JP2017022819A - Piezoelectric driving device and driving method for the same, and robot and driving method for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce capacitance of a piezoelectric driving device.SOLUTION: A piezoelectric driving device comprises a first piezoelectric vibration section 100a and a second piezoelectric vibration section 100b individually having diaphragms 200 provided with a plurality of piezoelectric elements 110 formed of first electrodes 130, second electrodes 150 and piezoelectric materials 140. The first and second piezoelectric vibration sections have first piezoelectric elements 100a and second piezoelectric elements 100d as the plurality of piezoelectric elements. The first piezoelectric elements and the second piezoelectric elements included in the first piezoelectric vibration section are connected to one another with a first connection system and form a first piezoelectric element group. The first piezoelectric elements and the second piezoelectric elements included in the second piezoelectric vibration section are connected to one another with the first connection system and form a second piezoelectric element group. The first piezoelectric element group and the second piezoelectric element group are connected to each other with a second connection system. One of the first connection system and the second connection system is series connection, and the other is parallel connection.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a piezoelectric driving device and a driving method thereof, a robot and a driving method thereof.

  A piezoelectric actuator (piezoelectric driving device) that drives a driven body by vibrating a piezoelectric body is used in various fields because it does not require a magnet or a coil (for example, Patent Document 1). The basic configuration of this piezoelectric drive device is a configuration in which four piezoelectric elements are arranged in two rows and two columns on each of two surfaces of the reinforcing plate, and a total of eight piezoelectric elements are included in the reinforcing plate. It is provided on both sides. Each piezoelectric element is a unit in which a piezoelectric body is sandwiched between two electrodes, and the reinforcing plate is also used as one electrode of the piezoelectric element. One end of the reinforcing plate is provided with a protrusion for rotating the rotor in contact with the rotor as a driven body. When an AC voltage is applied to two of the four piezoelectric elements arranged diagonally, the two piezoelectric elements expand and contract, and the protrusion of the reinforcing plate reciprocates or elliptically moves accordingly. I do. And according to the reciprocating motion or elliptical motion of the protrusion of the reinforcing plate, the rotor as the driven body rotates in a predetermined rotation direction. In addition, the rotor can be rotated in the reverse direction by switching the two piezoelectric elements to which the AC voltage is applied to the other two piezoelectric elements.

JP 2004-320979 A

  When a piezoelectric drive device is housed in a small space (for example, in a joint of a robot) and used, a piezoelectric drive device using a conventional piezoelectric body may run out of wiring space. is there. However, the capacitance of the vibrating body of the piezoelectric drive device is inversely proportional to the distance between the electrodes that sandwich the piezoelectric body. Therefore, if the piezoelectric body is thinned, the capacitance increases. In particular, a plurality of vibrating bodies are driven simultaneously. When doing so, there was a problem that it was necessary to supply a large current.

  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.

(1) According to one aspect of the present invention, a piezoelectric driving device is provided. The piezoelectric driving device includes a diaphragm provided with a plurality of piezoelectric elements formed by a first electrode, a second electrode, and a piezoelectric body positioned between the first electrode and the second electrode. A first piezoelectric vibrating section and a second piezoelectric vibrating section, each of the first piezoelectric vibrating section and the second piezoelectric vibrating section having a first piezoelectric element and a second piezoelectric element as the plurality of piezoelectric elements; A first piezoelectric element group is formed by connecting the first piezoelectric element and the second piezoelectric element included in the first piezoelectric vibration part by a first connection method, and the first piezoelectric element group included in the second piezoelectric vibration part. A first piezoelectric element and the second piezoelectric element are connected by the first connection method to form a second piezoelectric element group, and the first piezoelectric element group and the second piezoelectric element group are connected by the second connection method. And one of the first connection method and the second connection method is a series connection, It is a parallel connection. According to the piezoelectric drive device of this aspect, since the connection form between the piezoelectric element and the piezoelectric element includes serial connection, the capacitance can be reduced, and a large current is supplied when simultaneously driving a plurality of vibrators. It does not have to be.

(2) In the piezoelectric drive device according to the above aspect, the first connection method may be a parallel connection, and the second connection method may be a series connection. According to the piezoelectric driving device of this aspect, the voltage applied to the piezoelectric element of the first piezoelectric vibrating section or the voltage applied to the piezoelectric element of the second piezoelectric vibrating section can be made equal.

(3) In the piezoelectric drive device according to the above aspect, the plurality of piezoelectric elements connected in series may have the same size. According to the piezoelectric drive device of this aspect, the voltages applied to the piezoelectric elements connected in series can be made equal.

(4) In the above piezoelectric driving device, when a driving voltage is applied to the plurality of piezoelectric elements, the direction in which the voltage is applied to the plurality of piezoelectric elements may be the same direction. Since the direction of voltage application to the piezoelectric element does not change in one direction, durability can be improved.

(5) In the piezoelectric driving device described above, the first electrode is positioned closer to the diaphragm side than the second electrode, and a direction in which the voltage is applied is a direction from the second electrode toward the first electrode. There may be. According to the piezoelectric drive device of this aspect, since the voltage application direction is the direction from the second electrode toward the first electrode, the durability can be increased compared to the direction in which the voltage application direction is from the first electrode toward the second electrode.

(6) In the piezoelectric driving device according to the above aspect, the first electrodes of the plurality of piezoelectric elements connected in parallel may form one integrally formed electrode. According to the piezoelectric driving device of this aspect, the wiring connecting the first electrodes may not be formed using another wiring layer. Further, the connection between the first electrodes is difficult to be disconnected.

(7) According to one aspect of the present invention, a robot is provided. The piezoelectric drive according to any one of claims 1 to 6, wherein the robot rotates a plurality of link portions, a joint portion connecting the plurality of link portions, and the plurality of link portions at the joint portion. An apparatus. According to this embodiment, the piezoelectric driving device can be used for driving the robot.

(8) According to one aspect of the present invention, a method for driving a robot is provided. In this driving method, the piezoelectric driving device is driven by applying a periodically changing voltage between the first electrode and the second electrode of the piezoelectric driving device, and the plurality of link portions are connected to the joint. Rotate at the part.

(9) According to an aspect of the present invention, there is provided a driving method for the piezoelectric driving device according to the above aspect. In this driving method, the voltage periodically changes between the first electrode and the second electrode of the piezoelectric element, and the direction of the voltage applied to the piezoelectric body of the piezoelectric element is A pulsating voltage that is one direction from one electrode to the other electrode is applied. According to this aspect, since the voltage applied to the piezoelectric body of the piezoelectric element is only in one direction, the durability of the piezoelectric body can be improved.

  The present invention can be realized in various forms. For example, in addition to a piezoelectric driving device, a driving method of the piezoelectric driving device, a manufacturing method of the piezoelectric driving device, a robot equipped with the piezoelectric driving device, and a piezoelectric driving device. It can be realized in various forms such as a driving method of a robot to be mounted, an electronic component conveying device, a liquid feeding pump, a medication pump, and the like.

Explanatory drawing which shows schematic structure of a piezoelectric drive device. The top view of a diaphragm. Explanatory drawing which shows the example of operation | movement of a piezoelectric drive device. Explanatory drawing which shows an example of the wiring of the 1st electrode and 2nd electrode in 1st Embodiment. Explanatory drawing which shows a comparative example. Explanatory drawing which shows 2nd Embodiment. Explanatory drawing which shows 3rd Embodiment. Explanatory drawing which shows 4th Embodiment. Explanatory drawing which shows 5th Embodiment. The equivalent circuit of 5th Embodiment. The top view of the piezoelectric vibration part as other embodiment. Explanatory drawing which shows an example of a robot. Explanatory drawing of the wrist part of a robot. Explanatory drawing which shows an example of a liquid feeding pump.

  FIG. 1A is a plan view showing a schematic configuration of a piezoelectric driving device 10 according to an embodiment of the present invention, and FIG. The piezoelectric drive device 10 includes a vibration plate 200 and a piezoelectric vibration unit 100. The piezoelectric vibration unit 100 is disposed on the first surface 211 (also referred to as “front surface”) of the vibration plate 200 and is not disposed on the second surface 212 (also referred to as “back surface”). However, as will be described later, the piezoelectric vibrating portion 100 may be disposed on each of the two surfaces 211 and 212 of the diaphragm. The piezoelectric vibration unit 100 includes a substrate 120, a first electrode 130 formed on the substrate 120, a piezoelectric body 140 formed on the first electrode 130, and a second electrode formed on the piezoelectric body 140. An electrode 150. The first electrode 130 and the second electrode 150 sandwich the piezoelectric body 140 and constitute the piezoelectric element 110.

The substrate 120 of the piezoelectric vibration unit 100 is used as a substrate for forming the first electrode 130, the piezoelectric body 140, and the second electrode 150 by a film forming process. The substrate 120 also has a function as a diaphragm that performs mechanical vibration. The substrate 120 can be formed of, for example, Si, Al ₂ O ₃ , ZrO ₂ or the like. As the Si substrate 120, for example, a Si wafer for semiconductor manufacturing can be used. In this embodiment, the planar shape of the substrate 120 is a rectangle. The thickness of the substrate 120 is preferably in the range of 10 μm to 100 μm, for example. When the thickness of the substrate 120 is 50 μm or more, the substrate 120 can be handled relatively easily during the film forming process on the substrate 120. If the thickness of the substrate 120 is 100 μm or less, the substrate 120 can be easily vibrated according to the expansion and contraction of the piezoelectric body 140 formed of a thin film.

  As shown in FIG. 1A, the first electrode 130 is divided into five conductor layers 130a to 130e (also referred to as “first electrodes 130a to 130e”). The first electrode 130e at the center is formed in a rectangular shape that extends substantially in the longitudinal direction of the substrate 120 at the center in the width direction of the substrate 120. The other four first electrodes 130 a, 130 b, 130 c, and 130 d have the same planar shape and are formed at the four corner positions of the substrate 120. Similarly, the second electrode 150 is divided into five conductor layers 150a to 150e (also referred to as “second electrodes 150a to 150e”) as shown in FIG. The second electrode 150e at the center is formed in a rectangular shape covering almost the entire length of the substrate 120 at the center in the width direction of the substrate 120. The other four second electrodes 150 a, 150 b, 150 c, and 150 d have the same planar shape and are formed at the four corner positions of the substrate 120. In the example of FIG. 1, both the first electrode 130 and the second electrode 150 have a rectangular planar shape. The first electrode 130 and the second electrode 150 are thin films formed by sputtering, for example. As a material of the first electrode 130 and the second electrode 150, for example, any material having high conductivity such as Al (aluminum), Ni (nickel), Au (gold), Pt (platinum), Ir (iridium) or the like is used. Is available.

  The piezoelectric body 140 is formed as five piezoelectric bodies (also referred to as “piezoelectric layers”) 140a, 140b, 140c, 140d, and 140e having substantially the same planar shape as the second electrodes 150a to 150e.

The piezoelectric body 140 is a thin film formed by, for example, a sol-gel method or a sputtering method. As a material of the piezoelectric body 140, any material exhibiting a piezoelectric effect such as ceramics having an ABO ₃ type perovskite structure can be used. Examples of ceramics having an ABO ₃ type perovskite structure include lead zirconate titanate (PZT), barium titanate, lead titanate, potassium niobate, lithium niobate, lithium tantalate, sodium tungstate, zinc oxide, titanium Barium strontium acid (BST), strontium bismuth tantalate (SBT), lead metaniobate, lead zinc niobate, lead scandium niobate, or the like can be used. It is also possible to use a material exhibiting a piezoelectric effect other than ceramic, such as polyvinylidene fluoride and quartz. The thickness of the piezoelectric body 140 is preferably in the range of, for example, 50 nm (0.05 μm) to 20 μm. A thin film of the piezoelectric body 140 having a thickness in this range can be easily formed using a film forming process. If the thickness of the piezoelectric body 140 is 0.05 μm or more, a sufficiently large force can be generated according to the expansion and contraction of the piezoelectric body 140. If the thickness of the piezoelectric body 140 is 20 μm or less, the piezoelectric driving device 10 can be sufficiently downsized.

  A piezoelectric element 110a is formed by the first electrode 130a, the second electrode 150a, and the piezoelectric body 140a. The same applies to the other piezoelectric elements 110b, 110c, 110d, and 110e shown in FIG.

  In the present embodiment, as the first electrode 130, five divided conductor layers 130 a to 130 e (first electrodes 130 a to 130 e) are provided, but depending on the connection method of the five piezoelectric elements 110 a to 110 e, the first electrode 130 130 to 130e may be formed as one continuous conductor layer. Also, the piezoelectric body 140 may be formed as one continuous piezoelectric body 140 instead of the five piezoelectric bodies 140a, 140b, 140c, 140d, 140e. Wiring for electrical connection of the five first electrodes 130a to 130e and the five second electrodes 150a to 150e will be described later.

  FIG. 2 is a plan view of the diaphragm 200. The diaphragm 200 has a rectangular-shaped vibrating body portion 210 and three connecting portions 220 that extend from the left and right long sides of the vibrating body portion 210, respectively. Two attachment portions 230 are connected to each other. In FIG. 2, the vibrating body portion 210 is hatched for convenience of illustration. The attachment portion 230 is used for attaching the piezoelectric driving device 10 to another member with a screw 240. The diaphragm 200 can be formed of a metal material such as stainless steel, aluminum, an aluminum alloy, titanium, a titanium alloy, copper, a copper alloy, or an iron-nickel alloy, for example.

  The piezoelectric vibrating portion 100 (FIG. 1) is bonded to the first surface 211 (FIG. 1) of the vibrating body portion 210 using an adhesive. The ratio of the length L to the width W of the vibrating body part 210 is preferably L: W = about 7: 2. This ratio is a preferable value for performing ultrasonic vibration (described later) in which the vibrating body portion 210 bends left and right along the plane. The length L of the vibrating body portion 210 can be set in a range of, for example, 0.1 mm or more and 30 mm or less, and the width W can be set in a range of, for example, 0.02 mm or more and 9 mm or less. In addition, in order for the vibrating body part 210 to perform ultrasonic vibration, the length L is preferably set to 50 mm or less. The thickness of the vibrating body part 210 (thickness of the vibration plate 200) can be in the range of 20 μm or more and 800 μm or less, for example. When the thickness of the vibrating body portion 210 is 20 μm or more, the vibrating body portion 210 has sufficient rigidity to support the piezoelectric vibrating portion 100. In addition, if the thickness of the vibrating body portion 210 is 800 μm or less, a sufficiently large deformation can be generated according to the deformation of the piezoelectric vibrating portion 100.

On one short side of the diaphragm 200, a protrusion 20 (also referred to as “contact portion” or “action portion”) is provided. The protrusion 20 is a member that is in contact with the driven body and applies a force to the driven body. The protrusion 20 is preferably formed of a durable material such as ceramics (for example, Al ₂ O ₃ ).

  FIG. 3 is an explanatory diagram illustrating an example of the operation of the piezoelectric driving device 10. The protrusion 20 of the piezoelectric driving device 10 is in contact with the outer periphery of the rotor 50 as a driven body. In the example shown in FIG. 3, the drive circuit (not shown in FIG. 3) is provided between the piezoelectric element 110a and the first electrodes 130a and 130d and the second electrodes 150a and 150d of the piezoelectric element 110d arranged diagonally. An alternating voltage or pulsating voltage that is a periodically changing voltage is applied. As a result, the piezoelectric elements 110a and 110d expand and contract in the direction of the arrow x in FIG. In response to this, the vibrating body portion 210 of the piezoelectric driving device 10 is bent in the plane of the vibrating body portion 210 and deformed into a meandering shape (S-shape), and the tip of the protrusion 20 reciprocates in the direction of the arrow y. Or elliptical motion. As a result, the rotor 50 rotates around the center 51 in a predetermined direction z (clockwise direction in FIG. 3). The three connection portions 220 (FIG. 2) of the diaphragm 200 described with reference to FIG. 2 are provided at the positions of the vibration nodes (interferences) of the vibration body portion 210. When the drive circuit applies an AC voltage or a pulsating voltage between the first electrode and the second electrode of the piezoelectric elements 110b and 110c (FIG. 1) arranged at other diagonals, the rotor 50 Rotates in the opposite direction. If the same voltage is applied to the central piezoelectric element 110e as the piezoelectric elements 110a and 110d, the piezoelectric driving device 10 expands and contracts in the longitudinal direction, so that the force applied from the protrusion 20 to the rotor 50 is increased. Is possible. Such an operation of the piezoelectric driving device 10 (or the piezoelectric vibration unit 100) is described in the above-mentioned prior art document 1 (Japanese Patent Laid-Open No. 2004-320979 or corresponding US Pat. No. 7,224,102). The disclosure of which is incorporated by reference.

  When applying the driving voltage, the pulsating voltage is applied so that the polarization directions of the plurality of piezoelectric elements 110 are the same direction, that is, the application directions of the voltages applied to the piezoelectric elements 110 are the same direction. May be. Since the direction of polarization of the piezoelectric body of the piezoelectric vibration unit 100 does not reverse during operation, the durability of the piezoelectric element 110 can be improved. In this case, the pulsating voltage may be a voltage that makes the voltage of the second electrode 150 larger than the voltage of the first electrode 130. The durability can be improved as compared with the case where the voltage of the second electrode 150 is smaller than the voltage of the first electrode 130.

First embodiment:
FIG. 4 is an explanatory diagram illustrating an example of the wiring of the first electrode and the second electrode in the first embodiment. FIG. 4A is an explanatory diagram showing an example of connection, and FIG. 4B is an explanatory diagram showing an equivalent circuit. The piezoelectric drive device 10a of the first embodiment includes two piezoelectric vibration units 100a and 100b and a drive circuit 300. The first piezoelectric vibration unit 100a includes a plurality (five) of piezoelectric elements 110a to 110e, and the second piezoelectric vibration unit 100b includes a plurality (five) of piezoelectric elements 110a ′ to 110e ′. The symbols “130” and “150” attached to the piezoelectric elements 110a to 110e and 110a ′ to 110e ′ in FIG. 4B mean “first electrode 130” and “second electrode 150”, respectively. The meanings of the symbols “130” and “150” are the same in FIGS. 6, 7, 8, and 10 described later.

  Among the plurality of piezoelectric elements of the first piezoelectric vibrating portion 100a, the first piezoelectric element 110a and the second piezoelectric element 110d are connected by a first connection method (parallel connection in FIG. 4), and the first piezoelectric element group 115a is connected. Forming. Of the plurality of piezoelectric elements of the second piezoelectric vibrating portion 100b, the first piezoelectric element 110a ′ and the second piezoelectric element 110d ′ are connected by the first connection method (parallel connection in FIG. 4), and the second piezoelectric element is connected. An element group 115b is formed. The first piezoelectric element group 115a and the second piezoelectric element group 115b are connected by a second connection method (series connection in FIG. 4), and are connected to the terminal 300A of the drive circuit 300. Here, the first connection method means a connection method in which a plurality of piezoelectric elements 110 in the piezoelectric vibration unit 100 are connected, and there are a parallel connection shown in the first embodiment and a serial connection described later. The second connection method is a connection method in which a plurality of piezoelectric elements (piezoelectric element group) connected in the first connection method or piezoelectric elements of different piezoelectric vibration parts are connected. In the case of the series connection shown in the first embodiment, In some cases, a parallel connection will be described later. In other words, the first connection method means a connection method within one piezoelectric vibration unit 100, and the second connection method means a connection method between a plurality of piezoelectric vibration units 100. However, as will be described later, the connection method of the piezoelectric elements 110 respectively disposed on the two surfaces of the same diaphragm 200 can be regarded as a connection method in the same piezoelectric vibration part, and therefore may be referred to as a first connection method. is there.

  Among the plurality of piezoelectric elements of the first piezoelectric vibrating part 100a, the third piezoelectric element 110b and the fourth piezoelectric element 110c are connected by the first connection method (parallel connection in FIG. 4), and the third piezoelectric element group 115c is connected. Forming. In addition, among the plurality of piezoelectric elements of the second piezoelectric vibrating portion 100b, the third piezoelectric element 110b ′ and the fourth piezoelectric element 110c ′ are connected by the first connection method (parallel connection in FIG. 4), and the fourth piezoelectric element is connected. An element group 115d is formed. The third piezoelectric element group 115c and the fourth piezoelectric element group 115d are connected by the second connection method (series connection in FIG. 4), and are connected to the terminal 300C of the drive circuit 300.

  The fifth piezoelectric element 110e out of the plurality of piezoelectric elements of the first piezoelectric vibration unit 100a and the fifth piezoelectric element 110e ′ out of the plurality of piezoelectric elements of the second piezoelectric vibration unit 100b are in a second connection method (FIG. 4). Are connected in series) and connected to the terminal 300B of the drive circuit 300.

The connection methods in FIG. 4 are summarized as follows.
(1) Connection method of piezoelectric elements in the same piezoelectric vibration part 100 (first connection method): parallel connection (2) Connection method of piezoelectric elements of different piezoelectric vibration parts 100 (second connection method): series connection

  In the present embodiment, the piezoelectric elements 110a to 110d have the same size, and the piezoelectric element 110e has a size twice that of the piezoelectric element 110a. The same applies to the piezoelectric elements 110a 'to 110e'. Assuming that the capacitance of the piezoelectric element 110a is C1, the capacitances of the first piezoelectric element group 115a and the second piezoelectric element group 115b are 2 × C1, respectively. Since the first piezoelectric element group 115a and the second piezoelectric element group 115b are connected in series, the total capacitance of the piezoelectric elements 110a, 110d, 110a ', and 110d' is C1. Similarly, the total capacitance of the piezoelectric elements 110b, 110c, 110b ', 110c' is C1. Further, assuming that the drive voltage from the terminal 300A is V1, the voltages applied to the piezoelectric elements 110a to 110d and 110a 'to 110d' are all V1 / 2, and the same voltage is applied. Therefore, in order to apply the voltage V1 to each of the piezoelectric elements 110a to 110d and 110a 'to 110d', the driving voltage from the terminal 300A may be 2 * V1.

  FIG. 5 is an explanatory diagram showing a comparative example. In the comparative example, only the equivalent circuit of the piezoelectric elements 110a, 110d, 110a ', and 110d' is illustrated. 5A shows Comparative Example 1 in which all the piezoelectric elements 110a, 110d, 110a ′, and 110d ′ are connected in parallel, and FIG. 5B shows all the piezoelectric elements 110a, 110d, 110a ′, and 110d ′ in series. The connected comparative example 2 is shown.

  In the case of Comparative Example 1 shown in FIG. 5A, the total capacitance of the piezoelectric elements 110a, 110d, 110a ′, and 110d ′ is 4 × C1, and each of the piezoelectric elements 110a, 110d, 110a ′, and 110d ′. The amplitude of the voltage applied to is V1. Therefore, the driving circuit 300 needs to supply a large current when driving the piezoelectric elements 110a, 110d, 110a ', and 110d'. In the first embodiment, (i) the first piezoelectric element 110a and the second piezoelectric element 110d included in the first piezoelectric vibrating portion 100a are connected by a first connection method (parallel connection in the first embodiment) to be the first. The piezoelectric element group 115a is formed, and (ii) the first piezoelectric element 110a ′ and the second piezoelectric element 110d ′ included in the second piezoelectric vibration unit 100b are connected by the first connection method (parallel connection in the first embodiment). Then, the second piezoelectric element group 115b is formed, and (iii) the first piezoelectric element group 115a and the second piezoelectric element group 115b are connected by the second connection method (series connection in the first embodiment). As a result, the total capacitance of the piezoelectric elements 110a, 110d, 110a ', and 110d' does not increase, and the drive circuit 300 does not need to supply a larger current than that of the first comparative example.

  In the case shown in FIG. 5B, the total capacitance of the piezoelectric elements 110a, 110d, 110a ′, and 110d ′ is C1 / 4, and the voltage applied to each of the piezoelectric elements 110a, 110d, 110a ′, and 110d ′. The amplitude is V1 / 4. Therefore, in order to apply the voltage V1 to each of the piezoelectric elements 110a, 110d, 110a ', and 110d', the drive voltage must be 4 × V1. In such a case, the drive circuit 300 must be configured using components with a high breakdown voltage in order to generate a high voltage. According to the first embodiment, since the drive voltage may be 2 × V1, the withstand voltage of the components constituting the drive circuit 300 may be lower than that of the comparative example 2.

  As described above, in the first embodiment, the piezoelectric driving device 10 includes the first piezoelectric vibrating unit 100a and the second piezoelectric vibrating unit 100b. The first piezoelectric vibration unit 100a includes a plurality of piezoelectric elements 110a to 110e including a first piezoelectric element 110a and a second piezoelectric element 110d, and the second piezoelectric vibration unit 100b includes a first piezoelectric element 110a ′ and a second piezoelectric element. A plurality of piezoelectric elements 110a to 110e including the element 110d ′ are included. The first piezoelectric element 110a and the second piezoelectric element 110d included in the first piezoelectric vibrating part 100a are connected by the first connection method to form the first piezoelectric element group 115a, and the first piezoelectric element group 115a is included in the second piezoelectric vibrating part 100b. The first piezoelectric element 110a ′ and the second piezoelectric element 110d ′ are connected by the first connection method to form a first piezoelectric element group 115b. The first piezoelectric element group 115a and the second piezoelectric element group 115b are connected by the second connection method. Here, the first connection method is parallel connection, and the second connection method is series connection. When such a configuration is adopted, the drive circuit 300 does not need to supply a larger current than in the first comparative example, and compared with the second comparative example, the breakdown voltage of the components constituting the drive circuit 300 may be lower. .

Second embodiment:
FIG. 6 is an explanatory diagram showing the second embodiment. FIG. 6A is an explanatory diagram showing an example of connection, and FIG. 6B is an explanatory diagram showing an equivalent circuit. The difference from the first embodiment is that a plurality (five) of piezoelectric elements 110a to 110e of the first piezoelectric vibrating part 100a and a plurality (five) of piezoelectric elements 110a 'to 110e' of the second piezoelectric vibrating part 100b. It is a connection. The connection methods in FIG. 6 are summarized as follows.
(1) Connection method of piezoelectric elements in the same piezoelectric vibration part 100 (first connection method): series connection (2) Connection method of piezoelectric elements of different piezoelectric vibration parts 100 (second connection method): parallel connection

  Assuming that the capacitance of the piezoelectric element 110a is C1, the capacitances of the first piezoelectric element group 115a and the second piezoelectric element group 115b are each C1 / 2. Since the first piezoelectric element group 115a and the second piezoelectric element group 115b are connected in parallel, the total capacitance of the piezoelectric elements 110a, 110d, 110a ', and 110d' is C1. Similarly, the total capacitance of the piezoelectric elements 110b, 110c, 110b ', 110c' is C1. Further, assuming that the drive voltage from the terminal 300A is V1, the voltages applied to the piezoelectric elements 110a to 110d and 110a 'to 110d' are all V1 / 2, and the same voltage is applied. Therefore, in order to apply the voltage V1 to each of the piezoelectric elements 110a to 110d and 110a 'to 110d', the driving voltage from the terminal 300A may be 2 * V1. These values are the same as in the first embodiment.

  As described above, in the second embodiment, the piezoelectric driving device 10 includes the first piezoelectric vibrating unit 100a and the second piezoelectric vibrating unit 100b. The first piezoelectric vibration unit 100a includes a plurality of piezoelectric elements 110a to 110e including a first piezoelectric element 110a and a second piezoelectric element 110d, and the second piezoelectric vibration unit 100b includes a first piezoelectric element 110a ′ and a second piezoelectric element. A plurality of piezoelectric elements 110a to 110e including the element 110d ′ are included. The first piezoelectric element 110a and the second piezoelectric element 110d included in the first piezoelectric vibrating part 100a are connected by the first connection method to form the first piezoelectric element group 115a, and the first piezoelectric element group 115a is included in the second piezoelectric vibrating part 100b. The first piezoelectric element 110a ′ and the second piezoelectric element 110d ′ are connected by the first connection method to form a first piezoelectric element group 115b. The first piezoelectric element group 115a and the second piezoelectric element group 115b are connected by the second connection method. Here, the first connection method is parallel connection, and the second connection method is series connection. Therefore, the total capacitance of the piezoelectric elements 110a, 110d, 110a ′, and 110d ′ does not increase, and the drive circuit 300 does not need to supply a larger current than that of the first comparative example. Further, as compared with the second comparative example, the breakdown voltage of the components constituting the drive circuit 300 may be lower.

As described above, when the first embodiment and the second embodiment are summarized, the piezoelectric driving device 10 has the following configuration.
(1) Connection method of piezoelectric elements in the same piezoelectric vibration unit 100 (first connection method): parallel connection or series connection (2) Connection method of piezoelectric elements of different piezoelectric vibration units 100 (second connection method) : Series connection when the first connection method is parallel connection, parallel connection when the first connection method is series connection. When such a configuration is adopted, the drive circuit 300 supplies a larger current than that of the first comparative example. Compared with Comparative Example 2, the withstand voltage of the components constituting the drive circuit 300 may be low.

  In the first embodiment and the second embodiment, it is preferable to adopt the first embodiment in which the first connection method is parallel connection and the second connection method is series connection for the following reasons. The piezoelectric elements 110a to 110e are preferably applied with the same voltage because the thickness of the piezoelectric bodies 140a to 140e is the same. Assuming that the drive voltage of the drive circuit 300 is V1, in the first embodiment, the voltage applied to the piezoelectric element 110a and the piezoelectric element 110e is V1 / 2, which is the same. In contrast, in the second embodiment, the voltage applied to the piezoelectric element 110a is V1 / 2, but the voltage applied to the piezoelectric element 110e is V1. Therefore, in the first embodiment, the drive circuit 300 does not need to change the magnitude of the drive voltage output to the terminals 300A and 300B, but in the second embodiment, the voltages applied to the piezoelectric elements 110a and 110e are the same. Therefore, the drive circuit 300 needs to change the magnitude of the drive voltage output to the terminals 300A and 300B, and the drive circuit 300 may be complicated. Therefore, the first embodiment is preferable.

  The plurality of piezoelectric elements 110 connected in series (for example, the piezoelectric elements 110a and 110d in the second embodiment) preferably have the same size. If the magnitudes are the same, the capacitances are also the same, so the voltages applied to the piezoelectric elements 110 connected in series are also equal. Note that the same size here is not required to be completely the same, and may be almost the same. For example, the second piezoelectric element 110d may be about ± 10% in area with respect to the size of the first piezoelectric element 110a. That is, a difference in size of about ± 10% may be included in a range of the same size and the same size.

Third embodiment:
FIG. 7 is an explanatory diagram showing the third embodiment. The difference from the first embodiment is that the piezoelectric element 110e of the first embodiment is divided into two piezoelectric elements 110f and 110g, and the piezoelectric element 110e 'is divided into two piezoelectric elements 110f' and 110g '. It is. The piezoelectric elements 110f, 110g, 110f ′, and 110g ′ have the same size as the other piezoelectric elements 110a to 110d and 110a ′ to 110d ′. The connection method of the third embodiment is the same as that of the first embodiment for the piezoelectric elements 110a to 110d and 110a ′ to 110d ′, and the following two are also applicable to the piezoelectric elements 110f, 110g, 110f ′, and 110g ′. Street.
(1) Connection method of piezoelectric elements in the same piezoelectric vibration part 100 (first connection method): parallel connection (2) Connection method of piezoelectric elements of different piezoelectric vibration parts 100 (second connection method): series connection

  As described above, in the third embodiment, the piezoelectric driving device 10 includes the first piezoelectric vibrating unit 100a and the second piezoelectric vibrating unit 100b. The first piezoelectric vibration unit 100a includes a plurality of piezoelectric elements 110a to 110g including a first piezoelectric element 110f and a second piezoelectric element 110g, and the second piezoelectric vibration unit 100b includes a first piezoelectric element 110f ′ and a second piezoelectric element. A plurality of piezoelectric elements 110a ′ to 110g ′ including the element 110g ′ are included. The first piezoelectric element 110f and the second piezoelectric element 110g included in the first piezoelectric vibration unit 100a are connected by the first connection method to form the first piezoelectric element group 115e, and the first piezoelectric element group 115e is included in the second piezoelectric vibration unit 100b. The first piezoelectric element 110f ′ and the second piezoelectric element 110g ′ are connected by the first connection method to form a first piezoelectric element group 115f. The first piezoelectric element group 115e and the second piezoelectric element group 115f are connected by the second connection method. Here, the first connection method is parallel connection, and the second connection method is series connection. Therefore, like the piezoelectric elements 110a, 110d, 110a ′, 110d ′ of the first embodiment, the total capacitance of the piezoelectric elements 110f, 110g, 110f ′, 110g ′ does not increase in the third embodiment, The drive circuit 300 may not supply a larger current than that in the first comparative example. Further, as compared with the second comparative example, the breakdown voltage of the components constituting the drive circuit 300 may be lower. The other piezoelectric elements 110a to 110d and 110a 'to 110d' are the same as in the first embodiment.

  In the third embodiment, the equivalent circuits of the piezoelectric elements 110f, 110g, 110f ', and 110g' are the same as the equivalent circuits of the piezoelectric elements 110a, 110d, 110a ', and 110d'. As a result, in the driving circuit 300, the circuit that drives the piezoelectric elements 110f, 110g, 110f ', and 110g' and the circuit that drives the piezoelectric elements 110a, 110d, 110a ', and 110d' can be configured with the same circuit configuration.

-Fourth embodiment:
FIG. 8 is an explanatory diagram showing the fourth embodiment. The difference from the third embodiment is that in the fourth embodiment, the first connection method is connected in series and the second connection method is connected in parallel. The connection method of the fourth embodiment is the same as that of the second embodiment for the piezoelectric elements 110a to 110d and 110a ′ to 110d ′, and the following two are also applicable to the piezoelectric elements 110f, 110g, 110f ′, and 110g ′. Street.
(1) Connection method of piezoelectric elements in the same piezoelectric vibration part 100 (first connection method): series connection (2) Connection method of piezoelectric elements of different piezoelectric vibration parts 100 (second connection method): parallel connection

  In the fourth embodiment, the piezoelectric driving device 10 includes a first piezoelectric vibrating unit 100a and a second piezoelectric vibrating unit 100b. The first piezoelectric vibration unit 100a includes a plurality of piezoelectric elements 110a to 110g including a first piezoelectric element 110f and a second piezoelectric element 110g, and the second piezoelectric vibration unit 100b includes a first piezoelectric element 110f ′ and a second piezoelectric element. A plurality of piezoelectric elements 110a ′ to 110g ′ including the element 110g ′ are included. The first piezoelectric element 110f and the second piezoelectric element 110g included in the first piezoelectric vibration unit 100a are connected by the first connection method to form the first piezoelectric element group 115e, and the first piezoelectric element group 115e is included in the second piezoelectric vibration unit 100b. The first piezoelectric element 110f ′ and the second piezoelectric element 110g ′ are connected by the first connection method to form a first piezoelectric element group 115f. The first piezoelectric element group 115e and the second piezoelectric element group 115f are connected by the second connection method. Here, the first connection method is a series connection, and the second connection method is a parallel connection. Therefore, like the piezoelectric elements 110a, 110d, 110a ′, and 110d ′ of the second embodiment, the total capacitance of the piezoelectric elements 110f, 110g, 110f ′, and 110g ′ of the fourth embodiment does not increase and is driven. The circuit 300 may not supply a larger current than that in the first comparative example. Further, as compared with the second comparative example, the breakdown voltage of the components constituting the drive circuit 300 may be lower. The other piezoelectric elements 110a to 110d and 110a 'to 110d' are the same as in the second embodiment.

  Also in the fourth embodiment, the equivalent circuit of the piezoelectric elements 110f, 110g, 110f ', and 110g' is the same as the equivalent circuit of the piezoelectric elements 110a, 110d, 110a ', and 110d'. As a result, in the driving circuit 300, the circuit that drives the piezoelectric elements 110f, 110g, 110f ', and 110g' and the circuit that drives the piezoelectric elements 110a, 110d, 110a ', and 110d' can be configured with the same circuit configuration.

-Fifth embodiment:
FIG. 9 is an explanatory diagram showing the fifth embodiment. FIG. 10 is an equivalent circuit of the fifth embodiment. In the first embodiment, the piezoelectric elements 110a to 110e are disposed on one surface (for example, the surface 211) of the diaphragm 200a, and the piezoelectric elements 110a ′ to 110e ′ are disposed on one surface (for example, the surface 211) of the vibrating body 200b. In the fifth embodiment, the piezoelectric elements 110a to 110e are disposed on one surface 211 of the diaphragm 200a, and the piezoelectric elements 110a to 110e are disposed on the other surface 212, and one of the diaphragms 200b is disposed. The piezoelectric elements 110 a ′ to 110 e ′ are arranged on the surface 211, and the piezoelectric elements 110 a ′ to 110 e ′ are also arranged on the other surface 212. In this case, the two first piezoelectric elements 110a and the two second piezoelectric elements 110d of the diaphragm 200a are connected by a first connection method (parallel connection) to form the piezoelectric element group 115a, and the two second piezoelectric elements 110b of the diaphragm 200b are formed. One piezoelectric element 110a ′ and two second piezoelectric elements 100d ′ are connected by a first connection method (parallel connection) to form a piezoelectric element group 115b, and the piezoelectric element groups 115a and 115b are connected by a second connection method (in series). Connection). The other piezoelectric elements 110b, 110c, 110e, 110b ′, 110c ′, and 110e ′ are similarly connected by the first connection method and the second connection method. In the fifth embodiment, one diaphragm 200a and the piezoelectric elements 110a to 110e of the two surfaces 211 and 212 are regarded as one piezoelectric vibration part, and one diaphragm 200b and its two surfaces 211 and 212 are combined. The two piezoelectric vibration parts 100a ′ to 110e ′ are regarded as one piezoelectric vibration part. In the fifth embodiment, two first piezoelectric elements 110a and two second piezoelectric elements 110d of a piezoelectric vibrating portion regarded as one piezoelectric vibrating portion are connected by a first connection method (parallel connection) to thereby obtain a piezoelectric element. Forming a group and connecting the two first piezoelectric elements 110a ′ and the two second piezoelectric elements 110d ′ of the two piezoelectric vibrating parts 100b by a first connection method (parallel connection) to form a piezoelectric element group. These two piezoelectric element groups are connected by the second connection method (series connection). You may comprise in this way.

The connection methods of the fifth embodiment are summarized as follows.
(1) Connection method of piezoelectric elements in the same piezoelectric vibration part 100a or 100b (first connection method): Parallel connection (2) Connection method of piezoelectric elements between different piezoelectric vibration parts 100a and 100b (first 2 connection method): Series connection

  According to the fifth embodiment, the piezoelectric driving device 10a includes the first piezoelectric vibrating unit 100a and the second piezoelectric vibrating unit 100b. The first piezoelectric vibration unit 100a includes a plurality of piezoelectric elements 110a to 110e including a first piezoelectric element 110a and a second piezoelectric element 110d, and the second piezoelectric vibration unit 100b includes a first piezoelectric element 110a ′ and a second piezoelectric element. A plurality of piezoelectric elements 110a ′ to 110e ′ including the element 110d ′ are included. The first piezoelectric element 110a and the second piezoelectric element 110d included in the first piezoelectric vibrating part 100a are connected by the first connection method to form the first piezoelectric element group 115a, and the first piezoelectric element group 115a is included in the second piezoelectric vibrating part 100b. The first piezoelectric element 110a ′ and the second piezoelectric element 110d ′ are connected by the first connection method to form a first piezoelectric element group 115b. The first piezoelectric element group 115a and the second piezoelectric element group 115b are connected by the second connection method. Here, the first connection method is parallel connection, and the second connection method is series connection. When such a configuration is employed, the drive circuit 300 may not supply a larger current than that in the first comparative example.

  FIGS. 11A and 11B are plan views of a piezoelectric vibrating portion 100g as another embodiment of the present invention, and correspond to FIG. 1A of the first embodiment. 11A and 11B, for convenience of illustration, only the vibrating body portion 210 is illustrated, and the connection portion 220 and the attachment portion 230 are not illustrated. In the piezoelectric vibrating portion 100g of FIG. 11A, the pair of piezoelectric elements 110b and 110c are omitted. The piezoelectric vibrating portion 100g can also rotate the rotor 50 in one direction z as shown in FIG. Since the same voltage is applied to the three piezoelectric elements 110a, 110e, and 110d in FIG. 11A, the second electrodes (150a, 150e, and 150d) of these three piezoelectric elements 110a, 110e, and 110d. ) May be formed as one continuous electrode layer.

  FIG. 11B is a plan view of a piezoelectric vibrating portion 100h as still another embodiment of the present invention. In the piezoelectric vibrating portion 100h, the central piezoelectric element 110e in FIG. 1A is omitted, and the other four piezoelectric elements 110a, 110b, 110c, and 110d are formed in a larger area than in FIG. 1A. ing. This piezoelectric vibrating portion 100h can also achieve substantially the same effect as in the first embodiment.

  As can be understood from FIG. 1 and FIGS. 11A and 11B, at least one electrode layer can be provided as the second electrode 150 of the piezoelectric vibrating portion 100. However, as in the embodiment shown in FIGS. 1 and 11A and 11B, if the piezoelectric element 110 (second electrode 150) is provided at the diagonal position of the rectangular vibrating body 210, The vibrating part 210 is preferable in that it can be deformed into a meandering shape that bends in the plane.

  In each of the above embodiments, the first electrode 130 is divided into a plurality of first electrodes 130a to 130e. However, when the first connection method is parallel connection, the first electrodes 130a to 130e are integrally formed. One first electrode 130 may be formed. In the case of parallel connection, since the first electrode 130 has the same potential, there is no problem even if one integrally formed first electrode 130 is formed. Further, by forming the first electrode 130 that is integrally formed, a wiring is also automatically formed. Therefore, another wiring for connecting in parallel is not necessary, and the disconnection of the wiring hardly occurs.

-Embodiments of a device using a piezoelectric drive:
The piezoelectric drive device 10 described above can apply a large force to the driven body by utilizing resonance, and can be applied to various devices. The piezoelectric driving device 10 is, for example, a robot (including an electronic component conveying device (IC handler)), a dosing pump, a calendar feeding device for a clock, and a printing device (for example, a paper feeding mechanism. However, a piezoelectric driving device used for a head. Then, since the diaphragm is not resonated, it cannot be applied to the head. Hereinafter, representative embodiments will be described.

  FIG. 12 is an explanatory diagram showing an example of a robot 2050 using the piezoelectric driving device 10 described above. The robot 2050 includes a plurality of link portions 2012 (also referred to as “link members”) and an arm 2010 (“a” that includes a plurality of joint portions 2020 that connect the link portions 2012 in a rotatable or bendable state. It is also called “arm”. Each joint portion 2020 includes the above-described piezoelectric drive device 10, and the joint portion 2020 can be rotated or bent by an arbitrary angle using the piezoelectric drive device 10. A robot hand 2000 is connected to the tip of the arm 2010. The robot hand 2000 includes a pair of grip portions 2003. The robot hand 2000 also has a built-in piezoelectric driving device 10, and the piezoelectric driving device 10 can be used to open and close the gripping unit 2003 to grip an object. The piezoelectric drive device 10 is also provided between the robot hand 2000 and the arm 2010, and the robot hand 2000 can be rotated with respect to the arm 2010 using the piezoelectric drive device 10.

  FIG. 13 is an explanatory diagram of the wrist portion of the robot 2050 shown in FIG. The wrist joint portion 2020 sandwiches the wrist rotating portion 2022, and the wrist link portion 2012 is attached to the wrist rotating portion 2022 so as to be rotatable around the central axis O of the wrist rotating portion 2022. . The wrist rotation unit 2022 includes the piezoelectric driving device 10, and the piezoelectric driving device 10 rotates the wrist link unit 2012 and the robot hand 2000 around the central axis O. The robot hand 2000 is provided with a plurality of gripping units 2003. The proximal end portion of the grip portion 2003 can be moved in the robot hand 2000, and the piezoelectric driving device 10 is mounted on the base portion of the grip portion 2003. For this reason, by operating the piezoelectric driving device 10, it is possible to move the gripping part 2003 and grip the object.

  In the embodiment shown in FIG. 13, the wrist link portion 2012 and the robot hand 2000 are rotated around the central axis O by using two piezoelectric driving devices 10 (diaphragm). In this case, the two piezoelectric driving devices 10 may be connected in series. The effect of reducing current and omitting wiring can be obtained. In addition, in each piezoelectric drive device 10 connected in series, the plurality of piezoelectric elements may be connected either in series or in parallel.

  The robot is not limited to a single-arm robot, and the piezoelectric driving device 10 can be applied to a multi-arm robot having two or more arms. Here, in addition to the piezoelectric drive device 10, a power line for supplying power to various devices such as a force sensor and a gyro sensor, a signal line for transmitting a signal, and the like are provided inside the wrist joint portion 2020 and the robot hand 2000. Included and requires a great deal of wiring. Therefore, it is very difficult to arrange the wiring inside the joint portion 2020 and the robot hand 2000. However, since the piezoelectric drive device 10 of the above-described embodiment can reduce the drive current compared to a normal electric motor or a conventional piezoelectric drive device, the joint portion 2020 (particularly, the joint portion at the tip of the arm 2010) or a robot hand. Wiring can be arranged even in a small space such as 2000.

  FIG. 14 is an explanatory view showing an example of a liquid feed pump 2200 using the piezoelectric driving device 10 described above. The liquid feed pump 2200 includes a reservoir 2211, a tube 2212, the piezoelectric driving device 10, a rotor 2222, a deceleration transmission mechanism 2223, a cam 2202, a plurality of fingers 2213, 2214, 2215, 2216, and a case 2230. 2217, 2218, and 2219 are provided. The reservoir 2211 is a storage unit for storing a liquid to be transported. The tube 2212 is a tube for transporting the liquid sent out from the reservoir 2211. The protrusion 20 of the piezoelectric driving device 10 is provided in a state of being pressed against the side surface of the rotor 2222, and the piezoelectric driving device 10 rotationally drives the rotor 2222. The rotational force of the rotor 2222 is transmitted to the cam 2202 via the deceleration transmission mechanism 2223. Fingers 2213 to 2219 are members for closing the tube 2212. When the cam 2202 rotates, the fingers 2213 to 2219 are sequentially pushed outward in the radial direction by the protrusion 2202A of the cam 2202. The fingers 2213 to 2219 close the tube 2212 in order from the upstream side in the transport direction (reservoir 2211 side). Thereby, the liquid in the tube 2212 is transported to the downstream side in order. In this way, it is possible to realize a small liquid feed pump 2200 that can deliver an extremely small amount with high accuracy and that is small. In addition, arrangement | positioning of each member is not restricted to what was illustrated. Further, a member such as a finger may not be provided, and a ball or the like provided on the rotor 2222 may close the tube 2212. The liquid feed pump 2200 as described above can be used for a medication device that administers a drug solution such as insulin to the human body. Here, by using the piezoelectric driving device 10 according to the above-described embodiment, the driving current is smaller than that of the conventional piezoelectric driving device, so that the power consumption of the dosing device can be suppressed. Therefore, it is particularly effective when the medication apparatus is battery-driven.

・ Modification:
The present invention is not limited to the above-described examples and embodiments, and can be implemented in various modes without departing from the gist thereof. For example, the following modifications are possible.

Modification 1:
In the fifth embodiment, the first connection method is connected in parallel and the second connection method is connected in series. However, as in the second embodiment, the first connection method may be connected in series and the second connection method may be connected in parallel. Good.

Modification 2
In the above embodiment, the first electrode 130, the piezoelectric body 140, and the second electrode 150 are formed on the substrate 120. However, the substrate 120 is omitted, and the first electrode 130 and the piezoelectric material are formed on the vibration plate 200. The body 140 and the second electrode 150 may be formed.

・ Modification 3:
In each of the above embodiments, for example, taking the second embodiment (FIG. 6) as an example, the polarization directions of the piezoelectric elements 110a to 110e of the piezoelectric vibration unit 100 are the same (for example, the direction of the applied voltage is the first). The piezoelectric elements 110a to 110e are connected in series or in parallel so as to be in the direction from the electrode 130 toward the second electrode 150). Here, a part of the piezoelectric elements 110 a to 110 e of the piezoelectric vibration unit 100 (for example, the piezoelectric elements 110 b and 110 d) are reversely connected, and a part thereof is reversed. The polarization direction of the piezoelectric elements (piezoelectric elements 110b and 110d) is opposite to the polarization direction of the other piezoelectric elements (110a, 110c, 110e) (the direction of the applied voltage is from the second electrode 150 toward the first electrode 130). Direction). Even in this case, the electrostatic capacity can be reduced, and an equivalent effect is obtained in that it is not necessary to supply a large current when driving the piezoelectric vibration unit 100. The same applies to other embodiments.

  The embodiments of the present invention have been described above based on some examples. However, the above-described embodiments of the present invention are for facilitating the understanding of the present invention and limit the present invention. It is not a thing. The present invention can be changed and improved without departing from the spirit and scope of the claims, and it is needless to say that the present invention includes equivalents thereof.

    DESCRIPTION OF SYMBOLS 10, 10a ... Piezoelectric drive device 20 ... Protrusion part 50 ... Rotor 51 ... Center 100, 100a, 100b, 100c, 100d, 100g, 100h ... Piezoelectric vibration part 110, 110a-110g, 110a'-110g '... Piezoelectric element 115a- 115f ... Piezoelectric element group 120 ... Substrate 130, 130a-130e ... First electrode 140,140a-140e ... Piezoelectric body 150,150a-150e ... Second electrode 200,200a, 200b ... Vibrating plate 210 ... Vibrating body part 211,212 ... Surface 220 ... Connecting part 230 ... Mounting part 240 ... Screw 300 ... Drive circuit 300A, 300B, 300C ... Terminal 2000 ... Robot hand 2003 ... Grip part 2010 ... Arm 2012 ... Link part 2020 ... Joint part 202 ... wrist rotation unit 2050 ... robot 2200 ... feeding pump 2202 ... cam 2202A ... projections 2211 ... reservoir 2212 ... tube 2213 ... fingers 2222 ... Rotor 2223 ... reduction transmission mechanism

Claims (9)

A first piezoelectric vibrating section having a diaphragm provided with a plurality of piezoelectric elements formed by a first electrode, a second electrode, and a piezoelectric body positioned between the first electrode and the second electrode; A second piezoelectric vibration unit;
Each of the first piezoelectric vibrating section and the second piezoelectric vibrating section includes a first piezoelectric element and a second piezoelectric element as the plurality of piezoelectric elements,
A first piezoelectric element group is formed by connecting the first piezoelectric element and the second piezoelectric element included in the first piezoelectric vibration unit by a first connection method;
A first piezoelectric element group is formed by connecting the first piezoelectric element and the second piezoelectric element included in the second piezoelectric vibration unit by the first connection method;
Connecting the first piezoelectric element group and the second piezoelectric element group by a second connection method;
One of the first connection method and the second connection method is a series connection, and the other is a parallel connection. The piezoelectric drive device according to claim 1,
The first connection method is parallel connection;
The said 2nd connection system is a piezoelectric drive apparatus which is a serial connection. In the piezoelectric drive device according to claim 1 or 2,
The plurality of piezoelectric elements connected in series have the same size. In the piezoelectric drive device according to any one of claims 1 to 3,
A piezoelectric driving device, wherein when a driving voltage is applied to the plurality of piezoelectric elements, a direction in which a voltage is applied to the plurality of piezoelectric elements is the same direction. The piezoelectric drive device according to claim 4.
The first electrode is located closer to the diaphragm than the second electrode;
The piezoelectric drive device, wherein the voltage application direction is a direction from the second electrode toward the first electrode. The piezoelectric drive device according to claim 2,
The piezoelectric drive device, wherein the first electrodes of the plurality of piezoelectric elements connected in parallel form one integrally formed electrode. A plurality of link portions and a joint portion connecting the plurality of link portions;
The piezoelectric drive device according to any one of claims 1 to 6, wherein the plurality of link portions are rotated by the joint portions.
Robot equipped with. The robot driving method according to claim 7, wherein the piezoelectric driving device is driven by applying a periodically changing voltage between the first electrode and the second electrode of the piezoelectric driving device, A robot driving method in which the plurality of link portions are rotated by the joint portions. It is a drive method of the piezoelectric drive device according to any one of claims 1 to 6,
The voltage periodically changes between the first electrode and the second electrode of the piezoelectric element, and the direction of the voltage applied to the piezoelectric body of the piezoelectric element is from one of the electrodes to the other. Driving method of a piezoelectric driving device for applying a pulsating voltage which is one direction toward the electrode of

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