JP6020022B2 - Piezoelectric actuator, robot hand, robot, electronic component transport device, electronic component inspection device, liquid feed pump, printing device, electronic watch, projection device, transport device - Google Patents

Description

  The present invention relates to a piezoelectric actuator, a robot hand, a robot, an electronic component transport device, an electronic component inspection device, a liquid feed pump, a printing device, an electronic timepiece, a projection device, and a transport device.

  The piezoelectric actuator is a drive device having at least a piezoelectric element that converts a driving voltage such as a high-frequency AC voltage into mechanical vibration, and a driven member that is driven by the piezoelectric element. A piezoelectric motor is a type of piezoelectric actuator. That is, the piezoelectric motor is a driving device that uses a rotor as the above-mentioned driven member, and is a driving device that can use the vibration of the piezoelectric element as a rotational force.

  When a piezoelectric motor is used as a driving means for a robot hand (or robot), it is required that the rotation direction can be reversed between forward rotation (left rotation) and reverse rotation (right rotation).

  As a method of changing the rotation direction of the piezoelectric motor, the electrodes constituting the piezoelectric element are composed of a plurality of electrodes including a forward rotation electrode and a reverse rotation electrode, and a drive voltage is applied during forward rotation and reverse rotation. A technique for switching the electrodes to be used is known. For example, as shown in Patent Document 1, there is known a technique in which one piezoelectric element is combined with a plurality of driven parts each having a unique resonance frequency.

JP 2003-111457 A

  However, among the above methods, the former method requires a dedicated electrode for forward rotation and reverse rotation, and additionally requires a mechanism for switching electrodes to which a drive voltage is applied. The latter method requires a plurality of driven parts. Therefore, both methods have the problem of increasing the complexity and cost of the piezoelectric actuator.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

  Application Example 1 A piezoelectric actuator according to this application example includes a piezoelectric element including a piezoelectric body, a rectangular plate member on which the piezoelectric element is disposed, and a diaphragm having a protruding portion protruding from the short side of the rectangle. A piezoelectric actuator including at least a rotor abutting on the protrusion, wherein the protrusion passes through the center of the diaphragm and is offset from a first center line parallel to the long side of the rectangle. The diaphragm is provided with a counterweight formed so as to protrude from the long side of the rectangle in a direction orthogonal to the first center line at a diagonal position of the position where the protrusion is disposed. It is characterized by. Note that the first center line does not need to pass through the center of the diaphragm in the strict sense, and may pass through the center roughly. Further, the counterweight does not need to be in a diagonal position in a strict sense with respect to the protruding portion, but may be roughly in a diagonal position.

  With a piezoelectric actuator having a diaphragm having such a structure, the impedance at the resonance point of longitudinal primary vibration and the impedance at the resonance point of bending secondary vibration can be made equal to each other (including roughly equal values). . Therefore, the respective vibrations at the two resonance points can have an elliptical shape that is line symmetric (including roughly line symmetric) with respect to the long side direction. Therefore, by switching the frequency of the driving voltage applied to the piezoelectric layer, it is possible to switch between normal rotation and reverse rotation of the protrusion in the rotation direction. Therefore, a piezoelectric actuator capable of switching between normal rotation and reverse rotation without complicating the structure can be realized. Note that the forward rotation and reverse rotation described above are defined for the sake of convenience in that the left rotation is forward rotation and the right rotation is reverse rotation.

  Application Example 2 In the piezoelectric actuator described above, the counterweight is formed so as to protrude from a short side of the rectangle in a direction parallel to the first center line.

  In such a piezoelectric actuator, the counterweight protrudes from the short side of the rectangle in the direction parallel to the first center line, so without increasing the length of the protruding portion from the long side of the rectangle, The weight of the counterweight can be increased. As a result, since the length of the protruding portion of the piezoelectric actuator can be reduced, it is possible to realize a piezoelectric actuator with a small mounting space. In addition, the counterweight can adjust the moment acting on the diaphragm by adjusting the balance between the part protruding from the long side of the rectangle and the part protruding from the short side of the rectangle, so that the resonance weight becomes a more appropriate resonance point. Can be adjusted. Further, after the diaphragm is formed, the protruding portion can be removed from any part of the counterweight from either the direction parallel to the first center line or the direction perpendicular to the first center line. Fine adjustment of the moment acting on the diaphragm can be easily executed.

  Application Example 3 The piezoelectric actuator described above, wherein a counterweight is provided at a position symmetrical to the counterweight with respect to the first center line.

  In such a piezoelectric actuator, the counterweight is also provided at a position that is symmetrical with respect to the first center line (including a position that is roughly symmetrical), so that the length of the protruding portion of each counterweight can be reduced. The total weight of the counterweight can be increased without increasing it. As a result, each protruding portion can be reduced, and a piezoelectric actuator with a small mounting space can be realized. Further, by adjusting the balance of each counterweight, the moment acting on the diaphragm can be adjusted, so that the resonance point can be adjusted to a more appropriate resonance point. In addition, when adjusting the moment acting on the diaphragm, it is possible to remove a more appropriate part from each counterweight, making it possible to easily fine-tune the moment acting on the diaphragm. It becomes.

  Application Example 4 In the piezoelectric actuator described above, the second center line that is the center line of the protruding portion is parallel to the first center line of the diaphragm, and the center of the rotation axis of the rotor Is located on the second center line.

  In such a piezoelectric actuator, since the center of the rotation axis of the rotor is located on the center line (second center line) of the protrusion, even when the rotor is rotated clockwise, it is counterclockwise. Even in the case where the rotor and the projecting portion are rotated, the positional relationship between the rotor and the protruding portion is almost the same. Therefore, it is possible to realize a piezoelectric actuator that can rotate evenly (including roughly equal cases) in either direction.

  Application Example 5 A piezoelectric actuator as described above, wherein the piezoelectric element is a single plate.

  With such a piezoelectric actuator, the configuration can be simplified and the cost can be reduced as compared with a piezoelectric element that is not a single plate (stacked type). Note that “single plate” indicates a single plate-like member.

  Application Example 6 In the piezoelectric actuator described above, the ratio between the long side dimension of the diaphragm (long side length of the rectangle) and the short side dimension of the diaphragm (long side length of the rectangle) is A piezoelectric actuator characterized by 7 to 2 (including roughly 7 to 2).

  With a diaphragm having such a dimensional ratio, when a driving voltage is applied to the piezoelectric element, resonance in either the expansion mode or the bending mode of the diaphragm is likely to occur, so the diaphragm vibrates efficiently. . Therefore, a piezoelectric actuator that can rotate with high energy conversion efficiency in either direction can be realized without complicating the structure.

  [Application Example 7] A robot hand according to this application example includes a plurality of finger parts, a base body erected so that the finger parts are movable, and a piezoelectric actuator that moves the finger parts relative to the base body. The piezoelectric actuator includes a piezoelectric element including a piezoelectric body, a rectangular plate member on which the piezoelectric element is disposed, and a diaphragm having a protruding portion protruding from the short side of the rectangle; A piezoelectric actuator including at least a rotor abutting on the protrusion, wherein the protrusion is disposed at a position that is offset from a first center line that passes through the center of the diaphragm and is parallel to the long side of the rectangle. The diaphragm is a counter formed by projecting from the long side of the rectangle in a direction perpendicular to the first center line at a diagonal position where the protrusion is disposed. Characterized in that it comprises a Eito. Note that the first center line does not need to pass through the center of the diaphragm in the strict sense, and may pass through the center roughly. Further, the counterweight does not need to be in a diagonal position in a strict sense with respect to the protruding portion, but may be roughly in a diagonal position.

  With such a robot hand, the forward rotation and the reverse rotation of the piezoelectric actuator can be switched by switching the frequency of the drive voltage applied to the piezoelectric element. For this reason, it is possible to realize a high-performance robot hand without complicating the structure.

  Application Example 8 In the robot hand described above, the counterweight is formed so as to protrude from a short side of the rectangle in a direction parallel to the first center line.

  In such a robot hand, since the counterweight protrudes from the short side of the rectangle, the weight of the counterweight can be increased without increasing the length of the protruding portion from the long side of the rectangle. it can. As a result, the length of the protruding portion of the piezoelectric actuator can be reduced, and the space for mounting the piezoelectric actuator can be reduced. Therefore, a miniaturized robot hand can be realized.

  Application Example 9 A robot hand according to the above-described robot hand, wherein the counter weight is provided at a position symmetrical to the counter weight with respect to the first center line.

  In such a robot hand, since at least two counterweights are provided with reference to the first center line, the weight of the entire counterweight is increased without increasing the length of the protruding portion of each counterweight. be able to. As a result, each protruding portion can be reduced, and the space for mounting the piezoelectric actuator can be reduced. Therefore, a miniaturized robot hand can be realized.

  Application Example 10 In the robot hand described above, the second center line, which is the center line of the protruding portion, is parallel to the first center line of the diaphragm, and the center of the rotation axis of the rotor Is located on the second center line.

With such a robot hand, the protruding portion can be evenly contacted with the rotor. Therefore, the piezoelectric actuator can be rotated substantially equally in either direction. For this reason, it is possible to realize a high-performance robot hand without complicating the structure.
Application Example 11 The robot hand described above, wherein the piezoelectric element is a single plate.

  With such a robot hand, the configuration of the piezoelectric actuator can be simplified and the cost can be reduced. For this reason, the above-described robot hand can be realized at low cost.

  Application Example 12 In the robot hand described above, the ratio of the long side dimension of the diaphragm to the short side dimension of the diaphragm is 7 to 2 (including roughly 7 to 2). Robot hand characterized by

  With such a robot hand, when a driving voltage is applied to the piezoelectric element, the diaphragm vibrates efficiently. Therefore, the piezoelectric actuator can be rotated with high energy conversion efficiency in either direction without complicating the structure. For this reason, it is possible to realize a high-performance robot hand without complicating the structure.

  Application Example 13 A robot according to this application example includes: an arm part provided with a rotatable joint part; a hand part provided on the arm part; and a main body part provided with the arm part. A robot equipped with a piezoelectric actuator provided at the joint for bending or rotating the joint; and the piezoelectric actuator includes a piezoelectric element including a piezoelectric body and the piezoelectric element. A piezoelectric actuator comprising at least a diaphragm that is a rectangular plate and has a protruding portion that protrudes from the short side of the rectangle, and a rotor that contacts the protruding portion, wherein the protruding portion is the vibrating plate The diaphragm is disposed at a position offset from a first center line parallel to the long side of the rectangle, and the diaphragm is located at a diagonal position of the position where the protrusion is disposed. Characterized in that from the long side and a counterweight formed by projecting orthogonally from the first center line. Note that the first center line does not need to pass through the center of the diaphragm in the strict sense, and may pass through the center roughly. Further, the counterweight does not need to be in a diagonal position in a strict sense with respect to the protruding portion, but may be roughly in a diagonal position.

  With such a robot, the forward rotation and reverse rotation of the piezoelectric actuator can be switched by switching the frequency of the drive voltage applied to the piezoelectric element. Therefore, it is possible to realize a high-performance robot without complicating the structure.

  Application Example 14 An electronic component transport apparatus according to this application example is an electronic component transport apparatus including a grip portion that grips an electronic component and a piezoelectric actuator that drives the grip portion that grips the electronic component. The piezoelectric actuator is in contact with the protruding portion, a piezoelectric element including a piezoelectric body, a rectangular plate member on which the piezoelectric element is disposed, and a protruding portion protruding from a short side of the rectangular shape. A piezoelectric actuator including at least a rotor, wherein the protrusion is disposed at a position that is offset from a first center line that passes through the center of the diaphragm and is parallel to the long side of the rectangle. The plate is provided with a counterweight formed so as to protrude in a direction orthogonal to the first center line from the long side of the rectangle at a diagonal position where the protrusion is disposed. And wherein the are. Note that the first center line does not need to pass through the center of the diaphragm in the strict sense, and may pass through the center roughly. Further, the counterweight does not need to be in a diagonal position in a strict sense with respect to the protruding portion, but may be roughly in a diagonal position.

  With such an electronic component conveying apparatus, it is possible to switch between normal rotation and reverse rotation of the piezoelectric actuator by switching the frequency of the drive voltage applied to the piezoelectric element. For this reason, it becomes possible to implement | achieve a high performance electronic component conveying apparatus, without complicating a structure.

  Application Example 15 An electronic component inspection apparatus according to this application example includes a gripping unit that grips an electronic component, a piezoelectric actuator that drives the gripping unit that grips the electronic component, and an inspection unit that inspects the electronic component. The piezoelectric actuator includes a piezoelectric element including a piezoelectric body, a rectangular plate member on which the piezoelectric element is disposed, and a vibration having a protruding portion protruding from the rectangular short side. A piezoelectric actuator comprising at least a plate and a rotor abutted against the protrusion, wherein the protrusion is offset from a first center line passing through the center of the diaphragm and parallel to the long side of the rectangle. The diaphragm extends from the long side of the rectangle in a direction perpendicular to the first center line at a diagonal position of the position where the protrusion is disposed. Characterized in that it includes a counterweight that is made. Note that the first center line does not need to pass through the center of the diaphragm in the strict sense, and may pass through the center roughly. Further, the counterweight does not need to be in a diagonal position in a strict sense with respect to the protruding portion, but may be roughly in a diagonal position.

  With such an electronic component inspection device, it is possible to switch between normal rotation and reverse rotation of the piezoelectric actuator by switching the frequency of the drive voltage applied to the piezoelectric element. For this reason, it is possible to realize a high-performance electronic component inspection apparatus without complicating the structure.

  Application Example 16 A liquid feed pump according to this application example holds a liquid tube in which a liquid can flow, a closed portion that contacts a part of the liquid tube to close the liquid tube, and the closed portion. A liquid feed pump comprising: a moving unit that moves the closed position of the liquid tube by moving in a state; and a piezoelectric actuator that drives the moving unit, wherein the piezoelectric actuator includes a piezoelectric element including a piezoelectric body A piezoelectric plate that is at least a rectangular plate member on which the piezoelectric element is disposed and has a protruding portion protruding from a short side of the rectangular shape, and a rotor that contacts the protruding portion. The projecting portion is disposed at a position offset from a first center line passing through the center of the diaphragm and parallel to the long side of the rectangle. , The diagonal positions of the position where the projecting portion is disposed, characterized in that it comprises a counterweight formed by projecting orthogonally from the first center line from the rectangular long side. Note that the first center line does not need to pass through the center of the diaphragm in the strict sense, and may pass through the center roughly. Further, the counterweight does not need to be in a diagonal position in a strict sense with respect to the protruding portion, but may be roughly in a diagonal position.

  With such a liquid feed pump, normal rotation and reverse rotation of the piezoelectric actuator can be switched by switching the frequency of the drive voltage applied to the piezoelectric element. For this reason, it is possible to realize a high-performance liquid feed pump without complicating the structure.

  Application Example 17 A printing apparatus according to this application example is a printing apparatus that includes a print head that prints an image on a medium and a piezoelectric actuator that moves the print head. The piezoelectric actuator includes a piezoelectric body. A piezoelectric element including at least a piezoelectric element including a piezoelectric plate, a diaphragm having a protruding portion protruding from a short side of the rectangle, and a rotor that is in contact with the protruding portion. It is an actuator, The said protrusion part is arrange | positioned in the position offset from the 1st center line parallel to the long side of the said rectangle through the center of the said diaphragm, and the said protrusion part arrange | positions the said diaphragm. And a counterweight formed so as to protrude from a long side of the rectangle in a direction orthogonal to the first center line at a diagonal position of the position.Note that the first center line does not need to pass through the center of the diaphragm in the strict sense, and may pass through the center roughly. Further, the counterweight does not need to be in a diagonal position in a strict sense with respect to the protruding portion, but may be roughly in a diagonal position.

  In such a printing apparatus, the forward rotation and the reverse rotation of the piezoelectric actuator can be switched by switching the frequency of the drive voltage applied to the piezoelectric element. For this reason, a high-performance printing apparatus can be realized without complicating the structure.

  Application Example 18 An electronic timepiece according to this application example is provided with gears coaxially, and is connected to the gear train including a rotatable rotating disc, a gear train including a plurality of gears, and the gear train. An electronic timepiece including a pointer for indicating time and a piezoelectric actuator for driving the rotating disk, wherein the piezoelectric actuator is a piezoelectric element including a piezoelectric body and a rectangular plate member on which the piezoelectric element is disposed. And a piezoelectric actuator having at least a diaphragm having a protruding portion protruding from the short side of the rectangle, and a rotor in contact with the protruding portion, the protruding portion passing through the center of the diaphragm The diaphragm is disposed at a position offset from a first center line parallel to the long side of the rectangle, and the diaphragm is located diagonally to the position where the protrusion is disposed from the long side of the rectangle to the first side. Characterized in that it includes a central line perpendicular counterweight formed to protrude in the direction of. Note that the first center line does not need to pass through the center of the diaphragm in the strict sense, and may pass through the center roughly. Further, the counterweight does not need to be in a diagonal position in a strict sense with respect to the protruding portion, but may be roughly in a diagonal position.

  In such an electronic timepiece, the forward rotation and the reverse rotation of the piezoelectric actuator can be switched by switching the frequency of the drive voltage applied to the piezoelectric element. For this reason, it is possible to realize a high-performance electronic timepiece without complicating the structure.

  Application Example 19 A projection apparatus according to this application example includes an optical lens, a projection unit that projects light from a light source, an adjustment unit that adjusts the projection state of the light by the optical lens, and the adjustment unit. A projection device including a piezoelectric actuator for driving, wherein the piezoelectric actuator is a piezoelectric element including a piezoelectric body, a rectangular plate member on which the piezoelectric element is disposed, and a protrusion protruding from a short side of the rectangle A piezoelectric actuator comprising at least a diaphragm having a rotor and a rotor in contact with the protrusion, wherein the protrusion extends from a first center line passing through the center of the diaphragm and parallel to the long side of the rectangle. The diaphragm is disposed at an offset position, and the diaphragm is stretched in a direction perpendicular to the first center line from the long side of the rectangle at a diagonal position of the position where the protrusion is disposed. Characterized in that it comprises a counterweight formed by. Note that the first center line does not need to pass through the center of the diaphragm in the strict sense, and may pass through the center roughly. Further, the counterweight does not need to be in a diagonal position in a strict sense with respect to the protruding portion, but may be roughly in a diagonal position.

  With such a projection apparatus, it is possible to switch between normal rotation and reverse rotation of the piezoelectric actuator by switching the frequency of the drive voltage applied to the piezoelectric element. For this reason, it is possible to realize a high-performance projection apparatus without complicating the structure.

  Application Example 20 A transport apparatus according to this application example is a transport apparatus that transports an object using a driving force of a piezoelectric actuator. The piezoelectric actuator includes a piezoelectric element including a piezoelectric body and the piezoelectric element. A piezoelectric plate actuator comprising at least a diaphragm having a protruding portion protruding from a short side of the rectangle, and a rotor in contact with the protruding portion, wherein the protruding portion is It is arranged at a position that is offset from a first center line that passes through the center of the diaphragm and is parallel to the long side of the rectangle, and the diaphragm is at a diagonal position of the position where the protrusion is arranged, The counterweight is characterized in that the counterweight is formed so as to protrude from the long side of the rectangle in a direction orthogonal to the first center line. Note that the first center line does not need to pass through the center of the diaphragm in the strict sense, and may pass through the center roughly. Further, the counterweight does not need to be in a diagonal position in a strict sense with respect to the protruding portion, but may be roughly in a diagonal position.

  With such a transport device, it is possible to switch between normal rotation and reverse rotation of the piezoelectric actuator by switching the frequency of the drive voltage applied to the piezoelectric element. For this reason, it becomes possible to implement | achieve a high performance conveying apparatus, without complicating a structure.

The top view which shows the outline of the piezoelectric motor concerning embodiment of this invention. The schematic perspective view which shows the support body etc. which support the laminated body of a piezoelectric element and a diaphragm, and this laminated body so that a vibration is possible. The figure which shows the cross section of a piezoelectric motor. The top view which shows the diaphragm with which the piezoelectric motor of this embodiment is provided with a rotor. The figure which shows the impedance characteristic of a diaphragm. The figure which shows two types of locus | trajectories which the protrusion part of a diaphragm draws. The figure which shows the rotation direction of the rotor with which the piezoelectric motor concerning this embodiment is provided. It is explanatory drawing which illustrated the robot hand incorporating the piezoelectric motor of this embodiment. It is explanatory drawing which illustrated the single arm robot provided with the robot hand. It is explanatory drawing which illustrated the robot of the multiple arms provided with the robot hand. It is the perspective view which illustrated the electronic component inspection apparatus comprised incorporating the piezoelectric motor of this embodiment. It is explanatory drawing about the fine adjustment mechanism incorporated in the holding | grip apparatus. It is explanatory drawing which illustrated the liquid feeding pump comprised incorporating the piezoelectric motor of this embodiment. It is the perspective view which illustrated the printing apparatus incorporating the piezoelectric motor of this embodiment. It is explanatory drawing which illustrated the internal structure of the electronic timepiece incorporating the piezoelectric motor of this embodiment. It is explanatory drawing which illustrated the projection apparatus incorporating the piezoelectric motor of this embodiment. FIG. 11 is a plan view showing a member and a protruding portion in which a diaphragm according to Modification 1 is integrally formed. It is a top view which shows the member and protrusion part in which the diaphragm of the modification 2-the modification 4 was formed integrally. FIG. 10 is a plan view illustrating an outline of a piezoelectric motor of a fifth modification.

  Hereinafter, a piezoelectric actuator according to an embodiment of the present invention, that is, a piezoelectric motor 1 capable of converting a rotation direction into forward rotation / reverse rotation will be described with reference to the drawings. The embodiment of the present invention is not limited to the structure and shape shown in the following drawings. In each of the following drawings, the scale of each component is different from the actual scale so that each component can be recognized in the drawing.

(Embodiment)
<Piezoelectric motor>
FIG. 1 is a plan view showing an outline of a piezoelectric motor 1 as a piezoelectric actuator according to an embodiment of the present invention. FIG. 2 is a schematic perspective view showing the piezoelectric element 22 and the diaphragm 21, which are components of the piezoelectric motor 1, and the support 3 that supports the laminated body of the piezoelectric element 22 and the diaphragm 21 so as to vibrate. 3 is a cross-sectional view showing a cross section of the piezoelectric motor 1 taken along the line AA ′ of FIG.

  As shown in FIG. 1, the piezoelectric motor 1 includes at least a laminate of the piezoelectric element 22 and the diaphragm 21, the support 3 that supports the laminate, and the rotor 100 that is a driven member. It is provided as a component. The plurality of components are arranged on one surface of the base 4.

  As shown in FIG. 2, the piezoelectric element 22 and the diaphragm 21 are rectangular plate materials having a short side and a long side in a plan view. The piezoelectric elements 22 are arranged on both the front and back surfaces of the diaphragm 21. The piezoelectric element 22 includes a piezoelectric layer 120 and a pair of electrodes formed on both front and back surfaces of the piezoelectric layer. The electrode on the diaphragm 21 side is the first electrode 121, and the other electrode is the second electrode 122. In addition, the electrode wiring which connects between this electrode and the control circuit of the electronic device which uses the piezoelectric motor 1 as a drive actuator is connected to both electrodes (121,122). In this figure and each figure to be described later, such electrode wiring is not shown.

  The material of the piezoelectric layer 120 is not particularly limited. Lead zirconate titanate (PZT (registered trademark)), crystal, lithium niobate, barium titanate, lead titanate, lead metaniobate, polyvinylidene fluoride, zinc Various materials such as lead niobate and lead scandium niobate can be used. The material of both electrodes (121, 122) is not particularly limited, and Ni (nickel), Au (gold), or the like can be used. As a method of forming the electrode, a method such as plating, sputtering, or vapor deposition can be used.

  The piezoelectric element 22 of this embodiment is a single plate. A single plate indicates that both the piezoelectric layer 120 and the electrodes (121, 122) described above are not divided. That is, the piezoelectric layer 120 has a rectangular shape that overlaps with the vibration plate 21, and the pair of electrodes (121, 122) is formed on the entire surface of the piezoelectric layer. Therefore, the same drive voltage is applied to the entire area of the piezoelectric layer 120 during the operation of the piezoelectric motor 1. Therefore, the drive voltage cannot be applied to the piezoelectric layer 120 locally, that is, for each region. The piezoelectric motor 1 of the present embodiment uses both the piezoelectric element 22 having electrodes (121, 122) formed on the entire surface, that is, not divided, by devising the shape of the diaphragm 21 and the like. Direction rotation is possible.

  The diaphragm 21 is integrally formed with an arm portion 24 that protrudes from the long side to the outside in the short side direction. A through hole 241 is formed at the end of each arm portion 24. The support body 3 includes a pair of fixing portions 31 to which the diaphragm 21 is fixed, and a slide portion 32 formed integrally with the fixing portion between the both fixing portions 31. A screw part 34 is formed in the fixing part 31 at a position corresponding to the through hole 241 of the arm part 24. The vibration plate 21 (more specifically, the laminated body of the piezoelectric element 22 and the vibration plate 21) is fixed to the fixing portion 31 by screwing the screw 26 through the through hole 241 to the screw portion 34. The

  As shown in FIG. 3, the slide portion 32 is disposed in a slide groove 41 formed in a concave shape on the base 4. In addition, elongated holes 33 are formed (two places) along the contact direction of the protrusion 23 with respect to the rotor 100 at the substantially center in the width direction of the slide portion 32. A screw 421 passes through the long hole 33. The screw 421 is screwed into a screw hole 42 formed in the base 4. With this configuration, the support 3 is supported by the base 4 so as to be slidable in the longitudinal direction of the long hole 33. Therefore, the vibration plate 21 (more specifically, a laminated body of the piezoelectric element 22 and the vibration plate 21) fixed to the fixing portion 31 of the support body 3 is movable toward the center direction of the rotor 100.

  Here, the fixed portion 31 and the slide portion 32 are formed to have a step. Therefore, when the fixing part 31 is considered as a convex part, the slide part 32 becomes a concave part. With this configuration, when the vibration plate 21 is attached to the fixed portion 31, a gap is secured between the stacked body of the piezoelectric element 22 and the vibration plate 21 and the slide portion 32. Accordingly, even when a driving voltage is applied to the piezoelectric element 22 and the above-described laminated body vibrates, the piezoelectric element 22 does not interfere with the screw 421 that penetrates the slide portion 32.

  As shown in FIGS. 1 and 3, in the fixing portions 31 on both sides of the support body 3, spring mounting portions 35 protruding in a columnar shape are formed on the side surfaces of the end portions opposite to the rotor 100 side, respectively. Yes. One end of a spring 36 is inserted into the spring mounting portion 35. The other end of the spring 36 is fixed to a locking piece 37 provided on the base 4. The spring 36 is arranged so that its expansion / contraction direction is substantially parallel to the long side direction of the diaphragm 21. Due to the spring force of the spring 36, the later-described protrusion 23 is pressed against the rotor 100 with a suitable biasing force.

  As shown in FIGS. 1 and 2, a protruding portion (sliding portion) 23 is disposed on the short side of the diaphragm 21 on the rotor 100 side so as to contact the rotor. On the other short side of the vibration plate 21, a counterweight 25 from which a part of the vibration plate 21 protrudes is integrally formed in the same manner as the arm portion 24. “Integral” indicates that the arm 24 and the counterweight 25 are formed continuously when the plate member is molded by press working or the like to form the diaphragm 21. Of the integrally formed (molded) members, in the present embodiment, a rectangular portion in a plan view overlapping with the piezoelectric element 22 is defined as the diaphragm 21. The protrusion 23 is not formed integrally with the diaphragm 21.

The rotor 100 has a diameter of approximately 6.0 mm and is made of a material having high hardness such as SUS440C. A concave portion 97 having an arcuate cross section is formed along the outer periphery. The rotor 100 has a shaft 44 and is rotatably supported by a bearing pin 43 formed in a direction perpendicular to the one surface of the base 4.
The protrusion 23 is in contact with the recess 97. As will be described later, when a drive voltage is applied to the piezoelectric element 22, the piezoelectric element and the diaphragm 21 vibrate. As a result, the protruding portion 23 that is a portion protruding from the diaphragm 21 vibrates so as to draw an elliptical orbit. The rotor 100 is rotated by the vibration that draws the elliptical orbit.

<Vibration plate>
FIG. 4 is a plan view showing the diaphragm 21 provided in the piezoelectric motor 1 of the present embodiment together with the rotor 100. In addition, illustration of the recessed part 97 is abbreviate | omitted.
The diaphragm 21 is made of SUS301 having a thickness of 0.5 mm, and has a horizontal (X) direction dimension of approximately 2.0 mm and a vertical (Y) direction dimension of approximately 7.0 mm. Therefore, the aspect ratio, that is, the ratio between the vertical dimension and the horizontal dimension is 7: 2.

  The protrusion 23 and the counterweight 25 are arranged at diagonal corners of the diaphragm 21, that is, at positions that are diagonal to each other in plan view, so that both outer contour lines are continuous with the long side of the diaphragm 21. Arranged (formed). That is, the protrusion 23 and the counterweight 25 are arranged (formed) at a position offset from the first center line 71 that is the center line in the long side direction of the diaphragm 21.

  The protruding portion 23 is formed by adhering a circular member made of alumina having a thickness of about 0.5 mm and a diameter R of about 1.0 mm so that a semicircle protrudes from the short side of the diaphragm 21. Accordingly, the protruding portion 23 of the vibration plate 21 is cut out in a semicircular shape at the corner portion to which the vibration plate 21 is bonded. Among the circular members, the protruding portion 23 is a portion protruding from the short side of the diaphragm 21, that is, from the end portion in the long side direction. Therefore, the dimension in the long side direction of the protrusion 23 is approximately 0.5 mm. The diaphragm 21 and the protruding portion 23 are bonded with an adhesive such as an epoxy resin.

  The protrusion 23 has a second center line 72 parallel to the first center line 71 of the diaphragm 21, and has a symmetrical shape in the X direction with respect to the second center line. . The center of the rotor 100 is located on the second center line 72. That is, the support 3 and the rotor 100 are arranged on the base 4 so that the diaphragm 21 supported by the support 3 and the center of the rotor 100 have the above positional relationship.

The dimension of the counterweight 25 is such that the dimension W in the short side direction (X direction) is approximately 0.5 mm, and the dimension L in the long side direction (Y direction) is approximately 1.0 mm, and the ratio of the short side dimension to the long side dimension. Is 1: 2. As described above, the counterweight 25 is formed in an elongated shape in the long side direction, and the tip reaches a position away from the center (center of gravity) of the diaphragm 21. Therefore, when the diaphragm 21 vibrates, the balance with the protrusion 23 can be effectively obtained (obtained).
Further, the dimension L (approximately 1.0 mm) of the counterweight 25 in the long side direction is larger than the dimension (approximately 0.5 mm) of the protruding part 23 in the long side direction. Such a dimensional ratio also contributes to securing a balance when the diaphragm 21 vibrates.

  The ratio of the horizontal dimension and the vertical dimension of the counterweight 25 is not limited to the above-described value. If the vertical dimension is larger than the horizontal dimension, the effect can be sufficiently exerted. Further, the vertical dimension may exceed twice the horizontal dimension. Even if the vertical dimension is smaller than the horizontal dimension, it is possible to balance the protrusion 23 by increasing the entire area of the counterweight 25.

  FIG. 5 is a diagram showing impedance characteristics (frequency-impedance characteristics) of the diaphragm 21 having the shape shown in FIG. The horizontal axis indicates the drive frequency (the drive voltage applied to the piezoelectric element 22, that is, the frequency of the alternating voltage), and the vertical axis indicates the impedance.

  As shown in the figure, two resonance points where the impedance with respect to the drive frequency is minimal appear. Of the two resonance points, the lower one is the resonance point of the longitudinal primary vibration, and the higher one is the resonance point of the bending secondary vibration. The impedances at both resonance points are substantially equal. The inventor succeeded in aligning both the impedance values by devising the shape of the diaphragm 21 and the shapes of the protruding portion 23 and the counterweight 25 arranged on the diaphragm. And it succeeded in making the protrusion part 23 draw a suitable elliptical orbit only by one vibration of said two vibrations.

Here, the longitudinal primary vibration is vibration in which the piezoelectric element 22 expands and contracts in the long side direction, and the bending secondary vibration is vibration in which the piezoelectric element 22 bends in the short side direction, that is, in a direction substantially orthogonal to the long side direction. is there. In a general piezoelectric actuator that is rotationally driven, that is, the piezoelectric motor 1, a vibration that draws an elliptical orbit is generated in the protruding portion 23 by synthesizing both of the above vibrations. For this reason, a substantially central frequency of the two resonance frequencies is selected as the driving frequency, and the longitudinal primary vibration and the bending secondary vibration are simultaneously generated.
However, in the case of such a driving method, in order to reverse the rotational direction of the elliptical orbit, it is necessary to form a plurality of electrodes on one surface of the piezoelectric element 22 as described above. Since the piezoelectric motor 1 according to the present embodiment rotates the rotor 100 by only one of the vibrations, the piezoelectric element 22 having single electrodes on both the front and back surfaces can be rotated in both the left and right directions.

FIG. 6 is a diagram illustrating two types of trajectories drawn by the protrusion 23 of the diaphragm 21 included in the piezoelectric motor 1 according to the present embodiment, that is, the displacement of the protrusion 23. 101 is a trajectory of longitudinal primary vibration obtained by applying a drive voltage of 279143 Hz, and 102 is a trajectory of bent secondary vibration obtained by applying a drive voltage of 283443 Hz.
As shown in the figure, it has an inclination of about 40 degrees with respect to the horizontal axis, that is, the short side direction of the diaphragm 21. Therefore, when the protrusion 23 is brought into contact with the rotor 100, the rotor can be suitably rotated.

FIG. 7 is a diagram illustrating the rotation direction of the rotor 100 included in the piezoelectric motor 1 according to the present embodiment. In addition, illustration is abbreviate | omitted about the arm part 24 and the through-hole 241 in this figure. Further, the description of the protrusion 23 and the counterweight 25 is omitted.
FIG. 7A shows a case where longitudinal primary vibration is generated in the diaphragm 21. Since the trajectory 101 of the longitudinal primary vibration draws a clockwise ellipse, the rotor 100 rotates counterclockwise. That is, it rotates forward.
FIG. 7B shows a case where the bending secondary vibration is generated in the diaphragm 21. Since the trajectory 102 of the bending secondary vibration draws a counterclockwise ellipse, the rotor 100 rotates clockwise. That is, it reverses.

Here, as shown in this figure and FIG. 6, the trajectory 101 of the longitudinal primary vibration and the trajectory 102 of the bending secondary vibration are substantially line symmetric about the second center line 72 (see FIG. 4). Yes. Therefore, the rotor 100 rotates at substantially the same speed or the like during both the forward rotation and the reverse rotation.
As described above, the piezoelectric motor 1 according to the present embodiment can switch between the longitudinal primary vibration and the bending secondary vibration by switching the frequency of the drive voltage. Therefore, the piezoelectric motor 1 of the present embodiment can switch between forward rotation and reverse rotation in the rotation direction only by switching the frequency of the drive voltage.

<Effect of this embodiment>
As described above, the piezoelectric motor 1 of the present embodiment can rotate in both the forward and reverse directions. Therefore, it can be used as an actuator for driving an electronic device that requires a reciprocating motion such as a robot (robot hand). As described above, the piezoelectric motor 1 according to the present embodiment can switch the rotation direction only by switching the frequency of the drive voltage. Therefore, the electrodes (121, 122) formed on the front and back surfaces of the piezoelectric element 22 can also be a single object (single plate), and the cost can be reduced.
In addition, the electronic apparatus using the piezoelectric motor 1 of the present embodiment can omit the electrode wiring and the electrode wiring switching mechanism for applying the driving voltage, and can simplify the driving circuit and the like. Therefore, by using the piezoelectric motor 1 of the present embodiment, an electronic device that can reciprocate can be manufactured at low cost.

<Application example>
The above-described piezoelectric motor 1 of the present embodiment can be suitably incorporated in the following apparatus.

  FIG. 8 is an explanatory view illustrating a robot hand 600 incorporating the piezoelectric motor 1 of the present embodiment. In the illustrated robot hand 600, a plurality of fingers 603 are erected from a base 602, and are connected to an arm 610 via a wrist 604. Here, the base portion of the finger portion 603 is movable in the base 602, and the piezoelectric motor 1 is mounted in a state where the protruding portion 23 is pressed against the base portion of the finger portion 603. For this reason, by operating the piezoelectric motor 1, the finger part 603 can be moved and the target can be gripped. The piezoelectric motor 1 is also mounted on the wrist 604 in a state where the protruding portion 23 is pressed against the end surface of the wrist 604. For this reason, it is possible to rotate the whole base 602 by operating the piezoelectric motor 1.

  FIG. 9 is an explanatory diagram illustrating a single-arm robot 650 provided with a robot hand 600 (hand unit). As shown in the figure, the robot 650 has an arm 610 (arm portion) including a plurality of link portions 612 (link members) and a joint portion 620 that connects the link portions 612 in a bendable state. doing. The robot hand 600 is connected to the tip of the arm 610. In the joint portion 620, the piezoelectric motor 1 is built. For this reason, it is possible to bend each joint part 620 only by arbitrary angles by operating the piezoelectric motor 1.

  FIG. 10 is an explanatory view illustrating a multi-arm robot 660 including the robot hand 600. As illustrated, the robot 650 includes a plurality of arms 610 (two in the illustrated example) each including a plurality of link portions 612 and joint portions 620 that connect the link portions 612 in a bendable state. ) A robot hand 600 and a tool 601 (hand unit) are connected to the tip of the arm 610. In addition, a plurality of cameras 663 are mounted on the head 662, and a control unit 666 that controls the entire operation is mounted inside the main body 664. Further, it can be conveyed by a caster 668 provided on the bottom surface of the main body 664. This robot 660 also includes the piezoelectric motor 1 in the joint portion 620. For this reason, it is possible to bend each joint part 620 only by arbitrary angles by operating the piezoelectric motor 1.

  FIG. 11 is a perspective view illustrating an electronic component inspection apparatus 700 configured by incorporating the piezoelectric motor 1 of this embodiment. The illustrated electronic component inspection apparatus 700 generally includes a base 710 and a support base 730 erected on the side surface of the base 710. On the upper surface of the base 710, an upstream stage 712u on which the electronic component 10 to be inspected is placed and transported, and a downstream stage 712d on which the inspected electronic component 10 is placed and transported are provided. ing. Further, between the upstream stage 712u and the downstream stage 712d, an imaging device 714 for confirming the posture of the electronic component 10 and an inspection table on which the electronic component 10 is set for inspecting electrical characteristics. 716 (inspection unit). Representative examples of the electronic component 10 include “semiconductor”, “semiconductor wafer”, “display device such as CLD and OLED”, “crystal device”, “various sensors”, “inkjet head”, “various types” MEMS device "etc. are mentioned.

  Further, the support base 730 is provided with a Y stage 732 that can move in a direction (Y direction) parallel to the upstream stage 712u and the downstream stage 712d of the base 710. An arm portion 734 extends in a direction toward the 710 (X direction). An X stage 736 is provided on the side surface of the arm 734 so as to be movable in the X direction. The X stage 736 is provided with an imaging camera 738 and a gripping device 750 with a built-in Z stage movable in the vertical direction (Z direction). In addition, a grip portion 752 that grips the electronic component 10 is provided at the tip of the grip device 750. Further, a control device 718 for controlling the entire operation of the electronic component inspection apparatus 700 is also provided on the front side of the base 710. In the present embodiment, the Y stage 732, the arm portion 734, the X stage 736, and the gripping device 750 provided on the support base 730 correspond to the “electronic component transport device” of the present invention.

  The electronic component inspection apparatus 700 having the above configuration inspects the electronic component 10 as follows. First, the electronic component 10 to be inspected is placed on the upstream stage 712u and moved to the vicinity of the inspection table 716. Next, the Y stage 732 and the X stage 736 are moved to move the gripping device 750 to a position directly above the electronic component 10 placed on the upstream stage 712u. At this time, the position of the electronic component 10 can be confirmed using the imaging camera 738. When the gripping device 750 is lowered using the Z stage built in the gripping device 750 and the electronic component 10 is gripped by the gripping portion 752, the gripping device 750 is moved onto the imaging device 714 as it is. The posture of the electronic component 10 is confirmed using the device 714. Subsequently, the posture of the electronic component 10 is adjusted using a fine adjustment mechanism built in the gripping device 750. Then, after moving the gripping device 750 onto the inspection table 716, the Z stage built in the gripping device 750 is moved to set the electronic component 10 on the inspection table 716. Since the attitude of the electronic component 10 is adjusted using the fine adjustment mechanism in the gripping device 750, the electronic component 10 can be set at the correct position on the inspection table 716. When the inspection of the electrical characteristics of the electronic component 10 is completed using the inspection table 716, the electronic component 10 is again picked up from the inspection table 716, and then the Y stage 732 and the X stage 736 are moved to downstream. The gripping device 750 is moved above the side stage 712d, and the electronic component 10 is placed on the downstream stage 712d. Thereafter, the downstream stage 712d is moved to transport the electronic component 10 that has been inspected to a predetermined position.

  FIG. 12 is an explanatory diagram of a fine adjustment mechanism built in the gripping device 750. As shown in the figure, in the gripping device 750, a rotating shaft 754 connected to the gripping portion 752, a fine adjustment plate 756 to which the rotating shaft 754 is rotatably attached, and the like are provided. Further, the fine adjustment plate 756 is movable in the X direction and the Y direction while being guided by a guide mechanism (not shown).

  Here, as shown by hatching in FIG. 12, a piezoelectric motor 1θ for rotation direction is mounted toward the end surface of the rotating shaft 754, and a protruding portion (not shown) of the piezoelectric motor 1θ rotates. It is pressed against the end face of the shaft 754. Therefore, by operating the piezoelectric motor 1θ, the rotation shaft 754 (and the gripping portion 752) can be accurately rotated by an arbitrary angle in the θ direction. In addition, an X-direction piezoelectric motor 1x and a Y-direction piezoelectric motor 1y are provided toward the fine adjustment plate 756, and each protrusion (not shown) is pressed against the surface of the fine adjustment plate 756. It has been. Therefore, by operating the piezoelectric motor 1x, the fine adjustment plate 756 (and the grip portion 752) can be accurately moved by an arbitrary distance in the X direction. Similarly, by operating the piezoelectric motor 1y, The fine adjustment plate 756 (and the grip portion 752) can be accurately moved by an arbitrary distance in the Y direction. Therefore, the electronic component inspection apparatus 700 of FIG. 11 can finely adjust the posture of the electronic component 10 gripped by the gripping portion 752 by operating the piezoelectric motor 1θ, the piezoelectric motor 1x, and the piezoelectric motor 1y.

  FIG. 13 is an explanatory view illustrating a liquid feed pump 800 configured to incorporate the piezoelectric motor 1 of this embodiment. FIG. 13A shows a plan view of the liquid feed pump 800 as viewed from above, and FIG. 13B shows a cross-sectional view of the liquid feed pump 800 as viewed from the side. As shown in the figure, a liquid-feed pump 800 has a disk-shaped rotor 804 (moving part) rotatably provided in a rectangular-shaped case 802. Between the case 802 and the rotor 804, a chemical solution or the like is provided. A tube 806 (liquid tube) through which the liquid flows is sandwiched. Further, a part of the tube 806 is in a state of being closed by being crushed by a ball 808 (blocking portion) provided on the rotor 804. Therefore, when the rotor 804 rotates, the position where the ball 808 crushes the tube 806 moves, so that the liquid in the tube 806 is fed. And if the protrusion part 23 of the piezoelectric motor 1 of this embodiment is provided in the state pressed against the side surface of the rotor 804, the rotor 804 can be driven. In this way, it is possible to realize a small liquid feed pump 800 that can accurately deliver a very small amount of liquid.

  FIG. 14 is a perspective view illustrating a printing apparatus 850 incorporating the piezoelectric motor 1 of this embodiment. The illustrated printing apparatus 850 is a so-called inkjet printer that prints an image by ejecting ink onto the surface of the print medium 2. The printing device 850 is roughly box-shaped in appearance, and is provided with a paper discharge tray 851, a discharge port 852, and a plurality of operation buttons 855 at substantially the center of the front surface. Further, on the back side, a paper holder 853 for setting the printing medium 2 (roll paper 854) wound in a roll shape is provided. When the roll paper 854 is set in the paper holder 853 and the operation button 855 is operated, the roll paper 854 set in the paper holder 853 is sucked and an image is printed on the surface of the print medium 2 inside the printing apparatus 850. . In addition, the roll paper 854 is discharged from a discharge port 852 after being cut by a cutting mechanism 880 described later mounted inside the printing apparatus 850.

  Inside the printing apparatus 850, a print head 870 that reciprocates in the main scanning direction on the print medium 2 and a guide rail 860 that guides the movement of the print head 870 in the main scanning direction are provided. The illustrated print head 870 includes a print unit 872 that ejects ink onto the print medium 2 and a scan unit 874 that scans the print head 870 in the main scanning direction. A plurality of ejection nozzles are provided on the bottom surface side (side facing the printing medium 2) of the printing unit 872, and ink can be ejected from the ejection nozzles toward the printing medium 2. The scanning unit 874 is equipped with piezoelectric motors 1m and 10s. The protrusion (not shown) of the piezoelectric motor 1m is pressed against the guide rail 860. For this reason, the print head 870 can be moved in the main scanning direction by operating the piezoelectric motor 1m. Further, the protruding portion 23 of the piezoelectric motor 1 s is pressed against the printing portion 872. For this reason, by operating the piezoelectric motor 1 s, it is possible to bring the bottom surface side of the printing unit 872 closer to the printing medium 2 or away from the printing medium 2. The printing apparatus 850 is also equipped with a cutting mechanism 880 for cutting the roll paper 854. The cutting mechanism 880 includes a cutter holder 884 on which a paper cutter 886 is mounted at the tip, and a guide shaft 882 that extends through the cutter holder 884 in the main scanning direction. A piezoelectric motor 1c is mounted in the cutter holder 884, and a protrusion (not shown) of the piezoelectric motor 1c is pressed against the guide shaft 882. Therefore, when the piezoelectric motor 1c is operated, the cutter holder 884 moves in the main scanning direction along the guide shaft 882, and the paper cutter 886 cuts the roll paper 854. It is also possible to use the piezoelectric motor 1 to feed the print medium 2 to paper.

  FIG. 15 is an explanatory view illustrating the internal structure of an electronic timepiece 900 incorporating the piezoelectric motor 1 of this embodiment. FIG. 15 is a plan view of the electronic timepiece 900 viewed from the side opposite to the time display side (the back cover side). An electronic timepiece 900 illustrated in FIG. 15 includes a disc-shaped rotating disc 902, a gear train 904 that transmits the rotation of the rotating disc 902 to a pointer (not shown) that displays time, and a rotating circle. The piezoelectric motor 1 for driving the plate 902, a power supply unit 906, a crystal chip 908, and an IC 910 are provided. The power supply unit 906, the crystal chip 908, and the IC 910 are mounted on a circuit board (not shown). The gear train 904 includes a plurality of gears and a ratchet (not shown). In order to avoid complication of the illustration, in FIG. 15, a line connecting the gear teeth is represented by a thin alternate long and short dash line, and a line connecting the gear teeth is represented by a thick solid line. Accordingly, a double circle formed by a thick solid line and a thin one-dot chain line represents a gear. In addition, for the thin dash-dot line indicating the tooth tip, the entire circumference is not displayed, but only the periphery of the portion that meshes with another gear.

  The rotating disk 902 is provided with a small gear 902 g coaxially, and this gear 902 g is meshed with the gear train 904. Therefore, the rotation of the rotating disk 902 is transmitted through the gear train 904 while being decelerated at a predetermined ratio. Then, the rotation of the gear is transmitted to a hand indicating the time to display the time. And if the protrusion part 23 of the piezoelectric motor 1 of this embodiment is provided in the state pressed against the side surface of the rotation disc 902, the rotation disc 902 can be rotated.

  FIG. 16 is an explanatory view illustrating a projection device 950 incorporating the piezoelectric motor 1 of this embodiment. As shown in the figure, the projection apparatus 950 includes a projection unit 952 including an optical lens, and displays an image by projecting light from a built-in light source (not shown). Then, an adjustment mechanism 954 (adjustment unit) for focusing the optical lens included in the projection unit 952 may be driven using the piezoelectric motor 1 of the present embodiment. Since the piezoelectric motor 1 has a high positioning resolution, fine focusing can be performed. Further, while the light from the light source is not projected, it is possible to prevent the optical lens from being damaged by covering the optical lens of the projection unit 952 with the lens cover 956. In order to avoid opening and closing the lens cover 956, the piezoelectric motor 1 of this embodiment can also be used.

  Various modifications of the embodiment of the present invention are possible in addition to the above-described embodiment. Hereinafter, a modification will be described.

(Modification 1)
As described above, the shape of the protrusion 23 and the shape and arrangement of the counterweight 25 (the shape of the member in which the diaphragm is integrally formed) can be variously considered other than those shown in FIG. FIG. 17 is a plan view showing a member integrally formed with the diaphragm 151 of the modification 1 and the protruding portion 162. In this modification, the shape of the protrusion 162 and the shape of the diaphragm 151 to which the protrusion 162 is attached are different from the above-described embodiment.

  As shown in the figure, the protrusion 162 attached to the diaphragm 151 is not circular but has a long shape with only the tip being semicircular. The material of the protruding portion 23 is alumina as in the above-described embodiment, and the thickness is the same (including almost the same case). In addition, the shape of the attachment portion of the protruding portion 162 in the diaphragm 151 is a shape that is cut out in accordance with the shape of the protruding portion 162. Although it has been described above that the shape of the counterweight 25 can be changed, the shape of the protruding portion 23 can be changed to various types as described above. That is, the protrusion 23 and the counterweight 25 can be used in various shapes as long as the balance between the two can be achieved.

(Modification 2)
In the above-described embodiment, the counterweight 25 of the diaphragm 21 is formed so as to protrude from the short side to the long side (direction along the long side). However, the portion where the counterweight 25 is extended is not limited to the short side, but may be extended from the long side.

  FIG. 18A is a plan view showing a member integrally formed with the diaphragm 21 of the modification 2 and the protrusion 23. As shown in the drawing, the counterweight 250 according to the second modified example has a length of the diaphragm 21 at a diagonal position (including a case where the protruding portion 23 of the diaphragm 21 is disposed roughly). It is formed so as to protrude from the side in the short side direction (direction along the short side). By configuring as in Modification 2, it is possible to obtain the same effects as those of the above-described embodiment.

(Modification 3)
In the above-described embodiment or modification, the counter weight 25 of the diaphragm 21 has been described as being formed so as to protrude from either the short side or the long side. However, the counterweight 25 may be formed so as to protrude from both the short side and the long side.

  FIG. 18B is a plan view showing a member integrally formed with the diaphragm 21 of the modification 3 and the protrusion 23. As shown in the figure, the counterweight 350 according to the modified example 3 has a length of the diaphragm 21 at a diagonal position (including a rough diagonal position) where the protrusion 23 of the diaphragm 21 is disposed. It is formed so as to project from the side in the short side direction and from the short side so as to project in the long side direction.

  By configuring as in Modification 3, in addition to the same effects as in the above-described embodiment, the following effects can be obtained. That is, because the counterweight 350 protrudes not only from the long side but also from the short side, the weight of the counterweight should be increased while suppressing the length of the protruding part from the short side and the length of the protruding part from the long side. Can do. As a result, the protruding portion of the piezoelectric motor can be reduced, and a piezoelectric motor with a small mounting space can be realized.

  Further, the moment acting on the diaphragm 21 can be adjusted by adjusting the balance of the amount of protrusion between the protruding portion from the long side and the protruding portion from the short side of the counterweight. As a result, the resonance point of the diaphragm 21 can be adjusted more finely.

  Furthermore, when the moment acting on the diaphragm 21 is adjusted by cutting a part of the counterweight 350 after the diaphragm 21 is formed, either the projecting part from the short side or the projecting part from the long side can be removed. . For this reason, fine adjustment of the moment acting on the diaphragm 21 can be easily performed.

(Modification 4)
Further, in the above-described embodiment or modification, the counterweight 25 of the diaphragm 21 is formed at one position that is a diagonal position with respect to the protrusion 23. However, the counterweight 25 can be provided at a place other than the diagonal position.

  FIG. 18C is a plan view showing a member integrally formed with the diaphragm 21 of the modified example 4 and the protruding portion 23. As shown in the figure, the counterweight 450 according to the modified example 4 is formed only at the diagonal position (including the case where it is roughly at the diagonal position) where the protrusion 23 of the diaphragm 21 is disposed. Rather, it is also formed at a symmetric position (including a case of a roughly symmetric position) with respect to the first center line 71 as a reference.

  By configuring as in Modification 4, in addition to the same effects as those of the above-described embodiment, the following effects can be obtained. That is, since the two counterweights 450 are provided at positions symmetrical with respect to the first center line 71, the weight of the entire counterweight can be increased without increasing the length of the protruding portion of each counterweight. Can do. As a result, the length of the protruding portion of the piezoelectric motor can be reduced, and a piezoelectric motor with a small mounting space can be realized. In addition, the moment acting on the diaphragm 21 can be adjusted by adjusting the balance (size, shape, position to be formed) of the two counterweights 450, so that the resonance point can be adjusted more appropriately. It becomes. Further, when a part of the counterweight 450 is removed to adjust the moment acting on the diaphragm 21, it can be removed from either of the two counterweights 450, so that fine adjustment of the moment acting on the diaphragm 21 can be easily performed. Can be done.

(Modification 5)
FIG. 19 is a plan view schematically illustrating a piezoelectric motor according to the fifth modification. As described above with reference to FIGS. 1 and 3, the piezoelectric motor 1 according to the above-described embodiment is configured to include the arm portions 24 on the long sides on both sides of the diaphragm 21. On the other hand, the piezoelectric motor of Modification 5 shown in FIG. 19 includes only one of these arm portions 24. Specifically, the arm part 24 is formed on the long side on the protruding part 23 side (opposite side of the counterweight 25) among the long sides on both sides of the diaphragm 21. Accordingly, the fixing part 31, the screw part 34, the attachment part 35, the spring 36, and the screw 26 of the support 3 are provided with only one corresponding to the arm part 24 on the projecting part 23 side.

  With the above configuration, the diaphragm 21 of the modified example 5 is cantilevered by the support 3. As a result, the degree of freedom of movement of the diaphragm 21 in the rotational direction with the screwed portion (the through hole 241 of the arm portion 24) as a fulcrum increases, and consequently the movement distance of the protrusion 23 relative to the rotor 100 increases. Thus, the rotor 100 can be suitably rotated.

  Needless to say, the piezoelectric motors of the first to fourth modifications include the robot hand, robot, electronic component transport device, electronic component inspection device, liquid feed pump, printing device, electronic timepiece, which are described above with reference to FIGS. It can be applied to a projection apparatus.

    DESCRIPTION OF SYMBOLS 1 ... Piezoelectric motor as a piezoelectric actuator, 3 ... Support body, 4 ... Base, 21 ... Diaphragm, 22 ... Piezoelectric element, 23 ... Projection part, 24 ... Arm part, 25 ... Counterweight, 26 ... Screw, 31 ... Fixed part, 32 ... Slide part, 33 ... Long hole, 34 ... Screw part, 35 ... Spring mounting part, 36 ... Spring, 37 ... Locking piece, 41 ... Slide groove, 42 ... Screw hole, 43 ... Bearing pin, 44 DESCRIPTION OF SYMBOLS: 71, 1st center line, 72 ... 2nd center line, 97 ... Recessed part, 100 ... Rotor, 101 ... Trajectory of longitudinal primary vibration, 102 ... Trajectory of bending secondary vibration, 120 ... Piezoelectric layer, 121 ... 1st electrode, 122 ... 2nd electrode, 151 ... Diaphragm of the modification 1 226 ... Groove, 241 ... Through-hole, 421 ... Screw, 250 ... Deformation 2 counter weight 350 350 counter weight 450 450 counter weight 601 robot 601 tool 602 base 603 finger 604 wrist 610 arm 612: Link unit, 620: Joint unit, 650 ... Robot, 660 ... Robot, 662 ... Head, 663 ... Camera, 664 ... Main unit, 666 ... Control unit, 668 ... Caster, 700 ... Electronic component inspection device, 710 ... Base, 712d ... downstream stage, 712u ... upstream stage, 714 ... imaging device, 716 ... inspection table, 718 ... control device, 730 ... support base, 734 ... arm, 738 ... imaging camera, 750 ... gripping device, 752 ... gripping part, 754 ... Rotating shaft, 756 ... fine adjustment plate, 800 ... liquid feed pump, 802 ... case, 804 ... rotor, 806 ... tube, 808 ... ball, 850 ... printing device, 851 ... discharge tray, 852 ... discharge port, 853 ... paper Holder, 854 ... Roll paper, 855 ... Operation button, 860 ... Guide rail, 870 ... Print head, 872 ... Printing section, 874 ... Scanning section, 880 ... Cutting mechanism, 882 ... Guide shaft, 884 ... Cutter holder, 886 ... Paper Cutter, 900 ... Electronic clock, 902 ... Rotating disc, 902g ... Gear, 904 ... Gear train, 906 ... Power supply unit, 908 ... Crystal chip, 910 ... IC, 950 ... Projection device, 952 ... Projection unit, 954 ... Adjustment Mechanism, 956 ... lens cover .

Claims (18)

A piezoelectric element including a piezoelectric body;
A diaphragm having a protruding portion protruding from a short side of the rectangle, and a rectangular plate material on which the piezoelectric element is disposed;
A rotor abutting on the protrusion, and a piezoelectric actuator comprising:
The protrusion is disposed at a position offset from a first center line that passes through the center of the diaphragm and is parallel to the long side of the rectangle.
The vibration plate,
The diagonal positions of the front Symbol protrusion is arranged, and counterweight that protrudes from the rectangular long side in a direction orthogonal to the first center line,
A piezoelectric actuator, comprising: a counterweight disposed at a position symmetrical to the counterweight with respect to the first center line . The piezoelectric actuator according to claim 1,
The piezoelectric actuator is characterized in that the counterweight is formed so as to protrude from a short side of the rectangle in a direction parallel to the first center line. The piezoelectric actuator according to claim 1 or 2 , wherein
The second center line, which is the center line of the protrusion, is parallel to the first center line of the diaphragm, and the center of the rotation axis of the rotor is located on the second center line. A piezoelectric actuator characterized by A piezoelectric actuator according to any one of claims 1 to 3 ,
A piezoelectric actuator, wherein the piezoelectric element is a single plate. A piezoelectric actuator according to any one of claims 1 to 4 , wherein
The piezoelectric actuator according to claim 1, wherein a ratio of a long side dimension of the diaphragm and a short side dimension of the diaphragm is 7: 2. Multiple fingers,
A base body erected so that the finger portion is movable;
A piezoelectric actuator for moving the finger relative to the substrate;
A robot hand comprising:
The piezoelectric actuator is
A piezoelectric element including a piezoelectric body;
A diaphragm having a protruding portion protruding from a short side of the rectangle, and a rectangular plate material on which the piezoelectric element is disposed;
A rotor in contact with the protrusion,
With
The protrusion is disposed at a position offset from a first center line that passes through the center of the diaphragm and is parallel to the long side of the rectangle.
The vibration plate,
The diagonal positions of the front Symbol protrusion is arranged, and counterweight that protrudes from the rectangular long side in a direction orthogonal to the first center line,
A robot hand comprising: a counterweight disposed at a position symmetrical to the counterweight with respect to the first center line . The robot hand according to claim 6,
The robot hand according to claim 1, wherein the counterweight is formed so as to protrude from a short side of the rectangle in a direction parallel to the first center line. The robot hand according to claim 6 or 7 ,
The second center line, which is the center line of the protrusion, is parallel to the first center line of the diaphragm, and the center of the rotation axis of the rotor is located on the second center line. Robot hand characterized by A robot hand according to any one of claims 6 to 8 ,
The robot hand according to claim 1, wherein the piezoelectric element is a single plate. A robot hand according to any one of claims 6 to 9 ,
The robot hand according to claim 1, wherein a ratio of a long side dimension of the diaphragm and a short side dimension of the diaphragm is 7: 2. An arm provided with a rotatable joint, and
A hand portion provided on the arm portion;
A main body provided with the arm,
A piezoelectric actuator for bending or rotating the joint, and
A robot equipped with
The piezoelectric actuator is
A piezoelectric element including a piezoelectric body;
A diaphragm having a protruding portion protruding from a short side of the rectangle, and a rectangular plate material on which the piezoelectric element is disposed;
A rotor in contact with the protrusion,
With
The protrusion is disposed at a position offset from a first center line that passes through the center of the diaphragm and is parallel to the long side of the rectangle.
The vibration plate,
The diagonal positions of the front Symbol protrusion is arranged, and counterweight that protrudes from the rectangular long side in a direction orthogonal to the first center line,
And a counterweight disposed at a position symmetrical to the counterweight with respect to the first center line . A gripper for gripping electronic components;
A piezoelectric actuator that drives the gripping part that grips the electronic component;
An electronic component transport device comprising:
The piezoelectric actuator is
A piezoelectric element including a piezoelectric body;
A diaphragm having a protruding portion protruding from a short side of the rectangle, and a rectangular plate material on which the piezoelectric element is disposed;
A rotor in contact with the protrusion,
With
The protrusion is disposed at a position offset from a first center line that passes through the center of the diaphragm and is parallel to the long side of the rectangle.
The vibration plate,
The diagonal positions of the front Symbol protrusion is arranged, and counterweight that protrudes from the rectangular long side in a direction orthogonal to the first center line,
An electronic component transport apparatus comprising: a counterweight disposed at a position symmetrical to the counterweight with respect to the first center line . A gripper for gripping electronic components;
A piezoelectric actuator that drives the gripping part that grips the electronic component;
An inspection unit for inspecting the electronic component;
An electronic component inspection apparatus comprising:
The piezoelectric actuator is
A piezoelectric element including a piezoelectric body;
A diaphragm having a protruding portion protruding from a short side of the rectangle, and a rectangular plate material on which the piezoelectric element is disposed;
A rotor in contact with the protrusion,
With
The protrusion is disposed at a position offset from a first center line that passes through the center of the diaphragm and is parallel to the long side of the rectangle.
The vibration plate,
The diagonal positions of the front Symbol protrusion is arranged, and counterweight that protrudes from the rectangular long side in a direction orthogonal to the first center line,
An electronic component inspection apparatus, comprising: a counterweight disposed at a position symmetrical to the counterweight with respect to the first center line . A liquid tube through which the liquid can flow;
A blocking portion that contacts a part of the liquid tube and closes the liquid tube;
A moving unit that moves the closed position of the liquid tube by moving in a state of holding the closed unit;
A piezoelectric actuator for driving the moving unit;
A liquid feed pump comprising:
The piezoelectric actuator is
A piezoelectric element including a piezoelectric body;
A diaphragm having a protruding portion protruding from a short side of the rectangle, and a rectangular plate material on which the piezoelectric element is disposed;
A rotor in contact with the protrusion,
With
The protrusion is disposed at a position offset from a first center line that passes through the center of the diaphragm and is parallel to the long side of the rectangle.
The vibration plate,
The diagonal positions of the front Symbol protrusion is arranged, and counterweight that protrudes from the rectangular long side in a direction orthogonal to the first center line,
A liquid feed pump, comprising: a counterweight disposed at a position symmetrical to the counterweight with respect to the first center line . A print head for printing an image on a medium;
A piezoelectric actuator for moving the print head;
A printing apparatus comprising:
The piezoelectric actuator is
A piezoelectric element including a piezoelectric body;
A diaphragm having a protruding portion protruding from a short side of the rectangle, and a rectangular plate material on which the piezoelectric element is disposed;
A rotor in contact with the protrusion,
With
The protrusion is disposed at a position offset from a first center line that passes through the center of the diaphragm and is parallel to the long side of the rectangle.
The vibration plate,
The diagonal positions of the front Symbol protrusion is arranged, and counterweight that protrudes from the rectangular long side in a direction orthogonal to the first center line,
And a counterweight disposed at a position symmetrical to the counterweight with respect to the first center line . A coaxial rotating gear is provided, and a rotatable disc,
A gear train including a plurality of gears;
A pointer connected to the gear train and indicating the time;
A piezoelectric actuator for driving the rotating disk;
An electronic timepiece comprising:
The piezoelectric actuator is
A piezoelectric element including a piezoelectric body;
A diaphragm having a protruding portion protruding from a short side of the rectangle, and a rectangular plate material on which the piezoelectric element is disposed;
A rotor in contact with the protrusion,
With
The protrusion is disposed at a position offset from a first center line that passes through the center of the diaphragm and is parallel to the long side of the rectangle.
The vibration plate,
The diagonal positions of the front Symbol protrusion is arranged, and counterweight that protrudes from the rectangular long side in a direction orthogonal to the first center line,
An electronic timepiece comprising: a counterweight disposed at a position symmetrical to the counterweight with respect to the first center line . A projection unit including an optical lens and projecting light from the light source;
An adjustment unit for adjusting a projection state of the light by the optical lens;
A projection device comprising: a piezoelectric actuator that drives the adjusting unit;
The piezoelectric actuator is
A piezoelectric element including a piezoelectric body;
A diaphragm having a protruding portion protruding from a short side of the rectangle, and a rectangular plate material on which the piezoelectric element is disposed;
A rotor in contact with the protrusion,
With
The protrusion is disposed at a position offset from a first center line that passes through the center of the diaphragm and is parallel to the long side of the rectangle.
The vibration plate,
The diagonal positions of the front Symbol protrusion is arranged, and counterweight that protrudes from the rectangular long side in a direction orthogonal to the first center line,
A projection apparatus, comprising: a counterweight disposed at a position symmetrical to the counterweight with respect to the first center line . A transport device that transports an object using the driving force of a piezoelectric actuator,
The piezoelectric actuator is
A piezoelectric element including a piezoelectric body;
A diaphragm having a protruding portion protruding from a short side of the rectangle, and a rectangular plate material on which the piezoelectric element is disposed;
A rotor in contact with the protrusion,
With
The protrusion is disposed at a position offset from a first center line that passes through the center of the diaphragm and is parallel to the long side of the rectangle.
The vibration plate,
The diagonal positions of the front Symbol protrusion is arranged, and counterweight that protrudes from the rectangular long side in a direction orthogonal to the first center line,
And a counterweight disposed at a position symmetrical to the counterweight with respect to the first center line .

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