JPH08266073A - Impact drive type actuator - Google Patents

Abstract

PURPOSE: To provide an impact drive type actuator which can be made smaller in size, eliminate as many as possible the restrictions on outer dimensions, and also perform two-dimensional or three dimensional movements. CONSTITUTION: This is an impact drive type actuator 10 equipped with with a relative motion member 11 of a hollow construction, an electromechanical conversion element 12 to be installed inside the relative motion member 11, and an inertial body 14 attached to other end of the electromechanical conversion element 12 and provided inside the relative motion member 11. Since the electromechanical conversion element 12 and the inertial body 14 are built in the relative motion member 11, miniaturization and the enlargement of the degree of freedom of external dimensions are realized and any error in the amount of motion step of the relative motion member 11 can be reduced. In addition, two-dimensional and three-dimensional movement is made possible by providing a plurality of units of the electromechanical conversion elements 12 and inertial bodies 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an impact drive type actuator capable of minute movement utilizing rapid deformation of an electromechanical conversion element.

[0002]

2. Description of the Related Art For example, in JP-A-63-299785 and JP-A-4-207982, an electromechanical conversion element such as a piezoelectric element is used, and a minute movement is performed by an impact force generated by its rapid deformation. An impact drive type actuator that can achieve this has been proposed. FIG. 7 is a front view schematically showing the structure of such an impact drive type actuator.

As shown in FIG. 1, in an impact drive type actuator 1, one end of an electromechanical conversion element 3 is attached to a substantially rectangular parallelepiped relative movement member 2, and an inertial body 4 is attached to the other end of the electromechanical conversion element 3. Install. Then, the impact drive type actuator 1 is placed on the fixed body 5,
When an applied voltage having a steep voltage increase rate is applied to the electromechanical conversion element 3, the electromechanical conversion element 3 rapidly expands or expands or contracts, so that the inertial body 4 is shockedly driven, and the reaction force of the impact force is applied. As a result, a dynamic friction state is created between the relative motion member 2 and the fixed body 5, and the relative motion member 2 moves.

After that, the applied voltage is lowered at a slow rate of voltage reduction so that the electromechanical conversion element 3 is gradually contracted or extended, whereby a static friction state is created between the relative motion member 2 and the fixed body 5. 2 stops. Hereinafter, by repeating such a cycle, the relative motion member 2 continuously makes a minute movement.

[0005]

In such a conventional impact drive type actuator 1, since the electromechanical conversion element 3 and the inertial body 4 are attached to the outer surface of the relative motion member 2, the impact drive type actuator 1 must be used. Has a problem that it is larger than the relative motion member 2 and it is difficult to reduce the size. Therefore, it was necessary to set restrictions on usage conditions and usage environments. Further, it is also necessary to set a restriction on the outer shape of the relative motion member 2 to which the electromechanical conversion element 3 and the inertial body 4 are mounted for mounting.

Further, during acceleration or deceleration during movement, a moment acts on the relative motion member 2 with the corner portion 2a or 2b of the relative motion member 2 as a fulcrum, so that the relative motion member 2 and the fixed body 5 are separated from each other. There has been a problem that the contact situation between them is likely to fluctuate and an error is likely to occur in the movement step amount in one cycle. Further, such a conventional impact drive type actuator 1 is driven by an impact force generated in the relative motion member 2 in the deformation direction of the electromechanical conversion element 3, that is, the rapid deformation in the left and right directions in FIG. . Therefore, although such an impact drive type actuator 1 can move one-dimensionally on the fixed body 5, it cannot move two-dimensionally or three-dimensionally. Therefore, such a conventional impact drive type actuator 1 cannot move inside a tube which is two-dimensionally bent, for example.

A first object of the present invention is to provide an impact drive type actuator which can be miniaturized. A second object of the present invention is to provide an impact drive type actuator that can remove restrictions on external dimensions as much as possible.

A third object of the present invention is to provide an impact drive type actuator in which an error does not easily occur in the movement step amount in one cycle. Furthermore, a fourth object of the present invention is not only a one-dimensional movement but also a two-dimensional or three-dimensional movement, for example, an impact drive capable of performing movement inside a two-dimensionally bent pipe. Type actuator.

[0009]

In order to solve the above-mentioned problems, an impact drive type actuator according to a first aspect of the present invention is configured such that a relative movement member having a hollow structure and one end thereof are installed inside the relative movement member, An electromechanical conversion element that is excited by an applied voltage and an electromechanical conversion element that is attached to the other end of the electromechanical conversion element and is provided inside the relative motion member. By driving the electromechanical conversion element, an impact force is applied to the relative motion member. And an inertial body.

An impact drive type actuator according to a second aspect is the impact drive type actuator according to the first aspect, wherein the relative movement member receives an external signal and a voltage applied to the electromechanical conversion element. It is characterized by including a control unit for controlling the.

An impact drive type actuator according to a third aspect is the impact drive type actuator according to the first or second aspect, wherein the relative movement member has a rectangular parallelepiped outer shape. .

The impact drive type actuator described in claim 4 is the impact drive type actuator described in claim 1 or 2, wherein the relative movement member has a spherical outer shape. .

An impact drive type actuator according to a fifth aspect is the impact drive type actuator according to the third or fourth aspect, wherein the electromechanical conversion element is a plane including a center point of the relative motion member. In the above, it is characterized in that they are respectively arranged at positions that are point-symmetric with respect to the center point.
Four positions where two virtual straight lines orthogonal to each other at the center of the relative motion member intersect with the relative motion member,
It is possible to exemplify six positions where three virtual straight lines orthogonal to each other at the center of the relative movement member intersect the relative movement member.

The impact drive type actuator described in claim 6 is any one of claims 1 to 5.
In the impact drive type actuator described in the paragraph 1, the relative movement member is provided with an outer layer having greater flexibility than the tubular body when the contact target is inside the tubular body.

Introducing such an impact drive type actuator into a two-dimensionally or three-dimensionally bent tubular body and applying an applied voltage to the electromechanical conversion element to give an impact force to the relative motion member. Thus, in order to drive the impact drive type actuator while contacting the inner wall of the tubular body, when the flexibility of the tubular body is larger than that of the relative movement member, the maximum outer diameter of the relative movement member is set to the tubular shape. Set larger than the inner diameter of the body, when the flexibility of the tubular body is smaller than the relative movement member, while setting the maximum outer diameter of the relative movement member larger than the inner diameter of the tubular body, It is desirable to coat the outer surface of the relative motion member with a material having greater flexibility than the tubular body.

[0016]

According to the first aspect of the present invention, since the electromechanical conversion element and the inertial member are provided inside the relative motion member having the hollow structure, no protrusion is provided outside the relative motion member, and the impact drive type actuator is provided. It becomes possible to downsize. Further, since the electromechanical conversion element and the inertial body are not provided outside, these mounting surfaces and the like are unnecessary, and the degree of freedom regarding the outer shape is increased. further,
Since the electromechanical conversion element and the inertial body are built in, the center of gravity of the relative motion member and the overall center of gravity can be made closer than in the conventional case, and in the best case, they can be made to coincide with each other, acting around the center of gravity of the relative motion member As a result, the contact moment between the relative motion member and the fixed body becomes more stable than before.

According to the invention of claim 2, in the invention of claim 1, the relative motion member has a built-in controller for receiving an external signal and controlling a voltage applied to the electromechanical conversion element. It becomes possible to control the movement of the impact drive type actuator.

According to the invention of claim 3, in the invention of claim 1 or 2, the relative movement member has a rectangular parallelepiped outer shape, and according to the invention of claim 4, claim 1 or claim In the invention of item 2, since the outer shape of the relative motion member is a sphere, it can be easily introduced into a groove having a rectangular cross section or a tube having a circular cross section.

According to the invention of claim 5, in the invention of claim 3 or claim 4, the electromechanical conversion element is located at a position which is point-symmetric with respect to the center point on the plane including the center point of the relative motion member. Since they are respectively arranged, the impact drive type actuator can move in at least two directions.

According to a sixth aspect of the present invention, in the invention according to any one of the first to fifth aspects, the relative movement member includes an outer layer having a greater flexibility than that of the tubular body to be contacted. Therefore, the relative motion member is pressed against the inner wall of the tubular body in a two-dimensional or three-dimensional manner so that the influence of gravity can be ignored.
It becomes possible to move inside a tubular body that bends dimensionally.

[0021]

【Example】

(First Embodiment) An embodiment of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a front view showing the structure of an impact drive type actuator 10 of the first embodiment.

The relative movement member 11 is a hollow structure body formed by fixing two hollow structure parts. In this embodiment, the outer shape is a substantially rectangular parallelepiped. This relative movement member 1
One end of the laminated piezoelectric element 12, which is an electromechanical conversion element, is attached to one of the inner wall surfaces 11a of the first embodiment. further,
The relative movement member 11 includes a control unit 13 that receives an external signal output from a driving voltage device 15 arranged outside and controls a voltage applied to the piezoelectric element 12. The drive voltage device 15 is a device that can apply an applied voltage having an arbitrary waveform to the piezoelectric element 12. The relative motion member 11
The device built into the device is installed before the two hollow structural parts are fixed.

In this embodiment, the driving voltage device 15 is a microcomputer that outputs a digital signal, and a D / D that converts the output digital signal into an analog signal and outputs the analog signal.
It is composed of an A converter and a drive amplifier for inputting the output analog signal to the piezoelectric element 12. A keyboard with a display is connected to the microcomputer to input data for forming a desired waveform and monitor the waveform to input a drive voltage having a desired asymmetric waveform to the piezoelectric element 12.

The control signal output from the control unit 13 is guided to the piezoelectric element 12, and an applied voltage is sent to the piezoelectric element 12 to be excited. At the other end of the piezoelectric element 12, an inertial body 14 that gives an impact force to the relative motion member 11 by exciting the piezoelectric element 12 is installed. The impact drive type actuator 10 in this embodiment is configured as described above, and is used by being mounted on the fixed body 16.

In FIG. 1, when a drive voltage having a large voltage increase rate is applied to the piezoelectric element 12 from the drive voltage device 15 via the control unit 13, the piezoelectric element 12 is excited and expands or contracts to be provided on the piezoelectric element 12. The inertial body 14 thus moved moves, and the relative motion member 11 also moves with the movement of the inertial body 14. After that, since the driving voltage is reduced by a small voltage decrease rate, the relative motion member 11 is stopped, but the inertial body 14 continues to move due to contraction or extension of the piezoelectric element 12,
This is the same state as when the inertial body 14 collides with the relative motion member 11.

Therefore, the relative motion member 11 is driven by the impact force generated by this collision. The impact drive type actuator 10 of the present embodiment has all the functions of the conventional impact drive type actuator, and the piezoelectric element 12 and the inertial body 14 are built in the relative movement member 11 having a hollow structure. Exercise member 1
There is no protrusion on the outside of 1. Therefore, the size is reduced, and it is not necessary to provide the mounting surface of the piezoelectric element 12 to the outside, and the degree of freedom of the outer shape is increased.

Further, the center of gravity of the relative motion member 11 and the center of gravity of the whole are closer than in the conventional case, and in the best case, they can be matched. Therefore, the moment acting on the relative motion member 11 is reduced, and the relative motion member 11 and the fixed body 1 are
The contact condition with 6 is more stable than before, and the error of the movement step amount per cycle is reduced.

(Second Embodiment) FIG. 2 schematically shows a situation in which the impact drive type actuator of the second embodiment moves inside a groove having a square cross section which is two-dimensionally bent into a crank shape. FIG. Note that, in FIG. 2, for ease of understanding, the description of both the control unit 13 and the drive voltage device 15 in FIG. 1 is omitted.

In this embodiment, four piezoelectric elements 12-1a, 12-1b, 12-1c and 12-1 are provided inside the hollow relative movement member 11-1 having an approximately cubic outer shape.
d One end of each is installed. The installation positions are four points where two virtual straight lines orthogonal to each other at the center of the relative motion member 11-1 intersect the inner surface of the relative motion member 11-1, and in a plane including the center point of the relative motion member 11-1. , Is a position that is point-symmetric with respect to the above-mentioned center point.

The four piezoelectric elements 12-1a, 12-1b,
The inertial bodies 14-1a, 14-1b, 14-1c and 14-1d are provided at one end of each of 12-1c and 12-1d. The impact drive type actuator 10-1 in the present embodiment is configured as described above, and is introduced into the interior from the inlet opening 17a of the groove 17 having a square cross section that is two-dimensionally bent into a crank shape.

At this time, the relative movement member 11-1 and the groove 17 are brought into contact with each other by making the length of one side of the relative movement member 11-1 and the inner diameter of the groove 17 substantially the same. The relative motion member 11-1 is prevented from falling due to its own weight of 1. At a position A in FIG. 2, when a driving voltage is applied to the piezoelectric element 12-1a from a driving voltage device (not shown), the piezoelectric element 12-1a is excited, so that the relative motion member 11-1 contacts the inner surface of the groove 17. While moving from the position A to the position B.

At position B, when the application of the drive voltage to the piezoelectric element 12-1a is stopped and the drive voltage is applied to the piezoelectric element 12-1b, the piezoelectric element 12-1b is excited, so that the relative motion member 11-1 moves in the groove. It moves from position B to position C while contacting the inner surface of 17. At the position C, the piezoelectric element 12
If the drive voltage is continuously applied to -1b, the piezoelectric element 12-1
Since b is excited, the relative motion member 11-1 moves from the position C to the position D while contacting the inner surface of the groove 17.

Further, at the position D, the piezoelectric element 12-
The application of the drive voltage to 1b is stopped and the piezoelectric element 1
When a drive voltage is applied to 2-1a, the piezoelectric element 12-1a
Is excited, the relative motion member 11-1 moves from the position D to the position E while contacting the inner surface of the groove 17. As described above, in the present embodiment, the piezoelectric elements to which the driving voltage is applied are switched at the position B and the position D, but in the present embodiment, the sensor that detects the arrival of the relative motion member 11-1 at the position B and the position D is detected. Is installed on the wall surface of the groove 17.

Contrary to the above description, the relative movement member 11- is operated in the order of position E → position D → position C → position B → position A.
1 can be moved by moving the piezoelectric elements 12-1a and 12-1b.
The piezoelectric elements 12-1c and 12 installed at a position facing each other
The drive voltage is applied to -1d in order.

(Third Embodiment) FIG. 3 shows that the impact drive type actuator of the third embodiment is bent in a crank shape,
It is explanatory drawing which shows typically the condition at the time of moving inside the groove | channel of square cross section installed in the horizontal surface. In FIG. 3, the control unit 13 and the driving voltage device 15 in FIG. 1 are omitted for easy understanding. Although not shown, a sensor is installed on the wall surface of the groove 17.

In this embodiment, six piezoelectric elements 12-2a, 12-2b, 12-2c and 12-2 are provided inside the hollow relative movement member 11-2 having an approximately cubic outer shape.
One end of each of d, 12-2e and 12-2f is installed. 12-2b and 12-2d are installed at 12
-2c and 12-2e are on the same plane, and 12-2b and 12-2e are 12-2d and 12-.
2c are 6 points which are positions where 12-2a and 12-2f face each other, and are positions which are point-symmetric with respect to the above-mentioned center point on a plane including the center point of the relative motion member 11-2. .

Six piezoelectric elements 12-2a, 12-2b,
At one end of each of 12-2c, 12-2d, 12-2e and 12-2f, inertial bodies 14-2a, 14-2b, 1 are attached.
4-2c, 14-2d, 14-2e and 14-2f are provided. The impact drive type actuator 10-2 in this embodiment is configured as described above, and the inlet opening 17a of the groove 17 having a square cross section bent in a crank shape.
It is introduced from the inside.

At a position A in FIG. 3, when a driving voltage is applied to the piezoelectric element 12-2a from a driving voltage device (not shown), the piezoelectric element 12-2a is excited, so that the relative motion member 11-2 moves in the groove 17. It moves from position A to position B while contacting the bottom surface. In the vicinity of the position B, it is necessary to change the traveling direction by 90 degrees.
Unlike the embodiment, the driving voltage applied to the piezoelectric element 12-2a remains constant, and the piezoelectric elements 12-2b, 12-2c or 12-2d arranged in the direction orthogonal to the piezoelectric element 12-2a. , 12-2e are applied to rotate the relative motion member 11-2, thereby changing the traveling direction.

When the application of the drive voltage to the piezoelectric elements 12-2b and 12-2c or the piezoelectric elements 12-2d and 12-2e is stopped at the time when the orientation is changed by 90 degrees near the position B, the impact drive type actuator 10 -2, since the drive voltage is continuously applied to the piezoelectric element 12-2a,
It moves from the position B to the position C and then moves toward the position D in order. In the vicinity of the position D, the drive voltage applied to the piezoelectric element 12-2a remains constant, and the piezoelectric elements 12-2b, 12-2c or the piezoelectric element 12-2d, which are arranged in the direction orthogonal to the piezoelectric element 12-2a, By applying a drive voltage to 12-2e and rotating the relative motion member 11-2, the traveling direction is changed near the position D.

When the application of the drive voltage to the piezoelectric elements 12-2b, 12-2c or the piezoelectric elements 12-2d, 12-2e is stopped when the orientation is changed by 90 degrees in the vicinity of the position D, the impact drive type actuator 10 -2, since the drive voltage is continuously applied to the piezoelectric element 12-2a,
Move from position D to position E. In this way,
For moving a plurality of installed piezoelectric elements (12-2a and 12-
2f), for direction change (12-2b, 12-2c, 12-
2d and 12-2e) makes it easy to control the application of the drive voltage to each piezoelectric element.

(Fourth Embodiment) FIG. 4 is a front view showing the structure of an impact drive type actuator of the fourth embodiment. In addition, in order to facilitate understanding also in FIG.
The control unit 13 and the drive voltage device 15 in FIG.

The relative movement member 11-3 is a hollow structure formed by fixing two hollow structure parts, and in this embodiment, the outer shape is a sphere. This relative movement member 11
-3 on the inner wall surface of the laminated piezoelectric elements 12-3a, 12-3b, 12-3c, 12-3 which are electromechanical conversion elements.
One ends of d, 12-3e and 12-3f are attached. Regarding the installation position, three virtual straight lines orthogonal to each other at the center of the relative motion member 11-3 are relative motion members 11-3.
6 points intersecting the inner surface of the relative movement member 11-3, and are positions that are point-symmetrical with respect to the above-mentioned center point on the plane including the center point of the relative motion member 11-3.

Six piezoelectric elements 12-3a, 12-3b,
The inertial bodies 14-3a, 14-3b, 1 are provided at one end of each of 12-3c, 12-3d, 12-3e and 12-3f.
4-3c, 14-3d, 14-3e and 14-3f are provided. Each device incorporated in the relative motion member 11-3 is incorporated before the above-mentioned two hollow structural parts are fixed. The impact drive type actuator 10-3 in the present embodiment is configured as described above.

In FIG. 4, when a driving voltage having a large voltage increase rate is applied to the piezoelectric element 12-3a from a driving voltage device (not shown) through a controller (not shown), the piezoelectric element 12-3a is excited and expands. The inertial body 14-3a provided on the piezoelectric element 12-3a moves to move the inertial body 14-3a.
-3a moves, the relative motion member 11-3 also moves. After that, since the drive voltage is reduced by a small voltage decrease rate, the relative motion member 11-3 stops, but the inertial body 1
4-3a is pulled by the piezoelectric element 12-3a and continues to move, which is the same state as when the inertial body 14-3a collides with the relative motion member 11-3.

Therefore, the relative motion member 11-3 is driven by the impact force generated by this collision. The impact drive type actuator 10-3 of this embodiment is
In addition to having all the functions of the conventional impact drive type actuator, the piezoelectric element 12-3a and the inertial body 14-
Since 3 and 3 are built in the relative motion member 11-3 having a hollow structure, there is no protrusion outside the relative motion member 11-3.
Therefore, miniaturization is achieved and the piezoelectric element 12-
It is not necessary to provide the mounting surface of 3a outside, and the degree of freedom of the outer shape is increased.

Further, the center of gravity of the relative motion member 11-3 and the center of gravity of the whole are closer than in the conventional case, and in the best case, they can be matched. Therefore, the relative motion member 11-
The moment acting on 3 decreases, and the relative motion member 11-
The contact state between 3 and the fixed body is more stable than before, and the error of the movement step amount per cycle is reduced. further,
Since the outer shape of the relative motion member 11-3 is a sphere, it is possible to move inside the tubular body having a circular cross section, for example.

FIG. 5 is an explanatory view schematically showing the situation when the impact drive type actuator 10-3 of the present embodiment moves inside a two-dimensionally bent pipe having a circular cross section. Although not shown, a sensor is installed on the inner wall surface of the pipe to detect the arrival of the impact drive type actuator 10-3. The impact drive type actuator 10-3 of the present embodiment is introduced into the interior from an inlet opening 18a of a tube 18 which is two-dimensionally bent and has a circular cross section.

In the embodiment shown in FIG. 5, the pipe 18 is made of a material having greater flexibility than the relative motion member 11-3, and the outer diameter of the relative motion member 11-3 is set to the inner diameter of the pipe 18. Set slightly larger than. The impact drive type actuator 10-3 is connected to the inlet opening 18a of the pipe 18.
When introduced from the inside to the position A, the side surface of the tube 18 extends along the outer surface of the relative motion member 11-3 due to the difference in flexibility. Due to this extension, a force for holding the relative motion member 11-3 from the pipe 18 acts, so that the relative motion member 1-3
1-3 are pressed against the inner surface of the tube 18. When the circular tube is bent two-dimensionally or three-dimensionally by setting the diameter of the relative motion member 11-3 so that this force becomes sufficiently larger than the gravity applied to the impact drive type actuator. However, it is possible to prevent the relative motion member 11-3 from falling inside the tube 18 due to the influence of gravity.

At position A, when a driving voltage having a large voltage increase rate is applied to the piezoelectric element 12-3a, the piezoelectric element 12-
3a abruptly expands, and if the force generated by this abrupt expansion is larger than the frictional force between the relative motion member 11-3 and the inner wall of the pipe 18, the relative motion member 11-3 will move to the left in the drawing. Make a small movement to. After that, the piezoelectric element 12-3a is gently contracted, and the driving voltage is gently decreased at a small voltage reduction rate so that the force generated by the displacement becomes smaller than the frictional force described above.

By continuously applying such a driving voltage, the relative movement member 11-3 moves from the position A to the position B. After the relative motion member 11-3 approaches the position B, the drive voltage applied to the piezoelectric element 12-3a is gradually decreased and the drive voltage applied to the piezoelectric element 12-3b is gradually increased.

At the position B, the values of the drive voltages applied to the piezoelectric elements 12-3a and 12-3b are the same. After this, further piezoelectric element 12-3a
By lowering the drive voltage applied to the piezoelectric element 12-3b and increasing the drive voltage applied to the piezoelectric element 12-3b, the relative motion member 1
1-3 moves from the position B to the position C, and when reaching the position C, the drive voltage is not applied to the piezoelectric element 12-3a and the drive voltage is applied only to the piezoelectric element 12-3b.

In this way, the impact drive type actuator 10-3 moves inside the pipe 18 from the position A to the position B.
And move toward position C. At the time of such movement, a voltage having a rapid voltage change rate is applied to the piezoelectric element 12-3a, and at the same time, the piezoelectric element 12-3c is applied to the piezoelectric element 12-3c.
When the piezoelectric element 12-3c is rapidly displaced by applying a drive voltage having an amplitude opposite to that of the drive voltage applied to 3a, a double force acts in the traveling direction, so that the relative motion member 11-3. The movement speed of can be increased.

Although FIG. 5 shows the movement inside the two-dimensionally bent pipe, the piezoelectric element 12-3e and the piezoelectric element 12-3f installed at a position opposite thereto are further provided.
It is also possible to move the inside of the three-dimensionally bent tube by applying a drive voltage in the same manner as above.

(Fifth Embodiment) FIG. 6 is a front view showing the structure of an impact drive type actuator of the fifth embodiment. In addition, in order to facilitate understanding also in FIG. 6, FIG.
The control unit 13 and the drive voltage device 15 in FIG.

FIG. 6 shows a case where the impact drive type actuator 10-4 is introduced into a tube 19 made of a material having small flexibility and being hard to be deformed.
The outer layer 20 made of a material having greater flexibility than the tube 19.
To coat. As shown in FIG. 6, the relative motion member 11
-4 is introduced into the pipe 19, the outer layer 20 of the relative motion member 11-4 is deformed, and the relative motion member 11 is removed from the pipe 19.
-4 makes it possible to press the relative motion member 11-4 against the inner wall of the tube 19. By setting the outer diameter of the impact drive type actuator 10-4 so that this pressure is sufficiently larger than the gravity applied to the impact drive type actuator 10-4,
The influence of gravity applied to the impact drive type actuator 10-4 can be ignored, and even if the pipe 19 is bent two-dimensionally or three-dimensionally, it moves inside the pipe 19 without falling. be able to.

(Modification) In the first to fifth embodiments described above, the piezoelectric element is used as the electromechanical conversion element. However, the electromechanical conversion element is not limited to this. For example, an electrostrictive element may be used. Can also be used. Also, the outer shape of the relative motion member has been described by taking the case of a rectangular parallelepiped shape, a cubic shape, or a spherical shape as an example, but the present invention is not limited to this and may be, for example, a spindle shape.

[0057]

As described in detail above, according to the first aspect of the invention, since the electromechanical conversion element and the inertial body are provided inside the relative movement member having the hollow structure, the outside of the relative movement member is provided. Since the protrusion is eliminated, the impact drive type actuator can be downsized, and the degree of freedom in setting the outer shape is increased. Further, since the electromechanical conversion element and the inertial body are incorporated, the center of gravity of the relative motion member can be closer to the overall center of gravity than in the past, and in the best case, the center of gravity of the relative motion member can be matched. The moment acting on is reduced, the contact state between the relative motion member and the fixed body is more stable than before, and the error in the movement step amount can be reduced more than ever.

According to the invention of claim 2, in the invention of claim 1, since the relative movement member has a built-in control section for receiving an external signal and controlling the voltage applied to the electromechanical conversion element, the relative movement member is externally controlled. The movement of the impact drive type actuator can be controlled.

According to the invention of claim 3, in the invention of claim 1 or claim 2, the outer shape of the relative movement member is a rectangular parallelepiped, and according to the invention of claim 4, claim 1 or In the invention of Item 2, since the relative movement member has a spherical outer shape, it can be introduced into a groove having a rectangular section or a tube having a circular section. For example, considering a paint hose of a painting apparatus as the pipe, by introducing the impact drive type actuator of claim 3 or 4 into the paint hose, it is possible to remove the dirt in the paint hose.

According to a fifth aspect of the invention, in the third or fourth aspect of the invention, the electromechanical conversion element is located at a position symmetrical with respect to the center point on the plane including the center point of the relative motion member. Since they are arranged respectively, the impact drive type actuator can move in at least two directions.

According to a sixth aspect of the invention, in the invention according to any one of the first to fifth aspects, the relative motion member is more flexible than the tubular body when the contact object is inside the tubular body. Since the outer layer having high elasticity is provided, the relative motion member is pressed against the inner wall of the tubular body so that the influence of gravity can be ignored, and can move inside the tubular body that bends in three dimensions.

[Brief description of drawings]

FIG. 1 is a front view showing the structure of an impact drive type actuator of a first embodiment.

FIG. 2 is an explanatory diagram schematically showing a situation when the impact drive type actuator of the second embodiment moves inside a groove having a square cross section that is bent like a crank.

FIG. 3 is an explanatory view schematically showing a situation when the impact drive type actuator of the third embodiment moves inside a crank-shaped groove having a square cross section.

FIG. 4 is a front view showing the structure of an impact drive type actuator according to a fourth embodiment.

FIG. 5 is an explanatory view schematically showing the situation when the impact drive type actuator of the fourth embodiment moves inside a two-dimensionally bent pipe having a circular cross section.

FIG. 6 is a front view showing the structure of an impact drive type actuator of a fifth embodiment.

FIG. 7 is a front view schematically showing a conventional impact drive type actuator.

[Explanation of symbols]

10, 10-1, 10-2, 10-3, 10-4 Impact drive type actuator 11, 11-1, 11-2, 11-3, 11-4 Relative movement member 12, 12-1a-12-1d , 12-2a to 12-2
f, 12-3a to 12-3f, 12-4a to 12-4f
Electromechanical conversion element (piezoelectric element) 13 Control unit 14, 14-1a to 14-1d, 14-2a to 14-2
f, 14-3a to 14-3f, 14-4a to 14-4f
Inertia 15 Drive voltage device 16 Fixed body 17 Groove 17a Upper opening 18 Tube 18a Upper opening 19 Tube 20 Outer layer

Claims (6)

[Claims] 1. A relative movement member having a hollow structure, an electromechanical conversion element having one end installed inside the relative movement member and excited by an applied voltage, and the other end of the electromechanical conversion element attached to the relative movement member. An impact drive type actuator, comprising: an inertial body that is provided inside a motion member and applies an impact force to the relative motion member by driving the electromechanical conversion element. 2. The impact drive type actuator according to claim 1, wherein the relative movement member includes a control unit that receives an external signal and controls a voltage applied to the electromechanical conversion element. Impact drive type actuator. 3. The impact drive type actuator according to claim 1 or 2, wherein the relative movement member has a rectangular parallelepiped outer shape. 4. The impact drive type actuator according to claim 1 or 2, wherein the relative movement member has a spherical outer shape. 5. The impact drive type actuator according to claim 3 or 4, wherein the electromechanical conversion element is a position that is point-symmetric with respect to the center point on a plane including the center point of the relative motion member. An impact drive type actuator, which is characterized in that the actuators are respectively arranged in the. 6. The impact drive type actuator according to any one of claims 1 to 5, wherein the relative movement member is more flexible than the tubular body when the contact target is inside the tubular body. An impact drive type actuator comprising an outer layer having high flexibility.