JP2000220610A - Fluidity control method for fluid, fluidity control device and bristled valve mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control the fluidity characteristic of a fluid in an uniform system by opposing at least a pair of electrodes to each other through an insulating fluid, and planting a fiber containing a conductive fiber having a specified specific resistance on the surface of one electrode. SOLUTION: A fiber 18 is planted on the surface of one electrode 12 of a pair of electrodes 12, 14 opposed to each other in a fluid 16, and at least part of the fiber 18 consists of a conductive fiber having a specific resistance value of 102 Ω.cm or less. According to this, the potential difference between the open tip 31 of the fiber 18 and the electrode 14 is extremely increased, and an extremely strong moving flow 33 is formed between the tip 31 and the electrode 14 when a voltage is applied between the electrodes 12, 14. While a fluid 16 is moved along the surfaces of the electrodes 12, 13, the moving flow 33 is formed substantially vertically to the flowing direction of the fluid 16 and detected as the viscosity increase of the fluid 16. As the fiber having such a specific resistance graphite, metallic fiber, carbon composite fiber and the like can be used. Thus, the fluidity characteristic of a fluid in a uniform system substantially containing no particle can be fluctuated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling the fluidity of a substantially insulating fluid by applying a voltage, a flow control device suitable for carrying out the method, and a flocking using the method. For valves.

[0002]

BACKGROUND OF THE INVENTION In an electric field, certain liquids have an internal electrical force due to the non-uniformity of their conductivity and dielectric constant. In a DC electric field, the Coulomb force acting on free electrification becomes dominant due to the dielectrophoretic force of the dielectric liquid,
This Coulomb force can cause hydrodynamic instability. Due to the hydrodynamic instability due to the Coulomb force, convection or secondary flow occurs when a certain type of dielectric liquid is placed under an electric field. This phenomenon is called electro-hydrodynamic (abbreviated as [EHD]).
Called the effect. However, the EHD phenomenon is a general term that captures the phenomenon that a dielectric liquid moves under an electric field as described above, and the EHD phenomenon does not indicate the flow movement of a liquid based on a specific generation principle. Rather, research on the principle of generation of the phenomenon of liquid movement under an electric field, called the EHD phenomenon, has not yet been sufficiently conducted, and the entire picture including the cause of the EHD phenomenon is still completely unknown. is there.

By the way, the present inventor disposes a pair of electrodes in a specific insulating liquid, and when a DC voltage is applied to these electrodes, an electric field in which a strong jet flow is generated from one electrode toward the other electrode. The conjugate fluid phenomenon was found. In a broad sense, this phenomenon may be the EHD phenomenon, but the chemical structure, operating conditions, flow velocity, etc. of the dielectric liquid are significantly different from the EHD phenomenon known so far,
It is unlikely that both occur due to the same generation principle. Therefore, the present inventor has referred to a liquid exhibiting the electric field conjugate fluid phenomenon, which is a phenomenon different from the EHD phenomenon, as an electric field conjugate fluid (hereinafter, abbreviated as “ECF”), and is a conventional EHD. It is distinguished from the liquid that causes the phenomenon.

The phenomenon caused by the ECF is too different from the conventionally known EHD phenomenon, and the phenomenon cannot be explained from the EHD phenomenon, and the ECF phenomenon is different from the EHD phenomenon. The perception that it is something is taking root.

Under such circumstances, the present inventor has already filed many applications for inventions utilizing the fact that applying a voltage to the ECF generates a strong jet jet which cannot be explained by the EHD phenomenon (eg, : Japanese Patent Application 8-16
No. 871, Japanese Patent Application No. 8-248417, Japanese Patent Application No. 8-
241679, Japanese Patent Application No. 8-16872, Japanese Patent Application No. 8-
No. 76259, Japanese Patent Application No. 9-290826, Japanese Patent Application No. 9-
25557).

Among these, Japanese Patent Application No. 9-25557 states that at least a pair of electrodes capable of forming a non-uniform electric field is disposed in a fluid, and a voltage is applied between the electrodes to apply a voltage between the electrodes. A method for forming a moving flow of a fluid and controlling the fluidity of the fluid by the moving flow. "

According to the present invention, by applying a voltage to an ER fluid (Electro-Rheological Fluid) which is also a liquid exhibiting the ECF phenomenon, the mechanical properties such as the viscosity are reversibly increased according to the applied voltage. It changes at high speed to control the flow characteristics of the fluid. In the invention according to the above-mentioned application, a flocked electrode is mainly used as one electrode, and a non-uniform electric field is formed between the tip of a fiber forming the flocked electrode and the other electrode, so that the original fluid is formed. By forming a new moving flow at a right angle to the flow direction,
This moving flow acts as a shear stress on the original flow direction of the fluid, thereby expressing the fluidity of the fluid.

Therefore, the larger the potential difference between the open end of the flocking and the other electrode, the greater the moving flow of the fluid orthogonal to the direction of the fluid flow.

The present invention is a method for more efficiently controlling the fluidity of a fluid as described above and an improved apparatus used for this control.

Generally, ER fluids are roughly classified into a heterogeneous system (particle dispersion system) and a homogeneous system. The heterogeneous ER fluid is obtained by dispersing fine particles such as silica gel in insulating oil. When a voltage is applied to such a heterogeneous ER fluid, the dispersed fine particles are linked by an electrostatic force to form a chain, and the fluidity of the fluid can be changed using the chains of the fine particles.

However, such a heterogeneous ER fluid has a problem that the particles settle or float due to the specific gravity difference between the particles and the medium. Further, even if the specific gravity is the same at room temperature, the temperature dependence of the specific gravity of the particles and the specific gravity of the medium are not the same at a low temperature or a high temperature.

[0012] In such a heterogeneous ER fluid,
When a voltage is applied, the dispersed particles form a chain structure, which changes their mechanical properties.The formation of such a chain structure not only increases the viscosity but also increases the viscosity of the liquid. It also exhibits elasticity and exhibits a mechanical response similar to a solid state. Therefore, such an inhomogeneous ER fluid has a problem that linear control is difficult, and in many cases, a complicated control mechanism such as feedback control must be used.

In view of the above, it is preferable that the ER fluid is a uniform fluid containing no particles or the like. A liquid crystal is known as a homogeneous ER fluid that does not exhibit elasticity. In such a homogeneous ER fluid, the elasticity of the ER fluid does not appear even when a voltage is applied, so that control is easy, and since it is a homogeneous system, there is no problem such as sedimentation of particles.

However, as represented by a liquid crystal,
Since such homogeneous ER fluids are very expensive, they are currently used only for very high value-added products such as display devices. In addition, homogeneous ER
Liquid crystal, which is a fluid, cannot be driven unless it is in a temperature range that indicates the state of the liquid crystal, and therefore, the temperature range that can be used as an ER fluid is extremely narrow. For example, the operating temperature of the ER fluid is believed to be about -30 to 120 ° C,
It is impossible to drive the liquid crystal in such a wide temperature range.

As described above, the control of fluidity in an ER fluid is highly useful especially in a homogeneous ER fluid.

By the way, Proceedings of the 8th Symposium on “Dynamics Related to Electromagnetic Force” No.96-252 Nos. 437-438
On the page, there is a description of "Research on electrostatic devices (new stress transmission system using fibers)". This electrostatic device is based on the application that when a voltage is applied to a heterogeneous ER fluid in which particles are dispersed, the particles form a rigid chain due to the electrostatic voltage, and this chain becomes a flow resistance of the fluid. Instead of using an ER fluid containing particles, instead of using an ER fluid containing particles, a fabric fiber that is not likely to settle and float is stuck and fixed to the electrode, and a voltage is applied to the fabric fiber, so that the fabric fiber is applied to the electrode. The fluid is controlled by standing up and expressing the dynamic resistance of the upstanding fabric fiber. Therefore, the voltage application here is for raising the fiber so as to be perpendicular to the flow direction to form the flow resistance of the fluid, and by this voltage application, the voltage is applied to the fluid as in the ECF fluid. No specific high-speed jet flow is formed.

The 39th Automobile Control Alliance Lecture (1996)
On Oct. 16, 17, 18), a new novel torque transmission system using fibers is disclosed on pages 203-206, in which a fabric fiber is stuck to a disc and fixed. It is described that the shear stress is increased by rotating while applying an electric field.

However, in these methods, it is described that when a voltage is applied, the fabric fibers take a rigid structure and are oriented in the direction of the electric field to increase the shear stress. That is, in this case, by applying a voltage and stiffening and orienting the textile fibers that flow in the fluid in a state where no voltage is applied so as to resist the relative movement between the fluid and the electrode, a voltage is applied when the voltage is applied. They are trying to increase the shear stress.

Further, in these methods, since the fabric fiber is stuck to the electrode, there is no portion where the conductive electrode is exposed to the fluid, and the electrode is uniformly covered with the fabric fiber. Furthermore, there is no observation report of the emergence of the moving flow, and from the explanation that the used fabric fiber flutters according to the shearing speed in the absence of an electric field, the moving flow by the ECF is generated as claimed by the present inventor. The flow control mechanism is different from the shear stress development of the fluid by the flow.

The shear stress developed in the present invention has mechanical continuity, does not have a yield stress indicating solidification, and exhibits easily controllable properties. There are no special characteristics.

[0021]

SUMMARY OF THE INVENTION An object of the present invention is to provide a novel method for controlling the flow characteristics of a homogeneous fluid substantially free of particles and the like by applying a voltage.

It is a further object of the present invention to provide a novel method capable of easily controlling the fluidity of an insulating liquid over a wide temperature range.

It is another object of the present invention to provide a control device suitable for controlling the fluidity of a fluid as described above.

Still another object of the present invention is to provide a valve which changes the apparent viscosity of a fluid by applying a voltage and utilizes the apparent viscosity change.

[0025]

SUMMARY OF THE INVENTION The method of controlling fluidity of a fluid according to the present invention comprises disposing at least a pair of electrodes so as to face each other via a substantially insulating fluid, and applying a voltage between the electrodes. Forming a moving flow in the substantially insulating fluid substantially along the direction of voltage application to control the fluidity of the fluid, wherein one of the pair of opposed electrodes is Is characterized in that it is a flocked electrode in which fibers containing conductive fibers having a specific resistance of 10 ² Ω · cm or less are planted on the surface.

Further, the fluidity control device according to the present invention comprises at least one pair of electrodes having as one electrode a flocking electrode in which a large number of fibers containing conductive fibers having a specific resistance of 10 ² Ω · cm or less are planted on the surface. Are arranged so as to face each other via a substantially insulating fluid, and a voltage can be applied between the electrodes, and the fluid can flow between the pair of electrodes facing each other. It is characterized by.

Further, the flocked valve mechanism of the present invention comprises at least one pair of electrodes having as one electrode a flocked electrode in which a large number of fibers containing conductive fibers having a specific resistance of 10 ² Ω · cm or less are implanted on the surface. It is fixedly arranged so as to face each other through a substantially insulating fluid, and a voltage can be applied between the electrodes, and a fluid can flow between the pair of electrodes facing each other. It is characterized by having.

In the method for controlling fluidity of a fluid according to the present invention, a pair of electrodes consisting of a flocked electrode and the other electrode are arranged to face each other via a substantially insulating fluid, and a voltage is applied between the electrodes. By applying this to form a non-uniform electric field in this fluid,
A moving flow (for example, a circulating flow) of the fluid is formed in a direction substantially orthogonal to the flow direction of the fluid. If this newly formed moving flow (for example, a circulating flow) is formed so as to be substantially perpendicular to the original flow direction of the fluid, the moving flow will have a force opposing the original flow of the fluid, ie, shearing. Becomes stress.

Therefore, when a voltage is applied to the fluid in accordance with the method of the present invention, a shear stress is applied to the original flow of the fluid, and the fluidity of the fluid is controlled using the shear stress. be able to.

The moving flow formed when a voltage is applied is likely to be formed between the electrodes having the highest potential difference. Therefore, by implanting a conductive fiber having a predetermined specific resistance value as a flocked electrode, Thus, a very strong moving flow can be formed between the tip of the conductive fiber and the other electrode.

[0031]

DETAILED DESCRIPTION OF THE INVENTION Next, the method for controlling the fluidity of the fluid of the present invention, the apparatus used for the method, and the flocking valve will be described in detail.

FIG. 1 schematically shows an example of a flow control device that can be used in the method of the present invention.
FIG. 3 is a diagram schematically showing a state in which a moving flow is formed by implanted fibers.

The fluid flow control device 10 used in the present invention
Has at least a pair of electrodes 12 and 14. The electrodes 12, 14 forming this pair of electrodes are adapted to form a non-uniform electric field in the fluid 16.
That is, if a pair of electrodes having smooth surfaces are used, the fluid 1
6, it is difficult to form a non-uniform electric field, and it is difficult to form a new moving flow in the fluid. In the present invention, the fiber 18 is provided on the surface of one of the pair of electrodes 12 and 14 facing each other.
Are implanted, and the electrode with the number 12 is a flocked electrode. In the present invention, at least a part of the fibers 18 forming the flocking electrode 12 is formed of conductive fibers. Here, the conductive fiber has a specific resistance value of
It is necessary that it be 10 ² Ω · cm or less. By implanting the conductive fiber having such a specific resistance value on the surface of the electrode 12, the potential difference between the open distal end portion 31 of the implanted conductive fiber 18 and the other electrode 14 is extremely low. When a voltage is applied between the electrodes 12 and 14, a very strong fluid flow (jet flow) 33 is formed between the open tip 31 and the other electrode 14. Fluid 1
6 moves along the plane of the electrodes 12 and 14, while the moving flow 33 is substantially perpendicular to the flow direction of the fluid 16 between the open end 31 of the conductive fiber 18 and the electrode 14. Therefore, the moving flow 33 is detected as an increase in the viscosity of the fluid 16. That is, by applying a voltage, a new moving flow of the fluid that opposes the flow direction is formed in the fluid between the electrodes 12 and 14, and the apparent viscosity of the fluid increases. According to the method of the present invention, the electric rheology (E
An effect equivalent to the (R) effect is obtained.

The electrode 1 is connected from the open end 31 of the plant fiber.
After reaching the surface of the electrode 14, the jet flow 33 formed in the four directions changes its direction to the direction of the flocked electrode 12, and the moving flow turned back on the surface of the flocked electrode 12 returns from the open end 31 of the fiber. It is sent out as a jet stream.

By applying such a voltage to form a strong jet stream generated by forming a non-uniform electric field in the fluid so as to oppose the original flow direction of the fluid, this device can be used. It can be used as a valve mechanism.

For example, in FIG. 2 and FIG.
By applying a voltage to the electrodes 12, 14, the fluid 16 flowing from the right to the right (B) increases the apparent viscosity of the fluid 16 between the electrodes, and decreases its flow rate and / or flow rate. Since the increase in the apparent viscosity of the fluid 16 depends on the applied voltage, the increase in the flow rate and / or the flow rate of the fluid 16 can be changed by the applied voltage. For example, the region A and the region B shown in FIGS. Are connected via the fluidity control device 50, when the liquid in the region A is pressurized and the liquid is moved to the region B, by changing the applied voltage in the flow control device 50, the moving speed of the liquid,
The amount of movement can be controlled.

The fluidity control device 50 can function as a valve.

In order to form a new moving flow of the fluid between the electrodes 12 and 14 as described above, it is necessary to form a non-uniform electric field in the fluid.
The larger the potential difference between the electrode and the electrode 14, the more easily the moving flow is formed.

In the present invention, the conductive fiber forming the flocking electrode
As a fiber, the specific resistance value is 10^TwoΩcm or less, preferably
10^-Five-10⁰Use a fiber within the range of Ω · cm.
Specific resistance value is 10^TwoIf you use fibers that exceed Ωcm,
In comparison with other fibers, the superiority of this conductive fiber
Position does not become apparent. However, when the specific resistance value is 10^-FiveΩcm
Low fibers are perfect conductors and break at relatively low voltages.
May form an effective moving flow that may lead to a breakdown voltage
May not be possible. Further, when the specific resistance value is 10 ⁰Ωcm
If the fibers are significantly higher than
In such a case, an effective moving flow
It may not be formed.

The specific resistance of synthetic fibers (ordinary fibers) such as rayon fibers and acrylic fibers generally used for flocking greatly exceeds 10 ² Ω · cm, and usually 10 ¹⁰ Ω · c.
m. Therefore, the specific resistance value of the conductive fiber implanted in the electrode 12 in the present invention is significantly lower than the specific resistance value of the normal fiber, and the normal fiber and the conductive fiber are mixed and implanted to form the normal fiber. In the group of fiber tips consisting of, very high voltage parts are scattered, and a non-uniform electric field suitable for forming a moving flow is formed in the fluid .

As shown in FIG. 2, as shown in FIG.
2 and the other electrode are fixed, a fluid is caused to flow between the electrodes while applying a voltage between the electrodes, and the change in apparent viscosity caused by the formation of the moving flow may be measured, as shown in FIG. As shown in FIG.
2 rotates, immerses the device in which the other electrode 14 is fixed, rotates the flocking electrode 12 while applying a voltage between the electrodes 12, 14, and makes the liquid 16 relatively to the flocking electrode 12. By moving (flowing with respect to the electrode) and measuring the stress applied to the rotating flocking electrode 12 at this time, it is possible to measure the change in apparent viscosity due to voltage application.

FIG. 1 shows a pair of disks 12 having a diameter of 35 mm.
14 shows an example of an electrode using an electrode in which normal fibers and conductive fibers are implanted on the surface of the upper disk 12 facing the lower disk. The upper disk 12 is rotatably arranged with respect to the lower disk 14. Number 22
Is a motor for rotating the upper electrode 12. The upper disc 12 and the lower disc 14 are arranged with a gap of 1.5 mm, and the length of the flocking fiber 18 is 1 mm.
Therefore, the tip of the implanted fiber 18 and the lower disk 14
Are arranged such that a gap of 0.5 mm is formed between them. The upper disk 12 and the lower disk 14 are electrically insulated. In FIG. 1, a rotating contact is provided on a rotating shaft 26 of the motor 22 so that the upper disk 12
A voltage can be applied between the lower disk and the lower disk. The applied voltage is controlled by the controller 24.

The upper disk 12 is connected to a motor 22, which is a driving device, by a rotating shaft 26. The rotating shaft 26 has a measuring device (not shown) for measuring a shearing stress during rotation. ) Is provided.

In the present invention, the flocking electrode 12 is an electrode in which ordinary fibers and conductive fibers are planted on the surface of a metal substrate.

In the present invention, as the conductive fibers, fibers or yarns having the above-mentioned specific resistance, textiles, woven fabrics, and nonwoven fabrics obtained by punching are used. Examples of fibers having such a specific resistance value include:
Graphite, conductive treated fiber, metal fiber, metal wire, metal plating fiber, metal deposition fiber, carbon composite fiber,
Fibers which have been rendered conductive by blending or weaving these conductive fibers can be mentioned. Here, the conductive treatment of the fiber is a treatment of coating the fiber with a conductive substance, a treatment of chemically bonding the fiber with a substance that imparts conductivity to the fiber such as copper sulfate, or a conductive treatment of a metal or the like on the fiber. process of plating the sexual substances, a process for depositing a conductive material such as metal fibers, and the like blended or union processing of these fibers having a conductivity, and 10 ² Omega a specific resistance value of the fibers by the process -It refers to processing to make the size of cm or less.

The conductive fibers as described above are usually fibers having a higher specific resistance than the conductive fibers (fibers other than the conductive fibers such as ordinary synthetic fibers are referred to as “normal fibers” in the present invention). May be implanted on the surface of the flat electrode 12.

Here, examples of the ordinary fibers implanted together with the conductive fibers include organic fibers, inorganic fibers and insulating metal fibers. Specifically, as organic fibers, polyamide fibers (nylon fibers), polyester fibers, acrylic fibers, rayon fibers, acetate fibers,
Chemical fibers such as vinylon fiber, polypropylene fiber and polyvinyl chloride fiber; natural fibers such as cotton, hemp and wool;
Organic material whiskers can be used. Also,
Examples of the inorganic fibers include glass fibers, asbestos fibers, and inorganic whiskers. Examples of the insulating metal fibers include metal compounds such as metal oxides, metal nitrides, and metal carbides, and whiskers such as insulating metal derivatives.

Particularly, in the present invention, it is preferable to use organic fibers as the ordinary fibers implanted together with the conductive fibers.

The lengths of the conductive fibers and the ordinary fibers 18 implanted on the upper disk 12 can be appropriately set according to the distance between the electrodes. Usually, 1/100 to 95 of the distance between electrode plates
/ 100, preferably about 1/100 to 80/100. For example, in the apparatus 10 shown in FIG. 1, the distance between the upper disk 12 and the lower disk 14 is 1.5 mm, and in this example, the lengths of the conductive fibers and the normal fibers 18 implanted are: 1.0 mm. The thickness of the conductive fiber and the normal fiber 18 is usually 0.5 to 1
It is in the range of 5 denier, preferably 1.0 to 5.0 denier. When the thickness of the conductive fiber and the normal fiber greatly deviates from the above range, it becomes difficult to uniformly implant the fiber on the electrode surface, and the shear stress exhibited by the obtained flocking electrode varies.

In the present invention, the planting area of the conductive fibers and the planting area of the ordinary fibers can be appropriately set in consideration of the characteristics of the fluid and the characteristics of the conductive fibers. The ratio of the installation area to the planting area of ordinary fibers is 1: 9
It is preferably in the range of 9 to 50:50, and particularly preferably in the range of 3:97 to 35:65.

The planting density of such fibers can be appropriately set in consideration of the fluidity of the fluid to be controlled, but is usually 1,000 to 50,000 fibers / cm ² , preferably 3,000 to 30,000 fibers / cm ^2. And the cross-sectional area of the conductive fiber and the normal fiber is usually 2 to 75%, preferably 5 to 35% of the area of the implanted electrode. In the method of the present invention, since the moving flow of the fluid is mainly formed between the tip of the implanted conductive fiber 18 (tip of the conductive flocking electrode) and the other electrode 14, the planting density of the fiber is If the flow rate is low, the size of the moving flow of the formed fluid is small. Therefore, if the planting density of the fibers is low, the moving flow formed by applying the voltage is small, and the fluid flow may not be sufficiently controlled. More than the number of flocking can not be practically done industrially. In addition, it is also possible to implant a conductive fiber or a thread obtained by blending or interweaving the conductive fiber and the ordinary fiber in the ratio described above.

Although there is no particular limitation on the method of implanting the fiber into the electrode as described above, for example, a conductive adhesive (flocked glue) layer 28 formed on the surface of a metal or the like serving as an electrode forms an end between the electrode and the fiber. And a method of fusing the fiber end to the surface of the electrode material without using an adhesive. When the fiber is a metal or an inorganic material, the metal or the inorganic material may be grown in a fibrous form on the electrode surface.

The other electrode 14 facing the flocking electrode on which the fibers 18 are implanted as described above may be formed of various materials as long as a voltage can be applied between the electrodes. . For example, the other electrode 14 is made of metal,
It can be formed of a carbon material such as graphite, a conductive metal oxide, a coating film of a coating material for forming a conductive layer, a conductive film, or the like. The surface of these electrode forming materials may be covered with a cloth or the like. 1 and 2,
In FIG. 3, the other electrode 14 is formed of metal.

The flocking electrode 12 and the other electrode 1 as described above
Between them, a substantially insulating fluid 16 is sandwiched at the service temperature. In FIG.
And the other electrode 14 are shown as being immersed in a container 30 filled with a fluid.
2 and the other electrode 14 are connected to a container 30 filled with the fluid 16.
By immersing in the inside, the flocking electrode 12 and the other electrode 1
The fluid 16 is supplied to the gap with the fluid 4.

The fluid 16 supplied between the flocking electrode 12 and the other electrode 14 as described above may be any liquid that exhibits fluidity at the operating temperature. In the present invention, a fluid having substantially insulating properties at the operating temperature is used as the fluid 16. In the present invention, "the fluid is substantially insulating" means that the fluid has a conductivity (σ) of usually 5 × 10 ⁻⁶ S · m ⁻¹ or less, preferably 2.5 × 10 ⁻⁶ S · m ^−1.
It means that it is 10 ⁻⁶ S · m ⁻¹ or less. Examples of such fluids include silicone oil, hydraulic oil, mechanical oil, transformer oil, lubricating oil, mineral oil, cutting oil, bearing oil, EC
F.

A voltage is applied between the flocked electrode 12 holding the substantially insulating fluid 16 as described above and the other electrode 14. Here, the applied voltage is, for example, a rectangular wave, a pulse wave,
It can be applied in a state such as a continuous wave. The applied voltage is usually 10 V to 10 KV, preferably 50 V to 6 KV. Even if the fluid to which such a voltage is applied is a fluid having a substantially insulating property, a current flows though a very small amount when the voltage is applied as described above. The amount of current flowing at this time varies depending on the type of fluid, the type of flocked electrode, the distance between the electrodes, and the like.
00μA / cm ^2, are within the scope of the often 0.05~20μA / cm ^2.

When a voltage is applied between the electrodes as described above, a moving flow of the fluid is selectively formed between the tip 31 of the conductive fiber 18 of the flocking electrode 12 and the other electrode 14.
That is, by using the flocking electrode, a non-uniform electric field is formed in the fluid 16 held between the electrodes, and a new moving flow is formed in the fluid by the non-uniform electric field. This moving flow is formed between the tip of each conductive fiber and the other electrode substantially when, for example, a flocking electrode is used,
In many cases, it is a circulating flow of fluid. For example, FIGS. 1 and 2
In the above, a plurality of circulating flows are formed in the vertical direction between the tip of the conductive fiber of the flocking electrode 12 and the other electrode 14.
Since this circulating flow is formed in a direction substantially perpendicular to the movement of the fluid flowing laterally between the electrodes, it functions as a shear stress for the fluid moving laterally between the electrodes.
The amount of the circulating flow (or the strength of the flow) can be controlled by the strength of the voltage applied between the flocked electrode and the other electrode. The fluidity of the flowing fluid can be controlled by changing the voltage applied between the flocked electrode 12 and the other electrode 14.

In FIG. 5, the distance between the tip 33 of the conductive fiber of the flocking electrode and the other electrode 14 is set to 0.5 mm, and a hydraulic oil of ISO viscosity grade 32 (Idemitsu Kosan Co., Ltd.) which is a general hydraulic oil is provided in this gap. This shows the change in viscosity of the working oil when the upper disk is rotated by applying a DC voltage of 1 KV with a product name: Daphne Super Hydrourik Fluid 32 manufactured by K.K. For comparison, the viscosity of the hydraulic oil when no voltage is applied is also shown.

In general, a change in viscosity of a fluid when a voltage is applied to the fluid is known as an electrorheological effect. This is due to a state change of the fluid by an electric field. That is, it is understood that, for example, in a particle-dispersed electrorheological fluid, the particles undergo dielectric polarization by an electric field to form a chain structure between the electrodes, thereby increasing the shear stress and increasing the fluid viscosity. Further, it is understood that the liquid crystal, which is a uniform electrorheological fluid, is one in which the liquid crystal material between the electrodes is oriented in one direction by an electric field, the shear stress increases, and the fluid viscosity increases.

However, the hydraulic oil used in the example of the control method of the present invention is electrically stable, and does not have the orientation property of the above-mentioned liquid dispersion or liquid crystal. Therefore, the particles cannot form a chain structure like a heterogeneous fluid, nor can they be oriented like liquid crystals. Hydraulic oils are known to exhibit a stable state of matter in electric fields, and are therefore widely used today as excellent electrical insulating fluids.

Even when such an electrically stable substance, such as hydraulic oil, is used, if a voltage is applied between the flocking electrode and the other electrode as defined in the present invention, the fiber which is the flocking electrode can be used. A moving flow of the fluid, often a circulating flow, is observed between the tip and the other electrode, and the formation of this moving flow increases the shear stress of the hydraulic oil in the flow direction, thereby reducing the apparent viscosity of the hydraulic oil. The rise causes a change in liquidity. The fluidity of the hydraulic oil can be controlled by the voltage applied between the electrodes. The behavior of the fluid as described above is not limited to hydraulic oil, and ordinary hydraulic oil and the like also exhibit similar behavior.

Therefore, according to the present invention, the fluidity of the fluid can be easily controlled by applying a voltage to the electrodes. Moreover, the control according to the present invention can be controlled with extremely high precision by adjusting the voltage applied between the electrodes.

In the method of the present invention, the fluid is controlled by disposing electrodes in an existing device, using a generally used insulating liquid without mixing particles or the like into the fluid. It does not require extensive changes in equipment. Further, as shown in FIG.
The electrodes can be moved, or as shown in FIGS. 2 and 3, the electrodes are fixed, a fluid flows between the fixed electrodes, a voltage is applied to the fixed electrodes, and the electrodes pass between the fixed electrodes. The fluidity of the fluid can be controlled. That is, the method of the present invention can control the flow characteristics of the fluid relative to the electrode.

In particular, as shown in FIGS. 2 and 3, the implanted electrode 12 and the other electrode 14 are fixed, and when the fluid is moved between them, a voltage is applied between the implanted electrodes to reduce the apparent viscosity of the fluid. By changing, the amount, speed, and the like of the fluid passing between the flocking electrode 12 and the other electrode 14 can be controlled. Then, by passing a fluid while controlling and applying a voltage between the electrodes whose positions are fixed to each other as described above, the amount and speed of the fluid passing between the electrodes can be controlled. Such an electrode corresponds to a valve body for flowing fluid, and instead of mechanically opening and closing the valve body, controlling the flow rate and flow rate of the fluid by changing the voltage applied between the electrodes. Can be.

The control method and control device of the present invention can be applied to a wide range of industrial applications. As shown in FIG. 3, a hydraulic mechanism using a normal hydraulic oil has no sliding portion and can be controlled by voltage as a hydraulic valve. Can be used. Further, the method of the present invention can be applied to automobile parts such as clutches and shock absorbers, industrial machine parts, vibration damping mechanisms and the like.

The method for controlling the fluidity of a fluid according to the present invention is to control the fluidity characteristics of a fluid by applying a voltage to an insulating fluid using a flocking electrode as described in detail above. Can be further variously modified.

For example, the fluid used in the present invention does not need to be particularly blended with any other component. Examples thereof include an antioxidant, a stabilizer, a coloring agent, a rust inhibitor, a viscosity modifier, a preservative, and a fungicide. Additives such as agents, various solvents, fluidity modifiers, and surfactants can also be blended.

In the above description, the conductive fiber and the normal fiber are individually and individually planted. However, the conductive fiber and the normal fiber are mixed and spun to form the conductive portion in one fiber. The non-uniform electric field can be formed in the fluid also by implanting the composite fiber having the insulating portion and the insulating fiber, and the same operation and effect as described above can be obtained.

Further, by using a flame-retardant or non-flammable fluid as the fluid, even if the applied voltage is higher than usual, the fluid is less likely to ignite or to cause thermal decomposition. be able to.

[0070]

According to the present invention, by implanting conductive fibers, a new moving flow of the fluid is formed at the open end of the conductive fibers in a direction substantially perpendicular to the fluid.
This moving flow increases the apparent viscosity of the fluid.
Therefore, in the method of the present invention, the flow characteristics of the fluid can be changed by applying a voltage between the electrodes.
In particular, in the flow control method of the present invention, by using ECF in a homogeneous system substantially free of particles and the like,
By applying a voltage between the electrodes, a very strong jet stream is formed on the conductive fibers implanted in the flocked electrode, and this jet stream changes the apparent viscosity of the fluid. Can easily be controlled.

An apparatus using a flocking electrode used in this method has an electrode in which conductive fibers and ordinary fibers are planted on a substrate, and the conductive fiber portion is stronger than other portions. Very good ER with jet flow formed
Show the effect.

By using a non-heat-resistant compound or composition as the fluid, the fluid can be used stably for a very long time without fear of ignition of the fluid although the applied voltage is high.

Further, according to the present invention, the generated shear stress has mechanical continuity, has no yield stress indicating solidification, exhibits easy controllability, and simplifies the control device and the like.

[0074]

EXAMPLES Next, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto.

[0075]

Example 1 As shown in FIG. 1, 85 parts by weight of rayon fiber having a diameter of 1.0 mm and a thickness of 3 deniers (trade name: Corona, manufactured by Daiwabo Co., Ltd.), a length of 1.0 mm and a thickness of 3 Denier, 15 parts by weight of acrylic fiber (trade name: Sandalon, manufactured by Nippon Silk Wool Dyeing Co., Ltd.) which has been subjected to a conductive treatment with a specific resistance of 3.2 × 10 ⁻² Ω · cm, are thoroughly planted. Fiber.

[0076] Flocked glue was applied to a thickness of 0.1 mm on a circular metal flat plate having a diameter of 35 mm, and then fibers were transplanted by electrostatic flocking under an electric field of 30,000 V to produce a flocking electrode. The flocking density at this time was 8,300 fibers / cm ² . The conductive fiber planting area was 1.4 cm ² , the rayon fiber planting area was 8.2 cm ² , and the planting area ratio between the two was 15:85.

The flocking electrode thus obtained was arranged as a disk above the parallel plate type measurement sensor.

Below the flocking electrode plate, a lower electrode is arranged with a gap of 0.5 mm from the tip of the planted fibers. This container was filled with a hydraulic fluid of ISO viscosity grade 32 (trade name: Daphne Super Hydrolick Fluid 32, manufactured by Idemitsu Kosan Co., Ltd.).

By rotating the above-mentioned electrode (flocked electrode), a shear rate is given to the hydraulic oil, the upper electrode is used as a positive electrode, the lower electrode is used as a negative electrode, and a voltage of 1.0 KV is applied to adjust the viscosity at each shear rate. It was measured.

FIG. 4 shows the results. The current value at the time of voltage application was 0.3 μA / cm ² at each shear rate.

[0081]

Example 2 Rayon fiber 95 used in Example 1
5 parts by weight of the conductive fiber used in Example 1 and 5 parts by weight of the acrylic fiber used in Example 1 were mixed well to produce a flocking electrode, except that the flocking fiber was manufactured, and the viscosity at each shear rate was measured. did. The flocking density at this time was 8300 fibers / cm ²
Met. Among them, the planting area of conductive fiber is 0.5c
m ² , the planting area of rayon fibers was 9.1 cm ² , and the planting area ratio between the two was 5:95.

FIG. 5 shows the results.

The current value at this time was 0.3 μA / cm ² at each shear rate.

[0084]

Example 3 Rayon fiber 70 used in Example 1
A flocking electrode was manufactured in the same manner as in Example 1 except that 30 parts by weight of the conductive fiber used in Example 1 was mixed well with 30 parts by weight of the acrylic fiber used in Example 1 to obtain a fiber for flocking. The flocking density at this time was 8,300 fibers / cm ² .
Among them, the planting area of conductive fiber is 2.9cm ² ,
The planting area of the rayon fiber was 6.2 cm ² , and the planting area ratio between the two was 30:70.

When the upper electrode (flocked electrode) was rotated in the same manner as in Example 1, and the viscosity was measured when the shearing rate of 10 ² / s was applied to the hydraulic oil, the viscosity was 4.8 × 10 ^-2 Pa · s. 500, with the upper electrode as the positive electrode and the lower electrode as the negative electrode.
The viscosity when a DC voltage of V is applied is 3.1 × 10 ^-1 Pa · s
And the current value at that time was 15 μA / cm ² .

[0086]

Example 4 Instead of the acrylic fiber subjected to the conductive treatment used in Example 1, the length was 1.0 mm, the fiber diameter was 7 μm,
Flocked electrodes were manufactured in the same manner except that graphite fibers having a specific resistance of 1.5 × 10 ⁻³ Ω · cm (trade name: Vesfite, manufactured by Toho Rayon Co., Ltd.) were used. The flocking density at this time was 8,300 fibers / cm ² . Among them, the planting area of the conductive fiber was 1.2 cm ² , the planting area of the rayon fiber was 8.4 cm ² , and the planting area ratio of both was 13: 8.
It was 7.

As in Example 1, the upper electrode (flocked electrode)
Was rotated, and the viscosity when a shear rate of 10 ² / s was applied to the hydraulic oil was measured. The viscosity when a DC voltage of 500 V was applied was 4.3 × 10 ⁻¹ Pa · s. The current value at this time was 57 μA / cm ² .

[Brief description of the drawings]

FIG. 1 is a schematic diagram schematically showing an example of a control device suitably used in the present invention.

FIG. 2 is a diagram schematically showing a moving flow in a flocked electrode.

FIG. 3 is a diagram schematically illustrating an example of a flocked valve.

FIG. 4 is a graph showing the viscosity of a fluid at each shear rate measured in Example 1.

FIG. 5 is a graph showing the viscosity of a fluid at each shear rate measured in Example 2.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Flow control apparatus 12, 14 ... Electrode (disc) 16 ... Fluid 18 ... Fiber 22 ... Motor 26 ... Rotation axis 28 ... Conductive adhesive 30 ... Container 31 ... Open fiber end 50 ... Flow control apparatus (flocked) valve)

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3H082 AA23 CC02 CC05 DB01 EE13 3J048 AC04 BE04 3J069 BB10 DD25

Claims (10)

[Claims] At least one pair of electrodes are arranged so as to face each other via a substantially insulating fluid, and by applying a voltage between the electrodes, the substantially insulating fluid is A method of controlling a fluidity of a fluid by forming a moving flow substantially along a voltage application direction, wherein one of the pair of opposed electrodes has a specific resistance value of 10 ² Ω on the surface.
A method for controlling fluidity of a fluid, characterized in that the electrode is a flocked electrode in which fibers containing conductive fibers of not more than cm are implanted. 2. The method according to claim 1, wherein the ratio of the planting area of the conductive fibers to the planting area of other fibers is in the range of 1:99 to 50:50. Fluid flow control method. 3. The conductive fiber according to claim 1, wherein the conductive fiber is made of at least one kind of conductive material selected from the group consisting of a fiber subjected to a conductive treatment, graphite, and a metal fiber. The method for controlling fluidity of a fluid according to the above item. 4. The method according to claim 1, wherein the voltage is applied in a direction substantially perpendicular to a flow direction of the substantially insulating fluid. 5. An average length of a fiber forming the flocking electrode is in a range of 10 mm to 50 μm, a thickness of the fiber is in a range of 0.1 to 10 denier, and the fiber is 1 c
^{2. The} method according to claim 1, wherein 1,000 to 50,000 plants are planted per m < ² >. 6. The method according to claim 1, wherein a DC voltage of 10 V to 10 KV or a pulse voltage of 10 V to 10 KV is applied between the pair of electrodes. 7. The fluid has a conductivity at a use temperature,
2. The method according to claim 1, wherein the flow rate is 5 × 10 ⁻⁶ S · m ⁻¹ or less. 8. A method according to claim 1, wherein at least one pair of electrodes each having at least one flocked electrode in which a large number of fibers including conductive fibers having a specific resistance value of not more than 10 ² Ω · cm are implanted on the surface thereof. Are arranged so as to face each other, and a voltage can be applied between the electrodes, and the fluid is allowed to flow between the pair of electrodes facing each other. Fluidity control device. 9. The fluidity control of a fluid according to claim 8, wherein a relative position between the flocking electrode and another electrode is fixed, and the fluid flows between the pair of electrodes. apparatus. 10. A substantially insulating fluid comprising at least one pair of electrodes having, as one electrode, a flocked electrode in which a large number of fibers containing conductive fibers having a specific resistance of 10 ² Ω · cm or less are implanted on the surface. And fixedly arranged to face each other,
And a voltage can be applied between the electrodes, and a fluid can flow between the pair of electrodes facing each other.