) shows an enlarged view of the 1600 Hz to 2000 Hz frequency range in Figure 13(A). The horizontal axis of Figures 13(A) and (B) represents frequency (Hz), and the vertical axis represents inertance (dB). It was confirmed that Example 5 had a lower peak gain frequency than Examples 3 and 4. This shows that by providing a longer cut in the wedge-shaped portion, it is possible to effectively damp vibrations at lower frequencies.

《Vibration analysis》
Vibration analysis of each of the following vibration control structures was performed using analysis software NX-Nastran (manufactured by Siemens AG).

[Example 6]
Elastic member model:
Material: Steel Volume: 3744mm ³
Thickness of the center part: 2 mm
Minimum thickness of wedge: 0.2 mm
Planar shape: square with sides of 64 mm Size of central part: square with sides of 32 mm Size of through hole: circle with diameter of 17 mm In formula (1), n = 2, ε = (2 - 0.2)/(16) ² , y = 0.2.

Model of vibration damping member:
Density: 300kg/ ^m3
Young's modulus: 30 MPa
Poisson's ratio: 0.49
Structural damping coefficient: 3
Dimensions: Positioned 4.5 mm inward from the periphery of the elastic member.

Model of shaft member:
Material: Steel Length: 50mm
Diameter: 17mm
An elastic member is fixed to the center of the shaft-shaped member (at a position 25 mm from one end and the other end).

The inertance was obtained for the above vibration control structure model. Specifically, the other end of the shaft-shaped member was connected to the following vibration-controlled member, and the response acceleration at the corner of the vibration-controlled member when a vibration force of 0 to 8000 Hz and 1 N was applied to one end of the shaft-shaped member was calculated by simulation:
Material: Steel Dimensions: Length 300mm, width 300mm, thickness 1.6mm
Support method: free support.

[Example 7]
The inertance was obtained in the same manner as in Example 6 above, except that the following elastic member model was used:
Elastic member model:
Material: Steel Volume: 2715mm ³
Thickness of the center part: 2 mm
Minimum thickness of wedge: 0.2 mm
Planar shape: regular hexagon with a circumscribed circle having a diameter of 64 mm. Size of central part: circle with a diameter of 32 mm. Size of through hole: circle with a diameter of 17 mm. In formula (1), n = 2, ε = (2 - 0.2)/(16) ² , y = 0.2.

[Example 8]
The inertance was obtained in the same manner as in Example 6 above, except that the following elastic member model was used:
Elastic member model:
Material: Steel Volume: 2843mm ³
Thickness of the center part: 2 mm
Minimum thickness of wedge: 0.2 mm
Planar shape: circle with a diameter of 64 mm Size of central part: circle with a diameter of 32 mm Size of through hole: circle with a diameter of 17 mm In formula (1), n = 2, ε = (2 - 0.2)/(16) ² , y = 0.2.

[Example 9]
The inertance was obtained in the same manner as in Example 6 above, except that the following elastic member model was used:
Elastic member model:
Material: Steel Volume: 3429mm ³
Thickness of the center part: 2 mm
Minimum thickness of wedge: 0.2 mm
Planar shape: ellipse with major axis 82 mm and minor axis 50 mm Size of central part: circle with diameter 32 mm Size of through hole: circle with diameter 17 mm In formula (1), n = 2, ε = (2 - 0.2)/(25) ² , y = 0.2.

[Comparative Example 3]
The inertance was obtained in the same manner as in Example 6 above, except that the following elastic member model was used and no vibration-damping member model was used:
Elastic member model:
Material: Steel Volume: 2843mm ³
Thickness: 0.95 mm (constant)
Planar shape: circle with a diameter of 64 mm Size of through hole: diameter 17 mm

The inertance obtained in Examples 6 to 9 and Comparative Example 3 is shown in Figure 14. The horizontal axis of Figure 14 represents frequency (Hz), and the vertical axis represents inertance (dB). In Examples 6 to 9, in which the elastic member has an acoustic black hole structure, it was confirmed that most peak gains were lower in the 3000 to 5000 Hz band compared to Comparative Example 3. It was also confirmed that the peak gain tended to decrease as the symmetry of the planar shape of the elastic member increased.

The above describes the vibration-damping structure of the present invention using embodiments, modifications, and examples. However, those skilled in the art can make additions, modifications, and omissions to the present invention as appropriate within the scope of its technical concept. For example, the configurations, shapes, sizes, etc. of each part of the vibration-damping structure described in the above embodiments, modifications, and examples are merely examples, and other configurations, shapes, sizes, etc. may also be used.

For example, in the above embodiments, an example was described in which a vibration-damping structure was attached to a plate-shaped member to be damped, but the shape of the member to be damped may be other shapes, such as a rod shape.

In addition, in the above embodiments, examples have been described in which the wedge-shaped portion 11W is provided from a position adjacent to the central portion 11C to the periphery of the elastic member 11, but the wedge-shaped portion 11W may also be provided in a portion between the central portion 11C and the periphery of the elastic member 11.

In addition, in the above-mentioned variant example 1, an example was described in which a washer 15 is provided between the fixed member 14 and the elastic member 11, but the elastic member 11 may be fixed to the shaft-shaped member 13 without using a washer.

10 Vibration control structure 11 Elastic member 11C Central portion 11W Wedge-shaped portion 11WA First wedge-shaped portion 11WB Second wedge-shaped portion 11H Through hole 11n Notch 12 Vibration control member 13 Shaft-shaped member 14 Fixing member 15 Washer 16 Raising member 20 Member to be damped 30 Vibration source 1000 Vibration control structure e1 Periphery x Distance L Length.

Claims (16)

a shaft-shaped member having one end and another end;
an elastic member including a central portion directly connected between the one end and the other end of the shaft-shaped member, and a wedge-shaped portion provided on an outer periphery of the central portion and satisfying the following formula (1);
a vibration-damping member joined to the periphery of the wedge-shaped portion ,
The vibration-damping structure , wherein the central portion and the wedge-shaped portion are integrated .
a shaft-shaped member having one end and another end;
an elastic member including a central portion connected between the one end and the other end of the shaft-shaped member, and a wedge-shaped portion provided on an outer periphery of the central portion and satisfying the following formula (1);
a vibration-damping member joined to the periphery of the wedge-shaped portion;
Equipped with
The wedge-shaped portion includes a first wedge-shaped portion and a second wedge- shaped portion that face each other in the extension direction of the shaft-shaped member.
a shaft-shaped member having one end and another end;
an elastic member including a central portion connected between the one end and the other end of the shaft-shaped member, and a wedge-shaped portion provided on an outer periphery of the central portion and satisfying the following formula (1);
a vibration-damping member joined to the periphery of the wedge-shaped portion;
Equipped with
The wedge- shaped portion has a notch extending from the periphery toward the central portion.
4. The vibration damping structure according to claim 3 , wherein the cuts are provided in a non-linear manner. 5. The vibration damping structure according to claim 3 , wherein the notches are provided in a curved shape. 6. The vibration-damping structure according to claim 1, wherein the vibration-damping member has a shape that follows the periphery of the wedge-shaped portion and is joined to the wedge-shaped portion at a position where the vibration-damping member overlaps the wedge-shaped portion. The vibration damping structure according to claim 1 , wherein the central portion has a through-hole through which the shaft-shaped member passes. 8. The vibration damping structure according to claim 1 , further comprising a fixing member that fixes the central portion at a predetermined position on the shaft-shaped member. The vibration damping structure according to claim 8 , wherein the central portion is wider than the fixing member. 10. The vibration damping structure according to claim 1 , further comprising a raising member having a predetermined thickness and arranged at a position overlapping the central portion of the elastic member. A vibration damping structure according to any one of claims 1 to 10, wherein the elastic member has a circular or regular polygonal planar shape. A vibration-damping structure according to any one of claims 1 to 11, wherein the vibration-damping member includes a viscoelastic material. A vibration damping structure according to any one of claims 1 to 12, wherein the elastic member includes a metal material. A vibration damping structure according to any one of claims 1 to 13, wherein a vibration source is provided on one end of the shaft-shaped member, and a damped member is provided on the other end of the shaft-shaped member. An automotive interior part having the vibration damping structure described in any one of claims 1 to 14. An automobile having a vibration damping structure according to any one of claims 1 to 14 or an interior part according to claim 15.