Vibration-type actuator, optical apparatus, and electronic apparatus

Abstract

To reduce variation in performance of a vibration type actuator while sufficiently securing vibration damping performance.SOLUTION: In the vibration type actuator 100, a vibrator 104 including an electromechanical energy conversion element is vibrated to relatively move the vibrator 104 and a contact body 101 in contact with the vibrator 104 in an X direction. The vibration actuator includes the pressing member that presses the vibrator 104 and the contact body 101 in the Z direction intersecting with the X direction, the vibration damping member 117 that is provided in the Z direction with respect to the contact body 101 and damps unnecessary vibration generated in the contact body 101, and the restraint member 116 that is provided on the side opposite to the side on which the contact body 101 is provided in the vibration damping member 117 and has rigidity larger than that of the vibration damping member 117, and is configured such that the vibration damping member 117 does not receive a force in the Z direction generated by pressing of the pressing member.SELECTED DRAWING: Figure 1F

Description

[Technical Field]

[0001] The present invention relates to a vibration actuator, an optical device, and an electronic device. [Background technology]

[0002] A vibration type actuator is known in which a vibrating body using an electromechanical energy conversion element is brought into pressure contact with a contact body, a predetermined vibration is excited in the vibrating body, and a frictional driving force is applied from the vibrating body to the contact body, thereby moving the vibrating body and the contact body relative to each other. Patent Document 1 describes a vibration type actuator in which a vibration-damping member (vibration-damping member) containing a viscoelastic material such as rubber is provided on the contact body in order to suppress unnecessary vibrations that cause abnormal noise. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-108498 Summary of the Invention [Problem to be solved by the invention]

[0004] Specifically, Patent Document 1 describes a first configuration example in which a vibration-damping member, which is a vibration-damping member, is arranged relative to the contact body in the direction in which the pressure unit presses the vibrator and contact body, and the vibration-damping member receives the force generated by the pressure unit. In this first configuration example described in Patent Document 1, if the thickness of the rubber or the like included in the vibration-damping member, which is a vibration-damping member, varies during mass production, the pressure force (pressing force) generated by the pressure unit also varies, and as a result, the performance of the vibration-type actuator is likely to vary.

[0005] Furthermore, Patent Document 1 also describes a second configuration example in which a vibration-damping member, which is a vibration-damping member, is arranged on a side of the contact body that is different from the direction in which the pressure unit presses the vibrator and contact body. In this second configuration example described in Patent Document 1, the vibration-damping member, which is a vibration-damping member, is arranged on a side position of the contact body where distortion is small and which may generate unnecessary vibrations, so vibration damping is insufficient.

[0006] The present invention has been made in view of the above problems, and has an object to reduce the variation in performance of a vibration-type actuator while ensuring sufficient vibration damping. [Means for solving the problem]

[0007] The vibration actuator of the present invention is a vibration actuator comprising a vibrating body including an electromechanical energy conversion element and a contact body in contact with the vibrating body, in which the vibrating body and the contact body move relatively in a first direction by vibrating the vibrating body, and further comprising: a pressing member that presses the vibrating body and the contact body in a second direction that intersects with the first direction; a vibration damping member that is provided in the second direction relative to the contact body and damps unnecessary vibrations generated in the contact body; and a restraint member that is provided on the vibration damping member opposite the side on which the contact body is provided and has greater rigidity than the vibration damping member, and is configured so that the vibration damping member is not subjected to a force in the second direction generated by the pressing of the pressing member. [Effects of the Invention]

[0008] According to the present invention, it is possible to reduce variations in the performance of a vibration-type actuator while ensuring sufficient vibration damping. [Brief explanation of the drawings]

[0009] [Figure 1A] 1 is a perspective view showing a schematic configuration of a vibration type actuator according to a first embodiment. [Figure 1B] FIG. 1B is an exploded perspective view of the vibration actuator shown in FIG. 1A. [Figure 1C] FIG. 1B is a cross-sectional perspective view of the vibration actuator shown in FIG. 1A. [Figure 1D] 1B is a view of the vibration actuator shown in FIG. 1A as viewed from the positive Z direction (+Z direction). [Figure 1E] 1B is a view of the vibration actuator shown in FIG. 1A as viewed from the negative Z direction (−Z direction). [Figure 1F] 1F is a cross-sectional view of the vibration actuator shown in FIG. 1E taken along the cross section BB. [Figure 2A] 1 is a diagram illustrating a first vibration mode (hereinafter referred to as "mode A") of two bending vibration modes excited in a vibrating body in a vibration actuator according to a first embodiment. FIG. [Figure 2B] 4 is a diagram for explaining a second vibration mode (hereinafter referred to as "mode B") of two bending vibration modes excited in the vibrating body in the vibration actuator according to the first embodiment. FIG. [Figure 3A] 2A and 2B are diagrams showing an example of the configuration of a vibrating body, a contact body, a vibration damping member, a restraining member, a fixed-side guide member, and rolling balls in the vibration actuator according to the first embodiment. [Figure 3B] 2A and 2B are diagrams showing an example of the configuration of a vibrating body, a contact body, a vibration damping member, a restraining member, a fixed-side guide member, and rolling balls in the vibration actuator according to the first embodiment. [Figure 3C] 2A and 2B are diagrams showing an example of the configuration of a vibrating body, a contact body, a vibration damping member, a restraining member, a fixed-side guide member, and rolling balls in the vibration actuator according to the first embodiment. [Figure 3D] 2A and 2B are diagrams showing an example of the configuration of a vibrating body, a contact body, a vibration damping member, a restraining member, a fixed-side guide member, and rolling balls in the vibration actuator according to the first embodiment. [Figure 3E] 2A and 2B are diagrams showing an example of the configuration of a vibrating body, a contact body, a vibration damping member, a restraining member, a fixed-side guide member, and rolling balls in the vibration actuator according to the first embodiment. [Figure 3F]2A and 2B are diagrams showing an example of the configuration of a vibrating body, a contact body, a vibration damping member, a restraining member, a fixed-side guide member, and rolling balls in the vibration actuator according to the first embodiment. [Figure 3G] 2A and 2B are diagrams showing an example of the configuration of a vibrating body, a contact body, a vibration damping member, a restraining member, a fixed-side guide member, and rolling balls in the vibration actuator according to the first embodiment. [Figure 3H] 2A and 2B are diagrams showing an example of the configuration of a vibrating body, a contact body, a vibration damping member, a restraining member, a fixed-side guide member, and rolling balls in the vibration actuator according to the first embodiment. [Figure 3I] 2A and 2B are diagrams showing an example of the configuration of a vibrating body, a contact body, a vibration damping member, a restraining member, a fixed-side guide member, and rolling balls in the vibration actuator according to the first embodiment. [Figure 4] 5A and 5B are diagrams showing examples of experimental results of vibration damping properties of the vibration actuator according to the first embodiment and a vibration actuator according to a comparative example. [Figure 5] FIG. 10 is a top view showing an example of a schematic configuration of an imaging device that is an optical apparatus according to a second embodiment. [Figure 6] FIG. 10 is a perspective view showing an example of a schematic configuration of an industrial robot that is an electronic device according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0011] (First embodiment) First, the first embodiment will be described.

[0012] FIG. 1A is a perspective view showing a schematic configuration of a vibration actuator 100 according to a first embodiment. FIG. 1A illustrates an XYZ coordinate system in which the vertical direction is the Z direction and two mutually orthogonal directions defining a horizontal plane orthogonal to the Z direction are the X and Y directions. FIG. 1B is an exploded perspective view of the vibration actuator 100 shown in FIG. 1A. FIG. 1C is a cross-sectional perspective view of the vibration actuator 100 shown in FIG. 1A. FIG. 1D is a view of the vibration actuator 100 shown in FIG. 1A as seen from the positive Z direction (+Z direction). FIG. 1E is a view of the vibration actuator 100 shown in FIG. 1A as seen from the negative Z direction (-Z direction). FIG. 1F is a cross-sectional view of the vibration actuator 100 shown in FIG. 1E, taken along the line BB. In FIGS. 1A to 1F, the same components are designated by the same reference numerals. FIGS. 1B to 1F also illustrate an XYZ coordinate system corresponding to the XYZ coordinate system shown in FIG. 1A.

[0013] 1B and 1F, the vibration actuator 100 has a vibrating body 104 and a contact body 101 that contacts the vibrating body 104. In this embodiment, the vibrating body 104 is rectangular. As shown in FIG. 1F, the vibrating body 104 has a flat elastic body 102, a piezoelectric element 103 that is an electromechanical energy conversion element bonded to one surface of the elastic body 102, and two protrusions 5 provided on the other surface of the elastic body 102.

[0014] Here, two bending vibration modes excited in the vibrating body 104 will be described with reference to FIGS. 2A and 2B.

[0015] FIG. 2A is a diagram illustrating a first vibration mode (hereinafter referred to as "mode A") of two bending vibration modes excited in the vibrating body 104 in the vibration actuator 100 according to the first embodiment. In FIG. 2A, the same components as those shown in FIG. 1F are denoted by the same reference numerals, and detailed description thereof will be omitted. FIG. 2A also illustrates an XYZ coordinate system corresponding to the XYZ coordinate system shown in FIGS. 1A to 1F. In the vibrating body 104, a common electrode (full-surface electrode) (not shown) is formed on the surface of the piezoelectric element 103 facing the elastic body 102, and a driving electrode (not shown) divided into two equal parts in the length direction is formed on the surface of the piezoelectric element 103 opposite the elastic body 102 side. The mode A shown in FIG. 2A is a second-order bending vibration in the longitudinal direction (X direction) of the vibrating body 104, and has three nodal lines substantially parallel to the lateral direction (Y direction (width direction)) of the vibrating body 104. By applying an alternating voltage with a predetermined frequency and a phase shift of 180° to the drive electrode of the piezoelectric element 103, it is possible to excite A-mode vibration in the vibrating body 104. The protrusion 5 is disposed near a position that becomes a node in the A-mode vibration, and when A-mode vibration is excited in the vibrating body 104, it performs a reciprocating motion in the X direction.

[0016] FIG. 2B is a diagram illustrating a second vibration mode (hereinafter referred to as "B mode") of the two bending vibration modes excited in the vibrating body 104 in the vibration actuator 100 according to the first embodiment. FIG. 2B illustrates an XYZ coordinate system corresponding to the XYZ coordinate systems illustrated in FIGS. 1A to 1F. The B mode is a primary bending vibration in the short-side direction (Y direction) of the vibrating body 104, and has two nodal lines that are approximately parallel to the long-side direction (X direction) of the vibrating body 104. B-mode vibration can be excited in the vibrating body 104 by applying an in-phase alternating voltage at a predetermined frequency to the drive electrodes of the piezoelectric element 103. The protrusions 5 are disposed near positions that correspond to antinodes in the B-mode vibration, and reciprocating motion occurs in the axial direction (Z direction) of the protrusions 5 when B-mode vibration is excited in the vibrating body 104.

[0017] The vibrating body 104 is configured so that the nodal lines in the A mode and the B mode are approximately perpendicular in the XY plane. A flexible substrate (not shown) is attached to the piezoelectric element 103, and by supplying an AC current to the piezoelectric element 103 through this flexible substrate, it is possible to simultaneously excite the vibrating body 104 in the A mode and the B mode. Therefore, by exciting the A mode and the B mode vibrations with a predetermined phase difference, it is possible to generate elliptical motion at the tip of the protrusion 5 in the ZX plane.

[0018] In the vibration actuator 100, the vibrating body 104 is in contact with the contact body 101. Therefore, by simultaneously exciting the vibrating body 104 to vibrations in A mode and B mode, the vibrating body 104 moves relatively to the contact body 101 due to the approximately elliptical motion generated at the tips of the two protrusions 5. In this embodiment, the direction in which the vibrating body 104 and the contact body 101 move relatively to each other by vibrating the vibrating body 104 (first direction: in this embodiment, for example, the X direction) is set as the drive direction.

[0019] Here, we return to the explanation of FIGS. 1 to 1F. 1A and 1B, tension springs 110 (pressure members) are arranged at four locations around the vibrating body 104, and generate a pressure force that presses the vibrating body 104 and the contact body 101 together to bring them into pressure contact. Note that the configuration does not necessarily require four springs 110 to apply the pressure force, and the type of spring 110 is not limited to tension springs. In this embodiment, the direction of the pressure force that presses the vibrating body 104 and the contact body 101 into pressure contact is defined as the pressure direction, and this pressure direction is defined as the Z direction in FIGS. 1A to 1F.

[0020] As shown in Figures 1A and 1B, one end of each of the four springs 110 is supported by the pressure plate 109, and the other end of each of the four springs 110 is supported by the movable side guide member 115, generating a pressure force that brings the vibrating body 104 and the contact body 101 into pressurized contact.

[0021] 1B, the pressure plate 109 contacts the elastic member attaching member 126 and transmits the pressure force of the spring 110 to the elastic member attaching member 126. The elastic member 106 is disposed between the elastic member attaching member 126 and the vibrating body 104 (piezoelectric element 103). The elastic member attaching member 126 and the elastic member 106 are members that prevent direct contact between the pressure plate 109 and the vibrating body 104 (piezoelectric element 103) and prevent damage to the vibrating body 104 (piezoelectric element 103), but one or both of them may be omitted.

[0022] As shown in FIG. 1B, the movable-side guide member 115 has two movable-side rolling grooves 115a that are substantially V-shaped grooves, and a rolling ball 114 is disposed in each of the movable-side rolling grooves 115a. The movable-side guide member 115 also has a hook portion for fixing the spring 110. On the other hand, as shown in FIG. 1F, the fixed-side guide member 113 has a fixed-side rolling groove 113a that is a substantially trapezoidal groove. The rolling ball 114 is sandwiched between the fixed-side rolling groove 113a of the fixed-side guide member 113 and the movable-side rolling groove 115a of the movable-side guide member 115. This sandwiching is performed by the spring 110, and the sandwiching force is the same as the pressure force that pressurizes and contacts the vibrating body 104 and the contact body 101.

[0023] The vibrating body 104 moves relative to the contact body 101 by a guide mechanism formed by the fixed side rolling groove 113a, the rolling balls 114, and the movable side rolling groove 115a.

[0024] 1B and 1C holds the vibrating body 104 by holding the arms extending from the flat plate portion of the elastic body 102. When holding the arms of the elastic body 102, the vibrating body holding member 105 holds the nodes or the vicinity of the nodes of the vibration excited in the vibrating body 104. The vibrating body holding member 105 and the elastic body 102 are fixed together with an adhesive or the like.

[0025] 1B is connected to the vibrating body holding member 105 via a thin metal plate 108. In this case, the relative movement between the vibrating body holding member 105 and the movable frame member 107 in the drive direction is restricted more than the relative movement in the direction of the pressure force. With this configuration, it is possible to bring the vibrating body 104 into stable pressure contact with the contact member 101 while suppressing rattles between the vibrating body holding member 105 and the movable frame member 107 in the drive direction. Note that the configuration for connecting the movable frame member 107 and the vibrating body holding member 105 is not limited as long as it has a configuration that can obtain the same effect as the thin metal plate 108.

[0026] Here, the configurations of the contact body 101, vibration damping member 117, restraining member 116, fixed-side guide member 113, and fixed frame member 118 shown in FIGS. 1A to 1F will be described.

[0027] As shown in FIG. 1C , the contact body 101 is fixed at both ends in the driving direction to a fixed frame member 118, which is a fixed member made of resin, with screws. The resin material constituting the fixed frame member 118 is preferably at least one of LCP resin, ABS resin, and carbon fiber reinforced PC resin, which have vibration damping properties. Furthermore, a fixed-side guide member 113, which is made of metal and guides the relative movement between the vibrating body 104 and the contact body 101, is also fixed to the fixed frame member 118 at both ends in the driving direction with screws (not shown). That is, in this embodiment, the contact body 101, vibration damping member 117, restraining member 116, fixed-side guide member 113, and fixed frame member 118 are integrated. In the example shown in FIG. 1C , the fixed-side guide member 113 is connected to the contact body 101 via the fixed frame member 118, which is a fixed member. Furthermore, rolling balls 114, which are rolling members, roll on the surface (the lower surface in FIG. 1C ) of the fixed-side guide member 113.

[0028] 1F, fixed-side rolling grooves 113a having convex portions extending in the X direction are formed in the fixed-side guide member 113. The position of the fixed-side rolling grooves 113a having convex portions is such that they overlap the protrusions 5 of the vibrating body 104 in the Z direction. The fixed-side rolling grooves 113a having convex portions are formed by, for example, press working, and the side opposite to the side having the convex portions is formed as concave portions 113b, forming a rolling groove in which the rolling balls 114 roll.

[0029] 1B and 1F is provided in the Z direction, which is a second direction intersecting (more specifically, perpendicular to) the first direction described above, with respect to the contact body 101. Specifically, the vibration damping member 117 extends in the X direction like the contact body 101, and is in contact with the contact body 101 on the side opposite to the vibrating body 104, and has the function of damping unnecessary vibrations generated in the contact body 101. Furthermore, the surface of the vibration damping member 117 opposite to the surface in contact with the contact body 101 is in contact with the restraining member 116.

[0030] From the viewpoint of vibration damping performance, it is desirable that the width of the vibration damping member 117 is equal to or larger than the width of the contact body 101. Note that the width of each member here refers to the length of each member in the Y direction (the direction perpendicular to the first direction described above).

[0031] The vibration damping member 117 is preferably formed from rubber or resin with high vibration damping properties (for example, a high vibration damping rate). When the vibration damping member 117 is formed from rubber, it is preferable to use, for example, butyl rubber, butadiene rubber, silicone rubber, or the like. When butyl rubber is used as the material for the vibration damping member 117, the butyl rubber preferably has a high hardness of 50° or 70°. The shear deformation of the vibration damping member 117 caused by bending vibration converts the vibration energy of unnecessary out-of-plane vibrations generated in the contact body 101 into thermal energy, thereby damping the unnecessary vibrations generated in the contact body 101.

[0032] As a further effect, although the vibration damping member 117 has elasticity, it is not clamped or crushed by the contact body 101 and the fixed-side guide member 113, and therefore does not generate an elastic reaction force on the contact body 101 and the fixed-side guide member 113. With this configuration, deformation of the contact body 101, the fixed frame member 118 connected to the contact body 101, etc. due to the vibration damping member 117 does not occur.

[0033] If the vibration damping member 117 were thick enough to be crushed when sandwiched between the contact body 101 and the fixed-side guide member 113, the contact body 101 would receive a reaction force and bend at the center relative to both ends. As a result, when the vibrating body 104 is positioned at the center, the spring 110 for applying pressure would stretch by the length of the bent contact body 101, increasing the pressure and increasing power consumption, but the configuration of this embodiment can avoid such a problem.

[0034] In this embodiment, the vibration damping member 117 is more likely to have dimensional variations between lots than the other members that make up the vibration actuator 100, but the dimensions of each member are set so that even if the thickness reaches the upper limit of the tolerance, there will be no interference between the fixed-side guide member 113 and the restraint member 116. This prevents variations in pressure force due to variations in the thickness of the vibration damping member 117, and makes it possible to reduce variations in the drive performance of the vibration actuator 100.

[0035] 1B and 1F is a member for restraining (shear) deformation of the vibration damping member 117. This restraining member 116 is provided on the side of the vibration damping member 117 opposite to the side on which the contact body 101 is provided, and is a member with greater rigidity than the vibration damping member 117. In the vibration actuator 100 of this embodiment, as shown in FIG. 1F, the restraining member 116 is configured not to contact the fixed-side rolling groove 113a having a convex portion of the fixed-side guide member 113. This configuration of the vibration actuator 100 prevents the vibration damping member 117 from substantially receiving a pressing force generated by the action of the spring 110, which is a pressing member for pressing the contact body 101 and the vibrating body 104. In this embodiment, a gap between the restraining member 116 and the fixed-side guide member 113 in the Z direction, which is the second direction described above, prevents the vibration damping member 117 from receiving a pressing force generated by the action of the spring 110. At this time, the pressing force generated by the action of the spring 110 is a force in the Z direction, which is the second direction described above. In this embodiment, it is preferable that at least one of gas containing air, cotton, felt, gel, grease, and a foam material is present in the gap between the restraining member 116 and the fixed-side guide member 113 in the Z direction.

[0036] It is not necessary to provide one vibration damping member 117 and one constraint member 116, but a multi-layer structure may be used in which a plurality of vibration damping members 117 and a plurality of constraint members 116 are alternately arranged. By using this multi-layer structure, the vibration amplitude of unnecessary vibrations generated in contact body 101 can be effectively reduced.

[0037] 3A to 3I are diagrams showing examples of the configuration of the vibration actuator 100 according to the first embodiment, including the vibrating body 104, the contact body 101, the vibration damping member 117, the restraining member 116, the fixed-side guide member 113, and the rolling balls 114. These Figures 3A to 3I show an XYZ coordinate system corresponding to the XYZ coordinate system shown in Figures 1A to 1F.

[0038] As shown in FIGS. 3A to 3H , the fixed-side guide member 113 has a wall portion 113c protruding in the Z direction and has a concave (U-shaped) cross section. Providing the wall portion 113c on the fixed-side guide member 113 increases its rigidity and mass, thereby improving vibration damping. In this embodiment, the fixed frame member 118 (made of resin with excellent vibration damping properties) to which the contact body 101 is fixed plays a role similar to that of rubber, and the fixed-side guide member 113 (made of metal) fixed to the fixed frame member 118 also plays a role as the restraining member 116. This is because the greater the difference in bending rigidity between the fixed frame member 118 and the fixed-side guide member 113, the greater the deformation and slippage at the interface, increasing loss in the fixed frame member 118 and improving damping performance. This is because the greater the difference in rigidity, the greater the deformation and slippage at the interface, which generates shear stress. The vibration-damping member 117 absorbs this shear stress as internal friction and dissipates the energy as heat. This increases the energy loss in the vibration damping member 117, improving the overall vibration damping performance.

[0039] 3A and 3B, the vibration damping member 117 and the constraint member 116 are provided on the side of the contact body 101 opposite to the side on which the vibrating body 104 is provided. In addition, in FIGS. 3A and 3B, the constraint member 116 has a bent portion (which may also be referred to as a "wall portion") 116a protruding in the Z direction, giving it a concave cross-sectional shape. Providing the bent portion 116a in the constraint member 116 increases the rigidity (moment of inertia) and mass, thereby improving vibration damping. This is because the greater the difference between the bending rigidity of the vibration damping member 117 (e.g., rubber) and the bending rigidity of the constraint member 116 (metal plate), the greater the deformation and slippage at the interface, increasing loss in the vibration damping member 117 and improving damping performance. In this embodiment, the orientation of the bent portion 116a of the constraint member 116 is determined taking into account the space of the vibration actuator 100.

[0040] 3C, the vibration-damping member 117 and the restraining member 116 are provided on the side of the contact body 101 opposite to the side on which the vibrating body 104 is provided. Furthermore, in FIG. 3C, the restraining member 116 has a bent portion 116a protruding in the Z direction and a through hole 116b extending in the X direction. In this embodiment, the position of the hole 116b of the restraining member 116 is such that it overlaps with the convex portion of the fixed-side guide member 113 in the Z direction (the convex portion of the fixed-side rolling groove 113a shown in FIG. 1F). As shown in FIG. 3C, the shape of the restraining member 116 is designed to avoid interference with the fixed-side guide member 113, and the thickness of the restraining member 116 can be increased to improve vibration damping.

[0041] 1 to 1F, the high adhesive strength of the vibration-damping member 117 is utilized to integrate the vibration-damping member 117 with the contact body 101 and the restraining member 116 by applying pressure once. After that, even if the pressure is released and the vibration-type actuator 100 is constructed by combining the vibration-damping member 117 with other members, the adhesive strength of the vibration-damping member 117 will prevent the vibration-damping member 117 from peeling off.

[0042] However, depending on the material and hardness of vibration damping member 117, and the materials and surface roughness of contact body 101 and restraining member 116, the adhesive strength between vibration damping member 117 and contact body 101 and restraining member 116 may be insufficient, resulting in peeling. For example, butyl rubber, which can be used as the material for vibration damping member 117, has higher vibration damping properties when the hardness is 70° than when it is 30°, but the adhesive strength is lower at 70°. Furthermore, in order to further improve vibration damping, if the material of contact body 101 is made of resin except for the portion that comes into contact with vibrating body 104, the adhesive strength will be reduced.

[0043] 3D and 3E show examples of configurations in which double-sided tape or adhesive is used as vibration damping member 117 in addition to rubber in order to improve the peel strength of rubber that can be used as the material for vibration damping member 117.

[0044] In FIG. 3D, vibration damping member 117 and restraining member 116 are provided on the side of contact body 101 opposite to the side on which vibrating body 104 is provided. Furthermore, in FIG. 3D, vibration damping member 117 is configured with rubber 117a and double-sided tape 117b between rubber 117a and contact body 101 and between contact body 101 and restraining member 116. Double-sided tape 117b is preferably a rubber-based double-sided adhesive tape with a thickness of 0.1 mm, containing a special rubber-based adhesive as a component. Using this double-sided tape 117b can improve vibration damping, particularly at high temperatures. Note that an adhesive (such as a cyanoacrylate adhesive) may be used instead of double-sided tape 117b.

[0045] In Fig. 3E, vibration damping member 117 and constraint member 116 are provided on the side of contact body 101 opposite to the side on which vibrating body 104 is provided. Moreover, in Fig. 3E, vibration damping member 117 is configured to include rubber 117a and adhesive 117c that bonds rubber 117a, contact body 101, and constraint member 116. In Fig. 3E, adhesive 117c is applied in advance to predetermined locations on constraint member 116, and then rubber 117a and contact body 101 are assembled under pressure, and adhesive 117c is cured to integrate them.

[0046] 3F, vibration damping member 117 and restraining member 116 are provided on the side of contact body 101 where vibrating body 104 is provided. Specifically, in FIG. 3F, vibration damping member 117 is provided on the surface of contact body 101 that comes into contact with vibrating body 104. When contact body 101 is sufficiently wide or when protrusion 5 of vibrating body 104 has a large height, the contact area and thickness of vibration damping member 117 can be made sufficiently large, and out-of-plane vibration of the surface that comes into contact with vibrating body 104 can be effectively damped.

[0047] In Fig. 3G, vibration damping member 117 and restraining member 116 are provided on the side of contact body 101 where vibrating body 104 is provided. Specifically, in Fig. 3G, the YZ cross section of contact body 101 has a convex shape, and vibration damping member 117 and restraining member 116 are provided on a thinner portion of contact body 101. In the configuration example shown in Fig. 3G, the thickness of vibration damping member 117 and restraining member 116 can be increased, thereby improving vibration damping performance.

[0048] In Fig. 3H, vibration damping member 117 and restraining member 116 are provided on the side of contact body 101 where vibrating body 104 is provided. Specifically, in Fig. 3H, the YZ cross section of contact body 101 is approximately dumbbell-shaped, and vibration damping member 117 and restraining member 116 are provided in the thicker part of contact body 101. In the configuration example shown in Fig. 3H, for out-of-plane vibration of contact body 101 that is desired to be reduced, vibration can be effectively suppressed by arranging vibration damping member 117 and restraining member 116 in a position far from the neutral plane.

[0049] In Fig. 3I, vibration damping member 117 and restraining member 116 are provided on the side of contact body 101 opposite to the side on which vibrating body 104 is provided. In addition, in Fig. 3E, contact body 101 also serves the function of fixed-side guide member 113. Specifically, in the configuration example shown in Fig. 3G, rolling balls 114 roll on the surface (lower surface) of contact body 101 opposite to the surface (upper surface) that comes into contact with vibrating body 104.

[0050] 4 is a diagram showing an example of experimental results of vibration damping performance of the vibration actuator 100 according to the first embodiment and a vibration actuator according to a comparative example. A method for evaluating the vibration damping performance shown in FIG. 4 will be described below.

[0051] FIG. 4 shows experimental results of vibration damping for the vibration actuator 100 according to the first embodiment of the present invention and the vibration actuators according to Comparative Examples 1 and 2. For each of these three vibration actuators, a vibrating body 104 including a piezoelectric element 103 was first placed at the center of a contact body 101. The contact body 101, vibration-damping member 117, restraining member 116, and fixed-side guide member 113 were then attached to a fixed frame member 118. Gmax, the maximum value of the real part of the admittance of the piezoelectric element 103, was measured using an impedance measuring device in the frequency range of 1 kHz to 100 kHz. Several peaks appeared within the measured frequency range, and the highest Gmax value near 65 kHz was extracted. FIG. 4 shows the average value of measurements taken for three units of the vibration actuator 100 according to the first embodiment of the present invention and the vibration actuators according to Comparative Examples 1 and 2. In FIG. 4, a smaller Gmax indicates better vibration damping. From the FEM analysis, it is considered that the fifth mode out of the plane of the contact body 101 is excited around 65 kHz.

[0052] 4, the characteristics of the present invention indicated by the solid line show the experimental results of the vibration damping performance of the vibration actuator 100 shown in Fig. 3E among the vibration actuators 100 according to the first embodiment of the present invention. In this case, butyl rubber with a hardness of 70° was used as the vibration damping member 117.

[0053] 4, the characteristics of Comparative Example 1, indicated by the dotted line, show the results of an experiment on the vibration damping properties of a vibration actuator that does not use the constraint member 116 of the vibration actuator 100 according to the present invention, but instead uses a thick piece of butyl rubber with a hardness of 70° as the vibration damping member 117. The vibration actuator of Comparative Example 1 is configured so that the rubber that constitutes the vibration damping member 117 is sandwiched and crushed between the contact body 101 and the fixed-side guide member 113.

[0054] In Figure 4, the characteristics of Comparative Example 2, shown by the dotted line, show the experimental results of the vibration damping properties of a vibration actuator in which the hardness of the butyl rubber used as the vibration damping member 117 is changed to 30° compared to the vibration actuator of Comparative Example 1 described above.

[0055] 4, it can be seen that the vibration damping performance of the vibration actuator 100 according to the present invention is superior to the vibration damping performance of the vibration actuators according to Comparative Examples 1 and 2, and has a higher vibration damping effect. In particular, the vibration actuators according to Comparative Examples 1 and 2 exhibit poor vibration damping performance at 45°C, which is higher than 25°C, but the vibration actuator 100 according to the present invention exhibits good vibration damping performance at this high temperature.

[0056] The vibration actuator 100 according to the first embodiment described above includes a vibrating body 104 including a piezoelectric element 103, which is an electromechanical energy conversion element, and a contact body 101 that contacts the vibrating body 104. The vibration actuator 100 according to the first embodiment is a vibration actuator in which the vibrating body 104 and the contact body 101 move relatively in a first direction (for example, the X direction in this embodiment) by vibrating the vibrating body 104. In addition, the vibration actuator 100 according to the first embodiment includes a spring 110 that is a pressing member that presses the vibrating body 104 and the contact body 101 in a second direction (for example, the Z direction in this embodiment) that intersects with the first direction. The vibration actuator 100 according to the first embodiment also includes a vibration damping member 117 that is provided in the second direction relative to the contact body 101 and damps unwanted vibrations generated in the contact body 101. Furthermore, the vibration actuator 100 according to the first embodiment has a constraint member 116 that is provided on the side of the vibration damping member 117 opposite to the side on which the contact body 101 is provided, and that has greater rigidity than the vibration damping member 117. The vibration actuator 100 according to the first embodiment is configured so that the vibration damping member 117 is not subjected to a force in the second direction that is generated by the pressing of the spring 110, which serves as a pressing member. For example, the vibration actuator 100 according to the first embodiment is configured so that the vibration damping member 117 is not subjected to a force in the second direction that is generated by the pressing of the spring 110, due to a gap in the second direction between the constraint member 116 and the fixed-side guide member 113. According to this configuration, it is possible to reduce variations in the performance of the vibration actuator 100 while ensuring sufficient vibration damping.

[0057] (Second embodiment) Next, a second embodiment will be described. In the following description of the second embodiment, matters common to the first embodiment will be omitted, and only matters different from the first embodiment will be described.

[0058] The second embodiment is in the form of an optical device or electronic device that includes the vibration actuator 100 according to the first embodiment described above.

[0059] Fig. 5 is a top view showing an example of a schematic configuration of an imaging device 500, which is an optical device according to the second embodiment. The imaging device 500 shown in Fig. 5 is configured to include the vibration actuator 100 according to the first embodiment described above.

[0060] The imaging device 500 includes a camera body 510 equipped with a vibration actuator 100, an imaging element 511, and a power button 512. The imaging device 500 also includes the vibration actuator 100 and a lens barrel 520 equipped with a lens group 521 that is an optical element. The lens barrel 520 is replaceable as an interchangeable lens, and a lens barrel 520 suitable for a subject to be photographed by the imaging device 500 can be attached to the camera body 510.

[0061] The vibration actuator 100 mounted on the lens barrel 520 mechanically drives a lens group 521, which is an optical element. In this case, the driving of the lens group 521 by the vibration actuator 100 is considered to be suitable for driving an autofocus lens, but is not limited to this and may also be applicable to driving a zoom lens, for example.

[0062] The vibration actuator 100 mounted on the camera body 510 mechanically drives the image pickup element 511 .

[0063] In the example shown in FIG. 5, the vibration actuator 100 can also be used to drive the lens group 521 or the image pickup element 511 during image stabilization.

[0064] Fig. 6 is a perspective view showing an example of a schematic configuration of an industrial robot 600, which is an electronic device according to the second embodiment. Here, Fig. 6 illustrates a horizontal articulated robot as an example of the industrial robot 600.

[0065] The industrial robot 600 has an arm joint 611, a hand 612, and an arm 620. The arm joint 611 connects the two arms 620 so that the angle at which the two arms 620 intersect can be changed. As shown in Fig. 6, the hand 612 has the arm 620, a gripper 621 attached to one end of the arm 620, and a hand joint 622 connecting the arm 620 and the gripper 621.

[0066] The vibration actuator 100 according to the first embodiment is built into an arm joint 611 or a gripping portion 621, and mechanically drives the arm joint 611 or the gripping portion 621, which are members to be driven, to adjust the angle or rotate the arm 620 or the hand joint 622. Note that for the bending operation of the arm joint 611, which is an example of a member to be driven, or the gripping operation of the gripping portion 621, the vibration actuator 100, which has a TN characteristic (drooping characteristic indicating the relationship between load torque and rotation speed) of high torque at low rotation speed, is preferably used.

[0067] In the second embodiment, an imaging device 500 (optical device) shown in Fig. 5 and an industrial robot 600 (electronic device) shown in Fig. 6 are exemplified as devices having the vibration actuator 100 according to the first embodiment described above, but the present invention is not limited to these devices. For example, an XY stage can be cited as a device that can drive a flat contact body 101 in any direction within its plane.

[0068] According to the second embodiment, it is possible to provide an optical device or an electronic device that includes the vibration actuator 100 in which the performance variation is reduced while ensuring sufficient vibration damping.

[0069] It should be noted that the above-described embodiments of the present invention are merely illustrative examples of the implementation of the present invention, and the technical scope of the present invention should not be construed as being limited by these. In other words, the present invention can be implemented in various forms without departing from its technical concept or main features.

[0070] The disclosure of this embodiment includes the following configuration. [Configuration 1] a vibrating body including an electromechanical energy conversion element; a contact body that comes into contact with the vibrating body; a vibration type actuator including: a vibration body that vibrates to cause the vibration body and the contact body to move relatively in a first direction; a pressing member that presses the vibrating body and the contact body in a second direction that intersects with the first direction; a vibration damping member provided in the second direction relative to the contact body and configured to damp unnecessary vibrations generated in the contact body; a restraining member provided on the vibration damping member opposite to the side where the contact body is provided, the restraining member having greater rigidity than the vibration damping member; and The vibration damping member is configured so as not to receive the force in the second direction generated by the pressing of the pressing member. A vibration type actuator characterized by: [Configuration 2] a guide member that guides the relative movement of the vibrating body and the contact body, A gap between the restraining member and the guide member in the second direction prevents the vibration damping member from receiving a force in the second direction generated by the pressing of the pressing member. 2. The vibration type actuator according to configuration 1, wherein: [Configuration 3] At least one of a gas containing air, cotton, felt, gel, grease, and a foam member is present in the gap. 3. The vibration type actuator according to configuration 2, wherein: [Configuration 4] the guide member is connected to the contact body via a fixing member, The guide member further includes a rolling member that rolls on the surface of the guide member. 4. The vibration actuator according to configuration 2 or 3, wherein: [Configuration 5] The fixing member is made of at least one resin selected from the group consisting of LCP resin, ABS resin, and carbon fiber reinforced PC resin. 5. The vibration actuator according to configuration 4, wherein: [Configuration 6] The contact body further includes a rolling member that rolls on a surface opposite to the surface that contacts the vibrating body. 4. The vibration actuator according to any one of configurations 1 to 3, wherein: [Configuration 7] The vibration damping member is formed by including rubber and double-sided tape or adhesive. 7. The vibration actuator according to any one of configurations 1 to 6, wherein: [Configuration 8] The vibration damping member and the restraining member are provided on the side of the contact body opposite to the side on which the vibrating body is provided. 8. The vibration type actuator according to any one of configurations 1 to 7, wherein: [Configuration 9] The vibration damping member and the restraining member are provided on the contact body on the side where the vibrating body is provided. 8. The vibration type actuator according to any one of configurations 1 to 7, wherein: [Configuration 10] The restraining member has a bent portion and a hole portion. 10. The vibration actuator according to any one of configurations 1 to 9, wherein: [Configuration 11] The restraining member is a member for restraining deformation of the vibration damping member. 11. The vibration actuator according to any one of configurations 1 to 10, wherein: [Configuration 12] a vibration type actuator according to any one of configurations 1 to 11; an optical element; An imaging element; and The vibration type actuator mechanically drives at least one of the optical element and the imaging element. An optical instrument characterized by: [Configuration 13] a vibration type actuator according to any one of configurations 1 to 11; A driven member; and The vibration type actuator mechanically drives the driven member. An electronic device characterized by: [Explanation of symbols]

[0071] 100: vibration type actuator, 101: contact body, 102: elastic body, 103: piezoelectric element (electrical-mechanical energy conversion element), 104: vibrating body, 106: elastic member, 107: movable frame member, 108: thin metal plate, 109: pressure plate, 110: spring, 113: fixed side guide member, 114: rolling ball, 115: movable side guide member, 116: restraining member, 117: vibration damping member, 118: fixed frame member

Claims

1. a vibrating body including an electromechanical energy conversion element; a contact body that comes into contact with the vibrating body; a vibration type actuator including: a vibration body that vibrates to cause the vibration body and the contact body to move relatively in a first direction; a pressing member that presses the vibrating body and the contact body in a second direction that intersects with the first direction; a vibration damping member provided in the second direction relative to the contact body and configured to damp unnecessary vibrations generated in the contact body; a restraining member provided on the vibration damping member opposite to the side where the contact body is provided, the restraining member having greater rigidity than the vibration damping member; and The vibration damping member is configured not to receive the force in the second direction generated by the pressing of the pressing member. A vibration type actuator characterized by:

2. a guide member that guides the relative movement of the vibrating body and the contact body, A gap between the restraining member and the guide member in the second direction prevents the vibration damping member from receiving a force in the second direction generated by the pressing of the pressing member.

2. The vibration actuator according to claim 1.

3. At least one of a gas containing air, cotton, felt, gel, grease, and a foam member is present in the gap.

3. The vibration type actuator according to claim 2.

4. the guide member is connected to the contact body via a fixing member, The guide member further includes a rolling member that rolls on the surface of the guide member.

3. The vibration type actuator according to claim 2.

5. The fixing member is made of at least one resin selected from the group consisting of an LCP resin, an ABS resin, and a carbon fiber reinforced PC resin.

5. The vibration actuator according to claim 4.

6. The contact body further includes a rolling member that rolls on a surface opposite to the surface that contacts the vibrating body.

2. The vibration actuator according to claim 1.

7. The vibration damping member is formed by including rubber and double-sided tape or adhesive.

2. The vibration actuator according to claim 1.

8. The vibration damping member and the restraining member are provided on the side of the contact body opposite to the side on which the vibrating body is provided.

2. The vibration actuator according to claim 1.

9. The vibration damping member and the restraining member are provided on the contact body on the side where the vibrating body is provided.

2. The vibration actuator according to claim 1.

10. The restraining member has a bent portion and a hole portion.

2. The vibration actuator according to claim 1.

11. The restraining member is a member for restraining deformation of the vibration damping member.

2. The vibration actuator according to claim 1.

12. A vibration type actuator according to any one of claims 1 to 11, an optical element; An imaging element; and The vibration type actuator mechanically drives at least one of the optical element and the imaging element. An optical instrument characterized by:

13. A vibration type actuator according to any one of claims 1 to 11, A driven member; and The vibration type actuator mechanically drives the driven member. An electronic device characterized by:

Images