JP5701020B2 - Vibrating body and manufacturing method thereof in vibration type driving device, vibration type driving device and vibrator thereof - Google Patents

Description

The present invention, the vibrating body and a manufacturing method thereof in the vibration type driving apparatus, a the vibrator and the vibration type driving apparatus, in particular the vibrating body and a manufacturing method thereof in the linear-type ultrasonic motor (vibration type driving apparatus), the vibration type driving The present invention relates to a device and its vibrator .
Moreover, the vibrator of the vibration type driving device of the present invention includes the vibrator in the vibration type driving device described above and the electromechanical energy conversion element.
Further, the vibrating body in the vibration type driving device of the present invention includes a base portion to which the electro-mechanical energy conversion element is joined,
At least one protrusion;
Have
The protrusion is formed by at least two wall portions extending in an out-of-plane direction with respect to the base portion, and a contact portion having a contact surface with the driven body that connects between the wall portions,
The base and the at least one protrusion are integrally formed from one member.

As a linear ultrasonic motor for driving a driven object in a straight line, a vibration type driving device as in Patent Document 1 has been proposed.
The driving principle of such a linear ultrasonic motor (vibration type driving device) will be described with reference to the drawings.
As shown in the external perspective view of the linear ultrasonic motor in FIG. 8A, the linear ultrasonic motor 510 includes a vibrator 501, a slider 506, and a pressurizing member (not used for pressing the vibrator against the slider). (Illustrated).
The vibrator 501 is composed of an electro-mechanical energy conversion element 505 typified by a piezoelectric element and the like and a vibrating body that is joined and integrated on one surface of the electro-mechanical energy conversion element 505.
The vibrating body has a base 502 formed in a rectangular shape and two protrusions 503 and 504 formed in a convex shape with respect to the upper surface of the base.

In an ultrasonic motor, by applying a voltage of a specific frequency (also called an alternating electric field) to a piezoelectric element, a plurality of desired vibration modes are excited, and these vibration modes are superimposed to generate vibration for driving. Form.
In the motor shown in FIG. 8A, the vibrator 501 is excited by two bending vibration modes shown in FIGS. 8B-1 and 8B-2.
Both of these two bending vibration modes are bending vibration modes in the out-of-plane direction of the plate-like vibrator 501.
One vibration mode is a secondary bending vibration mode (Mode-A: feed mode) in the longitudinal direction of the vibrator 501, and the other vibration mode is a primary bending vibration mode (in the width direction of the vibrator 501). Mode-B: push-up mode).
The shape of the vibrator 501 is designed so that the resonance frequencies of the two vibration modes match or are close to each other.
The protrusions 503 and 504 are arranged in the vicinity of a position that becomes a vibration node in Mode-A (feed mode) vibration. Due to the vibration of Mode-A, the protrusion front end surfaces 503-1 and 504-1 reciprocate in the X direction (feeding direction) because they perform a pendulum movement with the vibration node as a fulcrum.
In addition, the protrusions 503 and 504 are disposed in the vicinity of the position where the vibration occurs in the vibration of Mode-B (push-up mode), and the protrusion front end surfaces 503-1 and 504- are caused by the vibration of Mode-B. 1 reciprocates in the Z direction (also referred to as the push-up direction or normal direction).

By simultaneously exciting and superimposing these two vibration modes (Mode-A and Mode-B) so that the vibration phase difference is in the vicinity of ± π / 2, the protrusion tip surfaces 503-1 and 504-1 have , An elliptical motion in the XZ plane is generated.
By this elliptical motion, the slider 506 in contact with pressure can be driven in one direction.
At this time, the protrusions 503 and 504 of the vibrator 501 and the slider 506 repeat intermittent contact at the driving frequency of the vibrator 501 (several tens of kHz or more), and thus one of them has an appropriate spring characteristic. Otherwise, a good contact state cannot be obtained.
On the other hand, the protrusions 503 and 504 also have a function of amplifying vibration in the X direction as described above.

In order to satisfy these two functions, in Patent Document 2, as shown in FIG. 9, the protrusions 503 and 504 have a spring property and the protrusions 503 and 504 have an appropriate shape. A vibration type actuator (linear type ultrasonic motor) that realizes simple driving has been proposed.
In this vibration type actuator, the projecting portions 609 and 610 having spring properties are processed as separate members and joined to the base portion 602 to form a vibrating body.

Japanese Patent Laid-Open No. 2004-304877 JP 2008-125147 A

However, in the configuration of the vibration type actuator of Patent Document 2, there is a limit to speeding up the motor as described below. As one countermeasure for driving the motor at higher speed, there is a method of increasing the vibration amplitude in the feeding direction (X direction) of the protrusion of the vibrating body.
One method for increasing the vibration amplitude in the feed direction (X direction) is to increase the height of the protrusion.
However, in the vibrating body of the vibration type driving device of Patent Document 1, although it is possible to increase the speed by increasing the height of the protrusion, it is inevitable that the manufacturing cost increases.
On the other hand, in the vibrator 601 of Patent Document 2, when the height of the protruding portion is increased, the rigidity of the protruding portion in the feeding direction is lowered and the driving efficiency is lowered. In addition, it becomes difficult to set the vibration angle at the tip of the protrusion to a desired value in the feed mode (Mode-A). As a result, an unnecessary amplitude in the Z direction is generated, and the contact with the slider may be unstable.

In view of the above problems, the present invention provides a vibrating body in a vibration type driving apparatus and a method for manufacturing the same , and a vibrating type driving apparatus and a vibrator thereof, which can manufacture a vibrating body capable of speeding up at low cost. It is intended to provide.

The vibrating body in the vibration type driving device of the present invention is:
A base where the electromechanical energy conversion element is bonded to the first surface ;
A protrusion provided on the second surface side of the base ,
Have
By applying a voltage to the electro-mechanical energy conversion element, an elliptical motion occurs in the protrusion,
The projecting portion has a cross section perpendicular to the feeding direction of the elliptical motion, and a contact surface between at least two wall portions extending in an out-of-plane direction with respect to the base portion and the driven body connecting between the wall portions. And a contact portion having
The normal direction component of the first surface of the elliptical motion is obtained by an out-of-plane bending vibration mode,
Each boundary portion between the base of the wall, in the normal direction, the direction of displacement is provided in the same position,
The base and the at least one protrusion are integrally formed from one member .

ADVANTAGE OF THE INVENTION According to this invention, the vibration body in the vibration-type drive device which can manufacture the vibration body which can aim at high speed at low cost, its manufacturing method , a vibration-type drive device, and its vibrator | oscillator are implement | achieved. be able to.

It is a perspective view explaining the vibrating body of the vibration type drive device (linear type ultrasonic motor) in Example 1 of this invention. It is a figure explaining the vibrating body of the vibration type drive device in Example 1 of this invention. It is a figure explaining the vibrating body of the vibration type drive device in Example 2 of this invention. It is a figure explaining the vibrating body of the vibration type drive device in Example 3 of this invention. It is a figure showing the tertiary push-up mode in Example 4 of this invention. It is a figure explaining the vibrating body of the vibration type drive device in Example 5 of this invention. It is sectional drawing explaining the primary bending mode (push-up mode) of the vibrating body in Example 1 of this invention. (A) shows a case where the boundary surface between the protrusion and the base is provided between the nodes of vibration in the first bending mode in the Y direction, and (b) shows that the boundary surface is in the first bending mode. It is a figure explaining the case where it is provided in the outer side of the node of a vibration and a node. It is a figure explaining the vibration type drive device (linear type ultrasonic motor) which is a prior art example, (a) is an external appearance perspective view of the linear type ultrasonic motor of patent document 1, (b-1), (b-2) ) Is a diagram showing a vibration mode excited by the vibrator. FIG. 5A is a perspective view of a vibrator of a vibration type actuator (linear ultrasonic motor) described in Patent Document 2 as a conventional example, FIG. 5B is an enlarged view of a protruding portion, and FIG.

  The mode for carrying out the present invention will be described with reference to the following examples.

[Example 1]
As a first embodiment, a configuration example of a vibrating body constituting a vibrator of a vibration type driving device to which the present invention is applied will be described with reference to FIGS.
The vibrator according to the present embodiment includes a vibrator that is bonded to an electromechanical energy conversion element and has one or more protrusions.
The vibrator has a first bending vibration mode vibration in the width direction of the vibrating body and a second bending vibration mode in a direction orthogonal to the width direction of the vibrating body by application to the electromechanical energy conversion element. By the combination with the vibration, the protrusion of the vibrating body moves so as to draw an elliptical locus in the XZ plane.
Thereby, the driven body brought into contact with the protrusion of the vibrating body can be moved in a direction intersecting (typically orthogonal) with the width direction by friction driving.
Specifically, as shown in FIGS. 1 and 2, the vibrator 111 of this embodiment includes a piezoelectric element 107 that is an electro-mechanical energy conversion element formed in a rectangular thin plate shape, and the piezoelectric element 107. And an oscillating body 101 that is joined to and integrated with one end surface of the oscillating member.
The vibrating body 101 is provided with two projecting portions 109 and 110 that come into contact with a slider (not shown) as a driven body, and the slider and the vibrating body 101 are pressurized via the projecting portions 109 and 110. In contact.
When an AC electric field is applied to the piezoelectric element 107, two bending vibration modes are excited in the vibrator 111, and elliptical motion is excited on the contact surfaces of the protrusions 109 and 110.
As a result, the slider in pressure contact with the protrusions 109 and 110 receives the frictional driving force and is driven in the X direction (feed direction).

Here, the configuration of the vibrator 101 constituting the vibrator 111 will be described with reference to FIG.
The vibrating body 101 includes a base 102 and protrusions 109 and 110. These protrusions 109 and 110 are formed in the vicinity of a node portion in the secondary bending mode (feed mode) similar to that shown in FIG.
Here, the protrusions 109 and 110 are constituted by two wall portions 14a and 14b and a contact portion 16 that connects the two wall portions. In this embodiment, there are two wall portions, but the number of wall portions may be increased as necessary. For example, the two wall portions 14a and 14b can be divided into a plurality of portions by providing a slit or the like between them.
The contact portion 16 has a contact surface that is pressed against the slider on the surface.
The two wall portions 14a and 14b provided on the base portion 102 are in the same ZY plane. The wall portion is formed so as to extend in an out-of-plane direction of the base portion, and is typically formed so as to extend in a direction perpendicular to the base portion. It can also be given. The “out-of-plane direction” means a direction that is not parallel to the main surface of the base (the surface on which the protrusion is formed).
That is, the protrusions 109 and 110 have two roots arranged in parallel in a direction parallel to the direction (Y direction) intersecting (typically orthogonal) with the feeding direction (X direction). In the present invention, “parallel” is not limited to the case of being strictly parallel or design error, but may be deviated from parallel in a range that does not cause a practical problem in vibration characteristics. For example, even if it is deviated by 10 ° from the parallel, it is allowed when a desired vibration can be obtained.
The wall portion is formed with a predetermined plate width and plate thickness. In this embodiment, the plate width is formed of a plate-like member larger than the plate thickness, the plate thickness direction of the plate-like member is directed to the width direction of the vibrating member, and the plate width direction of the plate-like member is the width of the vibrating member. It is formed in a direction orthogonal to the direction.
With this configuration, the wall thickness direction of the wall portions 14a, 14b is the Y direction, and the wall portions 14a, 14b are large in the X direction. Predetermined rigidity is ensured.

FIG. 7A is a cross-sectional view of a first-order bending mode as a result of performing FEM analysis (Finite Element Method) in a state where the vibrating body and the piezoelectric element are bonded, and FIG. It is sectional drawing of the secondary bending mode.
In the case of the primary bending mode of the present embodiment, as shown in FIG. 7A, the boundary portions 18a and 18b of the wall portion of the protrusion and the base portion 102 of the vibrating body are in the primary bending mode (protrusion) in the Y direction. It is desirable to be located between the nodes 13a and 13b of the vibration in the raising mode).
That is, in the primary bending mode (push-up mode), the boundary portion between the projection and the base is located at a position (position) where the displacement directions in the Z direction (push-up direction / normal direction) of the main surface of the base are the same. It is desirable to provide 18a and 18b. In the case of this embodiment, the boundary portions 18a and 18b between the projection and the base are provided at locations (positions) that have the same displacement direction as the displacement direction in the Z direction at the center of the base. In the present invention, the above-mentioned “positions in which the directions of displacement are the same” refer to positions that are displaced in the same direction when an arbitrary moment during vibration of the vibrating body is taken out. That is, it refers to a position that is displaced in the same direction at the same moment. Typically, the displacement between adjacent nodes is the same direction of displacement. Conversely, when three nodes are arranged in the order of A, B, and C, the displacement between the nodes A and B and the displacement between the nodes B and C are in opposite directions.

In the present invention, the displacement in the Z direction (push-up direction / normal direction) of the main surface of the base portion refers to a component in the Z direction (push-up direction / normal direction) of the main surface of the base portion in the displacement direction of the displaced portion. As long as it is included.
In the present invention, as shown in FIG. 7B, the boundary portions 18a and 18b can be provided outside the nodes 13a and 13b of the primary bending mode vibration. In this case, as compared with FIG. 7A, the direction of deformation at the center of the base and the center of the contact surface of the protrusion is opposite, and therefore, when the contact surface of the protrusion contacts the slider, Although the transmission efficiency may be relatively lowered, there is no practical problem. This is significant in that the degree of freedom in designing the boundary between the protrusion and the base is improved. However, also in this case, it is necessary to provide the boundary between the protrusion and the base at a location (position) where the displacement directions in the Z direction (the push-up direction / normal direction) of the main surface of the base are the same. If the boundary between the protrusion and the base is provided at a location (position) where the displacement directions in the Z direction (push-up direction / normal direction) of the main surface of the base are different (reverse), the contact surface of the protrusion becomes the slider The transmission of force in the Z direction becomes unstable when it comes into contact with the motor, and stable driving cannot be obtained. As a specific example, in FIG. 7A, a boundary between the protrusion and the base is provided across the node 13b.

In the configuration shown in FIG. 2, the vibrator 111 and the slider can realize a good contact state by further providing the slider with a spring property. Further, by providing the contact portion with a spring property, it is possible to realize a stable contact without giving the slider a spring property. Thus, by providing spring property to at least one of the slider or the contact portion, each contact state can be improved. Further, even if the heights of the projections 109 and 110 are increased for speeding up, the projections 109 and 110 have the rigidity in the X direction, which is the driving direction of the slider, by the wall portions 14a and 14b. The driving force of the child 111 can be efficiently transmitted to the slider.
Further, as compared with the vibrating body 501 having the protrusions 503-1 and 504-1 shown in FIG. 8, the protrusions are the base, the two wall parts, and the contact part that connects between the two wall parts. A hollow structure surrounded by.
Thereby, since there is a space below the contact portion, the bending rigidity in the push-up mode is reduced, and the power efficiency can be improved.
The widths of the wall portions 14a and 14b and the width of the contact portion 16 in the X direction may not be the same.
Further, the widths of the wall portions 14a and 14b do not have to be the same along the Z direction.
For example, if the width of the walls 14a and 14b close to the base portion 102 is increased, the width of the walls 14a and 14b close to the contact portion 16 is decreased and the average width of the walls 14a and 14b is increased, the X direction of the walls 14a and 14b is increased. The rigidity of can be increased.
As a method of manufacturing the vibrating body of the present embodiment, for example, the protrusions 109 and 110 are formed, and the protrusions 109 and 110 are formed on the base 102 by joining such as laser welding or adhesion, whereby the vibration body is manufactured. it can.

[Example 2]
As Example 2, a configuration example of a vibrating body in which a protrusion and a base are integrally formed by providing a plurality of slits or notches at the base and performing drawing will be described with reference to FIG.
In the present embodiment, unlike the first embodiment, as shown in FIG. 3A, the through hole 21 is provided in a partial region of the base 202 under the contact portion 26 of the vibrating body 201.
For this reason, as shown in FIG. 3B, the slits 22 are provided on both sides of the portion to be drawn, and then the drawing is performed, so that the vibrating body 201 including the protrusions can be integrated at a low cost. Can be made.
By providing the through hole 21 in a part of the base 202, less energy is required to generate the thrust vibration, and as a result, driving efficiency can be increased.

[Example 3]
As a third embodiment, a configuration example of a vibrating body in a vibration type driving device having a different form from the above embodiments will be described with reference to FIG.
In this embodiment, unlike the above embodiments, the through hole 31 is provided below the contact portion 36 of the vibrating body 301, and the slit 32 is provided so that the base 302 is divided into two when the protrusion is removed. .
Thereby, the vibrating body including the protrusion can be integrally formed by bending.
By providing the through hole 31 and the slit 32 in a part of the base portion 302, less energy is required to generate the push-up vibration, and as a result, driving efficiency can be increased.

In this embodiment, a stainless material, particularly SUS420J2 or SUS440C having high wear resistance, is used as the material of the vibrator.
A plate having a dimension L4 larger than the total length L5 (dimension in the Y direction) of the vibrator 301 to be manufactured is prepared, and a notch or a slit is provided as shown in FIG.
The height of the protrusion can be set to an arbitrary length by adjusting the dimensions L1 and L2 before processing the vibrator.
The notch is processed by punching or the like by etching or pressing, and then the protrusions 109 and 110 are formed by bending.
The shape after processing is as shown in FIG. 4A, and a part of the notch is a narrow slit. In this way, by forming the protrusions by bending, it is possible to perform the process with almost no change in the plate thickness of the protrusions 109 and 110 before and after processing.
As a result, unlike drawing and forging processes that require a high elongation rate of the plate, there are fewer restrictions on the height and shape of the protrusions that can be produced.
Further, the wall portion 34 having a high rigidity can be formed with less reduction in the plate thickness of the projection portion as compared with the drawing process.

[Example 4]
As a fourth embodiment, a configuration example of a vibrating body in a vibration type driving device having a different form from the above embodiments will be described with reference to FIG.
In this embodiment, the boundary between the base portion and the wall portion of the protruding portion is provided at the same location as the phase of the central portion in the push-up mode.
As the push-up mode, not only a primary bending mode but also a secondary or tertiary bending mode may be used.
For example, in FIG. 5A, the base portion and the piezoelectric element are in a third-order bending mode, and the boundary portion between the wall portion of the protrusion and the base portion has the same phase as the phase including the center portion of the push-up mode. (Position). That is, the boundary between the protrusion and the base is provided at a location (position) where the displacement directions of the base in the Z direction (the push-up direction / normal direction) are the same.
As a result, as shown in the first embodiment, the phase of the two wall portions of the projection and the phase of the center of the contact surface of the projection become the same, and stable driving can be obtained. As shown in FIG. 5B, two boundary portions between the base portion and the wall portion of the projection portion may be provided asymmetrically with respect to the center of the base portion.

[Example 5]
As a fifth embodiment, a configuration example of a vibrating body in a vibration type driving device having a different form from the above embodiments will be described with reference to FIG.
In FIG. 6A, connecting portions 59a, 59b, 59c, and 59d having reduced rigidity in the Z direction are provided between the contact portion 56 and the wall portions 54a and 54b, so that the slider does not have a spring property. Stable contact can be realized.
The upper surface of the contact portion 56 is provided at a higher position than the upper surfaces of the connecting portions 59a, 59b, 59c, and 59d, so that the slider does not contact the connecting portions 59a, 59b, 59c, and 59d.
In such a configuration, the width of the wall portions 54a and 54b and the width 56 of the contact portion can be set independently, so that the width of the wall portion can be increased to further increase the rigidity in the driving direction.

The same applies to FIG. 6B, and by providing the connecting portions 59a and 59b with reduced rigidity in the Z direction between the contact portion 56 and the wall portions 54a and 54b, the slider is stable without having spring properties. Contact can be achieved.
The upper surface of the contact portion 56 is provided at a higher position than the upper surfaces of the connecting portions 59a and 59b, so that the slider does not contact the connecting portions 59a and 59b.
In such a configuration, the width of the wall portions 54a and 54b and the width 56 of the contact portion can be set independently, so that the width of the wall portion can be increased to further increase the rigidity in the driving direction.

13: Node of vibration in push-up mode 14: Wall portion 16: Contact portion 21: Through hole 32: Slit 59: Connection portion 101: Vibrating body 102: Base portion 107: Piezoelectric element 109, 110: Projection portion

Claims (12)

A base where the electromechanical energy conversion element is bonded to the first surface ;
A protrusion provided on the second surface side of the base ,
Have
By applying a voltage to the electro-mechanical energy conversion element, an elliptical motion occurs in the protrusion,
The protrusion has a contact surface between at least two wall portions extending in an out-of-plane direction with respect to the base portion and a driven body connecting between the wall portions in a cross section perpendicular to the feeding direction of the elliptical motion. A contact portion having ,
The normal direction component of the first surface of the elliptical motion is obtained by an out-of-plane bending vibration mode,
Each boundary portion between the base of the wall, in the normal direction, the direction of displacement is provided in the same position,
The vibrating body in the vibration type driving apparatus, wherein the base and the at least one protrusion are integrally formed from one member.   The said protrusion part is made into the hollow structure enclosed by the said base part, the said at least 2 wall part, and the said contact part which connects between this wall part, The Claim 1 characterized by the above-mentioned. A vibrating body in a vibration type driving device.   The vibrating body in the vibration type driving device according to claim 1, wherein the contact portion has a spring property. The wall portion has a predetermined plate width and plate thickness, and the plate width is formed of a plate-like member larger than the plate thickness,
A plate thickness direction of the plate-shaped member is directed to a width direction of the vibrating body, and a plate width direction of the plate-shaped member is formed to face a direction intersecting with the width direction of the vibrating body. The vibrating body in the vibration type driving device according to any one of claims 1 to 3.   The vibration according to any one of claims 1 to 4, wherein a through hole is provided in a partial region of the base portion sandwiched between the protrusion and the electro-mechanical energy conversion element. Vibration body in a mold drive device.   6. The projecting portion is formed integrally with the vibrating body by a member constituting one base through a plurality of slits or notches formed in the base. A vibrating body in the vibration type driving device according to any one of the above.   The vibrating body in the vibration type driving device according to any one of claims 1 to 6, wherein a displacement direction in the normal direction of the central portion of the base portion and a displacement direction of the boundary portion are the same. .   The vibrating body is configured to be able to move a driven body, in which a protruding portion of the vibrating body is pressed and contacted, by applying an AC electric field to the electromechanical energy conversion element in a driving direction. A vibrating body in the vibration type driving device according to any one of claims 1 to 7.   9. The vibrator according to claim 1, wherein an elliptical motion can be generated in a protrusion of the vibrator by applying an alternating electric field to the electro-mechanical energy conversion element. 2. A vibrating body in the vibration type driving device according to item 1. 10. The vibrator in the vibration type driving device according to claim 1, wherein the contact portion and the electromechanical energy conversion element are provided at a position overlapping in the normal direction. A vibrating body in the vibration type driving device according to any one of claims 1 to 10 ,
A vibrator of a vibration type driving apparatus, comprising: the electro-mechanical energy conversion element. A vibrator of a vibration type driving apparatus according to claim 1 1,
A vibration type driving apparatus comprising a moving body that is brought into pressure contact with the vibrator.

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