JPH06225555A - Ultrasonic motor - Google Patents

Abstract

PURPOSE:To magnify the oscillation amplitude and improve the efficiency by rotating it while inclining the end face of an oscillation generating section to the center shaft, and amplifying the amplitude of this rotating motion and transmits it to an oscillation piece, and shifting a driven member in the specified direction by the oscillation piece. CONSTITUTION:The polarization axes of the third piezoelectric element 3 and the fourth piezoelectric element 4 are arranged, sliding them 90 deg. in position from the polarization axes of the first piezoelectric element 1 and the second piezoelectric element 2, and sine wave voltages of resonance frequency or its vicinity, whose phases are slid by 90 deg. from each other are applied to electrode plates 6 and 7, whereupon flexural oscillation rotating around the center shaft occurs in an oscillation generating section 24. Therefore, elliptic motion rotating around the center shaft occurs at the end face of an oscillation piece 23, which rotates the pressed rotor 13. At this time, the flexural motion generated at the oscillation generating part 24 is transmitted to the oscillating piece 23 through a flange 16, and the oscillating piece 23 oscillates strongly to the resonance frequency, and it becomes the amplitude being magnified at the contact face with the rotor 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic motor, and more particularly to an ultrasonic motor which rotates by vibration generated by an electro-mechanical energy conversion element.

[0002]

2. Description of the Related Art Various ultrasonic motors have been proposed in the past, which rotate by vibration generated by an electro-mechanical energy conversion element.
It is disclosed in Japanese Patent Publication No. 91668. In the vibrator described in the publication, the outer diameters of both ends thereof are formed to be thicker than the outer diameter of the node position in the driving vibration mode. By forming the shape of the oscillator in this way, the natural frequency can be reduced compared to the oscillator with a uniform diameter, and conversely, the modal mass can be greatly increased to obtain a large vibration amplitude. Is something that can be done. By using such technical means, the efficiency of the motor including the circuit system for driving the motor is improved and the driving is stabilized.

Further, as another technical means for obtaining the same effect as described above, one having a large-diameter portion with a high-density portion is disclosed in Japanese Laid-Open Patent Publication No.
It is proposed in Japanese Patent No. 91670. In this technical means, in order to apply a voltage to the piezoelectric element of the Langevin type ultrasonic vibrator, a thin metal plate is formed into an electrode plate having substantially the same shape as the piezoelectric element, and a lead wire is connected from this electrode plate. A terminal portion for this purpose is provided in a protruding manner, and such electrode plates are fixed to both end faces of the piezoelectric element, and such a structure is common as a voltage applying means. Such voltage applying means has been widely used for a long time because it is easy to manufacture and can obtain good adhesion with the piezoelectric element.

[0004]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
The technical means for increasing the vibration amplitude by arranging the large-diameter portion at the antinode position of the vibration, as described in Japanese Patent No. 68, is very often used. It is feared that the weight will increase. If the outer circumference of the additional mass portion is increased relative to the outer diameter of the piezoelectric element that is the electro-mechanical energy conversion element, the size becomes larger in the radial direction, while if the portion of the additional mass portion is lengthened in the axial direction, The total length of the oscillator becomes large. An ultrasonic motor using such a vibrator does not pose a problem when used in a part with a relatively large space, but it is a major drawback when used in a limited space, and should be used in practice. I can't.

Further, as disclosed in the above-mentioned Japanese Patent Laid-Open No. 4-91670, when the high density portion is used at the antinode position of vibration, downsizing can be achieved, but two kinds of members made of different materials are required. Also, there is a problem that the cost increases due to an increase in the process of assembling these plural members.

On the other hand, the voltage applying means as described above has a space problem because the terminal portion of the electrode plate projects from the outer peripheral diameter of the ultrasonic transducer. Furthermore, when the piezoelectric element is laminated in multiple layers, in addition to many terminal portions projecting on the outer periphery of the ultrasonic transducer, the number of lead wires connected to these terminal portions also increases, which further increases the space. The problem gets bigger. Needless to say, the wiring becomes complicated. These are especially small ultrasonic motors (eg φ
This is an important problem in ultrasonic motors of 10 (mm) or less).

The present invention has been made in view of the above problems, and an object of the present invention is to provide an ultrasonic motor in a small space, which can increase the vibration amplitude and improve the efficiency.

[0008]

In order to achieve the above object, an ultrasonic motor according to the present invention has an electro-mechanical energy conversion element arranged at the center thereof and has an end face inclined while rotating with respect to a central axis. A vibration generating portion, a vibrating piece formed on one end surface of the vibration generating portion and having a groove on a side surface, a flange portion formed at a connecting portion between the vibrating piece and the vibration generating portion, and an end surface of the vibrating piece. And a driven member which is pressed by a pressing mechanism and is moved in a predetermined direction.

[0009]

The end face of the vibration generating part makes a rotary motion while inclining with respect to the central axis, and the flange part amplifies the amplitude of this rotary motion and transmits it to the vibrating piece, which vibrates the driven member in a predetermined direction. Moving.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 show a first embodiment of the present invention. In the first embodiment, a piezoelectric element having silver vapor deposited on the voltage application surface is used as the electromechanical energy conversion element.

FIG. 1 is a side view showing the whole of an ultrasonic motor whose right half from the central axis is shown in a cross section, and FIG. 2 is an exploded perspective view showing laminated piezoelectric elements stretched in the central axis direction. . In the ultrasonic motor of the first embodiment, the piezoelectric elements 1, 2, 3, with respect to the fastening member 10 forming the central axis.
A vibrator 13 formed by sandwiching an oscillator 5 composed of 4 or the like with a first resonator 9 and a second resonator 17 presses a rotor 13 as a driven member with a nut 21 via a disc spring 20. It is screwed to adjust the main part.

The oscillator 5 includes an electrode plate 8, a first piezoelectric element 1, an electrode plate 6, a second piezoelectric element 2, an electrode plate 8, a third piezoelectric element 3, an electrode plate 7, a fourth piezoelectric element 4 and an electrode. The plates 8 are laminated in this order. The doughnut-shaped first piezoelectric element 1, the second piezoelectric element 2, the third piezoelectric element 3, and the fourth piezoelectric element 4 are polarized in a direction perpendicular to the central axis, and the polarization direction of the first piezoelectric element 1 is the same. The polarization directions of the second piezoelectric element 2 and the second piezoelectric element 2 are arranged so as to be opposite to each other. Similarly, the polarization directions of the third piezoelectric element 3 and the fourth piezoelectric element 4 are also reversed. The polarization axes of the third piezoelectric element 3 and the fourth piezoelectric element 4 are displaced by 90 ° with respect to the polarization axes of the first piezoelectric element 1 and the second piezoelectric element 2.

The electrode plates 6, 8 and 7 are made of copper, and the electrode plates 6 and 7 have a sinusoidal voltage (for example, a Is s
inωt, a voltage having a waveform of cosωt) is applied to the electrode plate 7 from a drive circuit (not shown), and the electrode plate 8 is connected to the ground (indicated by a symbol G in the figure).

The first resonator 9 is made of a material excellent in vibration transmission (aluminum alloy, stainless steel, phosphor bronze, duralumin, titanium alloy, etc.). In this embodiment, SUS440C is hard-chrome plated. hand,
A hardness of Hv 800 or higher is used. A female screw 11 that is screwed into the fastening member 10 is engraved on the central axis portion of the first resonator 9, and extends from the direction of the end face of the vibrator 19 toward the voltage elements 1, 2, 3, 4. A cup-shaped recess 12 is formed so that the end face of the first resonator 9 does not come into contact with the fastening member 10. Therefore, the vicinity of the contact portion of the first resonator 9 with the rotor 13 has a thin cylindrical shape and constitutes the vibrating piece 23. The portion below the vibrating piece 23, that is, the lower portion of the first resonator 9 and the oscillator 5
And the second resonator 17 constitute a vibration generating section 24. Further, on the outer peripheral surface of the first resonator 9, a first peripheral groove 14 and a second peripheral groove 15 having a predetermined depth are engraved concentrically with the outer periphery. At this time, the portion connecting the second circumferential groove 15 and the circumferential surface of the resonator 9, that is, the vibrating piece 23 and the vibration generating portion 2
A thin flange portion 16 is formed at a portion connecting with 4.

The second resonator 17 arranged on the other end face of the piezoelectric elements 1, 2, 3, 4 is also made of the same material as that of the first resonator 6 and has a central axis portion. A female screw 18 for screwing with the fastening member 10 is engraved.

As shown, each piezoelectric element 1, 2, 3, 4
The electrode plates 6, 7 and 8 are sandwiched between the first resonator 9 and the second resonator 17 in a state where they are penetrated by a bolt having two threaded portions which is the fastening member 10, and between the respective constituent members. After the epoxy-based adhesive is applied to the above, it is pressure-bonded and the adhesive is cured to form the ultrasonic transducer 19.

The bolt 10 pressure-bonds the ultrasonic oscillator 19 and supports the rotor 13 having a pressing mechanism on the end face of the ultrasonic oscillator 19. In this embodiment, a pressing mechanism is used in which the amount of crimping of the disc spring 20 can be varied by the nut 21.

In this embodiment, the rotor 13 is made of an aluminum alloy, and its sliding portion is subjected to oxalic acid alumite treatment. The rotor 13 has a circumferential groove 22 formed in a slightly lower portion of its circumferential surface, and a lower surface side thereof forms a flange portion 22a. Then, the rotor 13 once becomes a peripheral surface that is formed thinly from the flange portion 22a downward, and then the flange portion 2 that faces inward again.
2b is formed, the lower part of which is a contact portion 2 with the vibrator.
It is 2c. With such a configuration, the rotor 13
The natural frequency of the contact portion is higher than the driving frequency of the ultrasonic transducer 19.

The operation of the first embodiment will be described.
When a sinusoidal voltage having a resonance frequency close to each other and having a phase difference of 90 ° is applied to the electrode plates 6 and 7, bending vibration that rotates around the central axis is generated in the vibration generating unit 24. Therefore, an elliptical motion of rotating about the central axis is generated on the end surface of the vibrating piece 23, and the rotor 13 that is pressed and installed is rotated. If the phase difference between the drive voltages applied to the electrode plates 6 and 7 is shifted by 180 °, the ultrasonic oscillator 19 causes an elliptical motion of reverse rotation, causing the rotor 13 to rotate in reverse.

FIG. 3 is a half cross-sectional view of the first resonator 9 showing a state where the ultrasonic transducer 19 bends and vibrates.
The flexural vibration generated by the vibration generating section 24 is transmitted to the vibrating piece 23 via the flange section 16. At this time, the length 1 and the thickness t of the flange portion 16 are adjusted so that the resonance frequency of the bending vibration of the vibrating piece 23 matches the resonance frequency of the bending vibration of the vibration generating portion 24. Since the flange portion 16 has a thin structure, it has spring characteristics and strongly vibrates the vibrating piece 23. Due to this action, the small vibration amplitude of the vibration generating section 24 becomes, for example, several tens of times larger on the end surface of the vibrating piece 23 (that is, the contact surface with the rotor 13).

FIG. 4 is a graph showing the relationship between the thickness t of the flange portion 16 and the vibration amplitude. As shown in the figure, the vibration amplitude is such that the thickness of the flange 16 is t = 0.225 (mm)
, The maximum amplitude is obtained, while the resonance frequency is the lowest at this time. In order to rotate the motor with relatively high efficiency, the thickness of the flange portion 16 should be 0.1 (mm) to 0.4 (mm).
In this case, the rotation of the rotor 13 is stable. On the other hand, the thickness of the flange portion 16 is 0.
When it is less than 1 (mm) or exceeds 0.4 (mm), the vibration amplitude becomes extremely small, the efficiency of the motor decreases, and the heat generation becomes severe.

According to such a first embodiment, the resonator element 2
A bending vibration of large amplitude is excited on the end face of 3, and the rotor 13 can be stably rotated. Further, since the resonance frequencies of the vibrating piece 23 and the vibration generating section 24 are accurately matched, the most efficient expansion can be performed and the motor can be made highly efficient. Further, the vibrating piece 23
Since the resonance frequency of 1 depends on the shape of the flange portion 16, it is not necessary to adjust the size of the vibrating piece 23, and the ultrasonic vibrator can be downsized. In this way, a compact and highly efficient ultrasonic motor can be obtained.

FIG. 5 shows a second embodiment of the present invention. In the second embodiment, since the vibrating element in the first embodiment is divided into four parts, the description of the same parts as those of the first embodiment will be omitted and only the different parts will be described.

The first resonator 9 has a cup-shaped recess 12, a first circumferential groove 14, and a second circumferential groove 1 as in the first embodiment.
5 and the flange part 16 are formed. Then, the first resonator 9 has four grooves 25 that divide it into four equal parts in the circumferential direction.
Is formed at a predetermined depth parallel to the central axis from the direction in which the rotor 13 (see FIG. 1) is arranged toward the piezoelectric elements 1, 2, 3, 4. That is, the vibrating piece 23
Are divided into four parts along the circumferential direction.

The operation of the second embodiment thus constructed will be described. Since the restriction of the radial movement of the vibrating piece 23 is largely eliminated, the vibrating piece 23 vibrates greatly. At this time, the shape of the flange portion 16 is adjusted so that the resonance frequencies of the vibration generating portion and each of the vibrating pieces 23 are the same as in the first embodiment.

According to the second embodiment as described above, substantially the same effect as that of the first embodiment is obtained, and since a larger vibration amplitude is generated on the vibrating end face, the ultrasonic motor having a relatively high rotation speed is obtained. Is obtained.

FIG. 6 shows a third embodiment of the present invention. Since the third embodiment is a modification of the shape of the flange portion in the first embodiment, the description of the same parts as the first embodiment will be omitted, and only the different parts will be described.

As shown in the drawing, the flange portion 26 of the third embodiment is formed so that its cross-sectional shape is L-shaped. That is, the thin vertical flange portion 26a once rises vertically from the lower portion of the first resonator 9 along the axial direction, and then the thin horizontal flange portion 26b is formed outward perpendicular to the axis. .

As described above, the shape of the flange portion formed on the first resonator is not limited to the thin-walled shape formed perpendicularly to the axis, but may be any shape that resonates the resonator element by using the spring characteristic. For example, the function of enlarging the vibration amplitude can be realized for objects having a wide range of shapes. As a structure having such spring characteristics, for example, a structure as shown in FIG. In the structure shown in FIG. 7, the upper end surface of the flange portion is formed in a downward tapered shape so that the thinnest portion is provided at one place indicated by reference numeral 27, and the spring characteristic is provided at this portion. It is configured in.

The operation of the third embodiment thus constructed is almost the same as that of the first embodiment, except that the vibration generator 2
When the vibration generated from No. 4 is transmitted to the resonator element, the flange portion 26 bends in both the direction parallel to the central axis and the direction perpendicular to the central axis to increase the amplitude.

According to the third embodiment as described above, the same effect as that of the first embodiment can be obtained even in the case of the shape other than the thin plate-shaped flange portion, the vibration amplitude can be expanded, and the stability can be stabilized. It can be a rotating ultrasonic motor.

8 to 11 show a fourth embodiment of the present invention. In the fourth embodiment, a piezoelectric element 51 having silver vapor deposited on the voltage application surface is used as the electromechanical energy conversion element. FIG. 8 shows thin electrode plates 52, 5
FIG. 9 is a side view showing a cross section of the right half of the ultrasonic motor in which 3, 54 are incorporated. FIG. 9 shows the piezoelectric element 51 and the thin electrode plate 5.
2, 53 is an exploded perspective view in which the central axis direction is expanded, and FIG. 10 is a flexible substrate 55 which is a voltage supply member.
Is a partial perspective view showing the outline of the connection between the thin plate electrode plates 52, 53 and 54, and FIG. 11 is an enlarged sectional view showing the connection part.

The ultrasonic motor of this embodiment has an ultrasonic vibrator 56 and a rotor 58 which is pressed against the ultrasonic vibrator 56 by pressing means 57. The ultrasonic transducer 5
In FIG. 6, a plurality of piezoelectric elements 51 are laminated, and thin electrode plates 52, 53, 54 for applying a voltage to the voltage application surface are arranged between the layers of the piezoelectric elements 51 and on both end surface sides. Has been done. These thin plate electrode plates 52, 53, 54 are
As shown in FIG. 9, a minute joint portion 5 is provided at one place on the outer periphery thereof.
9 is projected. The electrode plates 52, 53, 54 are made of phosphor bronze having a thickness of 50 (μm), for example, and the surfaces thereof are nickel-plated. Electrode plates 52, 5
As shown in FIG. 10, the joint portion 59 formed so as to project from the reference numerals 3, 54 is bent downward along the peripheral surface of the ultrasonic transducer 56, for example.

For such a thin electrode plate 53, for example, sin
The voltage having a waveform of ωt, the thin plate electrode plate 54, the electrode plate 5
3, and a voltage having a waveform of, for example, cos ωt, which is 90 degrees out of phase with each other, is applied to each of the electrodes, while three thin electrode plates 52 are applied.
Is grounded.

A flexible substrate 55 having three copper patterns 60 formed thereon is connected to the electrode plates 52, 53 and 54 as described above. The flexible substrate 55 is provided with an insulating coating so as to cover the pattern 60, but the tip portion is not covered with the insulating coating, and is an exposed portion 61 where the pattern 60 is exposed. The surface of the exposed pattern 60 is nickel-plated. Such a flexible substrate 55 is curved and adhered along the peripheral surface of the ultrasonic transducer 56, as shown in FIG.

The thin electrode plates 52, 53, 54 as described above
The bonding portion 59 and the pattern exposed portion 61 of the flexible substrate 55 are ultrasonically bonded to each other through a thin wire 62 by a device such as a wire bonder. By this ultrasonic connection, as shown in FIG. 11, the tip portion of the wire 62 is deformed and alloyed with nickel of the joint portion 59 to be connected. Here, a thin wire of aluminum having a diameter of 50 (μm) is used as the wire 62. The maximum position height of the wire 62 when using such an aluminum thin wire is about 0.2 (mm). Although not shown, in order to protect the thin wire 62, the surface is coated with phenol resin after connection.

The operation of the ultrasonic motor as described above is almost the same as that of the first embodiment. That is, the piezoelectric element 51
When a voltage is applied to the ultrasonic transducer 56, the ultrasonic transducer 56 excites a primary bending vibration, and this bending vibration becomes a motion of rotating in a predetermined direction around the central axis. By this movement, the rotor 58 pressed by the pressing means 57 against the end surface of the vibrator 56 is rotated.

According to the fourth embodiment as described above, ultrasonic bonding is performed by ultrasonically bonding the joint portion of the thin electrode plate and the exposed portion of the flexible substrate, which is the voltage supply member, through the thin aluminum wire. The protrusion from the outer periphery of the motor can be reduced. In other words, the area required for the connection can be made very small as compared with the conventional space in which solder or the like rises. Even with the above-described protective coating of phenol resin formed, the amount of protrusion from the outer periphery can be suppressed to approximately 0.5 (mm) or less.

The connecting portion of the thin wire by ultrasonic bonding is very small, and when the diameter of the thin wire is d, it is about 1.5d, that is, about 1.5 times the diameter. That is, the joining portion of the thin electrode plates required for connecting the wires can be made very small. Also, the aluminum thin wire is firmly connected because it is alloyed with the bonding part of the nickel-plated thin electrode plate by ultrasonic bonding and the exposed pattern of the flexible substrate, and is disconnected by the ultrasonic vibration of the ultrasonic motor. There is no such thing.
Furthermore, such ultrasonic bonding has an effect that the piezoelectric element is not affected by heat and the piezoelectric characteristic is not deteriorated by heat.

As described above, the protrusion due to the wiring is extremely small, and the motor can be miniaturized. Even if the motor is small, the wiring connection work is simplified and the assembly time can be shortened.

FIG. 12 shows a fifth embodiment of the present invention and is an enlarged perspective view showing a connecting portion of a flexible substrate and a thin electrode plate. Since the fifth embodiment is almost the same as the fourth embodiment, only different parts will be described.
A flexible substrate 64 as a voltage supply member is connected to the thin electrode plates 52, 53, 54. The flexible substrate 64 has a slanted tip, and a plurality of copper patterns 60 are formed according to the number of the thin electrode plates 52, 53, 54. Among these copper patterns 60, the copper patterns to be connected to the ground are connected to each other in the flexible substrate 64 and are integrated. The flexible substrate 64 is provided with an insulating coating so as to cover the pattern 60, but the tip portion is not covered with the insulating coating and the pattern 60 is exposed. The surface of the exposed pattern 60 is nickel-plated. Such a flexible substrate 64 is curved and adhered along the peripheral surface of the ultrasonic transducer 56.

Nickel plated thin electrode plate 5
As shown in the figure, the joint portions 59 of the reference numerals 2, 53, 54 are arranged so as to be arranged obliquely with a slight offset in the circumferential direction so as to project. Further, the joint portion 59 is bent, for example, downward along the outer peripheral side surface of the ultrasonic transducer 56 as in the fourth embodiment.

The obliquely formed tip of the flexible substrate 64 is arranged in accordance with the joint portion 59, and each joint portion 59 and the copper pattern 60 are ultrasonically joined to each other through the aluminum thin wire 62. To connect. In addition,
Similar to the fourth embodiment, the protective coating is performed with a phenol resin (not shown) after the connection.

According to the fifth embodiment, since the connecting distance of the thin wire can be shortened, the maximum position height of the thin wire can be further reduced. In addition, because the ground is integrated into one in the flexible board,
Since the thin wires do not cross each other, ultrasonic bonding can be performed more easily.

In this way, the motor can be downsized by further reducing the protruding amount of the thin wire. in addition,
Since the connection distance is shortened, the reliability of the connection is improved, and the wiring work can be simplified.

FIG. 13 shows a modified example of the fifth embodiment, and is an enlarged perspective view showing the voltage supply member and the connecting portion of the thin electrode plate. In the fifth embodiment, the glass epoxy substrate 6 having a thickness of about 0.1 (mm) is used as the voltage supply member.
5 is used. On the glass epoxy substrate 65, as shown in the drawing, a copper pattern 60 is formed by connecting a ground to the inside of the substrate and collecting them together. The exposed portion 66 of the copper pattern 60 is formed on the side of the tip portion of the glass epoxy substrate 65, and the exposed copper pattern 60 is nickel-plated.

Corresponding to the exposed portion 66 of the glass epoxy substrate 65, the joint portions 59 of the thin electrode plates 52, 53 and 54 project in a line parallel to the central axis and further downward as shown. It has been folded. The glass epoxy substrate 65 is curved and bonded and fixed along the peripheral surface in the vicinity of the joint portion 59, and the joint portion 59 and the copper pattern 60 are ultrasonically joined to each other through the aluminum thin wire 62. Connected. With such a structure, the same operation and effect as those of the fifth embodiment can be obtained.

FIG. 14 shows a sixth embodiment of the present invention and is an enlarged perspective view showing a voltage supply member and a connecting portion of a thin plate electrode plate. Since the sixth embodiment is almost the same as the fourth embodiment, only different parts will be described. In the sixth embodiment, the voltage supply member has a thickness of 0.1 (mm)
The glass epoxy substrate 67 of is used.

As shown in the figure, the glass epoxy substrate 67 is formed in such a shape that the tip end portion thereof has a step substantially equal to the interval between the electrode plates, and an exposed portion 68 at which the copper pattern 60 is exposed at each step. The exposed portion of the copper pattern 60 is nickel-plated. The copper pattern connected to the ground is provided at the right end and has the longest exposed portion length.

A glass epoxy substrate 67 having this step
Corresponding to the shape of the tip of the thin plate electrode plate 52, 53, 5
4 joints 59 are arranged, and only two of these joints 59, which are connected to the ground, are arranged on the side of the rightmost ground pattern.

Thin electrode plates 52, 53, 54 as described above
The connecting portion 59 and the copper pattern 60 on the exposed portion 68 of the glass epoxy substrate 67 are ultrasonically connected to each other via the aluminum thin wire 62.

According to the sixth embodiment, the operation and effect are almost the same as those of the above-mentioned fourth embodiment, and it is not necessary to intersect the copper patterns of the glass epoxy substrate inside and the structure is simple. Therefore, the cost of manufacturing the substrate can be reduced. Further, as in the fifth embodiment, since the connection distance of the thin wire can be shortened, the protrusion amount can be reduced and the reliability can be improved.

15 to 17 show a seventh embodiment of the present invention. Since the seventh embodiment is almost the same as the fifth embodiment, only different parts will be described. The thin electrode plates 52, 53, 5 in the seventh embodiment
Reference numeral 4 shows the shape of the electrode plate 69 shown in FIG. 16, which is formed into a thin plate shape having a thickness of about 50 (μm) on the surface of which aluminum is provided on the surface after pretreatment using phosphor bronze as a base. An elongated projecting connecting portion 70 is provided in a part of the. The electrode plates 52, 53, 54 having such a shape are
As shown in FIG. 15, the voltage supply member is connected to the flexible substrate 64 having the distal end portion described in the fifth embodiment and formed obliquely.

Then, as shown in the figure, the flexible substrate 64 is curved and adhered and fixed along the peripheral surface of the ultrasonic transducer 56. After that, the connecting portion 70 is bent downward along the central axis direction of the ultrasonic transducer 56 to be aligned with the pattern exposed portion 71 of the flexible substrate 64. FIG. 17
Shows an enlarged cross-sectional view of such a connecting portion, and ultrasonically joins the matching portion of the connecting portion 70 and the pattern exposed portion 71 (that is, the portion indicated by the arrow 72).

According to the seventh embodiment as described above, since the long and thin connecting portions integrally formed with the thin electrode plate are ultrasonically joined to the voltage supply member, the number of portions required for connection is reduced to half. The assembly process can be reduced and the assembly time can be further shortened. Further, the amount of protrusion from the peripheral surface of the ultrasonic motor is reduced to only the amount of the thickness of the voltage supply member and the thickness of the thin electrode plate. In this way, the amount of protrusion from the peripheral surface of the ultrasonic motor is very small,
The motor can be further downsized. Since the distance required for connection is shortened and the number of connection points is reduced, the assembly cost of the motor is reduced and the reliability of the motor is improved.

[0056]

As described above, according to the present invention, it is possible to provide an ultrasonic motor in a small space in which the vibration amplitude can be increased to improve the efficiency.

[Brief description of drawings]

FIG. 1 is a side view showing an entire ultrasonic motor according to a first embodiment of the present invention, showing a right half from a central axis in a cross section.

FIG. 2 is an exploded perspective view showing the stacked piezoelectric elements of the first embodiment in a state of being stretched in a central axis direction.

FIG. 3 is a cross-sectional view of the right half of the first resonator, showing how the ultrasonic transducer of the first embodiment flexurally vibrates.

FIG. 4 is a diagram showing the relationship between the thickness of the flange portion and the vibration amplitude of the first embodiment.

5A and 5B are a plan view and a side view showing a right half from a central axis in a cross section of an ultrasonic transducer according to a second embodiment of the present invention.

FIG. 6 is a side view of the ultrasonic transducer according to the third embodiment of the present invention, showing a half section from the central axis in cross section.

FIG. 7 is a sectional view showing the right half of an ultrasonic transducer of another example of the third embodiment.

FIG. 8 is a side view showing the right half of the ultrasonic motor according to the fourth embodiment of the present invention in section.

FIG. 9 is an exploded perspective view showing the piezoelectric element and the thin plate electrode plate of the fourth embodiment by stretching them in the central axis direction.

FIG. 10 is a partial perspective view showing the outline of the connection between the voltage supply member and the thin plate electrode plate of the fourth embodiment.

FIG. 11 is an enlarged sectional view showing a connection portion of the fourth embodiment.

FIG. 12 is an enlarged perspective view showing a flexible substrate and a connection portion of a thin plate electrode plate according to a fifth embodiment of the present invention.

FIG. 13 is an enlarged perspective view showing a voltage supply member and a connecting portion of a thin plate electrode plate according to a modified example of the fifth embodiment.

FIG. 14 is an enlarged perspective view showing a voltage supply member and a connecting portion of a thin plate electrode plate according to a sixth embodiment of the present invention.

FIG. 15 is an enlarged perspective view showing a connecting portion of a flexible substrate and a thin electrode plate according to a seventh embodiment of the present invention.

FIG. 16 is a perspective view showing the shape of the thin electrode plate of the seventh embodiment.

FIG. 17 is an enlarged cross-sectional view showing the flexible substrate and the connecting portion of the thin plate electrode plate according to the seventh embodiment.

[Explanation of symbols]

1, 2, 3, 4 ... Piezoelectric element (electrical-mechanical energy conversion element) 13 ... Rotor (driven member) 16 ... Flange portion 20 ... Disc spring (pressing member) 23 ... Vibrating piece 24 ... Vibration generating portion

Claims (1)

[Claims] 1. A vibration generating part, in which an electro-mechanical energy conversion element is arranged at the center, and an end face is rotated while tilting with respect to a central axis, and a groove formed on one side face of the vibration generating part. A vibrating piece having: a flange portion formed at a connecting portion between the vibrating piece and the vibration generating section; and a driven member which is pressed against an end surface of the vibrating piece by a pressing mechanism and is moved in a predetermined direction. An ultrasonic motor characterized by being provided.