JP2006340528A - Piezoelectric actuator and apparatus equipped with it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive piezoelectric actuator of simple structure in which reliability of vibration is sustained by reducing chipping and cracking of a piezoelectric element, and to provide an apparatus equipped with that piezoelectric actuator. <P>SOLUTION: In the piezoelectric actuator 10 comprising an oscillator 20 including a rectangular thin plate-like piezoelectric element 80 and having the oscillating direction in the in-plane direction of the oscillator 20, an oscillator supporting member 40 is supporting the oscillator 20 while winding around the cross-section in the vicinity of a position becoming the central node of oscillation of the oscillator 20. The supporting member 40 has a shaft 43 for supporting the oscillator 20 in both surface and rear surface directions such that it becomes substantially perpendicular to the in-plane direction of oscillation of the oscillator 20, and when the supporting member 40 is urged in one direction by an urging means, the oscillator 20 is urged by a rotor 90 existing in the in-plane direction of oscillation. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a piezoelectric actuator and a device including the piezoelectric actuator.

  2. Description of the Related Art Conventionally, a piezoelectric actuator having a vibrating body including a piezoelectric element in the form of a rectangular thin plate, the vibration direction of which is the in-plane direction of the vibrating body, and the support member that supports the piezoelectric actuator is the vibration of the vibrating body. There is known a piezoelectric actuator in which a through hole is formed in a vibrating body at a position in the vicinity of the node, and a supporting member is inserted into the through hole to support the vibrating body (see, for example, Patent Document 1).

  In addition, a pair of arm portions are extended on both sides in the width direction of the vibrating body including the piezoelectric element, the arm portions are fixed to a rigid support body, and the support body is disposed along the radial direction of the driven body to vibrate. There is also known a piezoelectric actuator that is driven by bringing a protrusion formed on the body into contact with the outer periphery of the driven body (see, for example, Patent Document 2).

JP 2004-297949 A JP 2004-159399 A

  In Patent Document 1, a through hole is formed in a vibrating body including a piezoelectric element, and a supporting member is inserted into the through hole to support the vibrating body. However, the piezoelectric element is generally brittle. Therefore, when opening a through-hole or attaching and driving a piezoelectric actuator to a device, it is conceivable that the periphery of the through-hole is missing, the piezoelectric element is broken, or the vibration performance of the piezoelectric element is deteriorated. In addition, this requires a step of opening a through hole in the piezoelectric element, which may increase the cost.

  According to Patent Document 2, a pair of arms are extended on both sides in the width direction of a vibrating body provided with a piezoelectric element, and the arms are fixed to a rigid support, so that an external force is applied to the vibrating body. If the arm part is deformed in such a case, a drag is generated and the vibration is hindered, or if the arm part is repeatedly subjected to bending vibration and stress is continuously applied, fatigue failure of the arm part occurs. Is expected to occur.

  Furthermore, since the pair of arm portions extend on both sides in the width direction of the vibrating body, the occupied area of the vibrating body is increased, and the number of pieces taken from one base material is reduced, resulting in an increase in cost. Can be considered. Further, since the area occupied by the vibrating body is increased, it can be said that the structure is disadvantageous for downsizing the device.

  SUMMARY OF THE INVENTION The object of the present invention is to solve the above-mentioned problems, and a piezoelectric actuator that has few chippings and cracks, maintains vibration reliability, has a simple structure and is low in cost, and the piezoelectric actuator. It is providing the apparatus of high efficiency drive.

  The piezoelectric actuator of the present invention is a piezoelectric actuator having a vibrating body including a piezoelectric element having a rectangular thin plate shape, wherein the vibrating direction of the vibrating body is an in-plane direction of the vibrating body, and supporting the vibrating body The member supports the vibrating body by winding around a cross section in the vicinity of a position that becomes a central node of vibration of the vibrating body.

  According to the present invention, since the vibrating body is supported by being wound around the cross section in the vicinity of the position that becomes the center node of vibration by the supporting member, the supporting member is inserted into the vibrating body as in Patent Document 1 described above. Therefore, it is not necessary to provide a through-hole for the purpose, and it is possible to prevent the peripheral edge of the through-hole from being chipped and the piezoelectric element from being cracked by providing the through-hole. From this, stable vibration can be maintained, and since there is no step of opening a through hole in a brittle piezoelectric element, the yield can be improved and the cost can be reduced.

  In addition, it is preferable that the support member includes a support shaft that supports both front and back surface directions of the vibrating body so as to be substantially perpendicular to an in-plane direction of vibration of the vibrating body.

  According to this structure, since the support member is provided substantially perpendicular to the vibration plane and the vibrating body is supported in both the front and back surfaces, stable in-plane vibration can be obtained. In addition, since it vibrates in a direction perpendicular to the support member, the contact with the driven body is stable, wear of the contact surface of the vibrating body and the driven body is reduced, and reliable transmission of the driving force is maintained. Can do.

The present invention further includes a plurality of electrodes formed on the piezoelectric element and a voltage applying unit that applies a voltage to the plurality of electrodes, and the support member is interposed between the plurality of electrodes and the voltage applying unit. It is preferable to provide a conduction terminal that is inserted through the terminal.
Here, examples of the voltage applying unit include a lead wiring having a driving circuit and a detection circuit and a connection piece, a circuit board, and the like.

  According to this configuration, in the structure in which the periphery of the cross section near the position serving as the central node portion of the vibration of the vibrating body is wound by the support member, between the plurality of electrodes formed on the piezoelectric element and the connection piece of the circuit board Therefore, the connection reliability is improved and a thin piezoelectric actuator can be provided.

  In the present invention, it is preferable to insert-mold the vibrating body with a synthetic resin to form the support member.

  Therefore, since the support member is molded by a method of insert-molding the vibration body, the mutual positional accuracy between the vibration body and the support member can be increased, and the adhesion between the vibration body and the support member is good. The influence of vibration caused by providing the support member can be reduced.

In the present invention, a non-circular opening is opened in the vicinity of the vibration center node of the vibrating body of the electrode formed on the piezoelectric element, and when the vibrating body and the support member are insert-molded, It is preferable that a part of the support member is filled in the opening.
Here, as the non-circular opening, a shape having a function of preventing rotation and misalignment so that the support member and the vibrating body can be driven integrally is shown. There are polygons and ellipses.

  In this way, since the non-circular opening is partially filled with the support member, it is possible to prevent the vibrating body from rotating with respect to the support member and to prevent displacement, and to prevent vibration. Since the positional accuracy of the support member with respect to the body can be further increased, stable vibration and reliable transmission of driving force can be performed.

  Moreover, it is desirable that the conductive terminal is loaded when the vibrating body and the support member are insert-molded.

  Thus, since the vibrating body, the conductive terminal, and the support member are insert-molded, the relative positional accuracy of these can be improved, and the number of manufacturing steps can be reduced even if the conductive terminal is provided.

  Further, it is preferable that the support member is urged in one direction by an urging unit, and the vibrating body is urged by a driven member in an in-plane direction of vibration.

According to this invention, since the vibrating body is biased to the driven member in the in-plane direction of vibration by the biasing means, the driving force can be reliably transmitted to the driven body.
Further, even if a shape error and a position error of the vibrating body and the driven body occur in manufacturing, the contact between the vibrating body and the driven body can be surely obtained, and a stable driving force can be transmitted.

In the present invention, it is desirable that the urging means has elasticity.
Since the urging means has elasticity, the vibrating body and the driven body can be further reliably contacted, the change of the urging force with respect to the positional deviation is small, and the urging force is It can be stably obtained within the range of elastic force.

  The apparatus of the present invention includes a piezoelectric actuator having the above-described structure, a biasing means for biasing a vibrating body of the piezoelectric actuator to a driven member in a vibration in-plane direction, and applying a driving voltage to the piezoelectric actuator. And a transmission mechanism for transmitting the rotation of the driven member.

  According to the present invention, since the above-described piezoelectric actuator is provided, the above-described effects can be obtained, and a device capable of transmitting vibration and driving force with high efficiency and high efficiency can be realized.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a piezoelectric actuator according to Embodiment 1 of the present invention, and FIG. 2 shows a vibration form of the piezoelectric actuator. FIG. 3 shows a piezoelectric actuator according to Embodiment 2 of the present invention, and FIGS. 4 and 5 show a device including the piezoelectric actuator of the present invention.
(Embodiment 1)

  FIG. 1 is a perspective view showing a structure of a piezoelectric actuator 10 according to the first embodiment. In FIG. 1, the piezoelectric actuator 10 includes a vibrating body 20 and a support member 40 that supports the vibrating body 20 as a basic configuration.

The vibrating body 20 is formed in a rectangular thin plate shape having a longitudinal direction and has a dimensional ratio of long side: short side of about 7: 2, a motion transmission plate 70, piezoelectric elements 80 attached to both surfaces thereof, It is comprised including. The motion transmission plate 70 has a protrusion 71 within the width of the electrode 31 described later on one side of the short side, and this protrusion 71 is a rotor part of a rotor 90 (see FIG. 5) as a driven body. It abuts on the contact surface 91. In addition, the protrusion 71 is also provided at a point-symmetrical position with respect to the central node in order to balance the vibration.
In this embodiment, the motion transmission plate 70 is made of a material having excellent toughness and strength such as stainless steel.

  The piezoelectric element 80 includes lead zirconate titanate (PZT (registered trademark)), crystal, lithium niobate, barium titanate, lead titanate, lead metaniobate, polyvinylidene fluoride, lead zinc niobate, lead scandium niobate, etc. It is used by selecting from various types.

  The piezoelectric element 80 is divided into three equal parts in parallel to the longitudinal direction, and both sides of the piezoelectric element 80 are divided into two equal parts in the short side direction. Electrodes 31 to 35 are formed on the surface of the equally divided piezoelectric element 80. The electrodes 31 to 35 are formed on the piezoelectric elements 80 provided in both the front and back directions of the vibrating body 20 so that the planar shape is plane-symmetric.

  A central portion in the planar direction of the piezoelectric element 80 is a central node portion of vibration of the vibrating body 20 and is a fixed point. A support member 40 made of synthetic resin is formed by insert molding in the vicinity of the central node. The support member 40 is in close contact with the surface of the vibrating body 20 by insert molding. The support member 40 is configured by a frame portion 41 that is wound around the entire circumference of a cross section in the vicinity of the central node portion, and a projection portion centering on the central node portion is provided on the upper surface of the frame portion 41. The In this protrusion, a corner 42 and a support shaft 43 that are square in plan view are formed in a step shape. The corner portion 42 is fitted into a square hole provided in a pressing lever 101 (see FIG. 4) described later.

  The support shaft 43 protrudes substantially perpendicularly to the surface of the vibrating body 20 and is also formed on the back surface side of the vibrating body 20. The pair of support shafts 43 are provided above and below the piezoelectric actuator 10. It is supported by the substrate 97 and the second substrate 98 (see FIG. 5). Thus, the vibrating body 20 is supported by the support member 40 in a state of floating in the air.

  Conductive terminals 44 to 49 are inserted into the frame portion 41 of the support member 40 (see also FIG. 4). These conduction terminals 44 to 49 are made of metal, and the surface is covered with a material having good conductivity such as gold plating. The conduction terminals 44 to 49 are insert-molded after being loaded into the insert mold together with the vibrating body 20. The conduction terminals 44 to 48 are disposed at positions corresponding to the electrodes 31 to 35, respectively. The conduction terminal 49 is provided in the side surface direction of the frame portion 41, and is approximately at the center in the cross-sectional direction of the motion transmission plate 70. Has been placed.

  The conduction terminals 44 to 48 have one end face connected to the electrodes 31 to 35, and the conduction terminal 49 is connected to the motion transmission plate 70. The conduction terminal 49 is connected to the ground electrode. These conduction terminals 44 to 49 are connected to the electrodes 31 to 35 or the motion transmission plate 70 by connection means such as a conductive adhesive, solder bumps, and thermocompression bonding. The other end surfaces of the conduction terminals 44 to 49 slightly protrude from the surface of the frame portion 41 and are connected to connection pieces 61 to 66 formed on the circuit board 60 described later (see FIG. 4).

Next, the vibration mode of the piezoelectric actuator 10 (vibrating body 20) of this embodiment will be described with reference to the drawings.
FIG. 2 is a plan view schematically showing the vibration form of the vibrating body 20. FIG. 2A shows a vibration form when a drive voltage is applied between the electrode 33 and the motion transmission plate 70. First, when a drive voltage is applied to the electrode 33, the piezoelectric element 80 in the portion where the electrode 33 is formed performs expansion and contraction (in the direction of arrow L).
Since the vibrating body 20 has the longitudinal direction, the displacement of the expansion and contraction in the longitudinal direction is larger than the expansion and contraction in the direction orthogonal to the longitudinal direction (short side direction). The vertical primary vibration is performed with the center position of the vibration as the center node of the vibration. Since the support member 40 is formed at the central portion that is the central node of the longitudinal primary vibration, it is located at a fixed point that does not affect the longitudinal primary vibration.

  FIG. 2B shows a vibration mode when a drive voltage is applied to the electrodes 31 and 34 and the motion transmission plate 70. When a voltage is simultaneously applied to the electrode 31 and the electrode 34, the piezoelectric element 80 in the range where the electrodes 31 and 34 are formed vibrates and contracts (in the direction of arrow G). When the entire vibrating body 20 is viewed, the portions of the electrodes 31 and 34 that perform expansion and contraction and the portions of the electrodes 32 and 35 that do not perform expansion and contraction are asymmetrical and thus bend.

  Therefore, the vibrating body 20 bends and vibrates in the direction perpendicular to the longitudinal direction with the central part of the vibrating body 20 equidistant from the electrodes 31, 32, 34, 35 as a node (arrow K direction). Since the support member 40 supports the vicinity of the node of the bending secondary vibration, it is located at a fixed point that does not affect the bending secondary vibration.

  2A and 2B, the support member 40 supports the vibrating body 20 at a position where both nodes of the longitudinal primary vibration and the bending secondary vibration are closest to each other. The vibrating body 20 can be supported without affecting the above.

  FIG. 2C shows the movement of the protrusion 71 when a voltage is applied to the electrodes 31, 33, and 34 and the motion transmission plate 70. In FIG. 2 (c), the protrusion 71 has a longitudinal trajectory in the direction of the arrow H in the in-plane direction of the vibrating body 20 by combining longitudinal primary vibration and bending secondary vibration. Have an elliptical motion. In a part of this elliptical motion, the protrusion 71 gives a driving force corresponding to the direction and force of the elliptical motion to the rotor 90 which is a driven body.

  In order to reverse the direction of the driving force applied to the rotor 90 and reverse the rotation of the rotor 90, the electrode to which the voltage is applied is axisymmetric about the central node or one electrode is reversed. What is necessary is just to drive by a phase. That is, by applying a voltage to the electrodes 32, 33, 35 and the motion transmission plate 70, the protrusion 71 draws an elliptical motion in the opposite direction, and a driving force acts in a direction corresponding to the elliptical motion. At this time, it is preferable to appropriately adjust the contact position and angle between the protrusion 71 and the rotor 90.

  In the present embodiment, the electrodes to which no voltage is applied (corresponding to the electrodes 32 and 35 in FIG. 2A) are used for vibration detection, and the detection signal is transmitted via the connection pieces 65 and 63 (see FIG. 4). To a detection circuit (not shown). Thereby, it becomes possible to detect the vibration of the vibrating body 20 and adjust the voltage applied to the electrode by feedback control.

  Therefore, according to the first embodiment described above, since the vibrating body 20 is supported by the support member 40 in the vicinity of the center node portion of the vibration, the support member is inserted into the vibrating body as in Patent Document 1 described above. Therefore, it is possible to prevent occurrence of chipping of the peripheral edge of the through hole and cracking of the piezoelectric element due to the provision of the through hole. From this, stable vibration can be maintained, and since there is no step of opening a through hole in a brittle piezoelectric element, the yield can be improved and the cost can be reduced.

  In addition, since the support shaft 43 of the support member 40 is provided substantially perpendicular to the vibration plane and the vibrating body 20 is supported in both the front and back surfaces, the support state is stable and stable in-plane vibration is obtained. Can do. Further, since it vibrates in a direction perpendicular to the support shaft 43 and is not easily tilted, the contact with the rotor 90 is stable, the wear of the contact surface between the protrusion 71 of the vibrating body 20 and the rotor 90 is reduced, and reliable driving Power transmission can be maintained.

  Further, when the vibrating body 20 is flexibly vibrated, the support shaft 43 is set in a loose-fitting relationship. Therefore, compared with the structure in which the vibrating body is supported by a pair of arms as described in Patent Document 2, the drag is reduced. In addition to being less likely to occur and reducing vibration loss, it is possible to prevent fatigue failure of the vibrator.

  Further, in the structure in which the periphery of the cross section in the vicinity of the position serving as the central node of the vibration of the vibrating body 20 is wound by the support member 40, the plurality of electrodes 31 to 35 and the motion transmission plate 70 formed on the piezoelectric element 80 and the circuit board Since the connection between the 60 connection pieces 61 to 66 is performed by the conduction terminals 44 to 49, the connection reliability can be improved and a thin piezoelectric actuator can be provided.

  In addition, since the support member 40 is formed by insert molding of the vibration body 20, the mutual positional accuracy between the vibration body 20 and the support member 40 can be increased, and the adhesion between the vibration body 20 and the support member 40 can be improved. Therefore, the influence on the vibration by providing the support member 40 can be reduced.

Furthermore, since the conduction terminals 44 to 49 are also insert-molded, the relative positional accuracy with the electrodes 31 to 35 formed on the piezoelectric element 80 can be improved, and the number of manufacturing steps can be reduced even if the conduction terminals are provided. .
(Embodiment 2)

Next, a piezoelectric actuator according to Embodiment 2 of the present invention will be described with reference to the drawings. The second embodiment is characterized in that a rotation stopper is added between the vibrating body and the support member, and the other parts are the same as in the first embodiment described above, and therefore the description thereof will be omitted and the same reference numerals will be given. To do.
FIG. 3 is a partial cross-sectional view showing the piezoelectric actuator 10 of the present embodiment, and shows a structure in which the piezoelectric actuator 10 is cut in the width direction at the center node of vibration of the vibrating body 20.

  In FIG. 3, the piezoelectric actuator 10 has the same configuration as that of the first embodiment (see FIG. 1), and the center node portion of the vibration of the vibrating body 20 is insert-molded with a support member 40. The vibrating body 20 is configured by attaching piezoelectric elements 80 to both front and back surfaces of the motion transmission plate 70, and electrodes 31 to 35 are formed on the surface thereof. Here, a rectangular opening 33a is formed at the center of the electrode 33 shown in FIG.

  The opening 33a has a size that does not separate the electrode 33 in the longitudinal direction, and penetrates in the thickness direction. When the support member 40 is insert-molded in this state, a part of the support member 40 is filled into the opening 33a. Since the opening 33a is a quadrangle, when the vibrating body 20 is subjected to secondary bending vibration or when it is rotated in the direction of the rotor 90 by the biasing force of the spring 105 as the biasing means (see FIG. 4). The vibrating body 20 has a function of preventing rotation with no positional deviation in the rotational direction with respect to the support member 40.

  The planar shape of the opening 33a is not limited to a quadrangle, and is not limited as long as it has a function of preventing rotation, and may be a triangle, another polygon, or an ellipse. The opening 33a may be formed to a partial depth by half-etching the electrode 33 or the like.

Therefore, according to the second embodiment described above, the non-circular opening 33a is formed in the electrode 33, and since the opening 33a is partially filled with the support member 40, the support member 40 is vibrated. The body 20 can be prevented from rotating, the positional accuracy of the support member 40 with respect to the vibrating body 20 can be improved, and stable vibration and reliable driving force can be transmitted.
(Equipment with piezoelectric actuator)

Next, the device 1 including the piezoelectric actuator 10 described in the first embodiment and the second embodiment will be described with reference to the drawings.
FIG. 4 is a partial plan view showing the periphery of the piezoelectric actuator of the device 1 according to the present invention, and FIG. 5 is a partial cross-sectional view showing the AA cross section shown in FIG. 4 and 5, the device 1 including the piezoelectric actuator 10 according to the present embodiment includes a piezoelectric actuator 10, a drive circuit and a detection circuit (not shown) as voltage supply means for supplying a drive voltage to the piezoelectric actuator, A circuit board 60 for connecting the voltage supply means and the piezoelectric actuator 10; a spring 105 as an urging means for urging the piezoelectric actuator 10 toward the rotor 90 as a driven body; , And is configured.

  Since the piezoelectric actuator 10 has been described in the first and second embodiments, a description thereof will be omitted, but the conductive terminals 44 to 49 connected to the electrodes 31 to 35 and the motion transmission plate 70 are provided in the frame portion 41 of the support member 40. Has been planted. And the connection pieces 61-66 by which the electrode pattern formed in the circuit board 60 was extended are connected to the end surface of these conduction | electrical_connection terminals 44-49.

  The circuit board 60 is a flexible flexible board, and has a symmetrical shape with respect to the surface of the vibrating body 20 on both the front and back surfaces of the vibrating body 20, and is provided on the back side of the vibrating body 20. A connection piece is also connected to the terminal. The circuit board 60 is bent downward in the thickness direction at the position of the conduction terminal 49, and the connection piece 66 is connected to the conduction terminal 49. In addition, the electrode pattern group 67 continuing to each of the connection pieces 61 to 66 formed on the circuit board 60 is connected to a drive circuit and a detection circuit (not shown).

  A pressing lever 101 is attached to a corner portion 42 formed in the support member 40. A square hole 102 corresponding to the corner portion 42 is formed at one end of the pressing lever 101, and the corner hole 102 and the corner portion 42 are set in a tight fitting relationship. On the side surface of the other end of the pressing lever 101, a spring 105 as a biasing means is mounted.

The spring 105 is illustrated as a coil spring in FIG. One end of the spring 105 is in contact with the side surface of the pressing lever 101, and the other end is in contact with the pressing wall 103 provided in the device 1 to urge the pressing lever 101 in the direction of arrow C.
The pressing lever 101 can be formed integrally with the support member 40.

  Therefore, the piezoelectric actuator 10 is rotated in the direction of the rotor 90 as the driven body with the support shaft 43 as the center of rotation (in the direction of arrow D), and the protrusion 71 is urged against the contact surface of the rotor 91. When a driving voltage is applied, the vibrating body 20 vibrates in the above-described vibration form (see FIG. 2), and the protrusion 71 performs an elliptical motion in the arrow H direction to rotate the rotor 90 in the arrow F direction. The rotation of the rotor is transmitted to a transmission wheel 95 as a transmission mechanism, and is increased or decreased to a predetermined rotational speed.

  The piezoelectric actuator 10, the rotor 90, and the transmission wheel 95 are pivotally supported between the first substrate 97 and the second substrate 98. In more detail with reference to FIG. 5, the piezoelectric actuator 10 is pivotally supported by a first substrate 97 and a second substrate 98 on support shafts 43 formed on the upper and lower surfaces of the support member 40. The rotor 90 includes a rotor portion 91 and a gear 92, and the protrusion 71 of the vibrating body 20 abuts against the side surface of the rotor portion 91 to rotate the rotor 90. The rotation of the rotor 90 is transmitted to a transmission wheel 95 that meshes with the gear 92.

  Therefore, a device including the piezoelectric actuator 10 described above includes the piezoelectric actuator 10 having the above-described effects, a structure that floats the piezoelectric actuator 10 in a hollow state, and a biasing force to the rotor 90 by the spring 105. Efficiently good vibration and transmission of driving force can be obtained.

Further, since the vibrating body 20 is urged by the spring 105 to the rotor 90 as a driven member in the in-plane direction of vibration, the urging force can be stably obtained within the range of the elastic force of the spring 105. Therefore, a stable driving force can be transmitted to the rotor 90 as the driven body.
Further, even if a shape error and a position error of the vibrating body 20 and the rotor 90 occur in manufacturing, the vibrating body 20 and the rotor 90 can be brought into contact with each other, and the driving force can be reliably transmitted.

It should be noted that the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.
For example, the structure of the support member 40 and the connection structure between the voltage applying unit and the vibrating body 20 of the above-described embodiment can adopt other structures that can achieve the object of the present invention.

  In the second embodiment described above, an opening 33a is opened in the electrode 33 to prevent the vibration body 20 and the support member 40 from rotating, and the opening 33a is partially filled with the support member 40. The same effect can be obtained by forming a small protrusion or recess on the side surface of the motion transmission plate 70 in the vicinity of the central node of the motion transmission plate 70 and insert molding the support member 40.

  Furthermore, in Embodiment 1 described above, the conduction terminals 44 to 49 are insert-molded in the support member 40, but a through hole is opened in the support member 40, and the conduction terminals 44 to 49 are inserted into the through holes. Further, the connection pieces 61 to 66 formed on the circuit board 60 are inserted into the through holes, and the connection pieces are directly connected to the electrodes 31 to 35 and the motion transmission plate 70. You can also

  In the above-described embodiment, the protrusion 71 formed on the motion transmission plate 70 is disposed at a position corresponding to the electrode 31, but can be disposed at each position of the electrodes 32 to 35.

  Therefore, according to the present invention, it is possible to provide a piezoelectric actuator that prevents chipping and cracking of a piezoelectric element, maintains stable vibration, has a simple structure and is low in cost, and a highly efficient drive device including the piezoelectric actuator. Can do.

The perspective view which shows the piezoelectric actuator which concerns on Embodiment 1 of this invention. The schematic diagram which shows the vibration form of the vibrating body which concerns on Embodiment 1 of this invention. Sectional drawing which shows the piezoelectric actuator which concerns on Embodiment 2 of this invention. The partial top view which shows the piezoelectric actuator periphery of the apparatus by this invention. FIG. 5 is a cross-sectional view taken along the line AA in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Apparatus, 10 ... Piezoelectric actuator, 20 ... Vibrating body, 40 ... Support member, 70 ... Motion transmission board, 80 ... Piezoelectric element, 90 ... Rotor, 105 ... Spring as biasing means.

Claims (9)

A piezoelectric actuator having a vibrating body including a rectangular thin plate-like piezoelectric element, wherein the vibrating direction of the vibrating body is an in-plane direction of the vibrating body,
A piezoelectric actuator, wherein a support member that supports the vibrating body is wound around a cross section near a position that becomes a central node of vibration of the vibrating body to support the vibrating body. The piezoelectric actuator according to claim 1, wherein
The piezoelectric actuator according to claim 1, wherein the support member includes a support shaft that supports both front and back surfaces of the vibrating body so as to be substantially perpendicular to an in-plane direction of vibration of the vibrating body. The piezoelectric actuator according to claim 1 or 2,
A plurality of electrodes formed on the piezoelectric element; and voltage applying means for applying a voltage to the plurality of electrodes,
A piezoelectric actuator comprising a conduction terminal provided by being inserted through the support member between the plurality of electrodes and the voltage application means. The piezoelectric actuator according to any one of claims 1 to 3,
A piezoelectric actuator, wherein the vibration member is insert-molded with a synthetic resin to form the support member. The piezoelectric actuator according to claim 4, wherein
A non-circular opening is opened in the vicinity of the center node of the vibration of the vibrating body of the electrode formed in the piezoelectric element,
When insert-molding the vibrating body and the support member, a part of the support member is filled in the opening. The piezoelectric actuator according to claim 5, wherein
The piezoelectric actuator, wherein the conductive terminal is loaded when insert-molding the vibrating body and the support member. The piezoelectric actuator according to any one of claims 1 to 6,
The support member is biased in one direction by a biasing means;
The piezoelectric actuator, wherein the vibrating body is biased by a driven member in an in-plane direction of vibration. The piezoelectric actuator according to claim 7, wherein
The piezoelectric actuator, wherein the biasing means has elasticity. A piezoelectric actuator according to any one of claims 1 to 8,
An urging means for urging a vibrating body constituting the piezoelectric actuator to a driven member in an in-plane direction of vibration;
Voltage applying means for applying a driving voltage to the piezoelectric actuator;
A transmission mechanism for transmitting the movement of the driven member;
A device characterized by comprising:

Images