Piezoelectric actuator and manipulation system

Abstract

To provide a piezoelectric actuator which suppresses a flow-out of fine dust from the inside of the piezoelectric actuator to the outside, and a manipulation system.SOLUTION: A piezoelectric actuator 30 comprises: a housing 32; rolling bearings 342 and 343 disposed inside of the housing 32; a shaft part 344 which is inserted through the rolling bearings 342 and 343 in an axial direction A and protrudes from a tip end opening 323a of the housing 32 to a tip end side A1 in the axial direction A; a tool holder 35 which is fixed to the shaft part 344 and capable of holding a micro tool; a vibration part 33 which is disposed inside of the housing 32 and capable of vibrating the rolling bearings 342 and 343, the shaft part 344 and the tool holder 35 in the axial direction A; and a tip end sealing member 37b which is provided in the tip end opening 323a and in contact with the shaft part 344 and the housing 32 in a radial direction D of the rolling bearings 342 and 343.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a piezoelectric actuator and a manipulation system. [Background technology]

[0002] Conventionally, there is a manipulation system that performs fine operations using a microtool. For example, a manipulation system used for fine operations uses a piezoelectric actuator having a microtool at its tip (for example, Patent Document 1).

[0003] The piezoelectric actuator, for example, applies a voltage to a piezoelectric element to ultrasonically vibrate the piezoelectric element, and the ultrasonic vibration of the piezoelectric element causes the microtool to move slightly. The piezoelectric actuator performs drilling, cutting, etc. on a sample using the microtool that moves slightly. The tool holder that holds the microtool is supported by, for example, a bearing such as a rolling bearing.

[0004] Piezoelectric actuators capable of driving microtools to move in fine motion are used in the medical field to perform micro-operations on cells.

[0005] For example, when performing ICSI, a hole is drilled in an egg using a microtool attached to the tip of the piezoelectric actuator, and when observing the cross section of a spheroid, the microtool attached to the tip of the piezoelectric actuator cuts the spheroid to expose the area for observation.

[0006] Piezoelectric actuators capable of finely driving microtools are used in the industrial field for digging out foreign objects embedded in resin materials, marking for focused ion beam (FIB) processing, cutting fine wiring, and so on. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 5962204 Summary of the Invention [Problem to be solved by the invention]

[0008] However, when a piezoelectric actuator such as that described in Patent Document 1 is used in such a way that the piezoelectric element vibrates at high frequencies, fine dust particles are generated inside the piezoelectric actuator, and the generated fine dust particles may leak out of the piezoelectric actuator. For example, the fine dust particles leaking out of the piezoelectric actuator may contaminate cells performing fine manipulation or reduce visibility when performing fine manipulation.

[0009] In view of the above circumstances, an object of the present invention is to provide a piezoelectric actuator and a manipulation system that suppresses the outflow of fine dust particles from the inside of the piezoelectric actuator to the outside. [Means for solving the problem]

[0010] In order to solve the above problems, the present invention proposes the following means. The piezoelectric actuator of the present invention comprises a housing, a rolling bearing arranged inside the housing, a shank that is inserted axially through the rolling bearing and protrudes from a tip opening of the housing toward the tip in the axial direction, a tool holder that is fixed to the shank and can hold a microtool, a vibration unit that is arranged inside the housing and can vibrate the rolling bearing, the shank, and the tool holder in the axial direction, and a tip sealing member that is provided at the tip opening and comes into contact with the shank and the housing in the radial direction of the rolling bearing.

[0011] A manipulation system of the present invention includes the piezoelectric actuator described above, a manipulator connected to the housing and capable of moving the piezoelectric actuator, and a control unit capable of vibrating the vibration unit. [Effects of the Invention]

[0012] According to the piezoelectric actuator and manipulation system of the present invention, it is possible to provide a piezoelectric actuator and manipulation system that suppresses the outflow of fine dust particles from the inside to the outside of the piezoelectric actuator. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a perspective view schematically showing a configuration of a manipulation system according to an embodiment of the present invention. [Figure 2] FIG. 2 is a perspective view showing a piezoelectric actuator provided in the manipulation system. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram schematically showing the configuration of a manipulation system 1 according to this embodiment.

[0015] The manipulation system 1 includes a micromanipulator 2, a microscope 10, an input unit 50, and a control unit 60.

[0016] In this embodiment, as shown in FIG. 1 , the vertical direction in the manipulation system 1 is defined as the "up-down direction Z," the vertically upward direction as the "upward Z1" in the vertical direction Z, and the vertically downward direction as the "downward Z2" in the vertical direction Z. Furthermore, among the horizontal directions orthogonal to the vertical direction Z, the direction in which a user using the manipulation system 1 is primarily positioned with respect to the microscope 10 is defined as the "forward Y1," the direction opposite to the forward Y1 as the "backward Y2," and the direction connecting the forward Y1 and the backward Y2 as the "front-back direction Y." Furthermore, the direction orthogonal to the vertical direction Z and the front-back direction Y is defined as the "left-right direction X," with one side of the left-right direction X being defined as the "rightward X1" and the other side being defined as the "leftward X2" in the left-right direction X.

[0017] The micromanipulator 2 includes a manipulator 20 , a piezoelectric actuator 30 , and a microtool 40 .

[0018] The manipulator 20 includes a first movable part 21, a second movable part 22, and a third movable part 23. The manipulator 20 may be an electric manipulator that is driven electrically, or may be a manual manipulator.

[0019] A piezoelectric actuator 30 is connected to the tip of the first movable portion 21. The first movable portion 21 is capable of moving the piezoelectric actuator 30 in the up-down direction Z. Details of the piezoelectric actuator 30 will be described later.

[0020] The second movable portion 22 is capable of moving the piezoelectric actuator 30 and the first movable portion 21 in the front-rear direction Y.

[0021] The third movable portion 23 is capable of moving the piezoelectric actuator 30, the first movable portion 21, and the second movable portion 22 in the left-right direction X.

[0022] The first movable portion 21, the second movable portion 22, and the third movable portion 23 are, for example, an XYZ axis table, a linear motion mechanism configured with an electric motor and a ball screw, or the like.

[0023] The manipulator 20 may be an articulated robot arm as long as it can move the piezoelectric actuator 30 in any direction.

[0024] The microtool 40 is provided at the tip of the piezoelectric actuator 30. The microtool 40 is a microtool that can be used for fine work.

[0025] The microtool 40 is a microtool that can be used for, for example, intracytoplasmic sperm injection, and is a capillary with a tip diameter of about several μm.

[0026] The micromanipulator 2 is a micromanipulator device that can move a piezoelectric actuator 30 with a microtool 40 attached to the tip thereof using a manipulator 20 .

[0027] In this embodiment, the manipulation system 1 includes two micromanipulators 2. The two micromanipulators 2 are independent of each other, so that the two micromanipulators 2 can move the piezoelectric actuators 30 and the microtools 40 in different directions by means of the manipulators 20.

[0028] The microscope 10 includes an objective optical system 11 and an acquisition unit 12 .

[0029] The microscope 10 is a microscope that can observe samples such as cells, ova, etc. at a predetermined magnification. The microscope 10 has a table 10a on which a container such as a petri dish containing a sample can be placed.

[0030] The objective optical system 11 is an objective lens provided above the table 10a in the position Z1. The objective optical system 11 can be an objective lens having any magnification.

[0031] The acquisition unit 12 is capable of acquiring an image of the sample observed through the objective optical system 11, and is, for example, an imaging device such as a camera capable of taking microscopic photographs. Here, a microscopic photograph refers to an image captured of the actual field of view of the microscope 10.

[0032] The user can view the image acquired by the acquisition unit 12 by looking into the observation unit 10b of the microscope 10. The image acquired by the acquisition unit 12 may be displayed on a display device such as a display connected to the microscope 10.

[0033] By using the microscope 10, a user can observe a sample in a container placed on a table 10a of the microscope 10 at a predetermined magnification.

[0034] The input unit 50 is an input device that can input operations for operating the micromanipulator 2. The input unit 50 includes an input element 51 through which the user inputs operations.

[0035] In this embodiment, the input unit 50 includes two input elements 51 corresponding to the two micromanipulators 2. The input elements 51 are, for example, joysticks.

[0036] A user can input operations into the input unit 50 to drive the micromanipulator 2, thereby moving the piezoelectric actuator 30 and the microtool 40 connected to the manipulator 20 to any desired position. The input unit 50 may be an input device such as a keyboard, a mouse, a lever, a dial, or a knob.

[0037] The control unit 60 is a control device that can control a part or the whole of the manipulation system 1. The control unit 60 is connected to the micromanipulator 2 and the input unit 50 by wire or wirelessly, and can control the micromanipulator 2 based on operations input to the input unit 50.

[0038] The control unit 60 is, for example, a programmable device (computer) equipped with a processor, a memory, a storage unit, etc. Each function of the control unit 60 is realized by one or more processors, such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit), executing a program stored in a program memory. However, all or part of these functions may be realized by hardware (e.g., circuitry) such as an LSI (Large Scale Integration), an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a PLD (Programmable Logic Device). Furthermore, all or part of the above functions may be realized by a combination of software and hardware. The storage unit is realized by a flash memory, an EEPROM (Electrically Erasable Programmable Read-Only Memory), a ROM (Read-Only Memory), a RAM (Random Access Memory), etc.

[0039] The user places a container containing a sample on the table 10a, operates the input unit 50 to move the piezoelectric actuators 30 provided on the right side X1 and left side X2 of the table 10a, and performs micro-operations on the sample using the microtools 40 provided at the tips of the piezoelectric actuators 30.

[0040] For example, the user is positioned at the front Y1 of the microscope 10 and performs fine work while checking the sample displayed enlarged by the objective optical system 11 through the observation unit 10b.

[0041] Next, the configuration of the piezoelectric actuator 30 will be described.

[0042] Fig. 2 is a perspective view showing the piezoelectric actuator 30. Fig. 3 is a cross-sectional view taken along line III-III in Fig. 2.

[0043] The piezoelectric actuator 30 includes a connection portion 31 , a housing 32 , a vibrating portion 33 , a vibrated portion 34 , a tool holder 35 , lead wires 36 , and a sealing member 37 .

[0044] As shown in Figures 2 and 3, in the piezoelectric actuator 30, the direction in which the tool holder 35 extends is defined as the "axial direction A," the side on which the microtool 40 is attached is defined as the "tip side A1" in the axial direction A, and the opposite side is defined as the "base side A2" in the axial direction A.

[0045] The axial direction A coincides with the direction in which an axis O, which is the central axis of rolling bearings 342 and 343 described later, extends.

[0046] In the following description, the radial direction of the rolling bearings 342, 343 is defined as the "radial direction D," the side approaching the axis O is defined as the "inner side IN" in the radial direction D, and the side away from the axis O is defined as the "outer side OU" in the radial direction D. The radial direction D is a direction perpendicular to the axial direction A.

[0047] The connecting portion 31 is a member that connects the first movable portion 21 and the piezoelectric actuator 30. To the connecting portion 31, a housing 32 of the piezoelectric actuator 30 is connected.

[0048] The housing 32 is connected to the first movable part 21 via the connecting part 31. The piezoelectric actuator 30 may be configured not to include the connecting part 31, and the housing 32 may be directly attached to the first movable part 21.

[0049] 2 and 3, the housing 32 includes a housing main body 321, a housing base end portion 322, and a housing tip end portion (outer ring restriction portion) 323. In this embodiment, the housing 32 has a rectangular shape in a plan view seen from the axial direction A, as shown in FIG.

[0050] The housing main body 321 is a cover member that surrounds the vibrating part 33 and the vibrated part 34 from the outside OU. In this embodiment, the housing 32 is connected to the connecting part 31 by fixing the housing main body 321 to the connecting part 31.

[0051] The housing body 321 has a rectangular cylindrical shape with openings on the distal end side A1 and the proximal end side A2. The housing body 321 does not necessarily have to have a rectangular cylindrical shape in the strict sense.

[0052] The housing base end portion 322 is a cover member connected to the base end side A2 of the housing main body 321. The housing base end portion 322 has a flat plate shape extending in the radial direction D, and has a through hole (base end opening portion) 322a passing through the axis O. A tool holder 35, which will be described later, is inserted in the axial direction A into the base end opening portion 322a.

[0053] The housing tip portion 323 is a lid member connected to the tip side A1 of the housing main body 321. The housing tip portion 323 has a rectangular cylindrical shape with a bottom that opens to the base end side A2. The housing tip portion 323 does not necessarily have to have a rectangular cylindrical shape in the strict sense.

[0054] A through-hole (tip opening) 323a passing through the axis O is provided in the bottom surface of the tip side A1 of the housing tip portion 323. A vibration receiving portion 34 and a tool holder 35, which will be described later, are inserted in the axial direction A through the tip opening 323a.

[0055] The vibrating part 33 is provided on the tip side A1 of the housing base end 322. An end of the vibrating part 33 on the base side A2 is in contact with the housing base end 322 in the axial direction A. In this embodiment, the vibrating part 33 is a piezoelectric element that expands and contracts when a voltage is applied.

[0056] The vibration part 33 has a cylindrical shape with the axis O as the central axis. The vibration part 33 is not limited to a cylindrical shape, and may have a rectangular tubular shape. The vibration part 33 may be two or more flat plate-shaped piezoelectric elements arranged on either side of the axis O. The vibration part 33 is not in contact with the housing main body 321.

[0057] In this embodiment, the vibration section 33 is disposed inside the housing 32. The inside of the housing 32 refers to the internal space of the housing 32 surrounded by the housing 32 in the radial direction D.

[0058] The vibrated portion 34 is provided on the tip side A1 of the vibrating portion 33. The vibrated portion 34 can be vibrated in the axial direction A by the vibrating portion 33.

[0059] As shown in FIG. 3, the vibrated portion 34 includes a transmission portion 341, rolling bearings 342 and 343, a shaft portion 344, a holder holding portion 345, and a holder fastening portion 346.

[0060] The transmission part 341 is provided on the tip side A1 of the vibration part 33, and is a cylindrical member with the axis O as its central axis. The transmission part 341 does not need to be strictly cylindrical. The transmission part 341 is in contact with the end of the tip side A1 of the vibration part 33.

[0061] The rolling bearings 342 and 343 are angular contact ball bearings that include inner rings 342a and 343a, balls 342b and 343b, and outer rings 342c and 343c. The rolling bearings 342 and 343 are disposed inside the housing 32.

[0062] The vibrated part 34 has two rolling bearings arranged side by side in the axial direction A. Of the two rolling bearings provided in the vibrated part 34, the rolling bearing provided on the base end side A2 is referred to as a first rolling bearing 342, and the rolling bearing provided on the tip end side A1 is referred to as a second rolling bearing 343.

[0063] The first rolling bearing 342 includes a first inner ring 342a, first balls 342b, and a first outer ring 342c. The transmission part 341 is in contact with the base end side A2 of the first outer ring 342c.

[0064] The second rolling bearing 343 includes a second inner ring 343a, second balls 343b, and a second outer ring 343c. An outer ring restricting portion (housing front end portion) 323 contacts the front end side A1 of the second outer ring 343c.

[0065] The first rolling bearing 342 and the second rolling bearing 343 are angular contact ball bearings having the axis O as their central axes. The first rolling bearing 342 and the second rolling bearing 343 are arranged side by side and coaxially.

[0066] A gap 34s is formed between the first outer ring 342c and the second outer ring 343c in the axial direction A. Therefore, the first outer ring 342c and the second outer ring 343c are movable in the axial direction A relative to each other.

[0067] Shaft portion 344 is inserted in axial direction A into axial holes of inner rings 342a, 343a of rolling bearings 342, 343. Here, the axial holes of inner rings 342a, 343a refer to openings that pass through the central axis of cylindrical inner rings 342a, 343a, whose central axis is axis O.

[0068] The shaft portion 344 is a cylindrical member with the axis O as its central axis. The shaft portion 344 does not need to be strictly cylindrical. The shaft portion 344 is inserted in the axial direction A through the tip opening 323a of the housing tip portion 323. An end portion of the shaft portion 344 on the tip side A1 protrudes further toward the tip side A1 than the housing tip portion 323.

[0069] An inner ring spacer 344a that is convex outwardly OU is provided near the center of the shaft portion 344 in the axial direction A. The inner ring spacer 344a is sandwiched between the first inner ring 342a and the second inner ring 343a in the axial direction A. The inner ring spacer 344a is in contact with the first inner ring 342a and the second inner ring 343a in the axial direction A.

[0070] In the shaft portion 344, an inner ring restricting portion 344b that comes into contact with the second inner ring 343a in the axial direction A is provided in a portion on the tip side A1 from the second rolling bearing 343.

[0071] The first rolling bearing 342 and the second rolling bearing 343 are sandwiched between the housing main body 321 and the shaft portion 344 in the radial direction D.

[0072] The holder holding portion 345 is detachably provided at an end portion on the tip side A1 of the shaft portion 344. In this embodiment, the holder holding portion 345 is provided closer to the tip side A1 than the housing tip portion 323.

[0073] 2, the end portion of the tip side A1 of the shaft portion 344 and the holder holding portion 345 have a semi-cylindrical shape with the axis O as the central axis. The end portion of the tip side A1 of the shaft portion 344 and the holder holding portion 345 do not necessarily have to have a semi-cylindrical shape in the strict sense.

[0074] A groove into which the tool holder 35 can be inserted is provided in the end portion on the tip side A1 of the shaft portion 344 and the holder holding portion 345. The holder holding portion 345 can be attached to the shaft portion 344 by a fastening member such as a screw.

[0075] 3, the tool holder 35 has the shank 344 inserted in the axial direction A. At the end portion on the tip side A1 of the shank 344, the tool holder 35 is sandwiched between the shank 344 and the holder holding portion 345 in the radial direction D and fixed to the shank 344.

[0076] The holder fastening portion 346 is provided at the end of the base end side A2 of the shaft portion 344, and is a cylindrical member with the axis O as its central axis. The holder fastening portion 346 does not need to be strictly cylindrical. The shaft portion 344 is inserted into the holder fastening portion 346 in the axial direction A.

[0077] The holder fastening portion 346 is provided on the base end side A2 of the first inner race 342a and is in contact with the first inner race 342a in the axial direction A.

[0078] 3, the holder fastening portion 346 is provided with a fastening hole penetrating from the outer peripheral surface to the inner peripheral surface. In addition, the shaft portion 344 is provided with a through hole communicating with the fastening hole of the holder fastening portion 346.

[0079] A fastening member 346a is inserted in the radial direction D through the fastening hole of the holder fastening portion 346 and the through-hole of the shaft portion 344. The fastening member 346a is, for example, a fastening bolt whose central axis extends in the radial direction D.

[0080] A fastening groove that can be threaded with a fastening member 346a is formed on the inner circumferential surface of the fastening hole of the holder fastening portion 346. In addition, a groove that can be fitted with a tool such as a screwdriver or hexagonal wrench is provided on the end of the outer side OU of the fastening member 346a.

[0081] The fastening member 346a can move in the radial direction D within the fastening hole of the holder fastening portion 346 by rotating around a central axis extending in the radial direction D. For example, a user fits a tool into the fastening member 346a from the outside OU, and moves the fastening member 346a in the radial direction D by rotating the fastening member 346a using the tool.

[0082] When the fastening member 346a is rotated in the tightening direction and moved inward IN, the tip of the fastening member 346a comes into contact with the tool holder 35. By moving the fastening member 346a inward IN and sandwiching the tool holder 35 in the radial direction D between the fastening member 346a and the shank 344, the tool holder 35 can be fixed to the shank 344.

[0083] Conversely, when the fastening member 346a is rotated in the loosening direction and moved to the outside OU, the fastening member 346a moves away from the tool holder 35, and the fixation between the tool holder 35 and the shaft portion 344 can be released.

[0084] The first inner ring 342a is sandwiched between the holder fastening portion 346 and the inner ring spacer 344a in the axial direction A. Therefore, the first inner ring 342a does not move in the axial direction A relative to the shaft portion 344.

[0085] The second inner ring 343a is sandwiched between the inner ring spacer 344a and the inner ring restricting portion 344b in the axial direction A. Therefore, the second inner ring 343a does not move in the axial direction A relative to the shaft portion 344.

[0086] The tool holder 35 includes a holder main body 35a extending in the axial direction A, a holder tip end portion 35b connected to a tip side A1 of the holder main body 35a, and a holder base end portion 35c connected to a base side A2 of the holder main body 35a. The tool holder 35 protrudes from a base end opening 322a of the housing base end portion 322 toward the base side A2.

[0087] As shown in FIG. 3, the shaft portion 344 is inserted in the axial direction A into the holder main body 35a.

[0088] The holder tip portion 35b is capable of holding the microtool 40. The holder tip portion 35b is disposed on the tip side A1 of the housing tip portion 323.

[0089] That is, the holder tip portion 35b and the microtool 40 are disposed outside the housing 32. The outside of the housing 32 refers to the external space that is not surrounded by the housing 32 in the radial direction D.

[0090] By attaching the microtool 40 to the holder tip 35b, the microtool 40 and the piezoelectric actuator 30 can be connected.

[0091] The holder base end portion 35c is disposed closer to the base end side A2 than the housing base end portion 322.

[0092] The tool holder 35 has a cylindrical shape with the axis O as its central axis, and has an internal space that penetrates the holder main body 35a, the holder tip end 35b, and the holder base end 35c in the axial direction A. The tool holder 35 does not need to be strictly cylindrical.

[0093] For example, when the microtool 40 is a capillary, the internal space of the capillary and the internal space of the tool holder 35 are communicated by attaching the microtool 40 to the holder tip 35b.

[0094] A pump device such as a syringe pump is connected to the holder base end portion 35c, and by driving the pump device, the internal space of the tool holder 35 and the microtool 40 can be made to have a negative or positive pressure.

[0095] For example, when the internal space of the microtool 40 is made negative pressure by the pump device, a sample can be adsorbed onto the tip of the microtool 40 and held by the microtool 40. Also, when the internal space of the microtool 40 is made positive pressure by the pump device, the microtool 40 that has adsorbed and held the sample can be made to release the sample.

[0096] When attaching the tool holder 35 to the shaft portion 344, the user inserts the tool holder 35 into the proximal end opening 322a of the housing proximal end portion 322 from the proximal end side A2.

[0097] The tool holder 35 inserted into the base end opening 322a passes through the housing base end portion 322, the vibration portion 33, the transmission portion 341 and the shaft portion 344 in the axial direction A, and protrudes to the tip side A1 of the shaft portion 344.

[0098] At this time, a part of the holder body 35a is fitted into a groove at the end of the tip side A1 of the shaft portion 344. The user attaches the holder holding part 345 to the end of the tip side A1 of the shaft portion 344 in the fitted state of the holder body 35a, and clamps and fixes the tool holder 35 in the radial direction D between the shaft portion 344 and the holder holding part 345.

[0099] Furthermore, the user uses a tool to move the fastening member 346a inward IN, and clamps and fixes the tool holder 35 in the radial direction D between the fastening member 346a and the shaft portion 344.

[0100] The shaft portion 344 to which the tool holder 35 is fixed is supported by rolling bearings 342 and 343 so as to be rotatable in the circumferential direction of the axis O. Therefore, a user can rotate the tool holder 35 in the circumferential direction of the axis O relative to the housing 32.

[0101] The lead wire 36 is an electric wire connected to the vibrating part 33. By applying a voltage to the vibrating part 33 via the lead wire 36, the vibrating part 33 can be expanded or contracted.

[0102] The lead wires 36 are connected, for example, to the vibration unit 33 and the control unit 60. The user inputs an operation to an input device (for example, the input unit 50) connected to the control unit 60. The control unit 60 applies a voltage to the vibration unit 33 via the lead wires 36 based on the input operation, causing the vibration unit 33 to expand, contract, and vibrate.

[0103] The voltage waveform that can be used for the voltage applied to the vibration unit 33 may be a sine wave, a square wave, a triangular wave, etc. In addition, as a method for applying a voltage to the vibration unit 33, a signal waveform may be output continuously while the user is pressing a button on the input device, or a burst waveform may be used.

[0104] The housing body 321 is provided with a through hole (lead wire opening) 321a through which the lead wire 36 passes.

[0105] The housing main body 321 is also provided with a through-hole (fastening opening) 321b into which a tool for advancing and retracting the fastening member 346a in the radial direction D can be inserted.

[0106] As shown in FIG. 3, the transmission part 341 has a through hole 341a provided on a straight line connecting the fastening opening 321b and the fastening member 346a, and therefore does not hinder the engagement between the tool inserted through the fastening opening 321b and the fastening member 346a.

[0107] The sealing member 37 includes a base end sealing member 37a, a tip end sealing member 37b, a lead wire sealing member 37c, and a fastening sealing member 37d. The sealing member 37 is a member for preventing fine dust particles generated inside the piezoelectric actuator 30 from leaking out of the piezoelectric actuator 30.

[0108] The base-end sealing member 37a is provided in a base-end opening 322a of the housing base end 322. The base-end sealing member 37a is, for example, an annular O-ring with the axis O as its central axis. The base-end sealing member 37a is provided in the base-end opening 322a so as to be sandwiched between the housing base end 322 and the tool holder 35 in the radial direction D.

[0109] The base end sealing member 37a is in contact with the tool holder 35 and the housing 32 in the radial direction D. In this embodiment, the base end sealing member 37a seals the gap in the radial direction D between the housing base end portion 322 and the tool holder 35.

[0110] The tip sealing member 37b is provided at the tip opening 323a of the housing tip portion 323. The tip sealing member 37b is, for example, an annular O-ring with the axis O as its central axis. The tip sealing member 37b is provided at the tip opening 323a so as to be sandwiched between the housing tip portion 323 and the shaft portion 344 in the radial direction D.

[0111] The tip sealing member 37b is in contact with the shaft portion 344 and the housing 32 in the radial direction D. In this embodiment, the tip sealing member 37b seals the gap in the radial direction D between the housing tip portion 323 and the shaft portion 344.

[0112] The lead wire sealing member 37c is provided in the lead wire opening 321a of the housing body 321.

[0113] The lead wire sealing member 37c contacts the lead wire 36 and the housing 32 at the lead wire opening 321a. In this embodiment, the lead wire sealing member 37c seals the gap between the lead wire 36 and the housing 32.

[0114] The fastening sealing member 37d is a cover member provided in the fastening opening 321b of the housing main body 321. The fastening sealing member 37d is detachably provided in the fastening opening 321b.

[0115] When moving the fastening member 346a in the radial direction D using a tool, the user removes the fastening sealing member 37d from the fastening opening 321b and moves the fastening member 346a by inserting the tip of the tool into the inside of the housing 32 through the fastening opening 321b.

[0116] For example, when the user fixes the tool holder 35 to the shank 344 or when the user releases the fixation between the tool holder 35 and the shank 344, the user removes the fastening sealing member 37d from the fastening opening 321b.

[0117] Furthermore, when the user drives the piezoelectric actuator 30, the fastening sealing member 37d is attached to the fastening opening 321b, and the fastening opening 321b is sealed by the fastening sealing member 37d.

[0118] By sealing the openings provided in the housing 32 with the sealing member 37, even if fine dust particles are generated inside the housing 32, the outflow of the fine dust particles to the outside of the housing 32 can be prevented.

[0119] The sealing member 37 does not need to strictly seal the openings of the housing 32. The sealing member 37 is provided in at least a portion of the base end opening 322a, the tip end opening 323a, the lead wire opening 321a, or the fastening opening 321b, and by blocking at least a portion of the gap connecting the inside and outside of the housing 32, it is possible to prevent fine dust generated inside the housing 32 from flowing out to the outside of the housing 32.

[0120] Next, the operation of the piezoelectric actuator 30 will be described.

[0121] When a voltage is applied to the vibrating part 33, the vibrating part 33 expands and contracts in the axial direction A. When the vibrating part 33 expands in the axial direction A, the base end side A2 of the vibrating part 33 is fixed by the housing base end part 322, so the vibrating part 33 expands to the tip side A1.

[0122] When the vibrating part 33 extends to the tip side A1, the transmission part 341 is pushed by the vibrating part 33 and moves to the tip side A1. The transmission part 341 moving to the tip side A1 moves while pushing the first outer ring 342c toward the tip side A1.

[0123] Since a gap 34s is formed between the first outer ring 342c and the second outer ring 343c in the axial direction A, the first outer ring 342c is pushed by the transmission part 341 and moves to the tip side A1.

[0124] In the first rolling bearing 342, when the first outer ring 342c moves to the tip side A1, the first balls 342b and the first inner ring 342a move to the tip side A1 due to the force applied to the tip side A1 from the first outer ring 342c.

[0125] The first inner ring 342a and the second inner ring 343a are sandwiched in the axial direction A by the holder fastening portion 346, the inner ring spacer 344a, and the inner ring restricting portion 344b.

[0126] Therefore, when the first inner race 342a moves toward the tip side A1, the holder fastening portion 346, the second inner race 343a, and the shaft portion 344 move toward the tip side A1 together with the first inner race 342a.

[0127] At this time, since the movement of the second outer ring 343c toward the tip side A1 is restricted by the outer ring restriction portion 323 of the housing 32, the second outer ring 343c does not move toward the tip side A1.

[0128] In this way, the rolling bearings 342 and 343 are elastically deformed by the force applied from the transmission part 341 to the tip side A1.

[0129] The tool holder 35 is fixed to the shaft portion 344. Therefore, when the rolling bearings 342, 343 are elastically deformed by the force applied from the transmission portion 341, the tool holder 35 moves together with the shaft portion 344 toward the tip side A1.

[0130] At this time, the housing 32 does not move toward the tip end side A1. That is, the tool holder 35 moves toward the tip end side A1 relative to the housing 32.

[0131] When the vibrating part 33 returns from the state in which it is extended toward the tip side A1 to its original state, the rolling bearings 342 and 343 return to their original positions due to their elasticity.

[0132] That is, the first inner ring 342a and the second inner ring 343a move to the base end side A2, and the shaft portion 344, the holder fastening portion 346, the tool holder 35, and the transmission portion 341 move to the base end side A2 together with the first inner ring 342a and the second inner ring 343a.

[0133] At this time, the housing 32 does not move toward the base end side A2. That is, the tool holder 35 moves toward the base end side A2 relative to the housing 32.

[0134] The amount of displacement in the axial direction A of the expanding and contracting vibrating part 33 is extremely minute, so when the vibrating part 33 expands and contracts, the vibrated part 34 and the tool holder 35 fixed to the vibrated part 34 move slightly in the axial direction A.

[0135] By attaching the microtool 40 to the tool holder 35, the microtool 40 can be slightly moved in the axial direction A.

[0136] The manipulation system 1 can apply a voltage to the vibration part 33 to repeatedly expand and contract the vibration part 33, thereby slightly moving the microtool 40 in the axial direction A.

[0137] For example, when performing intracytoplasmic sperm injection, the user can make a hole in the egg by pressing the tip of the micro-tool 40, which moves slightly, against the egg.

[0138] When performing fine work such as drilling and cutting using the microtool 40 that moves slightly, dust may be generated from the vibrated part 34 that moves slightly inside the piezoelectric actuator 30. For example, dust may be generated from the grease in the rolling bearings 342 and 343.

[0139] Piezoelectric actuator 30 includes sealing members 37 that seal base end opening 322a, tip end opening 323a, lead wire opening 321a, and fastening opening 321b. Therefore, even if fine dust particles are generated inside piezoelectric actuator 30, the fine dust particles can be prevented from leaking out of piezoelectric actuator 30.

[0140] For example, if fine dust particles flow out onto the tip side A1 of the piezoelectric actuator 30, the cells in the container placed on the table 10a may be contaminated by the fine dust particles.

[0141] By providing a tip sealing member 37b that can seal at least a portion of the tip opening 323a, it is possible to prevent fine dust particles from leaking to the tip side A1 of the piezoelectric actuator 30, and to prevent cells in a container placed on the table 10a from being contaminated by fine dust particles.

[0142] The base end sealing member 37a and the tip end sealing member 37b are formed from a material that can absorb the amount of movement of the shaft portion 344 and the tool holder 35 by sliding when the shaft portion 344 and the tool holder 35 vibrate in the axial direction A.

[0143] Therefore, the base end sealing member 37a and the tip end sealing member 37b can maintain a state in which the gap between the shaft portion 344 and the tool holder 35 and the housing 32 is sealed even when the vibrated portion 34 is vibrating.

[0144] For example, an O-ring made of a fluorine-based material can be used as the proximal end sealing member 37a and the distal end sealing member 37b.

[0145] According to the manipulation system 1 of this embodiment, the piezoelectric actuator 30 comprises a housing 32, rolling bearings 342, 343 arranged inside the housing 32, a shaft portion 344 that is inserted through the rolling bearings 342, 343 in the axial direction A and protrudes from a tip opening 323a of the housing 32 to the tip side A1, a tool holder 35 that is fixed to the shaft portion 344 and can hold a microtool 40, a vibration portion 33 that is arranged inside the housing 32 and can vibrate the rolling bearings 342, 343, the shaft portion 344 and the tool holder 35 in the axial direction A, and a tip sealing member 37b that is provided at the tip opening 323a and contacts the shaft portion 344 and the housing 32 in the radial direction D.

[0146] As a result, it is possible to provide a piezoelectric actuator 30 and a manipulation system 1 that prevent fine dust particles from flowing out from the inside of the piezoelectric actuator 30 to the outside.

[0147] Although one embodiment of the present invention has been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and design modifications and the like are also included within the scope of the present invention. Furthermore, the components shown in the above-described embodiment and the following modified examples can be appropriately combined to form a configuration.

[0148] (Variation 1) In the above embodiment, the manipulation system 1 includes the microscope 10, but the aspect of the manipulation system is not limited to this. The manipulation system may not include a microscope and may be used together with a microscope provided outside the manipulation system.

[0149] (Variation 2) In the above embodiment, the tool holder 35 is a hollow shaft having an internal space passing through in the axial direction A, but the form of the tool holder is not limited to this. The tool holder may also be a solid shaft without an internal space.

[0150] (Variation 3) In the above embodiment, the vibrated part 34 holds the tool holder 35 at the end of the tip side A1 of the shaft part 344 by a holder holding part 345 that is detachable from the shaft part 344, but the form of the vibrated part is not limited to this.

[0151] For example, the tip of the shaft portion is provided with a hollow truncated cone shape whose diameter is reduced on the tip side A1 and whose central axis is the axis O. In addition, a plurality of slits are provided on the side surface of this truncated cone shape.

[0152] After inserting the tool holder 35 into the hollow portion of the truncated cone, the truncated cone may be tightened toward the inside IN with a member that covers the truncated cone from the outside OU, thereby fixing the tool holder 35 to the vibrated part.

[0153] Also, the tool holder 35 may be fixed to the vibrated part using a set screw.

[0154] (Variation 4) In the above embodiment, the housing 32 has a rectangular shape in a plan view seen from the axial direction A, but the shape of the housing is not limited to this.

[0155] The housing may have a polygonal, circular or elliptical shape in a plan view seen in the axial direction A. [Explanation of symbols]

[0156] 1 Manipulation System 10. Microscope 20 Manipulator 30 Piezoelectric Actuator 32 Housing 322a Proximal opening 323a Tip opening 321a Lead Wire Opening 321b Fastening opening 323 Housing tip (outer ring restriction part) 33 Vibration unit 341 Transmission Unit 342 First Rolling Bearing (Rolling Bearing) 342a First Inner Ring (Inner Ring) 342c First outer ring (outer ring) 343 Secondary rolling bearing (rolling bearing) 343a Second Inner Ring (Inner Ring) 343c Second outer ring (outer ring) 344 Shaft 344a Inner ring spacer 344b Inner ring regulation part 346a Fastening members 35 Tool holder 36 Lead Wire 37 Sealing member 37a Proximal sealing member 37b Tip sealing member 37c Lead wire sealing material 37d Fastening sealing member 40 Micro Tools 60 Control Unit A axis direction A1 Tip side A2 proximal side D Radial direction IN Inside OU outside

Claims

1. Housing and a rolling bearing disposed inside the housing; a shaft portion that is inserted through the rolling bearing in the axial direction and protrudes from a tip opening of the housing toward a tip end in the axial direction; a tool holder fixed to the shaft portion and capable of holding a microtool; a vibration unit disposed inside the housing and capable of vibrating the rolling bearing, the shaft portion, and the tool holder in the axial direction; a tip sealing member provided at the tip opening and in contact with the shaft portion and the housing in the radial direction of the rolling bearing; Equipped with Piezoelectric actuator.

2. the tool holder has the shank inserted therethrough in the axial direction and protrudes from a base end opening of the housing toward a base end in the axial direction; a proximal end sealing member provided in the proximal end opening and in radial contact with the tool holder and the housing; The piezoelectric actuator according to claim 1 .

3. The vibration unit is a piezoelectric element. The piezoelectric actuator according to claim 2 .

4. the housing has a lead wire opening through which a lead wire connected to the vibrating portion can be inserted, a lead wire sealing member provided in the lead wire opening and in contact with the lead wire and the housing; The piezoelectric actuator according to claim 2 .

5. a fastening member that detachably fastens the tool holder to the shank, The fastening member is moving the tool holder inward in the radial direction to fix the tool holder to the shank; releasing the fixation between the tool holder and the shank by moving outward in the radial direction; the housing has a fastening opening into which a tool can be inserted to move the fastening member; a fastener sealing member that is detachable in the fastener opening; The piezoelectric actuator according to claim 2 .

6. The rolling bearing includes a first rolling bearing arranged on the base end side and a second rolling bearing arranged on the tip end side, the first rolling bearing and the second rolling bearing are arranged coaxially in the axial direction, a transmission part that connects the vibration part and the outer ring of the first rolling bearing in the axial direction, The piezoelectric actuator according to claim 2 .

7. The shaft portion is an inner ring spacer sandwiched in the axial direction between an inner ring of the first rolling bearing and an inner ring of the second rolling bearing; an inner ring restricting portion connected to the tip side of the inner ring of the second rolling bearing; and the housing has an outer ring restricting portion connected to the tip side of the outer ring of the second rolling bearing, 7. The piezoelectric actuator according to claim 6.

8. The piezoelectric actuator according to any one of claims 1 to 7; a manipulator connected to the housing and capable of moving the piezoelectric actuator; a control unit that can vibrate the vibration unit; Equipped with Manipulation system.

9. two of the piezoelectric actuators and two of the manipulators; The manipulation system according to claim 8 .

10. a microscope capable of observing the microtool; The manipulation system according to claim 9 .

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