WO1992000469A1

WO1992000469A1 - Method and apparatus for operation control using liquid crystal, and measuring equipment for liquid crystal

Info

Publication number: WO1992000469A1
Application number: PCT/JP1991/000881
Authority: WO
Inventors: Takuri Sakurai; Tadahiro Asada
Original assignee: Toyo Tire & Rubber Co., Ltd.
Priority date: 1990-06-29
Filing date: 1991-06-29
Publication date: 1992-01-09

Abstract

A container including one or more narrowed portions is filled with liquid crystal and sealed. The rheological properties of the liquid crystal are varied by applying an electric field to the narrowed portion. As a result, the resistance to the flow of the liquid crystal at the narrowed portion varies so that mechanical work can be controlled using liquid crystal. This operation is performed with stability at a low voltage. Further, an instrument is provided for dynamic measurements of electrorheological properties of a fluid.

Description

Specification

Operation control method and apparatus using liquid crystalline fluid and measuring apparatus for liquid crystalline fluid

Industrial applications

The present invention relates to a method and an apparatus for controlling an operation using a liquid having a liquid crystal property, and an apparatus for measuring the electric rheological properties of the liquid crystal liquid.

Conventional technology and its problems

Various methods or devices have been proposed for controlling fluid operation using an ER fluid that changes the elastic modulus by applying an electric field. For example, a two-chamber engine mount having a hydraulic damping performance (Japanese Patent Laid-Open No. 60-108488) is formed by a rubber wall supporting the engine and a rubber film under the rubber wall. A partition plate is provided in the chamber, an orifice is formed in the partition plate, a counter electrode is provided in the orifice, and an ER fluid is sealed in the chamber. In this engine mount, when the electrodes are energized, the viscosity of the ER fluid increases and the flow velocity of the orifice decreases, thereby obtaining damping performance according to the load imposed by the engine. In addition, the use of ER fluid for clutches, valves, vibration generators, etc. has been proposed.

However, these devices using ER fluids There were the following problems.

1) Since the ER fluid requires a high voltage of several kV Z mm to change its viscosity, the power supply and wiring will be large.o

2) Since the ER fluid is a dispersion, sedimentation occurs in a matter of minutes to hours, and the operating characteristics are significantly deteriorated.

3) Ordinary ER fluids contain a certain amount of water in the dispersion system, and the dispersed particles tend to absorb moisture, so that the ER characteristics are likely to change and the electrical insulation is reduced by increasing the water content. However, application of a high voltage may cause dielectric breakdown or breakdown of the device itself.

On the other hand, for the substances used for such operation control, it is extremely important to know their electrical rheological properties, especially the dynamic properties corresponding to the operating state, in selecting and adjusting the substances and applied voltage. It is. However, conventionally, as a device for measuring the electro-rheological properties of an ER fluid, a fluid is inserted between the double cylinders, and a voltage is applied between them to measure the electro-rheological properties in a steady flow. There was only a static measuring device to measure, and there was no means to measure dynamic properties that were particularly important for motion control. For this reason, there has been a demand for a device capable of dynamically measuring the electric rheological properties of a fluid. An object of the present invention is to solve such a problem of the prior art, and to provide an operation control method and apparatus using a fluid that can be operated at a low voltage and has stable operation characteristics.

Another object of the present invention is to provide an apparatus that enables dynamic measurement of the electro-rheological properties of a fluid related to the operation control.

Means for solving the problem

The first object of the present invention is to seal a fluid having a liquid crystal property in a storage section provided with one or a plurality of narrow portions, and apply an electric field to the narrow portion to reduce the rheological properties of the fluid. The operation control method using a liquid crystal fluid characterized by changing the resistance to movement in the narrow portion and controlling mechanical work, and one or more It is characterized by comprising a storage section provided with a narrow portion, a fluid having liquid crystallinity sealed in the storage section, and electrodes provided in the narrow portion and facing each other to form a pair. This is achieved by an operation control device using a liquid crystalline fluid.

The second object of the present invention is to provide a container having an open upper surface for accommodating a liquid having liquid crystallinity, a support for supporting the container, and a small space between the container inner surface and the container. An insertion member that can be inserted, and the insertion member is inserted into the container. A vibrator for vertically vibrating the container, a vibration detector for detecting vibration of the container caused by the vibration, and a liquid crystal fluid by the vibration. Liquid crystal flow characterized by comprising: a load sensor for detecting a force acting on the insertion member through the load member; and a voltage application device for applying a voltage between the container and the insertion member. This is achieved by a device for measuring the electrical rheological properties of the body.

Typical examples of Leo mouth-like properties include the elastic modulus, and the following.

· Storage shear modulus (G ')

(Loss shear modulus)

• tan 5 (= G ^# / G ')

• η one (= G * / (2 x ^ x F) (poise)

Where F is the frequency of the electric field (H z).

As the narrow portion, various forms such as a hole-like one such as an orifice, a line-like one such as a slit, and a plane-like one such as a gap between two opposing surfaces can be adopted. Monkey

Action and effect

Liquid crystal is a substance composed of organic rod-shaped molecules. It is a substance that indicates an intermediate state between an irregular state as seen in the body. The definition of liquid crystal is that the long-range order of molecules is lost, but the long-range order of molecules is maintained.

According to the present invention, it is possible to provide an operation control method and apparatus using a liquid crystalline fluid having the following effects by utilizing such characteristics of liquid crystal. That is,

1) A liquid crystal fluid can sufficiently change its rheological properties such as elastic modulus at a low voltage of, for example, 200 VZ mm to 300 V V 麵. Practical application is easy. For example, in the case of Merck's NP-1289 (cyanobiphenyl-based P-type mixed liquid crystal), a shear modulus of 0.09 dyn Zcrf without an electric field is applied at 520 V. The shear modulus of 99 dyn Z cii is shown.

2) The liquid crystalline fluid changes its rheological properties according to the electric field strength, and it is not always necessary for the current to flow in the fluid like the ER fluid. Therefore, the liquid crystal fluid does not need to be brought into direct contact with the electrode, for example, a glass plate can be interposed between the liquid crystal fluid and the electrode, and stability can be obtained in both material and operation. In. 3) Since the change in rheological properties such as the elastic modulus is based on the orientation state of the liquid crystalline fluid, a slight change in voltage can cause a sharp change. Therefore, the influence of a transient current or the like generated at the time of high voltage ONZOFF hardly occurs, and stable and reliable control can be performed.

4) Since the liquid crystalline fluid is a liquid mixture or solution, stable operation can be obtained without precipitation.

5) Liquid crystalline fluids are inherently materials with good electrical insulation, and the voltage required for operation is low, so that problems with dielectric breakdown are unlikely to occur.

In addition, the rheological properties of the liquid crystalline liquid show temperature dependence 周波数 frequency dependence of the mechanical load, and changes in the rheological properties due to an electric field depending on the temperature conditions and the load frequency. May not be enough. In this case, the change in the resistance to the movement of the liquid crystalline fluid in the narrow portion may not be sufficient, and the mechanical work may not be properly controlled. On the other hand, by setting the frequency of the electric field applied to the narrow part to an appropriate relationship with the frequency of the mechanical load on the controlled part, for example, the same frequency, such temperature dependence and frequency dependence can be reduced. The control of mechanical work can be more precise or broader.

Also, the electric field applied to the narrow part is It is desirable to follow. This is because the permissible amount of impurities for the functioning of the liquid crystalline fluid is larger in the case of an AC electric field than in the case of a DC electric field, and the operation stability is better. In addition, by using an alternating electric field having a high frequency, for example, from 500 Hz to 5 kHz, there is an advantage that the service life of the liquid crystalline fluid is prolonged. As described above, it is desirable to set the control conditions in consideration of the ambient temperature, mechanical load, operation stability, service life, and the like.

An electrorheological property measuring apparatus according to the present invention is characterized in that a liquid crystal fluid to be measured is accommodated in a minute gap between a container and an insertion member, and a predetermined electric field is applied to the gap. The structure detects the vibration state of the container and the force acting on the insertion member. Therefore, the dynamic rheological properties of a liquid crystalline fluid at a given electric field can be known from the force propagation characteristics in the minute gap. This makes it possible to know the voltage dependence of the storage shear modulus G, tan, and other mechanical quantities that cannot be obtained from static property measurements. In particular, when controlling the operation of a liquid crystalline fluid using a change in rheological properties due to voltage application, it is important to grasp the dynamic properties corresponding to the operating state. Is very significant. Examples of liquid crystalline substances that can be used in the method and apparatus of the present invention are as follows.

#Samstro liquid crystal

* Nematic, smectic liquid crystal

(1) azomethine compound

♦ 4-methyl-4'-n-butyl-benzylidene-2-lin (MBBA)

• 4—Ethkin-4'—n—butyl-benzylidene aniline (E B B A)

· 4—Ethoxy 4 '— η—Hexinole-benzylidaniline

• 4-1 η-butoxy 4 '-1 η-octyl-2-methyl-benzylidene aniline

• 4 'η-propoxy 4' 1 η-octynolebenzylidenyaniline

• 4-η-Hexinole-4 '-Cyan-Benzylidenaniline

• 4-η-heptyl-4 '-cyanobenzylideneanilin

· 4-1 η-octyl 4 '-cyanobenzylidene anilin

♦ 4—Cyan 4 ' In

• 4—Methoxy 4 'pentanoyloxybenzene

• 4—Ptanoyloxy 4'—Methoxy-benzylidenelinine

♦ 4-Methoxy 4 '-(3-methylpentanoyloxy) benzylidenylaniline

• 4—Hexyloxy 4'-1 (5-Methylhexanoloxy) 1-benzylideneaniline

• 4—n—butyl-1 4'-yS—cyanoethyl-benzylidenaniline

(2) azo compounds

• 4— n—Pininole 4 '— n—Hexinoleoxyazobenzene

♦ 4-Ethyl 4'-n-hexanoinyl

♦ N—Ptylyl 4— (4'-n-Putylphenylazo) 1-phenylcarbonate

• 4-Ethoxy 4'-n-pentanoyloxybenzobenzene

• 4— n—pentyl- 4 '— methoxyazobenzene

(3) Azoxy compounds • 4, 4'—Dimethoxyazoxybenzene (PAA)

• 4—Methoxy 4'-n-butyl-azoxybenzene

· 4-n-hexyl-4'-butoxyzoxybenzene

• 4-ethoxy-4'-n-hexanoyloxyzoxybenzene

• 4-n-pentyl-4'-n-pentanoylazoxybenzene

• 4—n—Heptanoyloxy 4'—Cyanazoxybenzene

(4) Ester compounds

• 4-n-butylbenzoic acid 4 -'- n-hexyloxyphenyl ester

• 4-n-hexyloxybenzoic acid 4'-n-heptoxyphenyl ester

• 4— (4'—n—pentyloxybenzoyloxy) benzaldehide

· 4-hexyl carbonate 1'-pentoxyphenyl benzoate

• 4—Hexylcarbonate 1 4 '1 heptoxif Phenyl benzoate

• 4— (4-n-butoxybenzoyloxy) benzoic acid 1 4'-1n-hexyloxyphenylester

· 4- (4-methoxybenzoyloxy) benzoic acid 4 '—— n-propynolefeninolester

• 4— (4—methoxybenzoyloxy) benzoic acid 1 4'-one (4-butyl phenyloxycarbonyl) fuyunyl ester

• 4-n-Heptinobenzoic acid quasi-acid 4'1-n-Cyanophenyl ester

• 4-1 (4-n—pentyl phenol) 4 '-(4-n—pentyl phenol) 4'-(4-n—pentyl phenol) 4 '-(4—n—pentyl phenol) ester

• 4-n-hexynolbenzoic acid 1 4'-n-isocyanophenyl ester

• 4—n—octyloxy 3—cyanobenzoic acid 4′—n—pentinolephenyl ester

• 4— (4— n —octyl-3—cyanobenzoyl Quinine) Benzoic acid 4'-n-pentylphenyl ester

• 4- (4-n-pentylbenzoyloxy) benzoic acid 1 4'-n-pentylphenyl ester

• 4— (4—n—pentylbenzoyloxy) 1 3 1 benzoic acid 1 4 '— n—pentyl phenyl ester

• 4—n—Heptylthiobenzoic acid 4'—n—Cyanophenyl ester

5) Stilbene compounds

• 4, 4'—Diethoxy-Trans-Stilbene

• 4—Ethoxy—4'—n—Phtyl—Methyl—Trans—Stilbene

· 4-Etkin 2-methyl 4 '-η-butyl-trans-stilbene

• 4-Ethoxy- 1 '4'-I η-butyl-α-chloro trans-stilbene

• 4-Ethoxy-4 '— η-butyl-one-cloth-trans-one-stilbene

• 4-ethoxy-1'-octyl-α-methyl-trans-stilbene , 4-Ethoxy 4 '1 (2-methylhexyl)-1-chloro-trans- 1-stilbene

(6) Biphenyl and terphenyl compounds

• 4-n-pentyl-4'-cyano biphenyl (CB-5)

• 4— n—hexinole 1 '

• 4-n-hexyl 1 4 '— cyano biphenyl • 4-n-hexyl 4'-cyano biphenyl • 4-n-heptyloxy 4 '-cyano biphenyl

• 4-n-hexyloxy 4'-cyano biphenyl

• 4—n-pentanoinoleoxy 1 '4'-cyano bifenenole

· 4-1-n-Heptyloxy— 4'-Propylcarbo-2rubiphenyl

• 4—n—propinole 4'—cyan p—terfenyl

• 4—n—octinole 4'—cyano p—terphenyl

• 4-decyl-4'-hexanoylbiphenyl

• 4—Hexinoleoxy-1 4'—Hexinolebifeninole (7) Transcyclohexane

• 4-1 (Trans-1-4-pentylcyclohexyl) benzonitrile

• Transformer, Transformer 4 'to Propinoresicuro Xylor 41-Carboxy Liquid

• Transformer, Transformer 4 '—Propyldicyclohexylol 4—Power Rubinitrile

• Trans 1-4 (4 * 1-n-pentinocyclohexyl) 1 4 '-Cyanobiphenyl

· Trans-1,4-bis (4-propoxycarbonyl) cyclohexane

• Trans-1,4-bis (4-nonyloxycarbonyl) cyclohexane

(8) Pyrimidine

· 5-n-hexyl 2- (4-hexynoleoxyphenyl) pyrimidine

• 5—n—Heptyl 2— (4—Cyanophenyl) pyrimidine

• 5—cyanone 2— (4-n-hexylphenyl) pyrimidine

• 5—Cyan 2 -— (4-n-pentyloxyphenyl) pyrimidine • 5—Cyanophenyl 2—Heptylphenyl pyrimidine

• 5- (4-n-butylphenyl) — 2- (4-cyanophenyl) pyrimidine

· 5-Cyanophenyl 1-Petilphenyl pyrimidine

• 5—n—Propyl 2— (4'—Cyan 4—Biphenyl) pyrimidine

♦ 5 — cyano 2 — (4 '— n — propyl 1 4 — biphenyl) pyrimidine

() Other

• 4-Methoxy 4'-ptanoyloxydiphenylacetylene

• 4— (4'—n—Tetradecyloxy benzoinoleoxy) Benzylidene 4 * 1 Toluidine

• Trans 1 4 1 π — Butinole 1 Methinole 4 '1 Cyanophenylcinnamate

• 2—n—octyl-5— (4-methoxybenzylideneamino) pyridine

· 7— n — butyl 2 — aminofluorene

Resteric LCD

(1) Cholesterol derivative 6 koresterinole pro mid

レレ一へ —

Cholesteryl n-heptanoate

Cholesteryl n-heptyl carbonate Cholesteryl n-heptyl mercaptocarbonate

Colesterinole Benzoate

Cholesterinol ω-phenylheptanoate Cholesteryl elkate

4 η-dodecyloxy 1 naphthyl zico resteryl 1 ρ-amino benzoate

(2) Chiral and mesogenic substances

• Ν-(4-ethoxybenzylidene) 1-41 (2-methylbutyl) aniline

• 4-ethoxy-4 '-(2-methylbutyl) azobenzene

• 4-ethoxy-4 '-(2-methylbutyl) azoxybenzene

• 4- (2-Methylbutyl) benzoic acid-4'-η-hexyloxyphenyl ester

• 4- η-Heptoxy 4 '-(2-methylbutyloxycarbonyl) biphenyl • 4-1 [4- (2-methylbutyl) benzoyloxy] benzoic acid 1 4'-1 n-pentynole phenyl ester

♦ 4— [4-1 (2-methylbutyl) benzoyloxy] Benzoic acid 1 4 '— Cyanophene 2

♦ 4-1 [4-1 (2-methylbutyl) benzoyloxy] benzoic acid 1 4'-12 trifluorophenyl ester

· 4-(4-(3-methylpentyl) benzoyloxy) benzoic acid 1 4'-methylphenyl ester

• 4-1 (2-methylbutyl) 4-1'-cyano bihue

· 4-(3-methyl pentyl) 1 4 '-Ciano Bifenenore

• 4-1 [4-1 (2-methylbutyl) phenyl] Benzoids Quantitative 1 4 '— n-Ptinolepheninolete Stenole

· 4-[4- (2-methylphenyl) phenyl] Benzoids Quasidot 4 ' • Trans-one (2-Methylbutyl) cyclohexyl carboxylic acid acid 4'-Cyanobipheninolester

• 4-n-hexyloxybenzoic acid 1 '4'-(2-methylptoxycarbonyl) phenyl

♦ 4-1 (4-methylbutyl) 4-1 * -cyano p—terfuunil

* Main chain type thermotropic liquid crystalline polymer

As shown in Fig. 5 (a), it has a repeating structure of mesogen (rigid group necessary for liquid crystal formation) and spacer (flexible bent chain). In addition to polyester, polyether, polycarbonate, etc. are included.

* Side chain type thermotropic liquid crystalline polymer

As shown in Fig. 5 (b), a comb polymer having a flexible main chain and side chains containing mesogen. For the main chain skeleton, an amorphous polymer such as a vinyl-based polymer or polysiloxane is used. * Rigid main chain polymer

As shown in Fig. 5 (c), a lyotropic liquid crystalline polymer using polyglutamic acid ester, cellulose derivative, and polyisocynate as macromolecular species.

#Lyotropic LCD * Stiff polymer solution

• Poly-p-phenylene terephthalamide (eg trade name Kepler) sulfuric acid

• Hydroxypropyl cell mouth / water

Bar-shaped beer water

* One helix

• Poly (benzyl-L-glutamate) Jokisan

D N A, t-R N A Z Water

* Block copolymer

* Amphiphilic substances

• Ishiken (Sodium palmitate, etc.)

• Surfactants (such as sodium dodecyl sulfate)

· Phospholipid

The present invention will become more apparent from the following description of embodiments with reference to the drawings.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1A is a longitudinal sectional view of an example of an engine mount equipped with the operation control device according to the present invention,

Figure 1B is a partial plan view,

FIG. 2 shows a shot equipped with the operation control device according to the present invention. A longitudinal section of the quarbsorber (Damba),

FIG. 3 is a longitudinal sectional view of a clutch equipped with the operation control device according to the present invention,

FIG. 4 is a longitudinal sectional view of a biplane equipped with the operation control device according to the present invention,

FIG. 5 is an explanatory diagram of an example of a liquid crystalline fluid,

FIG. 6 is a perspective view schematically showing one embodiment of the measuring device of the present invention,

FIG. 7 is a graph showing the properties of the liquid crystalline fluid measured using the measuring device of the present invention.

Example

Figure 1A is an example of a two-chamber engine mount. In the figure, (1) is the engine support plate, which is connected to the rubber wall (2). The lower part of the rubber wall (2) is continuous with the rubber film (3), and the two form a chamber (4). The chamber (4) is partitioned by a partition (5) having an orifice (6). The rubber wall (2) is surrounded by an outer wall (7), the rubber membrane (3) is surrounded by a cap (9) via an air chamber (8), and the cap (9) is a car chassis. Is connected to the network. The chamber (4) contains a liquid crystal liquid (A). The orifices (6) are connected to the opposing electrodes (61) and (6) as shown in Fig. 1B. 2) and an insulating member (63) between them. The electrodes (61) and (62) are connected to a power source (not shown). When mounted on a car, this engine mount acts to absorb the vibration of the engine by deformation of the rubber wall (2), but this involves a change in the volume of the room (4). At that time, the liquid crystalline fluid in the chamber (4) moves up and down the partition (5) through the orifice (6), and the flow resistance at that time makes vibration absorption more efficient. Therefore, when the voltage applied to the electrodes (61) and (62) is adjusted to 0 NZO FF or the applied voltage is adjusted, the rheological properties such as the elastic modulus of the liquid crystalline fluid change. The flow resistance when passing through the orifice changes. As a result, the vibration damping characteristics can be changed, and efficient vibration absorption according to the vibration state can be performed. In this case, by setting the frequency of the engine and the frequency of the voltage applied to the electrodes (61) and (62) to an appropriate relationship, for example, the same, the change in the rheological properties of the liquid crystalline fluid can be reduced. By reducing the temperature dependency and the frequency dependency, effective vibration absorption can be achieved over a wide range of temperature and frequency, or at a lower applied voltage.

In addition, multiple orifices are provided and the voltage is controlled separately to adjust the total amount of orifice passing through in more detail. You can also.

FIG. 2 shows an example of application of the present invention to a shock absorber for automobiles (damper). This absorber has an outer cylinder (11) and an inner cylinder (12), and is connected to each other by a rubber cylinder (13) so as to be mutually movable. A rubber film (14) is provided at the lower part of the inner cylinder (1 2), and a liquid crystal fluid (A) is sealed in the upper part and the outer cylinder (11). An orifice (15) is formed at the upper end of the inner cylinder (12). The orifice is composed of electrodes (16) and (17) at the edge, and these electrodes are connected to a power source (not shown) by wires. In this absorber, the inner cylinder and the outer cylinder move with the deformation of the rubber film (14). At this time, the resistance of the fluid passing through the orifice acts on the vibration. When the electrodes (16) and (17) are energized, the elastic modulus of the liquid crystalline fluid increases, the flow resistance through the orifice increases, and as a result, the vibration damping characteristics change. Therefore, by controlling the energization, it is possible to obtain an appropriate vibration damping characteristic compatible with the impact mitigation action of the spring. For example, when a large street hammer is applied, the electrodes are de-energized to reduce the flow resistance at the orifice, effectively mitigating the street hammer by springs, and immediately after that, the electrodes are energized to flow. Control to increase resistance and accelerate vibration damping Can be. Also in this example, it is of course possible to provide a plurality of orifices and separately control the voltage so that the total passing amount of the orifices can be adjusted in more detail.

FIG. 3 shows an application example of the present invention to a clutch. This clutch includes an input side clutch plate (21) connected to the input shaft (23) and an output side clutch plate (22) connected to the output shaft (24). The output-side clutch plate (22) has a disk shape, the input-side clutch plate (21) has a hollow structure surrounding the disk, and the distal end side of the output shaft (24) is provided with a sealing member (25). Liquid-tight. The gap between the input side clutch plate (22) and the output side clutch plate (21) forms a planar narrow portion, in which the liquid crystalline fluid (A) is sealed. The input-side clutch plate (22) and the output-side clutch plate (21) are connected to a power source (not shown) via a lead (27) via an input shaft (23) and an output shaft (24), respectively. This clutch acts as a fluid clutch utilizing the liquid crystalline fluid. The two clutch plates (21) and (22) also act as electrodes, and if a voltage is applied during this period, the rheological properties such as the elasticity of the liquid crystalline fluid change, so that both clutch plates are used. The resistance to relative rotational movement changes, and the transmission of rotational force Can be controlled. It is also possible to increase the number of the clutch plates connected to the input / output shaft and to operate each of them as an electrode for more detailed control.

FIG. 4 shows an example in which the present invention is applied to a vibrator. The vibrator includes a cylinder (31), a piston (32) slidably supported through the cylinder, and valves (33), (3) arranged in the cylinder (31). 4), (35) and (36) are provided. These valves are composed of multi-layered electrode plates concentric with the piston (32), and the mating layers in each valve are wired so as to be opposite electrodes. Each gap between the layered electrode plates is a narrow portion through which a fluid can pass in the axial direction. The valves (33) and (36) at both ends are fixed to the cylinder (31), and the valves (34) and (35) between them are fixed to the piston (32). The cylinder (31) has a supply port (37) at a position corresponding to the position between the valves (34) and (35), and a discharge port (38) outside the valves (33) and (36) in the axial direction. It has. From the supply port (37), a liquid crystalline fluid is pumped into the cylinder. In this state, when the valves (33) and (35) are energized, the flow resistance increases due to a change in the rheo-original properties, such as an increase in the elastic modulus of the liquid crystalline fluid, between the electrode layers of these valves. And As a result, the piston (32) moves to the right due to the pumping force of the liquid crystalline fluid. Next, when the current is released and the valves (34) and (36) are energized, the piston (32) moves to the left in the figure due to the reverse action. By alternately energizing the valve with the applied force, the piston oscillates according to the alternating frequency.

In each of the above examples, each operation is controlled using a fluid having a liquid crystal property, so that a stable operation at a low voltage can be obtained as described above.

Further, in the same manner as in the above example, the present invention can exert the above-described effects by using a liquid crystalline fluid with respect to various methods and apparatuses which have conventionally used an ER fluid. The following is a list of examples to which the present invention can be applied (the parentheses indicate publications describing methods or apparatuses using ER fluid).

• Clutches (JP-A-63-318326, JP-A-63-215431, JP-A-63-199993, JP-A-61-2966, JP-A-53-84666)

• Electro-mechanical conversion and amplification equipment (JP-A-61-143262, JP-A-48-35286)

• Flow control device (JP-A-58-10610)

• Hydraulic valve (US Patent No. 2661 596) ♦ Vibration generator (US Patent No. 3984086) • Damping bearing (JP-A-63-135612)

• Pressure compensation mechanism (JP-A-59-170593)

• Differential device (JP 52-126829)

· Seal (JP-A-63-306288, JP-A-48-58246)

FIG. 6 shows an apparatus for measuring the electrical properties of a liquid crystalline fluid. In the figure, (101) is a container having an open top for accommodating a liquid having a liquid crystal property, and the container is supported by a support (102). The insertion member (103) is inserted into the container (101) at a small interval from the inner surface of the container, and the insertion member is supported by the hanging portion (104) in the inserted state. It has been. A vibration exciter (105) for vertically vibrating the support base together with the container (101) is connected to the support base (102), and the insertion member (103) is connected to the support member (103). A load sensor (106) for detecting a force acting on the input member is connected. Further, the output part of the high voltage generator (107) is connected to the container (101), and the input member (103) is electrically grounded via the suspension part (104). A potential difference is generated between the container (101) and the input member (103) by the output from the high-voltage generating device (107). As described above, at least the conductive material is provided on the inner surface of the container (101) and the outer surface of the insertion member (103). A vibration detector (108) is connected to the support (102) so that the actual vibration state of the container (101) can be detected. A computer (109) is further connected to the load sensor (106), the high-voltage generator (107), and the vibration detection device (108). A signal is sent. The computer (109) calculates the storage shear modulus G ', the loss shear modulus, tan (5. η', and other kinetic parameters) from the transmitted signal. It is as follows.

Slit width: W (cm)

Slit depth: T (cm)

Slit interval: CL (cm)

Dynamic stress (D. FORCE): D F (r a m)

Dynamic displacement (D. DISP): D D (cm)

Phase difference: P (deg)

Frequency: F (H z)

Equipment constant (changes depending on phase difference): A

Then

G * = (D F X 980. 6 C L X A)

/ (DDX 2 XWX T) (dyne / cif) G '= G cos (P)

G "= G s i n (P)

t a n 5 = / G '

η '= G * / (2 x ^ r F) (poise)

Further, based on the output from the load sensor (106), the high voltage generator (107) and the vibration detecting device (108) and the signal sent according to the detected value, the vibrator (105) The control signal can be sent from the computer (109) to the vibrator (105) so that it can be controlled.

The dimensions of the container (101) and the insertion member (103), and the characteristics of the vibrator (105) and the high voltage generator (107) are exemplified below.

Inner distance of container

Width 20 mm

Depth 1.2 5 mm

问 25 mm

Insert dimensions

Width mm

Thickness 0.25 mm

0 mm immersion depth in container

Exciter characteristics Frequency: 1.0 to 1 000 Hz

Amplitude: 0.1 to: L O O O ^ m

Characteristics of high voltage generator

Maximum output voltage: 3000 V

Alternating frequency: 0.1mHz ~: 1.2MHz To perform measurement using this device, place the liquid crystalline fluid to be measured in the container (101) in the state shown in Fig. 6, and The input member (103) is immersed to a predetermined depth, and the vibrator (105) and the high-voltage generator (107) are operated. The introduction member (103) has a minute gap of, for example, about 0.5 mm between the inner surface of the container (101) and the gap, and the gap is filled with a liquid crystalline fluid. When the vibrator (105) is vibrated in this state, a shear force acts on the liquid crystal fluid between the inner wall of the container (101) and the outer surface of the insertion member (103). Accordingly, a force acts on the insertion member (103) based on the viscoelasticity of the liquid crystal fluid against shearing due to the vibration of the container (101), and the force is detected by the load sensor (106). A signal corresponding to the output of the vibrator (105) and the detection values of the load sensor (106) and the vibration detector (108) is sent to the computer (109), and the G- and G- G ", tan 5 and other mechanical quantities are calculated. The desired voltage difference and its applied frequency are calculated by the high voltage generator (107). If a voltage is applied between the container (101) and the insertion member (103) while changing the number, the electric field dependence of the above value can be obtained.

Next, the results of the measurement of the electrical rheological properties of the liquid crystalline fluid using the above-described apparatus will be described.

As liquid crystalline fluid, MERCK's mixed liquid crystal N.P.-289 (p-type nematic liquid crystal (m ε <0) composed mainly of cyanobiphenyl, showing liquid crystal state at room temperature) The frequency of the shaker was 25 Hz, the displacement amplitude was 10 O / im, the electrode spacing was 0.5 mm, and the room temperature was 24 ° C. A simple shear deformation and a voltage were applied to the sample between the steps (1) and (2), and the electric field dependence of the liquid crystalline fluid was measured.

FIG. 7 shows a graph of the voltage dependence of the dynamic viscoelastic properties obtained from the measurement results, that is, the storage shear modulus G ′, the loss shear modulus and ta η ά. From this graph, it can be seen that G 'and ta η5 show a unique voltage dependence, but G "shows little change. That is, G' shows little change at low voltage. not an increase from around ² X 1 0 2 0. 5 mm is observed et been, rapidly增加at ^{3. 5 1 0 2 V / 0.} 5 mm. further increasing the voltage, 5. 5 X 1 0 ² V / 0.5 mm The voltage decreases sharply at this point, and shows little change at higher voltages. ta η 5 shows a similar change, reversing the trend of increase and decrease.

Thus, the fact that there is little change at a low voltage, and that there is a sudden and significant change in rheological properties only in a certain voltage range means that the liquid crystalline fluid is operated by applying an electric field to the liquid crystal fluid. In the case of control, it means that control can be performed at a low level of voltage first, and then that operation can be changed with a slight voltage change. A good control system can be configured.

Claims

2 Claims

By enclosing a fluid having liquid crystallinity in a storage portion having one or more narrow portions, and applying an electric field to the narrow portion to change the rheological properties of the fluid, the narrow portion is formed. An operation control method using a liquid crystalline fluid, characterized in that mechanical resistance is controlled by changing the resistance to movement in a part.

The operation control method according to claim 1, wherein the liquid crystalline fluid contains one or more liquid crystal components, and the liquid crystalline fluid comprises one or more thermootropic liquid crystal components. 2. The operation control method according to claim 1, wherein:

5. The operation control method according to claim 3, wherein the liquid crystal component is a low-molecular liquid crystal of 30 wt% or more.

The operation control method according to claim 1, wherein the liquid crystal component is a P-type liquid crystal.

The operation control method according to claim 1, wherein the liquid crystal component is an n-type liquid crystal.

The operation control method using a liquid crystalline fluid according to claim 1, wherein the narrow portion is formed between two chambers in which the liquid crystalline fluid moves.

The narrow part between two objects that interact in motion 2. The method according to claim 1, wherein the liquid crystal fluid in the narrow portion contributes to the interaction by transmitting the operation.

2. The operation control method using a liquid crystalline fluid according to claim 1, wherein the electric field applied to the narrow portion is obtained by applying an AC voltage.

A container having one or a plurality of narrow portions, a liquid crystal material sealed in the container, and an electrode provided in the narrow portion and opposed to each other to form a pair. And an operation control device using a liquid crystalline fluid. 10. The container according to claim 10, wherein the housing section includes two chambers for moving the liquid crystalline fluid between each other, and the narrow portion formed between the two chambers. Operation controller using liquid crystalline fluid.

The container has a narrow portion formed between two objects that interact with each other, and the liquid crystal fluid in the narrow portion contributes to the interaction by transmitting the motion. An operation control device using a liquid crystalline fluid according to claim 10.

The operation control according to claim 10, wherein the electrode is connected to an AC power supply. A container having an open upper surface for accommodating a liquid having a liquid crystal property, a support for supporting the container, an insertion member that can be inserted at a small interval between the container inner surface, A suspension unit for supporting the insertion member inserted into the container, a vibrator for vertically vibrating the container, a vibration detector for detecting vibration of the container due to the vibration, A load sensor for detecting a force acting on the input member via the liquid crystal fluid by the vibration; and a voltage applying device for applying a voltage between the container and the input member. An apparatus for measuring the electric rheological properties of a liquid crystalline fluid, characterized in that: