JP2020022360A - Piezoelectric driving device and driving method for the same, and robot and driving method for the same - Google Patents

Abstract

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 in series connection, and the other is in parallel connection.SELECTED DRAWING: Figure 4

Description

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

  2. Description of the Related Art A piezoelectric actuator (piezoelectric driving device) that drives a driven body by vibrating a piezoelectric body is used in various fields because a magnet and a coil are unnecessary (for example, Patent Document 1). The basic configuration of this piezoelectric driving device is a configuration in which four piezoelectric elements are arranged in two rows and two columns on each of two surfaces of a reinforcing plate, and a total of eight piezoelectric elements are provided on 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. At one end of the reinforcing plate, a projection is provided 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 protrusions of the reinforcing plate reciprocate or move in an elliptical manner. I do. Then, the rotor as the driven body rotates in a predetermined rotation direction in accordance with the reciprocating motion or the elliptical motion of the protrusion of the reinforcing plate. Further, by switching the two piezoelectric elements to which the AC voltage is applied to the other two piezoelectric elements, the rotor can be rotated in the opposite direction.

JP 2004-320979 A

  When a piezoelectric drive device is used in a small space (for example, in a joint of a robot) and used, there is a possibility that a conventional piezoelectric drive device using a piezoelectric material requires a shortage of wiring space. is there. However, the capacitance of the vibrating body of the piezoelectric driving device is inversely proportional to the distance between the electrodes sandwiching the piezoelectric body. Therefore, when the piezoelectric body is made thinner, the capacitance becomes large, and in particular, simultaneously drives a plurality of vibrating bodies. In such a case, it is 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 located between the first electrode and the second electrode. A first piezoelectric vibrating section and a second piezoelectric vibrating section, wherein the first piezoelectric vibrating section and the second piezoelectric vibrating section each have a first piezoelectric element and a second piezoelectric element as the plurality of piezoelectric elements; The first piezoelectric element and the second piezoelectric element included in the first piezoelectric vibrating section are connected by a first connection method to form a first piezoelectric element group, and the first piezoelectric element group included in the second piezoelectric vibrating section is formed. One 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 serial connection, It is a parallel connection. According to the piezoelectric driving device of this aspect, since the connection between the piezoelectric element and the piezoelectric element includes series connection, the capacitance can be reduced, and a large current is supplied when a plurality of vibrators are driven simultaneously. It is not necessary.

(2) In the piezoelectric driving 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 drive 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 equalized.

(3) In the piezoelectric driving 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 embodiment, the voltages applied to the piezoelectric elements connected in series can be equalized.

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

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

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

(7) According to one aspect of the present invention, there is provided a robot. 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 by the joint portions. And a device. According to this aspect, the piezoelectric driving device can be used for driving a robot.

(8) According to one aspect of the present invention, there is provided a driving method of a robot. This driving method drives the piezoelectric driving device by applying a periodically changing voltage between the first electrode and the second electrode of the piezoelectric driving device, and connects the plurality of link portions to the joint. Rotate in the section.

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

  The present invention can be realized in various forms, for example, 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. The present invention can be realized in various forms such as a driving method of a mounted robot, an electronic component transport device, a liquid feed pump, and a medication pump.

FIG. 2 is an explanatory diagram illustrating a schematic configuration of a piezoelectric driving device. The top view of a diaphragm. Explanatory drawing which shows the example of operation | movement of a piezoelectric drive device. FIG. 2 is an explanatory diagram illustrating an example of a wiring between a first electrode and a second electrode according to the first 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. 12 is an equivalent circuit of the fifth embodiment. FIG. 9 is a plan view of a piezoelectric vibrating unit according to another embodiment. Explanatory drawing showing an example of a robot. FIG. 3 is an explanatory diagram of a wrist portion of the robot. Explanatory drawing which shows an example of a liquid feed pump.

  FIG. 1A is a plan view illustrating a schematic configuration of a piezoelectric driving device 10 according to an embodiment of the present invention, and FIG. 1B is a cross-sectional view taken along line BB. The piezoelectric driving device 10 includes a vibration plate 200 and a piezoelectric vibration unit 100. The piezoelectric vibrating 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 described later, the piezoelectric vibrating unit 100 may be disposed on each of the two surfaces 211 and 212 of the diaphragm. The piezoelectric vibrating part 100 includes a substrate 120, a first electrode 130 formed on the substrate 120, a piezoelectric member 140 formed on the first electrode 130, and a second electrode formed on the piezoelectric member 140. And 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 vibrating section 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. Further, the substrate 120 also has a function as a diaphragm that performs mechanical vibration. Substrate 120, for example, can be formed by Si, etc. Al ₂ O _3, ZrO _2. As the substrate 120 made of Si, for example, a Si wafer for manufacturing a semiconductor can be used. In this embodiment, the planar shape of the substrate 120 is rectangular. The thickness of the substrate 120 is preferably, for example, in the range of 10 μm or more and 100 μm or less. When the thickness of the substrate 120 is 50 μm or more, the substrate 120 can be handled relatively easily during the film formation process on the substrate 120. When the thickness of the substrate 120 is set to 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.

  1A, the first electrode 130 is divided into five conductive 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 over substantially the entire length of the substrate 120 at the center in the width direction of the substrate 120. The other four first electrodes 130a, 130b, 130c, and 130d have the same planar shape and are formed at four corners 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 over substantially the entire length of the substrate 120 at the center in the width direction of the substrate 120. The other four second electrodes 150a, 150b, 150c, and 150d have the same planar shape and are formed at four corners of the substrate 120. In the example of FIG. 1, each of the first electrode 130 and the second electrode 150 has a rectangular planar shape. The first electrode 130 and the second electrode 150 are thin films formed by, for example, sputtering. 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), and Ir (iridium) is used. 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 a ceramic 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 oxide. Barium strontium oxide (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, for example, polyvinylidene fluoride, quartz, or the like. The thickness of the piezoelectric body 140 is preferably, for example, in a range of 50 nm (0.05 μm) or more and 20 μm or less. A thin film of the piezoelectric body 140 having a thickness in this range can be easily formed using a film forming process. When 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 set to 20 μm or less, the size of the piezoelectric driving device 10 can be sufficiently reduced.

  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, the first electrode 130 includes five divided conductive layers 130a to 130e (first electrodes 130a to 130e). However, depending on the connection method of the five piezoelectric elements 110a to 110e, the first electrode 130 may be used. 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, and 140e. Wiring for electrical connection between 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. FIG. The diaphragm 200 has a rectangular vibrating body portion 210 and three connecting portions 220 extending from the left and right long sides of the vibrating body portion 210, respectively. It has two mounting portions 230 connected to each other. In FIG. 2, the vibrating body 210 is hatched for convenience of illustration. The mounting portion 230 is used for mounting the piezoelectric driving device 10 to another member with a screw 240. 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, and an iron-nickel alloy, for example.

  The piezoelectric vibrating section 100 (FIG. 1) is bonded to the first surface 211 (FIG. 1) of the vibrating body section 210 using an adhesive. It is preferable that the ratio of the length L to the width W of the vibrating body 210 is 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 210 can be, for example, in a range of 0.1 mm to 30 mm, and the width W can be, for example, in a range of 0.02 mm to 9 mm. Note that the length L is preferably set to 50 mm or less so that the vibrator 210 performs ultrasonic vibration. The thickness of the vibrating part 210 (the thickness of the diaphragm 200) can be, for example, in a range of 20 μm or more and 800 μm or less. When the thickness of the vibrating part 210 is set to 20 μm or more, the vibrating part 210 has sufficient rigidity to support the piezoelectric vibrating part 100. When the thickness of the vibrating portion 210 is 800 μm or less, a sufficiently large deformation can be generated according to the deformation of the piezoelectric vibrating portion 100.

Protrusion 20 (also referred to as a “contact portion” or an “acting portion”) is provided on one short side of diaphragm 200. The protrusion 20 is a member for contacting the driven body and applying 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 a rotor 50 as a driven body. In the example shown in FIG. 3, the driving circuit (not shown in FIG. 3) is provided between the first electrodes 130a and 130d and the second electrodes 150a and 150d of the piezoelectric elements 110a and 110d arranged diagonally. An AC voltage or a pulsating voltage that is a voltage that changes periodically is applied. As a result, the piezoelectric elements 110a and 110d expand and contract in the direction of arrow x in FIG. In response, the vibrating body portion 210 of the piezoelectric driving device 10 bends in the plane of the vibrating body portion 210 and deforms into a meandering (S-shaped) shape, and the tip of the protrusion 20 reciprocates in the direction of arrow y. Or make an elliptical motion. As a result, the rotor 50 rotates around its center 51 in a predetermined direction z (clockwise 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 nodes of the vibration of the vibrating body portion 210. When the driving 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. When the same voltage as that of the piezoelectric elements 110a and 110d is applied to the central piezoelectric element 110e, the piezoelectric driving device 10 expands and contracts in the longitudinal direction. Is possible. Such an operation of the piezoelectric driving device 10 (or the piezoelectric vibrating section 100) is described in the above-mentioned prior art document 1 (Japanese Patent Application Laid-Open No. 2004-320979 or the corresponding US Pat. No. 7,224,102). , The disclosure of which is incorporated by reference.

  When the drive voltage is applied, the pulsating voltage is applied such that the directions of polarization of the plurality of piezoelectric elements 110 are the same, that is, the directions of the voltages applied to the piezoelectric elements 110 are the same. You may. Since the direction of polarization of the piezoelectric body of the piezoelectric vibrating section 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 higher 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 lower than the voltage of the first electrode 130.

-1st Embodiment:
FIG. 4 is an explanatory diagram illustrating an example of the wiring between the first electrode and the second electrode in the first embodiment. FIG. 4A is an explanatory diagram showing a connection example, and FIG. 4B is an explanatory diagram showing an equivalent circuit. The piezoelectric driving device 10a according to the first embodiment includes two piezoelectric vibrating units 100a and 100b and a driving circuit 300. The first piezoelectric vibrating section 100a has a plurality (five) of piezoelectric elements 110a to 110e, and the second piezoelectric vibrating section 100b has a plurality (five) of piezoelectric elements 110a 'to 110e'. Reference numerals “130” and “150” given 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 section 100a, the first piezoelectric element 110a and the second piezoelectric element 110d are connected by a first connection method (parallel connection in FIG. 4) to connect the first piezoelectric element group 115a. Has formed. Further, among the plurality of piezoelectric elements of the second piezoelectric vibrating part 100b, the first piezoelectric element 110a ′ and the second piezoelectric element 110d ′ are connected by a first connection method (parallel connection in FIG. 4) and An element group 115b is formed. The first piezoelectric element group 115a and the second piezoelectric element group 115b are connected by the 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 refers to a connection method for connecting a plurality of piezoelectric elements 110 in the piezoelectric vibrating unit 100, and includes a case of parallel connection shown in the first embodiment and a case of series connection described later. The second connection method is a connection method for connecting a plurality of piezoelectric elements (piezoelectric element groups) connected in the first connection method or piezoelectric elements of different piezoelectric vibrating parts, and is different from the case of the series connection shown in the first embodiment. , May be connected in parallel as described below. That is, the first connection method refers to a connection method in one piezoelectric vibration unit 100, and the second connection method refers to a connection method between a plurality of piezoelectric vibration units 100. However, as described later, the connection method of the piezoelectric elements 110 arranged on the two surfaces of the same diaphragm 200 can be regarded as the connection method in the same piezoelectric vibrating portion, and is sometimes referred to as the 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 a first connection method (parallel connection in FIG. 4) to connect the third piezoelectric element group 115c. Has formed. The third piezoelectric element 110b ′ and the fourth piezoelectric element 110c ′ among the plurality of piezoelectric elements of the second piezoelectric vibrating portion 100b are connected by a first connection method (parallel connection in FIG. 4) to form a fourth piezoelectric element. An element group 115d is formed. The third piezoelectric element group 115c and the fourth piezoelectric element group 115d are connected by a second connection method (series connection in FIG. 4), and are connected to a terminal 300C of the drive circuit 300.

  The fifth piezoelectric element 110e of the plurality of piezoelectric elements of the first piezoelectric vibrating section 100a and the fifth piezoelectric element 110e 'of the plurality of piezoelectric elements of the second piezoelectric vibrating section 100b are connected by a second connection method (FIG. 4). In series, and is connected to the terminal 300B of the drive circuit 300.

The connection methods of FIG. 4 are summarized as follows.
(1) Connection method between piezoelectric elements in the same piezoelectric vibrating section 100 (first connection method): parallel connection (2) Connection method between piezoelectric elements in different piezoelectric vibration sections 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 twice the size 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 capacitance of each of the first piezoelectric element group 115a and the second piezoelectric element group 115b is 2 × C1. 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. Assuming that the drive voltage from the terminal 300A is V1, the voltage applied to each of the piezoelectric elements 110a to 110d and 110a 'to 110d' is V1 / 2, and the same voltage is applied. Therefore, in order to apply a voltage of V1 to each of the piezoelectric elements 110a to 110d and 110a 'to 110d', the driving voltage from the terminal 300A may be set to 2 × V1.

  FIG. 5 is an explanatory diagram showing a comparative example. In the comparative example, only equivalent circuits of the piezoelectric elements 110a, 110d, 110a ', and 110d' are shown. FIG. 5A shows Comparative Example 1 in which all of the piezoelectric elements 110a, 110d, 110a ′, and 110d ′ are connected in parallel, and FIG. 5B shows that all of the piezoelectric elements 110a, 110d, 110a ′, and 110d ′ are connected in series. 7 shows a comparative example 2 connected.

  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 ′. Is V1. Therefore, the drive 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 section 100a are connected by a first connection method (parallel connection in the first embodiment) to form a first piezoelectric element 110a. A piezoelectric element group 115a is formed, and (ii) the first piezoelectric element 110a 'and the second piezoelectric element 110d' included in the second piezoelectric vibrating section 100b are connected by a 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 in the first comparative example.

  In the case shown in FIG. 5B, the total capacitance of the piezoelectric elements 110a, 110d, 110a ′, and 110d ′ is C４, and the total capacitance of the piezoelectric elements 110a, 110d, 110a ′, and 110d ′ is The amplitude is V1 / 4. Therefore, in order to apply a voltage of V1 to each of the piezoelectric elements 110a, 110d, 110a ', and 110d', the drive voltage must be 4 * V1. In such a case, in order to generate a high voltage, the drive circuit 300 must be configured using components having a high withstand voltage. According to the first embodiment, since the drive voltage may be 2 × V1, the withstand voltage of 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 vibrating section 100a has a plurality of piezoelectric elements 110a to 110e including a first piezoelectric element 110a and a second piezoelectric element 110d, and the second piezoelectric vibrating section 100b has a first piezoelectric element 110a ′ and a second piezoelectric element 110a ′. It has a plurality of piezoelectric elements 110a to 110e including an element 110d '. The first piezoelectric element 110a and the second piezoelectric element 110d included in the first piezoelectric vibrating section 100a are connected by a first connection method to form a first piezoelectric element group 115a, and the first piezoelectric element group 115a included in the second piezoelectric vibrating section 100b. The first piezoelectric element 110a 'and the second piezoelectric element 110d' are connected by a 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 a second connection method. Here, the first connection method is a parallel connection, and the second connection method is a series connection. When such a configuration is adopted, the drive circuit 300 does not need to supply a large current as compared with the comparative example 1, and the withstand voltage of the components constituting the drive circuit 300 may be lower than the comparative example 2. .

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

  Assuming that the capacitance of the piezoelectric element 110a is C1, the capacitance of each of the first piezoelectric element group 115a and the second piezoelectric element group 115b is 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. Assuming that the drive voltage from the terminal 300A is V1, the voltage applied to each of the piezoelectric elements 110a to 110d and 110a 'to 110d' is V1 / 2, and the same voltage is applied. Therefore, in order to apply a voltage of V1 to each of the piezoelectric elements 110a to 110d and 110a 'to 110d', the driving voltage from the terminal 300A may be set to 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 vibrating section 100a has a plurality of piezoelectric elements 110a to 110e including a first piezoelectric element 110a and a second piezoelectric element 110d, and the second piezoelectric vibrating section 100b has a first piezoelectric element 110a ′ and a second piezoelectric element 110a ′. It has a plurality of piezoelectric elements 110a to 110e including an element 110d '. The first piezoelectric element 110a and the second piezoelectric element 110d included in the first piezoelectric vibrating section 100a are connected by a first connection method to form a first piezoelectric element group 115a, and the first piezoelectric element group 115a included in the second piezoelectric vibrating section 100b. The first piezoelectric element 110a 'and the second piezoelectric element 110d' are connected by a 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 a second connection method. Here, the first connection method is a parallel connection, and the second connection method is a series connection. Therefore, the total capacitance of the piezoelectric elements 110a, 110d, 110a ', and 110d' does not increase, and the driving circuit 300 does not need to supply a large current as compared with the first comparative example. Also, as compared with Comparative Example 2, the components constituting the drive circuit 300 may have lower withstand voltages.

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 between piezoelectric elements in the same piezoelectric vibration unit 100 (first connection method): parallel connection or series connection (2) Connection method between piezoelectric elements in different piezoelectric vibration units 100 (second connection method) : When the first connection method is parallel connection, the connection is series connection, and when the first connection method is series connection, the connection is parallel connection. When such a configuration is adopted, the drive circuit 300 supplies a larger current as compared with the comparative example 1. The components constituting the drive circuit 300 may have lower withstand voltages as compared with Comparative Example 2.

  In the first embodiment and the second embodiment, it is preferable to adopt the first embodiment in which the first connection method is connected in parallel and the second connection method is connected in series for the following reasons. Since the piezoelectric elements 110a to 110e have the same thickness of the piezoelectric bodies 140a to 140e, it is preferable to apply the same voltage. Assuming that the drive voltage of the drive circuit 300 is V1, in the case of the first embodiment, the voltage applied to the piezoelectric elements 110a and 110e is V1 / 2, which is the same. On the other hand, in the case of 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 driving circuit 300 needs to change the magnitude of the driving voltage output to the terminals 300A and 300B, and the driving circuit 300 may be complicated. Therefore, the first embodiment is more preferable.

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

-Third embodiment:
FIG. 7 is an explanatory diagram illustrating 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 ', 110g' have the same size as the other piezoelectric elements 110a to 110d, 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 methods are also applied to the piezoelectric elements 110f, 110g, 110f ', and 110g'. It is on the street.
(1) Connection method between piezoelectric elements in the same piezoelectric vibrating section 100 (first connection method): parallel connection (2) Connection method between piezoelectric elements in different piezoelectric vibration sections 100 (second connection method): series connection

  As described above, in the third embodiment, the piezoelectric driving device 10 has the first piezoelectric vibrating unit 100a and the second piezoelectric vibrating unit 100b. The first piezoelectric vibrating section 100a has a plurality of piezoelectric elements 110a to 110g including a first piezoelectric element 110f and a second piezoelectric element 110g, and the second piezoelectric vibrating section 100b has a first piezoelectric element 110f ′ and a second piezoelectric element 110f ′. It has a plurality of piezoelectric elements 110a 'to 110g' including the element 110g '. The first piezoelectric element 110f and the second piezoelectric element 110g included in the first piezoelectric vibrating section 100a are connected by a first connection method to form a first piezoelectric element group 115e, and the first piezoelectric element group 115e included in the second piezoelectric vibrating section 100b. The first piezoelectric element 110f ′ and the second piezoelectric element 110g ′ are connected by a 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 a second connection method. Here, the first connection method is a parallel connection, and the second connection method is a series connection. Therefore, like the piezoelectric elements 110a, 110d, 110a ', and 110d' of the first embodiment, in the third embodiment, the total capacitance of the piezoelectric elements 110f, 110g, 110f ', and 110g' does not increase. The drive circuit 300 does not need to supply a larger current than in the first comparative example. Also, as compared with Comparative Example 2, the components constituting the drive circuit 300 may have lower withstand voltages. 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 circuit of the piezoelectric elements 110f, 110g, 110f ', 110g' is the same as the equivalent circuit of the piezoelectric elements 110a, 110d, 110a ', 110d'. As a result, in the drive circuit 300, the circuit for driving the piezoelectric elements 110f, 110g, 110f ', and 110g' and the circuit for driving the piezoelectric elements 110a, 110d, 110a ', and 110d' can have 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 2 is also applied to the piezoelectric elements 110f, 110g, 110f ', and 110g'. It is on the street.
(1) Connection method between piezoelectric elements in the same piezoelectric vibration unit 100 (first connection method): series connection (2) Connection method between piezoelectric elements in different piezoelectric vibration units 100 (second connection method): parallel connection

  In the fourth embodiment, the piezoelectric driving device 10 has a first piezoelectric vibration unit 100a and a second piezoelectric vibration unit 100b. The first piezoelectric vibrating section 100a has a plurality of piezoelectric elements 110a to 110g including a first piezoelectric element 110f and a second piezoelectric element 110g, and the second piezoelectric vibrating section 100b has a first piezoelectric element 110f ′ and a second piezoelectric element 110f ′. It has a plurality of piezoelectric elements 110a 'to 110g' including the element 110g '. The first piezoelectric element 110f and the second piezoelectric element 110g included in the first piezoelectric vibrating section 100a are connected by a first connection method to form a first piezoelectric element group 115e, and the first piezoelectric element group 115e included in the second piezoelectric vibrating section 100b. The first piezoelectric element 110f ′ and the second piezoelectric element 110g ′ are connected by a 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 a second connection method. Here, the first connection method is a series connection, and the second connection method is a parallel connection. Therefore, as in the case of 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. The circuit 300 does not need to supply a larger current than in the first comparative example. Also, as compared with Comparative Example 2, the components constituting the drive circuit 300 may have lower withstand voltages. 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 ', 110g' is the same as the equivalent circuit of the piezoelectric elements 110a, 110d, 110a ', 110d'. As a result, in the drive circuit 300, the circuit for driving the piezoelectric elements 110f, 110g, 110f ', and 110g' and the circuit for driving the piezoelectric elements 110a, 110d, 110a ', and 110d' can have 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 arranged on one surface (for example, the surface 211) of the vibration plate 200a, and the piezoelectric elements 110a 'to 110e' are arranged on one surface (for example, the surface 211) of the vibrating body 200b. However, in the fifth embodiment, the piezoelectric elements 110a to 110e are arranged on one surface 211 of the diaphragm 200a, and the piezoelectric elements 110a to 110e are also arranged on the other surface 212. The piezoelectric elements 110 a ′ to 110 e ′ are arranged on the surface 211, and the piezoelectric elements 110 a ′ to 110 e ′ are arranged on the other surface 212. In this case, the two first piezoelectric elements 110a and the two second piezoelectric elements 110d of the vibration plate 200a are connected by a first connection method (parallel connection) to form a piezoelectric element group 115a, and the two first piezoelectric elements 110a of the vibration plate 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 (series connection). Connection). The other piezoelectric elements 110b, 110c, 110e, 110b ', 110c', 110e 'are similarly connected by the first connection method and the second connection method. In the fifth embodiment, a single vibration plate 200b and its two surfaces 211 and 212 are regarded as one piezoelectric vibration unit by combining one vibration plate 200a and the piezoelectric elements 110a to 110e of its two surfaces 211 and 212. The two piezoelectric vibrating portions 100a 'to 110e' are regarded as one piezoelectric vibrating portion. In the fifth embodiment, two first piezoelectric elements 110a and two second piezoelectric elements 110d of a piezoelectric vibrating section regarded as one piezoelectric vibrating section are connected by a first connection method (parallel connection) to form a piezoelectric element. A group is formed, and two first piezoelectric elements 110a 'and two second piezoelectric elements 110d' of two piezoelectric vibrating portions 100b are connected by a first connection method (parallel connection) to form a piezoelectric element group. 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 between piezoelectric elements in the same piezoelectric vibrating part 100a or 100b (first connection method): parallel connection (2) Connection method between piezoelectric elements between different piezoelectric vibrating parts 100a and 100b (first connection method) 2 connection method): Series connection

  According to the fifth embodiment, the piezoelectric driving device 10a has the first piezoelectric vibrating unit 100a and the second piezoelectric vibrating unit 100b. The first piezoelectric vibrating section 100a has a plurality of piezoelectric elements 110a to 110e including a first piezoelectric element 110a and a second piezoelectric element 110d, and the second piezoelectric vibrating section 100b has a first piezoelectric element 110a ′ and a second piezoelectric element 110a ′. It has a plurality of piezoelectric elements 110a 'to 110e' including an element 110d '. The first piezoelectric element 110a and the second piezoelectric element 110d included in the first piezoelectric vibrating section 100a are connected by a first connection method to form a first piezoelectric element group 115a, and the first piezoelectric element group 115a included in the second piezoelectric vibrating section 100b. The first piezoelectric element 110a 'and the second piezoelectric element 110d' are connected by a 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 a second connection method. Here, the first connection method is a parallel connection, and the second connection method is a series connection. When such a configuration is adopted, the drive circuit 300 does not need to supply a large current as compared with Comparative Example 1.

  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. 11 (A) and 11 (B), only the vibrating body 210 is illustrated for convenience of illustration, and the illustration of the connecting part 220 and the mounting part 230 is omitted. In the piezoelectric vibrating section 100g of FIG. 11A, the pair of piezoelectric elements 110b and 110c are omitted. This piezoelectric vibrating part 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 the three piezoelectric elements 110a, 110e, and 110d are applied. ) 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 an area larger than that in FIG. ing. This piezoelectric vibrating part 100h can also achieve substantially the same effects as in the first embodiment.

  As can be understood from FIGS. 1 and 11A and 11B, at least one electrode layer can be provided as the second electrode 150 of the piezoelectric vibrating section 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 a diagonal position of the rectangular vibrating body 210, This is preferable in that the vibrating body 210 can be deformed into a meandering shape that is bent 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 the parallel connection, since the first electrodes 130 have the same potential, there is no problem even if one integrated first electrode 130 is formed. Further, by forming one first electrode 130 formed integrally, a wiring is automatically formed, so that another wiring for connecting in parallel is not required, and disconnection of the wiring hardly occurs.

-Embodiment of the device using the piezoelectric drive device:
The above-described piezoelectric drive device 10 can apply a large force to a driven body by utilizing resonance, and is applicable to various devices. The piezoelectric driving device 10 is, for example, a robot (including an electronic component conveying device (IC handler)), a medication pump, a calendar feed device for a clock, a printing device (for example, a paper feeding mechanism, but a piezoelectric driving device used for a head). In this case, since the diaphragm does not resonate, it cannot be applied to a head.) Hereinafter, typical embodiments will be described.

  FIG. 12 is an explanatory diagram illustrating an example of a robot 2050 using the above-described piezoelectric driving device 10. The robot 2010 includes an arm 2010 ("") having a plurality of link portions 2012 (also referred to as "link members") and a plurality of joint portions 2020 that connect the link portions 2012 in a rotatable or bendable state. Arm portion). Each of the joints 2020 incorporates the above-described piezoelectric driving device 10, and the joint 2020 can be rotated or bent by an arbitrary angle using the piezoelectric driving device 10. A robot hand 2000 is connected to a tip of the arm 2010. The robot hand 2000 includes a pair of holding portions 2003. The piezoelectric drive device 10 is also incorporated in the robot hand 2000, and the gripper 2003 can be opened and closed using the piezoelectric drive device 10 to grip an object. The piezoelectric driving 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 driving device 10.

  FIG. 13 is an explanatory diagram of a 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 drive device 10, and the piezoelectric drive device 10 rotates the link portion 2012 of the wrist and the robot hand 2000 around the central axis O. The robot hand 2000 has a plurality of gripping portions 2003 erected. The base end of the gripper 2003 is movable within the robot hand 2000, and the piezoelectric driving device 10 is mounted on the base of the gripper 2003. For this reason, by operating the piezoelectric driving device 10, the gripper 2003 can be moved to grip the target object.

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

  The piezoelectric drive device 10 is not limited to a single-arm robot, but may be applied to a multi-arm robot having two or more arms. Here, inside the joint part 2020 of the wrist and the robot hand 2000, in addition to the piezoelectric driving 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. Includes and requires a great deal of wiring. Therefore, it was very difficult to arrange the wiring inside the joint 2020 or the robot hand 2000. However, the piezoelectric drive device 10 of the above-described embodiment can reduce the drive current as compared with a normal electric motor or a conventional piezoelectric drive device, so that the joint 2020 (particularly, the joint at the tip of the arm 2010) or the robot hand Wiring can be arranged even in a small space such as 2000.

  FIG. 14 is an explanatory diagram illustrating an example of a liquid feed pump 2200 using the above-described piezoelectric driving device 10. The liquid feeding pump 2200 includes a reservoir 2211, a tube 2212, a piezoelectric driving device 10, a rotor 2222, a reduction transmission mechanism 2223, a cam 2202, and a plurality of fingers 2213, 2214, 2215, 2216, inside 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 from the reservoir 2211. The protrusion 20 of the piezoelectric driving device 10 is provided in a state pressed against the side surface of the rotor 2222, and the piezoelectric driving device 10 drives the rotor 2222 to rotate. The rotational force of the rotor 2222 is transmitted to the cam 2202 via the reduction transmission mechanism 2223. The fingers 2213 to 2219 are members for closing the tube 2212. When the cam 2202 rotates, the projections 2202A of the cam 2202 sequentially push the fingers 2213 to 2219 outward in the radial direction. 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 sequentially transported to the downstream side. In this way, it is possible to realize a small-sized liquid sending pump 2200 that can send an extremely small amount of liquid with high accuracy. The arrangement of each member is not limited to the illustrated one. Further, a configuration may be adopted in which a ball or the like provided on the rotor 2222 closes the tube 2212 without a member such as a finger. The liquid sending pump 2200 as described above can be used for a drug dispensing device that administers a drug solution such as insulin to a human body. Here, by using the piezoelectric driving device 10 of the above-described embodiment, the driving current becomes smaller than that of the conventional piezoelectric driving device, so that the power consumption of the administration device can be suppressed. Therefore, it is particularly effective when the dosing device is driven by a battery.

・ 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 parallel connection, and the second connection method is series connection. However, similarly to the second embodiment, the first connection method may be series connection and the second connection method may be parallel connection. 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 The body 140 and the second electrode 150 may be formed.

-Modified example 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 vibrating portion 100 are the same (for example, the direction of the applied voltage is the first direction). The piezoelectric elements 110a to 110e are connected in series or in parallel so that the direction from the electrode 130 toward the second electrode 150). Here, for some of the piezoelectric elements 110 a to 110 e of the piezoelectric vibrating part 100 (for example, the piezoelectric elements 110 b and 110 d), the connection between the first electrode 130 and the second electrode 150 is reversed, and The direction of polarization of the piezoelectric element (piezoelectric elements 110b and 110d) is opposite to the direction of polarization of the other piezoelectric elements (110a, 110c, 110e) (the direction of the applied voltage is from the second electrode 150 to the first electrode 130). Direction). Even in this case, the same effect that the capacitance can be reduced and a large current need not be supplied when driving the piezoelectric vibrating unit 100 can be obtained. The same applies to other embodiments.

  As described above, the embodiments of the present invention have been described based on some examples. However, the above embodiments of the present invention are for facilitating understanding of the present invention, and limit the present invention. Not something. The present invention can be modified 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.

    10, 10a: piezoelectric driving device 20: protrusion 50: rotor 51: center 100, 100a, 100b, 100c, 100d, 100g, 100h: piezoelectric vibrating unit 110, 110a to 110g, 110a 'to 110g': piezoelectric element 115a to 115f: piezoelectric element group 120: substrate 130, 130a to 130e: first electrode 140, 140a to 140e: piezoelectric body 150, 150a to 150e: second electrode 200, 200a, 200b: diaphragm 210: vibrator section 211, 212 ... surface 220 ... connecting part 230 ... mounting part 240 ... screw 300 ... drive circuit 300A, 300B, 300C ... terminal 2000 ... robot hand 2003 ... gripping 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 portion having a diaphragm provided with a plurality of piezoelectric elements formed by a first electrode, a second electrode, and a piezoelectric body located between the first electrode and the second electrode; and A second piezoelectric vibrating section,
The first piezoelectric vibrating section and the second piezoelectric vibrating section each have a first piezoelectric element and a second piezoelectric element as the plurality of piezoelectric elements,
Connecting the first piezoelectric element and the second piezoelectric element included in the first piezoelectric vibrating section by a first connection method to form a first piezoelectric element group;
Connecting the first piezoelectric element and the second piezoelectric element included in the second piezoelectric vibrating section by the first connection method to form a second piezoelectric element group;
Connecting the first piezoelectric element group and the second piezoelectric element group by a second connection method;
A piezoelectric driving device, wherein one of the first connection method and the second connection method is connected in series, and the other is connected in parallel. The piezoelectric driving device according to claim 1,
The first connection method is a parallel connection,
The piezoelectric driving device, wherein the second connection method is a series connection. The piezoelectric driving device according to claim 1 or 2,
The piezoelectric driving device, wherein the plurality of piezoelectric elements connected in series have the same size. The piezoelectric drive according to any one of claims 1 to 3,
A piezoelectric drive device, wherein when a drive voltage is applied to the plurality of piezoelectric elements, the direction of voltage application to the plurality of piezoelectric elements is the same. The piezoelectric driving device according to claim 4,
The first electrode is located closer to the diaphragm than the second electrode,
The piezoelectric driving device, wherein the voltage application direction is a direction from the second electrode to the first electrode. The piezoelectric driving device according to claim 2,
The piezoelectric driving device, wherein the first electrodes of the plurality of piezoelectric elements connected in parallel form one integrally formed electrode. A plurality of link portions; 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 method of driving a robot 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 driving method for a robot, wherein the plurality of link portions are rotated by the joint portions. A driving method of the piezoelectric driving device according to any one of claims 1 to 6,
A voltage that varies periodically 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 changed from one of the electrodes to the other. A driving method of a piezoelectric driving device for applying a pulsating voltage in one direction toward the electrode.

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