JP2023087202A - Vibration control structure, interior component and vehicle - Google Patents

Abstract

To provide a vibration control structure that can acquire a larger vibration damping amount, and to provide an interior component and a vehicle.SOLUTION: A vibration control structure includes: a shaft-like member including one end and the other end; an elastic member including a central part connected between the one end and the other end of the shaft-like member and a wedge-shaped part provided on an outer periphery of the central part and satisfying the following expression (1); and a vibration control member joined to a peripheral edge of the wedge-shaped part.SELECTED DRAWING: Figure 1

Description

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

Vibration damping structures for suppressing vibration are used, for example, in automobiles and the like. Various configurations have been proposed for damping structures, and for example, Non-Patent Document 1 describes a damping structure using 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) 1 74-184

In such a damping structure, it is desirable to obtain a greater amount of vibration damping. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a damping structure, an interior component, and an automobile capable of obtaining a greater amount of vibration damping.

A vibration damping structure according to the present invention comprises 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 provided on the outer periphery of the central portion. and a damping member joined to a peripheral edge 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-like member. Thereby, the vibration transmitted from one end of the shaft-like member to the other end is effectively damped by the elastic member. Therefore, it becomes possible to obtain a larger amount of vibration damping.

1 is a perspective view showing the configuration of a damping structure according to an embodiment of the present invention together with a damped member and a vibration source; FIG. FIG. 2 is a diagram showing a cross-sectional configuration along the II-II line shown in FIG. 1; FIG. 2 is a perspective view showing a configuration of an elastic member shown in FIG. 1; FIG. 5 is a cross-sectional view showing the configuration of a damping structure according to a comparative example together with a damped member and a vibration source; FIG. 10 is a side view showing the configuration of a damping structure according to Modification 1 together with a damped member and a vibration source; FIG. 11 is a cross-sectional view showing the configuration of a main part of a damping structure according to Modification 2; FIG. 11 is a cross-sectional view showing the configuration of a main part of a damping structure according to Modification 3; (A) and (B) are plan views showing a configuration of a main part of a damping structure according to Modification 4. FIG. 10A, 10B, and 10C are plan views showing the configuration of main parts of a damping structure according to Modification 5. FIG. 1 is a block diagram showing the configuration of a measurement system that measures inertance; FIG. 4 is a diagram showing inertances measured in Example 1 and Comparative Example 1. FIG. 5 is a diagram showing inertances measured in Example 2 and Comparative Example 2. FIG. (A) is a diagram showing inertances measured in Examples 1 and 3 to 5, and (B) is an enlarged diagram showing a part of (A). FIG. 10 is a diagram showing inertances obtained in Examples 6 to 9 and Comparative Example 3;

EMBODIMENT OF THE INVENTION Hereinafter, although embodiment of this invention is described, referring drawings, the technical scope of this invention is not restricted only to the following forms. Note that the dimensional ratios in the drawings are exaggerated for convenience of explanation, and may differ from the actual ratios. In this specification, "a to b" indicating a range means "a or more and b or less". In addition, unless otherwise specified, operations and measurements of physical properties are performed under conditions of room temperature (20 to 25° C.)/relative humidity of 40 to 50%.

<Embodiment>
[Configuration of damping structure]
1 and 2 show the configuration of a damping structure 10 according to an embodiment of the present invention together with a damped member 20 and a vibration source 30. FIG. FIG. 2 is a cross-sectional view taken along line II--II shown in FIG. The damping structure 10 includes an elastic member 11 , a damping member 12 and a shaft member 13 . A vibration source 30 is provided on one end side of the shaft-like member 13 and a damped member 20 is provided on the other end side thereof. In the following description, the extending direction of the shaft-like member 13 may be called the Z direction, and the directions crossing the Z direction may be called the X direction and the Y direction.

(elastic member)
FIG. 3 shows an example of the configuration of the elastic member 11. As shown in FIG. The elastic member 11 is composed of, for example, a plate-like member having a circular planar shape (shape on the XY plane). For example, the main surface (XY plane) of this elastic member 11 is provided substantially perpendicular to the extending direction of the shaft-like member 13 . The elastic member 11 may be made of an elastic material, but is preferably made of a metal material such as iron or steel from the viewpoint of ease of handling.

The elastic member 11 includes a central portion 11C connected between one end and the other end of the shaft-like member 13, and a wedge-shaped portion 11W provided on the outer circumference of the central portion 11C (FIGS. 2 and 3). 3). The central portion 11</b>C has, for example, a circular planar shape and is provided in the central portion of the elastic member 11 . The wedge-shaped portion 11W has an annular shape surrounding the central portion 11C.

The central portion 11C has a predetermined thickness hc (FIG. 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, more preferably 5 mm or less. The diameter of the central portion 11C is, for example, 1 mm to 500 mm, preferably 5 mm to 100 mm.

A through hole 11H for connecting the elastic member 11 to the shaft member 13 is provided in the central portion 11C. The through-hole 11H is a hole penetrating through the elastic member 11 in the thickness direction, and has, for example, a circular planar shape. The through hole 11H is arranged at the center of the central portion 11C, that is, at the center of the elastic member 11, for example. The through hole 11H has, for example, substantially the same size as the shaft diameter of the shaft member 13 . The central portion 11C is connected between one end and the other end of the shaft-like member 13 by passing the shaft-like member 13 through the through-hole 11H. By providing such a through-hole 11H in the elastic member 11, attachment to the shaft-like member 13 is facilitated, and applicability can be improved.

Wedge-shaped portion 11W is provided, for example, adjacent to central portion 11C. The wedge-shaped portion 11W has a predetermined length (length L) from a position adjacent to the central portion 11C to the peripheral edge e1 (FIG. 2). A peripheral edge e1 of the wedge-shaped portion 11W corresponds to the peripheral edge of the elastic member 11, for example. A damping member 12 is joined to the peripheral edge e1 of the wedge-shaped portion 11W. A peripheral edge e<b>1 of the wedge-shaped portion 11</b>W may be provided at a position different from the peripheral edge of the elastic member 11 .

In the wedge-shaped portion 11W, the thickness h 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 the largest at the position adjacent to the central portion 11C and the smallest at the peripheral edge e1. For example, one main surface of the wedge-shaped portion 11W (the main surface on the damped member 20 side) is flat, and the other main surface (the main surface on the vibration source 30 side) is curved. The thickness h of this wedge-shaped portion 11W satisfies the following formula (1).

The arbitrary position on the peripheral edge e1 side, which is the measurement starting point of the distance x in the above formula (1), is an arbitrary position closer to the peripheral edge e1 than the central portion 11C, for example, a predetermined position on the peripheral edge e1. The distance x is measured, for example, along a straight line from the measurement starting point (periphery e1) to the center of the elastic member 11, that is, along the length L direction. As will be described later, when the elastic member 11 is provided with a cut (for example, a cut 11n in FIGS. 8A and 8B to be described later), the direction of the length L is along the cut. . Moreover, y corresponds to the thickness of the elastic member 11 at the measurement starting point of the distance x (for example, a predetermined position on the peripheral edge e1), and is, for example, 0.01 to 1 mm. It is desirable that y is 0.5 mm or less in order to suppress the reflection of vibration waves.

A so-called acoustic black hole structure is realized by providing such a wedge-shaped portion 11W on the outer periphery of the central portion 11C. As a result, the reflection of the vibration wave at the peripheral edge e1 is suppressed, and the vibration can be effectively damped. During damping, for example, the peripheral edge e1 of the wedge-shaped portion 11W vibrates.

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

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

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-like member 13 . Although the details will be described later, this effectively damps the vibration transmitted from the vibration source 30 to the damped member 20 via the shaft-shaped member 13 .

(Damping member)
The vibration damping member 12 joined to the peripheral edge e1 of the wedge-shaped portion 11W plays a role of converting the vibration energy collected at the peripheral edge e1 by the acoustic black hole structure into heat energy and damping it. Damping member 12 is joined to one main surface of elastic member 11, for example. The damping member 12 has, for example, an annular shape having a peripheral edge along the peripheral edge e1 of the wedge-shaped portion 11W, and is arranged at a position overlapping the wedge-shaped portion 11W. In other words, the peripheral edge of the vibration damping member 12 and the peripheral edge e1 of the wedge-shaped portion 11W are arranged at positions overlapping each other in plan view (XY plane). This makes it possible to more effectively attenuate the vibrational energy collected on the peripheral edge e1.

The damping member 12 is made of, for example, a plate-shaped viscoelastic material. The thickness of the plate-shaped damping member 12 is preferably greater than the thickness of the peripheral edge e1 of the wedge-shaped portion 11W. The viscoelastic material forming the damping member 12 is preferably a polymeric material such as rubber. It is preferable that the specific gravity of the damping member 12 is approximately the same as the specific gravity of the elastic member 11 or higher 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-like member 13 can transmit vibrations in its extending direction. For example, a vibration source 30 is connected to one end of the shaft-shaped member 13 and a damped member 20 is connected to the other end thereof. can be transmitted to The shaft-like member 13 is, for example, a bolt or the like. The shaft-like member 13 may be an automobile part such as a suspension and a shaft. The shaft-like member 13 is made of, for example, metal such as iron. The shaft-like member 13 may be made of stainless steel.

[Structure of Damped Member]
A 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, the plate-like damped member 20 is provided substantially parallel to the elastic member 11 . By using the damping structure 10 for the damped member 20 having a smaller vibration damping action (damping coefficient), the vibration of the damped member 20 can be suppressed more effectively. The member 20 to be damped is preferably arranged so as to have 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 damping, transmission of vibration to the damped member 20 can be effectively suppressed. The damped member 20 may be provided between the elastic member 11 and the other end of the shaft-like member 13 . The damped member 20 may be the body of an automobile or the like.

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

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

FIG. 4 shows the configuration of a damping structure 1000 according to a comparative example. The elastic member 11 of this damping structure 1000 is attached to the damped member 20 . In other words, the elastic member 11 is not provided on the vibration transmission path from the vibration source 30 to the damped member 20 via the shaft-like member 13 . When vibration is transmitted to the damped member 20, which is an oscillation system, bending waves are generated in the entire damped member 20. As shown in FIG. Therefore, it is difficult to sufficiently attenuate the vibration with the elastic member 11 attached to a part of the damped member 20 .

On the other hand, in the damping structure 10, the elastic member 11 is attached to the shaft-shaped member 13 connecting the vibration source 30 and the damped member 20, that is, the shaft-shaped member 13, which is a vibration transmission system. Vibration is effectively damped upstream of the damped member 20, which is an oscillation system. Therefore, compared to the damping structure 1000, it is possible to obtain a greater amount of vibration attenuation.

Modifications of the damping structure 10 described in the above embodiment will be described below. In the following, in order to avoid duplication of description, detailed description of the same configurations as those of the damping structure 10 described in the above embodiment will be omitted.

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

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

A washer 15 is provided between the fixed member 14 and the elastic member 11 . By providing the washer 15 , it becomes possible to suppress the occurrence of damage to the elastic member 11 caused by the fixing member 14 .

The central portion 11</b>C 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, it is preferable that the fixing member 14, the damped member 20, and the vibration source 30 are provided inside the central portion 11C in plan view (XY plane). In such an elastic member 11, the wedge-shaped portion 11W is arranged away from the fixing member 14, damped member 20, and vibration source 30 in the XY plane. (Specifically, contact with the fixed member 14, damped member 20, and vibration source 30) can be prevented. As a result, the transmission of vibration to the member 20 to be damped can be effectively suppressed.

The vibration damping structure 10 according to Modification 1 also has an elastic structure having an acoustic black hole structure between one end and the other end of the shaft-like member 13, similarly to the vibration damping structure 10 described in the above embodiment. A member 11 is provided. Therefore, it is possible to obtain a large amount of vibration damping. Furthermore, since the fixing member 14 is provided, the elastic member 11 can be easily attached to a predetermined position of the shaft-like member 13 .

<Modification 2>
FIG. 6 shows the configuration of the main part of the damping structure 10 according to Modification 2. As shown in FIG. In FIG. 6, illustration of the shaft-like member 13 is omitted. The elastic member 11 of this damping structure 10 has a first wedge-shaped portion 11WA and a second wedge-shaped portion 11WB facing each other in the Z direction. Except for this point, the damping structure 10 has the same configuration as the 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 facing each other in the Z direction. ha and hb satisfy the above formula (1). Both main surfaces of the wedge-shaped portion 11W including the first wedge-shaped portion 11WA and the second wedge-shaped portion 11WB 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 peripheral edge e1. This makes it easier to prevent the wedge-shaped portion 11W from coming into contact with other members (for example, damped member 20 and vibration source 30) during 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. The thicknesses ha and hb are preferably the same. Thereby, the symmetry of the elastic member 11 is improved, and the vibration of the damped member 20 can be efficiently suppressed.

The damping structure 10 according to Modification 2 also has an elastic structure having an acoustic black hole structure between one end and the other end of the shaft-like member 13, like the damping structure 10 described in the above embodiment. A member 11 is provided. Therefore, it is possible to obtain a large amount of vibration damping. Furthermore, since the wedge-shaped portion 11W has the first wedge-shaped portion 11WA and the second wedge-shaped portion 11WB, it becomes easier to prevent the wedge-shaped portion 11W from coming into contact with other members during damping.

<Modification 3>
FIG. 7 shows the configuration of the main part of the damping structure 10 according to Modification 3. As shown in FIG. In FIG. 7, illustration of the shaft-like member 13 is omitted. This damping structure 10 has a raised member 16 at a position overlapping the central portion 11C of the elastic member 11 . Except for this point, the damping structure 10 has the same configuration as the damping structure 10 described in the above embodiment.

The raising member 16 is arranged at a position overlapping the central portion 11C in plan view (XY plane). This raising member 16 is provided, for example, in contact with the central portion 11C. Raising member 16 is, for example, a plate member and has a predetermined thickness. Raising member 16 is configured by a washer or the like, for example. Since the damping structure 10 has 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 is increased. This makes it easier to prevent the wedge-shaped portion 11W from coming into contact with other members (for example, damped member 20 or vibration source 30) during damping.

The raising member 16 is preferably provided in the central portion 11 of the wedge-shaped portion 11W on the flat surface side (the lower side of the paper surface of FIG. 7). The flat surface side of the wedge-shaped portion 11W is more likely to come into contact with other members (adjacent to the vertical direction of the paper surface of FIG. 7) than the curved surface side (upper side of the paper surface of FIG. 7). Therefore, by providing the raising member 16 in the central portion 11 on the flat surface side of the wedge-shaped portion 11W, contact between the wedge-shaped portion 11W and other members can be more effectively prevented.

The damping structure 10 according to Modification 3 also has an elastic structure having an acoustic black hole structure between one end and the other end of the shaft-like member 13, like the damping structure 10 described in the above embodiment. A member 11 is provided. Therefore, it is possible to obtain a large amount of vibration damping. Furthermore, since the raised member 16 is provided at a position overlapping the central portion 11C of the elastic member 11, it is easy to prevent the wedge-shaped portion 11W from coming into contact with other members during damping.

<Modification 4>
FIGS. 8A and 8B show the configuration of the main parts of the damping structure 10 according to Modification 4. FIG. In FIGS. 8A and 8B, illustration of the damping member 12 and the shaft-like member 13 is omitted. In this damping structure 10, the wedge-shaped portion 11W of the elastic member 11 is provided with a cut 11n extending from the peripheral edge e1 to the central portion 11C. Except for this point, the damping structure 10 has the same configuration as the damping structure 10 described in the above embodiment.

The wedge-shaped portion 11W is provided with, for example, a plurality of notches 11n. The plurality of cuts 11n are, for example, arranged radially in plan view (XY plane). Each notch 11n may be provided linearly from the peripheral edge e1 toward the central portion 11C (FIG. 8(A)), but is preferably provided non-linearly. The notch 11n is provided in a curved line, for example, and preferably has an arc shape (FIG. 8(B)). Thus, by providing the notch 11n in a non-linear manner, the length L (FIG. 2) of the wedge-shaped portion 11W becomes longer than the length L when the notch 11n is not provided. As a result, the threshold f _cut-on obtained from the above equation (2) can be lowered. Therefore, it is possible to efficiently attenuate lower frequency vibrations.

The damping structure 10 according to Modification 4 also has an elastic structure having an acoustic black hole structure between one end and the other end of the shaft-like member 13, like the damping structure 10 described in the above embodiment. A member 11 is provided. Therefore, it is possible to obtain a large amount of vibration damping. Furthermore, since the wedge-shaped portion 11W of the elastic member 11 is provided with the notch 11n, it is possible to efficiently attenuate low-frequency vibrations.

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

The elastic member 11 has, for example, a polygonal planar shape such as a square (FIG. 9A) and a hexagon (FIG. 9B). The elastic member 11 may have a triangular planar shape, or may have a polygonal planar shape of heptagon or more. Alternatively, the elastic member 11 may have an elliptical planar shape (FIG. 9(C)). The elastic member 11 preferably has a highly symmetrical planar shape such as a circle or a regular polygon. As a result, it becomes possible to attenuate the vibration transmitted through the shaft-like member 13 while enhancing manufacturability and mountability (attachability).

The vibration damping structure 10 according to Modification 5 also has an elastic structure having an acoustic black hole structure between one end and the other end of the shaft-like member 13, similarly to the vibration damping structure 10 described in the above embodiment. A member 11 is provided. Therefore, it is possible to obtain a large amount of vibration damping.

<Application example>
The damping structure 10 described in the above embodiment can be suitably used for damping various vibrations. Above all, it is preferable that the vibration damping structure 10 is used by being mounted on a vehicle. Examples of applications include dash insulators, dash panels, floor carpets, spacers, door trims, sound absorbing structures inside door trims, sound absorbing structures inside compartments, instrument panels, instrument center boxes, instrument upper boxes, and air conditioners. housing, roof trim, sound absorbing structure inside roof trim, sun visor, air conditioning duct for rear seats, cooling duct for battery cooling system in battery-equipped vehicle, cooling fan, center console trim, sound absorbing structure inside console, parcel trim , parcel panels, seat headrests, front seat backs, rear seat backs, and the like. Furthermore, in the trunk, it can be applied to the trunk floor trim, trunk board, trunk side trim, sound absorbing structure in the trim, drafter cover, and the like. It can also be applied inside the frame of a vehicle or between panels, for example, it can be applied to pillar trims and fenders. Among them, it is preferable to use it for automobile interior parts because it is excellent in vibration damping in a low frequency range and is relatively lightweight.

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

《Measuring Inertance》
The inertance of each damping structure was measured using the measurement system 300 shown in FIG. The measurement system 300 includes an impulse hammer 310 (manufactured by PCB Piezotronics, Inc., model 086C03, hard chip), an acceleration sensor 320 (manufactured by PCB Piezotronics, Inc., model 356A01), and a data conversion module 330 (manufactured by The Modal Shop, Inc.). , model 485B39) and a PC (Personal Computer) 340. Impulse hammer 310 and acceleration sensor 320 are connected to data conversion module 330 , and data conversion module 330 is communicably connected to 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 to digitally output a signal from a USB signal. A damping structure and an acceleration sensor 320 were attached to the member to be damped, and one end of the shaft-like member was hit 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 the PC 340 using the data conversion module 330, subjected to Fourier transform, and inertance was obtained. The member to be damped was placed on the sponge. The method of supporting the members to be damped was free support.

[Example 1]
An elastic member was prepared under the following conditions:
Material: Stainless Steel Volume: 2843mm ³
Thickness of central part: 2 mm
Minimum thickness of wedge: 0.2 mm
Planar shape: Circle with a diameter of 64 mm Size of the central part: Diameter of 32 mm
Through-hole size: 17 mm in diameter
In formula (1), n=2, ε=(2−0.2)/(16) ² , y=0.2.

We prepared damping members under the following conditions:
Material: Rubber Dimensions: 64 mm outer diameter, 44 mm inner diameter.

A shaft-shaped member was prepared under the following conditions:
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 having the vibration damping member joined to the peripheral edge thereof. A nut (fixing member) and a washer were used to attach the elastic member to the shaft-shaped member.

After connecting the other end of the shaft-shaped member of the damping structure obtained above to a damped member under the following conditions, one end of the shaft-shaped member was hit 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 damping member bonded to its periphery was bonded to the damped member using double-sided tape (see FIG. 4). ).

The inertance results measured in Example 1 and Comparative Example 1 are shown in FIG. The horizontal axis of FIG. 11 represents frequency (Hz), and the vertical axis represents inertance (dB). As indicated by arrows in FIG. 11, in Example 1, frequencies at which the peak gain was lower than in Comparative Example 1 were confirmed. On the other hand, in Example 1, compared with Comparative Example 1, almost no frequency at which the peak gain increased was confirmed. As a result, it was found that the vibration damping structure of Example 1 has a larger vibration damping amount than the vibration damping structure of Comparative Example 1.

[Example 2]
An elastic member was prepared under the following conditions:
Material: Stainless Steel Volume: 2843mm ³
Thickness of central part: 2mm
Minimum thickness of the first and second wedge-shaped portions: 0.2 mm
Planar shape: Circle with a diameter of 64 mm Size of the central part: Diameter of 32 mm
Through-hole size: 17 mm in diameter
In formula (1), n=2, ε=(2−0.2)/(16) ² , y=0.2.

We prepared damping members under the following conditions:
Material: Rubber Dimensions: 64 mm outer diameter, 44 mm inner diameter.

A shaft-shaped member was prepared under the following conditions:
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 having the vibration damping member joined to the peripheral edge thereof. A nut (fixing member) was used to attach the elastic member to the shaft-like member.

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

[Comparative Example 2]
The inertance was measured in the same manner as in Example 2 except that an elastic member having a constant thickness, that is, an elastic member without an acoustic black hole structure was used.

The inertance results measured in Example 2 and Comparative Example 2 are shown in FIG. The horizontal axis of FIG. 12 represents frequency (Hz), and the vertical axis represents inertance (dB). In Example 2, it was confirmed that most peak gains above 4000 Hz were lower than those in Comparative Example 2. As a result, it was found that the vibration damping structure of Example 2 having the first and second wedge-shaped portions had a larger vibration damping amount than that of Comparative Example 2.

[Example 3]
The inertance was measured in the same manner as in Example 2 above, except that eight linear cuts were provided in the wedge-shaped portion of the elastic member used in Example 1 above. Eight incisions were arranged radially.

[Example 4]
The inertance was measured in the same manner as in Example 3 above, except that the shape of the cut was circular.

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

The results of inertance measured in Examples 3 to 5 are shown in FIGS. 13A and 13B together with the results of Example 1. FIG. 13(B) is an enlarged view of the frequency range of 1600 Hz to 2000 Hz in FIG. 13(A). The horizontal axis of FIGS. 13A and 13B represents frequency (Hz), and the vertical axis represents inertance (dB). It was confirmed that in Example 5, the peak gain frequency was lower than in Examples 3 and 4. FIG. From this, it was found that by providing a longer cut in the wedge-shaped portion, lower frequency vibrations can be effectively damped.

《Vibration analysis》
Using the analysis software NX-Nastran (manufactured by Siemens KK), the following vibration analysis of each damping structure was performed.

[Example 6]
Model of elastic member:
Material: Steel Volume: 3744mm ³
Thickness of central part: 2mm
Minimum thickness of wedge: 0.2 mm
Planar shape: square with one side of 64 mm Size of central part: square with one side 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.

Damping member model:
Density: 300kg/ ^m3
Young's modulus: 30 MPa
Poisson's ratio: 0.49
Structural damping factor: 3
Dimensions: 4.5 mm inside from the edge of the elastic member.

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

Inertance was obtained for the above damping structure model. Specifically, the other end of the above shaft-shaped member is connected to the damped member below, and the corner of the damped member when a vibration force of 0 to 8000 Hz and 1 N is applied to one end of the shaft-shaped member The response acceleration at the part was calculated by simulation:
Material: Steel Dimensions: Length 300mm, Width 300mm, Thickness 1.6mm
Support method: free support.

[Example 7]
Inertance was obtained as in Example 6 above, except that the following elastic member model was used:
Model of elastic member:
Material: Steel Volume: 2715mm ³
Thickness of central part: 2 mm
Minimum thickness of wedge: 0.2 mm
Planar shape: regular hexagon with a circumscribed circle diameter of 64 mm Size of the central part: a circle with a diameter of 32 mm Size of the through hole: a circle with a diameter of 17 mm In formula (1), n = 2, ε = (2-0. 2)/(16) ² , y=0.2.

[Example 8]
Inertance was obtained as in Example 6 above, except that the following elastic member model was used:
Model of elastic member:
Material: Steel Volume: 2843mm ³
Thickness of central part: 2mm
Minimum thickness of wedge: 0.2 mm
Planar shape: circle with a diameter of 64 mm Size of the 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]
Inertance was obtained as in Example 6 above, except that the following elastic member model was used:
Model of elastic member:
Material: Steel Volume: 3429mm ³
Thickness of central part: 2 mm
Minimum thickness of wedge: 0.2 mm
Planar shape: ellipse with major axis of 82 mm and minor axis of 50 mm Size of central portion: circle with diameter of 32 mm Size of through hole: circle with diameter of 17 mm In formula (1), n = 2, ε = (2-0.2 )/(25) ² , y=0.2.

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

The inertances obtained in Examples 6 to 9 and Comparative Example 3 are shown in FIG. The horizontal axis of FIG. 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, compared to Comparative Example 3, it was confirmed that most peak gains were lower in the 3000 to 5000 Hz band. It was also confirmed that the peak gain tends to decrease as the symmetry of the planar shape of the elastic member increases.

The vibration damping structure of the present invention has been described above using the embodiment, modified examples, and examples. However, the present invention can be appropriately added, modified, and omitted within the scope of its technical ideas by those skilled in the art. For example, the configuration, shape, size, etc. of each part of the vibration damping structure described in the above embodiments, modifications, and examples are examples, and other configurations, shapes, sizes, etc. may be used.

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

In the above-described embodiment and the like, the wedge-shaped portion 11W extends from the position adjacent to the central portion 11C to the peripheral edge of the elastic member 11. 11 may be provided in a part between the peripheral edges.

In the first modification, the washer 15 is provided between the fixing member 14 and the elastic member 11. However, the elastic member 11 may be fixed to the shaft member 13 without using the washer. good.

10 damping 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 damping member 13 shaft-shaped member 14 fixing member 15 washer 16 raising member 20 Damped member 30 Vibration source 1000 Damping structure e1 Periphery x Distance L Length.

Claims (16)

a shaft-shaped member having one end and the other 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 the outer circumference of the central portion and satisfying the following formula (1);
and a damping member joined to a peripheral edge of the wedge-shaped portion.

2. The vibration damping structure according to claim 1, wherein said damping member has a shape along the periphery of said wedge-shaped portion and is joined to a position overlapping said wedge-shaped portion. 3. The vibration damping structure according to claim 1, wherein said central portion has a through hole through which said shaft-like member is passed. 4. The vibration damping structure according to any one of claims 1 to 3, further comprising a fixing member for fixing said central portion to a predetermined position of said shaft-like member. 5. The vibration damping structure according to claim 4, wherein said central portion is wider than said fixing member. 6. The vibration damping structure according to claim 1, wherein said wedge-shaped portion includes a first wedge-shaped portion and a second wedge-shaped portion facing each other in the extending direction of said shaft-shaped member. 7. The vibration damping structure according to any one of claims 1 to 6, further comprising a raised member having a predetermined thickness and arranged at a position overlapping said central portion of said elastic member. The vibration damping structure according to any one of claims 1 to 7, wherein the wedge-shaped portion is provided with a notch extending from the peripheral edge toward the central portion. 9. A damping structure according to claim 8, wherein said cuts are provided non-linearly. 10. The damping structure according to claim 8 or 9, wherein said cuts are curved. The vibration damping structure according to any one of claims 1 to 10, wherein said elastic member has a circular or regular polygonal planar shape. A damping structure according to any preceding claim, wherein the damping member comprises a viscoelastic material. The damping structure according to any one of claims 1 to 12, wherein said elastic member comprises a metal material. 14. The vibration damping structure according to any one of claims 1 to 13, wherein a vibration source is provided on one end side of said shaft-shaped member, and a damped member is provided on the other end side of said shaft-shaped member. An automotive interior part comprising the damping structure according to any one of claims 1 to 14. A motor vehicle comprising the damping structure according to any one of claims 1 to 14 or the interior component according to claim 15.

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