JPH0795781A - Ultrasonic actuator - Google Patents

Abstract

PURPOSE:To improve the efficiency of the output fetching mechanism of an ultrasonic actuator utilizing the flexural oscillation of a bar-shaped vibrating body. CONSTITUTION:Piezoelectric bodies are respectively stuck to the orthogonal two surfaces of a vibrating body 11 and fixed to the surfaces by means of vibrating body holding sections 13a and 13b. A traveling body 12 and traveling body fitting 17 are stuck to each other and a supporting shaft 16 is passed through the fitting 17 so that the fitting 17 can be moved in the direction of the shaft 16. Both ends of the shaft 16 are fixed to shaft supports 15a and 15b. When the supports 15a and 15b are elastically pressurized with, for example, springs, etc., the traveling body 12 is press-contacted with the center of one surface of the vibrating body 11. When an AC electric field is impressed upon the vibrating body 11 from electric field impressing wiring 14, rotary motions are generated on the surface of the vibrating body 11 due to the flexural oscillation of the vibrating body 11 and the traveling body 12 makes reciprocating motions in the direction perpendicular to the length direction of the vibrating body 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic actuator for driving a moving body arranged in pressure contact with a vibrating body composed of a piezoelectric body and an elastic body to excite elastic vibration. And the application of the ultrasonic actuator to a pyroelectric infrared sensor for detecting an object by detecting the infrared ray by making the infrared ray incident on the infrared detecting section.

[0002]

2. Description of the Related Art A conventional ultrasonic actuator and pyroelectric infrared sensor will be described below with reference to the drawings.

FIG. 11 shows a vibrating body of a conventional ultrasonic actuator, in which a rod-shaped vibrating body excites flexural vibration to generate a rotary motion on the surface of the vibrating body. The figure shows a quadrangular prism vibrating body, 111 is an elastic body such as metal, and 112a and 112b are piezoelectric bodies such as piezoelectric ceramics. The piezoelectric bodies 112a and 112b are polarized in the thickness direction and deform in the length direction when an electric field is applied.

The piezoelectric bodies 112a and 112b are shown in FIG.
As shown in (a), the vibrating body is formed by adhering to the two surfaces of the elastic body 111 so as to be arranged at right angles to each other. When an electric field is applied to the piezoelectric body 112a in a direction perpendicular to the elastic body surface, that is, in the same direction as the polarization, the piezoelectric body 112a deforms, and the elastic body 111 deforms accordingly, so that the entire vibrating body is deformed as shown in FIG. 11B. It will be in a bent state.

In FIG. 11B, the piezoelectric body 112a is bent in a contracting direction. However, by reversing the direction of the electric field applied to the piezoelectric body 112a, the vibrating body is bent in the extending direction of the piezoelectric body 112a. You can stumble. Piezoelectric body 11
The same phenomenon can be caused for 2b.

FIG. 11C is a view of the vibrating body as seen from its end face. Piezoelectric body 112 constituting this vibrating body
When an AC electric field having a phase difference of 90 degrees is applied to a and 112b, as shown in FIG. 10D, each surface of the vibrating body causes a rotational motion of a magnitude corresponding to the vibration amplitude of the vibrating body. . This rotational movement can change the rotational direction according to the phase difference of the alternating electric field applied to the piezoelectric bodies 112a and 112b. By setting the frequency of the AC electric field near the resonance frequency of the vibrating body, it is possible to increase the amplitude of the flexural vibration and efficiently generate the vibration. This rotary motion is used to drive as an ultrasonic actuator.

FIG. 12 is a perspective view showing a conventional example of an ultrasonic actuator using the vibrator of FIG. In the figure, 121 is a vibrating body, 122 is a moving body, 123a, 1
23b is a vibrating body holding part, 124 is a moving body supporting part, 125
Is a wiring for applying an electric field (lead wire).

The vibrating body 121 is constructed by bonding a piezoelectric body for vibration excitation to the side surface and the lower surface of the elastic body. A moving body 122 is supported on the upper surface of the vibrating body 121 by a moving body supporting portion 124, and is arranged in pressure contact with the vibrating body 121. The moving body 122 is supported by the moving body supporting portion 124 so as to be movable only in a direction orthogonal to the longitudinal direction of the vibrating body 121. The vibrating body 121 is fixed by vibrating body holding portions 123a and 123b.

An electric field applying wiring 125 is attached to the elastic body and the piezoelectric body of the vibrating body 121, and by applying an electric field to the vibrating body 121, flexural vibration is generated in the vibrating body 121, and the vibrating body 121 rotates. The moving body 122 is reciprocated in the moving direction indicated by the arrow in the figure by this rotational movement.

Further, in recent years, the pyroelectric infrared sensor has been used in a wide range of fields such as temperature measurement of cooked food in a microwave oven and position detection of a human body in an air conditioner, and it is expected that demand will greatly increase in the future.

The pyroelectric infrared sensor utilizes the pyroelectric effect of a pyroelectric material such as a LiTaO ₃ single crystal. Pyroelectric materials have spontaneous polarization, and surface charges are always generated, but in the normal state in the atmosphere, they are electrically neutral because they are associated with the charges in the atmosphere. When infrared rays are incident on this, the temperature of the pyroelectric body changes, and along with this, the charge state of the surface also changes, breaking the neutral state.

At this time, the pyroelectric infrared sensor detects the electric charge generated on the surface and measures the amount of incident infrared rays. The object emits infrared rays according to its temperature, and the position and temperature of the object can be detected by using this sensor.

The pyroelectric effect is caused by a change in the incident amount of infrared rays, and it is necessary to change the incident amount of infrared rays when the temperature of an object is detected by a pyroelectric infrared sensor.
A chopper is used as this means and detects the temperature of the detection object by forcibly interrupting the incident infrared rays.

A conventional example of the pyroelectric sensor will be described with reference to FIGS. FIG. 13 is a conventional example of a pyroelectric infrared sensor using an electromagnetic motor type chopper. 131
Is an infrared detecting element, 132 is infrared, 133 is an electromagnetic motor, 134 is a chopper position detector, and 135 is a rotating body.

A rotating body 135 having a cutout portion is attached to the rotating shaft of the electromagnetic motor 133, and when the electromagnetic motor 133 rotates, the infrared ray 132 entering the infrared detecting element 131 is intermittently connected with the rotating body 135. As the prior art, for example, Japanese Patent Laid-Open No. 3-23
There is one described in Japanese Patent No. 1125.

FIG. 14 shows a conventional example of a pyroelectric infrared sensor using a piezoelectric bimorph type chopper. 141 is an infrared detecting element, 142 is infrared, 143 is a substrate, 144
Is a bimorph and 145 is a shielding plate.

The bimorph 144 has one end fixed to the substrate 143 and the other end to which a shielding plate 145 is attached. When an AC signal is applied to the bimorph 144, one end to which the shield plate 145 is attached vibrates in a fixed direction, which vibrates the shield plate 145 and makes the infrared ray 142 incident on the infrared detection element 141.
Japanese Patent Application Laid-Open No. 1-21 as a prior art.
There is one described in Japanese Patent No. 9712.

[0018]

However, in the ultrasonic actuator of the conventional example, the frictional load due to the supporting portion of the moving body is large, and the driving force of the vibrating body is consumed due to the frictional load, so that a sufficient moving distance is achieved. There was a problem that it was not possible to obtain a smooth movement of the moving body.

Further, it is difficult for the conventional moving body supporting portion to accurately maintain the position and posture of the moving body, and therefore, the pressurization becomes unstable, and the driving force of the vibrating body cannot be efficiently transmitted to the moving body. There was also a problem.

Further, in the conventional pyroelectric infrared sensor, when an electromagnetic motor is used, the structure of the electromagnetic motor itself is large, so that the structure of the chopper portion is large, and it is necessary to secure a moving space for the entire rotating body. Therefore, it has been an obstacle to downsizing of the entire pyroelectric infrared sensor.

When a bimorph is used, in order to secure a sufficient vibration amplitude of the bimorph, it is necessary to increase the length of the bimorph in the longitudinal direction to expand the vibration amplitude. It had a problem that it became large.

The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide a highly efficient ultrasonic actuator capable of improving the output take-out mechanism of the ultrasonic actuator and ensuring a sufficient movement distance. A further object of the present invention is to provide a pyroelectric infrared sensor that is small in size and has improved sensitivity by using the ultrasonic actuator as a chopper.

[0023]

To achieve the above object, a contact area is reduced or rolling contact is used in order to reduce a frictional load between a moving body and a moving body supporting portion. Further, the moving body is supported by an elastic body having a low elastic modulus, a member having a rotating node, and a plurality of vibrating bodies. Furthermore, we will reduce the friction load by improving the shape of the moving body, and stabilize the pressurization by selecting the pressurizing location and improving the mechanism, reduce the size of the mechanism, and reduce the friction load by supporting. Further, by utilizing the above ultrasonic actuator as a chopper of a pyroelectric infrared sensor, a compact pyroelectric infrared sensor with improved sensitivity is realized.

[0024]

With the above means, the influence of the frictional load due to the support and pressurization of the moving body is reduced, the position / posture of the moving body is stabilized, and the stable pressurization is performed. Is efficiently transmitted to a moving body, the moving distance of the moving body is increased, and a stable ultrasonic actuator with improved drive efficiency is realized.

Further, by using an ultrasonic actuator for the pyroelectric infrared sensor, it is possible to realize the miniaturization of the chopper portion which is very large in volume, and the miniaturization of the pyroelectric infrared sensor itself is realized. In addition, the high-speed response characteristics of the ultrasonic actuator are utilized to realize high-speed and efficient opening / closing of the shield plate.

[0026]

(Embodiment 1) Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view of an ultrasonic actuator when sliding contact is used as a support mechanism for a moving body according to a first embodiment of the present invention.

In the figure, 11 is a vibrating body, 12 is a moving body, 13a and 13b are vibrating body holding portions, 14 is a wire for applying an electric field, 15a and 15b are shaft supports, 16 is a moving body support shaft, 17 Is a mobile attachment.

The vibrating body 11 is a square rod having a square cross section, and a piezoelectric body is adhered to two surfaces which are orthogonal to each other, and an electric field applying wiring 14 is attached thereto. And the vibrating body 11
Are held by the vibrating body holding portions 13a and 13b so as not to hinder vibration.

The movable body 12 and the movable body mounting member 17 are adhered to each other, the movable body mounting member 17 has a concave shape, through holes are formed on two facing surfaces, and the movable body supporting shaft 16 is inserted into this hole. It The moving body 12 and the moving body mounting tool 17 are supported so as to be movable as a unit in the direction of the moving body supporting shaft 16.

Both ends of the movable body supporting shaft 16 are shaft supporting members 15
They are fixed by a and 15b, and are arranged orthogonal to the longitudinal direction of the vibrating body 11. Moving body 12
Contact with each other at the center of one surface of the vibrating body 11, and although not shown here, the vibrating body 11 is pressed by the elastic force of a spring or the like at the shaft supporters 15a and 15b.
The moving body 12 is uniformly pressed.

When an AC electric field is applied to the vibrating body 11 by the electric field applying wiring 14, a flexural vibration of the vibrating body 11 causes a rotational motion to appear on the surface of the vibrating body 11, and the rotational motion drives the moving body 12 to vibrate. It moves in a direction orthogonal to the longitudinal direction of the body 11. The moving body mounting member 17 is made of a thin plate to reduce the contact area with the moving body supporting shaft 16,
Care is taken to reduce friction by applying lubricating oil.
Of course, friction can be further reduced by interposing a bearing between the moving body mounting member 17 and the moving body supporting shaft 16.

In this embodiment, pressure is applied between the vibrating body and the moving body via the moving body supporting portion, but the moving body supporting portion is fixed and the above-mentioned pressure is applied via the vibrating body. Needless to say, it does not matter.

(Embodiment 2) FIG. 2 is a perspective view of an ultrasonic actuator according to a second embodiment of the present invention, in which rolling contact is used as a moving body supporting and pressing mechanism. .

In FIG. 2, 21 is a vibrating body, 22 is a moving body, 23a and 23b are vibrating body holding portions, 24 is an electric field applying wiring, 25 is a pressing and supporting roller, and 26a and 26b.
Is a roller fixing tool, 27 is a roller shaft, 28 is a roller supporting tool, and 29 is a moving body supporting tool.

The vibrating body 21 is a square rod having a square cross section, and piezoelectric bodies are bonded to two surfaces orthogonal to each other, and electric field applying wirings 24 are attached to the vibrating body 21. The vibrating body 21 is held by the vibrating body holding portions 23a and 23b so as not to hinder vibration. The moving body 22 has a thin plate shape, and as an example of the material, a material having high hardness and a high friction coefficient, which contains carbon fiber in PPS, is used.

The moving body 22 is arranged in surface contact with the flat surface of the vibrating body 21. The vibrating body 21 and the moving body 22 are pressed against each other, and the supporting roller 25 of the moving body 22 is placed in contact with the moving body 22. To do. The pressurizing and supporting roller 25 rotates about a roller shaft 27, and roller fixing tools 26a and 26b.
Positioned by One end of the roller support shaft 28 is fixed to the roller support tool 28, and pressure is applied between the vibrating body 21 and the moving body 22 via the roller support shaft 28. That is, eventually, the moving body 22 is pressed by the vibrating body 21 by the roller 25. In addition, the moving body 22 is the moving body support 2
The position of the movable body 22 is regulated by 9, and the movable body 22 is supported so as to be movable only in a direction orthogonal to the longitudinal direction of the vibrating body 21.

When an AC electric field is applied to the vibrating body 21 by the electric field applying wiring 24, the flexural vibration of the vibrating body 21 causes a rotational movement to appear on the surface of the vibrating body 21. Vibrator 2 indicated by an arrow inside
It reciprocates in the direction orthogonal to 1.

In this structure, the pressure is applied between the vibrating body and the moving body through rolling friction, and the moving body has a thin plate shape. Since the regulation is performed, the frictional load on the portion where the moving body is in contact with other members is small, and the driving force due to the vibration of the vibrating body can be effectively transmitted to the moving body.

Further, since pressure can be applied right above the contact portion between the vibrating body and the moving body, stable and uniform pressure can be applied, and the driving force from the vibrating body can be effectively taken out. If a ball bearing is used for the roller, the friction load can be further reduced and the movement of the moving body can be improved.

(Third Embodiment) FIG. 3 is a perspective view of an ultrasonic actuator showing a third embodiment of the present invention in which a movable body is supported by an elastic member.

In FIG. 3, 31 is a vibrating body, 32 is a moving body, 33 is a vibrating body holding portion, 34 is electric field applying wiring, and 35 is
Reference numerals a and 35b are movable body support springs, and 36 is a spring support tool.

The vibrating body 31 is a square bar having a square cross section, and piezoelectric bodies are bonded to two surfaces which are orthogonal to each other, and electric field applying wires 34 are attached. The vibrating body 31 is held by the vibrating body holding portion 33.

The moving body 32 is adhered and held by moving body supporting springs 35a and 35b having a thin plate shape, and one end of each of the moving body supporting springs 35a and 35b is fixed to a spring support 36.

Pressurization of the vibrating body 31 and the moving body 32 is performed via a spring support 36 although not shown here. In this embodiment, the moving body 32 can move in a direction orthogonal to the vibrating body 31 with a path that is almost a straight line as shown by an arrow in the figure.

When an AC electric field is applied to the vibrating body 31 by the electric field applying wiring 34, the flexural vibration of the vibrating body 31 causes a rotational motion to appear on the surface of the vibrating body 31, and the rotary motion causes the moving body 32 to move to the vibrating body 31. Driven in the direction orthogonal to the longitudinal direction, the movable body support springs 35a and 35b elastically deform. The moving direction of the moving body 32 can be changed by changing the phase of the applied voltage.

With this structure, it is possible to easily realize the positioning of the movable body, the stable pressurization, and the support in which the posture is kept constant. In this embodiment, the support by the elastic member uses the cantilever support by the thin plate spring, but the support by the both ends enables more stable support of the moving body. Further, by arranging the coil spring so as to expand and contract in the moving direction of the moving body and supporting the moving body, it is possible to realize driving on a moving path that is closer to a straight line.

(Embodiment 4) FIG. 4 is a perspective view of an ultrasonic actuator according to a fourth embodiment of the present invention, in which a movable body is supported by a member having a rotary node.

In FIG. 4, 41 is a vibrating body, 42 is a moving body, 43a and 43b are vibrating body holding portions, 44 is an electric field applying wiring, 45a and 45b are moving body supporting link mechanisms, and 46 is a moving body supporting link mechanism.
Reference numerals a and 46b are movable body support tools. The vibrating body 41 has a shape of a regular square pole, a piezoelectric body is bonded to two surfaces orthogonal to each other, and an electric field applying wiring 44 is attached. The vibrating body 41 is held by the vibrating body holding portions 43a and 43b.

The moving body 42 has a rectangular parallelepiped shape and has rotary nodes on two parallel surfaces thereof, and the moving body supporting link mechanism 4 is provided.
5a and 45b have four rod-shaped members and four rotation treatment nodes, and have a quadrilateral configuration.

The rotary joint portion of the moving body 42 and one rotary joint of each of the moving body supporting link mechanisms 45a and 45b are mounted so as to be reciprocally rotatable only in one direction.

Further, the movable body supporters 46a and 46b also have rotary joints, and the joints of the movable body supporting link mechanisms 45a and 45b to which the movable body 4 is attached and the non-adjacent rotary joints are arranged in one direction. It is attached so that it can rotate back and forth only.

With the above structure, the movable body 42 can be freely moved only within one plane, and the movable body supports 46a,
Positioning of the moving body 4 and contact pressure with the vibrating body 41 are performed via 6b.

Therefore, the moving body 42 can stably move on the vibrating body 41, and when an AC electric field is applied to the vibrating body 41 by the electric field applying wiring 44, the flexural vibration of the vibrating body 41 causes the vibrating body 41 to move to the surface of the vibrating body 41. Rotational motion appears, and by receiving the force of this rotational motion, the moving body supporting link mechanisms 45a, 4
5b, the moving body 42, and the rotary nodes of the moving body supporting members 46a and 46b rotate, and the moving body 42 reciprocates in the directions shown in the drawing.

In the above structure, since the movement of the moving body is performed by the rotation of the rotary node, the frictional load can be made extremely small, and the load due to inertia can be reduced by making the member of the moving body supporting link mechanism extremely fine. Furthermore, since the moving body can move freely within the movable plane, the moving direction of the moving body can be easily changed by providing an appropriate guide.

By supporting the moving body in the longitudinal direction of the vibrating body with rod-shaped members having rotary nodes at both ends, it is possible to easily realize the reciprocating motion of the moving body along a path close to a straight line. In this way, by changing the shape and the number of members of the mechanism used to support the moving body, it is possible to easily realize a wide variety of low-load supporting structures.

(Fifth Embodiment) FIG. 5 is a perspective view of an ultrasonic actuator according to a fifth embodiment of the present invention, in which a thread-like member is used to support a moving body.

In FIG. 5, reference numeral 51 is a vibrating body, 52 is a moving body, 53a and 53b are vibrating body holding portions, 54 is an electric field applying wire, 55a and 55b are moving body supporting rollers, and 56 is a moving body supporting thread. It is a member. The vibrating body 51 has a shape of a regular square pole, a piezoelectric body is adhered to two surfaces orthogonal to each other, and an electric field applying wiring 54 is attached. The vibrating body 51 is held by the vibrating body holding portions 53a and 53b.

The moving body supporting thread members 56 are attached to the two opposing surfaces of the moving body 52 at both ends, and the moving body 52 is crossed to form a loop. The movable body supporting rollers 55a and 55b are arranged in this loop, and the vibrating body 51 is positioned in the loop.

The moving body 52 is brought into pressure contact with one plane of the vibrating body 51 through the tension of the moving body supporting thread member 56 generated by the movement of the moving body supporting rollers 55a and 55b,
When an AC electric field is applied to the vibrating body 51 by the electric field applying wiring 54, a rotational motion appears on the surface of the vibrating body 51 due to the flexural vibration of the vibrating body 51, and the driving force due to this rotational movement causes the moving body supporting thread member 56 to move. The supported moving body 52 moves.

In the above structure, since the moving body is supported by the filamentous member and the roller, the inertial load and the frictional load can be greatly reduced. Furthermore, since it is a thread-like member, it can be supported in a small space. Needless to say, when the number of thread-like members is increased or a band-like member is used instead of the thread-like members, it is possible to more stably support the moving body while maintaining the above effect.

(Embodiment 6) FIG. 6 is a perspective view of an ultrasonic actuator according to a sixth embodiment of the present invention in which magnetic force is used as a pressurizing means between a vibrating body and a moving body. is there.

In FIG. 6, 61 is a vibrating body, and 62a and 6a.
2b is a moving body, 63a and 63b are vibrating body holding portions, 64 is an electric field applying wire, 65 is a pressing magnet, 66 is a magnetic plate,
Reference numeral 67 is a moving body supporting shaft, and 68a and 68b are moving body supporting tools. The vibrating body 61 has a regular quadrangular prism shape, a piezoelectric body is adhered to two surfaces orthogonal to each other, and an electric field applying wiring 64 is attached. The vibrating body 61 includes vibrating body holding portions 63a, 6a.
It is held by 3b.

The pressurizing magnet 65 is sandwiched between the moving bodies 62a and 62b and fixed by adhesion, and a through hole is provided in the moving body 62b, and the moving body support shaft 67 is inserted into this through hole to guide the guide shaft. Play a role. Both ends of the moving body support shaft 67 are fixed by moving body support tools 68a and 68b.

When one surface of the moving body 62a is brought into contact with one surface of the vibrating body 61, and a magnetic plate 66 is fixedly arranged on the opposite surface side of the vibrating body 61 so as not to touch the vibrating body 61, the pressure is applied. The magnet 65 and the magnetic plate 66 are attracted to each other, and pressure is applied to the contact surface between the vibrating body 61 and the moving body 62a.

When an AC electric field is applied to the vibrating body 61 by the electric field applying wiring 64, a rotational movement appears due to the flexural vibration of the vibrating body 61, and the moving body 62 is orthogonal to the longitudinal direction of the vibrating body 61 shown by the arrow in the figure. Move in the direction. Magnetic plate 66
Is more stable than the moving range of the moving body.

With the above structure, a mechanical structure for pressurization is not required, the entire structure is simplified, the influence of the tilt in the pressurizing direction is reduced, and the force applied between the vibrating body and the moving body is reduced. The pressure can be made more stable and uniform. Further, since there is no contact point between the pressure mechanism and the moving body, the influence of the friction load can be greatly reduced.

From the point of view of using electromagnetic force, it is conceivable that a magnetic plate is placed inside the moving body and a pressurizing magnet is placed on the lower surface of the vibrating body. Needless to say, the above effect does not change even when the vibrating body itself is made of a magnetic material or an electromagnetic force is used.

(Embodiment 7) FIG. 7 is a perspective view of an ultrasonic actuator showing a seventh embodiment of the present invention in which a pressure mechanism between a vibrating body and a moving body is provided inside the moving body. It is a figure.

In FIG. 7, reference numeral 71 is a vibrating body, and 72a and 7a.
2b is a moving body, 73a and 73b are vibrating body holding portions, 74 is an electric field applying wire, 75 is a pressing mechanism pin, 76 is a pressing spring, 77a and 77b are moving body support tools, and 78 is a moving body support shaft. Is.

The vibrating body 71 has a shape of a regular quadrangular prism, and a piezoelectric body is adhered to two surfaces which are orthogonal to each other.
Is attached. The vibrating body 71 is a vibrating body holding portion 73.
It is held by a and 73b. The moving body 72b has a concave shape, a through hole is provided on the opposite surface, the moving body support shaft 78 is inserted, and a hole for inserting the pressing mechanism pin 75 is provided on the other surface. .

The pressing mechanism pin 75 is inserted into the moving body 72b, the pressing spring 76 is passed through the pressing mechanism pin 75, and then the pressing mechanism pin 75 and the moving body 72a are fixedly attached. Both ends of the movable body support shaft 78 are movable body support tools 77.
They are fixed by a and 77b, and are arranged in a method orthogonal to the longitudinal direction of the vibrating body 71.

In the above structure, the moving body 72a and the vibrating body 7
The movable body supporting members 77a, 7
When 7b is moved toward the vibrating body 71, the distance between the moving bodies 72a and 72b is decreased, and the reaction force of the pressing spring 76 presses the vibrating body 71 and the moving body 72a. When an AC electric field is applied to the vibrating body 71 by the electric field applying wiring 74, a rotational motion appears on the surface of the vibrating body 71 due to the flexural vibration of the vibrating body 71, and the moving bodies 72a and 72b are the vibrating body 71 indicated by the arrows in the figure. Moves in a direction orthogonal to the longitudinal direction of the.

With this structure, by applying pressure in the vicinity of the contact point between the vibrating body and the moving body, stable and uniform pressure can be applied to the contact surface with little inclination in the pressing direction, and the entire mechanism can be pressed. Can be miniaturized.

(Embodiment 8) FIG. 8 is a perspective view of an ultrasonic actuator according to an eighth embodiment of the present invention, in which a plurality of vibrators are provided.

In FIG. 8, 81a and 81b are vibrating bodies,
Reference numeral 82 is a moving body, 83a, 83b, 83c and 83d are vibrating body holding portions, and 84 is an electric field applying wiring. Vibrating body 81
Reference numerals a and 81b each have a square prism shape, and piezoelectric bodies are bonded to two surfaces that are orthogonal to each other and do not contact the moving body 82, and electric field applying wiring 84 is attached. The vibrating bodies 81a and 81b are respectively vibrating body holding portions 83a and 83b.
And 83c and 83d.

The moving body 82 is in the shape of a thin plate, and is sandwiched by the two parallel surfaces facing each other by the vibrating bodies 81a and 81b and is in contact therewith. The pressing force at the contact surface with the moving body 82 changes according to the magnitude of the force sandwiched between the vibrating bodies 81a and 81b.

The vibrating bodies 81a and 81b are arranged so that their longitudinal directions are parallel to each other, and the moving body 82 is movable only in a direction orthogonal to the longitudinal directions of the vibrating bodies 81a and 81b by a suitable supporting member. Supported by.

The vibrating body 81a is connected to the electric field applying wiring 84.
When an AC electric field is applied to 81b, the vibrators 81a and 81b
Rotational motion appears on each surface due to the flexural vibration of the moving body 82, and the moving body 82 moves to the vibrating bodies 81a and 8a indicated by arrows in the figure.
It moves in a direction orthogonal to the longitudinal direction of 1b. At this time, it is necessary that the rotational movement directions of the vibrating bodies 81a and 81b are always opposite to each other, that is, the moving direction of the moving body 82 is always matched.

With the above structure, a larger driving force can be obtained by using a plurality of vibrating bodies, and if the moving body is supported by sandwiching the moving body with a plurality of vibrating bodies, the friction load due to the supporting of the moving body is greatly increased. Besides being reduced, direct and stable pressurization can be performed between the vibrating body and the moving body at a plurality of locations, and the drive characteristics of the ultrasonic actuator are improved.

A method of using a plurality of vibrating bodies other than this embodiment is conceivable. For example, a plurality of vibrating bodies are arranged in parallel and brought into contact with one surface of the moving body to reduce the thickness of the mechanism and reduce the moving body. It is also possible to stabilize the support and increase the torque, and the advantage of using a plurality of vibrators is great.

(Embodiment 9) FIG. 9 shows a case where the above-mentioned ultrasonic actuator is used as a chopper of a pyroelectric infrared sensor in the ninth embodiment of the present invention and rolling contact is used for supporting a moving body. It is a perspective view shown.

In FIG. 9, 91 is a vibrating body, 92 is a moving body, 93a and 93b are vibrating body holding portions, 94 is an electric field applying wire, 95 is a pressing and supporting roller, and 96a and 96b.
Is a roller fixing tool, 97 is a roller shaft, 98 is a roller supporting tool, 99 is a moving pair supporting tool, 100 is an infrared detecting element, and 101 is infrared.

The vibrating body 91 has a shape of a regular square pole, and a piezoelectric body is adhered to two surfaces orthogonal to each other.
Is attached. The moving body 92 is arranged in surface contact with the plane portion of the vibrating body 91, and a pressing and supporting roller is arranged directly above the vibrating body 91 and the moving body 92 in contact with the moving body 92.

The pressing and supporting roller 95 rotates about the roller shaft 97 and is positioned by the roller fixtures 96a and 96b. One end of the roller support shaft 97 is fixed to the roller support tool 98, and the contact surface between the vibrating body 91 and the moving body 92 is pressed by the vertical movement of the roller support shaft 98.

The position of the moving body 92 is regulated by the moving body supporting member 98, and the moving body 92 is supported so as to be movable only in the direction orthogonal to the longitudinal direction of the vibrating body 91.

When an electric field is applied to the vibrating body 91 by the electric field applying wiring 94 while reversing the positive and negative polarities, a rotational motion appears on the surface of the vibrating body 91 due to the flexural vibration of the vibrating body 91, and the moving body 92 moves in the longitudinal direction of the vibrating body 91. Reciprocates in the direction orthogonal to the direction. The moving body 92 is provided with a slit, and the infrared detecting element 100 is arranged in the vicinity of this slit.
Infrared ray 101 is infrared ray detecting element 1 due to the reciprocating movement of 2.
It is intermittently incident on 00.

Since the ultrasonic actuator has a large torque per volume, the chopper can be downsized, and the high-speed response characteristics of the ultrasonic actuator can be used to open and close the chopper at a high speed to improve the sensitivity as a sensor. Since the holding torque at the time of stop is large, no electric power is required during this period, which leads to a reduction in electric power.

An increase in temperature change of the infrared detecting element will be described with reference to FIG. FIG. 10A is a characteristic diagram showing the energy received by the infrared detecting element from the outside when the chopper is opened and closed and the temperature change of the infrared detecting element at that time when the conventional chopper is used.

FIG. 10 (b) is a characteristic diagram similar to FIG. 10 (a) when an ultrasonic actuator is used as a chopper.

In the conventional chopper, the infrared rays incident on the infrared detecting element are partially blocked by the shield plate during the time from the completely closed state to the fully opened state of the shield plate and from the completely opened state to the completely closed state. During that time, the energy received from the outside by the infrared detecting element becomes lower than that in the completely opened state, and the energy applied to the infrared detecting element as a whole is in a sinusoidal state as shown in the upper diagram of FIG. 10 (a). Becomes The temperature change of the infrared detecting element depends on the integral form of the energy applied to the infrared detecting element.
The temperature rise at each opening / closing of the shield plate becomes Ta.

When the ultrasonic actuator is used for the chopper, the ultrasonic actuator has a high-speed response characteristic, so that the time required to open and close the shield plate is shortened compared to the conventional case, and the energy received by the infrared detecting element is reduced. Figure 10
(B) As shown in the above figure, it has a rectangular wave shape. Therefore, the integrated value of the energy applied to the infrared detecting element is larger than that of the conventional chopper, and the temperature change is also large.

That is, the temperature change Tb when the ultrasonic actuator is used as the chopper in the lower part of FIG. 10B is larger than the temperature change Ta in the conventional chopper. Since the pyroelectric effect in the infrared detection element depends on the temperature change, the chopper using the ultrasonic actuator capable of increasing the temperature change is more advantageous than the conventional chopper.

Although the ultrasonic actuator of this embodiment supports the moving body by rolling contact, it goes without saying that any of the other embodiments described above can be used. Further, it is also possible to use the output extracting mechanism in combination.

[0094]

As described above, according to the present invention, in the ultrasonic actuator using the flexural vibration of the vibrating body, the frictional load or the inertial load due to the supporting mechanism or the pressurizing mechanism of the moving body can be eliminated by the guide shaft or the slippery surface. It can be reduced by rolling contact, use of a filamentous support member, thinning of the moving body, etc., and the driving force due to the vibration of the vibrating body can be efficiently transmitted to the moving body. Further, by using a plurality of vibrating bodies, not only a larger driving force can be obtained as an ultrasonic actuator, but also it is possible to support a frictional load against the movement of a moving body with an extremely small amount, and ultrasonic waves with better characteristics can be supported. The actuator can be easily realized.

Further, according to the present invention, the ultrasonic actuator having a large output per unit volume is used as the driving force source of the chopper of the pyroelectric infrared sensor, so that the chopper portion can be downsized and the pyroelectric sensor itself can be downsized. Contribute to. Further, since the holding torque is maintained even when the power is not supplied, lower power consumption is possible, and a large amount of current is not required, so that it is possible to realize a chopper that is indispensable to heat generation and is indispensable as a temperature sensor. Further, since the ultrasonic actuator has a high torque, it has a high-speed response, and since the amount of infrared rays incident upon opening / closing the shield plate can be increased, the sensitivity as a sensor can be improved. Further, when the linear ultrasonic actuator is used as the drive source of the chopper, the movement form of the shield plate is planar and can be configured with the same size as the size of the element, so that not only the structure can be simplified but also the movement space is reduced. It can be made extremely small including.

[Brief description of drawings]

FIG. 1 is a perspective view showing the configuration of a first embodiment of the present invention.

FIG. 2 is a perspective view showing a configuration of a second embodiment of the present invention.

FIG. 3 is a perspective view showing a configuration of a third embodiment of the present invention.

FIG. 4 is a perspective view showing the configuration of a fourth embodiment of the present invention.

FIG. 5 is a perspective view showing a configuration of a fifth embodiment of the present invention.

FIG. 6 is a perspective view showing a configuration of a sixth embodiment of the present invention.

FIG. 7 is a perspective view showing the configuration of a seventh embodiment of the present invention.

FIG. 8 is a perspective view showing the configuration of an eighth embodiment of the present invention.

FIG. 9 is a perspective view showing a configuration of a ninth embodiment of the present invention.

FIG. 10 is a characteristic comparison diagram when the ultrasonic actuator of the present invention is applied to a pyroelectric infrared sensor.

FIG. 11 is an operation explanatory view of a conventional ultrasonic actuator.

FIG. 12 is a perspective view showing a configuration of a conventional ultrasonic actuator.

FIG. 13 is a perspective view showing the configuration of a conventional pyroelectric infrared sensor.

FIG. 14 is a perspective view showing the configuration of another conventional pyroelectric infrared sensor.

[Explanation of symbols]

11, 21, 31, 41, 51, 61 Vibrating body 71, 81a, 81b, 91, 121 Vibrating body 12, 22, 32, 42, 52, 62a Moving body 62b, 72a, 72b, 82, 92, 122 Moving Body 111 Elastic body 112a, 112b Piezoelectric body 100, 131, 141 Infrared detecting element

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Osamu Kawasaki 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (11)

[Claims] 1. An ultrasonic actuator for driving a moving body, which is placed in pressure contact with the vibrating body by exciting elastic vibration in a vibrating body composed of a piezoelectric body and an elastic body, wherein the vibrating body is An ultrasonic wave, which is a rod-shaped vibrating body, in which elastic vibration of flexural vibration is excited in the vibrating body, and the moving body is supported by sliding contact by contact with a guide shaft or a guide surface. Actuator. 2. An ultrasonic actuator for driving a moving body arranged in pressure contact with the vibrating body by exciting elastic vibration in the vibrating body composed of a piezoelectric body and an elastic body, wherein the vibrating body is It is a rod-shaped vibrating body, the elastic vibration of the flexural vibration is excited in the vibrating body, on the contact surface of the moving body and the moving body supporting portion, through the roller-shaped and spherical members,
An ultrasonic actuator, wherein a moving body is supported by rolling contact. 3. An ultrasonic actuator for driving a moving body arranged in pressure contact with the vibrating body by exciting elastic vibration in the vibrating body composed of a piezoelectric body and an elastic body, wherein the vibrating body is It is a rod-shaped vibrating body, the elastic vibration of flexural vibration is excited in the percussion vibrating body, the movable body is supported by being fixed to an elastic member, and by the driving force transmitted from the vibrating body to the movable body, An ultrasonic actuator, wherein a moving body moves due to deformation of an elastic member. 4. An ultrasonic actuator for driving a moving body arranged in pressure contact with the vibrating body by exciting elastic vibration in the vibrating body composed of a piezoelectric body and an elastic body, wherein the vibrating body is It is a rod-shaped vibrating body, the elastic vibration of flexural vibration is excited in the vibrating body, and one or both of the moving body and the moving body supporting member has a rotary node, and through the rotating action of the rotary node. An ultrasonic actuator characterized by moving a moving body. 5. An ultrasonic actuator for driving a moving body arranged in pressure contact with the vibrating body by exciting elastic vibration in the vibrating body composed of a piezoelectric body and an elastic body, wherein the vibrating body is A rod-shaped vibrating body, wherein the vibrating body is excited by elastic vibration of flexural vibration, and a thread-shaped or strip-shaped member is used as the moving body supporting member.
Ultrasonic actuator. 6. An ultrasonic actuator for driving a moving body, which is arranged in pressure contact with the vibrating body by exciting elastic vibration in a vibrating body composed of a piezoelectric body and an elastic body, wherein the vibrating body is An ultrasonic actuator, which is a rod-shaped vibrating body, wherein elastic vibration of flexural vibration is excited in the vibrating body, and pressure is applied between the vibrating body and the moving body using magnetic force. 7. An ultrasonic actuator for driving a moving body, which is disposed in pressure contact with the vibrating body by exciting elastic vibration in a vibrating body composed of a piezoelectric body and an elastic body, wherein the vibrating body is 2. A rod-shaped vibrating body, wherein the vibrating body is provided with a member and a mechanism that excites elastic vibration of flexural vibration and pressurizes between the vibrating body and the moving body inside the moving body. The ultrasonic actuator described. 8. An ultrasonic actuator for driving a moving body, which is arranged in pressure contact with the vibrating body by exciting elastic vibration in a vibrating body composed of a piezoelectric body and an elastic body, wherein the vibrating body is It is a rod-shaped vibrating body, and elastic vibration of flexural vibration is excited in the vibrating body, and the moving body is supported by the plurality of vibrating bodies and pressure is applied between the vibrating body. , Ultrasonic actuator. 9. An ultrasonic actuator for driving a moving body, which is arranged in pressure contact with the vibrating body by exciting elastic vibration in a vibrating body composed of a piezoelectric body and an elastic body, wherein the vibrating body is It is a rod-shaped vibrating body, and elastic vibration of flexural vibration is excited in the vibrating body, and pressurization between the vibrating body and the moving body is performed in the vicinity of a contact portion between the vibrating body and the vibrating body. An ultrasonic actuator characterized by: 10. An ultrasonic actuator for driving a moving body arranged in pressure contact with the vibrating body by exciting elastic vibration in the vibrating body composed of a piezoelectric body and an elastic body, wherein the vibrating body is An ultrasonic actuator, which is a rod-shaped vibrating body, in which elastic vibration of flexural vibration is vibrated in the vibrating body, and the moving body has a thin plate shape. 11. The ultrasonic actuator according to claim 1, wherein the moving body of the ultrasonic actuator passes or shields infrared rays incident on an infrared detection element of a pyroelectric infrared sensor. Piezoelectric actuator for infrared sensors, which is designed to move like this.