JP5375487B2 - Actuator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an actuator capable of linearly moving a movable body correctly in assumed direction, even with a simple structure. <P>SOLUTION: The actuator includes actuator elements 12 and 12 wherein two sheets formed of electrostrictive material are laminated together and bent in bellows, and a movable body 11 supported by the plurality of actuator elements 12 and 12. In the actuator elements 12 and 12, electrode parts 13 and 13 are intermittently formed on both surfaces of one sheet being laminated. In the bellows form, a tilted part where the electrode parts 13 and 13 are formed and a tilted part where no electrode is formed are presented alternately. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an actuator capable of minutely feeding a movable body sandwiched by a feeding member using an electrostrictive material in a substantially linear shape.

  Medical devices, industrial robots, and the like often require precise movements. Therefore, there is an urgent need to develop an actuator that is small, lightweight, and flexible. For example, a polymer actuator using an ion conductive polymer is composed of an ion conductive polymer film and a metal electrode joined to the surface in an insulated state. By applying a voltage between the metal electrodes, Deformation such as bending is caused in the ion conductive polymer film.

  There has also been proposed an operation mechanism that converts a deformation operation such as bending into a linear motion, a rotational motion, or the like by combining the above-described actuators. For example, Patent Literature 1 discloses an actuator system that can linearly move a flat plate in a certain direction. FIG. 1 is a schematic diagram showing a configuration of a conventional actuator system.

  In FIG. 1, a conventional actuator system 1 has a flat plate 2 to be moved on a plurality of polymer actuator elements 4a, 4b, 4c, 4d. A claw portion 3 is provided on the side of the flat plate 2 facing the polymer actuator elements 4a, 4b, 4c and 4d.

  Electrode films are provided on both surfaces of the polymer actuator elements 4a, 4b, 4c, and 4d. When a voltage is applied to the polymer actuator elements 4a, 4b, 4c, and 4d by the power sources E1 and E2, the voltage depends on the polarity of the voltage. Thus, the polymer actuator elements 4a, 4b, 4c, and 4d are curved in the left-right direction in FIG. By connecting the power supplies E1 and E2 to the polymer actuator elements 4a, 4c, 4b, and 4d every other power supply and reversing the polarities, the polymer actuators are applied according to the polarity of the applied voltage. When the elements 4a and 4c are bent in the right (left) direction, the polymer actuator elements 4b and 4d are bent in the left (right) direction.

  When the polymer actuator elements 4a, 4b, 4c, and 4d are bent in the right direction, the curved portion is caught by the claw portion 3 of the flat plate 2 and the flat plate 2 moves in the right direction. On the other hand, when the polymer actuator elements 4a, 4b, 4c, and 4d are bent in the left direction, the curved portion is not caught by the claw portion 3 of the flat plate 2, and the flat plate 2 does not move. Therefore, the flat plate 2 can be smoothly moved rightward by bending the polymer actuator elements 4a and 4c and the polymer actuator elements 4b and 4d alternately to the left and right.

JP 2007-151249 A

  However, in the actuator system 1 described in Patent Literature 1, it is necessary to perform processing for promoting the movement of the claw portion 3 and the like on the flat plate 2 that is the movement target, which causes an increase in cost. In addition, there is a problem that the polymer actuator elements 4a, 4b, 4c, and 4d need to be arranged in the vertical direction, and the structure of the entire apparatus becomes complicated.

  The flat plate 2 is placed on the polymer actuator elements 4a, 4b, 4c, and 4d, and can move linearly, but it is difficult to control the moving direction. That is, when an external force is applied, the flat plate 2 is easily displaced, and it is difficult to move the straight line correctly.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an actuator that can be linearly moved in a direction assuming a movable body even with a simple structure.

  In order to achieve the above object, an actuator according to the first invention is supported by an actuator element in which two sheets made of an electrostrictive material are laminated and bent into a bellows shape, and a plurality of top portions of the plurality of actuator elements. The actuator element has an electrode film intermittently formed on both front and back surfaces of one of the sheets that are bonded together, and the electrode film is formed in a bellows shape. The inclined portions that are formed and the inclined portions that are not formed are alternately arranged.

  In the first invention, the movable body is supported by a plurality of apexes of the actuator element in which two sheets made of an electrostrictive material are bonded and bent into a bellows shape. In the actuator element, electrode films are intermittently formed on both the front and back surfaces of one of the laminated sheets, and in the bellows shape, the inclined portions where the electrode films are formed and the inclined portions where the electrode films are not formed are alternately arranged. It is. When a voltage is applied to the electrode film, the sheet formed of the electrostrictive material is stretched and cured in the inclined portion where the electrode film is formed, and before the voltage is applied in the inclined portion where the electrode film is not formed. Maintained at the length of Therefore, the bellows shape that is in contact with the movable body is deformed to the right (left) direction when the electrode film is formed on, for example, an upward slope (downward right), and the top of the bellows shape is on the right. Move in the (left) direction. Therefore, the movable body in contact with the top can be linearly moved.

  The actuator according to a second aspect of the invention is characterized in that, in the first aspect, the actuator element has a plurality of apexes positioned on the side opposite to the side in contact with the movable body fixed to a fixed member. To do.

  In the second invention, the actuator element has a plurality of apexes located on the side opposite to the side in contact with the movable body fixed to the fixed member. When a voltage is applied to the electrode film, the sheet formed of the electrostrictive material is stretched and cured in the inclined portion where the electrode film is formed, and before the voltage is applied in the inclined portion where the electrode film is not formed. Maintained at the length of Since the tops located on the side opposite to the side in contact with the movable body are fixed to the fixed member, a plurality of positions located on the side in contact with the movable body due to deformation of the bellows shape in contact with the movable body The top of the movable body moves, and the movable body in contact with the top can be moved linearly.

  An actuator according to a third invention is characterized in that, in the first or second invention, the movable body is plate-shaped, and the actuator elements are arranged at positions facing each other across the movable body. Actuator.

  In the third aspect of the invention, the plate-shaped movable body can be surely linearly moved in a certain direction by sandwiching the plate-shaped movable body between the actuator elements arranged at positions facing each other.

  According to a fourth aspect of the present invention, there is provided the actuator according to the third aspect, further comprising polarity switching means for switching a polarity of a voltage applied to the electrode films facing each other with the movable body interposed therebetween.

  In the fourth invention, by switching the polarity of the voltage applied to the electrode films facing each other across the movable body, the movable body can be moved when both have the same polarity, and both have different polarities. It is possible to configure an actuator that can hold a movable body.

  The actuator according to a fifth aspect is the actuator according to the first or second aspect, wherein the actuator element is disposed on the fixed member at a position facing each other with the fixed member interposed therebetween, and the movable body is The actuator element is supported by a plurality of top portions located on the side opposite to the side in contact with the fixing member.

  In the fifth invention, the actuator element is arranged on the fixing member at a position facing each other across the fixing member. The movable body is supported by a plurality of top portions of the actuator element located on the side opposite to the side in contact with the fixed member. Thereby, even if it is a movable body of the shape which pinches | interposes an actuator element from both sides, it becomes possible to move linearly reliably.

  An actuator according to a sixth aspect of the present invention is characterized in that, in any one of the first to fifth aspects, the electrode film is formed of a metal material.

  In the sixth invention, it is possible to provide a relatively inexpensive actuator by forming the electrode film from a metal material.

  An actuator according to a seventh invention is characterized in that, in any one of the first to fifth inventions, the electrode film is formed of a conductive polymer material.

  In the seventh invention, by forming the electrode film from a conductive polymer material, the electrode film can be easily adhered to a sheet formed of an electrostrictive material, and the electrode film is effectively peeled off due to deformation of the actuator element. Can be suppressed.

  With the above configuration, the electrode films are intermittently formed on both surfaces of one of the laminated sheets, and in the bellows shape, the inclined portions where the electrode films are formed and the inclined portions where the electrode films are not formed are alternately arranged. It is. When a voltage is applied to the electrode film, the sheet formed of the electrostrictive material is stretched and cured in the inclined portion where the electrode film is formed, and before the voltage is applied in the inclined portion where the electrode film is not formed. Maintained at the length of Therefore, the bellows shape that is in contact with the movable body is deformed to the right (left) direction when the electrode film is formed on, for example, an upward slope (downward right), and the top of the bellows shape is on the right. Move in the (left) direction. Therefore, the movable body in contact with the top can be linearly moved.

It is a schematic diagram which shows the structure of the conventional actuator system. It is sectional drawing which shows typically the structure of the actuator which concerns on Embodiment 1 of this invention. It is sectional drawing which shows typically the manufacturing process of the actuator element of the actuator which concerns on Embodiment 1 of this invention. It is explanatory drawing of the principle of operation of a unimorph type actuator. It is a schematic diagram for demonstrating operation | movement of the actuator which concerns on Embodiment 1 of this invention. It is a schematic diagram for operation | movement description at the time of switching the polarity of the voltage to apply of the actuator which concerns on Embodiment 1 of this invention. It is sectional drawing which shows typically the structure of the actuator which concerns on Embodiment 2 of this invention. It is sectional drawing which shows typically the structure of the actuator which concerns on Embodiment 3 of this invention. It is a fragmentary sectional view showing typically the composition of the actuator concerning Embodiment 4 of the present invention. It is a fragmentary sectional view showing typically the composition of the actuator concerning Embodiment 5 of the present invention. It is sectional drawing which shows typically the attachment process of the actuator element in the case of providing the elastic member of the actuator which concerns on Embodiment 5 of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following embodiments, the case where the movable body is a plate-like member will be described. However, the movable body is not particularly limited to this, and may have a shape that can move according to the deformation of the actuator element. Anything is fine.

(Embodiment 1)
FIG. 2 is a cross-sectional view schematically showing the configuration of the actuator according to Embodiment 1 of the present invention. In the actuator 10 according to the first embodiment, a plate-like movable body 11 that can move in the arrow direction is sandwiched from above and below by a plurality of apexes of the actuator elements 12, 12. A plurality of top portions located on the side opposite to the side in contact with the movable body 11 are fixed to the fixing member 14. The actuator elements 12, 12 have a bellows shape, and every other inclined electrode portion (electrode film) 13, 13,... Is formed on the inclined portion. In other words, the electrode portion 13 is formed on an inclined portion that is inclined in the same direction (in FIG. 2, the inclined portion that is inclined downward in the right direction in the upper actuator element 12 and in the upward direction in the lower actuator element 12). , 13,... Are formed.

  FIG. 3 is a cross-sectional view schematically showing a manufacturing process of the actuator element 12 of the actuator 10 according to the first embodiment of the present invention. First, as shown in FIG. 3A, two electrostrictive sheets (sheets) 31 and 32 formed of a polymer electrostrictive material are prepared, and electrode portions 13 are provided on both front and back surfaces of one electrostrictive sheet 31. As a result, the electrode films 33 and 34 are formed at predetermined intervals.

  The polymer electrostrictive material forming the electrostrictive sheets 31 and 32 is not particularly limited as long as it is a polymer piezoelectric material having ferroelectricity. For example, PVDF (polyvinylidene fluoride), PVDF (polyvinylidene fluoride) -based copolymer PVDF-TrFE, or PVDF-based terpolymers, such as PVDF-TrFE-CFE, PVDF-TrFE-CTFE, PVDF-TrFE-CDFE, PVDF-TrFE-HFA, PVDF-TrFE-HFP, PVDF-TrFE-VC and the like are preferable. TrFE is trifluoroethylene, CFE is chlorofluoroethylene, CTFE is chlorotrifluoroethylene, CDFE is chlorodifluoroethylene, HFA is hexafluoroacetone, HFP is hexafluoropropylene, and VC is vinyl chloride. Respectively.

  Specifically, as the electrostrictive sheets 31 and 32, a sheet having a thickness of several μm to 100 μm is formed using the above-described polymer electrostrictive material. Then, Ni (nickel), Pt (platinum), Pt—Pd (platinum-palladium alloy), Al (aluminum), Au (gold), Au— are formed on both the front and back surfaces of one electrostrictive sheet 31 by vapor deposition or sputtering. A metal film of Pd (gold palladium alloy) or the like is formed as electrode films 33 and 34 at a predetermined interval of about 20 nm to 50 nm. After forming the electrode films 33 and 34, as shown in FIG. 3B, the electrostrictive sheets 31 and 32 are bonded together using an epoxy thermosetting adhesive, a UV curable adhesive, or the like.

  Thereafter, as shown in FIG. 3 (c), the two electrostrictive sheets 31 and 32 are folded together into a bellows shape, and electrode films 33 and 34 are formed on every other inclined portion of the bellows shape. In other words, the actuator element 12 formed in the inclined portion inclined in the same direction (inclined portion inclined in the upward direction in FIG. 3) is obtained. In FIG. 3 (c), the electrode films 33 and 34 are formed on the upwardly inclined portion, and are not formed on the downwardly inclined portion.

  By doing in this way, it can function as what is called a unimorph type actuator which formed electrode part 13 in every other inclined part of a bellows shape. FIG. 4 is an explanatory diagram of the operating principle of the unimorph actuator.

  In the example of FIG. 4, the electrode films 43 and 44 are formed on the front and back surfaces of one electrostrictive sheet 41 of the two electrostrictive sheets 41 and 42 made of the above-described polymer electrostrictive material. 41 and 42 are bonded together using an epoxy thermosetting adhesive, a UV curable adhesive, or the like. One end of the electrostrictive sheets 41 and 42 bonded together is fixed to the support member, and the other end is opened so that it can be deformed.

  When the electrode films 43 and 44 are connected to the power source 45 and a predetermined voltage is applied, the electrostrictive sheet 41 on which the electrode films 43 and 44 are formed contracts in the thickness direction, and the length thereof depends on the Poisson's ratio. Stretch. However, since the length of the bonded electrostrictive sheet 42 does not vary, the combined body of the electrostrictive sheets 41 and 42 is deformed so as to be bent in the arrow direction in FIG.

  In the first embodiment, the unimorph actuator that bends in accordance with the principle shown in FIG. 4 exists in every other inclined portion of the bellows shape of the actuator element 12, that is, exists in the inclined portion that is inclined in a certain direction. Then you can think. FIG. 5 is a schematic diagram for explaining the operation of the actuator 10 according to the first embodiment of the present invention.

  In FIG. 5, the movable body 11 is supported by a plurality of apexes located on the side in contact with the movable body 11 of the actuator element 12, and the plural apexes located on the side opposite to the side in contact with the movable body 11 are fixed members. 14 is fixed. In this state, when a voltage is applied to the electrode films 33 and 34, the upwardly inclined portion on which the electrode films 33 and 34 are formed functions as a unimorph actuator and bends to the right. On the other hand, since it does not curve in the downward sloping portion where the electrode films 33 and 34 are not formed, the top movement vector located on the side in contact with the movable body 11 is in the upper right direction. Therefore, the deformation of the actuator element 12 can move the movable body 11 to the right while pressing.

  Thereafter, when the application of the voltage to the electrode films 33 and 34 is stopped, the upwardly inclined portion where the electrode films 33 and 34 are formed does not function as a unimorph actuator and returns to the original shape. On the other hand, since the downward sloping portion where the electrode films 33 and 34 are not formed is not originally deformed, the top movement vector located on the side in contact with the movable body 11 is in the lower left direction. At this time, there is a movement vector component that moves the movable body 11 in the left direction, but the apex located on the side in contact with the movable body 11 has a length of an upwardly inclined portion shortened (original length). Therefore, the contact pressure with the movable body 11 is reduced, and the movable body 11 does not move leftward. Therefore, by repeatedly applying and stopping the voltage application to the electrode films 33 and 34, it is possible to configure an actuator that can move the movable body 11 in the right direction (arrow direction).

  In the example of FIG. 2, the movable body 11 is supported by the plurality of apexes of the actuator elements 12 and 12 from both the left and right sides. Therefore, the movable body 11 can be moved or held by switching the polarity of the applied voltage. Is also possible. FIG. 6 is a schematic diagram for explaining the operation of the actuator 10 according to Embodiment 1 of the present invention when the polarity of the voltage to be applied is switched.

  6A shows the case where the polarities of the voltages applied to the electrode films 62 and 63 facing each other with the movable body 11 in between are the same polarity on both sides of the movable body 11, and FIG. The case where the polarities of the voltages applied to the electrode films 62 and 63 facing each other across the body 11 are different on both sides of the movable body 11 is shown. The actuator element 61 schematically shows a state in which two electrostrictive sheets are bonded together, and the electrode films 62 and 63 are formed on both the front and back surfaces of one electrostrictive sheet, but in FIG. For convenience, it is shown on both front and back surfaces of the actuator element 61.

  As shown in FIG. 6 (a), when a voltage is applied so that the electrode film 62 opposed to the movable body 11 is a negative electrode and the electrode film 63 is a positive electrode, the slope in which the electrode films 62 and 63 are formed. The portion functions as a unimorph type actuator and bends in the right direction while pressing the movable body 11. Since the polarity of the applied voltage is the same on both sides of the movable body 11, an electric repulsive force is generated between the electrode films 62 and 62 or the electrode films 63 and 63 facing each other with the movable body 11 interposed therebetween. Thus, the movable body 11 can move smoothly along the deformation of the inclined portion on which the electrode films 62 and 63 are formed.

  On the other hand, as shown in FIG. 6 (b), in the upper actuator element 61, a voltage is applied so that the electrode film 62 is a positive electrode and the electrode film 63 is a negative electrode, while in the lower actuator element 61, the electrode film 62 is applied. When the voltage is applied so that the electrode film 63 becomes the positive electrode, the inclined portion on which the electrode films 62 and 63 are formed functions as a unimorph type actuator and curves to the right while pressing the movable body 11. To do. However, since the polarity of the applied voltage is different on both sides of the movable body 11, an electric attractive force is generated between the electrode films 62 and 62 or between the electrode films 63 and 63 across the movable body 11. The movable body 11 moves even when the inclined portions where the electrode films 62 and 63 are formed are curved even when the movable body 11 is deformed because the movable body 11 is attracted to each other by the electric attractive force. Cannot be held by the actuator element 61.

  The polarity of the voltage to be applied may be fixed by the power supply, or the polarity of the voltage to be applied may be switched by providing a plurality of power supplies having different polarities and switching the connection as necessary. The polarity switching means for switching the polarity of the voltage to be applied is not particularly limited. For example, a high voltage relay may be used.

  As described above, according to the first embodiment, the electrode films 33 and 34 are formed on every other inclined portion of the bellows shape, that is, on the inclined portion inclined in the same direction. The inclined portions where the electrode films 33 and 34 are formed and the inclined portions where the electrode films 33 and 34 are not formed are alternately arranged. When a voltage is applied to the electrode films 33 and 34, the electrostrictive sheet 31 is stretched and cured in the inclined portion where the electrode films 33 and 34 are formed, and the inclined portion where the electrode films 33 and 34 are not formed is The length before the voltage is applied is maintained. Therefore, the bellows shape that is in contact with the movable body 11 is deformed in the right (left) direction when the electrode films 33 and 34 are formed on the inclined portion that rises to the right (lower right), for example, and the bellows shape. Moves to the right (left). Therefore, the movable body 11 in contact with the top can be moved linearly.

  In the first embodiment described above, the electrode films 33 and 34 are formed on both the front and back surfaces of the electrostrictive sheet 31, and then bonded to the electrostrictive sheet 32 on which no electrode film is formed. It is not limited to forming a film, and it goes without saying that electrostrictive sheets having electrode films formed on one surface may be bonded together.

(Embodiment 2)
FIG. 7 is a cross-sectional view schematically showing the configuration of the actuator 10 according to Embodiment 2 of the present invention. Unlike the first embodiment, the actuator elements 12 and 12 are arranged at positions facing each other across the fixing portion 141 so as to sandwich the plate-like fixing portion 141 formed on the fixing member 14. The top of the actuator element 12 that is located on the side opposite to the side that contacts the movable body 11 is fixed to the fixed portion 141, and the top that is located on the side opposite to the side that contacts the fixed portion 141 is movable body. 11 is supported.

  In the example of FIG. 7, the cross-sectional shape of the movable body 11 is a U-shape, but is not particularly limited to this, and the actuator elements arranged at positions facing each other with the fixed portion 141 interposed therebetween. Any shape can be used as long as it can contact the tops of 12 and 12.

  Similarly to the first embodiment, the actuator 10 according to the second embodiment is bent into a bellows shape with two electrostrictive sheets bonded together, and every other inclined electrode portion has an electrode portion. 13, 13, ... are formed. That is, an inclined portion that is inclined in the same direction (in FIG. 7, an inclined portion that is inclined upward in the upper actuator element 12 and an inclined portion that is inclined downward in the lower actuator element 12). Is formed. Therefore, every other inclined portion of the bellows shape can function as a so-called unimorph type actuator.

  Focusing on the upper (lower) actuator element 12, the movable body 11 is supported at the top located on the side in contact with the movable body 11, and the fixed portion is located on the top opposite to the side in contact with the movable body 11. 141. In this state, when a voltage is applied to the electrode portions 13, 13,..., The inclined portion formed in the electrode portions 13, 13,... Functions as a unimorph actuator, and moves to the right in FIG. And bend. On the other hand, since it does not curve in the inclined part where the electrode parts 13, 13,... Are not formed, the movement vector of the top part located on the side in contact with the movable body 11 is in the upper right (lower right) direction. Therefore, the deformation of the actuator element 12 can move the movable body 11 to the right while pressing.

  After that, when the application of voltage to the electrode portions 13, 13,... Is stopped, the inclined portion where the electrode portions 13, 13,... Are not functioning as a unimorph type actuator, and returns to the original shape. Return. On the other hand, since the inclined portion where the electrode portions 13, 13,... Are not formed is originally not deformed, the movement vector of the top portion located on the side in contact with the movable body 11 is in the left direction. At this time, there is a movement vector component that moves the movable body 11 to the left, but at the top located on the side in contact with the movable body 11, the length of the upwardly inclined portion is shortened (original length). Therefore, the contact pressure with the movable body 11 is reduced, and the movable body 11 does not move leftward. Therefore, it is possible to configure an actuator that can move the movable body 11 in the right direction (arrow direction) by repeatedly applying and stopping the application of voltage to the electrode portions 13, 13,. Become.

  As described above, according to the second embodiment, when a voltage is applied to the electrode portion 13, the electrostrictive sheet is stretched and cured at the inclined portion where the electrode portion 13 is formed, and the electrode portion 13 is formed. In the not inclined portion, the length before the voltage is applied is maintained. Therefore, the bellows-shaped top portion located on the side in contact with the movable body 11 is bent in a direction in which the inclined portion where the electrode portion 13 is formed is inclined, whereby the movable body 11 in contact with the top portion. Can be moved in a direction in which the inclined portion on which the electrode portion 13 is formed is inclined.

  In addition, in Embodiment 2 mentioned above, although the fixing | fixed part 141 is used, it is not limited to a plate-shaped member in particular, A cylindrical member may be sufficient. In this case, an actuator capable of moving the movable body 11 by using a cylindrical member as the fixed portion 141 and using the cylindrical movable body 11 that accommodates the plurality of actuator elements 12, 12,... It can be configured. The actuator elements 12 need only be arranged at positions facing each other with the columnar fixing portion 141 interposed therebetween. Therefore, the actuator elements 12 are not limited to a pair of actuator elements 12 and 12, and the columnar fixing portion 141 is not limited. A plurality of sets of actuator elements 12, 12,... May be arranged around the periphery.

(Embodiment 3)
FIG. 8 is a cross-sectional view schematically showing the configuration of the actuator 10 according to the third embodiment of the present invention. As in the first and second embodiments, the top of the actuator element 12 located on the side opposite to the side in contact with the movable body 11 is not fixed to the fixed member. For example, by providing the movable body 11 in the vertical direction so that the movable body 11 can be moved in the vertical direction, the top of the actuator element 12 located on the side opposite to the side in contact with the movable body 11 is not fixed to the fixed member. Can also function as a unimorph actuator.

  In FIG. 8, a cylindrical fixing member 14 is installed in the vertical direction, and the movable body 11 is arranged at the center of the cylindrical fixing member 14. Around the movable body 11, one set or a plurality of sets of actuator elements 12, 12,...

  Similarly to the first embodiment, the actuator element 12 is bent into a bellows shape with two electrostrictive sheets bonded together, and every other inclined electrode portion 13, 13,.・ ・ Is formed. That is, in an inclined portion that is inclined in the same direction (in FIG. 8, an inclined portion that is inclined upward in the left actuator element 12 and an inclined portion that is inclined downward in the right actuator element 12). Electrode portions 13, 13,... Are formed. Therefore, every other inclined portion of the bellows shape can function as a so-called unimorph type actuator.

  When attention is paid to the left side (right side) actuator element 12, the movable body 11 is supported by the top located on the side in contact with the movable body 11, and the top located on the side opposite to the side in contact with the movable body 11 is fixed. It is not fixed to the plate material 14. In this state, when a voltage is applied to the electrode portions 13, 13,..., The inclined portion on which the electrode portions 13, 13,... Function functions as a unimorph actuator, and moves upward in FIG. And bend. On the other hand, since it does not curve in the inclined part where the electrode parts 13, 13,... Are not formed, the movement vector of the top part located on the side in contact with the movable body 11 is upward. Although the top located on the side opposite to the side in contact with the movable body 11 is not fixed to the fixed plate member 14, the actuator element 12 is supported by the bottom surface, so that the movable body 11 is pressed by the deformation of the actuator element 12. However, it can be moved upward.

  Moreover, the polarity of the voltage applied to the electrode parts 13, 13,... Facing each other of the actuator elements 12, 12 is alternately the same as, for example, the same polarity, different polarity, same polarity, different polarity,. .. Are connected to a power source so as to have different polarities and different polarities, and the electrode portions 13, 13,... Having the same polarity and the electrode portions 13, 13,. Thus, the movable body 11 can be moved upward without being displaced downward.

  That is, first, the high voltage relay is switched so as to apply a voltage to the odd-numbered electrode portions 13, 13,. As a result, the odd-numbered electrode portions 13, 13,... From the bottom are deformed and have the same polarity, so that an electric repulsive force acts, so that the movable body 11 can be moved upward. Next, the high voltage relay is switched so as to apply a voltage to the even-numbered electrode portions 13, 13,. As a result, the odd-numbered electrode portions 13, 13,... From the bottom return to the original state, and the even-numbered electrode portions 13, 13,. Since the attractive force works, the movable body 11 is held without falling downward. As described above, the movable body 11 can be moved more stably by repeatedly performing the operations of upward movement, holding, upward movement, holding, and so on.

  In addition, the actuator element 12 may be comprised as one actuator element over the full length of the fixing member 14, and may be comprised by the several actuator element.

(Embodiment 4)
FIG. 9 is a partial cross-sectional view schematically showing the configuration of the actuator 10 according to Embodiment 4 of the present invention. In FIG. 9, for the sake of simplicity, the actuator element 12 has a bellows shape that is bent substantially linearly, but is not limited to this shape. In the fourth embodiment, unlike the first to third embodiments, a reinforcing member is provided in an inclined portion where the electrode portions 13, 13,... Of the actuator element 12 are not formed.

  In the example of FIG. 9, electrode portions 13, 13,... Are formed on the upwardly inclined portion of the actuator element 12, and reinforcing members 91, 91,. . The reinforcing member 91 is an elastomeric small sheet made of urethane, acrylic, silicon or the like, and is thermoset to an inclined portion where the electrode portions 13, 13,... Are not formed before the actuator element 12 is bent into a bellows shape. It is pasted with an adhesive or a UV curable adhesive.

  As described above, by providing the reinforcing members 91, 91,..., Even if an excessive external force is applied from the side opposite to the side where the top of the actuator element 12 is fixed to the fixing member 14, the actuator The element 12 is less likely to be damaged due to buckling or the like, and an actuator having high resistance to external force can be configured.

(Embodiment 5)
FIG. 10 is a partial cross-sectional view schematically showing the configuration of the actuator 10 according to the fifth embodiment of the present invention. In FIG. 10, for simplicity of explanation, the actuator element 12 has a bellows shape that is bent substantially linearly, but is not particularly limited to this shape. In the fifth embodiment, unlike the first to fourth embodiments, an elastic member 101 having elasticity is provided in the gap between the actuator element 12 and the fixing member 14.

  In the example of FIG. 10, electrode portions 13, 13,... Are formed on the upwardly inclined portion of the actuator element 12, and an elastic member 101 is provided in the gap between the actuator element 12 and the fixing member 14. It is. The elastic member 101 is an elastomeric rubber material made of urethane, acrylic, silicon or the like, and has a certain elasticity. Therefore, the elastic member 101 is excessive from the side opposite to the side where the top of the actuator element 12 is fixed to the fixing member 14. Even when an external force is applied, the possibility of buckling or the like due to the elasticity of the elastic member 101 is reduced.

  Actually, since it is difficult to provide the elastic member 101 in the gap between the actuator element 12 and the fixing member 14 without a gap, the actuator element 12 is bent into a bellows shape and the top is fixed to the fixing member 14. The elastic member 101 is provided. FIG. 11 is a cross-sectional view schematically showing the mounting process of the actuator element 12 when the elastic member 101 is provided in the actuator 10 according to Embodiment 5 of the present invention.

  FIG. 11A shows a state before the actuator element 12 is bent into a bellows shape, and FIG. 11B shows a state after the actuator element 12 is bent into a bellows shape. First, as shown in FIG. 11A, a predetermined amount of the elastic member 101 is placed on the fixing member 14, and the lower surface is adhered to the fixing member 14 with a thermosetting adhesive or a UV curable adhesive. On top of that, the actuator element 12 before being bent, on which the electrode films 13, 13,.

  Next, as shown in FIG. 11B, one end of the portion of the actuator element 12 where the electrode film 13 is formed is fixed to the fixing member 14 at a point A, and the next electrode is covered so as to cover the elastic member 101. One end of the portion where the film 13 is formed is fixed to the fixing member 14 at a point B. In this case, since the hardness is different between the portion of the actuator element 12 where the electrode films 13, 13,... Are formed and the portion where the electrode films 13, 13,. Although the shape after deformation of 101 is asymmetrical, the boundary between the portion where the electrode films 13, 13,... Are formed and the portion where the electrode films 13, 13,. It is formed in the vicinity.

  When a voltage is applied in this state, only the portion where the electrode films 13, 13,... Function as a so-called unimorph actuator, so that the upper end portion of the elastic member 101 having an asymmetric shape is deformed. This functions as the actuator 10.

  As described above, by providing the elastic members 101, 101,..., Even when an excessive external force is applied from the side opposite to the side where the actuator element 12 is fixed to the fixing member 14, the actuator element 12 is provided. Therefore, it is possible to construct an actuator having high resistance to external force.

  In addition, the present invention is not limited to the above-described embodiments, and it goes without saying that various modifications and substitutions are possible within the scope of the gist of the present invention. For example, the above-described metal material may be used for the electrode film, or a conductive polymer material may be used. For example, when forming an electrode film with 3,4-polyethylenedioxythiophene-polystyrene sulfonic acid (hereinafter referred to as PEDOT / PSS), PEDOT / PSS is mechanically pulverized and mixed with an organic binder such as acrylic resin with propanol (organic It dissolves in the solvent. Then, a PEDOT / PSS paste is created by mechanical stirring, and an electrode film is formed by screen printing. As a result, an actuator that does not easily peel off due to deformation can be easily configured.

DESCRIPTION OF SYMBOLS 10 Actuator 11 Movable body 12 Actuator element 13 Electrode part 14 Fixing member 31, 32 Electrostrictive sheet 33, 34 Electrode film 91 Reinforcing member 101 Elastic member

Claims (7)

An actuator element in which two sheets formed of an electrostrictive material are bonded together and bent into a bellows shape;
An actuator having a movable body supported by a plurality of top portions of the plurality of actuator elements,
In the actuator element, electrode films are intermittently formed on both front and back surfaces of one of the sheets that are bonded together, and in an accordion shape, an inclined portion where the electrode film is formed and an inclined portion where the electrode film is not formed. Actuators arranged alternately.   The actuator according to claim 1, wherein the actuator element has a plurality of apexes positioned on the side opposite to the side in contact with the movable body fixed to a fixed member. The movable body is plate-shaped,
The actuator according to claim 1, wherein the actuator elements are arranged at positions facing each other across the movable body.   The actuator according to claim 3, further comprising a polarity switching unit that switches a polarity of a voltage applied to the electrode films facing each other with the movable body interposed therebetween. The actuator element is disposed on the fixing member at a position facing each other across the fixing member,
3. The actuator according to claim 1, wherein the movable body is supported by a plurality of top portions of the actuator element located on a side opposite to a side in contact with the fixed member.   The actuator according to claim 1, wherein the electrode film is formed of a metal material.   The actuator according to claim 1, wherein the electrode film is made of a conductive polymer material.

Images