JP2016077056A - Vibration actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibration actuator capable of selectively perform multi-axial rotation or direct-acting driving by one actuator.SOLUTION: A vibration actuator whose output shaft act by vibrations is provided with a through hole or a plurality of non-through holes on a substantially center axis of a vibratory element in a substantially polyhedral shape, and a plurality of output shafts are inserted into the holes. A plurality of piezoelectric elements having patterned electrodes are stuck on an outer peripheral surface of the vibratory element substantially parallel with the respective output shafts, and a voltage is applied to the pattern electrodes in sequence so as to generate a traveling wave in the vibratory element, thereby selectively rotating or axially displacing the plurality of output shafts.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a vibration actuator in which vibration waves are individually given to a plurality of output shafts by vibration of a vibrator such as a piezoelectric element, and each output shaft rotates or linearly moves.

The progress of medical devices is rapid, and in recent years, operation support robots capable of performing operations by remote control have appeared. Fingers are attached to the tips of the two manipulators of the surgery support robot, and the fingers can be opened and closed at 180 degrees, and the root can be changed by ± 90 degrees so that the human wrist can be folded. Generally, these operations are generally performed by pushing and pulling a long wire stretched in a tube-shaped arm with a plurality of sufficiently large electromagnetic motors provided on the main body device side (the anti-finger side) of the arm. It is driven by that.
However, with the emergence of vibration actuators (or ultrasonic actuators) that are small and have a diameter of 5 millimeters or less, they are mounted on the tip of the manipulator, and the fingers are driven directly without using wires. There is a demand for realizing a manipulator with good operability without backlash close to the sense.

  Among the various drive principles such as electromagnetic motors, piezoelectric actuators, and shape memory alloy actuators, vibration actuators using piezoelectric elements or electrostrictive elements that can provide a large driving force with a small diameter are promising as the driving source required for manipulators. ing.

  For example, in Patent Document 1, a male screw shaft (120) is slidably inserted into a female threaded nut member (110), and a clearance (697b) is provided between the nut member (110) and the male screw shaft (120). The male screw shaft (120) is rotated by sequentially applying a voltage to the piezoelectric elements (132a to 132d) attached to the four surfaces of the nut member (110) and applying rotational vibration to the nut member (110). At the same time, a linear motor system (100) that moves in the axial direction is shown.

  However, in the linear motor system shown in Patent Document 1, the number of output shafts is limited to one, and a plurality of piezoelectric elements cannot selectively rotate or linearly vibrate the plurality of output shafts.

  In Patent Document 2, a shaft-like actuator (12) is press-fitted or inserted into a hole of a prismatic stator (11), and voltage is applied to a plurality of piezoelectric elements (13) attached to the stator (11). An ultrasonic scanning device that rotates or moves an axial actuator in an axial direction by sequentially applying, and generating a vibration wave is shown.

However, in the ultrasonic scanning device shown in Patent Document 2, the output shaft is limited to one, and a plurality of piezoelectric elements cannot selectively rotate or linearly vibrate the plurality of output shafts.

US Patent Application Publication No. 2010/0039715 JP 2013-183563 A

The present invention has been made in view of the above-described conventional circumstances, and a problem to be solved is a vibration actuator that can be driven in a small size and multi-axis by selectively rotating or linearly vibrating a plurality of output shafts. Is to provide.

One means for solving the above problem is that in a vibration actuator in which an output shaft moves due to vibration, a through-hole or a non-through-hole is provided in the surface of the substantially polyhedral-shaped vibration element, and the output shaft is inserted into the hole. . A vibrator having a patterned electrode is affixed to a portion of the configuration surface of the vibration element where no hole is formed, and a traveling wave is applied to the vibration element by sequentially applying a voltage to the electrode pattern. And generating rotation or axial displacement on the output shaft.

According to the present invention, a plurality of vibrators provided in the vibration element selectively rotate or linearly vibrate a plurality of output shafts, thereby obtaining a vibration actuator that is small and capable of multi-axis driving. By mounting this multi-axis actuator on the tip of a remotely operated surgical support robot manipulator, the fingers can be driven directly without using wires, and the operation is more responsive and closer to the sensation of human hands. An excellent manipulator can be obtained.

The perspective view which shows one Embodiment of the vibration actuator which concerns on this invention Electrode pattern explanatory drawing of the vibration actuator Linear motion explanatory diagram of the first output shaft in the same vibration actuator Explanatory diagram of linear motion traveling wave of the first output shaft in the same vibration actuator Rotation operation explanatory view of the first output shaft in the vibration actuator Rotational traveling wave explanatory diagram of the first output shaft in the vibration actuator Rotation operation explanatory diagram of the second output shaft in the vibration actuator Rotational vibration wave explanatory diagram of the second output shaft in the same vibration actuator Rotation operation explanatory diagram of the third output shaft in the vibration actuator Rotational vibration wave explanatory diagram in the same vibration actuator Explanatory drawing of application form of vibration actuator according to the present invention

The first feature of the vibration actuator according to the present embodiment is that the vibration actuator in which the output shaft moves by vibration has a substantially polyhedral-shaped vibration element, and at least a plurality of the substantially polyhedral-shaped constituent surfaces of the vibration element are included. A through-hole or a non-through hole is formed on the surface. A vibrator having a patterned electrode is attached to a portion of the configuration surface of the vibration element where no hole is formed, and an output shaft is inserted through a plurality of holes, By sequentially applying a voltage to the electrode pattern, a traveling wave is generated in the vibration element, and rotation or axial displacement is applied to the output shaft.
With this configuration, vibration waves can be individually applied to a plurality of output shafts, and the respective output shafts can be rotated and linearly moved, so that a compact and multifunctional vibration actuator can be obtained.

As a second feature, holes that are substantially coaxial with each other are provided on the opposing surfaces of the substantially polyhedral-shaped vibration element, and one output shaft is inserted into each of the holes, Two output shafts arranged on the same axis and facing each other are configured to be able to rotate independently or synchronously in the same direction.
According to this configuration, it is possible to provide a vibration actuator that can selectively rotate or linearly move a plurality of output shafts by a plurality of piezoelectric elements provided on a vibration element, and that is small and capable of multi-axis driving. Can do.

As a third feature, at least one or more output shafts are configured so that an operating member that operates by the output shaft is integrally fixed.
According to this configuration, an optical component such as a lens, various tool components such as a drill or a cutter can be arranged as an operation member, and this can be operated in multiple axes in a small space. The operational performance of various devices can be improved.

As a fourth feature, the operating member is a claw-shaped operating claw, and the operating claw is fixedly arranged integrally with each of at least two or more output shafts directly or via a holding part such as a rotating arm. . And it is comprised so that the operation | movement which opens and closes the said some operation | movement claws can be performed by operation | movement of an output shaft.
According to this configuration, in addition to the opening and closing operation of the operating claw, the manipulator having a large degree of freedom in the operation range can be operated by rotating / directly moving the vibration element by the output shaft not provided with the operating claw. Can be used as For example, more specifically, a highly accurate multi-axis drive manipulator that can be applied to a finger unit of an advanced minimally invasive surgery support robot can be realized.

As a fifth feature, a piezoelectric element or an electrostrictive element that generates distortion when a voltage is applied is used as the vibrator.
According to this configuration, the movement of the output shaft can be controlled with higher accuracy by using an element that can be displaced minutely and has excellent responsiveness.

Next, preferred embodiments of the present invention will be described with reference to the drawings.

  One configuration of an embodiment of the vibration actuator of the present invention will be described with reference to FIGS.

  FIG. 1 is a perspective view of a vibration actuator according to an embodiment of the present invention. In FIG. 1, a substantially polyhedral-shaped vibrating element 1 (substantially cubic in FIG. 1) has holes 3a, 3c, 3d, 3e, 3f on each of the surfaces 1a, 1b, 1c, 1d, 1e, and 1f constituting the polygon. The operating shafts 2a, 2c, 2d, 2e, and 2f are respectively inserted or lightly press-fitted.

  FIG. 2 is an explanatory diagram of an electrode pattern according to this embodiment, and shows a development view of each surface 1a, 1b, 1c, 1d, 1e, and 1f of the vibration element 1. FIG. A plurality of piezoelectric elements 5 having electrodes 6 formed on the surface are affixed, each pattern electrode is connected to an electric wire 11, and a voltage is applied from a drive circuit 12.

  FIG. 3 is a diagram for explaining the linear motion of the first output shaft of the present embodiment, and the first output shaft indicates 2a in the figure. In FIG. 3, the substantially polyhedral vibrating element 1 has a hole 3a penetrating from the facing surface 1a to the surface 1b out of the substantially flat surface forming the polygon, and the output shaft 2a is inserted into the hole 3a. ing. The holes 3a are processed with radially extending slits 4 for imparting spring properties to the vibrating element 1. The vibrating element 1 sandwiches the inserted output shaft 2a with an appropriate force, and the output shaft 2a and the vibrating element 1 are connected to each other. In the meantime, a stable frictional force (for example, a force of about 1 Newton) is generated.

  Preferably, a shaft hole 2g is formed in the approximate center of the output shaft 2a, and the shaft hole 2g discharges an optical fiber, an electric wire of a CCD camera for an endoscope, or cleaning water sprayed on an affected part during an operation as necessary. A nozzle or the like to be inserted is inserted.

  A piezoelectric element 5 is attached to one surface 1e on the outer periphery of the vibration element 1 parallel to the output shaft 2a and its opposing surface 1f. Patterned electrodes 6e1, 6e2, 6e3, 6e4 are formed on the surface of the piezoelectric element 5 attached to the surface 1e. Further, as shown in FIG. 2, patterned electrodes 6f1, 6f2, 6f3, and 6f4 are formed on the surface of the piezoelectric element 5 attached to the surface 1f.

  Each of the piezoelectric elements 5 is provided with a patterned electrode 6 by a noble metal sputtering method or a conductive ink printing method. The electrodes 6a1, 6a2, 6a3, and 6a4 may be formed on one piezoelectric element 5, or an electrode may be formed on each of the four piezoelectric elements 5 divided into four.

  The surface of the vibration element 1 is preferably attached with the piezoelectric element 5 having the electrodes 6 also on the surfaces 1a and 1b including the through hole 3a through which the shaft 2a is inserted. Electrodes 6a1, 6a2, 6a3, 6a4 are formed on the piezoelectric element 5 attached to the surface 1a, and electrodes 6b1, 6b2, 6b3, 6b4 are formed on the piezoelectric element 5 attached to the surface 1b.

  The linear motion operation of the first output shaft shown in FIG. 3 will be further described. FIG. 4 is an explanatory diagram of the linear motion traveling wave of the first output shaft in the present embodiment. 3 to 4, a substantially sinusoidal or sawtooth voltage is sequentially applied from the drive circuit 12 to the patterned electrode 6 through the electric wire 11, and will be described below by changing the application order. Further, the output shaft 2a can be operated in a linear motion direction or a rotational direction.

  When the output shaft 2a is linearly moved in the direction of arrow M in FIG. 4, the voltage is first applied to a total of four electrodes 6a1, 6a2, 6a3, 6a4, and then the second 6e3, 6e4, 6f3, 6f4 applied to a total of four electrodes, then third applied to a total of four electrodes 6e1, 6e2, 6f1, 6f2, then fourth applied to electrodes The voltage is applied to a total of four electrodes 6b1, 6b2, 6b3, and 6b4. Then, the voltage is again applied to a total of four electrodes 6a1, 6a2, 6a3, and 6a4 that are first applied, and this is repeated. As a result, traveling waves are generated as indicated by N and O in the figure, which propagates to the output shaft 2a, and the output shaft 2a slides in the direction of arrow M.

  If the order of repeated application to these electrodes 6 is reversed, a traveling wave in the direction of rotation opposite to N and O in the figure is generated inside the vibration element 1, and the output shaft 2a slides in the direction opposite to the arrow M in FIG. Move.

  Further, there are the following operation methods as a method for more easily operating. The voltage is first applied to a total of four electrodes, electrodes 6e3, 6e4, 6f3, and 6f4, and then the second is applied to a total of four electrodes, electrodes 6e1, 6e2, 6f1, and 6f2. Next, the first applied voltage 6e3, 6e4, 6f3, 6f4 is applied to a total of four electrodes, and this is repeated. This also causes the output shaft 2a to slide in the arrow M direction. In the case of this method, the electrodes 6 and the electric wires 11 can be reduced.

Next, the case where the output shaft 2a is rotated will be described with reference to FIGS.
FIG. 5 is an explanatory view of the rotation operation of the first output shaft (2a in the figure) of the first embodiment of the present invention, and the shape of the output shaft 2a is to operate in both directions of rotation and linear motion in this embodiment. It has a cylindrical shape. When only the linear motion is performed, either a cylindrical shape or a prismatic shape may be used.

  FIG. 6 is an explanatory diagram of a state in which a rotational traveling wave is generated on the first output shaft (2a). When the output shaft 2a is rotated in the direction of the arrow P, the voltage is first applied to a total of four electrodes 6c3, 6c1, 6d3, and 6d1, and then secondly, the electrodes 6e4, 6e2, 6f4 and 6f2 are applied to a total of four electrodes, then third is applied to a total of four electrodes 6e3, 6e1, 6f3 and 6f1, and then fourth is applied to electrodes 6d4, 6d2, The voltage is applied to a total of four electrodes 6c4 and 6c2. Next, the voltage is again applied to a total of four electrodes 6c3, 6c1, 6d3, and 6d1 applied first, and this is repeated. As a result, a traveling wave in the direction of the arrow shown in FIG. 5 is generated inside the vibration element 1, and this propagates to the output shaft 2a, and the output shaft 2a rotates in the direction of the arrow P.

  When the order of repeated application to these electrodes 6 is reversed, the output shaft 2a rotates in the direction opposite to the arrow P in FIG.

  Further, there are the following operation methods as a method of rotating more simply. A voltage is first applied to a total of four electrodes, electrodes 6e4, 6e2, 6f4, and 6f2, and then a second is applied to a total of four electrodes, electrodes 6e3, 6e1, 6f3, and 6f1, Next, the voltage is again applied to a total of four electrodes 6e4, 6e2, 6f4, and 6f2 applied first, and this is repeated. As a result, the same traveling wave is generated inside the vibration element 1, and the output shaft 2a slides in the direction of the arrow M. In the case of this method, the electrodes 6 and the electric wires 11 can be reduced.

  FIG. 7 is an explanatory view of the rotation operation of the second output shaft in this embodiment, and FIG. 8 is an explanatory view of the rotational vibration wave of the second output shaft.

  The case where the output shaft 2c is rotated will be described with reference to FIGS. A hole 3c is provided in the surface 1c of the vibrating element 1, and the output shaft 2c is lightly press-fitted. When rotating the output shaft 2c in the direction of the arrow Q, first, a voltage is first applied to a total of two electrodes 6a2 and 6b2, and then secondly, a total of two electrodes 6e4 and 6f1. Next, the third electrode is applied to a total of two electrodes 6e2 and 6f3, and the fourth is applied to a total of two electrodes 6b4 and 6a4. Then, the first 6a2 and 6b2 applied again are applied to a total of two electrodes, and this is repeated. As a result, a traveling wave in the direction of the arrow shown in FIG. 7 is generated inside the vibration element 1, and this propagates to the output shaft 2c, and the output shaft 2c rotates in the direction of the arrow Q.

  When the order of repeated application to these electrodes 6 is reversed, the output shaft 2c rotates in the direction opposite to the arrow Q in FIG.

  Here, since the hole 3c and the operating shaft 2c provided on the surface 1c and the hole 3d and the operating shaft 2d provided on the surface 1d are respectively driven by different electrodes 6, the operating shafts 2c and 2d are independent of each other. Driven separately.

  FIG. 9 is an explanatory view of the rotation operation of the third output shaft (output shafts 2e, 2f) in this embodiment, and FIG. 10 is an explanatory view of the rotational vibration wave of the third output shaft.

  The case where the output shaft 2e and the output shaft 2f are rotated will be described with reference to FIGS. A hole 3e is provided in the surface 1e of the vibration element 1, and the output shaft 2e is lightly press-fitted. Further, a hole 3f is provided in the surface 1f, and the output shaft 2f is lightly press-fitted. When the output shafts 2e and 2f are rotated in the directions of arrows S1 and S2, the voltage is first applied to a total of four electrodes 6c1, 6c2, 6d4, and 6d3, and then secondly, the electrodes 6b4, 6b2, 6a1, 6a3 applied to a total of 4 electrodes, then third applied to a total of 4 electrodes 6b3, 6b1, 6a2, 6a4, then 4th It is applied to a total of four electrodes 6d2, 6d1, 6c3, and 6c4. Next, the voltage is again applied to a total of four electrodes 6c1, 6c2, 6d4, and 6d3 applied first, and this is repeated. As a result, a traveling wave in the direction of the arrow shown in FIG. 9 and FIG. 10 is generated inside the vibration element 1 and propagates to the output shafts 2e and 2f, and the output shafts 2e and 2f are separate parts, but apparently an integral part. As is the case, they rotate in the directions of arrows S1 and S2 almost simultaneously.

When the order of repeated application to these electrodes 6 is reversed, the output shafts 2e and 2f rotate in the opposite directions to the arrows S1 and S2 in FIG.

  FIG. 11 is an explanatory diagram of an application example of the vibration actuator according to the present invention to a manipulator, and is a diagram of a configuration example of a finger unit capable of a five-axis operation used at the tip of a manipulator used in a minimally invasive surgical instrument or the like.

  In FIG. 11, a rotating arm 9c and an operating claw 10C are attached to the output shaft 2c, and a rotating arm 9d and an operating claw 10d are attached to the output shaft 2d, respectively. The operating shaft 2c and the operating shaft 2d can be independently rotated in a wide range of about ± 100 degrees by the operation of the drive circuit 12, and the practitioner can move the operating claws 10C and 10d to the thumb of a person at a medical site or the like. It is also possible to open and close freely as if to move the index finger, and to handle and handle surgical threads and needles.

  The output shafts 2e and 2f are fixed to the output shaft folders 8a and 8b, and the output shaft folders 8a and 8b are fixed to the arm 13 of the manipulator integrally with the output shafts 2e and 2f. When a rotational force is generated on the output shafts 2e and 2f by the operation of the drive circuit 12, the vibration element 1 rotates in a range of about ± 80 degrees in the directions of arrows S1 and S2 in the figure. Can be freely handled as if bent together with the operating claws 10c and 10d.

  The output shaft 2a can be operated both linearly and rotationally. However, a nozzle that discharges cleaning water during the treatment or a CCD is provided on the end of the output shaft 2a on the side of the operating claws 10c and 10d as necessary. By attaching a camera or the like and sliding in the direction of arrow M in the figure or rotating in the direction of arrow P, the practitioner can finely clean and observe the affected area during the operation. In the figure, reference numeral 14 denotes a flexible pipe for supplying cleaning water. Here, the nozzle and the CCD camera are not shown.

  In this way, the vibration actuator 7 can perform a total of five axes of motion and can handle the fingers freely.

  The vibrating element 1 is made of a material of a piezoelectric element or an electrostrictive element. Thereby, it is possible to perform control with high accuracy and excellent responsiveness.

  In the embodiment of FIG. 11, the outer diameter of the output shaft 2a is about 2 millimeters, the diameter of the main shafts 2c, 2d, 2e, and 2f is about 1.2 millimeters, the vibration element is about 5 millimeters square, the operating claw 10c, The length of 10d is about 15 millimeters. The piezoelectric element 5 has a thickness of about 0.2 millimeters, and the electrode 6 has a thickness of about 0.05 millimeters. A thin electric wire 11 having a diameter of about 0.025 mm is wired to the electrode 6 by soldering or the like.

  Further, the output shaft 2 and the vibration element 1 are made of metal or ceramics and are finished by machining.

  Since the vibration element 1 is desired to have a spring property and not to have a large difference in coefficient of linear expansion from the piezoelectric element 9, it is processed with stainless steel, alumina ceramics, zirconia ceramics, or the like.

According to the present invention, since one vibration actuator performs multi-axis rotation and at least one linear motion, it is compact. Further, when this actuator is used for a manipulator or the like, a manipulator that is compact, has a large operating force, and is excellent in operability without backlash can be realized.

Since the vibration actuator of the present invention can perform multi-axis movements with a single vibration element, it is easy to operate by incorporating it into a manipulator or the like of a minimally invasive surgical device that has rapidly advanced in recent years, and can obtain a small and large driving force. Can do. In addition, the present invention can be applied to an endoscopic camera swing device and a zoom lens sliding device.

1 Vibrator 1a, 1b, 1c, 1d, 1e, 1f Surface 2a, 2c, 2d, 2e, 2f Output shaft 2g Shaft hole 3a, 3c, 3d, 3e, 3f Hole 4 Slit
5 Piezoelectric element 6a1, 6a2, 6a3, 6a4 (surface 1a) electrode 6b1, 6b2, 6b3, 6b4 (surface 1b) electrode 6c1, 6c2, 6c3, 6c4 (surface 1c) electrode 6d1, 6d2, 6d3, 6d4 (surface 1c) Electrode 6e1, 6e2, 6e3, 6e4 (of surface 1d) Electrode 6f1, 6f2, 6f3, 6f4 (of surface 1e) 7 Vibration actuator 8a, 8b Output shaft folder 9c, 9d Rotating arm 10c, 10d Actuation Claw 11 Electric wire 12 Drive circuit 13 Arm 14 Flexible piping

Claims (5)

In the vibration actuator where the output shaft moves by vibration,
It has a substantially polyhedral shaped pendulum,
A through-hole or a non-through-hole is formed in at least a plurality of surfaces of the substantially polyhedral-shaped component surface,
A vibrator having a patterned electrode is attached to a portion on the surface where the hole is not formed,
The output shaft is inserted through the plurality of holes,
A vibration actuator characterized in that a traveling wave is generated in a vibration element by sequentially applying a voltage to an electrode pattern of the electrode, and a rotation or an axial displacement is applied to the output shaft.
Of the substantially polyhedral-shaped constituent surfaces of the vibrating element, the surfaces facing each other are provided with the holes that are substantially coaxial with each other, and the one output shaft is inserted into each of the holes,
2. The vibration actuator according to claim 1, wherein the two output shafts arranged substantially opposite to each other on the same axis can rotate independently or synchronously in the same direction.
The vibration actuator according to claim 1 or 2, wherein an operation member that is operated by the output shaft is integrally fixed to at least one of the output shafts.
The actuating member is a claw-shaped actuating claw, and the actuating claw is integrally fixed to each of at least two or more of the output shafts. The vibration actuator according to claim 3, wherein the operation of opening and closing the claws is possible.
  The vibration actuator according to any one of claims 1 to 4, wherein the vibrator is a piezoelectric element or an electrostrictive element.

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