JP2010074900A - Drive unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drive unit which can obtain a relatively-large displacement amount by using a passive element which generates a relatively-small displacement amount of ER gel, or the like. <P>SOLUTION: A plurality of elements 11A, 11B which contract in directions parallel with electric fields when the electric fields are applied, and in directions different from the directions parallel with the electric fields are used in an actuator. A movable part 3 is supported in a prescribed direction so as to advance and retreat and is moved by the deformation of the elements caused by the application of the electric fields and the removal of the electric fields. The electric fields applied to the elements are generated by a plurality of electrodes 12A, 12B which are arranged so as to sandwich the elements, and a power supply 6 which feeds DC power to the electrodes. A control part 7 controls power fed to the electrodes 12 from the power supply 6 so that the electric fields are generated intermittently at prescribed cycles. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a drive device. More specifically, the present invention relates to a drive device using an element with a relatively small displacement such as a piezoelectric body or ER gel.

In recent years, piezoelectric elements (piezo elements) have been widely used as elements constituting actuators and sensors of mechanisms that require minute and accurate operation (see, for example, Patent Document 1). A piezo element is a passive element made of a material that has the property of generating electrical energy when applying mechanical energy (piezoelectric effect) and conversely generating mechanical energy when applying electrical energy (reverse piezoelectric effect). It is. For example, when an electric field of about 10 ⁶ V / m is applied to a ferroelectric material such as barium titanate, a distortion of about 0.001 occurs with respect to the entire length. Such displacement is used to open and close the valve and turn the switch on and off.

  In recent years, an ER fluid having a characteristic (electrorheological effect) in which apparent viscoelasticity is reversibly greatly changed by application of an electric field is very responsive and has a wide range of characteristic changes. For the reason, it is attracting attention as being applicable to various fields. Various proposals have been made on using an ER gel obtained by gelling the ER fluid in order to facilitate handling as an actuator element (see, for example, Patent Document 2).

JP-A-4-81907 JP-A-6-74212

As described above, piezo elements are currently widely used as elements and sensors, but ER fluids or ER gels are currently only considered to be applied to some devices such as clutches and dampers. It is hard to say that it is still widely used. The reason is considered that ER gel is slow in response as compared with a piezo element, so that the applicable range is limited.
On the other hand, since the displacement amount of ER gel is larger than that of a piezo element, if a technique for applying it as an actuator in various fields is established, such an actuator can be a very useful device. The development of such technology is expected not only for ER gels but also for piezo elements having similar properties, which will open up new possibilities for application. In recent years, research on materials for ER gels has progressed, and responsiveness has also improved. Therefore, since it is expected that the range in which ER gel can be applied as an actuator is expected to expand more and more, the development of such a technology is urgently needed.

  The present invention has been made in view of the above problems, and provides a drive device that can obtain a relatively large amount of displacement using a passive element that generates a relatively small amount of displacement, such as an ER gel. The purpose is to do.

In order to achieve the above object, the driving device of the present invention uses a plurality of elements that contract in a direction parallel to the electric field and expand in a direction different from the direction parallel to the electric field when an electric field is applied. Drive device,
A movable part supported so as to be able to advance and retreat in a predetermined direction, and moved by deformation of the element by applying and removing the electric field;
An electric field generating means for generating an electric field applied to the element;
Control means for controlling the electric field generating means to intermittently generate the electric field at a predetermined period;
It comprises.

Here, in the driving apparatus of the present invention, it is preferable that the control means adjusts at least one of the intensity of the electric field and the period for generating the electric field according to the moving speed of the movable part.
The element is preferably divided into a group in which the component in the predetermined direction of the force exerted on the movable part by the deformation is positive and a group in which the component in the predetermined direction of the force is negative. .

The elements are preferably arranged in parallel to each other and in parallel to the predetermined direction in each group, and the groups of the elements are preferably arranged in parallel to each other.
Moreover, it is preferable that each group of the elements is arranged on one straight line parallel to the predetermined direction.

Further, it is preferable that the movable portion is driven by extension of the element in a direction different from a direction parallel to the electric field when the electric field is applied to the element.
The movable part is driven by deformation of the element when the element contracted in a direction parallel to the electric field by application of the electric field returns to the original state by removal of the applied electric field. Is also preferable.

Further, the electric field generating means includes a pair of electrodes disposed so as to be substantially parallel to each other with the element interposed therebetween,
It is preferable that at least one of the pair of electrodes is provided so as to be movable following the deformation of the element due to the application and removal of the electric field.
It is also preferable that the movable electrode is biased so as to move following the deformation of the element.

Moreover, it is preferable that the element is composed of a piezoelectric body.
Moreover, it is also preferable that the element is composed of an ER gel obtained by gelling an ER fluid in which fine particles that are electrically polarized under an electric field are dispersed.

Further, the electric field generating means has individual electric field generating means for generating an electric field applied individually to each of the plurality of elements,
It is also preferable that the control means controls the individual electric field generating means to intermittently generate the electric field with a predetermined period and a predetermined phase difference.

The drive device of the present invention is supported by a plurality of elements that contract in a direction parallel to the electric field when applied with an electric field and extend in a direction different from the direction parallel to the electric field, and are capable of moving back and forth in a predetermined direction. And a movable part that is moved by deformation of the element by applying and removing the electric field. The drive device of the present invention includes an electric field generating means for generating the electric field applied to the element, and a control means for controlling the electric field generating means to intermittently generate the electric field at a predetermined period. ing. Since the movable part supported so as to be able to advance and retreat in the predetermined direction is driven by an element to which an electric field is applied / removed by control of the control means so as to repeatedly expand and contract, the movable part is greatly displaced by small deformation of the element. be able to.
Here, it is possible to move the movable part at a high speed by using an ER gel having a very fast response, for example, as an element and increasing the frequency at which the application and removal of the electric field is repeated.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
<Embodiment 1>
FIG. 1 is a perspective view showing a schematic configuration of a drive device according to Embodiment 1 of the present invention. FIG. 2 is a side view of the drive device as viewed from the side where the drive source unit is provided. FIG. 3 is a two-side view of the forward drive source portion and the reverse drive source portion of the drive source portion as seen from above and from the side.
The drive device 1 outputs a drive source unit 2 including a plurality of actuators, a movable unit 3 that is linearly driven by the drive source unit 2 to advance and retreat in a predetermined direction, and a signal corresponding to the position of the movable unit 3. The linear encoder 4 and the movable unit 3 are supported so as to be able to advance and retreat in the predetermined direction, and the support unit 5 that supports the drive source unit 2 and the linear encoder 4, and the power source unit that supplies DC power to the drive source unit 2 6, and a control unit 7 that controls the drive source unit 2 and the power supply unit 6.

  As shown in FIG. 2, the drive source unit 2 includes a positive direction drive source unit 2A that drives the movable unit 3 in a predetermined direction (for example, the right direction in FIG. 2, hereinafter referred to as a positive direction), and the movable unit 3 in the predetermined direction. And a reverse direction drive source unit 2B that drives in the opposite direction (for example, the left direction in FIG. 2, hereinafter referred to as the reverse direction). Correspondingly, the power supply unit 6 includes a forward drive power source 6A (see FIG. 3) and a reverse drive power source 6B.

  As shown in FIG. 3, the forward direction drive source unit 2A and the reverse direction drive source unit 2B each include a plurality of elements 11A or 11B made of ER gel and a plurality of electrodes for applying an electric field to the elements 11A and 11B. 12A or 12B, a switch 13A or 13B controlled by the controller 7, a plate-like base 14A or 14B on which the elements 11A and 11B and the electrodes 12A and 12B are attached to one surface, and the elements 11A and 11B And an insulating plate 15A or 15B. The base part 14A of the forward direction drive source part 2A and the base part 14B of the backward direction drive source part 2B are located on the same plane, and the forward direction drive source part 2A and the backward direction drive source part 2B are parallel to each other. Are lined up.

  Hereinafter, the operation principle of the actuator composed of the ER gel will be described with reference to FIGS. 4 and 5. FIG. 4 is a front view of an actuator model using an ER gel as an element, showing a state where an electric field is not applied to the ER gel. FIG. 5 is a front view of an actuator model using an ER gel as an element, showing a state in which an electric field is applied to the ER gel.

The ER gel is obtained by gelling an ER fluid (Electro-rheological Fluid) having a property that the apparent viscoelasticity is reversibly greatly changed by application of an electric field in order to facilitate handling. In the first embodiment, as shown in FIG. 4, an ER gel composed of a particle-dispersed ER fluid in which fine particles (hereinafter referred to as ER particles) 21 polarized under an electric field are dispersed is used as the actuator element 11. Yes. In the example of FIG. 4, the element 11 is formed in a prismatic shape, electrodes 12 are arranged on both sides in one width direction (left-right direction in the figure), and the other one in the width direction (direction perpendicular to the paper surface). On both sides, plate-like insulators (not shown) are fixedly disposed so as to be in close contact with each other. The element 11, the electrode 12, and the insulator are erected on one surface of a base portion 14 made of a plate-like insulator.
In the present embodiment, the element 11 is formed in a prismatic shape, but the same effect can be obtained even if the element 11 formed in a sheet shape or a plate shape is used.

  The ER particles 21 are particles made of an organic-inorganic composite having a diameter of about 10 to 20 μm, for example, and are polarized under an electric field. The polarized ER particles 21 attract each other in the polarized direction (electric field direction). When the ER particles 21 attract each other in the direction of the electric field, as shown in FIG. 5, the ER gel in which the ER particles 21 are dispersed is compressed in that direction (indicated by the white arrow 22 in the figure). The As a result, since the element 11 made of ER gel has a constant volume, it extends in a direction perpendicular to the direction of the electric field (indicated by a white arrow 23 in the figure).

  The elements 11A and 11B of the first embodiment are formed by molding the ER gel having the above-described properties into a prismatic shape whose side surface is a parallelogram. Here, all the elements 11A included in the positive direction drive source section 2A are inclined in the positive direction from the direction perpendicular to the direction in which the movable section 3 is driven to advance and retract (hereinafter simply referred to as the drive direction). The base 14A is erected so as to cross the drive direction obliquely. Further, all the elements 11A included in the positive direction drive source unit 2A are arranged in parallel with each other so as to be arranged in a line in the drive direction.

  On the other hand, all the elements 11B included in the reverse direction drive source unit 2B stand on the base portion 14B so that their longitudinal directions are inclined in the reverse direction from the direction perpendicular to the drive direction and obliquely intersect the drive direction. It is installed. Further, all the elements 11B included in the reverse direction drive source unit 2B are arranged in parallel with each other so as to be aligned in a line in the drive direction.

  Here, as shown in FIG. 3, the elements 11 </ b> A of the positive direction drive source unit 2 </ b> A are sandwiched by the insulating plates 15 </ b> A on both sides in the row direction. Then, both sides in the direction perpendicular to the row direction are sandwiched between electrodes 12A arranged so as to be in close contact with the element 11A. One of the electrodes 12A on both sides of the element 11A is connected via a switch 13A to a positive terminal of a positive direction driving power source 6A whose negative electrode is grounded. The other of the electrodes 12A on both sides of the element 11A is grounded. In addition, at least one of the electrodes 12A on both sides of the element 11A is movably provided so that both the electrodes 12A are kept in close contact with the element 11A even when the element 11A is deformed.

  Further, the elements 11B of the reverse direction drive source unit 2B are sandwiched between both sides in the row direction by the insulating plates 15B. Then, both sides in a direction perpendicular to the direction in which the rows are arranged are sandwiched between electrodes 12B arranged so as to be in close contact with the element 11B. One of the electrodes 12B on both sides of the element 11B is connected via a switch 13B to the positive terminal of the reverse drive power supply 6B whose negative electrode is grounded. The other of the electrodes 12B on both sides of the element 11B is grounded. Further, at least one of the electrodes 12B on both sides of the element 11B is provided so as to be movable so that both the electrodes 12B are kept in close contact with the element 11B even when the element 11B is deformed.

  In the example of FIG. 3, an electric field is applied to both the elements 11A and 11B by a grounded electrode and a positive potential electrode, but one of the elements 11A and 11B has a grounded electrode and An electric field generated by a negative potential electrode may be applied. Moreover, it is good also as what applies the electric field by the electrode grounded and the electrode of negative potential to both element 11A and 11B. It is not essential that the electrode is grounded, and an electric field generated by a positive potential electrode and a negative potential electrode may be applied to both or one of the elements 11A and 11B. The above is the same in the case of FIG. 4 and FIG. In short, if there is a potential difference between the electrodes sandwiching each of the elements 11A and 11B, the drive device of the present invention can be operated normally.

  Further, the forward driving power source 6A and the backward driving power source 6B of the power source unit 6 are configured to be able to independently adjust the voltage under the control of the control unit 7.

  Here, the electric fields are applied to all the elements 11A and 11B of the forward drive source unit 2A and the reverse drive source unit 2B from the electrodes 12A or 12B on both sides when the corresponding switch 13A or 13B is turned on. . As a result, the elements 11A and 11B extend in the longitudinal direction, and the tops are in contact with the movable part 3. When the corresponding switch 13A or 13B is turned off, the applied electric field is removed, the length in the longitudinal direction returns to the original length, and the tops of the elements 11A and 11B are separated from the movable part 3.

In addition, when the corresponding switch 13A is turned “ON” in the positive direction drive source unit 2A and the element 11A extends in the longitudinal direction and the top part contacts the movable part 3, the force applied to the movable part 3 from the element 11A at this time The component in the positive direction becomes positive, and thereby the movable part 3 is driven in the positive direction. On the other hand, when the corresponding switch 13B is turned on in the reverse direction drive source unit 2B and the element 11B expands in the longitudinal direction and the top part contacts the movable part 3, the force applied to the movable part 3 from the element 11B at this time The component in the positive direction is negative, in other words, the component in the reverse direction is positive, thereby driving the movable part 3 in the reverse direction.
As described above, all of the elements 11A and 11B of the forward direction drive source unit 2A and the reverse direction drive source unit 2B include the electrodes 12A or 12B on both sides, the base portions 14A or 14B, and the insulating plates 15A or 15B. In addition, one actuator is configured.

  Next, the operation of the drive device 1 having the above configuration will be described. When the movable unit 3 is driven in the forward direction in the driving device 1, the switch 13B of the reverse direction driving source unit 2B is turned off by the control of the control unit 7, as shown in FIG. Thereby, all the elements 11B of the reverse direction drive source unit 2B are in a state in which the tops are separated from the movable unit 3.

  On the other hand, as shown in FIG. 8, the switch 13A of the positive direction drive source unit 2A is controlled to be repeatedly turned on and off at a predetermined cycle. As a result, the element 11A of the positive direction drive source unit 2A expands in the longitudinal direction when the switch 13A is “ON”, and the top part contacts the movable unit 3 to drive the movable unit 3 in the positive direction. When the switch 13 is turned “OFF”, the extension is released and the original length is returned. Thereby, the movable part 3 moves in the forward direction.

  On the other hand, when the movable unit 3 is driven in the reverse direction in the drive device 1, the switch 13A of the forward direction drive source unit 2A is turned off as shown in FIG. Thereby, all the elements 11 </ b> A of the positive direction drive source unit 2 </ b> A are in a state in which the tops are separated from the movable unit 3.

  On the other hand, as shown in FIG. 8, the switch 13B of the reverse direction drive source unit 2B is controlled to be repeatedly turned on and off at a predetermined cycle. As a result, the element 11B of the reverse direction drive source section 2B expands in the longitudinal direction when the switch 13B is turned “on”, and the top portion contacts the movable section 3 to drive the movable section 3 in the reverse direction. When the switch 13 is turned “OFF”, the extension is released and the original length is returned. Thereby, the movable part 3 moves in the reverse direction.

  Here, the moving speed of the movable part 3 is increased or decreased by adjusting the cycle in which the switch 13A of the forward direction drive source part 2A or the switch 13B of the reverse direction drive source part 2B is repeatedly turned on and off. More specifically, when the moving speed of the movable part 3 is increased, the ON / OFF cycle of the switch 13A of the forward direction drive source part 2A to be turned on / off or the switch 13B of the reverse direction drive source part 2B is shortened. To do. When the moving speed of the movable part 3 is slowed, the cycle is lengthened.

Further, the moving speed of the movable portion 3 can be increased or decreased by adjusting the voltage of the forward driving power source 6A or the backward driving power source 6B. More specifically, when the moving speed of the movable part 3 is increased, the voltage of the forward driving power supply 6A or the reverse driving power supply 6B that is turned on / off is increased, and the moving speed of the movable part 3 is decreased. If so, lower the voltage.
In addition, the drive device of this Embodiment 1 and the drive device of each following embodiment can be used as a positioning device.

<Embodiment 2>
Next, a second embodiment of the present invention will be described with reference to FIG. The second embodiment is a modification of the first embodiment. Hereinafter, only parts different from the first embodiment will be described, and description of the same parts will be omitted.

As shown in FIG. 9, in the second embodiment, the forward direction drive source unit 2 </ b> A and the reverse direction drive source unit 2 </ b> B are one straight line parallel to the drive direction of the movable unit 3 (left and right direction in FIG. 9). The drive source unit 2G is arranged so as to be lined up.
The control of the control unit 7 when the movable unit 3 is driven by the drive source unit 2G is the same as in the first embodiment.

  As described above, even when the forward direction drive source unit 2A and the reverse direction drive source unit 2B are arranged on a single straight line parallel to the drive direction of the movable unit 3, By the same control, the movable part 3 can be driven back and forth in a predetermined direction.

<Embodiment 3>
Next, Embodiment 3 of the present invention will be described with reference to FIG. The third embodiment is a modification of the first embodiment. Hereinafter, only parts different from the first embodiment will be described, and description of the same parts will be omitted.

  As shown in FIG. 10, in the third embodiment, the forward direction drive source unit 2C and the reverse direction drive source unit 2D are provided on both sides of each element 11 in a direction perpendicular to the direction in which the elements 11 are arranged in a row. Electrodes 12 are disposed, and insulators 15 are disposed on both sides in the direction in which the respective elements 11 are arranged in the row. One electrode 12 of the electrodes 12 on both sides of each element 11 is connected via a switch 13A or 13B to the positive terminal of the forward drive power source 6A or the reverse drive source unit 6B whose negative electrode is grounded. The other electrode 12 is grounded.

  Then, one of the electrodes 12 on both sides of each element 11 (for example, the electrode 12 connected to the positive terminal of the forward drive power source 6A or the reverse drive source unit 6B) is springed toward the element 11. The other electrode 12 is fixed to a base portion 14 (not shown).

  Thus, in the present embodiment, each element 11, the electrodes 12 on both sides thereof, the base 14 and the spring 17 constitute one actuator.

  The forward direction drive source unit 2C and the reverse direction drive source unit 2D having the above-described configuration are arranged in the same manner as in the first or second embodiment, and the forward direction drive source unit 2C and the reverse direction are the same as in the first embodiment. The movable part 3 can be driven by controlling the direction drive source part 2D.

  In this manner, at least one electrode 12 of the pair of electrodes 12 arranged to face each other with the element 11 interposed therebetween is biased toward the element 11 because the element 11 is applied by applying and removing the electric field. This is because the electrode 12 disposed so as to be in close contact with the element 11 can be more reliably prevented from being separated from the element 11 even when deformed. Thereby, the operation of the drive device can be stabilized.

  In the example of FIG. 10 as well, each electrode 12 may have any potential as long as there is a predetermined potential difference between the electrodes 12 that are opposed to each other with the element 11 therebetween. This is the same as the first embodiment.

<Embodiment 4>
Next, a fourth embodiment of the present invention will be described with reference to FIG. 11 and FIG. The fourth embodiment is a modification of the first embodiment. Hereinafter, only parts different from the first embodiment will be described, and description of the same parts will be omitted.

As shown in FIG. 11, in the fourth embodiment, the drive source section 2H includes a group of elements 11A that drive the movable section 3 in the forward direction, and a group of elements 11B that drive the movable section 3 in the reverse direction. Including both.
The elements 11A of the group that drives the movable part 3 in the forward direction are arranged such that the longitudinal direction is inclined in the positive direction from the direction perpendicular to the drive direction of the movable part 3 and obliquely intersects the drive direction. . Further, the elements 11B of the group that drives the movable part 3 in the reverse direction are arranged so that the longitudinal direction is inclined in the reverse direction from the direction perpendicular to the drive direction of the movable part 3 and obliquely intersects the drive direction. ing.

  The two groups of elements 11 </ b> A and 11 </ b> B are provided so as to be alternately arranged in a line in a direction parallel to the driving direction of the movable portion 3. Insulating plates 15A are arranged on both sides of the element 11A in the row direction. Further, electrodes 12A are arranged on both sides of the element 11A in the direction perpendicular to the direction of the row. One electrode 12A of the electrodes 12A arranged on both sides is connected via a switch 13A to a positive terminal of a positive direction driving power supply 6A whose negative electrode is grounded. The other electrode 12A is grounded.

  On the other hand, insulating plates 15B are disposed on both sides of the element 11B in the row direction. Further, electrodes 12B are disposed on both sides of the element 11B in the direction perpendicular to the row direction. One electrode 12B of the electrodes 12B arranged on both sides is connected via a switch 13B to a positive terminal of a reverse drive power supply 6B whose negative electrode is grounded. The other electrode 12B is grounded. When the two switches 13A and 13B are “off”, no electric field is applied to any of the elements 11A and 11B, and the tops of the elements 11A and 11B are both separated from the movable part 3. The elements 11A and 11B and the electrodes 12A and 12B are provided on one surface of one plate-like base portion 14C.

  When the switch 13A provided in the connection line connecting the positive terminal of the positive direction driving power source 6A and the electrode 12A is turned “ON”, an electric field is applied to the element 11A, and the element 11A expands in the longitudinal direction. The top part of 11A contacts the movable part 3, and the movable part 3 is driven in the forward direction. On the other hand, when the switch 13B provided in the connection line connecting the positive terminal of the reverse drive power source 6B and the electrode 12B is turned “ON”, an electric field is applied to the element 11B, and the element 11B expands in the longitudinal direction. The top of the element 11B comes into contact with the movable part 3, and the movable part 3 is driven in the reverse direction.

Next, the operation of the apparatus of the present embodiment having the above configuration will be described.
When the movable part 3 is driven in the forward direction, as shown in FIG. 12, the switch 13B provided between the positive terminal of the reverse direction driving power source 6B and the electrode plate 12B is turned “off”, As shown in FIG. 8, on / off of the switch 13A provided between the positive terminal of the positive direction driving power source 6A and the electrode plate 12A is controlled to be repeated at a predetermined cycle.

  On the other hand, when the movable part 3 is driven in the reverse direction, the switch 13A provided between the positive terminal of the positive direction drive power supply 6A and the electrode plate 12A is turned off, while the reverse direction drive power supply As shown in FIG. 8, on / off of the switch 13B provided between the positive terminal of 6B and the electrode plate 12B is controlled to repeat at a predetermined cycle.

  As described above, in the present invention, the drive source unit 2H is alternately provided with the elements 11A for driving the movable part 3 in the forward direction and the elements 11B for driving the movable part 3 in the reverse direction so as to be arranged in a line. Even in this configuration, the movable part 3 can be driven back and forth in a predetermined direction by the same control as in the first embodiment.

  Also in this embodiment, as long as a predetermined potential difference exists between the electrodes 12A and 12B that are arranged to face each other with the elements 11A and 11B interposed therebetween, what kind of potential the electrodes 12A and 12B are at. It is the same as in the first embodiment.

<Embodiment 5>
Next, a fifth embodiment of the present invention will be described with reference to FIGS. The fifth embodiment is a modification of the first embodiment. Hereinafter, only parts different from the first embodiment will be described, and description of the same parts will be omitted.

As shown in FIG. 13, in the fifth embodiment, the drive source unit reverses the positive direction drive source unit 2 </ b> E that drives the movable unit 3 in the forward direction and the movable unit 3 in the same manner as in the first embodiment. And a reverse drive source unit 2F for driving in the direction.
In the forward direction drive source unit 2E and the reverse direction drive source unit 2F, the element 11A or 11B is arranged on the electrode 12C or 12D instead of the bases 14A and 14B in the same manner as in the first and second embodiments. The direction is provided so as to be oblique to the driving direction.

  The electrode 12C of the positive direction drive source unit 2E is connected via a switch 13A to a positive terminal of a positive direction drive power supply 6A whose negative electrode is grounded. The electrode 12D of the reverse drive source unit 2F is connected via a switch 13B to the positive terminal of the reverse drive power supply 6B whose ground is negative.

  In each of the forward direction drive source unit 2E and the reverse direction drive source unit 2F, the elements 11A and 11B are arranged in parallel to each other so as to form a row in a direction parallel to the drive direction of the movable unit 3. Insulating plates 15A or 15B are disposed on both sides of the respective elements 11A and 11B in the row direction. Although not shown, insulating plates are also provided on both sides of each element 11A, 11B in the direction perpendicular to the direction of the row. A grounded electrode 12E or 12F is placed on the top of each of the elements 11A and 11B.

  Next, with reference to FIG. 14 and FIG. 15, the operation principle of the actuator of the present embodiment configured from ER gel will be described. FIG. 14 is a front view of an actuator model using an ER gel as an element, showing a state in which an electric field is applied to the ER gel. FIG. 15 is a front view of an actuator model using an ER gel as an element, showing a state where an electric field is not applied to the ER gel.

As shown in FIG. 14, in the element 11 formed by forming an ER gel in which ER particles 21 are dispersed into a prism shape, both sides in one width direction are sandwiched between a pair of insulating plates 15. Although not shown, both sides of the other width direction of the element 11 are sandwiched between a pair of insulating plates.
The element 11 and each insulating plate are fixed on one plate-like electrode 12, and the other electrode 12 is placed on the element 11. With this configuration, when an electric field is applied in the longitudinal direction of the element 11, the ER particles 21 are polarized in the direction of the electric field. The polarized ER particles 21 attract each other in the polarized direction (electric field direction). When the ER particles 21 attract each other in the direction of the electric field, the element 11 made of ER gel in which the ER particles 21 are dispersed contracts in the longitudinal direction.
On the other hand, as shown in FIG. 15, when the applied electric field is removed, the length of the element 11 returns to the original length.

When the switch 13A or 13B of the forward drive source unit 2E and the reverse drive source unit 2F is turned “ON” according to the operation principle described above, an electric field is applied to the elements 11A and 11B in the longitudinal direction and contracts in the longitudinal direction. To do. At this time, the top portions of the respective elements 11 </ b> A and 11 </ b> B are separated from the movable portion 3.
On the other hand, when the switch 13A or 13B of the forward direction drive source unit 2E and the reverse direction drive source unit 2F is turned off, the lengths of the elements 11A and 11B in the longitudinal direction return to the original lengths. At this time, the top portions of the respective elements 11 </ b> A and 11 </ b> B are in contact with the movable portion 3.

Next, the operation of the apparatus of the present embodiment having the above configuration will be described.
When the movable unit 3 is driven in the forward direction, the switch 13B provided between the reverse drive power source 6B and the electrode plate 12D is turned “ON”, and the top of the element 11B of the reverse drive source unit 2F is turned on. On the other hand, the switch 13A provided between the positive driving power supply 6A and the electrode plate 12C is controlled to be turned on and off at a predetermined cycle as shown in FIG.
Further, when the movable part 3 is driven in the reverse direction, the switch 13A provided between the positive direction driving power source 6A and the electrode plate 12C is turned “ON”, and the element 11A of the positive direction driving source part 2E is turned on. While the top portion is separated from the movable portion 3, the switch 13B provided between the positive terminal of the reverse drive power source 6B and the electrode plate 12D is repeatedly turned on and off at a predetermined cycle as shown in FIG. To control.

  As described above, in the present invention, even when the electric field is applied in the longitudinal direction of the elements 11A and 11B, the force when the element 11 contracted in the longitudinal direction by the application of the electric field returns to the original length. Utilizing this, the movable part 3 can be driven back and forth in a predetermined direction.

  In the present embodiment, as long as a predetermined potential difference exists between the pair of electrodes 12C and 12E or 12D and 12F that are opposed to each other with the elements 11A and 11B sandwiched therebetween, how each electrode is changed. It is the same as in Embodiment 1 that the potential may be set to a different potential. The above is the same in the case of FIG. 14 and FIG.

<Embodiment 6>
Next, a sixth embodiment of the present invention will be described with reference to FIGS. The sixth embodiment is a modification of the first embodiment, and only the parts different from the first embodiment will be described below, and the description of the same parts will be omitted.

  As shown in FIG. 16, in the sixth embodiment, the drive source 2I includes a plurality of elements 11C that are erected vertically on one surface of the plate-like base portion 14D. Each element 11 </ b> C is formed by forming ER gel into a prismatic shape having a rectangular side surface, and is arranged in a row in a direction parallel to the driving direction of the movable portion 3.

  Insulating plates 15C are arranged on both sides of each element 11C in the row direction. Further, electrodes 12G are arranged on both sides of each element 11C in the direction perpendicular to the direction of the row. One of the electrodes 12G arranged on both sides is connected to the positive terminal of the driving power supply 6C whose negative electrode is grounded via any one of the switches 13C, 13D, and 13E. The other of the electrodes 12G is grounded. All the elements 11D, the electrodes 12G, and the insulating plate 15C are provided on one surface of one plate-like base portion 14D.

  As illustrated in FIGS. 17 and 18, the control unit 7 performs control so that the switches 13 </ b> C to 13 </ b> E are sequentially turned on / off with a predetermined period and a predetermined phase difference. Note that, as described above, in the present embodiment, the power supply unit is configured only from the driving power supply 6C.

Next, the operation of the apparatus of the present embodiment having the above configuration will be described.
When the movable unit 3 is driven in the forward direction, as shown in FIG. 17, control is performed so that the repetition of ON / OFF is sequentially started with a predetermined phase difference from the switch corresponding to the rear element 11C in the forward direction. I do. According to the illustrated example, the switches 13 </ b> C, 13 </ b> D, and 13 </ b> E perform control so as to start repetition of on / off in this order. By controlling in this way, it is repeated that the top part sequentially contacts the movable part 3 with a predetermined time difference from the rear element 11C in the positive direction. Thereby, the movable part 3 is driven in the forward direction.

  Further, when the movable portion 3 is driven in the reverse direction, as shown in FIG. 18, the repetition of ON / OFF is sequentially started with a predetermined phase difference from the switch corresponding to the rear element 11C in the reverse direction. To control. According to the illustrated example, the switches 13 </ b> C, 13 </ b> D, and 13 </ b> E perform control so as to start repetition of on / off in the reverse order. By controlling in this way, it is repeated that the top part sequentially contacts the movable part 3 with a predetermined time difference from the rear element 11C in the reverse direction. Thereby, the movable part 3 is driven in the reverse direction.

  As described above, even when the element 11 is arranged so that the longitudinal direction of the element 11C is perpendicular to the driving direction of the movable portion 3, an electric field is applied to each element 11C with a predetermined period and a predetermined phase difference. By applying intermittently, the movable part 3 can be driven back and forth in a predetermined direction.

  In the present embodiment as well, it is possible that each electrode may have any potential as long as a predetermined potential difference exists between the pair of electrodes 12G arranged to face each other with the element 11C interposed therebetween. The same as in the first embodiment.

<Embodiment 7>
Next, a seventh embodiment of the present invention will be described with reference to FIGS. FIG. 19 is a perspective view showing a schematic configuration of the drive apparatus according to Embodiment 7 of the present invention. FIG. 20 is a side view of the drive device, showing details of the drive source section of the drive device. FIG. 21 is a circuit diagram showing details of a control system and a power system of the drive device. 22 and 23 are graphs showing the control operation of turning on / off the switch by the control unit.

  As shown in FIG. 19, the drive device 1A includes a drive source unit 2J including a plurality of actuators, and a round shaft-shaped movable unit 3A that is linearly driven so as to advance and retract in a predetermined direction by being rotated by the drive source unit 2J. And a linear encoder 4 that outputs a signal corresponding to the position of the movable portion 3A, a support portion 5A that supports the linear encoder 4 and supports the movable portion 3A so that the movable portion 3A can rotate and advance and retreat in the axial direction. A power supply unit 6D that supplies DC power to the source unit 2J and a control unit 7 that controls the drive source unit 2J and the power supply unit 6D are provided.

  Here, the movable portion 3A has a male screw 25 formed on the peripheral surface. The support portion 5A has a screw hole 26 in which a female screw (not shown) that is screwed with the male screw 25 of the movable portion 3A is formed. When the movable portion 3A rotates around the axis, the support portion 5A shown in FIG. Move to the right or left. For convenience of explanation, the right direction in FIG. 19 is defined as the forward direction, and the left direction is defined as the reverse direction. In FIG. 20, when the movable portion 3A rotates clockwise, the movable portion 3A moves in the positive direction and counterclockwise. The following description will be given on the assumption that it moves in the reverse direction when it rotates.

  As shown in FIGS. 20 and 21, the drive source unit 2J includes a plurality of (four in the illustrated example) elements disposed at a predetermined angular pitch (90 ° pitch in the illustrated example) around the movable unit 3A. 11D is included. The element 11D is formed by molding ER gel into a prismatic shape having a rectangular side surface, and electrodes 12I for applying an electric field are arranged on both sides in one width direction. Although not shown, insulating plates are arranged on both sides in the other width direction (direction perpendicular to the paper surface) of each element 11D. Each element 11D and the electrodes 12I on both sides thereof are erected on a plate-like base portion 14E so that the longitudinal direction of the element 11D is parallel to the radial direction every 90 degrees of the movable portion 3A. Thus, each set of the element 11D, the electrodes 12I and insulating plates on both sides thereof, and the base portion 14E constitutes a plurality of actuators 17A, 17B, 17C and 17D.

  One of the electrodes 12I on both sides of each element 11D of each of the actuators 17A to 17D is either one of the power supplies 6F to 6I whose negative electrode is grounded via any of the switches 13F to 13I shown in FIG. Each is connected to a positive terminal. The other of the electrodes 12I on both sides of each element 11D is grounded. Thus, in this Embodiment, the power supplies 6F-6I comprise the power supply part 6J.

  When any of the switches 13F to 13I is turned “ON”, an electric field is applied to any one of the elements 11D of the actuators 17A to 17D, and the element 11D of the actuator expands in the longitudinal direction, and the top thereof is a movable part. Contact 3A. On the other hand, when the electric field is removed, the longitudinal extension of the element 11D of the actuator is released, and the top portion is separated from the movable portion 3A. As shown in FIGS. 22 and 23, the control unit 7 performs control so that the switches 13F to 13I are sequentially turned on and off with a predetermined period and a predetermined phase difference.

  Hereinafter, an electric field is applied to the element 11D of the actuator 17A when the switch 13F is turned on, an electric field is applied to the element 11D of the actuator 17B when the switch 13G is turned on, and an actuator 17C when the switch 13H is turned on. The operation of the driving device according to the present embodiment will be described on the assumption that wiring is provided so that an electric field is applied to the element 11D of the actuator 17D and the electric field is applied to the element 11D of the actuator 17D when the switch 13I is turned on. To do.

  When the movable portion 3A is driven in the forward direction, as shown in FIG. 22, the switches 13F, 13G, 13H, and 13I are controlled so as to sequentially start ON / OFF repeatedly with a predetermined phase difference in this order. . By controlling in this way, the tops of the actuators 17A to 17D sequentially contact the peripheral surface of the movable portion 3A in the clockwise direction in FIG. As a result, the movable portion 3 rotates clockwise in FIG. 20, and as a result, is driven in the positive direction.

  On the other hand, when the movable portion 3A is driven in the reverse direction, as shown in FIG. 23, the switches 13F, 13G, 13H, and 13I are repeatedly turned on and off sequentially with a predetermined phase difference in the reverse order. Control to start. By controlling in this way, the tops of the actuators 17A to 17D sequentially come into contact with the peripheral surface of the movable part 3A in the counterclockwise direction in FIG. Thereby, the movable part 3 rotates counterclockwise in FIG. 20, and as a result, is driven in the reverse direction. Further, the rotational speed of the movable part 3 can be adjusted by changing the cycle of turning on / off the switches 13F, 13G, 13H, and 13I or changing the voltage values of the power supplies 6F to 6I. It is.

  As described above, the element 11D made of ER gel can be driven to rotate the round shaft-shaped movable part, and the movable part can be driven in the axial direction by the rotation.

  In the present embodiment as well, it is possible that each electrode may have any potential as long as a predetermined potential difference exists between the pair of electrodes 12I arranged to face each other with the element 11D interposed therebetween. The same as in the first embodiment.

In each of the above embodiments, the magnitude of the electric field applied to the ER gel is desirably 3 KV / mm or less in consideration of the difficulty of insulation in an actual machine. By applying such an electric field, contraction of the ER gel occurs in the order of μ, and the driving operation as disclosed in the above embodiments can be stably realized.
As mentioned above, although this invention was demonstrated by embodiment, this invention is not limited to these, A various change is possible. For example, in each of the above-described embodiments, only the driving in one axis direction is performed, but a two-axis or three-axis driving device is realized by combining two or more driving devices in any of the above-described embodiments. Is also possible.
The actuator element is not limited to the ER gel, and the same effect can be obtained by using a piezoelectric element. This is because the behavior of a piezoelectric element when an electric field is applied and when the electric field is removed is almost the same as that of an ER gel.

  However, in the piezoelectric element, since thermal expansion is larger than that of the ER gel, stricter temperature management is required. In this regard, temperature management can be simplified by using the ER gel as an actuator element.

  In addition, when the frequency for turning on / off the switch exceeds 100 Hz, the heat generated in the piezoelectric element increases and the risk of destruction of the element increases. Therefore, when using a piezoelectric element, a cooling means is required. On the other hand, when using ER gel, such a cooling means is unnecessary until a higher frequency is reached.

  In addition, since the piezoelectric effect decreases by 0.2% every time the temperature decreases, the piezoelectric effect decreases by about 30% in the extremely low temperature range close to absolute zero compared to the normal temperature. On the other hand, the efficiency of the ER gel does not decrease even in the extremely low temperature range close to absolute zero. Therefore, by using ER gel as an actuator element, it is possible to realize a drive device that operates even in a cryogenic environment.

  According to the drive device of the present invention, it is possible to realize a drive device with a large amount of displacement using an element with relatively small deformation such as ER gel.

It is a perspective view which shows schematic structure of the drive device which concerns on Embodiment 1 of this invention. It is the side view which looked at the apparatus of FIG. 1 from the side in which the drive source part was provided. It is the two views which looked at the normal direction drive source part and reverse direction drive source part of the drive source part from the side and the upper part, respectively. It is a front view of the model of the actuator which uses the ER gel as an element which shows the state where the electric field is not applied to ER gel of the apparatus. It is a front view of the model of the actuator which uses the ER gel as an element which shows the state where the electric field was applied to ER gel of the apparatus. FIG. 4 is a two-side view schematically showing a state of a drive source unit when a movable part of the apparatus of FIG. 3 is driven in a positive direction. It is a two-plane figure which shows typically the state of the drive source part when driving a movable part to a reverse direction. It is a graph which shows an example of the control which turns on / off the switch of a drive source part. It is the side view which looked at the drive device which concerns on Embodiment 2 of this invention from the side in which the drive source part was provided. It is a perspective view which shows schematic structure of the drive source part of the drive device which concerns on Embodiment 3 of this invention. It is the two views which looked at the forward direction drive source part and reverse direction drive source part of the drive source part of the drive device which concern on Embodiment 4 of this invention from the side and the upper direction, respectively. FIG. 12 is a two-view diagram illustrating an operation example of the apparatus of FIG. 11. It is a side view which shows schematic structure of the drive source part of the drive device which concerns on Embodiment 5 of this invention. It is a front view of the model of the actuator which uses the ER gel as an element which shows the state where the electric field is not applied to ER gel of the apparatus. It is a front view of the model of the actuator which uses the ER gel as an element which shows the state where the electric field was applied to ER gel of the apparatus. It is the side view which made the cross section a part which shows schematic structure of the drive device which concerns on Embodiment 6 of this invention. It is a graph which shows an example of the control which turns on / off the switch of the drive source part of the apparatus. It is a graph which shows another example of the control which turns on / off the switch of the drive source part of the apparatus. It is a perspective view which shows schematic structure of the drive device which concerns on Embodiment 7 of this invention. It is a side view which shows schematic structure of the drive source part of the apparatus. It is a block diagram of the control system of the apparatus. It is a graph which shows an example of the control which turns on / off the switch of the drive source part of the apparatus. It is a graph which shows another example of the control which turns on / off the switch of the drive source part of the apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Drive device 2 Drive source part 3 Movable part 6 Power supply part 7 Control part 11 Element 12 Electrode 13 Switch 14 Base

Claims (13)

A driving device using a plurality of elements that contracts in a direction parallel to the electric field and extends in a direction different from the direction parallel to the electric field when an electric field is applied,
A movable part supported so as to be able to advance and retreat in a predetermined direction and moved by deformation of the element by applying and removing the electric field;
An electric field generating means for generating an electric field applied to the element;
Control means for controlling the electric field generating means to intermittently generate the electric field at a predetermined period;
A drive device comprising:   The driving device according to claim 1, wherein the control unit adjusts at least one of the intensity of the electric field and a period of generating the electric field according to a moving speed of the movable part.   The element is divided into a group in which a component in the predetermined direction of a force exerted on the movable part by the deformation is positive and a group in which a component in the predetermined direction of the force is negative. The drive device described.   The driving device according to claim 1, wherein the elements are arranged in parallel to each other and in the predetermined direction in each group.   The driving device according to claim 4, wherein each group of the elements is arranged in parallel to each other.   The driving device according to claim 4, wherein each group of the elements is arranged on one straight line parallel to the predetermined direction.   The driving device according to claim 1, wherein the movable portion is driven by extension of the element in a direction different from a direction parallel to the electric field when the electric field is applied to the element.   2. The movable portion is driven by deformation of the element when the element contracted in a direction parallel to the electric field by application of the electric field returns to the original state by removal of the applied electric field. The drive apparatus in any one of -6. The electric field generating means includes a pair of electrodes disposed so as to be substantially parallel to each other with the element interposed therebetween,
9. The driving device according to claim 1, wherein at least one of the pair of electrodes is provided so as to be able to move following the deformation of the element by applying and removing the electric field.   The drive device according to claim 9, wherein the movable electrode is biased so as to move following the deformation of the element.   The drive device according to claim 1, wherein the element is made of a piezoelectric body.   The drive device according to any one of claims 1 to 10, wherein the element is composed of an ER gel obtained by gelling an ER fluid obtained by dispersing fine particles that are electrically polarized under an electric field. The electric field generating means includes individual electric field generating means for generating an electric field individually applied to each of the plurality of elements;
The driving device according to any one of claims 1 to 12, wherein the control unit controls the individual electric field generation unit to intermittently generate the electric field at a predetermined cycle and a predetermined phase difference.

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