Vibration type actuator, moving body having the same, moving body control system, and vacuum device

Abstract

To provide a vibration type actuator capable of improving wear resistance and being stably driven in a vacuum environment such as cosmic space and a vacuum device.SOLUTION: A vibration type actuator includes: a vibrating body having a rectangular elastic body and an electromechanical energy conversion element; and a contact body in contact with the elastic body, and is configured such that the contact body and the vibrating body relatively move by vibration of the vibrating body. With the elastic body, a flat plate portion and a protruding portion having a top portion and a wall portion are integrally formed, and both ends or the entire circumference of the top portion is supported by the wall portion. A friction material different from the elastic body is provided on the top portion so as to come into contact with the contact body. The friction material is a sphere or a cylinder. The friction material is supported with respect to a slope formed on the top portion.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a vibration actuator and a moving body having the same. [Background technology]

[0002] Due to their characteristics of low speed and high thrust, vibration actuators have been put to practical use as actuators for driving autofocus in the photographic lenses of single-lens reflex cameras, and in recent years, they are expected to be used in devices used in special environments, such as artificial satellites used in outer space and vacuum equipment used in manufacturing and analysis, where actuators must operate in the special vacuum environment.

[0003] Patent Document 1 discloses a linear type vibration actuator having a vibrator with two protrusions on the surface of a rectangular elastic body, and a stainless steel sintered body impregnated with resin as a friction member at the tip of the protrusion, in addition to the elastic body. The vibration actuator excites two out-of-plane bending vibration modes by pressing a contact body against the tip of the protrusion and applying a predetermined AC voltage to an electromechanical energy conversion element. The excited vibrations cause an elliptical motion and frictional force at the tip of the protrusion to move the vibrator and the contact body relative to each other.

[0004] In the vibration actuator of Patent Document 1, in a vacuum environment such as outer space or a vacuum device, the heat generated on the friction surface between the vibrating body and the contact body has extremely low thermal diffusion into the vacuum, so the friction heat remains. Furthermore, in a vacuum where there is almost no oxygen or moisture, a metal oxide coating that functions as a protective layer is not formed on the friction surface, and there is a risk of adhesion of the friction surface. As a result, there is a risk of a large amount of wear on the friction surface of the vibrating body, which deteriorates the friction characteristics and reduces the driving performance. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6938218 Summary of the Invention [Problem to be solved by the invention]

[0006] SUMMARY OF THE PRESENT EMBODIMENTS An object of the present invention is to provide a vibration actuator that has sufficient wear resistance and is capable of stable operation even in a vacuum environment such as outer space or a vacuum device. [Means for solving the problem]

[0007] In order to solve the above problems, A vibrator having a rectangular elastic body and an electromechanical energy conversion element, and a contact body in contact with the elastic body, A vibration actuator in which the contact body and the vibrating body move relatively to each other due to vibration of the vibrating body, The elastic body is formed with a flat plate portion and a protruding portion having a top portion and a wall portion, and the top portion is supported at both ends or at the entire periphery by the wall portion, a friction member separate from the elastic body is provided on the top of the head so as to come into contact with the contact body; The friction member is a sphere or a cylinder, The vibration actuator is characterized in that the friction member is supported against a slope formed on the top portion. Effect of the Invention

[0008] According to the above invention, it is possible to provide a vibration actuator capable of improving wear resistance in a vacuum environment such as outer space or a vacuum device, and capable of stable operation. [Brief description of the drawings]

[0009] [Figure 1] 1 is a perspective view showing a schematic configuration of a vibration actuator according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is an exploded perspective view of the vibration actuator in FIG. [Diagram 3] 2 is a perspective view showing a configuration of a vibrating body and a holding member in FIG. 1. [Figure 4] 4 is an exploded perspective view of the vibrating body and the holding member in FIG. 3. [Diagram 5] 2 is a perspective view for explaining a vibration mode excited in a vibrating body of the vibration actuator in FIG. 1. FIG. [Figure 6] 4 is a cross-sectional view showing the vibrating body in FIG. [Figure 7] 4 is a cross-sectional view showing a part of the vibrating body in FIG. [Figure 8] 4 is an exploded cross-sectional view showing a part of the vibrating body in FIG. 3. [Figure 9] 4 is an exploded cross-sectional view showing a part of the vibrating body in FIG. 3. [Figure 10] 4 is a cross-sectional view showing a part of a first modified example of the vibrating body in accordance with the first embodiment. [Figure 11] 11 is a cross-sectional view showing a part of a second modified example of the vibrating body in accordance with the first embodiment. [Figure 12] 13 is a cross-sectional view showing a part of a third modified example of the vibrating body in accordance with the first embodiment. FIG. [Figure 13] FIG. 11 is a perspective view showing a fourth modified example of the vibrating body according to the first embodiment. [Figure 14] 14 is a cross-sectional view showing a part of the vibrating body in FIG. 13. [Figure 15] 14 is a cross-sectional view showing a part of the vibrating body in FIG. 13. [Figure 16] FIG. 1 is a schematic diagram showing a moving object including a body on which a vibration actuator is mounted. [Figure 17] FIG. 1 is a schematic diagram showing a vacuum device equipped with a vibration actuator. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0011] In addition, "vacuum" refers to low vacuum (less than atmospheric pressure, 100 Pa or more) according to the Japanese Industrial Standard JISZ8126-1, medium vacuum, high vacuum, ultra-high vacuum, and extremely high vacuum (1×10 -9 The term "sphere" or "cylinder" refers to any atmospheric pressure within the scope of the present invention, including not only perfect spheres and circles, but also ellipsoids close to spheres and cylinders with elliptical cross sections. EXAMPLES

[0012] Fig. 1 is a perspective view showing a schematic configuration of a vibration actuator 100 according to a first embodiment of the present invention. Fig. 2 is an exploded perspective view of the vibration actuator 100 shown in Fig. 1. Here, the moving direction of the contact body 9 is defined as X, the pressure direction as Z, and the direction perpendicular to the X and Z directions as Y.

[0013] Fig. 3 is a perspective view that shows a schematic configuration of the vibrating body 2 and the holding member 6 in Fig. 1. Fig. 4 is an exploded perspective view of the vibrating body 2 and the holding member 6 in Fig. 3. The flexible printed circuit board 5 is not shown in Figs. 3 and 4.

[0014] The vibration actuator 100 has a vibrating body 2 having an electromechanical energy conversion element 4 and an elastic body 3. The vibrating body 2 is held by a holding member 6 and is in contact with a contact body 9, and the vibrating body 2 and the contact body 9 are configured to be movable relative to each other due to vibrations generated in the vibrating body 2.

[0015] As a specific configuration example, it includes a contact body 9 that comes into pressure contact with the elastic body 3, and a retaining member 6 having two protrusions 61 (61-1, 61-2) that are abutment portions that abut against the node portion on the side opposite to the side facing the contact body 9.

[0016] The vibrating body 2 has an elastic body 3, two friction members 13 (13-1, 13-2), and an electro-mechanical energy conversion element 4, and is supplied with power from a power source (not shown) via a flexible printed circuit board 5. The electro-mechanical energy conversion element 4 is integrally provided on one main surface (back surface in FIG. 3) of the elastic body 3 via an adhesive or the like. On the side opposite to the surface facing the electro-mechanical energy conversion element 4 and the elastic body 3, a flexible printed circuit board 5 is disposed, and the flexible printed circuit board 5 and the electro-mechanical energy conversion element 4 are electrically connected.

[0017] A protrusion 31 is provided on the elastic body 3 on the opposite side to the opposing surface of the elastic body 3 and the electromechanical energy conversion element 4. The protrusion 31 has a wall portion supported against the flat surface of the elastic body 3, and a top portion supported by the wall portion. The top portion has a structure in which both ends or the entire circumference are supported by the wall portion, making the structure strong against pressure in the Z direction. The following describes an example of a structure in which the top portion is supported all around by the wall portion.

[0018] Separate friction members 13 (13-1, 13-2) are provided on the tops of the two protrusions 31. Although two protrusions 31 (31-1, 31-2) are shown in FIG. 3, the relative movement of the vibrating body 2 and the contact body 9 is possible if there is at least one protrusion 31.

[0019] The elastic body 3 is made of a metal material with low vibration damping, and the specific material will be described later. A piezoelectric element can be suitably used as the electromechanical energy conversion element 4, and is attached to the elastic body 3 with an adhesive or the like. The piezoelectric element serving as the electromechanical energy conversion element 4 has a structure in which electrodes of a predetermined shape are formed on both sides of a plate-like piezoelectric ceramic. A driving voltage (AC voltage) of a predetermined frequency is applied to the electrodes of the electromechanical energy conversion element 4 from a flexible printed circuit board 5.

[0020] In Fig. 3, a holding member 6 that holds the vibrating body 2 is provided below the vibrating body 2. An example of a means for pressurizing the vibrating body 2 against the contact body 9 is a pressure spring 7. The pressure spring 7 presses the holding member 6 in the Z direction in Fig. 3, and the reaction force received by the pressure spring 7 is received by a base 8.

[0021] It is preferable to use a conical coil spring as the pressure spring 7 in order to reduce the size of the vibration actuator 100 in the Z direction. Note that the coil shape is illustrated in a simplified form. The pressure spring 7 applies a predetermined pressure force, which is several hundred gf in this embodiment, to the vibration body 2.

[0022] The method of positioning the vibrating body 2 in the X and Y directions will be described. Loose-fitting parts 61-1, 61-2, 61-3, and 61-4 provided on the holding member 6 are fitted into the four extension parts 34-1, 34-2, 34-3, and 34-4 extending in the X-axis direction of the elastic body 2. This structure prevents the vibrating body 2 from moving in the X and Y directions relative to the pressure spring 7 without excessively inhibiting the vibration in the Z direction. A strong support structure is achieved by supporting the four extension parts 34 by loosely fitting the four corners of the vibrating body 2 with the loose-fitting parts.

[0023] As shown in FIG. 2, the contact body holder 10 holds the contact body 9. In addition, two ball rails 12-1 and 12-2 that sandwich three balls 11-1, 11-2, and 11-3 are provided on the side surface along the longitudinal direction of the contact body holder 10. In this state, by fixing the ball rails 12-1 and 12-2 to the base 8, the integrated body of the contact body 9 and the contact body holder 10 can move in the X direction relative to other parts. In particular, the vibration of the vibrating body 2 that abuts against the contact body causes the integrated body of the vibrating body 2, the contact body 9, and the contact body holder 10 to move relatively along the X direction in FIG. 2. By attaching an output transmission unit of a desired shape to this contact body holder 10, it is possible to transmit output to the outside, and it is possible to function as an actuator.

[0024] Next, the vibration modes excited in the vibrator 2 will be described with reference to Fig. 5. The vibrator in Fig. 5 has the configuration described in Patent Document 1, and the vibrator of this embodiment is essentially the same. In this embodiment, an AC voltage is applied to the electromechanical energy conversion element 4 through a flexible printed circuit board 5 to excite the vibrator 2 with out-of-plane bending vibrations of two different vibration modes, generating a vibration that is a combination of these vibrations. These vibration modes are vibrations between adjacent nodes, and include the following vibration mode A and vibration mode B.

[0025] The first vibration mode, vibration mode A, is a primary out-of-plane bending vibration mode in which two nodes appear parallel to the X direction, which is the longitudinal direction of the vibrating body 2, sandwiching the two protrusions. Vibration in vibration mode A displaces the two protrusions in the Z direction, which is the pressure direction. The second vibration mode, vibration mode B, is a secondary out-of-plane bending vibration mode in which three nodes appear approximately parallel to the Y direction, which is the short side direction of the vibrating body 2. Vibration in vibration mode B displaces the two protrusions in the X direction. Note that vibration mode B is not limited to a secondary vibration mode, and can also be an Nth order vibration mode (N is an integer of 1 or 3 or more).

[0026] By combining the vibrations of these vibration modes A and B, the two protrusions 31-1 and 31-2 perform elliptical or circular motion in the ZX plane. By bringing the contact body 9 into pressure contact with the two protrusions, a frictional force is generated in the X direction, and a driving force (thrust) is generated that moves one of the vibrating body 2 and the contact body 9 relative to the other. In this embodiment, since the vibrating body 2 is held by a method described later, the contact body 9 moves in the X direction. It is also possible to fix the position of the contact body with a predetermined fixing member or the like and configure the vibrating body 2 to move in the X direction.

[0027] In order to drive the vibration actuator 100 efficiently, it is necessary to support the vibrating body 2 without impeding the vibration (displacement) of the two vibration modes excited in the vibrating body 2.

[0028] For this reason, it is desirable to support the vicinity of the nodes of these two vibration modes. For this reason, in order to pressurize and hold the common node of the two vibration modes excited in the vibrating body 2, two protrusions 61-1 and 61-2 are provided on the holding member 6 that holds the vibrating body 2, as shown in FIG.

[0029] Next, the detailed configurations and materials of the elastic body 3 and the friction member 13 will be described with reference to Fig. 6, Fig. 7, and Fig. 8. Fig. 6 is a cross-sectional view that shows a schematic representation of the vibrating body in Fig. 3. Fig. 7 is a cross-sectional view that shows a schematic representation of a portion of the vibrating body in Fig. 3. Fig. 8 is a cross-sectional view that shows an exploded view of the vibrating body in Fig. 7.

[0030] There is no limitation on the configuration of the protruding portion 31, but as a preferred example, it may be a hollow protrusion formed integrally with the flat plate portion 31a of the elastic body 3 by pressing or cutting the plate material constituting the elastic body 3. As another example, a separate member may be prepared as the protruding portion 31 and disposed by means of welding, adhesion, or the like.

[0031] The protrusion 31 is formed by a cylindrical wall portion 31b and a disk portion 31c, which is a top portion supported on the outer periphery side by the wall portion 31b. The disk portion 31c is formed with a thickness that provides springiness that allows it to deform in the Z direction due to a load in the Z direction caused by contact with the contact body 9.

[0032] As illustrated in FIG. 7, a cylindrical first recess 32 is formed by cutting out the disk portion 31c at the center of the disk portion 31c, and a truncated cone-shaped second recess 33 is formed at the bottom surface of the first recess 32 and penetrates the disk portion 31c. The second recess 33 is a truncated cone whose diameter decreases in the Z direction from the first recess 32. The substantially spherical friction member 13 (13-1, 13-2) is in contact with the inclined surface 33a, which is the side wall of the truncated cone-shaped second recess 33, in a substantially circumferential manner at the curved surface 13b, and is fixed by an adhesive or the like (not shown). Note that the second recess 33 may have a cylindrical shape as long as a part of the side wall is an inclined surface, or a part of the side wall may be cylindrical.

[0033] The second recess 33 is brought into contact with the inclined surface 33a of the truncated cone shape and the curved surface 13b of the friction member 13 in a substantially circumferential manner, so that the friction member 13 and the disk portion 31c can be positioned with high precision in three directions, the X direction, the Y direction, and the Z direction. The first recess 32 and the second recess 33 have gaps into which the adhesive is filled, so that the friction member 13 can be firmly fixed. The diameter of the first recess 32 is larger than that of the friction member 13, and the adhesive pool is formed, so that the friction member 13 can be fixed more firmly. In addition, since the first recess 32 and the second recess 33 are provided in the disk portion 31c, the adhesive overflows into the adhesive pool during bonding, so that overflow of the adhesive that goes over the friction member 13 can be suppressed. As a result, it is possible to prevent the unhardened adhesive from coming into contact with the contact body 9. Since the Young's modulus of the adhesive is low because the Young's modulus of the metal material constituting the disk portion 31c is low, the adhesive has little effect on the springiness of the disk portion 31c. Therefore, the adhesive may protrude from the first recess 32 and the second recess 33 to the extent that it does not come into contact with the contact body 9. With the above configuration, the friction member 13 can be firmly fixed with high precision, thereby improving the frictional driving force of the vibration body 2 to the contact body 9 and achieving efficient and stable driving even in a vacuum environment.

[0034] The friction member 13 has a substantially spherical shape with a portion of the sphere cut off, and the cut surface serves as the friction surface 13a that comes into contact with the contact body 9. Because the friction surface 13a is a flat surface with a predetermined area, the friction member 13 and the contact body 9 do not come into point contact but into surface contact, which reduces the contact pressure and wear.

[0035] Furthermore, while the vibration actuator is being driven, the contact state between the friction surface 13a and the contact body 9 is constantly changing, and in the process of this change, the friction surface 13a and the contact body 9 come into contact over a wide area, thereby further improving wear resistance. Since the friction surface 13a receives a pressure force in the Z direction from the contact body 9, the disk portion 31c bends in the Z direction with the friction surface 13a as the load point. Since the disk portion 31c has a double-supported structure (cylindrical support structure) in which the outer periphery is supported by the cylindrical wall portion 31b, the friction surface 13a is displaced in the Z direction while maintaining a state parallel to the XY plane.

[0036] As a result, the disk portion 31c can contact the contact body 9 over almost the entire surface of the friction surface 12a during the deformation process, reducing the contact surface pressure and wear. These effects can improve wear resistance and achieve stable driving. This is particularly effective in a vacuum environment where wear resistance is an issue.

[0037] The material of the elastic body 3 will be described. Since the elastic body 3 has a complex shape, it is preferable that the elastic body 3 has good workability. A material with a high Vickers hardness is difficult to process and is not suitable, and it is preferable that the Vickers hardness (HV) is low. Furthermore, in order to reduce interference from electron beams in vacuum devices and to reduce magnetic interference with other devices in artificial satellites and to realize stable operation in a vacuum environment, it is preferable that the elastic body 3 is a non-magnetic material. Metal materials that satisfy these conditions include, for example, aluminum alloys (HV120 or less), brass (HV160 or less), austenitic stainless steel (HV200 or less), etc. Note that the above Vickers hardness (HV) is a representative value and is not limited to this value.

[0038] The material of the friction member 13 will be described. The friction member 13 is preferably made of a material having high wear resistance and a high friction coefficient because the friction surface 13a of the friction member 13 comes into contact with the contact body 9 and is frictionally driven. Since wear resistance is significantly affected by the mating material, there is no clear indicator, but it is correlated with Vickers hardness (HV). Since the higher the Vickers hardness, the higher the wear resistance tends to be, it is preferable that the friction member 13 is made of a material having a high Vickers hardness. On the other hand, since good processability is required for the elastic body 3, it is preferable that the Vickers hardness is low. Therefore, it is preferable that the Vickers hardness of the friction member 13 is higher than that of the elastic body 3.

[0039] For example, a hardened steel material with a high Vickers hardness, a nitrided steel material, ceramics, or a cemented carbide is used for the friction member 13. However, the present invention is not limited to this, and glass, a nickel alloy, a cobalt alloy, or a cermet may be used as long as the Vickers hardness is higher than that of the elastic body 3.

[0040] The hardened steel material has a hardness of about HV600 to 800, and martensitic stainless steel SUS440C or SUS420J2, or high carbon chromium bearing steel SUJ2, etc. are used as the material. The nitrided steel material has a hardness of about HV800 to 1200, and austenitic stainless steel or other steel material is used as the material. The ceramics used are alumina, zirconia, silicon nitride, silicon carbide, etc., with a hardness of about HV1000 to 2000. The cemented carbide used is a material using tungsten carbide with a binder of cobalt or nickel with a hardness of about HV1500 to 2000. The glass used is soda glass with a hardness of about HV500, quartz with a hardness of about HV1000, sapphire, ruby, etc. with a hardness of HV2000 or more. The above Vickers hardness (HV) is a representative value, and is not limited to this value.

[0041] In order to improve both the workability of the elastic body 3 and the wear resistance of the friction member 13, it is preferable that the Vickers hardness of the friction member 13 is at least twice as high as that of the elastic body 3. It is even more preferable that the Vickers hardness of the friction member 13 is at least three times as high as that of the elastic body 3.

[0042] 9 shows an exploded view of a part of the vibrating body 2 before the friction surface 13a is formed. Before the friction surface 13a is formed, the friction member 14 is a spherical precision ball 14. The precision ball 14 is preferably one used in ball bearings, scientific laboratory equipment, ballpoint pens, etc. Precision balls 14 with high Vickers hardness, high wear resistance, and high dimensional accuracy are used.

[0043] A method for forming the friction member 13 having the friction surface 13a that comes into surface contact with the contact body 9 will be described. The vibration body 2 is manufactured by adhering spherical precision balls 14 to an elastic body 3, and is then assembled into a vibration actuator 100 and driven. In this way, the precision balls 14 wear away in a short time due to friction with the contact body 9, changing from point contact to surface contact, and the friction member 13 having the friction surface 13a is formed. At this time, by making the Vickers hardness of the contact body 9 greater than that of the friction member 13, it is possible to reduce wear of the contact body 9 while shortening the time required to form the friction surface 13a.

[0044] Moreover, after the precision ball 14 is bonded to the elastic body 3, a part of the precision ball 14 may be cut by lapping or the like to form the friction surface 13a.

[0045] The contact position between the contact body 9 and the vibrator 2 moves in the X direction by driving the vibration actuator 100, so the friction surface of the contact body 9 with the vibrator 2 is formed in a line shape having a predetermined width along the X direction. If the wear depth of the friction surface of the contact body 9 varies greatly depending on the position, the friction state changes depending on the relative position with the vibrator 2, and unevenness in the driving performance of the vibration actuator 100 occurs. In order to suppress this unevenness in the driving performance, it is preferable to suppress the wear depth of the friction surface of the contact body 9 as much as possible. In order to reduce the wear of the contact body 9, it is preferable that the friction member 13 of the vibrator 2 immediately transitions from point contact to surface contact due to wear at the initial driving stage. Therefore, it is preferable that the wear resistance of the friction member 13 is lower than that of the contact body 9 and that it is easily worn. It is preferable that the Vickers hardness of the contact body 9 is greater than that of the friction member 13. When the elastic body 3 is also included, it is preferable that the Vickers hardness is greatest in the order of the elastic body 3, the friction member 13, and the contact body 9. The contact body 9 is made of, for example, a material obtained by nitriding a steel material such as stainless steel, ceramic, or a metal material coated with ceramic.

[0046] It is preferable that at least one of the friction member 13 and the contact body 9 is mainly made of a nonmetallic inorganic material, and it is more preferable that both are made of nonmetallic inorganic materials. It is preferable that at least one of the friction member 13 and the contact body 9 is mainly made of a nonmetallic inorganic material, and this results in a wear mode in which a metal oxide film formed by friction is not used as a protective film. It is more preferable that at least the friction member 13 contains a nonmetallic inorganic material.

[0047] In other words, since oxygen and moisture in the atmosphere are not required, wear resistance in a vacuum environment can be improved. Note that a material mainly made of nonmetallic inorganic materials includes at least one material selected from the group consisting of ceramics, cemented carbide, glass, and cermet. Although cemented carbide uses cobalt or nickel as a binder, it is mainly made of tungsten carbide and is therefore included in materials mainly made of nonmetallic inorganic materials.

[0048] Motor performance and wear resistance differ depending on the combination of materials for the friction member 13 and the contact body 9. In the inventor's research, the motor performance and wear resistance in a vacuum were good when the friction material for the friction member 13 was made of ultra-hard material and the friction material for the contact body 9 was made of ceramics made of a titanium nitride compound.

[0049] The cemented carbide used in the friction member 13 has a composition of about 92% tungsten carbide, about 8% cobalt, and 1% or less of other components, and has a Vickers hardness of HV1400 to 1500. Note that the composition of the cemented carbide is not limited to these values, and it is sufficient that the composition is 60% or more and 97% or less of tungsten carbide, with other components such as cobalt and nickel used as a binder.

[0050] The material of the friction member may mainly contain ultra-hard metal, or may contain a material other than ultra-hard metal in part.

[0051] The coating of the titanium nitride compound used for the contact body 9 is TiSiN, and has a Vickers hardness of HV3000 to 3500. The titanium nitride compound is not limited to TiSiN, and may be TiN or TiAlN. The base material of the contact body 9 is stainless steel SUS304 or SUS420J2, which is hardened by nitriding or quenching and then coated with TiSiN by PVD. This is to reduce the difference in hardness between the base material stainless steel and the coating TiSiN, and to improve adhesion. A TiSiN undercoat may be applied to improve adhesion. The base material may be any metal material that can be coated with a ceramic coating.

[0052] FIG. 10 is a cross-sectional view that illustrates a schematic view of a part of a first modified example of the vibrating body according to the present embodiment.

[0053] This modified example does not have a cylindrical recess. Only a first recess 34 having a truncated cone shape is formed in the center of the disk portion 31d of the protrusion, penetrating the disk portion 31d. The friction member 13 contacts the inclined surface 34a of the first recess 34 and is fixed thereto by adhesion or the like. In the configuration of this modified example, the shape of the recess is simple, so that it is possible to reduce processing costs.

[0054] FIG. 11 is a cross-sectional view that illustrates a schematic view of a portion of a second modified example of the vibrating body according to this embodiment.

[0055] In this modified example, the recess does not penetrate the disk portion. A cylindrical first recess 35 and a truncated cone second recess 36 are formed in the center of the disk portion 31d of the protruding portion, and a bottom surface portion 31f is formed without penetrating the disk portion 31d. The friction member 13 contacts the inclined surface 36a of the second recess 36 and is fixed by adhesion or the like. Although the shape of the bottom surface portion 31f is shown as being linear, it may be a curved shape. In the configuration of this modified example, since the recess does not penetrate, the shape is suitable for press processing, and it is possible to reduce processing costs during mass production.

[0056] FIG. 12 is a cross-sectional view that illustrates a schematic view of a portion of a third modified example of the vibrating body according to this embodiment.

[0057] This modified example has a configuration in which the recesses are two cylindrical. A cylindrical first recess 37 and a cylindrical second recess 38 having a smaller diameter than the first recess 37 are formed in the center of the disk portion 31g of the protrusion. A minute inclined surface 38a is formed on the ridge where the first recess 37 and the second recess 38 meet, and the friction member 13 comes into contact with the minute inclined surface 38a and is fixed by adhesion or the like. That is, the configuration depicted in FIG. 12 is realized as a minute inclined surface formed on the portion connecting the bottom surface of the first recess 37 and the inner wall of the second recess 38.

[0058] The inclined surface 38a may be formed as a chamfer during machining (pressing or cutting), or may be formed by forming a corner during machining and then crushing the corner by contacting with the friction member 13. In the configuration of this modified example, the formation of the inclined surface can be simplified, and therefore the processing cost can be reduced.

[0059] Fig. 13 is a perspective view that shows a fourth modified example of the vibrating body according to this embodiment. Fig. 14 is a cross-sectional view that shows a part of the vibrating body in Fig. 13. Fig. 15 is a cross-sectional view of Fig. 14 with the friction member not shown.

[0060] This modified example uses a friction member 113 having a substantially cylindrical shape. The friction member 113 has a friction surface 113a that is a flat surface formed by cutting a part of the curved surface of the cylindrical shape. The protrusion 131 (131-1, 131-2) is a hollow protrusion formed integrally with the flat plate portion 131a of the elastic body 3, and has a gate-like shape with both ends supported by the top of the head in a double-supported structure with both ends open in the Y direction. The protrusion 131 is composed of wall portions 131b (131b-1, 131b-2) arranged in the X direction and a rectangular plate portion 131c as a top portion whose both ends are supported by the wall portion 131b. The rectangular plate portion 131c is formed with a thickness that has a spring property that deforms in the Z direction due to a load in the Z direction caused by contact with the contact body 9. A rectangular first recess 132 is formed in the center of the rectangular plate portion 131c in the X direction, and a second recess 133 is formed in the bottom surface of the first recess 132 and penetrates the rectangular plate portion 131c. The side walls of the second recess 133 aligned in the X direction are inclined surfaces 133a that are inclined so that the width narrows in the Z direction from the first recess 132, and the approximately cylindrical friction member 113 (113-1, 113-2) is in approximately linear contact with the curved surface 113b and fixed by adhesion or the like. In the configuration of this modification, the friction member 113 is lengthened in the Y direction to increase the contact area and reduce the contact surface pressure, thereby improving wear resistance.

[0061] The vibration actuator of this embodiment realizes improved wear resistance and stable driving in a vacuum environment, and can be mounted and used in artificial satellites used in outer space and vacuum devices used for manufacturing and analysis. For example, in artificial satellites, it can be used to drive the linear motion and rotation of camera lenses, image pickup elements, communication antennas, etc. Or, in vacuum devices, it can be used to drive the linear motion and rotation of members such as stages inside a vacuum chamber. FIG. 16 is a schematic diagram showing a moving body equipped with a machine body equipped with a vibration actuator. As illustrated in FIG. 16, the vibration actuator of this embodiment can be mounted and used on a moving body 300 that revolves around the orbit of a celestial body (the size of the moving body is exaggerated for the purpose of explanation). That is, the moving body 300 includes a machine body 200 capable of navigating outer space and the above-mentioned vibration actuator 100, and can be used for the various applications mentioned above. In this case, there is no particular restriction on the configuration of the control unit that controls the machine body 200 and the vibration actuator 100, and a desired configuration can be adopted depending on the application. The control unit may be mounted on the machine body, or may be arranged on the ground of a celestial body such as the Earth separately from the machine body. That is, a mobile object control system can be configured that includes a mobile object and a control unit that controls the mobile object.

[0062] 17 is a schematic diagram showing a vacuum device that drives a member in a vacuum chamber using a vibration actuator of the present invention. This vacuum device is capable of driving a member 400, such as a stage, provided inside the vacuum chamber using a vibration actuator 100. In this vacuum device, a vacuum state is generated in the vacuum chamber isolated from the outside air by a vacuum pump connected to the vacuum chamber, and the member 400 can be driven by the vibration actuator 100 of the present invention in this vacuum environment. [Explanation of symbols]

[0063] 2,102 Vibration body 3,103 Elastic body 4,104 Electromechanical energy conversion elements 5 Flexible Printed Circuit Boards 6 Retaining member 9 Contact body 13,131 Friction materials 13a,131a Friction surface 14 Precision ball (sphere) 200 aircraft 300 Mobile 400 parts

Claims

1. A vibrator having a rectangular elastic body and an electromechanical energy conversion element, and a contact body in contact with the elastic body, A vibration actuator in which the contact body and the vibrating body move relatively to each other due to vibration of the vibrating body, The elastic body is formed with a flat plate portion and a protruding portion having a top portion and a wall portion, and the top portion is supported at both ends or at the entire periphery by the wall portion, a friction member separate from the elastic body is provided on the top of the head so as to come into contact with the contact body; The friction member is a sphere or a cylinder, 4. A vibration actuator, comprising: a head portion having a top surface and a friction member supported on the top surface of the head portion;

2. 2. The vibration actuator according to claim 1, wherein the top portion is a disk, and the wall portion is a cylinder that supports an outer periphery of the top portion.

3. 2. The vibration actuator according to claim 1, wherein the friction member has a friction surface which is a flat surface formed by cutting a part of a curved surface, and the friction surface comes into contact with the contact body.

4. A vibrator having a rectangular elastic body and an electromechanical energy conversion element, and a contact body in contact with the elastic body, A vibration actuator in which the contact body and the vibrating body move relatively to each other due to vibration of the vibrating body, the elastic body is formed with a flat plate portion and a hollow protruding portion, and a friction member separate from the elastic body is provided on a top portion of the protruding portion so as to come into contact with the contact body, The friction member is a sphere or a cylinder, The friction member includes a non-metallic inorganic material, A vibration actuator, characterized in that the Vickers hardness of the friction member is greater than that of the elastic body.

5. 5. The vibration actuator according to claim 4, wherein the Vickers hardness of the friction member is at least twice as high as that of the elastic body.

6. 5. The vibration actuator according to claim 4, wherein the Vickers hardness of the contact body is greater than that of the friction member.

7. 7. The vibration actuator according to claim 1, wherein the elastic body contains a non-magnetic material.

8. 8. The vibration actuator according to claim 7, wherein the non-magnetic material includes at least one material selected from the group consisting of an aluminum alloy, brass, and austenitic stainless steel.

9. 5. The vibration actuator according to claim 4, wherein the non-metallic inorganic material includes at least one material selected from the group consisting of ceramics, cemented carbide, glass, and cermet.

10. 5. The vibration actuator according to claim 1, wherein the protrusion including the top portion and the wall portion is integrally formed.

11. 5. The vibration actuator according to claim 1, wherein the material of the friction member includes a superhard material, and the material of the contact body includes a metal material coated with a titanium nitride compound.

12. 12. The vibration actuator according to claim 11, wherein the titanium nitride compound is TiSiN.

13. 5. The vibration actuator according to claim 1, which operates in a vacuum environment.

14. A space-navigable aircraft, A moving body comprising the vibration type actuator according to claim 1 or 4.

15. A moving body according to claim 12; A mobile object control system including a control unit of the mobile object.

16. A vacuum chamber; a vacuum pump coupled to the vacuum chamber; 5. A vacuum device comprising the vibration actuator according to claim 1.

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