JPH08160968A - Echo adjusting device - Google Patents

Abstract

PURPOSE: To easily change an echo characteristic and to change the acoustic characteristics of an acoustic space by selecting the impressed voltage on electrode plates housing an ENC fluid compsn., removing the sound waves of the frequency band desired to be removed and reflecting the sound waves exclusive of this band. CONSTITUTION: This echo adjusting device has the ENC(electrosensitive type sound wave adsorption controlling) fluid compsn. prepd. by incorporating EA particles having an EA (electric field arrangement) effect into an electrically insulating medium and a pair of the electrode plates housing the ENC fluid compsn. in this spacing and has sound wave absorption control plates 39a to 39c extended on the outer peripheral surfaces of columnar members 31 and a voltage impressing and regulating means 60 for impressing voltage between a pair of the electrode plates and regulating this voltage. The EA particles form chain bodies when the voltage is impressed between a pair of the electrode plates. These chain bodies resonate with the sound waves of the frequencies coinciding with the characteristic frequencies and absorb these sound waves. The sound waves of the other frequencies are reflected. The characteristic frequencies of the chain bodies themselves are made to coincide with the frequencies of the components desired to be removed by regulating the impressed voltage.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an echo adjusting device which is installed in an acoustic space such as an audio room and changes the acoustic characteristics of the space.

[0002]

2. Description of the Related Art Generally, a sound wave absorbing material that characterizes acoustic characteristics is attached to a wall, a floor, a ceiling or the like of an acoustic space such as an audio room. The sound wave absorbing material has a certain reverberant property (sound absorption coefficient), and is classified into a porous type, a plate vibrating type, a resonance type and the like depending on the mechanism of the reverberant property. In an actual acoustic space, the acoustic characteristics unique to the acoustic space are realized by arranging these sound wave absorbing materials in combination.

By the way, since the sound absorbing material used as described above has a constant natural frequency depending on its material,
In the case of one kind of sound wave absorbing material, there is a problem that only the sound wave of the component that matches the natural frequency can be absorbed. That is, it has a reverberation that absorbs only a certain frequency band of a sound wave and reflects another frequency band. Therefore, when changing the acoustic characteristics, it is necessary to replace the acoustic wave absorbing material with a reverberant property corresponding to the acoustic characteristics. However, a large amount of work is required to replace the acoustic wave absorber once placed in the acoustic space, and in order to obtain the desired acoustic characteristics, bring in acoustic wave absorbers with various reverberations and combine them. There is a problem in that the adjustment work, such as changing the arrangement position or the arrangement position, requires a great deal of work.

Conventionally, as a means for changing the reverberation of a wall or a ceiling without changing the sound wave absorbing material as described above in order to change the acoustic characteristics, for example, Japanese Patent Application Laid-Open No. 2-2
There is an echo adjusting device proposed in Japanese Patent No. 26299. This echo adjusting device has a structure in which a plurality of sound absorbing materials such as felt materials having different reverberations (sound absorption coefficients) are provided on the outer surfaces of a plurality of columnar members arranged in parallel, and the respective columnar members are rotatable. Have This echo control device is installed on the wall or ceiling of the acoustic space, and if you want to change the acoustic characteristics of the acoustic space, you can rotate the columnar member so that the surface of the sound absorbing material that corresponds to the acoustic characteristics is directed in the acoustic space. I was adjusting and changing the reverberation toward.

[0005]

However, even the above-described conventional echo adjusting device has the following unsolved problems. That is, there has been a problem that the reverberation can be changed only by the number of surfaces of the sound wave absorbing material that divides the outer surface of the columnar member. Further, as the number of types of sound wave absorbers provided increases, the occupancy of the outer surface of the columnar member per type decreases, and there is the inconvenience that effective and selective reverberation cannot be provided. Therefore, substantially, this echo control device can have only a few types of effective reverberation, and the frequency band of sound waves that can be absorbed is limited to several bands.

Further, since the acoustic characteristics of the acoustic space also change depending on the direction in which sound waves are reflected by the wall, ceiling, etc., when changing the acoustic characteristics, the angle of the reflecting surface of the sound wave absorbing material in the acoustic space is changed. It is desirable to be able to change. However, in the above-mentioned echo adjusting device, the angle of the surface of the sound absorbing material provided on the outer surface can be changed by rotating the columnar member, but at the same time, the sound wave is transmitted to the sound absorbing material having other reverberation. There was an inconvenience that it was incident. That is, there is a problem that the frequency band of the sound wave that can be absorbed changes from a predetermined band, and the angle of the reflecting surface cannot be changed while maintaining the frequency band of the sound wave that can be absorbed.

By the way, the inventors of the present invention have proposed a novel electric field arrangement characteristic (hereinafter referred to as Electric A
The lightness characteristic is abbreviated as “EA characteristic”)
An electrosensitive sound wave absorption control fluid composition having
Electric Noise-Control fluid composition is abbreviated as “ENC fluid composition”). This fluid composition is, for example, a fluid obtained by dispersing solid particles in an electrically insulating medium. When an electric field is applied to the fluid composition, the solid particles cause dielectric polarization, and electrostatic attraction based on the dielectric polarization causes the solid particles to undergo dielectric polarization. It has the property of forming a chain structure by aligning and aligning in the direction of the electric field. In addition, some solid particles exhibit the property of exhibiting an array lump structure by electrophoresis and array alignment. In this way, the array orientation of particles under an electric field is called an electric field array effect (hereinafter, Electric Alignment effect is abbreviated as “EA effect”), and solid particles having such a property are referred to as electric field array particles (hereinafter, referred to as “EA effect”). Elect
abbreviated ric Alignment particle "EA particle"
Will be called). Then, the present inventors arrived at the present invention by advancing research on the ENC fluid composition having this novel structure.

In view of the above circumstances, the present invention adjusts the reverberation by varying the frequency band of sound waves that can be absorbed in an acoustic space such as an audio room, while maintaining the frequency band of sound waves that can be absorbed at the same time. It is an object of the present invention to provide an echo adjusting device that can change the angle of a reflecting surface to variously change the acoustic characteristics of the space.

[0009]

The present invention has the following features to attain the object mentioned above. That is, in the echo adjusting device of the present invention, a plurality of columnar members are rotatably supported in the circumferential direction and are arranged in parallel, and a sound wave absorption control plate is stretched on the outer peripheral surfaces of the columnar members. The sound wave absorption control plate and the electro-sensitive type sound wave absorption control fluid composition containing solid particles having an electric field array effect in an electrically insulating medium are opposed to each other with a gap, And a pair of electrode plates accommodating the fluid composition for electro-sensitive sound wave absorption control, further comprising a voltage application adjusting means for applying a voltage between the pair of electrode plates and adjusting the voltage. It is characterized by comprising.

[0010]

According to the echo adjusting device of the present invention, the ENC fluid composition containing the EA particles having the EA effect in the electric insulating medium and the ENC fluid composition facing each other with a gap therebetween, and the ENC fluid composition in the gap. With a pair of electrode plates that accommodate objects,
A sound wave absorption control plate stretched over the outer peripheral surface of the columnar member and a voltage application adjusting means for applying a voltage between the pair of electrode plates and adjusting the voltage are provided, and a voltage is applied between the pair of electrode plates. EA in the ENC fluid composition when no voltage is applied.
The effective EA particles are randomly suspended and dispersed in the electrically insulating medium. When a voltage is applied to the pair of electrode plates by the voltage application adjusting means, the EA particles are arrayed and linked in a chain to form a chain (particle chain), and the chain is arrayed parallel to the electric field direction. When a sound wave (air vibration) is applied to one of the electrode plates in this state, the electrode plate vibrates in the opposite direction, but the chain body itself has elasticity, so the chain body is stretched. When the particles are opposed to each other, they attract each other to generate an attractive force, and when they are compressed, they bend to generate a repulsive force, which causes a viscous resistance due to the movement of the chain in the electrically insulating medium, which causes a sound wave. Loss of energy (dissipation) occurs.

That is, the sound wave incident on the electrode plate causes the ENC fluid composition containing the chain to resonate with the electrode plate. The sound wave frequency that gives vibration to such a chain is determined by the characteristic frequency of the chain (which is presumed to be the so-called natural frequency, which is the balance between the elasticity of the chain and the inertia of the electrode plate). When a sound wave having a frequency matching the characteristic frequency is incident on the electrode plate, the chain resonates and absorbs the sound wave, and sound waves of other frequencies are reflected.

Since the attractive force (stress generated in the chain) acting between the particles increases as the voltage applied to the pair of electrode plates increases, the elastic modulus and viscosity of the chain itself are applied. It will increase as the voltage increases.

Therefore, by adjusting the applied voltage by the voltage application adjusting means, the characteristic frequency of the chain itself can be made equal to the frequency of the component of the incident sound wave (air vibration) to be removed. Then, the chain resonates with the sound wave of the frequency of the component to be removed, consumes the energy of the sound wave, and reflects the sound waves of the other components. FIG. 9 is a graph showing the results of measuring the effect of the electric field strength on the EA characteristics for a 30 wt% EA particle dispersion system. It is clear from this graph that the stress acting on the chain increases as the applied voltage increases. The EA characteristic is that the dielectrically polarized particles are arranged in the electric field direction by an electric attraction.
Due to the formation of a chain structure. At low shear rates, electrical attraction dominates, resulting in a gradual cycle of breaking and reforming chain structures. The yield stress is the force that is generated when a chain arranged in the direction of the electric field undergoes shear failure in the direction perpendicular to it. Considering that the particles of all chains formed have the same diameter and connect the electrode plates in a straight line, the number of chains is proportional to the particle concentration, so the yield stress is also proportional to the particle concentration. It will be. FIG. 10 shows an equivalent circuit of the vibration system of the present invention, that is, a coil spring 22 having an elastic modulus K and a dashpot 23 having a viscosity C are connected in parallel between a pair of electrode plates.

As described above, by selecting the applied voltage by the voltage application adjusting means and selecting an unnecessary frequency band from the sound waves in the acoustic space, the sound waves in this frequency band can be selectively removed. The reverberation can be adjusted by reflecting sound waves in the frequency band of. Further, when it is desired to change the acoustic characteristics according to the type of the sound source in the acoustic space or the taste of the listener, the applied voltage is selected again by the voltage application adjusting unit, and the frequency band to be absorbed is reset. Further, by rotating the columnar member in the circumferential direction, the angle of the sound wave absorption control plate serving as the sound wave reflection surface changes. At this time, since the sound wave absorption control plate stretched over the entire outer peripheral surface of the columnar member is adjusted by the same applied voltage, the frequency bands of the sound waves to be absorbed are the same, and which outer peripheral surface the sound wave is incident on. Can obtain the same reverberation. Therefore, the angle of the reflection surface of the sound wave can be changed while maintaining the frequency band of the sound wave to be absorbed.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the echo adjusting device of the present invention will be described below with reference to the drawings. In these figures, reference numeral 30
Is an echo control device. As shown in FIG. 1, a plurality of triangular columnar members 31 are erected side by side on a wall or the like of the acoustic space. A shaft 32 is provided inside each of the triangular columnar members 31 so as to be inserted on the central axis and projected from both ends of each of the triangular columnar members 31. The shafts 32 are rotatably supported by bearings or the like. A pinion gear 32a having the same axis as that of the shaft 32 is formed on the shafts 32. The pinion gear 32a is a rack gear 33a formed on a side portion of a rack shaft 33 that is supported so as to be movable back and forth.
It is arranged to mesh with.

At the end of the rack shaft 33, a device having a drive mechanism for allowing the rack shaft 33 to move forward and backward, such as an electric motor, is provided. By operating this device, the rack shaft 33 moves forward and backward. At the same time, the pinion gear 32a rotates, and the triangular prism members 31 simultaneously rotate in the same direction and at the same angle.

Sound wave absorption control plates 39a, 39b, 39c are stretched on the outer peripheral surface of each triangular prism member 31, and the triangular prism members 31 are adjacent to each other so that they do not contact each other when the triangular prism members 31 rotate. Are distributed. Further, the surfaces of the sound wave absorption control plates 39a, 39b, 39c are set to be parallel to each other between the triangular columnar members 31, and the sound wave absorption control of the triangular columnar members 31 is performed by advancing and retracting the rack shaft 33. The surfaces of the plates 39a, 39b, 39c are set to rotate about the shaft 32 and all have the same angle with respect to the length direction of the rack shaft 33.

Sound wave absorption control plate 3 provided as described above
9a, 39b, 39c are configured as follows.
As shown in FIG. 3, a pair of electrode plates 17 and 18 are provided along the outer peripheral surface of the triangular prism-shaped member 31 and are arranged to face each other with a gap (composition storage space) therebetween. , 18 between the electric insulating medium 1 containing the EA particles 2 having the EA effect of the present invention described above.
An NC fluid composition is contained. One electrode plate 18 is fixedly arranged on the outer peripheral surface of the triangular columnar member 31, and the other electrode plate 17 is evenly adhered to the lower surface of a PET (polyethylene terephthalate) film 17a that is flexible against sound waves. There is. A frame-shaped sealing member 15 is fixed to the periphery of the pair of electrode plates 17 and 18 and the periphery of the PET film 17a.

The ENC fluid composition is housed in the space defined by the pair of electrode plates 17 and 18 and the seal member 15 in a hermetically sealed state. Also, one electrode plate 1
7 and the PET film 17a have their peripheral edges fixed, but the direction in which the pair of electrode plates 17 and 18 face each other (arrow X
It is configured to be able to vibrate in the up and down direction shown by.
Thereby, the sound wave (air vibration) 11 is transmitted to the PET film 1
When incident on 7a, the PET film 17a and one electrode plate 17 can vibrate vertically.

A voltage is applied between the pair of electrode plates 17 and 18 of each of the sound wave absorption control plates 39a, 39b and 39c constructed as described above, and the voltage is adjusted. The voltage application adjusting device 60 (voltage application adjusting means) is electrically connected by the wiring 60a.
The voltage application adjusting device 60 is connected to a power source (not shown), and has both a switch 14 for turning on or off the application of voltage and a dial 13 for adjusting the applied voltage. As shown in FIG. 1, the voltage application adjusting device 60 is attached to a predetermined position such as a wall of an acoustic space.

In the ENC fluid composition, as shown in FIG. 4, EA particles (electric field arranging particles) 2 which are EA particles are uniformly dispersed in an electrically insulating medium 1. The EA particles 2 include a core body 3 made of an organic polymer compound and an electric field aligning inorganic substance (hereinafter referred to as Electric Alignmen).
t inorganic material is abbreviated as “EA inorganic material”), and the surface layer 5 is composed of particles 4 to form inorganic-organic composite particles. In this specific example, the electrically insulating medium 1 is colorless and transparent silicone oil, the organic polymer compound forming the core body 3 of the inorganic / organic composite particles is polyacrylic ester, and the EA inorganic substance forming the surface layer 5 is used. The particles 4 are white titanium hydroxide that is an inorganic ion exchanger and an electric semiconductor inorganic substance. The color of the EA particles (inorganic / organic composite particles) is, for example, white. The proportion of the EA particles 2 contained in the electrically insulating medium 1 is, for example, 7.5% by weight.

Next, the operation of the echo adjusting device 30 of the above embodiment will be described. In the acoustic space in which the echo adjusting device 30 is arranged, sound waves such as music and voice are incident on the sound wave absorption control plates 39a, 39b, 39c stretched on the outer peripheral surface of the echo adjusting device 30 provided on a wall or the like. To do. As shown in FIG. 2, the switch 14 of the voltage application adjusting device 60 is turned off.
At this time, in a state in which a voltage is not applied between the pair of electrode plates 17 and 18, the EA particles 2 of the ENC fluid composition are randomly suspended / irregularly dispersed in the electrically insulating medium 1 (Fig. 6).

Next, the switch 1 of the voltage application adjusting device 60
When 4 is turned on and a voltage is applied to the pair of electrode plates 17 and 18, the EA particles 2 in the ENC fluid composition are arranged and linked in a chain to form a chain (particle chain) 6, and the chain The bodies 6 are arranged parallel to the electric field direction (see FIG. 7). In this state,
When a sound wave (air vibration) 11 is incident on one of the electrode plates 17, the states of (a), (b), (c) and (d) of FIG.
Although it vibrates in the opposite direction as indicated by arrow X (see FIG. 3 and FIG. 4) together with a, the chain 6 itself has elasticity, and therefore, as shown in FIG. Form 6
When compressed, it bends in a V shape, for example, to generate a repulsive force, and as shown in FIG.
When pulled, the EA particles 2 facing each other attract each other to generate an attractive force. As a result, due to the movement of the chain-like body 6 in the ENC fluid composition, viscous resistance is generated and energy loss (dissipation) of the sound wave 11 occurs.

As the electrode plate 17 vibrates,
The chain 6 is repeatedly pulled and compressed,
As a result, the chain body 6 itself also vibrates. That is, the sound wave 11 incident on the electrode plate 17, the ENC fluid composition containing the chain body 6, the electrode plate 17 and the PET film 17
The electrode plate structure composed of a resonates. The sound wave frequency that gives vibration to the chain 6 is as follows.
When the sound wave 11 having a frequency that is determined by the characteristic frequency of the light enters the electrode plate 17, the chain 17 resonates (see arrows A and B in FIG. 4) and absorbs the sound wave. , Sound waves 12 of other frequencies will be reflected.

The force acting between the EA particles 2 (stress generated in the chain-like body 6) increases as the voltage applied to the pair of electrode plates 17 and 18 increases, so that the elasticity of the chain-like body 6 itself. The modulus and viscosity increase with increasing applied voltage. The present invention utilizes this fact to remove a desired component of a sound wave. That is, by adjusting the applied voltage,
By matching the characteristic frequency of the particle chain 6 itself with the frequency of the component (sound wave having a specific wavelength) to be removed in the sound wave (air vibration) incident on the electrode plate 17, as shown in FIG. The body 6 is caused to resonate by the action of the inertial force as indicated by the left and right arrows A and B, and the energy of the component of the incident sound wave 11 to be removed is consumed, while the other sound wave components (reference numeral 1) are consumed.
2) is reflected. In this way, the applied voltage can absorb the component of the desired specific wavelength of the incident sound wave.

The characteristic frequency of the sound wave absorption control plates 39a, 39b, 39c depends on the size of the EA particles (solid particles), the elastic force acting between the EA particles, the natural frequency of the electrode plates and the distance between the electrode plates. Change. In the present invention, since the spherical EA particles having a substantially uniform particle size are dispersed in the electrically insulating medium (without using irregular particles), the above-mentioned repulsive force and attractive force fluctuate under a constant voltage. No, and EA
The balance between the elastic force acting between particles and the inertial force of the electrode plate does not easily change. In the above-mentioned embodiment, the chain-like body is supposed to be bent in a V shape, but in addition to this, for example, an S-shape as shown in FIG.
It is considered that there is a case where it is bent into a W-shape as shown in 1 (b).

Further, in the above embodiment, the phenomenon in which the EA particles (inorganic / organic composite particles) 2 form a row of chain-like bodies 6 and are arranged in parallel by the application of an electric field has been described. When the number of slabs exceeds several% by weight,
Instead of the chained bodies 6 in a row, the chained bodies 6 are joined to each other in a plurality of rows to form a column 19 as shown in FIG. In this column 19, the left and right chain-shaped EA particles 2 are staggered by one and adjoin each other. With respect to this, the inventors of the present invention, as shown in (b) of FIG. 12, have the EA particles 2 that are dielectrically polarized in the + pole portion and the − pole portion.
It is presumed that this is because it is more stable in terms of energy when the positive pole portion and the negative pole portion are alternately arranged adjacent to each other. Furthermore, although the ENC fluid composition is directly accommodated between the pair of electrode plates in the above-described embodiment, the present invention is not limited to this, and the porous body sufficiently impregnated with the ENC fluid composition is used as the pair of electrodes. It may be housed between the plates. In this case, the porous body preferably has open cells so as not to impair the EA effect.

As described above, when the applied voltage is adjusted by the dial 13 of the voltage application adjusting device 60, the characteristic frequency of the chain 6 itself is changed to the incident sound wave (air vibration) 1 shown in FIG.
It is possible to match the frequency (frequency) of the component to be removed out of 1. Then, the chain 6 in FIG. 6 resonates with the sound wave having the frequency of the component to be removed, and consumes the energy of the sound wave. And the sound wave 12 of other components
Will be reflected as shown in FIG. in this way,
By selecting the applied voltage with the dial 13 of the voltage application adjusting device 60, the echo adjusting device 30 can select the frequency band of the sound wave to be removed and at the same time reflect the sound wave of another frequency band.

When it is desired to change the frequency band of the sound wave to be removed and the frequency band of the sound wave to be reflected in order to change the acoustic characteristics of the acoustic space, the dial 13 is adjusted and the applied voltage is selected again to select the sound wave to be removed. A sound wave in this frequency band can be removed by setting the frequency band. As described above, the reverberation adjusting device 30 can arbitrarily select the frequency band to be removed by the sound wave absorption control plates 39a, 39b, 39c, and can freely change the reverberation.

Further, in the state shown in FIG. 1, one sound wave absorption control plate 39a of each triangular columnar member 31 is set to be located on the same plane. Therefore, it is possible to form the same plane as the installed wall or the like. In this state, the sound waves in the acoustic space are blocked by the sound wave absorption control plates 39a, so that the other sound wave absorption control plates 39b and 39c.
Is not incident on. From this state, when the rack shaft 33 is moved back and forth in the length direction by an electric motor or the like provided at the end of the rack shaft 33, the pinion gears 32a of the shafts 32 meshing with the rack gears 33a of the rack shaft 33 rotate,
As shown in FIG. 3, all the triangular columnar members 31 simultaneously rotate in the same direction in the circumferential direction by the same angle. Therefore,
The sound wave absorption control plates 39a, which are stretched around the outer peripheral surface of each triangular columnar member 31, are positioned parallel to each other and at a constant angle with respect to the rack shaft 33.

Thus, the angle of each sound wave absorption control plate 39a, that is, the angle of the reflecting surface formed by the surface of each sound wave absorption control plate 39a can be freely changed. In this way, by changing the angle of the sound wave absorption control plate 39a, the reflection direction of the sound wave other than the frequency band to be removed can be variously changed. When the triangular prism members 31 are rotated, the sound waves in the acoustic space also enter the two sound wave absorption control plates 39b and 39c other than the sound wave absorption control plate 39a from the gaps between the triangular prism members 31. At this time, the sound wave absorption control plates 39b and 39c are also the sound wave absorption control plates 39a.
Since it is adjusted by the same applied voltage as the above, the frequency bands of the sound waves that can be absorbed are the same, and the sound wave absorption control plate 39
Since it has the same reverberation as a, the reverberation of the whole reverberation adjusting device 30 does not change even if the triangular prismatic member 31 rotates.

From the above, according to the echo adjusting device 30, by adjusting the dial 13 of the voltage application adjusting device 60, a sound wave such as music or voice in the acoustic space is selected in the frequency band of the sound wave to be removed. Sound waves in other frequency bands can be reflected, and by rotating the triangular prism member 31, the angle of the sound wave reflection surface can be arbitrarily changed to variously change the reflection direction of the incident sound wave. be able to. In this way, the reverberation adjusting device 30 can freely change the reverberation and the reflection direction of the sound wave, and can variously change the acoustic characteristics of the acoustic space.

The electrically insulating medium 1 of FIG. 6 used in the ENC fluid composition of the present invention is, for example, diphenyl chloride, butyl sebacate, aromatic polycarboxylic acid higher alcohol ester, halophenyl alkyl ether, trans oil. , Chlorinated paraffin, fluorine-based oil, silicone-based oil, fluorosilicone-based oil, etc., as long as they have high electrical insulation and electrical breakdown strength, are chemically stable, and can stably disperse EA particles. Fluids or mixtures of these can also be used. This electrically insulating medium 1 can be colored according to the purpose.
For coloring, it is preferable to use a type and amount of an oil-soluble dye or a dispersible dye that is soluble in the selected electrically insulating medium and does not impair its electrical properties. The electrically insulating medium 1 may further contain a dispersant, a surfactant, a viscosity modifier, an antioxidant, a stabilizer and the like.

The kinematic viscosity of this electrically insulating medium 1 is 1 cS.
It is preferably in the range of t to 30,000 cSt. When the kinematic viscosity is less than 1 cSt, the storage stability of the fluid composition is insufficient, and when the kinematic viscosity is more than 30,000 cSt, it becomes difficult to uniformly disperse the EA particles, and bubbles are entrained during the adjustment, and the bubbles are It is difficult to pull out, and it is difficult to handle, which is not preferable. From this viewpoint, the kinematic viscosity is preferably in the range of 10 cSt to 1000 cSt, particularly preferably in the range of 10 cSt to 100 cSt. Of course, the kinematic viscosity of the electrically insulating medium 1 changes with temperature, and this temperature effect can be suppressed by the applied voltage.

The EA particles 2 used in the present invention are, if they are inorganic / organic composite particles having the EA effect, an element, an organic compound, an inorganic compound, or a mixture thereof.
Either material can be used. Examples thereof include particles of inorganic ion exchangers, metal oxides, silica gel, inorganic substances having electric semiconductors, carbon black, and particles having these as a surface layer. However, as shown in the above examples, the EA particles 2 are composed of the core body 3 made of an organic polymer compound and the EA inorganic particle 4
It is particularly preferable that the inorganic-organic composite particles are formed by the surface layer 5 consisting of. In this inorganic-organic composite particle, a surface layer 5 composed of particles 4 of EA inorganic material having a relatively high specific gravity is carried on a core body 3 which is an organic polymer compound having a relatively low specific gravity, and the specific gravity of the entire particle is changed to an electric value. It can be adjusted to approximate the insulating medium 1. Therefore, the ENC fluid composition obtained by dispersing this in the electrically insulating medium 1 has excellent storage stability.

Examples of the organic polymer compound that can be used as the core 3 of the EA particles (inorganic / organic composite particles) 2 are poly (meth) acrylic acid ester, (meth) acrylic acid ester-styrene copolymer, Polystyrene, polyethylene, polypropylene, nitrile rubber, butyl rubber, AB
S resin, nylon, polyvinyl butyrate, ionomer, ethylene-vinyl acetate copolymer, vinyl acetate resin,
One or a mixture of two or more such as a polycarbonate resin or a copolymer may be mentioned.

Particles 4 which are the EA inorganic substance forming the surface layer 5
Although various compounds can be used, preferred examples include inorganic ion exchangers, silica gel, and electrically semiconducting inorganic substances. When these particles 4 are used to form the surface layer 5 on the core 3 made of an organic polymer compound, the obtained inorganic / organic composite particles become useful EA particles 2.

Examples of the above inorganic ion exchanger include (1)
Hydroxide of polyvalent metal, (2) hydrotalcites,
(3) Acid salt of polyvalent metal, (4) Hydroxyapatite, (5) Nasicon type compound, (6) Clay mineral, (7)
Mention may be made of potassium titanates, (8) heteropolyacid salts, and (9) insoluble ferrocyanide.

The respective inorganic ion exchangers will be described in detail below. (1) Hydroxide of polyvalent metal. These compounds are represented by the general formula MO _x (OH) _y (M is a polyvalent metal, x is a number of 0 or more, and y is a positive number), and examples thereof include titanium hydroxide and hydroxide. zirconium,
Examples include bismuth hydroxide, tin hydroxide, lead hydroxide, aluminum hydroxide, tantalum hydroxide, niobium hydroxide, molybdenum hydroxide, magnesium hydroxide, manganese hydroxide, and iron hydroxide. Here, for example, titanium hydroxide refers to hydrous titanium oxide (also known as metatitanic acid or β-titanic acid, Ti
It contains both O (OH) ₂ ) and titanium hydroxide (also known as orthotitanic acid or α-titanic acid, Ti (OH) ₄ ), and the same applies to other compounds.

(2) Hydrotalcites. These compounds have the general formula M ₁₃ Al ₆ (OH) ₄₃ (C
O) ₃ · 12H ₂ O (M is a divalent metal),
For example, the divalent metal M is Mg, Ca or Ni. (3) Acid salt of polyvalent metal. These are, for example, titanium phosphate, zirconium phosphate, tin phosphate, cerium phosphate, chromium phosphate, zirconium arsenate, titanium arsenate, tin arsenate, cerium arsenate, titanium antimonate, tin antimonate, tantalum antimonate. , Niobium antimonate, zirconium tungstate, titanium vanadate, zirconium molybdate, titanium selenate, and tin molybdate.

(4) Hydroxyapatite. These are, for example, calcium apatite, lead apatite,
Examples include strontium apatite and cadmium apatite. (5) Nasicon type compound. These include, for example, (H ₃ O) Zr ₂ (PO ₄ ) ₃ but in the present invention, a Nasicon type compound in which H ₃ O is replaced with Na can also be used. (6) Clay mineral. These are, for example, montmorillonite, sepiolite, bentonite and the like, with sepiolite being particularly preferred.

(7) Potassium titanates. These general formula _{aK 2 O · bTiO 2 · nH} 2 O (a 0
<A is a positive number that satisfies a ≦ 1, b is a positive number that satisfies 1 ≦ b ≦ 6, and n is a positive number), for example, K ₂ ·
TiO ₂ · 2H ₂ O, K ₂ O · 2TiO ₂ · 2H ₂ O, 0.
5K ₂ O ・ TiO ₂・ 2H ₂ O, and K ₂ O ・ 2.5TiO
₂ · 2H ₂ O, and the like. In addition, among the above compounds, a compound in which a or b is not an integer is easily synthesized by subjecting a compound in which a or b is an appropriate integer to an acid treatment and replacing K with H.

(8) Heteropolyacid salt. These are represented by the general formula H ₃ AE ₁₂ O ₄₀ .nH ₂ O (A is phosphorus, arsenic, germanium, or silicon, E is molybdenum, tungsten, or vanadium, and n is a positive number), For example, ammonium molybdophosphate and ammonium tungstophosphate. (9) Insoluble ferrocyanide. These are compounds represented by the following general formula. M _b-pxa
A [E (CN) ₆ ] (M is an alkali metal or hydrogen ion, A is a heavy metal ion such as zinc, copper, nickel, cobalt, manganese, cadmium, iron (III) or titanium, E is iron (II), iron (III), cobalt (II) or the like, b is 4 or 3, a is a valence of A, and p is a positive number of 0 to b / a.) These include, for example, Cs. Insoluble ferrocyanine compounds such as ₂ Zn [Fe (CN) ₆ ] and K ₂ Co [Fe (CN) ₆ ] are included.

The inorganic ion exchangers (1) to (6) each have an OH group, and some or all of the ions present at the ion exchange sites of these inorganic ion exchangers are different from other ions. Those substituted with (hereinafter, referred to as a substitutional inorganic ion exchanger) are also included in the inorganic ion exchanger of the present invention. That, R-M ¹ inorganic ion exchanger described above (M ¹ represents an ion species of the ion exchange sites) is expressed as a part or all of M ¹ in the R-M ^1, the ion exchange reaction below A substituted inorganic ion exchanger in which an ionic species M ² different from M ¹ is substituted by
It is an inorganic ion exchanger in the present invention. xR−M ¹ + yM ² → Rx− (M ² ) y + xM ¹ (where x and y represent the valences of the ion species M ² and M ¹ , respectively). M ¹ varies depending on the type of the inorganic ion exchanger having an OH group, but when the inorganic ion exchanger exhibits a cation exchange property, M ¹ is generally H ⁺ , and in this case, M ² is an alkali metal or an alkali. Any metal ion other than H ⁺ , such as earth metals, polyvalent typical metals, transition metals or rare earth metals. When the inorganic ion exchanger having an OH group exhibits anion exchange property, M ¹ is generally OH ^−.
Where M ² is, for example, I, Cl, SCN, N
Any of anions other than OH ⁻ such as O ₂ , Br, F, CH ₃ COO, SO ₄ or CrO ₄ and complex ions.

Further, regarding the inorganic ion exchanger which has once lost the OH group due to the high temperature heat treatment but becomes to have the OH group again by an operation such as immersion in water, the inorganic ion after the high temperature heat treatment is used. Exchangers and the like are also a kind of inorganic ion exchangers that can be used in the present invention, and specific examples thereof include a Nasicon type compound such as (H ₃ O) Zr ₂
(PO ₄₎ HZr ₂ obtained by heating ₃ (PO _{4) 3} and high-temperature heat treatment of hydrotalcite (500 to 70
Heat treated at 0 ° C.) and the like. These inorganic ion exchangers can be used not only in one kind but also in many kinds simultaneously as a surface layer. It is particularly preferable to use a hydroxide of a polyvalent metal and an acid salt of a polyvalent metal as the above-mentioned inorganic ion exchanger.

An example of an electrically semiconductive inorganic material that can be used as the surface layer 5 of the EA particles (inorganic / organic composite particles) 2 is a metal having an electric conductivity of 10 ³ to 10 ^-11 Ω ^-1 / cm at room temperature. Oxides, metal hydroxides, metal oxide hydroxides, inorganic ion exchangers, or metal-doped at least one of these, or at least any one of these regardless of the presence or absence of metal doping For example, those applied as an electric semiconductor layer on another support.

Examples of preferable electric semiconductor inorganic materials are shown below. (A) Metal oxide: For example, SnO ₂ or amorphous titanium dioxide (manufactured by Idemitsu Petrochemical Co., Ltd.). (B) Metal hydroxide: For example, titanium hydroxide or niobium hydroxide. Here, titanium hydroxide means hydrous titanium oxide (manufactured by Ishihara Sangyo Co., Ltd.), metatitanic acid (also known as β-titanic acid,
TiO (OH) ₂ ) and orthotitanic acid (also known as α-titanic acid, Ti (OH) ₄ ) are included. (C) Metal oxide hydroxide: For example, FeO
(OH) (goethite) and the like can be mentioned. (D) Hydroxide of polyvalent metal: equivalent to inorganic ion exchanger (1). (E) Hydrotalcites: Inorganic ion exchanger (2)
Equivalent to (F) Acid salt of polyvalent metal: equivalent to the inorganic ion exchanger (3). (G) Hydroxyapatite: Inorganic ion exchanger (4)
Equivalent to (H) Nashicon type compound: equivalent to the inorganic ion exchanger (5). (I) Clay mineral: equivalent to the inorganic ion exchanger (6). (J) Potassium titanate: equivalent to the inorganic ion exchanger (7). (K) Heteropolyacid salt: equivalent to the inorganic ion exchanger (8). (L) Insoluble ferrocyanide: equivalent to inorganic ion exchanger (9). (M) Metal-Doped Electric Field Alignment Inorganic Material: This is an ER inorganic material doped with a metal such as antimony (Sb) in order to increase the electric conductivity of the above-mentioned electric semiconductor inorganic materials (A) to (L). As an example, antimony (Sb) -doped tin oxide (SnO ₂ ) and the like can be mentioned. (N) An electric field arranging inorganic substance as an electric semiconductor layer on another support: for example, inorganic oxide particles such as titanium oxide, silica, alumina, or silica-alumina as a support,
Alternatively, organic polymer particles such as polyethylene and polypropylene are used, and antimony (S
b) Doped tin oxide (SnO ₂ ) may be used. The particles in which the electric field aligning inorganic substance is applied to the other support in this manner can be regarded as the electric field aligning inorganic substance as a whole. These electric field aligning inorganic materials may be used not only in one kind but also in two kinds or more simultaneously as a surface layer.

The EA particles (inorganic / organic composite particles) 2 can be manufactured by various methods. For example, there is a method in which a particulate core body 3 made of an organic polymer compound and fine particulate particles 4 are transported by a jet stream and collided with each other to produce them. In this case, the fine particles of the particles 4 collide with the surface of the particulate core 3 at a high speed and are fixed to form the surface layer 5. Another example of the manufacturing method is a method in which the particulate core body 3 is suspended in a gas, and a solution of the particles 4 is atomized and sprayed on the surface. In this case, the surface layer 5 is formed by adhering the solution onto the surface of the core 3 and drying it.

A particularly preferred method for producing the EA particles (inorganic / organic composite particles) 2 is to form the surface layer 5 at the same time as the core body 3. In this method, for example, when emulsion-polymerizing, suspension-polymerizing, or dispersion-polymerizing a monomer of an organic polymer compound forming the core body 3 in a polymerization medium, particles 4 which are EA inorganic particles in the form of fine particles, Alternatively, it is present in the polymerization medium. Water is preferred as the polymerization medium, but a mixture of water and a water-soluble organic solvent can also be used, and an organic poor solvent can also be used. According to this method, the monomers are polymerized in the polymerization medium to form the core particles 3, and at the same time, the fine particle EA inorganic particles 4 are layered on the surface of the core 3 to cover the core particles 3. The surface layer 5 is formed.

In the case of producing EA particles (inorganic / organic composite particles) by emulsion polymerization or suspension polymerization, particles 4 of EA inorganic substance are combined by combining the hydrophobic property of the monomer and the hydrophilic property of the EA inorganic substance. Can be attached to the surface of the core body 3. According to the method of simultaneously forming the core body 3 and the surface layer 5, the EA inorganic particles 4 are densely and firmly adhered to the surface of the core body 3 made of an organic polymer compound, and the EA particles (inorganic / organic composite) Particles 2) are formed.

The shape of the EA particles 2 used in the present invention does not necessarily have to be spherical, but when the particulate core 3 is produced by the controlled emulsion / suspension polymerization method, the EA particles obtained are obtained. The shape of the particles 2 is almost spherical. EA
The particle size of the particles 2 is not particularly limited, but is 0.1
The thickness is preferably in the range of μm to 500 μm, particularly 5 μm to 200 μm. Fine particle EA at this time
The particle size of the inorganic particles 4 is not particularly limited, but is preferably 0.005 μm to 100 μm, and more preferably 0.01 μm to 10 μm.

In the EA particles (inorganic / organic composite particles) 2, the particles 4 and the core 3 which are the EA inorganic substance forming the surface layer 5 are formed.
The weight ratio of the organic polymer compound forming the is not particularly limited, but in order to obtain an ENC fluid composition having high storage stability, the EA inorganic particles 4 and the organic polymer compound core 3 are used. 1% by weight of particles 4 to 6% of the total weight
It is preferably in the range of 0% by weight, particularly preferably in the range of 4% by weight to 30% by weight. If the proportion of the core body 3 is less than 1% by weight, the EA characteristics of the obtained EA particles 2 will be insufficient, and if it exceeds 60% by weight, the specific gravity of the EA particles 2 will be excessive and the storage stability will be impaired. There is Further, the ENC fluid composition of the present invention can be produced by uniformly stirring and mixing the above-mentioned EA particles 2 together with a dispersant and other components in an electrically insulating medium. As the stirrer, any stirrer normally used for dispersing solid particles in a liquid dispersion medium can be used. In an electrically insulating medium 1
The content of the EA particles 2 in is not particularly limited, but is preferably 0.5 to 75% by weight, and particularly preferably 5 to 50% by weight. If the content is less than 1%, a sufficient EA effect cannot be obtained, and if the content is 75% or more, the initial viscosity of the ENC fluid composition when a voltage is not applied becomes too large, which makes it difficult to use.

The EA particles 2 produced by the above various methods, particularly the method of simultaneously forming the core 3 and the surface layer 5,
When all or part of the surface layer 5 is covered with a thin film of an organic polymer substance, a dispersant, an emulsifier or other additive substances used in the manufacturing process, and the EA effect as electric field aligning particles is not sufficiently exhibited. There is. This thin film of inert material can be easily removed by polishing the surface of the particles. Therefore, when the core body 3 and the surface layer 5 are simultaneously formed, it is preferable to polish the surfaces thereof.

The surface of the particles can be polished by various methods. For example, EA, which is an inorganic / organic composite particle
The method can be performed by dispersing the particles 2 in a dispersion medium such as water and stirring this. At this time, a method of mixing an abrasive such as sand particles or balls into the dispersion medium and stirring with the EA particles 2, a method of stirring with a grinding wheel, or the like can be used. For example, it is also possible to dry-stir without using a dispersion medium, using the EA particles 2 and the above-mentioned abrasive or grinding stone.

A more preferable polishing method is a method in which the EA particles 2 are agitated by a jet stream or the like. This is a method of polishing particles by violently colliding with each other in a gas phase, and is a preferable method in that the polished particles can be easily separated by classification without the need for another abrasive. In the above jet stream agitation, it is necessary to select polishing conditions depending on the type of equipment used, the agitation speed, the material of the EA particles 2, etc., but generally 60
It is preferable to perform jet stream stirring at a stirring speed of 00 rpm for about 0.5 min to 15 min.

The ENC fluid composition of the present invention has the above EA
The particles 2 can be produced by uniformly stirring and mixing them in the electrically insulating medium 1 together with other components such as a dispersant, if necessary. As the stirrer, any stirrer normally used for dispersing solid particles in a liquid dispersion medium can be used.

Although the PET film 17a is used in the above embodiment, another plastic film or the like may be used. For example, various plastic films such as PVC (vinyl chloride) film, nylon film, polyethylene film, polypropylene film and acrylic film may be used.

In the above embodiment, the triangular columnar member 31 is used.
However, a pillar member having another shape may be used. For example, it may be a quadrangular prism. Further, in the above-described embodiment, the rotating means for rotating the triangular columnar member 31 by the rack shaft 33 having the rack gear 33a and the shaft 32 having the pinion gear 32a is used, but other rotating means may be used. For example, each triangular columnar member 31 may be manually rotated, or an electric motor may be directly connected to each shaft 32 to rotate the triangular columnar member 31.

[0059]

The present invention has the following effects. (1) By selecting the voltage applied to the pair of electrode plates by the voltage application adjusting means, the frequency band to be removed is selected in the frequency band of sound waves such as music and voice in the acoustic space, and the The sound wave can be removed and the sound wave in a frequency band other than the frequency band can be reflected. Thereby, the reverberation can be easily changed, and the acoustic characteristics of the acoustic space can be changed. (2) When it is desired to change the acoustic characteristics according to the music, voice, etc. of the acoustic space, or the taste of the listener, the voltage application adjusting means adjusts the applied voltage again and changes the frequency band to be removed to improve the reverberation. It can be changed to change the acoustic characteristics. (3) Since the sound wave absorption control plate, which is the reflection surface, can be set at an arbitrary angle by rotating the pillar member, the reflection direction of the sound wave can be changed while maintaining the reverberation of the sound wave absorption control plate. . As a result, more various acoustic characteristics can be obtained.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of an echo control device according to the present invention.

FIG. 2 is an enlarged cross-sectional view showing a triangular prismatic member of an embodiment of the echo adjusting device according to the present invention.

FIG. 3 is a schematic top view of an embodiment of the echo control device according to the present invention.

FIG. 4 is a cross-sectional view showing a state in which a chain and one of the electrode plates resonate when a sound wave is incident on the sound wave absorption control plate of the echo adjusting device according to the present invention.

FIG. 5 is a cross-sectional view showing an example of the ENC fluid composition of the echo control device according to the present invention.

FIG. 6 is a cross-sectional view showing an aspect of the echo control device according to the present invention when an ENC fluid composition is powered off.

FIG. 7 is a cross-sectional view showing a state of the ENC fluid composition of the echo control device according to the present invention when the power is turned on.

FIG. 8 is a cross-sectional view showing a state where a sound wave is incident on the sound wave absorption control plate of the echo adjusting device according to the present invention and one of the electrode plates vibrates.

FIG. 9 is a graph showing the results of measuring the effect of electric field strength on EA characteristics of an EA particle dispersion system.

FIG. 10 is a diagram showing an equivalent circuit of a vibration system.

FIG. 11 is a diagram showing another example of the bending state of the chain in the sound wave absorption control plate of the echo adjusting device according to the present invention.

FIG. 12 is a view showing a column in which a plurality of chains are joined to each other in the sound wave absorption control plate of the echo control device according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Electrically insulating medium, 2 ... Electric field arrangement particles (EA particles,
Solid particles, inorganic / organic composite particles), 4 particles (particles of an electric field aligning inorganic material), 17, 18 ... Electrode plate, 30 ... Echo adjusting device, 31 ... Triangular column members, 39a, 39b, 39c
... Sound wave absorption control plate, 60 ... Voltage application adjusting device (voltage application adjusting means)

Front page continuation (72) Inventor Moritaka Goto 1-5-1, Kiba, Koto-ku, Tokyo, Fujikura Ltd. (72) Inventor Kenji Furuichi 1-1-5, Kiba, Koto-ku, Tokyo Fujikura Ltd. (72) Inventor Yasufumi Otsubo 206-1, Konakadai, Inage-ku, Chiba, Chiba 206

Claims (1)

[Claims] 1. A plurality of columnar members are rotatably supported in the circumferential direction and are arranged in parallel, and a sound wave absorption control plate is stretched on the outer peripheral surfaces of the columnar members. The absorption control plate and the electro-sensitive acoustic absorption control fluid composition containing solid particles having an electric field array effect in an electrically insulating medium are opposed to each other with a gap, and the electro-sensitive type is provided in the gap. A structure comprising a pair of electrode plates containing a fluid composition for controlling sound wave absorption, and further comprising voltage application adjusting means for applying a voltage between the pair of electrode plates and adjusting the voltage. An echo control device characterized by.