JPH11217891A - Damping panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the function of a damping panel by enclosing powder and grain having an elastic deformability in the hysteresis under a specified condition into a plurality of cell spaces formed between two sheets of plates. SOLUTION: Elastic powder and grain 5 having an elastic deformability in the hysteresis made of rubber or the like having 100 μm or smaller in the mean particle size are enclosed in a plurality of cell sapces 4 between two sheets of plates 1, 2 to form a damping panel. A void of at least 2% is formed in the enclosed space 4 of the powder and grain to prevent deterioration of the damping function resulting from restriction of the powder and grain. Further, the Young's modulus of the powder and grain is set lower than 10<5> N/m to absorb more vibration energy. Then, when the powder and grain of 5% or more are added to rigid powder and grain, the dampimg capacity increases compared with a single kind of rigid powder and grain. In this way, the vibration energy can be absorbed by the friction among the elastic powder and grain in a low frequency zone, by the friction and collision caused by the convection of the elastic powder and grain in a middle frequency zone, and by the jamping collision of the elastic powder and grain in a high frequency zone.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration damping panel for absorbing vibration and sound.

[0002]

2. Description of the Related Art Conventionally, as shown in FIGS. 18 (a) and 18 (b), as a vibration damping panel, a metal base and viscoelastic plates 1 and 2 are used.
And those having a laminated structure of the following have been proposed. In (a), viscoelastic plates 1 and 2 are stacked on a metal substrate, and in (b), viscoelastic plates 1 and 2 are sandwiched between two opposing metal substrates.

[0003] When vibration energy is applied to the damping panel, in (a), the vibration energy is consumed as heat energy due to the expansion and contraction of the viscoelastic plates 1 and 2 in the plane direction, and the vibration is absorbed. In this case, the vibration energy is consumed as heat energy due to the shear deformation due to the difference in the direction of expansion and contraction between the upper surface portion and the lower surface portion of the viscoelastic plate materials 1 and 2, and the vibration is absorbed.

As shown in FIGS. 19 (a) and 19 (b), as a sound absorbing panel for absorbing a sound wave propagating in the air, a sound absorbing panel having a porous structure such as a fibrous body or a foamed body has been proposed. I have. (A) shows a fibrous body and (b) shows a foam.

When a sound wave is applied to one side of the sound absorbing panel, the sound energy is consumed as heat energy due to friction, viscous resistance, and vibration of the fiber or foam when the sound wave passes through the porous void. The sound is absorbed.

[0006]

However, in the above-mentioned conventional vibration damping panel, although the effect of vibration damping and sound absorption is high in the middle and high frequency bands, the vibration damping panel in the low frequency band where the need for noise countermeasures is very high. There is a problem that the effect of vibration and sound absorption is small.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a vibration damping panel having a high vibration damping and sound absorbing effect in a wide frequency band including a low frequency band. is there.

[0008]

In order to achieve the above-mentioned object, the invention according to claim 1 comprises two opposing plate members 1, 2
A plurality of cell spaces 4 are formed by partitioning a space between the cells, and an elastic powder 5 having hysteresis elastic deformation is sealed in the cell spaces 4.

In such a vibration damping panel, the behavior of the elastic granular material 5 changes due to the difference in the frequency band. That is,
In the low frequency band, the vibration energy is converted into heat energy by the friction between the elastic particles 5 due to the elastic vibration in the elastic particles 5 than in the relatively hard particles such as the glass beads, and the vibration damping panel is formed. Vibration is absorbed. Further, in the middle frequency band, since the elastic particles 5 have a convection, the vibration energy is converted into kinetic energy by the collision between the elastic particles 5 in addition to the friction between the elastic particles 5, and the vibration energy is changed. Is promoted. Further, in the high frequency band, since the particles jump, the collision between the elastic particles 5 converts the vibration energy into kinetic energy, and the absorption of the vibration energy is promoted.

Further, since the elastic powder 5 has hysteresis elastic deformation, vibration energy is absorbed and consumed by the elastic deformation of the elastic powder 5 with an absorption amount corresponding to the area within the loop of hysteresis. .

Further, the invention according to claim 2 is characterized in that, in the invention according to claim 1, at least 2% of voids are provided in the cell space 4 in which the elastic powder 5 is sealed. doing.

In such a vibration damping panel, at least 2% of the voids in the cell space 4 allow the elastic powder 5 to move without being restrained by elastic vibration or convection. Vibration energy is converted to heat energy or kinetic energy by friction or collision of the, and the vibration energy is absorbed.

According to a third aspect of the present invention, in the first or second aspect of the invention, the elastic granular material 5 is 10 ^-5 (N
/ M).

In such a vibration damping panel, the elastic powder 5
Has a Young's modulus lower than 10-5 (N / m), the vibration energy is converted into heat energy by the friction between the elastic particles 5 and the hysteresis loop is formed by the elastic deformation of the elastic particles 5. The inner area becomes larger, and more vibration energy is absorbed and consumed.

A fourth aspect of the present invention is characterized in that, in the first to third aspects of the present invention, a rigid powder 6 is mixed into the cell space 4.

In such a vibration damping panel, even when the rigid particles 6 are mixed in the cell space 4, vibration energy is absorbed by friction between the elastic particles 5 and elastic deformation of hysteresis of the elastic particles 5. Is done.

The invention according to claim 5 is characterized in that, in the invention according to claim 4, at least 5% of the elastic granular material 5 is sealed in the cell space 4.

In such a vibration damping panel, if at least 5% of the elastic particles 5 are enclosed in the cell space 4, friction between the elastic particles 5 and elastic deformation of hysteresis of the elastic particles 5 occur. Absorption of vibration energy works effectively.

Further, according to a sixth aspect of the present invention, in the first to fifth aspects, the average particle size of the elastic granular material 5 is one.
It is characterized by being smaller than 00 (μm).

In such a vibration damping panel, the elastic powder 5
Is smaller than 100 (μm), the adhesion between the particles increases, the jumping phenomenon of the elastic particles 5 in a high frequency band decreases, and the vibration energy due to the friction between the elastic particles 5 Since the amount of conversion into thermal energy increases, more vibration energy is absorbed.

The invention according to claim 7 is characterized in that, in the inventions according to claims 1 to 6, the elastic granular material 5 is made of a rubber material.

In such a vibration damping panel, the rubber material has elasticity and elastic deformation of hysteresis and is inexpensive, so that it can be easily manufactured.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A vibration damping panel according to an embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a sectional view showing a vibration damping panel according to an embodiment of the present invention. FIG. 2 is a front view showing a vibration damping performance measuring device for measuring the vibration damping performance of the above vibration damping panel.

As shown in FIG. 1, this vibration damping panel partitions a space between two opposing plate members 1 and 2 to form a plurality of cell spaces 4, and the cell spaces 4 have elastic deformation of hysteresis. It is formed by enclosing an elastic granular material 5 having properties.

Hereinafter, the damping performance is measured by a damping performance measuring device using a test piece beam 51 which is a panel cut sample of the above damping panel. Test piece beam 5
In 1, elastic powders 5 are sealed in ten cell spaces 4 equally divided by a partition plate 3.

[0027] As shown in FIG.
It comprises a vibrator 53, FFT 54, input amplifier 55, impedance head 56 and output amplifier 57. The center of the test piece beam 51 is fixed to the vibrator 53 via an impedance head 56 and is held horizontally.

In such a vibration damping performance measuring apparatus, first, a random wave generated by the FFT 54 as a signal generator is amplified via an input amplifier 55 and
Is input to Next, the vibrator 53 outputs vibration according to the magnitude of the input signal, and randomly vibrates the test piece beam 51 in the vertical direction. Further, the impedance of the test piece beam 51 is adjusted by the impedance head 56 at the center of the test piece beam 51.
The acceleration and force of the first vibration are sensed, amplified via the output amplifier 57, and then input to the FFT 54. Then, the FFT 54 measures transfer characteristics such as inertance (acceleration / force) and apparent mass (force / acceleration), and extracts a loss coefficient, which is a parameter representing vibration suppression performance. If the value of the loss coefficient is large, it means that the damping performance is high.

First, for comparison, the following (A):
Using the three types of test piece beams 51 of (B) and (C), vibration measurement was performed by the vibration suppression performance measuring device of the above.
The loss coefficient was measured while changing the vibration acceleration level La = 20 log (A / 10 ^-5 ). In the above equation, A is the acceleration value
(M / sec ² ). This loss coefficient is derived from the primary vibration mode of the test piece beam, and in other words, represents the vibration damping performance in a low frequency band.

(A): In the case where glass beads of rigid particles 6 and an average particle diameter of φ300 (μm) are sealed in place of the elastic particles 5

(B): When the viscoelastic sheet t = 1.0 (mm) is adhered to the back surface of the test piece beam without enclosing the elastic powder 5

(C): The case where the elastic granular material 5 is not enclosed. FIG.
The results of vibration measurement by the vibration suppression performance measurement device are shown,
(A) is a graph. Curves A, B, and C correspond to the test piece beams of (A), (B), and (C), respectively. (B) to (d) show three modes of Mode-1, Mode-2, and Mode-3 in the vibration measurement results of the test piece beam 51 shown in FIG.
It is sectional drawing which shows the behavior of the rigid granular material 6 in the range of the kind of vibration acceleration level.

As shown in FIG. 3A, when the vibration damping sheet is adhered, the loss coefficient is improved by about 10 times to about 0.05, but it is not sufficient performance for noise control. . This is also a problem of the conventional vibration damping material that the vibration damping performance is poor in a low frequency band.

On the other hand, in the case of enclosing the rigid granular material 6 with glass beads, the loss coefficient exceeds 0.1, and very good performance is obtained. In addition, as a characteristic in this case, a nonlinear vibration damping performance in which the loss coefficient changes according to the vibration acceleration level is shown. This is because the behavior of the granular material changes according to the vibration acceleration level, and is roughly classified into three behavior modes shown in FIGS.

First, when the vibration acceleration level of Mode-1 is relatively small at 120 dB (≒ 1 G) or less, the powdery material exhibits elastic vibration behavior, and the vibration acceleration level of Mode-2 becomes 120 dB or more. When it comes, it shows a convective behavior that forms a small hill, and when the vibration acceleration level of Mode-3 exceeds 140 dB, a jumping behavior of particles occurs.

How these three types of behavior affect the vibration damping performance will be described below.

First, a mode in which the powdery material elastically vibrates.
In the state of -1, conversion to thermal energy is performed by friction between particles due to particle elastic vibration, and vibration energy is absorbed. In the case of relatively hard rigid particles 6 such as glass beads, the performance in this state is poor. Next, in the state of Mode-2 in which the granular material is convected, conversion into kinetic energy due to collision between particles and conversion into heat energy due to friction between particles are performed, and absorption of vibration energy is promoted. The damping performance is dramatically improved. Further, in the state of Mode-3 in which the granular material jumps, conversion into kinetic energy due to collision between particles is performed, but conversion into heat energy due to friction between particles is reduced, and the vibration damping performance is slightly reduced.

FIG. 4 is a graph showing the results of vibration measurement of the test piece beam 51 using the elastic powder 5 by the vibration damping performance measuring apparatus of the above, and the curve B shows the loss coefficient. . The average particle diameter of the elastic powder 5 is 300
(Μm) NBR rubber beads are used. For comparison, the curve A also shows the measurement results of the rigid granular material 6 glass beads described above.

As shown in FIG. 4, the elastic powder 5 has a larger loss coefficient than the rigid powder 6, and the vibration damping performance is improved. In particular, the vibration energy absorption by the particle elastic vibration in the Mode-1 state is remarkable. The reason will be described below.

FIG. 5 is an explanatory diagram showing the elastic deformability of the hysteresis of the elastic granular material 5 according to the first embodiment.

As shown in FIG. 5, the elastic granular material 5 having hysteresis elastic deformability is a low elastic body having energy loss and hysteresis due to particle deformation. , A hysteresis loop. The area inside the hysteresis loop is the amount of energy absorbed and consumed by the particle deformation. This is due to the fact that the amount of energy absorption due to hysteresis of elastic deformation of the particles increases in addition to the conversion into thermal energy due to friction between the particles.

The test piece beam 51 has at least a 2% void in the cell space 4 in which the elastic powder 5 is sealed, so that the elastic powder 5 is restrained and damped by locking. Prevents performance degradation. This is because, when 100% of the elastic particles 5 are sealed in the cell space 4, the movement of the elastic particles 5 is restricted, and there is a tendency that the vibration control performance is deteriorated because the elastic particles 5 cannot move such as elastic vibration and convection. That's why.

Further, the elastic powder 5 has a particle size of 10 ^-5 (N /
m), vibration energy is converted into heat energy by friction between the elastic particles 5, and the area within the loop of hysteresis due to elastic deformation of the elastic particles 5 is reduced. Larger and more vibrational energy is absorbed and consumed.

FIGS. 6A and 6B show a micro-compression test device 58 for measuring the Young's modulus of a normal granular material. FIG. 6A is a front view, and FIG. 6B is an enlarged view of a portion A in the figure. .

As shown in FIG.
Is a method in which one particle 65 of a granular material is placed on a measurement table 61, a minute compressive load is applied by a plane indenter 62, a minute compressive displacement is measured, and the measurement result is taken into a personal computer 59 and graphed. is there.

FIG. 7 is a graph showing the compressive force with respect to the compressive displacement of the elastic granular material 5 measured by the micro-compression test device 58 of the above. In the figure, the curve A indicates that the granular material is a rigid granular material. In the case of 6, the curve B is a case where the granular material is the elastic granular material 5. Glass beads having an average particle size of 300 (μm) were used as the rigid powder particles 6 and their Young's modulus was 2 × 10 ⁵ (N /
m). The elastic powder 5 has an average particle diameter of 30.
0 (μm) NBR rubber beads are used, and their Young's modulus is 5 × 10 ² (N / m).

As shown in FIG. 7, the curve A shows nonlinearity. This can be explained in terms of material mechanics such as Hertz's contact theory. Here, the Young's modulus of a single particle of the rigid granular material 6 is defined by the gradient of the curve A, assuming linearity within minute deformation.

When the Young's modulus of the granular material is reduced, the characteristics shift from the curve (A) to the curve (B), and the vibration damping performance tends to be improved.

This change in vibration damping performance is due to an increase in energy absorption due to hysteresis of particle elastic deformation in addition to conversion into thermal energy due to friction between particles. And to make this effect work effectively,
The Young's modulus of the single particle of the elastic granular material 5 is 10 ⁵ (N / m)
It is necessary to use the following low elastic body.

FIG. 8 is a cross-sectional view showing a vibration damping panel different from that of the embodiment of the present invention.

As shown in FIG. 8, this damping panel is composed of two opposing plate members 1, 2 in substantially the same manner as the above damping panel.
A plurality of cell spaces 4 are formed by partitioning a space between the cells, and an elastic powder 5 having hysteresis and elastic deformability is sealed in the cell spaces 4. The difference is that the rigid powder 6 is mixed in the cell space 4.

FIG. 9 is a graph showing the vibration damping performance of the above vibration damping panel. Curve B shows the loss characteristic. This vibration damping panel is obtained by mixing 10% of NBR rubber beads having an average particle diameter of 300 (μm) with 6 glass beads of rigid powder particles having an average particle diameter of 300 (μm). Also,
As a comparative example, the curve A also shows the loss characteristics in the case where only the rigid granular material 6 glass beads having an average particle diameter of 300 (μm) are sealed in the cell space 4. As shown in FIG.
At a low vibration acceleration level of 0 (≒ 1 G) or less, the vibration damping performance of glass beads mixed with NBR rubber beads is improved as compared with glass beads alone.

This is because the addition of the NBR rubber beads, which are the elastic particles 5, acts as a cushion, widens the motion range of the glass beads, which are particles of high rigidity and high specific gravity, and reduces the friction between particles. This is due to the fact that the amount of vibration energy absorbed by the conversion into heat energy by the heat treatment is improved. In addition, at least 5 elastic particles 5 are contained in the cell space 4.
%.

FIG. 10 is a cross-sectional view showing a vibration damping panel different from that of the embodiment of the present invention. As shown in FIG. 10, this damping panel is similar to the above damping panel,
A plurality of cell spaces 4 are formed by partitioning a space between two opposing plate materials 1 and 2, and rigid and granular materials 6 and elastic and granular materials 5 are mixed and sealed in the cell spaces 4. The difference is that the average particle size of the elastic granular material 5 is smaller than 100 (μm).

FIG. 11 is a graph showing the vibration damping performance of the above vibration damping panel. Curve C shows the loss characteristic. This damping panel has an average particle size of 300 (μm)
NBR rubber beads having an average particle size of 100 (μm) were mixed with the glass beads of Example 1. As a comparative example, a loss characteristic when only the rigid granular material 6 glass beads having an average particle diameter of 300 (μm) is sealed in the cell space 4 is shown in a curve A. Curve B shows the loss characteristics when NBR rubber beads having a particle size of 300 (μm) are mixed.

As shown in FIG. 11, the vibration damping performance is further improved by reducing the average particle size of the NBR rubber beads to be mixed. In addition, a decrease in vibration damping performance particularly at a high vibration acceleration level is suppressed.

This is because when the average particle diameter of the NBR rubber beads becomes 100 (μm) or less, the influence of the adhesion force between the particles becomes apparent, and the jump phenomenon of Mode-3, which is observed at a high vibration acceleration level, is reduced. Vibration energy absorption due to conversion into thermal energy by friction acts.

The elastic powders 5 used in the vibration damping panels shown in FIGS. 1 to 11 described above include nitrile rubber (NBR) and styrene-butanediene rubber (SB).
Powdered rubber materials such as synthetic rubber represented by R), natural rubber (NR), and reclaimed rubber can be exemplified.

This powdery rubber material is a low elastic material, has an energy loss due to particle deformation, and has a hysteresis property.
R), styrene-butadiene rubber (SBR), butadiene rubber (BR), ethylene-propylene rubber (EPM,
EPDM), butyl rubber (IIR), chloroprene rubber (CR), nitrile rubber (NBR), acrylic rubber (A
CM), synthetic rubber such as epichlorohydrin rubber (CO, ECO), chlorinated polyethylene (CM), chlorosulfonated polyethylene (CSM), and natural rubber (N
R) and recycled rubber for recycling.

Hereinafter, a specific example of the above-described vibration damping panel will be described.

FIG. 12 is a perspective view showing a specific example of the vibration damping panel shown in FIG.

As shown in FIG. 12, this vibration damping panel
Size 300 (mm) × 300 (mm), thickness t = 1.2
(Mm) aluminum plate 11 and width 300 (mm)
A 1/4 inch aluminum honeycomb 13 having a height of 20 (mm) is sandwiched between an aluminum plate 12 having a size of 300 mm and a thickness t of 0.6 mm, and the honeycomb 13 As a partition plate 3 in the cell space 4 with a bulk density 542 (k
g / m ³ ), NBR powder particles having an average particle diameter of 300 (μm) are naturally filled by free fall to a height of 5 (mm),
It has a honeycomb sandwich structure filled and bonded to a surface weight of 2.71 (kg / m ² ). In addition, the plate materials 1 and 2
Metals other than aluminum, wood materials, and the like can also be used as the honeycomb.

FIG. 13 is a front view showing a main part of a vibration damping performance measuring device for measuring the vibration damping performance of the above vibration damping panel.

This vibration damping performance measuring device is fixed to a vibration damper 67 via an impedance head 68 at the center of a vibration damping panel 66 and vibrates randomly in the vertical direction. At this time, the transfer function inertance (acceleration / force) sensed by the impedance head is measured to evaluate the damping performance. Further, the excitation force of the random excitation is adjusted so as to be constant with respect to changes in panel conditions.

FIG. 14 is a graph showing the measurement results of the vibration damping performance of the above vibration damping panel, and the curve B shows the transfer function inertance. As a comparative example, the curve A shows the transfer function inertance when the elastic powder 5 is not sealed in the cell space 4 of the damping panel 66.

As shown in FIG. 14, in the curve B, the transfer function has smooth peaks and dips due to resonance and anti-resonance, and the vibration damping effect is clear.

FIGS. 15 and 16 show the narrow band at the position 300 mm away from the center of the panel under the same conditions.
It is a graph which shows the noise level in / 3Band.

As shown in FIGS. 15 and 16, the noise level is clearly reduced with the improvement of the vibration damping performance.

FIG. 17 is a graph showing the results of measuring the vibration damping performance of a vibration damping panel different from the above vibration damping panel, and the curve B shows the transfer function inertance.
As a comparative example, the curve A shows the transfer function inertance when the elastic powder 5 is not sealed in the cell space 4 of the damping panel 66.

This vibration damping panel is composed of an elastic powder 5 to be enclosed.
The bulk density is 1600 (kg / m ³ ) and the average particle size is 3
The glass beads of 00 (μm) have a bulk density of 341 (kg)
/ M ³ ) and NBR rubber powder having an average particle size of 50 (μm)
0% is mixed and filled to a height of 5 (mm).

As shown in FIG. 17, the transfer function inertance has a clear vibration damping effect in which the peak and dip of the curve due to resonance and antiresonance are smoothed.

[0072]

According to the first aspect of the present invention, the behavior of the elastic granular material changes depending on the difference in the frequency band. In other words, in the low frequency band, the vibration energy is converted to heat energy by the friction between the elastic particles due to the elastic vibration in the elastic particles, compared with the relatively hard particles such as glass beads, and the vibration damping panel is formed. Vibration is absorbed. Further, in the middle frequency band, since the elastic particles are convected, the vibration energy is converted into kinetic energy by the collision between the elastic particles in addition to the friction between the elastic particles, and the absorption of the vibration energy is reduced. Promoted. Further, in the high frequency band, the particles jump, so that the collision between the elastic particles converts the vibration energy into kinetic energy, thereby promoting the absorption of the vibration energy. Therefore, the effect of vibration suppression and sound absorption is high in a wide frequency band including a low frequency band.

Further, since the elastic particles have an elastic deformation property of hysteresis, the elastic particles are elastically deformed.
Vibration energy is absorbed and consumed by an absorption amount corresponding to the area within the loop of hysteresis. Therefore, vibration absorption / damping in a broad frequency band including a low frequency band can be performed.

According to the second aspect of the present invention, at least 2% of the voids in the cell space 4 allow the elastic particles to move without being restrained, such as elastic vibration and convection. Vibration energy is converted to heat energy or kinetic energy by friction or collision of the, and the vibration energy is absorbed.

According to the third aspect of the present invention, since the Young's modulus of the elastic particles is lower than 10 ^-5 (N / m), the vibration energy is converted into the heat energy by the friction between the elastic particles. At the same time, the area within the loop of hysteresis becomes larger due to the elastic deformation of the elastic granular material 5, and more vibration energy is absorbed and consumed.

According to the fourth aspect of the present invention, even when rigid particles are mixed in the cell space, vibration energy is absorbed by friction between the elastic particles and elastic deformation of hysteresis of the elastic particles. .

According to the fifth aspect of the invention, if at least 5% of the elastic particles are filled in the cell space, the vibration energy due to the elastic deformation of the elastic particles due to the friction between the elastic particles and the hysteresis of the elastic particles. Absorption works effectively.

According to the sixth aspect of the present invention, since the average particle diameter of the elastic particles is smaller than 100 (μm), the adhesion between the particles is increased, and the elastic particles 5 in the high frequency band are increased. The jump phenomenon is reduced, and the amount of conversion of vibration energy to heat energy due to friction between the elastic particles is increased, so that more vibration energy is absorbed.

According to the seventh aspect of the present invention, since the rubber material has elasticity and elastic deformation of hysteresis and is inexpensive, it can be easily manufactured.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a vibration damping panel according to an embodiment of the present invention.

FIG. 2 is a front view showing a vibration damping performance measuring device for measuring the vibration damping performance of the above vibration damping panel.

FIG. 3 shows a result of vibration measurement using the above-described three types of test piece beams by the vibration suppression performance measuring apparatus according to the above.
(A) is a graph.

FIG. 4 is a graph showing a result of vibration measurement of a test piece beam using the above-mentioned elastic powder by the vibration damping performance measuring device of the above.

FIG. 5 is an explanatory view showing the elastic deformability of hysteresis of the elastic granular material 5 according to the first embodiment.

FIGS. 6A and 6B show a micro-compression test apparatus for measuring the Young's modulus of a normal granular material, wherein FIG. 6A is a front view and FIG. 6B is an enlarged view of a portion A in the figure.

FIG. 7 is a graph showing a compressive force with respect to a compressive displacement of the elastic powder measured by the micro-compression test apparatus.

FIG. 8 is a cross-sectional view showing a vibration damping panel different from the above according to the embodiment of the present invention.

FIG. 9 is a graph showing the vibration damping performance of the above vibration damping panel.

FIG. 10 is a cross-sectional view illustrating a vibration damping panel different from the above according to the embodiment of the present invention.

FIG. 11 is a graph showing the vibration damping performance of the above vibration damping panel.

FIG. 12 is a perspective view showing a specific example of the vibration damping panel shown in FIG.

FIG. 13 is a front view showing a main part of a vibration damping performance measuring device for measuring the vibration damping performance of the above vibration damping panel.

FIG. 14 is a graph showing the results of measuring the damping performance of the damping panel.

FIG. 15 is a graph showing a noise level in a narrow band at a position distant from the center of the panel by 300 mm in the vibration damping panel.

FIG. 16 is a graph showing a noise level at 1/3 Band at a position 300 mm far from the center of the vibration damping panel of the above.

FIG. 17 is a graph showing measurement results of vibration damping performance of a vibration damping panel different from the above vibration damping panel.

FIG. 18 is an explanatory view showing a vibration damping principle of a conventional vibration damping panel.

FIG. 19 is an explanatory view showing a vibration-damping principle of a vibration-damping panel different from that of the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Top plate material 2 Bottom plate material 3 Partition plate 4 Cell space 5 Elastic granular material 6 Rigid granular material 11 Aluminum panel upper plate 12 Aluminum panel lower plate 13 Aluminum honeycomb 14 Elastic granular material 20 Hysteresis loop 31 Base material 32 Viscoelastic material 33 Restraining material 34 Fiber type sound absorbing material 35 Foaming type sound absorbing material 51 Test piece beam material 52 Granular material 53 Exciter 54 Fourier spectrum analyzer 55 Exciter amplifier 56 Impedance head 57 Force, acceleration converter amplifier 58 Micro load tester 59 Monitor (PC) 60 Printer 61 Measurement table 62 Flat indenter 63 Objective lens 64 Eyepiece 65 Powder sample 66 Test panel 67 Vibrator 68 Impedance head

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tsuyoshi Yanagita 1048 Kadoma Kadoma, Osaka Prefecture Inside Matsushita Electric Works, Ltd.

Claims (7)

[Claims] The present invention is characterized in that a plurality of cell spaces are formed by partitioning a space between two opposing plate members, and an elastic powder having hysteresis elastic deformation is sealed in the cell spaces. Vibration control panel. 2. The vibration damping panel according to claim 1, wherein at least 2% of voids are provided in the cell space in which the elastic particles are sealed. 3. The elastic powder according to claim 1, wherein the elastic powder has a Young's modulus lower than 10 ⁻⁵ (N / m).
Or the damping panel according to 2. 4. The vibration damping panel according to claim 1, wherein a rigid granular material is mixed into the cell space. 5. The cell space contains at least 5% of elastic particles.
The vibration damping panel according to claim 4, wherein the vibration damping panel is enclosed. 6. An elastic powder having an average particle diameter of 100 (μm)
The vibration damping panel according to claim 1, wherein the vibration damping panel is smaller than the vibration damping panel. 7. The vibration damping panel according to claim 1, wherein the elastic particles are made of a rubber material.