JP3329042B2 - Stacked actuator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated actuator which is constituted by a laminate of thin plates formed by using a deformable member such as a piezoelectric element or a bimetal and takes out a force to the outside in a bending operation.

[0002]

2. Description of the Related Art Conventionally, laminated piezoelectric actuators and electromagnetic motors have been known as telescopic actuators and rotary actuators whose length can be expanded and contracted. However, such an actuator can basically move only in one direction.Therefore, for example, when configuring a moving mechanism in a bent pipe, or configuring a scanning mechanism, a plurality of actuators are required. Therefore, development of an actuator that performs two-dimensional or three-dimensional operation is desired.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and particularly, a bending motion is made possible so that a two-dimensional or three-dimensional movement is made possible. It is an object of the present invention to provide a laminated actuator that can constitute a robot mechanism or the like that can smoothly control movement in a bent pipe.

[0004]

According to the present invention, there is provided a laminated actuator in which a plurality of thin plates, which are bent and deformed in the direction of a surface by an external signal, are connected in parallel by a first support member. Of the actuator, and these actuators are sequentially laminated via a second support member to form an actuator body. The first support member is divided into a plurality of sections of the thin plate. The second support member is set at a different position on the lamination surface from the support member forming the first support member.

Here, the thin plates are each composed of a metal plate and a piezoelectric element plate bonded to the surface of the metal plate, or a disk-shaped insulating plate and a bimetal bonded to the surface of the insulating plate, respectively. The element plate or the bimetal is divided as necessary according to a plurality of regions by radiation extending from the center of the metal plate, and a signal that is bent and deformed in each of the divided regions is applied.

[0006]

In the stacked actuator configured as described above, by controlling the application state of the external signal,
The thin plate is deformed in the plane, and the outer surface is locally deformed, for example, to expand by the actuator alone connected by the first support member. Therefore, if the second support member is set corresponding to the bulging portion, the distance between the stacked actuator bodies differs depending on the portion, and the entire stacked body is bent. Become.

[0007]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1A shows a configuration viewed from the side, and includes a plurality of disc-shaped metal plates 101, 102,... And a disc-shaped piezoelectric material having a slightly smaller diameter than the metal plates 101, 102,. The actuator body 13 is constituted by the piezoelectric element plates 111, 112,. Specifically, the metal plate 10
The plurality of piezoelectric unimorphs 14 are formed by joining each of the piezoelectric element plates 111, 112,.
A thin plate composed of 1, 142,... Is formed.
, 152,...

The actuators 151, 152,... Are paired with a pair of metal plates, specifically, the metal plates 101 and 10 so that the surfaces to which the piezoelectric element plates 111, 112,.
, 103, 104,... Are set in parallel so that an interval is set between the piezoelectric element plates, and are connected by a first support member 16 therebetween.

FIG. 1B shows a single piezoelectric unimorph 14 taken out. The piezoelectric element plate 11 bonded to the surface of the metal plate 10 is set at an equal angle from the center of the metal plate 10. First to third radiations that are separated by three radiations, specifically, three radiations set at an angle of 120 °.
The electrodes 12a to 12c are joined and formed. A voltage is selectively applied between each of the electrodes 12a to 12c and the metal plate 10 although not shown in detail.

The first support member 16 is located on the outer peripheral edge of the metal plate 10, and is constituted by columnar supports 16a to 16c which are set on radiation set at an equal angle from the center of the metal plate 10. Is done. The supports 16a to 16c are made of, for example, a conductive material such as solder or brazing material.

The plurality of actuators 151, 152,... Configured as described above are stacked so that the metal plates are adjacent to each other, and the metal plates are connected to the second support member 17.
Are combined. The second support member 17 includes support members 16a to 16a constituting the first support member 16 as shown in FIG.
Each of the support members 17a to 17c is set at a position between each of the support members 16c and 16c.
Specifically, it is set at a position near the center of each of the first to third electrodes 12a to 12c.

A plurality of actuators 151, 152,...
A voltage is selectively applied between each of the three divided electrodes 12a to 12c and the metal plate 10 in the piezoelectric unimorph 14 which constitutes When a voltage is applied only during this time, only the region corresponding to the electrode 12a of the piezoelectric element 11 is deformed so as to shrink, and the metal plate 10 is deformed in the shrinking direction only at this electrode 12a, and that portion is locally deformed. Deforms to protrude in the plane direction.

When such control of the applied voltage is performed in each of the actuators 151, 152,...
As shown by, the local deformations are accumulated, and the actuator body 13 is deformed so as to be bent, and a force corresponding to the bending is taken out.

FIGS. 3A to 3C show, for example, a case in which the diameter is 2.times.
First support member 16 of a piezoelectric unimorph 14 of 0 × 0.4 mm
The following shows a typical deformed shape for. This figure shows the distribution pattern of the displacement amount viewed from the metal plate 11,
(A) The figure shows that when a voltage is applied only to the electrode 12a,
(B) shows a case where a voltage is applied to the two electrodes 12b and 12c, and (C) shows a case where a voltage is equally applied to all of the electrodes 12a to 12c. Here, the applied voltage is 300V.

That is, each actuator 151, 15
In each case, when a voltage is applied only to the electrode 12a, the electrode bends as shown in FIG. 2 and when a voltage is applied equally to the electrodes 12a to 12c as shown in FIG. Then, the actuator body 13 is deformed in the extending direction. That is, by individually controlling the applied voltage to each of the three electrodes 12a to 12c, the amount of bending can be controlled together with the bending direction. Here, by selecting the number of divided electrodes, the position of the support constituting the support member, and the number of the supports, the bending characteristics thereof are changed, and the actuator can be bent in a manner suitable for the purpose.

Here, in the embodiment, the thickness of the metal plate is made constant, and the piezoelectric element 11 is divided into regions by the electrodes 12a to 12c. , The deformation of the laminated plate can be made asymmetric with respect to the laminating direction, and this is particularly applicable to the case where the purpose is to cause a bending operation in only one direction. Here, when the area of the piezoelectric element 11 is divided, the operation is not limited to the area division by the electrode, and the same operation is performed even when the piezoelectric element 11 is divided in accordance with the area division of the electrode.

Further, even when the laminated thin plate made of the piezoelectric unimorph is configured symmetrically with respect to the laminating direction, specifically, as shown in FIG. Even when the disk-shaped electrode 12 is concentrically joined to the surface of the disk-shaped piezoelectric element plate to form the piezoelectric unimorph 14, particularly, the support forming the second support member 17 By setting 17d and 17e at asymmetric positions with respect to the center of the disc-shaped piezoelectric unimorph 14, the actuator 13 can be bent in the laminating direction. In this case, the supports 16a to 16c constituting the first support member 16 for connecting the two sets of piezoelectric unimorphs
Are set symmetrically with respect to the center.

In the embodiments described above, the bending operation is performed by using the difference in the displacement amount between the plurality of support portions. For example, as shown in FIG.
In the case where the second support member is constituted by one support member 17f, the support member 17f can be configured to be set at a position eccentric from the center position. That is, the bending operation in the stacking direction of the laminate is performed by utilizing the partial inclination of the metal plate 11 to which the support 17f is connected, and the bending direction can be set by the position of the support. .

Further, in the embodiment, the actuator and the single body are connected by the support members which are all independently formed, or the actuator alone is formed by connecting a pair of piezoelectric unimorphs. Without separate arrangement, it is also possible to configure by a partial connection structure of the members to be laminated, even in such a case, it is possible to configure a laminated actuator that performs the same bending operation as the previous embodiment, Applicable to various robot mechanisms.

Further, in the embodiment, a thin plate made of a piezoelectric unimorph constituted by a piezoelectric element plate using a piezoelectric material which contracts when a voltage is applied is formed, and an actuator is constituted by the laminated body.
However, the member deformed by an external signal such as a voltage is not limited to the piezoelectric element, and other members exist.For example, a piezoelectric bimorph or a shape memory alloy can be applied. A similar stacked actuator can be constructed using a controllable bimetal.

FIG. 6A shows a configuration of an embodiment using a bimetal.
By stacking 152,..., The columnar actuator body 13 is formed. This actuator alone 15
1, 152,..., Respectively, are two metal plates having different coefficients of thermal expansion as represented by the actuator unit 151.
It is composed of two sets of thin plates 24a and 24b in which a heating plate 23 on which an electric resistance wire is arranged via an insulator plate 22 is laminated on a bimetal-constituting metal plate 21 formed by bonding 21a and 21b. The two sets of thin plates 241 and 24b are connected to each other by the first support member 16 similar to the first embodiment. The plurality of actuators 151
, 152,... Are sequentially stacked and connected to each other by a second support member 17 configured in the same manner as in the first embodiment.

The heating plate 23 for heating the bimetallic metal plate 21 is shown in FIG. 1B as shown in a plan view in FIG.
As in the case of the electrodes 12a to 12c, the resistance wire regions 23a to 23c are divided into three regions, and heating power is selectively supplied to the heating resistance lines of the resistance line regions 23a to 23c. So that That is, the bimetal-constituting metal plates 21 corresponding to each of the three divided areas are independently deformed and controlled, thereby forming a laminated actuator in which the bending operation similar to that of the first embodiment is performed. Is done.

[0023]

As described above, in the laminated actuator according to the present invention, since the laminated thin plates are deformed independently by the deformation of the piezoelectric element or the bimetal, the laminated actuator is, for example, a laminated electrostatic actuator. There is no need to control the spacing between the laminates. That is, in the actuator according to the present invention, even if the distance between the laminated piezoelectric unimorphs or the like changes, the displacement and the generated force are not affected, and the manufacturing thereof is simplified.
Also, depending on the voltage and the electrode portion and the shape of the laminated thin plate, which are applied external signals, and the arrangement and the number of laminated portions of the connecting portion,
The generated force, displacement amount, and bending direction can be arbitrarily selected.

[Brief description of the drawings]

FIG. 1A is a cross-sectional view of a multilayer actuator according to an embodiment of the present invention as viewed from a side, and FIG. 1B is a diagram illustrating a planar structure of one piezoelectric unimorph constituting the actuator.

FIG. 2 is a diagram illustrating a bending operation of the laminated actuator.

FIGS. 3A to 3C are diagrams for explaining deformation patterns with respect to an applied voltage in a piezoelectric unimorph. FIGS.

FIG. 4 is a diagram showing a planar configuration of a piezoelectric unimorph for describing a second embodiment of the present invention.

FIG. 5 is a diagram showing a planar configuration of a piezoelectric unimorph for explaining a third embodiment of the present invention.

FIG. 6A is a configuration diagram of a multilayer actuator according to a fourth embodiment of the present invention as viewed from the side, and FIG. 6B is a diagram illustrating a planar structure.

[Explanation of symbols]

10, 101, 102,... Metal plate, 11, 111, 112,... Piezoelectric element plate, 12a to 12c... Electrodes (divided), 13 ... actuator body, 14, 141, 142,.
.., 152, an actuator alone, 16, a first support member, 17, a second support, 16 a-16 c, 17 a-17 f, a support, 21 a bimetallic metal plate, 22 an insulator plate, 23 heat generation Board.

Claims (6)

(57) [Claims] 1. A plurality of actuators each formed by connecting a pair of thin plates bent and deformed in the direction of a surface in response to a signal from the outside in a parallel state by a first support member; An actuator main body that is stacked with two support members interposed therebetween, wherein the first support member is constituted by a plurality of supports corresponding to a plurality of divided regions of the thin plate; Wherein the supporting member is set at a different position on the laminating surface from a supporting member constituting the first supporting member. 2. The thin plate is constituted by a piezoelectric unimorph comprising a metal plate and a piezoelectric element plate joined to the metal plate surface, and the piezoelectric element plate is formed in a plurality of regions by radiation extending from the center of the metal plate. 2. The multilayer actuator according to claim 1, wherein the actuator is divided so as to correspond to each other, and a voltage is selectively applied between the piezoelectric element plate and the metal plate. 3. The piezoelectric element plate includes an electrode member joined to a surface of the plate, and a plate made of one piezoelectric material joined to the surface of the metal plate is separated by radiation passing through the center of the metal plate. 3. The multilayer actuator according to claim 2, wherein the plurality of electrodes are divided into regions. 4. The thin plate is constituted by a piezoelectric unimorph composed of a disk-shaped metal plate and a disk-shaped piezoelectric element plate joined to the surface of the metal plate. The first support member is configured by a plurality of support members set at positions corresponding to the divided radiation, while being configured to be divided corresponding to a plurality of regions divided by radiation extending from the center. And
2. The multilayer actuator according to claim 1, wherein the second support is constituted by a plurality of supports set corresponding to each of the divided areas deviated from the position of the radiation. 3. 5. The thin plate comprises a disc-shaped insulating plate and a bimetal bonded to the insulating plate surface, and the bimetal is divided into a plurality of regions separated by radiation extending from the center of the insulating plate. 2. The multilayer actuator according to claim 1, wherein each of the divided bimetals is selectively heated and controlled. 6. The thin plate is composed of a disk-shaped metal plate and a disk-shaped piezoelectric element plate joined to the surface of the metal plate, and the first support member is provided at a peripheral portion of the metal plate. The second support member is constituted by at least one support member set at a position off the center of the piezoelectric element plate, while being constituted by a plurality of supports arranged at equal intervals. 2. The laminated actuator according to 1.