JP5316075B2 - Fastening structure of vibration actuator - Google Patents

Description

  The present invention relates to a fastening structure for a vibration actuator.

  A vibration actuator for rotating a rotor using ultrasonic vibration has been put into practical use. The vibration actuator uses a piezoelectric element to generate a standing wave or traveling wave on the surface of the stator, presses the rotor against the stator, and rotates the rotor via a frictional force therebetween.

  When the vibration actuator is applied to an actual industrial application, it is necessary to fasten and fix the vibration actuator to some attachment target member. At this time, when the vibration actuator is simply directly attached to the attachment target member and fastened, the vibration system includes the vibration actuator and the attachment target member, and the resonance frequency of the vibration actuator changes. Therefore, the fastening structure of the vibration actuator is required to have a small influence on the vibration of the vibration actuator when fastened and fixed to the attachment target member. Moreover, it is desirable to have high rigidity with respect to the vibration and external force of the vibration actuator.

  For example, Patent Document 1 includes a stator including a plurality of piezoelectric elements that generate longitudinal vibration in the Z-axis direction, flexural vibration in the X-axis direction, and flexural vibration in the Y-axis direction. A cylindrical vibration actuator is described which produces In this vibration actuator, the position of the longitudinal vibration node in the Z-axis direction and the position of the flexural vibration node in the X-axis and Y-axis directions substantially coincide with each other in the design stage, and the flange shape extends outward in the radial direction of the vibration actuator. The support plate is provided in the vicinity of the position of the vibration node, and the support plate is fastened and fixed to the attachment target member. When the vibration actuator vibrates, the flange-shaped support plate bends, so that the influence on the vibration of the vibration actuator when fastened to the member to be attached is fixed.

Japanese Patent Laid-Open No. 11-220892

  However, as described in Patent Document 1, the position of the longitudinal vibration node in the Z-axis direction and the position of the flexural vibration node in the X-axis and Y-axis directions are substantially matched in the design stage, and the vibration actuator In the fastening structure in which the flange-shaped support plate extending radially outward is provided near the position of the vibration node, the degree of freedom in designing the vibration actuator is greatly limited. In addition, in order to suppress the influence on the vibration of the vibration actuator, it is necessary to reduce the rigidity by forming a thin support plate. However, if the rigidity of the support plate is low, the vibration actuator may deteriorate or be damaged when used for a long time. It becomes easy to get up.

  The present invention has been made in order to solve such a problem, and does not limit the freedom of design of the vibration actuator. An object of the present invention is to provide a fastening structure of a vibration actuator that can suppress the influence of the vibration actuator.

In order to solve the above problems, the fastening structure of the vibration actuator according to the present invention includes a stator formed by sandwiching a vibrator between a base block and a stator, a rotor in contact with the stator, and a preload on the rotor. Comprising a vibration actuator, a mounting target member to which the vibration actuator is attached, and a bolt for fastening the vibration actuator to the mounting target member, and constituting a part of the stator of the vibration actuator. The block is provided with a female screw portion, a through hole is formed in the attachment target member, and the bolt shaft portion passes through the through hole of the attachment target member and is screwed into the female screw portion of the base block of the vibration actuator. by, it is fastened to the target member mounting base block of the vibration actuator, groups of the vibration actuator The first vibration isolation member is provided between the block and the mounting target member is sandwiched, between the head portion of the mounting object member and the bolt, characterized in that the second vibration isolation member is sandwiched.

The first vibration insulating member may be a thin plate.
Thereby, when fastening and fixing a vibration actuator, it becomes very small and space-saving.

The second vibration insulating member may have a thin plate shape.
Thereby, when fastening and fixing a vibration actuator, it becomes very small and space-saving.

  The bottom of the base block may be fastened to the attachment target member.

  The side part of the base block may be fastened to the attachment target member.

  The stator may include a plurality of piezoelectric elements.

The outer diameter of the base block may be larger than the outer diameter of the vibrator of the stator.
As a result, when the vibration actuator vibrates, the displacement of the base block of the stator is smaller than the displacement of the portion in contact with the rotor, and the influence on the vibration of the vibration actuator is further increased when fastened to the member to be attached and fixed. It can be suppressed.

  The vibration actuator fastening structure according to the present invention includes a fastening member that fastens the vibration actuator to the attachment target member, and a first vibration insulating member that is sandwiched between the base block of the vibration actuator and the attachment target member. Thereby, the influence which it has on the vibration of a vibration actuator when it fastens to the attachment object member and is fixed is suppressed. Further, there is no limit on the degree of freedom in designing the vibration actuator.

It is a perspective view which shows the vibration actuator which concerns on Embodiment 1 of this invention. It is a front fragmentary sectional view which shows the fastening structure of the vibration actuator which concerns on Embodiment 1 of this invention. It is a bottom view which shows the fastening structure of the vibration actuator which concerns on Embodiment 1 of this invention. It is a front fragmentary sectional view which shows the fastening structure of the vibration actuator which concerns on Embodiment 2 of this invention. It is a bottom view which shows the fastening structure of the vibration actuator which concerns on Embodiment 2 of this invention. It is a front fragmentary sectional view which shows the fastening structure of the vibration actuator which concerns on Embodiment 3 of this invention. It is a bottom view which shows the fastening structure of the vibration actuator which concerns on Embodiment 3 of this invention.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
Embodiment 1 FIG.
A fastening structure for a vibration actuator according to Embodiment 1 of the present invention will be described with reference to FIGS.
First, the configuration of the vibration actuator 10 according to the first embodiment will be described. As shown in FIG. 1, in the vibration actuator 10, a vibrator 13 is sandwiched between a base block 11 and a stator 12, thereby forming a stator 14 having a substantially cylindrical outer shape. The stator 12 has a recess 15 formed on the side opposite to the surface in contact with the vibrator 13, and the lower half of the spherical rotor 16 is accommodated in the recess 15 and is rotatably supported. .
A support member 17 is disposed on the top of the stator 12. The support member 17 has an annular portion 18 fixed on the upper surface of the stator 12 and an inverted L-shaped angle portion 19 extending upward from the annular portion 18, and a preload portion 20 is provided at the tip of the angle portion 19. Is provided.
Further, the outer diameter of the base block 11 of the stator 14 is formed larger than the outer diameter of the vibrator 13, and a tapped hole 11 a in which a female screw is cut is formed at the bottom of the base block 11. Are equally provided at four locations on the same circumference.

Here, for convenience of explanation, the central axis O of the stator 14 from the base block 11 toward the stator 12 is defined as the Z axis, and the X axis is perpendicular to the Z axis and perpendicular to the Z axis and the X axis. It is assumed that the Y-axis extends respectively.
The preload portion 20 is in contact with the vicinity of the apex that is the highest point in the + Z-axis direction of the rotor 16. The angle portion 19 of the support member 17 has elasticity, whereby the preload portion 20 is pressed against the rotor 16 to apply a preload in the −Z-axis direction to the rotor 16.

  The vibrator 13 is for generating ultrasonic vibrations in the stator 12 and rotating the rotor 16 about the X axis. The first piezoelectric element 13a and the Y axis generate longitudinal vibration in the Z axis direction. It comprises a second piezoelectric element 13b that generates a directional deflection vibration.

Next, a structure for fastening the vibration actuator 10 to the attachment target member will be described.
As shown in FIGS. 2 and 3, the disk-shaped fixing plate 30 has a bolt through hole 31 for allowing the shaft portion 40 a of the bolt 40 to pass therethrough, and has the same circumference around the central axis O of the stator 14. Four portions are equally provided on the top, and a male screw is cut at the tip of the shaft portion 40 a of the bolt 40. The shaft portions 40a of the four bolts 40 respectively pass through the bolt through holes 31 of the fixing plate 30 and are screwed into the tap holes 11a of the base block 11 of the vibration actuator 10, whereby the base block of the vibration actuator 10 is obtained. 11 is fastened to the fixed plate 30. Further, between the base block 11 and the fixing plate 30, a thin plate-like (ie, sheet-like) vibration insulating sheet 50 in which the inside is cut out in a circular shape is sandwiched, and the head of the fixing plate 30 and the bolt 40 is sandwiched. A thin plate-like vibration insulating sheet 60, which is also disk-shaped and hollowed out in a circular shape, is sandwiched between the portion 40b.

Next, the operation of the vibration actuator fastening structure according to Embodiment 1 of the present invention will be described.
Now, when an AC voltage having a phase difference of 90 degrees is applied to each of the first piezoelectric element 13a and the second piezoelectric element 13b in the stator 14 of the vibration actuator 10, longitudinal vibration in the Z-axis direction is generated by the first piezoelectric element 13a. And the flexural vibration in the Y-axis direction by the second piezoelectric element 13b combine to generate elliptical motion in the YZ plane in the stator 12 that contacts the rotor 16, and the rotor 16 rotates about the X-axis. At this time, since the vibration of the vibration actuator 10 is insulated by being attenuated by the vibration insulating sheets 50 and 60, the fixing plate 30 hardly vibrates.

As described above, according to the fastening structure of the vibration actuator according to the first embodiment of the present invention, when the vibration actuator 10 vibrates, the vibration is insulated by the vibration insulating sheets 50 and 60. Hardly vibrate. Therefore, the influence on the vibration of the vibration actuator 10 when the fastening plate 30 is fastened and fixed is suppressed.
Further, since the base block 11 of the vibration actuator 10 is fastened to the fixing plate 30 by the bolt 40, it has a high fastening force. Therefore, it has high rigidity with respect to the vibration and external force of the vibration actuator 10.
In addition, since it is not necessary to design the vibration actuator 10 in consideration of the vibration system including the fixed plate 30, the degree of freedom in designing the vibration actuator 10 is not limited.
Furthermore, since no special support mechanism or the like is used, the space is very small.
Since the outer diameter of the base block 11 of the vibration actuator 10 is formed larger than the outer diameter of the vibrator 13, the displacement of the base block 11 is smaller than the displacement of the portion in contact with the rotor 16. This also contributes to suppressing the influence on the vibration of the vibration actuator 10 when fastened to the fixed plate 30 and fixed.

Embodiment 2. FIG.
Next, a fastening structure for a vibration actuator according to Embodiment 2 of the present invention will be described with reference to FIGS. In the following description of the embodiments, the same reference numerals as those in FIG. 1 to FIG. 3 are the same or similar components, and the detailed description thereof will be omitted.

  In the vibration actuator fastening structure according to the first embodiment, the bottom of the base block of the vibration actuator is fastened to the attachment target member. In contrast, in the vibration actuator fastening structure according to the second embodiment, the side portion of the base block of the vibration actuator is fastened to the attachment target member.

Specifically, as shown in FIGS. 4 and 5, in the vibration actuator 210, tapped holes 211 a are equally provided around the central axis O of the stator 214 in the side portion of the base block 211 of the stator 214. It has been. In addition, a box-shaped member 230 that is open at the top and bottom is disposed so as to surround the side surface of the vibration actuator 210, and a bolt through hole 231 is provided at the center of each side of the box-shaped member 230. The shaft portions 240a of the four bolts 240 respectively pass through the bolt through holes 231 of the box-like member 230 and are screwed into the tap holes 211a of the base block 211 of the vibration actuator 210, whereby the base portion of the vibration actuator 210 is obtained. A side portion of the block 211 is fastened to the box-shaped member 230. A vibration insulation sheet 250 is sandwiched between the base block 211 and the box-shaped member 230, and a vibration insulation sheet 260 is sandwiched between the box-shaped member 230 and the head 240 b of the bolt 240. .
Even if such a fastening structure of the vibration actuator is used, the same effect as in the first embodiment can be obtained.

Embodiment 3 FIG.
Next, a vibration actuator fastening structure according to Embodiment 3 of the present invention will be described with reference to FIGS.

  In the vibration actuator fastening structure according to the first or second embodiment, the bolt passes through the attachment target member and is screwed into the tap hole provided in the bottom or side of the base block of the vibration actuator, whereby the vibration actuator is It was fastened to the attachment target member. On the other hand, in the fastening structure of the vibration actuator according to the third embodiment, the bolt passes through the side of the attachment target member and the base block of the vibration actuator and is screwed to the nut, so that the vibration actuator is attached to the member. To be concluded.

  Specifically, as shown in FIGS. 6 and 7, in the vibration actuator 310, a bolt through hole 311 a is provided in the side portion of the base block 311 of the stator 314 along the Y-axis direction. In addition, a box-shaped member 330 whose upper and lower sides are opened is arranged so as to surround the side surface of the vibration actuator 310, and bolt through holes 331a and 331b are provided at the center portions of two opposite sides perpendicular to the Y-axis direction of the box-shaped member 330. Are provided. Then, the shaft portion 340a of one bolt 340 passes through the bolt through hole 331a of the box-shaped member 330, the bolt through hole 311a of the base block 311 of the vibration actuator 310, and the bolt through hole 331b of the box-shaped member 330. By screwing with the nut 370, the base block 311 of the vibration actuator 310 is fastened to the box-shaped member 330. Further, a vibration insulation sheet 350 is sandwiched between the base block 311 and the box-shaped member 330, and a vibration insulation sheet 360 is sandwiched between the box-shaped member 330 and the head 340 b and the nut 370 of the bolt 340. Has been.

  In such a fastening structure of the vibration actuator, since the base block 311 of the vibration actuator 310 and the bolt 340 and the nut 370 are not directly screwed together, a vibration system that does not include the bolt 340 and the nut 370 when the vibration actuator 310 vibrates. Become. Therefore, the influence of the bolt 340 and the nut 370 on the vibration of the vibration actuator 310 is suppressed. Further, no vibration energy is lost between the base block 311 of the vibration actuator 310 and the fastening member.

Other embodiments.

  In the first to third embodiments, the vibration actuator (so-called ultrasonic motor) in which the rotor 16 rotates around the X axis has been described as an example, but the first to third embodiments of the present invention are also applied to other vibration actuators. The fastening structure which concerns on can be used. For example, the present invention is applied to a vibration actuator including a stator that generates longitudinal vibration in the Z-axis direction, flexural vibration in the X-axis direction, and flexural vibration in the Y-axis direction as described in Patent Document 1. The fastening structure according to the first to third embodiments may be used.

  In the first to third embodiments, the vibration actuators 10, 210, and 310 include the stators 14, 214, and 314 including the plurality of piezoelectric elements 13a to 13b. However, the vibration actuator includes the stator including only one piezoelectric element. On the other hand, you may use the fastening structure which concerns on Embodiment 1-3 of this invention.

  In the first to third embodiments, the outer diameters of the base blocks 11, 211, 311 of the stators 14, 214, 314 in the vibration actuators 10, 210, 310 are preferably formed larger than the outer diameter of the vibrator 13. May be the same or smaller.

  In the first to third embodiments, the vibration insulating sheets 50, 250, 350, 60, 260, and 360 have the diameters of the heads 40b of the bolts 40, 240, and 340 as shown in FIGS. Although it is smaller than the diameter of 240b, 340b, it may be larger. Further, the vibration insulating sheets 50, 250, 350, 60, 260, and 360 may have other shapes such as a rectangular shape.

  In the first to third embodiments, the vibration insulating sheets 50, 250, 350, 60, 260, and 360 can be made of rubber, resin, felt, or the like.

  In the first to third embodiments, the vibration insulating sheets 60, 260, and 360 may be omitted.

  In the first and second embodiments, the fastening member may be a pin, a rivet or the like in addition to the bolts 40 and 240.

  The first to third embodiments may be combined so that the bottom and side portions of the base block of the vibration actuator are both fastened to the attachment target member. For example, a rectangular plate may be disposed at the bottom of the box-shaped member 230 in the second embodiment, and the bottom of the base block 211 of the vibration actuator 210 may be fastened to the rectangular plate.

  10, 210, 310 Vibration actuator, 11, 211, 311 Base block, 11a, 211a Tap hole (female thread), 311a Bolt through hole, 13 vibrator, 13a-13b Piezoelectric element, 14, 214, 314 Stator, 30 , 230, 330 Fixing plate, box-shaped member (member to be attached) 31, 231, 331a, 331b bolt through hole, 40, 240, 340 bolt (fastening member), 50, 250, 350 vibration insulating sheet (first Vibration insulation member), 60, 260, 360 vibration insulation sheet (second vibration insulation member), 370 nut (fastening member).

Claims (7)

A fastening structure vibration actuator,
A vibration actuator comprising a stator formed by sandwiching a vibrator between a base block and a stator, a rotor in contact with the stator, and preload means for applying preload to the rotor;
An attachment target member to which the vibration actuator is attached;
Bolts and fastening the vibration actuator to the attachment object member
With
The base block that constitutes a part of the stator of the vibration actuator is provided with a female screw portion, a through hole is formed in the attachment target member, and a shaft portion of the bolt is the through hole of the attachment target member. And the base block of the vibration actuator is fastened to the attachment target member by screwing into the female screw portion of the base block of the vibration actuator.
Between the base block and the mounting target member of said vibration actuator is clamped the first vibration isolation member, a second vibration isolation member is sandwiched between the head portion of the mounting object member and the bolt characterized in that that fastening structure of the vibration actuator. The fastening structure for a vibration actuator according to claim 1 , wherein the first vibration insulating member is a thin plate. Said second vibration isolation member characterized in that it is a thin plate, the fastening structure of the vibration actuator according to claim 1 or 2. The bottom of the base block, characterized in that it is fastened to the mounting object member, the fastening structure of the vibration actuator according to any one of claims 1-3. It said side of the base block, characterized in that it is fastened to the mounting object member, the fastening structure of the vibration actuator according to any one of claims 1-3. The stator is characterized in that it comprises a plurality of piezoelectric elements, fastening structure of a vibration actuator according to any one of claims 1-5. The outer diameter of the base block, and greater than the outer diameter of the transducers in the stator, the fastening structure of the vibration actuator according to any one of claims 1-6.

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