JPH10164681A - Damper plate, damper device using the plate, and loudspeaker cabinet and music box using the device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a damper plate which can more effectively damp the vibration of a source of vibration, has a stable vibration absorbing characteristic and a simple structure, and can be manufactured at a low cost. SOLUTION: A damper plate 1 is composed of an arm section 2 which has a fixed end 2a on one side and a prescribed width w1 and a mass section 3 connected to the other end 2b of the arm section 2. Part 3e of the mass section 3 is extended to the arm section 2 side from the connecting section between the sections 2 and 3 at an interval 4 from the arm section 2. The periphery of the mass section 3 is formed in a polygon having corners 3a-3d and, at the same time, the mass of the section 3 is biased to the fixed end 2a side from the corner 3a on the extension lines of the arm section 2. Therefore, the natural frequency (f) of the damper plate 1 varies depending upon the position on the periphery of the mass section 3. Because of the interval 4, in addition, the band of the natural frequency (f) of the plate 1 is largely expanded and considerably shifted to the lower side as a whole.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration damping plate for suppressing a vibration generated when a vibration source such as a speaker cabinet or a music box of an audio device is driven, and a vibration damping device using the vibration damping plate. A vibration damping plate which belongs to the field, and particularly effectively suppresses vibrations from a low frequency to a high frequency, a vibration damping device using the vibration damping plate, and the generated sound is a resonance sound pressure and / or driving of the sound The present invention belongs to the technical field of a speaker cabinet and a music box for generating a clear sound without being modulated by the vibration of time.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 26, a speaker cabinet of an audio apparatus has a front plate 32 on which a speaker 31 for generating a reproduced sound is fixed and supported, and a front plate 3 having the same.
2 and a top plate 34 connecting the front plate 32 and the back plate 33 to each other.
The lower bottom plate 35 and the left and right side plates 36 are formed in a box shape. As a result, as shown in FIG.
The reproduced sound generated from the speaker cabinet is radiated to the front of the speaker cabinet.

[0003]

By the way, in such a speaker cabinet, the sound radiated from the speaker 31 is not only transmitted from the front of the speaker cabinet but also into the speaker cabinet behind the speaker 31 from the front. A sound wave having a phase opposite to that of the sound wave is emitted. Therefore, a resonance phenomenon occurs due to the natural vibration of the cabinet inside the speaker cabinet, and a standing wave is generated by the resonance phenomenon.

Since the sound pressure of the standing wave acts on the speaker cone from the rear side and modulates the reproduced sound from the front side, the sound waveform of the reproduced sound is not the same as the signal waveform input to the speaker 31. And a distorted waveform. In this case, the modulation of the reproduced sound by the standing wave becomes maximum when the natural frequency of the cabinet and the frequency of the radiated sound wave to the inside match. At this time, the vibration of each plate constituting the cabinet is maximized, and particularly, the vibration of the back plate 33 facing the speaker 31 is maximized, and the sound wave is emitted from the back plate 33 to the outside. . Therefore, at this time, if the user listens to the reproduced sound from the front, the reproduced sound is heard as a sound of a box, and the original sound itself cannot be heard.

Therefore, conventionally, as shown in FIG. 26, the thickness of each plate of the speaker cabinet is increased to about 9 mm or more.
The sound of the standing wave is sealed in the speaker cabinet by minimizing the vibration of each plate by the sound pressure of the standing wave. However, simply increasing the plate thickness in this way cannot not only sufficiently suppress the vibration of each plate, but also amplifies the sound reflected on each plate, thereby increasing the standing wave. Would.
Therefore, a sound absorbing material 37 is further adhered to the inner surface of each plate to absorb the sound of the standing wave as much as possible, or not shown, but a paper balloon for sound absorption is enclosed in a cabinet to reduce the sound of the standing wave as much as possible. Sound absorption has been performed.

However, not only the sound absorbing material and the paper balloon cannot effectively and sufficiently prevent the standing wave from being generated, but also the state of sticking of the sound absorbing material, the internal pressure state of the balloon, and the sealed state of the worker. However, there is still a problem that stable sound absorption characteristics cannot be always obtained.

Further, increasing the thickness of each plate not only increases the weight of the cabinet, but also complicates the operation of attaching the sound absorbing material and the operation of enclosing the balloon, and also has the problem that the cost is high.

[0008] Also in the music box, there is a problem that a standing wave is generated inside the music box box due to the vibration of the sound source movement or the sound generated by the sound source movement, and the sound radiated to the outside is modulated.

The present invention has been made in view of such circumstances, and has as its object to provide a structure capable of more effectively damping the vibration of a vibration source and having a stable vibration absorbing characteristic. To provide a simple and inexpensive vibration damping plate and vibration damping device.

It is another object of the present invention to provide a speaker cabinet which can produce a clear sound as close as possible to the original sound itself while preventing the reproduced sound from the speaker from being modulated.

Still another object of the present invention is to provide a music box capable of producing a clear sound as close as possible to the sound itself generated by the sound source movement by preventing the sound generated by the sound source movement from being modulated. That is.

[0012]

According to a first aspect of the present invention, there is provided a vibration damping plate having an arm portion having a fixed end at one end and an other end of the arm portion. The arm portion and the mass portion are both formed of a flat thin plate, and the mass portion has a center of gravity G of the vibration suppression plate. The mass part is connected to the arm part so as to be located on one side of the arm part, and a part of the mass part extends toward the arm part side from a connection part with the arm part, and the mass part A gap having a predetermined width and a predetermined length is formed between a part of the arm and the arm, and has a predetermined natural frequency band.

According to a second aspect of the present invention, the connecting portion between the part of the mass portion and the arm portion, which is the tip of the gap, is located closer to the arm portion than the center of gravity of the vibration damping plate; It is characterized by being very close to the center of gravity.

Further, the invention according to claim 3 is characterized in that the thickness of the arm portion is smaller than the thickness of the mass portion. Further, the invention according to claim 4 is characterized in that a peripheral edge shape of the mass portion opposite to the arm portion is formed in a polygonal shape or a curved shape. Further, the invention of claim 5 is:
The surface of the damping plate is flocked.

Further, the invention according to claim 6 comprises a predetermined number of the above-mentioned damping plates formed in various different similar shapes, and these damping plates have different natural frequency bands. And a natural frequency of each of the vibration damping plates such that a part of the natural frequency band of one damping plate and a part of the natural frequency band of the next-sized vibration damping plate overlap each other. It is characterized in that each band is set.

According to a seventh aspect of the present invention, there is provided a vibration damping device according to any one of the first to fifth aspects, a vibration plate vibrated by vibration of a vibration source, and fixed to the vibration plate.
And a fixed support for fixedly supporting the arm of the vibration damping plate.

According to an eighth aspect of the present invention, there is provided the damping plate according to the sixth aspect, a vibrating plate vibrated by the vibration of a vibration source, and the respective arm portions of the respective damping plates fixed to the vibrating plate. And a fixed support base for fixedly supporting the vibration control device.

Further, according to the ninth aspect of the present invention, the vibration damping plate is divided into various numbers and divided into a predetermined number of sets. It is characterized by being fixedly supported by a support base. Further, the invention according to claim 10 is characterized in that a damper is provided between the damping plate and the fixed support.

The speaker cabinet according to the invention of claim 11 is a speaker cabinet formed in a box shape from a front plate, a back plate, a top plate, a bottom plate, and left and right side plates for supporting the speaker. At least one of the plate, the bottom plate and the left and right side plates is formed of a thin plate that vibrates due to the sound generated by the speaker to form the diaphragm, and the inner surface of the speaker cabinet of the one plate constituting the diaphragm The vibration damping device according to any one of claims 7 to 9 is fixedly supported on the side.

According to a twelfth aspect of the present invention, there is provided a speaker cabinet formed in a box shape from a front plate, a back plate, a top plate, a bottom plate, and left and right side plates for supporting a speaker. It is characterized in that at least one of the front plate, the back plate, the top plate, the bottom plate and the left and right side plates is fixedly supported on the inner side of the speaker cabinet.

A music box according to a thirteenth aspect of the present invention is a music box having a box-shaped music box, comprising a sound source movement for generating a driving sound and a bottom plate for fixedly supporting the sound source movement. When the movement is driven, the vibration of the sound source movement itself and / or
Alternatively, the vibration plate is formed of a thin plate that vibrates due to sound from the sound source movement to constitute the diaphragm, and the vibration damping device according to any one of claims 7 to 9 is fixedly supported at a predetermined position of the bottom plate. It is characterized by having.

Further, according to a fourteenth aspect of the present invention, there is provided a box-shaped music box having a sound source movement for generating a sound during driving, and a bottom plate for fixedly supporting the sound source movement. The vibration damping device according to claim 10 is fixedly supported.

[0023]

In the vibration damping plate and the vibration damping device of the present invention having the above-described structure, the gap is provided so that the width of the natural frequency band is effectively widened, and the natural frequency band is generally increased. It shifts to the lower frequency side. As a result, the vibration damping plate resonates in accordance with the frequency of the wider frequency band, and the mechanical energy of the vibration of the vibration source is reduced by the internal friction of the vibration damping plate due to the resonance plate vibration of the vibration damping plate. The vibrations are absorbed by being converted into heat energy by the above. Therefore, the vibration damping plate reliably and sufficiently absorbs vibration whose frequency is over a wide frequency band.

In this case, since the fundamental natural frequency of the damping plate changes depending on the size and shape of the damping plate, the thickness of the arm portion, and the mass of the mass portion, these elements of the damping plate are set to appropriate values. Thereby, the fundamental frequency of the damping plate can be adjusted.

Further, by combining a plurality of vibration damping plates having similar shapes with different sizes, different natural frequency bands of the respective vibration damping plates are combined, so that the total natural frequency band becomes extremely large. It spreads. Therefore, by forming a vibration damping device using such a plurality of vibration damping plates, vibrations in an extremely wide frequency band from a low frequency to a high frequency can be reliably and sufficiently absorbed.

Further, by implanting hairs on the damping plate, not only does the damping plate absorb vibrations due to the vibration of the plate, but also an air layer is formed between a large number of piles of the implanted flocking. It functions as a material and absorbs sound waves in the middle and high frequency range of about 200 Hz or more.

Further, by providing a weight having a predetermined weight to the damping plate, the position of the center of gravity is adjusted, and the natural frequency of the region of the damping plate including the weighted portion changes. . Therefore, by appropriately setting the position where the weight of the damping plate is provided, the natural frequency band of the damping plate can be adjusted.

Further, by providing a damping plate on the back plate of the speaker cabinet, when the back plate vibrates due to the sound from the speaker, the damping plate resonates in accordance with the frequency of the sound. Due to the resonance of the damping plate, the energy of the vibration of the backing plate is converted into the thermal energy of the damping plate, so that the vibration of the backing plate is absorbed and the reflection of the sound wave from the backing plate to the inside of the cabinet is suppressed. As a result, there is no resonance inside the cabinet, and no standing wave is generated. Therefore, the reproduced sound radiated forward from the loudspeaker is hardly distorted by being modulated by the standing wave, and is a clear, well-defined sound very close to the original sound itself.

Further, the bottom plate for fixedly supporting the sound source movement of the music box is formed of a thin plate which resonates by vibration when the sound source movement is driven and / or vibration generated by the sound source movement, and a vibration damping plate is provided on the bottom plate. Accordingly, when the bottom plate vibrates due to the driving of the sound source movement, the damping plate resonates in accordance with the frequency of the bottom plate. The vibration of the sound source movement is modulated and distorted from the surface of the music box because the resonance of the vibration damping plate absorbs the sound inside the music box and prevents the generation of standing waves as described above. Not radiated to the outside as no clear sound.

[0030]

Embodiments of the present invention will be described below with reference to the drawings. 1A and 1B show an example of an embodiment of a damping plate according to the present invention, wherein FIG. 1A is a plan view, FIG. 1B is a front view, and FIG. 1C is a right side view.

The damper plate 1 of the present embodiment, as shown in Figure 1, the arm portions 2 of a predetermined width w ₁ of which one end is in the fixed end 2a, is connected to the other end 2b of the arms 2 The arm portion 2 and the mass portion 3 are integrally formed from a single member of a flat plate having a predetermined thickness (for example, 2 mm) of a resin such as bakelite, acrylic or vinyl, or a metal plate.

The mass 3 is connected to the arm 2 such that the center of gravity G of the damping plate 1 is located on one side of the arm 2. The mass 3 is formed in a polygon having four corners 3a, 3b, 3c, and 3d, and its mass is closer to the fixed end 2a than to the corner 3a on the extension of the arm 2. The shape, that is, the corner 3a is tapered, and the fixed end 2a is wide. Further, a portion 3e of the mass 3 extends from the connection with the arm 2 (the position of the other end 2b of the arm 2) to the arm 2 side.

A gap 4 having a predetermined width w ₂ and a predetermined length L is substantially equal between a portion 3 e forming a corner 3 d and the arm 2 in the mass portion 3. That is, a part 3 e of the mass 3 protrudes from the other end 2 b of the arm 2 toward the fixed end 2 a so as to form a gap 4 with the arm 2. The gap 4 can be formed by a slit, a notch, or a narrow concave fitting formed in a single integrated flat plate of the arm 2 and the mass 3.

In order to make the vibration frequency band of the vibration damping plate 1 as wide as possible, it is desirable to set the width w ₂ of the gap as small as possible, and one end 4 a of the gap 4.
1A, the position in the left-right direction (that is, the arm 2
The same) and the position in the lateral direction of the other end 2b is, the position in the lateral direction G ₁ in a range not exceeding the position in the lateral direction G ₁ of the center of gravity G to the left
It is desirable to set as close as possible. But,
The gap 4 is not necessarily limited to this, and can be arbitrarily set arbitrarily according to the use state of the damping plate 1.

[0035] In order to widen as much as possible the vibration frequency band of the damper plate 1 in the same manner, when it is desirable that the width w ₁ of the arm portion 2 is set as small as possible, to reduce too much the width w _1, Since the strength of the arm 2 cannot be obtained, the vibration damping plate 1
There needs to be set small width w ₁ in a range where the strength needed to exert vibration suppressing function is obtained.

The vibration damping plate 1 of the present embodiment thus configured is
As shown in FIGS. 2A and 2B, the fixed end 2 of the arm 2
a, for example, is placed on the fixed base 5, and the fixed end 2 a is pressed from above by the pressing member 6, and the fixing bolt 7 is fastened to the fixed base 5 so that the fixed end 2 a is sandwiched between the fixed base 5 and the pressing member 6. By pressing, it is firmly fixed and supported.

In the state where the vibration damping plate 1 is fixed and supported as described above, when one point on the periphery of the mass portion 3 is pressed from above with a force F and pushed down, the vibration damping plate 1 is vibrated. I will be. At this time, the primary natural frequency (hereinafter, simply referred to as a natural frequency) f changes depending on the position of the peripheral edge of the mass portion 3. As a result of the actual test, as shown in FIG. 3, the peripheral position 3 of the mass portion 3 between the corners 3a and 3b and close to the corner 3b.
f, the natural frequency f _3f is the lowest, and the angles 3a, 3b, 3
It was found that the natural frequencies f _3a , f _3b , f _3c , and f _3d increase in the order of c and 3d (that is, f _3f <f _3a <f _3b <f _3c <f _3d ). In FIG. 3, the vertical axis indicates that resonance is likely to occur at a large amplitude at each position on the periphery of the damping plate 3f, and for convenience, this will be referred to as resonance ease (or resonance sharpness) in the present invention.

As described above, each position 3 on the peripheral edge of the damping plate 3f
It is considered that the natural frequencies at a, 3b, 3c, 3d, and 3f are different from each other as follows. Now, when the positions 3a, 3b, 3c, 3d, and 3f of the periphery of the mass portion 3 are pushed down, as shown in FIG. In the present invention, this is called a vibration axis for convenience) is generated corresponding to each of the positions 3a, 3b, 3c, 3d, and 3f. In this case, each vibration axis always crosses the arm portion 2 and each distance from the center of gravity G to each vibration axis is L _3a , L _3b , L _3c , L _3d , L _3f. , L
The _{3f> L 3a> L 3b>} L 3c> L 3d. Since the natural frequency f is considered to be lower as the distance from the center of gravity G to the vibration axis is longer, each natural frequency is f as described above.
_3f <it believed the _{f 3a <f 3b <f 3c} <f 3d.

Next, consider a damping plate 1 'having no gap 4 as shown in FIG. This damping plate 1 'is formed in the same outer shape as the above-described damping plate 1 shown in FIG. For convenience, the reference numerals of the respective portions of the vibration damping plate 1 'are denoted by adding "'" to the reference numerals of the portions corresponding to the vibration damping plate 1 in FIG. Since the damping plate 1 'has no gap 4, it does not substantially have the function of the arm 2 of the damping plate 1 shown in FIG. 1, and the corner 3'd corresponding to the projecting corner 3d is Not protruding.

When this vibration damping plate 1 'is firmly fixed and supported on a fixed base 5 in the same manner as shown in FIG. 2 and its natural frequencies are measured, FIG. The results, shown as natural frequency bands, were obtained. As is clear from these results, it was found that the vibration damping plate 1 'having no gap 4 has a smaller degree of resonance than the vibration damping plate 1 having the gap 4 of the present invention, that is, it is difficult to resonate at a large amplitude. this is,
It is considered that the absence of the gap 4 is due to the fact that the overall rigidity of the bending and torsion of the vibration suppressing plate 1 ′ is larger than that of the vibration damping plate 1 having the gap 4.

Further, in the vibration damping plate 1 'having no gap 4, the natural frequency f' at the position 3'd was hardly obtained.
This is because the position 3'd is very close to the fixed end 2a of the damping plate 1 ', that is, the fixed supporting portion, and the damping plate 1' has substantially no arms. This is probably due to little movement.

Further, the band of the natural frequency f 'of the vibration damping plate 1' having no gap 4 is much narrower than the band of the natural frequency f of the vibration damping plate 1 having the gap 4, and the vibration damping plate is entirely formed. It can be seen that the natural frequency f 'of 1' is higher than the natural frequency f of the damping plate 1. That is, it can be seen that the provision of the gap 4 greatly widens the band of the natural frequency f of the damping plate 1 and shifts the natural frequency considerably lower as a whole.

Next, an example of a vibration damping device using the vibration damping plate 1 of the present embodiment configured as described above will be described. FIG.
As shown in (a) and (b), this vibration damping device 8
It includes four vibration damping plates 1 of the same shape and the same size, a fixing base 5, a holding member 6, and a fixing bolt 7. Then, the fixed base 5 is firmly fixed to a vibration plate 9 vibrated by a vibration source or the like (not shown), and the fixed ends 2a of the arms 2 of the vibration damping plates 1 are fixed to the fixed base 5 and the pressing member 6, respectively. And is firmly fixed and supported by being pinched by a fixing bolt 7 between the two.

In the vibration damping device 8 of the present embodiment thus configured, when the vibration plate 9 vibrates, the vibration damping plate 1 vibrates via the fixed base 5. When the vibration frequency of the vibration plate 9 is within the natural frequency band of the vibration damping plate 1 shown in FIG. 3, the natural frequency f is the same as the vibration frequency of the vibration plate 9.
Along the vibration axis at the peripheral position of the damping plate 1 having
The damping plate 1 resonates. In that case, the mechanical energy of the vibration of the vibration source is converted into the mechanical energy of the vibration of the diaphragm 9, and the mechanical energy of the diaphragm 9 is further converted to the mechanical energy of the vibration damper 1.
Are converted into heat energy and dissipated by the internal friction of the damping plate 1 generated by the plate vibration.

As described above, the mechanical energy of the vibration of the vibration plate 9 is converted into the heat energy of the vibration damping plate 1 and dissipated, so that the vibration of the vibration plate 9 has an effect by vibrating these vibration damping plates 1. Will be suppressed. In this case, the vibration absorption of the vibration plate 9 by the vibration suppression plate 1 becomes maximum when the vibration suppression plate 1 resonates.
Vibration is greatly suppressed. Since the band of the natural frequency f of the vibration damping plate 1 extends over a relatively wide range as shown in FIG. 3, the vibration of the diaphragm 9 is suppressed over a relatively wide range of the frequency.

The damping plate 1 is formed by cutting a conventional bakelite, acrylic or vinyl resin plate, a thin steel plate or a phosphor bronze plate into a simple predetermined shape and forming a gap 4. Since only punching or injection molding (in the case of resin) is required, mass production can be performed easily, inexpensively, and in large quantities. In addition, it is sufficient to simply combine a predetermined number of the vibration damping plates 1 and firmly fix them with a fixing tool such as a bolt.
Is extremely simple in construction and assembly. In this case, since the shape and structure of the damping plate 1 are simple, the vibration characteristics of the damping plate 1 hardly vary depending on the manufacturer of the damping plate 1, and the damping plate 1 has stable vibration characteristics. Become like Therefore, the vibration absorbing performance of the vibration damping device 8 is stable without variation, and the vibration damping device 8 that can reliably absorb the vibration of the desired frequency can be easily designed.

The number of the damping plates 1 is not limited to four. For example, five damping plates 1 can be provided as shown in FIG. Any number of sheets can be provided. Further, a vibration damping plate 1, a fixed base 5
The holding member 6 does not necessarily need to be provided on the vibration plate 9 vibrated by the vibration source, and may be provided directly on the vibration source itself. Further, by directly fixing the vibration damping plate 1 to the vibration source or the vibration plate 9, the fixing base 5 and the pressing member 6 can be omitted. Further, the vibration damping plate 1 does not necessarily need to be fixedly supported by the fixing bolts 7 and may be fixedly supported using screws or other fixing tools such as screws, or may be bonded without using these fixing tools. It can be directly fixed and supported by an agent or the like.

FIGS. 7A to 7D are views showing another embodiment of the vibration damping device according to the present invention. FIG. 7 (a)
As shown in (d), the vibration damping device 8 of this example includes four vibration damping plates 1A, 1B, 1C, and 1D having the same shape and different dimensions, and the four vibration damping plates 1A. , 1B, 1C, 1
D decreases in these order. Although not shown in FIG. 7, the reference numerals of the respective positions of the damping plates 1A, 1B, 1C, 1D will be described with the same reference numerals as those of the corresponding positions shown in FIG.

As shown in FIG. 8, these damping plates 1A, 1A
B, 1C, and 1D have natural frequency bands of different widths, respectively, and the natural frequencies are generally higher in these order, and the ease of resonance is smaller in these order. In this case, a part of the natural frequency band of the damping plate 1A and a part of the natural frequency band of the damping plate 1B overlap each other, and another part of the natural frequency band of the damping plate 1B. Another part of the natural frequency band of the damping plate 1C and a part of the natural frequency band of the damping plate 1D are further overlapped so that the part of the natural frequency band of the damping plate 1C overlaps with the part of the natural frequency band of the damping plate 1C. The natural frequency bands of the respective damping plates 1A, 1B, 1C, 1D are set so as to overlap each other. Thus, the damping plates 1A, 1
Since the natural frequencies vary depending on the sizes of B, 1C, and 1D, the natural frequencies can be adjusted by appropriately setting the sizes of the damping plates 1A, 1B, 1C, and 1D.
The natural frequency also varies depending on the magnitude of the mass of the mass portion or the thickness of the arm portion, and therefore, the vibration damping plates 1A, 1B,
By appropriately setting these values of 1C and 1D, the natural frequency can be similarly adjusted. (Details of the difference in the natural frequency due to the magnitude of the mass of the mass portion or the thickness of the arm portion will be described later.) Do).

As shown in FIGS. 9 (a) and 9 (b), each of these damping plates 1A, 1B, 1C, 1D has the same structure as the damping device 8 of the above-described example. Fixed table 5 and holding member 6 each having fixed ends 2a fixed to diaphragm 9
Is firmly fixed and supported by being pinched by a fixing bolt 7. In that case, the damping plates 1A, 1B, 1
They are arranged counterclockwise in the order of C and 1D. But,
The arrangement order of these damping plates 1A, 1B, 1C, 1D is not limited to this, and can be set arbitrarily.

In the vibration damping device 8 of the present embodiment thus configured, each of the vibration damping plates 1A, 1B, 1C and 1D has a natural frequency band as shown in FIG. The total natural frequency band is the minimum natural frequency 3f of the damping plate 1A.
From 3 to the maximum natural frequency 3d of the damping plate 1D. Therefore, the vibration damping device 8 of this example
Thus, the vibration of the diaphragm 9 is effectively suppressed over a wider frequency range.

In the vibration damping device 8 of this embodiment, similarly to the vibration damping device 8 shown in FIG. 6, for example, as shown in FIG. 10, vibration damping plates 1A, 1B, 1C,
In addition to providing five 1D and 1E sheets, two or more arbitrary sheets can be provided depending on the state of the diaphragm 9. Others are the same as those in FIGS. 5 and 6.

As shown in FIG. 11, for example, six damping plates 1A, 1B, 1C, 1D, 1E, 1F are
According to a, 6b, and 6c, three stages may be provided at predetermined intervals and overlapped. Of course, it goes without saying that two or more damping plates can be stacked in an appropriate number of stages, and one or more appropriate number of damping plates can be provided per stage. Stacking the damping plates in this manner is particularly suitable when there is not much planar installation space.

FIG. 12 illustrates still another embodiment of the vibration damping device according to the present invention. As shown in FIG.
The vibration damping device 8 of this example includes eight vibration damping plates 1A, 1B, 1C, 1D, 1E, 1F, 1G, and 1H having the same shape and different dimensions. These eight damping plates 1A, 1B, 1C, 1D, 1
E, 1F, 1G, and 1H are set such that a part of each of the natural frequency bands overlaps, similarly to the natural frequency band shown in FIG. And these damping plates are 4
One sheet at a time is firmly fixed and supported by two fixing tables 5a and 5b, which are firmly fixed to the diaphragm 9, respectively, by the same fixing method as described above. Eight damping plates 1A, 1B, 1
C, 1D, 1E, 1F, 1G, and 1H are all arranged in the same direction, but the direction of each damping plate and the order of arrangement can be set arbitrarily.

Further, the fixed bases 5a and 5b of the two damping plates are both fixed at predetermined positions on the diaphragm 9. In this case, if the largest vibration damping plate 1A is arranged at the position of the largest amplitude of the diaphragm 9 (for example, substantially at the center position in the case of the peripherally fixed diaphragm), the vibration frequency of the diaphragm 9 can be reduced. Vibration can be more effectively suppressed.
However, without being limited to this, the two sets of damping plates may be arranged so as to be able to effectively absorb the vibration of the diaphragm 9 from a low frequency to a high frequency.

In the vibration damping device 8 of the present embodiment thus configured, the total natural frequency band is the eight vibration damping plates 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H. Due to the different natural vibration bands, the vibration damping device 8 of the above-described example is much wider than the total natural frequency band shown in FIG. It is particularly preferable that the two fixed bases 5a and 5b are divided into two planes to provide the vibration damping plate in a case where there is a planar installation space.

In the vibration damping device 8 of this example, two or more vibration damping plates 1 can be provided on each of the fixed bases 5a and 5b in a stacked manner as shown in FIG. By doing so, the total natural frequency band of the vibration damping device 8 is set even wider.

FIG. 13 is a view showing still another example of the embodiment of the vibration damping plate 1 of the present invention. As shown in FIG. 13, the damping plate 1 of this example includes a weight 10 fixed at the position of the corner 3b. The mass of the weight 10 is set smaller than the mass of the damping plate 1. Other configurations of the damping plate 1 of the present example are the same as those of the above-described respective examples of the damping plate.

By providing the weight 10 in this manner, the position of the center of gravity G 'of the damping plate 1 is slightly shifted from the position of the center of gravity G of the damping plate 1 having no weight 10 in the direction of the weight 10, that is, in the direction of the corner 3b. It will shift. Due to this movement of the center of gravity, of the distance from the center of gravity G ′ to each vibration axis, the angle 3b,
The distances L _3b , L _3c to the vibration axis corresponding to _3c change slightly, and the distances L _3a , L _3d , L _3f to the vibration axis corresponding to angles 3a, 3f, 3d hardly change. That is, among the natural frequencies f at the respective positions, the natural frequencies f _3a and f _{3d at} the angles 3b and 3c slightly change, and the natural frequencies ff _3a , f _3d and f _3f at the angles 3a, 3d and 3f almost change. It does not change.
By providing the weight 10 at the corner 3b in this manner, some natural frequencies of the vibration damping plate 1 can be slightly changed without substantially changing other natural frequencies. The position at which the weight 10 is provided is not limited to the corner 3b, and may be provided at an arbitrary position on the damping plate 1.

Therefore, by appropriately setting the installation position of the weight 10, for example, the minimum natural frequency of the damping plate 1 is slightly reduced, or the maximum natural frequency of the damping plate 1 is slightly increased. For example, the predetermined natural frequency of the damping plate 1 can be finely adjusted. Other functions and effects of the vibration damping plate 1 of this embodiment are substantially the same as the functions and effects shown in FIG.

The damping plate 8 of this embodiment can be used to construct the damping device 8 in the same manner as the damping device 8 of each of the above-described embodiments. The effect is the same as the operation effect of the vibration damping device 8 of each of the above-described examples.

FIG. 14 is a view showing still another example of the embodiment of the vibration damping plate 1 of the present invention. Although the outer shape of the mass portion 3 of the damping plate 1 shown in each of the above-described examples is all formed in a polygonal shape, as shown in FIG. The peripheral edge connecting 3a, 3f, 3b, 3c, 3d is formed in a curved shape. Therefore, the protruding corner is formed only by the points 3a, 3d, and the other points 3b, 3c, 3f
No corners are formed. The mass of the mass 3 is biased toward the fixed end of the arm 2 as in the above-described examples. Other configurations of the damping plate 1 of the present example are the same as those of the above-described respective examples of the damping plate. The operation and effect of the vibration damping plate 1 of this embodiment are almost the same as the operation and effect shown in FIG. Further, by using the vibration damping plate 1 of the present embodiment, the vibration damping device 8 can be configured in the same manner as the vibration damping device 8 of each of the above-described examples. This is the same as the operation and effect of the vibration damping device 8 of each example.

FIGS. 15 and 16 are views showing another example of the embodiment of the vibration damping device 8 of the present invention. FIG.
The vibration damping device 8 shown in FIG. 5 has a peripheral edge shown in FIG. 1 having a polygonal shape and the peripheral edge shown in FIG. 14 has a curved arc shape, and is substantially the same as the vibration damping plate 1 shown in FIG. Vibration control board 1 of size
Are combined two by two. The other configuration of the present example is the same as that of the vibration damping device 8 shown in FIG. 5, and the operation and effect of the vibration damping device 8 of this example are the same as those of the vibration damping device 8 shown in FIG.

Further, the vibration damping device 8 shown in FIG. 16 includes a vibration damping plate 1 shown in FIG. 1 having a peripheral edge formed in a polygonal shape and a vibration damping plate 1 shown in FIG. And two of different sizes are combined. The other configuration of the present example is the same as that of the vibration damping device 8 shown in FIG. 9, and the operation and effect of the vibration damping device 8 of this example are the same as those of the vibration damping device 8 shown in FIG.

The vibration damping device 8 shown in FIG. 15 and FIG.
In each case, two damping plates having different shapes are combined, but another number of damping plates having different shapes can be combined, or a different number of damping plates can be combined.

FIGS. 17A to 17D are views showing still another example of the embodiment of the vibration damping plate 1 of the present invention. FIG.
As shown in FIGS. 7 (a) to 7 (d), the damping plate 1 of the present example has a flock 11 applied to the entire surface of the arm 2 and the mass 3 thereof. The treatment of the flocking 11 is performed by, for example, using a static electricity of about 20,000 V, and electroplating a large number of piles of resin of about several mm perpendicular to the surface of the damping plate 1.
The flock 11 has an air layer formed between a large number of piles, functions as a porous sound absorbing material, and absorbs sound waves in a middle to high frequency range of about 200 Hz or more.

Therefore, in the vibration damping plate 1 on which such flocking 11 is applied, when this vibration damping plate 1 is used for an acoustic device as described later, for example, sound waves in the middle and high frequency range of about 200 Hz or more are mainly used. In addition to being absorbed by the flock 11, sound waves in a low frequency region smaller than about 200 Hz are mainly absorbed by the plate vibration of the damping plate 1. The other configuration of the damping plate 1 of this example is the same as that of the damping plate 1 shown in FIG. Further, the function and effect of the damping plate 1 of the present example and the damping device 8 using the damping plate 1 of the present example are the same as the damping device 8 using the damping plate 1 shown in FIG.

Next, some specific applications of the vibration damping device using such a vibration damping plate 1 will be described. FIG.
It is a figure explaining an example when the vibration control device of the present invention is applied to a speaker cabinet in audio equipment.

As shown in FIG. 18, the speaker cabinet 12 has a front plate 12a, a top plate 12b, and a bottom plate 12c to which a speaker 13 such as a woofer is attached. Although it is formed so that it hardly vibrates,
The back plate 12d is formed of a plate material having a relatively small thickness (for example, about 2.3 mm), and vibrates by the sound pressure of the sound of the speaker 11.

The vibration damping device 8 of this embodiment uses the back plate 12d as the above-mentioned diaphragm 9 and attaches the back plate 12d to, for example, FIG.
As shown in FIG. 1 and FIG. 14, a predetermined number (6 in the example shown in FIG.
The vibration damping plates 1A, 1B, 1C, 1D, 1E, 1F are stacked in a predetermined number of stages (three in the example shown in FIG. 18) without contacting each other even when they vibrate. In that case,
Each damping plate may be provided at any appropriate position on the back plate 12d. In particular, in order to effectively suppress the vibration of the back plate 12d, the position where the amplitude of the vibration of the back plate 12d is the largest, that is, the back plate It is desirable to provide a damping plate at the center of 12d.

Each vibration damping device 8 has a total natural frequency band shown in FIG. 8 so as to have a size covering a frequency band from about 20 Hz to about 200 Hz which causes a box noise phenomenon. The size, thickness, shape and material of the plate are set. Further, the flocking 11 is also applied to the inside of the cabinet of the back plate 12d.

In the speaker cabinet 12 of the present embodiment thus configured, the back plate 12d functioning as the diaphragm 9 vibrates due to the sound pressure of the sound emitted from the speaker 13, and the vibration of the back plate 12d is reduced. Each damping plate 1
A, 1B, 1C, 1D, 1E, and 1F are transmitted, and these damping plates also vibrate. At this time, the frequency of the vibration of the back plate 12d is determined by the frequency of the sound emitted from the speaker 13, and therefore, each of the damping plates has a natural frequency band including a natural frequency equal to the frequency of the sound. The damping plate resonates at its natural frequency. Thereby, the vibration of the back plate 12d is absorbed and suppressed. In particular, about 2
Low frequency sound wave lower than 00Hz is mainly used for vibration damping plates 1A-1F
Is effectively absorbed by the plate vibration of
Medium to high frequency sound waves of not less than Hz are effectively absorbed mainly by the flocking 11 applied respectively to the damping plates 1A to 1F and the back plate 12d. Thereby, even if the sound emitted from the speaker 13 is radiated into the speaker cabinet 12, there is no reflected sound, and therefore no standing wave is generated, so that the box sound of the speaker cabinet 12 is effectively suppressed. Become like As a result, the reproduced sound emitted forward from the speaker 13 is hardly modulated, and has a better transient characteristic than the reproduced sound modulated by the standing wave as in a conventional speaker cabinet, and the sound that is actually heard. (Hereinafter, also referred to as the audible sound range in the present invention) is expanded and the division is improved, so that a clear sound can be heard.

Therefore, compared to the conventional speaker cabinet, the speaker cabinet 12 of the present embodiment emits a clearer reproduction sound closer to the live sound forward, and the user can enjoy music closer to the live performance. Become like

As shown in FIG. 19, in the conventional speaker cabinet, the frequencies f ₁ ′ and f ₂ ′ of the sound reproduced from the conventional speaker cabinet are higher in a high-frequency region having a frequency higher than the natural frequency f _{0 of the} cabinet. The frequency of the sound reproduced from the conventional speaker cabinet in the low frequency range where the sound is actually audible and lower than the frequencies f ₁ and f _{2 of} the original sound (frequency of the oscillator) and lower than the natural frequency f _{0 of the} cabinet. It is felt that f ₃ ′, f ₄ ′ is actually higher than the frequencies f ₃ , f _{4 of} the original sound (frequency of the oscillator). That is, since the sound reproduced from the conventional speaker 13 is modulated by the standing wave having the natural frequency f ₀ of the cabinet generated inside the speaker cabinet and the audible sound range is compressed, sounds above and below the natural frequency f ₀ are generated. It sounds like this sound falls into the natural frequency f ₀ . This is a phenomenon called so-called cabinet sounding. On the other hand, in the speaker cabinet 12 of the present invention,
Since the standing wave is absorbed by the vibration damping device 8, the reproduced sound is hardly modulated, the reproduced sound generated from the speaker 13 is close to the original sound, and the box sound does not occur.
This box noise phenomenon is as follows. That is,
As is clear from FIG. 19, in the conventional cabinet in which the back plate 12d is a thick plate, the perceived sound range of the sound reproduced from the speaker is compressed, and a large amount of modulation distortion is included. Such compression of the audible sound range of the speaker reproduction sound is generally referred to as cabinet sounding.

Further, as described above, the speaker cabinet 1
2 is absorbed by the vibration damping device 8, so that the standing wave shown in FIG.
A back chamber for covering the back of the speaker as shown in FIG.

In this embodiment, the vibration damping plate 1 and the back plate 12d
Although the hair implantation 11 is performed, the hair implantation 11 is not always necessary, and even if the hair implantation 11 is omitted, a sufficient sound absorbing effect can be obtained. Of course, the flocking 11 may be omitted from the back plate 12d and provided only on the damping plate 1.

Further, in order to further effectively suppress the generation of standing waves in the speaker cabinet 12 due to the sound pressure of the sound from the speaker 13, the vibration damping device 8 and the flocking 11 are provided with a top plate 12b, a bottom plate 12c, and At least one of the side plates 12e may be provided. Furthermore, flocking 1
Instead of 1, the sound absorbing material 12 may be provided on the inner surface side of the cabinet as in the related art. Further, a plurality of vibration damping plates and a fixed base may be integrally manufactured by an injection molding machine.

FIG. 20 is a diagram for explaining another example in which the vibration damping device of the present invention is applied to a speaker cabinet in audio equipment. The same components as those in the above-described example are denoted by the same reference numerals, and detailed description thereof will be omitted.

The speaker cabinet 1 of the example shown in FIG.
In FIG. 2, the back plate 12d is formed as a diaphragm 9 from a thin plate. As shown in FIG. 20, however, the speaker cabinet 12 of the present example is a conventional generally commercially available speaker such as the speaker cabinet shown in FIG. Cabinet 12
Is used as it is. Therefore, the back plate 12d is extremely thick, and vibration generated by sound waves radiated into the cabinet 12 is suppressed to some extent. The vibration damping device 8 is attached to the back plate 12d. The vibration damping device 8 includes a damper 18, four vibration damping plate assemblies 19A, 19B, 19C, 19D, a screw rod 20,
The butterfly nut 21 is configured as a unit.

As shown in FIG. 21, the damper 18 has two upper and lower cushioning plates 22 and 23 formed of thin strips.
These buffer plates 22 and 23 are formed of the same plate material having the same thickness as the damping plate 1A, and are held at predetermined intervals by spacing members 24 and 25 bonded to both ends thereof with an adhesive. Note that the buffer plates 22 and 23 can be formed from other thin plates made of a material different from the material of the damping plate 1A, or can be formed to have a thickness different from the thickness of the damping plate 1A.

At the center of the upper buffer plate 22, a screw rod 2
0 is screwed and fixed, and a female screw member 26 formed of a square thick plate with a female screw 26a fixed thereto is adhered, and a fixing base 5 is attached to the center of the lower buffer plate 22 with an adhesive. It is adhered by. In this case, by setting the width of the buffer plate 22 larger than the width of the fixed base 5, a greater vibration absorbing effect can be obtained. In short, it is desirable that the dimension in the length direction and the width direction of the fixing base 5 be as small as possible compared to the dimension of the buffer plate 22. However, it is not limited to this.

Further, as shown in FIG. 21 (c), relatively large diameter through holes 22a,
22b are formed, and through holes 23a, 23b; 5a, 5b smaller in diameter than through holes 22a, 22b are formed in lower buffer plate 23 and fixing base 5 through holes 22a, 22b.
And coaxially. Small-diameter through holes 23a, 23
b; the diameter of 5a, 5b is the mounting screw 27 (shown in FIG. 24 (b) described later) for mounting the vibration damping device 8 to the back plate 12d.
Are set to a size that can penetrate, and the diameter of the large-diameter through holes 22a and 22b
The tool is set to a size that allows a tool such as a screwdriver to be fastened to d to penetrate and allow a fastening operation with the tool. In addition, as shown by the two-dot chain line α in FIG.
The four corners of the upper and lower buffer plates 22 and 23 and the portions of the spacers 24 and 25 corresponding to the two-dot chain line α may be cut out. By notching in this manner, it becomes possible to mount the vibration damping device 8 in a narrow space of the speaker cabinet 12 by appropriately tilting the vibration damping device 8 so as not to interfere with other speaker components or the other vibration damping devices 8. The degree increases.

The damping plate assembly 19A includes the four largest damping plates 1A as shown in FIG. 22 (a), and their arms 2 are arranged as shown in FIG. 22 (b). Is formed by being sandwiched between a pair of upper and lower square spacing members 28 and 29 and adhered by an adhesive. In this case, as clearly shown in FIG. 22C, the arm portion 2 has a thinned portion 2c formed by cutting, and is made thinner than the mass portion 3 by a predetermined thickness. By making the arm portion 2 thin in this way, the natural frequency of the vibration damping plate 1A can be lowered, and the sound absorbing effect in a low frequency region is further increased. Further, a through hole 30 penetrating in the vertical direction is formed at the center of the spacers 28 and 29. This through hole 30 is set to a size that allows the threaded rod 20 to penetrate. Further, as is clear from FIG. 22 (a), the upper left damping plate 1A and the lower right damping plate 1A have the thinned portion 2c directed upward, and the lower left damping plate 1A and the upper right damping plate 1A. With the vibration damping plate 1A, the thinned portion 2c is directed downward.

It is needless to say that a bilaterally symmetric damping plate 1A can be manufactured, and that all of the four damping plates 1A can be set so that the thinned portion 2c faces upward or downward. As a method of thinning the arm 2, besides the method by cutting as described above, for example, a chemical method such as etching, or forming one thin vibration damping plate from an extremely thin flat plate and using the same thin flat plate There is another method such as a thin plate joining method in which a mass part having the same shape and the same size as the mass part (that is, excluding the arm part 2) of this thin vibration damping plate is produced, and these mass parts are bonded with an adhesive. Needless to say.

A vibration damping plate assembly 19B having four vibration damping plates 1B and a vibration damping plate assembly 1 having four vibration damping plates 1C
9C and a damping plate assembly 1 having four damping plates 1D
Similarly, 9D is formed in such a manner that the arm portions of the respective vibration damping plates are sandwiched between a pair of upper and lower spacing members 28 and 29, and are bonded with an adhesive.

The size of each of the damping plates 1A to 1D is
A is the largest, and then becomes smaller in the order of the damping plate 1B, the damping plate 1C, and the damping plate 1D. In the vibration damping device 8 of this example, these vibration damping plates 1A to 1D are formed as follows. That is, as shown in FIG. 23A, first, a relatively large square thin plate made of a material for a vibration damping plate is prepared, and this square thin plate is cut along a diagonal line into two right-angled isosceles triangular plates. Next, as shown in FIG. 23 (b), a predetermined gap 4 is formed by using one right-angled isosceles triangular plate and cutting out from one side of the isosceles along the oblique side β. In this case, one end 4a of the gap 4 is set at a position of a perpendicular line δ lowered from the vertex γ of the right isosceles triangle to the hypotenuse β. Then, a portion on one side of the notched isosceles is cut off so that the side ε is equal to the side 等 し く, and the arm 2
Is cut to a predetermined length. Lastly, the arm portion 2 is made thinner than the mass portion 3 and flocking (not shown) over the front surface of the thin plate, thereby forming the vibration damping plate 1A.

Next, as shown in FIG.
(A) The other right-angled isosceles triangular plate is cut along a perpendicular line drawn from its vertex to the hypotenuse to form two right-angled isosceles triangular plates again. Then, in the same manner as described above, one of the two right-angled isosceles triangular plates is used, and in the same manner as the damping plate 1A shown in FIG. 23B, the damping plate 1B shown in FIG.
To form Hereinafter, as shown in FIGS. 23 (e) and (g), damping plates 1C and 1D shown in FIGS. 23 (f) and 23 (h) are formed by the same method.

In order to assemble the vibration damping device 8 formed as described above, first, as shown in FIG.
One end of the screw rod 20 is screwed and fixed to the female screw 26a of the female screw member 26 of FIG. Then, the largest damping plate assembly 19A is first attached to the threaded rod 20 by the spacing member 28,
The threaded rod 20 is fitted so that the threaded rod 20 passes through the hole 30 of 29. Next, another damping plate assembly 19B,
19C and 19D are similarly fitted to the screw rods 20 in descending order. Then, the butterfly nut 21 is screwed into the screw rod 20 via a washer and tightened, so that the respective vibration damping plate assemblies 19A, 19B, 19C, 19D are connected to the female screw member 26.
And the nut 21. Thus, the vibration damping device 8 is assembled as a unit. In the vibration damping device 8 assembled in this way, each of the vibration damping plates 1A, 1
B, 1C and 1D are prevented from interfering with each other by the spacers 28 and 29. In the present invention, the damping plate assembly 19
The order in which A, 19B, 19C, and 19D are fitted to the threaded bar 20 does not necessarily need to be in the order of larger order, but may be in an appropriate order. Also, as shown in FIGS. 24 (a) and (c),
By attaching the protection plate 30 to the uppermost portion, it is possible to prevent the damping plate from being broken at the time of attachment or the like.

The vibration damping device 8 thus assembled is
The speaker cabinet 12 is attached to a predetermined position of the back plate 12 d with screws 27. For this attachment, the fixing stand 5 of the vibration damping device 8 is applied to a predetermined position on the inner surface of the back plate 12d, and the screws 27 are inserted through the washers.
Through the through-holes 22a, 22b; 23a, 23b of the damper 18 and the through-holes 5a, 5b of the fixing base 5 and screw it into the back plate 12d with an appropriate tool such as a screwdriver.
The vibration damping device 8 is fixed to the back plate 12d. In this case, the vibration damping device 8 is attached to the components of the speaker device in the cabinet 12 and other plates such as the side plate 12e of the cabinet 12 so as not to interfere with each other.

The position at which the vibration damping device 8 is attached to the back plate 12d is desirably the position facing the speaker 13 in terms of the sound absorbing effect, but is not limited to this, and can be set to a desired position. . Further, the vibration damping device 8 can be attached to a desired plate other than the back plate 12d and other plates constituting the cabinet 12, such as the top plate 12b and the side plate 12e,
It can be attached to multiple boards.

According to the speaker cabinet of this example,
Since the damping plates 1A, 1B, 1C, 1D are attached via the damper 18, the shock due to the sound pressure of the sound radiated from the speaker 13 into the cabinet 12 is effectively absorbed. Thereby, the sound absorbing effect of the damping plates 1A, 1B, 1C, 1D can be further improved, and the user can hear the reproduced sound radiated forward from the speaker 13 as a sound closer to the original sound. become.

Further, according to the speaker cabinet of this example, it is only necessary to mount the vibration control device 8 of the present invention only on the inner surface of the existing speaker cabinet, using the existing speaker cabinet as it is. There is no need to make a dedicated speaker cabinet for the device 8. In addition, since it is only necessary to screw the screw 27 into the plate of the cabinet 12 with an appropriate tool such as a screwdriver, even a layman can easily attach it. Therefore, anyone can attach the vibration damping device 8 to the speaker cabinet inexpensively and easily. Moreover, if the vibration damping device 8 is attached to one end and the cabinet 12, the screws 27 hardly loosen, so that maintenance of the mounting is almost unnecessary.

The vibration damping device 8 can be appropriately attached to a desired position of any of the front plate 12a, the top plate 12b, the bottom plate 12c, and the left and right side plates 12e in addition to the back plate 12d. Further, the vibration damping device 8 can be arranged so as to be spread over the entire surface of the back plate 12d and the like. In this case, a better sound absorbing effect can be obtained. Further, the vibration damping device 8 can be attached by an adhesive or a double-sided tape. According to this, attachment of the vibration damping device 8 is further simplified. Other functions and effects of the speaker device of this example are the same as those of the above-described speaker device shown in FIG.

FIG. 25 is a diagram illustrating a case where an example of the embodiment of the vibration damping device of the present invention is applied to a music box. As shown in FIG. 25, the music box 14 of the present example
A bottom plate 16 on which the sound source movement 15 is mounted and fixed is formed of a relatively thin plate material.
5 is vibrated by the vibration of the sound source movement 15 itself and the sound pressure of the sound from the sound source movement 15 when the sound is generated.

The vibration damping device 8 of this embodiment uses the bottom plate 16 as the above-mentioned diaphragm 9 and, for example,
As shown in FIG. 17, four damping plates (only two are shown in FIG. 25) on which the flocking 11 is applied and which have the same shape but different sizes are fixed. In this case, the damping plate may be provided at an arbitrary position on the bottom plate 16 as appropriate. In particular, it is desirable to provide the damping plate at a central position directly below the accessory case 17 for effective damping.

Then, the total natural frequency band of the vibration damping device 8 shown in FIG. 8 is controlled so as to cover the region from the low frequency to the high frequency where the sound source movement 15 is considered to be emitted in the same manner as described above. The size, shape and material of the diaphragm are set.

Thus, when the bottom plate 16 vibrates when the sound source movement 15 is driven, the sound wave radiated into the music box by the vibration damping device 8 is effectively absorbed in the same manner as described above, and the generation of the standing wave is prevented. Since the sound is prevented from being emitted, the sound emitted from the sound source movement 15 is radiated from the outer surface of the music box without being modulated, and the clear sound can be enjoyed.

The vibration damping plate and the vibration damping device of the present invention
It is not limited to the above-mentioned speaker cabinet and music box. For example, if it is necessary to suppress vibration of a vibration isolation device or the like of a high-rise building or if it is necessary to absorb sound waves such as noise prevention of a machine. Needless to say, it can be applied to any object.

[0099]

As is clear from the above description, according to the vibration damping plate and the vibration damping device of the present invention, the width of the natural frequency band of the vibration damping plate can be effectively widened. Therefore,
The vibration damping plate of the present invention can reliably and sufficiently absorb vibration whose frequency covers a wide frequency band.

In particular, by combining a plurality of vibration damping plates having similar shapes with different sizes, the total natural frequency band can be extremely widened. Therefore, it is possible to reliably and sufficiently absorb vibration in an extremely wide frequency band from a low frequency to a high frequency.

In addition, it is only necessary to perform simple cutting, punching, or injection molding in the case of a conventional resin plate of bakelite, acrylic or vinyl, or a thin plate of thin steel plate or phosphor bronze plate. In addition, the damping plate can be manufactured easily, inexpensively, and in large quantities. Moreover, simply combining a predetermined number of these damping plates,
Since it is only necessary to fix firmly with a fixing tool such as a bolt, the configuration and assembly of the vibration damping device are extremely simplified. Moreover, since the shape and structure of the damping plate are simple, the vibration characteristics of the damping plate can be stabilized. Therefore, the vibration damping performance of the vibration damping device is stable without variation, and a vibration damping device capable of reliably damping a vibration of a desired frequency can be easily designed.

Furthermore, by implanting hairs on the damping plate, the damping plate not only absorbs vibrations due to the vibration of the plate but also absorbs sound waves in the middle and high frequency range of about 200 Hz or more by the flocking. become.

Further, by applying the vibration damping device of the present invention to the back plate of the speaker cabinet, the vibration of the back plate can be absorbed, and the emission of sound waves from the back plate to the outside of the cabinet can be suppressed. Therefore, the reproduced sound radiated forward from the speaker is hardly modulated and distorted, and can be made clear and clear, and very close to the original sound itself. In this case, the same effect can be obtained regardless of whether the cabinet is a closed type or a bass reflex type.

Further, by applying the vibration damping device of the present invention to the bottom plate for fixedly supporting the sound source movement of the music box, the generation of standing waves inside the music box box is prevented, and the sound emitted from the sound source movement is almost distorted. Without any clear sound.

[Brief description of the drawings]

FIG. 1 shows an example of an embodiment of a damping plate according to the present invention, wherein (a) is a plan view, (b) is a front view, and (c) is a side view.

2A and 2B illustrate a vibration characteristic of a damping plate. FIG. 2A is a plan view, and FIG. 2B is a front view partially showing a cross section.

FIG. 3 is a diagram illustrating a natural frequency band of the damping plate shown in FIG. 1 and the damping plate shown in FIG.

4A and 4B show a damping plate having no gap between the damping plates shown in FIG. 1, wherein FIG. 4A is a plan view, FIG. 4B is a front view, and FIG.
Is a side view.

5A and 5B show an example of an embodiment of a vibration damping device according to the present invention, wherein FIG. 5A is a plan view and FIG. 5B is a cross-sectional view taken along line VB-VB in FIG.

FIG. 6 is a plan view showing another example of the embodiment of the vibration damping device of the present invention.

FIG. 7 is a diagram for explaining various types of similar damping plates having different sizes of damping plates shown in FIG. 1;

FIG. 8 is a diagram illustrating setting of each natural frequency band in each damping plate shown in FIG. 7;

9A and 9B show an example of a vibration damping device configured using the vibration damping plate shown in FIG. 7, wherein FIG. 9A is a plan view and FIG. 9B is a cross-sectional view taken along line IXB-IXB in FIG.

FIG. 10 is a plan view showing still another example of the embodiment of the vibration damping device of the present invention.

FIG. 11 is a partial sectional view partially showing still another example of the embodiment of the vibration damping device of the present invention.

12 (a) is a plan view, and FIG. 12 (b) is a cross-sectional view taken along line XIIB-XIIB in FIG. 12 (a). .

FIG. 13 is a plan view showing still another example of the embodiment of the vibration damping plate of the present invention.

14A and 14B show still another example of the embodiment of the vibration damping plate of the present invention, wherein FIG. 14A is a plan view, FIG. 14B is a front view, and FIG. 14C is a side view.

FIG. 15 is a plan view showing still another example of the embodiment of the vibration damping device of the present invention.

FIG. 16 is a plan view showing still another example of the embodiment of the vibration damping device of the present invention.

17A and 17B show still another example of the embodiment of the damping plate of the present invention, wherein FIG. 17A is a plan view, FIG. 17B is a front view, and FIG.

FIG. 18 is a cross-sectional view schematically showing one example of an embodiment of the speaker cabinet of the present invention.

FIG. 19 is a diagram showing a test apparatus for comparing a speaker cabinet of the present invention with a conventional speaker cabinet and the results thereof.

FIG. 20 is a diagram illustrating another example in which the vibration damping device of the present invention is applied to a speaker cabinet in audio equipment.

21 shows a damper which is a component of the vibration damping device shown in FIG. 20, (a) is a plan view, (b) is a front view, and (c) is a cross-sectional view along line XXIC-XXIC in (a). It is.

22A and 22B show respective vibration damping plate assemblies which are components of the vibration damping device shown in FIG. 20, (a) is a plan view, (b) is a cross-sectional view taken along line XXIIB-XXIIB in (a), (c) is a cross-sectional view along the line XXIIC-XXIIC in (a), and (d) to (f) are plan views each showing another damping plate assembly.

FIG. 23 is a diagram illustrating a method of manufacturing each damping plate used in the damping device shown in FIG.

24 (a) is a plan view, and FIG. 24 (b) is a sectional view taken along line XXIVB-XXIVB in FIG. 20 (a).

FIG. 25 is a cross-sectional view schematically illustrating an example of a music box according to an embodiment of the present invention.

FIG. 26 is a cross-sectional view schematically illustrating an example of a conventional speaker cabinet.

FIG. 27 is a cross-sectional view schematically showing another example of a conventional speaker cabinet.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Vibration suppression board, 2 ... Arm part, 2a ... Fixed end, 3 ... Mass part, 3
a, 3b, 3c, 3d, 3f ... Peripheral positions of the mass part 3, 3e ...
Extension part of the mass part 3 on the side of the arm part 2, 4 ... gap, 4a ... gap 4
, 5 ... fixing base, 6 ... holding member, 7 ... fixing bolt, 8 ... vibration damping device, 9 ... vibrating plate, 10 ... weight, 11 ... flocked, 12 ... speaker cabinet, 12a ... top plate, 12
b: top plate, 12c: bottom plate, 12d: back plate, 12e: side plate, 13: speaker, 14: music box, 15: sound source movement, 16: bottom plate, 18: damper, 19A, 19
B, 19C, 19D: damping plate assembly, 20: screw rod, 21
… Butterfly nuts, 22, 23… cushioning plates, 24, 25… spacing material, 26… female screw members, 27… mounting screws, 28, 29…
Spacing material

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[Procedure amendment]

[Submission date] February 19, 1997

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] FIG.

[Correction method] Change

[Correction contents]

FIG.

Claims (14)

[Claims] 1. An arm having a fixed width at one end and a mass connected to the other end of the arm, wherein the arm and the mass are both flat thin plates. Wherein the mass portion is connected to the arm portion such that a center of gravity G of the vibration damping plate is located on one side of the arm portion, and the mass portion of the mass portion A part of the arm extends from the connection with the arm toward the arm, and a gap having a predetermined width and a predetermined length is formed between a part of the mass and the arm. A damping plate having a predetermined natural frequency band. 2. A connecting portion between a part of the mass portion and the arm portion, which is a tip of the gap, is located closer to the arm portion than the center of gravity of the damping plate and is very close to the center of gravity. The damping plate according to claim 1, wherein 3. The vibration damping plate according to claim 1, wherein a thickness of said arm portion is smaller than a thickness of said mass portion. 4. The vibration damping plate according to claim 1, wherein a peripheral edge of said mass portion on a side opposite to said arm portion is formed in a polygonal shape or a curved shape. 5. The vibration damping plate according to claim 1, wherein flocking is performed on a surface of the vibration damping plate. 6. A predetermined number of said damping plates formed in various similar shapes having different sizes, each of said damping plates having a different natural frequency band.
The natural frequency bands of the respective damping plates are respectively set so that a part of the natural frequency bands of the two damping plates and a part of the natural frequency bands of the next-sized damping plate overlap each other. The vibration damping plate according to claim 1, wherein the vibration damping plate is set. 7. The vibration damping plate according to claim 1, a vibration plate vibrated by vibration of a vibration source, and fixed to the vibration plate, and fixing the arm of the vibration damping plate. A vibration damping device comprising at least a fixed support base for supporting. 8. A vibration damping plate according to claim 6, a vibration plate vibrated by vibration of a vibration source, and fixed to said vibration plate.
A vibration damping device, comprising: at least a fixed support base for fixedly supporting each arm of each of the vibration damping plates. 9. The vibration damping plate is divided into various numbers and divided into a predetermined number of sets, and the vibration damping plates are fixedly supported on the fixed support table in a state where the vibration damping plates are stacked at a predetermined interval. 9. The vibration damping device according to claim 8, wherein said vibration damping device is provided. 10. The vibration damping device according to claim 9, wherein a damper is provided between said vibration damping plate and said fixed support base. 11. A front plate, a back plate, a top plate for supporting a speaker,
In a speaker cabinet formed in a box shape from a bottom plate and left and right side plates, at least one of the front plate, the back plate, the top plate, the bottom plate, and the left and right side plates is formed of a thin plate that vibrates due to the sound generated by the speaker. The vibration plate is configured to be provided, and the vibration damping device according to any one of Claims 7 to 9 is fixedly supported on an inner surface side of the speaker cabinet of the one plate constituting the vibration plate. Speaker cabinet. 12. A front plate, a back plate, a top plate for supporting a speaker,
11. A speaker cabinet formed in a box shape from a bottom plate and left and right side plates, wherein the vibration damping device according to claim 10 is provided on at least one of a top plate, a back plate, a top plate, a bottom plate, and left and right side plates. A speaker cabinet fixedly supported on the side. 13. A box-shaped music box comprising: a sound source movement for generating a sound during driving; and a bottom plate for fixedly supporting the sound source movement, wherein the bottom plate is a sound source movement itself when the sound source movement is driven. The vibration damping device according to any one of claims 7 to 9, wherein the vibration plate is formed of a thin plate that vibrates due to the vibration of and / or the sound from the sound source movement, and the vibration plate is provided at a predetermined position on the bottom plate. A music box characterized by being fixedly supported. 14. A box-shaped music box, comprising: a sound source movement for generating a driving sound; and a bottom plate for fixedly supporting the sound source movement. A music box, wherein a vibration device is fixedly supported.