JP2010233332A - Piezoelectric motor, liquid jetting device, and timepiece - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a piezoelectric motor in which durability is improved by improving a bonding force between a piezoelectric element and a vibration member and displacement characteristics are improved without skyrocketing a cost, and to provide a liquid jetting head and a timepiece. <P>SOLUTION: The piezoelectric motor includes: a piezoelectric actuator 10 including piezoelectric elements 30 each having a piezoelectric layer 40 and a first electrode 50 and a second electrode 60 each provided on both surfaces with the piezoelectric layer 40 sandwiched, and a vibration member 20 bonded to the first electrode 50 side of the piezoelectric element 30 via an adhesive 25; and a rotating shaft allowing the vibration member 20 to abut thereon and rotating. The first electrode 50 includes a closely attached layer 52 provided on the piezoelectric layer 40 side, and a conductive layer 51 provided on the vibration member 20 side, wherein a removing part 53 penetrating through the thickness direction is provided on the conductive layer 51, and the adhesive 25 is poured into the removing part 53 to bond the vibration member 20 to the closely attached layer 52. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a piezoelectric motor that drives a driven portion with a piezoelectric element, a liquid ejecting apparatus that uses the piezoelectric motor, and a timepiece that uses the piezoelectric motor.

  The piezoelectric motor rotates a rotation shaft by a piezoelectric actuator having a piezoelectric element. Here, the piezoelectric actuator used for the piezoelectric motor includes a vibrating member and a piezoelectric element held on one surface side of the vibrating member. The piezoelectric element includes a first electrode provided on the vibration member side and a second electrode provided on the opposite side of the piezoelectric layer and the first electrode, and the vibration member and the first electrode are bonded to each other. It is bonded through an agent.

  In such a piezoelectric actuator, a voltage is applied between the first electrode and the second electrode of the piezoelectric element, and the piezoelectric element is longitudinally and flexibly vibrated in the in-plane direction of the vibrating member, whereby the end of the vibrating member Is driven to rotate. Then, the rotating shaft is rotated by bringing the end of the vibration member into contact with the rotating shaft.

JP 2007-267482 A

  However, when the adhesive force between the first electrode and the vibration member is low, there is a problem that the first electrode and the vibration member are peeled off.

  Further, if a material having a good adhesive force is used as the first electrode to be bonded to the vibration member, there is a problem that the cost increases.

  Furthermore, the adhesive having a relatively high adhesive force has a high rigidity after curing, and there is a problem that the adhesive may hinder the displacement of the piezoelectric element and cannot obtain a desired displacement amount.

  In view of such circumstances, the present invention provides a piezoelectric motor, a liquid ejecting head, and a timepiece that have improved durability by improving the adhesive force between the piezoelectric element and the vibration member without increasing costs, and improved displacement characteristics. The purpose is to provide.

  According to an aspect of the present invention for solving the above-described problem, a piezoelectric element having a piezoelectric layer, and a first electrode and a second electrode provided on both sides of the piezoelectric layer, and the first of the piezoelectric element are provided. A piezoelectric motor comprising: a vibration member that is bonded to one electrode side via an adhesive; and a rotating shaft that rotates in contact with the vibration member, wherein the first electrode is And an adhesion layer provided on the piezoelectric layer side and a conductive layer provided on the vibration member side. The conductive layer is provided with a removal portion penetrating in the thickness direction, and the removal is performed. In the piezoelectric motor, the inside is filled with the adhesive, and the vibration member and the adhesion layer are bonded.

In this aspect, the adhesion force is improved by adhering the vibration member and the adhesion layer via the removal portion provided on the conductive layer, thereby suppressing the separation between the piezoelectric element and the vibration member. be able to. In addition, since the adhesive force can be improved only by removing a part of the conductive layer and forming the removed portion, it is not necessary to form a new second adhesion layer or the like, and the increase in cost can be suppressed. further,
Here, the adhesive is preferably an epoxy-based adhesive. According to this, the vibration member and the piezoelectric element can be manufactured at low cost by using a relatively low cost adhesive.

  Moreover, it is preferable that the said conductive layer has as a main component at least 1 metal material selected from gold | metal | money, iridium, and platinum. According to this, the conductivity of the first electrode can be ensured, the first electrode can be formed relatively thin, and the displacement of the piezoelectric element due to the increase in the thickness of the first electrode can be suppressed. it can.

  Moreover, it is preferable that the said adhesion layer has as a main component at least 1 metal material selected from nickel, chromium, titanium, tungsten, and aluminum. According to this, by using a predetermined metal material as the adhesion layer, the adhesion force between the conductive layer and the piezoelectric layer can be improved, and by forming the adhesion layer with an oxidizing metal material, an adhesive can be obtained. The bonding strength can be improved by forming a C—O bond or an O—H bond on the adherend surface.

  Furthermore, another aspect of the invention is a liquid ejecting apparatus including the piezoelectric motor according to the above aspect. In this aspect, it is possible to realize a liquid ejecting apparatus that is downsized and improved in durability.

  Here, it is preferable that the piezoelectric motor is used as a transport unit that transports a medium to be ejected from which liquid is ejected. According to this, it is possible to realize a liquid ejecting apparatus that is particularly downsized.

  According to another aspect of the present invention, there is provided a timepiece including the piezoelectric motor according to the above aspect. In this aspect, a timepiece having a reduced size and improved durability can be realized.

1 is an exploded perspective view of a piezoelectric motor according to Embodiment 1. FIG. 3 is a plan view of the piezoelectric motor according to Embodiment 1. FIG. 1 is a cross-sectional view of a piezoelectric motor according to Embodiment 1. FIG. FIG. 3 is an enlarged cross-sectional view of a main part of the piezoelectric actuator according to the first embodiment. FIG. 3 is a plan view showing the operation of the piezoelectric actuator according to the first embodiment. FIG. 3 is a plan view showing the operation of the piezoelectric actuator according to the first embodiment. 6 is a plan view of a piezoelectric motor according to Embodiment 2. FIG. 1 is a schematic perspective view of a recording apparatus according to an embodiment. FIG. 2 is an enlarged plan view of a main part of a recording apparatus according to an embodiment. It is a top view of the timepiece concerning one embodiment.

Hereinafter, the present invention will be described in detail based on embodiments.
(Embodiment 1)
1 is an exploded perspective view of a piezoelectric motor according to Embodiment 1 of the present invention, FIG. 2 is a plan view of the piezoelectric motor, FIG. 3 is a cross-sectional view of the piezoelectric motor, and FIG. It is a principal part expanded sectional view of an actuator.

  As shown in the figure, the piezoelectric actuator 10 constituting the piezoelectric motor 1 of the present embodiment includes a vibration member 20 and piezoelectric elements 30 respectively bonded to both surfaces of the vibration member 20.

  The piezoelectric elements 30 provided on both surfaces of the vibration member 20 include a piezoelectric layer 40, a first electrode 50 provided on the vibration member 20 side of the piezoelectric layer 40, and a first electrode 50 of the piezoelectric layer 40. Has a second electrode 60 provided on the opposite side.

The piezoelectric layer 40 is made of a piezoelectric material having an electromechanical conversion action, particularly a metal oxide having a perovskite structure represented by the general formula ABO ₃ among piezoelectric materials. As the piezoelectric layer 40, for example, a ferroelectric material such as lead zirconate titanate (PZT) or a material obtained by adding a metal oxide such as niobium oxide, nickel oxide, or magnesium oxide to the ferroelectric material is suitable. Specifically, lead titanate (PbTiO ₃ ), lead zirconate titanate (Pb (Zr, Ti) O ₃ ), lead zirconate (PbZrO ₃ ), lead lanthanum titanate ((Pb, La), TiO ₃ ) ), Lead lanthanum zirconate titanate ((Pb, La) (Zr, Ti) O ₃ ), lead magnesium titanate zirconate titanate (Pb (Zr, Ti) (Mg, Nb) O ₃ ), etc. Can do. Of course, the piezoelectric layer 40 of the present embodiment is not limited to the above-described materials, but examples of the piezoelectric layer 40 having an excellent electromechanical conversion function include those containing lead.

  The first electrode 50 is a common electrode continuously provided over the surface of the piezoelectric layer 40 on the vibration member 20 side, and includes a conductive layer 51 provided on the vibration member 20 side, the conductive layer 51, and the piezoelectric body. And an adhesion layer 52 provided between the layer 40.

  As the conductive layer 51, a material having relatively high conductivity, for example, gold (Au), platinum (Pt), iridium (Ir), or the like can be used.

  The adhesion layer 52 is a material having conductivity and improving the adhesion between the conductive layer 51 and the piezoelectric layer 40, for example, nickel (Ni), chromium (Cr), titanium (Ti), tungsten (W ) Or at least one selected from aluminum (Al). In the present embodiment, nickel chrome (NiCr) is used as the adhesion layer 52.

  Thus, by providing the conductive layer 51 having relatively high conductivity (low resistance) as the first electrode 50, the thickness of the entire first electrode 50 can be made relatively thin. Accordingly, it is possible to improve the displacement characteristics of the piezoelectric element 30 by suppressing the displacement of the piezoelectric element 30 from being inhibited by the rigidity of the first electrode 50. In addition, since the first electrode 50 includes the adhesion layer 52, the adhesion between the piezoelectric layer 40 and the first electrode 50 (conductive layer 51) is improved, and the piezoelectric layer 40 and the first electrode 50 are driven when the piezoelectric element 30 is driven. Delamination between the electrodes 50 can be suppressed.

  Further, as shown in FIG. 4, the conductive layer 51 is provided with a plurality of removal portions 53 that penetrates in the thickness direction. It is preferable that the removing portions 53 are provided so as to be scattered uniformly over the surface of the vibration member 20. Although this will be described in detail later, since the adhesive strength between the vibration member 20 and the piezoelectric element 30 is increased in the region where the removal portion 53 is provided, the removal portion 53 is unevenly distributed and the adhesive strength is within the plane of the vibration member 20. This is because if there is a bias, stress concentration may occur in a region where the adhesive strength is low, causing destruction. As will be described later in detail, the piezoelectric element 30 has a central portion in the longitudinal direction serving as a base point in longitudinal vibration and bending vibration, and the central portion in the longitudinal direction has a relatively small amount of displacement. Therefore, the removal portion 53 may be provided so as to have a small opening area in the central portion in the longitudinal direction of the piezoelectric element 30.

  The second electrode 60 is provided on the opposite side of the piezoelectric layer 40 from the first electrode 50, and is electrically isolated from each other by the groove portion 70 and divided into a plurality in the in-plane direction.

  The groove part 70 that divides the second electrode 60 includes a first groove part 71 formed so as to divide the width (short direction) of the piezoelectric element 30 into three equal parts, and three electrodes divided by the first groove part 71. Of these, the second groove portion 72 is formed so that the electrodes on both sides in the short direction are substantially bisected in the longitudinal direction. The second electrode 60 includes a longitudinal vibration electrode portion 61 provided in the longitudinal direction at the center portion in the short direction by the groove portion 70 including the first groove portion 71 and the second groove portion 72, and the longitudinal vibration electrode portion. On both sides in the short direction of 61, it is divided into a total of five, including two pairs of bending vibration electrode portions 62, 63 that are arranged diagonally across the longitudinal vibration electrode portion 61. . Here, in the piezoelectric element 30, a region in which the longitudinal vibration electrode portion 61 of the second electrode 60 is provided is a longitudinal vibration excitation region 41 that excites longitudinal vibration in the longitudinal direction of the piezoelectric element 30. On the other hand, the bending vibration excitation region 42 in which the bending vibration electrode portions 62 and 63 on both sides in the short direction of the longitudinal vibration excitation region 41 are excited in the short direction of the piezoelectric element 30 respectively. 43.

  In such a piezoelectric element 30, the first electrode 50 side is bonded to the vibration member 20 via the adhesive 25. Here, the vibration member 20 is formed of a plate-like member formed of a metal such as stainless steel (SUS) or a resin material. In the present embodiment, the vibrating member 20 is made of conductive stainless steel, and functions as a common electrode that conducts the first electrodes 50 of the two piezoelectric elements 30.

  Further, as shown in FIG. 1, the vibration member 20 has the same surface shape as that of the first electrode 50 side of the piezoelectric element 30 as described above, and protrudes from the piezoelectric element 30 to one end side in the longitudinal direction. An abutting portion 21 extending in the direction is provided. In addition, a pair of arm portions 22 extending toward both sides in the lateral direction of the piezoelectric element 30 are provided at the longitudinal center portion of the piezoelectric element 30 of the vibration member 20. The arm portion 22 is provided with a through hole 23 penetrating in the thickness direction, and is fixed to a holding member 81 described later in detail via a screw member 86 through which the through hole 23 is inserted. That is, in the piezoelectric actuator 10, the arm portion 22 of the vibration member 20 is fixed to the holding member 81, so that the piezoelectric element 30 can perform longitudinal vibration and bending vibration with respect to the holding member 81 with the arm portion 22 as a base point. To be held.

  As shown in FIG. 4, the first electrode 50 side of the piezoelectric element 30 is bonded to such a vibration member 20 via an adhesive 25. The adhesive 25 that bonds the vibration member 20 and the piezoelectric element 30 is provided between the vibration member 20 and the piezoelectric element 30 and is filled in the removal portion 53 provided in the conductive layer 51. The vibration member 20 and the piezoelectric element 30 are in close contact with the vibration member 20 by being provided in the adhesive 25 provided between the surface of the conductive layer 51 and the vibration member 20 and the removal portion 53 of the conductive layer 51. It is bonded with an adhesive 25 that bonds the layer 52.

  Such an adhesive 25 is made of, for example, an epoxy adhesive. In the epoxy adhesive 25, although the bonding strength is increased by forming a C—O bond and an O—H bond with a general adherend surface, gold (Au that forms the conductive layer 51) The non-oxidizing metal material such as) and the epoxy adhesive 25 form an Au—C bond, and a C—O bond and an O—H bond are not formed. On the other hand, an oxidizing metal material such as nickel chromium (NiCr) forming the adhesion layer 52 is bonded to the epoxy adhesive 25 because a Ni—O—C bond and a Cr—O—C bond are formed. Strength increases.

  Therefore, compared with the case where only the conductive layer 51 made of a non-oxidizing metal is bonded to the vibration member 20 with the epoxy adhesive 25, the adhesion layer 52 that is an oxidizing metal through the removal portion 53 of the conductive layer 51 Adhesive strength between the first electrode 50 and the vibration member 20 can be improved by simultaneously bonding the vibration member 20 with the epoxy adhesive 25.

  Incidentally, it is conceivable to form the first electrode 50 only with the material of the adhesion layer 52, but in order to ensure sufficient conductivity (amount of current) with an oxidizing metal, the first electrode 50 is not formed thick. This is not preferable because the rigidity of the first electrode 50 is increased and the displacement characteristics may be affected.

  Further, although it is conceivable to form a second adhesion layer of the same oxidizing metal as that of the adhesion layer 52 on the vibration member 20 side of the conductive layer 51, the cost increases to newly form the second adhesion layer. This is not preferable.

  In the present invention, since the adhesive strength for bonding the first electrode 50 and the vibration member 20 can be improved by a simple method of forming the removal portion 53 in the conductive layer 51, the displacement characteristics of the piezoelectric element 30 are reduced. The long-term durability can be improved without increasing the cost.

  In such a piezoelectric actuator 10, the longitudinal vibration excitation region 41 and the bending vibration excitation regions 42 and 43 of the piezoelectric element 30 are driven so as to perform longitudinal vibration and bending vibration in the plane direction, respectively. That is, as shown in FIG. 5A, in the surface direction of the vibration member 20, the longitudinal vibration excitation region 41 is expanded and contracted in the longitudinal direction (longitudinal direction), thereby causing the piezoelectric element 30 to vibrate longitudinally in the longitudinal direction. Let it be done.

  Further, as shown in FIGS. 5B and 5C, the piezoelectric element 30 is driven to bend by extending and contracting the bending vibration excitation regions 42 and 43 in the surface direction of the vibration member 20. Specifically, one set of bending vibration excitation regions 42 that are diagonal in the short direction of the piezoelectric element 30 are expanded, and at the same time, the other pair of bending vibration excitation regions 43 that are diagonal are contracted. As a result, the piezoelectric element 30 is deformed into an S shape as shown in FIG. Further, by contracting the flexural vibration excitation region 42 that has been stretched, the flexural vibration excitation region 43 that has been contracted is stretched, thereby making the piezoelectric element 30 in an inverted S shape as shown in FIG. Bend. By alternately repeating the bending deformation shown in FIGS. 5B and 5C, the piezoelectric element 30 is subjected to S-shaped and inverted S-shaped bending vibrations.

  Then, by causing the piezoelectric element 30 to alternately repeat the longitudinal vibration caused by the longitudinal vibration excitation region 41 and the bending vibration caused by the bending vibration excitation regions 42 and 43, as shown in FIG. That is, the contact portion 21 of the vibration member 20 can be rotationally driven so as to draw an elliptical orbit. Specifically, the contact portion 21 is caused by causing the piezoelectric element 30 to repeatedly perform longitudinal (longitudinal) expansion, S-shaped bending, vertical contraction, and reverse S-shaped bending. Can be rotationally driven so as to draw an elliptical orbit in the clockwise direction in the plane of the vibration member 20. Further, when the piezoelectric element 30 is deformed, the abutting portion 21 can be rotationally driven so as to draw an elliptical orbit in the counterclockwise direction within the plane of the vibration member 20 by changing the order of bending. In the present embodiment, the piezoelectric elements 30 are provided on both surfaces of the vibration member 20, but the two piezoelectric elements 30 perform the same longitudinal vibration and bending vibration within the surface of the vibration member 20. That is, the longitudinal vibration excitation regions 41 and the bending vibration excitation regions 42 and 43 of the two piezoelectric elements 30 are arranged so as to overlap when the piezoelectric actuator 10 is viewed in plan from the second electrode 60 side of one piezoelectric element 30. In addition, the vibration member 20 is deformed in the in-plane direction by causing the same expansion / contraction to be performed in the overlapping region when seen in a plan view. Of course, the piezoelectric element 30 on both surfaces of the vibrating member 20 can be driven by being deformed in the stacking direction of the vibrating member 20 and the piezoelectric element 30 by making different deformations.

  On the other hand, as shown in FIGS. 1 and 2, the piezoelectric motor 1 is provided with a rotating shaft 3 that is rotatable about an axis in the apparatus body 2. The rotating shaft 3 is rotated by contacting the rotating shaft 3 with a contact portion 21 that is rotationally driven so as to draw an elliptical orbit of the piezoelectric actuator 10. In the present embodiment, the contact portion 21 has a circumferential surface of the rotary shaft 3 such that the rotation direction in which the contact portion 21 of the piezoelectric actuator 10 forms an elliptical orbit is opposite to the rotation direction of the rotary shaft 3. To abut. Of course, the abutting portion 21 may abut on the end surface of the rotating shaft 3.

  The piezoelectric motor 1 is provided with pressing means 80 that presses the piezoelectric actuator 10 with a predetermined pressure in the direction of the rotation axis 3.

  The pressing means 80 is in contact with the holding member 81 for holding the piezoelectric actuator 10, a spring member 82 such as a coil spring having one end fixed to the holding member 81, and the other end of the spring member 82 and is fixed to the apparatus main body 2. And an eccentric pin 83 for adjusting the urging force of the spring member 82.

  The holding member 81 includes a pair of fixed portions 84 to which the arm portion 22 of the piezoelectric actuator 10 is fixed, and a slide portion that is integrally provided between the fixed portions 84 and is slidably supported with respect to the apparatus main body 2. 85. In the fixing portion 84, a female screw portion 87 to which the screw member 86 is screwed is formed corresponding to the through hole 23 of the arm portion 22. The piezoelectric actuator 10 is held by the holding member 81 by screwing the screw member 86 inserted through the through hole 23 of the arm portion 22 into the female screw portion 87.

  The slide portion 85 is provided with two slide holes 88 that are long holes penetrating in the thickness direction and extending in the slide direction. The slide portion 85 is supported so as to be slidable with respect to the apparatus main body 2 by slide pins 89 inserted into the slide holes 88 and fixed to the apparatus main body 2.

  The spring member 82 is formed of a coil spring, and one end thereof is fixed to the fixing portion 84 and is arranged so that the other end abuts against a side surface of the eccentric pin 83 fixed to the apparatus main body 2 so as to be eccentrically rotatable. Further, the spring member 82 is disposed along the sliding direction of the sliding portion 85. Such a spring member 82 urges the piezoelectric actuator 10 toward the rotating shaft 3 with respect to the apparatus main body 2. Incidentally, the eccentric pin 83 is provided so as to be eccentrically rotatable with respect to the apparatus main body 2, and by rotating the eccentric pin 83 eccentrically, the distance between the side surface of the eccentric pin 83 and the holding member 81 is changed, and the spring. The biasing force by the member 82 can be adjusted.

  In this embodiment, a coil spring is used as the spring member 82. However, the spring member 82 is not particularly limited to this, and for example, a leaf spring or the like may be used.

  By such pressing means 80, the piezoelectric actuator 10 is pressed against the rotating shaft 3 with a predetermined pressure so that the longitudinal direction (longitudinal vibration direction) of the piezoelectric element 30 is the axis center of the rotating shaft 3. That is, the piezoelectric actuator 10 of the present embodiment is disposed so that the longitudinal direction of the piezoelectric element 30 is the radial direction of the rotary shaft 3 and is slidable in the radial direction of the rotary shaft 3. Therefore, the piezoelectric actuator 10 is pressed so that the longitudinal direction of the piezoelectric element 30 is the radial direction of the rotary shaft 3.

  Then, as described above, while pressing the abutting portion 21 of the piezoelectric actuator 10 against the rotating shaft 3 by the pressing means 80, the piezoelectric element 30 is caused to alternately perform longitudinal vibration and bending vibration so that the abutting portion 21 is elliptically orbited. The rotational shaft 3 can be rotationally driven by being rotationally driven so as to draw.

  Note that the rotational speed of the rotary shaft 3 rotated by the piezoelectric actuator 10 is greatly influenced by the vibration period in which longitudinal vibration and bending vibration are performed, and the torque of the rotary shaft 3 depends on the rotational axis of the piezoelectric actuator 10 by the pressing means 80. 3 is greatly affected by the pressing force.

  As described above, the piezoelectric actuator 10 used in the piezoelectric motor 1 of the present embodiment has the first electrode when the vibration member 20 and the first electrode 50 of the piezoelectric element 30 are bonded via the adhesive 25. The vibration member 20 and the adhesion layer 52 on the piezoelectric layer 40 side that constitutes the first electrode 50 are bonded to each other through the removing portion 53 that is provided on the conductive layer 51 that constitutes 50. Thereby, the adhesiveness of the vibration member 20 and the piezoelectric element 30 can be improved, and long-term durability can be improved.

(Embodiment 2)
FIG. 7 is an exploded perspective view of the piezoelectric motor according to Embodiment 2 of the present invention. In addition, the same code | symbol is attached | subjected to the member similar to Embodiment 1 mentioned above, and the overlapping description is abbreviate | omitted.

  As shown in FIG. 7, in the piezoelectric element 30A mounted on the piezoelectric actuator 10A constituting the piezoelectric motor 1A, the second electrode 60A is divided into three by the groove portion 70A. Specifically, the second electrode 60A is electrically connected to the drive electrode 64 so as to be approximately Z-shaped in the center by providing an L-shaped groove 70A at the diagonal of the piezoelectric element 30A. Is formed. The two electrodes divided by the groove portion 70A outside the drive electrode 64 are non-drive electrodes 65 that are not driven.

  On the other hand, the vibration member 20A is provided with a contact portion 21A at a position biased toward the drive electrode 64 at one end portion in the longitudinal direction of the piezoelectric element 30A.

  A pair of arm portions 22 extending in the short direction is provided at the center of the vibration member 20A in the longitudinal direction of the piezoelectric element 30A, and the distal end portion of one arm portion 22 is attached to the apparatus main body 2. It is fixed. One arm portion 22 fixed to the apparatus main body 2 has a leaf spring shape, and also functions as a pressing means for pressing the piezoelectric actuator 10A against the rotation shaft.

  In such a piezoelectric actuator 10A, when a drive signal is applied to the drive electrode 64, the piezoelectric element 30A expands in a rhombus shape along the diagonal line where the drive electrode 64 is provided within the plane of the vibration member 20A.・ Shrink. Then, the contact portion 21A of the piezoelectric actuator 10A is brought into contact with a position eccentric from the axial center of the rotary shaft 3, and the longitudinal direction of the piezoelectric element 30 is arranged in a direction intersecting with the radial direction of the rotary shaft 3. Thus, the rotating shaft 3 is driven to rotate in only one direction.

  Specifically, when the piezoelectric element 30 extends along the diagonal line, the contact portion 21 presses a position eccentric from the axis center of the rotation shaft 3. At this time, since the rotation shaft 3 can move only in the rotation direction, the pressing by the contact portion 21A is converted into the rotation direction. As the rotary shaft 3 rotates, pressure in the rotational direction of the rotary shaft 3 is also applied to the contact portion 21A of the piezoelectric actuator 10A. As a result, the contact portion 21A is rotationally driven to draw an elliptical orbit. .

  Even in the piezoelectric motor 1A having such a configuration, the first electrode 50 includes the conductive layer 51 and the adhesion layer 52 and penetrates the conductive layer 51 in the thickness direction, as in the first embodiment. By providing the removed portion 53 and bonding the vibration member 20 </ b> A and the adhesion layer 52 via the adhesive 25 via the removal portion 53, the adhesive strength between them can be improved.

(Other embodiments)
As mentioned above, although each embodiment of this invention was described, the fundamental structure of this invention is not limited to what was mentioned above. For example, in the first and second embodiments described above, the piezoelectric actuators 10 and 10A in which the piezoelectric elements 30 and 30A are provided on both surfaces of the vibration members 20 and 20A, respectively, are illustrated, but the present invention is not particularly limited thereto, and the vibration members 20 and 20A are not limited thereto. The present invention can be applied even to the piezoelectric actuators 10 and 10A in which the piezoelectric elements 30 and 30A are provided on only one of them.

  In the first and second embodiments described above, the piezoelectric actuators 10 and 10A are pressed toward the rotating shaft 3 by the pressing means 80 and 22, but the invention is not particularly limited thereto. For example, the rotating shaft 3 is piezoelectric. You may make it press toward the actuators 10 and 10A. Of course, the pressing means 80 and 22 are not necessarily required.

  In addition, the piezoelectric motors 1 and 1A according to the above-described embodiments can be used as a driving unit of an ink jet recording apparatus which is an example of a liquid ejecting apparatus. Here, an example of an ink jet recording apparatus using the piezoelectric motor 1 of Embodiment 1 is shown in FIGS. FIG. 8 is a schematic perspective view of an ink jet recording apparatus which is an example of a liquid ejecting apparatus according to an embodiment, and FIG. 9 is an enlarged plan view of a main part.

  In the ink jet recording apparatus 100 shown in FIG. 8, a recording head unit 102 having an ink jet recording head 101 for ejecting ink is provided with a cartridge 103 that constitutes an ink supply means, and the recording head unit 102 is mounted. The carriage 104 is provided on a carriage shaft 106 attached to the recording apparatus main body 105 so as to be movable in the axial direction. The recording head unit 102 ejects, for example, a black ink composition and a color ink composition.

  Then, the driving force of the driving motor 107 is transmitted to the carriage 104 via a plurality of gears and a timing belt 108 (not shown), so that the carriage 104 on which the recording head unit 102 is mounted is moved along the carriage shaft 106. On the other hand, the recording apparatus main body 105 is provided with a platen 109 along the carriage shaft 106, and a recording sheet S, which is an ejection medium such as paper fed by the paper feeding means 110, is wound around the platen 109. Be transported. The recording sheet S is printed with ink ejected from the ink jet recording head 101 on the platen 109. The recording sheet S printed on the platen 109 is discharged by a discharge unit 120 provided on the opposite side of the platen 109 from the paper supply unit 110.

  As shown in FIG. 9, the paper feeding means 110 is composed of a paper feeding roller 111 and a driven roller 112. The rotation shaft 3 of the piezoelectric motor 1 described above is fixed to the end portion of the paper feed roller 111 and is driven to rotate by driving of the piezoelectric actuator 10. The paper feed roller 111 is provided with a first gear 113 on the same axis.

  The paper discharge unit 120 includes a paper discharge roller 121 and a driven roller 122. The paper discharge roller 121 is provided with a second gear 123 coaxially. The first gear 113 of the paper feed roller 111 is discharged via a third gear 130 that meshes with the first gear 113, a fourth gear 131 that meshes with the third gear 130, and a fifth gear 132 that meshes with the fourth gear. By engaging with the second gear 123 of the roller 121, the driving force of the piezoelectric motor 1 that rotationally drives the paper feed roller 111 is transmitted to the paper discharge roller 121.

  In the example shown in FIGS. 8 and 9, the sheet feeding unit 110 and the sheet discharge unit 120 are rotationally driven by the piezoelectric motor 1. For example, the piezoelectric motor 1 of the above-described embodiment is replaced with the carriage 104. It can also be used instead of the drive motor 107 to be moved. Of course, the piezoelectric motor 1 can also be used in other drive systems, such as a pump for supplying ink to the ink jet recording head 101. Moreover, in this embodiment, although the piezoelectric motor 1 of Embodiment 1 mentioned above was used, it is not limited to this in particular, For example, you may make it use 1 A of piezoelectric motors of Embodiment 2 mentioned above.

  The present invention is intended for a wide range of liquid ejecting apparatuses in general, and the piezoelectric motor can be mounted on a liquid ejecting apparatus other than the ink jet recording apparatus described above. Other liquid ejecting apparatuses include, for example, a color material ejecting apparatus used for manufacturing a color filter such as a liquid crystal display, an electrode material ejecting apparatus used for electrode formation such as an organic EL display, FED (field emission display), and a biochip. Examples thereof include a bio-organic matter injection device used for manufacturing.

  Furthermore, the piezoelectric motors 1 and 1A of the above-described embodiment can also be used as timepiece driving means. Here, an example of a timepiece using the piezoelectric motor 1 of Embodiment 1 is shown in FIG.

  As shown in FIG. 10, the calendar display function constituting the timepiece 200 is connected to the piezoelectric motor 1 and is driven by the driving force.

  The main part of the calendar display function includes a speed reduction wheel train that decelerates the rotation of the rotary shaft 3 of the piezoelectric motor 1 and a ring-shaped date wheel 201. The speed reduction wheel train includes a date indicator driving intermediate wheel 202 and a date indicator driving wheel 203.

  Then, when the rotary shaft 3 is driven to rotate clockwise by the piezoelectric actuator 10 of the piezoelectric motor 1 described above, the rotation of the rotary shaft 3 is transmitted to the date indicator driving wheel 203 via the date turning intermediate wheel 202, and this date turning. The car 203 rotates the date dial 201 clockwise. Transmission of force from the piezoelectric actuator 10 to the rotating shaft 3, from the rotating shaft 3 to the reduction wheel train (date turning intermediate wheel 202, date turning wheel 203), and from the reduction wheel train to the date indicator 201 is performed in the in-plane direction. Is called. For this reason, the calendar display mechanism can be thinned.

  In addition, a disk-shaped dial plate 204 on which characters representing the date are printed along the circumferential direction is fixed to the date dial 201. The main body of the watch 200 is provided with a window 205 that exposes one character provided on the dial 204 so that the date can be seen from the window 205. Although not particularly illustrated, the timepiece 200 is provided with a long hand and a short hand, a movement for driving the long hand and the short hand, and the like.

  The piezoelectric motor 1 can be used not only as a calendar display mechanism but also as a movement for driving the long hand and short hand of a timepiece. The structure for driving the long hand, the short hand, etc. of these timepieces is possible only by incorporating the above-described piezoelectric motors 1 and 1A in place of the conventionally known electromagnetic motors.

  In addition, the present invention is widely intended for general piezoelectric motors, and can be used for small devices other than the above-described liquid ejecting apparatuses and watches. Examples of small devices that can use piezoelectric motors include medical pumps, cameras, and robots for industrial and artificial hands.

  1, 1A piezoelectric motor, 10, 10A piezoelectric actuator, 20, 20A vibration member, 25 adhesive, 30, 30A piezoelectric element, 40 piezoelectric layer, 50 first electrode, 51 conductive layer, 52 adhesion layer, 53 removal unit, 60 second electrode, 70 groove, 80 pressing means, 100 recording device, 200 watch

Claims (7)

A piezoelectric element having a piezoelectric layer, and a first electrode and a second electrode respectively provided on both sides of the piezoelectric layer;
A piezoelectric member comprising: a vibration member bonded to the first electrode side of the piezoelectric element via an adhesive;
A piezoelectric motor comprising: a rotating shaft that contacts and rotates with the vibration member;
The first electrode includes an adhesion layer provided on the piezoelectric layer side, and a conductive layer provided on the vibration member side,
The conductive layer is provided with a removal portion penetrating in the thickness direction, and the removal portion is filled with the adhesive to bond the vibration member and the adhesion layer. Piezoelectric motor.   The piezoelectric motor according to claim 1, wherein the adhesive is an epoxy adhesive.   3. The piezoelectric motor according to claim 1, wherein the conductive layer contains at least one metal material selected from gold, iridium, and platinum as a main component.   The piezoelectric motor according to any one of claims 1 to 3, wherein the adhesion layer includes, as a main component, at least one metal material selected from nickel, chromium, titanium, tungsten, and aluminum.   A liquid ejecting apparatus comprising the piezoelectric motor according to claim 1.   The liquid ejecting apparatus according to claim 5, wherein the piezoelectric motor is used as a paper feeding unit that transports a medium to be ejected from which liquid is ejected.   A timepiece comprising the piezoelectric motor according to claim 1.

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