JP2006042430A - Control device for er fluid - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To propose a control device for ER fluid which is applicable to a micromotor or a pump by enabling the flow of ER fluid to be controlled easily, and which is applicable to a micromachine by enabling the downsizing of a device. <P>SOLUTION: This control device for ER fluid enables the ER fluid to flow within a tube 10, being made of the tube 10 of a predetermined overall length. Flow is induced in the ER fluid and besides the flow is controlled, by arranging a plurality of electrodes 12 at intervals so as to form a tube wall, and shifting, in a predetermined direction, an electric field that is generated by applying voltage to the electrodes 12. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a control device for an ER fluid whose rheological properties change according to an electric field.

  The property that changes rheological properties such as elasticity and viscosity of a material by applying an electric field is called ER (electro-rheological) effect. As an ER fluid having such properties, an insulating liquid is mixed with dielectric solid fine particles. There are suspensions and liquid crystals in which are dispersed. Conventionally, the expression of the ER effect of such an ER fluid and a control method thereof include a structure in which a pair of flat plate electrodes are opposed to each other in parallel, two flat plate electrodes, one positive and negative electrode on the inner cylinder, and the other on the outer cylinder. Some have a double cylindrical structure in which electrodes are arranged (see Japanese Patent Application Laid-Open No. 2003-113814).

In such an ER fluid control method, the parallel two-plate electrode structure requires a predetermined area for the plate electrode, and the double-cylindrical structure makes it difficult to reduce the diameter of the cylinder due to the structure. There was a limit to microdevices.
JP 2003-113814 A

  The present invention proposes a control device for ER fluid formed by a tube having a predetermined length, and can easily control the flow of ER fluid. For example, a micromotor having a rotor in a tube enclosing ER fluid And an ER fluid control device that is provided in the ER fluid flow passage and can function as a driving device (pump) having no movable mechanism. Further, the present invention proposes an ER fluid control device that can be miniaturized by reducing the diameter of the tube and can be applied to a micromachine.

  In order to solve the above-described problem, the present invention is an ER fluid control device that is formed by a tube body 10 having a predetermined total length and that allows the ER fluid to flow in the tube body 10. A tube wall is formed by arranging and arranging, an electric field generated by applying a voltage to the electrode 12 is moved in a predetermined direction, thereby inducing a flow in the ER fluid and controlling the flow. .

  According to the second aspect of the present invention, the tube wall of the tube body 10 is formed by arranging the electrode 12 along the axial direction.

  According to a third aspect of the present invention, the tube wall of the tube body 10 is formed by arranging a plurality of electrodes 12 in an annular shape.

  According to the fourth aspect of the present invention, the flow of the ER fluid is controlled by applying a three-phase voltage to the electrode 12.

  The structure of Claim 5 uses a liquid crystal as ER fluid.

  In the ER fluid control device according to the present invention, the tube wall of the tube body 10 in which the ER fluid can flow is formed by arranging a plurality of electrodes 12 at intervals, and the electric field is moved in a predetermined direction. ER fluid flow that induces flow in the fluid, switching the electric field movement direction to switch the ER fluid flow direction, and controlling the electric field strength and electric field movement speed to control the flow rate and flow rate of the ER fluid. Can be controlled easily. Further, unlike the conventional double cylindrical structure, the tube body 10 can be reduced in diameter, the device can be miniaturized, and can be applied to a micromachine as a microdevice.

  Moreover, if a plurality of electrodes 12 along the axial direction are arranged to form a tube wall, a rotational flow can be induced in the ER fluid to generate a vortex. According to this configuration, by controlling the electric field strength to vary the apparent viscosity of the ER fluid, the axial flow velocity and flow rate of the ER fluid can be controlled. In addition, by controlling the electric field strength and the electric field moving speed, the rotational flow speed of the ER fluid can be controlled, and a rotor (gear) is provided in the tube enclosing the ER fluid, and the electric field strength and electric field moving speed are provided. It can be applied as an applied device such as a micromotor that controls the rotational speed and torque of the rotor by controlling the motor.

  Further, if a plurality of electrodes 12 are arranged in an annular shape to form a tube wall, a flow along the axial direction can be induced in the ER fluid. Therefore, according to this structure, it can function as a pump which is provided in the flow path of ER fluid and does not have a movable mechanism part.

  In addition, if the structure is such that a three-phase voltage is applied to the electrode 12, the flow of the ER fluid can be easily controlled by controlling the voltage, the frequency, the order of the three phases, etc., and the control circuit is simply configured. can do.

  Embodiments of the present invention will be specifically described below with reference to examples of the drawings.

  1 to 4 show the first embodiment of the present invention and the most basic configuration for explaining the operation principle. As shown in the figure, this control device is formed of a tube body 10 having a predetermined full length, and the ER fluid can flow in the tube body 10. The tube wall of the tube body 10 is formed by arranging a plurality of electrodes 12 with the insulating portion 11 interposed therebetween, and the electrodes 12 are juxtaposed along the axial direction at intervals and arranged at radial positions.

Next, the operating principle of this control device will be described.
In a state where liquid crystal is used as the ER fluid and no voltage is applied to the electrode 12, the liquid crystal molecules 15 are disordered and irregular as shown in FIG.

  FIG. 3 (a) shows a state in which a voltage is applied to a pair of adjacent electrodes (positive electrode and negative electrode) located at opposite positions. Here, according to the electric field generated by the application of voltage, the liquid crystal molecules 15 are partially aligned as shown in the figure. Next, as shown in (b), when a voltage is applied so that the positive electrode and the negative electrode move to the electrode 12 at the position adjacent in the clockwise direction, the electric field moves in the clockwise direction, and the liquid crystal molecules 15 follow the movement of the electric field. Reorient. Further, as shown in (c) and (d), when a voltage is applied so that the positive electrode and the negative electrode sequentially move to the electrode 12 at the position adjacent to the clockwise direction, the liquid crystal molecules 15 are sequentially reoriented as the electric field moves. . In this way, when the electric field is moved in a predetermined direction, the liquid crystal molecules 15 are sequentially reoriented and moved, and as a result, as shown in FIG. A rotational flow (vortex) in the direction of the white arrow is induced.

  In this example, since the orientation state (strength) of the liquid crystal molecules 15 depends on the electric field strength, the apparent viscosity of the liquid crystal can be varied by controlling the electric field strength, and this control device can be used as a flow path of the liquid crystal. It can function as a control valve that varies the flow velocity and flow rate in the axial direction of the liquid crystal by controlling the electric field strength. Further, by controlling the electric field strength and the electric field moving speed, the rotational flow speed of the liquid crystal can be controlled, and a control device is configured by providing a rotor in the tube 10 enclosing the liquid crystal, and the electric field moving direction. It can be applied as an applied device such as a micro motor for controlling the rotation direction, rotation speed, and torque of the rotor by controlling the electric field strength and the electric field moving speed.

  FIG. 5 shows a second embodiment of the control device of the present invention. In this example, as in the previous example, a plurality of electrodes 12 are arranged along the axial direction to form a tube wall, and a voltage is applied to the electrodes 12 with the positive electrode and the negative electrode in an alternating relationship. Is rotated in a predetermined direction. As shown in the figure, the liquid crystal molecules 15 are aligned according to the electric field generated by the application of the voltage, and when the tube body 10 is rotated in the clockwise direction (arrow direction), the electric field similarly moves in the clockwise direction. According to the direction, rotational flow can be induced in the tube body 10 in the same manner as in the previous example. Therefore, the rotational flow rate of the liquid crystal can be easily controlled by controlling the rotational speed of the tube body 10.

  FIG. 6 shows a third embodiment of the control device of the present invention. In this example, six electrodes 12 are arranged along the axial direction with the insulating portion 11 interposed therebetween to form a tube wall, and two sets of three-phase (RST) voltages are applied to the electrodes 12. is there. This control device moves the electric field in a predetermined direction by reversing the positive and negative electrodes of each phase in a predetermined cycle, and inducing the rotational flow in the liquid crystal as in the previous example, controlling the voltage, frequency, the order of three phases, etc. Thus, the rotational flow is controlled. Further, by using a three-phase voltage, the control circuit can be easily configured.

  7 and 8 show a fourth embodiment of the control device of the present invention. As shown in the figure, the control device of this example is also formed of a tube body 10 having a predetermined total length, and the liquid crystal can flow in the tube body 10. The tube wall of the tube body 10 is formed by arranging annular electrodes 12 and insulating portions 11 alternately in parallel and arranging a large number of electrodes 12 in an annular manner with intervals.

  The control device applies a voltage to a pair of electrodes (positive electrode and negative electrode) adjacent to each other at a predetermined interval along the axial direction so that the positive electrode and the negative electrode sequentially move to the electrode 12 at a position adjacent to the right direction. A voltage is applied to and the electric field is moved sequentially. In this way, when the electric field is moved in a predetermined direction, the liquid crystal molecules 15 are sequentially reoriented and moved, and as a result, as shown in FIG. An axial flow in the direction of the white arrow is induced. This control device is provided in the flow path of the liquid crystal and controls the direction of flow in the axial direction, the flow velocity, and the flow rate by controlling the moving direction of the electric field, the electric field strength, and the moving speed of the electric field. As applicable.

  FIG. 9 shows a fifth embodiment of the control device of the present invention. In this example, the tube wall of the tube body 10 is formed by arranging a large number of electrodes 12 in a ring shape, and a three-phase (RST) voltage is sequentially applied to the electrodes 12 as in the previous example. This control device moves the electric field in a predetermined direction by reversing the positive electrode and negative electrode of each phase in a predetermined cycle, and inducing axial flow in the liquid crystal in the same manner as in the previous example, and setting the voltage, frequency, three-phase order, etc. To control the axial flow. As in the third embodiment, the control circuit can be easily configured by using a three-phase voltage.

The side view of 1st Example. The AA line expanded sectional view in FIG. Explanatory drawing which shows an operation principle. Explanatory drawing which shows an operation state. Sectional drawing of 2nd Example. Sectional drawing of 3rd Example. The side view of 4th Example. The BB line expanded sectional view in FIG. Sectional drawing of 5th Example.

Explanation of symbols

10 Tube 12 Electrode

Claims (5)

An ER fluid control device that is formed of a tube body 10 having a predetermined length, and that allows the ER fluid to flow in the tube body 10
A plurality of electrodes 12 are arranged at intervals to form a tube wall, and an electric field generated by applying a voltage to the electrodes 12 is moved in a predetermined direction to induce a flow in the ER fluid and control the flow. ER fluid control device characterized by the above.   The ER fluid control device according to claim 1, wherein the electrode 12 is disposed along the axial direction.   The ER fluid control device according to claim 1, wherein the electrode 12 is arranged in an annular shape.   The ER fluid control device according to claim 1, wherein a three-phase voltage is applied to the electrode 12.   The ER fluid control device according to claim 1, wherein the ER fluid is a liquid crystal.

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