JP2019103193A - Bell crank type drive device and power transmission type drive device - Google Patents

Abstract

To provide a bell crank type drive device which can be further miniaturized and a power transmission type drive device including the same.SOLUTION: The bell crank type drive device for moving an action member includes first fixing means, a piezoelectric element and a bell crank, connected in this order. The bell crank is rotated by expansion and contraction of the piezoelectric element with the first fixing means as a fixed end. The action member moves by the bell crank being rotated. When a distance from the rotation center to a straight line that vertically bisects a width of a surface where the bell crank and the piezoelectric element are connected is denoted as s and a distance from the rotation center to a straight line that vertically bisects a width of a surface connecting the bell crank and the action member is denoted as t, t/s>1 is satisfied.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an expansion and contraction of a piezoelectric element, a bell crank mechanism, and a bell crank type drive device and a power transmission type drive device using an action member (plate-like elastic member).

  An ultrasonic motor is one of drive devices using a piezoelectric element. An ultrasonic motor is a friction-driven actuator that causes a stator excited by mechanical vibration in the ultrasonic region to contact a rotor or slider to rotate or linearly move the device. In addition, it is used in various fields such as multi-dimensional motors incorporated in security cameras and surgical instruments.

  For example, in Patent Document 1, a bimorph piezoelectric element is connected to both ends of an elastic body, the elastic body is deformed by the movement of the bimorph piezoelectric element, and the operating point on the elastic body is brought into contact with the moving body to move the moving body Is disclosed, which is capable of moving the However, in the drive device disclosed in Patent Document 1, the drive amount is small, and the bimorph piezoelectric element is enlarged to increase the operation amount and the drive amount of the moving main body. We have to make the Therefore, it has been difficult to incorporate the device into small devices such as surgical devices, for example.

  Alternatively, Patent Document 2 includes a plurality of piezoelectric elements arranged so that the expansion and contraction directions are in the same plane, a base for fixing the piezoelectric elements, and a dome-shaped elastic body fixed to the expansion and contraction ends of the piezoelectric elements. An ultrasonic transducer is disclosed, and a driving device such as an ultrasonic motor can be configured by the transducer. However, in the ultrasonic transducer disclosed in Patent Document 2, it is necessary to prepare a plurality of piezoelectric elements, and it is premised to use a dome-shaped elastic body. That is, a large space is required to install the piezoelectric element and the elastic body, and the drive device is also upsized and it is difficult to incorporate it in a small device such as a surgical device.

  Among the present inventors, longline and Komatsu have developed the technique described in Patent Document 3 in view of the problems of the techniques described in Patent Documents 1 and 2. That is, Patent Document 3 discloses a stator in which a first fixing means, a first piezoelectric element, a plate-like elastic member and a second fixing means are connected in this order, and interaction with the plate-like elastic member of the stator. The stator includes a movable portion, and the stator extends and retracts the first piezoelectric element by using the first fixing means as a fixed end, so that the distance between the second fixing means and the end portion of the first piezoelectric element on the plate-like elastic member side is As the distance between the end of the first piezoelectric element on the side of the plate-like elastic member and the second fixing means decreases, the deflection produced in the plate-like elastic member increases, and the first piezoelectric element A drive device is disclosed in which a plate-like elastic member is bent so as to be convex in a direction perpendicular to the direction of expansion and contraction of the plate.

Patent No. 4452275 Unexamined-Japanese-Patent No. 5-191988 Patent No. 6124331

  According to the drive device described in Patent Document 3, it becomes easy to miniaturize the drive device and to incorporate it into a small device such as a surgical device. However, in order to cope with further multifunctionalization and miniaturization of small-sized equipment, further miniaturization of the drive device is also required. Then, this invention makes it a subject to provide the power transmission type drive device which can be further miniaturized.

  The inventors of the present invention have found that it is possible to miniaturize the drive device by introducing a bell crank mechanism using a piezoelectric element in the drive device as a result of intensive studies.

  That is, one aspect of the present invention is a bell-crank drive device (10) for moving the action member (4b, 14b, 24b, 34b), the first fixing means (1), the piezoelectric element (2), and The bell crank (3) is connected in this order, and the bell crank is rotated by the expansion and contraction of the piezoelectric element with the first fixing means as the fixed end, and the action member is moved by the rotation of the bell crank. The distance from the center of rotation to the straight line (L1) that vertically bisects the width of the surface where the bell crank and the piezoelectric element are connected from the center of rotation in the cross section orthogonal to the center of rotation (O) of the bell crank The bell crank type driving device is such that t / s> 1 where t is a distance to a straight line (L2) which bisects the width of the surface where the bell crank and the action member are vertically connected.

  In the present invention, "connected in this order" refers to a form in which each part is connected directly in order, and also to a form in which each part is connected indirectly in order via some member other than each part. It is an included concept. "Piezoelectric element" refers to an expansion-type piezoelectric element, and mainly corresponds to a laminated piezoelectric element. The "rotation center" is the rotation axis of the rotating bell crank. The "surface where the bell crank and the piezoelectric element are connected" means the surface where the bell crank and the piezoelectric element contact when the bell crank and the piezoelectric element are directly connected, and the bell crank and the piezoelectric element are other members. In the case of connecting via, it means the surface where the other member and the bell crank contact. "The surface where the bell crank and the action member are connected" means the surface where the bell crank and the action member contact when the bell crank and the action member are directly connected, and the bell crank and the action member are other members In the case of connecting through the term “2”, it means the surface where the other member and the action member make contact. The “width of the surface where the bell crank and the piezoelectric element are connected” is a length connecting two end portions in the surface where the bell crank and the piezoelectric element are connected in a cross section orthogonal to the rotation center of the bell crank. Similarly, “the width of the surface where the bell crank and the action member are connected” is the length connecting the two ends of the surface where the bell crank and the action member are connected in a cross section orthogonal to the rotation center of the bell crank. . The term "action member" does not mean to refer to the entire action member described later, but means only a member that substantially acts on the device. For example, the action part 4 b in FIG. 1 and the bending part 14 b in FIG. 4 correspond to the “action member” referred to here.

  In the present invention, the bell crank (3) is preferably L-shaped.

  Another aspect of the present invention is a power transmission drive (100, 200, 300, 400, 500, 600) including the above-mentioned bell crank drive (10), wherein the action member is plate-like. It is an elastic member (14b, 24b, 34b), and the first fixing means (1), the piezoelectric element (2), the bell crank (3), the plate-like elastic member and the second fixing means (5) are connected in this order And a movable portion (8) operated by interaction with the plate-like elastic member (4) of the stator (7), and the plate-like elasticity of the bell crank by the rotation of the bell crank As the distance between the end (3b) on the member side and the second fixing means increases or decreases and the distance between the end on the plate-like elastic member of the bell crank and the second fixing means decreases, the plate-like elastic member is produced. Configured to increase deflection A power transmission type driving device.

  In the present invention, the "plate-like" of the "plate-like elastic member" means that it becomes a shape having no curvature in the state where the deflection is most eliminated. However, as long as the amount of expansion and contraction of the piezoelectric element can be expanded by the bell crank and the plate elastic member, the plate elastic member in the case where the distance between the end portion on the plate elastic member side of the bell crank and the second fixing means is maximum. May be curved. By curving the plate-like elastic member in advance, it is easy to be deformed in a desired direction into a scoop type.

  In the present invention, preferably, the plate-like elastic member (14b, 24b, 34b) is bent so as to be convex in the direction orthogonal to the direction (X) orthogonal to the expansion / contraction direction (Y) of the piezoelectric element (2). . This is because the amount of deflection of the plate-like elastic member can be increased most. In the present application, “a direction orthogonal to the direction perpendicular to the expansion and contraction direction of the piezoelectric element” does not have to be a direction orthogonal to the direction orthogonal to the expansion and contraction direction of the piezoelectric element. This is an acceptable principle. For example, when the angle between the direction perpendicular to the expansion and contraction direction of the piezoelectric element and the convex direction of the deflection of the plate-like elastic member is 75 ° or more and 105 ° or less, the error range is “a direction orthogonal to the expansion and contraction direction of piezoelectric element It shall be included in the “orthogonal direction”. In addition, it is also possible to adjust the angle formed by the direction perpendicular to the expansion and contraction direction of the piezoelectric element and the convex direction of the deflection of the plate-like elastic member to an arbitrary angle by adjusting the arrangement of the second fixing means.

  In the present invention, preferably, the stator (7) includes a bell crank support (6) that connects the first fixing means (1) and the bell crank (3) and supports the bell crank (3).

  In the present invention, preferably, the bell crank support (6) or the bell crank (3) has a hinge (6a). This is to facilitate the pivoting of the bell crank accompanying the expansion and contraction of the piezoelectric element. The hinge (6a) is preferably an elastic hinge in which the notch (6b) is formed.

  In the present invention, a plurality of stators (7) may be provided. That is, the movable part can be operated more efficiently by increasing or decreasing the number of installed stators according to the form of the movable part. Further, by providing a plurality of stators, for example, it is possible to operate the movable part in multiple dimensions.

  In the present invention, a plurality of plate-like elastic members (14b, 24b, 34b) are connected to one second fixing means (5), and each plate-like elastic member is a bell crank (3), a piezoelectric element (2) And the first fixing means (1) may be connected. In other words, it is possible to provide a form in which a plurality of plate-like elastic members and the like are connected while providing a predetermined interval in the circumferential direction about the second fixing means. In such a configuration, for example, a sphere is installed as a movable part in the vicinity of the second fixing means, and each of the plurality of plate-like elastic members is bent by an arbitrary deflection amount to contact the sphere. The sphere can be operated in multiple dimensions by increasing or decreasing the deflection of the plate-like elastic member.

  In the present invention, the first fixing means (1), the bell crank support (6), the bell crank (3), the plate-like elastic member (34b) and the second fixing means (5) are integrally formed. It is also good.

  In the present invention, it is preferable that a control means (19a) for controlling the direction of bending of the plate-like elastic member (14b) is provided in contact with the plate-like elastic member (14b). Further, as the restricting means (29a), a convex portion may be provided at the end of the plate-like elastic member (24b). By providing the regulating means, the control of the deflection of the plate-like elastic member becomes more precise, and the movable part can be operated efficiently.

  In the present invention, the plate-like elastic members (14b, 24b, 34b) and the second fixing means (5) may be connected via a piezoelectric element (12) different from the piezoelectric element (2).

  According to the bell crank mechanism device of the present invention, since the first fixing means, the piezoelectric element and the bell crank are connected, the expansion amount (displacement amount) of the piezoelectric element can be enlarged via the bell crank. The size of the device can be reduced. In addition, since the direction of displacement expansion can be adjusted in an arbitrary direction by the shape of the bell crank, installation of the device becomes possible even when the installation place is restricted.

Further, according to the power transmission type drive device of the present invention, the piezoelectric element, the bell crank and the plate-like elastic member are connected between the fixing means to constitute a stator, and the expansion and contraction amount of the piezoelectric element It is expanded through a mechanism, and is further expanded to the amount of deflection (the amount of deformation) of the plate-like elastic member. Therefore, a large amount of deformation can be obtained even when using a small-sized piezoelectric element or when there is a restriction on the type of piezoelectric element that can be arranged. Moreover, it is also possible to minimize the installation space of a stator by using a plate-like elastic member.
For example, when it is desired to install a power transmission drive in a pipe, the stator can be installed along the inner wall surface of the pipe in the pipe longitudinal direction or the pipe circumferential direction, and the installation space in the pipe radial direction can be minimized. As described above, according to the present invention, by expanding the amount of expansion and contraction of the piezoelectric element with the bell crank and the plate-like elastic member, it is possible to operate the object while obtaining the necessary driving force while being miniaturized. A power transmission drive can be provided.

FIG. 5 is a schematic view for explaining an operation aspect of the bell crank type drive device 10; It is a figure which illustrates typically displacement expansion by the bell crank type drive device 10, and is a figure which shows the mode before and behind rotation of a L-shaped bell crank. It is a figure explaining the example of the shape of the bell crank 3. FIG. It is the schematic for demonstrating the operation | movement aspect of the power transmission type drive device 100 of this invention which concerns on 1st Embodiment. FIG. 7 is a view for explaining the relationship between the displacement amount x of the end 3 b of the bell crank 3 in the X direction and the deflection amount y of the plate-like elastic member 3. When operating the power transmission type drive device 100, it is a figure which shows an example of the waveform of the voltage applied to the piezoelectric element 2. FIG. It is the schematic for demonstrating the other operation aspect of the power transmission type drive device 100 of this invention which concerns on 1st Embodiment. It is the schematic for demonstrating the power transmission type drive device 200 of this invention which concerns on 2nd Embodiment, and is a figure corresponding to FIG. It is the schematic for demonstrating the power transmission type drive device 300 of this invention which concerns on 3rd Embodiment, and is a figure corresponding to FIG. 4 (A). It is the schematic for demonstrating the stator 17 provided in the power transmission type drive device 300 of this invention which concerns on 3rd Embodiment. It is the schematic for demonstrating the power transmission type drive device 400 of this invention which concerns on 4th Embodiment. It is the schematic for demonstrating the power transmission type drive device 400 of this invention which concerns on 4th Embodiment. It is the schematic for demonstrating the power transmission type drive device 500 of this invention which concerns on 5th Embodiment, and is a figure corresponding to FIG. 4 (A). It is the schematic for demonstrating the power transmission type drive device 600 of this invention which concerns on 6th Embodiment, and is a figure corresponding to FIG. 4 (A). It is the schematic for demonstrating the control means 19a. It is the schematic for demonstrating the control means 29a. It is the schematic for demonstrating the power transmission type drive device which concerns on an Example.

  The above-described effects and advantages of the present invention will be apparent from the modes for carrying out the invention described below. Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the form shown below is an illustration of this invention, and this invention is not limited to these forms.

1. Bell Crank Drive One embodiment of the bell crank drive of the present invention will be described with reference to FIG. FIG. 1 is a schematic view for explaining the operation mode of the bell crank type drive device 10, and shows a cross section (a cross section perpendicular to the thickness direction) orthogonal to the rotation center O of the bell crank type drive device 10. As shown in FIG. 1, the bell crank mechanism device 10 moves the action member 4, and the first fixing means 1, the piezoelectric element 2 and the bell crank 3 are connected in this order. The bell crank type drive device 10 has a cross-sectional shape shown in FIG. 1 and extends in the front and back direction in FIG. 1 and has a predetermined thickness in the front and back direction in FIG.

1.1. First fixing means 1
In the bell crank type drive device 10, the first fixing means 1 is a means for fixing one end 2a of the piezoelectric element 2. The form of the first fixing means 1 is not particularly limited as long as the end 2a of the piezoelectric element 2 is fixed and the piezoelectric element 2 can be expanded and contracted using the first fixing means 1 as the fixed end. For example, a metal piece, a plastic piece, a ceramic piece or the like fixed to a location (not shown) where the bell crank type drive device 10 is installed can be used as the first fixing means 1.

1.2. Piezoelectric element 2
In the bell crank type drive device 10, the piezoelectric element 2 is an element which is fixed to the first fixing means 1 at one end 2a and which expands and contracts with the first fixing means 1 as the fixed end. The piezoelectric element 2 is not particularly limited as long as it is a stretchable piezoelectric element. For example, a multilayer piezoelectric element in which a plurality of piezoelectric elements are stacked in the stretch direction can be applied. The amount of expansion of the piezoelectric element 2 can be determined in accordance with the shape, size, etc. of the bell crank 3 or the like, but is preferably set to 0.01 μm to 30 μm.

1.3. Bell crank 3
In the bell crank type drive device 10, the bell crank 3 is a member which is connected to the other end 2b of the piezoelectric element 2 and whose other end 3b is in contact with the action member 4 and which rotates with expansion and contraction of the piezoelectric element 2 It is. FIG. 1 shows an embodiment in which the action member is connected to the other end 3b. As a component of the bell crank 3, any material may be used as long as it has a rigidity that allows one end 3 a to rotate without receiving pressure from the piezoelectric element 2 and deforming the action member, and For example, it can be composed of metal, plastic, ceramics and the like.

  The shape of the bell crank 3 includes an arm 3 s connected to the other end 2 b of the piezoelectric element 2 and an arm 3 t in contact with the action member 4, and the amount of expansion of the piezoelectric element 2 is displaced by the bell crank mechanism as described later. In order to enlarge, the distance from the rotation center O of the bell crank 3 to the straight line L1 which divides the width of the surface where the bell crank 3 and the piezoelectric element 2 are vertically divided into two vertically is the rotation center O of the bell crank 3 From the above, it is formed such that t / s> 1 where t is a distance to a straight line L2 which bisects the width of the surface connecting the bell crank 3 and the acting member vertically. As a shape of such a bell crank, for example, an L shape, a V shape, or an I shape can be used. Among them, L-shaped is preferable. The arm 3s and the arm 3t may be integral or separate members, but if integral, it is preferable because the power of the piezoelectric element can be transmitted without loss. However, as long as the power of the piezoelectric element can be transmitted without loss, it may be a separate member.

Here, "the surface where the bell crank 3 and the piezoelectric element 2 are connected" means the surface where the bell crank 3 and the piezoelectric element 2 are in contact when the bell crank 3 and the piezoelectric element 2 are directly connected. When 3 and the piezoelectric element 2 are connected via another member, the surface where the other member and the bell crank 3 contact is said. "The surface where the bell crank 3 and the action member are connected" means the surface where the bell crank 3 and the action member contact when the bell crank 3 and the action member are directly connected, and the bell crank 3 and the action member When connecting via other members, it means the surface where other members and the action member contact. “The width of the surface where the bell crank 3 and the piezoelectric element 2 are connected” refers to two end portions in the surface where the bell crank 3 and the piezoelectric element 2 are connected in a cross section orthogonal to the rotation center O of the bell crank 3 It is a connecting length. Similarly, “a width of a surface where the bell crank 3 and the action member are connected” also connects two ends in a face where the bell crank 3 and the action member are connected in a cross section orthogonal to the rotation center O of the bell crank 3 It is a length. The width of the surface where the bell crank 3 and the piezoelectric element 2 are connected is preferably larger than the width of the surface where the bell crank 3 and the action member are connected. The action member herein does not mean to indicate the entire action member 4 but means only a member substantially acting on the device. For example, in FIG. 1, the action part 4 b corresponds to the “action member” mentioned here.
In FIG. 1, the bell crank 3 and the piezoelectric element 2 are in direct contact with each other. Therefore, the straight line L1 is a straight line which vertically bisects the width of the contact surface between the bell crank 3 and the piezoelectric element 2. The bell crank 3 and the acting portion 4b are in direct contact with each other via the first engaging portion 4a. Therefore, the straight line L2 is a straight line which vertically bisects the width of the surface where the first engagement portion 4a and the action portion 4b contact. Thus, the action part 4b cuts out and considers only the part that can substantially act in the device. It is preferable that the surface to be cut out is in a direction parallel to the surface where the bell crank and the other member (first engaging portion 4a) contact. When the first engaging portion 4a which is another member penetrates into the bell crank 3 as shown in FIG. 1, the surface of the bell crank 3 into which the first engaging portion 4 a penetrates is divided into the bell crank 3 and the third crank crank. It can be regarded as a surface in contact with the first engaging portion 4a. The same applies to the case where the bell crank 3 and the piezoelectric element 2 are connected via other members.

Here, the rotation center O will be described with reference to FIG.
The rotation center O is a rotation axis of rotation of the bell crank 3, and when the bell crank 3 can freely rotate, it becomes the center of gravity of the bell crank 3. However, since the bell crank 3 is supported by the piezoelectric element 2 or the piezoelectric element 2 and the bell crank supporting portion 6 described later, in many cases the rotation center O deviates from the center of gravity and contacts the bell crank 3 and the bell crank supporting portion 6 Located at or near the outer end point (I in FIG. 1 (A)). When the bell crank support 6 is a rigid body, the rotation center O coincides with the end point I. On the other hand, when the bell crank support portion 6 is provided with the hinge 6b or the like and has a certain degree of flexibility, the rotation center O is in the vicinity of the end point I. FIGS. 1A and 1B illustrate an embodiment in which the rotation center O is in the vicinity of the end point I. FIG.

1.4. Working member 4
In the bell crank mechanism 10, the action member 4 is not particularly limited as long as it is a member movable by the rotation of the bell crank 3 accompanying the expansion and contraction of the piezoelectric element 2. In FIG. 1, the operating member 4 has a first engaging portion 4a having an L-shaped cross section and engaged with the bell crank 3 and an operating portion 4b having an I-shaped cross section, the first engaging portion One end is connected and fixed to the bell crank 3 by 4a. And the action | operation member 4 of FIG. 1 is moved with rotation of a bell crank. However, not only the form in which the action member 4 is thus fixed to the bell crank 3 but also the form in which the action member 4 is located apart from the bell crank 3 and moves by contacting by moving the bell crank 3 . In FIG. 1, the mechanism in which the actuating member 4 slides on the member Z is shown.
It does not specifically limit as a component of the action member 4, For example, it can comprise from a metal, a plastics, etc.

1.5. Bell crank support 6
Preferably, the bell crank type drive device 10 includes a bell crank support portion 6 that connects the first fixing means 1 and the bell crank 3 and supports the bell crank 3. The bell crank support 6 preferably has a hinge 6a. The bell crank support 6 having the hinge 6 a can facilitate the rotation of the bell crank 3 along with the expansion and contraction of the piezoelectric element 2. The position of the hinge 6 a is not particularly limited as long as the bell crank 3 can be pivoted, but is preferably provided at the end on the bell crank 3 side. The components of the bell crank support 6 are not particularly limited as long as they support the bell crank 3 and facilitate the rotation of the bell crank 3. For example, it can be made of metal, plastic or the like. The hinge 6a is preferably an elastic hinge in which the notch 6b is formed from the viewpoint of facilitating rotation.
Note that, as described later, the hinge may be provided on the bell crank 3 instead of being provided on the bell crank support 6.

1.6. Displacement Expansion in Bell Crank Drive 10 FIG. 2 is a view for schematically explaining the displacement expansion by the bell crank drive 10, and shows the front and rear rotation when the L-shaped bell crank 3 is rotated at an angle θ. It is a schematic sectional drawing which shows the mode of. In FIG. 2, the lengths s and t are as described above. Further, S represents the displacement of the arm 3s when the bell crank 3 rotates by θ, and T represents the displacement of the arm 3t when the bell crank 3 rotates by θ.
According to the bell crank type drive device 10 shown in FIG. 2, the displacement amount S is enlarged by t / s times (t> s) to become the displacement amount T (hereinafter, this effect is referred to as “first displacement enlargement effect” Sometimes). However, since the piezoelectric element 2, the bell crank 3, and the action member 4 have a certain thickness, errors due to the thickness may occur.

Here, considering that the amount of expansion and contraction of the piezoelectric element 2 of the present invention and the size of the bell crank are very small, it can be considered that the rotation center O coincides with the end point I. Further, the length s is a length from the end point I to a straight line parallel to a straight line L1 passing through the far end of the width of the surface connecting the bell crank 3 and the piezoelectric element 2; in FIG. It can be regarded as a length A in a direction (longitudinal direction of the arm 3s) orthogonal to the expansion and contraction direction of the element 2. The length t is the length from the end point I to the straight line parallel to the straight line L2 passing through the far end of the width of the face where the bell crank 3 and the action member 4 are connected, and in FIG. The length B can be regarded as a direction (longitudinal direction of the arm 3t) obtained by adding the angle formed by the arm 3s and the arm 3t in the direction orthogonal to the expansion and contraction direction. Further, the displacement amount S can be regarded as the displacement amount d ₁ (the expansion / contraction amount of the piezoelectric element 2) in the expansion / contraction direction (the lateral direction of the arm 3s) of the piezoelectric element 2 of the arm 3s in FIG. The amount of displacement T is the amount of displacement d ₂ (the amount of displacement of the bell crank) in the direction (the lateral direction of the arm 3 t) in which the angle formed by the arm 3 s and the arm 3 t is added to the expansion and contraction direction of the piezoelectric element 2 of the arm 3 t in FIG. It can be regarded as
Therefore, in consideration of the fact that the amount of expansion and contraction of the piezoelectric element 2 of the present invention and the size of the bell crank 3 are very small, the above-mentioned “displacement amount S is enlarged by t / s times to become displacement amount T” is It can be considered that “the amount of expansion and contraction d ₁ of the piezoelectric element 2 is enlarged by B / A and becomes the amount of displacement d ₂ of the bell crank 3”.
Here, “the expansion amount of the piezoelectric element 2 and the size of the bell crank are very small” means that the expansion amount of the piezoelectric element is 0.01 μm or more and 30 μm or less, and the size of the bell crank, for example, the length A, B is less than 10 ⁵ times the amount of expansion or contraction of the piezoelectric element, preferably 5 × 10 ⁴ times or less, more preferably it refers to is ¹⁰⁴ times less.

When this is applied to FIG. 1, it becomes as follows. As shown in FIG. 1B, the amount of expansion and contraction d ₁ of the piezoelectric element 2 due to the rotation of the bell crank 3 accompanying the expansion and contraction of the piezoelectric element 2 is the expansion and contraction direction of the piezoelectric element 2 (vertical direction in FIG. sometimes referred to as "Y direction". a direction perpendicular to) (left-right direction in FIG. 1. the following is enlarged to the displacement amount d ₂ of sometimes referred to as "X direction".). Then, the action member 4 is moved by the enlarged piece. As a result, the size of the piezoelectric element necessary to obtain the displacement amount necessary for driving can be miniaturized, and the apparatus including the bell crank type driving device can be miniaturized.

Such displacement enlargement is not limited to the L-shaped bell crank 3 in FIGS. 1 and 2, but as shown in FIG. 3, the angle formed by the arms 3 s and 3 t of the bell crank is an arbitrary angle. The present invention is also applicable to the set bell crank 3. As a result, the direction of displacement expansion can be adjusted in an arbitrary direction by the shape of the bell crank, so installation of the device becomes possible even when the installation place is restricted.
In FIG. 3, based on the L-shaped bell crank shown in FIGS. 1 and 2 (the angle 90 ° between the arm 3 s and the arm 3 t), the arm 3 t is rotated clockwise from the reference. When it is represented by + and the form rotated counterclockwise is represented by −, ± 45 ° (V-shaped), ± 90 ° (I-shaped), ± 135 ° (V-shaped), ± 180 ° L-shaped) is shown. However, the L-shape and the I-shape are not limited to the above angles, but include an error range of ± 5 °. The V-shaped shape is not limited to the above angle, and all cases other than L-shaped and I-shaped correspond to V-shaped.

  As described above, according to the bell crank type drive device of the present invention, the amount of expansion and contraction (displacement amount) of the piezoelectric element can be expanded through the bell crank, so the device can be miniaturized. In addition, since the direction of displacement expansion can be adjusted in an arbitrary direction by the shape of the bell crank, installation of the device becomes possible even when the installation place is restricted.

2. Power Transmission Drive Device Next, a power transmission drive device including the bell-crank drive device of the present invention described above will be described by way of illustrating each embodiment. In the power transmission type drive device of the present invention, a plate-like elastic member is used as the action member. The bell crank uses an L-shaped one. Further, in the following embodiments, the same reference numerals are given to members overlapping with the bell crank type drive device of the present invention described above, and the description will be omitted. Furthermore, in the following embodiments, it is assumed that the amount of expansion and contraction of the piezoelectric element and the size of the bell crank are very small. However, the present invention is not limited to this.

2.1. First Embodiment A power transmission drive apparatus 100 according to a first embodiment will be described with reference to FIG. FIG. 4 is a schematic view for explaining the operation mode of the power transmission drive device 100, and shows a cross section orthogonal to the thickness direction of the power transmission drive device 100 (cross section orthogonal to the rotation center of the bell crank). . As shown in FIG. 4, the power transmission type drive device 100 includes a stator 7 in which a first fixing means 1, a piezoelectric element 2, a bell crank 3, a plate-like elastic member 14 and a second fixing means 5 are connected in this order. The movable portion 8 is operated by interaction with the plate-like elastic member 14 of the stator 7. The power transmission type drive device 100 has the cross-sectional shape shown in FIG. 1 and extends in the front and back direction of the paper surface of FIG. 1 and has a predetermined thickness in the front and back direction of the paper surface of FIG. In addition, although the movable part 8 shown in FIG. 1 is a rotor disc, this invention is not limited to the said form, You may use a linear moving body like a slider as a movable part.

2.1.1. Plate-like elastic member 14
In the power transmission type drive device 10, the plate-like elastic member 14 is a member in which bending is generated or eliminated with rotation of the bell crank 3 accompanying expansion and contraction of the piezoelectric element 2, and the end 3b of the bell crank 3 is The amount of deflection varies depending on the distance between the second fixing means 5 and the second fixing means 5. As shown in FIG. 4, the plate-like elastic member 14 has an L-shaped cross section and engages with the bell crank 3, a first engaging portion 14 a, and a bending portion 14 b that causes the bell crank 3 to bend. And a second engaging portion 14c having an I-shaped cross section and engaged with the second fixing means 5, and the first engaging portion 14a brings one end to the bell crank 3 and the second engaging portion 14c. Thus, the other ends are respectively connected and fixed to the second fixing member 5. As shown in FIG. 4B, with the rotation of the bell crank 3 accompanied by the expansion and contraction of the piezoelectric element 2, bending occurs in the bending portion 14b of the plate-like elastic member 14. The constituent material of the plate-like elastic member 14 may be any material having elasticity, and can be made of, for example, metal, plastic or the like. The shape of the plate-like elastic member 14 may be a shape having a bending portion 14 b and having no bending in the bending portion 14 b in a state where the bending is eliminated. For example, only made the flexure 14b elastic plate member 14, the end portion _14b 1, 14b ₂ of the bending portion 14b is adhesive or the like end 3b of the bell crank 3, respectively, the end portion 5a of the second fastening means 5 It may be in a fixed form. The shape of the bending portion 14b of the plate-like elastic member 14 can be, for example, a shape along a straight line connecting the end 3b of the bell crank and the second fixing means 5 in a state where the bending is eliminated. However, as described later, the bending direction of the bending portion 14b may be regulated by slightly bending the bending portion 14b of the plate-like elastic member 14. The thickness and size of the flexible portion 14 b of the plate-like elastic member 14 can be determined in accordance with the shape, size, and the like of the movable portion 8. As described above, it is preferable to use one with a few microns (0.01 μm to 30 μm) of deflection (deformation) by the expansion of the piezoelectric element 2 and the rotation of the bell crank 3. The direction of the strip extending from one end 14b ₁ of the bending portion 14b in the expansion and contraction direction of the piezoelectric element 2 of the first engagement portion 14a, and the second engagement portion 14c also functions as the regulating means described later, the deflection To the movable portion 8 side.

2.1.2. Second fixing means 5
In the power transmission type drive device 100, the second fixing means 5 engages with the second engaging portion 14c of the plate-like elastic member 14 to fix the second engaging portion 14c and one end 14b ₂ of the bending portion 14b. Means of Form of the second fixing means 5, one end 14b ₂ fixed to the second engagement portion 14c and the bending portion 14b, there flexure portion 14b in a restraint forms between the bell crank 3 and the second fastening means 5 For example, it is not particularly limited. For example, a metal piece, a plastic piece, a ceramic piece or the like fixed to a location (not shown) where the power transmission drive device 100 is installed can be used as the second fixing means 5.

2.1.3. Stator 7
In the power transmission type drive device 100, the stator 7 is formed by connecting the first fixing means 1, the piezoelectric element 2, the bell crank 3, the plate-like elastic member 14 and the second fixing means 5 in this order. Thus, the bell crank 3 is rotated by the expansion and contraction of the piezoelectric element 2 with the first fixing means 1 as the fixed end, and the end 3 b of the bell crank 3 on the plate-like elastic member 14 side and the second fixing means 5 As the distance between the second fixing means 5 and the end 3b of the bell crank 3 on the side of the plate-like elastic member 14 decreases, the deflection produced in the plate-like elastic member 14 increases. Can.

In the power transmission driving device 10, as shown in FIG. 4 (B), by the rotation of the bell crank 3 with the expansion and contraction of the piezoelectric element 2, expansion amount d ₁ of the piezoelectric element 2, the elongating and contracting direction of the piezoelectric element 2 (up-down direction in FIG. 4. hereinafter, sometimes referred to as "Y direction".) direction perpendicular to the (left-right direction in FIG. 4. hereinafter, sometimes referred to as "X direction".) of the displacement amount d ₂ is enlarged, further X-direction displacement amount d _2, is magnified by the plate-like elastic member 4 to the deflection amount d ₃ in the Y direction. Thus, in the power transmission-type drive 10, expansion amount d ₁ of the piezoelectric element 2, through the displacement enlarging two-stage due to the bell crank 3 and the plate-like elastic member 14, and d 1 _<d 2 _{<d 3} So that the deflection amount d ₃ is enlarged. Therefore, according to the power transmission type drive device of the present invention, the conventional power transmission type drive device using only expansion and contraction of the piezoelectric element or the piezoelectric element using only the shear insect type deformation of the plate-like elastic member The amount of displacement of the stator can be increased as compared with the conventional power transmission drive device in which the amount of expansion and contraction is increased. As a result, it is possible to miniaturize the size of the piezoelectric element necessary to obtain the displacement amount necessary for driving, and miniaturize the power transmission type driving device.

Next, with reference to FIG. 5, the relationship between the displacement amount of the end 3 b of the bell crank 3 obtained by the rotation of the bell crank 3 and the deflection amount of the plate-like elastic member 14 will be described.
The relationship between the displacement amount of the end 3b of the bell crank 3 in the power transmission type drive device 10 in the X direction and the deflection amount of the plate-like elastic member 14 is considered to be approximate to a triangle as shown in FIG. Can. As a result of applying a voltage to the piezoelectric element 2, it is assumed that the bell crank 3 rotates with the expansion of the piezoelectric element 2, and the distance between the end 3b of the bell crank 3 and the second fixing means 5 decreases by x. Assuming that the length of the plate-like elastic member 14 (the length in the state in which the deflection is eliminated) is a, the amount of deflection y in the case of bending into a scoop type is y = (2ax−x ² ) ^1/2 It will be / 2. For example, in the case of a = 20 mm and x = 5 μm, y = 158 μm, and the displacement of the end 3b of the bell crank 3 in the X direction is enlarged about 32 times to the deflection of the plate-like elastic member 14.
In fact, since the plate-like elastic member 14 is curved and deformed, the enlargement ratio is reduced depending on the material and shape of the plate-like elastic member 14, but in any case, the displacement amount of the end 3b of the bell crank 3 in the X direction (Hereinafter, this effect may be referred to as “the second displacement amount enlarging effect”). In particular, in the region where the displacement amount x of the end 3b of the bell crank 3 in the X direction is small, the second displacement amount enlarging effect by the bending of the plate-like elastic member 14 becomes large. Specifically, it is preferable to use in a region where the amount of displacement of the end 3b of the bell crank 3 in the X direction is enlarged by about 2 to 10 times by the deflection of the plate-like elastic member 14.

  Moreover, in the power transmission type drive device 100, the plate-like elastic member 14 is on the extension in the displacement direction of the end 3b of the bell crank 3 and in substantially the same plane in a state where the bending is eliminated. With such a configuration, the plate-like elastic member 14 can be bent so as to be convex in the direction orthogonal to the direction orthogonal to the expansion and contraction direction of the piezoelectric element 2, and the second displacement amount enlarging effect is maximized. Become. That is, this leads to further downsizing of the power transmission drive device 100, which is preferable.

2.1.4. Movable part 8
As described above, the expansion and contraction of the piezoelectric element 2 is converted to bending of the plate-like elastic member 4 through the bell crank 3 so that the power transmission drive is performed by the interaction with the plate-like elastic member 14. The movable part 8 of the device 100 can be operated. The form of the movable part 8 may be a form generally used for a power transmission type drive device, for example, a rotary body such as a rotor or a sphere, or a straight line such as a slider operable in one or two dimensions. It can be a mobile body, a rod-like body, a flat plate or the like. Hereinafter, the operations of the stator 7 and the movable portion (rotor) 8 in the power transmission type drive device 100 will be described with reference to FIG.

  As shown in FIG. 4A, in the power transmission type drive device 100, the stator 7 and the movable portion 8 are installed such that the movable portion 8 is in the vicinity of the flexible portion 14b of the plate-like elastic member 14. When a voltage is applied to the piezoelectric element 2 in such a state, the bell crank 3 is rotated by the expansion of the piezoelectric element 2 depending on the applied voltage, and the end portion of the bell crank 3 on the plate-like elastic member 14 side As the distance between the second fixing means 5 and the second fixing means 5b decreases, the bending portion 14b of the plate-like elastic member 14 is pushed up and bends into a scoop type. As the distance between the second fixing means 5 and the end portion 3b of the bell crank 3 on the side of the plate-like elastic member 14 decreases, the deflection produced in the flexing portion 14b of the plate-like elastic member 14 increases, as shown in FIG. As shown, the bending portion 14b eventually contacts the movable portion 8. By further increasing the bending of the bending portion 14 b from here, the movable portion 8 can be rotated by the friction between the bending portion 14 b and the movable portion 8.

  Here, in the power transmission drive device 100, it is possible to continuously rotate the movable portion 8 by adjusting the waveform of the voltage applied to the piezoelectric element 2. For example, it is preferable that the waveform of the applied voltage be a sine waveform, a trapezoidal waveform, or a sawtooth waveform as shown in FIG. That is, as the voltage applied to the piezoelectric element 2 is gradually increased, the flexible portion 14b of the plate-like elastic member 14 is slowly flexed into a scoop type to be in contact with the movable portion 8. Thereafter, when the voltage is further increased gradually, the movable portion 8 is rotated in the direction indicated by the arrow in FIG. 4 (B). Then, by rapidly reducing the applied voltage so that the piezoelectric element 2 is rapidly contracted, the movable portion 8 is slid as shown in FIG. While being rotated in the direction of the arrow of (B), for example, it is possible to return to the state of FIG. As described above, the movable portion 8 can be continuously rotated by periodically applying a voltage to the piezoelectric element 2 with a predetermined waveform. Note that low speed driving can be realized by thinning out the driving waveform.

  The magnitude of the voltage applied to the piezoelectric element 2 is determined according to the characteristics of the piezoelectric element 2, the device configuration, and the like, and is not particularly limited. Also, the frequency of the voltage is not particularly limited, but it may be, for example, about 100 Hz to 20 kHz, and the power transmission type of the present invention can be achieved by setting the frequency of the voltage to an ultrasonic frequency of about 20 kHz or more. It is also possible to use the drive as a so-called ultrasonic motor. In addition, when the frequency is changed at the time of driving, the rotation speed of the movable portion can be changed.

  In the above description, in the power transmission type drive device 100, by bringing the flexible portion 14b of the plate-like elastic member 14 into contact with the movable portion 8 from the state where the plate-like elastic member 14 and the movable portion 8 are not in contact. Although the case where the movable portion 8 is operated has been described, the operation of the power transmission type drive device 10 is not limited to this aspect. For example, an aspect as shown in FIG. 7 is also possible. FIG. 7 is a schematic view for explaining another operation aspect of the power transmission type drive device 10, focusing on the periphery of the contact portion between the plate-like elastic member 14 and the movable portion 8. That is, as shown in FIG. 7A, in the power transmission type drive device 100, a predetermined voltage is applied to the piezoelectric element 2, and the bending portion 14b of the plate-like elastic member 14 is bent according to the same principle as described above. The movable portion 8 is in contact with the movable portion 8. In such a state, when the voltage applied to the piezoelectric element 2 is gradually changed, the distance between the second fixing means 5 and the end 3b of the bell crank 3 on the side of the plate-like elastic member 14 depends on the applied voltage. Gradually increases and the deflection of the plate-like elastic member 14 decreases. When the deflection of the plate-like elastic member 14 is reduced, a frictional force is generated between the plate-like elastic member 14 and the movable portion 8, and the movable portion can be rotated as shown in FIG. 7 (B).

  Alternatively, in the above description, the movable portion 8 is rotated counterclockwise by changing the non-contact state of the plate-like elastic member 4 to the movable portion 8 from the non-contact state (FIG. 4B); Although the form (FIG. 5 (B)) which rotates the movable part 8 clockwise by making the member 14 into a non-contact state from a contact state was demonstrated, the rotation direction of the movable part 8 is not limited to these The movable portion 8 is rotated clockwise by, for example, bringing the plate-like elastic member 14 into contact with the movable portion 8 by adjusting the waveform of the drive voltage. On the other hand, it is possible to appropriately change the rotation direction of the movable portion 8, such as a form in which the movable portion 8 is rotated counterclockwise by changing the plate-like elastic member 14 from the contact state to the non-contact state.

2.2. Second Embodiment In the power transmission drive according to the present invention, the hinge may be provided on the bell crank 3 instead of the bell crank support 6. FIG. 8 is a schematic diagram for explaining the operation mode of the power transmission type drive device 200 of the present invention according to the second embodiment, and FIGS. 8 (A) and 8 (B) are respectively FIGS. It is a figure corresponding to B). In FIG. 8, the same components as those of the power transmission drive device 100 are denoted by the same reference numerals, and the description thereof will be omitted.

  As shown in FIG. 8, in the power transmission type drive device 200, the bell crank support 6 does not have a hinge, and the hinge 3 has a hinge 3c in which a notch 3d is formed. Also according to this embodiment, the rotation of the bell crank 3 accompanying the expansion and contraction of the piezoelectric element 2 can be facilitated. The position of the hinge 3 c is not particularly limited as long as the bell crank 3 can be pivoted, but it is preferable that the hinge 3 c be provided at an end on the bell crank support 6 side.

2.3. Third Embodiment In the present invention, the form of the stator provided in the power transmission type drive device is not limited to the form as the stator 7 described above. FIG. 9 schematically shows a stator 17 provided in a power transmission drive apparatus 300 according to a third embodiment of the present invention. Further, FIG. 10 schematically shows the operation mode of the power transmission drive apparatus 300 according to the third embodiment of the present invention. FIG. 10 is a view exemplifying a deformed (bent) state of the plate-like elastic member 24 accompanying the rotation of the bell crank 3 and / or the expansion and contraction of the piezoelectric element 12 and the description of the movable portion 8 and the like is omitted. . Further, in FIGS. 9 and 10, the same components as those of the power transmission type drive device 100 are denoted by the same reference numerals, and the description thereof will be omitted.

As shown in FIG. 9, in the stator 17, a plate-like elastic member 24 consisting only of the first fixing means 1, the piezoelectric element 2, the bell crank 3, and the bending portion 24b and the second fixing means 15 are connected in this order. And, the plate-like elastic member 24 and the second fixing means 15 are characterized in that they are connected via the piezoelectric element 12 different from the piezoelectric element 2. In other words, in the stator 17 provided in the power transmission type drive device 300, both ends (24 b ₁ , 24 b ₂ ) of the plate-like elastic member 24 are held between the end 3 b of the bell crank 3 and the piezoelectric element 12. It is connected. The piezoelectric element 12 is preferably a stretchable piezoelectric element, and can have the same form as that of the piezoelectric element 2 described above, for example.

  As shown in FIGS. 10A to 10D, according to the stator 17, the deflection amount and the deflection position of the plate-like elastic member 24 are adjusted by adjusting the voltage applied to the piezoelectric element 2 and the piezoelectric element 12 respectively. Can be adjusted arbitrarily, and it is possible to precisely control the operation of the movable portion 8 with more variations as compared with a mode in which only one piezoelectric element is provided. Further, since it is not necessary to generate the amount of deflection of the plate-like elastic member 24 necessary to operate the movable portion 8 depending only on the amount of extension of the piezoelectric element 2, the piezoelectric element 2 can be miniaturized. Also, even when a sufficient space can not be secured between the first fixing means 1 and the bell crank 3, the power transmission drive can be easily installed.

2.4. Fourth Embodiment In the power transmission drive according to the present invention, a plurality of stators may be provided. 11 and 12 schematically show a power transmission drive apparatus 400 according to a fourth embodiment of the present invention. In FIGS. 11 and 12, the same components as those of the power transmission drive device 10 are denoted by the same reference numerals, and the description thereof will be omitted.

  In the power transmission type drive device 400, a plurality of plate-like elastic members 24, 24, 24 are connected to one second fixing means 15, and the bell crank 3, the piezoelectric element 2, and the first It is characterized in that the fixing means 1 is connected. In the illustrated embodiment, the stators 7, 7 and 7 are circumferentially provided at intervals of 120 ° around the second fixing means 15. With such a configuration, it is possible to operate the sphere in multiple dimensions, for example, using the sphere 18 as the movable portion. That is, by changing the voltage applied to each of the stators 7, 7 and 7 to adjust the amount of deflection of the plate-like elastic member 24, it is possible to change the rotational direction of the sphere in multiple dimensions.

2.5. Fifth Embodiment In the power transmission type drive device according to the present invention, the first fixing means, the bell crank support portion, the bell crank and the second fixing means may be integrally formed of the same material. FIG. 13 schematically shows a power transmission drive apparatus 500 according to a fifth embodiment of the present invention. In the power transmission type drive device 500 shown in FIG. 13, the first fixing means 1, the bell crank support 6, the bell crank 3 and the second fixing means 5 are integrally formed, and other than having the annular stator 27. About the part, it can be set as the structure similar to the power transmission type drive device 10, and attaches | subjects the same code | symbol here, and abbreviate | omits description.

2.6. Sixth Embodiment In the power transmission drive according to the present invention, the first fixing means, the bell crank support portion, the bell crank, the plate-like elastic member and the second fixing means are integrally formed of the same material. May be FIG. 14 schematically shows a power transmission drive apparatus 600 according to a sixth embodiment of the present invention. In the power transmission type drive device 600 shown in FIG. 14, the plate-like elastic member 34 consisting only of the first fixing means 1, the bell crank supporting portion 6, the bell crank 3 and the bending portion 34b and the second fixing means 5 are integrally formed. The parts other than having the annular stator 37 can be configured similarly to the power transmission type drive device 10, and here, the same reference numerals are given and the description will be omitted.

2.7. Other Configurations As described above, the power transmission type drive device according to the present invention obtains the second displacement amount enlarging effect by bending the plate-like elastic member into a worm-like insect shape, thereby moving the plate-like elastic member to the movable portion By moving the movable part. Therefore, it is preferable to provide the power transmission drive apparatus with a control means for restricting the direction of the deflection (convex direction) of the plate-like elastic member to the movable portion side.

  FIG. 15 schematically shows a form in which a restraining means 19a for restraining the direction of deflection of the plate-like elastic member 14 is provided in the power transmission type drive device 100. As shown in FIG. The restricting means 19a is a means provided separately from the stator 7, and in contact with the bending portion 14b of the plate-like elastic member 14 in a state where the bending of the bending portion 14b of the plate-like elastic member 14 is eliminated. Alternatively, it is provided in the vicinity of the bending portion 14 b of the plate-like elastic member 14. When bending occurs in the bending portion 14b of the plate-like elastic member 14, the bending portion 14b of the plate-like elastic member 4 always bends so as to be convex on the opposite side to the restriction means 19a due to the presence of the restriction means 19a. Ru.

Alternatively, as in the plate-like elastic member 24, in a mode in which the plate-like elastic member comprises only a bending portion, the direction of the bending of the plate-like elastic member may be restricted by devising the plate-like elastic member itself. Good. As an example, the control means 29a, 29a provided on the plate-like elastic member 24 is schematically shown in FIG. In FIG. 16, a cross-sectional view in the thickness direction of the plate-like elastic member 24 is schematically shown. As shown in FIG. 16, by providing convex portions as regulating means 29a, 29a at the end of the plate-like elastic member 24, the direction of deflection of the plate-like elastic member 24 is regulated in the direction of the illustrated arrow. In the plate-like elastic member 14, pieces extending from one end 14b ₁ of the bending portion 14b in the expansion and contraction direction of the piezoelectric element 2 (Y-direction) of the first engagement portion 14c, and, from one end 14b ₂ of the flexures 14b The second engaging portion 4c extending in the expansion and contraction direction (Y direction) functions as a restricting means.

  The plate-like elastic members 14 and 24 are slightly curved in advance within a range not impairing the second displacement amount enlarging effect according to the present invention, thereby causing the plate-like shape to operate the power transmission drive device according to the present invention. The direction of deflection of the elastic members 14, 24 can also be regulated in a desired direction.

  As described above, in the power transmission type drive device according to the present invention, the stator is configured by connecting the piezoelectric element, the bell crank, and the plate-like elastic member between the fixing means, and the bell crank is expanded and contracted by the piezoelectric element. By rotating the plate-like elastic member in a worm-like manner, the expansion and contraction amount of the piezoelectric element can be expanded to the amount of deflection (deformation amount) of the plate-like elastic member. Therefore, even if only one piezoelectric element is used and it is a small-sized piezoelectric element, a large amount of deformation can be obtained by the rotation of the bell crank and the deflection of the plate-like elastic member. Moreover, it is also possible to abbreviate | omit the installation space of a stator by making an elastic member into plate shape. By providing a plurality of piezoelectric elements or a plurality of stators, it is also possible to operate the movable portion in multiple dimensions. As described above, according to the power transmission type drive device of the present invention, the amount of expansion and contraction of the piezoelectric element is expanded by the bell crank and the plate-like elastic member to obtain the necessary driving force while being miniaturized. It is possible to operate

  In the above description, the elastic member having a rectangular planar shape is exemplified as the flexible portion 14b of the plate-like elastic member 14 and the plate-like elastic member 24 formed only of the flexible portion 24b. It is not limited. Various planar shapes such as trapezoidal shape and triangular shape can be adopted. However, from the viewpoint of bending the plate-like elastic member equally from both ends and deforming so as to be convex at the approximate center, it is preferable to use a plate-like elastic member in which the planar shape of the bending portion is rectangular.

  Further, in the above description, referring to FIGS. 9 and 10, in the case where a plurality of piezoelectric elements are provided on one stator, an embodiment in which the piezoelectric elements 12 are provided between the plate-like elastic member 24 and the second fixing means 15 is illustrated. However, the present invention is not limited to the embodiment. Depending on the shape of the plate-like elastic member, three or more piezoelectric elements may be provided in one stator. However, from the viewpoint of miniaturizing the power transmission type drive device, the number of piezoelectric elements relative to one plate-like elastic member should be small, and it is preferable to use one or two piezoelectric elements.

  Further, in the above description, while referring to FIGS. 11 and 12, in the case of providing a plurality of stators, an example is illustrated in which three stators 7 are provided at intervals of 120 ° centering on the second fixing means 15. It is not limited to the form. The number of stators and the installation mode of the stators can be determined according to the shape of the movable portion, the location where the power transmission drive apparatus is installed, and the like.

  Further, in the above description, only the form in which the restricting means 19a, 29a or the plate-like elastic member is slightly curved is exemplified as the restricting means, but the form of the restricting means is not limited thereto. Any means capable of restricting the deflection of the plate-like elastic members 14 and 24 is included in the present invention.

  Hereinafter, although the effect is further explained in detail about a power transmission type drive concerning the present invention by an example, the present invention is not limited to the following concrete forms.

<Configuration of Power Transmission Drive Device>
The power transmission type drive device shown in FIG. 17 was manufactured and performance evaluation was performed. In the produced power transmission type drive device, the length of the laminated piezoelectric element (NEC TOKIN, AE0203D16F) is 5 mm (E in FIG. 17), and the length in the expansion / contraction direction of the bell crank's laminated piezoelectric element is 10 mm (FIG. 17 D), the length of the bell crank's laminated piezoelectric element in the direction orthogonal to the expansion and contraction direction is 3.8 mm (C in FIG. 17), and the length of the flexible portion of the plate-like elastic member (phosphor bronze) is 4.8 mm It is referred to as B) of FIG. 17, and the thickness of the plate-like elastic member is 0.2 mm.

<Confirmation of displacement expansion effect>
The stator constructed as described above, the laminated piezoelectric device With a voltage of 140V, the extension amount of the laminated piezoelectric element (corresponding to d ₁ in FIG. 4 (B)) is 4.15μm, and the bell crank end displacement amount in the direction orthogonal to the elongating and contracting direction of the piezoelectric element parts (corresponding to d ₂ in FIG. 4 (B)) corresponding to d ₃ of the amount of deflection of 7.25μm, and the elastic plate member (see FIG. 4 (B) ) Became 9.72 μm. That is, about 2.3 times the displacement amount enlargement effect was obtained. It is considered that this enlargement ratio can be further improved by changing the shape and dimension of the plate-like elastic member.

<Operational Experiment of Power Transmission Drive>
As shown in FIG. 17, the rotor having a diameter of 30 mm (A in FIG. 17) was rotated by interacting with the above-described stator. As a result of applying a trapezoidal wave voltage of about 1 kHz to the laminated piezoelectric element, the rotor could be rotated continuously. The rotor could be rotated continuously at other frequencies.

  As described above, the bell crank is rotated by the expansion and contraction of the piezoelectric element, and the plate-like elastic member is deformed into a worm shape, and the expansion and contraction amount of the piezoelectric element is expanded, thereby achieving a large drive while reducing in size. It has been possible to provide a power transmission drive capable of obtaining a force.

  While the present invention has been described above in connection with embodiments which are presently practical and which are believed to be preferred, the present invention is limited to the embodiments disclosed herein. Rather, it can be suitably modified without departing from the scope and spirit of the invention which can be read from the claims and the specification as a whole, and a power transmission drive with such modifications is also included in the technical scope of the present invention. It must be understood as

  The power transmission type drive device according to the present invention can be used as a friction drive type actuator for causing a stator excited by mechanical vibration to contact a movable portion such as a rotor or a slider and causing rotation or linear motion operation. The present invention can be suitably used in various fields such as an autofocus and an XY stage, a security camera, a surgical instrument, and a multi-dimensional motor incorporated in a door mirror of a car or the like.

DESCRIPTION OF SYMBOLS 10 bell crank type drive 1 1st fixing means 2 piezoelectric element 3 bell crank 4 action member 4a 1st engaging part 4b action part 6 bell crank support part 6a hinge 6b notch 100 power transmission type drive 14 plate-like elasticity Member 14a first engagement portion 14b flexure portion 14c second engagement portion 5 second fixing means 7 stator 8 movable portion (rotor)
19a Regulation Means 200 Power Transmission Type Drive Device 3c Hinge 3d Notched Portion 300 Power Transmission Type Drive Device 12 Piezoelectric Element 24 Plate-like Elastic Member 14b Flexure Part 15 Second Fixing Means 17 Stator 29a Regulation Means 400 Power Transmission Type Drive Device 18 Movable Department (sphere)
500 power transmission type drive 27 stator 600 power transmission type drive 34 plate-like elastic member 37 stator

Claims (13)

A bell crank type drive for moving an action member, wherein
The first fixing means, the piezoelectric element, and the bell crank are connected in this order,
The bell crank is rotated by expansion and contraction of the piezoelectric element with the first fixing means as a fixed end,
When the bell crank rotates, the action member moves.
In a cross section orthogonal to the rotation center of the bell crank,
A distance from the rotation center to a straight line that bisects vertically the width of the surface where the bell crank and the piezoelectric element are connected;
Let t be the distance from the center of rotation to a straight line that bisects the width of the surface connecting the bell crank and the action member vertically.
t / s> 1
Bell crank type drive.   The bell crank mechanism device according to claim 1, wherein the bell crank is L-shaped. A power transmission drive comprising the bell crank drive according to claim 1 or 2, wherein
The action member is a plate-like elastic member,
The first fixing means, the piezoelectric element, the bell crank, the stator formed by connecting the plate-like elastic member and the second fixing means in this order, and the action by interaction with the plate-like elastic member of the stator A movable part,
By the rotation of the bell crank, the distance between the end of the bell crank on the side of the plate-like elastic member and the second fixing means increases or decreases, and the end of the bell crank on the side of the plate-like elastic member and the As the distance to the two fixing means decreases, the deflection occurring in the plate-like elastic member is configured to increase.
Power transmission type drive unit.   The power transmission drive according to claim 3, wherein the plate-like elastic member is bent so as to be convex in a direction orthogonal to the direction orthogonal to the expansion and contraction direction of the piezoelectric element.   The power transmission drive according to claim 3 or 4, wherein the stator comprises a bell crank support connecting the first fixing means and the bell crank and supporting the bell crank.   The power transmission drive according to any one of claims 1 to 5, wherein the bell crank or the bell crank support has a hinge.   The power transmission drive according to claim 6, wherein the hinge is a resilient hinge having a notch.   The power transmission drive according to any one of claims 3 to 7, wherein a plurality of the stators are provided.   The plurality of plate-like elastic members are connected to one of the second fixing means, and the bell crank, the piezoelectric element and the first fixing means are connected to the respective plate-like elastic members. The power transmission drive according to any one of 8.   The power transmission according to any one of claims 5 to 9, wherein the first fixing means, the bell crank support portion, the bell crank, the plate-like elastic member and the second fixing means are integrally formed. Mold drive.   The power transmission drive according to any one of claims 3 to 10, wherein a restricting means for restricting the direction of deflection of the plate-like elastic member is provided to be in contact with the plate-like elastic member.   The power transmission drive according to any one of claims 3 to 11, wherein a convex portion is provided at an end portion of the plate-like elastic member as a regulating means for regulating the direction of bending of the plate-like elastic member.   The power transmission drive according to any one of claims 3 to 12, wherein the plate-like elastic member and the second fixing means are connected via a piezoelectric element different from the piezoelectric element.