JPH07116601A - Ultrasonic vibrator - Google Patents

Abstract

PURPOSE:To provide an ultrasonic vibrator having a moving body movable at a high speed and in a large degree of design freedom. CONSTITUTION:An ultrasonic vibrator is provided with a base part 2 consisting of a rod-like elastic body, bar parts 1 and 3 each of which is formed integrally with the base part 2 and projects from the base part 2 at a predetermined angle to its extending direction and a vibratory object 6 for causing the curvature vibration of the bar parts 1 and 3. Alternating voltage is applied to the vibratory object 6 to induce the resonance curvature vibration of the bar parts 1 and 3, thereby exciting the base part 2 into the curvature vibration synchronous with the resonance curvature vibration of the bar parts 1 and 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic vibrator, and more particularly to an ultrasonic vibrator using a piezoelectric element or an electrostrictive element.

[0002]

2. Description of the Related Art Conventionally, various ultrasonic vibrators using a piezoelectric element or an electrostrictive element have been proposed.
In Japanese Patent Laid-Open No. 223388, a piezoelectric element is pressure-fixed between a fixing member and a flexural vibrating body by a pressure-bonding material, and a projection is provided on the flexural vibrating body, and a high-frequency power source is applied to the piezoelectric element to form the projection. There is disclosed a technical means for oscillating to the left and moving the moving body by pressing it against the moving body.

Further, in Japanese Patent Application Laid-Open No. 1-107669, two driving feet having different resonance frequencies are provided, and a piezoelectric element for vibrating the feet is further provided, and a moving element is provided at the ends of the two feet. There is disclosed a technical means for bringing the piezoelectric element into contact with the piezoelectric element to apply a predetermined frequency to move the moving element.

On the other hand, in Japanese Utility Model Application Laid-Open No. 64-50695, a piezoelectric element is provided with a base portion made of an elastic body, and a moving element having feet vertically provided on the back surface of the base element is formed to form the piezoelectric element. There has been proposed a technical means for moving the mover by applying a predetermined frequency to the.

[0005]

However, in the technical means disclosed in the above-mentioned Japanese Patent Laid-Open No. 2-223388,
Even if an AC voltage is applied according to the resonance frequency of the bending vibration body, the amplitude of the projection tip has a large amplitude because there is a laminated body below the projection and the free vibration of the bending vibration body is hindered. There is a problem that the moving speed is slow because it cannot be obtained.

Further, in the above-mentioned Japanese Patent Laid-Open Publication No. 1-107669 and Japanese Utility Model Laid-Open No. 64-50695, the technical means proposed can be driven only by the tip of the foot portion on which the elastic body is constructed, and there is no freedom in design. There is a point.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an ultrasonic transducer in which the moving speed of a moving body is high and the degree of freedom in design is large.

[0008]

In order to achieve the above-mentioned object, an ultrasonic transducer according to the present invention comprises a base portion made of a rod-shaped elastic body, and the base portion formed integrally with the base portion. A beam portion that protrudes so as to extend at a predetermined angle with respect to the direction in which the portion extends, and an electro-mechanical energy conversion element that causes the beam portion to bend and vibrate,
By applying an AC voltage to the electro-mechanical energy conversion element to generate resonance bending vibration in the beam portion,
A bending vibration is generated in the base portion in synchronization with the resonance bending vibration of the beam portion.

[0009]

In the ultrasonic vibrator according to the present invention, an AC voltage is applied to the electro-mechanical energy conversion element to generate resonant bending vibration in the beam portion, whereby the base portion is
A bending vibration is generated in synchronization with the resonance bending vibration of the beam portion.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a side view (a) and a front view (b) of an ultrasonic transducer showing a first embodiment of the present invention.

As shown in the drawing, in the first embodiment, a base portion 2 made of a rod-shaped elastic body is integrally formed with the base portion 2, and extends at right angles from both ends of the base portion 2. And a vibrating body 6 composed of a laminated piezoelectric element that flexurally vibrates the beam sections 1 and 3, and a driving body 5 that includes a vibrating body 6 that has a U-shape. is doing.

The vibrating body 6 is composed of a laminated piezoelectric element sandwiched between the beam portion 1 and the beam portion 3 with an adhesive such as an epoxy resin. Further, a high frequency power source 8 for high frequency driving is connected to the vibrating body 6.

On the other hand, on the upper surface of the beam portion 1 of the elastic body 4, a rotating body 7 is arranged as a moving body. The rotating body 7 is provided on the upper surface of the beam portion 1 of the elastic body 4 with the center of rotation 7
A crimping force (not shown) is used to apply a crimping force around a.

FIG. 2 shows a vibrating state in the vicinity of the beam portion 1 when the vibrating body 6 is driven by the high frequency power source 8 in the ultrasonic transducer of the first embodiment constructed as described above. FIG.

As shown in FIG. 2, when the vibrating body 6 vibrates, the beam portion 1 causes bending vibration in the vibrating direction of the vibrating body 6. In addition, in the experiment by the applicant, it has been confirmed that, at this time, bending vibration occurs in the base portion 2 in a direction perpendicular to the vibration direction of the vibrating body 6 due to the bending vibration force of the beam portion 1.

When the vibration locus of the tip of the beam portion 1 when the vibrating body 6 vibrates is seen, as shown by an arrow in FIG. 3, a vertically elongated elliptical locus is formed. Beam part 1 in this vibration state
When the rotating body 7 is brought into pressure contact with the rotating body 7, the rotating body 7 rotates in the L direction shown in FIG.

In the present embodiment, a laminated piezoelectric element is used as the vibrating body 6, and a large longitudinal amplitude can be obtained without causing the vibrating body 6 to resonate. Therefore, the vibrating body under the resonance condition of the beam portion 1 is used. 6 is being driven.

That is, assuming that the bending vibration resonance frequency of the beam portion 1 is f, the length from the attachment end of the base portion 2 of the beam portion 1 to the free end thereof is 1, and the lateral elastic modulus of the beam portion 1 is shown in FIG. Let G be the moment of inertia of area of the beam 1, the density of the beam 1 be ρ, and the cross-sectional area of the beam 1 be A, the value of the resonance frequency f is Becomes

For example, if the beam 1 has a rectangular cross section with a width B and a thickness h, Therefore, the vibrating body 6 may be driven at this frequency.

In this embodiment, a multi-layer laminated piezoelectric element is used as the vibrating body 6 of the ultrasonic vibrator. However, several piezoelectric elements are sandwiched between the beam portion 1 and the beam portion 3 and the piezoelectric element is You may make it resonate. In this case, the resonant frequencies of the piezoelectric elements composed of several sheets and the beam portion 1 may be made to substantially match.

In the present embodiment, the rotating body 7 is adopted as the moving body that comes into pressure contact with the beam portion 1 of the elastic body 4, but the present invention is not limited to this, and a moving body such as a rod-like body is brought into pressure contact with the rotating body 7 instead of the rotating body 7. However, the rod-shaped moving body may be moved.

The base 2 and the beams 1 and 3 are made of an elastic material having a high mechanical Qm, that is, stainless steel,
Brass, phosphor bronze, aluminum, ceramics glass, or composite materials of these are suitable. Further, the frictional contact surface of the moving body with the driving body 5 is made of a material having excellent wear resistance.

FIG. 5 is a side view showing an essential part of an ultrasonic transducer according to the second embodiment of the present invention. Note that only the elastic body 14 excluding the moving body and the like is shown here.

The second embodiment is an example in which the beam portion 3 in the first embodiment is used only for sandwiching the vibrating body 6, and the length of the beam portion 3 is shorter than that of the beam portion 1. (In the figure, reference numeral 13).

Also in the second embodiment constructed as described above, a high frequency voltage which is the bending resonance frequency of the beam portion 1 is applied to the vibrating body 6 to resonate the beam portion 1 as in the first embodiment. Then, the rotating body 7 (see FIG. 1) is pressure-bonded to the beam portion 1 to rotate the rotating body 7. Further, the rotating body rotates even if the beam portion 13 is fixed to a fixed object or the like.

FIG. 6 is a side view showing an essential part of an ultrasonic transducer according to the third embodiment of the present invention.

In the third embodiment, the shape of the elastic body is a U-shape as in the first embodiment.
In the vibrating body 26 of this embodiment, a plate-shaped piezoelectric element is fixed to the lower surface of the beam portion 1 in the vibration direction of bending vibration, and a high-frequency voltage that is the bending resonance frequency of the beam portion 1 is applied to this plate-shaped piezoelectric element. Resonant vibration is generated in the beam portion 1 by the rotating body 7 (FIG. 1) on the surface of the beam portion 1 opposite to the plate-shaped piezoelectric element fixing surface.
(See reference) is pressed to rotate the rotating body 7.

Although the vibrating body 26 is fixed to the lower surface of the beam portion 1 in the third embodiment, the vibrating body 26 is fixed to the upper surface of the beam portion 1,
Alternatively, it may be fixed to the beam portion 3.

FIG. 7 is a side view showing an essential part of an ultrasonic transducer according to the fourth embodiment of the present invention.

The fourth embodiment has an L-shaped shape in which the beam portion 3 in the third embodiment is removed.

Also in the fourth embodiment, as in the third embodiment, a high frequency voltage which is a bending resonance frequency of the beam 1 is applied to the vibrating body 26 to cause the beam 1 to resonate and vibrate.
A rotating body 7 (see FIG. 1) is pressed against the beam portion 1 to rotate the rotating body 7.

FIG. 8 is a side view showing the essential parts of an ultrasonic transducer of the fifth embodiment of the present invention.

In the fifth embodiment, the elastic body 44 has an H-shaped shape composed of the beam portion 41, the beam portion 43, and the base portion 42, and the vibrating body 6 which is a laminated piezoelectric element is the beam. It is sandwiched between the portion 41 and the beam portion 43.

Also in the case of this embodiment, the vibrating body 6 is provided with the beam portion 41.
Resonance vibration is generated in the beam portion 41 by applying a high-frequency voltage that is the bending resonance frequency of the rotating body 7, and the rotating body 7 (see FIG. 1) is pressed against the surface of the beam portion 41 in the vibration direction of the bending vibration. The rotating body 7 is rotated.

When a high frequency voltage which is the bending resonance frequency of the beam portion 43 is applied to the laminated piezoelectric element, the beam portion 43 is applied.
In the same manner as described above, the rotating body 7 (see FIG. 1) can be rotated, and the beam portion 41 and the beam portion 43 can be further rotated.
If the bending resonance frequencies of and are the same, it is possible to rotate the rotating body 7 in the beam portion 41 and the beam portion 43 at the same time.

In this embodiment, the laminated piezoelectric element, which is the vibrating body of the ultrasonic vibrator, is sandwiched between the right side of the base portion 42 in the figure, but the same applies to the left side of the base portion 42. It goes without saying that various effects can be obtained.

FIG. 9 is a side view showing an essential part of an ultrasonic transducer according to the sixth embodiment of the present invention.

In the sixth embodiment, the vibrating body 56 made of a plate-shaped piezoelectric element is fixed to the beam portion 41 instead of the vibrating body 6 made of the laminated piezoelectric element in the fifth embodiment.

Also in the sixth embodiment, the vibrating body 5 is used.
A high frequency voltage, which is the bending resonance wave number of the beam portion 41, is applied to the beam portion 41 to generate resonant vibration in the beam portion 41, and the rotating body 7 (see FIG. 1) is pressed against the beam portion 41 so that the rotating body 7 is attached. Rotate.

FIG. 10 is a side view showing the main part of the ultrasonic transducer of the seventh embodiment of the present invention.

In the seventh embodiment, the elastic body 64 has an L-shaped shape composed of the beam portion 61 and the base portion 62. Further, both ends of a vibrating body 66 composed of a laminated piezoelectric element are fixed to grooves formed in the beam portion 61 and the base portion 62.

Also in this embodiment, by applying a high frequency voltage, which is the bending resonance frequency of the beam portion 61, to the vibrating body 66, resonance vibration is generated in the beam portion 61, and the beam portion 6
The rotating body 7 (see FIG. 1) is pressed against 1 to rotate the rotating body 7.

In this embodiment, the beam portion 61 and the base portion 6 are
Although it is perpendicular to 2, the angle is not limited to this and may be an acute angle or an obtuse angle.

FIG. 11 is a side view showing an essential part of the ultrasonic transducer of the eighth embodiment of the present invention.

In the eighth embodiment, the elastic body 74 has a T-shaped shape composed of the beam portion 71 and the base portion 72. Further, both ends of the vibrating body 76 composed of the laminated piezoelectric element are fixed to the grooves provided in the beam portion 71 and the base portion 72.

Also in this embodiment, the beam portion 7 is attached to the vibrating body 76.
Resonance vibration is generated in the beam portion 71 by applying a high frequency voltage having a bending resonance frequency of 1.
The rotating body 7 (see FIG. 1) is pressed against and the rotating body 7 is rotated.

Although the laminated piezoelectric element is used for the vibrating body 76 in this embodiment, it is of course possible to fix the plate-shaped piezoelectric element to the beam portion 71.

As described above, according to each of the above embodiments, the bending vibration of the beam portion and the bending vibration of the base portion due to the bending vibration force of the beam portion are combined, so that the elliptical ellipse is formed at the tip end and the upper and lower surfaces of the beam portion. Is generated, it is possible to move the moving body by pressing the moving body to the tip of the beam portion and any position on the upper and lower surfaces. Therefore, it is possible to provide an ultrasonic transducer having a very wide range of driving points.

[0050]

As described above, according to the present invention, it is possible to provide an ultrasonic transducer in which the moving speed of the moving body is fast and the degree of freedom in design is large.

[Brief description of drawings]

FIG. 1A is a side view and FIG. 1B is a front view of an ultrasonic transducer according to a first embodiment of the present invention.

FIG. 2 is a side view showing a vibrating state in the vicinity of a beam portion when the vibrating body is driven by a high frequency power source in the ultrasonic transducer of the first embodiment.

FIG. 3 is a diagram showing a vibration locus at the tip of the beam portion when the vibrating body of the ultrasonic transducer of the first embodiment vibrates.

FIG. 4 is a side view of a main part of the ultrasonic vibrator according to the first embodiment for explaining a bending vibration resonance frequency of a beam portion thereof.

FIG. 5 is a side view showing a main part of an ultrasonic transducer according to a second embodiment of the present invention.

FIG. 6 is a side view showing a main part of an ultrasonic transducer according to a third embodiment of the present invention.

FIG. 7 is a side view showing a main part of an ultrasonic transducer according to a fourth embodiment of the present invention.

FIG. 8 is a side view showing a main part of an ultrasonic transducer according to a fifth embodiment of the present invention.

FIG. 9 is a side view showing a main part of an ultrasonic transducer according to a sixth embodiment of the present invention.

FIG. 10 is a side view showing a main part of an ultrasonic transducer according to a seventh embodiment of the present invention.

FIG. 11 is a side view showing a main part of an ultrasonic transducer according to an eighth embodiment of the present invention.

[Explanation of symbols]

 1, 3 ... Beam part 2 ... Base part 4 ... Elastic body 5 ... Driving body 6 ... Vibrating body 7 ... Rotating body 8 ... High frequency power source

Claims (2)

[Claims] 1. A base portion made of a rod-shaped elastic body; a beam portion integrally formed with the base portion; and a beam portion protruding so as to extend at a predetermined angle with respect to a direction in which the base portion extends. An electro-mechanical energy conversion element for flexurally vibrating the beam portion is provided, and an alternating voltage is applied to the electro-mechanical energy conversion element to generate resonant flexural vibration in the beam portion, thereby the base An ultrasonic transducer, wherein bending vibration is generated in the portion in synchronization with the resonance bending vibration of the beam portion. 2. The ultrasonic vibration according to claim 1, further comprising a moving body that is pressed against the plane of the beam portion formed parallel or perpendicular to the amplitude direction of the resonance bending vibration. Child.